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Commit | Line | Data |
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fd558d18 JC |
1 | /* |
2 | * L2TP core. | |
3 | * | |
4 | * Copyright (c) 2008,2009,2010 Katalix Systems Ltd | |
5 | * | |
6 | * This file contains some code of the original L2TPv2 pppol2tp | |
7 | * driver, which has the following copyright: | |
8 | * | |
9 | * Authors: Martijn van Oosterhout <kleptog@svana.org> | |
10 | * James Chapman (jchapman@katalix.com) | |
11 | * Contributors: | |
12 | * Michal Ostrowski <mostrows@speakeasy.net> | |
13 | * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> | |
14 | * David S. Miller (davem@redhat.com) | |
15 | * | |
16 | * This program is free software; you can redistribute it and/or modify | |
17 | * it under the terms of the GNU General Public License version 2 as | |
18 | * published by the Free Software Foundation. | |
19 | */ | |
20 | ||
a4ca44fa JP |
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
22 | ||
fd558d18 JC |
23 | #include <linux/module.h> |
24 | #include <linux/string.h> | |
25 | #include <linux/list.h> | |
e02d494d | 26 | #include <linux/rculist.h> |
fd558d18 JC |
27 | #include <linux/uaccess.h> |
28 | ||
29 | #include <linux/kernel.h> | |
30 | #include <linux/spinlock.h> | |
31 | #include <linux/kthread.h> | |
32 | #include <linux/sched.h> | |
33 | #include <linux/slab.h> | |
34 | #include <linux/errno.h> | |
35 | #include <linux/jiffies.h> | |
36 | ||
37 | #include <linux/netdevice.h> | |
38 | #include <linux/net.h> | |
39 | #include <linux/inetdevice.h> | |
40 | #include <linux/skbuff.h> | |
41 | #include <linux/init.h> | |
0d76751f | 42 | #include <linux/in.h> |
fd558d18 JC |
43 | #include <linux/ip.h> |
44 | #include <linux/udp.h> | |
0d76751f | 45 | #include <linux/l2tp.h> |
fd558d18 JC |
46 | #include <linux/hash.h> |
47 | #include <linux/sort.h> | |
48 | #include <linux/file.h> | |
49 | #include <linux/nsproxy.h> | |
50 | #include <net/net_namespace.h> | |
51 | #include <net/netns/generic.h> | |
52 | #include <net/dst.h> | |
53 | #include <net/ip.h> | |
54 | #include <net/udp.h> | |
309795f4 | 55 | #include <net/inet_common.h> |
fd558d18 | 56 | #include <net/xfrm.h> |
0d76751f | 57 | #include <net/protocol.h> |
d2cf3361 BL |
58 | #include <net/inet6_connection_sock.h> |
59 | #include <net/inet_ecn.h> | |
60 | #include <net/ip6_route.h> | |
d499bd2e | 61 | #include <net/ip6_checksum.h> |
fd558d18 JC |
62 | |
63 | #include <asm/byteorder.h> | |
60063497 | 64 | #include <linux/atomic.h> |
fd558d18 JC |
65 | |
66 | #include "l2tp_core.h" | |
67 | ||
68 | #define L2TP_DRV_VERSION "V2.0" | |
69 | ||
70 | /* L2TP header constants */ | |
71 | #define L2TP_HDRFLAG_T 0x8000 | |
72 | #define L2TP_HDRFLAG_L 0x4000 | |
73 | #define L2TP_HDRFLAG_S 0x0800 | |
74 | #define L2TP_HDRFLAG_O 0x0200 | |
75 | #define L2TP_HDRFLAG_P 0x0100 | |
76 | ||
77 | #define L2TP_HDR_VER_MASK 0x000F | |
78 | #define L2TP_HDR_VER_2 0x0002 | |
f7faffa3 | 79 | #define L2TP_HDR_VER_3 0x0003 |
fd558d18 JC |
80 | |
81 | /* L2TPv3 default L2-specific sublayer */ | |
82 | #define L2TP_SLFLAG_S 0x40000000 | |
83 | #define L2TP_SL_SEQ_MASK 0x00ffffff | |
84 | ||
85 | #define L2TP_HDR_SIZE_SEQ 10 | |
86 | #define L2TP_HDR_SIZE_NOSEQ 6 | |
87 | ||
88 | /* Default trace flags */ | |
89 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 | |
90 | ||
fd558d18 JC |
91 | /* Private data stored for received packets in the skb. |
92 | */ | |
93 | struct l2tp_skb_cb { | |
f7faffa3 | 94 | u32 ns; |
fd558d18 JC |
95 | u16 has_seq; |
96 | u16 length; | |
97 | unsigned long expires; | |
98 | }; | |
99 | ||
100 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) | |
101 | ||
102 | static atomic_t l2tp_tunnel_count; | |
103 | static atomic_t l2tp_session_count; | |
f8ccac0e | 104 | static struct workqueue_struct *l2tp_wq; |
fd558d18 JC |
105 | |
106 | /* per-net private data for this module */ | |
107 | static unsigned int l2tp_net_id; | |
108 | struct l2tp_net { | |
109 | struct list_head l2tp_tunnel_list; | |
e02d494d | 110 | spinlock_t l2tp_tunnel_list_lock; |
f7faffa3 | 111 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
e02d494d | 112 | spinlock_t l2tp_session_hlist_lock; |
fd558d18 JC |
113 | }; |
114 | ||
fc130840 | 115 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version); |
116 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); | |
fc130840 | 117 | |
8d8a51e2 DM |
118 | static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) |
119 | { | |
120 | return sk->sk_user_data; | |
121 | } | |
122 | ||
fd558d18 JC |
123 | static inline struct l2tp_net *l2tp_pernet(struct net *net) |
124 | { | |
125 | BUG_ON(!net); | |
126 | ||
127 | return net_generic(net, l2tp_net_id); | |
128 | } | |
129 | ||
fc130840 | 130 | /* Tunnel reference counts. Incremented per session that is added to |
131 | * the tunnel. | |
132 | */ | |
133 | static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) | |
134 | { | |
135 | atomic_inc(&tunnel->ref_count); | |
136 | } | |
137 | ||
138 | static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) | |
139 | { | |
140 | if (atomic_dec_and_test(&tunnel->ref_count)) | |
141 | l2tp_tunnel_free(tunnel); | |
142 | } | |
143 | #ifdef L2TP_REFCNT_DEBUG | |
a4ca44fa JP |
144 | #define l2tp_tunnel_inc_refcount(_t) \ |
145 | do { \ | |
146 | pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", \ | |
147 | __func__, __LINE__, (_t)->name, \ | |
148 | atomic_read(&_t->ref_count)); \ | |
149 | l2tp_tunnel_inc_refcount_1(_t); \ | |
150 | } while (0) | |
151 | #define l2tp_tunnel_dec_refcount(_t) | |
152 | do { \ | |
153 | pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", \ | |
154 | __func__, __LINE__, (_t)->name, \ | |
155 | atomic_read(&_t->ref_count)); \ | |
156 | l2tp_tunnel_dec_refcount_1(_t); \ | |
157 | } while (0) | |
fc130840 | 158 | #else |
159 | #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) | |
160 | #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) | |
161 | #endif | |
162 | ||
f7faffa3 JC |
163 | /* Session hash global list for L2TPv3. |
164 | * The session_id SHOULD be random according to RFC3931, but several | |
165 | * L2TP implementations use incrementing session_ids. So we do a real | |
166 | * hash on the session_id, rather than a simple bitmask. | |
167 | */ | |
168 | static inline struct hlist_head * | |
169 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) | |
170 | { | |
171 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; | |
172 | ||
173 | } | |
174 | ||
80d84ef3 TP |
175 | /* Lookup the tunnel socket, possibly involving the fs code if the socket is |
176 | * owned by userspace. A struct sock returned from this function must be | |
177 | * released using l2tp_tunnel_sock_put once you're done with it. | |
178 | */ | |
179 | struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel) | |
180 | { | |
181 | int err = 0; | |
182 | struct socket *sock = NULL; | |
183 | struct sock *sk = NULL; | |
184 | ||
185 | if (!tunnel) | |
186 | goto out; | |
187 | ||
188 | if (tunnel->fd >= 0) { | |
189 | /* Socket is owned by userspace, who might be in the process | |
190 | * of closing it. Look the socket up using the fd to ensure | |
191 | * consistency. | |
192 | */ | |
193 | sock = sockfd_lookup(tunnel->fd, &err); | |
194 | if (sock) | |
195 | sk = sock->sk; | |
196 | } else { | |
197 | /* Socket is owned by kernelspace */ | |
198 | sk = tunnel->sock; | |
8abbbe8f | 199 | sock_hold(sk); |
80d84ef3 TP |
200 | } |
201 | ||
202 | out: | |
203 | return sk; | |
204 | } | |
205 | EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_lookup); | |
206 | ||
207 | /* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */ | |
208 | void l2tp_tunnel_sock_put(struct sock *sk) | |
209 | { | |
210 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); | |
211 | if (tunnel) { | |
212 | if (tunnel->fd >= 0) { | |
213 | /* Socket is owned by userspace */ | |
214 | sockfd_put(sk->sk_socket); | |
215 | } | |
216 | sock_put(sk); | |
217 | } | |
8abbbe8f | 218 | sock_put(sk); |
80d84ef3 TP |
219 | } |
220 | EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put); | |
221 | ||
f7faffa3 JC |
222 | /* Lookup a session by id in the global session list |
223 | */ | |
224 | static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) | |
225 | { | |
226 | struct l2tp_net *pn = l2tp_pernet(net); | |
227 | struct hlist_head *session_list = | |
228 | l2tp_session_id_hash_2(pn, session_id); | |
229 | struct l2tp_session *session; | |
f7faffa3 | 230 | |
e02d494d | 231 | rcu_read_lock_bh(); |
b67bfe0d | 232 | hlist_for_each_entry_rcu(session, session_list, global_hlist) { |
f7faffa3 | 233 | if (session->session_id == session_id) { |
e02d494d | 234 | rcu_read_unlock_bh(); |
f7faffa3 JC |
235 | return session; |
236 | } | |
237 | } | |
e02d494d | 238 | rcu_read_unlock_bh(); |
f7faffa3 JC |
239 | |
240 | return NULL; | |
241 | } | |
242 | ||
fd558d18 JC |
243 | /* Session hash list. |
244 | * The session_id SHOULD be random according to RFC2661, but several | |
245 | * L2TP implementations (Cisco and Microsoft) use incrementing | |
246 | * session_ids. So we do a real hash on the session_id, rather than a | |
247 | * simple bitmask. | |
248 | */ | |
249 | static inline struct hlist_head * | |
250 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) | |
251 | { | |
252 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; | |
253 | } | |
254 | ||
255 | /* Lookup a session by id | |
256 | */ | |
f7faffa3 | 257 | struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) |
fd558d18 | 258 | { |
f7faffa3 | 259 | struct hlist_head *session_list; |
fd558d18 | 260 | struct l2tp_session *session; |
fd558d18 | 261 | |
f7faffa3 JC |
262 | /* In L2TPv3, session_ids are unique over all tunnels and we |
