mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Tom Parkin](/assets/img/avatar_default.png)
All callers pass the session structure's hdr_len field as the header length parameter to l2tp_xmit_skb. Since we're passing a pointer to the session structure to l2tp_xmit_skb anyway, there's not much point breaking the header length out as a separate argument. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
370 lines
8.4 KiB
C
370 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* L2TPv3 ethernet pseudowire driver
|
|
*
|
|
* Copyright (c) 2008,2009,2010 Katalix Systems Ltd
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/socket.h>
|
|
#include <linux/hash.h>
|
|
#include <linux/l2tp.h>
|
|
#include <linux/in.h>
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/spinlock.h>
|
|
#include <net/sock.h>
|
|
#include <net/ip.h>
|
|
#include <net/icmp.h>
|
|
#include <net/udp.h>
|
|
#include <net/inet_common.h>
|
|
#include <net/inet_hashtables.h>
|
|
#include <net/tcp_states.h>
|
|
#include <net/protocol.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/net_namespace.h>
|
|
#include <net/netns/generic.h>
|
|
#include <linux/ip.h>
|
|
#include <linux/ipv6.h>
|
|
#include <linux/udp.h>
|
|
|
|
#include "l2tp_core.h"
|
|
|
|
/* Default device name. May be overridden by name specified by user */
|
|
#define L2TP_ETH_DEV_NAME "l2tpeth%d"
|
|
|
|
/* via netdev_priv() */
|
|
struct l2tp_eth {
|
|
struct l2tp_session *session;
|
|
atomic_long_t tx_bytes;
|
|
atomic_long_t tx_packets;
|
|
atomic_long_t tx_dropped;
|
|
atomic_long_t rx_bytes;
|
|
atomic_long_t rx_packets;
|
|
atomic_long_t rx_errors;
|
|
};
|
|
|
|
/* via l2tp_session_priv() */
|
|
struct l2tp_eth_sess {
|
|
struct net_device __rcu *dev;
|
|
};
|
|
|
|
static int l2tp_eth_dev_init(struct net_device *dev)
|
|
{
|
|
eth_hw_addr_random(dev);
|
|
eth_broadcast_addr(dev->broadcast);
|
|
netdev_lockdep_set_classes(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void l2tp_eth_dev_uninit(struct net_device *dev)
|
|
{
|
|
struct l2tp_eth *priv = netdev_priv(dev);
|
|
struct l2tp_eth_sess *spriv;
|
|
|
|
spriv = l2tp_session_priv(priv->session);
|
|
RCU_INIT_POINTER(spriv->dev, NULL);
|
|
/* No need for synchronize_net() here. We're called by
|
|
* unregister_netdev*(), which does the synchronisation for us.
|
|
*/
|
|
}
|
|
|
|
static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
|
|
{
|
|
struct l2tp_eth *priv = netdev_priv(dev);
|
|
struct l2tp_session *session = priv->session;
|
|
unsigned int len = skb->len;
|
|
int ret = l2tp_xmit_skb(session, skb);
|
|
|
|
if (likely(ret == NET_XMIT_SUCCESS)) {
|
|
atomic_long_add(len, &priv->tx_bytes);
|
|
atomic_long_inc(&priv->tx_packets);
|
|
} else {
|
|
atomic_long_inc(&priv->tx_dropped);
|
|
}
|
|
return NETDEV_TX_OK;
|
|
}
|
|
|
|
static void l2tp_eth_get_stats64(struct net_device *dev,
|
|
struct rtnl_link_stats64 *stats)
|
|
{
|
|
struct l2tp_eth *priv = netdev_priv(dev);
|
|
|
|
stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes);
|
|
stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets);
|
|
stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped);
|
|
stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes);
|
|
stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets);
|
|
stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors);
|
|
}
|
