Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
fd558d18 JC |
2 | /* |
3 | * L2TP core. | |
4 | * | |
5 | * Copyright (c) 2008,2009,2010 Katalix Systems Ltd | |
6 | * | |
7 | * This file contains some code of the original L2TPv2 pppol2tp | |
8 | * driver, which has the following copyright: | |
9 | * | |
10 | * Authors: Martijn van Oosterhout <kleptog@svana.org> | |
11 | * James Chapman (jchapman@katalix.com) | |
12 | * Contributors: | |
13 | * Michal Ostrowski <mostrows@speakeasy.net> | |
14 | * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> | |
15 | * David S. Miller (davem@redhat.com) | |
fd558d18 JC |
16 | */ |
17 | ||
a4ca44fa JP |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
fd558d18 JC |
20 | #include <linux/module.h> |
21 | #include <linux/string.h> | |
22 | #include <linux/list.h> | |
e02d494d | 23 | #include <linux/rculist.h> |
fd558d18 JC |
24 | #include <linux/uaccess.h> |
25 | ||
26 | #include <linux/kernel.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/kthread.h> | |
29 | #include <linux/sched.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/jiffies.h> | |
33 | ||
34 | #include <linux/netdevice.h> | |
35 | #include <linux/net.h> | |
36 | #include <linux/inetdevice.h> | |
37 | #include <linux/skbuff.h> | |
38 | #include <linux/init.h> | |
0d76751f | 39 | #include <linux/in.h> |
fd558d18 JC |
40 | #include <linux/ip.h> |
41 | #include <linux/udp.h> | |
0d76751f | 42 | #include <linux/l2tp.h> |
fd558d18 JC |
43 | #include <linux/hash.h> |
44 | #include <linux/sort.h> | |
45 | #include <linux/file.h> | |
46 | #include <linux/nsproxy.h> | |
47 | #include <net/net_namespace.h> | |
48 | #include <net/netns/generic.h> | |
49 | #include <net/dst.h> | |
50 | #include <net/ip.h> | |
51 | #include <net/udp.h> | |
85644b4d | 52 | #include <net/udp_tunnel.h> |
309795f4 | 53 | #include <net/inet_common.h> |
fd558d18 | 54 | #include <net/xfrm.h> |
0d76751f | 55 | #include <net/protocol.h> |
d2cf3361 BL |
56 | #include <net/inet6_connection_sock.h> |
57 | #include <net/inet_ecn.h> | |
58 | #include <net/ip6_route.h> | |
d499bd2e | 59 | #include <net/ip6_checksum.h> |
fd558d18 JC |
60 | |
61 | #include <asm/byteorder.h> | |
60063497 | 62 | #include <linux/atomic.h> |
fd558d18 JC |
63 | |
64 | #include "l2tp_core.h" | |
65 | ||
66 | #define L2TP_DRV_VERSION "V2.0" | |
67 | ||
68 | /* L2TP header constants */ | |
69 | #define L2TP_HDRFLAG_T 0x8000 | |
70 | #define L2TP_HDRFLAG_L 0x4000 | |
71 | #define L2TP_HDRFLAG_S 0x0800 | |
72 | #define L2TP_HDRFLAG_O 0x0200 | |
73 | #define L2TP_HDRFLAG_P 0x0100 | |
74 | ||
75 | #define L2TP_HDR_VER_MASK 0x000F | |
76 | #define L2TP_HDR_VER_2 0x0002 | |
f7faffa3 | 77 | #define L2TP_HDR_VER_3 0x0003 |
fd558d18 JC |
78 | |
79 | /* L2TPv3 default L2-specific sublayer */ | |
80 | #define L2TP_SLFLAG_S 0x40000000 | |
81 | #define L2TP_SL_SEQ_MASK 0x00ffffff | |
82 | ||
91c52470 | 83 | #define L2TP_HDR_SIZE_MAX 14 |
fd558d18 JC |
84 | |
85 | /* Default trace flags */ | |
86 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 | |
87 | ||
fd558d18 JC |
88 | /* Private data stored for received packets in the skb. |
89 | */ | |
90 | struct l2tp_skb_cb { | |
f7faffa3 | 91 | u32 ns; |
fd558d18 JC |
92 | u16 has_seq; |
93 | u16 length; | |
94 | unsigned long expires; | |
95 | }; | |
96 | ||
97 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) | |
98 | ||
f8ccac0e | 99 | static struct workqueue_struct *l2tp_wq; |
fd558d18 JC |
100 | |
101 | /* per-net private data for this module */ | |
102 | static unsigned int l2tp_net_id; | |
103 | struct l2tp_net { | |
104 | struct list_head l2tp_tunnel_list; | |
e02d494d | 105 | spinlock_t l2tp_tunnel_list_lock; |
f7faffa3 | 106 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
e02d494d | 107 | spinlock_t l2tp_session_hlist_lock; |
fd558d18 JC |
108 | }; |
109 | ||
b954f940 PA |
110 | #if IS_ENABLED(CONFIG_IPV6) |
111 | static bool l2tp_sk_is_v6(struct sock *sk) | |
112 | { | |
113 | return sk->sk_family == PF_INET6 && | |
114 | !ipv6_addr_v4mapped(&sk->sk_v6_daddr); | |
115 | } | |
116 | #endif | |
fc130840 | 117 | |
8d8a51e2 DM |
118 | static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) |
119 | { | |
120 | return sk->sk_user_data; | |
121 | } | |
122 | ||
9aaef50c | 123 | static inline struct l2tp_net *l2tp_pernet(const struct net *net) |
fd558d18 | 124 | { |
fd558d18 JC |
125 | return net_generic(net, l2tp_net_id); |
126 | } | |
127 | ||
f7faffa3 JC |
128 | /* Session hash global list for L2TPv3. |
129 | * The session_id SHOULD be random according to RFC3931, but several | |
130 | * L2TP implementations use incrementing session_ids. So we do a real | |
131 | * hash on the session_id, rather than a simple bitmask. | |
132 | */ | |
133 | static inline struct hlist_head * | |
134 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) | |
135 | { | |
136 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; | |
137 | ||
138 | } | |
139 | ||
fd558d18 JC |
140 | /* Session hash list. |
141 | * The session_id SHOULD be random according to RFC2661, but several | |
142 | * L2TP implementations (Cisco and Microsoft) use incrementing | |
143 | * session_ids. So we do a real hash on the session_id, rather than a | |
144 | * simple bitmask. | |
145 | */ | |
146 | static inline struct hlist_head * | |
147 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) | |
148 | { | |
149 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; | |
150 | } | |
151 | ||
d00fa9ad JC |
152 | void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
153 | { | |
154 | sock_put(tunnel->sock); | |
155 | /* the tunnel is freed in the socket destructor */ | |
156 | } | |
157 | EXPORT_SYMBOL(l2tp_tunnel_free); | |
158 | ||
54652eb1 GN |
159 | /* Lookup a tunnel. A new reference is held on the returned tunnel. */ |
160 | struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) | |
161 | { | |
162 | const struct l2tp_net *pn = l2tp_pernet(net); | |
163 | struct l2tp_tunnel *tunnel; | |
164 | ||
165 | rcu_read_lock_bh(); | |
166 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
a622b400 ED |
167 | if (tunnel->tunnel_id == tunnel_id && |
168 | refcount_inc_not_zero(&tunnel->ref_count)) { | |
54652eb1 GN |
169 | rcu_read_unlock_bh(); |
170 | ||
171 | return tunnel; | |
172 | } | |
173 | } | |
174 | rcu_read_unlock_bh(); | |
175 | ||
176 | return NULL; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get); | |
179 | ||
5846c131 GN |
