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 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/list.h> | |
e02d494d | 24 | #include <linux/rculist.h> |
fd558d18 JC |
25 | #include <linux/uaccess.h> |
26 | ||
27 | #include <linux/kernel.h> | |
28 | #include <linux/spinlock.h> | |
29 | #include <linux/kthread.h> | |
30 | #include <linux/sched.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/errno.h> | |
33 | #include <linux/jiffies.h> | |
34 | ||
35 | #include <linux/netdevice.h> | |
36 | #include <linux/net.h> | |
37 | #include <linux/inetdevice.h> | |
38 | #include <linux/skbuff.h> | |
39 | #include <linux/init.h> | |
0d76751f | 40 | #include <linux/in.h> |
fd558d18 JC |
41 | #include <linux/ip.h> |
42 | #include <linux/udp.h> | |
0d76751f | 43 | #include <linux/l2tp.h> |
fd558d18 JC |
44 | #include <linux/hash.h> |
45 | #include <linux/sort.h> | |
46 | #include <linux/file.h> | |
47 | #include <linux/nsproxy.h> | |
48 | #include <net/net_namespace.h> | |
49 | #include <net/netns/generic.h> | |
50 | #include <net/dst.h> | |
51 | #include <net/ip.h> | |
52 | #include <net/udp.h> | |
309795f4 | 53 | #include <net/inet_common.h> |
fd558d18 | 54 | #include <net/xfrm.h> |
0d76751f | 55 | #include <net/protocol.h> |
fd558d18 JC |
56 | |
57 | #include <asm/byteorder.h> | |
58 | #include <asm/atomic.h> | |
59 | ||
60 | #include "l2tp_core.h" | |
61 | ||
62 | #define L2TP_DRV_VERSION "V2.0" | |
63 | ||
64 | /* L2TP header constants */ | |
65 | #define L2TP_HDRFLAG_T 0x8000 | |
66 | #define L2TP_HDRFLAG_L 0x4000 | |
67 | #define L2TP_HDRFLAG_S 0x0800 | |
68 | #define L2TP_HDRFLAG_O 0x0200 | |
69 | #define L2TP_HDRFLAG_P 0x0100 | |
70 | ||
71 | #define L2TP_HDR_VER_MASK 0x000F | |
72 | #define L2TP_HDR_VER_2 0x0002 | |
f7faffa3 | 73 | #define L2TP_HDR_VER_3 0x0003 |
fd558d18 JC |
74 | |
75 | /* L2TPv3 default L2-specific sublayer */ | |
76 | #define L2TP_SLFLAG_S 0x40000000 | |
77 | #define L2TP_SL_SEQ_MASK 0x00ffffff | |
78 | ||
79 | #define L2TP_HDR_SIZE_SEQ 10 | |
80 | #define L2TP_HDR_SIZE_NOSEQ 6 | |
81 | ||
82 | /* Default trace flags */ | |
83 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 | |
84 | ||
85 | #define PRINTK(_mask, _type, _lvl, _fmt, args...) \ | |
86 | do { \ | |
87 | if ((_mask) & (_type)) \ | |
88 | printk(_lvl "L2TP: " _fmt, ##args); \ | |
89 | } while (0) | |
90 | ||
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; | |
104 | ||
105 | /* per-net private data for this module */ | |
106 | static unsigned int l2tp_net_id; | |
107 | struct l2tp_net { | |
108 | struct list_head l2tp_tunnel_list; | |
e02d494d | 109 | spinlock_t l2tp_tunnel_list_lock; |
f7faffa3 | 110 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
e02d494d | 111 | spinlock_t l2tp_session_hlist_lock; |
fd558d18 JC |
112 | }; |
113 | ||
fc130840 | 114 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version); |
115 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); | |
116 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel); | |
117 | ||
fd558d18 JC |
118 | static inline struct l2tp_net *l2tp_pernet(struct net *net) |
119 | { | |
120 | BUG_ON(!net); | |
121 | ||
122 | return net_generic(net, l2tp_net_id); | |
123 | } | |
124 | ||
fc130840 | 125 | |
126 | /* Tunnel reference counts. Incremented per session that is added to | |
127 | * the tunnel. | |
128 | */ | |
129 | static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) | |
130 | { | |
131 | atomic_inc(&tunnel->ref_count); | |
132 | } | |
133 | ||
134 | static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) | |
135 | { | |
136 | if (atomic_dec_and_test(&tunnel->ref_count)) | |
137 | l2tp_tunnel_free(tunnel); | |
138 | } | |
139 | #ifdef L2TP_REFCNT_DEBUG | |
140 | #define l2tp_tunnel_inc_refcount(_t) do { \ | |
141 | printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ | |
142 | l2tp_tunnel_inc_refcount_1(_t); \ | |
143 | } while (0) | |
144 | #define l2tp_tunnel_dec_refcount(_t) do { \ | |
145 | printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ | |
146 | l2tp_tunnel_dec_refcount_1(_t); \ | |
147 | } while (0) | |
148 | #else | |
149 | #define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) | |
150 | #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) | |
151 | #endif | |
152 | ||
f7faffa3 JC |
153 | /* Session hash global list for L2TPv3. |
154 | * The session_id SHOULD be random according to RFC3931, but several | |
155 | * L2TP implementations use incrementing session_ids. So we do a real | |
156 | * hash on the session_id, rather than a simple bitmask. | |
157 | */ | |
158 | static inline struct hlist_head * | |
159 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) | |
160 | { | |
161 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; | |
162 | ||
163 | } | |
164 | ||
165 | /* Lookup a session by id in the global session list | |
166 | */ | |
167 | static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) | |
168 | { | |
169 | struct l2tp_net *pn = l2tp_pernet(net); | |
170 | struct hlist_head *session_list = | |
171 | l2tp_session_id_hash_2(pn, session_id); | |
172 | struct l2tp_session *session; | |
173 | struct hlist_node *walk; | |
174 | ||
e02d494d JC |
175 | rcu_read_lock_bh(); |
176 | hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) { | |
f7faffa3 | 177 | if (session->session_id == session_id) { |
e02d494d | 178 | rcu_read_unlock_bh(); |
f7faffa3 JC |
179 | return session; |
180 | } | |
181 | } | |
e02d494d | 182 | rcu_read_unlock_bh(); |
f7faffa3 JC |
183 | |
184 | return NULL; | |
185 | } | |
186 | ||
fd558d18 JC |
187 | /* Session hash list. |
188 | * The session_id SHOULD be random according to RFC2661, but several | |
189 | * L2TP implementations (Cisco and Microsoft) use incrementing | |
190 | * session_ids. So we do a real hash on the session_id, rather than a | |
191 | * simple bitmask. | |
192 | */ | |
193 | static inline struct hlist_head * | |
194 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) | |
195 | { | |
196 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; | |
197 | } | |
198 | ||
199 | /* Lookup a session by id | |
200 | */ | |
f7faffa3 | 201 | struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) |
fd558d18 | 202 | { |
f7faffa3 | 203 | struct hlist_head *session_list; |
fd558d18 JC |
204 | struct l2tp_session *session; |
205 | struct hlist_node *walk; | |
206 | ||
f7faffa3 JC |
207 | /* In L2TPv3, session_ids are unique over all tunnels and we |
208 | * sometimes need to look them up before we know the | |
209 | * tunnel. | |
210 | */ | |
211 | if (tunnel == NULL) | |
212 | return l2tp_session_find_2(net, session_id); | |
213 | ||
214 | session_list = l2tp_session_id_hash(tunnel, session_id); | |
fd558d18 JC |
215 | read_lock_bh(&tunnel->hlist_lock); |
216 | hlist_for_each_entry(session, walk, session_list, hlist) { | |
217 | if (session->session_id == session_id) { | |
218 | read_unlock_bh(&tunnel->hlist_lock); | |
219 | return session; | |
220 | } | |
221 | } | |
222 | read_unlock_bh(&tunnel->hlist_lock); | |
223 | ||
224 | return NULL; | |
225 | } | |
226 | EXPORT_SYMBOL_GPL(l2tp_session_find); | |
227 | ||
228 | struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) | |
229 | { | |
230 | int hash; | |
231 | struct hlist_node *walk; | |
232 | struct l2tp_session *session; | |
233 | int count = 0; | |
234 | ||
235 | read_lock_bh(&tunnel->hlist_lock); | |
236 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { | |
237 | hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) { | |
238 | if (++count > nth) { | |
239 | read_unlock_bh(&tunnel->hlist_lock); | |
240 | return session; | |
241 | } | |
242 | } | |
243 | } | |