263 | * sometimes need to look them up before we know the | |
264 | * tunnel. | |
265 | */ | |
266 | if (tunnel == NULL) | |
267 | return l2tp_session_find_2(net, session_id); | |
268 | ||
269 | session_list = l2tp_session_id_hash(tunnel, session_id); | |
fd558d18 | 270 | read_lock_bh(&tunnel->hlist_lock); |
b67bfe0d | 271 | hlist_for_each_entry(session, session_list, hlist) { |
fd558d18 JC |
272 | if (session->session_id == session_id) { |
273 | read_unlock_bh(&tunnel->hlist_lock); | |
274 | return session; | |
275 | } | |
276 | } | |
277 | read_unlock_bh(&tunnel->hlist_lock); | |
278 | ||
279 | return NULL; | |
280 | } | |
281 | EXPORT_SYMBOL_GPL(l2tp_session_find); | |
282 | ||
283 | struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) | |
284 | { | |
285 | int hash; | |
fd558d18 JC |
286 | struct l2tp_session *session; |
287 | int count = 0; | |
288 | ||
289 | read_lock_bh(&tunnel->hlist_lock); | |
290 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { | |
b67bfe0d | 291 | hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { |
fd558d18 JC |
292 | if (++count > nth) { |
293 | read_unlock_bh(&tunnel->hlist_lock); | |
294 | return session; | |
295 | } | |
296 | } | |
297 | } | |
298 | ||
299 | read_unlock_bh(&tunnel->hlist_lock); | |
300 | ||
301 | return NULL; | |
302 | } | |
303 | EXPORT_SYMBOL_GPL(l2tp_session_find_nth); | |
304 | ||
309795f4 JC |
305 | /* Lookup a session by interface name. |
306 | * This is very inefficient but is only used by management interfaces. | |
307 | */ | |
308 | struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) | |
309 | { | |
310 | struct l2tp_net *pn = l2tp_pernet(net); | |
311 | int hash; | |
309795f4 JC |
312 | struct l2tp_session *session; |
313 | ||
e02d494d | 314 | rcu_read_lock_bh(); |
309795f4 | 315 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
b67bfe0d | 316 | hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { |
309795f4 | 317 | if (!strcmp(session->ifname, ifname)) { |
e02d494d | 318 | rcu_read_unlock_bh(); |
309795f4 JC |
319 | return session; |
320 | } | |
321 | } | |
322 | } | |
323 | ||
e02d494d | 324 | rcu_read_unlock_bh(); |
309795f4 JC |
325 | |
326 | return NULL; | |
327 | } | |
328 | EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); | |
329 | ||
fd558d18 JC |
330 | /* Lookup a tunnel by id |
331 | */ | |
332 | struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) | |
333 | { | |
334 | struct l2tp_tunnel *tunnel; | |
335 | struct l2tp_net *pn = l2tp_pernet(net); | |
336 | ||
e02d494d JC |
337 | rcu_read_lock_bh(); |
338 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
fd558d18 | 339 | if (tunnel->tunnel_id == tunnel_id) { |
e02d494d | 340 | rcu_read_unlock_bh(); |
fd558d18 JC |
341 | return tunnel; |
342 | } | |
343 | } | |
e02d494d | 344 | rcu_read_unlock_bh(); |
fd558d18 JC |
345 | |
346 | return NULL; | |
347 | } | |
348 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find); | |
349 | ||
350 | struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) | |
351 | { | |
352 | struct l2tp_net *pn = l2tp_pernet(net); | |
353 | struct l2tp_tunnel *tunnel; | |
354 | int count = 0; | |
355 | ||
e02d494d JC |
356 | rcu_read_lock_bh(); |
357 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
fd558d18 | 358 | if (++count > nth) { |
e02d494d | 359 | rcu_read_unlock_bh(); |
fd558d18 JC |
360 | return tunnel; |
361 | } | |
362 | } | |
363 | ||
e02d494d | 364 | rcu_read_unlock_bh(); |
fd558d18 JC |
365 | |
366 | return NULL; | |
367 | } | |
368 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); | |
369 | ||
370 | /***************************************************************************** | |
371 | * Receive data handling | |
372 | *****************************************************************************/ | |
373 | ||
374 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence | |
375 | * number. | |
376 | */ | |
377 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
378 | { | |
379 | struct sk_buff *skbp; | |
380 | struct sk_buff *tmp; | |
f7faffa3 | 381 | u32 ns = L2TP_SKB_CB(skb)->ns; |
fd558d18 JC |
382 | |
383 | spin_lock_bh(&session->reorder_q.lock); | |
384 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { | |
385 | if (L2TP_SKB_CB(skbp)->ns > ns) { | |
386 | __skb_queue_before(&session->reorder_q, skbp, skb); | |
a4ca44fa JP |
387 | l2tp_dbg(session, L2TP_MSG_SEQ, |
388 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", | |
389 | session->name, ns, L2TP_SKB_CB(skbp)->ns, | |
390 | skb_queue_len(&session->reorder_q)); | |
7b7c0719 | 391 | atomic_long_inc(&session->stats.rx_oos_packets); |
fd558d18 JC |
392 | goto out; |
393 | } | |
394 | } | |
395 | ||
396 | __skb_queue_tail(&session->reorder_q, skb); | |
397 | ||
398 | out: | |
399 | spin_unlock_bh(&session->reorder_q.lock); | |
400 | } | |
401 | ||
402 | /* Dequeue a single skb. | |
403 | */ | |
404 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
405 | { | |
406 | struct l2tp_tunnel *tunnel = session->tunnel; | |
407 | int length = L2TP_SKB_CB(skb)->length; | |
408 | ||
409 | /* We're about to requeue the skb, so return resources | |
410 | * to its current owner (a socket receive buffer). | |
411 | */ | |
412 | skb_orphan(skb); | |
413 | ||
7b7c0719 TP |
414 | atomic_long_inc(&tunnel->stats.rx_packets); |
415 | atomic_long_add(length, &tunnel->stats.rx_bytes); | |
416 | atomic_long_inc(&session->stats.rx_packets); | |
417 | atomic_long_add(length, &session->stats.rx_bytes); | |
fd558d18 JC |
418 | |
419 | if (L2TP_SKB_CB(skb)->has_seq) { | |
420 | /* Bump our Nr */ | |
421 | session->nr++; | |
8a1631d5 | 422 | session->nr &= session->nr_max; |
f7faffa3 | 423 | |
a4ca44fa JP |
424 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", |
425 | session->name, session->nr); | |
fd558d18 JC |
426 | } |
427 | ||
428 | /* call private receive handler */ | |
429 | if (session->recv_skb != NULL) | |
430 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); | |
431 | else | |
432 | kfree_skb(skb); | |
433 | ||
434 | if (session->deref) | |
435 | (*session->deref)(session); | |
436 | } | |
437 | ||
438 | /* Dequeue skbs from the session's reorder_q, subject to packet order. | |
439 | * Skbs that have been in the queue for too long are simply discarded. | |
440 | */ | |
441 | static void l2tp_recv_dequeue(struct l2tp_session *session) | |
442 | { | |
443 | struct sk_buff *skb; | |
444 | struct sk_buff *tmp; | |
445 | ||
446 | /* If the pkt at the head of the queue has the nr that we | |
447 | * expect to send up next, dequeue it and any other | |
448 | * in-sequence packets behind it. | |
449 | */ | |
e2e210c0 | 450 | start: |
fd558d18 JC |
451 | spin_lock_bh(&session->reorder_q.lock); |
452 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { | |
453 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { | |
7b7c0719 TP |
454 | atomic_long_inc(&session->stats.rx_seq_discards); |
455 | atomic_long_inc(&session->stats.rx_errors); | |
a4ca44fa JP |
456 | l2tp_dbg(session, L2TP_MSG_SEQ, |
457 | "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", | |
458 | session->name, L2TP_SKB_CB(skb)->ns, | |
459 | L2TP_SKB_CB(skb)->length, session->nr, | |
460 | skb_queue_len(&session->reorder_q)); | |
38d40b3f | 461 | session->reorder_skip = 1; |
fd558d18 JC |
462 | __skb_unlink(skb, &session->reorder_q); |
463 | kfree_skb(skb); | |
464 | if (session->deref) | |
465 | (*session->deref)(session); | |
466 | continue; | |
467 | } | |
468 | ||
469 | if (L2TP_SKB_CB(skb)->has_seq) { | |
38d40b3f | 470 | if (session->reorder_skip) { |
a4ca44fa JP |
471 | l2tp_dbg(session, L2TP_MSG_SEQ, |
472 | "%s: advancing nr to next pkt: %u -> %u", | |
473 | session->name, session->nr, | |
474 | L2TP_SKB_CB(skb)->ns); | |
38d40b3f JC |
475 | session->reorder_skip = 0; |
476 | session->nr = L2TP_SKB_CB(skb)->ns; | |
477 | } | |
fd558d18 | 478 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
a4ca44fa JP |
479 | l2tp_dbg(session, L2TP_MSG_SEQ, |
480 | "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", | |
481 | session->name, L2TP_SKB_CB(skb)->ns, | |
482 | L2TP_SKB_CB(skb)->length, session->nr, | |
483 | skb_queue_len(&session->reorder_q)); | |
fd558d18 JC |
484 | goto out; |
485 | } | |
486 | } | |
487 | __skb_unlink(skb, &session->reorder_q); | |
488 | ||
489 | /* Process the skb. We release the queue lock while we | |
490 | * do so to let other contexts process the queue. | |
491 | */ | |
492 | spin_unlock_bh(&session->reorder_q.lock); | |
493 | l2tp_recv_dequeue_skb(session, skb); | |
e2e210c0 | 494 | goto start; |
fd558d18 JC |
495 | } |
496 | ||
497 | out: | |
498 | spin_unlock_bh(&session->reorder_q.lock); | |
499 | } | |
500 | ||
501 | static inline int l2tp_verify_udp_checksum(struct sock *sk, | |
502 | struct sk_buff *skb) | |
503 | { | |
504 | struct udphdr *uh = udp_hdr(skb); | |
505 | u16 ulen = ntohs(uh->len); | |
fd558d18 JC |
506 | __wsum psum; |
507 | ||
d2cf3361 | 508 | if (sk->sk_no_check || skb_csum_unnecessary(skb)) |
fd558d18 JC |
509 | return 0; |
510 | ||
d2cf3361 | 511 | #if IS_ENABLED(CONFIG_IPV6) |
8d8a51e2 | 512 | if (sk->sk_family == PF_INET6 && !l2tp_tunnel(sk)->v4mapped) { |
d2cf3361 BL |
513 | if (!uh->check) { |
514 | LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n"); | |
515 | return 1; | |
516 | } | |
517 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && | |
518 | !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, | |
519 | &ipv6_hdr(skb)->daddr, ulen, | |
520 | IPPROTO_UDP, skb->csum)) { | |
521 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
522 | return 0; | |
523 | } | |
524 | skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, | |
525 | &ipv6_hdr(skb)->daddr, | |
526 | skb->len, IPPROTO_UDP, | |
527 | 0)); | |
528 | } else | |