180 | struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth) |
181 | { | |
182 | const struct l2tp_net *pn = l2tp_pernet(net); | |
183 | struct l2tp_tunnel *tunnel; | |
184 | int count = 0; | |
185 | ||
186 | rcu_read_lock_bh(); | |
187 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
a622b400 ED |
188 | if (++count > nth && |
189 | refcount_inc_not_zero(&tunnel->ref_count)) { | |
5846c131 GN |
190 | rcu_read_unlock_bh(); |
191 | return tunnel; | |
192 | } | |
193 | } | |
194 | rcu_read_unlock_bh(); | |
195 | ||
196 | return NULL; | |
197 | } | |
198 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth); | |
199 | ||
01e28b92 GN |
200 | struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, |
201 | u32 session_id) | |
61b9a047 GN |
202 | { |
203 | struct hlist_head *session_list; | |
204 | struct l2tp_session *session; | |
205 | ||
01e28b92 | 206 | session_list = l2tp_session_id_hash(tunnel, session_id); |
61b9a047 | 207 | |
01e28b92 GN |
208 | read_lock_bh(&tunnel->hlist_lock); |
209 | hlist_for_each_entry(session, session_list, hlist) | |
210 | if (session->session_id == session_id) { | |
211 | l2tp_session_inc_refcount(session); | |
212 | read_unlock_bh(&tunnel->hlist_lock); | |
61b9a047 | 213 | |
01e28b92 | 214 | return session; |
61b9a047 | 215 | } |
01e28b92 | 216 | read_unlock_bh(&tunnel->hlist_lock); |
61b9a047 | 217 | |
01e28b92 GN |
218 | return NULL; |
219 | } | |
220 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get_session); | |
61b9a047 | 221 | |
01e28b92 GN |
222 | struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id) |
223 | { | |
224 | struct hlist_head *session_list; | |
225 | struct l2tp_session *session; | |
226 | ||
227 | session_list = l2tp_session_id_hash_2(l2tp_pernet(net), session_id); | |
228 | ||
229 | rcu_read_lock_bh(); | |
230 | hlist_for_each_entry_rcu(session, session_list, global_hlist) | |
61b9a047 GN |
231 | if (session->session_id == session_id) { |
232 | l2tp_session_inc_refcount(session); | |
01e28b92 | 233 | rcu_read_unlock_bh(); |
61b9a047 GN |
234 | |
235 | return session; | |
236 | } | |
01e28b92 | 237 | rcu_read_unlock_bh(); |
61b9a047 GN |
238 | |
239 | return NULL; | |
240 | } | |
241 | EXPORT_SYMBOL_GPL(l2tp_session_get); | |
242 | ||
a4346210 | 243 | struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth) |
fd558d18 JC |
244 | { |
245 | int hash; | |
fd558d18 JC |
246 | struct l2tp_session *session; |
247 | int count = 0; | |
248 | ||
249 | read_lock_bh(&tunnel->hlist_lock); | |
250 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { | |
b67bfe0d | 251 | hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { |
fd558d18 | 252 | if (++count > nth) { |
e08293a4 | 253 | l2tp_session_inc_refcount(session); |
fd558d18 JC |
254 | read_unlock_bh(&tunnel->hlist_lock); |
255 | return session; | |
256 | } | |
257 | } | |
258 | } | |
259 | ||
260 | read_unlock_bh(&tunnel->hlist_lock); | |
261 | ||
262 | return NULL; | |
263 | } | |
e08293a4 | 264 | EXPORT_SYMBOL_GPL(l2tp_session_get_nth); |
fd558d18 | 265 | |
309795f4 JC |
266 | /* Lookup a session by interface name. |
267 | * This is very inefficient but is only used by management interfaces. | |
268 | */ | |
9aaef50c | 269 | struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, |
a4346210 | 270 | const char *ifname) |
309795f4 JC |
271 | { |
272 | struct l2tp_net *pn = l2tp_pernet(net); | |
273 | int hash; | |
309795f4 JC |
274 | struct l2tp_session *session; |
275 | ||
e02d494d | 276 | rcu_read_lock_bh(); |
309795f4 | 277 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
b67bfe0d | 278 | hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { |
309795f4 | 279 | if (!strcmp(session->ifname, ifname)) { |
2777e2ab | 280 | l2tp_session_inc_refcount(session); |
e02d494d | 281 | rcu_read_unlock_bh(); |
2777e2ab | 282 | |
309795f4 JC |
283 | return session; |
284 | } | |
285 | } | |
286 | } | |
287 | ||
e02d494d | 288 | rcu_read_unlock_bh(); |
309795f4 JC |
289 | |
290 | return NULL; | |
291 | } | |
2777e2ab | 292 | EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); |
309795f4 | 293 | |
3953ae7b GN |
294 | int l2tp_session_register(struct l2tp_session *session, |
295 | struct l2tp_tunnel *tunnel) | |
dbdbc73b GN |
296 | { |
297 | struct l2tp_session *session_walk; | |
298 | struct hlist_head *g_head; | |
299 | struct hlist_head *head; | |
300 | struct l2tp_net *pn; | |
f3c66d4e | 301 | int err; |
dbdbc73b GN |
302 | |
303 | head = l2tp_session_id_hash(tunnel, session->session_id); | |
304 | ||
305 | write_lock_bh(&tunnel->hlist_lock); | |
f3c66d4e GN |
306 | if (!tunnel->acpt_newsess) { |
307 | err = -ENODEV; | |
308 | goto err_tlock; | |
309 | } | |
310 | ||
dbdbc73b | 311 | hlist_for_each_entry(session_walk, head, hlist) |
f3c66d4e GN |
312 | if (session_walk->session_id == session->session_id) { |
313 | err = -EEXIST; | |
314 | goto err_tlock; | |
315 | } | |
dbdbc73b GN |
316 | |
317 | if (tunnel->version == L2TP_HDR_VER_3) { | |
318 | pn = l2tp_pernet(tunnel->l2tp_net); | |
363a341d | 319 | g_head = l2tp_session_id_hash_2(pn, session->session_id); |
dbdbc73b GN |
320 | |
321 | spin_lock_bh(&pn->l2tp_session_hlist_lock); | |
f3c66d4e | 322 | |
dbdbc73b | 323 | hlist_for_each_entry(session_walk, g_head, global_hlist) |
f3c66d4e GN |
324 | if (session_walk->session_id == session->session_id) { |
325 | err = -EEXIST; | |
326 | goto err_tlock_pnlock; | |
327 | } | |
dbdbc73b | 328 | |
f3c66d4e | 329 | l2tp_tunnel_inc_refcount(tunnel); |
dbdbc73b | 330 | hlist_add_head_rcu(&session->global_hlist, g_head); |
f3c66d4e | 331 | |
dbdbc73b | 332 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e GN |
333 | } else { |
334 | l2tp_tunnel_inc_refcount(tunnel); | |
dbdbc73b GN |
335 | } |
336 | ||
337 | hlist_add_head(&session->hlist, head); | |
338 | write_unlock_bh(&tunnel->hlist_lock); | |
339 | ||
340 | return 0; | |
341 | ||
f3c66d4e | 342 | err_tlock_pnlock: |
dbdbc73b | 343 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e | 344 | err_tlock: |
dbdbc73b GN |
345 | write_unlock_bh(&tunnel->hlist_lock); |
346 | ||
f3c66d4e | 347 | return err; |
dbdbc73b | 348 | } |
3953ae7b | 349 | EXPORT_SYMBOL_GPL(l2tp_session_register); |
dbdbc73b | 350 | |
fd558d18 JC |
351 | /***************************************************************************** |
352 | * Receive data handling | |
353 | *****************************************************************************/ | |
354 | ||
