linux-stable/net/bridge/br_if.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

759 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Userspace interface
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*/
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netpoll.h>
#include <linux/ethtool.h>
#include <linux/if_arp.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>
#include <linux/if_ether.h>
#include <linux/slab.h>
#include <net/dsa.h>
#include <net/sock.h>
#include <linux/if_vlan.h>
#include <net/switchdev.h>
#include <net/net_namespace.h>
#include "br_private.h"
/*
* Determine initial path cost based on speed.
* using recommendations from 802.1d standard
*
* Since driver might sleep need to not be holding any locks.
*/
static int port_cost(struct net_device *dev)
{
struct ethtool_link_ksettings ecmd;
if (!__ethtool_get_link_ksettings(dev, &ecmd)) {
switch (ecmd.base.speed) {
case SPEED_10000:
return 2;
case SPEED_1000:
return 4;
case SPEED_100:
return 19;
case SPEED_10:
return 100;
}
}
/* Old silly heuristics based on name */
if (!strncmp(dev->name, "lec", 3))
return 7;
if (!strncmp(dev->name, "plip", 4))
return 2500;
return 100; /* assume old 10Mbps */
}
/* Check for port carrier transitions. */
void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
{
struct net_device *dev = p->dev;
struct net_bridge *br = p->br;
if (!(p->flags & BR_ADMIN_COST) &&
netif_running(dev) && netif_oper_up(dev))
p->path_cost = port_cost(dev);
*notified = false;
if (!netif_running(br->dev))
return;
spin_lock_bh(&br->lock);
if (netif_running(dev) && netif_oper_up(dev)) {
if (p->state == BR_STATE_DISABLED) {
br_stp_enable_port(p);
*notified = true;
}
} else {
if (p->state != BR_STATE_DISABLED) {
br_stp_disable_port(p);
*notified = true;
}
}
spin_unlock_bh(&br->lock);
}
static void br_port_set_promisc(struct net_bridge_port *p)
{
int err = 0;
if (br_promisc_port(p))
return;
err = dev_set_promiscuity(p->dev, 1);
if (err)
return;
br_fdb_unsync_static(p->br, p);
p->flags |= BR_PROMISC;
}
static void br_port_clear_promisc(struct net_bridge_port *p)
{
int err;
/* Check if the port is already non-promisc or if it doesn't
* support UNICAST filtering. Without unicast filtering support
* we'll end up re-enabling promisc mode anyway, so just check for
* it here.
*/
if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
return;
/* Since we'll be clearing the promisc mode, program the port
* first so that we don't have interruption in traffic.
*/
err = br_fdb_sync_static(p->br, p);
if (err)
return;
dev_set_promiscuity(p->dev, -1);
p->flags &= ~BR_PROMISC;
}
/* When a port is added or removed or when certain port flags
* change, this function is called to automatically manage
* promiscuity setting of all the bridge ports. We are always called
* under RTNL so can skip using rcu primitives.
*/
void br_manage_promisc(struct net_bridge *br)
{
struct net_bridge_port *p;
bool set_all = false;
/* If vlan filtering is disabled or bridge interface is placed
* into promiscuous mode, place all ports in promiscuous mode.
*/
if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
set_all = true;
list_for_each_entry(p, &br->port_list, list) {
if (set_all) {
br_port_set_promisc(p);
} else {
/* If the number of auto-ports is <= 1, then all other
* ports will have their output configuration
* statically specified through fdbs. Since ingress
* on the auto-port becomes forwarding/egress to other
* ports and egress configuration is statically known,
* we can say that ingress configuration of the
* auto-port is also statically known.
* This lets us disable promiscuous mode and write
* this config to hw.
*/
if (br->auto_cnt == 0 ||
(br->auto_cnt == 1 && br_auto_port(p)))
br_port_clear_promisc(p);
else
br_port_set_promisc(p);
}
}
}
int nbp_backup_change(struct net_bridge_port *p,
struct net_device *backup_dev)
{
struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
struct net_bridge_port *backup_p = NULL;
ASSERT_RTNL();
if (backup_dev) {
if (!netif_is_bridge_port(backup_dev))
return -ENOENT;
backup_p = br_port_get_rtnl(backup_dev);
if (backup_p->br != p->br)
return -EINVAL;
}
if (p == backup_p)
return -EINVAL;
if (old_backup == backup_p)
return 0;
/* if the backup link is already set, clear it */
if (old_backup)
old_backup->backup_redirected_cnt--;
if (backup_p)
backup_p->backup_redirected_cnt++;
rcu_assign_pointer(p->backup_port, backup_p);
return 0;
}
static void nbp_backup_clear(struct net_bridge_port *p)
{
nbp_backup_change(p, NULL);
if (p->backup_redirected_cnt) {
struct net_bridge_port *cur_p;
list_for_each_entry(cur_p, &p->br->port_list, list) {
struct net_bridge_port *backup_p;
backup_p = rtnl_dereference(cur_p->backup_port);
if (backup_p == p)
nbp_backup_change(cur_p, NULL);
}
}
WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
}
static void nbp_update_port_count(struct net_bridge *br)
{
struct net_bridge_port *p;
u32 cnt = 0;
list_for_each_entry(p, &br->port_list, list) {
if (br_auto_port(p))
cnt++;
}
if (br->auto_cnt != cnt) {
br->auto_cnt = cnt;
br_manage_promisc(br);
}
}
static void nbp_delete_promisc(struct net_bridge_port *p)
{
/* If port is currently promiscuous, unset promiscuity.
