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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 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/socket.h> | |
15 | #include <linux/hash.h> | |
16 | #include <linux/l2tp.h> | |
17 | #include <linux/in.h> | |
18 | #include <linux/etherdevice.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <net/sock.h> | |
21 | #include <net/ip.h> | |
22 | #include <net/icmp.h> | |
23 | #include <net/udp.h> | |
24 | #include <net/inet_common.h> | |
25 | #include <net/inet_hashtables.h> | |
26 | #include <net/tcp_states.h> | |
27 | #include <net/protocol.h> | |
28 | #include <net/xfrm.h> | |
29 | #include <net/net_namespace.h> | |
30 | #include <net/netns/generic.h> | |
31 | ||
32 | #include "l2tp_core.h" | |
33 | ||
34 | /* Default device name. May be overridden by name specified by user */ | |
35 | #define L2TP_ETH_DEV_NAME "l2tpeth%d" | |
36 | ||
37 | /* via netdev_priv() */ | |
38 | struct l2tp_eth { | |
39 | struct net_device *dev; | |
40 | struct sock *tunnel_sock; | |
41 | struct l2tp_session *session; | |
42 | struct list_head list; | |
43 | }; | |
44 | ||
45 | /* via l2tp_session_priv() */ | |
46 | struct l2tp_eth_sess { | |
47 | struct net_device *dev; | |
48 | }; | |
49 | ||
50 | /* per-net private data for this module */ | |
51 | static unsigned int l2tp_eth_net_id; | |
52 | struct l2tp_eth_net { | |
53 | struct list_head l2tp_eth_dev_list; | |
54 | spinlock_t l2tp_eth_lock; | |
55 | }; | |
56 | ||
57 | static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net) | |
58 | { | |
59 | return net_generic(net, l2tp_eth_net_id); | |
60 | } | |
61 | ||
62 | static int l2tp_eth_dev_init(struct net_device *dev) | |
63 | { | |
64 | struct l2tp_eth *priv = netdev_priv(dev); | |
65 | ||
66 | priv->dev = dev; | |
67 | random_ether_addr(dev->dev_addr); | |
68 | memset(&dev->broadcast[0], 0xff, 6); | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static void l2tp_eth_dev_uninit(struct net_device *dev) | |
74 | { | |
75 | struct l2tp_eth *priv = netdev_priv(dev); | |
76 | struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); | |
77 | ||
78 | spin_lock(&pn->l2tp_eth_lock); | |
79 | list_del_init(&priv->list); | |
80 | spin_unlock(&pn->l2tp_eth_lock); | |
81 | dev_put(dev); | |
82 | } | |
83 | ||
84 | static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) | |
85 | { | |
86 | struct l2tp_eth *priv = netdev_priv(dev); | |
87 | struct l2tp_session *session = priv->session; | |
88 | ||
89 | l2tp_xmit_skb(session, skb, session->hdr_len); | |
90 | ||
91 | dev->stats.tx_bytes += skb->len; | |
92 | dev->stats.tx_packets++; | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | static struct net_device_ops l2tp_eth_netdev_ops = { | |
98 | .ndo_init = l2tp_eth_dev_init, | |
99 | .ndo_uninit = l2tp_eth_dev_uninit, | |
100 | .ndo_start_xmit = l2tp_eth_dev_xmit, | |
101 | }; | |
102 | ||
103 | static void l2tp_eth_dev_setup(struct net_device *dev) | |
104 | { | |
105 | ether_setup(dev); | |
106 | ||
107 | dev->netdev_ops = &l2tp_eth_netdev_ops; | |
108 | dev->destructor = free_netdev; | |
109 | } | |
110 | ||
111 | static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) | |
112 | { | |
113 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
114 | struct net_device *dev = spriv->dev; | |
115 | ||
116 | if (session->debug & L2TP_MSG_DATA) { | |
117 | unsigned int length; | |
118 | int offset; | |
119 | u8 *ptr = skb->data; | |
120 | ||