529 | #endif | |
530 | { | |
531 | struct inet_sock *inet; | |
532 | if (!uh->check) | |
533 | return 0; | |
534 | inet = inet_sk(sk); | |
535 | psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, | |
536 | ulen, IPPROTO_UDP, 0); | |
537 | ||
538 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && | |
539 | !csum_fold(csum_add(psum, skb->csum))) | |
540 | return 0; | |
541 | skb->csum = psum; | |
542 | } | |
fd558d18 JC |
543 | |
544 | return __skb_checksum_complete(skb); | |
545 | } | |
546 | ||
8a1631d5 JC |
547 | static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) |
548 | { | |
549 | u32 nws; | |
550 | ||
551 | if (nr >= session->nr) | |
552 | nws = nr - session->nr; | |
553 | else | |
554 | nws = (session->nr_max + 1) - (session->nr - nr); | |
555 | ||
556 | return nws < session->nr_window_size; | |
557 | } | |
558 | ||
b6dc01a4 JC |
559 | /* If packet has sequence numbers, queue it if acceptable. Returns 0 if |
560 | * acceptable, else non-zero. | |
561 | */ | |
562 | static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) | |
563 | { | |
8a1631d5 JC |
564 | if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { |
565 | /* Packet sequence number is outside allowed window. | |
566 | * Discard it. | |
567 | */ | |
568 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
569 | "%s: pkt %u len %d discarded, outside window, nr=%u\n", | |
570 | session->name, L2TP_SKB_CB(skb)->ns, | |
571 | L2TP_SKB_CB(skb)->length, session->nr); | |
572 | goto discard; | |
573 | } | |
574 | ||
b6dc01a4 JC |
575 | if (session->reorder_timeout != 0) { |
576 | /* Packet reordering enabled. Add skb to session's | |
577 | * reorder queue, in order of ns. | |
578 | */ | |
579 | l2tp_recv_queue_skb(session, skb); | |
a0dbd822 JC |
580 | goto out; |
581 | } | |
582 | ||
583 | /* Packet reordering disabled. Discard out-of-sequence packets, while | |
584 | * tracking the number if in-sequence packets after the first OOS packet | |
585 | * is seen. After nr_oos_count_max in-sequence packets, reset the | |
586 | * sequence number to re-enable packet reception. | |
587 | */ | |
588 | if (L2TP_SKB_CB(skb)->ns == session->nr) { | |
589 | skb_queue_tail(&session->reorder_q, skb); | |
b6dc01a4 | 590 | } else { |
a0dbd822 JC |
591 | u32 nr_oos = L2TP_SKB_CB(skb)->ns; |
592 | u32 nr_next = (session->nr_oos + 1) & session->nr_max; | |
593 | ||
594 | if (nr_oos == nr_next) | |
595 | session->nr_oos_count++; | |
596 | else | |
597 | session->nr_oos_count = 0; | |
598 | ||
599 | session->nr_oos = nr_oos; | |
600 | if (session->nr_oos_count > session->nr_oos_count_max) { | |
601 | session->reorder_skip = 1; | |
602 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
603 | "%s: %d oos packets received. Resetting sequence numbers\n", | |
604 | session->name, session->nr_oos_count); | |
605 | } | |
606 | if (!session->reorder_skip) { | |
b6dc01a4 JC |
607 | atomic_long_inc(&session->stats.rx_seq_discards); |
608 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
609 | "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", | |
610 | session->name, L2TP_SKB_CB(skb)->ns, | |
611 | L2TP_SKB_CB(skb)->length, session->nr, | |
612 | skb_queue_len(&session->reorder_q)); | |
613 | goto discard; | |
614 | } | |
615 | skb_queue_tail(&session->reorder_q, skb); | |
616 | } | |
617 | ||
a0dbd822 | 618 | out: |
b6dc01a4 JC |
619 | return 0; |
620 | ||
621 | discard: | |
622 | return 1; | |
623 | } | |
624 | ||
f7faffa3 JC |
625 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
626 | * and L2TPv3 data frames here. | |
627 | * | |
628 | * L2TPv2 Data Message Header | |
629 | * | |
630 | * 0 1 2 3 | |
631 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |
632 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
633 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | | |
634 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
635 | * | Tunnel ID | Session ID | | |
636 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
637 | * | Ns (opt) | Nr (opt) | | |
638 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
639 | * | Offset Size (opt) | Offset pad... (opt) | |
640 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
641 | * | |
642 | * Data frames are marked by T=0. All other fields are the same as | |
643 | * those in L2TP control frames. | |
644 | * | |
645 | * L2TPv3 Data Message Header | |
646 | * | |
647 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
648 | * | L2TP Session Header | | |
649 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
650 | * | L2-Specific Sublayer | | |
651 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
652 | * | Tunnel Payload ... | |
653 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
654 | * | |
655 | * L2TPv3 Session Header Over IP | |
656 | * | |
657 | * 0 1 2 3 | |
658 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |
659 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
660 | * | Session ID | | |
661 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
662 | * | Cookie (optional, maximum 64 bits)... | |
663 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
664 | * | | |
665 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
666 | * | |
667 | * L2TPv3 L2-Specific Sublayer Format | |
668 | * | |
669 | * 0 1 2 3 | |
670 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |
671 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
672 | * |x|S|x|x|x|x|x|x| Sequence Number | | |
673 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
674 | * | |
675 | * Cookie value, sublayer format and offset (pad) are negotiated with | |
676 | * the peer when the session is set up. Unlike L2TPv2, we do not need | |
677 | * to parse the packet header to determine if optional fields are | |
678 | * present. | |
679 | * | |
680 | * Caller must already have parsed the frame and determined that it is | |
681 | * a data (not control) frame before coming here. Fields up to the | |
682 | * session-id have already been parsed and ptr points to the data | |
683 | * after the session-id. | |
fd558d18 | 684 | */ |
f7faffa3 JC |
685 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
686 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, | |
687 | int length, int (*payload_hook)(struct sk_buff *skb)) | |
fd558d18 | 688 | { |
f7faffa3 | 689 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 690 | int offset; |
f7faffa3 | 691 | u32 ns, nr; |
fd558d18 JC |
692 | |
693 | /* The ref count is increased since we now hold a pointer to | |
694 | * the session. Take care to decrement the refcnt when exiting | |
695 | * this function from now on... | |
696 | */ | |
697 | l2tp_session_inc_refcount(session); | |
698 | if (session->ref) | |
699 | (*session->ref)(session); | |
700 | ||
f7faffa3 JC |
701 | /* Parse and check optional cookie */ |
702 | if (session->peer_cookie_len > 0) { | |
703 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { | |
a4ca44fa JP |
704 | l2tp_info(tunnel, L2TP_MSG_DATA, |
705 | "%s: cookie mismatch (%u/%u). Discarding.\n", | |
706 | tunnel->name, tunnel->tunnel_id, | |
707 | session->session_id); | |
7b7c0719 | 708 | atomic_long_inc(&session->stats.rx_cookie_discards); |
f7faffa3 JC |
709 | goto discard; |
710 | } | |
711 | ptr += session->peer_cookie_len; | |
712 | } | |
713 | ||
fd558d18 JC |
714 | /* Handle the optional sequence numbers. Sequence numbers are |
715 | * in different places for L2TPv2 and L2TPv3. | |
716 | * | |
717 | * If we are the LAC, enable/disable sequence numbers under | |
718 | * the control of the LNS. If no sequence numbers present but | |
719 | * we were expecting them, discard frame. | |
720 | */ | |
721 | ns = nr = 0; | |
722 | L2TP_SKB_CB(skb)->has_seq = 0; | |
f7faffa3 JC |
723 | if (tunnel->version == L2TP_HDR_VER_2) { |
724 | if (hdrflags & L2TP_HDRFLAG_S) { | |
725 | ns = ntohs(*(__be16 *) ptr); | |
726 | ptr += 2; | |
727 | nr = ntohs(*(__be16 *) ptr); | |
728 | ptr += 2; | |
fd558d18 | 729 | |
f7faffa3 JC |
730 | /* Store L2TP info in the skb */ |
731 | L2TP_SKB_CB(skb)->ns = ns; | |
732 | L2TP_SKB_CB(skb)->has_seq = 1; | |
fd558d18 | 733 | |
a4ca44fa JP |
734 | l2tp_dbg(session, L2TP_MSG_SEQ, |
735 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", | |
736 | session->name, ns, nr, session->nr); | |
f7faffa3 JC |
737 | } |
738 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
739 | u32 l2h = ntohl(*(__be32 *) ptr); | |
740 | ||
741 | if (l2h & 0x40000000) { | |
742 | ns = l2h & 0x00ffffff; | |
743 | ||
744 | /* Store L2TP info in the skb */ | |
745 | L2TP_SKB_CB(skb)->ns = ns; | |
746 | L2TP_SKB_CB(skb)->has_seq = 1; | |
747 | ||
a4ca44fa JP |
748 | l2tp_dbg(session, L2TP_MSG_SEQ, |
749 | "%s: recv data ns=%u, session nr=%u\n", | |
750 | session->name, ns, session->nr); | |
f7faffa3 | 751 | } |
fd558d18 JC |
752 | } |
753 | ||
f7faffa3 JC |
754 | /* Advance past L2-specific header, if present */ |
755 | ptr += session->l2specific_len; | |
756 | ||
fd558d18 JC |
757 | if (L2TP_SKB_CB(skb)->has_seq) { |
758 | /* Received a packet with sequence numbers. If we're the LNS, | |
759 | * check if we sre sending sequence numbers and if not, | |
760 | * configure it so. | |
761 | */ | |
762 | if ((!session->lns_mode) && (!session->send_seq)) { | |
a4ca44fa JP |
763 | l2tp_info(session, L2TP_MSG_SEQ, |
764 | "%s: requested to enable seq numbers by LNS\n", | |
765 | session->name); | |
fd558d18 | 766 | session->send_seq = -1; |
f7faffa3 | 767 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
768 | } |
769 | } else { | |
770 | /* No sequence numbers. | |
771 | * If user has configured mandatory sequence numbers, discard. | |
772 | */ | |
773 | if (session->recv_seq) { | |
a4ca44fa JP |
774 | l2tp_warn(session, L2TP_MSG_SEQ, |
775 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