244 | ||
245 | read_unlock_bh(&tunnel->hlist_lock); | |
246 | ||
247 | return NULL; | |
248 | } | |
249 | EXPORT_SYMBOL_GPL(l2tp_session_find_nth); | |
250 | ||
309795f4 JC |
251 | /* Lookup a session by interface name. |
252 | * This is very inefficient but is only used by management interfaces. | |
253 | */ | |
254 | struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) | |
255 | { | |
256 | struct l2tp_net *pn = l2tp_pernet(net); | |
257 | int hash; | |
258 | struct hlist_node *walk; | |
259 | struct l2tp_session *session; | |
260 | ||
e02d494d | 261 | rcu_read_lock_bh(); |
309795f4 | 262 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
e02d494d | 263 | hlist_for_each_entry_rcu(session, walk, &pn->l2tp_session_hlist[hash], global_hlist) { |
309795f4 | 264 | if (!strcmp(session->ifname, ifname)) { |
e02d494d | 265 | rcu_read_unlock_bh(); |
309795f4 JC |
266 | return session; |
267 | } | |
268 | } | |
269 | } | |
270 | ||
e02d494d | 271 | rcu_read_unlock_bh(); |
309795f4 JC |
272 | |
273 | return NULL; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); | |
276 | ||
fd558d18 JC |
277 | /* Lookup a tunnel by id |
278 | */ | |
279 | struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) | |
280 | { | |
281 | struct l2tp_tunnel *tunnel; | |
282 | struct l2tp_net *pn = l2tp_pernet(net); | |
283 | ||
e02d494d JC |
284 | rcu_read_lock_bh(); |
285 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
fd558d18 | 286 | if (tunnel->tunnel_id == tunnel_id) { |
e02d494d | 287 | rcu_read_unlock_bh(); |
fd558d18 JC |
288 | return tunnel; |
289 | } | |
290 | } | |
e02d494d | 291 | rcu_read_unlock_bh(); |
fd558d18 JC |
292 | |
293 | return NULL; | |
294 | } | |
295 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find); | |
296 | ||
297 | struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) | |
298 | { | |
299 | struct l2tp_net *pn = l2tp_pernet(net); | |
300 | struct l2tp_tunnel *tunnel; | |
301 | int count = 0; | |
302 | ||
e02d494d JC |
303 | rcu_read_lock_bh(); |
304 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
fd558d18 | 305 | if (++count > nth) { |
e02d494d | 306 | rcu_read_unlock_bh(); |
fd558d18 JC |
307 | return tunnel; |
308 | } | |
309 | } | |
310 | ||
e02d494d | 311 | rcu_read_unlock_bh(); |
fd558d18 JC |
312 | |
313 | return NULL; | |
314 | } | |
315 | EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); | |
316 | ||
317 | /***************************************************************************** | |
318 | * Receive data handling | |
319 | *****************************************************************************/ | |
320 | ||
321 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence | |
322 | * number. | |
323 | */ | |
324 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
325 | { | |
326 | struct sk_buff *skbp; | |
327 | struct sk_buff *tmp; | |
f7faffa3 | 328 | u32 ns = L2TP_SKB_CB(skb)->ns; |
fd558d18 JC |
329 | |
330 | spin_lock_bh(&session->reorder_q.lock); | |
331 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { | |
332 | if (L2TP_SKB_CB(skbp)->ns > ns) { | |
333 | __skb_queue_before(&session->reorder_q, skbp, skb); | |
334 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
335 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", | |
336 | session->name, ns, L2TP_SKB_CB(skbp)->ns, | |
337 | skb_queue_len(&session->reorder_q)); | |
338 | session->stats.rx_oos_packets++; | |
339 | goto out; | |
340 | } | |
341 | } | |
342 | ||
343 | __skb_queue_tail(&session->reorder_q, skb); | |
344 | ||
345 | out: | |
346 | spin_unlock_bh(&session->reorder_q.lock); | |
347 | } | |
348 | ||
349 | /* Dequeue a single skb. | |
350 | */ | |
351 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
352 | { | |
353 | struct l2tp_tunnel *tunnel = session->tunnel; | |
354 | int length = L2TP_SKB_CB(skb)->length; | |
355 | ||
356 | /* We're about to requeue the skb, so return resources | |
357 | * to its current owner (a socket receive buffer). | |
358 | */ | |
359 | skb_orphan(skb); | |
360 | ||
361 | tunnel->stats.rx_packets++; | |
362 | tunnel->stats.rx_bytes += length; | |
363 | session->stats.rx_packets++; | |
364 | session->stats.rx_bytes += length; | |
365 | ||
366 | if (L2TP_SKB_CB(skb)->has_seq) { | |
367 | /* Bump our Nr */ | |
368 | session->nr++; | |
f7faffa3 JC |
369 | if (tunnel->version == L2TP_HDR_VER_2) |
370 | session->nr &= 0xffff; | |
371 | else | |
372 | session->nr &= 0xffffff; | |
373 | ||
fd558d18 JC |
374 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
375 | "%s: updated nr to %hu\n", session->name, session->nr); | |
376 | } | |
377 | ||
378 | /* call private receive handler */ | |
379 | if (session->recv_skb != NULL) | |
380 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); | |
381 | else | |
382 | kfree_skb(skb); | |
383 | ||
384 | if (session->deref) | |
385 | (*session->deref)(session); | |
386 | } | |
387 | ||
388 | /* Dequeue skbs from the session's reorder_q, subject to packet order. | |
389 | * Skbs that have been in the queue for too long are simply discarded. | |
390 | */ | |
391 | static void l2tp_recv_dequeue(struct l2tp_session *session) | |
392 | { | |
393 | struct sk_buff *skb; | |
394 | struct sk_buff *tmp; | |
395 | ||
396 | /* If the pkt at the head of the queue has the nr that we | |
397 | * expect to send up next, dequeue it and any other | |
398 | * in-sequence packets behind it. | |
399 | */ | |
400 | spin_lock_bh(&session->reorder_q.lock); | |
401 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { | |
402 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { | |
403 | session->stats.rx_seq_discards++; | |
404 | session->stats.rx_errors++; | |
405 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
f7faffa3 JC |
406 | "%s: oos pkt %u len %d discarded (too old), " |
407 | "waiting for %u, reorder_q_len=%d\n", | |
fd558d18 JC |
408 | session->name, L2TP_SKB_CB(skb)->ns, |
409 | L2TP_SKB_CB(skb)->length, session->nr, | |
410 | skb_queue_len(&session->reorder_q)); | |
411 | __skb_unlink(skb, &session->reorder_q); | |
412 | kfree_skb(skb); | |
413 | if (session->deref) | |
414 | (*session->deref)(session); | |
415 | continue; | |
416 | } | |
417 | ||
418 | if (L2TP_SKB_CB(skb)->has_seq) { | |
419 | if (L2TP_SKB_CB(skb)->ns != session->nr) { | |
420 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
f7faffa3 JC |
421 | "%s: holding oos pkt %u len %d, " |
422 | "waiting for %u, reorder_q_len=%d\n", | |
fd558d18 JC |
423 | session->name, L2TP_SKB_CB(skb)->ns, |
424 | L2TP_SKB_CB(skb)->length, session->nr, | |
425 | skb_queue_len(&session->reorder_q)); | |
426 | goto out; | |
427 | } | |
428 | } | |
429 | __skb_unlink(skb, &session->reorder_q); | |
430 | ||
431 | /* Process the skb. We release the queue lock while we | |
432 | * do so to let other contexts process the queue. | |
433 | */ | |
434 | spin_unlock_bh(&session->reorder_q.lock); | |
435 | l2tp_recv_dequeue_skb(session, skb); | |
436 | spin_lock_bh(&session->reorder_q.lock); | |
437 | } | |
438 | ||
439 | out: | |
440 | spin_unlock_bh(&session->reorder_q.lock); | |
441 | } | |
442 | ||
443 | static inline int l2tp_verify_udp_checksum(struct sock *sk, | |
444 | struct sk_buff *skb) | |
445 | { | |
446 | struct udphdr *uh = udp_hdr(skb); | |
447 | u16 ulen = ntohs(uh->len); | |
448 | struct inet_sock *inet; | |
449 | __wsum psum; | |
450 | ||
451 | if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check) | |
452 | return 0; | |
453 | ||
454 | inet = inet_sk(sk); | |
455 | psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, ulen, | |
456 | IPPROTO_UDP, 0); | |
457 | ||
458 | if ((skb->ip_summed == CHECKSUM_COMPLETE) && | |
