2 * L2TPv3 ethernet pseudowire driver
4 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/socket.h>
17 #include <linux/hash.h>
18 #include <linux/l2tp.h>
20 #include <linux/etherdevice.h>
21 #include <linux/spinlock.h>
26 #include <net/inet_common.h>
27 #include <net/inet_hashtables.h>
28 #include <net/tcp_states.h>
29 #include <net/protocol.h>
31 #include <net/net_namespace.h>
32 #include <net/netns/generic.h>
34 #include <linux/ipv6.h>
35 #include <linux/udp.h>
37 #include "l2tp_core.h"
39 /* Default device name. May be overridden by name specified by user */
40 #define L2TP_ETH_DEV_NAME "l2tpeth%d"
42 /* via netdev_priv() */
44 struct net_device *dev;
45 struct sock *tunnel_sock;
46 struct l2tp_session *session;
47 struct list_head list;
48 atomic_long_t tx_bytes;
49 atomic_long_t tx_packets;
50 atomic_long_t tx_dropped;
51 atomic_long_t rx_bytes;
52 atomic_long_t rx_packets;
53 atomic_long_t rx_errors;
56 /* via l2tp_session_priv() */
57 struct l2tp_eth_sess {
58 struct net_device *dev;
61 /* per-net private data for this module */
62 static unsigned int l2tp_eth_net_id;
64 struct list_head l2tp_eth_dev_list;
65 spinlock_t l2tp_eth_lock;
68 static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
70 return net_generic(net, l2tp_eth_net_id);
73 static int l2tp_eth_dev_init(struct net_device *dev)
75 struct l2tp_eth *priv = netdev_priv(dev);
78 eth_hw_addr_random(dev);
79 eth_broadcast_addr(dev->broadcast);
80 netdev_lockdep_set_classes(dev);
85 static void l2tp_eth_dev_uninit(struct net_device *dev)
87 struct l2tp_eth *priv = netdev_priv(dev);
88 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
90 spin_lock(&pn->l2tp_eth_lock);
91 list_del_init(&priv->list);
92 spin_unlock(&pn->l2tp_eth_lock);
96 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
98 struct l2tp_eth *priv = netdev_priv(dev);
99 struct l2tp_session *session = priv->session;
100 unsigned int len = skb->len;
101 int ret = l2tp_xmit_skb(session, skb, session->hdr_len);
103 if (likely(ret == NET_XMIT_SUCCESS)) {
104 atomic_long_add(len, &priv->tx_bytes);
105 atomic_long_inc(&priv->tx_packets);
107 atomic_long_inc(&priv->tx_dropped);
112 static void l2tp_eth_get_stats64(struct net_device *dev,
113 struct rtnl_link_stats64 *stats)
115 struct l2tp_eth *priv = netdev_priv(dev);
117 stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes);
118 stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
119 stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
120 stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes);
121 stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
122 stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors);
126 static const struct net_device_ops l2tp_eth_netdev_ops = {
127 .ndo_init = l2tp_eth_dev_init,
128 .ndo_uninit = l2tp_eth_dev_uninit,
129 .ndo_start_xmit = l2tp_eth_dev_xmit,
130 .ndo_get_stats64 = l2tp_eth_get_stats64,
131 .ndo_set_mac_address = eth_mac_addr,
134 static struct device_type l2tpeth_type = {
138 static void l2tp_eth_dev_setup(struct net_device *dev)
140 SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
142 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
143 dev->features |= NETIF_F_LLTX;
144 dev->netdev_ops = &l2tp_eth_netdev_ops;
145 dev->needs_free_netdev = true;
148 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
150 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
151 struct net_device *dev = spriv->dev;
152 struct l2tp_eth *priv = netdev_priv(dev);
154 if (session->debug & L2TP_MSG_DATA) {
157 length = min(32u, skb->len);
158 if (!pskb_may_pull(skb, length))
161 pr_debug("%s: eth recv\n", session->name);
162 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
165 if (!pskb_may_pull(skb, ETH_HLEN))
170 /* checksums verified by L2TP */
171 skb->ip_summed = CHECKSUM_NONE;
176 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
177 atomic_long_inc(&priv->rx_packets);
178 atomic_long_add(data_len, &priv->rx_bytes);
180 atomic_long_inc(&priv->rx_errors);
185 atomic_long_inc(&priv->rx_errors);
189 static void l2tp_eth_delete(struct l2tp_session *session)
191 struct l2tp_eth_sess *spriv;
192 struct net_device *dev;
195 spriv = l2tp_session_priv(session);
198 unregister_netdev(dev);
200 module_put(THIS_MODULE);
205 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
206 static void l2tp_eth_show(struct seq_file *m, void *arg)
208 struct l2tp_session *session = arg;
209 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
210 struct net_device *dev = spriv->dev;
212 seq_printf(m, " interface %s\n", dev->name);
216 static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
217 struct l2tp_session *session,
218 struct net_device *dev)
220 unsigned int overhead = 0;
221 struct dst_entry *dst;
224 /* if the encap is UDP, account for UDP header size */
225 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
226 overhead += sizeof(struct udphdr);
227 dev->needed_headroom += sizeof(struct udphdr);
229 if (session->mtu != 0) {
230 dev->mtu = session->mtu;
231 dev->needed_headroom += session->hdr_len;
234 lock_sock(tunnel->sock);
235 l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
236 release_sock(tunnel->sock);
237 if (l3_overhead == 0) {
238 /* L3 Overhead couldn't be identified, this could be
239 * because tunnel->sock was NULL or the socket's
240 * address family was not IPv4 or IPv6,
241 * dev mtu stays at 1500.