776 | session->name); | |
7b7c0719 | 777 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
778 | goto discard; |
779 | } | |
780 | ||
781 | /* If we're the LAC and we're sending sequence numbers, the | |
782 | * LNS has requested that we no longer send sequence numbers. | |
783 | * If we're the LNS and we're sending sequence numbers, the | |
784 | * LAC is broken. Discard the frame. | |
785 | */ | |
786 | if ((!session->lns_mode) && (session->send_seq)) { | |
a4ca44fa JP |
787 | l2tp_info(session, L2TP_MSG_SEQ, |
788 | "%s: requested to disable seq numbers by LNS\n", | |
789 | session->name); | |
fd558d18 | 790 | session->send_seq = 0; |
f7faffa3 | 791 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 | 792 | } else if (session->send_seq) { |
a4ca44fa JP |
793 | l2tp_warn(session, L2TP_MSG_SEQ, |
794 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
795 | session->name); | |
7b7c0719 | 796 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
797 | goto discard; |
798 | } | |
799 | } | |
800 | ||
f7faffa3 JC |
801 | /* Session data offset is handled differently for L2TPv2 and |
802 | * L2TPv3. For L2TPv2, there is an optional 16-bit value in | |
803 | * the header. For L2TPv3, the offset is negotiated using AVPs | |
804 | * in the session setup control protocol. | |
805 | */ | |
806 | if (tunnel->version == L2TP_HDR_VER_2) { | |
807 | /* If offset bit set, skip it. */ | |
808 | if (hdrflags & L2TP_HDRFLAG_O) { | |
809 | offset = ntohs(*(__be16 *)ptr); | |
810 | ptr += 2 + offset; | |
811 | } | |
812 | } else | |
813 | ptr += session->offset; | |
fd558d18 JC |
814 | |
815 | offset = ptr - optr; | |
816 | if (!pskb_may_pull(skb, offset)) | |
817 | goto discard; | |
818 | ||
819 | __skb_pull(skb, offset); | |
820 | ||
821 | /* If caller wants to process the payload before we queue the | |
822 | * packet, do so now. | |
823 | */ | |
824 | if (payload_hook) | |
825 | if ((*payload_hook)(skb)) | |
826 | goto discard; | |
827 | ||
828 | /* Prepare skb for adding to the session's reorder_q. Hold | |
829 | * packets for max reorder_timeout or 1 second if not | |
830 | * reordering. | |
831 | */ | |
832 | L2TP_SKB_CB(skb)->length = length; | |
833 | L2TP_SKB_CB(skb)->expires = jiffies + | |
834 | (session->reorder_timeout ? session->reorder_timeout : HZ); | |
835 | ||
836 | /* Add packet to the session's receive queue. Reordering is done here, if | |
837 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. | |
838 | */ | |
839 | if (L2TP_SKB_CB(skb)->has_seq) { | |
b6dc01a4 JC |
840 | if (l2tp_recv_data_seq(session, skb)) |
841 | goto discard; | |
fd558d18 JC |
842 | } else { |
843 | /* No sequence numbers. Add the skb to the tail of the | |
844 | * reorder queue. This ensures that it will be | |
845 | * delivered after all previous sequenced skbs. | |
846 | */ | |
847 | skb_queue_tail(&session->reorder_q, skb); | |
848 | } | |
849 | ||
850 | /* Try to dequeue as many skbs from reorder_q as we can. */ | |
851 | l2tp_recv_dequeue(session); | |
852 | ||
853 | l2tp_session_dec_refcount(session); | |
854 | ||
f7faffa3 | 855 | return; |
fd558d18 JC |
856 | |
857 | discard: | |
7b7c0719 | 858 | atomic_long_inc(&session->stats.rx_errors); |
fd558d18 JC |
859 | kfree_skb(skb); |
860 | ||
861 | if (session->deref) | |
862 | (*session->deref)(session); | |
863 | ||
864 | l2tp_session_dec_refcount(session); | |
f7faffa3 JC |
865 | } |
866 | EXPORT_SYMBOL(l2tp_recv_common); | |
867 | ||
48f72f92 TP |
868 | /* Drop skbs from the session's reorder_q |
869 | */ | |
870 | int l2tp_session_queue_purge(struct l2tp_session *session) | |
871 | { | |
872 | struct sk_buff *skb = NULL; | |
873 | BUG_ON(!session); | |
874 | BUG_ON(session->magic != L2TP_SESSION_MAGIC); | |
875 | while ((skb = skb_dequeue(&session->reorder_q))) { | |
876 | atomic_long_inc(&session->stats.rx_errors); | |
877 | kfree_skb(skb); | |
878 | if (session->deref) | |
879 | (*session->deref)(session); | |
880 | } | |
881 | return 0; | |
882 | } | |
883 | EXPORT_SYMBOL_GPL(l2tp_session_queue_purge); | |
884 | ||
f7faffa3 JC |
885 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
886 | * here. The skb is not on a list when we get here. | |
887 | * Returns 0 if the packet was a data packet and was successfully passed on. | |
888 | * Returns 1 if the packet was not a good data packet and could not be | |
889 | * forwarded. All such packets are passed up to userspace to deal with. | |
890 | */ | |
fc130840 | 891 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, |
892 | int (*payload_hook)(struct sk_buff *skb)) | |
f7faffa3 JC |
893 | { |
894 | struct l2tp_session *session = NULL; | |
895 | unsigned char *ptr, *optr; | |
896 | u16 hdrflags; | |
897 | u32 tunnel_id, session_id; | |
f7faffa3 JC |
898 | u16 version; |
899 | int length; | |
900 | ||
901 | if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) | |
902 | goto discard_bad_csum; | |
903 | ||
904 | /* UDP always verifies the packet length. */ | |
905 | __skb_pull(skb, sizeof(struct udphdr)); | |
906 | ||
907 | /* Short packet? */ | |
908 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { | |
a4ca44fa JP |
909 | l2tp_info(tunnel, L2TP_MSG_DATA, |
910 | "%s: recv short packet (len=%d)\n", | |
911 | tunnel->name, skb->len); | |
f7faffa3 JC |
912 | goto error; |
913 | } | |
914 | ||
f7faffa3 JC |
915 | /* Trace packet contents, if enabled */ |
916 | if (tunnel->debug & L2TP_MSG_DATA) { | |
917 | length = min(32u, skb->len); | |
918 | if (!pskb_may_pull(skb, length)) | |
919 | goto error; | |
920 | ||
a4ca44fa JP |
921 | pr_debug("%s: recv\n", tunnel->name); |
922 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); | |
f7faffa3 JC |
923 | } |
924 | ||
e50e705c ED |
925 | /* Point to L2TP header */ |
926 | optr = ptr = skb->data; | |
927 | ||
f7faffa3 JC |
928 | /* Get L2TP header flags */ |
929 | hdrflags = ntohs(*(__be16 *) ptr); | |
930 | ||
931 | /* Check protocol version */ | |
932 | version = hdrflags & L2TP_HDR_VER_MASK; | |
933 | if (version != tunnel->version) { | |
a4ca44fa JP |
934 | l2tp_info(tunnel, L2TP_MSG_DATA, |
935 | "%s: recv protocol version mismatch: got %d expected %d\n", | |
936 | tunnel->name, version, tunnel->version); | |
f7faffa3 JC |
937 | goto error; |
938 | } | |
939 | ||
940 | /* Get length of L2TP packet */ | |
941 | length = skb->len; | |
942 | ||
943 | /* If type is control packet, it is handled by userspace. */ | |
944 | if (hdrflags & L2TP_HDRFLAG_T) { | |
a4ca44fa JP |
945 | l2tp_dbg(tunnel, L2TP_MSG_DATA, |
946 | "%s: recv control packet, len=%d\n", | |
947 | tunnel->name, length); | |
f7faffa3 JC |
948 | goto error; |
949 | } | |
950 | ||
951 | /* Skip flags */ | |
952 | ptr += 2; | |
953 | ||
954 | if (tunnel->version == L2TP_HDR_VER_2) { | |
955 | /* If length is present, skip it */ | |
956 | if (hdrflags & L2TP_HDRFLAG_L) | |
957 | ptr += 2; | |
958 | ||
959 | /* Extract tunnel and session ID */ | |
960 | tunnel_id = ntohs(*(__be16 *) ptr); | |
961 | ptr += 2; | |
962 | session_id = ntohs(*(__be16 *) ptr); | |
963 | ptr += 2; | |
964 | } else { | |
965 | ptr += 2; /* skip reserved bits */ | |
966 | tunnel_id = tunnel->tunnel_id; | |
967 | session_id = ntohl(*(__be32 *) ptr); | |
968 | ptr += 4; | |
969 | } | |
970 | ||
971 | /* Find the session context */ | |
972 | session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); | |
309795f4 | 973 | if (!session || !session->recv_skb) { |
f7faffa3 | 974 | /* Not found? Pass to userspace to deal with */ |
a4ca44fa JP |
975 | l2tp_info(tunnel, L2TP_MSG_DATA, |
976 | "%s: no session found (%u/%u). Passing up.\n", | |
977 | tunnel->name, tunnel_id, session_id); | |
f7faffa3 JC |
978 | goto error; |
979 | } | |
980 | ||
981 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); | |
fd558d18 JC |
982 | |
983 | return 0; | |
984 | ||
985 | discard_bad_csum: | |
986 | LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); | |
987 | UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); | |
7b7c0719 | 988 | atomic_long_inc(&tunnel->stats.rx_errors); |
fd558d18 JC |
989 | kfree_skb(skb); |
990 | ||
991 | return 0; | |
992 | ||
993 | error: | |
994 | /* Put UDP header back */ | |
995 | __skb_push(skb, sizeof(struct udphdr)); | |
996 | ||
997 | return 1; | |
998 | } | |
fd558d18 JC |
999 | |
1000 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. | |
1001 | * Return codes: | |
1002 | * 0 : success. | |
1003 | * <0: error | |
1004 | * >0: skb should be passed up to userspace as UDP. | |
1005 | */ | |
1006 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) | |
1007 | { | |
1008 | struct l2tp_tunnel *tunnel; | |
1009 | ||
1010 | tunnel = l2tp_sock_to_tunnel(sk); | |
1011 | if (tunnel == NULL) | |
1012 | goto pass_up; | |
1013 | ||
a4ca44fa JP |
1014 | l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", |
1015 | tunnel->name, skb->len); | |
fd558d18 JC |
1016 | |
1017 | if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) | |
1018 | goto pass_up_put; | |
1019 | ||
1020 | sock_put(sk); | |
1021 | return 0; | |
1022 | ||
1023 | pass_up_put: | |
1024 | sock_put(sk); | |
1025 | pass_up: | |
1026 | return 1; | |
1027 | } | |
1028 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); | |
1029 | ||
1030 | /************************************************************************ | |
1031 | * Transmit handling | |
1032 | ***********************************************************************/ | |
1033 | ||
1034 | /* Build an L2TP header for the session into the buffer provided. | |
1035 | */ | |
f7faffa3 | 1036 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
fd558d18 | 1037 | { |
f7faffa3 | 1038 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 1039 | __be16 *bufp = buf; |
f7faffa3 | 1040 | __be16 *optr = buf; |
fd558d18 JC |
1041 | u16 flags = L2TP_HDR_VER_2; |