459 | !csum_fold(csum_add(psum, skb->csum))) | |
460 | return 0; | |
461 | ||
462 | skb->csum = psum; | |
463 | ||
464 | return __skb_checksum_complete(skb); | |
465 | } | |
466 | ||
f7faffa3 JC |
467 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
468 | * and L2TPv3 data frames here. | |
469 | * | |
470 | * L2TPv2 Data Message Header | |
471 | * | |
472 | * 0 1 2 3 | |
473 | * 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 | |
474 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
475 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | | |
476 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
477 | * | Tunnel ID | Session ID | | |
478 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
479 | * | Ns (opt) | Nr (opt) | | |
480 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
481 | * | Offset Size (opt) | Offset pad... (opt) | |
482 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
483 | * | |
484 | * Data frames are marked by T=0. All other fields are the same as | |
485 | * those in L2TP control frames. | |
486 | * | |
487 | * L2TPv3 Data Message Header | |
488 | * | |
489 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
490 | * | L2TP Session Header | | |
491 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
492 | * | L2-Specific Sublayer | | |
493 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
494 | * | Tunnel Payload ... | |
495 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
496 | * | |
497 | * L2TPv3 Session Header Over IP | |
498 | * | |
499 | * 0 1 2 3 | |
500 | * 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 | |
501 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
502 | * | Session ID | | |
503 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
504 | * | Cookie (optional, maximum 64 bits)... | |
505 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
506 | * | | |
507 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
508 | * | |
509 | * L2TPv3 L2-Specific Sublayer Format | |
510 | * | |
511 | * 0 1 2 3 | |
512 | * 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 | |
513 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
514 | * |x|S|x|x|x|x|x|x| Sequence Number | | |
515 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
516 | * | |
517 | * Cookie value, sublayer format and offset (pad) are negotiated with | |
518 | * the peer when the session is set up. Unlike L2TPv2, we do not need | |
519 | * to parse the packet header to determine if optional fields are | |
520 | * present. | |
521 | * | |
522 | * Caller must already have parsed the frame and determined that it is | |
523 | * a data (not control) frame before coming here. Fields up to the | |
524 | * session-id have already been parsed and ptr points to the data | |
525 | * after the session-id. | |
fd558d18 | 526 | */ |
f7faffa3 JC |
527 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
528 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, | |
529 | int length, int (*payload_hook)(struct sk_buff *skb)) | |
fd558d18 | 530 | { |
f7faffa3 | 531 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 532 | int offset; |
f7faffa3 | 533 | u32 ns, nr; |
fd558d18 JC |
534 | |
535 | /* The ref count is increased since we now hold a pointer to | |
536 | * the session. Take care to decrement the refcnt when exiting | |
537 | * this function from now on... | |
538 | */ | |
539 | l2tp_session_inc_refcount(session); | |
540 | if (session->ref) | |
541 | (*session->ref)(session); | |
542 | ||
f7faffa3 JC |
543 | /* Parse and check optional cookie */ |
544 | if (session->peer_cookie_len > 0) { | |
545 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { | |
546 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, | |
547 | "%s: cookie mismatch (%u/%u). Discarding.\n", | |
548 | tunnel->name, tunnel->tunnel_id, session->session_id); | |
549 | session->stats.rx_cookie_discards++; | |
550 | goto discard; | |
551 | } | |
552 | ptr += session->peer_cookie_len; | |
553 | } | |
554 | ||
fd558d18 JC |
555 | /* Handle the optional sequence numbers. Sequence numbers are |
556 | * in different places for L2TPv2 and L2TPv3. | |
557 | * | |
558 | * If we are the LAC, enable/disable sequence numbers under | |
559 | * the control of the LNS. If no sequence numbers present but | |
560 | * we were expecting them, discard frame. | |
561 | */ | |
562 | ns = nr = 0; | |
563 | L2TP_SKB_CB(skb)->has_seq = 0; | |
f7faffa3 JC |
564 | if (tunnel->version == L2TP_HDR_VER_2) { |
565 | if (hdrflags & L2TP_HDRFLAG_S) { | |
566 | ns = ntohs(*(__be16 *) ptr); | |
567 | ptr += 2; | |
568 | nr = ntohs(*(__be16 *) ptr); | |
569 | ptr += 2; | |
fd558d18 | 570 | |
f7faffa3 JC |
571 | /* Store L2TP info in the skb */ |
572 | L2TP_SKB_CB(skb)->ns = ns; | |
573 | L2TP_SKB_CB(skb)->has_seq = 1; | |
fd558d18 | 574 | |
f7faffa3 JC |
575 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
576 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", | |
577 | session->name, ns, nr, session->nr); | |
578 | } | |
579 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
580 | u32 l2h = ntohl(*(__be32 *) ptr); | |
581 | ||
582 | if (l2h & 0x40000000) { | |
583 | ns = l2h & 0x00ffffff; | |
584 | ||
585 | /* Store L2TP info in the skb */ | |
586 | L2TP_SKB_CB(skb)->ns = ns; | |
587 | L2TP_SKB_CB(skb)->has_seq = 1; | |
588 | ||
589 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
590 | "%s: recv data ns=%u, session nr=%u\n", | |
591 | session->name, ns, session->nr); | |
592 | } | |
fd558d18 JC |
593 | } |
594 | ||
f7faffa3 JC |
595 | /* Advance past L2-specific header, if present */ |
596 | ptr += session->l2specific_len; | |
597 | ||
fd558d18 JC |
598 | if (L2TP_SKB_CB(skb)->has_seq) { |
599 | /* Received a packet with sequence numbers. If we're the LNS, | |
600 | * check if we sre sending sequence numbers and if not, | |
601 | * configure it so. | |
602 | */ | |
603 | if ((!session->lns_mode) && (!session->send_seq)) { | |
604 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, | |
605 | "%s: requested to enable seq numbers by LNS\n", | |
606 | session->name); | |
607 | session->send_seq = -1; | |
f7faffa3 | 608 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
609 | } |
610 | } else { | |
611 | /* No sequence numbers. | |
612 | * If user has configured mandatory sequence numbers, discard. | |
613 | */ | |
614 | if (session->recv_seq) { | |
615 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, | |
616 | "%s: recv data has no seq numbers when required. " | |
617 | "Discarding\n", session->name); | |
618 | session->stats.rx_seq_discards++; | |
619 | goto discard; | |
620 | } | |
621 | ||
622 | /* If we're the LAC and we're sending sequence numbers, the | |
623 | * LNS has requested that we no longer send sequence numbers. | |
624 | * If we're the LNS and we're sending sequence numbers, the | |
625 | * LAC is broken. Discard the frame. | |
626 | */ | |
627 | if ((!session->lns_mode) && (session->send_seq)) { | |
628 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, | |
629 | "%s: requested to disable seq numbers by LNS\n", | |
630 | session->name); | |
631 | session->send_seq = 0; | |
f7faffa3 | 632 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
633 | } else if (session->send_seq) { |
634 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, | |
635 | "%s: recv data has no seq numbers when required. " | |
636 | "Discarding\n", session->name); | |
637 | session->stats.rx_seq_discards++; | |
638 | goto discard; | |
639 | } | |
640 | } | |
641 | ||
f7faffa3 JC |
642 | /* Session data offset is handled differently for L2TPv2 and |
643 | * L2TPv3. For L2TPv2, there is an optional 16-bit value in | |
