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linux-stable/net/core/dev.c
Jakub Kicinski 759ab1edb5 net: store netdevs in an xarray 
Iterating over the netdev hash table for netlink dumps is hard.
Dumps are done in "chunks" so we need to save the position
after each chunk, so we know where to restart from. Because
netdevs are stored in a hash table we remember which bucket
we were in and how many devices we dumped.

Since we don't hold any locks across the "chunks" - devices may
come and go while we're dumping. If that happens we may miss
a device (if device is deleted from the bucket we were in).
We indicate to user space that this may have happened by setting
NLM_F_DUMP_INTR. User space is supposed to dump again (I think)
if it sees that. Somehow I doubt most user space gets this right..

To illustrate let's look at an example:

               System state:
  start:       # [A, B, C]
  del:  B      # [A, C]

with the hash table we may dump [A, B], missing C completely even
tho it existed both before and after the "del B".

Add an xarray and use it to allocate ifindexes. This way we
can iterate ifindexes in order, without the worry that we'll
skip one. We may still generate a dump of a state which "never
existed", for example for a set of values and sequence of ops:

               System state:
  start:       # [A, B]
  add:  C      # [A, C, B]
  del:  B      # [A, C]

we may generate a dump of [A], if C got an index between A and B.
System has never been in such state. But I'm 90% sure that's perfectly
fine, important part is that we can't _miss_ devices which exist before
and after. User space which wants to mirror kernel's state subscribes
to notifications and does periodic dumps so it will know that C exists
from the notification about its creation or from the next dump
(next dump is _guaranteed_ to include C, if it doesn't get removed).

To avoid any perf regressions keep the hash table for now. Most
net namespaces have very few devices and microbenchmarking 1M lookups
on Skylake I get the following results (not counting loopback
to number of devs):

 #devs | hash |  xa  | delta
    2  | 18.3 | 20.1 | + 9.8%
   16  | 18.3 | 20.1 | + 9.5%
   64  | 18.3 | 26.3 | +43.8%
  128  | 20.4 | 26.3 | +28.6%
  256  | 20.0 | 26.4 | +32.1%
 1024  | 26.6 | 26.7 | + 0.2%
 8192  |541.3 | 33.5 | -93.8%

No surprises since the hash table has 256 entries.
The microbenchmark scans indexes in order, if the pattern is more
random xa starts to win at 512 devices already. But that's a lot
of devices, in practice.

Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230726185530.2247698-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-28 11:35:58 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* NET3 Protocol independent device support routines.
*
* Derived from the non IP parts of dev.c 1.0.19
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Mark Evans, <evansmp@uhura.aston.ac.uk>
*
* Additional Authors:
* Florian la Roche <rzsfl@rz.uni-sb.de>
* Alan Cox <gw4pts@gw4pts.ampr.org>
* David Hinds <dahinds@users.sourceforge.net>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
* Adam Sulmicki <adam@cfar.umd.edu>
* Pekka Riikonen <priikone@poesidon.pspt.fi>
*
* Changes:
* D.J. Barrow : Fixed bug where dev->refcnt gets set
* to 2 if register_netdev gets called
* before net_dev_init & also removed a
* few lines of code in the process.
* Alan Cox : device private ioctl copies fields back.
* Alan Cox : Transmit queue code does relevant
* stunts to keep the queue safe.
* Alan Cox : Fixed double lock.
* Alan Cox : Fixed promisc NULL pointer trap
* ???????? : Support the full private ioctl range
* Alan Cox : Moved ioctl permission check into
* drivers
* Tim Kordas : SIOCADDMULTI/SIOCDELMULTI
* Alan Cox : 100 backlog just doesn't cut it when
* you start doing multicast video 8)
* Alan Cox : Rewrote net_bh and list manager.
* Alan Cox : Fix ETH_P_ALL echoback lengths.
* Alan Cox : Took out transmit every packet pass
* Saved a few bytes in the ioctl handler
* Alan Cox : Network driver sets packet type before
* calling netif_rx. Saves a function
* call a packet.
* Alan Cox : Hashed net_bh()
* Richard Kooijman: Timestamp fixes.
* Alan Cox : Wrong field in SIOCGIFDSTADDR
* Alan Cox : Device lock protection.
* Alan Cox : Fixed nasty side effect of device close
* changes.
* Rudi Cilibrasi : Pass the right thing to
* set_mac_address()
* Dave Miller : 32bit quantity for the device lock to
* make it work out on a Sparc.
* Bjorn Ekwall : Added KERNELD hack.
* Alan Cox : Cleaned up the backlog initialise.
* Craig Metz : SIOCGIFCONF fix if space for under
* 1 device.
* Thomas Bogendoerfer : Return ENODEV for dev_open, if there
* is no device open function.
* Andi Kleen : Fix error reporting for SIOCGIFCONF
* Michael Chastain : Fix signed/unsigned for SIOCGIFCONF
* Cyrus Durgin : Cleaned for KMOD
* Adam Sulmicki : Bug Fix : Network Device Unload
* A network device unload needs to purge
* the backlog queue.
* Paul Rusty Russell : SIOCSIFNAME
* Pekka Riikonen : Netdev boot-time settings code
* Andrew Morton : Make unregister_netdevice wait
* indefinitely on dev->refcnt
* J Hadi Salim : - Backlog queue sampling
* - netif_rx() feedback
*/
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/cpu.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/skbuff.h>
#include <linux/kthread.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/busy_poll.h>
#include <linux/rtnetlink.h>
#include <linux/stat.h>
#include <net/dsa.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
#include <net/gro.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include <net/tcx.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#include <linux/delay.h>
#include <net/iw_handler.h>
#include <asm/current.h>
#include <linux/audit.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/mpls.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <trace/events/napi.h>
#include <trace/events/net.h>
#include <trace/events/skb.h>
#include <trace/events/qdisc.h>
#include <linux/inetdevice.h>
#include <linux/cpu_rmap.h>
#include <linux/static_key.h>
#include <linux/hashtable.h>
#include <linux/vmalloc.h>
#include <linux/if_macvlan.h>
#include <linux/errqueue.h>
#include <linux/hrtimer.h>
#include <linux/netfilter_netdev.h>
#include <linux/crash_dump.h>
#include <linux/sctp.h>
#include <net/udp_tunnel.h>
#include <linux/net_namespace.h>
#include <linux/indirect_call_wrapper.h>
#include <net/devlink.h>
#include <linux/pm_runtime.h>
#include <linux/prandom.h>
#include <linux/once_lite.h>
#include "dev.h"
#include "net-sysfs.h"
static DEFINE_SPINLOCK(ptype_lock);
struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
struct list_head ptype_all __read_mostly; /* Taps */
static int netif_rx_internal(struct sk_buff *skb);
static int call_netdevice_notifiers_extack(unsigned long val,
struct net_device *dev,
struct netlink_ext_ack *extack);
static struct napi_struct *napi_by_id(unsigned int napi_id);
/*
* The @dev_base_head list is protected by @dev_base_lock and the rtnl
* semaphore.
*
* Pure readers hold dev_base_lock for reading, or rcu_read_lock()
*
* Writers must hold the rtnl semaphore while they loop through the
* dev_base_head list, and hold dev_base_lock for writing when they do the
* actual updates. This allows pure readers to access the list even
* while a writer is preparing to update it.
*
* To put it another way, dev_base_lock is held for writing only to
* protect against pure readers; the rtnl semaphore provides the
* protection against other writers.
*
* See, for example usages, register_netdevice() and
* unregister_netdevice(), which must be called with the rtnl
* semaphore held.
*/
DEFINE_RWLOCK(dev_base_lock);
EXPORT_SYMBOL(dev_base_lock);
static DEFINE_MUTEX(ifalias_mutex);
/* protects napi_hash addition/deletion and napi_gen_id */
static DEFINE_SPINLOCK(napi_hash_lock);
static unsigned int napi_gen_id = NR_CPUS;
static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
static DECLARE_RWSEM(devnet_rename_sem);
static inline void dev_base_seq_inc(struct net *net)
{
while (++net->dev_base_seq == 0)
;
}
static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
{
unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
}
static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
{
return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
}
static inline void rps_lock_irqsave(struct softnet_data *sd,
unsigned long *flags)
{
if (IS_ENABLED(CONFIG_RPS))
spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_save(*flags);
}
static inline void rps_lock_irq_disable(struct softnet_data *sd)
{
if (IS_ENABLED(CONFIG_RPS))
spin_lock_irq(&sd->input_pkt_queue.lock);
else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_disable();
}
static inline void rps_unlock_irq_restore(struct softnet_data *sd,
unsigned long *flags)
{
if (IS_ENABLED(CONFIG_RPS))
spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_restore(*flags);
}
static inline void rps_unlock_irq_enable(struct softnet_data *sd)
{
if (IS_ENABLED(CONFIG_RPS))
spin_unlock_irq(&sd->input_pkt_queue.lock);
else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
local_irq_enable();
}
static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
const char *name)
{
struct netdev_name_node *name_node;
name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
if (!name_node)
return NULL;
INIT_HLIST_NODE(&name_node->hlist);
name_node->dev = dev;
name_node->name = name;
return name_node;
}
static struct netdev_name_node *
netdev_name_node_head_alloc(struct net_device *dev)
{
struct netdev_name_node *name_node;
name_node = netdev_name_node_alloc(dev, dev->name);
if (!name_node)
return NULL;
INIT_LIST_HEAD(&name_node->list);
return name_node;
}
static void netdev_name_node_free(struct netdev_name_node *name_node)
{
kfree(name_node);
}
static void netdev_name_node_add(struct net *net,
struct netdev_name_node *name_node)
{
hlist_add_head_rcu(&name_node->hlist,
dev_name_hash(net, name_node->name));
}
static void netdev_name_node_del(struct netdev_name_node *name_node)
{
hlist_del_rcu(&name_node->hlist);
}
static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
const char *name)
{
struct hlist_head *head = dev_name_hash(net, name);
struct netdev_name_node *name_node;
hlist_for_each_entry(name_node, head, hlist)
if (!strcmp(name_node->name, name))
return name_node;
return NULL;
}
static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
const char *name)
{
struct hlist_head *head = dev_name_hash(net, name);
struct netdev_name_node *name_node;
hlist_for_each_entry_rcu(name_node, head, hlist)
if (!strcmp(name_node->name, name))
return name_node;
return NULL;
}
bool netdev_name_in_use(struct net *net, const char *name)
{
return netdev_name_node_lookup(net, name);
}
EXPORT_SYMBOL(netdev_name_in_use);
int netdev_name_node_alt_create(struct net_device *dev, const char *name)
{
struct netdev_name_node *name_node;
struct net *net = dev_net(dev);
name_node = netdev_name_node_lookup(net, name);
if (name_node)
return -EEXIST;
name_node = netdev_name_node_alloc(dev, name);
if (!name_node)
return -ENOMEM;
netdev_name_node_add(net, name_node);
/* The node that holds dev->name acts as a head of per-device list. */
list_add_tail(&name_node->list, &dev->name_node->list);
return 0;
}
static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
{
list_del(&name_node->list);
netdev_name_node_del(name_node);
kfree(name_node->name);
netdev_name_node_free(name_node);
}
int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
{
struct netdev_name_node *name_node;
struct net *net = dev_net(dev);
name_node = netdev_name_node_lookup(net, name);
if (!name_node)
return -ENOENT;
/* lookup might have found our primary name or a name belonging
* to another device.
*/
if (name_node == dev->name_node || name_node->dev != dev)
return -EINVAL;
__netdev_name_node_alt_destroy(name_node);
return 0;
}
static void netdev_name_node_alt_flush(struct net_device *dev)
{
struct netdev_name_node *name_node, *tmp;
list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
__netdev_name_node_alt_destroy(name_node);
}
/* Device list insertion */
static void list_netdevice(struct net_device *dev)
{
struct net *net = dev_net(dev);
ASSERT_RTNL();
write_lock(&dev_base_lock);
list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
netdev_name_node_add(net, dev->name_node);
hlist_add_head_rcu(&dev->index_hlist,
dev_index_hash(net, dev->ifindex));
write_unlock(&dev_base_lock);
/* We reserved the ifindex, this can't fail */
WARN_ON(xa_store(&net->dev_by_index, dev->ifindex, dev, GFP_KERNEL));
dev_base_seq_inc(net);
}
/* Device list removal
* caller must respect a RCU grace period before freeing/reusing dev
*/
static void unlist_netdevice(struct net_device *dev, bool lock)
{
struct net *net = dev_net(dev);
ASSERT_RTNL();
xa_erase(&net->dev_by_index, dev->ifindex);
/* Unlink dev from the device chain */
if (lock)
write_lock(&dev_base_lock);
list_del_rcu(&dev->dev_list);
netdev_name_node_del(dev->name_node);
hlist_del_rcu(&dev->index_hlist);
if (lock)
write_unlock(&dev_base_lock);
dev_base_seq_inc(dev_net(dev));
}
/*
* Our notifier list
*/
static RAW_NOTIFIER_HEAD(netdev_chain);
/*
* Device drivers call our routines to queue packets here. We empty the
* queue in the local softnet handler.
*/
DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
EXPORT_PER_CPU_SYMBOL(softnet_data);
#ifdef CONFIG_LOCKDEP
/*
* register_netdevice() inits txq->_xmit_lock and sets lockdep class
* according to dev->type
*/
static const unsigned short netdev_lock_type[] = {
ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
static const char *const netdev_lock_name[] = {
"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
static inline unsigned short netdev_lock_pos(unsigned short dev_type)
{
int i;
for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
if (netdev_lock_type[i] == dev_type)
return i;
/* the last key is used by default */
return ARRAY_SIZE(netdev_lock_type) - 1;
}
static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
unsigned short dev_type)
{
int i;
i = netdev_lock_pos(dev_type);
lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
netdev_lock_name[i]);
}
static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
{
int i;
i = netdev_lock_pos(dev->type);
lockdep_set_class_and_name(&dev->addr_list_lock,
&netdev_addr_lock_key[i],
netdev_lock_name[i]);
}
#else
static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
unsigned short dev_type)
{
}
static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
{
}
#endif
/*******************************************************************************
*
* Protocol management and registration routines
*
*******************************************************************************/
/*
* Add a protocol ID to the list. Now that the input handler is
* smarter we can dispense with all the messy stuff that used to be
* here.
*
* BEWARE!!! Protocol handlers, mangling input packets,
* MUST BE last in hash buckets and checking protocol handlers
* MUST start from promiscuous ptype_all chain in net_bh.
* It is true now, do not change it.
* Explanation follows: if protocol handler, mangling packet, will
* be the first on list, it is not able to sense, that packet
* is cloned and should be copied-on-write, so that it will
* change it and subsequent readers will get broken packet.
* --ANK (980803)
*/
static inline struct list_head *ptype_head(const struct packet_type *pt)
{
if (pt->type == htons(ETH_P_ALL))
return pt->dev ? &pt->dev->ptype_all : &ptype_all;
else
return pt->dev ? &pt->dev->ptype_specific :
&ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
}
/**
* dev_add_pack - add packet handler
* @pt: packet type declaration
*
* Add a protocol handler to the networking stack. The passed &packet_type
* is linked into kernel lists and may not be freed until it has been
* removed from the kernel lists.
*
* This call does not sleep therefore it can not
* guarantee all CPU's that are in middle of receiving packets
* will see the new packet type (until the next received packet).
*/
void dev_add_pack(struct packet_type *pt)
{
struct list_head *head = ptype_head(pt);
spin_lock(&ptype_lock);
list_add_rcu(&pt->list, head);
spin_unlock(&ptype_lock);
}
EXPORT_SYMBOL(dev_add_pack);
/**
* __dev_remove_pack - remove packet handler
* @pt: packet type declaration
*
* Remove a protocol handler that was previously added to the kernel
* protocol handlers by dev_add_pack(). The passed &packet_type is removed
* from the kernel lists and can be freed or reused once this function
* returns.
*
* The packet type might still be in use by receivers
* and must not be freed until after all the CPU's have gone
* through a quiescent state.
*/
void __dev_remove_pack(struct packet_type *pt)
{
struct list_head *head = ptype_head(pt);
struct packet_type *pt1;
spin_lock(&ptype_lock);
list_for_each_entry(pt1, head, list) {
if (pt == pt1) {
list_del_rcu(&pt->list);
goto out;
}
}
pr_warn("dev_remove_pack: %p not found\n", pt);
out:
spin_unlock(&ptype_lock);
}
EXPORT_SYMBOL(__dev_remove_pack);
/**
* dev_remove_pack - remove packet handler
* @pt: packet type declaration
*
* Remove a protocol handler that was previously added to the kernel
* protocol handlers by dev_add_pack(). The passed &packet_type is removed
* from the kernel lists and can be freed or reused once this function
* returns.
*
* This call sleeps to guarantee that no CPU is looking at the packet
* type after return.
*/
void dev_remove_pack(struct packet_type *pt)
{
__dev_remove_pack(pt);
synchronize_net();
}
EXPORT_SYMBOL(dev_remove_pack);
/*******************************************************************************
*
* Device Interface Subroutines
*
*******************************************************************************/
/**
* dev_get_iflink - get 'iflink' value of a interface
* @dev: targeted interface
*
* Indicates the ifindex the interface is linked to.
* Physical interfaces have the same 'ifindex' and 'iflink' values.
*/
int dev_get_iflink(const struct net_device *dev)
{
if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
return dev->netdev_ops->ndo_get_iflink(dev);
return dev->ifindex;
}
EXPORT_SYMBOL(dev_get_iflink);
/**
* dev_fill_metadata_dst - Retrieve tunnel egress information.
* @dev: targeted interface
* @skb: The packet.
*
* For better visibility of tunnel traffic OVS needs to retrieve
* egress tunnel information for a packet. Following API allows
* user to get this info.
*/
int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info;
if (!dev->netdev_ops || !dev->netdev_ops->ndo_fill_metadata_dst)
return -EINVAL;
info = skb_tunnel_info_unclone(skb);
if (!info)
return -ENOMEM;
if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
return -EINVAL;
return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
}
EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
{
int k = stack->num_paths++;
if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
return NULL;
return &stack->path[k];
}
int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
struct net_device_path_stack *stack)
{
const struct net_device *last_dev;
struct net_device_path_ctx ctx = {
.dev = dev,
};
struct net_device_path *path;
int ret = 0;
memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
stack->num_paths = 0;
while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
last_dev = ctx.dev;
path = dev_fwd_path(stack);
if (!path)
return -1;
memset(path, 0, sizeof(struct net_device_path));
ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
if (ret < 0)
return -1;
if (WARN_ON_ONCE(last_dev == ctx.dev))
return -1;
}
if (!ctx.dev)
return ret;
path = dev_fwd_path(stack);
if (!path)
return -1;
path->type = DEV_PATH_ETHERNET;
path->dev = ctx.dev;
return ret;
}
EXPORT_SYMBOL_GPL(dev_fill_forward_path);
/**
* __dev_get_by_name - find a device by its name
* @net: the applicable net namespace
* @name: name to find
*
* Find an interface by name. Must be called under RTNL semaphore
* or @dev_base_lock. If the name is found a pointer to the device
* is returned. If the name is not found then %NULL is returned. The
* reference counters are not incremented so the caller must be
* careful with locks.
*/
struct net_device *__dev_get_by_name(struct net *net, const char *name)
{
struct netdev_name_node *node_name;
node_name = netdev_name_node_lookup(net, name);
return node_name ? node_name->dev : NULL;
}
EXPORT_SYMBOL(__dev_get_by_name);
/**
* dev_get_by_name_rcu - find a device by its name
* @net: the applicable net namespace
* @name: name to find
*
* Find an interface by name.
* If the name is found a pointer to the device is returned.
* If the name is not found then %NULL is returned.
* The reference counters are not incremented so the caller must be
* careful with locks. The caller must hold RCU lock.
*/
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
{
struct netdev_name_node *node_name;
node_name = netdev_name_node_lookup_rcu(net, name);
return node_name ? node_name->dev : NULL;
}
EXPORT_SYMBOL(dev_get_by_name_rcu);
/* Deprecated for new users, call netdev_get_by_name() instead */
struct net_device *dev_get_by_name(struct net *net, const char *name)
{
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_name_rcu(net, name);
dev_hold(dev);
rcu_read_unlock();
return dev;
}
EXPORT_SYMBOL(dev_get_by_name);
/**
* netdev_get_by_name() - find a device by its name
* @net: the applicable net namespace
* @name: name to find
* @tracker: tracking object for the acquired reference
* @gfp: allocation flags for the tracker
*
* Find an interface by name. This can be called from any
* context and does its own locking. The returned handle has
* the usage count incremented and the caller must use netdev_put() to
* release it when it is no longer needed. %NULL is returned if no
* matching device is found.
*/
struct net_device *netdev_get_by_name(struct net *net, const char *name,
netdevice_tracker *tracker, gfp_t gfp)
{
struct net_device *dev;
dev = dev_get_by_name(net, name);
if (dev)
netdev_tracker_alloc(dev, tracker, gfp);
return dev;
}
EXPORT_SYMBOL(netdev_get_by_name);
/**
* __dev_get_by_index - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
*
* Search for an interface by index. Returns %NULL if the device
* is not found or a pointer to the device. The device has not
* had its reference counter increased so the caller must be careful
* about locking. The caller must hold either the RTNL semaphore
* or @dev_base_lock.
*/
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
struct hlist_head *head = dev_index_hash(net, ifindex);
hlist_for_each_entry(dev, head, index_hlist)
if (dev->ifindex == ifindex)
return dev;
return NULL;
}
EXPORT_SYMBOL(__dev_get_by_index);
/**
* dev_get_by_index_rcu - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
*
* Search for an interface by index. Returns %NULL if the device
* is not found or a pointer to the device. The device has not
* had its reference counter increased so the caller must be careful
* about locking. The caller must hold RCU lock.
*/
struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
{
struct net_device *dev;
struct hlist_head *head = dev_index_hash(net, ifindex);
hlist_for_each_entry_rcu(dev, head, index_hlist)
if (dev->ifindex == ifindex)
return dev;
return NULL;
}
EXPORT_SYMBOL(dev_get_by_index_rcu);
/* Deprecated for new users, call netdev_get_by_index() instead */
struct net_device *dev_get_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
dev_hold(dev);
rcu_read_unlock();
return dev;
}
EXPORT_SYMBOL(dev_get_by_index);
/**
* netdev_get_by_index() - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
* @tracker: tracking object for the acquired reference
* @gfp: allocation flags for the tracker
*
* Search for an interface by index. Returns NULL if the device
* is not found or a pointer to the device. The device returned has
* had a reference added and the pointer is safe until the user calls
* netdev_put() to indicate they have finished with it.
*/
struct net_device *netdev_get_by_index(struct net *net, int ifindex,
netdevice_tracker *tracker, gfp_t gfp)
{
struct net_device *dev;
dev = dev_get_by_index(net, ifindex);
if (dev)
netdev_tracker_alloc(dev, tracker, gfp);
return dev;
}
EXPORT_SYMBOL(netdev_get_by_index);
/**
* dev_get_by_napi_id - find a device by napi_id
* @napi_id: ID of the NAPI struct
*
* Search for an interface by NAPI ID. Returns %NULL if the device
* is not found or a pointer to the device. The device has not had
* its reference counter increased so the caller must be careful
* about locking. The caller must hold RCU lock.
*/
struct net_device *dev_get_by_napi_id(unsigned int napi_id)
{
struct napi_struct *napi;
WARN_ON_ONCE(!rcu_read_lock_held());
if (napi_id < MIN_NAPI_ID)
return NULL;
napi = napi_by_id(napi_id);
return napi ? napi->dev : NULL;
}
EXPORT_SYMBOL(dev_get_by_napi_id);
/**
* netdev_get_name - get a netdevice name, knowing its ifindex.
* @net: network namespace
* @name: a pointer to the buffer where the name will be stored.
* @ifindex: the ifindex of the interface to get the name from.
*/
int netdev_get_name(struct net *net, char *name, int ifindex)
{
struct net_device *dev;
int ret;
down_read(&devnet_rename_sem);
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (!dev) {
ret = -ENODEV;
goto out;
}
strcpy(name, dev->name);
ret = 0;
out:
rcu_read_unlock();
up_read(&devnet_rename_sem);
return ret;
}
/**
* dev_getbyhwaddr_rcu - find a device by its hardware address
* @net: the applicable net namespace
* @type: media type of device
* @ha: hardware address
*
* Search for an interface by MAC address. Returns NULL if the device
* is not found or a pointer to the device.
* The caller must hold RCU or RTNL.
* The returned device has not had its ref count increased
* and the caller must therefore be careful about locking
*
*/
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
const char *ha)
{
struct net_device *dev;
for_each_netdev_rcu(net, dev)
if (dev->type == type &&
!memcmp(dev->dev_addr, ha, dev->addr_len))
return dev;
return NULL;
}
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
{
struct net_device *dev, *ret = NULL;
rcu_read_lock();
for_each_netdev_rcu(net, dev)
if (dev->type == type) {
dev_hold(dev);
ret = dev;
break;
}
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(dev_getfirstbyhwtype);
/**
* __dev_get_by_flags - find any device with given flags
* @net: the applicable net namespace
* @if_flags: IFF_* values
* @mask: bitmask of bits in if_flags to check
*
* Search for any interface with the given flags. Returns NULL if a device
* is not found or a pointer to the device. Must be called inside
* rtnl_lock(), and result refcount is unchanged.
*/
struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
unsigned short mask)
{
struct net_device *dev, *ret;
ASSERT_RTNL();
ret = NULL;
for_each_netdev(net, dev) {
if (((dev->flags ^ if_flags) & mask) == 0) {
ret = dev;
break;
}
}
return ret;
}
EXPORT_SYMBOL(__dev_get_by_flags);
/**
* dev_valid_name - check if name is okay for network device
* @name: name string
*
* Network device names need to be valid file names to
* allow sysfs to work. We also disallow any kind of
* whitespace.
*/
bool dev_valid_name(const char *name)
{
if (*name == '\0')
return false;
if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
return false;
if (!strcmp(name, ".") || !strcmp(name, ".."))
return false;
while (*name) {
if (*name == '/' || *name == ':' || isspace(*name))
return false;
name++;
}
return true;
}
EXPORT_SYMBOL(dev_valid_name);
/**
* __dev_alloc_name - allocate a name for a device
* @net: network namespace to allocate the device name in
* @name: name format string
* @buf: scratch buffer and result name string
*
* Passed a format string - eg "lt%d" it will try and find a suitable
* id. It scans list of devices to build up a free map, then chooses
* the first empty slot. The caller must hold the dev_base or rtnl lock
* while allocating the name and adding the device in order to avoid
* duplicates.
* Limited to bits_per_byte * page size devices (ie 32K on most platforms).
* Returns the number of the unit assigned or a negative errno code.
*/
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
{
int i = 0;
const char *p;
const int max_netdevices = 8*PAGE_SIZE;
unsigned long *inuse;
struct net_device *d;
if (!dev_valid_name(name))
return -EINVAL;
p = strchr(name, '%');
if (p) {
/*
* Verify the string as this thing may have come from
* the user. There must be either one "%d" and no other "%"
* characters.
*/
if (p[1] != 'd' || strchr(p + 2, '%'))
return -EINVAL;
/* Use one page as a bit array of possible slots */
inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
if (!inuse)
return -ENOMEM;
for_each_netdev(net, d) {
struct netdev_name_node *name_node;
list_for_each_entry(name_node, &d->name_node->list, list) {
if (!sscanf(name_node->name, name, &i))
continue;
if (i < 0 || i >= max_netdevices)
continue;
/* avoid cases where sscanf is not exact inverse of printf */
snprintf(buf, IFNAMSIZ, name, i);
if (!strncmp(buf, name_node->name, IFNAMSIZ))
__set_bit(i, inuse);
}
if (!sscanf(d->name, name, &i))
continue;
if (i < 0 || i >= max_netdevices)
continue;
/* avoid cases where sscanf is not exact inverse of printf */
snprintf(buf, IFNAMSIZ, name, i);
if (!strncmp(buf, d->name, IFNAMSIZ))
__set_bit(i, inuse);
}
i = find_first_zero_bit(inuse, max_netdevices);
free_page((unsigned long) inuse);
}
snprintf(buf, IFNAMSIZ, name, i);
if (!netdev_name_in_use(net, buf))
return i;
/* It is possible to run out of possible slots
* when the name is long and there isn't enough space left
* for the digits, or if all bits are used.
*/
return -ENFILE;
}
static int dev_alloc_name_ns(struct net *net,
struct net_device *dev,
const char *name)
{
char buf[IFNAMSIZ];
int ret;
BUG_ON(!net);
ret = __dev_alloc_name(net, name, buf);
if (ret >= 0)
strscpy(dev->name, buf, IFNAMSIZ);
return ret;
}
/**
* dev_alloc_name - allocate a name for a device
* @dev: device
* @name: name format string
*
* Passed a format string - eg "lt%d" it will try and find a suitable
* id. It scans list of devices to build up a free map, then chooses
* the first empty slot. The caller must hold the dev_base or rtnl lock
* while allocating the name and adding the device in order to avoid
* duplicates.
* Limited to bits_per_byte * page size devices (ie 32K on most platforms).
* Returns the number of the unit assigned or a negative errno code.
*/
int dev_alloc_name(struct net_device *dev, const char *name)
{
return dev_alloc_name_ns(dev_net(dev), dev, name);
}
EXPORT_SYMBOL(dev_alloc_name);
static int dev_get_valid_name(struct net *net, struct net_device *dev,
const char *name)
{
BUG_ON(!net);
if (!dev_valid_name(name))
return -EINVAL;
if (strchr(name, '%'))
return dev_alloc_name_ns(net, dev, name);
else if (netdev_name_in_use(net, name))
return -EEXIST;
else if (dev->name != name)
strscpy(dev->name, name, IFNAMSIZ);
return 0;
}
/**
* dev_change_name - change name of a device
* @dev: device
* @newname: name (or format string) must be at least IFNAMSIZ
*
* Change name of a device, can pass format strings "eth%d".
* for wildcarding.
*/
int dev_change_name(struct net_device *dev, const char *newname)
{
unsigned char old_assign_type;
char oldname[IFNAMSIZ];
int err = 0;
int ret;
struct net *net;
ASSERT_RTNL();
BUG_ON(!dev_net(dev));
net = dev_net(dev);
down_write(&devnet_rename_sem);
if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
up_write(&devnet_rename_sem);
return 0;
}
memcpy(oldname, dev->name, IFNAMSIZ);
err = dev_get_valid_name(net, dev, newname);
if (err < 0) {
up_write(&devnet_rename_sem);
return err;
}
if (oldname[0] && !strchr(oldname, '%'))
netdev_info(dev, "renamed from %s%s\n", oldname,
dev->flags & IFF_UP ? " (while UP)" : "");
old_assign_type = dev->name_assign_type;
dev->name_assign_type = NET_NAME_RENAMED;
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;
up_write(&devnet_rename_sem);
return ret;
}
up_write(&devnet_rename_sem);
netdev_adjacent_rename_links(dev, oldname);
write_lock(&dev_base_lock);
netdev_name_node_del(dev->name_node);
write_unlock(&dev_base_lock);
synchronize_rcu();
write_lock(&dev_base_lock);
netdev_name_node_add(net, dev->name_node);
write_unlock(&dev_base_lock);
ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
ret = notifier_to_errno(ret);
if (ret) {
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
down_write(&devnet_rename_sem);
memcpy(dev->name, oldname, IFNAMSIZ);
memcpy(oldname, newname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;
old_assign_type = NET_NAME_RENAMED;
goto rollback;
} else {
netdev_err(dev, "name change rollback failed: %d\n",
ret);
}
}
return err;
}
/**
* dev_set_alias - change ifalias of a device
* @dev: device
* @alias: name up to IFALIASZ
* @len: limit of bytes to copy from info
*
* Set ifalias for a device,
*/
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
struct dev_ifalias *new_alias = NULL;
if (len >= IFALIASZ)
return -EINVAL;
if (len) {
new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
if (!new_alias)
return -ENOMEM;
memcpy(new_alias->ifalias, alias, len);
new_alias->ifalias[len] = 0;
}
mutex_lock(&ifalias_mutex);
new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
mutex_is_locked(&ifalias_mutex));
mutex_unlock(&ifalias_mutex);
if (new_alias)
kfree_rcu(new_alias, rcuhead);
return len;
}
EXPORT_SYMBOL(dev_set_alias);
/**
* dev_get_alias - get ifalias of a device
* @dev: device
* @name: buffer to store name of ifalias
* @len: size of buffer
*
* get ifalias for a device. Caller must make sure dev cannot go
* away, e.g. rcu read lock or own a reference count to device.
*/
int dev_get_alias(const struct net_device *dev, char *name, size_t len)
{
const struct dev_ifalias *alias;
int ret = 0;
rcu_read_lock();
alias = rcu_dereference(dev->ifalias);
if (alias)
ret = snprintf(name, len, "%s", alias->ifalias);
rcu_read_unlock();
return ret;
}
/**
* netdev_features_change - device changes features
* @dev: device to cause notification
*
* Called to indicate a device has changed features.
