Commit | Line | Data |
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d9e31d17 JC |
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 | ||
a4ca44fa JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
d9e31d17 JC |
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> | |
b784e7eb P |
33 | #include <linux/ip.h> |
34 | #include <linux/ipv6.h> | |
35 | #include <linux/udp.h> | |
d9e31d17 JC |
36 | |
37 | #include "l2tp_core.h" | |
38 | ||
39 | /* Default device name. May be overridden by name specified by user */ | |
40 | #define L2TP_ETH_DEV_NAME "l2tpeth%d" | |
41 | ||
42 | /* via netdev_priv() */ | |
43 | struct l2tp_eth { | |
d9e31d17 | 44 | struct l2tp_session *session; |
a2842a1e ED |
45 | atomic_long_t tx_bytes; |
46 | atomic_long_t tx_packets; | |
b8c84307 | 47 | atomic_long_t tx_dropped; |
a2842a1e ED |
48 | atomic_long_t rx_bytes; |
49 | atomic_long_t rx_packets; | |
50 | atomic_long_t rx_errors; | |
d9e31d17 JC |
51 | }; |
52 | ||
53 | /* via l2tp_session_priv() */ | |
54 | struct l2tp_eth_sess { | |
ee28de6b | 55 | struct net_device __rcu *dev; |
d9e31d17 JC |
56 | }; |
57 | ||
d9e31d17 JC |
58 | |
59 | static int l2tp_eth_dev_init(struct net_device *dev) | |
60 | { | |
f2cedb63 | 61 | eth_hw_addr_random(dev); |
1cea7e2c | 62 | eth_broadcast_addr(dev->broadcast); |
d3fff6c4 | 63 | netdev_lockdep_set_classes(dev); |
f9eb8aea | 64 | |
d9e31d17 JC |
65 | return 0; |
66 | } | |
67 | ||
68 | static void l2tp_eth_dev_uninit(struct net_device *dev) | |
69 | { | |
ee28de6b GN |
70 | struct l2tp_eth *priv = netdev_priv(dev); |
71 | struct l2tp_eth_sess *spriv; | |
72 | ||
73 | spriv = l2tp_session_priv(priv->session); | |
74 | RCU_INIT_POINTER(spriv->dev, NULL); | |
75 | /* No need for synchronize_net() here. We're called by | |
76 | * unregister_netdev*(), which does the synchronisation for us. | |
77 | */ | |
d9e31d17 JC |
78 | } |
79 | ||
80 | static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) | |
81 | { | |
82 | struct l2tp_eth *priv = netdev_priv(dev); | |
83 | struct l2tp_session *session = priv->session; | |
b8c84307 ED |
84 | unsigned int len = skb->len; |
85 | int ret = l2tp_xmit_skb(session, skb, session->hdr_len); | |
86 | ||
a4cd0271 | 87 | if (likely(ret == NET_XMIT_SUCCESS)) { |
b8c84307 ED |
88 | atomic_long_add(len, &priv->tx_bytes); |
89 | atomic_long_inc(&priv->tx_packets); | |
90 | } else { | |
91 | atomic_long_inc(&priv->tx_dropped); | |
92 | } | |
aa214de0 | 93 | return NETDEV_TX_OK; |
d9e31d17 JC |
94 | } |
95 | ||
bc1f4470 | 96 | static void l2tp_eth_get_stats64(struct net_device *dev, |
97 | struct rtnl_link_stats64 *stats) | |
a2842a1e ED |
98 | { |
99 | struct l2tp_eth *priv = netdev_priv(dev); | |
100 | ||
9b3dc0a1 DH |
101 | stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes); |
102 | stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets); | |
103 | stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped); | |
104 | stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes); | |
105 | stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets); | |
106 | stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors); | |
107 | ||
a2842a1e ED |
108 | } |
109 | ||
eb94737d | 110 | static const struct net_device_ops l2tp_eth_netdev_ops = { |