* Otherwise, it is a static port so remove all addresses
* from it.
*/
dev_set_allmulti(p->dev, -1);
if (br_promisc_port(p))
dev_set_promiscuity(p->dev, -1);
else
br_fdb_unsync_static(p->br, p);
}
static void release_nbp(struct kobject *kobj)
{
struct net_bridge_port *p
= container_of(kobj, struct net_bridge_port, kobj);
kfree(p);
}
static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
{
struct net_bridge_port *p = kobj_to_brport(kobj);
net_ns_get_ownership(dev_net(p->dev), uid, gid);
}
static struct kobj_type brport_ktype = {
#ifdef CONFIG_SYSFS
.sysfs_ops = &brport_sysfs_ops,
#endif
.release = release_nbp,
.get_ownership = brport_get_ownership,
};
static void destroy_nbp(struct net_bridge_port *p)
{
struct net_device *dev = p->dev;
p->br = NULL;
p->dev = NULL;
dev_put(dev);
kobject_put(&p->kobj);
}
static void destroy_nbp_rcu(struct rcu_head *head)
{
struct net_bridge_port *p =
container_of(head, struct net_bridge_port, rcu);
destroy_nbp(p);
}
static unsigned get_max_headroom(struct net_bridge *br)
{
unsigned max_headroom = 0;
struct net_bridge_port *p;
list_for_each_entry(p, &br->port_list, list) {
unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
if (dev_headroom > max_headroom)
max_headroom = dev_headroom;
}
return max_headroom;
}
static void update_headroom(struct net_bridge *br, int new_hr)
{
struct net_bridge_port *p;
list_for_each_entry(p, &br->port_list, list)
netdev_set_rx_headroom(p->dev, new_hr);
br->dev->needed_headroom = new_hr;
}
/* Delete port(interface) from bridge is done in two steps.
* via RCU. First step, marks device as down. That deletes
* all the timers and stops new packets from flowing through.
*
* Final cleanup doesn't occur until after all CPU's finished
* processing packets.
*
* Protected from multiple admin operations by RTNL mutex
*/
static void del_nbp(struct net_bridge_port *p)
{
struct net_bridge *br = p->br;
struct net_device *dev = p->dev;
sysfs_remove_link(br->ifobj, p->dev->name);
nbp_delete_promisc(p);
spin_lock_bh(&br->lock);
br_stp_disable_port(p);
spin_unlock_bh(&br->lock);
br_ifinfo_notify(RTM_DELLINK, NULL, p);
list_del_rcu(&p->list);
if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
update_headroom(br, get_max_headroom(br));
netdev_reset_rx_headroom(dev);
nbp_vlan_flush(p);
br_fdb_delete_by_port(br, p, 0, 1);
switchdev_deferred_process();
nbp_backup_clear(p);
nbp_update_port_count(br);
netdev_upper_dev_unlink(dev, br->dev);
dev->priv_flags &= ~IFF_BRIDGE_PORT;
netdev_rx_handler_unregister(dev);
br_multicast_del_port(p);
kobject_uevent(&p->kobj, KOBJ_REMOVE);
kobject_del(&p->kobj);
br_netpoll_disable(p);
call_rcu(&p->rcu, destroy_nbp_rcu);
}
/* Delete bridge device */
void br_dev_delete(struct net_device *dev, struct list_head *head)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p, *n;
list_for_each_entry_safe(p, n, &br->port_list, list) {
del_nbp(p);
}
br_recalculate_neigh_suppress_enabled(br);
br_fdb_delete_by_port(br, NULL, 0, 1);
cancel_delayed_work_sync(&br->gc_work);
br_sysfs_delbr(br->dev);
unregister_netdevice_queue(br->dev, head);
}
/* find an available port number */
static int find_portno(struct net_bridge *br)
{
int index;
struct net_bridge_port *p;
unsigned long *inuse;
inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
if (!inuse)
return -ENOMEM;
set_bit(0, inuse); /* zero is reserved */
list_for_each_entry(p, &br->port_list, list) {
set_bit(p->port_no, inuse);
}
index = find_first_zero_bit(inuse, BR_MAX_PORTS);
bitmap_free(inuse);
return (index >= BR_MAX_PORTS) ? -EXFULL : index;
}