*/
void netdev_features_change(struct net_device *dev)
{
call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
}
EXPORT_SYMBOL(netdev_features_change);
/**
* netdev_state_change - device changes state
* @dev: device to cause notification
*
* Called to indicate a device has changed state. This function calls
* the notifier chains for netdev_chain and sends a NEWLINK message
* to the routing socket.
*/
void netdev_state_change(struct net_device *dev)
{
if (dev->flags & IFF_UP) {
struct netdev_notifier_change_info change_info = {
.info.dev = dev,
};
call_netdevice_notifiers_info(NETDEV_CHANGE,
&change_info.info);
rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
}
}
EXPORT_SYMBOL(netdev_state_change);
/**
* __netdev_notify_peers - notify network peers about existence of @dev,
* to be called when rtnl lock is already held.
* @dev: network device
*
* Generate traffic such that interested network peers are aware of
* @dev, such as by generating a gratuitous ARP. This may be used when
* a device wants to inform the rest of the network about some sort of
* reconfiguration such as a failover event or virtual machine
* migration.
*/
void __netdev_notify_peers(struct net_device *dev)
{
ASSERT_RTNL();
call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
}
EXPORT_SYMBOL(__netdev_notify_peers);
/**
* netdev_notify_peers - notify network peers about existence of @dev
* @dev: network device
*
* Generate traffic such that interested network peers are aware of
* @dev, such as by generating a gratuitous ARP. This may be used when
* a device wants to inform the rest of the network about some sort of
* reconfiguration such as a failover event or virtual machine
* migration.
*/
void netdev_notify_peers(struct net_device *dev)
{
rtnl_lock();
__netdev_notify_peers(dev);
rtnl_unlock();
}
EXPORT_SYMBOL(netdev_notify_peers);
static int napi_threaded_poll(void *data);
static int napi_kthread_create(struct napi_struct *n)
{
int err = 0;
/* Create and wake up the kthread once to put it in
* TASK_INTERRUPTIBLE mode to avoid the blocked task
* warning and work with loadavg.
*/
n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
n->dev->name, n->napi_id);
if (IS_ERR(n->thread)) {
err = PTR_ERR(n->thread);
pr_err("kthread_run failed with err %d\n", err);
n->thread = NULL;
}
return err;
}
static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
int ret;
ASSERT_RTNL();
dev_addr_check(dev);
if (!netif_device_present(dev)) {
/* may be detached because parent is runtime-suspended */
if (dev->dev.parent)
pm_runtime_resume(dev->dev.parent);
if (!netif_device_present(dev))
return -ENODEV;
}
/* Block netpoll from trying to do any rx path servicing.
* If we don't do this there is a chance ndo_poll_controller
* or ndo_poll may be running while we open the device
*/
netpoll_poll_disable(dev);
ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
ret = notifier_to_errno(ret);
if (ret)
return ret;
set_bit(__LINK_STATE_START, &dev->state);
if (ops->ndo_validate_addr)
ret = ops->ndo_validate_addr(dev);
if (!ret && ops->ndo_open)
ret = ops->ndo_open(dev);
netpoll_poll_enable(dev);
if (ret)
clear_bit(__LINK_STATE_START, &dev->state);
else {
dev->flags |= IFF_UP;
dev_set_rx_mode(dev);
dev_activate(dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
}
return ret;
}
/**
* dev_open - prepare an interface for use.
* @dev: device to open
* @extack: netlink extended ack
*
* Takes a device from down to up state. The device's private open
* function is invoked and then the multicast lists are loaded. Finally
* the device is moved into the up state and a %NETDEV_UP message is
* sent to the netdev notifier chain.
*
* Calling this function on an active interface is a nop. On a failure
* a negative errno code is returned.
*/
int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
{
int ret;
if (dev->flags & IFF_UP)
return 0;
ret = __dev_open(dev, extack);
if (ret < 0)
return ret;
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
call_netdevice_notifiers(NETDEV_UP, dev);
return ret;
}
EXPORT_SYMBOL(dev_open);
static void __dev_close_many(struct list_head *head)
{
struct net_device *dev;
ASSERT_RTNL();
might_sleep();
list_for_each_entry(dev, head, close_list) {
/* Temporarily disable netpoll until the interface is down */
netpoll_poll_disable(dev);
call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
clear_bit(__LINK_STATE_START, &dev->state);
/* Synchronize to scheduled poll. We cannot touch poll list, it
* can be even on different cpu. So just clear netif_running().
*
* dev->stop() will invoke napi_disable() on all of it's
* napi_struct instances on this device.
*/
smp_mb__after_atomic(); /* Commit netif_running(). */
}
dev_deactivate_many(head);
list_for_each_entry(dev, head, close_list) {
const struct net_device_ops *ops = dev->netdev_ops;
/*
* Call the device specific close. This cannot fail.
* Only if device is UP
*
* We allow it to be called even after a DETACH hot-plug
* event.
*/
if (ops->ndo_stop)
ops->ndo_stop(dev);
dev->flags &= ~IFF_UP;
netpoll_poll_enable(dev);
}
}
static void __dev_close(struct net_device *dev)
{
LIST_HEAD(single);
list_add(&dev->close_list, &single);
__dev_close_many(&single);
list_del(&single);
}
void dev_close_many(struct list_head *head, bool unlink)
{
struct net_device *dev, *tmp;
/* Remove the devices that don't need to be closed */
list_for_each_entry_safe(dev, tmp, head, close_list)
if (!(dev->flags & IFF_UP))
list_del_init(&dev->close_list);
__dev_close_many(head);
list_for_each_entry_safe(dev, tmp, head, close_list) {
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
call_netdevice_notifiers(NETDEV_DOWN, dev);
if (unlink)
list_del_init(&dev->close_list);
}
}
EXPORT_SYMBOL(dev_close_many);
/**
* dev_close - shutdown an interface.
* @dev: device to shutdown
*
* This function moves an active device into down state. A
* %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
* is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
* chain.
*/
void dev_close(struct net_device *dev)
{
if (dev->flags & IFF_UP) {
LIST_HEAD(single);
list_add(&dev->close_list, &single);
dev_close_many(&single, true);
list_del(&single);
}
}
EXPORT_SYMBOL(dev_close);
/**
* dev_disable_lro - disable Large Receive Offload on a device
* @dev: device
*
* Disable Large Receive Offload (LRO) on a net device. Must be
* called under RTNL. This is needed if received packets may be
* forwarded to another interface.
*/
void dev_disable_lro(struct net_device *dev)
{
struct net_device *lower_dev;
struct list_head *iter;
dev->wanted_features &= ~NETIF_F_LRO;
netdev_update_features(dev);
if (unlikely(dev->features & NETIF_F_LRO))
netdev_WARN(dev, "failed to disable LRO!\n");
netdev_for_each_lower_dev(dev, lower_dev, iter)
dev_disable_lro(lower_dev);
}
EXPORT_SYMBOL(dev_disable_lro);
/**
* dev_disable_gro_hw - disable HW Generic Receive Offload on a device
* @dev: device
*
* Disable HW Generic Receive Offload (GRO_HW) on a net device. Must be
* called under RTNL. This is needed if Generic XDP is installed on
* the device.
*/
static void dev_disable_gro_hw(struct net_device *dev)
{
dev->wanted_features &= ~NETIF_F_GRO_HW;
netdev_update_features(dev);
if (unlikely(dev->features & NETIF_F_GRO_HW))
netdev_WARN(dev, "failed to disable GRO_HW!\n");
}
const char *netdev_cmd_to_name(enum netdev_cmd cmd)
{
#define N(val) \
case NETDEV_##val: \
return "NETDEV_" __stringify(val);
switch (cmd) {
N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
N(XDP_FEAT_CHANGE)
}
#undef N
return "UNKNOWN_NETDEV_EVENT";
}
EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
struct net_device *dev)
{
struct netdev_notifier_info info = {
.dev = dev,
};
return nb->notifier_call(nb, val, &info);
}
static int call_netdevice_register_notifiers(struct notifier_block *nb,
struct net_device *dev)
{
int err;
err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
err = notifier_to_errno(err);
if (err)
return err;
if (!(dev->flags & IFF_UP))
return 0;
call_netdevice_notifier(nb, NETDEV_UP, dev);
return 0;
}
static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
struct net_device *dev)
{
if (dev->flags & IFF_UP) {
call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
dev);
call_netdevice_notifier(nb, NETDEV_DOWN, dev);
}
call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
}
static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
struct net *net)
{
struct net_device *dev;
int err;
for_each_netdev(net, dev) {
err = call_netdevice_register_notifiers(nb, dev);
if (err)
goto rollback;
}
return 0;
rollback:
for_each_netdev_continue_reverse(net, dev)
call_netdevice_unregister_notifiers(nb, dev);
return err;
}
static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
struct net *net)
{
struct net_device *dev;
for_each_netdev(net, dev)
call_netdevice_unregister_notifiers(nb, dev);
}
static int dev_boot_phase = 1;
/**
* register_netdevice_notifier - register a network notifier block
* @nb: notifier
*
* Register a notifier to be called when network device events occur.
* The notifier passed is linked into the kernel structures and must
* not be reused until it has been unregistered. A negative errno code
* is returned on a failure.
*
* When registered all registration and up events are replayed
* to the new notifier to allow device to have a race free
* view of the network device list.
*/
int register_netdevice_notifier(struct notifier_block *nb)
{
struct net *net;
int err;
/* Close race with setup_net() and cleanup_net() */
down_write(&pernet_ops_rwsem);
rtnl_lock();
err = raw_notifier_chain_register(&netdev_chain, nb);
if (err)
goto unlock;
if (dev_boot_phase)
goto unlock;
for_each_net(net) {
err = call_netdevice_register_net_notifiers(nb, net);
if (err)
goto rollback;
}
unlock:
rtnl_unlock();
up_write(&pernet_ops_rwsem);
return err;
rollback:
for_each_net_continue_reverse(net)
call_netdevice_unregister_net_notifiers(nb, net);
raw_notifier_chain_unregister(&netdev_chain, nb);
goto unlock;
}
EXPORT_SYMBOL(register_netdevice_notifier);
/**
* unregister_netdevice_notifier - unregister a network notifier block
* @nb: notifier
*
* Unregister a notifier previously registered by
* register_netdevice_notifier(). The notifier is unlinked into the
* kernel structures and may then be reused. A negative errno code
* is returned on a failure.
*
* After unregistering unregister and down device events are synthesized
* for all devices on the device list to the removed notifier to remove
* the need for special case cleanup code.
*/
int unregister_netdevice_notifier(struct notifier_block *nb)
{
struct net *net;
int err;
/* Close race with setup_net() and cleanup_net() */
down_write(&pernet_ops_rwsem);
rtnl_lock();
err = raw_notifier_chain_unregister(&netdev_chain, nb);
if (err)
goto unlock;
for_each_net(net)
call_netdevice_unregister_net_notifiers(nb, net);
unlock:
rtnl_unlock();
up_write(&pernet_ops_rwsem);
return err;
}
EXPORT_SYMBOL(unregister_netdevice_notifier);
static int __register_netdevice_notifier_net(struct net *net,
struct notifier_block *nb,
bool ignore_call_fail)
{
int err;
err = raw_notifier_chain_register(&net->netdev_chain, nb);
if (err)
return err;
if (dev_boot_phase)
return 0;
err = call_netdevice_register_net_notifiers(nb, net);
if (err && !ignore_call_fail)
goto chain_unregister;
return 0;
chain_unregister:
raw_notifier_chain_unregister(&net->netdev_chain, nb);
return err;
}
static int __unregister_netdevice_notifier_net(struct net *net,
struct notifier_block *nb)
{
int err;
err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
if (err)
return err;
call_netdevice_unregister_net_notifiers(nb, net);
return 0;
}
/**
* register_netdevice_notifier_net - register a per-netns network notifier block
* @net: network namespace
* @nb: notifier
*
* Register a notifier to be called when network device events occur.
* The notifier passed is linked into the kernel structures and must
* not be reused until it has been unregistered. A negative errno code
* is returned on a failure.
*
* When registered all registration and up events are replayed
* to the new notifier to allow device to have a race free
* view of the network device list.
*/
int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
{
int err;
rtnl_lock();
err = __register_netdevice_notifier_net(net, nb, false);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(register_netdevice_notifier_net);
/**
* unregister_netdevice_notifier_net - unregister a per-netns
* network notifier block
* @net: network namespace
* @nb: notifier
*
* Unregister a notifier previously registered by
* register_netdevice_notifier_net(). The notifier is unlinked from the
* kernel structures and may then be reused. A negative errno code
* is returned on a failure.
*
* After unregistering unregister and down device events are synthesized
* for all devices on the device list to the removed notifier to remove
* the need for special case cleanup code.
*/
int unregister_netdevice_notifier_net(struct net *net,
struct notifier_block *nb)
{
int err;
rtnl_lock();
err = __unregister_netdevice_notifier_net(net, nb);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(unregister_netdevice_notifier_net);
static void __move_netdevice_notifier_net(struct net *src_net,
struct net *dst_net,
struct notifier_block *nb)
{
__unregister_netdevice_notifier_net(src_net, nb);
__register_netdevice_notifier_net(dst_net, nb, true);
}
int register_netdevice_notifier_dev_net(struct net_device *dev,
struct notifier_block *nb,
struct netdev_net_notifier *nn)
{
int err;
rtnl_lock();
err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
if (!err) {
nn->nb = nb;
list_add(&nn->list, &dev->net_notifier_list);
}
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
int unregister_netdevice_notifier_dev_net(struct net_device *dev,
struct notifier_block *nb,
struct netdev_net_notifier *nn)
{
int err;
rtnl_lock();
list_del(&nn->list);
err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
static void move_netdevice_notifiers_dev_net(struct net_device *dev,
struct net *net)
{
struct netdev_net_notifier *nn;
list_for_each_entry(nn, &dev->net_notifier_list, list)
__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
}
/**
* call_netdevice_notifiers_info - call all network notifier blocks
* @val: value passed unmodified to notifier function
* @info: notifier information data
*
* Call all network notifier blocks. Parameters and return value
* are as for raw_notifier_call_chain().
*/
int call_netdevice_notifiers_info(unsigned long val,
struct netdev_notifier_info *info)
{
struct net *net = dev_net(info->dev);
int ret;
ASSERT_RTNL();
/* Run per-netns notifier block chain first, then run the global one.
* Hopefully, one day, the global one is going to be removed after
* all notifier block registrators get converted to be per-netns.
*/
ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
if (ret & NOTIFY_STOP_MASK)
return ret;
return raw_notifier_call_chain(&netdev_chain, val, info);
}
/**
* call_netdevice_notifiers_info_robust - call per-netns notifier blocks
* for and rollback on error
* @val_up: value passed unmodified to notifier function
* @val_down: value passed unmodified to the notifier function when
* recovering from an error on @val_up
* @info: notifier information data
*
* Call all per-netns network notifier blocks, but not notifier blocks on
* the global notifier chain. Parameters and return value are as for
* raw_notifier_call_chain_robust().
*/
static int
call_netdevice_notifiers_info_robust(unsigned long val_up,
unsigned long val_down,
struct netdev_notifier_info *info)
{
struct net *net = dev_net(info->dev);
ASSERT_RTNL();
return raw_notifier_call_chain_robust(&net->netdev_chain,
val_up, val_down, info);
}
static int call_netdevice_notifiers_extack(unsigned long val,
struct net_device *dev,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_info info = {
.dev = dev,
.extack = extack,
};
return call_netdevice_notifiers_info(val, &info);
}
/**
* call_netdevice_notifiers - call all network notifier blocks
* @val: value passed unmodified to notifier function
* @dev: net_device pointer passed unmodified to notifier function
*
* Call all network notifier blocks. Parameters and return value
* are as for raw_notifier_call_chain().
*/
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
{
return call_netdevice_notifiers_extack(val, dev, NULL);
}
EXPORT_SYMBOL(call_netdevice_notifiers);
/**
* call_netdevice_notifiers_mtu - call all network notifier blocks
* @val: value passed unmodified to notifier function
* @dev: net_device pointer passed unmodified to notifier function
* @arg: additional u32 argument passed to the notifier function
*
* Call all network notifier blocks. Parameters and return value
* are as for raw_notifier_call_chain().
*/
static int call_netdevice_notifiers_mtu(unsigned long val,
struct net_device *dev, u32 arg)
{
struct netdev_notifier_info_ext info = {
.info.dev = dev,
.ext.mtu = arg,
};
BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
return call_netdevice_notifiers_info(val, &info.info);
}
#ifdef CONFIG_NET_INGRESS
static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
void net_inc_ingress_queue(void)
{
static_branch_inc(&ingress_needed_key);
}
EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
void net_dec_ingress_queue(void)
{
static_branch_dec(&ingress_needed_key);
}
EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
#endif
#ifdef CONFIG_NET_EGRESS
static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
void net_inc_egress_queue(void)
{
static_branch_inc(&egress_needed_key);
}
EXPORT_SYMBOL_GPL(net_inc_egress_queue);
void net_dec_egress_queue(void)
{
static_branch_dec(&egress_needed_key);
}
EXPORT_SYMBOL_GPL(net_dec_egress_queue);
#endif
DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
EXPORT_SYMBOL(netstamp_needed_key);
#ifdef CONFIG_JUMP_LABEL
static atomic_t netstamp_needed_deferred;
static atomic_t netstamp_wanted;
static void netstamp_clear(struct work_struct *work)
{
int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
int wanted;
wanted = atomic_add_return(deferred, &netstamp_wanted);
if (wanted > 0)
static_branch_enable(&netstamp_needed_key);
else
static_branch_disable(&netstamp_needed_key);
}
static DECLARE_WORK(netstamp_work, netstamp_clear);
#endif
void net_enable_timestamp(void)
{
#ifdef CONFIG_JUMP_LABEL
int wanted = atomic_read(&netstamp_wanted);
while (wanted > 0) {
if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
return;
}
atomic_inc(&netstamp_needed_deferred);
schedule_work(&netstamp_work);
#else
static_branch_inc(&netstamp_needed_key);
#endif
}
EXPORT_SYMBOL(net_enable_timestamp);
void net_disable_timestamp(void)
{
#ifdef CONFIG_JUMP_LABEL
int wanted = atomic_read(&netstamp_wanted);
while (wanted > 1) {
if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
return;
}
atomic_dec(&netstamp_needed_deferred);
schedule_work(&netstamp_work);
#else
static_branch_dec(&netstamp_needed_key);
#endif
}
EXPORT_SYMBOL(net_disable_timestamp);
static inline void net_timestamp_set(struct sk_buff *skb)
{
skb->tstamp = 0;
skb->mono_delivery_time = 0;
if (static_branch_unlikely(&netstamp_needed_key))
skb->tstamp = ktime_get_real();
}
#define net_timestamp_check(COND, SKB) \
if (static_branch_unlikely(&netstamp_needed_key)) { \
if ((COND) && !(SKB)->tstamp) \
(SKB)->tstamp = ktime_get_real(); \
} \
bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
{
return __is_skb_forwardable(dev, skb, true);
}
EXPORT_SYMBOL_GPL(is_skb_forwardable);
static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
bool check_mtu)
{
int ret = ____dev_forward_skb(dev, skb, check_mtu);
if (likely(!ret)) {
skb->protocol = eth_type_trans(skb, dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
}
return ret;
}
int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
return __dev_forward_skb2(dev, skb, true);
}
EXPORT_SYMBOL_GPL(__dev_forward_skb);
/**
* dev_forward_skb - loopback an skb to another netif
*
* @dev: destination network device
* @skb: buffer to forward
*
* return values:
* NET_RX_SUCCESS (no congestion)
* NET_RX_DROP (packet was dropped, but freed)
*
* dev_forward_skb can be used for injecting an skb from the
* start_xmit function of one device into the receive queue
* of another device.
*
* The receiving device may be in another namespace, so
* we have to clear all information in the skb that could
* impact namespace isolation.
*/
int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);
int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
{
return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
}
static inline int deliver_skb(struct sk_buff *skb,
struct packet_type *pt_prev,
struct net_device *orig_dev)
{
if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
return -ENOMEM;
refcount_inc(&skb->users);
return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}
static inline void deliver_ptype_list_skb(struct sk_buff *skb,
struct packet_type **pt,
struct net_device *orig_dev,
__be16 type,
struct list_head *ptype_list)
{
struct packet_type *ptype, *pt_prev = *pt;
list_for_each_entry_rcu(ptype, ptype_list, list) {
if (ptype->type != type)
continue;
if (pt_prev)
deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
*pt = pt_prev;
}
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
if (!ptype->af_packet_priv || !skb->sk)
return false;
if (ptype->id_match)
return ptype->id_match(ptype, skb->sk);
else if ((struct sock *)ptype->af_packet_priv == skb->sk)
return true;
return false;
}
/**
* dev_nit_active - return true if any network interface taps are in use
*
* @dev: network device to check for the presence of taps
*/
bool dev_nit_active(struct net_device *dev)
{
return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
}
EXPORT_SYMBOL_GPL(dev_nit_active);
/*
* Support routine. Sends outgoing frames to any network
* taps currently in use.
*/
void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
{
struct packet_type *ptype;
struct sk_buff *skb2 = NULL;
struct packet_type *pt_prev = NULL;
struct list_head *ptype_list = &ptype_all;
rcu_read_lock();
again:
list_for_each_entry_rcu(ptype, ptype_list, list) {
if (ptype->ignore_outgoing)
continue;
/* Never send packets back to the socket
* they originated from - MvS (miquels@drinkel.ow.org)
*/
if (skb_loop_sk(ptype, skb))
continue;
if (pt_prev) {
deliver_skb(skb2, pt_prev, skb->dev);
pt_prev = ptype;
continue;
}
/* need to clone skb, done only once */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
goto out_unlock;
net_timestamp_set(skb2);
/* skb->nh should be correctly
* set by sender, so that the second statement is
* just protection against buggy protocols.
*/
skb_reset_mac_header(skb2);
if (skb_network_header(skb2) < skb2->data ||
skb_network_header(skb2) > skb_tail_pointer(skb2)) {
net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
ntohs(skb2->protocol),
dev->name);
skb_reset_network_header(skb2);
}
skb2->transport_header = skb2->network_header;
skb2->pkt_type = PACKET_OUTGOING;
pt_prev = ptype;
}
if (ptype_list == &ptype_all) {
ptype_list = &dev->ptype_all;
goto again;
}
out_unlock:
if (pt_prev) {
if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
else
kfree_skb(skb2);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
/**
* netif_setup_tc - Handle tc mappings on real_num_tx_queues change
* @dev: Network device
* @txq: number of queues available
*
* If real_num_tx_queues is changed the tc mappings may no longer be
* valid. To resolve this verify the tc mapping remains valid and if
* not NULL the mapping. With no priorities mapping to this
* offset/count pair it will no longer be used. In the worst case TC0
* is invalid nothing can be done so disable priority mappings. If is
* expected that drivers will fix this mapping if they can before
* calling netif_set_real_num_tx_queues.
*/
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
{
int i;
struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
/* If TC0 is invalidated disable TC mapping */
if (tc->offset + tc->count > txq) {
netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
dev->num_tc = 0;
return;
}
/* Invalidated prio to tc mappings set to TC0 */
for (i = 1; i < TC_BITMASK + 1; i++) {
int q = netdev_get_prio_tc_map(dev, i);
tc = &dev->tc_to_txq[q];
if (tc->offset + tc->count > txq) {
netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
i, q);
netdev_set_prio_tc_map(dev, i, 0);
}
}
}
int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
{
if (dev->num_tc) {
struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
int i;
/* walk through the TCs and see if it falls into any of them */
for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
if ((txq - tc->offset) < tc->count)
return i;
}
/* didn't find it, just return -1 to indicate no match */
return -1;
}
return 0;
}
EXPORT_SYMBOL(netdev_txq_to_tc);
#ifdef CONFIG_XPS
static struct static_key xps_needed __read_mostly;
static struct static_key xps_rxqs_needed __read_mostly;
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P) \
rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
struct xps_dev_maps *old_maps, int tci, u16 index)
{
struct xps_map *map = NULL;
int pos;
map = xmap_dereference(dev_maps->attr_map[tci]);
if (!map)
return false;
for (pos = map->len; pos--;) {
if (map->queues[pos] != index)
continue;
if (map->len > 1) {
map->queues[pos] = map->queues[--map->len];
break;
}
if (old_maps)
RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
kfree_rcu(map, rcu);
return false;
}
return true;
}
static bool remove_xps_queue_cpu(struct net_device *dev,
struct xps_dev_maps *dev_maps,
int cpu, u16 offset, u16 count)
{
int num_tc = dev_maps->num_tc;
bool active = false;
int tci;
for (tci = cpu * num_tc; num_tc--; tci++) {
int i, j;
for (i = count, j = offset; i--; j++) {
if (!remove_xps_queue(dev_maps, NULL, tci, j))
break;
}
active |= i < 0;
}
return active;
}
static void reset_xps_maps(struct net_device *dev,
struct xps_dev_maps *dev_maps,
enum xps_map_type type)
{
static_key_slow_dec_cpuslocked(&xps_needed);
if (type == XPS_RXQS)
static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
RCU_INIT_POINTER(dev->xps_maps[type], NULL);
kfree_rcu(dev_maps, rcu);
}
static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
u16 offset, u16 count)
{
struct xps_dev_maps *dev_maps;
bool active = false;
int i, j;
dev_maps = xmap_dereference(dev->xps_maps[type]);
if (!dev_maps)
return;
for (j = 0; j < dev_maps->nr_ids; j++)
active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
if (!active)
reset_xps_maps(dev, dev_maps, type);
if (type == XPS_CPUS) {
for (i = offset + (count - 1); count--; i--)
netdev_queue_numa_node_write(
netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
}
}
static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
u16 count)
{
if (!static_key_false(&xps_needed))
return;
cpus_read_lock();
mutex_lock(&xps_map_mutex);
if (static_key_false(&xps_rxqs_needed))
clean_xps_maps(dev, XPS_RXQS, offset, count);
clean_xps_maps(dev, XPS_CPUS, offset, count);
mutex_unlock(&xps_map_mutex);
cpus_read_unlock();
}
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
{
netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
}
static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
u16 index, bool is_rxqs_map)
{
struct xps_map *new_map;
int alloc_len = XPS_MIN_MAP_ALLOC;
int i, pos;
for (pos = 0; map && pos < map->len; pos++) {
if (map->queues[pos] != index)
continue;
return map;
}
/* Need to add tx-queue to this CPU's/rx-queue's existing map */
if (map) {
if (pos < map->alloc_len)
return map;
alloc_len = map->alloc_len * 2;
}
/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
* map
*/
if (is_rxqs_map)
new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
else
new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
cpu_to_node(attr_index));
if (!new_map)
return NULL;
for (i = 0; i < pos; i++)
new_map->queues[i] = map->queues[i];
new_map->alloc_len = alloc_len;
new_map->len = pos;
return new_map;
}
/* Copy xps maps at a given index */
static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
struct xps_dev_maps *new_dev_maps, int index,
int tc, bool skip_tc)
{
int i, tci = index * dev_maps->num_tc;
struct xps_map *map;
/* copy maps belonging to foreign traffic classes */
for (i = 0; i < dev_maps->num_tc; i++, tci++) {
if (i == tc && skip_tc)
continue;
/* fill in the new device map from the old device map */
map = xmap_dereference(dev_maps->attr_map[tci]);
RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
}
}
/* Must be called under cpus_read_lock */
int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
u16 index, enum xps_map_type type)
{
struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
const unsigned long *online_mask = NULL;
bool active = false, copy = false;
int i, j, tci, numa_node_id = -2;
int maps_sz, num_tc = 1, tc = 0;
struct xps_map *map, *new_map;
unsigned int nr_ids;
WARN_ON_ONCE(index >= dev->num_tx_queues);
if (dev->num_tc) {
/* Do not allow XPS on subordinate device directly */
num_tc = dev->num_tc;
if (num_tc < 0)
return -EINVAL;
/* If queue belongs to subordinate dev use its map */
dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
tc = netdev_txq_to_tc(dev, index);
if (tc < 0)
return -EINVAL;
}
mutex_lock(&xps_map_mutex);
dev_maps = xmap_dereference(dev->xps_maps[type]);
if (type == XPS_RXQS) {
maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
nr_ids = dev->num_rx_queues;
} else {
maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
if (num_possible_cpus() > 1)
online_mask = cpumask_bits(cpu_online_mask);
nr_ids = nr_cpu_ids;
}
if (maps_sz < L1_CACHE_BYTES)
maps_sz = L1_CACHE_BYTES;
/* The old dev_maps could be larger or smaller than the one we're
* setting up now, as dev->num_tc or nr_ids could have been updated in
* between. We could try to be smart, but let's be safe instead and only
* copy foreign traffic classes if the two map sizes match.
*/
if (dev_maps &&
dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
copy = true;
/* allocate memory for queue storage */
for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
j < nr_ids;) {
if (!new_dev_maps) {
new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
if (!new_dev_maps) {
mutex_unlock(&xps_map_mutex);
return -ENOMEM;
}
new_dev_maps->nr_ids = nr_ids;
new_dev_maps->num_tc = num_tc;
}
tci = j * num_tc + tc;
map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
map = expand_xps_map(map, j, index, type == XPS_RXQS);
if (!map)
goto error;
RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
}
if (!new_dev_maps)
goto out_no_new_maps;
if (!dev_maps) {
/* Increment static keys at most once per type */
static_key_slow_inc_cpuslocked(&xps_needed);
if (type == XPS_RXQS)
static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
}
for (j = 0; j < nr_ids; j++) {
bool skip_tc = false;
tci = j * num_tc + tc;
if (netif_attr_test_mask(j, mask, nr_ids) &&
netif_attr_test_online(j, online_mask, nr_ids)) {
/* add tx-queue to CPU/rx-queue maps */
int pos = 0;
skip_tc = true;
map = xmap_dereference(new_dev_maps->attr_map[tci]);
while ((pos < map->len) && (map->queues[pos] != index))
pos++;
if (pos == map->len)
map->queues[map->len++] = index;
#ifdef CONFIG_NUMA
if (type == XPS_CPUS) {
if (numa_node_id == -2)
numa_node_id = cpu_to_node(j);
else if (numa_node_id != cpu_to_node(j))
numa_node_id = -1;
}
#endif
}
if (copy)
xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
skip_tc);
}
rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
/* Cleanup old maps */
if (!dev_maps)
goto out_no_old_maps;
for (j = 0; j < dev_maps->nr_ids; j++) {
for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
map = xmap_dereference(dev_maps->attr_map[tci]);
if (!map)
continue;
if (copy) {
new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
if (map == new_map)
continue;
}
RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
kfree_rcu(map, rcu);
}
}
old_dev_maps = dev_maps;
out_no_old_maps:
dev_maps = new_dev_maps;
active = true;
out_no_new_maps:
if (type == XPS_CPUS)
/* update Tx queue numa node */
netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
(numa_node_id >= 0) ?
numa_node_id : NUMA_NO_NODE);
if (!dev_maps)
goto out_no_maps;
/* removes tx-queue from unused CPUs/rx-queues */
for (j = 0; j < dev_maps->nr_ids; j++) {
tci = j * dev_maps->num_tc;
for (i = 0; i < dev_maps->num_tc; i++, tci++) {
if (i == tc &&
netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
continue;
active |= remove_xps_queue(dev_maps,
copy ? old_dev_maps : NULL,
tci, index);
}
}
if (old_dev_maps)
kfree_rcu(old_dev_maps, rcu);
/* free map if not active */
if (!active)
reset_xps_maps(dev, dev_maps, type);
out_no_maps:
mutex_unlock(&xps_map_mutex);
return 0;
error:
/* remove any maps that we added */
for (j = 0; j < nr_ids; j++) {
for (i = num_tc, tci = j * num_tc; i--; tci++) {
new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
map = copy ?
xmap_dereference(dev_maps->attr_map[tci]) :
NULL;
if (new_map && new_map != map)
kfree(new_map);
}
}
mutex_unlock(&xps_map_mutex);
kfree(new_dev_maps);
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
u16 index)
{
int ret;
cpus_read_lock();
ret = __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
cpus_read_unlock();
return ret;
}
EXPORT_SYMBOL(netif_set_xps_queue);
#endif
static void netdev_unbind_all_sb_channels(struct net_device *dev)
{
struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
/* Unbind any subordinate channels */
while (txq-- != &dev->_tx[0]) {
if (txq->sb_dev)
netdev_unbind_sb_channel(dev, txq->sb_dev);
}
}
void netdev_reset_tc(struct net_device *dev)
{
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, 0);
#endif
netdev_unbind_all_sb_channels(dev);
/* Reset TC configuration of device */
dev->num_tc = 0;
memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
}
EXPORT_SYMBOL(netdev_reset_tc);
int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
{
if (tc >= dev->num_tc)
return -EINVAL;
#ifdef CONFIG_XPS
netif_reset_xps_queues(dev, offset, count);
#endif
dev->tc_to_txq[tc].count = count;
dev->tc_to_txq[tc].offset = offset;
return 0;
}
EXPORT_SYMBOL(netdev_set_tc_queue);
int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
{
if (num_tc > TC_MAX_QUEUE)
return -EINVAL;
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, 0);
#endif
netdev_unbind_all_sb_channels(dev);
dev->num_tc = num_tc;
return 0;
}
EXPORT_SYMBOL(netdev_set_num_tc);
void netdev_unbind_sb_channel(struct net_device *dev,
struct net_device *sb_dev)
{
struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(sb_dev, 0);
#endif
memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
while (txq-- != &dev->_tx[0]) {
if (txq->sb_dev == sb_dev)
txq->sb_dev = NULL;
}
}
EXPORT_SYMBOL(netdev_unbind_sb_channel);
int netdev_bind_sb_channel_queue(struct net_device *dev,
struct net_device *sb_dev,
u8 tc, u16 count, u16 offset)
{
/* Make certain the sb_dev and dev are already configured */
if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
return -EINVAL;
/* We cannot hand out queues we don't have */
if ((offset + count) > dev->real_num_tx_queues)
return -EINVAL;
/* Record the mapping */
sb_dev->tc_to_txq[tc].count = count;
sb_dev->tc_to_txq[tc].offset = offset;
/* Provide a way for Tx queue to find the tc_to_txq map or
* XPS map for itself.