d9e31d17 JC |
111 | .ndo_init = l2tp_eth_dev_init, |
112 | .ndo_uninit = l2tp_eth_dev_uninit, | |
113 | .ndo_start_xmit = l2tp_eth_dev_xmit, | |
a2842a1e | 114 | .ndo_get_stats64 = l2tp_eth_get_stats64, |
fe159122 | 115 | .ndo_set_mac_address = eth_mac_addr, |
d9e31d17 JC |
116 | }; |
117 | ||
a485c2b8 GN |
118 | static struct device_type l2tpeth_type = { |
119 | .name = "l2tpeth", | |
120 | }; | |
121 | ||
d9e31d17 JC |
122 | static void l2tp_eth_dev_setup(struct net_device *dev) |
123 | { | |
a485c2b8 | 124 | SET_NETDEV_DEVTYPE(dev, &l2tpeth_type); |
d9e31d17 | 125 | ether_setup(dev); |
a2842a1e ED |
126 | dev->priv_flags &= ~IFF_TX_SKB_SHARING; |
127 | dev->features |= NETIF_F_LLTX; | |
d9e31d17 | 128 | dev->netdev_ops = &l2tp_eth_netdev_ops; |
cf124db5 | 129 | dev->needs_free_netdev = true; |
d9e31d17 JC |
130 | } |
131 | ||
132 | static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) | |
133 | { | |
134 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
ee28de6b GN |
135 | struct net_device *dev; |
136 | struct l2tp_eth *priv; | |
d9e31d17 JC |
137 | |
138 | if (session->debug & L2TP_MSG_DATA) { | |
139 | unsigned int length; | |
d9e31d17 JC |
140 | |
141 | length = min(32u, skb->len); | |
142 | if (!pskb_may_pull(skb, length)) | |
143 | goto error; | |
144 | ||
a4ca44fa | 145 | pr_debug("%s: eth recv\n", session->name); |
a2842a1e | 146 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); |
d9e31d17 JC |
147 | } |
148 | ||
c0cc88a7 | 149 | if (!pskb_may_pull(skb, ETH_HLEN)) |
d9e31d17 JC |
150 | goto error; |
151 | ||
152 | secpath_reset(skb); | |
153 | ||
154 | /* checksums verified by L2TP */ | |
155 | skb->ip_summed = CHECKSUM_NONE; | |
156 | ||
157 | skb_dst_drop(skb); | |
158 | nf_reset(skb); | |
159 | ||
ee28de6b GN |
160 | rcu_read_lock(); |
161 | dev = rcu_dereference(spriv->dev); | |
162 | if (!dev) | |
163 | goto error_rcu; | |
164 | ||
165 | priv = netdev_priv(dev); | |
d9e31d17 | 166 | if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { |
a2842a1e ED |
167 | atomic_long_inc(&priv->rx_packets); |
168 | atomic_long_add(data_len, &priv->rx_bytes); | |
169 | } else { | |
170 | atomic_long_inc(&priv->rx_errors); | |
171 | } | |
ee28de6b GN |
172 | rcu_read_unlock(); |
173 | ||
d9e31d17 JC |
174 | return; |
175 | ||
ee28de6b GN |
176 | error_rcu: |
177 | rcu_read_unlock(); | |
d9e31d17 | 178 | error: |
d9e31d17 JC |
179 | kfree_skb(skb); |
180 | } | |
181 | ||
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); | |
ee28de6b GN |
189 | |
190 | rtnl_lock(); | |
191 | dev = rtnl_dereference(spriv->dev); | |
d9e31d17 | 192 | if (dev) { |
ee28de6b GN |
193 | unregister_netdevice(dev); |
194 | rtnl_unlock(); | |
a06998b8 | 195 | module_put(THIS_MODULE); |
ee28de6b GN |
196 | } else { |
197 | rtnl_unlock(); | |
d9e31d17 JC |
198 | } |
199 | } | |
200 | } | |
201 | ||
9dd79945 | 202 | #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) |
0ad66140 JC |
203 | static void l2tp_eth_show(struct seq_file *m, void *arg) |
204 | { | |
205 | struct l2tp_session *session = arg; | |
206 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
ee28de6b GN |
207 | struct net_device *dev; |
208 | ||
209 | rcu_read_lock(); | |
210 | dev = rcu_dereference(spriv->dev); | |
211 | if (!dev) { | |
