Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
d9e31d17 JC |
2 | /* |
3 | * L2TPv3 ethernet pseudowire driver | |
4 | * | |
5 | * Copyright (c) 2008,2009,2010 Katalix Systems Ltd | |
d9e31d17 JC |
6 | */ |
7 | ||
a4ca44fa JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
d9e31d17 JC |
10 | #include <linux/module.h> |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/socket.h> | |
13 | #include <linux/hash.h> | |
14 | #include <linux/l2tp.h> | |
15 | #include <linux/in.h> | |
16 | #include <linux/etherdevice.h> | |
17 | #include <linux/spinlock.h> | |
18 | #include <net/sock.h> | |
19 | #include <net/ip.h> | |
20 | #include <net/icmp.h> | |
21 | #include <net/udp.h> | |
22 | #include <net/inet_common.h> | |
23 | #include <net/inet_hashtables.h> | |
24 | #include <net/tcp_states.h> | |
25 | #include <net/protocol.h> | |
26 | #include <net/xfrm.h> | |
27 | #include <net/net_namespace.h> | |
28 | #include <net/netns/generic.h> | |
b784e7eb P |
29 | #include <linux/ip.h> |
30 | #include <linux/ipv6.h> | |
31 | #include <linux/udp.h> | |
d9e31d17 JC |
32 | |
33 | #include "l2tp_core.h" | |
34 | ||
35 | /* Default device name. May be overridden by name specified by user */ | |
36 | #define L2TP_ETH_DEV_NAME "l2tpeth%d" | |
37 | ||
38 | /* via netdev_priv() */ | |
39 | struct l2tp_eth { | |
d9e31d17 | 40 | struct l2tp_session *session; |
a2842a1e ED |
41 | atomic_long_t tx_bytes; |
42 | atomic_long_t tx_packets; | |
b8c84307 | 43 | atomic_long_t tx_dropped; |
a2842a1e ED |
44 | atomic_long_t rx_bytes; |
45 | atomic_long_t rx_packets; | |
46 | atomic_long_t rx_errors; | |
d9e31d17 JC |
47 | }; |
48 | ||
49 | /* via l2tp_session_priv() */ | |
50 | struct l2tp_eth_sess { | |
ee28de6b | 51 | struct net_device __rcu *dev; |
d9e31d17 JC |
52 | }; |
53 | ||
d9e31d17 JC |
54 | static int l2tp_eth_dev_init(struct net_device *dev) |
55 | { | |
f2cedb63 | 56 | eth_hw_addr_random(dev); |
1cea7e2c | 57 | eth_broadcast_addr(dev->broadcast); |
1a33e10e | 58 | netdev_lockdep_set_classes(dev); |
f9eb8aea | 59 | |
d9e31d17 JC |
60 | return 0; |
61 | } | |
62 | ||
63 | static void l2tp_eth_dev_uninit(struct net_device *dev) | |
64 | { | |
ee28de6b GN |
65 | struct l2tp_eth *priv = netdev_priv(dev); |
66 | struct l2tp_eth_sess *spriv; | |
67 | ||
68 | spriv = l2tp_session_priv(priv->session); | |
69 | RCU_INIT_POINTER(spriv->dev, NULL); | |
70 | /* No need for synchronize_net() here. We're called by | |
71 | * unregister_netdev*(), which does the synchronisation for us. | |
72 | */ | |
d9e31d17 JC |
73 | } |
74 | ||
433f17a9 | 75 | static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) |
d9e31d17 JC |
76 | { |
77 | struct l2tp_eth *priv = netdev_priv(dev); | |
78 | struct l2tp_session *session = priv->session; | |
b8c84307 ED |
79 | unsigned int len = skb->len; |
80 | int ret = l2tp_xmit_skb(session, skb, session->hdr_len); | |
81 | ||
a4cd0271 | 82 | if (likely(ret == NET_XMIT_SUCCESS)) { |
b8c84307 ED |
83 | atomic_long_add(len, &priv->tx_bytes); |
84 | atomic_long_inc(&priv->tx_packets); | |
85 | } else { | |
86 | atomic_long_inc(&priv->tx_dropped); | |
87 | } | |
aa214de0 | 88 | return NETDEV_TX_OK; |
d9e31d17 JC |
89 | } |
90 | ||
bc1f4470 | 91 | static void l2tp_eth_get_stats64(struct net_device *dev, |
92 | struct rtnl_link_stats64 *stats) | |
a2842a1e ED |
93 | { |