355 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence | |
356 | * number. | |
357 | */ | |
358 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
359 | { | |
360 | struct sk_buff *skbp; | |
361 | struct sk_buff *tmp; | |
f7faffa3 | 362 | u32 ns = L2TP_SKB_CB(skb)->ns; |
fd558d18 JC |
363 | |
364 | spin_lock_bh(&session->reorder_q.lock); | |
365 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { | |
366 | if (L2TP_SKB_CB(skbp)->ns > ns) { | |
367 | __skb_queue_before(&session->reorder_q, skbp, skb); | |
a4ca44fa JP |
368 | l2tp_dbg(session, L2TP_MSG_SEQ, |
369 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", | |
370 | session->name, ns, L2TP_SKB_CB(skbp)->ns, | |
371 | skb_queue_len(&session->reorder_q)); | |
7b7c0719 | 372 | atomic_long_inc(&session->stats.rx_oos_packets); |
fd558d18 JC |
373 | goto out; |
374 | } | |
375 | } | |
376 | ||
377 | __skb_queue_tail(&session->reorder_q, skb); | |
378 | ||
379 | out: | |
380 | spin_unlock_bh(&session->reorder_q.lock); | |
381 | } | |
382 | ||
383 | /* Dequeue a single skb. | |
384 | */ | |
385 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
386 | { | |
387 | struct l2tp_tunnel *tunnel = session->tunnel; | |
388 | int length = L2TP_SKB_CB(skb)->length; | |
389 | ||
390 | /* We're about to requeue the skb, so return resources | |
391 | * to its current owner (a socket receive buffer). | |
392 | */ | |
393 | skb_orphan(skb); | |
394 | ||
7b7c0719 TP |
395 | atomic_long_inc(&tunnel->stats.rx_packets); |
396 | atomic_long_add(length, &tunnel->stats.rx_bytes); | |
397 | atomic_long_inc(&session->stats.rx_packets); | |
398 | atomic_long_add(length, &session->stats.rx_bytes); | |
fd558d18 JC |
399 | |
400 | if (L2TP_SKB_CB(skb)->has_seq) { | |
401 | /* Bump our Nr */ | |
402 | session->nr++; | |
8a1631d5 | 403 | session->nr &= session->nr_max; |
f7faffa3 | 404 | |
a4ca44fa JP |
405 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", |
406 | session->name, session->nr); | |
fd558d18 JC |
407 | } |
408 | ||
409 | /* call private receive handler */ | |
410 | if (session->recv_skb != NULL) | |
411 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); | |
412 | else | |
413 | kfree_skb(skb); | |
fd558d18 JC |
414 | } |
415 | ||
416 | /* Dequeue skbs from the session's reorder_q, subject to packet order. | |
417 | * Skbs that have been in the queue for too long are simply discarded. | |
418 | */ | |
419 | static void l2tp_recv_dequeue(struct l2tp_session *session) | |
420 | { | |
421 | struct sk_buff *skb; | |
422 | struct sk_buff *tmp; | |
423 | ||
424 | /* If the pkt at the head of the queue has the nr that we | |
425 | * expect to send up next, dequeue it and any other | |
426 | * in-sequence packets behind it. | |
427 | */ | |
e2e210c0 | 428 | start: |
fd558d18 JC |
429 | spin_lock_bh(&session->reorder_q.lock); |
430 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { | |
431 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { | |
7b7c0719 TP |
432 | atomic_long_inc(&session->stats.rx_seq_discards); |
433 | atomic_long_inc(&session->stats.rx_errors); | |
a4ca44fa JP |
434 | l2tp_dbg(session, L2TP_MSG_SEQ, |
435 | "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", | |
436 | session->name, L2TP_SKB_CB(skb)->ns, | |
437 | L2TP_SKB_CB(skb)->length, session->nr, | |
438 | skb_queue_len(&session->reorder_q)); | |
38d40b3f | 439 | session->reorder_skip = 1; |
fd558d18 JC |
440 | __skb_unlink(skb, &session->reorder_q); |
441 | kfree_skb(skb); | |
fd558d18 JC |
442 | continue; |
443 | } | |
444 | ||
445 | if (L2TP_SKB_CB(skb)->has_seq) { | |
38d40b3f | 446 | if (session->reorder_skip) { |
a4ca44fa JP |
447 | l2tp_dbg(session, L2TP_MSG_SEQ, |
448 | "%s: advancing nr to next pkt: %u -> %u", | |
449 | session->name, session->nr, | |
450 | L2TP_SKB_CB(skb)->ns); | |
38d40b3f JC |
451 | session->reorder_skip = 0; |
452 | session->nr = L2TP_SKB_CB(skb)->ns; | |
453 | } | |
fd558d18 | 454 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
a4ca44fa JP |
455 | l2tp_dbg(session, L2TP_MSG_SEQ, |
456 | "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", | |
457 | session->name, L2TP_SKB_CB(skb)->ns, | |
458 | L2TP_SKB_CB(skb)->length, session->nr, | |
459 | skb_queue_len(&session->reorder_q)); | |
fd558d18 JC |
460 | goto out; |
461 | } | |
462 | } | |
463 | __skb_unlink(skb, &session->reorder_q); | |
464 | ||
465 | /* Process the skb. We release the queue lock while we | |
466 | * do so to let other contexts process the queue. | |
467 | */ | |
468 | spin_unlock_bh(&session->reorder_q.lock); | |
469 | l2tp_recv_dequeue_skb(session, skb); | |
e2e210c0 | 470 | goto start; |
fd558d18 JC |
471 | } |
472 | ||
473 | out: | |
474 | spin_unlock_bh(&session->reorder_q.lock); | |
475 | } | |
476 | ||
8a1631d5 JC |
477 | static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) |
478 | { | |
479 | u32 nws; | |
480 | ||
481 | if (nr >= session->nr) | |
482 | nws = nr - session->nr; | |
483 | else | |
484 | nws = (session->nr_max + 1) - (session->nr - nr); | |
485 | ||
486 | return nws < session->nr_window_size; | |
487 | } | |
488 | ||
b6dc01a4 JC |
489 | /* If packet has sequence numbers, queue it if acceptable. Returns 0 if |
490 | * acceptable, else non-zero. | |
491 | */ | |
492 | static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) | |
493 | { | |
8a1631d5 JC |
494 | if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { |
495 | /* Packet sequence number is outside allowed window. | |
496 | * Discard it. | |
497 | */ | |
498 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
499 | "%s: pkt %u len %d discarded, outside window, nr=%u\n", | |
500 | session->name, L2TP_SKB_CB(skb)->ns, | |
501 | L2TP_SKB_CB(skb)->length, session->nr); | |
502 | goto discard; | |
503 | } | |
504 | ||
b6dc01a4 JC |
505 | if (session->reorder_timeout != 0) { |
506 | /* Packet reordering enabled. Add skb to session's | |
507 | * reorder queue, in order of ns. | |
508 | */ | |
509 | l2tp_recv_queue_skb(session, skb); | |
a0dbd822 JC |
510 | goto out; |
511 | } | |
512 | ||
513 | /* Packet reordering disabled. Discard out-of-sequence packets, while | |
514 | * tracking the number if in-sequence packets after the first OOS packet | |
515 | * is seen. After nr_oos_count_max in-sequence packets, reset the | |
516 | * sequence number to re-enable packet reception. | |
517 | */ | |
518 | if (L2TP_SKB_CB(skb)->ns == session->nr) { | |
519 | skb_queue_tail(&session->reorder_q, skb); | |