/* called with RTNL but without bridge lock */
static struct net_bridge_port *new_nbp(struct net_bridge *br,
struct net_device *dev)
{
struct net_bridge_port *p;
int index, err;
index = find_portno(br);
if (index < 0)
return ERR_PTR(index);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL)
return ERR_PTR(-ENOMEM);
p->br = br;
dev_hold(dev);
p->dev = dev;
p->path_cost = port_cost(dev);
p->priority = 0x8000 >> BR_PORT_BITS;
p->port_no = index;
p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
br_init_port(p);
br_set_state(p, BR_STATE_DISABLED);
br_stp_port_timer_init(p);
err = br_multicast_add_port(p);
if (err) {
dev_put(dev);
kfree(p);
p = ERR_PTR(err);
}
return p;
}
int br_add_bridge(struct net *net, const char *name)
{
struct net_device *dev;
int res;
dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
br_dev_setup);
if (!dev)
return -ENOMEM;
dev_net_set(dev, net);
dev->rtnl_link_ops = &br_link_ops;
res = register_netdev(dev);
if (res)
free_netdev(dev);
return res;
}
int br_del_bridge(struct net *net, const char *name)
{
struct net_device *dev;
int ret = 0;
rtnl_lock();
dev = __dev_get_by_name(net, name);
if (dev == NULL)
ret = -ENXIO; /* Could not find device */
else if (!(dev->priv_flags & IFF_EBRIDGE)) {
/* Attempt to delete non bridge device! */
ret = -EPERM;
}
else if (dev->flags & IFF_UP) {
/* Not shutdown yet. */
ret = -EBUSY;
}
else
br_dev_delete(dev, NULL);
rtnl_unlock();
return ret;
}
/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
static int br_mtu_min(const struct net_bridge *br)
{
const struct net_bridge_port *p;
int ret_mtu = 0;
list_for_each_entry(p, &br->port_list, list)
if (!ret_mtu || ret_mtu > p->dev->mtu)
ret_mtu = p->dev->mtu;
return ret_mtu ? ret_mtu : ETH_DATA_LEN;
}
void br_mtu_auto_adjust(struct net_bridge *br)
{
ASSERT_RTNL();
/* if the bridge MTU was manually configured don't mess with it */
if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
return;
/* change to the minimum MTU and clear the flag which was set by
* the bridge ndo_change_mtu callback
*/
dev_set_mtu(br->dev, br_mtu_min(br));
br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
}
static void br_set_gso_limits(struct net_bridge *br)
{
unsigned int gso_max_size = GSO_MAX_SIZE;
u16 gso_max_segs = GSO_MAX_SEGS;
const struct net_bridge_port *p;
list_for_each_entry(p, &br->port_list, list) {
gso_max_size = min(gso_max_size, p->dev->gso_max_size);
gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
}
br->dev->gso_max_size = gso_max_size;
br->dev->gso_max_segs = gso_max_segs;
}
/*
* Recomputes features using slave's features
*/
netdev_features_t br_features_recompute(struct net_bridge *br,
netdev_features_t features)
{
struct net_bridge_port *p;
netdev_features_t mask;
if (list_empty(&br->port_list))
return features;
mask = features;
features &= ~NETIF_F_ONE_FOR_ALL;
list_for_each_entry(p, &br->port_list, list) {
features = netdev_increment_features(features,
p->dev->features, mask);
}
features = netdev_add_tso_features(features, mask);
return features;
}
/* called with RTNL */
int br_add_if(struct net_bridge *br, struct net_device *dev,
struct netlink_ext_ack *extack)
{
struct net_bridge_port *p;
int err = 0;
unsigned br_hr, dev_hr;
bool changed_addr;
/* Don't allow bridging non-ethernet like devices, or DSA-enabled
* master network devices since the bridge layer rx_handler prevents
* the DSA fake ethertype handler to be invoked, so we do not strip off
* the DSA switch tag protocol header and the bridge layer just return
* RX_HANDLER_CONSUMED, stopping RX processing for these frames.