94 | struct l2tp_eth *priv = netdev_priv(dev); | |
95 | ||
b71a61cc TP |
96 | stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes); |
97 | stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets); | |
98 | stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped); | |
99 | stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes); | |
100 | stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets); | |
101 | stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors); | |
a2842a1e ED |
102 | } |
103 | ||
eb94737d | 104 | static const struct net_device_ops l2tp_eth_netdev_ops = { |
d9e31d17 JC |
105 | .ndo_init = l2tp_eth_dev_init, |
106 | .ndo_uninit = l2tp_eth_dev_uninit, | |
107 | .ndo_start_xmit = l2tp_eth_dev_xmit, | |
a2842a1e | 108 | .ndo_get_stats64 = l2tp_eth_get_stats64, |
fe159122 | 109 | .ndo_set_mac_address = eth_mac_addr, |
d9e31d17 JC |
110 | }; |
111 | ||
a485c2b8 GN |
112 | static struct device_type l2tpeth_type = { |
113 | .name = "l2tpeth", | |
114 | }; | |
115 | ||
d9e31d17 JC |
116 | static void l2tp_eth_dev_setup(struct net_device *dev) |
117 | { | |
a485c2b8 | 118 | SET_NETDEV_DEVTYPE(dev, &l2tpeth_type); |
d9e31d17 | 119 | ether_setup(dev); |
a2842a1e ED |
120 | dev->priv_flags &= ~IFF_TX_SKB_SHARING; |
121 | dev->features |= NETIF_F_LLTX; | |
d9e31d17 | 122 | dev->netdev_ops = &l2tp_eth_netdev_ops; |
cf124db5 | 123 | dev->needs_free_netdev = true; |
d9e31d17 JC |
124 | } |
125 | ||
126 | static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) | |
127 | { | |
128 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
ee28de6b GN |
129 | struct net_device *dev; |
130 | struct l2tp_eth *priv; | |
d9e31d17 JC |
131 | |
132 | if (session->debug & L2TP_MSG_DATA) { | |
133 | unsigned int length; | |
d9e31d17 JC |
134 | |
135 | length = min(32u, skb->len); | |
136 | if (!pskb_may_pull(skb, length)) | |
137 | goto error; | |
138 | ||
a4ca44fa | 139 | pr_debug("%s: eth recv\n", session->name); |
a2842a1e | 140 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); |
d9e31d17 JC |
141 | } |
142 | ||
c0cc88a7 | 143 | if (!pskb_may_pull(skb, ETH_HLEN)) |
d9e31d17 JC |
144 | goto error; |
145 | ||
146 | secpath_reset(skb); | |
147 | ||
148 | /* checksums verified by L2TP */ | |
149 | skb->ip_summed = CHECKSUM_NONE; | |
150 | ||
151 | skb_dst_drop(skb); | |
895b5c9f | 152 | nf_reset_ct(skb); |
d9e31d17 | 153 | |
ee28de6b GN |
154 | rcu_read_lock(); |
155 | dev = rcu_dereference(spriv->dev); | |
156 | if (!dev) | |
157 | goto error_rcu; | |
158 | ||
159 | priv = netdev_priv(dev); | |
d9e31d17 | 160 | if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { |
a2842a1e ED |
161 | atomic_long_inc(&priv->rx_packets); |
162 | atomic_long_add(data_len, &priv->rx_bytes); | |
163 | } else { | |
164 | atomic_long_inc(&priv->rx_errors); | |
165 | } | |
ee28de6b GN |
166 | rcu_read_unlock(); |
167 | ||
d9e31d17 JC |
168 | return; |
169 | ||
ee28de6b GN |
170 | error_rcu: |
171 | rcu_read_unlock(); | |
d9e31d17 | 172 | error: |
d9e31d17 JC |
173 | kfree_skb(skb); |
174 | } | |
175 | ||
176 | static void l2tp_eth_delete(struct l2tp_session *session) | |
177 | { | |
178 | struct l2tp_eth_sess *spriv; | |
179 | struct net_device *dev; | |
180 | ||
181 | if (session) { | |
182 | spriv = l2tp_session_priv(session); | |
ee28de6b GN |
183 | |
184 | rtnl_lock(); | |