121 | length = min(32u, skb->len); | |
122 | if (!pskb_may_pull(skb, length)) | |
123 | goto error; | |
124 | ||
125 | printk(KERN_DEBUG "%s: eth recv: ", session->name); | |
126 | ||
127 | offset = 0; | |
128 | do { | |
129 | printk(" %02X", ptr[offset]); | |
130 | } while (++offset < length); | |
131 | ||
132 | printk("\n"); | |
133 | } | |
134 | ||
135 | if (data_len < ETH_HLEN) | |
136 | goto error; | |
137 | ||
138 | secpath_reset(skb); | |
139 | ||
140 | /* checksums verified by L2TP */ | |
141 | skb->ip_summed = CHECKSUM_NONE; | |
142 | ||
143 | skb_dst_drop(skb); | |
144 | nf_reset(skb); | |
145 | ||
146 | if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { | |
147 | dev->last_rx = jiffies; | |
148 | dev->stats.rx_packets++; | |
149 | dev->stats.rx_bytes += data_len; | |
150 | } else | |
151 | dev->stats.rx_errors++; | |
152 | ||
153 | return; | |
154 | ||
155 | error: | |
156 | dev->stats.rx_errors++; | |
157 | kfree_skb(skb); | |
158 | } | |
159 | ||
160 | static void l2tp_eth_delete(struct l2tp_session *session) | |
161 | { | |
162 | struct l2tp_eth_sess *spriv; | |
163 | struct net_device *dev; | |
164 | ||
165 | if (session) { | |
166 | spriv = l2tp_session_priv(session); | |
167 | dev = spriv->dev; | |
168 | if (dev) { | |
169 | unregister_netdev(dev); | |
170 | spriv->dev = NULL; | |
171 | } | |
172 | } | |
173 | } | |
174 | ||
0ad66140 JC |
175 | #ifdef CONFIG_L2TP_DEBUGFS |
176 | static void l2tp_eth_show(struct seq_file *m, void *arg) | |
177 | { | |
178 | struct l2tp_session *session = arg; | |
179 | struct l2tp_eth_sess *spriv = l2tp_session_priv(session); | |
180 | struct net_device *dev = spriv->dev; | |
181 | ||
182 | seq_printf(m, " interface %s\n", dev->name); | |
183 | } | |
184 | #endif | |
185 | ||
d9e31d17 JC |
186 | static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) |
187 | { | |
188 | struct net_device *dev; | |
189 | char name[IFNAMSIZ]; | |
190 | struct l2tp_tunnel *tunnel; | |
191 | struct l2tp_session *session; | |
192 | struct l2tp_eth *priv; | |
193 | struct l2tp_eth_sess *spriv; | |
194 | int rc; | |
195 | struct l2tp_eth_net *pn; | |
196 | ||
197 | tunnel = l2tp_tunnel_find(net, tunnel_id); | |
198 | if (!tunnel) { | |
199 | rc = -ENODEV; | |
200 | goto out; | |
201 | } | |
202 | ||
203 | session = l2tp_session_find(net, tunnel, session_id); | |
204 | if (session) { | |
205 | rc = -EEXIST; | |
206 | goto out; | |
207 | } | |
208 | ||
209 | if (cfg->ifname) { | |
210 | dev = dev_get_by_name(net, cfg->ifname); | |
211 | if (dev) { | |
212 | dev_put(dev); | |
213 | rc = -EEXIST; | |
214 | goto out; | |
215 | } | |
216 | strlcpy(name, cfg->ifname, IFNAMSIZ); | |
217 | } else | |
218 | strcpy(name, L2TP_ETH_DEV_NAME); | |
219 | ||
220 | session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, | |
221 | peer_session_id, cfg); | |
222 | if (!session) { | |
223 | rc = -ENOMEM; | |
224 | goto out; | |
225 | } | |
226 | ||
227 | dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup); | |
228 | if (!dev) { | |
229 | rc = -ENOMEM; | |
230 | goto out_del_session; | |
231 | } | |
232 | ||
233 | dev_net_set(dev, net); | |
234 | if (session->mtu == 0) | |
235 | session->mtu = dev->mtu - session->hdr_len; | |
236 | dev->mtu = session->mtu; | |
237 | dev->needed_headroom += session->hdr_len; | |
238 | ||
239 | priv = netdev_priv(dev); | |
240 | priv->dev = dev; | |
241 | priv->session = session; | |
242 | INIT_LIST_HEAD(&priv->list); | |
243 | ||
244 | priv->tunnel_sock = tunnel->sock; | |