212 | rcu_read_unlock(); | |
213 | return; | |
214 | } | |
215 | dev_hold(dev); | |
216 | rcu_read_unlock(); | |
0ad66140 JC |
217 | |
218 | seq_printf(m, " interface %s\n", dev->name); | |
ee28de6b GN |
219 | |
220 | dev_put(dev); | |
0ad66140 JC |
221 | } |
222 | #endif | |
223 | ||
b784e7eb P |
224 | static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, |
225 | struct l2tp_session *session, | |
226 | struct net_device *dev) | |
227 | { | |
228 | unsigned int overhead = 0; | |
229 | struct dst_entry *dst; | |
230 | u32 l3_overhead = 0; | |
231 | ||
232 | /* if the encap is UDP, account for UDP header size */ | |
233 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
234 | overhead += sizeof(struct udphdr); | |
235 | dev->needed_headroom += sizeof(struct udphdr); | |
236 | } | |
237 | if (session->mtu != 0) { | |
238 | dev->mtu = session->mtu; | |
239 | dev->needed_headroom += session->hdr_len; | |
240 | return; | |
241 | } | |
57240d00 | 242 | lock_sock(tunnel->sock); |
b784e7eb | 243 | l3_overhead = kernel_sock_ip_overhead(tunnel->sock); |
57240d00 | 244 | release_sock(tunnel->sock); |
b784e7eb P |
245 | if (l3_overhead == 0) { |
246 | /* L3 Overhead couldn't be identified, this could be | |
247 | * because tunnel->sock was NULL or the socket's | |
248 | * address family was not IPv4 or IPv6, | |
249 | * dev mtu stays at 1500. | |
250 | */ | |
251 | return; | |
252 | } | |
253 | /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr | |
254 | * UDP overhead, if any, was already factored in above. | |
255 | */ | |
256 | overhead += session->hdr_len + ETH_HLEN + l3_overhead; | |
257 | ||
258 | /* If PMTU discovery was enabled, use discovered MTU on L2TP device */ | |
259 | dst = sk_dst_get(tunnel->sock); | |
260 | if (dst) { | |
261 | /* dst_mtu will use PMTU if found, else fallback to intf MTU */ | |
262 | u32 pmtu = dst_mtu(dst); | |
263 | ||
264 | if (pmtu != 0) | |
265 | dev->mtu = pmtu; | |
266 | dst_release(dst); | |
267 | } | |
268 | session->mtu = dev->mtu - overhead; | |
269 | dev->mtu = session->mtu; | |
270 | dev->needed_headroom += session->hdr_len; | |
271 | } | |
272 | ||
f026bc29 GN |
273 | static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, |
274 | u32 session_id, u32 peer_session_id, | |
275 | struct l2tp_session_cfg *cfg) | |
d9e31d17 | 276 | { |
c39855fe | 277 | unsigned char name_assign_type; |
d9e31d17 JC |
278 | struct net_device *dev; |
279 | char name[IFNAMSIZ]; | |
d9e31d17 JC |
280 | struct l2tp_session *session; |
281 | struct l2tp_eth *priv; | |
282 | struct l2tp_eth_sess *spriv; | |
283 | int rc; | |
d9e31d17 | 284 | |
d9e31d17 | 285 | if (cfg->ifname) { |
d9e31d17 | 286 | strlcpy(name, cfg->ifname, IFNAMSIZ); |
c39855fe GN |
287 | name_assign_type = NET_NAME_USER; |
288 | } else { | |
d9e31d17 | 289 | strcpy(name, L2TP_ETH_DEV_NAME); |
c39855fe GN |
290 | name_assign_type = NET_NAME_ENUM; |
291 | } | |
d9e31d17 JC |
292 | |
293 | session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, | |
294 | peer_session_id, cfg); | |
dbdbc73b GN |
295 | if (IS_ERR(session)) { |
296 | rc = PTR_ERR(session); | |
ee28de6b | 297 | goto err; |
3953ae7b GN |
298 | } |
299 | ||
c39855fe | 300 | dev = alloc_netdev(sizeof(*priv), name, name_assign_type, |
c835a677 | 301 | l2tp_eth_dev_setup); |