245 /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
246 * UDP overhead, if any, was already factored in above.
248 overhead += session->hdr_len + ETH_HLEN + l3_overhead;
250 /* If PMTU discovery was enabled, use discovered MTU on L2TP device */
251 dst = sk_dst_get(tunnel->sock);
253 /* dst_mtu will use PMTU if found, else fallback to intf MTU */
254 u32 pmtu = dst_mtu(dst);
260 session->mtu = dev->mtu - overhead;
261 dev->mtu = session->mtu;
262 dev->needed_headroom += session->hdr_len;
265 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
267 unsigned char name_assign_type;
268 struct net_device *dev;
270 struct l2tp_tunnel *tunnel;
271 struct l2tp_session *session;
272 struct l2tp_eth *priv;
273 struct l2tp_eth_sess *spriv;
275 struct l2tp_eth_net *pn;
277 tunnel = l2tp_tunnel_find(net, tunnel_id);
284 strlcpy(name, cfg->ifname, IFNAMSIZ);
285 name_assign_type = NET_NAME_USER;
287 strcpy(name, L2TP_ETH_DEV_NAME);
288 name_assign_type = NET_NAME_ENUM;
291 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
292 peer_session_id, cfg);
293 if (IS_ERR(session)) {
294 rc = PTR_ERR(session);
298 dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
302 goto out_del_session;
305 dev_net_set(dev, net);
307 dev->max_mtu = ETH_MAX_MTU;
308 l2tp_eth_adjust_mtu(tunnel, session, dev);
310 priv = netdev_priv(dev);
312 priv->session = session;
313 INIT_LIST_HEAD(&priv->list);
315 priv->tunnel_sock = tunnel->sock;
316 session->recv_skb = l2tp_eth_dev_recv;
317 session->session_close = l2tp_eth_delete;
318 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
319 session->show = l2tp_eth_show;
322 spriv = l2tp_session_priv(session);
325 rc = register_netdev(dev);
329 __module_get(THIS_MODULE);
330 /* Must be done after register_netdev() */
331 strlcpy(session->ifname, dev->name, IFNAMSIZ);
334 pn = l2tp_eth_pernet(dev_net(dev));
335 spin_lock(&pn->l2tp_eth_lock);
336 list_add(&priv->list, &pn->l2tp_eth_dev_list);
337 spin_unlock(&pn->l2tp_eth_lock);
345 l2tp_session_delete(session);
350 static __net_init int l2tp_eth_init_net(struct net *net)
352 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
354 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
355 spin_lock_init(&pn->l2tp_eth_lock);
360 static struct pernet_operations l2tp_eth_net_ops = {
361 .init = l2tp_eth_init_net,
362 .id = &l2tp_eth_net_id,
363 .size = sizeof(struct l2tp_eth_net),
367 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
368 .session_create = l2tp_eth_create,
369 .session_delete = l2tp_session_delete,
373 static int __init l2tp_eth_init(void)
377 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
381 err = register_pernet_device(&l2tp_eth_net_ops);
385 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
390 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
395 static void __exit l2tp_eth_exit(void)
397 unregister_pernet_device(&l2tp_eth_net_ops);
398 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
401 module_init(l2tp_eth_init);
402 module_exit(l2tp_eth_exit);
404 MODULE_LICENSE("GPL");
405 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
406 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
407 MODULE_VERSION("1.0");
408 MODULE_ALIAS_L2TP_PWTYPE(5);