185 | dev = rtnl_dereference(spriv->dev); | |
d9e31d17 | 186 | if (dev) { |
ee28de6b GN |
187 | unregister_netdevice(dev); |
188 | rtnl_unlock(); | |
a06998b8 | 189 | module_put(THIS_MODULE); |
ee28de6b GN |
190 | } else { |
191 | rtnl_unlock(); | |
d9e31d17 JC |
192 | } |
193 | } | |
194 | } | |
195 | ||
0ad66140 JC |
196 | static void l2tp_eth_show(struct seq_file *m, void *arg) |
197 | { | |
198 | struct l2tp_session *session = arg; | |
199 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
ee28de6b GN |
200 | struct net_device *dev; |
201 | ||
202 | rcu_read_lock(); | |
203 | dev = rcu_dereference(spriv->dev); | |
204 | if (!dev) { | |
205 | rcu_read_unlock(); | |
206 | return; | |
207 | } | |
208 | dev_hold(dev); | |
209 | rcu_read_unlock(); | |
0ad66140 JC |
210 | |
211 | seq_printf(m, " interface %s\n", dev->name); | |
ee28de6b GN |
212 | |
213 | dev_put(dev); | |
0ad66140 | 214 | } |
0ad66140 | 215 | |
b784e7eb P |
216 | static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, |
217 | struct l2tp_session *session, | |
218 | struct net_device *dev) | |
219 | { | |
220 | unsigned int overhead = 0; | |
b784e7eb | 221 | u32 l3_overhead = 0; |
1f5cd2a0 | 222 | u32 mtu; |
b784e7eb P |
223 | |
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); | |
228 | } | |
e9697e2e | 229 | |
57240d00 | 230 | lock_sock(tunnel->sock); |
b784e7eb | 231 | l3_overhead = kernel_sock_ip_overhead(tunnel->sock); |
57240d00 | 232 | release_sock(tunnel->sock); |
e9697e2e | 233 | |
b784e7eb P |
234 | if (l3_overhead == 0) { |
235 | /* L3 Overhead couldn't be identified, this could be | |
236 | * because tunnel->sock was NULL or the socket's | |
237 | * address family was not IPv4 or IPv6, | |
238 | * dev mtu stays at 1500. | |
239 | */ | |
240 | return; | |
241 | } | |
242 | /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr | |
243 | * UDP overhead, if any, was already factored in above. | |
244 | */ | |
245 | overhead += session->hdr_len + ETH_HLEN + l3_overhead; | |
246 | ||
e9697e2e GN |
247 | mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead; |
248 | if (mtu < dev->min_mtu || mtu > dev->max_mtu) | |
249 | dev->mtu = ETH_DATA_LEN - overhead; | |
250 | else | |
1f5cd2a0 | 251 | dev->mtu = mtu; |
e9697e2e | 252 | |
b784e7eb P |
253 | dev->needed_headroom += session->hdr_len; |
254 | } | |
255 | ||
f026bc29 GN |
256 | static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, |
257 | u32 session_id, u32 peer_session_id, | |
258 | struct l2tp_session_cfg *cfg) | |
d9e31d17 | 259 | { |
c39855fe | 260 | unsigned char name_assign_type; |
d9e31d17 JC |
261 | struct net_device *dev; |
262 | char name[IFNAMSIZ]; | |
d9e31d17 JC |
263 | struct l2tp_session *session; |
264 | struct l2tp_eth *priv; | |
265 | struct l2tp_eth_sess *spriv; | |
266 | int rc; | |
d9e31d17 | 267 | |
d9e31d17 | 268 | if (cfg->ifname) { |
d9e31d17 | 269 | strlcpy(name, cfg->ifname, IFNAMSIZ); |
c39855fe GN |
270 | name_assign_type = NET_NAME_USER; |
271 | } else { | |
d9e31d17 | 272 | strcpy(name, L2TP_ETH_DEV_NAME); |
c39855fe GN |
273 | name_assign_type = NET_NAME_ENUM; |
274 | } | |
d9e31d17 JC |
275 | |
276 | session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, | |
277 | peer_session_id, cfg); | |
dbdbc73b GN |
278 | if (IS_ERR(session)) { |
279 | rc = PTR_ERR(session); | |
ee28de6b | 280 | goto err; |
3953ae7b GN |