*/
while (count--)
netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
return 0;
}
EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
int netdev_set_sb_channel(struct net_device *dev, u16 channel)
{
/* Do not use a multiqueue device to represent a subordinate channel */
if (netif_is_multiqueue(dev))
return -ENODEV;
/* We allow channels 1 - 32767 to be used for subordinate channels.
* Channel 0 is meant to be "native" mode and used only to represent
* the main root device. We allow writing 0 to reset the device back
* to normal mode after being used as a subordinate channel.
*/
if (channel > S16_MAX)
return -EINVAL;
dev->num_tc = -channel;
return 0;
}
EXPORT_SYMBOL(netdev_set_sb_channel);
/*
* Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
* greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
*/
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
{
bool disabling;
int rc;
disabling = txq < dev->real_num_tx_queues;
if (txq < 1 || txq > dev->num_tx_queues)
return -EINVAL;
if (dev->reg_state == NETREG_REGISTERED ||
dev->reg_state == NETREG_UNREGISTERING) {
ASSERT_RTNL();
rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
txq);
if (rc)
return rc;
if (dev->num_tc)
netif_setup_tc(dev, txq);
dev_qdisc_change_real_num_tx(dev, txq);
dev->real_num_tx_queues = txq;
if (disabling) {
synchronize_net();
qdisc_reset_all_tx_gt(dev, txq);
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, txq);
#endif
}
} else {
dev->real_num_tx_queues = txq;
}
return 0;
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
#ifdef CONFIG_SYSFS
/**
* netif_set_real_num_rx_queues - set actual number of RX queues used
* @dev: Network device
* @rxq: Actual number of RX queues
*
* This must be called either with the rtnl_lock held or before
* registration of the net device. Returns 0 on success, or a
* negative error code. If called before registration, it always
* succeeds.
*/
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
int rc;
if (rxq < 1 || rxq > dev->num_rx_queues)
return -EINVAL;
if (dev->reg_state == NETREG_REGISTERED) {
ASSERT_RTNL();
rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
rxq);
if (rc)
return rc;
}
dev->real_num_rx_queues = rxq;
return 0;
}
EXPORT_SYMBOL(netif_set_real_num_rx_queues);
#endif
/**
* netif_set_real_num_queues - set actual number of RX and TX queues used
* @dev: Network device
* @txq: Actual number of TX queues
* @rxq: Actual number of RX queues
*
* Set the real number of both TX and RX queues.
* Does nothing if the number of queues is already correct.
*/
int netif_set_real_num_queues(struct net_device *dev,
unsigned int txq, unsigned int rxq)
{
unsigned int old_rxq = dev->real_num_rx_queues;
int err;
if (txq < 1 || txq > dev->num_tx_queues ||
rxq < 1 || rxq > dev->num_rx_queues)
return -EINVAL;
/* Start from increases, so the error path only does decreases -
* decreases can't fail.
*/
if (rxq > dev->real_num_rx_queues) {
err = netif_set_real_num_rx_queues(dev, rxq);
if (err)
return err;
}
if (txq > dev->real_num_tx_queues) {
err = netif_set_real_num_tx_queues(dev, txq);
if (err)
goto undo_rx;
}
if (rxq < dev->real_num_rx_queues)
WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
if (txq < dev->real_num_tx_queues)
WARN_ON(netif_set_real_num_tx_queues(dev, txq));
return 0;
undo_rx:
WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
return err;
}
EXPORT_SYMBOL(netif_set_real_num_queues);
/**
* netif_set_tso_max_size() - set the max size of TSO frames supported
* @dev: netdev to update
* @size: max skb->len of a TSO frame
*
* Set the limit on the size of TSO super-frames the device can handle.
* Unless explicitly set the stack will assume the value of
* %GSO_LEGACY_MAX_SIZE.
*/
void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
{
dev->tso_max_size = min(GSO_MAX_SIZE, size);
if (size < READ_ONCE(dev->gso_max_size))
netif_set_gso_max_size(dev, size);
if (size < READ_ONCE(dev->gso_ipv4_max_size))
netif_set_gso_ipv4_max_size(dev, size);
}
EXPORT_SYMBOL(netif_set_tso_max_size);
/**
* netif_set_tso_max_segs() - set the max number of segs supported for TSO
* @dev: netdev to update
* @segs: max number of TCP segments
*
* Set the limit on the number of TCP segments the device can generate from
* a single TSO super-frame.
* Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
*/
void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
{
dev->tso_max_segs = segs;
if (segs < READ_ONCE(dev->gso_max_segs))
netif_set_gso_max_segs(dev, segs);
}
EXPORT_SYMBOL(netif_set_tso_max_segs);
/**
* netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
* @to: netdev to update
* @from: netdev from which to copy the limits
*/
void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
{
netif_set_tso_max_size(to, from->tso_max_size);
netif_set_tso_max_segs(to, from->tso_max_segs);
}
EXPORT_SYMBOL(netif_inherit_tso_max);
/**
* netif_get_num_default_rss_queues - default number of RSS queues
*
* Default value is the number of physical cores if there are only 1 or 2, or
* divided by 2 if there are more.
*/
int netif_get_num_default_rss_queues(void)
{
cpumask_var_t cpus;
int cpu, count = 0;
if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
return 1;
cpumask_copy(cpus, cpu_online_mask);
for_each_cpu(cpu, cpus) {
++count;
cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
}
free_cpumask_var(cpus);
return count > 2 ? DIV_ROUND_UP(count, 2) : count;
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);
static void __netif_reschedule(struct Qdisc *q)
{
struct softnet_data *sd;
unsigned long flags;
local_irq_save(flags);
sd = this_cpu_ptr(&softnet_data);
q->next_sched = NULL;
*sd->output_queue_tailp = q;
sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
void __netif_schedule(struct Qdisc *q)
{
if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
__netif_reschedule(q);
}
EXPORT_SYMBOL(__netif_schedule);
struct dev_kfree_skb_cb {
enum skb_drop_reason reason;
};
static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
{
return (struct dev_kfree_skb_cb *)skb->cb;
}
void netif_schedule_queue(struct netdev_queue *txq)
{
rcu_read_lock();
if (!netif_xmit_stopped(txq)) {
struct Qdisc *q = rcu_dereference(txq->qdisc);
__netif_schedule(q);
}
rcu_read_unlock();
}
EXPORT_SYMBOL(netif_schedule_queue);
void netif_tx_wake_queue(struct netdev_queue *dev_queue)
{
if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
struct Qdisc *q;
rcu_read_lock();
q = rcu_dereference(dev_queue->qdisc);
__netif_schedule(q);
rcu_read_unlock();
}
}
EXPORT_SYMBOL(netif_tx_wake_queue);
void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
{
unsigned long flags;
if (unlikely(!skb))
return;
if (likely(refcount_read(&skb->users) == 1)) {
smp_rmb();
refcount_set(&skb->users, 0);
} else if (likely(!refcount_dec_and_test(&skb->users))) {
return;
}
get_kfree_skb_cb(skb)->reason = reason;
local_irq_save(flags);
skb->next = __this_cpu_read(softnet_data.completion_queue);
__this_cpu_write(softnet_data.completion_queue, skb);
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
{
if (in_hardirq() || irqs_disabled())
dev_kfree_skb_irq_reason(skb, reason);
else
kfree_skb_reason(skb, reason);
}
EXPORT_SYMBOL(dev_kfree_skb_any_reason);
/**
* netif_device_detach - mark device as removed
* @dev: network device
*
* Mark device as removed from system and therefore no longer available.
*/
void netif_device_detach(struct net_device *dev)
{
if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
netif_running(dev)) {
netif_tx_stop_all_queues(dev);
}
}
EXPORT_SYMBOL(netif_device_detach);
/**
* netif_device_attach - mark device as attached
* @dev: network device
*
* Mark device as attached from system and restart if needed.
*/
void netif_device_attach(struct net_device *dev)
{
if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
netif_running(dev)) {
netif_tx_wake_all_queues(dev);
__netdev_watchdog_up(dev);
}
}
EXPORT_SYMBOL(netif_device_attach);
/*
* Returns a Tx hash based on the given packet descriptor a Tx queues' number
* to be used as a distribution range.
*/
static u16 skb_tx_hash(const struct net_device *dev,
const struct net_device *sb_dev,
struct sk_buff *skb)
{
u32 hash;
u16 qoffset = 0;
u16 qcount = dev->real_num_tx_queues;
if (dev->num_tc) {
u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
qoffset = sb_dev->tc_to_txq[tc].offset;
qcount = sb_dev->tc_to_txq[tc].count;
if (unlikely(!qcount)) {
net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
sb_dev->name, qoffset, tc);
qoffset = 0;
qcount = dev->real_num_tx_queues;
}
}
if (skb_rx_queue_recorded(skb)) {
DEBUG_NET_WARN_ON_ONCE(qcount == 0);
hash = skb_get_rx_queue(skb);
if (hash >= qoffset)
hash -= qoffset;
while (unlikely(hash >= qcount))
hash -= qcount;
return hash + qoffset;
}
return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
}
void skb_warn_bad_offload(const struct sk_buff *skb)
{
static const netdev_features_t null_features;
struct net_device *dev = skb->dev;
const char *name = "";
if (!net_ratelimit())
return;
if (dev) {
if (dev->dev.parent)
name = dev_driver_string(dev->dev.parent);
else
name = netdev_name(dev);
}
skb_dump(KERN_WARNING, skb, false);
WARN(1, "%s: caps=(%pNF, %pNF)\n",
name, dev ? &dev->features : &null_features,
skb->sk ? &skb->sk->sk_route_caps : &null_features);
}
/*
* Invalidate hardware checksum when packet is to be mangled, and
* complete checksum manually on outgoing path.
*/
int skb_checksum_help(struct sk_buff *skb)
{
__wsum csum;
int ret = 0, offset;
if (skb->ip_summed == CHECKSUM_COMPLETE)
goto out_set_summed;
if (unlikely(skb_is_gso(skb))) {
skb_warn_bad_offload(skb);
return -EINVAL;
}
/* Before computing a checksum, we should make sure no frag could
* be modified by an external entity : checksum could be wrong.
*/
if (skb_has_shared_frag(skb)) {
ret = __skb_linearize(skb);
if (ret)
goto out;
}
offset = skb_checksum_start_offset(skb);
ret = -EINVAL;
if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
goto out;
}
csum = skb_checksum(skb, offset, skb->len - offset, 0);
offset += skb->csum_offset;
if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
goto out;
}
ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
if (ret)
goto out;
*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
out_set_summed:
skb->ip_summed = CHECKSUM_NONE;
out:
return ret;
}
EXPORT_SYMBOL(skb_checksum_help);
int skb_crc32c_csum_help(struct sk_buff *skb)
{
__le32 crc32c_csum;
int ret = 0, offset, start;
if (skb->ip_summed != CHECKSUM_PARTIAL)
goto out;
if (unlikely(skb_is_gso(skb)))
goto out;
/* Before computing a checksum, we should make sure no frag could
* be modified by an external entity : checksum could be wrong.
*/
if (unlikely(skb_has_shared_frag(skb))) {
ret = __skb_linearize(skb);
if (ret)
goto out;
}
start = skb_checksum_start_offset(skb);
offset = start + offsetof(struct sctphdr, checksum);
if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
ret = -EINVAL;
goto out;
}
ret = skb_ensure_writable(skb, offset + sizeof(__le32));
if (ret)
goto out;
crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
skb->len - start, ~(__u32)0,
crc32c_csum_stub));
*(__le32 *)(skb->data + offset) = crc32c_csum;
skb_reset_csum_not_inet(skb);
out:
return ret;
}
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
{
__be16 type = skb->protocol;
/* Tunnel gso handlers can set protocol to ethernet. */
if (type == htons(ETH_P_TEB)) {
struct ethhdr *eth;
if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
return 0;
eth = (struct ethhdr *)skb->data;
type = eth->h_proto;
}
return vlan_get_protocol_and_depth(skb, type, depth);
}
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
{
netdev_err(dev, "hw csum failure\n");
skb_dump(KERN_ERR, skb, true);
dump_stack();
}
void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
{
DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif
/* XXX: check that highmem exists at all on the given machine. */
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
{
#ifdef CONFIG_HIGHMEM
int i;
if (!(dev->features & NETIF_F_HIGHDMA)) {
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
if (PageHighMem(skb_frag_page(frag)))
return 1;
}
}
#endif
return 0;
}
/* If MPLS offload request, verify we are testing hardware MPLS features
* instead of standard features for the netdev.
*/
#if IS_ENABLED(CONFIG_NET_MPLS_GSO)
static netdev_features_t net_mpls_features(struct sk_buff *skb,
netdev_features_t features,
__be16 type)
{
if (eth_p_mpls(type))
features &= skb->dev->mpls_features;
return features;
}
#else
static netdev_features_t net_mpls_features(struct sk_buff *skb,
netdev_features_t features,
__be16 type)
{
return features;
}
#endif
static netdev_features_t harmonize_features(struct sk_buff *skb,
netdev_features_t features)
{
__be16 type;
type = skb_network_protocol(skb, NULL);
features = net_mpls_features(skb, features, type);
if (skb->ip_summed != CHECKSUM_NONE &&
!can_checksum_protocol(features, type)) {
features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
}
if (illegal_highdma(skb->dev, skb))
features &= ~NETIF_F_SG;
return features;
}
netdev_features_t passthru_features_check(struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
return features;
}
EXPORT_SYMBOL(passthru_features_check);
static netdev_features_t dflt_features_check(struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
return vlan_features_check(skb, features);
}
static netdev_features_t gso_features_check(const struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
u16 gso_segs = skb_shinfo(skb)->gso_segs;
if (gso_segs > READ_ONCE(dev->gso_max_segs))
return features & ~NETIF_F_GSO_MASK;
if (!skb_shinfo(skb)->gso_type) {
skb_warn_bad_offload(skb);
return features & ~NETIF_F_GSO_MASK;
}
/* Support for GSO partial features requires software
* intervention before we can actually process the packets
* so we need to strip support for any partial features now
* and we can pull them back in after we have partially
* segmented the frame.
*/
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
features &= ~dev->gso_partial_features;
/* Make sure to clear the IPv4 ID mangling feature if the
* IPv4 header has the potential to be fragmented.
*/
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
struct iphdr *iph = skb->encapsulation ?
inner_ip_hdr(skb) : ip_hdr(skb);
if (!(iph->frag_off & htons(IP_DF)))
features &= ~NETIF_F_TSO_MANGLEID;
}
return features;
}
netdev_features_t netif_skb_features(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
netdev_features_t features = dev->features;
if (skb_is_gso(skb))
features = gso_features_check(skb, dev, features);
/* If encapsulation offload request, verify we are testing
* hardware encapsulation features instead of standard
* features for the netdev
*/
if (skb->encapsulation)
features &= dev->hw_enc_features;
if (skb_vlan_tagged(skb))
features = netdev_intersect_features(features,
dev->vlan_features |
NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX);
if (dev->netdev_ops->ndo_features_check)
features &= dev->netdev_ops->ndo_features_check(skb, dev,
features);
else
features &= dflt_features_check(skb, dev, features);
return harmonize_features(skb, features);
}
EXPORT_SYMBOL(netif_skb_features);
static int xmit_one(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq, bool more)
{
unsigned int len;
int rc;
if (dev_nit_active(dev))
dev_queue_xmit_nit(skb, dev);
len = skb->len;
trace_net_dev_start_xmit(skb, dev);
rc = netdev_start_xmit(skb, dev, txq, more);
trace_net_dev_xmit(skb, rc, dev, len);
return rc;
}
struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
struct netdev_queue *txq, int *ret)
{
struct sk_buff *skb = first;
int rc = NETDEV_TX_OK;
while (skb) {
struct sk_buff *next = skb->next;
skb_mark_not_on_list(skb);
rc = xmit_one(skb, dev, txq, next != NULL);
if (unlikely(!dev_xmit_complete(rc))) {
skb->next = next;
goto out;
}
skb = next;
if (netif_tx_queue_stopped(txq) && skb) {
rc = NETDEV_TX_BUSY;
break;
}
}
out:
*ret = rc;
return skb;
}
static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
netdev_features_t features)
{
if (skb_vlan_tag_present(skb) &&
!vlan_hw_offload_capable(features, skb->vlan_proto))
skb = __vlan_hwaccel_push_inside(skb);
return skb;
}
int skb_csum_hwoffload_help(struct sk_buff *skb,
const netdev_features_t features)
{
if (unlikely(skb_csum_is_sctp(skb)))
return !!(features & NETIF_F_SCTP_CRC) ? 0 :
skb_crc32c_csum_help(skb);
if (features & NETIF_F_HW_CSUM)
return 0;
if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
switch (skb->csum_offset) {
case offsetof(struct tcphdr, check):
case offsetof(struct udphdr, check):
return 0;
}
}
return skb_checksum_help(skb);
}
EXPORT_SYMBOL(skb_csum_hwoffload_help);
static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
{
netdev_features_t features;
features = netif_skb_features(skb);
skb = validate_xmit_vlan(skb, features);
if (unlikely(!skb))
goto out_null;
skb = sk_validate_xmit_skb(skb, dev);
if (unlikely(!skb))
goto out_null;
if (netif_needs_gso(skb, features)) {
struct sk_buff *segs;
segs = skb_gso_segment(skb, features);
if (IS_ERR(segs)) {
goto out_kfree_skb;
} else if (segs) {
consume_skb(skb);
skb = segs;
}
} else {
if (skb_needs_linearize(skb, features) &&
__skb_linearize(skb))
goto out_kfree_skb;
/* If packet is not checksummed and device does not
* support checksumming for this protocol, complete
* checksumming here.
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (skb->encapsulation)
skb_set_inner_transport_header(skb,
skb_checksum_start_offset(skb));
else
skb_set_transport_header(skb,
skb_checksum_start_offset(skb));
if (skb_csum_hwoffload_help(skb, features))
goto out_kfree_skb;
}
}
skb = validate_xmit_xfrm(skb, features, again);
return skb;
out_kfree_skb:
kfree_skb(skb);
out_null:
dev_core_stats_tx_dropped_inc(dev);
return NULL;
}
struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
{
struct sk_buff *next, *head = NULL, *tail;
for (; skb != NULL; skb = next) {
next = skb->next;
skb_mark_not_on_list(skb);
/* in case skb wont be segmented, point to itself */
skb->prev = skb;
skb = validate_xmit_skb(skb, dev, again);
if (!skb)
continue;
if (!head)
head = skb;
else
tail->next = skb;
/* If skb was segmented, skb->prev points to
* the last segment. If not, it still contains skb.
*/
tail = skb->prev;
}
return head;
}
EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
static void qdisc_pkt_len_init(struct sk_buff *skb)
{
const struct skb_shared_info *shinfo = skb_shinfo(skb);
qdisc_skb_cb(skb)->pkt_len = skb->len;
/* To get more precise estimation of bytes sent on wire,
* we add to pkt_len the headers size of all segments
*/
if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
u16 gso_segs = shinfo->gso_segs;
unsigned int hdr_len;
/* mac layer + network layer */
hdr_len = skb_transport_offset(skb);
/* + transport layer */
if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
const struct tcphdr *th;
struct tcphdr _tcphdr;
th = skb_header_pointer(skb, hdr_len,
sizeof(_tcphdr), &_tcphdr);
if (likely(th))
hdr_len += __tcp_hdrlen(th);
} else {
struct udphdr _udphdr;
if (skb_header_pointer(skb, hdr_len,
sizeof(_udphdr), &_udphdr))
hdr_len += sizeof(struct udphdr);
}
if (shinfo->gso_type & SKB_GSO_DODGY)
gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
shinfo->gso_size);
qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
}
}
static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
struct sk_buff **to_free,
struct netdev_queue *txq)
{
int rc;
rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
if (rc == NET_XMIT_SUCCESS)
trace_qdisc_enqueue(q, txq, skb);
return rc;
}
static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
struct net_device *dev,
struct netdev_queue *txq)
{
spinlock_t *root_lock = qdisc_lock(q);
struct sk_buff *to_free = NULL;
bool contended;
int rc;
qdisc_calculate_pkt_len(skb, q);
if (q->flags & TCQ_F_NOLOCK) {
if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
qdisc_run_begin(q)) {
/* Retest nolock_qdisc_is_empty() within the protection
* of q->seqlock to protect from racing with requeuing.
*/
if (unlikely(!nolock_qdisc_is_empty(q))) {
rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
__qdisc_run(q);
qdisc_run_end(q);
goto no_lock_out;
}
qdisc_bstats_cpu_update(q, skb);
if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
!nolock_qdisc_is_empty(q))
__qdisc_run(q);
qdisc_run_end(q);
return NET_XMIT_SUCCESS;
}
rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
qdisc_run(q);
no_lock_out:
if (unlikely(to_free))
kfree_skb_list_reason(to_free,
SKB_DROP_REASON_QDISC_DROP);
return rc;
}
/*
* Heuristic to force contended enqueues to serialize on a
* separate lock before trying to get qdisc main lock.
* This permits qdisc->running owner to get the lock more
* often and dequeue packets faster.
* On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
* and then other tasks will only enqueue packets. The packets will be
* sent after the qdisc owner is scheduled again. To prevent this
* scenario the task always serialize on the lock.
*/
contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
if (unlikely(contended))
spin_lock(&q->busylock);
spin_lock(root_lock);
if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
__qdisc_drop(skb, &to_free);
rc = NET_XMIT_DROP;
} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
qdisc_run_begin(q)) {
/*
* This is a work-conserving queue; there are no old skbs
* waiting to be sent out; and the qdisc is not running -
* xmit the skb directly.
*/
qdisc_bstats_update(q, skb);
if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
if (unlikely(contended)) {
spin_unlock(&q->busylock);
contended = false;
}
__qdisc_run(q);
}
qdisc_run_end(q);
rc = NET_XMIT_SUCCESS;
} else {
rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
if (qdisc_run_begin(q)) {
if (unlikely(contended)) {
spin_unlock(&q->busylock);
contended = false;
}
__qdisc_run(q);
qdisc_run_end(q);
}
}
spin_unlock(root_lock);
if (unlikely(to_free))
kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
if (unlikely(contended))
spin_unlock(&q->busylock);
return rc;
}
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
static void skb_update_prio(struct sk_buff *skb)
{
const struct netprio_map *map;
const struct sock *sk;
unsigned int prioidx;
if (skb->priority)
return;
map = rcu_dereference_bh(skb->dev->priomap);
if (!map)
return;
sk = skb_to_full_sk(skb);
if (!sk)
return;
prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
if (prioidx < map->priomap_len)
skb->priority = map->priomap[prioidx];
}
#else
#define skb_update_prio(skb)
#endif
/**
* dev_loopback_xmit - loop back @skb
* @net: network namespace this loopback is happening in
* @sk: sk needed to be a netfilter okfn
* @skb: buffer to transmit
*/
int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
{
skb_reset_mac_header(skb);
__skb_pull(skb, skb_network_offset(skb));
skb->pkt_type = PACKET_LOOPBACK;
if (skb->ip_summed == CHECKSUM_NONE)
skb->ip_summed = CHECKSUM_UNNECESSARY;
DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
skb_dst_force(skb);
netif_rx(skb);
return 0;
}
EXPORT_SYMBOL(dev_loopback_xmit);
#ifdef CONFIG_NET_EGRESS
static struct netdev_queue *
netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
{
int qm = skb_get_queue_mapping(skb);
return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
}
static bool netdev_xmit_txqueue_skipped(void)
{
return __this_cpu_read(softnet_data.xmit.skip_txqueue);
}
void netdev_xmit_skip_txqueue(bool skip)
{
__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
}
EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
#endif /* CONFIG_NET_EGRESS */
#ifdef CONFIG_NET_XGRESS
static int tc_run(struct tcx_entry *entry, struct sk_buff *skb)
{
int ret = TC_ACT_UNSPEC;
#ifdef CONFIG_NET_CLS_ACT
struct mini_Qdisc *miniq = rcu_dereference_bh(entry->miniq);
struct tcf_result res;
if (!miniq)
return ret;
tc_skb_cb(skb)->mru = 0;
tc_skb_cb(skb)->post_ct = false;
mini_qdisc_bstats_cpu_update(miniq, skb);
ret = tcf_classify(skb, miniq->block, miniq->filter_list, &res, false);
/* Only tcf related quirks below. */
switch (ret) {
case TC_ACT_SHOT:
mini_qdisc_qstats_cpu_drop(miniq);
break;
case TC_ACT_OK:
case TC_ACT_RECLASSIFY:
skb->tc_index = TC_H_MIN(res.classid);
break;
}
#endif /* CONFIG_NET_CLS_ACT */
return ret;
}
static DEFINE_STATIC_KEY_FALSE(tcx_needed_key);
void tcx_inc(void)
{
static_branch_inc(&tcx_needed_key);
}
void tcx_dec(void)
{
static_branch_dec(&tcx_needed_key);
}
static __always_inline enum tcx_action_base
tcx_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb,
const bool needs_mac)
{
const struct bpf_mprog_fp *fp;
const struct bpf_prog *prog;
int ret = TCX_NEXT;
if (needs_mac)
__skb_push(skb, skb->mac_len);
bpf_mprog_foreach_prog(entry, fp, prog) {
bpf_compute_data_pointers(skb);
ret = bpf_prog_run(prog, skb);
if (ret != TCX_NEXT)
break;
}
if (needs_mac)
__skb_pull(skb, skb->mac_len);
return tcx_action_code(skb, ret);
}
static __always_inline struct sk_buff *
sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
struct net_device *orig_dev, bool *another)
{
struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
int sch_ret;
if (!entry)
return skb;
if (*pt_prev) {
*ret = deliver_skb(skb, *pt_prev, orig_dev);
*pt_prev = NULL;
}
qdisc_skb_cb(skb)->pkt_len = skb->len;
tcx_set_ingress(skb, true);
if (static_branch_unlikely(&tcx_needed_key)) {
sch_ret = tcx_run(entry, skb, true);
if (sch_ret != TC_ACT_UNSPEC)
goto ingress_verdict;
}
sch_ret = tc_run(tcx_entry(entry), skb);
ingress_verdict:
switch (sch_ret) {
case TC_ACT_REDIRECT:
/* skb_mac_header check was done by BPF, so we can safely
* push the L2 header back before redirecting to another
* netdev.
*/
__skb_push(skb, skb->mac_len);
if (skb_do_redirect(skb) == -EAGAIN) {
__skb_pull(skb, skb->mac_len);
*another = true;
break;
}
*ret = NET_RX_SUCCESS;
return NULL;
case TC_ACT_SHOT:
kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
*ret = NET_RX_DROP;
return NULL;
/* used by tc_run */
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
case TC_ACT_TRAP:
consume_skb(skb);
fallthrough;
case TC_ACT_CONSUMED:
*ret = NET_RX_SUCCESS;
return NULL;
}
return skb;
}
static __always_inline struct sk_buff *
sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
int sch_ret;
if (!entry)
return skb;
/* qdisc_skb_cb(skb)->pkt_len & tcx_set_ingress() was
* already set by the caller.
*/
if (static_branch_unlikely(&tcx_needed_key)) {
sch_ret = tcx_run(entry, skb, false);
if (sch_ret != TC_ACT_UNSPEC)
goto egress_verdict;
}
sch_ret = tc_run(tcx_entry(entry), skb);
egress_verdict:
switch (sch_ret) {
case TC_ACT_REDIRECT:
/* No need to push/pop skb's mac_header here on egress! */
skb_do_redirect(skb);
*ret = NET_XMIT_SUCCESS;
return NULL;
case TC_ACT_SHOT:
kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
*ret = NET_XMIT_DROP;
return NULL;
/* used by tc_run */
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
case TC_ACT_TRAP:
*ret = NET_XMIT_SUCCESS;
return NULL;
}
return skb;
}
#else
static __always_inline struct sk_buff *
sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
struct net_device *orig_dev, bool *another)
{
return skb;
}
static __always_inline struct sk_buff *
sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
return skb;
}
#endif /* CONFIG_NET_XGRESS */
#ifdef CONFIG_XPS
static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
struct xps_dev_maps *dev_maps, unsigned int tci)
{
int tc = netdev_get_prio_tc_map(dev, skb->priority);
struct xps_map *map;
int queue_index = -1;
if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
return queue_index;
tci *= dev_maps->num_tc;
tci += tc;
map = rcu_dereference(dev_maps->attr_map[tci]);
if (map) {
if (map->len == 1)
queue_index = map->queues[0];
else
queue_index = map->queues[reciprocal_scale(
skb_get_hash(skb), map->len)];
if (unlikely(queue_index >= dev->real_num_tx_queues))
queue_index = -1;
}
return queue_index;
}
#endif
static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
struct sk_buff *skb)
{
#ifdef CONFIG_XPS
struct xps_dev_maps *dev_maps;
struct sock *sk = skb->sk;
int queue_index = -1;
if (!static_key_false(&xps_needed))
return -1;
rcu_read_lock();
if (!static_key_false(&xps_rxqs_needed))
goto get_cpus_map;
dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
if (dev_maps) {
int tci = sk_rx_queue_get(sk);
if (tci >= 0)
queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
tci);
}
get_cpus_map:
if (queue_index < 0) {
dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
if (dev_maps) {
unsigned int tci = skb->sender_cpu - 1;
queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
tci);
}
}
rcu_read_unlock();
return queue_index;
#else
return -1;
#endif
}
u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
return 0;
}
EXPORT_SYMBOL(dev_pick_tx_zero);
u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
}
EXPORT_SYMBOL(dev_pick_tx_cpu_id);
u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
struct sock *sk = skb->sk;
int queue_index = sk_tx_queue_get(sk);
sb_dev = sb_dev ? : dev;
if (queue_index < 0 || skb->ooo_okay ||
queue_index >= dev->real_num_tx_queues) {
int new_index = get_xps_queue(dev, sb_dev, skb);
if (new_index < 0)
new_index = skb_tx_hash(dev, sb_dev, skb);
if (queue_index != new_index && sk &&
sk_fullsock(sk) &&
rcu_access_pointer(sk->sk_dst_cache))
sk_tx_queue_set(sk, new_index);
queue_index = new_index;
}
return queue_index;
}
EXPORT_SYMBOL(netdev_pick_tx);
struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
struct sk_buff *skb,
struct net_device *sb_dev)
{
int queue_index = 0;
#ifdef CONFIG_XPS
u32 sender_cpu = skb->sender_cpu - 1;
if (sender_cpu >= (u32)NR_CPUS)
skb->sender_cpu = raw_smp_processor_id() + 1;
#endif
if (dev->real_num_tx_queues != 1) {
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_select_queue)
queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
else
queue_index = netdev_pick_tx(dev, skb, sb_dev);
queue_index = netdev_cap_txqueue(dev, queue_index);
}
skb_set_queue_mapping(skb, queue_index);
return netdev_get_tx_queue(dev, queue_index);
}
/**
* __dev_queue_xmit() - transmit a buffer
* @skb: buffer to transmit
* @sb_dev: suboordinate device used for L2 forwarding offload
*
* Queue a buffer for transmission to a network device. The caller must
* have set the device and priority and built the buffer before calling
* this function. The function can be called from an interrupt.
*
* When calling this method, interrupts MUST be enabled. This is because
* the BH enable code must have IRQs enabled so that it will not deadlock.
*
* Regardless of the return value, the skb is consumed, so it is currently
* difficult to retry a send to this method. (You can bump the ref count
* before sending to hold a reference for retry if you are careful.)