b6dc01a4 | 520 | } else { |
a0dbd822 JC |
521 | u32 nr_oos = L2TP_SKB_CB(skb)->ns; |
522 | u32 nr_next = (session->nr_oos + 1) & session->nr_max; | |
523 | ||
524 | if (nr_oos == nr_next) | |
525 | session->nr_oos_count++; | |
526 | else | |
527 | session->nr_oos_count = 0; | |
528 | ||
529 | session->nr_oos = nr_oos; | |
530 | if (session->nr_oos_count > session->nr_oos_count_max) { | |
531 | session->reorder_skip = 1; | |
532 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
533 | "%s: %d oos packets received. Resetting sequence numbers\n", | |
534 | session->name, session->nr_oos_count); | |
535 | } | |
536 | if (!session->reorder_skip) { | |
b6dc01a4 JC |
537 | atomic_long_inc(&session->stats.rx_seq_discards); |
538 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
539 | "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", | |
540 | session->name, L2TP_SKB_CB(skb)->ns, | |
541 | L2TP_SKB_CB(skb)->length, session->nr, | |
542 | skb_queue_len(&session->reorder_q)); | |
543 | goto discard; | |
544 | } | |
545 | skb_queue_tail(&session->reorder_q, skb); | |
546 | } | |
547 | ||
a0dbd822 | 548 | out: |
b6dc01a4 JC |
549 | return 0; |
550 | ||
551 | discard: | |
552 | return 1; | |
553 | } | |
554 | ||
f7faffa3 JC |
555 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
556 | * and L2TPv3 data frames here. | |
557 | * | |
558 | * L2TPv2 Data Message Header | |
559 | * | |
560 | * 0 1 2 3 | |
561 | * 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 | |
562 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
563 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | | |
564 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
565 | * | Tunnel ID | Session ID | | |
566 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
567 | * | Ns (opt) | Nr (opt) | | |
568 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
569 | * | Offset Size (opt) | Offset pad... (opt) | |
570 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
571 | * | |
572 | * Data frames are marked by T=0. All other fields are the same as | |
573 | * those in L2TP control frames. | |
574 | * | |
575 | * L2TPv3 Data Message Header | |
576 | * | |
577 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
578 | * | L2TP Session Header | | |
579 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
580 | * | L2-Specific Sublayer | | |
581 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
582 | * | Tunnel Payload ... | |
583 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
584 | * | |
585 | * L2TPv3 Session Header Over IP | |
586 | * | |
587 | * 0 1 2 3 | |
588 | * 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 | |
589 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
590 | * | Session ID | | |
591 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
592 | * | Cookie (optional, maximum 64 bits)... | |
593 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
594 | * | | |
595 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
596 | * | |
597 | * L2TPv3 L2-Specific Sublayer Format | |
598 | * | |
599 | * 0 1 2 3 | |
600 | * 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 | |
601 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
602 | * |x|S|x|x|x|x|x|x| Sequence Number | | |
603 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
604 | * | |
23fe846f GN |
605 | * Cookie value and sublayer format are negotiated with the peer when |
606 | * the session is set up. Unlike L2TPv2, we do not need to parse the | |
607 | * packet header to determine if optional fields are present. | |
f7faffa3 JC |
608 | * |
609 | * Caller must already have parsed the frame and determined that it is | |
610 | * a data (not control) frame before coming here. Fields up to the | |
611 | * session-id have already been parsed and ptr points to the data | |
612 | * after the session-id. | |
fd558d18 | 613 | */ |
f7faffa3 JC |
614 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
615 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, | |
2b139e6b | 616 | int length) |
fd558d18 | 617 | { |
f7faffa3 | 618 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 619 | int offset; |
f7faffa3 | 620 | u32 ns, nr; |
fd558d18 | 621 | |
f7faffa3 JC |
622 | /* Parse and check optional cookie */ |
623 | if (session->peer_cookie_len > 0) { | |
624 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { | |
a4ca44fa JP |
625 | l2tp_info(tunnel, L2TP_MSG_DATA, |
626 | "%s: cookie mismatch (%u/%u). Discarding.\n", | |
627 | tunnel->name, tunnel->tunnel_id, | |
628 | session->session_id); | |
7b7c0719 | 629 | atomic_long_inc(&session->stats.rx_cookie_discards); |
f7faffa3 JC |
630 | goto discard; |
631 | } | |
632 | ptr += session->peer_cookie_len; | |
633 | } | |
634 | ||
fd558d18 JC |
635 | /* Handle the optional sequence numbers. Sequence numbers are |
636 | * in different places for L2TPv2 and L2TPv3. | |
637 | * | |
638 | * If we are the LAC, enable/disable sequence numbers under | |
639 | * the control of the LNS. If no sequence numbers present but | |
640 | * we were expecting them, discard frame. | |
641 | */ | |
642 | ns = nr = 0; | |
643 | L2TP_SKB_CB(skb)->has_seq = 0; | |
f7faffa3 JC |
644 | if (tunnel->version == L2TP_HDR_VER_2) { |
645 | if (hdrflags & L2TP_HDRFLAG_S) { | |
646 | ns = ntohs(*(__be16 *) ptr); | |
647 | ptr += 2; | |
648 | nr = ntohs(*(__be16 *) ptr); | |
649 | ptr += 2; | |
fd558d18 | 650 | |
f7faffa3 JC |
651 | /* Store L2TP info in the skb */ |
652 | L2TP_SKB_CB(skb)->ns = ns; | |
653 | L2TP_SKB_CB(skb)->has_seq = 1; | |
fd558d18 | 654 | |
a4ca44fa JP |
655 | l2tp_dbg(session, L2TP_MSG_SEQ, |
656 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", | |
657 | session->name, ns, nr, session->nr); | |
f7faffa3 JC |
658 | } |
659 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
660 | u32 l2h = ntohl(*(__be32 *) ptr); | |
661 | ||
662 | if (l2h & 0x40000000) { | |
663 | ns = l2h & 0x00ffffff; | |
664 | ||
665 | /* Store L2TP info in the skb */ | |
666 | L2TP_SKB_CB(skb)->ns = ns; | |
667 | L2TP_SKB_CB(skb)->has_seq = 1; | |
668 | ||
a4ca44fa JP |
669 | l2tp_dbg(session, L2TP_MSG_SEQ, |
670 | "%s: recv data ns=%u, session nr=%u\n", | |
671 | session->name, ns, session->nr); | |
f7faffa3 | 672 | } |
62e7b6a5 | 673 | ptr += 4; |
fd558d18 JC |
674 | } |
675 | ||
676 | if (L2TP_SKB_CB(skb)->has_seq) { | |
677 | /* Received a packet with sequence numbers. If we're the LNS, | |