281 | } |
282 | ||
c39855fe | 283 | dev = alloc_netdev(sizeof(*priv), name, name_assign_type, |
c835a677 | 284 | l2tp_eth_dev_setup); |
d9e31d17 JC |
285 | if (!dev) { |
286 | rc = -ENOMEM; | |
ee28de6b | 287 | goto err_sess; |
d9e31d17 JC |
288 | } |
289 | ||
290 | dev_net_set(dev, net); | |
8b1efc0f JW |
291 | dev->min_mtu = 0; |
292 | dev->max_mtu = ETH_MAX_MTU; | |
b784e7eb | 293 | l2tp_eth_adjust_mtu(tunnel, session, dev); |
d9e31d17 JC |
294 | |
295 | priv = netdev_priv(dev); | |
d9e31d17 | 296 | priv->session = session; |
d9e31d17 | 297 | |
d9e31d17 JC |
298 | session->recv_skb = l2tp_eth_dev_recv; |
299 | session->session_close = l2tp_eth_delete; | |
c2ebc256 AB |
300 | if (IS_ENABLED(CONFIG_L2TP_DEBUGFS)) |
301 | session->show = l2tp_eth_show; | |
d9e31d17 JC |
302 | |
303 | spriv = l2tp_session_priv(session); | |
d9e31d17 | 304 | |
ee28de6b GN |
305 | l2tp_session_inc_refcount(session); |
306 | ||
307 | rtnl_lock(); | |
308 | ||
309 | /* Register both device and session while holding the rtnl lock. This | |
310 | * ensures that l2tp_eth_delete() will see that there's a device to | |
311 | * unregister, even if it happened to run before we assign spriv->dev. | |
312 | */ | |
313 | rc = l2tp_session_register(session, tunnel); | |
314 | if (rc < 0) { | |
315 | rtnl_unlock(); | |
316 | goto err_sess_dev; | |
317 | } | |
318 | ||
319 | rc = register_netdevice(dev); | |
320 | if (rc < 0) { | |
321 | rtnl_unlock(); | |
322 | l2tp_session_delete(session); | |
323 | l2tp_session_dec_refcount(session); | |
324 | free_netdev(dev); | |
325 | ||
326 | return rc; | |
327 | } | |
d9e31d17 | 328 | |
d9e31d17 | 329 | strlcpy(session->ifname, dev->name, IFNAMSIZ); |
ee28de6b GN |
330 | rcu_assign_pointer(spriv->dev, dev); |
331 | ||
332 | rtnl_unlock(); | |
333 | ||
3953ae7b | 334 | l2tp_session_dec_refcount(session); |
d9e31d17 | 335 | |
ee28de6b | 336 | __module_get(THIS_MODULE); |
d9e31d17 JC |
337 | |
338 | return 0; | |
339 | ||
ee28de6b | 340 | err_sess_dev: |
3953ae7b | 341 | l2tp_session_dec_refcount(session); |
ee28de6b GN |
342 | free_netdev(dev); |
343 | err_sess: | |
344 | kfree(session); | |
345 | err: | |
d9e31d17 JC |
346 | return rc; |
347 | } | |
348 | ||
d9e31d17 JC |
349 | static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { |
350 | .session_create = l2tp_eth_create, | |
351 | .session_delete = l2tp_session_delete, | |
352 | }; | |
353 | ||
d9e31d17 JC |
354 | static int __init l2tp_eth_init(void) |
355 | { | |
356 | int err = 0; | |
357 | ||
358 | err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); | |
359 | if (err) | |
9f775ead | 360 | goto err; |
d9e31d17 | 361 | |
a4ca44fa | 362 | pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); |
d9e31d17 JC |
363 | |
364 | return 0; | |
365 | ||
9f775ead | 366 | err: |
d9e31d17 JC |
367 | return err; |
368 | } | |
369 | ||
370 | static void __exit l2tp_eth_exit(void) | |
371 | { | |
d9e31d17 JC |
372 | l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); |
373 | } | |
374 | ||
375 | module_init(l2tp_eth_init); | |
376 | module_exit(l2tp_eth_exit); | |
377 | ||
378 | MODULE_LICENSE("GPL"); | |
379 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
380 | MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); | |
381 | MODULE_VERSION("1.0"); | |
f1f39f91 | 382 | MODULE_ALIAS_L2TP_PWTYPE(5); |