mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
fd2f473787
In order to fix the data-race found by KCSAN, we can use the new u64_stats_t type and its accessors instead of plain u64 fields. This will still generate optimal code for both 32 and 64 bit platforms. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
277 lines
7 KiB
C
277 lines
7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* INET An implementation of the TCP/IP protocol suite for the LINUX
|
|
* operating system. INET is implemented using the BSD Socket
|
|
* interface as the means of communication with the user level.
|
|
*
|
|
* Pseudo-driver for the loopback interface.
|
|
*
|
|
* Version: @(#)loopback.c 1.0.4b 08/16/93
|
|
*
|
|
* Authors: Ross Biro
|
|
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
|
|
* Donald Becker, <becker@scyld.com>
|
|
*
|
|
* Alan Cox : Fixed oddments for NET3.014
|
|
* Alan Cox : Rejig for NET3.029 snap #3
|
|
* Alan Cox : Fixed NET3.029 bugs and sped up
|
|
* Larry McVoy : Tiny tweak to double performance
|
|
* Alan Cox : Backed out LMV's tweak - the linux mm
|
|
* can't take it...
|
|
* Michael Griffith: Don't bother computing the checksums
|
|
* on packets received on the loopback
|
|
* interface.
|
|
* Alexey Kuznetsov: Potential hang under some extreme
|
|
* cases removed.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/module.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/socket.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/in.h>
|
|
|
|
#include <linux/uaccess.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <linux/inet.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/ethtool.h>
|
|
#include <net/sock.h>
|
|
#include <net/checksum.h>
|
|
#include <linux/if_ether.h> /* For the statistics structure. */
|
|
#include <linux/if_arp.h> /* For ARPHRD_ETHER */
|
|
#include <linux/ip.h>
|
|
#include <linux/tcp.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/net_tstamp.h>
|
|
#include <net/net_namespace.h>
|
|
#include <linux/u64_stats_sync.h>
|
|
|
|
/* blackhole_netdev - a device used for dsts that are marked expired!
|
|
* This is global device (instead of per-net-ns) since it's not needed
|
|
* to be per-ns and gets initialized at boot time.
|
|
*/
|
|
struct net_device *blackhole_netdev;
|
|
EXPORT_SYMBOL(blackhole_netdev);
|
|
|
|
/* The higher levels take care of making this non-reentrant (it's
|
|
* called with bh's disabled).
|
|
*/
|
|
static netdev_tx_t loopback_xmit(struct sk_buff *skb,
|
|
struct net_device *dev)
|
|
{
|
|
int len;
|
|
|
|
skb_tx_timestamp(skb);
|
|
|
|
/* do not fool net_timestamp_check() with various clock bases */
|
|
skb->tstamp = 0;
|
|
|
|
skb_orphan(skb);
|
|
|
|
/* Before queueing this packet to netif_rx(),
|
|
* make sure dst is refcounted.
|
|
*/
|
|
skb_dst_force(skb);
|
|
|
|
skb->protocol = eth_type_trans(skb, dev);
|
|
|
|
len = skb->len;
|
|
if (likely(netif_rx(skb) == NET_RX_SUCCESS))
|
|
dev_lstats_add(dev, len);
|
|
|
|
return NETDEV_TX_OK;
|
|
}
|
|
|
|
void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes)
|
|
{
|
|
int i;
|
|
|
|
*packets = 0;
|
|
*bytes = 0;
|
|
|
|
for_each_possible_cpu(i) {
|
|
const struct pcpu_lstats *lb_stats;
|
|
u64 tbytes, tpackets;
|
|
unsigned int start;
|
|
|
|
lb_stats = per_cpu_ptr(dev->lstats, i);
|
|
do {
|
|
start = u64_stats_fetch_begin_irq(&lb_stats->syncp);
|
|
tpackets = u64_stats_read(&lb_stats->packets);
|
|
tbytes = u64_stats_read(&lb_stats->bytes);
|
|
} while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start));
|
|
*bytes += tbytes;
|
|
*packets += tpackets;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(dev_lstats_read);
|
|
|
|
static void loopback_get_stats64(struct net_device *dev,
|
|
struct rtnl_link_stats64 *stats)
|
|
{
|
|
u64 packets, bytes;
|
|
|
|
dev_lstats_read(dev, &packets, &bytes);
|
|
|
|
stats->rx_packets = packets;
|
|
stats->tx_packets = packets;
|
|
stats->rx_bytes = bytes;
|
|
stats->tx_bytes = bytes;
|
|
}
|
|
|
|
static u32 always_on(struct net_device *dev)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static const struct ethtool_ops loopback_ethtool_ops = {