644 | * the header. For L2TPv3, the offset is negotiated using AVPs | |
645 | * in the session setup control protocol. | |
646 | */ | |
647 | if (tunnel->version == L2TP_HDR_VER_2) { | |
648 | /* If offset bit set, skip it. */ | |
649 | if (hdrflags & L2TP_HDRFLAG_O) { | |
650 | offset = ntohs(*(__be16 *)ptr); | |
651 | ptr += 2 + offset; | |
652 | } | |
653 | } else | |
654 | ptr += session->offset; | |
fd558d18 JC |
655 | |
656 | offset = ptr - optr; | |
657 | if (!pskb_may_pull(skb, offset)) | |
658 | goto discard; | |
659 | ||
660 | __skb_pull(skb, offset); | |
661 | ||
662 | /* If caller wants to process the payload before we queue the | |
663 | * packet, do so now. | |
664 | */ | |
665 | if (payload_hook) | |
666 | if ((*payload_hook)(skb)) | |
667 | goto discard; | |
668 | ||
669 | /* Prepare skb for adding to the session's reorder_q. Hold | |
670 | * packets for max reorder_timeout or 1 second if not | |
671 | * reordering. | |
672 | */ | |
673 | L2TP_SKB_CB(skb)->length = length; | |
674 | L2TP_SKB_CB(skb)->expires = jiffies + | |
675 | (session->reorder_timeout ? session->reorder_timeout : HZ); | |
676 | ||
677 | /* Add packet to the session's receive queue. Reordering is done here, if | |
678 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. | |
679 | */ | |
680 | if (L2TP_SKB_CB(skb)->has_seq) { | |
681 | if (session->reorder_timeout != 0) { | |
682 | /* Packet reordering enabled. Add skb to session's | |
683 | * reorder queue, in order of ns. | |
684 | */ | |
685 | l2tp_recv_queue_skb(session, skb); | |
686 | } else { | |
687 | /* Packet reordering disabled. Discard out-of-sequence | |
688 | * packets | |
689 | */ | |
690 | if (L2TP_SKB_CB(skb)->ns != session->nr) { | |
691 | session->stats.rx_seq_discards++; | |
692 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
f7faffa3 JC |
693 | "%s: oos pkt %u len %d discarded, " |
694 | "waiting for %u, reorder_q_len=%d\n", | |
fd558d18 JC |
695 | session->name, L2TP_SKB_CB(skb)->ns, |
696 | L2TP_SKB_CB(skb)->length, session->nr, | |
697 | skb_queue_len(&session->reorder_q)); | |
698 | goto discard; | |
699 | } | |
700 | skb_queue_tail(&session->reorder_q, skb); | |
701 | } | |
702 | } else { | |
703 | /* No sequence numbers. Add the skb to the tail of the | |
704 | * reorder queue. This ensures that it will be | |
705 | * delivered after all previous sequenced skbs. | |
706 | */ | |
707 | skb_queue_tail(&session->reorder_q, skb); | |
708 | } | |
709 | ||
710 | /* Try to dequeue as many skbs from reorder_q as we can. */ | |
711 | l2tp_recv_dequeue(session); | |
712 | ||
713 | l2tp_session_dec_refcount(session); | |
714 | ||
f7faffa3 | 715 | return; |
fd558d18 JC |
716 | |
717 | discard: | |
718 | session->stats.rx_errors++; | |
719 | kfree_skb(skb); | |
720 | ||
721 | if (session->deref) | |
722 | (*session->deref)(session); | |
723 | ||
724 | l2tp_session_dec_refcount(session); | |
f7faffa3 JC |
725 | } |
726 | EXPORT_SYMBOL(l2tp_recv_common); | |
727 | ||
728 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame | |
729 | * here. The skb is not on a list when we get here. | |
730 | * Returns 0 if the packet was a data packet and was successfully passed on. | |
731 | * Returns 1 if the packet was not a good data packet and could not be | |
732 | * forwarded. All such packets are passed up to userspace to deal with. | |
733 | */ | |
fc130840 | 734 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, |
735 | int (*payload_hook)(struct sk_buff *skb)) | |
f7faffa3 JC |
736 | { |
737 | struct l2tp_session *session = NULL; | |
738 | unsigned char *ptr, *optr; | |
739 | u16 hdrflags; | |
740 | u32 tunnel_id, session_id; | |
741 | int offset; | |
742 | u16 version; | |
743 | int length; | |
744 | ||
745 | if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) | |
746 | goto discard_bad_csum; | |
747 | ||
748 | /* UDP always verifies the packet length. */ | |
749 | __skb_pull(skb, sizeof(struct udphdr)); | |
750 | ||
751 | /* Short packet? */ | |
752 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { | |
753 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, | |
754 | "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); | |
755 | goto error; | |
756 | } | |
757 | ||
758 | /* Point to L2TP header */ | |
759 | optr = ptr = skb->data; | |
760 | ||
761 | /* Trace packet contents, if enabled */ | |
762 | if (tunnel->debug & L2TP_MSG_DATA) { | |
763 | length = min(32u, skb->len); | |
764 | if (!pskb_may_pull(skb, length)) | |
765 | goto error; | |
766 | ||
767 | printk(KERN_DEBUG "%s: recv: ", tunnel->name); | |
768 | ||
769 | offset = 0; | |
770 | do { | |
771 | printk(" %02X", ptr[offset]); | |
772 | } while (++offset < length); | |
773 | ||
774 | printk("\n"); | |
775 | } | |
776 | ||
777 | /* Get L2TP header flags */ | |
778 | hdrflags = ntohs(*(__be16 *) ptr); | |
779 | ||
780 | /* Check protocol version */ | |
781 | version = hdrflags & L2TP_HDR_VER_MASK; | |
782 | if (version != tunnel->version) { | |
783 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, | |
784 | "%s: recv protocol version mismatch: got %d expected %d\n", | |
785 | tunnel->name, version, tunnel->version); | |
786 | goto error; | |
787 | } | |
788 | ||
789 | /* Get length of L2TP packet */ | |
790 | length = skb->len; | |
791 | ||
792 | /* If type is control packet, it is handled by userspace. */ | |
793 | if (hdrflags & L2TP_HDRFLAG_T) { | |
794 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, | |
795 | "%s: recv control packet, len=%d\n", tunnel->name, length); | |
796 | goto error; | |
797 | } | |
798 | ||
799 | /* Skip flags */ | |
800 | ptr += 2; | |
801 | ||
802 | if (tunnel->version == L2TP_HDR_VER_2) { | |
803 | /* If length is present, skip it */ | |
804 | if (hdrflags & L2TP_HDRFLAG_L) | |
805 | ptr += 2; | |
806 | ||
807 | /* Extract tunnel and session ID */ | |
808 | tunnel_id = ntohs(*(__be16 *) ptr); | |
809 | ptr += 2; | |
810 | session_id = ntohs(*(__be16 *) ptr); | |
811 | ptr += 2; | |
812 | } else { | |
813 | ptr += 2; /* skip reserved bits */ | |
814 | tunnel_id = tunnel->tunnel_id; | |
815 | session_id = ntohl(*(__be32 *) ptr); | |
816 | ptr += 4; | |
817 | } | |
818 | ||
819 | /* Find the session context */ | |
820 | session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); | |
309795f4 | 821 | if (!session || !session->recv_skb) { |
f7faffa3 JC |
822 | /* Not found? Pass to userspace to deal with */ |
823 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, | |
824 | "%s: no session found (%u/%u). Passing up.\n", | |
825 | tunnel->name, tunnel_id, session_id); | |
826 | goto error; | |
827 | } | |
828 | ||
829 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); | |
fd558d18 JC |
830 | |
831 | return 0; | |
832 | ||
833 | discard_bad_csum: | |
834 | LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); | |
835 | UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); | |
836 | tunnel->stats.rx_errors++; | |
837 | kfree_skb(skb); | |
838 | ||
839 | return 0; | |
840 | ||
841 | error: | |
842 | /* Put UDP header back */ | |
843 | __skb_push(skb, sizeof(struct udphdr)); | |
844 | ||
845 | return 1; | |
846 | } | |
fd558d18 JC |
847 | |
848 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. | |
849 | * Return codes: | |
850 | * 0 : success. | |
851 | * <0: error | |
852 | * >0: skb should be passed up to userspace as UDP. | |
853 | */ | |
854 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) | |
855 | { | |
856 | struct l2tp_tunnel *tunnel; | |
857 | ||
858 | tunnel = l2tp_sock_to_tunnel(sk); | |
859 | if (tunnel == NULL) | |
860 | goto pass_up; | |
861 | ||
862 | PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, | |