678 | * check if we sre sending sequence numbers and if not, | |
679 | * configure it so. | |
680 | */ | |
681 | if ((!session->lns_mode) && (!session->send_seq)) { | |
a4ca44fa JP |
682 | l2tp_info(session, L2TP_MSG_SEQ, |
683 | "%s: requested to enable seq numbers by LNS\n", | |
684 | session->name); | |
3f9b9770 | 685 | session->send_seq = 1; |
f7faffa3 | 686 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
687 | } |
688 | } else { | |
689 | /* No sequence numbers. | |
690 | * If user has configured mandatory sequence numbers, discard. | |
691 | */ | |
692 | if (session->recv_seq) { | |
a4ca44fa JP |
693 | l2tp_warn(session, L2TP_MSG_SEQ, |
694 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
695 | session->name); | |
7b7c0719 | 696 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
697 | goto discard; |
698 | } | |
699 | ||
700 | /* If we're the LAC and we're sending sequence numbers, the | |
701 | * LNS has requested that we no longer send sequence numbers. | |
702 | * If we're the LNS and we're sending sequence numbers, the | |
703 | * LAC is broken. Discard the frame. | |
704 | */ | |
705 | if ((!session->lns_mode) && (session->send_seq)) { | |
a4ca44fa JP |
706 | l2tp_info(session, L2TP_MSG_SEQ, |
707 | "%s: requested to disable seq numbers by LNS\n", | |
708 | session->name); | |
fd558d18 | 709 | session->send_seq = 0; |
f7faffa3 | 710 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 | 711 | } else if (session->send_seq) { |
a4ca44fa JP |
712 | l2tp_warn(session, L2TP_MSG_SEQ, |
713 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
714 | session->name); | |
7b7c0719 | 715 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
716 | goto discard; |
717 | } | |
718 | } | |
719 | ||
900631ee JC |
720 | /* Session data offset is defined only for L2TPv2 and is |
721 | * indicated by an optional 16-bit value in the header. | |
f7faffa3 JC |
722 | */ |
723 | if (tunnel->version == L2TP_HDR_VER_2) { | |
724 | /* If offset bit set, skip it. */ | |
725 | if (hdrflags & L2TP_HDRFLAG_O) { | |
726 | offset = ntohs(*(__be16 *)ptr); | |
727 | ptr += 2 + offset; | |
728 | } | |
900631ee | 729 | } |
fd558d18 JC |
730 | |
731 | offset = ptr - optr; | |
732 | if (!pskb_may_pull(skb, offset)) | |
733 | goto discard; | |
734 | ||
735 | __skb_pull(skb, offset); | |
736 | ||
fd558d18 JC |
737 | /* Prepare skb for adding to the session's reorder_q. Hold |
738 | * packets for max reorder_timeout or 1 second if not | |
739 | * reordering. | |
740 | */ | |
741 | L2TP_SKB_CB(skb)->length = length; | |
742 | L2TP_SKB_CB(skb)->expires = jiffies + | |
743 | (session->reorder_timeout ? session->reorder_timeout : HZ); | |
744 | ||
745 | /* Add packet to the session's receive queue. Reordering is done here, if | |
746 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. | |
747 | */ | |
748 | if (L2TP_SKB_CB(skb)->has_seq) { | |
b6dc01a4 JC |
749 | if (l2tp_recv_data_seq(session, skb)) |
750 | goto discard; | |
fd558d18 JC |
751 | } else { |
752 | /* No sequence numbers. Add the skb to the tail of the | |
753 | * reorder queue. This ensures that it will be | |
754 | * delivered after all previous sequenced skbs. | |
755 | */ | |
756 | skb_queue_tail(&session->reorder_q, skb); | |
757 | } | |
758 | ||
759 | /* Try to dequeue as many skbs from reorder_q as we can. */ | |
760 | l2tp_recv_dequeue(session); | |
761 | ||
f7faffa3 | 762 | return; |
fd558d18 JC |
763 | |
764 | discard: | |
7b7c0719 | 765 | atomic_long_inc(&session->stats.rx_errors); |
fd558d18 | 766 | kfree_skb(skb); |
f7faffa3 JC |
767 | } |
768 | EXPORT_SYMBOL(l2tp_recv_common); | |
769 | ||
48f72f92 TP |
770 | /* Drop skbs from the session's reorder_q |
771 | */ | |
2e67560e | 772 | static int l2tp_session_queue_purge(struct l2tp_session *session) |
48f72f92 TP |
773 | { |
774 | struct sk_buff *skb = NULL; | |
775 | BUG_ON(!session); | |
776 | BUG_ON(session->magic != L2TP_SESSION_MAGIC); | |
777 | while ((skb = skb_dequeue(&session->reorder_q))) { | |
778 | atomic_long_inc(&session->stats.rx_errors); | |
779 | kfree_skb(skb); | |
48f72f92 TP |
780 | } |
781 | return 0; | |
782 | } | |
48f72f92 | 783 | |
f7faffa3 JC |
784 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
785 | * here. The skb is not on a list when we get here. | |
786 | * Returns 0 if the packet was a data packet and was successfully passed on. | |
787 | * Returns 1 if the packet was not a good data packet and could not be | |
788 | * forwarded. All such packets are passed up to userspace to deal with. | |
789 | */ | |
2b139e6b | 790 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) |
f7faffa3 JC |
791 | { |
792 | struct l2tp_session *session = NULL; | |
793 | unsigned char *ptr, *optr; | |
794 | u16 hdrflags; | |
795 | u32 tunnel_id, session_id; | |
f7faffa3 JC |
796 | u16 version; |
797 | int length; | |
798 | ||
58d6085c | 799 | /* UDP has verifed checksum */ |
f7faffa3 JC |
800 | |
801 | /* UDP always verifies the packet length. */ | |
802 | __skb_pull(skb, sizeof(struct udphdr)); | |
803 | ||
804 | /* Short packet? */ | |
91c52470 | 805 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { |
a4ca44fa JP |
806 | l2tp_info(tunnel, L2TP_MSG_DATA, |
807 | "%s: recv short packet (len=%d)\n", | |
808 | tunnel->name, skb->len); | |
f7faffa3 JC |
809 | goto error; |
810 | } | |
811 | ||
f7faffa3 JC |
812 | /* Trace packet contents, if enabled */ |
813 | if (tunnel->debug & L2TP_MSG_DATA) { | |
814 | length = min(32u, skb->len); | |
815 | if (!pskb_may_pull(skb, length)) | |
816 | goto error; | |
817 | ||
a4ca44fa JP |
818 | pr_debug("%s: recv\n", tunnel->name); |
819 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); | |
f7faffa3 JC |
820 | } |
821 | ||
e50e705c ED |
822 | /* Point to L2TP header */ |
823 | optr = ptr = skb->data; | |
824 | ||
f7faffa3 JC |
825 | /* Get L2TP header flags */ |
826 | hdrflags = ntohs(*(__be16 *) ptr); | |
827 | ||
828 | /* Check protocol version */ | |
829 | version = hdrflags & L2TP_HDR_VER_MASK; | |
830 | if (version != tunnel->version) { | |
a4ca44fa JP |
831 | l2tp_info(tunnel, L2TP_MSG_DATA, |
832 | "%s: recv protocol version mismatch: got %d expected %d\n", | |
833 | tunnel->name, version, tunnel->version); | |
f7faffa3 JC |
834 | goto error; |
835 | } | |
836 | ||
837 | /* Get length of L2TP packet */ | |
838 | length = skb->len; | |
839 | ||
840 | /* If type is control packet, it is handled by userspace. */ | |
841 | if (hdrflags & L2TP_HDRFLAG_T) { | |