245 | session->recv_skb = l2tp_eth_dev_recv; | |
246 | session->session_close = l2tp_eth_delete; | |
0ad66140 JC |
247 | #ifdef CONFIG_L2TP_DEBUGFS |
248 | session->show = l2tp_eth_show; | |
249 | #endif | |
d9e31d17 JC |
250 | |
251 | spriv = l2tp_session_priv(session); | |
252 | spriv->dev = dev; | |
253 | ||
254 | rc = register_netdev(dev); | |
255 | if (rc < 0) | |
256 | goto out_del_dev; | |
257 | ||
258 | /* Must be done after register_netdev() */ | |
259 | strlcpy(session->ifname, dev->name, IFNAMSIZ); | |
260 | ||
261 | dev_hold(dev); | |
262 | pn = l2tp_eth_pernet(dev_net(dev)); | |
263 | spin_lock(&pn->l2tp_eth_lock); | |
264 | list_add(&priv->list, &pn->l2tp_eth_dev_list); | |
265 | spin_unlock(&pn->l2tp_eth_lock); | |
266 | ||
267 | return 0; | |
268 | ||
269 | out_del_dev: | |
270 | free_netdev(dev); | |
271 | out_del_session: | |
272 | l2tp_session_delete(session); | |
273 | out: | |
274 | return rc; | |
275 | } | |
276 | ||
277 | static __net_init int l2tp_eth_init_net(struct net *net) | |
278 | { | |
279 | struct l2tp_eth_net *pn; | |
280 | int err; | |
281 | ||
282 | pn = kzalloc(sizeof(*pn), GFP_KERNEL); | |
283 | if (!pn) | |
284 | return -ENOMEM; | |
285 | ||
286 | INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); | |
287 | spin_lock_init(&pn->l2tp_eth_lock); | |
288 | ||
289 | err = net_assign_generic(net, l2tp_eth_net_id, pn); | |
290 | if (err) | |
291 | goto out; | |
292 | ||
293 | return 0; | |
294 | ||
295 | out: | |
296 | kfree(pn); | |
297 | return err; | |
298 | } | |
299 | ||
300 | static __net_exit void l2tp_eth_exit_net(struct net *net) | |
301 | { | |
302 | struct l2tp_eth_net *pn; | |
303 | ||
304 | pn = net_generic(net, l2tp_eth_net_id); | |
305 | /* | |
306 | * if someone has cached our net then | |
307 | * further net_generic call will return NULL | |
308 | */ | |
309 | net_assign_generic(net, l2tp_eth_net_id, NULL); | |
310 | kfree(pn); | |
311 | } | |
312 | ||
313 | static __net_initdata struct pernet_operations l2tp_eth_net_ops = { | |
314 | .init = l2tp_eth_init_net, | |
315 | .exit = l2tp_eth_exit_net, | |
316 | .id = &l2tp_eth_net_id, | |
317 | .size = sizeof(struct l2tp_eth_net), | |
318 | }; | |
319 | ||
320 | ||
321 | static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { | |
322 | .session_create = l2tp_eth_create, | |
323 | .session_delete = l2tp_session_delete, | |
324 | }; | |
325 | ||
326 | ||
327 | static int __init l2tp_eth_init(void) | |
328 | { | |
329 | int err = 0; | |
330 | ||
331 | err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); | |
332 | if (err) | |
333 | goto out; | |
334 | ||
335 | err = register_pernet_device(&l2tp_eth_net_ops); | |
336 | if (err) | |
337 | goto out_unreg; | |
338 | ||
339 | printk(KERN_INFO "L2TP ethernet pseudowire support (L2TPv3)\n"); | |
340 | ||
341 | return 0; | |
342 | ||
343 | out_unreg: | |
344 | l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); | |
345 | out: | |
346 | return err; | |
347 | } | |
348 | ||
349 | static void __exit l2tp_eth_exit(void) | |
350 | { | |
351 | unregister_pernet_device(&l2tp_eth_net_ops); | |
352 | l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); | |
353 | } | |
354 | ||
355 | module_init(l2tp_eth_init); | |
356 | module_exit(l2tp_eth_exit); | |
357 | ||
358 | MODULE_LICENSE("GPL"); | |
359 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
360 | MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); | |
361 | MODULE_VERSION("1.0"); |