d9e31d17 JC |
302 | if (!dev) { |
303 | rc = -ENOMEM; | |
ee28de6b | 304 | goto err_sess; |
d9e31d17 JC |
305 | } |
306 | ||
307 | dev_net_set(dev, net); | |
8b1efc0f JW |
308 | dev->min_mtu = 0; |
309 | dev->max_mtu = ETH_MAX_MTU; | |
b784e7eb | 310 | l2tp_eth_adjust_mtu(tunnel, session, dev); |
d9e31d17 JC |
311 | |
312 | priv = netdev_priv(dev); | |
d9e31d17 | 313 | priv->session = session; |
d9e31d17 | 314 | |
d9e31d17 JC |
315 | session->recv_skb = l2tp_eth_dev_recv; |
316 | session->session_close = l2tp_eth_delete; | |
9dd79945 | 317 | #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) |
0ad66140 JC |
318 | session->show = l2tp_eth_show; |
319 | #endif | |
d9e31d17 JC |
320 | |
321 | spriv = l2tp_session_priv(session); | |
d9e31d17 | 322 | |
ee28de6b GN |
323 | l2tp_session_inc_refcount(session); |
324 | ||
325 | rtnl_lock(); | |
326 | ||
327 | /* Register both device and session while holding the rtnl lock. This | |
328 | * ensures that l2tp_eth_delete() will see that there's a device to | |
329 | * unregister, even if it happened to run before we assign spriv->dev. | |
330 | */ | |
331 | rc = l2tp_session_register(session, tunnel); | |
332 | if (rc < 0) { | |
333 | rtnl_unlock(); | |
334 | goto err_sess_dev; | |
335 | } | |
336 | ||
337 | rc = register_netdevice(dev); | |
338 | if (rc < 0) { | |
339 | rtnl_unlock(); | |
340 | l2tp_session_delete(session); | |
341 | l2tp_session_dec_refcount(session); | |
342 | free_netdev(dev); | |
343 | ||
344 | return rc; | |
345 | } | |
d9e31d17 | 346 | |
d9e31d17 | 347 | strlcpy(session->ifname, dev->name, IFNAMSIZ); |
ee28de6b GN |
348 | rcu_assign_pointer(spriv->dev, dev); |
349 | ||
350 | rtnl_unlock(); | |
351 | ||
3953ae7b | 352 | l2tp_session_dec_refcount(session); |
d9e31d17 | 353 | |
ee28de6b | 354 | __module_get(THIS_MODULE); |
d9e31d17 JC |
355 | |
356 | return 0; | |
357 | ||
ee28de6b | 358 | err_sess_dev: |
3953ae7b | 359 | l2tp_session_dec_refcount(session); |
ee28de6b GN |
360 | free_netdev(dev); |
361 | err_sess: | |
362 | kfree(session); | |
363 | err: | |
d9e31d17 JC |
364 | return rc; |
365 | } | |
366 | ||
d9e31d17 JC |
367 | |
368 | static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { | |
369 | .session_create = l2tp_eth_create, | |
370 | .session_delete = l2tp_session_delete, | |
371 | }; | |
372 | ||
373 | ||
374 | static int __init l2tp_eth_init(void) | |
375 | { | |
376 | int err = 0; | |
377 | ||
378 | err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); | |
379 | if (err) | |
9f775ead | 380 | goto err; |
d9e31d17 | 381 | |
a4ca44fa | 382 | pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); |
d9e31d17 JC |
383 | |
384 | return 0; | |
385 | ||
9f775ead | 386 | err: |
d9e31d17 JC |
387 | return err; |
388 | } | |
389 | ||
390 | static void __exit l2tp_eth_exit(void) | |
391 | { | |
d9e31d17 JC |
392 | l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); |
393 | } | |
394 | ||
395 | module_init(l2tp_eth_init); | |
396 | module_exit(l2tp_eth_exit); | |
397 | ||
398 | MODULE_LICENSE("GPL"); | |
399 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
400 | MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); | |
401 | MODULE_VERSION("1.0"); | |
f1f39f91 | 402 | MODULE_ALIAS_L2TP_PWTYPE(5); |