863 | "%s: received %d bytes\n", tunnel->name, skb->len); | |
864 | ||
865 | if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) | |
866 | goto pass_up_put; | |
867 | ||
868 | sock_put(sk); | |
869 | return 0; | |
870 | ||
871 | pass_up_put: | |
872 | sock_put(sk); | |
873 | pass_up: | |
874 | return 1; | |
875 | } | |
876 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); | |
877 | ||
878 | /************************************************************************ | |
879 | * Transmit handling | |
880 | ***********************************************************************/ | |
881 | ||
882 | /* Build an L2TP header for the session into the buffer provided. | |
883 | */ | |
f7faffa3 | 884 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
fd558d18 | 885 | { |
f7faffa3 | 886 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 887 | __be16 *bufp = buf; |
f7faffa3 | 888 | __be16 *optr = buf; |
fd558d18 JC |
889 | u16 flags = L2TP_HDR_VER_2; |
890 | u32 tunnel_id = tunnel->peer_tunnel_id; | |
891 | u32 session_id = session->peer_session_id; | |
892 | ||
893 | if (session->send_seq) | |
894 | flags |= L2TP_HDRFLAG_S; | |
895 | ||
896 | /* Setup L2TP header. */ | |
897 | *bufp++ = htons(flags); | |
898 | *bufp++ = htons(tunnel_id); | |
899 | *bufp++ = htons(session_id); | |
900 | if (session->send_seq) { | |
901 | *bufp++ = htons(session->ns); | |
902 | *bufp++ = 0; | |
903 | session->ns++; | |
f7faffa3 | 904 | session->ns &= 0xffff; |
fd558d18 | 905 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, |
f7faffa3 | 906 | "%s: updated ns to %u\n", session->name, session->ns); |
fd558d18 | 907 | } |
f7faffa3 JC |
908 | |
909 | return bufp - optr; | |
fd558d18 JC |
910 | } |
911 | ||
f7faffa3 | 912 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
fd558d18 | 913 | { |
0d76751f | 914 | struct l2tp_tunnel *tunnel = session->tunnel; |
f7faffa3 JC |
915 | char *bufp = buf; |
916 | char *optr = bufp; | |
f7faffa3 | 917 | |
0d76751f JC |
918 | /* Setup L2TP header. The header differs slightly for UDP and |
919 | * IP encapsulations. For UDP, there is 4 bytes of flags. | |
920 | */ | |
921 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
922 | u16 flags = L2TP_HDR_VER_3; | |
923 | *((__be16 *) bufp) = htons(flags); | |
924 | bufp += 2; | |
925 | *((__be16 *) bufp) = 0; | |
926 | bufp += 2; | |
927 | } | |
928 | ||
f7faffa3 JC |
929 | *((__be32 *) bufp) = htonl(session->peer_session_id); |
930 | bufp += 4; | |
931 | if (session->cookie_len) { | |
932 | memcpy(bufp, &session->cookie[0], session->cookie_len); | |
933 | bufp += session->cookie_len; | |
934 | } | |
935 | if (session->l2specific_len) { | |
936 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
937 | u32 l2h = 0; | |
938 | if (session->send_seq) { | |
939 | l2h = 0x40000000 | session->ns; | |
940 | session->ns++; | |
941 | session->ns &= 0xffffff; | |
942 | PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, | |
943 | "%s: updated ns to %u\n", session->name, session->ns); | |
944 | } | |
945 | ||
946 | *((__be32 *) bufp) = htonl(l2h); | |
947 | } | |
948 | bufp += session->l2specific_len; | |
949 | } | |
950 | if (session->offset) | |
951 | bufp += session->offset; | |
fd558d18 | 952 | |
f7faffa3 | 953 | return bufp - optr; |
fd558d18 | 954 | } |
fd558d18 | 955 | |
fc130840 | 956 | static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, |
d9d8da80 | 957 | struct flowi *fl, size_t data_len) |
fd558d18 JC |
958 | { |
959 | struct l2tp_tunnel *tunnel = session->tunnel; | |
960 | unsigned int len = skb->len; | |
961 | int error; | |
962 | ||
963 | /* Debug */ | |
964 | if (session->send_seq) | |
965 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, | |
f7faffa3 | 966 | "%s: send %Zd bytes, ns=%u\n", session->name, |
fd558d18 JC |
967 | data_len, session->ns - 1); |
968 | else | |
969 | PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, | |
970 | "%s: send %Zd bytes\n", session->name, data_len); | |
971 | ||
972 | if (session->debug & L2TP_MSG_DATA) { | |
973 | int i; | |
0d76751f JC |
974 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
975 | unsigned char *datap = skb->data + uhlen; | |
fd558d18 JC |
976 | |
977 | printk(KERN_DEBUG "%s: xmit:", session->name); | |
0d76751f | 978 | for (i = 0; i < (len - uhlen); i++) { |
fd558d18 JC |
979 | printk(" %02X", *datap++); |
980 | if (i == 31) { | |
981 | printk(" ..."); | |
982 | break; | |
983 | } | |
984 | } | |
985 | printk("\n"); | |
986 | } | |
987 | ||
988 | /* Queue the packet to IP for output */ | |
4e15ed4d | 989 | skb->local_df = 1; |
d9d8da80 | 990 | error = ip_queue_xmit(skb, fl); |
fd558d18 JC |
991 | |
992 | /* Update stats */ | |
993 | if (error >= 0) { | |
994 | tunnel->stats.tx_packets++; | |
995 | tunnel->stats.tx_bytes += len; | |
996 | session->stats.tx_packets++; | |
997 | session->stats.tx_bytes += len; | |
998 | } else { | |
999 | tunnel->stats.tx_errors++; | |
1000 | session->stats.tx_errors++; | |
1001 | } | |
1002 | ||
1003 | return 0; | |
1004 | } | |
fd558d18 JC |
1005 | |
1006 | /* Automatically called when the skb is freed. | |
1007 | */ | |
1008 | static void l2tp_sock_wfree(struct sk_buff *skb) | |
1009 | { | |
1010 | sock_put(skb->sk); | |
1011 | } | |
1012 | ||
1013 | /* For data skbs that we transmit, we associate with the tunnel socket | |
1014 | * but don't do accounting. | |
1015 | */ | |
1016 | static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) | |
1017 | { | |
1018 | sock_hold(sk); | |
1019 | skb->sk = sk; | |
1020 | skb->destructor = l2tp_sock_wfree; | |
1021 | } | |
1022 | ||
1023 | /* If caller requires the skb to have a ppp header, the header must be | |
1024 | * inserted in the skb data before calling this function. | |
1025 | */ | |
1026 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) | |
1027 | { | |
1028 | int data_len = skb->len; | |
0d76751f JC |
1029 | struct l2tp_tunnel *tunnel = session->tunnel; |
1030 | struct sock *sk = tunnel->sock; | |
d9d8da80 | 1031 | struct flowi *fl; |
fd558d18 | 1032 | struct udphdr *uh; |
fd558d18 JC |
1033 | struct inet_sock *inet; |
1034 | __wsum csum; | |
1035 | int old_headroom; | |
1036 | int new_headroom; | |
1037 | int headroom; | |
0d76751f JC |
1038 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1039 | int udp_len; | |
fd558d18 JC |
1040 | |
1041 | /* Check that there's enough headroom in the skb to insert IP, | |
1042 | * UDP and L2TP headers. If not enough, expand it to | |
1043 | * make room. Adjust truesize. | |
1044 | */ | |
1045 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + | |
0d76751f | 1046 | uhlen + hdr_len; |
fd558d18 JC |
1047 | old_headroom = skb_headroom(skb); |
1048 | if (skb_cow_head(skb, headroom)) | |
1049 | goto abort; | |
1050 | ||
1051 | new_headroom = skb_headroom(skb); | |
1052 | skb_orphan(skb); | |
1053 | skb->truesize += new_headroom - old_headroom; | |
1054 | ||
1055 | /* Setup L2TP header */ | |
f7faffa3 | 1056 | session->build_header(session, __skb_push(skb, hdr_len)); |
fd558d18 | 1057 | |
0d76751f | 1058 | /* Reset skb netfilter state */ |
fd558d18 JC |
1059 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
1060 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | | |
1061 | IPSKB_REROUTED); | |
1062 | nf_reset(skb); | |
1063 | ||
6af88da1 DM |
1064 | bh_lock_sock(sk); |
1065 | if (sock_owned_by_user(sk)) { | |
1066 | dev_kfree_skb(skb); | |
1067 | goto out_unlock; | |
1068 | } | |
1069 | ||
fd558d18 JC |
1070 | /* Get routing info from the tunnel socket */ |
1071 | skb_dst_drop(skb); | |
1072 | skb_dst_set(skb, dst_clone(__sk_dst_get(sk))); | |
fd558d18 | 1073 | |
d9d8da80 DM |