|
|
|
static const struct net_device_ops l2tp_eth_netdev_ops = {
|
|
.ndo_init = l2tp_eth_dev_init,
|
|
.ndo_uninit = l2tp_eth_dev_uninit,
|
|
.ndo_start_xmit = l2tp_eth_dev_xmit,
|
|
.ndo_get_stats64 = l2tp_eth_get_stats64,
|
|
.ndo_set_mac_address = eth_mac_addr,
|
|
};
|
|
|
|
static struct device_type l2tpeth_type = {
|
|
.name = "l2tpeth",
|
|
};
|
|
|
|
static void l2tp_eth_dev_setup(struct net_device *dev)
|
|
{
|
|
SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
|
|
ether_setup(dev);
|
|
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
|
|
dev->features |= NETIF_F_LLTX;
|
|
dev->netdev_ops = &l2tp_eth_netdev_ops;
|
|
dev->needs_free_netdev = true;
|
|
}
|
|
|
|
static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
|
|
{
|
|
struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
|
|
struct net_device *dev;
|
|
struct l2tp_eth *priv;
|
|
|
|
if (!pskb_may_pull(skb, ETH_HLEN))
|
|
goto error;
|
|
|
|
secpath_reset(skb);
|
|
|
|
/* checksums verified by L2TP */
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
|
|
skb_dst_drop(skb);
|
|
nf_reset_ct(skb);
|
|
|
|
rcu_read_lock();
|
|
dev = rcu_dereference(spriv->dev);
|
|
if (!dev)
|
|
goto error_rcu;
|
|
|
|
priv = netdev_priv(dev);
|
|
if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
|
|
atomic_long_inc(&priv->rx_packets);
|
|
atomic_long_add(data_len, &priv->rx_bytes);
|
|
} else {
|
|
atomic_long_inc(&priv->rx_errors);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return;
|
|
|
|
error_rcu:
|
|
rcu_read_unlock();
|
|
error:
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
static void l2tp_eth_delete(struct l2tp_session *session)
|
|
{
|
|
struct l2tp_eth_sess *spriv;
|
|
struct net_device *dev;
|
|
|
|
if (session) {
|
|
spriv = l2tp_session_priv(session);
|
|
|
|
rtnl_lock();
|
|
dev = rtnl_dereference(spriv->dev);
|
|
if (dev) {
|
|
unregister_netdevice(dev);
|
|
rtnl_unlock();
|
|
module_put(THIS_MODULE);
|
|
} else {
|
|
rtnl_unlock();
|
|
}
|
|
}
|
|
}
|
|
|
|
static void l2tp_eth_show(struct seq_file *m, void *arg)
|
|
{
|
|
struct l2tp_session *session = arg;
|
|
struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
|
|
struct net_device *dev;
|
|
|
|
rcu_read_lock();
|
|
dev = rcu_dereference(spriv->dev);
|
|
if (!dev) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
dev_hold(dev);
|
|
rcu_read_unlock();
|
|
|
|
seq_printf(m, " interface %s\n", dev->name);
|
|
|
|
dev_put(dev);
|
|
}
|
|
|
|
static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
|
|
struct l2tp_session *session,
|
|
struct net_device *dev)
|
|
{
|
|
unsigned int overhead = 0;
|
|
u32 l3_overhead = 0;
|
|
u32 mtu;
|
|
|
|
/* if the encap is UDP, account for UDP header size */
|
|
if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
|
|
overhead += sizeof(struct udphdr);
|
|
dev->needed_headroom += sizeof(struct udphdr);
|
|
}
|
|
|
|
lock_sock(tunnel->sock);
|
|
l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
|
|
release_sock(tunnel->sock);
|
|
|
|
if (l3_overhead == 0) {
|
|
/* L3 Overhead couldn't be identified, this could be
|
|
* because tunnel->sock was NULL or the socket's
|
|
* address family was not IPv4 or IPv6,
|
|
* dev mtu stays at 1500.
|
|
*/
|
|
return;
|
|
}
|
|
/* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
|
|
* UDP overhead, if any, was already factored in above.