1042 | u32 tunnel_id = tunnel->peer_tunnel_id; | |
1043 | u32 session_id = session->peer_session_id; | |
1044 | ||
1045 | if (session->send_seq) | |
1046 | flags |= L2TP_HDRFLAG_S; | |
1047 | ||
1048 | /* Setup L2TP header. */ | |
1049 | *bufp++ = htons(flags); | |
1050 | *bufp++ = htons(tunnel_id); | |
1051 | *bufp++ = htons(session_id); | |
1052 | if (session->send_seq) { | |
1053 | *bufp++ = htons(session->ns); | |
1054 | *bufp++ = 0; | |
1055 | session->ns++; | |
f7faffa3 | 1056 | session->ns &= 0xffff; |
a4ca44fa JP |
1057 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", |
1058 | session->name, session->ns); | |
fd558d18 | 1059 | } |
f7faffa3 JC |
1060 | |
1061 | return bufp - optr; | |
fd558d18 JC |
1062 | } |
1063 | ||
f7faffa3 | 1064 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
fd558d18 | 1065 | { |
0d76751f | 1066 | struct l2tp_tunnel *tunnel = session->tunnel; |
f7faffa3 JC |
1067 | char *bufp = buf; |
1068 | char *optr = bufp; | |
f7faffa3 | 1069 | |
0d76751f JC |
1070 | /* Setup L2TP header. The header differs slightly for UDP and |
1071 | * IP encapsulations. For UDP, there is 4 bytes of flags. | |
1072 | */ | |
1073 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
1074 | u16 flags = L2TP_HDR_VER_3; | |
1075 | *((__be16 *) bufp) = htons(flags); | |
1076 | bufp += 2; | |
1077 | *((__be16 *) bufp) = 0; | |
1078 | bufp += 2; | |
1079 | } | |
1080 | ||
f7faffa3 JC |
1081 | *((__be32 *) bufp) = htonl(session->peer_session_id); |
1082 | bufp += 4; | |
1083 | if (session->cookie_len) { | |
1084 | memcpy(bufp, &session->cookie[0], session->cookie_len); | |
1085 | bufp += session->cookie_len; | |
1086 | } | |
1087 | if (session->l2specific_len) { | |
1088 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
1089 | u32 l2h = 0; | |
1090 | if (session->send_seq) { | |
1091 | l2h = 0x40000000 | session->ns; | |
1092 | session->ns++; | |
1093 | session->ns &= 0xffffff; | |
a4ca44fa JP |
1094 | l2tp_dbg(session, L2TP_MSG_SEQ, |
1095 | "%s: updated ns to %u\n", | |
1096 | session->name, session->ns); | |
f7faffa3 JC |
1097 | } |
1098 | ||
1099 | *((__be32 *) bufp) = htonl(l2h); | |
1100 | } | |
1101 | bufp += session->l2specific_len; | |
1102 | } | |
1103 | if (session->offset) | |
1104 | bufp += session->offset; | |
fd558d18 | 1105 | |
f7faffa3 | 1106 | return bufp - optr; |
fd558d18 | 1107 | } |
fd558d18 | 1108 | |
fc130840 | 1109 | static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, |
d9d8da80 | 1110 | struct flowi *fl, size_t data_len) |
fd558d18 JC |
1111 | { |
1112 | struct l2tp_tunnel *tunnel = session->tunnel; | |
1113 | unsigned int len = skb->len; | |
1114 | int error; | |
1115 | ||
1116 | /* Debug */ | |
1117 | if (session->send_seq) | |
a4ca44fa JP |
1118 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes, ns=%u\n", |
1119 | session->name, data_len, session->ns - 1); | |
fd558d18 | 1120 | else |
a4ca44fa JP |
1121 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes\n", |
1122 | session->name, data_len); | |
fd558d18 JC |
1123 | |
1124 | if (session->debug & L2TP_MSG_DATA) { | |
0d76751f JC |
1125 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1126 | unsigned char *datap = skb->data + uhlen; | |
fd558d18 | 1127 | |
a4ca44fa JP |
1128 | pr_debug("%s: xmit\n", session->name); |
1129 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, | |
1130 | datap, min_t(size_t, 32, len - uhlen)); | |
fd558d18 JC |
1131 | } |
1132 | ||
1133 | /* Queue the packet to IP for output */ | |
4e15ed4d | 1134 | skb->local_df = 1; |
d2cf3361 | 1135 | #if IS_ENABLED(CONFIG_IPV6) |
e18503f4 | 1136 | if (skb->sk->sk_family == PF_INET6 && !tunnel->v4mapped) |
d2cf3361 BL |
1137 | error = inet6_csk_xmit(skb, NULL); |
1138 | else | |
1139 | #endif | |
1140 | error = ip_queue_xmit(skb, fl); | |
fd558d18 JC |
1141 | |
1142 | /* Update stats */ | |
1143 | if (error >= 0) { | |
7b7c0719 TP |
1144 | atomic_long_inc(&tunnel->stats.tx_packets); |
1145 | atomic_long_add(len, &tunnel->stats.tx_bytes); | |
1146 | atomic_long_inc(&session->stats.tx_packets); | |
1147 | atomic_long_add(len, &session->stats.tx_bytes); | |
fd558d18 | 1148 | } else { |
7b7c0719 TP |
1149 | atomic_long_inc(&tunnel->stats.tx_errors); |
1150 | atomic_long_inc(&session->stats.tx_errors); | |
fd558d18 JC |
1151 | } |
1152 | ||
1153 | return 0; | |
1154 | } | |
fd558d18 JC |
1155 | |
1156 | /* Automatically called when the skb is freed. | |
1157 | */ | |
1158 | static void l2tp_sock_wfree(struct sk_buff *skb) | |
1159 | { | |
1160 | sock_put(skb->sk); | |
1161 | } | |
1162 | ||
1163 | /* For data skbs that we transmit, we associate with the tunnel socket | |
1164 | * but don't do accounting. | |
1165 | */ | |
1166 | static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) | |
1167 | { | |
1168 | sock_hold(sk); | |
1169 | skb->sk = sk; | |
1170 | skb->destructor = l2tp_sock_wfree; | |
1171 | } | |
1172 | ||
d2cf3361 BL |
1173 | #if IS_ENABLED(CONFIG_IPV6) |
1174 | static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb, | |
1175 | int udp_len) | |
1176 | { | |
1177 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1178 | struct udphdr *uh = udp_hdr(skb); | |
1179 | ||
1180 | if (!skb_dst(skb) || !skb_dst(skb)->dev || | |
1181 | !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) { | |
1182 | __wsum csum = skb_checksum(skb, 0, udp_len, 0); | |
1183 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
efe4208f | 1184 | uh->check = csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr, udp_len, |
d2cf3361 BL |
1185 | IPPROTO_UDP, csum); |
1186 | if (uh->check == 0) | |
1187 | uh->check = CSUM_MANGLED_0; | |
1188 | } else { | |
1189 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1190 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
1191 | skb->csum_offset = offsetof(struct udphdr, check); | |
efe4208f | 1192 | uh->check = ~csum_ipv6_magic(&np->saddr, &sk->sk_v6_daddr, |
d2cf3361 BL |
1193 | udp_len, IPPROTO_UDP, 0); |
1194 | } | |
1195 | } | |
1196 | #endif | |
1197 | ||
fd558d18 JC |
1198 | /* If caller requires the skb to have a ppp header, the header must be |
1199 | * inserted in the skb data before calling this function. | |
1200 | */ | |
1201 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) | |
1202 | { | |
1203 | int data_len = skb->len; | |
0d76751f JC |
1204 | struct l2tp_tunnel *tunnel = session->tunnel; |
1205 | struct sock *sk = tunnel->sock; | |
d9d8da80 | 1206 | struct flowi *fl; |
fd558d18 | 1207 | struct udphdr *uh; |
fd558d18 JC |
1208 | struct inet_sock *inet; |
1209 | __wsum csum; | |
fd558d18 | 1210 | int headroom; |
0d76751f JC |
1211 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1212 | int udp_len; | |
b8c84307 | 1213 | int ret = NET_XMIT_SUCCESS; |
fd558d18 JC |
1214 | |
1215 | /* Check that there's enough headroom in the skb to insert IP, | |
1216 | * UDP and L2TP headers. If not enough, expand it to | |
1217 | * make room. Adjust truesize. | |
1218 | */ | |
1219 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + | |
0d76751f | 1220 | uhlen + hdr_len; |
835acf5d | 1221 | if (skb_cow_head(skb, headroom)) { |
b8c84307 ED |
1222 | kfree_skb(skb); |
1223 | return NET_XMIT_DROP; | |
835acf5d | 1224 | } |
fd558d18 | 1225 | |
fd558d18 | 1226 | skb_orphan(skb); |
fd558d18 | 1227 | /* Setup L2TP header */ |
f7faffa3 | 1228 | session->build_header(session, __skb_push(skb, hdr_len)); |
fd558d18 | 1229 | |
0d76751f | 1230 | /* Reset skb netfilter state */ |
fd558d18 JC |
1231 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
1232 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | | |
1233 | IPSKB_REROUTED); | |
1234 | nf_reset(skb); | |
1235 | ||
6af88da1 DM |
1236 | bh_lock_sock(sk); |
1237 | if (sock_owned_by_user(sk)) { | |
b8c84307 ED |
1238 | kfree_skb(skb); |
1239 | ret = NET_XMIT_DROP; | |
6af88da1 DM |
1240 | goto out_unlock; |
1241 | } | |
1242 | ||
fd558d18 JC |
1243 | /* Get routing info from the tunnel socket */ |
1244 | skb_dst_drop(skb); | |
71b1391a | 1245 | skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); |
fd558d18 | 1246 | |
d9d8da80 DM |
1247 | inet = inet_sk(sk); |
1248 | fl = &inet->cork.fl; | |
0d76751f JC |
1249 | switch (tunnel->encap) { |
1250 | case L2TP_ENCAPTYPE_UDP: | |
1251 | /* Setup UDP header */ | |
0d76751f JC |
1252 | __skb_push(skb, sizeof(*uh)); |
1253 | skb_reset_transport_header(skb); | |
1254 | uh = udp_hdr(skb); | |
1255 | uh->source = inet->inet_sport; | |
1256 | uh->dest = inet->inet_dport; | |
1257 | udp_len = uhlen + hdr_len + data_len; | |
1258 | uh->len = htons(udp_len); | |
1259 | uh->check = 0; | |
1260 | ||
1261 | /* Calculate UDP checksum if configured to do so */ | |
d2cf3361 | 1262 | #if IS_ENABLED(CONFIG_IPV6) |
e18503f4 | 1263 | if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) |
d2cf3361 BL |
1264 | l2tp_xmit_ipv6_csum(sk, skb, udp_len); |
1265 | else | |
1266 | #endif | |
0d76751f JC |
1267 | if (sk->sk_no_check == UDP_CSUM_NOXMIT) |
1268 | skb->ip_summed = CHECKSUM_NONE; | |
1269 | else if ((skb_dst(skb) && skb_dst(skb)->dev) && | |
1270 | (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { | |
1271 | skb->ip_summed = CHECKSUM_COMPLETE; | |
1272 | csum = skb_checksum(skb, 0, udp_len, 0); | |
1273 | uh->check = csum_tcpudp_magic(inet->inet_saddr, | |
1274 | inet->inet_daddr, | |
1275 | udp_len, IPPROTO_UDP, csum); | |
1276 | if (uh->check == 0) | |
1277 | uh->check = CSUM_MANGLED_0; | |
1278 | } else { | |
1279 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1280 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
1281 | skb->csum_offset = offsetof(struct udphdr, check); | |
1282 | uh->check = ~csum_tcpudp_magic(inet->inet_saddr, | |
1283 | inet->inet_daddr, | |
1284 | udp_len, IPPROTO_UDP, 0); | |
1285 | } | |
1286 | break; | |