1074 | inet = inet_sk(sk); |
1075 | fl = &inet->cork.fl; | |
0d76751f JC |
1076 | switch (tunnel->encap) { |
1077 | case L2TP_ENCAPTYPE_UDP: | |
1078 | /* Setup UDP header */ | |
0d76751f JC |
1079 | __skb_push(skb, sizeof(*uh)); |
1080 | skb_reset_transport_header(skb); | |
1081 | uh = udp_hdr(skb); | |
1082 | uh->source = inet->inet_sport; | |
1083 | uh->dest = inet->inet_dport; | |
1084 | udp_len = uhlen + hdr_len + data_len; | |
1085 | uh->len = htons(udp_len); | |
1086 | uh->check = 0; | |
1087 | ||
1088 | /* Calculate UDP checksum if configured to do so */ | |
1089 | if (sk->sk_no_check == UDP_CSUM_NOXMIT) | |
1090 | skb->ip_summed = CHECKSUM_NONE; | |
1091 | else if ((skb_dst(skb) && skb_dst(skb)->dev) && | |
1092 | (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { | |
1093 | skb->ip_summed = CHECKSUM_COMPLETE; | |
1094 | csum = skb_checksum(skb, 0, udp_len, 0); | |
1095 | uh->check = csum_tcpudp_magic(inet->inet_saddr, | |
1096 | inet->inet_daddr, | |
1097 | udp_len, IPPROTO_UDP, csum); | |
1098 | if (uh->check == 0) | |
1099 | uh->check = CSUM_MANGLED_0; | |
1100 | } else { | |
1101 | skb->ip_summed = CHECKSUM_PARTIAL; | |
1102 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
1103 | skb->csum_offset = offsetof(struct udphdr, check); | |
1104 | uh->check = ~csum_tcpudp_magic(inet->inet_saddr, | |
1105 | inet->inet_daddr, | |
1106 | udp_len, IPPROTO_UDP, 0); | |
1107 | } | |
1108 | break; | |
1109 | ||
1110 | case L2TP_ENCAPTYPE_IP: | |
1111 | break; | |
fd558d18 JC |
1112 | } |
1113 | ||
0d76751f JC |
1114 | l2tp_skb_set_owner_w(skb, sk); |
1115 | ||
d9d8da80 | 1116 | l2tp_xmit_core(session, skb, fl, data_len); |
6af88da1 DM |
1117 | out_unlock: |
1118 | bh_unlock_sock(sk); | |
fd558d18 JC |
1119 | |
1120 | abort: | |
1121 | return 0; | |
1122 | } | |
1123 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); | |
1124 | ||
1125 | /***************************************************************************** | |
1126 | * Tinnel and session create/destroy. | |
1127 | *****************************************************************************/ | |
1128 | ||
1129 | /* Tunnel socket destruct hook. | |
1130 | * The tunnel context is deleted only when all session sockets have been | |
1131 | * closed. | |
1132 | */ | |
fc130840 | 1133 | static void l2tp_tunnel_destruct(struct sock *sk) |
fd558d18 JC |
1134 | { |
1135 | struct l2tp_tunnel *tunnel; | |
1136 | ||
1137 | tunnel = sk->sk_user_data; | |
1138 | if (tunnel == NULL) | |
1139 | goto end; | |
1140 | ||
1141 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, | |
1142 | "%s: closing...\n", tunnel->name); | |
1143 | ||
1144 | /* Close all sessions */ | |
1145 | l2tp_tunnel_closeall(tunnel); | |
1146 | ||
0d76751f JC |
1147 | switch (tunnel->encap) { |
1148 | case L2TP_ENCAPTYPE_UDP: | |
1149 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ | |
1150 | (udp_sk(sk))->encap_type = 0; | |
1151 | (udp_sk(sk))->encap_rcv = NULL; | |
1152 | break; | |
1153 | case L2TP_ENCAPTYPE_IP: | |
1154 | break; | |
1155 | } | |
fd558d18 JC |
1156 | |
1157 | /* Remove hooks into tunnel socket */ | |
1158 | tunnel->sock = NULL; | |
1159 | sk->sk_destruct = tunnel->old_sk_destruct; | |
1160 | sk->sk_user_data = NULL; | |
1161 | ||
1162 | /* Call the original destructor */ | |
1163 | if (sk->sk_destruct) | |
1164 | (*sk->sk_destruct)(sk); | |
1165 | ||
1166 | /* We're finished with the socket */ | |
1167 | l2tp_tunnel_dec_refcount(tunnel); | |
1168 | ||
1169 | end: | |
1170 | return; | |
1171 | } | |
fd558d18 JC |
1172 | |
1173 | /* When the tunnel is closed, all the attached sessions need to go too. | |
1174 | */ | |
fc130840 | 1175 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
fd558d18 JC |
1176 | { |
1177 | int hash; | |
1178 | struct hlist_node *walk; | |
1179 | struct hlist_node *tmp; | |
1180 | struct l2tp_session *session; | |
1181 | ||
1182 | BUG_ON(tunnel == NULL); | |
1183 | ||
1184 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, | |
1185 | "%s: closing all sessions...\n", tunnel->name); | |
1186 | ||
1187 | write_lock_bh(&tunnel->hlist_lock); | |
1188 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { | |
1189 | again: | |
1190 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { | |
1191 | session = hlist_entry(walk, struct l2tp_session, hlist); | |
1192 | ||
1193 | PRINTK(session->debug, L2TP_MSG_CONTROL, KERN_INFO, | |
1194 | "%s: closing session\n", session->name); | |
1195 | ||
1196 | hlist_del_init(&session->hlist); | |
1197 | ||
1198 | /* Since we should hold the sock lock while | |
1199 | * doing any unbinding, we need to release the | |
1200 | * lock we're holding before taking that lock. | |
1201 | * Hold a reference to the sock so it doesn't | |
1202 | * disappear as we're jumping between locks. | |
1203 | */ | |
1204 | if (session->ref != NULL) | |
1205 | (*session->ref)(session); | |
1206 | ||
1207 | write_unlock_bh(&tunnel->hlist_lock); | |
1208 | ||
f7faffa3 JC |
1209 | if (tunnel->version != L2TP_HDR_VER_2) { |
1210 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1211 | ||
e02d494d JC |
1212 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1213 | hlist_del_init_rcu(&session->global_hlist); | |
1214 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
1215 | synchronize_rcu(); | |
f7faffa3 JC |
1216 | } |
1217 | ||
fd558d18 JC |
1218 | if (session->session_close != NULL) |
1219 | (*session->session_close)(session); | |
1220 | ||
1221 | if (session->deref != NULL) | |
1222 | (*session->deref)(session); | |
1223 | ||
1224 | write_lock_bh(&tunnel->hlist_lock); | |
1225 | ||
1226 | /* Now restart from the beginning of this hash | |
1227 | * chain. We always remove a session from the | |
1228 | * list so we are guaranteed to make forward | |
1229 | * progress. | |
1230 | */ | |
1231 | goto again; | |
1232 | } | |
1233 | } | |
1234 | write_unlock_bh(&tunnel->hlist_lock); | |
1235 | } | |
fd558d18 JC |
1236 | |
1237 | /* Really kill the tunnel. | |
1238 | * Come here only when all sessions have been cleared from the tunnel. | |
1239 | */ | |
fc130840 | 1240 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
fd558d18 JC |
1241 | { |
1242 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1243 | ||
1244 | BUG_ON(atomic_read(&tunnel->ref_count) != 0); | |
1245 | BUG_ON(tunnel->sock != NULL); | |
1246 | ||
1247 | PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, | |
1248 | "%s: free...\n", tunnel->name); | |
1249 | ||
1250 | /* Remove from tunnel list */ | |
e02d494d JC |
1251 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
1252 | list_del_rcu(&tunnel->list); | |
1253 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1254 | synchronize_rcu(); | |
fd558d18 JC |
1255 | |
1256 | atomic_dec(&l2tp_tunnel_count); | |
1257 | kfree(tunnel); | |
1258 | } | |
fd558d18 | 1259 | |
789a4a2c JC |
1260 | /* Create a socket for the tunnel, if one isn't set up by |
1261 | * userspace. This is used for static tunnels where there is no | |
1262 | * managing L2TP daemon. | |
1263 | */ | |
1264 | static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct socket **sockp) | |
1265 | { | |
1266 | int err = -EINVAL; | |
1267 | struct sockaddr_in udp_addr; | |
1268 | struct sockaddr_l2tpip ip_addr; | |
7bddd0db | 1269 | struct socket *sock = NULL; |
789a4a2c JC |
1270 | |
1271 | switch (cfg->encap) { | |
1272 | case L2TP_ENCAPTYPE_UDP: | |
1273 | err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp); | |
1274 | if (err < 0) | |
1275 | goto out; | |
1276 | ||
1277 | sock = *sockp; | |
1278 | ||
1279 | memset(&udp_addr, 0, sizeof(udp_addr)); | |
1280 | udp_addr.sin_family = AF_INET; | |
1281 | udp_addr.sin_addr = cfg->local_ip; | |
