1 /*
2 * L2TPv3 ethernet pseudowire driver
3 *
4 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
5 *
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.
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
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>
19 #include <linux/in.h>
20 #include <linux/etherdevice.h>
21 #include <linux/spinlock.h>
22 #include <net/sock.h>
23 #include <net/ip.h>
24 #include <net/icmp.h>
25 #include <net/udp.h>
26 #include <net/inet_common.h>
27 #include <net/inet_hashtables.h>
28 #include <net/tcp_states.h>
29 #include <net/protocol.h>
30 #include <net/xfrm.h>
31 #include <net/net_namespace.h>
32 #include <net/netns/generic.h>
33
34 #include "l2tp_core.h"
35
36 /* Default device name. May be overridden by name specified by user */
37 #define L2TP_ETH_DEV_NAME "l2tpeth%d"
38
39 /* via netdev_priv() */
40 struct l2tp_eth {
41 struct net_device *dev;
42 struct sock *tunnel_sock;
43 struct l2tp_session *session;
44 struct list_head list;
45 atomic_long_t tx_bytes;
46 atomic_long_t tx_packets;
47 atomic_long_t tx_dropped;
48 atomic_long_t rx_bytes;
49 atomic_long_t rx_packets;
50 atomic_long_t rx_errors;
51 };
52
53 /* via l2tp_session_priv() */
54 struct l2tp_eth_sess {
55 struct net_device *dev;
56 };
57
58 /* per-net private data for this module */
59 static unsigned int l2tp_eth_net_id;
60 struct l2tp_eth_net {
61 struct list_head l2tp_eth_dev_list;
62 spinlock_t l2tp_eth_lock;
63 };
64
l2tp_eth_pernet(struct net * net)65 static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
66 {
67 return net_generic(net, l2tp_eth_net_id);
68 }
69
l2tp_eth_dev_init(struct net_device * dev)70 static int l2tp_eth_dev_init(struct net_device *dev)
71 {
72 struct l2tp_eth *priv = netdev_priv(dev);
73
74 priv->dev = dev;
75 eth_hw_addr_random(dev);
76 eth_broadcast_addr(dev->broadcast);
77 netdev_lockdep_set_classes(dev);
78
79 return 0;
80 }
81
l2tp_eth_dev_uninit(struct net_device * dev)82 static void l2tp_eth_dev_uninit(struct net_device *dev)
83 {
84 struct l2tp_eth *priv = netdev_priv(dev);
85 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
86
87 spin_lock(&pn->l2tp_eth_lock);
88 list_del_init(&priv->list);
89 spin_unlock(&pn->l2tp_eth_lock);
90 dev_put(dev);
91 }
92
l2tp_eth_dev_xmit(struct sk_buff * skb,struct net_device * dev)93 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
94 {
95 struct l2tp_eth *priv = netdev_priv(dev);
96 struct l2tp_session *session = priv->session;
97 unsigned int len = skb->len;
98 int ret = l2tp_xmit_skb(session, skb, session->hdr_len);
99
100 if (likely(ret == NET_XMIT_SUCCESS)) {
101 atomic_long_add(len, &priv->tx_bytes);
102 atomic_long_inc(&priv->tx_packets);
103 } else {
104 atomic_long_inc(&priv->tx_dropped);
105 }
106 return NETDEV_TX_OK;
107 }
108
l2tp_eth_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * stats)109 static struct rtnl_link_stats64 *l2tp_eth_get_stats64(struct net_device *dev,
110 struct rtnl_link_stats64 *stats)
111 {
112 struct l2tp_eth *priv = netdev_priv(dev);
113
114 stats->tx_bytes = atomic_long_read(&priv->tx_bytes);
115 stats->tx_packets = atomic_long_read(&priv->tx_packets);
116 stats->tx_dropped = atomic_long_read(&priv->tx_dropped);
117 stats->rx_bytes = atomic_long_read(&priv->rx_bytes);
118 stats->rx_packets = atomic_long_read(&priv->rx_packets);
119 stats->rx_errors = atomic_long_read(&priv->rx_errors);
120 return stats;
121 }
122
123
124 static const struct net_device_ops l2tp_eth_netdev_ops = {
125 .ndo_init = l2tp_eth_dev_init,
126 .ndo_uninit = l2tp_eth_dev_uninit,
127 .ndo_start_xmit = l2tp_eth_dev_xmit,
128 .ndo_get_stats64 = l2tp_eth_get_stats64,
129 .ndo_set_mac_address = eth_mac_addr,
130 };
131
l2tp_eth_dev_setup(struct net_device * dev)132 static void l2tp_eth_dev_setup(struct net_device *dev)
133 {
134 ether_setup(dev);
135 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
136 dev->features |= NETIF_F_LLTX;
137 dev->netdev_ops = &l2tp_eth_netdev_ops;
138 dev->destructor = free_netdev;
139 }
140
l2tp_eth_dev_recv(struct l2tp_session * session,struct sk_buff * skb,int data_len)141 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
142 {
143 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
144 struct net_device *dev = spriv->dev;
145 struct l2tp_eth *priv = netdev_priv(dev);
146
147 if (session->debug & L2TP_MSG_DATA) {
148 unsigned int length;
149
150 length = min(32u, skb->len);
151 if (!pskb_may_pull(skb, length))
152 goto error;
153
154 pr_debug("%s: eth recv\n", session->name);
155 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
156 }
157
158 if (!pskb_may_pull(skb, ETH_HLEN))
159 goto error;
160
161 secpath_reset(skb);
162
163 /* checksums verified by L2TP */
164 skb->ip_summed = CHECKSUM_NONE;
165
166 skb_dst_drop(skb);
167 nf_reset(skb);
168