a4ca44fa JP |
842 | l2tp_dbg(tunnel, L2TP_MSG_DATA, |
843 | "%s: recv control packet, len=%d\n", | |
844 | tunnel->name, length); | |
f7faffa3 JC |
845 | goto error; |
846 | } | |
847 | ||
848 | /* Skip flags */ | |
849 | ptr += 2; | |
850 | ||
851 | if (tunnel->version == L2TP_HDR_VER_2) { | |
852 | /* If length is present, skip it */ | |
853 | if (hdrflags & L2TP_HDRFLAG_L) | |
854 | ptr += 2; | |
855 | ||
856 | /* Extract tunnel and session ID */ | |
857 | tunnel_id = ntohs(*(__be16 *) ptr); | |
858 | ptr += 2; | |
859 | session_id = ntohs(*(__be16 *) ptr); | |
860 | ptr += 2; | |
861 | } else { | |
862 | ptr += 2; /* skip reserved bits */ | |
863 | tunnel_id = tunnel->tunnel_id; | |
864 | session_id = ntohl(*(__be32 *) ptr); | |
865 | ptr += 4; | |
866 | } | |
867 | ||
868 | /* Find the session context */ | |
01e28b92 | 869 | session = l2tp_tunnel_get_session(tunnel, session_id); |
309795f4 | 870 | if (!session || !session->recv_skb) { |
a4346210 | 871 | if (session) |
61b9a047 | 872 | l2tp_session_dec_refcount(session); |
61b9a047 | 873 | |
f7faffa3 | 874 | /* Not found? Pass to userspace to deal with */ |
a4ca44fa JP |
875 | l2tp_info(tunnel, L2TP_MSG_DATA, |
876 | "%s: no session found (%u/%u). Passing up.\n", | |
877 | tunnel->name, tunnel_id, session_id); | |
f7faffa3 JC |
878 | goto error; |
879 | } | |
880 | ||
4522a70d JW |
881 | if (tunnel->version == L2TP_HDR_VER_3 && |
882 | l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) | |
883 | goto error; | |
884 | ||
2b139e6b | 885 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); |
61b9a047 | 886 | l2tp_session_dec_refcount(session); |
fd558d18 JC |
887 | |
888 | return 0; | |
889 | ||
fd558d18 JC |
890 | error: |
891 | /* Put UDP header back */ | |
892 | __skb_push(skb, sizeof(struct udphdr)); | |
893 | ||
894 | return 1; | |
895 | } | |
fd558d18 JC |
896 | |
897 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. | |
898 | * Return codes: | |
899 | * 0 : success. | |
900 | * <0: error | |
901 | * >0: skb should be passed up to userspace as UDP. | |
902 | */ | |
903 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) | |
904 | { | |
905 | struct l2tp_tunnel *tunnel; | |
906 | ||
c1c47721 | 907 | tunnel = rcu_dereference_sk_user_data(sk); |
fd558d18 JC |
908 | if (tunnel == NULL) |
909 | goto pass_up; | |
910 | ||
a4ca44fa JP |
911 | l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", |
912 | tunnel->name, skb->len); | |
fd558d18 | 913 | |
2b139e6b | 914 | if (l2tp_udp_recv_core(tunnel, skb)) |
d00fa9ad | 915 | goto pass_up; |
fd558d18 | 916 | |
fd558d18 JC |
917 | return 0; |
918 | ||
fd558d18 JC |
919 | pass_up: |
920 | return 1; | |
921 | } | |
922 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); | |
923 | ||
924 | /************************************************************************ | |
925 | * Transmit handling | |
926 | ***********************************************************************/ | |
927 | ||
928 | /* Build an L2TP header for the session into the buffer provided. | |
929 | */ | |
f7faffa3 | 930 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
fd558d18 | 931 | { |
f7faffa3 | 932 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 933 | __be16 *bufp = buf; |
f7faffa3 | 934 | __be16 *optr = buf; |
fd558d18 JC |
935 | u16 flags = L2TP_HDR_VER_2; |
936 | u32 tunnel_id = tunnel->peer_tunnel_id; | |
937 | u32 session_id = session->peer_session_id; | |
938 | ||
939 | if (session->send_seq) | |
940 | flags |= L2TP_HDRFLAG_S; | |
941 | ||
942 | /* Setup L2TP header. */ | |
943 | *bufp++ = htons(flags); | |
944 | *bufp++ = htons(tunnel_id); | |
945 | *bufp++ = htons(session_id); | |
946 | if (session->send_seq) { | |
947 | *bufp++ = htons(session->ns); | |
948 | *bufp++ = 0; | |
949 | session->ns++; | |
f7faffa3 | 950 | session->ns &= 0xffff; |
a4ca44fa JP |
951 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", |
952 | session->name, session->ns); | |
fd558d18 | 953 | } |
f7faffa3 JC |
954 | |
955 | return bufp - optr; | |
fd558d18 JC |
956 | } |
957 | ||
f7faffa3 | 958 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
fd558d18 | 959 | { |
0d76751f | 960 | struct l2tp_tunnel *tunnel = session->tunnel; |
f7faffa3 JC |
961 | char *bufp = buf; |
962 | char *optr = bufp; | |
f7faffa3 | 963 | |
0d76751f JC |
964 | /* Setup L2TP header. The header differs slightly for UDP and |
965 | * IP encapsulations. For UDP, there is 4 bytes of flags. | |
966 | */ | |
967 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
968 | u16 flags = L2TP_HDR_VER_3; | |
969 | *((__be16 *) bufp) = htons(flags); | |
970 | bufp += 2; | |
971 | *((__be16 *) bufp) = 0; | |
972 | bufp += 2; | |
973 | } | |
974 | ||
f7faffa3 JC |
975 | *((__be32 *) bufp) = htonl(session->peer_session_id); |
976 | bufp += 4; | |
977 | if (session->cookie_len) { | |
978 | memcpy(bufp, &session->cookie[0], session->cookie_len); | |
979 | bufp += session->cookie_len; | |
980 | } | |
62e7b6a5 LB |
981 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
982 | u32 l2h = 0; | |
f7faffa3 | 983 | |
62e7b6a5 LB |
984 | if (session->send_seq) { |
985 | l2h = 0x40000000 | session->ns; | |
986 | session->ns++; | |
987 | session->ns &= 0xffffff; | |
988 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
989 | "%s: updated ns to %u\n", | |
990 | session->name, session->ns); | |
f7faffa3 | 991 | } |
62e7b6a5 LB |
992 | |
993 | *((__be32 *)bufp) = htonl(l2h); | |
994 | bufp += 4; | |
f7faffa3 | 995 | } |
fd558d18 | 996 | |
f7faffa3 | 997 | return bufp - optr; |
fd558d18 | 998 | } |
fd558d18 | 999 | |
2685fbb8 GN |
1000 | static void l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, |
1001 | struct flowi *fl, size_t data_len) | |
fd558d18 JC |
1002 | { |
1003 | struct l2tp_tunnel *tunnel = session->tunnel; | |
1004 | unsigned int len = skb->len; | |
1005 | int error; | |
1006 | ||
1007 | /* Debug */ | |
1008 | if (session->send_seq) | |
5b5e0928 | 1009 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes, ns=%u\n", |
a4ca44fa | 1010 | session->name, data_len, session->ns - 1); |
fd558d18 | 1011 | else |
5b5e0928 | 1012 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes\n", |
a4ca44fa | 1013 | session->name, data_len); |
fd558d18 JC |
1014 | |
1015 | if (session->debug & L2TP_MSG_DATA) { | |
0d76751f JC |
1016 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1017 | unsigned char *datap = skb->data + uhlen; | |
fd558d18 | 1018 | |
a4ca44fa JP |