1282 | udp_addr.sin_port = htons(cfg->local_udp_port); | |
1283 | err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr)); | |
1284 | if (err < 0) | |
1285 | goto out; | |
1286 | ||
1287 | udp_addr.sin_family = AF_INET; | |
1288 | udp_addr.sin_addr = cfg->peer_ip; | |
1289 | udp_addr.sin_port = htons(cfg->peer_udp_port); | |
1290 | err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0); | |
1291 | if (err < 0) | |
1292 | goto out; | |
1293 | ||
1294 | if (!cfg->use_udp_checksums) | |
1295 | sock->sk->sk_no_check = UDP_CSUM_NOXMIT; | |
1296 | ||
1297 | break; | |
1298 | ||
1299 | case L2TP_ENCAPTYPE_IP: | |
1300 | err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp); | |
1301 | if (err < 0) | |
1302 | goto out; | |
1303 | ||
1304 | sock = *sockp; | |
1305 | ||
1306 | memset(&ip_addr, 0, sizeof(ip_addr)); | |
1307 | ip_addr.l2tp_family = AF_INET; | |
1308 | ip_addr.l2tp_addr = cfg->local_ip; | |
1309 | ip_addr.l2tp_conn_id = tunnel_id; | |
1310 | err = kernel_bind(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr)); | |
1311 | if (err < 0) | |
1312 | goto out; | |
1313 | ||
1314 | ip_addr.l2tp_family = AF_INET; | |
1315 | ip_addr.l2tp_addr = cfg->peer_ip; | |
1316 | ip_addr.l2tp_conn_id = peer_tunnel_id; | |
1317 | err = kernel_connect(sock, (struct sockaddr *) &ip_addr, sizeof(ip_addr), 0); | |
1318 | if (err < 0) | |
1319 | goto out; | |
1320 | ||
1321 | break; | |
1322 | ||
1323 | default: | |
1324 | goto out; | |
1325 | } | |
1326 | ||
1327 | out: | |
1328 | if ((err < 0) && sock) { | |
1329 | sock_release(sock); | |
1330 | *sockp = NULL; | |
1331 | } | |
1332 | ||
1333 | return err; | |
1334 | } | |
1335 | ||
fd558d18 JC |
1336 | 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) |
1337 | { | |
1338 | struct l2tp_tunnel *tunnel = NULL; | |
1339 | int err; | |
1340 | struct socket *sock = NULL; | |
1341 | struct sock *sk = NULL; | |
1342 | struct l2tp_net *pn; | |
0d76751f | 1343 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
fd558d18 JC |
1344 | |
1345 | /* Get the tunnel socket from the fd, which was opened by | |
789a4a2c JC |
1346 | * the userspace L2TP daemon. If not specified, create a |
1347 | * kernel socket. | |
fd558d18 | 1348 | */ |
789a4a2c JC |
1349 | if (fd < 0) { |
1350 | err = l2tp_tunnel_sock_create(tunnel_id, peer_tunnel_id, cfg, &sock); | |
1351 | if (err < 0) | |
1352 | goto err; | |
1353 | } else { | |
1354 | err = -EBADF; | |
1355 | sock = sockfd_lookup(fd, &err); | |
1356 | if (!sock) { | |
1357 | printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", | |
1358 | tunnel_id, fd, err); | |
1359 | goto err; | |
1360 | } | |
fd558d18 JC |
1361 | } |
1362 | ||
1363 | sk = sock->sk; | |
1364 | ||
0d76751f JC |
1365 | if (cfg != NULL) |
1366 | encap = cfg->encap; | |
1367 | ||
fd558d18 | 1368 | /* Quick sanity checks */ |
0d76751f JC |
1369 | switch (encap) { |
1370 | case L2TP_ENCAPTYPE_UDP: | |
1371 | err = -EPROTONOSUPPORT; | |
1372 | if (sk->sk_protocol != IPPROTO_UDP) { | |
1373 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", | |
1374 | tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); | |
1375 | goto err; | |
1376 | } | |
1377 | break; | |
1378 | case L2TP_ENCAPTYPE_IP: | |
1379 | err = -EPROTONOSUPPORT; | |
1380 | if (sk->sk_protocol != IPPROTO_L2TP) { | |
1381 | printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", | |
1382 | tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); | |
1383 | goto err; | |
1384 | } | |
1385 | break; | |
fd558d18 JC |
1386 | } |
1387 | ||
1388 | /* Check if this socket has already been prepped */ | |
1389 | tunnel = (struct l2tp_tunnel *)sk->sk_user_data; | |
1390 | if (tunnel != NULL) { | |
1391 | /* This socket has already been prepped */ | |
1392 | err = -EBUSY; | |
1393 | goto err; | |
1394 | } | |
1395 | ||
fd558d18 JC |
1396 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
1397 | if (tunnel == NULL) { | |
1398 | err = -ENOMEM; | |
1399 | goto err; | |
1400 | } | |
1401 | ||
1402 | tunnel->version = version; | |
1403 | tunnel->tunnel_id = tunnel_id; | |
1404 | tunnel->peer_tunnel_id = peer_tunnel_id; | |
1405 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; | |
1406 | ||
1407 | tunnel->magic = L2TP_TUNNEL_MAGIC; | |
1408 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); | |
1409 | rwlock_init(&tunnel->hlist_lock); | |
1410 | ||
1411 | /* The net we belong to */ | |
1412 | tunnel->l2tp_net = net; | |
1413 | pn = l2tp_pernet(net); | |
1414 | ||
0d76751f | 1415 | if (cfg != NULL) |
fd558d18 JC |
1416 | tunnel->debug = cfg->debug; |
1417 | ||
1418 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ | |
0d76751f JC |
1419 | tunnel->encap = encap; |
1420 | if (encap == L2TP_ENCAPTYPE_UDP) { | |
1421 | /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ | |
1422 | udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; | |
1423 | udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; | |
1424 | } | |
fd558d18 JC |
1425 | |
1426 | sk->sk_user_data = tunnel; | |
1427 | ||
1428 | /* Hook on the tunnel socket destructor so that we can cleanup | |
1429 | * if the tunnel socket goes away. | |
1430 | */ | |
1431 | tunnel->old_sk_destruct = sk->sk_destruct; | |
1432 | sk->sk_destruct = &l2tp_tunnel_destruct; | |
1433 | tunnel->sock = sk; | |
1434 | sk->sk_allocation = GFP_ATOMIC; | |
1435 | ||
1436 | /* Add tunnel to our list */ | |
1437 | INIT_LIST_HEAD(&tunnel->list); | |
fd558d18 JC |
1438 | atomic_inc(&l2tp_tunnel_count); |
1439 | ||
1440 | /* Bump the reference count. The tunnel context is deleted | |
1769192a | 1441 | * only when this drops to zero. Must be done before list insertion |
fd558d18 JC |
1442 | */ |
1443 | l2tp_tunnel_inc_refcount(tunnel); | |
1769192a ED |
1444 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
1445 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); | |
1446 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
fd558d18 JC |
1447 | |
1448 | err = 0; | |
1449 | err: | |
1450 | if (tunnelp) | |
1451 | *tunnelp = tunnel; | |
1452 | ||
789a4a2c JC |
1453 | /* If tunnel's socket was created by the kernel, it doesn't |
1454 | * have a file. | |
1455 | */ | |
1456 | if (sock && sock->file) | |
fd558d18 JC |
1457 | sockfd_put(sock); |
1458 | ||
1459 | return err; | |
1460 | } | |
1461 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); | |
1462 | ||
309795f4 JC |
1463 | /* This function is used by the netlink TUNNEL_DELETE command. |
1464 | */ | |
1465 | int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) | |
1466 | { | |
1467 | int err = 0; | |
789a4a2c | 1468 | struct socket *sock = tunnel->sock ? tunnel->sock->sk_socket : NULL; |
309795f4 JC |
1469 | |
1470 | /* Force the tunnel socket to close. This will eventually | |
1471 | * cause the tunnel to be deleted via the normal socket close | |
1472 | * mechanisms when userspace closes the tunnel socket. | |
1473 | */ | |
789a4a2c JC |
1474 | if (sock != NULL) { |
1475 | err = inet_shutdown(sock, 2); | |
1476 | ||
1477 | /* If the tunnel's socket was created by the kernel, | |
1478 | * close the socket here since the socket was not | |
1479 | * created by userspace. | |
1480 | */ | |
1481 | if (sock->file == NULL) | |
1482 | err = inet_release(sock); | |
1483 | } | |
309795f4 JC |
1484 | |
1485 | return err; | |
1486 | } | |
1487 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); | |
1488 | ||
fd558d18 JC |
1489 | /* Really kill the session. |
1490 | */ | |
1491 | void l2tp_session_free(struct l2tp_session *session) | |
1492 | { | |
1493 | struct l2tp_tunnel *tunnel; | |
1494 | ||
1495 | BUG_ON(atomic_read(&session->ref_count) != 0); | |
1496 | ||