*
* Return:
* * 0 - buffer successfully transmitted
* * positive qdisc return code - NET_XMIT_DROP etc.
* * negative errno - other errors
*/
int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
{
struct net_device *dev = skb->dev;
struct netdev_queue *txq = NULL;
struct Qdisc *q;
int rc = -ENOMEM;
bool again = false;
skb_reset_mac_header(skb);
skb_assert_len(skb);
if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
rcu_read_lock_bh();
skb_update_prio(skb);
qdisc_pkt_len_init(skb);
tcx_set_ingress(skb, false);
#ifdef CONFIG_NET_EGRESS
if (static_branch_unlikely(&egress_needed_key)) {
if (nf_hook_egress_active()) {
skb = nf_hook_egress(skb, &rc, dev);
if (!skb)
goto out;
}
netdev_xmit_skip_txqueue(false);
nf_skip_egress(skb, true);
skb = sch_handle_egress(skb, &rc, dev);
if (!skb)
goto out;
nf_skip_egress(skb, false);
if (netdev_xmit_txqueue_skipped())
txq = netdev_tx_queue_mapping(dev, skb);
}
#endif
/* If device/qdisc don't need skb->dst, release it right now while
* its hot in this cpu cache.
*/
if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
skb_dst_drop(skb);
else
skb_dst_force(skb);
if (!txq)
txq = netdev_core_pick_tx(dev, skb, sb_dev);
q = rcu_dereference_bh(txq->qdisc);
trace_net_dev_queue(skb);
if (q->enqueue) {
rc = __dev_xmit_skb(skb, q, dev, txq);
goto out;
}
/* The device has no queue. Common case for software devices:
* loopback, all the sorts of tunnels...
* Really, it is unlikely that netif_tx_lock protection is necessary
* here. (f.e. loopback and IP tunnels are clean ignoring statistics
* counters.)
* However, it is possible, that they rely on protection
* made by us here.
* Check this and shot the lock. It is not prone from deadlocks.
*Either shot noqueue qdisc, it is even simpler 8)
*/
if (dev->flags & IFF_UP) {
int cpu = smp_processor_id(); /* ok because BHs are off */
/* Other cpus might concurrently change txq->xmit_lock_owner
* to -1 or to their cpu id, but not to our id.
*/
if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
if (dev_xmit_recursion())
goto recursion_alert;
skb = validate_xmit_skb(skb, dev, &again);
if (!skb)
goto out;
HARD_TX_LOCK(dev, txq, cpu);
if (!netif_xmit_stopped(txq)) {
dev_xmit_recursion_inc();
skb = dev_hard_start_xmit(skb, dev, txq, &rc);
dev_xmit_recursion_dec();
if (dev_xmit_complete(rc)) {
HARD_TX_UNLOCK(dev, txq);
goto out;
}
}
HARD_TX_UNLOCK(dev, txq);
net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
dev->name);
} else {
/* Recursion is detected! It is possible,
* unfortunately
*/
recursion_alert:
net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
dev->name);
}
}
rc = -ENETDOWN;
rcu_read_unlock_bh();
dev_core_stats_tx_dropped_inc(dev);
kfree_skb_list(skb);
return rc;
out:
rcu_read_unlock_bh();
return rc;
}
EXPORT_SYMBOL(__dev_queue_xmit);
int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
{
struct net_device *dev = skb->dev;
struct sk_buff *orig_skb = skb;
struct netdev_queue *txq;
int ret = NETDEV_TX_BUSY;
bool again = false;
if (unlikely(!netif_running(dev) ||
!netif_carrier_ok(dev)))
goto drop;
skb = validate_xmit_skb_list(skb, dev, &again);
if (skb != orig_skb)
goto drop;
skb_set_queue_mapping(skb, queue_id);
txq = skb_get_tx_queue(dev, skb);
local_bh_disable();
dev_xmit_recursion_inc();
HARD_TX_LOCK(dev, txq, smp_processor_id());
if (!netif_xmit_frozen_or_drv_stopped(txq))
ret = netdev_start_xmit(skb, dev, txq, false);
HARD_TX_UNLOCK(dev, txq);
dev_xmit_recursion_dec();
local_bh_enable();
return ret;
drop:
dev_core_stats_tx_dropped_inc(dev);
kfree_skb_list(skb);
return NET_XMIT_DROP;
}
EXPORT_SYMBOL(__dev_direct_xmit);
/*************************************************************************
* Receiver routines
*************************************************************************/
int netdev_max_backlog __read_mostly = 1000;
EXPORT_SYMBOL(netdev_max_backlog);
int netdev_tstamp_prequeue __read_mostly = 1;
unsigned int sysctl_skb_defer_max __read_mostly = 64;
int netdev_budget __read_mostly = 300;
/* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
int weight_p __read_mostly = 64; /* old backlog weight */
int dev_weight_rx_bias __read_mostly = 1; /* bias for backlog weight */
int dev_weight_tx_bias __read_mostly = 1; /* bias for output_queue quota */
int dev_rx_weight __read_mostly = 64;
int dev_tx_weight __read_mostly = 64;
/* Called with irq disabled */
static inline void ____napi_schedule(struct softnet_data *sd,
struct napi_struct *napi)
{
struct task_struct *thread;
lockdep_assert_irqs_disabled();
if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
/* Paired with smp_mb__before_atomic() in
* napi_enable()/dev_set_threaded().
* Use READ_ONCE() to guarantee a complete
* read on napi->thread. Only call
* wake_up_process() when it's not NULL.
*/
thread = READ_ONCE(napi->thread);
if (thread) {
/* Avoid doing set_bit() if the thread is in
* INTERRUPTIBLE state, cause napi_thread_wait()
* makes sure to proceed with napi polling
* if the thread is explicitly woken from here.
*/
if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
wake_up_process(thread);
return;
}
}
list_add_tail(&napi->poll_list, &sd->poll_list);
WRITE_ONCE(napi->list_owner, smp_processor_id());
/* If not called from net_rx_action()
* we have to raise NET_RX_SOFTIRQ.
*/
if (!sd->in_net_rx_action)
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
}
#ifdef CONFIG_RPS
/* One global table that all flow-based protocols share. */
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
EXPORT_SYMBOL(rps_sock_flow_table);
u32 rps_cpu_mask __read_mostly;
EXPORT_SYMBOL(rps_cpu_mask);
struct static_key_false rps_needed __read_mostly;
EXPORT_SYMBOL(rps_needed);
struct static_key_false rfs_needed __read_mostly;
EXPORT_SYMBOL(rfs_needed);
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
struct rps_dev_flow *rflow, u16 next_cpu)
{
if (next_cpu < nr_cpu_ids) {
#ifdef CONFIG_RFS_ACCEL
struct netdev_rx_queue *rxqueue;
struct rps_dev_flow_table *flow_table;
struct rps_dev_flow *old_rflow;
u32 flow_id;
u16 rxq_index;
int rc;
/* Should we steer this flow to a different hardware queue? */
if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
!(dev->features & NETIF_F_NTUPLE))
goto out;
rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
if (rxq_index == skb_get_rx_queue(skb))
goto out;
rxqueue = dev->_rx + rxq_index;
flow_table = rcu_dereference(rxqueue->rps_flow_table);
if (!flow_table)
goto out;
flow_id = skb_get_hash(skb) & flow_table->mask;
rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
rxq_index, flow_id);
if (rc < 0)
goto out;
old_rflow = rflow;
rflow = &flow_table->flows[flow_id];
rflow->filter = rc;
if (old_rflow->filter == rflow->filter)
old_rflow->filter = RPS_NO_FILTER;
out:
#endif
rflow->last_qtail =
per_cpu(softnet_data, next_cpu).input_queue_head;
}
rflow->cpu = next_cpu;
return rflow;
}
/*
* get_rps_cpu is called from netif_receive_skb and returns the target
* CPU from the RPS map of the receiving queue for a given skb.
* rcu_read_lock must be held on entry.
*/
static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
struct rps_dev_flow **rflowp)
{
const struct rps_sock_flow_table *sock_flow_table;
struct netdev_rx_queue *rxqueue = dev->_rx;
struct rps_dev_flow_table *flow_table;
struct rps_map *map;
int cpu = -1;
u32 tcpu;
u32 hash;
if (skb_rx_queue_recorded(skb)) {
u16 index = skb_get_rx_queue(skb);
if (unlikely(index >= dev->real_num_rx_queues)) {
WARN_ONCE(dev->real_num_rx_queues > 1,
"%s received packet on queue %u, but number "
"of RX queues is %u\n",
dev->name, index, dev->real_num_rx_queues);
goto done;
}
rxqueue += index;
}
/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
flow_table = rcu_dereference(rxqueue->rps_flow_table);
map = rcu_dereference(rxqueue->rps_map);
if (!flow_table && !map)
goto done;
skb_reset_network_header(skb);
hash = skb_get_hash(skb);
if (!hash)
goto done;
sock_flow_table = rcu_dereference(rps_sock_flow_table);
if (flow_table && sock_flow_table) {
struct rps_dev_flow *rflow;
u32 next_cpu;
u32 ident;
/* First check into global flow table if there is a match.
* This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
*/
ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
if ((ident ^ hash) & ~rps_cpu_mask)
goto try_rps;
next_cpu = ident & rps_cpu_mask;
/* OK, now we know there is a match,
* we can look at the local (per receive queue) flow table
*/
rflow = &flow_table->flows[hash & flow_table->mask];
tcpu = rflow->cpu;
/*
* If the desired CPU (where last recvmsg was done) is
* different from current CPU (one in the rx-queue flow
* table entry), switch if one of the following holds:
* - Current CPU is unset (>= nr_cpu_ids).
* - Current CPU is offline.
* - The current CPU's queue tail has advanced beyond the
* last packet that was enqueued using this table entry.
* This guarantees that all previous packets for the flow
* have been dequeued, thus preserving in order delivery.
*/
if (unlikely(tcpu != next_cpu) &&
(tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
((int)(per_cpu(softnet_data, tcpu).input_queue_head -
rflow->last_qtail)) >= 0)) {
tcpu = next_cpu;
rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
}
if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
*rflowp = rflow;
cpu = tcpu;
goto done;
}
}
try_rps:
if (map) {
tcpu = map->cpus[reciprocal_scale(hash, map->len)];
if (cpu_online(tcpu)) {
cpu = tcpu;
goto done;
}
}
done:
return cpu;
}
#ifdef CONFIG_RFS_ACCEL
/**
* rps_may_expire_flow - check whether an RFS hardware filter may be removed
* @dev: Device on which the filter was set
* @rxq_index: RX queue index
* @flow_id: Flow ID passed to ndo_rx_flow_steer()
* @filter_id: Filter ID returned by ndo_rx_flow_steer()
*
* Drivers that implement ndo_rx_flow_steer() should periodically call
* this function for each installed filter and remove the filters for
* which it returns %true.
*/
bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
u32 flow_id, u16 filter_id)
{
struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
struct rps_dev_flow_table *flow_table;
struct rps_dev_flow *rflow;
bool expire = true;
unsigned int cpu;
rcu_read_lock();
flow_table = rcu_dereference(rxqueue->rps_flow_table);
if (flow_table && flow_id <= flow_table->mask) {
rflow = &flow_table->flows[flow_id];
cpu = READ_ONCE(rflow->cpu);
if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
((int)(per_cpu(softnet_data, cpu).input_queue_head -
rflow->last_qtail) <
(int)(10 * flow_table->mask)))
expire = false;
}
rcu_read_unlock();
return expire;
}
EXPORT_SYMBOL(rps_may_expire_flow);
#endif /* CONFIG_RFS_ACCEL */
/* Called from hardirq (IPI) context */
static void rps_trigger_softirq(void *data)
{
struct softnet_data *sd = data;
____napi_schedule(sd, &sd->backlog);
sd->received_rps++;
}
#endif /* CONFIG_RPS */
/* Called from hardirq (IPI) context */
static void trigger_rx_softirq(void *data)
{
struct softnet_data *sd = data;
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
smp_store_release(&sd->defer_ipi_scheduled, 0);
}
/*
* After we queued a packet into sd->input_pkt_queue,
* we need to make sure this queue is serviced soon.
*
* - If this is another cpu queue, link it to our rps_ipi_list,
* and make sure we will process rps_ipi_list from net_rx_action().
*
* - If this is our own queue, NAPI schedule our backlog.
* Note that this also raises NET_RX_SOFTIRQ.
*/
static void napi_schedule_rps(struct softnet_data *sd)
{
struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
#ifdef CONFIG_RPS
if (sd != mysd) {
sd->rps_ipi_next = mysd->rps_ipi_list;
mysd->rps_ipi_list = sd;
/* If not called from net_rx_action() or napi_threaded_poll()
* we have to raise NET_RX_SOFTIRQ.
*/
if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
return;
}
#endif /* CONFIG_RPS */
__napi_schedule_irqoff(&mysd->backlog);
}
#ifdef CONFIG_NET_FLOW_LIMIT
int netdev_flow_limit_table_len __read_mostly = (1 << 12);
#endif
static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
{
#ifdef CONFIG_NET_FLOW_LIMIT
struct sd_flow_limit *fl;
struct softnet_data *sd;
unsigned int old_flow, new_flow;
if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
return false;
sd = this_cpu_ptr(&softnet_data);
rcu_read_lock();
fl = rcu_dereference(sd->flow_limit);
if (fl) {
new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
old_flow = fl->history[fl->history_head];
fl->history[fl->history_head] = new_flow;
fl->history_head++;
fl->history_head &= FLOW_LIMIT_HISTORY - 1;
if (likely(fl->buckets[old_flow]))
fl->buckets[old_flow]--;
if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
fl->count++;
rcu_read_unlock();
return true;
}
}
rcu_read_unlock();
#endif
return false;
}
/*
* enqueue_to_backlog is called to queue an skb to a per CPU backlog
* queue (may be a remote CPU queue).
*/
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
unsigned int *qtail)
{
enum skb_drop_reason reason;
struct softnet_data *sd;
unsigned long flags;
unsigned int qlen;
reason = SKB_DROP_REASON_NOT_SPECIFIED;
sd = &per_cpu(softnet_data, cpu);
rps_lock_irqsave(sd, &flags);
if (!netif_running(skb->dev))
goto drop;
qlen = skb_queue_len(&sd->input_pkt_queue);
if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
if (qlen) {
enqueue:
__skb_queue_tail(&sd->input_pkt_queue, skb);
input_queue_tail_incr_save(sd, qtail);
rps_unlock_irq_restore(sd, &flags);
return NET_RX_SUCCESS;
}
/* Schedule NAPI for backlog device
* We can use non atomic operation since we own the queue lock
*/
if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
napi_schedule_rps(sd);
goto enqueue;
}
reason = SKB_DROP_REASON_CPU_BACKLOG;
drop:
sd->dropped++;
rps_unlock_irq_restore(sd, &flags);
dev_core_stats_rx_dropped_inc(skb->dev);
kfree_skb_reason(skb, reason);
return NET_RX_DROP;
}
static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct netdev_rx_queue *rxqueue;
rxqueue = dev->_rx;
if (skb_rx_queue_recorded(skb)) {
u16 index = skb_get_rx_queue(skb);
if (unlikely(index >= dev->real_num_rx_queues)) {
WARN_ONCE(dev->real_num_rx_queues > 1,
"%s received packet on queue %u, but number "
"of RX queues is %u\n",
dev->name, index, dev->real_num_rx_queues);
return rxqueue; /* Return first rxqueue */
}
rxqueue += index;
}
return rxqueue;
}
u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
void *orig_data, *orig_data_end, *hard_start;
struct netdev_rx_queue *rxqueue;
bool orig_bcast, orig_host;
u32 mac_len, frame_sz;
__be16 orig_eth_type;
struct ethhdr *eth;
u32 metalen, act;
int off;
/* The XDP program wants to see the packet starting at the MAC
* header.
*/
mac_len = skb->data - skb_mac_header(skb);
hard_start = skb->data - skb_headroom(skb);
/* SKB "head" area always have tailroom for skb_shared_info */
frame_sz = (void *)skb_end_pointer(skb) - hard_start;
frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
rxqueue = netif_get_rxqueue(skb);
xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
skb_headlen(skb) + mac_len, true);
orig_data_end = xdp->data_end;
orig_data = xdp->data;
eth = (struct ethhdr *)xdp->data;
orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
orig_eth_type = eth->h_proto;
act = bpf_prog_run_xdp(xdp_prog, xdp);
/* check if bpf_xdp_adjust_head was used */
off = xdp->data - orig_data;
if (off) {
if (off > 0)
__skb_pull(skb, off);
else if (off < 0)
__skb_push(skb, -off);
skb->mac_header += off;
skb_reset_network_header(skb);
}
/* check if bpf_xdp_adjust_tail was used */
off = xdp->data_end - orig_data_end;
if (off != 0) {
skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
skb->len += off; /* positive on grow, negative on shrink */
}
/* check if XDP changed eth hdr such SKB needs update */
eth = (struct ethhdr *)xdp->data;
if ((orig_eth_type != eth->h_proto) ||
(orig_host != ether_addr_equal_64bits(eth->h_dest,
skb->dev->dev_addr)) ||
(orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
__skb_push(skb, ETH_HLEN);
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, skb->dev);
}
/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
* before calling us again on redirect path. We do not call do_redirect
* as we leave that up to the caller.
*
* Caller is responsible for managing lifetime of skb (i.e. calling
* kfree_skb in response to actions it cannot handle/XDP_DROP).
*/
switch (act) {
case XDP_REDIRECT:
case XDP_TX:
__skb_push(skb, mac_len);
break;
case XDP_PASS:
metalen = xdp->data - xdp->data_meta;
if (metalen)
skb_metadata_set(skb, metalen);
break;
}
return act;
}
static u32 netif_receive_generic_xdp(struct sk_buff *skb,
struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
u32 act = XDP_DROP;
/* Reinjected packets coming from act_mirred or similar should
* not get XDP generic processing.
*/
if (skb_is_redirected(skb))
return XDP_PASS;
/* XDP packets must be linear and must have sufficient headroom
* of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
* native XDP provides, thus we need to do it here as well.
*/
if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
skb_headroom(skb) < XDP_PACKET_HEADROOM) {
int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
int troom = skb->tail + skb->data_len - skb->end;
/* In case we have to go down the path and also linearize,
* then lets do the pskb_expand_head() work just once here.
*/
if (pskb_expand_head(skb,
hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
goto do_drop;
if (skb_linearize(skb))
goto do_drop;
}
act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
switch (act) {
case XDP_REDIRECT:
case XDP_TX:
case XDP_PASS:
break;
default:
bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
fallthrough;
case XDP_ABORTED:
trace_xdp_exception(skb->dev, xdp_prog, act);
fallthrough;
case XDP_DROP:
do_drop:
kfree_skb(skb);
break;
}
return act;
}
/* When doing generic XDP we have to bypass the qdisc layer and the
* network taps in order to match in-driver-XDP behavior. This also means
* that XDP packets are able to starve other packets going through a qdisc,
* and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
* queues, so they do not have this starvation issue.
*/
void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
{
struct net_device *dev = skb->dev;
struct netdev_queue *txq;
bool free_skb = true;
int cpu, rc;
txq = netdev_core_pick_tx(dev, skb, NULL);
cpu = smp_processor_id();
HARD_TX_LOCK(dev, txq, cpu);
if (!netif_xmit_frozen_or_drv_stopped(txq)) {
rc = netdev_start_xmit(skb, dev, txq, 0);
if (dev_xmit_complete(rc))
free_skb = false;
}
HARD_TX_UNLOCK(dev, txq);
if (free_skb) {
trace_xdp_exception(dev, xdp_prog, XDP_TX);
dev_core_stats_tx_dropped_inc(dev);
kfree_skb(skb);
}
}
static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
{
if (xdp_prog) {
struct xdp_buff xdp;
u32 act;
int err;
act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
if (act != XDP_PASS) {
switch (act) {
case XDP_REDIRECT:
err = xdp_do_generic_redirect(skb->dev, skb,
&xdp, xdp_prog);
if (err)
goto out_redir;
break;
case XDP_TX:
generic_xdp_tx(skb, xdp_prog);
break;
}
return XDP_DROP;
}
}
return XDP_PASS;
out_redir:
kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
return XDP_DROP;
}
EXPORT_SYMBOL_GPL(do_xdp_generic);
static int netif_rx_internal(struct sk_buff *skb)
{
int ret;
net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
trace_netif_rx(skb);
#ifdef CONFIG_RPS
if (static_branch_unlikely(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
if (cpu < 0)
cpu = smp_processor_id();
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
} else
#endif
{
unsigned int qtail;
ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
}
return ret;
}
/**
* __netif_rx - Slightly optimized version of netif_rx
* @skb: buffer to post
*
* This behaves as netif_rx except that it does not disable bottom halves.
* As a result this function may only be invoked from the interrupt context
* (either hard or soft interrupt).
*/
int __netif_rx(struct sk_buff *skb)
{
int ret;
lockdep_assert_once(hardirq_count() | softirq_count());
trace_netif_rx_entry(skb);
ret = netif_rx_internal(skb);
trace_netif_rx_exit(ret);
return ret;
}
EXPORT_SYMBOL(__netif_rx);
/**
* netif_rx - post buffer to the network code
* @skb: buffer to post
*
* This function receives a packet from a device driver and queues it for
* the upper (protocol) levels to process via the backlog NAPI device. It
* always succeeds. The buffer may be dropped during processing for
* congestion control or by the protocol layers.
* The network buffer is passed via the backlog NAPI device. Modern NIC
* driver should use NAPI and GRO.
* This function can used from interrupt and from process context. The
* caller from process context must not disable interrupts before invoking
* this function.
*
* return values:
* NET_RX_SUCCESS (no congestion)
* NET_RX_DROP (packet was dropped)
*
*/
int netif_rx(struct sk_buff *skb)
{
bool need_bh_off = !(hardirq_count() | softirq_count());
int ret;
if (need_bh_off)
local_bh_disable();
trace_netif_rx_entry(skb);
ret = netif_rx_internal(skb);
trace_netif_rx_exit(ret);
if (need_bh_off)
local_bh_enable();
return ret;
}
EXPORT_SYMBOL(netif_rx);
static __latent_entropy void net_tx_action(struct softirq_action *h)
{
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
if (sd->completion_queue) {
struct sk_buff *clist;
local_irq_disable();
clist = sd->completion_queue;
sd->completion_queue = NULL;
local_irq_enable();
while (clist) {
struct sk_buff *skb = clist;
clist = clist->next;
WARN_ON(refcount_read(&skb->users));
if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
trace_consume_skb(skb, net_tx_action);
else
trace_kfree_skb(skb, net_tx_action,
get_kfree_skb_cb(skb)->reason);
if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
__kfree_skb(skb);
else
__napi_kfree_skb(skb,
get_kfree_skb_cb(skb)->reason);
}
}
if (sd->output_queue) {
struct Qdisc *head;
local_irq_disable();
head = sd->output_queue;
sd->output_queue = NULL;
sd->output_queue_tailp = &sd->output_queue;
local_irq_enable();
rcu_read_lock();
while (head) {
struct Qdisc *q = head;
spinlock_t *root_lock = NULL;
head = head->next_sched;
/* We need to make sure head->next_sched is read
* before clearing __QDISC_STATE_SCHED
*/
smp_mb__before_atomic();
if (!(q->flags & TCQ_F_NOLOCK)) {
root_lock = qdisc_lock(q);
spin_lock(root_lock);
} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
&q->state))) {
/* There is a synchronize_net() between
* STATE_DEACTIVATED flag being set and
* qdisc_reset()/some_qdisc_is_busy() in
* dev_deactivate(), so we can safely bail out
* early here to avoid data race between
* qdisc_deactivate() and some_qdisc_is_busy()
* for lockless qdisc.
*/
clear_bit(__QDISC_STATE_SCHED, &q->state);
continue;
}
clear_bit(__QDISC_STATE_SCHED, &q->state);
qdisc_run(q);
if (root_lock)
spin_unlock(root_lock);
}
rcu_read_unlock();
}
xfrm_dev_backlog(sd);
}
#if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
unsigned char *addr) __read_mostly;
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
#endif
/**
* netdev_is_rx_handler_busy - check if receive handler is registered
* @dev: device to check
*
* Check if a receive handler is already registered for a given device.
* Return true if there one.
*
* The caller must hold the rtnl_mutex.
*/
bool netdev_is_rx_handler_busy(struct net_device *dev)
{
ASSERT_RTNL();
return dev && rtnl_dereference(dev->rx_handler);
}
EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
/**
* netdev_rx_handler_register - register receive handler
* @dev: device to register a handler for
* @rx_handler: receive handler to register
* @rx_handler_data: data pointer that is used by rx handler
*
* Register a receive handler for a device. This handler will then be
* called from __netif_receive_skb. A negative errno code is returned
* on a failure.
*
* The caller must hold the rtnl_mutex.
*
* For a general description of rx_handler, see enum rx_handler_result.
*/
int netdev_rx_handler_register(struct net_device *dev,
rx_handler_func_t *rx_handler,
void *rx_handler_data)
{
if (netdev_is_rx_handler_busy(dev))
return -EBUSY;
if (dev->priv_flags & IFF_NO_RX_HANDLER)
return -EINVAL;
/* Note: rx_handler_data must be set before rx_handler */
rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
rcu_assign_pointer(dev->rx_handler, rx_handler);
return 0;
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
/**
* netdev_rx_handler_unregister - unregister receive handler
* @dev: device to unregister a handler from
*
* Unregister a receive handler from a device.
*
* The caller must hold the rtnl_mutex.
*/
void netdev_rx_handler_unregister(struct net_device *dev)
{
ASSERT_RTNL();
RCU_INIT_POINTER(dev->rx_handler, NULL);
/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
* section has a guarantee to see a non NULL rx_handler_data
* as well.
*/
synchronize_net();
RCU_INIT_POINTER(dev->rx_handler_data, NULL);
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
/*
* Limit the use of PFMEMALLOC reserves to those protocols that implement
* the special handling of PFMEMALLOC skbs.
*/
static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
{
switch (skb->protocol) {
case htons(ETH_P_ARP):
case htons(ETH_P_IP):
case htons(ETH_P_IPV6):
case htons(ETH_P_8021Q):
case htons(ETH_P_8021AD):
return true;
default:
return false;
}
}
static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
int *ret, struct net_device *orig_dev)
{
if (nf_hook_ingress_active(skb)) {
int ingress_retval;
if (*pt_prev) {
*ret = deliver_skb(skb, *pt_prev, orig_dev);
*pt_prev = NULL;
}
rcu_read_lock();
ingress_retval = nf_hook_ingress(skb);
rcu_read_unlock();
return ingress_retval;
}
return 0;
}
static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
struct packet_type **ppt_prev)
{
struct packet_type *ptype, *pt_prev;
rx_handler_func_t *rx_handler;
struct sk_buff *skb = *pskb;
struct net_device *orig_dev;
bool deliver_exact = false;
int ret = NET_RX_DROP;
__be16 type;
net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
trace_netif_receive_skb(skb);
orig_dev = skb->dev;
skb_reset_network_header(skb);
if (!skb_transport_header_was_set(skb))
skb_reset_transport_header(skb);
skb_reset_mac_len(skb);
pt_prev = NULL;
another_round:
skb->skb_iif = skb->dev->ifindex;
__this_cpu_inc(softnet_data.processed);
if (static_branch_unlikely(&generic_xdp_needed_key)) {
int ret2;
migrate_disable();
ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
migrate_enable();
if (ret2 != XDP_PASS) {
ret = NET_RX_DROP;
goto out;
}
}
if (eth_type_vlan(skb->protocol)) {
skb = skb_vlan_untag(skb);
if (unlikely(!skb))
goto out;
}
if (skb_skip_tc_classify(skb))
goto skip_classify;
if (pfmemalloc)
goto skip_taps;
list_for_each_entry_rcu(ptype, &ptype_all, list) {
if (pt_prev)
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
if (pt_prev)
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
skip_taps:
#ifdef CONFIG_NET_INGRESS
if (static_branch_unlikely(&ingress_needed_key)) {
bool another = false;
nf_skip_egress(skb, true);
skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
&another);
if (another)
goto another_round;
if (!skb)
goto out;
nf_skip_egress(skb, false);
if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
goto out;
}
#endif
skb_reset_redirect(skb);
skip_classify:
if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
goto drop;
if (skb_vlan_tag_present(skb)) {
if (pt_prev) {
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = NULL;
}
if (vlan_do_receive(&skb))
goto another_round;
else if (unlikely(!skb))
goto out;
}
rx_handler = rcu_dereference(skb->dev->rx_handler);
if (rx_handler) {
if (pt_prev) {
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = NULL;
}
switch (rx_handler(&skb)) {
case RX_HANDLER_CONSUMED:
ret = NET_RX_SUCCESS;
goto out;
case RX_HANDLER_ANOTHER:
goto another_round;
case RX_HANDLER_EXACT:
deliver_exact = true;
break;
case RX_HANDLER_PASS:
break;
default:
BUG();
}
}
if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
check_vlan_id:
if (skb_vlan_tag_get_id(skb)) {
/* Vlan id is non 0 and vlan_do_receive() above couldn't
* find vlan device.
*/
skb->pkt_type = PACKET_OTHERHOST;
} else if (eth_type_vlan(skb->protocol)) {
/* Outer header is 802.1P with vlan 0, inner header is
* 802.1Q or 802.1AD and vlan_do_receive() above could
* not find vlan dev for vlan id 0.
*/
__vlan_hwaccel_clear_tag(skb);
skb = skb_vlan_untag(skb);
if (unlikely(!skb))
goto out;
if (vlan_do_receive(&skb))
/* After stripping off 802.1P header with vlan 0
* vlan dev is found for inner header.
*/
goto another_round;
else if (unlikely(!skb))
goto out;
else
/* We have stripped outer 802.1P vlan 0 header.
* But could not find vlan dev.
* check again for vlan id to set OTHERHOST.
*/
goto check_vlan_id;
}
/* Note: we might in the future use prio bits
* and set skb->priority like in vlan_do_receive()
* For the time being, just ignore Priority Code Point
*/
__vlan_hwaccel_clear_tag(skb);
}
type = skb->protocol;
/* deliver only exact match when indicated */
if (likely(!deliver_exact)) {
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&ptype_base[ntohs(type) &
PTYPE_HASH_MASK]);
}
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&orig_dev->ptype_specific);
if (unlikely(skb->dev != orig_dev)) {
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&skb->dev->ptype_specific);
}
if (pt_prev) {
if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
goto drop;
*ppt_prev = pt_prev;
} else {
drop:
if (!deliver_exact)
dev_core_stats_rx_dropped_inc(skb->dev);
else
dev_core_stats_rx_nohandler_inc(skb->dev);
kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
/* Jamal, now you will not able to escape explaining
* me how you were going to use this. :-)
*/
ret = NET_RX_DROP;
}
out:
/* The invariant here is that if *ppt_prev is not NULL
* then skb should also be non-NULL.
*
* Apparently *ppt_prev assignment above holds this invariant due to
* skb dereferencing near it.
*/
*pskb = skb;
return ret;
}
static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
{
struct net_device *orig_dev = skb->dev;
struct packet_type *pt_prev = NULL;
int ret;
ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
if (pt_prev)
ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
skb->dev, pt_prev, orig_dev);
return ret;
}
/**
* netif_receive_skb_core - special purpose version of netif_receive_skb
* @skb: buffer to process
*
* More direct receive version of netif_receive_skb(). It should
* only be used by callers that have a need to skip RPS and Generic XDP.
* Caller must also take care of handling if ``(page_is_)pfmemalloc``.
*
* This function may only be called from softirq context and interrupts
* should be enabled.
*
* Return values (usually ignored):
* NET_RX_SUCCESS: no congestion
* NET_RX_DROP: packet was dropped
*/
int netif_receive_skb_core(struct sk_buff *skb)
{
int ret;
rcu_read_lock();
ret = __netif_receive_skb_one_core(skb, false);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(netif_receive_skb_core);
static inline void __netif_receive_skb_list_ptype(struct list_head *head,
struct packet_type *pt_prev,
struct net_device *orig_dev)
{
struct sk_buff *skb, *next;
if (!pt_prev)
return;
if (list_empty(head))
return;
if (pt_prev->list_func != NULL)
INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
ip_list_rcv, head, pt_prev, orig_dev);
else
list_for_each_entry_safe(skb, next, head, list) {
skb_list_del_init(skb);
pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}
}
static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
{
/* Fast-path assumptions:
* - There is no RX handler.
* - Only one packet_type matches.
* If either of these fails, we will end up doing some per-packet
* processing in-line, then handling the 'last ptype' for the whole
* sublist. This can't cause out-of-order delivery to any single ptype,
* because the 'last ptype' must be constant across the sublist, and all
* other ptypes are handled per-packet.