1019 | pr_debug("%s: xmit\n", session->name); |
1020 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, | |
1021 | datap, min_t(size_t, 32, len - uhlen)); | |
fd558d18 JC |
1022 | } |
1023 | ||
1024 | /* Queue the packet to IP for output */ | |
60ff7467 | 1025 | skb->ignore_df = 1; |
d2cf3361 | 1026 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1027 | if (l2tp_sk_is_v6(tunnel->sock)) |
b0270e91 | 1028 | error = inet6_csk_xmit(tunnel->sock, skb, NULL); |
d2cf3361 BL |
1029 | else |
1030 | #endif | |
b0270e91 | 1031 | error = ip_queue_xmit(tunnel->sock, skb, fl); |
fd558d18 JC |
1032 | |
1033 | /* Update stats */ | |
1034 | if (error >= 0) { | |
7b7c0719 TP |
1035 | atomic_long_inc(&tunnel->stats.tx_packets); |
1036 | atomic_long_add(len, &tunnel->stats.tx_bytes); | |
1037 | atomic_long_inc(&session->stats.tx_packets); | |
1038 | atomic_long_add(len, &session->stats.tx_bytes); | |
fd558d18 | 1039 | } else { |
7b7c0719 TP |
1040 | atomic_long_inc(&tunnel->stats.tx_errors); |
1041 | atomic_long_inc(&session->stats.tx_errors); | |
fd558d18 | 1042 | } |
fd558d18 | 1043 | } |
fd558d18 | 1044 | |
fd558d18 JC |
1045 | /* If caller requires the skb to have a ppp header, the header must be |
1046 | * inserted in the skb data before calling this function. | |
1047 | */ | |
1048 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) | |
1049 | { | |
1050 | int data_len = skb->len; | |
0d76751f JC |
1051 | struct l2tp_tunnel *tunnel = session->tunnel; |
1052 | struct sock *sk = tunnel->sock; | |
d9d8da80 | 1053 | struct flowi *fl; |
fd558d18 | 1054 | struct udphdr *uh; |
fd558d18 | 1055 | struct inet_sock *inet; |
fd558d18 | 1056 | int headroom; |
0d76751f JC |
1057 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1058 | int udp_len; | |
b8c84307 | 1059 | int ret = NET_XMIT_SUCCESS; |
fd558d18 JC |
1060 | |
1061 | /* Check that there's enough headroom in the skb to insert IP, | |
1062 | * UDP and L2TP headers. If not enough, expand it to | |
1063 | * make room. Adjust truesize. | |
1064 | */ | |
1065 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + | |
0d76751f | 1066 | uhlen + hdr_len; |
835acf5d | 1067 | if (skb_cow_head(skb, headroom)) { |
b8c84307 ED |
1068 | kfree_skb(skb); |
1069 | return NET_XMIT_DROP; | |
835acf5d | 1070 | } |
fd558d18 | 1071 | |
fd558d18 | 1072 | /* Setup L2TP header */ |
f7faffa3 | 1073 | session->build_header(session, __skb_push(skb, hdr_len)); |
fd558d18 | 1074 | |
0d76751f | 1075 | /* Reset skb netfilter state */ |
fd558d18 JC |
1076 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
1077 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | | |
1078 | IPSKB_REROUTED); | |
895b5c9f | 1079 | nf_reset_ct(skb); |
fd558d18 | 1080 | |
6af88da1 DM |
1081 | bh_lock_sock(sk); |
1082 | if (sock_owned_by_user(sk)) { | |
b8c84307 ED |
1083 | kfree_skb(skb); |
1084 | ret = NET_XMIT_DROP; | |
6af88da1 DM |
1085 | goto out_unlock; |
1086 | } | |
1087 | ||
b954f940 PA |
1088 | /* The user-space may change the connection status for the user-space |
1089 | * provided socket at run time: we must check it under the socket lock | |
1090 | */ | |
1091 | if (tunnel->fd >= 0 && sk->sk_state != TCP_ESTABLISHED) { | |
1092 | kfree_skb(skb); | |
1093 | ret = NET_XMIT_DROP; | |
1094 | goto out_unlock; | |
1095 | } | |
1096 | ||
fd558d18 JC |
1097 | /* Get routing info from the tunnel socket */ |
1098 | skb_dst_drop(skb); | |
6d37fa49 | 1099 | skb_dst_set(skb, sk_dst_check(sk, 0)); |
fd558d18 | 1100 | |
d9d8da80 DM |
1101 | inet = inet_sk(sk); |
1102 | fl = &inet->cork.fl; | |
0d76751f JC |
1103 | switch (tunnel->encap) { |
1104 | case L2TP_ENCAPTYPE_UDP: | |
1105 | /* Setup UDP header */ | |
0d76751f JC |
1106 | __skb_push(skb, sizeof(*uh)); |
1107 | skb_reset_transport_header(skb); | |
1108 | uh = udp_hdr(skb); | |
1109 | uh->source = inet->inet_sport; | |
1110 | uh->dest = inet->inet_dport; | |
1111 | udp_len = uhlen + hdr_len + data_len; | |
1112 | uh->len = htons(udp_len); | |
0d76751f JC |
1113 | |
1114 | /* Calculate UDP checksum if configured to do so */ | |
d2cf3361 | 1115 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1116 | if (l2tp_sk_is_v6(sk)) |
77157e19 TH |
1117 | udp6_set_csum(udp_get_no_check6_tx(sk), |
1118 | skb, &inet6_sk(sk)->saddr, | |
1119 | &sk->sk_v6_daddr, udp_len); | |
d2cf3361 BL |
1120 | else |
1121 | #endif | |
77157e19 TH |
1122 | udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, |
1123 | inet->inet_daddr, udp_len); | |
0d76751f JC |
1124 | break; |
1125 | ||
1126 | case L2TP_ENCAPTYPE_IP: | |
1127 | break; | |
fd558d18 JC |
1128 | } |
1129 | ||
d9d8da80 | 1130 | l2tp_xmit_core(session, skb, fl, data_len); |
6af88da1 DM |
1131 | out_unlock: |
1132 | bh_unlock_sock(sk); | |
fd558d18 | 1133 | |
b8c84307 | 1134 | return ret; |
fd558d18 JC |
1135 | } |
1136 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); | |
1137 | ||
1138 | /***************************************************************************** | |
1139 | * Tinnel and session create/destroy. | |
1140 | *****************************************************************************/ | |
1141 | ||
1142 | /* Tunnel socket destruct hook. | |
1143 | * The tunnel context is deleted only when all session sockets have been | |
1144 | * closed. | |
1145 | */ | |
fc130840 | 1146 | static void l2tp_tunnel_destruct(struct sock *sk) |
fd558d18 | 1147 | { |
8d8a51e2 | 1148 | struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); |
fd558d18 | 1149 | |
fd558d18 JC |
1150 | if (tunnel == NULL) |
1151 | goto end; | |
1152 | ||
a4ca44fa | 1153 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); |
fd558d18 | 1154 | |
f8ccac0e | 1155 | /* Disable udp encapsulation */ |
0d76751f JC |
1156 | switch (tunnel->encap) { |
1157 | case L2TP_ENCAPTYPE_UDP: | |
1158 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ | |
1159 | (udp_sk(sk))->encap_type = 0; | |
1160 | (udp_sk(sk))->encap_rcv = NULL; | |
9980d001 | 1161 | (udp_sk(sk))->encap_destroy = NULL; |
0d76751f JC |
1162 | break; |
1163 | case L2TP_ENCAPTYPE_IP: | |
1164 | break; | |
1165 | } | |
fd558d18 JC |
1166 | |
1167 | /* Remove hooks into tunnel socket */ | |
fd558d18 JC |
1168 | sk->sk_destruct = tunnel->old_sk_destruct; |
1169 | sk->sk_user_data = NULL; | |
1170 | ||
f8ccac0e TP |
1171 | /* Call the original destructor */ |
1172 | if (sk->sk_destruct) | |
1173 | (*sk->sk_destruct)(sk); | |
d00fa9ad JC |
1174 | |
1175 | kfree_rcu(tunnel, rcu); | |