1497 | tunnel = session->tunnel; | |
1498 | if (tunnel != NULL) { | |
1499 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); | |
1500 | ||
1501 | /* Delete the session from the hash */ | |
1502 | write_lock_bh(&tunnel->hlist_lock); | |
1503 | hlist_del_init(&session->hlist); | |
1504 | write_unlock_bh(&tunnel->hlist_lock); | |
1505 | ||
f7faffa3 JC |
1506 | /* Unlink from the global hash if not L2TPv2 */ |
1507 | if (tunnel->version != L2TP_HDR_VER_2) { | |
1508 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1509 | ||
e02d494d JC |
1510 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1511 | hlist_del_init_rcu(&session->global_hlist); | |
1512 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
1513 | synchronize_rcu(); | |
f7faffa3 JC |
1514 | } |
1515 | ||
fd558d18 JC |
1516 | if (session->session_id != 0) |
1517 | atomic_dec(&l2tp_session_count); | |
1518 | ||
1519 | sock_put(tunnel->sock); | |
1520 | ||
1521 | /* This will delete the tunnel context if this | |
1522 | * is the last session on the tunnel. | |
1523 | */ | |
1524 | session->tunnel = NULL; | |
1525 | l2tp_tunnel_dec_refcount(tunnel); | |
1526 | } | |
1527 | ||
1528 | kfree(session); | |
1529 | ||
1530 | return; | |
1531 | } | |
1532 | EXPORT_SYMBOL_GPL(l2tp_session_free); | |
1533 | ||
309795f4 JC |
1534 | /* This function is used by the netlink SESSION_DELETE command and by |
1535 | pseudowire modules. | |
1536 | */ | |
1537 | int l2tp_session_delete(struct l2tp_session *session) | |
1538 | { | |
1539 | if (session->session_close != NULL) | |
1540 | (*session->session_close)(session); | |
1541 | ||
1542 | l2tp_session_dec_refcount(session); | |
1543 | ||
1544 | return 0; | |
1545 | } | |
1546 | EXPORT_SYMBOL_GPL(l2tp_session_delete); | |
1547 | ||
1548 | ||
f7faffa3 JC |
1549 | /* We come here whenever a session's send_seq, cookie_len or |
1550 | * l2specific_len parameters are set. | |
1551 | */ | |
fc130840 | 1552 | static void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
f7faffa3 JC |
1553 | { |
1554 | if (version == L2TP_HDR_VER_2) { | |
1555 | session->hdr_len = 6; | |
1556 | if (session->send_seq) | |
1557 | session->hdr_len += 4; | |
1558 | } else { | |
0d76751f JC |
1559 | session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; |
1560 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) | |
1561 | session->hdr_len += 4; | |
f7faffa3 JC |
1562 | } |
1563 | ||
1564 | } | |
f7faffa3 | 1565 | |
fd558d18 JC |
1566 | 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) |
1567 | { | |
1568 | struct l2tp_session *session; | |
1569 | ||
1570 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); | |
1571 | if (session != NULL) { | |
1572 | session->magic = L2TP_SESSION_MAGIC; | |
1573 | session->tunnel = tunnel; | |
1574 | ||
1575 | session->session_id = session_id; | |
1576 | session->peer_session_id = peer_session_id; | |
f7faffa3 | 1577 | session->nr = 1; |
fd558d18 JC |
1578 | |
1579 | sprintf(&session->name[0], "sess %u/%u", | |
1580 | tunnel->tunnel_id, session->session_id); | |
1581 | ||
1582 | skb_queue_head_init(&session->reorder_q); | |
1583 | ||
1584 | INIT_HLIST_NODE(&session->hlist); | |
f7faffa3 | 1585 | INIT_HLIST_NODE(&session->global_hlist); |
fd558d18 JC |
1586 | |
1587 | /* Inherit debug options from tunnel */ | |
1588 | session->debug = tunnel->debug; | |
1589 | ||
1590 | if (cfg) { | |
f7faffa3 | 1591 | session->pwtype = cfg->pw_type; |
fd558d18 | 1592 | session->debug = cfg->debug; |
fd558d18 JC |
1593 | session->mtu = cfg->mtu; |
1594 | session->mru = cfg->mru; | |
1595 | session->send_seq = cfg->send_seq; | |
1596 | session->recv_seq = cfg->recv_seq; | |
1597 | session->lns_mode = cfg->lns_mode; | |
f7faffa3 JC |
1598 | session->reorder_timeout = cfg->reorder_timeout; |
1599 | session->offset = cfg->offset; | |
1600 | session->l2specific_type = cfg->l2specific_type; | |
1601 | session->l2specific_len = cfg->l2specific_len; | |
1602 | session->cookie_len = cfg->cookie_len; | |
1603 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); | |
1604 | session->peer_cookie_len = cfg->peer_cookie_len; | |
1605 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); | |
fd558d18 JC |
1606 | } |
1607 | ||
f7faffa3 JC |
1608 | if (tunnel->version == L2TP_HDR_VER_2) |
1609 | session->build_header = l2tp_build_l2tpv2_header; | |
1610 | else | |
1611 | session->build_header = l2tp_build_l2tpv3_header; | |
1612 | ||
1613 | l2tp_session_set_header_len(session, tunnel->version); | |
1614 | ||
fd558d18 JC |
1615 | /* Bump the reference count. The session context is deleted |
1616 | * only when this drops to zero. | |
1617 | */ | |
1618 | l2tp_session_inc_refcount(session); | |
1619 | l2tp_tunnel_inc_refcount(tunnel); | |
1620 | ||
1621 | /* Ensure tunnel socket isn't deleted */ | |
1622 | sock_hold(tunnel->sock); | |
1623 | ||
1624 | /* Add session to the tunnel's hash list */ | |
1625 | write_lock_bh(&tunnel->hlist_lock); | |
1626 | hlist_add_head(&session->hlist, | |
1627 | l2tp_session_id_hash(tunnel, session_id)); | |
1628 | write_unlock_bh(&tunnel->hlist_lock); | |
1629 | ||
f7faffa3 JC |
1630 | /* And to the global session list if L2TPv3 */ |
1631 | if (tunnel->version != L2TP_HDR_VER_2) { | |
1632 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1633 | ||
e02d494d JC |
1634 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1635 | hlist_add_head_rcu(&session->global_hlist, | |
1636 | l2tp_session_id_hash_2(pn, session_id)); | |
1637 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
f7faffa3 JC |
1638 | } |
1639 | ||
fd558d18 JC |
1640 | /* Ignore management session in session count value */ |
1641 | if (session->session_id != 0) | |
1642 | atomic_inc(&l2tp_session_count); | |
1643 | } | |
1644 | ||
1645 | return session; | |
1646 | } | |
1647 | EXPORT_SYMBOL_GPL(l2tp_session_create); | |
1648 | ||
1649 | /***************************************************************************** | |
1650 | * Init and cleanup | |
1651 | *****************************************************************************/ | |
1652 | ||
1653 | static __net_init int l2tp_init_net(struct net *net) | |
1654 | { | |
e773aaff | 1655 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
f7faffa3 | 1656 | int hash; |
fd558d18 | 1657 | |
fd558d18 | 1658 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
e02d494d | 1659 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
fd558d18 | 1660 | |
f7faffa3 JC |
1661 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
1662 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); | |
1663 | ||
e02d494d | 1664 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
f7faffa3 | 1665 | |
fd558d18 | 1666 | return 0; |
fd558d18 JC |
1667 | } |
1668 | ||
1669 | static struct pernet_operations l2tp_net_ops = { | |
1670 | .init = l2tp_init_net, | |
fd558d18 JC |
1671 | .id = &l2tp_net_id, |
1672 | .size = sizeof(struct l2tp_net), | |
1673 | }; | |
1674 | ||
1675 | static int __init l2tp_init(void) | |
1676 | { | |
1677 | int rc = 0; | |
1678 | ||
1679 | rc = register_pernet_device(&l2tp_net_ops); | |
1680 | if (rc) | |
1681 | goto out; | |
1682 | ||
1683 | printk(KERN_INFO "L2TP core driver, %s\n", L2TP_DRV_VERSION); | |
1684 | ||
1685 | out: | |
1686 | return rc; | |
1687 | } | |
1688 | ||
1689 | static void __exit l2tp_exit(void) | |
1690 | { | |
1691 | unregister_pernet_device(&l2tp_net_ops); | |
1692 | } | |
1693 | ||
1694 | module_init(l2tp_init); | |
1695 | module_exit(l2tp_exit); | |
1696 | ||
1697 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
1698 | MODULE_DESCRIPTION("L2TP core"); | |
1699 | MODULE_LICENSE("GPL"); | |
1700 | MODULE_VERSION(L2TP_DRV_VERSION); | |
1701 |