*/
/* Current (common) ptype of sublist */
struct packet_type *pt_curr = NULL;
/* Current (common) orig_dev of sublist */
struct net_device *od_curr = NULL;
struct list_head sublist;
struct sk_buff *skb, *next;
INIT_LIST_HEAD(&sublist);
list_for_each_entry_safe(skb, next, head, list) {
struct net_device *orig_dev = skb->dev;
struct packet_type *pt_prev = NULL;
skb_list_del_init(skb);
__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
if (!pt_prev)
continue;
if (pt_curr != pt_prev || od_curr != orig_dev) {
/* dispatch old sublist */
__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
/* start new sublist */
INIT_LIST_HEAD(&sublist);
pt_curr = pt_prev;
od_curr = orig_dev;
}
list_add_tail(&skb->list, &sublist);
}
/* dispatch final sublist */
__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
}
static int __netif_receive_skb(struct sk_buff *skb)
{
int ret;
if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
unsigned int noreclaim_flag;
/*
* PFMEMALLOC skbs are special, they should
* - be delivered to SOCK_MEMALLOC sockets only
* - stay away from userspace
* - have bounded memory usage
*
* Use PF_MEMALLOC as this saves us from propagating the allocation
* context down to all allocation sites.
*/
noreclaim_flag = memalloc_noreclaim_save();
ret = __netif_receive_skb_one_core(skb, true);
memalloc_noreclaim_restore(noreclaim_flag);
} else
ret = __netif_receive_skb_one_core(skb, false);
return ret;
}
static void __netif_receive_skb_list(struct list_head *head)
{
unsigned long noreclaim_flag = 0;
struct sk_buff *skb, *next;
bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
list_for_each_entry_safe(skb, next, head, list) {
if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
struct list_head sublist;
/* Handle the previous sublist */
list_cut_before(&sublist, head, &skb->list);
if (!list_empty(&sublist))
__netif_receive_skb_list_core(&sublist, pfmemalloc);
pfmemalloc = !pfmemalloc;
/* See comments in __netif_receive_skb */
if (pfmemalloc)
noreclaim_flag = memalloc_noreclaim_save();
else
memalloc_noreclaim_restore(noreclaim_flag);
}
}
/* Handle the remaining sublist */
if (!list_empty(head))
__netif_receive_skb_list_core(head, pfmemalloc);
/* Restore pflags */
if (pfmemalloc)
memalloc_noreclaim_restore(noreclaim_flag);
}
static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
{
struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
struct bpf_prog *new = xdp->prog;
int ret = 0;
switch (xdp->command) {
case XDP_SETUP_PROG:
rcu_assign_pointer(dev->xdp_prog, new);
if (old)
bpf_prog_put(old);
if (old && !new) {
static_branch_dec(&generic_xdp_needed_key);
} else if (new && !old) {
static_branch_inc(&generic_xdp_needed_key);
dev_disable_lro(dev);
dev_disable_gro_hw(dev);
}
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static int netif_receive_skb_internal(struct sk_buff *skb)
{
int ret;
net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
if (skb_defer_rx_timestamp(skb))
return NET_RX_SUCCESS;
rcu_read_lock();
#ifdef CONFIG_RPS
if (static_branch_unlikely(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu = get_rps_cpu(skb->dev, skb, &rflow);
if (cpu >= 0) {
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
return ret;
}
}
#endif
ret = __netif_receive_skb(skb);
rcu_read_unlock();
return ret;
}
void netif_receive_skb_list_internal(struct list_head *head)
{
struct sk_buff *skb, *next;
struct list_head sublist;
INIT_LIST_HEAD(&sublist);
list_for_each_entry_safe(skb, next, head, list) {
net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
skb_list_del_init(skb);
if (!skb_defer_rx_timestamp(skb))
list_add_tail(&skb->list, &sublist);
}
list_splice_init(&sublist, head);
rcu_read_lock();
#ifdef CONFIG_RPS
if (static_branch_unlikely(&rps_needed)) {
list_for_each_entry_safe(skb, next, head, list) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu = get_rps_cpu(skb->dev, skb, &rflow);
if (cpu >= 0) {
/* Will be handled, remove from list */
skb_list_del_init(skb);
enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
}
}
}
#endif
__netif_receive_skb_list(head);
rcu_read_unlock();
}
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
*
* netif_receive_skb() is the main receive data processing function.
* It always succeeds. The buffer may be dropped during processing
* for congestion control or by the protocol layers.
*
* This function may only be called from softirq context and interrupts
* should be enabled.
*
* Return values (usually ignored):
* NET_RX_SUCCESS: no congestion
* NET_RX_DROP: packet was dropped
*/
int netif_receive_skb(struct sk_buff *skb)
{
int ret;
trace_netif_receive_skb_entry(skb);
ret = netif_receive_skb_internal(skb);
trace_netif_receive_skb_exit(ret);
return ret;
}
EXPORT_SYMBOL(netif_receive_skb);
/**
* netif_receive_skb_list - process many receive buffers from network
* @head: list of skbs to process.
*
* Since return value of netif_receive_skb() is normally ignored, and
* wouldn't be meaningful for a list, this function returns void.
*
* This function may only be called from softirq context and interrupts
* should be enabled.
*/
void netif_receive_skb_list(struct list_head *head)
{
struct sk_buff *skb;
if (list_empty(head))
return;
if (trace_netif_receive_skb_list_entry_enabled()) {
list_for_each_entry(skb, head, list)
trace_netif_receive_skb_list_entry(skb);
}
netif_receive_skb_list_internal(head);
trace_netif_receive_skb_list_exit(0);
}
EXPORT_SYMBOL(netif_receive_skb_list);
static DEFINE_PER_CPU(struct work_struct, flush_works);
/* Network device is going away, flush any packets still pending */
static void flush_backlog(struct work_struct *work)
{
struct sk_buff *skb, *tmp;
struct softnet_data *sd;
local_bh_disable();
sd = this_cpu_ptr(&softnet_data);
rps_lock_irq_disable(sd);
skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
if (skb->dev->reg_state == NETREG_UNREGISTERING) {
__skb_unlink(skb, &sd->input_pkt_queue);
dev_kfree_skb_irq(skb);
input_queue_head_incr(sd);
}
}
rps_unlock_irq_enable(sd);
skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
if (skb->dev->reg_state == NETREG_UNREGISTERING) {
__skb_unlink(skb, &sd->process_queue);
kfree_skb(skb);
input_queue_head_incr(sd);
}
}
local_bh_enable();
}
static bool flush_required(int cpu)
{
#if IS_ENABLED(CONFIG_RPS)
struct softnet_data *sd = &per_cpu(softnet_data, cpu);
bool do_flush;
rps_lock_irq_disable(sd);
/* as insertion into process_queue happens with the rps lock held,
* process_queue access may race only with dequeue
*/
do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
!skb_queue_empty_lockless(&sd->process_queue);
rps_unlock_irq_enable(sd);
return do_flush;
#endif
/* without RPS we can't safely check input_pkt_queue: during a
* concurrent remote skb_queue_splice() we can detect as empty both
* input_pkt_queue and process_queue even if the latter could end-up
* containing a lot of packets.
*/
return true;
}
static void flush_all_backlogs(void)
{
static cpumask_t flush_cpus;
unsigned int cpu;
/* since we are under rtnl lock protection we can use static data
* for the cpumask and avoid allocating on stack the possibly
* large mask
*/
ASSERT_RTNL();
cpus_read_lock();
cpumask_clear(&flush_cpus);
for_each_online_cpu(cpu) {
if (flush_required(cpu)) {
queue_work_on(cpu, system_highpri_wq,
per_cpu_ptr(&flush_works, cpu));
cpumask_set_cpu(cpu, &flush_cpus);
}
}
/* we can have in flight packet[s] on the cpus we are not flushing,
* synchronize_net() in unregister_netdevice_many() will take care of
* them
*/
for_each_cpu(cpu, &flush_cpus)
flush_work(per_cpu_ptr(&flush_works, cpu));
cpus_read_unlock();
}
static void net_rps_send_ipi(struct softnet_data *remsd)
{
#ifdef CONFIG_RPS
while (remsd) {
struct softnet_data *next = remsd->rps_ipi_next;
if (cpu_online(remsd->cpu))
smp_call_function_single_async(remsd->cpu, &remsd->csd);
remsd = next;
}
#endif
}
/*
* net_rps_action_and_irq_enable sends any pending IPI's for rps.
* Note: called with local irq disabled, but exits with local irq enabled.
*/
static void net_rps_action_and_irq_enable(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
struct softnet_data *remsd = sd->rps_ipi_list;
if (remsd) {
sd->rps_ipi_list = NULL;
local_irq_enable();
/* Send pending IPI's to kick RPS processing on remote cpus. */
net_rps_send_ipi(remsd);
} else
#endif
local_irq_enable();
}
static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
return sd->rps_ipi_list != NULL;
#else
return false;
#endif
}
static int process_backlog(struct napi_struct *napi, int quota)
{
struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
bool again = true;
int work = 0;
/* Check if we have pending ipi, its better to send them now,
* not waiting net_rx_action() end.
*/
if (sd_has_rps_ipi_waiting(sd)) {
local_irq_disable();
net_rps_action_and_irq_enable(sd);
}
napi->weight = READ_ONCE(dev_rx_weight);
while (again) {
struct sk_buff *skb;
while ((skb = __skb_dequeue(&sd->process_queue))) {
rcu_read_lock();
__netif_receive_skb(skb);
rcu_read_unlock();
input_queue_head_incr(sd);
if (++work >= quota)
return work;
}
rps_lock_irq_disable(sd);
if (skb_queue_empty(&sd->input_pkt_queue)) {
/*
* Inline a custom version of __napi_complete().
* only current cpu owns and manipulates this napi,
* and NAPI_STATE_SCHED is the only possible flag set
* on backlog.
* We can use a plain write instead of clear_bit(),
* and we dont need an smp_mb() memory barrier.
*/
napi->state = 0;
again = false;
} else {
skb_queue_splice_tail_init(&sd->input_pkt_queue,
&sd->process_queue);
}
rps_unlock_irq_enable(sd);
}
return work;
}
/**
* __napi_schedule - schedule for receive
* @n: entry to schedule
*
* The entry's receive function will be scheduled to run.
* Consider using __napi_schedule_irqoff() if hard irqs are masked.
*/
void __napi_schedule(struct napi_struct *n)
{
unsigned long flags;
local_irq_save(flags);
____napi_schedule(this_cpu_ptr(&softnet_data), n);
local_irq_restore(flags);
}
EXPORT_SYMBOL(__napi_schedule);
/**
* napi_schedule_prep - check if napi can be scheduled
* @n: napi context
*
* Test if NAPI routine is already running, and if not mark
* it as running. This is used as a condition variable to
* insure only one NAPI poll instance runs. We also make
* sure there is no pending NAPI disable.
*/
bool napi_schedule_prep(struct napi_struct *n)
{
unsigned long new, val = READ_ONCE(n->state);
do {
if (unlikely(val & NAPIF_STATE_DISABLE))
return false;
new = val | NAPIF_STATE_SCHED;
/* Sets STATE_MISSED bit if STATE_SCHED was already set
* This was suggested by Alexander Duyck, as compiler
* emits better code than :
* if (val & NAPIF_STATE_SCHED)
* new |= NAPIF_STATE_MISSED;
*/
new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
NAPIF_STATE_MISSED;
} while (!try_cmpxchg(&n->state, &val, new));
return !(val & NAPIF_STATE_SCHED);
}
EXPORT_SYMBOL(napi_schedule_prep);
/**
* __napi_schedule_irqoff - schedule for receive
* @n: entry to schedule
*
* Variant of __napi_schedule() assuming hard irqs are masked.
*
* On PREEMPT_RT enabled kernels this maps to __napi_schedule()
* because the interrupt disabled assumption might not be true
* due to force-threaded interrupts and spinlock substitution.
*/
void __napi_schedule_irqoff(struct napi_struct *n)
{
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
____napi_schedule(this_cpu_ptr(&softnet_data), n);
else
__napi_schedule(n);
}
EXPORT_SYMBOL(__napi_schedule_irqoff);
bool napi_complete_done(struct napi_struct *n, int work_done)
{
unsigned long flags, val, new, timeout = 0;
bool ret = true;
/*
* 1) Don't let napi dequeue from the cpu poll list
* just in case its running on a different cpu.
* 2) If we are busy polling, do nothing here, we have
* the guarantee we will be called later.
*/
if (unlikely(n->state & (NAPIF_STATE_NPSVC |
NAPIF_STATE_IN_BUSY_POLL)))
return false;
if (work_done) {
if (n->gro_bitmask)
timeout = READ_ONCE(n->dev->gro_flush_timeout);
n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
}
if (n->defer_hard_irqs_count > 0) {
n->defer_hard_irqs_count--;
timeout = READ_ONCE(n->dev->gro_flush_timeout);
if (timeout)
ret = false;
}
if (n->gro_bitmask) {
/* When the NAPI instance uses a timeout and keeps postponing
* it, we need to bound somehow the time packets are kept in
* the GRO layer
*/
napi_gro_flush(n, !!timeout);
}
gro_normal_list(n);
if (unlikely(!list_empty(&n->poll_list))) {
/* If n->poll_list is not empty, we need to mask irqs */
local_irq_save(flags);
list_del_init(&n->poll_list);
local_irq_restore(flags);
}
WRITE_ONCE(n->list_owner, -1);
val = READ_ONCE(n->state);
do {
WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
NAPIF_STATE_SCHED_THREADED |
NAPIF_STATE_PREFER_BUSY_POLL);
/* If STATE_MISSED was set, leave STATE_SCHED set,
* because we will call napi->poll() one more time.
* This C code was suggested by Alexander Duyck to help gcc.
*/
new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
NAPIF_STATE_SCHED;
} while (!try_cmpxchg(&n->state, &val, new));
if (unlikely(val & NAPIF_STATE_MISSED)) {
__napi_schedule(n);
return false;
}
if (timeout)
hrtimer_start(&n->timer, ns_to_ktime(timeout),
HRTIMER_MODE_REL_PINNED);
return ret;
}
EXPORT_SYMBOL(napi_complete_done);
/* must be called under rcu_read_lock(), as we dont take a reference */
static struct napi_struct *napi_by_id(unsigned int napi_id)
{
unsigned int hash = napi_id % HASH_SIZE(napi_hash);
struct napi_struct *napi;
hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
if (napi->napi_id == napi_id)
return napi;
return NULL;
}
#if defined(CONFIG_NET_RX_BUSY_POLL)
static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
{
if (!skip_schedule) {
gro_normal_list(napi);
__napi_schedule(napi);
return;
}
if (napi->gro_bitmask) {
/* flush too old packets
* If HZ < 1000, flush all packets.
*/
napi_gro_flush(napi, HZ >= 1000);
}
gro_normal_list(napi);
clear_bit(NAPI_STATE_SCHED, &napi->state);
}
static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
u16 budget)
{
bool skip_schedule = false;
unsigned long timeout;
int rc;
/* Busy polling means there is a high chance device driver hard irq
* could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
* set in napi_schedule_prep().
* Since we are about to call napi->poll() once more, we can safely
* clear NAPI_STATE_MISSED.
*
* Note: x86 could use a single "lock and ..." instruction
* to perform these two clear_bit()
*/
clear_bit(NAPI_STATE_MISSED, &napi->state);
clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
local_bh_disable();
if (prefer_busy_poll) {
napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
timeout = READ_ONCE(napi->dev->gro_flush_timeout);
if (napi->defer_hard_irqs_count && timeout) {
hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
skip_schedule = true;
}
}
/* All we really want here is to re-enable device interrupts.
* Ideally, a new ndo_busy_poll_stop() could avoid another round.
*/
rc = napi->poll(napi, budget);
/* We can't gro_normal_list() here, because napi->poll() might have
* rearmed the napi (napi_complete_done()) in which case it could
* already be running on another CPU.
*/
trace_napi_poll(napi, rc, budget);
netpoll_poll_unlock(have_poll_lock);
if (rc == budget)
__busy_poll_stop(napi, skip_schedule);
local_bh_enable();
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
void *loop_end_arg, bool prefer_busy_poll, u16 budget)
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
void *have_poll_lock = NULL;
struct napi_struct *napi;
restart:
napi_poll = NULL;
rcu_read_lock();
napi = napi_by_id(napi_id);
if (!napi)
goto out;
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_disable();
for (;;) {
int work = 0;
local_bh_disable();
if (!napi_poll) {
unsigned long val = READ_ONCE(napi->state);
/* If multiple threads are competing for this napi,
* we avoid dirtying napi->state as much as we can.
*/
if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
NAPIF_STATE_IN_BUSY_POLL)) {
if (prefer_busy_poll)
set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
}
if (cmpxchg(&napi->state, val,
val | NAPIF_STATE_IN_BUSY_POLL |
NAPIF_STATE_SCHED) != val) {
if (prefer_busy_poll)
set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
}
have_poll_lock = netpoll_poll_lock(napi);
napi_poll = napi->poll;
}
work = napi_poll(napi, budget);
trace_napi_poll(napi, work, budget);
gro_normal_list(napi);
count:
if (work > 0)
__NET_ADD_STATS(dev_net(napi->dev),
LINUX_MIB_BUSYPOLLRXPACKETS, work);
local_bh_enable();
if (!loop_end || loop_end(loop_end_arg, start_time))
break;
if (unlikely(need_resched())) {
if (napi_poll)
busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_enable();
rcu_read_unlock();
cond_resched();
if (loop_end(loop_end_arg, start_time))
return;
goto restart;
}
cpu_relax();
}
if (napi_poll)
busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
preempt_enable();
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(napi_busy_loop);
#endif /* CONFIG_NET_RX_BUSY_POLL */
static void napi_hash_add(struct napi_struct *napi)
{
if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
return;
spin_lock(&napi_hash_lock);
/* 0..NR_CPUS range is reserved for sender_cpu use */
do {
if (unlikely(++napi_gen_id < MIN_NAPI_ID))
napi_gen_id = MIN_NAPI_ID;
} while (napi_by_id(napi_gen_id));
napi->napi_id = napi_gen_id;
hlist_add_head_rcu(&napi->napi_hash_node,
&napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
spin_unlock(&napi_hash_lock);
}
/* Warning : caller is responsible to make sure rcu grace period
* is respected before freeing memory containing @napi
*/
static void napi_hash_del(struct napi_struct *napi)
{
spin_lock(&napi_hash_lock);
hlist_del_init_rcu(&napi->napi_hash_node);
spin_unlock(&napi_hash_lock);
}
static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
{
struct napi_struct *napi;
napi = container_of(timer, struct napi_struct, timer);
/* Note : we use a relaxed variant of napi_schedule_prep() not setting
* NAPI_STATE_MISSED, since we do not react to a device IRQ.
*/
if (!napi_disable_pending(napi) &&
!test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
__napi_schedule_irqoff(napi);
}
return HRTIMER_NORESTART;
}
static void init_gro_hash(struct napi_struct *napi)
{
int i;
for (i = 0; i < GRO_HASH_BUCKETS; i++) {
INIT_LIST_HEAD(&napi->gro_hash[i].list);
napi->gro_hash[i].count = 0;
}
napi->gro_bitmask = 0;
}
int dev_set_threaded(struct net_device *dev, bool threaded)
{
struct napi_struct *napi;
int err = 0;
if (dev->threaded == threaded)
return 0;
if (threaded) {
list_for_each_entry(napi, &dev->napi_list, dev_list) {
if (!napi->thread) {
err = napi_kthread_create(napi);
if (err) {
threaded = false;
break;
}
}
}
}
dev->threaded = threaded;
/* Make sure kthread is created before THREADED bit
* is set.
*/
smp_mb__before_atomic();
/* Setting/unsetting threaded mode on a napi might not immediately
* take effect, if the current napi instance is actively being
* polled. In this case, the switch between threaded mode and
* softirq mode will happen in the next round of napi_schedule().
* This should not cause hiccups/stalls to the live traffic.
*/
list_for_each_entry(napi, &dev->napi_list, dev_list)
assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
return err;
}
EXPORT_SYMBOL(dev_set_threaded);
void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int weight)
{
if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
return;
INIT_LIST_HEAD(&napi->poll_list);
INIT_HLIST_NODE(&napi->napi_hash_node);
hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
napi->timer.function = napi_watchdog;
init_gro_hash(napi);
napi->skb = NULL;
INIT_LIST_HEAD(&napi->rx_list);
napi->rx_count = 0;
napi->poll = poll;
if (weight > NAPI_POLL_WEIGHT)
netdev_err_once(dev, "%s() called with weight %d\n", __func__,
weight);
napi->weight = weight;
napi->dev = dev;
#ifdef CONFIG_NETPOLL
napi->poll_owner = -1;
#endif
napi->list_owner = -1;
set_bit(NAPI_STATE_SCHED, &napi->state);
set_bit(NAPI_STATE_NPSVC, &napi->state);
list_add_rcu(&napi->dev_list, &dev->napi_list);
napi_hash_add(napi);
napi_get_frags_check(napi);
/* Create kthread for this napi if dev->threaded is set.
* Clear dev->threaded if kthread creation failed so that
* threaded mode will not be enabled in napi_enable().
*/
if (dev->threaded && napi_kthread_create(napi))
dev->threaded = 0;
}
EXPORT_SYMBOL(netif_napi_add_weight);
void napi_disable(struct napi_struct *n)
{
unsigned long val, new;
might_sleep();
set_bit(NAPI_STATE_DISABLE, &n->state);
val = READ_ONCE(n->state);
do {
while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
usleep_range(20, 200);
val = READ_ONCE(n->state);
}
new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
} while (!try_cmpxchg(&n->state, &val, new));
hrtimer_cancel(&n->timer);
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
EXPORT_SYMBOL(napi_disable);
/**
* napi_enable - enable NAPI scheduling
* @n: NAPI context
*
* Resume NAPI from being scheduled on this context.
* Must be paired with napi_disable.
*/
void napi_enable(struct napi_struct *n)
{
unsigned long new, val = READ_ONCE(n->state);
do {
BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
if (n->dev->threaded && n->thread)
new |= NAPIF_STATE_THREADED;
} while (!try_cmpxchg(&n->state, &val, new));
}
EXPORT_SYMBOL(napi_enable);
static void flush_gro_hash(struct napi_struct *napi)
{
int i;
for (i = 0; i < GRO_HASH_BUCKETS; i++) {
struct sk_buff *skb, *n;
list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
kfree_skb(skb);
napi->gro_hash[i].count = 0;
}
}
/* Must be called in process context */
void __netif_napi_del(struct napi_struct *napi)
{
if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
return;
napi_hash_del(napi);
list_del_rcu(&napi->dev_list);
napi_free_frags(napi);
flush_gro_hash(napi);
napi->gro_bitmask = 0;
if (napi->thread) {
kthread_stop(napi->thread);
napi->thread = NULL;
}
}
EXPORT_SYMBOL(__netif_napi_del);
static int __napi_poll(struct napi_struct *n, bool *repoll)
{
int work, weight;
weight = n->weight;
/* This NAPI_STATE_SCHED test is for avoiding a race
* with netpoll's poll_napi(). Only the entity which
* obtains the lock and sees NAPI_STATE_SCHED set will
* actually make the ->poll() call. Therefore we avoid
* accidentally calling ->poll() when NAPI is not scheduled.
*/
work = 0;
if (test_bit(NAPI_STATE_SCHED, &n->state)) {
work = n->poll(n, weight);
trace_napi_poll(n, work, weight);
}
if (unlikely(work > weight))
netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
n->poll, work, weight);
if (likely(work < weight))
return work;
/* Drivers must not modify the NAPI state if they
* consume the entire weight. In such cases this code
* still "owns" the NAPI instance and therefore can
* move the instance around on the list at-will.
*/
if (unlikely(napi_disable_pending(n))) {
napi_complete(n);
return work;
}
/* The NAPI context has more processing work, but busy-polling
* is preferred. Exit early.
*/
if (napi_prefer_busy_poll(n)) {
if (napi_complete_done(n, work)) {
/* If timeout is not set, we need to make sure
* that the NAPI is re-scheduled.
*/
napi_schedule(n);
}
return work;
}
if (n->gro_bitmask) {
/* flush too old packets
* If HZ < 1000, flush all packets.
*/
napi_gro_flush(n, HZ >= 1000);
}
gro_normal_list(n);
/* Some drivers may have called napi_schedule
* prior to exhausting their budget.
*/
if (unlikely(!list_empty(&n->poll_list))) {
pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
n->dev ? n->dev->name : "backlog");
return work;
}
*repoll = true;
return work;
}
static int napi_poll(struct napi_struct *n, struct list_head *repoll)
{
bool do_repoll = false;
void *have;
int work;
list_del_init(&n->poll_list);
have = netpoll_poll_lock(n);
work = __napi_poll(n, &do_repoll);
if (do_repoll)
list_add_tail(&n->poll_list, repoll);
netpoll_poll_unlock(have);
return work;
}
static int napi_thread_wait(struct napi_struct *napi)
{
bool woken = false;
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
/* Testing SCHED_THREADED bit here to make sure the current
* kthread owns this napi and could poll on this napi.
* Testing SCHED bit is not enough because SCHED bit might be
* set by some other busy poll thread or by napi_disable().
*/
if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
WARN_ON(!list_empty(&napi->poll_list));
__set_current_state(TASK_RUNNING);
return 0;
}
schedule();
/* woken being true indicates this thread owns this napi. */
woken = true;
set_current_state(TASK_INTERRUPTIBLE);
}
__set_current_state(TASK_RUNNING);
return -1;
}
static void skb_defer_free_flush(struct softnet_data *sd)
{
struct sk_buff *skb, *next;
/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
if (!READ_ONCE(sd->defer_list))
return;
spin_lock(&sd->defer_lock);
skb = sd->defer_list;
sd->defer_list = NULL;
sd->defer_count = 0;
spin_unlock(&sd->defer_lock);
while (skb != NULL) {
next = skb->next;
napi_consume_skb(skb, 1);
skb = next;
}
}
static int napi_threaded_poll(void *data)
{
struct napi_struct *napi = data;
struct softnet_data *sd;
void *have;
while (!napi_thread_wait(napi)) {
for (;;) {
bool repoll = false;
local_bh_disable();
sd = this_cpu_ptr(&softnet_data);
sd->in_napi_threaded_poll = true;
have = netpoll_poll_lock(napi);
__napi_poll(napi, &repoll);
netpoll_poll_unlock(have);
sd->in_napi_threaded_poll = false;
barrier();
if (sd_has_rps_ipi_waiting(sd)) {
local_irq_disable();
net_rps_action_and_irq_enable(sd);
}
skb_defer_free_flush(sd);
local_bh_enable();
if (!repoll)
break;
cond_resched();
}
}
return 0;
}
static __latent_entropy void net_rx_action(struct softirq_action *h)
{
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
unsigned long time_limit = jiffies +
usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
int budget = READ_ONCE(netdev_budget);
LIST_HEAD(list);
LIST_HEAD(repoll);
start:
sd->in_net_rx_action = true;
local_irq_disable();
list_splice_init(&sd->poll_list, &list);
local_irq_enable();
for (;;) {
struct napi_struct *n;
skb_defer_free_flush(sd);
if (list_empty(&list)) {
if (list_empty(&repoll)) {
sd->in_net_rx_action = false;
barrier();
/* We need to check if ____napi_schedule()
* had refilled poll_list while
* sd->in_net_rx_action was true.
*/
if (!list_empty(&sd->poll_list))
goto start;
if (!sd_has_rps_ipi_waiting(sd))
goto end;
}
break;
}
n = list_first_entry(&list, struct napi_struct, poll_list);
budget -= napi_poll(n, &repoll);
/* If softirq window is exhausted then punt.
* Allow this to run for 2 jiffies since which will allow
* an average latency of 1.5/HZ.
*/
if (unlikely(budget <= 0 ||
time_after_eq(jiffies, time_limit))) {
sd->time_squeeze++;
break;
}
}
local_irq_disable();
list_splice_tail_init(&sd->poll_list, &list);
list_splice_tail(&repoll, &list);
list_splice(&list, &sd->poll_list);
if (!list_empty(&sd->poll_list))
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
else
sd->in_net_rx_action = false;
net_rps_action_and_irq_enable(sd);
end:;
}
struct netdev_adjacent {
struct net_device *dev;
netdevice_tracker dev_tracker;
/* upper master flag, there can only be one master device per list */
bool master;
/* lookup ignore flag */
bool ignore;
/* counter for the number of times this device was added to us */
u16 ref_nr;
/* private field for the users */
void *private;
struct list_head list;
struct rcu_head rcu;
};
static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
struct list_head *adj_list)
{
struct netdev_adjacent *adj;
list_for_each_entry(adj, adj_list, list) {
if (adj->dev == adj_dev)
return adj;
}
return NULL;
}
static int ____netdev_has_upper_dev(struct net_device *upper_dev,
struct netdev_nested_priv *priv)
{
struct net_device *dev = (struct net_device *)priv->data;
return upper_dev == dev;
}
/**
* netdev_has_upper_dev - Check if device is linked to an upper device
* @dev: device
* @upper_dev: upper device to check
*
* Find out if a device is linked to specified upper device and return true
* in case it is. Note that this checks only immediate upper device,
* not through a complete stack of devices. The caller must hold the RTNL lock.
*/
bool netdev_has_upper_dev(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_nested_priv priv = {
.data = (void *)upper_dev,
};
ASSERT_RTNL();
return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
&priv);
}
EXPORT_SYMBOL(netdev_has_upper_dev);
/**
* netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
* @dev: device
* @upper_dev: upper device to check
*
* Find out if a device is linked to specified upper device and return true
* in case it is. Note that this checks the entire upper device chain.
* The caller must hold rcu lock.
*/
bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_nested_priv priv = {
.data = (void *)upper_dev,
};
return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
&priv);
}
EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
/**
* netdev_has_any_upper_dev - Check if device is linked to some device
* @dev: device
*
* Find out if a device is linked to an upper device and return true in case
* it is. The caller must hold the RTNL lock.
*/
bool netdev_has_any_upper_dev(struct net_device *dev)
{
ASSERT_RTNL();
return !list_empty(&dev->adj_list.upper);
}
EXPORT_SYMBOL(netdev_has_any_upper_dev);
/**
* netdev_master_upper_dev_get - Get master upper device
* @dev: device
*
* Find a master upper device and return pointer to it or NULL in case
* it's not there. The caller must hold the RTNL lock.
*/
struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
{
struct netdev_adjacent *upper;
ASSERT_RTNL();
if (list_empty(&dev->adj_list.upper))
return NULL;
upper = list_first_entry(&dev->adj_list.upper,
struct netdev_adjacent, list);
if (likely(upper->master))
return upper->dev;
return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);
static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
{
struct netdev_adjacent *upper;
ASSERT_RTNL();
if (list_empty(&dev->adj_list.upper))
return NULL;
upper = list_first_entry(&dev->adj_list.upper,
struct netdev_adjacent, list);
if (likely(upper->master) && !upper->ignore)
return upper->dev;
return NULL;
}
/**
* netdev_has_any_lower_dev - Check if device is linked to some device
* @dev: device
*
* Find out if a device is linked to a lower device and return true in case
* it is. The caller must hold the RTNL lock.
*/
static bool netdev_has_any_lower_dev(struct net_device *dev)
{
ASSERT_RTNL();
return !list_empty(&dev->adj_list.lower);
}
void *netdev_adjacent_get_private(struct list_head *adj_list)
{
struct netdev_adjacent *adj;
adj = list_entry(adj_list, struct netdev_adjacent, list);
return adj->private;
}
EXPORT_SYMBOL(netdev_adjacent_get_private);
/**
* netdev_upper_get_next_dev_rcu - Get the next dev from upper list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next device from the dev's upper list, starting from iter
* position. The caller must hold RCU read lock.
*/
struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *upper;
WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&upper->list == &dev->adj_list.upper)
return NULL;
*iter = &upper->list;
return upper->dev;
}
EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
struct list_head **iter,
bool *ignore)
{
struct netdev_adjacent *upper;
upper = list_entry((*iter)->next, struct netdev_adjacent, list);
if (&upper->list == &dev->adj_list.upper)
return NULL;
*iter = &upper->list;
*ignore = upper->ignore;
return upper->dev;
}
static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *upper;
WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&upper->list == &dev->adj_list.upper)
return NULL;
*iter = &upper->list;
return upper->dev;
}
static int __netdev_walk_all_upper_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
struct netdev_nested_priv *priv),
struct netdev_nested_priv *priv)
{
struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
int ret, cur = 0;
bool ignore;
now = dev;
iter = &dev->adj_list.upper;
while (1) {
if (now != dev) {
ret = fn(now, priv);
if (ret)
return ret;
}
next = NULL;
while (1) {
udev = __netdev_next_upper_dev(now, &iter, &ignore);
if (!udev)
break;
if (ignore)
continue;
next = udev;
niter = &udev->adj_list.upper;
dev_stack[cur] = now;
iter_stack[cur++] = iter;
break;
}
if (!next) {
if (!cur)
return 0;
next = dev_stack[--cur];
niter = iter_stack[cur];
}
now = next;
iter = niter;
}
return 0;
}
int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
struct netdev_nested_priv *priv),
struct netdev_nested_priv *priv)
{
struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
int ret, cur = 0;
now = dev;
iter = &dev->adj_list.upper;
while (1) {
if (now != dev) {
ret = fn(now, priv);
if (ret)
return ret;
}
next = NULL;
while (1) {
udev = netdev_next_upper_dev_rcu(now, &iter);
if (!udev)
break;
next = udev;
niter = &udev->adj_list.upper;
dev_stack[cur] = now;
iter_stack[cur++] = iter;
break;
}
if (!next) {
if (!cur)
return 0;
next = dev_stack[--cur];
niter = iter_stack[cur];
}
now = next;
iter = niter;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
static bool __netdev_has_upper_dev(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_nested_priv priv = {
.flags = 0,
.data = (void *)upper_dev,
};
ASSERT_RTNL();
return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
&priv);
}
/**
* netdev_lower_get_next_private - Get the next ->private from the
* lower neighbour list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent->private from the dev's lower neighbour
* list, starting from iter position. The caller must hold either hold the
* RTNL lock or its own locking that guarantees that the neighbour lower
* list will remain unchanged.