*/
if ((dev->flags & IFF_LOOPBACK) ||
dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
!is_valid_ether_addr(dev->dev_addr) ||
netdev_uses_dsa(dev))
return -EINVAL;
/* No bridging of bridges */
if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
NL_SET_ERR_MSG(extack,
"Can not enslave a bridge to a bridge");
return -ELOOP;
}
/* Device has master upper dev */
if (netdev_master_upper_dev_get(dev))
return -EBUSY;
/* No bridging devices that dislike that (e.g. wireless) */
if (dev->priv_flags & IFF_DONT_BRIDGE) {
NL_SET_ERR_MSG(extack,
"Device does not allow enslaving to a bridge");
return -EOPNOTSUPP;
}
p = new_nbp(br, dev);
if (IS_ERR(p))
return PTR_ERR(p);
call_netdevice_notifiers(NETDEV_JOIN, dev);
err = dev_set_allmulti(dev, 1);
if (err) {
kfree(p); /* kobject not yet init'd, manually free */
goto err1;
}
err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
SYSFS_BRIDGE_PORT_ATTR);
if (err)
goto err2;
err = br_sysfs_addif(p);
if (err)
goto err2;
err = br_netpoll_enable(p);
if (err)
goto err3;
err = netdev_rx_handler_register(dev, br_handle_frame, p);
if (err)
goto err4;
dev->priv_flags |= IFF_BRIDGE_PORT;
err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
if (err)
goto err5;
err = nbp_switchdev_mark_set(p);
if (err)
goto err6;
dev_disable_lro(dev);
list_add_rcu(&p->list, &br->port_list);
nbp_update_port_count(br);
netdev_update_features(br->dev);
br_hr = br->dev->needed_headroom;
dev_hr = netdev_get_fwd_headroom(dev);
if (br_hr < dev_hr)
update_headroom(br, dev_hr);
else
netdev_set_rx_headroom(dev, br_hr);
if (br_fdb_insert(br, p, dev->dev_addr, 0))
netdev_err(dev, "failed insert local address bridge forwarding table\n");
if (br->dev->addr_assign_type != NET_ADDR_SET) {
/* Ask for permission to use this MAC address now, even if we
* don't end up choosing it below.
*/
err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
if (err)
goto err7;
}
err = nbp_vlan_init(p, extack);
if (err) {
netdev_err(dev, "failed to initialize vlan filtering on this port\n");
goto err7;
}
spin_lock_bh(&br->lock);
changed_addr = br_stp_recalculate_bridge_id(br);
if (netif_running(dev) && netif_oper_up(dev) &&
(br->dev->flags & IFF_UP))
br_stp_enable_port(p);
spin_unlock_bh(&br->lock);
br_ifinfo_notify(RTM_NEWLINK, NULL, p);
if (changed_addr)
call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
br_mtu_auto_adjust(br);
br_set_gso_limits(br);
kobject_uevent(&p->kobj, KOBJ_ADD);
return 0;
err7:
list_del_rcu(&p->list);
br_fdb_delete_by_port(br, p, 0, 1);
nbp_update_port_count(br);
err6:
netdev_upper_dev_unlink(dev, br->dev);
err5:
dev->priv_flags &= ~IFF_BRIDGE_PORT;
netdev_rx_handler_unregister(dev);
err4:
br_netpoll_disable(p);
err3:
sysfs_remove_link(br->ifobj, p->dev->name);
err2:
kobject_put(&p->kobj);
dev_set_allmulti(dev, -1);
err1:
dev_put(dev);
return err;
}
/* called with RTNL */
int br_del_if(struct net_bridge *br, struct net_device *dev)
{
struct net_bridge_port *p;
bool changed_addr;
p = br_port_get_rtnl(dev);
if (!p || p->br != br)
return -EINVAL;
/* Since more than one interface can be attached to a bridge,
* there still maybe an alternate path for netconsole to use;
* therefore there is no reason for a NETDEV_RELEASE event.
*/
del_nbp(p);
br_mtu_auto_adjust(br);
br_set_gso_limits(br);
spin_lock_bh(&br->lock);
changed_addr = br_stp_recalculate_bridge_id(br);
spin_unlock_bh(&br->lock);
if (changed_addr)
call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
netdev_update_features(br->dev);
return 0;
}
void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
{
struct net_bridge *br = p->br;
if (mask & BR_AUTO_MASK)
nbp_update_port_count(br);
if (mask & BR_NEIGH_SUPPRESS)
br_recalculate_neigh_suppress_enabled(br);
}
bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
{
struct net_bridge_port *p;
p = br_port_get_rtnl_rcu(dev);
if (!p)
return false;
return p->flags & flag;
}
EXPORT_SYMBOL_GPL(br_port_flag_is_set);