1287 | ||
1288 | case L2TP_ENCAPTYPE_IP: | |
1289 | break; | |
fd558d18 JC |
1290 | } |
1291 | ||
0d76751f JC |
1292 | l2tp_skb_set_owner_w(skb, sk); |
1293 | ||
d9d8da80 | 1294 | l2tp_xmit_core(session, skb, fl, data_len); |
6af88da1 DM |
1295 | out_unlock: |
1296 | bh_unlock_sock(sk); | |
fd558d18 | 1297 | |
b8c84307 | 1298 | return ret; |
fd558d18 JC |
1299 | } |
1300 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); | |
1301 | ||
1302 | /***************************************************************************** | |
1303 | * Tinnel and session create/destroy. | |
1304 | *****************************************************************************/ | |
1305 | ||
1306 | /* Tunnel socket destruct hook. | |
1307 | * The tunnel context is deleted only when all session sockets have been | |
1308 | * closed. | |
1309 | */ | |
fc130840 | 1310 | static void l2tp_tunnel_destruct(struct sock *sk) |
fd558d18 | 1311 | { |
8d8a51e2 | 1312 | struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); |
f8ccac0e | 1313 | struct l2tp_net *pn; |
fd558d18 | 1314 | |
fd558d18 JC |
1315 | if (tunnel == NULL) |
1316 | goto end; | |
1317 | ||
a4ca44fa | 1318 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); |
fd558d18 | 1319 | |
fd558d18 | 1320 | |
f8ccac0e | 1321 | /* Disable udp encapsulation */ |
0d76751f JC |
1322 | switch (tunnel->encap) { |
1323 | case L2TP_ENCAPTYPE_UDP: | |
1324 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ | |
1325 | (udp_sk(sk))->encap_type = 0; | |
1326 | (udp_sk(sk))->encap_rcv = NULL; | |
9980d001 | 1327 | (udp_sk(sk))->encap_destroy = NULL; |
0d76751f JC |
1328 | break; |
1329 | case L2TP_ENCAPTYPE_IP: | |
1330 | break; | |
1331 | } | |
fd558d18 JC |
1332 | |
1333 | /* Remove hooks into tunnel socket */ | |
fd558d18 JC |
1334 | sk->sk_destruct = tunnel->old_sk_destruct; |
1335 | sk->sk_user_data = NULL; | |
f8ccac0e | 1336 | tunnel->sock = NULL; |
fd558d18 | 1337 | |
f8ccac0e TP |
1338 | /* Remove the tunnel struct from the tunnel list */ |
1339 | pn = l2tp_pernet(tunnel->l2tp_net); | |
1340 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); | |
1341 | list_del_rcu(&tunnel->list); | |
1342 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1343 | atomic_dec(&l2tp_tunnel_count); | |
fd558d18 | 1344 | |
f8ccac0e | 1345 | l2tp_tunnel_closeall(tunnel); |
fd558d18 JC |
1346 | l2tp_tunnel_dec_refcount(tunnel); |
1347 | ||
f8ccac0e TP |
1348 | /* Call the original destructor */ |
1349 | if (sk->sk_destruct) | |
1350 | (*sk->sk_destruct)(sk); | |
fd558d18 JC |
1351 | end: |
1352 | return; | |
1353 | } | |
fd558d18 JC |
1354 | |
1355 | /* When the tunnel is closed, all the attached sessions need to go too. | |
1356 | */ | |
e34f4c70 | 1357 | void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
fd558d18 JC |
1358 | { |
1359 | int hash; | |
1360 | struct hlist_node *walk; | |
1361 | struct hlist_node *tmp; | |
1362 | struct l2tp_session *session; | |
1363 | ||
1364 | BUG_ON(tunnel == NULL); | |
1365 | ||
a4ca44fa JP |
1366 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", |
1367 | tunnel->name); | |
fd558d18 JC |
1368 | |
1369 | write_lock_bh(&tunnel->hlist_lock); | |
1370 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { | |
1371 | again: | |
1372 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { | |
1373 | session = hlist_entry(walk, struct l2tp_session, hlist); | |
1374 | ||
a4ca44fa JP |
1375 | l2tp_info(session, L2TP_MSG_CONTROL, |
1376 | "%s: closing session\n", session->name); | |
fd558d18 JC |
1377 | |
1378 | hlist_del_init(&session->hlist); | |
1379 | ||
fd558d18 JC |
1380 | if (session->ref != NULL) |
1381 | (*session->ref)(session); | |
1382 | ||
1383 | write_unlock_bh(&tunnel->hlist_lock); | |
1384 | ||
f6e16b29 | 1385 | __l2tp_session_unhash(session); |
4c6e2fd3 TP |
1386 | l2tp_session_queue_purge(session); |
1387 | ||
fd558d18 JC |
1388 | if (session->session_close != NULL) |
1389 | (*session->session_close)(session); | |
1390 | ||
1391 | if (session->deref != NULL) | |
1392 | (*session->deref)(session); | |
1393 | ||
9980d001 TP |
1394 | l2tp_session_dec_refcount(session); |
1395 | ||
fd558d18 JC |
1396 | write_lock_bh(&tunnel->hlist_lock); |
1397 | ||
1398 | /* Now restart from the beginning of this hash | |
1399 | * chain. We always remove a session from the | |
1400 | * list so we are guaranteed to make forward | |
1401 | * progress. | |
1402 | */ | |
1403 | goto again; | |
1404 | } | |
1405 | } | |
1406 | write_unlock_bh(&tunnel->hlist_lock); | |
1407 | } | |
e34f4c70 | 1408 | EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); |
fd558d18 | 1409 | |
9980d001 TP |
1410 | /* Tunnel socket destroy hook for UDP encapsulation */ |
1411 | static void l2tp_udp_encap_destroy(struct sock *sk) | |
1412 | { | |
1413 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); | |
1414 | if (tunnel) { | |
1415 | l2tp_tunnel_closeall(tunnel); | |
1416 | sock_put(sk); | |
1417 | } | |
1418 | } | |
1419 | ||
fd558d18 JC |
1420 | /* Really kill the tunnel. |
1421 | * Come here only when all sessions have been cleared from the tunnel. | |
1422 | */ | |
fc130840 | 1423 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
fd558d18 | 1424 | { |
fd558d18 JC |
1425 | BUG_ON(atomic_read(&tunnel->ref_count) != 0); |
1426 | BUG_ON(tunnel->sock != NULL); | |
a4ca44fa | 1427 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); |
99469c32 | 1428 | kfree_rcu(tunnel, rcu); |
f8ccac0e | 1429 | } |
fd558d18 | 1430 | |
f8ccac0e TP |
1431 | /* Workqueue tunnel deletion function */ |
1432 | static void l2tp_tunnel_del_work(struct work_struct *work) | |
1433 | { | |
1434 | struct l2tp_tunnel *tunnel = NULL; | |
1435 | struct socket *sock = NULL; | |
1436 | struct sock *sk = NULL; | |
1437 | ||
1438 | tunnel = container_of(work, struct l2tp_tunnel, del_work); | |
1439 | sk = l2tp_tunnel_sock_lookup(tunnel); | |
1440 | if (!sk) | |
1441 | return; | |
1442 | ||
1443 | sock = sk->sk_socket; | |
f8ccac0e | 1444 | |
02d13ed5 TP |
1445 | /* If the tunnel socket was created by userspace, then go through the |
1446 | * inet layer to shut the socket down, and let userspace close it. | |
1447 | * Otherwise, if we created the socket directly within the kernel, use | |
1448 | * the sk API to release it here. | |
167eb17e TP |
1449 | * In either case the tunnel resources are freed in the socket |
1450 | * destructor when the tunnel socket goes away. | |
f8ccac0e | 1451 | */ |
02d13ed5 TP |
1452 | if (tunnel->fd >= 0) { |
1453 | if (sock) | |
1454 | inet_shutdown(sock, 2); | |
167eb17e | 1455 | } else { |
02d13ed5 TP |
1456 | if (sock) |
1457 | kernel_sock_shutdown(sock, SHUT_RDWR); | |
1458 | sk_release_kernel(sk); | |
167eb17e | 1459 | } |
f8ccac0e TP |
1460 | |
1461 | l2tp_tunnel_sock_put(sk); | |
fd558d18 | 1462 | } |
fd558d18 | 1463 | |
789a4a2c JC |
1464 | /* Create a socket for the tunnel, if one isn't set up by |
1465 | * userspace. This is used for static tunnels where there is no | |
1466 | * managing L2TP daemon. | |
167eb17e TP |
1467 | * |
1468 | * Since we don't want these sockets to keep a namespace alive by | |
1469 | * themselves, we drop the socket's namespace refcount after creation. | |
1470 | * These sockets are freed when the namespace exits using the pernet | |
1471 | * exit hook. | |
789a4a2c | 1472 | */ |
167eb17e TP |
1473 | static int l2tp_tunnel_sock_create(struct net *net, |
1474 | u32 tunnel_id, | |
1475 | u32 peer_tunnel_id, | |
1476 | struct l2tp_tunnel_cfg *cfg, | |
1477 | struct socket **sockp) | |
789a4a2c JC |
1478 | { |
1479 | int err = -EINVAL; | |
167eb17e TP |
1480 | struct socket *sock = NULL; |
1481 | struct sockaddr_in udp_addr = {0}; | |
1482 | struct sockaddr_l2tpip ip_addr = {0}; | |
f9bac8df | 1483 | #if IS_ENABLED(CONFIG_IPV6) |
167eb17e TP |
1484 | struct sockaddr_in6 udp6_addr = {0}; |
1485 | struct sockaddr_l2tpip6 ip6_addr = {0}; | |
f9bac8df | 1486 | #endif |
789a4a2c JC |
1487 | |
1488 | switch (cfg->encap) { | |
1489 | case L2TP_ENCAPTYPE_UDP: | |
f9bac8df CE |
1490 | #if IS_ENABLED(CONFIG_IPV6) |
1491 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
167eb17e | 1492 | err = sock_create_kern(AF_INET6, SOCK_DGRAM, 0, &sock); |
f9bac8df CE |
1493 | if (err < 0) |
1494 | goto out; | |
789a4a2c | 1495 | |
167eb17e | 1496 | sk_change_net(sock->sk, net); |
789a4a2c | 1497 | |
f9bac8df CE |
1498 | udp6_addr.sin6_family = AF_INET6; |
1499 | memcpy(&udp6_addr.sin6_addr, cfg->local_ip6, | |
1500 | sizeof(udp6_addr.sin6_addr)); | |
1501 | udp6_addr.sin6_port = htons(cfg->local_udp_port); | |
1502 | err = kernel_bind(sock, (struct sockaddr *) &udp6_addr, | |
1503 | sizeof(udp6_addr)); | |
1504 | if (err < 0) | |
1505 | goto out; | |
789a4a2c | 1506 | |
f9bac8df CE |
1507 | udp6_addr.sin6_family = AF_INET6; |
1508 | memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6, | |
1509 | sizeof(udp6_addr.sin6_addr)); | |
1510 | udp6_addr.sin6_port = htons(cfg->peer_udp_port); | |
1511 | err = kernel_connect(sock, | |
1512 | (struct sockaddr *) &udp6_addr, | |
1513 | sizeof(udp6_addr), 0); | |
1514 | if (err < 0) | |
1515 | goto out; | |
1516 | } else | |
1517 | #endif | |
1518 | { | |
167eb17e | 1519 | err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock); |
f9bac8df CE |
1520 | if (err < 0) |
1521 | goto out; | |
1522 | ||
167eb17e | 1523 | sk_change_net(sock->sk, net); |
f9bac8df | 1524 | |
f9bac8df CE |
1525 | udp_addr.sin_family = AF_INET; |
1526 | udp_addr.sin_addr = cfg->local_ip; | |
1527 | udp_addr.sin_port = htons(cfg->local_udp_port); | |
1528 | err = kernel_bind(sock, (struct sockaddr *) &udp_addr, | |
1529 | sizeof(udp_addr)); | |
1530 | if (err < 0) | |
1531 | goto out; | |
1532 | ||
1533 | udp_addr.sin_family = AF_INET; | |
1534 | udp_addr.sin_addr = cfg->peer_ip; | |