*/
void *netdev_lower_get_next_private(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry(*iter, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = lower->list.next;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private);
/**
* netdev_lower_get_next_private_rcu - Get the next ->private from the
* lower neighbour list, RCU
* variant
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent->private from the dev's lower neighbour
* list, starting from iter position. The caller must hold RCU read lock.
*/
void *netdev_lower_get_next_private_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
/**
* netdev_lower_get_next - Get the next device from the lower neighbour
* list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent from the dev's lower neighbour
* list, starting from iter position. The caller must hold RTNL lock or
* its own locking that guarantees that the neighbour lower
* list will remain unchanged.
*/
void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry(*iter, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = lower->list.next;
return lower->dev;
}
EXPORT_SYMBOL(netdev_lower_get_next);
static struct net_device *netdev_next_lower_dev(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->dev;
}
static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
struct list_head **iter,
bool *ignore)
{
struct netdev_adjacent *lower;
lower = list_entry((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
*ignore = lower->ignore;
return lower->dev;
}
int netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
struct netdev_nested_priv *priv),
struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
int ret, cur = 0;
now = dev;
iter = &dev->adj_list.lower;
while (1) {
if (now != dev) {
ret = fn(now, priv);
if (ret)
return ret;
}
next = NULL;
while (1) {
ldev = netdev_next_lower_dev(now, &iter);
if (!ldev)
break;
next = ldev;
niter = &ldev->adj_list.lower;
dev_stack[cur] = now;
iter_stack[cur++] = iter;
break;
}
if (!next) {
if (!cur)
return 0;
next = dev_stack[--cur];
niter = iter_stack[cur];
}
now = next;
iter = niter;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
static int __netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
struct netdev_nested_priv *priv),
struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
int ret, cur = 0;
bool ignore;
now = dev;
iter = &dev->adj_list.lower;
while (1) {
if (now != dev) {
ret = fn(now, priv);
if (ret)
return ret;
}
next = NULL;
while (1) {
ldev = __netdev_next_lower_dev(now, &iter, &ignore);
if (!ldev)
break;
if (ignore)
continue;
next = ldev;
niter = &ldev->adj_list.lower;
dev_stack[cur] = now;
iter_stack[cur++] = iter;
break;
}
if (!next) {
if (!cur)
return 0;
next = dev_stack[--cur];
niter = iter_stack[cur];
}
now = next;
iter = niter;
}
return 0;
}
struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->dev;
}
EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
static u8 __netdev_upper_depth(struct net_device *dev)
{
struct net_device *udev;
struct list_head *iter;
u8 max_depth = 0;
bool ignore;
for (iter = &dev->adj_list.upper,
udev = __netdev_next_upper_dev(dev, &iter, &ignore);
udev;
udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
if (ignore)
continue;
if (max_depth < udev->upper_level)
max_depth = udev->upper_level;
}
return max_depth;
}
static u8 __netdev_lower_depth(struct net_device *dev)
{
struct net_device *ldev;
struct list_head *iter;
u8 max_depth = 0;
bool ignore;
for (iter = &dev->adj_list.lower,
ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
ldev;
ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
if (ignore)
continue;
if (max_depth < ldev->lower_level)
max_depth = ldev->lower_level;
}
return max_depth;
}
static int __netdev_update_upper_level(struct net_device *dev,
struct netdev_nested_priv *__unused)
{
dev->upper_level = __netdev_upper_depth(dev) + 1;
return 0;
}
#ifdef CONFIG_LOCKDEP
static LIST_HEAD(net_unlink_list);
static void net_unlink_todo(struct net_device *dev)
{
if (list_empty(&dev->unlink_list))
list_add_tail(&dev->unlink_list, &net_unlink_list);
}
#endif
static int __netdev_update_lower_level(struct net_device *dev,
struct netdev_nested_priv *priv)
{
dev->lower_level = __netdev_lower_depth(dev) + 1;
#ifdef CONFIG_LOCKDEP
if (!priv)
return 0;
if (priv->flags & NESTED_SYNC_IMM)
dev->nested_level = dev->lower_level - 1;
if (priv->flags & NESTED_SYNC_TODO)
net_unlink_todo(dev);
#endif
return 0;
}
int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
struct netdev_nested_priv *priv),
struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
int ret, cur = 0;
now = dev;
iter = &dev->adj_list.lower;
while (1) {
if (now != dev) {
ret = fn(now, priv);
if (ret)
return ret;
}
next = NULL;
while (1) {
ldev = netdev_next_lower_dev_rcu(now, &iter);
if (!ldev)
break;
next = ldev;
niter = &ldev->adj_list.lower;
dev_stack[cur] = now;
iter_stack[cur++] = iter;
break;
}
if (!next) {
if (!cur)
return 0;
next = dev_stack[--cur];
niter = iter_stack[cur];
}
now = next;
iter = niter;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
/**
* netdev_lower_get_first_private_rcu - Get the first ->private from the
* lower neighbour list, RCU
* variant
* @dev: device
*
* Gets the first netdev_adjacent->private from the dev's lower neighbour
* list. The caller must hold RCU read lock.
*/
void *netdev_lower_get_first_private_rcu(struct net_device *dev)
{
struct netdev_adjacent *lower;
lower = list_first_or_null_rcu(&dev->adj_list.lower,
struct netdev_adjacent, list);
if (lower)
return lower->private;
return NULL;
}
EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
/**
* netdev_master_upper_dev_get_rcu - Get master upper device
* @dev: device
*
* Find a master upper device and return pointer to it or NULL in case
* it's not there. The caller must hold the RCU read lock.
*/
struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
{
struct netdev_adjacent *upper;
upper = list_first_or_null_rcu(&dev->adj_list.upper,
struct netdev_adjacent, list);
if (upper && likely(upper->master))
return upper->dev;
return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
static int netdev_adjacent_sysfs_add(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list)
{
char linkname[IFNAMSIZ+7];
sprintf(linkname, dev_list == &dev->adj_list.upper ?
"upper_%s" : "lower_%s", adj_dev->name);
return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
linkname);
}
static void netdev_adjacent_sysfs_del(struct net_device *dev,
char *name,
struct list_head *dev_list)
{
char linkname[IFNAMSIZ+7];
sprintf(linkname, dev_list == &dev->adj_list.upper ?
"upper_%s" : "lower_%s", name);
sysfs_remove_link(&(dev->dev.kobj), linkname);
}
static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list)
{
return (dev_list == &dev->adj_list.upper ||
dev_list == &dev->adj_list.lower) &&
net_eq(dev_net(dev), dev_net(adj_dev));
}
static int __netdev_adjacent_dev_insert(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list,
void *private, bool master)
{
struct netdev_adjacent *adj;
int ret;
adj = __netdev_find_adj(adj_dev, dev_list);
if (adj) {
adj->ref_nr += 1;
pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
dev->name, adj_dev->name, adj->ref_nr);
return 0;
}
adj = kmalloc(sizeof(*adj), GFP_KERNEL);
if (!adj)
return -ENOMEM;
adj->dev = adj_dev;
adj->master = master;
adj->ref_nr = 1;
adj->private = private;
adj->ignore = false;
netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
if (ret)
goto free_adj;
}
/* Ensure that master link is always the first item in list. */
if (master) {
ret = sysfs_create_link(&(dev->dev.kobj),
&(adj_dev->dev.kobj), "master");
if (ret)
goto remove_symlinks;
list_add_rcu(&adj->list, dev_list);
} else {
list_add_tail_rcu(&adj->list, dev_list);
}
return 0;
remove_symlinks:
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
free_adj:
netdev_put(adj_dev, &adj->dev_tracker);
kfree(adj);
return ret;
}
static void __netdev_adjacent_dev_remove(struct net_device *dev,
struct net_device *adj_dev,
u16 ref_nr,
struct list_head *dev_list)
{
struct netdev_adjacent *adj;
pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
dev->name, adj_dev->name, ref_nr);
adj = __netdev_find_adj(adj_dev, dev_list);
if (!adj) {
pr_err("Adjacency does not exist for device %s from %s\n",
dev->name, adj_dev->name);
WARN_ON(1);
return;
}
if (adj->ref_nr > ref_nr) {
pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
dev->name, adj_dev->name, ref_nr,
adj->ref_nr - ref_nr);
adj->ref_nr -= ref_nr;
return;
}
if (adj->master)
sysfs_remove_link(&(dev->dev.kobj), "master");
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
list_del_rcu(&adj->list);
pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
adj_dev->name, dev->name, adj_dev->name);
netdev_put(adj_dev, &adj->dev_tracker);
kfree_rcu(adj, rcu);
}
static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
struct net_device *upper_dev,
struct list_head *up_list,
struct list_head *down_list,
void *private, bool master)
{
int ret;
ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
private, master);
if (ret)
return ret;
ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
private, false);
if (ret) {
__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
return ret;
}
return 0;
}
static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
struct net_device *upper_dev,
u16 ref_nr,
struct list_head *up_list,
struct list_head *down_list)
{
__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
}
static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
struct net_device *upper_dev,
void *private, bool master)
{
return __netdev_adjacent_dev_link_lists(dev, upper_dev,
&dev->adj_list.upper,
&upper_dev->adj_list.lower,
private, master);
}
static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
struct net_device *upper_dev)
{
__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
&dev->adj_list.upper,
&upper_dev->adj_list.lower);
}
static int __netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev, bool master,
void *upper_priv, void *upper_info,
struct netdev_nested_priv *priv,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_changeupper_info changeupper_info = {
.info = {
.dev = dev,
.extack = extack,
},
.upper_dev = upper_dev,
.master = master,
.linking = true,
.upper_info = upper_info,
};
struct net_device *master_dev;
int ret = 0;
ASSERT_RTNL();
if (dev == upper_dev)
return -EBUSY;
/* To prevent loops, check if dev is not upper device to upper_dev. */
if (__netdev_has_upper_dev(upper_dev, dev))
return -EBUSY;
if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
return -EMLINK;
if (!master) {
if (__netdev_has_upper_dev(dev, upper_dev))
return -EEXIST;
} else {
master_dev = __netdev_master_upper_dev_get(dev);
if (master_dev)
return master_dev == upper_dev ? -EEXIST : -EBUSY;
}
ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
&changeupper_info.info);
ret = notifier_to_errno(ret);
if (ret)
return ret;
ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
master);
if (ret)
return ret;
ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
&changeupper_info.info);
ret = notifier_to_errno(ret);
if (ret)
goto rollback;
__netdev_update_upper_level(dev, NULL);
__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
__netdev_update_lower_level(upper_dev, priv);
__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
priv);
return 0;
rollback:
__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
return ret;
}
/**
* netdev_upper_dev_link - Add a link to the upper device
* @dev: device
* @upper_dev: new upper device
* @extack: netlink extended ack
*
* Adds a link to device which is upper to this one. The caller must hold
* the RTNL lock. On a failure a negative errno code is returned.
* On success the reference counts are adjusted and the function
* returns zero.
*/
int netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev,
struct netlink_ext_ack *extack)
{
struct netdev_nested_priv priv = {
.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
.data = NULL,
};
return __netdev_upper_dev_link(dev, upper_dev, false,
NULL, NULL, &priv, extack);
}
EXPORT_SYMBOL(netdev_upper_dev_link);
/**
* netdev_master_upper_dev_link - Add a master link to the upper device
* @dev: device
* @upper_dev: new upper device
* @upper_priv: upper device private
* @upper_info: upper info to be passed down via notifier
* @extack: netlink extended ack
*
* Adds a link to device which is upper to this one. In this case, only
* one master upper device can be linked, although other non-master devices
* might be linked as well. The caller must hold the RTNL lock.
* On a failure a negative errno code is returned. On success the reference
* counts are adjusted and the function returns zero.
*/
int netdev_master_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev,
void *upper_priv, void *upper_info,
struct netlink_ext_ack *extack)
{
struct netdev_nested_priv priv = {
.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
.data = NULL,
};
return __netdev_upper_dev_link(dev, upper_dev, true,
upper_priv, upper_info, &priv, extack);
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);
static void __netdev_upper_dev_unlink(struct net_device *dev,
struct net_device *upper_dev,
struct netdev_nested_priv *priv)
{
struct netdev_notifier_changeupper_info changeupper_info = {
.info = {
.dev = dev,
},
.upper_dev = upper_dev,
.linking = false,
};
ASSERT_RTNL();
changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
&changeupper_info.info);
__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
&changeupper_info.info);
__netdev_update_upper_level(dev, NULL);
__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
__netdev_update_lower_level(upper_dev, priv);
__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
priv);
}
/**
* netdev_upper_dev_unlink - Removes a link to upper device
* @dev: device
* @upper_dev: new upper device
*
* Removes a link to device which is upper to this one. The caller must hold
* the RTNL lock.
*/
void netdev_upper_dev_unlink(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_nested_priv priv = {
.flags = NESTED_SYNC_TODO,
.data = NULL,
};
__netdev_upper_dev_unlink(dev, upper_dev, &priv);
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);
static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
struct net_device *lower_dev,
bool val)
{
struct netdev_adjacent *adj;
adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
if (adj)
adj->ignore = val;
adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
if (adj)
adj->ignore = val;
}
static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
struct net_device *lower_dev)
{
__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
}
static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
struct net_device *lower_dev)
{
__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
}
int netdev_adjacent_change_prepare(struct net_device *old_dev,
struct net_device *new_dev,
struct net_device *dev,
struct netlink_ext_ack *extack)
{
struct netdev_nested_priv priv = {
.flags = 0,
.data = NULL,
};
int err;
if (!new_dev)
return 0;
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_disable(dev, old_dev);
err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
extack);
if (err) {
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_enable(dev, old_dev);
return err;
}
return 0;
}
EXPORT_SYMBOL(netdev_adjacent_change_prepare);
void netdev_adjacent_change_commit(struct net_device *old_dev,
struct net_device *new_dev,
struct net_device *dev)
{
struct netdev_nested_priv priv = {
.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
.data = NULL,
};
if (!new_dev || !old_dev)
return;
if (new_dev == old_dev)
return;
netdev_adjacent_dev_enable(dev, old_dev);
__netdev_upper_dev_unlink(old_dev, dev, &priv);
}
EXPORT_SYMBOL(netdev_adjacent_change_commit);
void netdev_adjacent_change_abort(struct net_device *old_dev,
struct net_device *new_dev,
struct net_device *dev)
{
struct netdev_nested_priv priv = {
.flags = 0,
.data = NULL,
};
if (!new_dev)
return;
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_enable(dev, old_dev);
__netdev_upper_dev_unlink(new_dev, dev, &priv);
}
EXPORT_SYMBOL(netdev_adjacent_change_abort);
/**
* netdev_bonding_info_change - Dispatch event about slave change
* @dev: device
* @bonding_info: info to dispatch
*
* Send NETDEV_BONDING_INFO to netdev notifiers with info.
* The caller must hold the RTNL lock.
*/
void netdev_bonding_info_change(struct net_device *dev,
struct netdev_bonding_info *bonding_info)
{
struct netdev_notifier_bonding_info info = {
.info.dev = dev,
};
memcpy(&info.bonding_info, bonding_info,
sizeof(struct netdev_bonding_info));
call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
&info.info);
}
EXPORT_SYMBOL(netdev_bonding_info_change);
static int netdev_offload_xstats_enable_l3(struct net_device *dev,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_offload_xstats_info info = {
.info.dev = dev,
.info.extack = extack,
.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
};
int err;
int rc;
dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
GFP_KERNEL);
if (!dev->offload_xstats_l3)
return -ENOMEM;
rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
NETDEV_OFFLOAD_XSTATS_DISABLE,
&info.info);
err = notifier_to_errno(rc);
if (err)
goto free_stats;
return 0;
free_stats:
kfree(dev->offload_xstats_l3);
dev->offload_xstats_l3 = NULL;
return err;
}
int netdev_offload_xstats_enable(struct net_device *dev,
enum netdev_offload_xstats_type type,
struct netlink_ext_ack *extack)
{
ASSERT_RTNL();
if (netdev_offload_xstats_enabled(dev, type))
return -EALREADY;
switch (type) {
case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
return netdev_offload_xstats_enable_l3(dev, extack);
}
WARN_ON(1);
return -EINVAL;
}
EXPORT_SYMBOL(netdev_offload_xstats_enable);
static void netdev_offload_xstats_disable_l3(struct net_device *dev)
{
struct netdev_notifier_offload_xstats_info info = {
.info.dev = dev,
.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
};
call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
&info.info);
kfree(dev->offload_xstats_l3);
dev->offload_xstats_l3 = NULL;
}
int netdev_offload_xstats_disable(struct net_device *dev,
enum netdev_offload_xstats_type type)
{
ASSERT_RTNL();
if (!netdev_offload_xstats_enabled(dev, type))
return -EALREADY;
switch (type) {
case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
netdev_offload_xstats_disable_l3(dev);
return 0;
}
WARN_ON(1);
return -EINVAL;
}
EXPORT_SYMBOL(netdev_offload_xstats_disable);
static void netdev_offload_xstats_disable_all(struct net_device *dev)
{
netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
}
static struct rtnl_hw_stats64 *
netdev_offload_xstats_get_ptr(const struct net_device *dev,
enum netdev_offload_xstats_type type)
{
switch (type) {
case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
return dev->offload_xstats_l3;
}
WARN_ON(1);
return NULL;
}
bool netdev_offload_xstats_enabled(const struct net_device *dev,
enum netdev_offload_xstats_type type)
{
ASSERT_RTNL();
return netdev_offload_xstats_get_ptr(dev, type);
}
EXPORT_SYMBOL(netdev_offload_xstats_enabled);
struct netdev_notifier_offload_xstats_ru {
bool used;
};
struct netdev_notifier_offload_xstats_rd {
struct rtnl_hw_stats64 stats;
bool used;
};
static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
const struct rtnl_hw_stats64 *src)
{
dest->rx_packets += src->rx_packets;
dest->tx_packets += src->tx_packets;
dest->rx_bytes += src->rx_bytes;
dest->tx_bytes += src->tx_bytes;
dest->rx_errors += src->rx_errors;
dest->tx_errors += src->tx_errors;
dest->rx_dropped += src->rx_dropped;
dest->tx_dropped += src->tx_dropped;
dest->multicast += src->multicast;
}
static int netdev_offload_xstats_get_used(struct net_device *dev,
enum netdev_offload_xstats_type type,
bool *p_used,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_offload_xstats_ru report_used = {};
struct netdev_notifier_offload_xstats_info info = {
.info.dev = dev,
.info.extack = extack,
.type = type,
.report_used = &report_used,
};
int rc;
WARN_ON(!netdev_offload_xstats_enabled(dev, type));
rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
&info.info);
*p_used = report_used.used;
return notifier_to_errno(rc);
}
static int netdev_offload_xstats_get_stats(struct net_device *dev,
enum netdev_offload_xstats_type type,
struct rtnl_hw_stats64 *p_stats,
bool *p_used,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_offload_xstats_rd report_delta = {};
struct netdev_notifier_offload_xstats_info info = {
.info.dev = dev,
.info.extack = extack,
.type = type,
.report_delta = &report_delta,
};
struct rtnl_hw_stats64 *stats;
int rc;
stats = netdev_offload_xstats_get_ptr(dev, type);
if (WARN_ON(!stats))
return -EINVAL;
rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
&info.info);
/* Cache whatever we got, even if there was an error, otherwise the
* successful stats retrievals would get lost.
*/
netdev_hw_stats64_add(stats, &report_delta.stats);
if (p_stats)
*p_stats = *stats;
*p_used = report_delta.used;
return notifier_to_errno(rc);
}
int netdev_offload_xstats_get(struct net_device *dev,
enum netdev_offload_xstats_type type,
struct rtnl_hw_stats64 *p_stats, bool *p_used,
struct netlink_ext_ack *extack)
{
ASSERT_RTNL();
if (p_stats)
return netdev_offload_xstats_get_stats(dev, type, p_stats,
p_used, extack);
else
return netdev_offload_xstats_get_used(dev, type, p_used,
extack);
}
EXPORT_SYMBOL(netdev_offload_xstats_get);
void
netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
const struct rtnl_hw_stats64 *stats)
{
report_delta->used = true;
netdev_hw_stats64_add(&report_delta->stats, stats);
}
EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
void
netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
{
report_used->used = true;
}
EXPORT_SYMBOL(netdev_offload_xstats_report_used);
void netdev_offload_xstats_push_delta(struct net_device *dev,
enum netdev_offload_xstats_type type,
const struct rtnl_hw_stats64 *p_stats)
{
struct rtnl_hw_stats64 *stats;
ASSERT_RTNL();
stats = netdev_offload_xstats_get_ptr(dev, type);
if (WARN_ON(!stats))
return;
netdev_hw_stats64_add(stats, p_stats);
}
EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
/**
* netdev_get_xmit_slave - Get the xmit slave of master device
* @dev: device
* @skb: The packet
* @all_slaves: assume all the slaves are active
*
* The reference counters are not incremented so the caller must be
* careful with locks. The caller must hold RCU lock.
* %NULL is returned if no slave is found.
*/
struct net_device *netdev_get_xmit_slave(struct net_device *dev,
struct sk_buff *skb,
bool all_slaves)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_get_xmit_slave)
return NULL;
return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
}
EXPORT_SYMBOL(netdev_get_xmit_slave);
static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
struct sock *sk)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_sk_get_lower_dev)
return NULL;
return ops->ndo_sk_get_lower_dev(dev, sk);
}
/**
* netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
* @dev: device
* @sk: the socket
*
* %NULL is returned if no lower device is found.
*/
struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
struct sock *sk)
{
struct net_device *lower;
lower = netdev_sk_get_lower_dev(dev, sk);
while (lower) {
dev = lower;
lower = netdev_sk_get_lower_dev(dev, sk);
}
return dev;
}
EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
static void netdev_adjacent_add_links(struct net_device *dev)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_add(dev, iter->dev,
&dev->adj_list.upper);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_add(dev, iter->dev,
&dev->adj_list.lower);
}
}
static void netdev_adjacent_del_links(struct net_device *dev)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, dev->name,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_del(dev, iter->dev->name,
&dev->adj_list.upper);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, dev->name,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_del(dev, iter->dev->name,
&dev->adj_list.lower);
}
}
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, oldname,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.lower);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, oldname,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.upper);
}
}
void *netdev_lower_dev_get_private(struct net_device *dev,
struct net_device *lower_dev)
{
struct netdev_adjacent *lower;
if (!lower_dev)
return NULL;
lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
if (!lower)
return NULL;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_dev_get_private);
/**
* netdev_lower_state_changed - Dispatch event about lower device state change
* @lower_dev: device
* @lower_state_info: state to dispatch
*
* Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
* The caller must hold the RTNL lock.
*/
void netdev_lower_state_changed(struct net_device *lower_dev,
void *lower_state_info)
{
struct netdev_notifier_changelowerstate_info changelowerstate_info = {
.info.dev = lower_dev,
};
ASSERT_RTNL();
changelowerstate_info.lower_state_info = lower_state_info;
call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
&changelowerstate_info.info);
}
EXPORT_SYMBOL(netdev_lower_state_changed);
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_change_rx_flags)
ops->ndo_change_rx_flags(dev, flags);
}
static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
{
unsigned int old_flags = dev->flags;
kuid_t uid;
kgid_t gid;
ASSERT_RTNL();
dev->flags |= IFF_PROMISC;
dev->promiscuity += inc;
if (dev->promiscuity == 0) {
/*
* Avoid overflow.
* If inc causes overflow, untouch promisc and return error.
*/
if (inc < 0)
dev->flags &= ~IFF_PROMISC;
else {
dev->promiscuity -= inc;
netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
return -EOVERFLOW;
}
}
if (dev->flags != old_flags) {
netdev_info(dev, "%s promiscuous mode\n",
dev->flags & IFF_PROMISC ? "entered" : "left");
if (audit_enabled) {
current_uid_gid(&uid, &gid);
audit_log(audit_context(), GFP_ATOMIC,
AUDIT_ANOM_PROMISCUOUS,
"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
dev->name, (dev->flags & IFF_PROMISC),
(old_flags & IFF_PROMISC),
from_kuid(&init_user_ns, audit_get_loginuid(current)),
from_kuid(&init_user_ns, uid),
from_kgid(&init_user_ns, gid),
audit_get_sessionid(current));
}
dev_change_rx_flags(dev, IFF_PROMISC);
}
if (notify)
__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
return 0;
}
/**
* dev_set_promiscuity - update promiscuity count on a device
* @dev: device
* @inc: modifier
*
* Add or remove promiscuity from a device. While the count in the device
* remains above zero the interface remains promiscuous. Once it hits zero
* the device reverts back to normal filtering operation. A negative inc
* value is used to drop promiscuity on the device.
* Return 0 if successful or a negative errno code on error.
*/
int dev_set_promiscuity(struct net_device *dev, int inc)
{
unsigned int old_flags = dev->flags;
int err;
err = __dev_set_promiscuity(dev, inc, true);
if (err < 0)
return err;
if (dev->flags != old_flags)
dev_set_rx_mode(dev);
return err;
}
EXPORT_SYMBOL(dev_set_promiscuity);
static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
{
unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
ASSERT_RTNL();
dev->flags |= IFF_ALLMULTI;
dev->allmulti += inc;
if (dev->allmulti == 0) {
/*
* Avoid overflow.
* If inc causes overflow, untouch allmulti and return error.
*/
if (inc < 0)
dev->flags &= ~IFF_ALLMULTI;
else {
dev->allmulti -= inc;
netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
return -EOVERFLOW;
}
}
if (dev->flags ^ old_flags) {
netdev_info(dev, "%s allmulticast mode\n",
dev->flags & IFF_ALLMULTI ? "entered" : "left");
dev_change_rx_flags(dev, IFF_ALLMULTI);
dev_set_rx_mode(dev);
if (notify)
__dev_notify_flags(dev, old_flags,
dev->gflags ^ old_gflags, 0, NULL);
}
return 0;
}
/**
* dev_set_allmulti - update allmulti count on a device
* @dev: device
* @inc: modifier
*
* Add or remove reception of all multicast frames to a device. While the
* count in the device remains above zero the interface remains listening
* to all interfaces. Once it hits zero the device reverts back to normal
* filtering operation. A negative @inc value is used to drop the counter
* when releasing a resource needing all multicasts.
* Return 0 if successful or a negative errno code on error.
*/
int dev_set_allmulti(struct net_device *dev, int inc)
{
return __dev_set_allmulti(dev, inc, true);
}
EXPORT_SYMBOL(dev_set_allmulti);
/*
* Upload unicast and multicast address lists to device and
* configure RX filtering. When the device doesn't support unicast
* filtering it is put in promiscuous mode while unicast addresses
* are present.
*/
void __dev_set_rx_mode(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
/* dev_open will call this function so the list will stay sane. */
if (!(dev->flags&IFF_UP))
return;
if (!netif_device_present(dev))
return;
if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
/* Unicast addresses changes may only happen under the rtnl,
* therefore calling __dev_set_promiscuity here is safe.
*/
if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
__dev_set_promiscuity(dev, 1, false);
dev->uc_promisc = true;
} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
__dev_set_promiscuity(dev, -1, false);
dev->uc_promisc = false;
}
}
if (ops->ndo_set_rx_mode)
ops->ndo_set_rx_mode(dev);
}
void dev_set_rx_mode(struct net_device *dev)
{
netif_addr_lock_bh(dev);
__dev_set_rx_mode(dev);
netif_addr_unlock_bh(dev);
}
/**
* dev_get_flags - get flags reported to userspace
* @dev: device
*
* Get the combination of flag bits exported through APIs to userspace.
*/
unsigned int dev_get_flags(const struct net_device *dev)
{
unsigned int flags;
flags = (dev->flags & ~(IFF_PROMISC |
IFF_ALLMULTI |
IFF_RUNNING |
IFF_LOWER_UP |
IFF_DORMANT)) |
(dev->gflags & (IFF_PROMISC |
IFF_ALLMULTI));
if (netif_running(dev)) {
if (netif_oper_up(dev))
flags |= IFF_RUNNING;
if (netif_carrier_ok(dev))
flags |= IFF_LOWER_UP;
if (netif_dormant(dev))
flags |= IFF_DORMANT;
}
return flags;
}
EXPORT_SYMBOL(dev_get_flags);
int __dev_change_flags(struct net_device *dev, unsigned int flags,
struct netlink_ext_ack *extack)
{
unsigned int old_flags = dev->flags;
int ret;
ASSERT_RTNL();
/*
* Set the flags on our device.
*/
dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
IFF_AUTOMEDIA)) |
(dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
IFF_ALLMULTI));
/*
* Load in the correct multicast list now the flags have changed.
*/
if ((old_flags ^ flags) & IFF_MULTICAST)
dev_change_rx_flags(dev, IFF_MULTICAST);
dev_set_rx_mode(dev);
/*
* Have we downed the interface. We handle IFF_UP ourselves
* according to user attempts to set it, rather than blindly
* setting it.
*/
ret = 0;
if ((old_flags ^ flags) & IFF_UP) {
if (old_flags & IFF_UP)
__dev_close(dev);
else
ret = __dev_open(dev, extack);
}
if ((flags ^ dev->gflags) & IFF_PROMISC) {
int inc = (flags & IFF_PROMISC) ? 1 : -1;
unsigned int old_flags = dev->flags;
dev->gflags ^= IFF_PROMISC;
if (__dev_set_promiscuity(dev, inc, false) >= 0)
if (dev->flags != old_flags)
dev_set_rx_mode(dev);
}
/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
* is important. Some (broken) drivers set IFF_PROMISC, when
* IFF_ALLMULTI is requested not asking us and not reporting.
*/
if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
dev->gflags ^= IFF_ALLMULTI;
__dev_set_allmulti(dev, inc, false);
}
return ret;
}
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
unsigned int gchanges, u32 portid,
const struct nlmsghdr *nlh)
{
unsigned int changes = dev->flags ^ old_flags;
if (gchanges)
rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
if (changes & IFF_UP) {
if (dev->flags & IFF_UP)
call_netdevice_notifiers(NETDEV_UP, dev);
else
call_netdevice_notifiers(NETDEV_DOWN, dev);
}
if (dev->flags & IFF_UP &&
(changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
struct netdev_notifier_change_info change_info = {
.info = {
.dev = dev,
},
.flags_changed = changes,
};
call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
}
}
/**
* dev_change_flags - change device settings
* @dev: device
* @flags: device state flags
* @extack: netlink extended ack
*
* Change settings on device based state flags. The flags are
* in the userspace exported format.
*/
int dev_change_flags(struct net_device *dev, unsigned int flags,
struct netlink_ext_ack *extack)
{
int ret;
unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
ret = __dev_change_flags(dev, flags, extack);
if (ret < 0)
return ret;
changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
__dev_notify_flags(dev, old_flags, changes, 0, NULL);
return ret;
}
EXPORT_SYMBOL(dev_change_flags);
int __dev_set_mtu(struct net_device *dev, int new_mtu)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_change_mtu)
return ops->ndo_change_mtu(dev, new_mtu);
/* Pairs with all the lockless reads of dev->mtu in the stack */
WRITE_ONCE(dev->mtu, new_mtu);
return 0;
}
EXPORT_SYMBOL(__dev_set_mtu);
int dev_validate_mtu(struct net_device *dev, int new_mtu,
struct netlink_ext_ack *extack)
{
/* MTU must be positive, and in range */
if (new_mtu < 0 || new_mtu < dev->min_mtu) {
NL_SET_ERR_MSG(extack, "mtu less than device minimum");
return -EINVAL;
}
if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
return -EINVAL;
}
return 0;
}
/**
* dev_set_mtu_ext - Change maximum transfer unit
* @dev: device
* @new_mtu: new transfer unit
* @extack: netlink extended ack
*
* Change the maximum transfer size of the network device.