|
|
.get_link = always_on,
|
|
.get_ts_info = ethtool_op_get_ts_info,
|
|
};
|
|
|
|
static int loopback_dev_init(struct net_device *dev)
|
|
{
|
|
dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
|
|
if (!dev->lstats)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void loopback_dev_free(struct net_device *dev)
|
|
{
|
|
dev_net(dev)->loopback_dev = NULL;
|
|
free_percpu(dev->lstats);
|
|
}
|
|
|
|
static const struct net_device_ops loopback_ops = {
|
|
.ndo_init = loopback_dev_init,
|
|
.ndo_start_xmit = loopback_xmit,
|
|
.ndo_get_stats64 = loopback_get_stats64,
|
|
.ndo_set_mac_address = eth_mac_addr,
|
|
};
|
|
|
|
static void gen_lo_setup(struct net_device *dev,
|
|
unsigned int mtu,
|
|
const struct ethtool_ops *eth_ops,
|
|
const struct header_ops *hdr_ops,
|
|
const struct net_device_ops *dev_ops,
|
|
void (*dev_destructor)(struct net_device *dev))
|
|
{
|
|
dev->mtu = mtu;
|
|
dev->hard_header_len = ETH_HLEN; /* 14 */
|
|
dev->min_header_len = ETH_HLEN; /* 14 */
|
|
dev->addr_len = ETH_ALEN; /* 6 */
|
|
dev->type = ARPHRD_LOOPBACK; /* 0x0001*/
|
|
dev->flags = IFF_LOOPBACK;
|
|
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
|
|
netif_keep_dst(dev);
|
|
dev->hw_features = NETIF_F_GSO_SOFTWARE;
|
|
dev->features = NETIF_F_SG | NETIF_F_FRAGLIST
|
|
| NETIF_F_GSO_SOFTWARE
|
|
| NETIF_F_HW_CSUM
|
|
| NETIF_F_RXCSUM
|
|
| NETIF_F_SCTP_CRC
|
|
| NETIF_F_HIGHDMA
|
|
| NETIF_F_LLTX
|
|
| NETIF_F_NETNS_LOCAL
|
|
| NETIF_F_VLAN_CHALLENGED
|
|
| NETIF_F_LOOPBACK;
|
|
dev->ethtool_ops = eth_ops;
|
|
dev->header_ops = hdr_ops;
|
|
dev->netdev_ops = dev_ops;
|
|
dev->needs_free_netdev = true;
|
|
dev->priv_destructor = dev_destructor;
|
|
}
|
|
|
|
/* The loopback device is special. There is only one instance
|
|
* per network namespace.
|
|
*/
|
|
static void loopback_setup(struct net_device *dev)
|
|
{
|
|
gen_lo_setup(dev, (64 * 1024), &loopback_ethtool_ops, ð_header_ops,
|
|
&loopback_ops, loopback_dev_free);
|
|
}
|
|
|
|
/* Setup and register the loopback device. */
|
|
static __net_init int loopback_net_init(struct net *net)
|
|
{
|
|
struct net_device *dev;
|
|
int err;
|
|
|
|
err = -ENOMEM;
|
|
dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
|
|
if (!dev)
|
|
goto out;
|
|
|
|
dev_net_set(dev, net);
|
|
err = register_netdev(dev);
|
|
if (err)
|
|
goto out_free_netdev;
|
|
|
|
BUG_ON(dev->ifindex != LOOPBACK_IFINDEX);
|
|
net->loopback_dev = dev;
|
|
return 0;
|
|
|
|
out_free_netdev:
|
|
free_netdev(dev);
|
|
out:
|
|
if (net_eq(net, &init_net))
|
|
panic("loopback: Failed to register netdevice: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
/* Registered in net/core/dev.c */
|
|
struct pernet_operations __net_initdata loopback_net_ops = {
|
|
.init = loopback_net_init,
|
|
};
|
|
|
|
/* blackhole netdevice */
|
|
static netdev_tx_t blackhole_netdev_xmit(struct sk_buff *skb,
|
|
struct net_device *dev)
|
|
{
|
|
kfree_skb(skb);
|
|
net_warn_ratelimited("%s(): Dropping skb.\n", __func__);
|
|
return NETDEV_TX_OK;
|
|
}
|
|
|
|
static const struct net_device_ops blackhole_netdev_ops = {
|
|
.ndo_start_xmit = blackhole_netdev_xmit,
|
|
};
|
|
|
|
/* This is a dst-dummy device used specifically for invalidated
|
|
* DSTs and unlike loopback, this is not per-ns.
|
|
*/
|
|
static void blackhole_netdev_setup(struct net_device *dev)
|
|
{
|
|
gen_lo_setup(dev, ETH_MIN_MTU, NULL, NULL, &blackhole_netdev_ops, NULL);
|
|
}
|
|
|
|
/* Setup and register the blackhole_netdev. */
|
|
static int __init blackhole_netdev_init(void)
|
|
{
|
|
blackhole_netdev = alloc_netdev(0, "blackhole_dev", NET_NAME_UNKNOWN,
|
|
blackhole_netdev_setup);
|
|
if (!blackhole_netdev)
|
|
return -ENOMEM;
|
|
|
|
rtnl_lock();
|
|
dev_init_scheduler(blackhole_netdev);
|
|
dev_activate(blackhole_netdev);
|
|
rtnl_unlock();
|
|
|
|
blackhole_netdev->flags |= IFF_UP | IFF_RUNNING;
|
|
dev_net_set(blackhole_netdev, &init_net);
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(blackhole_netdev_init);
|