1535 | udp_addr.sin_port = htons(cfg->peer_udp_port); | |
1536 | err = kernel_connect(sock, | |
1537 | (struct sockaddr *) &udp_addr, | |
1538 | sizeof(udp_addr), 0); | |
1539 | if (err < 0) | |
1540 | goto out; | |
1541 | } | |
789a4a2c JC |
1542 | |
1543 | if (!cfg->use_udp_checksums) | |
1544 | sock->sk->sk_no_check = UDP_CSUM_NOXMIT; | |
1545 | ||
1546 | break; | |
1547 | ||
1548 | case L2TP_ENCAPTYPE_IP: | |
f9bac8df CE |
1549 | #if IS_ENABLED(CONFIG_IPV6) |
1550 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
167eb17e TP |
1551 | err = sock_create_kern(AF_INET6, SOCK_DGRAM, |
1552 | IPPROTO_L2TP, &sock); | |
5dac94e1 JC |
1553 | if (err < 0) |
1554 | goto out; | |
789a4a2c | 1555 | |
167eb17e | 1556 | sk_change_net(sock->sk, net); |
789a4a2c | 1557 | |
5dac94e1 JC |
1558 | ip6_addr.l2tp_family = AF_INET6; |
1559 | memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, | |
1560 | sizeof(ip6_addr.l2tp_addr)); | |
1561 | ip6_addr.l2tp_conn_id = tunnel_id; | |
1562 | err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, | |
1563 | sizeof(ip6_addr)); | |
1564 | if (err < 0) | |
1565 | goto out; | |
789a4a2c | 1566 | |
5dac94e1 JC |
1567 | ip6_addr.l2tp_family = AF_INET6; |
1568 | memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, | |
1569 | sizeof(ip6_addr.l2tp_addr)); | |
1570 | ip6_addr.l2tp_conn_id = peer_tunnel_id; | |
1571 | err = kernel_connect(sock, | |
1572 | (struct sockaddr *) &ip6_addr, | |
1573 | sizeof(ip6_addr), 0); | |
1574 | if (err < 0) | |
1575 | goto out; | |
1576 | } else | |
1577 | #endif | |
1578 | { | |
167eb17e TP |
1579 | err = sock_create_kern(AF_INET, SOCK_DGRAM, |
1580 | IPPROTO_L2TP, &sock); | |
5dac94e1 JC |
1581 | if (err < 0) |
1582 | goto out; | |
789a4a2c | 1583 | |
167eb17e | 1584 | sk_change_net(sock->sk, net); |
5dac94e1 | 1585 | |
5dac94e1 JC |
1586 | ip_addr.l2tp_family = AF_INET; |
1587 | ip_addr.l2tp_addr = cfg->local_ip; | |
1588 | ip_addr.l2tp_conn_id = tunnel_id; | |
1589 | err = kernel_bind(sock, (struct sockaddr *) &ip_addr, | |
1590 | sizeof(ip_addr)); | |
1591 | if (err < 0) | |
1592 | goto out; | |
1593 | ||
1594 | ip_addr.l2tp_family = AF_INET; | |
1595 | ip_addr.l2tp_addr = cfg->peer_ip; | |
1596 | ip_addr.l2tp_conn_id = peer_tunnel_id; | |
1597 | err = kernel_connect(sock, (struct sockaddr *) &ip_addr, | |
1598 | sizeof(ip_addr), 0); | |
1599 | if (err < 0) | |
1600 | goto out; | |
1601 | } | |
789a4a2c JC |
1602 | break; |
1603 | ||
1604 | default: | |
1605 | goto out; | |
1606 | } | |
1607 | ||
1608 | out: | |
167eb17e | 1609 | *sockp = sock; |
789a4a2c | 1610 | if ((err < 0) && sock) { |
167eb17e TP |
1611 | kernel_sock_shutdown(sock, SHUT_RDWR); |
1612 | sk_release_kernel(sock->sk); | |
789a4a2c JC |
1613 | *sockp = NULL; |
1614 | } | |
1615 | ||
1616 | return err; | |
1617 | } | |
1618 | ||
37159ef2 ED |
1619 | static struct lock_class_key l2tp_socket_class; |
1620 | ||
fd558d18 JC |
1621 | int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) |
1622 | { | |
1623 | struct l2tp_tunnel *tunnel = NULL; | |
1624 | int err; | |
1625 | struct socket *sock = NULL; | |
1626 | struct sock *sk = NULL; | |
1627 | struct l2tp_net *pn; | |
0d76751f | 1628 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
fd558d18 JC |
1629 | |
1630 | /* Get the tunnel socket from the fd, which was opened by | |
789a4a2c JC |
1631 | * the userspace L2TP daemon. If not specified, create a |
1632 | * kernel socket. | |
fd558d18 | 1633 | */ |
789a4a2c | 1634 | if (fd < 0) { |
167eb17e TP |
1635 | err = l2tp_tunnel_sock_create(net, tunnel_id, peer_tunnel_id, |
1636 | cfg, &sock); | |
789a4a2c JC |
1637 | if (err < 0) |
1638 | goto err; | |
1639 | } else { | |
789a4a2c JC |
1640 | sock = sockfd_lookup(fd, &err); |
1641 | if (!sock) { | |
cbb95e0c | 1642 | pr_err("tunl %u: sockfd_lookup(fd=%d) returned %d\n", |
789a4a2c | 1643 | tunnel_id, fd, err); |
cbb95e0c TP |
1644 | err = -EBADF; |
1645 | goto err; | |
1646 | } | |
1647 | ||
1648 | /* Reject namespace mismatches */ | |
1649 | if (!net_eq(sock_net(sock->sk), net)) { | |
1650 | pr_err("tunl %u: netns mismatch\n", tunnel_id); | |
1651 | err = -EINVAL; | |
789a4a2c JC |
1652 | goto err; |
1653 | } | |
fd558d18 JC |
1654 | } |
1655 | ||
1656 | sk = sock->sk; | |
1657 | ||
0d76751f JC |
1658 | if (cfg != NULL) |
1659 | encap = cfg->encap; | |
1660 | ||
fd558d18 | 1661 | /* Quick sanity checks */ |
0d76751f JC |
1662 | switch (encap) { |
1663 | case L2TP_ENCAPTYPE_UDP: | |
1664 | err = -EPROTONOSUPPORT; | |
1665 | if (sk->sk_protocol != IPPROTO_UDP) { | |
a4ca44fa | 1666 | pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
0d76751f JC |
1667 | tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); |
1668 | goto err; | |
1669 | } | |
1670 | break; | |
1671 | case L2TP_ENCAPTYPE_IP: | |
1672 | err = -EPROTONOSUPPORT; | |
1673 | if (sk->sk_protocol != IPPROTO_L2TP) { | |
a4ca44fa | 1674 | pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
0d76751f JC |
1675 | tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); |
1676 | goto err; | |
1677 | } | |
1678 | break; | |
fd558d18 JC |
1679 | } |
1680 | ||
1681 | /* Check if this socket has already been prepped */ | |
8d8a51e2 | 1682 | tunnel = l2tp_tunnel(sk); |
fd558d18 JC |
1683 | if (tunnel != NULL) { |
1684 | /* This socket has already been prepped */ | |
1685 | err = -EBUSY; | |
1686 | goto err; | |
1687 | } | |
1688 | ||
fd558d18 JC |
1689 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
1690 | if (tunnel == NULL) { | |
1691 | err = -ENOMEM; | |
1692 | goto err; | |
1693 | } | |
1694 | ||
1695 | tunnel->version = version; | |
1696 | tunnel->tunnel_id = tunnel_id; | |
1697 | tunnel->peer_tunnel_id = peer_tunnel_id; | |
1698 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; | |
1699 | ||
1700 | tunnel->magic = L2TP_TUNNEL_MAGIC; | |
1701 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); | |
1702 | rwlock_init(&tunnel->hlist_lock); | |
1703 | ||
1704 | /* The net we belong to */ | |
1705 | tunnel->l2tp_net = net; | |
1706 | pn = l2tp_pernet(net); | |
1707 | ||
0d76751f | 1708 | if (cfg != NULL) |
fd558d18 JC |
1709 | tunnel->debug = cfg->debug; |
1710 | ||
e18503f4 FC |
1711 | #if IS_ENABLED(CONFIG_IPV6) |
1712 | if (sk->sk_family == PF_INET6) { | |
1713 | struct ipv6_pinfo *np = inet6_sk(sk); | |
1714 | ||
1715 | if (ipv6_addr_v4mapped(&np->saddr) && | |
efe4208f | 1716 | ipv6_addr_v4mapped(&sk->sk_v6_daddr)) { |
e18503f4 FC |
1717 | struct inet_sock *inet = inet_sk(sk); |
1718 | ||
1719 | tunnel->v4mapped = true; | |
1720 | inet->inet_saddr = np->saddr.s6_addr32[3]; | |
efe4208f ED |
1721 | inet->inet_rcv_saddr = sk->sk_v6_rcv_saddr.s6_addr32[3]; |
1722 | inet->inet_daddr = sk->sk_v6_daddr.s6_addr32[3]; | |
e18503f4 FC |
1723 | } else { |
1724 | tunnel->v4mapped = false; | |
1725 | } | |
1726 | } | |
1727 | #endif | |
1728 | ||
fd558d18 | 1729 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
0d76751f JC |
1730 | tunnel->encap = encap; |
1731 | if (encap == L2TP_ENCAPTYPE_UDP) { | |
1732 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ | |
1733 | udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; | |
1734 | udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; | |
9980d001 | 1735 | udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy; |
d2cf3361 | 1736 | #if IS_ENABLED(CONFIG_IPV6) |
e18503f4 | 1737 | if (sk->sk_family == PF_INET6 && !tunnel->v4mapped) |
d2cf3361 BL |
1738 | udpv6_encap_enable(); |
1739 | else | |
1740 | #endif | |
447167bf | 1741 | udp_encap_enable(); |
0d76751f | 1742 | } |
fd558d18 JC |
1743 | |
1744 | sk->sk_user_data = tunnel; | |
1745 | ||
1746 | /* Hook on the tunnel socket destructor so that we can cleanup | |
1747 | * if the tunnel socket goes away. | |
1748 | */ | |
1749 | tunnel->old_sk_destruct = sk->sk_destruct; | |
1750 | sk->sk_destruct = &l2tp_tunnel_destruct; | |
1751 | tunnel->sock = sk; | |
80d84ef3 | 1752 | tunnel->fd = fd; |
37159ef2 ED |
1753 | lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock"); |
1754 | ||
fd558d18 JC |
1755 | sk->sk_allocation = GFP_ATOMIC; |
1756 | ||
f8ccac0e TP |
1757 | /* Init delete workqueue struct */ |
1758 | INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); | |
1759 | ||
fd558d18 JC |
1760 | /* Add tunnel to our list */ |
1761 | INIT_LIST_HEAD(&tunnel->list); | |
fd558d18 JC |
1762 | atomic_inc(&l2tp_tunnel_count); |
1763 | ||
1764 | /* Bump the reference count. The tunnel context is deleted | |
1769192a | 1765 | * only when this drops to zero. Must be done before list insertion |
fd558d18 JC |
1766 | */ |
1767 | l2tp_tunnel_inc_refcount(tunnel); | |
1769192a ED |
1768 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
1769 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); | |
1770 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
fd558d18 JC |
1771 | |
1772 | err = 0; | |
1773 | err: | |
1774 | if (tunnelp) | |
1775 | *tunnelp = tunnel; | |
1776 | ||
789a4a2c JC |
1777 | /* If tunnel's socket was created by the kernel, it doesn't |
1778 | * have a file. | |
1779 | */ | |
1780 | if (sock && sock->file) | |
fd558d18 JC |
1781 | sockfd_put(sock); |
1782 | ||
1783 | return err; | |
1784 | } | |
1785 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); | |
1786 | ||
309795f4 JC |
1787 | /* This function is used by the netlink TUNNEL_DELETE command. |
1788 | */ | |
1789 | int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) | |
1790 | { | |
2b551c6e | 1791 | l2tp_tunnel_closeall(tunnel); |
f8ccac0e | 1792 | return (false == queue_work(l2tp_wq, &tunnel->del_work)); |
309795f4 JC |
1793 | } |
1794 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); | |
1795 | ||
fd558d18 JC |
1796 | /* Really kill the session. |
1797 | */ | |
1798 | void l2tp_session_free(struct l2tp_session *session) | |
1799 | { | |