*/
int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
struct netlink_ext_ack *extack)
{
int err, orig_mtu;
if (new_mtu == dev->mtu)
return 0;
err = dev_validate_mtu(dev, new_mtu, extack);
if (err)
return err;
if (!netif_device_present(dev))
return -ENODEV;
err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
err = notifier_to_errno(err);
if (err)
return err;
orig_mtu = dev->mtu;
err = __dev_set_mtu(dev, new_mtu);
if (!err) {
err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
orig_mtu);
err = notifier_to_errno(err);
if (err) {
/* setting mtu back and notifying everyone again,
* so that they have a chance to revert changes.
*/
__dev_set_mtu(dev, orig_mtu);
call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
new_mtu);
}
}
return err;
}
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
struct netlink_ext_ack extack;
int err;
memset(&extack, 0, sizeof(extack));
err = dev_set_mtu_ext(dev, new_mtu, &extack);
if (err && extack._msg)
net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
return err;
}
EXPORT_SYMBOL(dev_set_mtu);
/**
* dev_change_tx_queue_len - Change TX queue length of a netdevice
* @dev: device
* @new_len: new tx queue length
*/
int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
{
unsigned int orig_len = dev->tx_queue_len;
int res;
if (new_len != (unsigned int)new_len)
return -ERANGE;
if (new_len != orig_len) {
dev->tx_queue_len = new_len;
res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
res = notifier_to_errno(res);
if (res)
goto err_rollback;
res = dev_qdisc_change_tx_queue_len(dev);
if (res)
goto err_rollback;
}
return 0;
err_rollback:
netdev_err(dev, "refused to change device tx_queue_len\n");
dev->tx_queue_len = orig_len;
return res;
}
/**
* dev_set_group - Change group this device belongs to
* @dev: device
* @new_group: group this device should belong to
*/
void dev_set_group(struct net_device *dev, int new_group)
{
dev->group = new_group;
}
/**
* dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
* @dev: device
* @addr: new address
* @extack: netlink extended ack
*/
int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_pre_changeaddr_info info = {
.info.dev = dev,
.info.extack = extack,
.dev_addr = addr,
};
int rc;
rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
return notifier_to_errno(rc);
}
EXPORT_SYMBOL(dev_pre_changeaddr_notify);
/**
* dev_set_mac_address - Change Media Access Control Address
* @dev: device
* @sa: new address
* @extack: netlink extended ack
*
* Change the hardware (MAC) address of the device
*/
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
int err;
if (!ops->ndo_set_mac_address)
return -EOPNOTSUPP;
if (sa->sa_family != dev->type)
return -EINVAL;
if (!netif_device_present(dev))
return -ENODEV;
err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
if (err)
return err;
if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
err = ops->ndo_set_mac_address(dev, sa);
if (err)
return err;
}
dev->addr_assign_type = NET_ADDR_SET;
call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
return 0;
}
EXPORT_SYMBOL(dev_set_mac_address);
static DECLARE_RWSEM(dev_addr_sem);
int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
struct netlink_ext_ack *extack)
{
int ret;
down_write(&dev_addr_sem);
ret = dev_set_mac_address(dev, sa, extack);
up_write(&dev_addr_sem);
return ret;
}
EXPORT_SYMBOL(dev_set_mac_address_user);
int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
{
size_t size = sizeof(sa->sa_data_min);
struct net_device *dev;
int ret = 0;
down_read(&dev_addr_sem);
rcu_read_lock();
dev = dev_get_by_name_rcu(net, dev_name);
if (!dev) {
ret = -ENODEV;
goto unlock;
}
if (!dev->addr_len)
memset(sa->sa_data, 0, size);
else
memcpy(sa->sa_data, dev->dev_addr,
min_t(size_t, size, dev->addr_len));
sa->sa_family = dev->type;
unlock:
rcu_read_unlock();
up_read(&dev_addr_sem);
return ret;
}
EXPORT_SYMBOL(dev_get_mac_address);
/**
* dev_change_carrier - Change device carrier
* @dev: device
* @new_carrier: new value
*
* Change device carrier
*/
int dev_change_carrier(struct net_device *dev, bool new_carrier)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_change_carrier)
return -EOPNOTSUPP;
if (!netif_device_present(dev))
return -ENODEV;
return ops->ndo_change_carrier(dev, new_carrier);
}
/**
* dev_get_phys_port_id - Get device physical port ID
* @dev: device
* @ppid: port ID
*
* Get device physical port ID
*/
int dev_get_phys_port_id(struct net_device *dev,
struct netdev_phys_item_id *ppid)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_get_phys_port_id)
return -EOPNOTSUPP;
return ops->ndo_get_phys_port_id(dev, ppid);
}
/**
* dev_get_phys_port_name - Get device physical port name
* @dev: device
* @name: port name
* @len: limit of bytes to copy to name
*
* Get device physical port name
*/
int dev_get_phys_port_name(struct net_device *dev,
char *name, size_t len)
{
const struct net_device_ops *ops = dev->netdev_ops;
int err;
if (ops->ndo_get_phys_port_name) {
err = ops->ndo_get_phys_port_name(dev, name, len);
if (err != -EOPNOTSUPP)
return err;
}
return devlink_compat_phys_port_name_get(dev, name, len);
}
/**
* dev_get_port_parent_id - Get the device's port parent identifier
* @dev: network device
* @ppid: pointer to a storage for the port's parent identifier
* @recurse: allow/disallow recursion to lower devices
*
* Get the devices's port parent identifier
*/
int dev_get_port_parent_id(struct net_device *dev,
struct netdev_phys_item_id *ppid,
bool recurse)
{
const struct net_device_ops *ops = dev->netdev_ops;
struct netdev_phys_item_id first = { };
struct net_device *lower_dev;
struct list_head *iter;
int err;
if (ops->ndo_get_port_parent_id) {
err = ops->ndo_get_port_parent_id(dev, ppid);
if (err != -EOPNOTSUPP)
return err;
}
err = devlink_compat_switch_id_get(dev, ppid);
if (!recurse || err != -EOPNOTSUPP)
return err;
netdev_for_each_lower_dev(dev, lower_dev, iter) {
err = dev_get_port_parent_id(lower_dev, ppid, true);
if (err)
break;
if (!first.id_len)
first = *ppid;
else if (memcmp(&first, ppid, sizeof(*ppid)))
return -EOPNOTSUPP;
}
return err;
}
EXPORT_SYMBOL(dev_get_port_parent_id);
/**
* netdev_port_same_parent_id - Indicate if two network devices have
* the same port parent identifier
* @a: first network device
* @b: second network device
*/
bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
{
struct netdev_phys_item_id a_id = { };
struct netdev_phys_item_id b_id = { };
if (dev_get_port_parent_id(a, &a_id, true) ||
dev_get_port_parent_id(b, &b_id, true))
return false;
return netdev_phys_item_id_same(&a_id, &b_id);
}
EXPORT_SYMBOL(netdev_port_same_parent_id);
/**
* dev_change_proto_down - set carrier according to proto_down.
*
* @dev: device
* @proto_down: new value
*/
int dev_change_proto_down(struct net_device *dev, bool proto_down)
{
if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
return -EOPNOTSUPP;
if (!netif_device_present(dev))
return -ENODEV;
if (proto_down)
netif_carrier_off(dev);
else
netif_carrier_on(dev);
dev->proto_down = proto_down;
return 0;
}
/**
* dev_change_proto_down_reason - proto down reason
*
* @dev: device
* @mask: proto down mask
* @value: proto down value
*/
void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
u32 value)
{
int b;
if (!mask) {
dev->proto_down_reason = value;
} else {
for_each_set_bit(b, &mask, 32) {
if (value & (1 << b))
dev->proto_down_reason |= BIT(b);
else
dev->proto_down_reason &= ~BIT(b);
}
}
}
struct bpf_xdp_link {
struct bpf_link link;
struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
int flags;
};
static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
{
if (flags & XDP_FLAGS_HW_MODE)
return XDP_MODE_HW;
if (flags & XDP_FLAGS_DRV_MODE)
return XDP_MODE_DRV;
if (flags & XDP_FLAGS_SKB_MODE)
return XDP_MODE_SKB;
return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
}
static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
{
switch (mode) {
case XDP_MODE_SKB:
return generic_xdp_install;
case XDP_MODE_DRV:
case XDP_MODE_HW:
return dev->netdev_ops->ndo_bpf;
default:
return NULL;
}
}
static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
enum bpf_xdp_mode mode)
{
return dev->xdp_state[mode].link;
}
static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
enum bpf_xdp_mode mode)
{
struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
if (link)
return link->link.prog;
return dev->xdp_state[mode].prog;
}
u8 dev_xdp_prog_count(struct net_device *dev)
{
u8 count = 0;
int i;
for (i = 0; i < __MAX_XDP_MODE; i++)
if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
count++;
return count;
}
EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
{
struct bpf_prog *prog = dev_xdp_prog(dev, mode);
return prog ? prog->aux->id : 0;
}
static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
struct bpf_xdp_link *link)
{
dev->xdp_state[mode].link = link;
dev->xdp_state[mode].prog = NULL;
}
static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
struct bpf_prog *prog)
{
dev->xdp_state[mode].link = NULL;
dev->xdp_state[mode].prog = prog;
}
static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
bpf_op_t bpf_op, struct netlink_ext_ack *extack,
u32 flags, struct bpf_prog *prog)
{
struct netdev_bpf xdp;
int err;
memset(&xdp, 0, sizeof(xdp));
xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
xdp.extack = extack;
xdp.flags = flags;
xdp.prog = prog;
/* Drivers assume refcnt is already incremented (i.e, prog pointer is
* "moved" into driver), so they don't increment it on their own, but
* they do decrement refcnt when program is detached or replaced.
* Given net_device also owns link/prog, we need to bump refcnt here
* to prevent drivers from underflowing it.
*/
if (prog)
bpf_prog_inc(prog);
err = bpf_op(dev, &xdp);
if (err) {
if (prog)
bpf_prog_put(prog);
return err;
}
if (mode != XDP_MODE_HW)
bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
return 0;
}
static void dev_xdp_uninstall(struct net_device *dev)
{
struct bpf_xdp_link *link;
struct bpf_prog *prog;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
ASSERT_RTNL();
for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
prog = dev_xdp_prog(dev, mode);
if (!prog)
continue;
bpf_op = dev_xdp_bpf_op(dev, mode);
if (!bpf_op)
continue;
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
/* auto-detach link from net device */
link = dev_xdp_link(dev, mode);
if (link)
link->dev = NULL;
else
bpf_prog_put(prog);
dev_xdp_set_link(dev, mode, NULL);
}
}
static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
struct bpf_xdp_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog, u32 flags)
{
unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
struct bpf_prog *cur_prog;
struct net_device *upper;
struct list_head *iter;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
int err;
ASSERT_RTNL();
/* either link or prog attachment, never both */
if (link && (new_prog || old_prog))
return -EINVAL;
/* link supports only XDP mode flags */
if (link && (flags & ~XDP_FLAGS_MODES)) {
NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
return -EINVAL;
}
/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
if (num_modes > 1) {
NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
return -EINVAL;
}
/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
if (!num_modes && dev_xdp_prog_count(dev) > 1) {
NL_SET_ERR_MSG(extack,
"More than one program loaded, unset mode is ambiguous");
return -EINVAL;
}
/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
return -EINVAL;
}
mode = dev_xdp_mode(dev, flags);
/* can't replace attached link */
if (dev_xdp_link(dev, mode)) {
NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
return -EBUSY;
}
/* don't allow if an upper device already has a program */
netdev_for_each_upper_dev_rcu(dev, upper, iter) {
if (dev_xdp_prog_count(upper) > 0) {
NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
return -EEXIST;
}
}
cur_prog = dev_xdp_prog(dev, mode);
/* can't replace attached prog with link */
if (link && cur_prog) {
NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
return -EBUSY;
}
if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
NL_SET_ERR_MSG(extack, "Active program does not match expected");
return -EEXIST;
}
/* put effective new program into new_prog */
if (link)
new_prog = link->link.prog;
if (new_prog) {
bool offload = mode == XDP_MODE_HW;
enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
? XDP_MODE_DRV : XDP_MODE_SKB;
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
NL_SET_ERR_MSG(extack, "XDP program already attached");
return -EBUSY;
}
if (!offload && dev_xdp_prog(dev, other_mode)) {
NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
return -EEXIST;
}
if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
return -EINVAL;
}
if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
NL_SET_ERR_MSG(extack, "Program bound to different device");
return -EINVAL;
}
if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
return -EINVAL;
}
if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
return -EINVAL;
}
}
/* don't call drivers if the effective program didn't change */
if (new_prog != cur_prog) {
bpf_op = dev_xdp_bpf_op(dev, mode);
if (!bpf_op) {
NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
return -EOPNOTSUPP;
}
err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
if (err)
return err;
}
if (link)
dev_xdp_set_link(dev, mode, link);
else
dev_xdp_set_prog(dev, mode, new_prog);
if (cur_prog)
bpf_prog_put(cur_prog);
return 0;
}
static int dev_xdp_attach_link(struct net_device *dev,
struct netlink_ext_ack *extack,
struct bpf_xdp_link *link)
{
return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
}
static int dev_xdp_detach_link(struct net_device *dev,
struct netlink_ext_ack *extack,
struct bpf_xdp_link *link)
{
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
ASSERT_RTNL();
mode = dev_xdp_mode(dev, link->flags);
if (dev_xdp_link(dev, mode) != link)
return -EINVAL;
bpf_op = dev_xdp_bpf_op(dev, mode);
WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
dev_xdp_set_link(dev, mode, NULL);
return 0;
}
static void bpf_xdp_link_release(struct bpf_link *link)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
rtnl_lock();
/* if racing with net_device's tear down, xdp_link->dev might be
* already NULL, in which case link was already auto-detached
*/
if (xdp_link->dev) {
WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
xdp_link->dev = NULL;
}
rtnl_unlock();
}
static int bpf_xdp_link_detach(struct bpf_link *link)
{
bpf_xdp_link_release(link);
return 0;
}
static void bpf_xdp_link_dealloc(struct bpf_link *link)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
kfree(xdp_link);
}
static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
struct seq_file *seq)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
u32 ifindex = 0;
rtnl_lock();
if (xdp_link->dev)
ifindex = xdp_link->dev->ifindex;
rtnl_unlock();
seq_printf(seq, "ifindex:\t%u\n", ifindex);
}
static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
struct bpf_link_info *info)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
u32 ifindex = 0;
rtnl_lock();
if (xdp_link->dev)
ifindex = xdp_link->dev->ifindex;
rtnl_unlock();
info->xdp.ifindex = ifindex;
return 0;
}
static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
struct bpf_prog *old_prog)
{
struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
int err = 0;
rtnl_lock();
/* link might have been auto-released already, so fail */
if (!xdp_link->dev) {
err = -ENOLINK;
goto out_unlock;
}
if (old_prog && link->prog != old_prog) {
err = -EPERM;
goto out_unlock;
}
old_prog = link->prog;
if (old_prog->type != new_prog->type ||
old_prog->expected_attach_type != new_prog->expected_attach_type) {
err = -EINVAL;
goto out_unlock;
}
if (old_prog == new_prog) {
/* no-op, don't disturb drivers */
bpf_prog_put(new_prog);
goto out_unlock;
}
mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
xdp_link->flags, new_prog);
if (err)
goto out_unlock;
old_prog = xchg(&link->prog, new_prog);
bpf_prog_put(old_prog);
out_unlock:
rtnl_unlock();
return err;
}
static const struct bpf_link_ops bpf_xdp_link_lops = {
.release = bpf_xdp_link_release,
.dealloc = bpf_xdp_link_dealloc,
.detach = bpf_xdp_link_detach,
.show_fdinfo = bpf_xdp_link_show_fdinfo,
.fill_link_info = bpf_xdp_link_fill_link_info,
.update_prog = bpf_xdp_link_update,
};
int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct net *net = current->nsproxy->net_ns;
struct bpf_link_primer link_primer;
struct bpf_xdp_link *link;
struct net_device *dev;
int err, fd;
rtnl_lock();
dev = dev_get_by_index(net, attr->link_create.target_ifindex);
if (!dev) {
rtnl_unlock();
return -EINVAL;
}
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto unlock;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
link->dev = dev;
link->flags = attr->link_create.flags;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
kfree(link);
goto unlock;
}
err = dev_xdp_attach_link(dev, NULL, link);
rtnl_unlock();
if (err) {
link->dev = NULL;
bpf_link_cleanup(&link_primer);
goto out_put_dev;
}
fd = bpf_link_settle(&link_primer);
/* link itself doesn't hold dev's refcnt to not complicate shutdown */
dev_put(dev);
return fd;
unlock:
rtnl_unlock();
out_put_dev:
dev_put(dev);
return err;
}
/**
* dev_change_xdp_fd - set or clear a bpf program for a device rx path
* @dev: device
* @extack: netlink extended ack
* @fd: new program fd or negative value to clear
* @expected_fd: old program fd that userspace expects to replace or clear
* @flags: xdp-related flags
*
* Set or clear a bpf program for a device
*/
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
int fd, int expected_fd, u32 flags)
{
enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
struct bpf_prog *new_prog = NULL, *old_prog = NULL;
int err;
ASSERT_RTNL();
if (fd >= 0) {
new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
mode != XDP_MODE_SKB);
if (IS_ERR(new_prog))
return PTR_ERR(new_prog);
}
if (expected_fd >= 0) {
old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
mode != XDP_MODE_SKB);
if (IS_ERR(old_prog)) {
err = PTR_ERR(old_prog);
old_prog = NULL;
goto err_out;
}
}
err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
err_out:
if (err && new_prog)
bpf_prog_put(new_prog);
if (old_prog)
bpf_prog_put(old_prog);
return err;
}
/**
* dev_index_reserve() - allocate an ifindex in a namespace
* @net: the applicable net namespace
* @ifindex: requested ifindex, pass %0 to get one allocated
*
* Allocate a ifindex for a new device. Caller must either use the ifindex
* to store the device (via list_netdevice()) or call dev_index_release()
* to give the index up.
*
* Return: a suitable unique value for a new device interface number or -errno.
*/
static int dev_index_reserve(struct net *net, u32 ifindex)
{
int err;
if (!ifindex)
err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
xa_limit_31b, &net->ifindex, GFP_KERNEL);
else
err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
if (err < 0)
return err;
return ifindex;
}
static void dev_index_release(struct net *net, int ifindex)
{
/* Expect only unused indexes, unlist_netdevice() removes the used */
WARN_ON(xa_erase(&net->dev_by_index, ifindex));
}
/* Delayed registration/unregisteration */
LIST_HEAD(net_todo_list);
DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
static void net_set_todo(struct net_device *dev)
{
list_add_tail(&dev->todo_list, &net_todo_list);
atomic_inc(&dev_net(dev)->dev_unreg_count);
}
static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
struct net_device *upper, netdev_features_t features)
{
netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
netdev_features_t feature;
int feature_bit;
for_each_netdev_feature(upper_disables, feature_bit) {
feature = __NETIF_F_BIT(feature_bit);
if (!(upper->wanted_features & feature)
&& (features & feature)) {
netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
&feature, upper->name);
features &= ~feature;
}
}
return features;
}
static void netdev_sync_lower_features(struct net_device *upper,
struct net_device *lower, netdev_features_t features)
{
netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
netdev_features_t feature;
int feature_bit;
for_each_netdev_feature(upper_disables, feature_bit) {
feature = __NETIF_F_BIT(feature_bit);
if (!(features & feature) && (lower->features & feature)) {
netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
&feature, lower->name);
lower->wanted_features &= ~feature;
__netdev_update_features(lower);
if (unlikely(lower->features & feature))
netdev_WARN(upper, "failed to disable %pNF on %s!\n",
&feature, lower->name);
else
netdev_features_change(lower);
}
}
}
static netdev_features_t netdev_fix_features(struct net_device *dev,
netdev_features_t features)
{
/* Fix illegal checksum combinations */
if ((features & NETIF_F_HW_CSUM) &&
(features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
netdev_warn(dev, "mixed HW and IP checksum settings.\n");
features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
}
/* TSO requires that SG is present as well. */
if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
features &= ~NETIF_F_ALL_TSO;
}
if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
!(features & NETIF_F_IP_CSUM)) {
netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
features &= ~NETIF_F_TSO;
features &= ~NETIF_F_TSO_ECN;
}
if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
!(features & NETIF_F_IPV6_CSUM)) {
netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
features &= ~NETIF_F_TSO6;
}
/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
features &= ~NETIF_F_TSO_MANGLEID;
/* TSO ECN requires that TSO is present as well. */
if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
features &= ~NETIF_F_TSO_ECN;
/* Software GSO depends on SG. */
if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
features &= ~NETIF_F_GSO;
}
/* GSO partial features require GSO partial be set */
if ((features & dev->gso_partial_features) &&
!(features & NETIF_F_GSO_PARTIAL)) {
netdev_dbg(dev,
"Dropping partially supported GSO features since no GSO partial.\n");
features &= ~dev->gso_partial_features;
}
if (!(features & NETIF_F_RXCSUM)) {
/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
* successfully merged by hardware must also have the
* checksum verified by hardware. If the user does not
* want to enable RXCSUM, logically, we should disable GRO_HW.
*/
if (features & NETIF_F_GRO_HW) {
netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
features &= ~NETIF_F_GRO_HW;
}
}
/* LRO/HW-GRO features cannot be combined with RX-FCS */
if (features & NETIF_F_RXFCS) {
if (features & NETIF_F_LRO) {
netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
features &= ~NETIF_F_LRO;
}
if (features & NETIF_F_GRO_HW) {
netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
features &= ~NETIF_F_GRO_HW;
}
}
if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
features &= ~NETIF_F_LRO;
}
if (features & NETIF_F_HW_TLS_TX) {
bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
bool hw_csum = features & NETIF_F_HW_CSUM;
if (!ip_csum && !hw_csum) {
netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
features &= ~NETIF_F_HW_TLS_TX;
}
}
if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
features &= ~NETIF_F_HW_TLS_RX;
}
return features;
}
int __netdev_update_features(struct net_device *dev)
{
struct net_device *upper, *lower;
netdev_features_t features;
struct list_head *iter;
int err = -1;
ASSERT_RTNL();
features = netdev_get_wanted_features(dev);
if (dev->netdev_ops->ndo_fix_features)
features = dev->netdev_ops->ndo_fix_features(dev, features);
/* driver might be less strict about feature dependencies */
features = netdev_fix_features(dev, features);
/* some features can't be enabled if they're off on an upper device */
netdev_for_each_upper_dev_rcu(dev, upper, iter)
features = netdev_sync_upper_features(dev, upper, features);
if (dev->features == features)
goto sync_lower;
netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
&dev->features, &features);
if (dev->netdev_ops->ndo_set_features)
err = dev->netdev_ops->ndo_set_features(dev, features);
else
err = 0;
if (unlikely(err < 0)) {
netdev_err(dev,
"set_features() failed (%d); wanted %pNF, left %pNF\n",
err, &features, &dev->features);
/* return non-0 since some features might have changed and
* it's better to fire a spurious notification than miss it
*/
return -1;
}
sync_lower:
/* some features must be disabled on lower devices when disabled
* on an upper device (think: bonding master or bridge)
*/
netdev_for_each_lower_dev(dev, lower, iter)
netdev_sync_lower_features(dev, lower, features);
if (!err) {
netdev_features_t diff = features ^ dev->features;
if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
/* udp_tunnel_{get,drop}_rx_info both need
* NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
* device, or they won't do anything.
* Thus we need to update dev->features
* *before* calling udp_tunnel_get_rx_info,
* but *after* calling udp_tunnel_drop_rx_info.
*/
if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
dev->features = features;
udp_tunnel_get_rx_info(dev);
} else {
udp_tunnel_drop_rx_info(dev);
}
}
if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
dev->features = features;
err |= vlan_get_rx_ctag_filter_info(dev);
} else {
vlan_drop_rx_ctag_filter_info(dev);
}
}
if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
dev->features = features;
err |= vlan_get_rx_stag_filter_info(dev);
} else {
vlan_drop_rx_stag_filter_info(dev);
}
}
dev->features = features;
}
return err < 0 ? 0 : 1;
}
/**
* netdev_update_features - recalculate device features
* @dev: the device to check
*
* Recalculate dev->features set and send notifications if it
* has changed. Should be called after driver or hardware dependent
* conditions might have changed that influence the features.
*/
void netdev_update_features(struct net_device *dev)
{
if (__netdev_update_features(dev))
netdev_features_change(dev);
}
EXPORT_SYMBOL(netdev_update_features);
/**
* netdev_change_features - recalculate device features
* @dev: the device to check
*
* Recalculate dev->features set and send notifications even
* if they have not changed. Should be called instead of
* netdev_update_features() if also dev->vlan_features might
* have changed to allow the changes to be propagated to stacked
* VLAN devices.
*/
void netdev_change_features(struct net_device *dev)
{
__netdev_update_features(dev);
netdev_features_change(dev);
}
EXPORT_SYMBOL(netdev_change_features);
/**
* netif_stacked_transfer_operstate - transfer operstate
* @rootdev: the root or lower level device to transfer state from
* @dev: the device to transfer operstate to
*
* Transfer operational state from root to device. This is normally
* called when a stacking relationship exists between the root
* device and the device(a leaf device).
*/
void netif_stacked_transfer_operstate(const struct net_device *rootdev,
struct net_device *dev)
{
if (rootdev->operstate == IF_OPER_DORMANT)
netif_dormant_on(dev);
else
netif_dormant_off(dev);
if (rootdev->operstate == IF_OPER_TESTING)
netif_testing_on(dev);
else
netif_testing_off(dev);
if (netif_carrier_ok(rootdev))
netif_carrier_on(dev);
else
netif_carrier_off(dev);
}
EXPORT_SYMBOL(netif_stacked_transfer_operstate);
static int netif_alloc_rx_queues(struct net_device *dev)
{
unsigned int i, count = dev->num_rx_queues;
struct netdev_rx_queue *rx;
size_t sz = count * sizeof(*rx);
int err = 0;
BUG_ON(count < 1);
rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
if (!rx)
return -ENOMEM;
dev->_rx = rx;
for (i = 0; i < count; i++) {
rx[i].dev = dev;
/* XDP RX-queue setup */
err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
if (err < 0)
goto err_rxq_info;
}
return 0;
err_rxq_info:
/* Rollback successful reg's and free other resources */
while (i--)
xdp_rxq_info_unreg(&rx[i].xdp_rxq);
kvfree(dev->_rx);
dev->_rx = NULL;
return err;
}
static void netif_free_rx_queues(struct net_device *dev)
{
unsigned int i, count = dev->num_rx_queues;
/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
if (!dev->_rx)
return;
for (i = 0; i < count; i++)
xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
kvfree(dev->_rx);
}
static void netdev_init_one_queue(struct net_device *dev,
struct netdev_queue *queue, void *_unused)
{
/* Initialize queue lock */
spin_lock_init(&queue->_xmit_lock);
netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
queue->xmit_lock_owner = -1;
netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
queue->dev = dev;
#ifdef CONFIG_BQL
dql_init(&queue->dql, HZ);
#endif
}
static void netif_free_tx_queues(struct net_device *dev)
{
kvfree(dev->_tx);
}
static int netif_alloc_netdev_queues(struct net_device *dev)
{
unsigned int count = dev->num_tx_queues;
struct netdev_queue *tx;
size_t sz = count * sizeof(*tx);
if (count < 1 || count > 0xffff)
return -EINVAL;
tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
if (!tx)
return -ENOMEM;
dev->_tx = tx;
netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
spin_lock_init(&dev->tx_global_lock);
return 0;
}
void netif_tx_stop_all_queues(struct net_device *dev)
{
unsigned int i;
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
netif_tx_stop_queue(txq);
}
}
EXPORT_SYMBOL(netif_tx_stop_all_queues);
/**
* register_netdevice() - register a network device
* @dev: device to register
*
* Take a prepared network device structure and make it externally accessible.
* A %NETDEV_REGISTER message is sent to the netdev notifier chain.
* Callers must hold the rtnl lock - you may want register_netdev()
* instead of this.
*/
int register_netdevice(struct net_device *dev)
{
int ret;
struct net *net = dev_net(dev);
BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
NETDEV_FEATURE_COUNT);
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
might_sleep();
/* When net_device's are persistent, this will be fatal. */
BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
BUG_ON(!net);
ret = ethtool_check_ops(dev->ethtool_ops);
if (ret)
return ret;
spin_lock_init(&dev->addr_list_lock);
netdev_set_addr_lockdep_class(dev);
ret = dev_get_valid_name(net, dev, dev->name);
if (ret < 0)
goto out;
ret = -ENOMEM;
dev->name_node = netdev_name_node_head_alloc(dev);
if (!dev->name_node)
goto out;
/* Init, if this function is available */
if (dev->netdev_ops->ndo_init) {
ret = dev->netdev_ops->ndo_init(dev);
if (ret) {
if (ret > 0)
ret = -EIO;
goto err_free_name;
}
}
if (((dev->hw_features | dev->features) &
NETIF_F_HW_VLAN_CTAG_FILTER) &&
(!dev->netdev_ops->ndo_vlan_rx_add_vid ||
!dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
ret = -EINVAL;
goto err_uninit;
}
ret = dev_index_reserve(net, dev->ifindex);
if (ret < 0)
goto err_uninit;
dev->ifindex = ret;
/* Transfer changeable features to wanted_features and enable
* software offloads (GSO and GRO).
*/
dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
dev->features |= NETIF_F_SOFT_FEATURES;
if (dev->udp_tunnel_nic_info) {
dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
}
dev->wanted_features = dev->features & dev->hw_features;
if (!(dev->flags & IFF_LOOPBACK))
dev->hw_features |= NETIF_F_NOCACHE_COPY;
/* If IPv4 TCP segmentation offload is supported we should also
* allow the device to enable segmenting the frame with the option
* of ignoring a static IP ID value. This doesn't enable the
* feature itself but allows the user to enable it later.
*/
if (dev->hw_features & NETIF_F_TSO)
dev->hw_features |= NETIF_F_TSO_MANGLEID;
if (dev->vlan_features & NETIF_F_TSO)
dev->vlan_features |= NETIF_F_TSO_MANGLEID;
if (dev->mpls_features & NETIF_F_TSO)
dev->mpls_features |= NETIF_F_TSO_MANGLEID;
if (dev->hw_enc_features & NETIF_F_TSO)
dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
*/
dev->vlan_features |= NETIF_F_HIGHDMA;
/* Make NETIF_F_SG inheritable to tunnel devices.
*/
dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
/* Make NETIF_F_SG inheritable to MPLS.
*/
dev->mpls_features |= NETIF_F_SG;
ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
ret = notifier_to_errno(ret);
if (ret)
goto err_ifindex_release;
ret = netdev_register_kobject(dev);
write_lock(&dev_base_lock);
dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
write_unlock(&dev_base_lock);
if (ret)
goto err_uninit_notify;
__netdev_update_features(dev);
/*
* Default initial state at registry is that the
* device is present.
*/
set_bit(__LINK_STATE_PRESENT, &dev->state);
linkwatch_init_dev(dev);
dev_init_scheduler(dev);
netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
list_netdevice(dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
/* If the device has permanent device address, driver should
* set dev_addr and also addr_assign_type should be set to
* NET_ADDR_PERM (default value).
*/
if (dev->addr_assign_type == NET_ADDR_PERM)
memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
/* Notify protocols, that a new device appeared. */
ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
ret = notifier_to_errno(ret);
if (ret) {
/* Expect explicit free_netdev() on failure */
dev->needs_free_netdev = false;
unregister_netdevice_queue(dev, NULL);
goto out;
}
/*
* Prevent userspace races by waiting until the network
* device is fully setup before sending notifications.
*/
if (!dev->rtnl_link_ops ||
dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
out:
return ret;
err_uninit_notify:
call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
err_ifindex_release:
dev_index_release(net, dev->ifindex);
err_uninit:
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
if (dev->priv_destructor)
dev->priv_destructor(dev);
err_free_name:
netdev_name_node_free(dev->name_node);
goto out;
}
EXPORT_SYMBOL(register_netdevice);
/**
* init_dummy_netdev - init a dummy network device for NAPI
* @dev: device to init
*
* This takes a network device structure and initialize the minimum
* amount of fields so it can be used to schedule NAPI polls without
* registering a full blown interface. This is to be used by drivers
* that need to tie several hardware interfaces to a single NAPI
* poll scheduler due to HW limitations.
*/
int init_dummy_netdev(struct net_device *dev)
{
/* Clear everything. Note we don't initialize spinlocks
* are they aren't supposed to be taken by any of the
* NAPI code and this dummy netdev is supposed to be
* only ever used for NAPI polls
*/
memset(dev, 0, sizeof(struct net_device));
/* make sure we BUG if trying to hit standard
* register/unregister code path
*/
dev->reg_state = NETREG_DUMMY;
/* NAPI wants this */
INIT_LIST_HEAD(&dev->napi_list);
/* a dummy interface is started by default */
set_bit(__LINK_STATE_PRESENT, &dev->state);
set_bit(__LINK_STATE_START, &dev->state);
/* napi_busy_loop stats accounting wants this */
dev_net_set(dev, &init_net);
/* Note : We dont allocate pcpu_refcnt for dummy devices,
* because users of this 'device' dont need to change
* its refcount.