169 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
170 atomic_long_inc(&priv->rx_packets);
171 atomic_long_add(data_len, &priv->rx_bytes);
172 } else {
173 atomic_long_inc(&priv->rx_errors);
174 }
175 return;
176
177 error:
178 atomic_long_inc(&priv->rx_errors);
179 kfree_skb(skb);
180 }
181
l2tp_eth_delete(struct l2tp_session * session)182 static void l2tp_eth_delete(struct l2tp_session *session)
183 {
184 struct l2tp_eth_sess *spriv;
185 struct net_device *dev;
186
187 if (session) {
188 spriv = l2tp_session_priv(session);
189 dev = spriv->dev;
190 if (dev) {
191 unregister_netdev(dev);
192 spriv->dev = NULL;
193 module_put(THIS_MODULE);
194 }
195 }
196 }
197
198 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
l2tp_eth_show(struct seq_file * m,void * arg)199 static void l2tp_eth_show(struct seq_file *m, void *arg)
200 {
201 struct l2tp_session *session = arg;
202 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
203 struct net_device *dev = spriv->dev;
204
205 seq_printf(m, " interface %s\n", dev->name);
206 }
207 #endif
208
l2tp_eth_create(struct net * net,u32 tunnel_id,u32 session_id,u32 peer_session_id,struct l2tp_session_cfg * cfg)209 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
210 {
211 struct net_device *dev;
212 char name[IFNAMSIZ];
213 struct l2tp_tunnel *tunnel;
214 struct l2tp_session *session;
215 struct l2tp_eth *priv;
216 struct l2tp_eth_sess *spriv;
217 int rc;
218 struct l2tp_eth_net *pn;
219
220 tunnel = l2tp_tunnel_find(net, tunnel_id);
221 if (!tunnel) {
222 rc = -ENODEV;
223 goto out;
224 }
225
226 if (cfg->ifname) {
227 dev = dev_get_by_name(net, cfg->ifname);
228 if (dev) {
229 dev_put(dev);
230 rc = -EEXIST;
231 goto out;
232 }
233 strlcpy(name, cfg->ifname, IFNAMSIZ);
234 } else
235 strcpy(name, L2TP_ETH_DEV_NAME);
236
237 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
238 peer_session_id, cfg);
239 if (IS_ERR(session)) {
240 rc = PTR_ERR(session);
241 goto out;
242 }
243
244 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN,
245 l2tp_eth_dev_setup);
246 if (!dev) {
247 rc = -ENOMEM;
248 goto out_del_session;
249 }
250
251 dev_net_set(dev, net);
252 if (session->mtu == 0)
253 session->mtu = dev->mtu - session->hdr_len;
254 dev->mtu = session->mtu;
255 dev->needed_headroom += session->hdr_len;
256
257 priv = netdev_priv(dev);
258 priv->dev = dev;
259 priv->session = session;
260 INIT_LIST_HEAD(&priv->list);
261
262 priv->tunnel_sock = tunnel->sock;
263 session->recv_skb = l2tp_eth_dev_recv;
264 session->session_close = l2tp_eth_delete;
265 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
266 session->show = l2tp_eth_show;
267 #endif
268
269 spriv = l2tp_session_priv(session);
270 spriv->dev = dev;
271
272 rc = register_netdev(dev);
273 if (rc < 0)
274 goto out_del_dev;
275
276 __module_get(THIS_MODULE);
277 /* Must be done after register_netdev() */
278 strlcpy(session->ifname, dev->name, IFNAMSIZ);
279
280 dev_hold(dev);
281 pn = l2tp_eth_pernet(dev_net(dev));
282 spin_lock(&pn->l2tp_eth_lock);
283 list_add(&priv->list, &pn->l2tp_eth_dev_list);
284 spin_unlock(&pn->l2tp_eth_lock);
285
286 return 0;
287
288 out_del_dev:
289 free_netdev(dev);
290 spriv->dev = NULL;
291 out_del_session:
292 l2tp_session_delete(session);
293 out:
294 return rc;
295 }
296
l2tp_eth_init_net(struct net * net)297 static __net_init int l2tp_eth_init_net(struct net *net)
298 {
299 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
300
301 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
302 spin_lock_init(&pn->l2tp_eth_lock);
303
304 return 0;
305 }
306
307 static struct pernet_operations l2tp_eth_net_ops = {
308 .init = l2tp_eth_init_net,
309 .id = &l2tp_eth_net_id,
310 .size = sizeof(struct l2tp_eth_net),
311 };
312
313
314 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
315 .session_create = l2tp_eth_create,
316 .session_delete = l2tp_session_delete,
317 };
318
319
l2tp_eth_init(void)320 static int __init l2tp_eth_init(void)
321 {
322 int err = 0;
323
324 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
325 if (err)
326 goto out;
327
328 err = register_pernet_device(&l2tp_eth_net_ops);
329 if (err)
330 goto out_unreg;
331
332 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
333
334 return 0;
335
336 out_unreg:
337 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
338 out:
339 return err;
340 }
341
l2tp_eth_exit(void)342 static void __exit l2tp_eth_exit(void)
343 {
344 unregister_pernet_device(&l2tp_eth_net_ops);
345 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
346 }
347
348 module_init(l2tp_eth_init);
349 module_exit(l2tp_eth_exit);
350
351 MODULE_LICENSE("GPL");
352 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
353 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
354 MODULE_VERSION("1.0");
355 MODULE_ALIAS_L2TP_PWTYPE(5);
356