f6e16b29 | 1800 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 JC |
1801 | |
1802 | BUG_ON(atomic_read(&session->ref_count) != 0); | |
1803 | ||
f6e16b29 | 1804 | if (tunnel) { |
fd558d18 | 1805 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
f6e16b29 TP |
1806 | if (session->session_id != 0) |
1807 | atomic_dec(&l2tp_session_count); | |
1808 | sock_put(tunnel->sock); | |
1809 | session->tunnel = NULL; | |
1810 | l2tp_tunnel_dec_refcount(tunnel); | |
1811 | } | |
1812 | ||
1813 | kfree(session); | |
1814 | ||
1815 | return; | |
1816 | } | |
1817 | EXPORT_SYMBOL_GPL(l2tp_session_free); | |
1818 | ||
1819 | /* Remove an l2tp session from l2tp_core's hash lists. | |
1820 | * Provides a tidyup interface for pseudowire code which can't just route all | |
1821 | * shutdown via. l2tp_session_delete and a pseudowire-specific session_close | |
1822 | * callback. | |
1823 | */ | |
1824 | void __l2tp_session_unhash(struct l2tp_session *session) | |
1825 | { | |
1826 | struct l2tp_tunnel *tunnel = session->tunnel; | |
fd558d18 | 1827 | |
f6e16b29 TP |
1828 | /* Remove the session from core hashes */ |
1829 | if (tunnel) { | |
1830 | /* Remove from the per-tunnel hash */ | |
fd558d18 JC |
1831 | write_lock_bh(&tunnel->hlist_lock); |
1832 | hlist_del_init(&session->hlist); | |
1833 | write_unlock_bh(&tunnel->hlist_lock); | |
1834 | ||
f6e16b29 | 1835 | /* For L2TPv3 we have a per-net hash: remove from there, too */ |
f7faffa3 JC |
1836 | if (tunnel->version != L2TP_HDR_VER_2) { |
1837 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
e02d494d JC |
1838 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1839 | hlist_del_init_rcu(&session->global_hlist); | |
1840 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
1841 | synchronize_rcu(); | |
f7faffa3 | 1842 | } |
fd558d18 | 1843 | } |
fd558d18 | 1844 | } |
f6e16b29 | 1845 | EXPORT_SYMBOL_GPL(__l2tp_session_unhash); |
fd558d18 | 1846 | |
309795f4 JC |
1847 | /* This function is used by the netlink SESSION_DELETE command and by |
1848 | pseudowire modules. | |
1849 | */ | |
1850 | int l2tp_session_delete(struct l2tp_session *session) | |
1851 | { | |
f6e16b29 TP |
1852 | if (session->ref) |
1853 | (*session->ref)(session); | |
1854 | __l2tp_session_unhash(session); | |
4c6e2fd3 | 1855 | l2tp_session_queue_purge(session); |
309795f4 JC |
1856 | if (session->session_close != NULL) |
1857 | (*session->session_close)(session); | |
f6e16b29 | 1858 | if (session->deref) |
1b7c92b9 | 1859 | (*session->deref)(session); |
309795f4 | 1860 | l2tp_session_dec_refcount(session); |
309795f4 JC |
1861 | return 0; |
1862 | } | |
1863 | EXPORT_SYMBOL_GPL(l2tp_session_delete); | |
1864 | ||
f7faffa3 JC |
1865 | /* We come here whenever a session's send_seq, cookie_len or |
1866 | * l2specific_len parameters are set. | |
1867 | */ | |
fc130840 | 1868 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
f7faffa3 JC |
1869 | { |
1870 | if (version == L2TP_HDR_VER_2) { | |
1871 | session->hdr_len = 6; | |
1872 | if (session->send_seq) | |
1873 | session->hdr_len += 4; | |
1874 | } else { | |
0d76751f JC |
1875 | session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; |
1876 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) | |
1877 | session->hdr_len += 4; | |
f7faffa3 JC |
1878 | } |
1879 | ||
1880 | } | |
f7faffa3 | 1881 | |
fd558d18 JC |
1882 | struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) |
1883 | { | |
1884 | struct l2tp_session *session; | |
1885 | ||
1886 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); | |
1887 | if (session != NULL) { | |
1888 | session->magic = L2TP_SESSION_MAGIC; | |
1889 | session->tunnel = tunnel; | |
1890 | ||
1891 | session->session_id = session_id; | |
1892 | session->peer_session_id = peer_session_id; | |
d301e325 | 1893 | session->nr = 0; |
8a1631d5 JC |
1894 | if (tunnel->version == L2TP_HDR_VER_2) |
1895 | session->nr_max = 0xffff; | |
1896 | else | |
1897 | session->nr_max = 0xffffff; | |
1898 | session->nr_window_size = session->nr_max / 2; | |
a0dbd822 JC |
1899 | session->nr_oos_count_max = 4; |
1900 | ||
1901 | /* Use NR of first received packet */ | |
1902 | session->reorder_skip = 1; | |
fd558d18 JC |
1903 | |
1904 | sprintf(&session->name[0], "sess %u/%u", | |
1905 | tunnel->tunnel_id, session->session_id); | |
1906 | ||
1907 | skb_queue_head_init(&session->reorder_q); | |
1908 | ||
1909 | INIT_HLIST_NODE(&session->hlist); | |
f7faffa3 | 1910 | INIT_HLIST_NODE(&session->global_hlist); |
fd558d18 JC |
1911 | |
1912 | /* Inherit debug options from tunnel */ | |
1913 | session->debug = tunnel->debug; | |
1914 | ||
1915 | if (cfg) { | |
f7faffa3 | 1916 | session->pwtype = cfg->pw_type; |
fd558d18 | 1917 | session->debug = cfg->debug; |
fd558d18 JC |
1918 | session->mtu = cfg->mtu; |
1919 | session->mru = cfg->mru; | |
1920 | session->send_seq = cfg->send_seq; | |
1921 | session->recv_seq = cfg->recv_seq; | |
1922 | session->lns_mode = cfg->lns_mode; | |
f7faffa3 JC |
1923 | session->reorder_timeout = cfg->reorder_timeout; |
1924 | session->offset = cfg->offset; | |
1925 | session->l2specific_type = cfg->l2specific_type; | |
1926 | session->l2specific_len = cfg->l2specific_len; | |
1927 | session->cookie_len = cfg->cookie_len; | |
1928 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); | |
1929 | session->peer_cookie_len = cfg->peer_cookie_len; | |
1930 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); | |
fd558d18 JC |
1931 | } |
1932 | ||
f7faffa3 JC |
1933 | if (tunnel->version == L2TP_HDR_VER_2) |
1934 | session->build_header = l2tp_build_l2tpv2_header; | |
1935 | else | |
1936 | session->build_header = l2tp_build_l2tpv3_header; | |
1937 | ||
1938 | l2tp_session_set_header_len(session, tunnel->version); | |
1939 | ||
fd558d18 JC |
1940 | /* Bump the reference count. The session context is deleted |
1941 | * only when this drops to zero. | |
1942 | */ | |
1943 | l2tp_session_inc_refcount(session); | |
1944 | l2tp_tunnel_inc_refcount(tunnel); | |
1945 | ||
1946 | /* Ensure tunnel socket isn't deleted */ | |
1947 | sock_hold(tunnel->sock); | |
1948 | ||
1949 | /* Add session to the tunnel's hash list */ | |
1950 | write_lock_bh(&tunnel->hlist_lock); | |
1951 | hlist_add_head(&session->hlist, | |
1952 | l2tp_session_id_hash(tunnel, session_id)); | |
1953 | write_unlock_bh(&tunnel->hlist_lock); | |
1954 | ||
f7faffa3 JC |
1955 | /* And to the global session list if L2TPv3 */ |
1956 | if (tunnel->version != L2TP_HDR_VER_2) { | |
1957 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1958 | ||
e02d494d JC |
1959 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1960 | hlist_add_head_rcu(&session->global_hlist, | |
1961 | l2tp_session_id_hash_2(pn, session_id)); | |
1962 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
f7faffa3 JC |
1963 | } |
1964 | ||
fd558d18 JC |
1965 | /* Ignore management session in session count value */ |
1966 | if (session->session_id != 0) | |
1967 | atomic_inc(&l2tp_session_count); | |
1968 | } | |
1969 | ||
1970 | return session; | |
1971 | } | |
1972 | EXPORT_SYMBOL_GPL(l2tp_session_create); | |
1973 | ||
1974 | /***************************************************************************** | |
1975 | * Init and cleanup | |
1976 | *****************************************************************************/ | |
1977 | ||
1978 | static __net_init int l2tp_init_net(struct net *net) | |
1979 | { | |
e773aaff | 1980 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
f7faffa3 | 1981 | int hash; |
fd558d18 | 1982 | |
fd558d18 | 1983 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
e02d494d | 1984 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
fd558d18 | 1985 | |
f7faffa3 JC |
1986 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
1987 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); | |
1988 | ||
e02d494d | 1989 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
f7faffa3 | 1990 | |
fd558d18 | 1991 | return 0; |
fd558d18 JC |
1992 | } |
1993 | ||
167eb17e TP |
1994 | static __net_exit void l2tp_exit_net(struct net *net) |
1995 | { | |
1996 | struct l2tp_net *pn = l2tp_pernet(net); | |
1997 | struct l2tp_tunnel *tunnel = NULL; | |
1998 | ||
1999 | rcu_read_lock_bh(); | |
2000 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
2001 | (void)l2tp_tunnel_delete(tunnel); | |
2002 | } | |
2003 | rcu_read_unlock_bh(); | |
2004 | } | |
2005 | ||
fd558d18 JC |
2006 | static struct pernet_operations l2tp_net_ops = { |
2007 | .init = l2tp_init_net, | |
167eb17e | 2008 | .exit = l2tp_exit_net, |
fd558d18 JC |
2009 | .id = &l2tp_net_id, |
2010 | .size = sizeof(struct l2tp_net), | |
2011 | }; | |
2012 | ||
2013 | static int __init l2tp_init(void) | |
2014 | { | |
2015 | int rc = 0; | |
2016 | ||
2017 | rc = register_pernet_device(&l2tp_net_ops); | |
2018 | if (rc) | |
2019 | goto out; | |
2020 | ||
f8ccac0e TP |
2021 | l2tp_wq = alloc_workqueue("l2tp", WQ_NON_REENTRANT | WQ_UNBOUND, 0); |
2022 | if (!l2tp_wq) { | |
2023 | pr_err("alloc_workqueue failed\n"); | |
2024 | rc = -ENOMEM; | |
2025 | goto out; | |
2026 | } | |
2027 | ||
a4ca44fa | 2028 | pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); |
fd558d18 JC |
2029 | |
2030 | out: | |
2031 | return rc; | |
2032 | } | |
2033 | ||
2034 | static void __exit l2tp_exit(void) | |
2035 | { | |
2036 | unregister_pernet_device(&l2tp_net_ops); | |
f8ccac0e TP |
2037 | if (l2tp_wq) { |
2038 | destroy_workqueue(l2tp_wq); | |
2039 | l2tp_wq = NULL; | |
2040 | } | |
fd558d18 JC |
2041 | } |
2042 | ||
2043 | module_init(l2tp_init); | |
2044 | module_exit(l2tp_exit); | |
2045 | ||
2046 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
2047 | MODULE_DESCRIPTION("L2TP core"); | |
2048 | MODULE_LICENSE("GPL"); | |
2049 | MODULE_VERSION(L2TP_DRV_VERSION); | |
2050 |