*/
return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);
/**
* register_netdev - register a network device
* @dev: device to register
*
* Take a completed network device structure and add it to the kernel
* interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
* chain. 0 is returned on success. A negative errno code is returned
* on a failure to set up the device, or if the name is a duplicate.
*
* This is a wrapper around register_netdevice that takes the rtnl semaphore
* and expands the device name if you passed a format string to
* alloc_netdev.
*/
int register_netdev(struct net_device *dev)
{
int err;
if (rtnl_lock_killable())
return -EINTR;
err = register_netdevice(dev);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(register_netdev);
int netdev_refcnt_read(const struct net_device *dev)
{
#ifdef CONFIG_PCPU_DEV_REFCNT
int i, refcnt = 0;
for_each_possible_cpu(i)
refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
return refcnt;
#else
return refcount_read(&dev->dev_refcnt);
#endif
}
EXPORT_SYMBOL(netdev_refcnt_read);
int netdev_unregister_timeout_secs __read_mostly = 10;
#define WAIT_REFS_MIN_MSECS 1
#define WAIT_REFS_MAX_MSECS 250
/**
* netdev_wait_allrefs_any - wait until all references are gone.
* @list: list of net_devices to wait on
*
* This is called when unregistering network devices.
*
* Any protocol or device that holds a reference should register
* for netdevice notification, and cleanup and put back the
* reference if they receive an UNREGISTER event.
* We can get stuck here if buggy protocols don't correctly
* call dev_put.
*/
static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
{
unsigned long rebroadcast_time, warning_time;
struct net_device *dev;
int wait = 0;
rebroadcast_time = warning_time = jiffies;
list_for_each_entry(dev, list, todo_list)
if (netdev_refcnt_read(dev) == 1)
return dev;
while (true) {
if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
rtnl_lock();
/* Rebroadcast unregister notification */
list_for_each_entry(dev, list, todo_list)
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
__rtnl_unlock();
rcu_barrier();
rtnl_lock();
list_for_each_entry(dev, list, todo_list)
if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
&dev->state)) {
/* We must not have linkwatch events
* pending on unregister. If this
* happens, we simply run the queue
* unscheduled, resulting in a noop
* for this device.
*/
linkwatch_run_queue();
break;
}
__rtnl_unlock();
rebroadcast_time = jiffies;
}
if (!wait) {
rcu_barrier();
wait = WAIT_REFS_MIN_MSECS;
} else {
msleep(wait);
wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
}
list_for_each_entry(dev, list, todo_list)
if (netdev_refcnt_read(dev) == 1)
return dev;
if (time_after(jiffies, warning_time +
READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
list_for_each_entry(dev, list, todo_list) {
pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
dev->name, netdev_refcnt_read(dev));
ref_tracker_dir_print(&dev->refcnt_tracker, 10);
}
warning_time = jiffies;
}
}
}
/* The sequence is:
*
* rtnl_lock();
* ...
* register_netdevice(x1);
* register_netdevice(x2);
* ...
* unregister_netdevice(y1);
* unregister_netdevice(y2);
* ...
* rtnl_unlock();
* free_netdev(y1);
* free_netdev(y2);
*
* We are invoked by rtnl_unlock().
* This allows us to deal with problems:
* 1) We can delete sysfs objects which invoke hotplug
* without deadlocking with linkwatch via keventd.
* 2) Since we run with the RTNL semaphore not held, we can sleep
* safely in order to wait for the netdev refcnt to drop to zero.
*
* We must not return until all unregister events added during
* the interval the lock was held have been completed.
*/
void netdev_run_todo(void)
{
struct net_device *dev, *tmp;
struct list_head list;
#ifdef CONFIG_LOCKDEP
struct list_head unlink_list;
list_replace_init(&net_unlink_list, &unlink_list);
while (!list_empty(&unlink_list)) {
struct net_device *dev = list_first_entry(&unlink_list,
struct net_device,
unlink_list);
list_del_init(&dev->unlink_list);
dev->nested_level = dev->lower_level - 1;
}
#endif
/* Snapshot list, allow later requests */
list_replace_init(&net_todo_list, &list);
__rtnl_unlock();
/* Wait for rcu callbacks to finish before next phase */
if (!list_empty(&list))
rcu_barrier();
list_for_each_entry_safe(dev, tmp, &list, todo_list) {
if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
netdev_WARN(dev, "run_todo but not unregistering\n");
list_del(&dev->todo_list);
continue;
}
write_lock(&dev_base_lock);
dev->reg_state = NETREG_UNREGISTERED;
write_unlock(&dev_base_lock);
linkwatch_forget_dev(dev);
}
while (!list_empty(&list)) {
dev = netdev_wait_allrefs_any(&list);
list_del(&dev->todo_list);
/* paranoia */
BUG_ON(netdev_refcnt_read(dev) != 1);
BUG_ON(!list_empty(&dev->ptype_all));
BUG_ON(!list_empty(&dev->ptype_specific));
WARN_ON(rcu_access_pointer(dev->ip_ptr));
WARN_ON(rcu_access_pointer(dev->ip6_ptr));
if (dev->priv_destructor)
dev->priv_destructor(dev);
if (dev->needs_free_netdev)
free_netdev(dev);
if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
wake_up(&netdev_unregistering_wq);
/* Free network device */
kobject_put(&dev->dev.kobj);
}
}
/* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
* all the same fields in the same order as net_device_stats, with only
* the type differing, but rtnl_link_stats64 may have additional fields
* at the end for newer counters.
*/
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
const struct net_device_stats *netdev_stats)
{
size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
const atomic_long_t *src = (atomic_long_t *)netdev_stats;
u64 *dst = (u64 *)stats64;
BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
for (i = 0; i < n; i++)
dst[i] = (unsigned long)atomic_long_read(&src[i]);
/* zero out counters that only exist in rtnl_link_stats64 */
memset((char *)stats64 + n * sizeof(u64), 0,
sizeof(*stats64) - n * sizeof(u64));
}
EXPORT_SYMBOL(netdev_stats_to_stats64);
struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
{
struct net_device_core_stats __percpu *p;
p = alloc_percpu_gfp(struct net_device_core_stats,
GFP_ATOMIC | __GFP_NOWARN);
if (p && cmpxchg(&dev->core_stats, NULL, p))
free_percpu(p);
/* This READ_ONCE() pairs with the cmpxchg() above */
return READ_ONCE(dev->core_stats);
}
EXPORT_SYMBOL(netdev_core_stats_alloc);
/**
* dev_get_stats - get network device statistics
* @dev: device to get statistics from
* @storage: place to store stats
*
* Get network statistics from device. Return @storage.
* The device driver may provide its own method by setting
* dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
* otherwise the internal statistics structure is used.
*/
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
struct rtnl_link_stats64 *storage)
{
const struct net_device_ops *ops = dev->netdev_ops;
const struct net_device_core_stats __percpu *p;
if (ops->ndo_get_stats64) {
memset(storage, 0, sizeof(*storage));
ops->ndo_get_stats64(dev, storage);
} else if (ops->ndo_get_stats) {
netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
} else {
netdev_stats_to_stats64(storage, &dev->stats);
}
/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
p = READ_ONCE(dev->core_stats);
if (p) {
const struct net_device_core_stats *core_stats;
int i;
for_each_possible_cpu(i) {
core_stats = per_cpu_ptr(p, i);
storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
}
}
return storage;
}
EXPORT_SYMBOL(dev_get_stats);
/**
* dev_fetch_sw_netstats - get per-cpu network device statistics
* @s: place to store stats
* @netstats: per-cpu network stats to read from
*
* Read per-cpu network statistics and populate the related fields in @s.
*/
void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
const struct pcpu_sw_netstats __percpu *netstats)
{
int cpu;
for_each_possible_cpu(cpu) {
u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
const struct pcpu_sw_netstats *stats;
unsigned int start;
stats = per_cpu_ptr(netstats, cpu);
do {
start = u64_stats_fetch_begin(&stats->syncp);
rx_packets = u64_stats_read(&stats->rx_packets);
rx_bytes = u64_stats_read(&stats->rx_bytes);
tx_packets = u64_stats_read(&stats->tx_packets);
tx_bytes = u64_stats_read(&stats->tx_bytes);
} while (u64_stats_fetch_retry(&stats->syncp, start));
s->rx_packets += rx_packets;
s->rx_bytes += rx_bytes;
s->tx_packets += tx_packets;
s->tx_bytes += tx_bytes;
}
}
EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
/**
* dev_get_tstats64 - ndo_get_stats64 implementation
* @dev: device to get statistics from
* @s: place to store stats
*
* Populate @s from dev->stats and dev->tstats. Can be used as
* ndo_get_stats64() callback.
*/
void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
{
netdev_stats_to_stats64(s, &dev->stats);
dev_fetch_sw_netstats(s, dev->tstats);
}
EXPORT_SYMBOL_GPL(dev_get_tstats64);
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
{
struct netdev_queue *queue = dev_ingress_queue(dev);
#ifdef CONFIG_NET_CLS_ACT
if (queue)
return queue;
queue = kzalloc(sizeof(*queue), GFP_KERNEL);
if (!queue)
return NULL;
netdev_init_one_queue(dev, queue, NULL);
RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
rcu_assign_pointer(dev->ingress_queue, queue);
#endif
return queue;
}
static const struct ethtool_ops default_ethtool_ops;
void netdev_set_default_ethtool_ops(struct net_device *dev,
const struct ethtool_ops *ops)
{
if (dev->ethtool_ops == &default_ethtool_ops)
dev->ethtool_ops = ops;
}
EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
/**
* netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
* @dev: netdev to enable the IRQ coalescing on
*
* Sets a conservative default for SW IRQ coalescing. Users can use
* sysfs attributes to override the default values.
*/
void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
{
WARN_ON(dev->reg_state == NETREG_REGISTERED);
if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
dev->gro_flush_timeout = 20000;
dev->napi_defer_hard_irqs = 1;
}
}
EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
void netdev_freemem(struct net_device *dev)
{
char *addr = (char *)dev - dev->padded;
kvfree(addr);
}
/**
* alloc_netdev_mqs - allocate network device
* @sizeof_priv: size of private data to allocate space for
* @name: device name format string
* @name_assign_type: origin of device name
* @setup: callback to initialize device
* @txqs: the number of TX subqueues to allocate
* @rxqs: the number of RX subqueues to allocate
*
* Allocates a struct net_device with private data area for driver use
* and performs basic initialization. Also allocates subqueue structs
* for each queue on the device.
*/
struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
unsigned char name_assign_type,
void (*setup)(struct net_device *),
unsigned int txqs, unsigned int rxqs)
{
struct net_device *dev;
unsigned int alloc_size;
struct net_device *p;
BUG_ON(strlen(name) >= sizeof(dev->name));
if (txqs < 1) {
pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
return NULL;
}
if (rxqs < 1) {
pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
return NULL;
}
alloc_size = sizeof(struct net_device);
if (sizeof_priv) {
/* ensure 32-byte alignment of private area */
alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
alloc_size += sizeof_priv;
}
/* ensure 32-byte alignment of whole construct */
alloc_size += NETDEV_ALIGN - 1;
p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
if (!p)
return NULL;
dev = PTR_ALIGN(p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
ref_tracker_dir_init(&dev->refcnt_tracker, 128, name);
#ifdef CONFIG_PCPU_DEV_REFCNT
dev->pcpu_refcnt = alloc_percpu(int);
if (!dev->pcpu_refcnt)
goto free_dev;
__dev_hold(dev);
#else
refcount_set(&dev->dev_refcnt, 1);
#endif
if (dev_addr_init(dev))
goto free_pcpu;
dev_mc_init(dev);
dev_uc_init(dev);
dev_net_set(dev, &init_net);
dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
dev->xdp_zc_max_segs = 1;
dev->gso_max_segs = GSO_MAX_SEGS;
dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
dev->tso_max_segs = TSO_MAX_SEGS;
dev->upper_level = 1;
dev->lower_level = 1;
#ifdef CONFIG_LOCKDEP
dev->nested_level = 0;
INIT_LIST_HEAD(&dev->unlink_list);
#endif
INIT_LIST_HEAD(&dev->napi_list);
INIT_LIST_HEAD(&dev->unreg_list);
INIT_LIST_HEAD(&dev->close_list);
INIT_LIST_HEAD(&dev->link_watch_list);
INIT_LIST_HEAD(&dev->adj_list.upper);
INIT_LIST_HEAD(&dev->adj_list.lower);
INIT_LIST_HEAD(&dev->ptype_all);
INIT_LIST_HEAD(&dev->ptype_specific);
INIT_LIST_HEAD(&dev->net_notifier_list);
#ifdef CONFIG_NET_SCHED
hash_init(dev->qdisc_hash);
#endif
dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
setup(dev);
if (!dev->tx_queue_len) {
dev->priv_flags |= IFF_NO_QUEUE;
dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
}
dev->num_tx_queues = txqs;
dev->real_num_tx_queues = txqs;
if (netif_alloc_netdev_queues(dev))
goto free_all;
dev->num_rx_queues = rxqs;
dev->real_num_rx_queues = rxqs;
if (netif_alloc_rx_queues(dev))
goto free_all;
strcpy(dev->name, name);
dev->name_assign_type = name_assign_type;
dev->group = INIT_NETDEV_GROUP;
if (!dev->ethtool_ops)
dev->ethtool_ops = &default_ethtool_ops;
nf_hook_netdev_init(dev);
return dev;
free_all:
free_netdev(dev);
return NULL;
free_pcpu:
#ifdef CONFIG_PCPU_DEV_REFCNT
free_percpu(dev->pcpu_refcnt);
free_dev:
#endif
netdev_freemem(dev);
return NULL;
}
EXPORT_SYMBOL(alloc_netdev_mqs);
/**
* free_netdev - free network device
* @dev: device
*
* This function does the last stage of destroying an allocated device
* interface. The reference to the device object is released. If this
* is the last reference then it will be freed.Must be called in process
* context.
*/
void free_netdev(struct net_device *dev)
{
struct napi_struct *p, *n;
might_sleep();
/* When called immediately after register_netdevice() failed the unwind
* handling may still be dismantling the device. Handle that case by
* deferring the free.
*/
if (dev->reg_state == NETREG_UNREGISTERING) {
ASSERT_RTNL();
dev->needs_free_netdev = true;
return;
}
netif_free_tx_queues(dev);
netif_free_rx_queues(dev);
kfree(rcu_dereference_protected(dev->ingress_queue, 1));
/* Flush device addresses */
dev_addr_flush(dev);
list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
netif_napi_del(p);
ref_tracker_dir_exit(&dev->refcnt_tracker);
#ifdef CONFIG_PCPU_DEV_REFCNT
free_percpu(dev->pcpu_refcnt);
dev->pcpu_refcnt = NULL;
#endif
free_percpu(dev->core_stats);
dev->core_stats = NULL;
free_percpu(dev->xdp_bulkq);
dev->xdp_bulkq = NULL;
/* Compatibility with error handling in drivers */
if (dev->reg_state == NETREG_UNINITIALIZED) {
netdev_freemem(dev);
return;
}
BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
dev->reg_state = NETREG_RELEASED;
/* will free via device release */
put_device(&dev->dev);
}
EXPORT_SYMBOL(free_netdev);
/**
* synchronize_net - Synchronize with packet receive processing
*
* Wait for packets currently being received to be done.
* Does not block later packets from starting.
*/
void synchronize_net(void)
{
might_sleep();
if (rtnl_is_locked())
synchronize_rcu_expedited();
else
synchronize_rcu();
}
EXPORT_SYMBOL(synchronize_net);
/**
* unregister_netdevice_queue - remove device from the kernel
* @dev: device
* @head: list
*
* This function shuts down a device interface and removes it
* from the kernel tables.
* If head not NULL, device is queued to be unregistered later.
*
* Callers must hold the rtnl semaphore. You may want
* unregister_netdev() instead of this.
*/
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
{
ASSERT_RTNL();
if (head) {
list_move_tail(&dev->unreg_list, head);
} else {
LIST_HEAD(single);
list_add(&dev->unreg_list, &single);
unregister_netdevice_many(&single);
}
}
EXPORT_SYMBOL(unregister_netdevice_queue);
void unregister_netdevice_many_notify(struct list_head *head,
u32 portid, const struct nlmsghdr *nlh)
{
struct net_device *dev, *tmp;
LIST_HEAD(close_head);
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
if (list_empty(head))
return;
list_for_each_entry_safe(dev, tmp, head, unreg_list) {
/* Some devices call without registering
* for initialization unwind. Remove those
* devices and proceed with the remaining.
*/
if (dev->reg_state == NETREG_UNINITIALIZED) {
pr_debug("unregister_netdevice: device %s/%p never was registered\n",
dev->name, dev);
WARN_ON(1);
list_del(&dev->unreg_list);
continue;
}
dev->dismantle = true;
BUG_ON(dev->reg_state != NETREG_REGISTERED);
}
/* If device is running, close it first. */
list_for_each_entry(dev, head, unreg_list)
list_add_tail(&dev->close_list, &close_head);
dev_close_many(&close_head, true);
list_for_each_entry(dev, head, unreg_list) {
/* And unlink it from device chain. */
write_lock(&dev_base_lock);
unlist_netdevice(dev, false);
dev->reg_state = NETREG_UNREGISTERING;
write_unlock(&dev_base_lock);
}
flush_all_backlogs();
synchronize_net();
list_for_each_entry(dev, head, unreg_list) {
struct sk_buff *skb = NULL;
/* Shutdown queueing discipline. */
dev_shutdown(dev);
dev_tcx_uninstall(dev);
dev_xdp_uninstall(dev);
bpf_dev_bound_netdev_unregister(dev);
netdev_offload_xstats_disable_all(dev);
/* Notify protocols, that we are about to destroy
* this device. They should clean all the things.
*/
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
if (!dev->rtnl_link_ops ||
dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
GFP_KERNEL, NULL, 0,
portid, nlh);
/*
* Flush the unicast and multicast chains
*/
dev_uc_flush(dev);
dev_mc_flush(dev);
netdev_name_node_alt_flush(dev);
netdev_name_node_free(dev->name_node);
call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
if (skb)
rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
/* Notifier chain MUST detach us all upper devices. */
WARN_ON(netdev_has_any_upper_dev(dev));
WARN_ON(netdev_has_any_lower_dev(dev));
/* Remove entries from kobject tree */
netdev_unregister_kobject(dev);
#ifdef CONFIG_XPS
/* Remove XPS queueing entries */
netif_reset_xps_queues_gt(dev, 0);
#endif
}
synchronize_net();
list_for_each_entry(dev, head, unreg_list) {
netdev_put(dev, &dev->dev_registered_tracker);
net_set_todo(dev);
}
list_del(head);
}
/**
* unregister_netdevice_many - unregister many devices
* @head: list of devices
*
* Note: As most callers use a stack allocated list_head,
* we force a list_del() to make sure stack wont be corrupted later.
*/
void unregister_netdevice_many(struct list_head *head)
{
unregister_netdevice_many_notify(head, 0, NULL);
}
EXPORT_SYMBOL(unregister_netdevice_many);
/**
* unregister_netdev - remove device from the kernel
* @dev: device
*
* This function shuts down a device interface and removes it
* from the kernel tables.
*
* This is just a wrapper for unregister_netdevice that takes
* the rtnl semaphore. In general you want to use this and not
* unregister_netdevice.
*/
void unregister_netdev(struct net_device *dev)
{
rtnl_lock();
unregister_netdevice(dev);
rtnl_unlock();
}
EXPORT_SYMBOL(unregister_netdev);
/**
* __dev_change_net_namespace - move device to different nethost namespace
* @dev: device
* @net: network namespace
* @pat: If not NULL name pattern to try if the current device name
* is already taken in the destination network namespace.
* @new_ifindex: If not zero, specifies device index in the target
* namespace.
*
* This function shuts down a device interface and moves it
* to a new network namespace. On success 0 is returned, on
* a failure a netagive errno code is returned.
*
* Callers must hold the rtnl semaphore.
*/
int __dev_change_net_namespace(struct net_device *dev, struct net *net,
const char *pat, int new_ifindex)
{
struct net *net_old = dev_net(dev);
int err, new_nsid;
ASSERT_RTNL();
/* Don't allow namespace local devices to be moved. */
err = -EINVAL;
if (dev->features & NETIF_F_NETNS_LOCAL)
goto out;
/* Ensure the device has been registrered */
if (dev->reg_state != NETREG_REGISTERED)
goto out;
/* Get out if there is nothing todo */
err = 0;
if (net_eq(net_old, net))
goto out;
/* Pick the destination device name, and ensure
* we can use it in the destination network namespace.
*/
err = -EEXIST;
if (netdev_name_in_use(net, dev->name)) {
/* We get here if we can't use the current device name */
if (!pat)
goto out;
err = dev_get_valid_name(net, dev, pat);
if (err < 0)
goto out;
}
/* Check that new_ifindex isn't used yet. */
if (new_ifindex) {
err = dev_index_reserve(net, new_ifindex);
if (err < 0)
goto out;
} else {
/* If there is an ifindex conflict assign a new one */
err = dev_index_reserve(net, dev->ifindex);
if (err == -EBUSY)
err = dev_index_reserve(net, 0);
if (err < 0)
goto out;
new_ifindex = err;
}
/*
* And now a mini version of register_netdevice unregister_netdevice.
*/
/* If device is running close it first. */
dev_close(dev);
/* And unlink it from device chain */
unlist_netdevice(dev, true);
synchronize_net();
/* Shutdown queueing discipline. */
dev_shutdown(dev);
/* Notify protocols, that we are about to destroy
* this device. They should clean all the things.
*
* Note that dev->reg_state stays at NETREG_REGISTERED.
* This is wanted because this way 8021q and macvlan know
* the device is just moving and can keep their slaves up.
*/
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
rcu_barrier();
new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
new_ifindex);
/*
* Flush the unicast and multicast chains
*/
dev_uc_flush(dev);
dev_mc_flush(dev);
/* Send a netdev-removed uevent to the old namespace */
kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
netdev_adjacent_del_links(dev);
/* Move per-net netdevice notifiers that are following the netdevice */
move_netdevice_notifiers_dev_net(dev, net);
/* Actually switch the network namespace */
dev_net_set(dev, net);
dev->ifindex = new_ifindex;
/* Send a netdev-add uevent to the new namespace */
kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
netdev_adjacent_add_links(dev);
/* Fixup kobjects */
err = device_rename(&dev->dev, dev->name);
WARN_ON(err);
/* Adapt owner in case owning user namespace of target network
* namespace is different from the original one.
*/
err = netdev_change_owner(dev, net_old, net);
WARN_ON(err);
/* Add the device back in the hashes */
list_netdevice(dev);
/* Notify protocols, that a new device appeared. */
call_netdevice_notifiers(NETDEV_REGISTER, dev);
/*
* Prevent userspace races by waiting until the network
* device is fully setup before sending notifications.
*/
rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
synchronize_net();
err = 0;
out:
return err;
}
EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
static int dev_cpu_dead(unsigned int oldcpu)
{
struct sk_buff **list_skb;
struct sk_buff *skb;
unsigned int cpu;
struct softnet_data *sd, *oldsd, *remsd = NULL;
local_irq_disable();
cpu = smp_processor_id();
sd = &per_cpu(softnet_data, cpu);
oldsd = &per_cpu(softnet_data, oldcpu);
/* Find end of our completion_queue. */
list_skb = &sd->completion_queue;
while (*list_skb)
list_skb = &(*list_skb)->next;
/* Append completion queue from offline CPU. */
*list_skb = oldsd->completion_queue;
oldsd->completion_queue = NULL;
/* Append output queue from offline CPU. */
if (oldsd->output_queue) {
*sd->output_queue_tailp = oldsd->output_queue;
sd->output_queue_tailp = oldsd->output_queue_tailp;
oldsd->output_queue = NULL;
oldsd->output_queue_tailp = &oldsd->output_queue;
}
/* Append NAPI poll list from offline CPU, with one exception :
* process_backlog() must be called by cpu owning percpu backlog.
* We properly handle process_queue & input_pkt_queue later.
*/
while (!list_empty(&oldsd->poll_list)) {
struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
struct napi_struct,
poll_list);
list_del_init(&napi->poll_list);
if (napi->poll == process_backlog)
napi->state = 0;
else
____napi_schedule(sd, napi);
}
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
#ifdef CONFIG_RPS
remsd = oldsd->rps_ipi_list;
oldsd->rps_ipi_list = NULL;
#endif
/* send out pending IPI's on offline CPU */
net_rps_send_ipi(remsd);
/* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->process_queue))) {
netif_rx(skb);
input_queue_head_incr(oldsd);
}
while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
netif_rx(skb);
input_queue_head_incr(oldsd);
}
return 0;
}
/**
* netdev_increment_features - increment feature set by one
* @all: current feature set
* @one: new feature set
* @mask: mask feature set
*
* Computes a new feature set after adding a device with feature set
* @one to the master device with current feature set @all. Will not
* enable anything that is off in @mask. Returns the new feature set.
*/
netdev_features_t netdev_increment_features(netdev_features_t all,
netdev_features_t one, netdev_features_t mask)
{
if (mask & NETIF_F_HW_CSUM)
mask |= NETIF_F_CSUM_MASK;
mask |= NETIF_F_VLAN_CHALLENGED;
all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
all &= one | ~NETIF_F_ALL_FOR_ALL;
/* If one device supports hw checksumming, set for all. */
if (all & NETIF_F_HW_CSUM)
all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
return all;
}
EXPORT_SYMBOL(netdev_increment_features);
static struct hlist_head * __net_init netdev_create_hash(void)
{
int i;
struct hlist_head *hash;
hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
if (hash != NULL)
for (i = 0; i < NETDEV_HASHENTRIES; i++)
INIT_HLIST_HEAD(&hash[i]);
return hash;
}
/* Initialize per network namespace state */
static int __net_init netdev_init(struct net *net)
{
BUILD_BUG_ON(GRO_HASH_BUCKETS >
8 * sizeof_field(struct napi_struct, gro_bitmask));
INIT_LIST_HEAD(&net->dev_base_head);
net->dev_name_head = netdev_create_hash();
if (net->dev_name_head == NULL)
goto err_name;
net->dev_index_head = netdev_create_hash();
if (net->dev_index_head == NULL)
goto err_idx;
net->ifindex = 1;
xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC);
RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
return 0;
err_idx:
kfree(net->dev_name_head);
err_name:
return -ENOMEM;
}
/**
* netdev_drivername - network driver for the device
* @dev: network device
*
* Determine network driver for device.
*/
const char *netdev_drivername(const struct net_device *dev)
{
const struct device_driver *driver;
const struct device *parent;
const char *empty = "";
parent = dev->dev.parent;
if (!parent)
return empty;
driver = parent->driver;
if (driver && driver->name)
return driver->name;
return empty;
}
static void __netdev_printk(const char *level, const struct net_device *dev,
struct va_format *vaf)
{
if (dev && dev->dev.parent) {
dev_printk_emit(level[1] - '0',
dev->dev.parent,
"%s %s %s%s: %pV",
dev_driver_string(dev->dev.parent),
dev_name(dev->dev.parent),
netdev_name(dev), netdev_reg_state(dev),
vaf);
} else if (dev) {
printk("%s%s%s: %pV",
level, netdev_name(dev), netdev_reg_state(dev), vaf);
} else {
printk("%s(NULL net_device): %pV", level, vaf);
}
}
void netdev_printk(const char *level, const struct net_device *dev,
const char *format, ...)
{
struct va_format vaf;
va_list args;
va_start(args, format);
vaf.fmt = format;
vaf.va = &args;
__netdev_printk(level, dev, &vaf);
va_end(args);
}
EXPORT_SYMBOL(netdev_printk);
#define define_netdev_printk_level(func, level) \
void func(const struct net_device *dev, const char *fmt, ...) \
{ \
struct va_format vaf; \
va_list args; \
\
va_start(args, fmt); \
\
vaf.fmt = fmt; \
vaf.va = &args; \
\
__netdev_printk(level, dev, &vaf); \
\
va_end(args); \
} \
EXPORT_SYMBOL(func);
define_netdev_printk_level(netdev_emerg, KERN_EMERG);
define_netdev_printk_level(netdev_alert, KERN_ALERT);
define_netdev_printk_level(netdev_crit, KERN_CRIT);
define_netdev_printk_level(netdev_err, KERN_ERR);
define_netdev_printk_level(netdev_warn, KERN_WARNING);
define_netdev_printk_level(netdev_notice, KERN_NOTICE);
define_netdev_printk_level(netdev_info, KERN_INFO);
static void __net_exit netdev_exit(struct net *net)
{
kfree(net->dev_name_head);
kfree(net->dev_index_head);
xa_destroy(&net->dev_by_index);
if (net != &init_net)
WARN_ON_ONCE(!list_empty(&net->dev_base_head));
}
static struct pernet_operations __net_initdata netdev_net_ops = {
.init = netdev_init,
.exit = netdev_exit,
};
static void __net_exit default_device_exit_net(struct net *net)
{
struct net_device *dev, *aux;
/*
* Push all migratable network devices back to the
* initial network namespace
*/
ASSERT_RTNL();
for_each_netdev_safe(net, dev, aux) {
int err;
char fb_name[IFNAMSIZ];
/* Ignore unmoveable devices (i.e. loopback) */
if (dev->features & NETIF_F_NETNS_LOCAL)
continue;
/* Leave virtual devices for the generic cleanup */
if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
continue;
/* Push remaining network devices to init_net */
snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
if (netdev_name_in_use(&init_net, fb_name))
snprintf(fb_name, IFNAMSIZ, "dev%%d");
err = dev_change_net_namespace(dev, &init_net, fb_name);
if (err) {
pr_emerg("%s: failed to move %s to init_net: %d\n",
__func__, dev->name, err);
BUG();
}
}
}
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
/* At exit all network devices most be removed from a network
* namespace. Do this in the reverse order of registration.
* Do this across as many network namespaces as possible to
* improve batching efficiency.
*/
struct net_device *dev;
struct net *net;
LIST_HEAD(dev_kill_list);
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
default_device_exit_net(net);
cond_resched();
}
list_for_each_entry(net, net_list, exit_list) {
for_each_netdev_reverse(net, dev) {
if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
else
unregister_netdevice_queue(dev, &dev_kill_list);
}
}
unregister_netdevice_many(&dev_kill_list);
rtnl_unlock();
}
static struct pernet_operations __net_initdata default_device_ops = {
.exit_batch = default_device_exit_batch,
};
/*
* Initialize the DEV module. At boot time this walks the device list and
* unhooks any devices that fail to initialise (normally hardware not
* present) and leaves us with a valid list of present and active devices.
*
*/
/*
* This is called single threaded during boot, so no need
* to take the rtnl semaphore.
*/
static int __init net_dev_init(void)
{
int i, rc = -ENOMEM;
BUG_ON(!dev_boot_phase);
if (dev_proc_init())
goto out;
if (netdev_kobject_init())
goto out;
INIT_LIST_HEAD(&ptype_all);
for (i = 0; i < PTYPE_HASH_SIZE; i++)
INIT_LIST_HEAD(&ptype_base[i]);
if (register_pernet_subsys(&netdev_net_ops))
goto out;
/*
* Initialise the packet receive queues.
*/
for_each_possible_cpu(i) {
struct work_struct *flush = per_cpu_ptr(&flush_works, i);
struct softnet_data *sd = &per_cpu(softnet_data, i);
INIT_WORK(flush, flush_backlog);
skb_queue_head_init(&sd->input_pkt_queue);
skb_queue_head_init(&sd->process_queue);
#ifdef CONFIG_XFRM_OFFLOAD
skb_queue_head_init(&sd->xfrm_backlog);
#endif
INIT_LIST_HEAD(&sd->poll_list);
sd->output_queue_tailp = &sd->output_queue;
#ifdef CONFIG_RPS
INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
sd->cpu = i;
#endif
INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
spin_lock_init(&sd->defer_lock);
init_gro_hash(&sd->backlog);
sd->backlog.poll = process_backlog;
sd->backlog.weight = weight_p;
}
dev_boot_phase = 0;
/* The loopback device is special if any other network devices
* is present in a network namespace the loopback device must
* be present. Since we now dynamically allocate and free the
* loopback device ensure this invariant is maintained by
* keeping the loopback device as the first device on the
* list of network devices. Ensuring the loopback devices
* is the first device that appears and the last network device
* that disappears.
*/
if (register_pernet_device(&loopback_net_ops))
goto out;
if (register_pernet_device(&default_device_ops))
goto out;
open_softirq(NET_TX_SOFTIRQ, net_tx_action);
open_softirq(NET_RX_SOFTIRQ, net_rx_action);
rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
NULL, dev_cpu_dead);
WARN_ON(rc < 0);
rc = 0;
out:
return rc;
}
subsys_initcall(net_dev_init);
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