|
|
*/
|
|
overhead += session->hdr_len + ETH_HLEN + l3_overhead;
|
|
|
|
mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
|
|
if (mtu < dev->min_mtu || mtu > dev->max_mtu)
|
|
dev->mtu = ETH_DATA_LEN - overhead;
|
|
else
|
|
dev->mtu = mtu;
|
|
|
|
dev->needed_headroom += session->hdr_len;
|
|
}
|
|
|
|
static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
|
|
u32 session_id, u32 peer_session_id,
|
|
struct l2tp_session_cfg *cfg)
|
|
{
|
|
unsigned char name_assign_type;
|
|
struct net_device *dev;
|
|
char name[IFNAMSIZ];
|
|
struct l2tp_session *session;
|
|
struct l2tp_eth *priv;
|
|
struct l2tp_eth_sess *spriv;
|
|
int rc;
|
|
|
|
if (cfg->ifname) {
|
|
strlcpy(name, cfg->ifname, IFNAMSIZ);
|
|
name_assign_type = NET_NAME_USER;
|
|
} else {
|
|
strcpy(name, L2TP_ETH_DEV_NAME);
|
|
name_assign_type = NET_NAME_ENUM;
|
|
}
|
|
|
|
session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
|
|
peer_session_id, cfg);
|
|
if (IS_ERR(session)) {
|
|
rc = PTR_ERR(session);
|
|
goto err;
|
|
}
|
|
|
|
dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
|
|
l2tp_eth_dev_setup);
|
|
if (!dev) {
|
|
rc = -ENOMEM;
|
|
goto err_sess;
|
|
}
|
|
|
|
dev_net_set(dev, net);
|
|
dev->min_mtu = 0;
|
|
dev->max_mtu = ETH_MAX_MTU;
|
|
l2tp_eth_adjust_mtu(tunnel, session, dev);
|
|
|
|
priv = netdev_priv(dev);
|
|
priv->session = session;
|
|
|
|
session->recv_skb = l2tp_eth_dev_recv;
|
|
session->session_close = l2tp_eth_delete;
|
|
if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
|
|
session->show = l2tp_eth_show;
|
|
|
|
spriv = l2tp_session_priv(session);
|
|
|
|
l2tp_session_inc_refcount(session);
|
|
|
|
rtnl_lock();
|
|
|
|
/* Register both device and session while holding the rtnl lock. This
|
|
* ensures that l2tp_eth_delete() will see that there's a device to
|
|
* unregister, even if it happened to run before we assign spriv->dev.
|
|
*/
|
|
rc = l2tp_session_register(session, tunnel);
|
|
if (rc < 0) {
|
|
rtnl_unlock();
|
|
goto err_sess_dev;
|
|
}
|
|
|
|
rc = register_netdevice(dev);
|
|
if (rc < 0) {
|
|
rtnl_unlock();
|
|
l2tp_session_delete(session);
|
|
l2tp_session_dec_refcount(session);
|
|
free_netdev(dev);
|
|
|
|
return rc;
|
|
}
|
|
|
|
strlcpy(session->ifname, dev->name, IFNAMSIZ);
|
|
rcu_assign_pointer(spriv->dev, dev);
|
|
|
|
rtnl_unlock();
|
|
|
|
l2tp_session_dec_refcount(session);
|
|
|
|
__module_get(THIS_MODULE);
|
|
|
|
return 0;
|
|
|
|
err_sess_dev:
|
|
l2tp_session_dec_refcount(session);
|
|
free_netdev(dev);
|
|
err_sess:
|
|
kfree(session);
|
|
err:
|
|
return rc;
|
|
}
|
|
|
|
static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
|
|
.session_create = l2tp_eth_create,
|
|
.session_delete = l2tp_session_delete,
|
|
};
|
|
|
|
static int __init l2tp_eth_init(void)
|
|
{
|
|
int err = 0;
|
|
|
|
err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
|
|
if (err)
|
|
goto err;
|
|
|
|
pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
|
|
|
|
return 0;
|
|
|
|
err:
|
|
return err;
|
|
}
|
|
|
|
static void __exit l2tp_eth_exit(void)
|
|
{
|
|
l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
|
|
}
|
|
|
|
module_init(l2tp_eth_init);
|
|
module_exit(l2tp_eth_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
|
|
MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
|
|
MODULE_VERSION("1.0");
|
|
MODULE_ALIAS_L2TP_PWTYPE(5);
|