fd558d18 JC |
1176 | end: |
1177 | return; | |
1178 | } | |
fd558d18 JC |
1179 | |
1180 | /* When the tunnel is closed, all the attached sessions need to go too. | |
1181 | */ | |
d08532bb | 1182 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
fd558d18 JC |
1183 | { |
1184 | int hash; | |
1185 | struct hlist_node *walk; | |
1186 | struct hlist_node *tmp; | |
1187 | struct l2tp_session *session; | |
1188 | ||
1189 | BUG_ON(tunnel == NULL); | |
1190 | ||
a4ca44fa JP |
1191 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", |
1192 | tunnel->name); | |
fd558d18 JC |
1193 | |
1194 | write_lock_bh(&tunnel->hlist_lock); | |
f3c66d4e | 1195 | tunnel->acpt_newsess = false; |
fd558d18 JC |
1196 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
1197 | again: | |
1198 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { | |
1199 | session = hlist_entry(walk, struct l2tp_session, hlist); | |
1200 | ||
a4ca44fa JP |
1201 | l2tp_info(session, L2TP_MSG_CONTROL, |
1202 | "%s: closing session\n", session->name); | |
fd558d18 JC |
1203 | |
1204 | hlist_del_init(&session->hlist); | |
1205 | ||
b228a940 GN |
1206 | if (test_and_set_bit(0, &session->dead)) |
1207 | goto again; | |
1208 | ||
fd558d18 JC |
1209 | write_unlock_bh(&tunnel->hlist_lock); |
1210 | ||
f6e16b29 | 1211 | __l2tp_session_unhash(session); |
4c6e2fd3 TP |
1212 | l2tp_session_queue_purge(session); |
1213 | ||
fd558d18 JC |
1214 | if (session->session_close != NULL) |
1215 | (*session->session_close)(session); | |
1216 | ||
9980d001 TP |
1217 | l2tp_session_dec_refcount(session); |
1218 | ||
fd558d18 JC |
1219 | write_lock_bh(&tunnel->hlist_lock); |
1220 | ||
1221 | /* Now restart from the beginning of this hash | |
1222 | * chain. We always remove a session from the | |
1223 | * list so we are guaranteed to make forward | |
1224 | * progress. | |
1225 | */ | |
1226 | goto again; | |
1227 | } | |
1228 | } | |
1229 | write_unlock_bh(&tunnel->hlist_lock); | |
1230 | } | |
fd558d18 | 1231 | |
9980d001 TP |
1232 | /* Tunnel socket destroy hook for UDP encapsulation */ |
1233 | static void l2tp_udp_encap_destroy(struct sock *sk) | |
1234 | { | |
d00fa9ad JC |
1235 | struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); |
1236 | ||
1237 | if (tunnel) | |
1238 | l2tp_tunnel_delete(tunnel); | |
9980d001 TP |
1239 | } |
1240 | ||
f8ccac0e TP |
1241 | /* Workqueue tunnel deletion function */ |
1242 | static void l2tp_tunnel_del_work(struct work_struct *work) | |
1243 | { | |
d00fa9ad JC |
1244 | struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, |
1245 | del_work); | |
1246 | struct sock *sk = tunnel->sock; | |
1247 | struct socket *sock = sk->sk_socket; | |
28f5bfb8 | 1248 | struct l2tp_net *pn; |
12d656af RK |
1249 | |
1250 | l2tp_tunnel_closeall(tunnel); | |
1251 | ||
76a6abdb | 1252 | /* If the tunnel socket was created within the kernel, use |
02d13ed5 | 1253 | * the sk API to release it here. |
f8ccac0e | 1254 | */ |
76a6abdb | 1255 | if (tunnel->fd < 0) { |
26abe143 | 1256 | if (sock) { |
02d13ed5 | 1257 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 EB |
1258 | sock_release(sock); |
1259 | } | |
167eb17e | 1260 | } |
f8ccac0e | 1261 | |
28f5bfb8 JC |
1262 | /* Remove the tunnel struct from the tunnel list */ |
1263 | pn = l2tp_pernet(tunnel->l2tp_net); | |
1264 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); | |
1265 | list_del_rcu(&tunnel->list); | |
1266 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1267 | ||
d00fa9ad JC |
1268 | /* drop initial ref */ |
1269 | l2tp_tunnel_dec_refcount(tunnel); | |
1270 | ||
1271 | /* drop workqueue ref */ | |
06a15f51 | 1272 | l2tp_tunnel_dec_refcount(tunnel); |
fd558d18 | 1273 | } |
fd558d18 | 1274 | |
789a4a2c JC |
1275 | /* Create a socket for the tunnel, if one isn't set up by |
1276 | * userspace. This is used for static tunnels where there is no | |
1277 | * managing L2TP daemon. | |
167eb17e TP |
1278 | * |
1279 | * Since we don't want these sockets to keep a namespace alive by | |
1280 | * themselves, we drop the socket's namespace refcount after creation. | |
1281 | * These sockets are freed when the namespace exits using the pernet | |
1282 | * exit hook. | |
789a4a2c | 1283 | */ |
167eb17e TP |
1284 | static int l2tp_tunnel_sock_create(struct net *net, |
1285 | u32 tunnel_id, | |
1286 | u32 peer_tunnel_id, | |
1287 | struct l2tp_tunnel_cfg *cfg, | |
1288 | struct socket **sockp) | |
789a4a2c JC |
1289 | { |
1290 | int err = -EINVAL; | |
167eb17e | 1291 | struct socket *sock = NULL; |
85644b4d | 1292 | struct udp_port_cfg udp_conf; |
789a4a2c JC |
1293 | |
1294 | switch (cfg->encap) { | |
1295 | case L2TP_ENCAPTYPE_UDP: | |
85644b4d TH |
1296 | memset(&udp_conf, 0, sizeof(udp_conf)); |
1297 | ||
f9bac8df CE |
1298 | #if IS_ENABLED(CONFIG_IPV6) |
1299 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1300 | udp_conf.family = AF_INET6; |
1301 | memcpy(&udp_conf.local_ip6, cfg->local_ip6, | |
1302 | sizeof(udp_conf.local_ip6)); | |
1303 | memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, | |
1304 | sizeof(udp_conf.peer_ip6)); | |
1305 | udp_conf.use_udp6_tx_checksums = | |
018f8258 | 1306 | ! cfg->udp6_zero_tx_checksums; |
85644b4d | 1307 | udp_conf.use_udp6_rx_checksums = |
018f8258 | 1308 | ! cfg->udp6_zero_rx_checksums; |
f9bac8df CE |
1309 | } else |
1310 | #endif | |
1311 | { | |
85644b4d TH |
1312 | udp_conf.family = AF_INET; |
1313 | udp_conf.local_ip = cfg->local_ip; | |
1314 | udp_conf.peer_ip = cfg->peer_ip; | |
1315 | udp_conf.use_udp_checksums = cfg->use_udp_checksums; | |
f9bac8df | 1316 | } |
789a4a2c | 1317 | |
85644b4d TH |
1318 | udp_conf.local_udp_port = htons(cfg->local_udp_port); |
1319 | udp_conf.peer_udp_port = htons(cfg->peer_udp_port); | |
1320 | ||
1321 | err = udp_sock_create(net, &udp_conf, &sock); | |
1322 | if (err < 0) | |
1323 | goto out; | |
789a4a2c JC |
1324 | |
1325 | break; | |
1326 | ||
1327 | case L2TP_ENCAPTYPE_IP: | |
f9bac8df CE |
1328 | #if IS_ENABLED(CONFIG_IPV6) |
1329 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1330 | struct sockaddr_l2tpip6 ip6_addr = {0}; |
1331 | ||
26abe143 | 1332 | err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, |
167eb17e | 1333 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1334 | if (err < 0) |
1335 | goto out; | |
789a4a2c | 1336 | |
5dac94e1 JC |
1337 | ip6_addr.l2tp_family = AF_INET6; |
1338 | memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, | |
1339 | sizeof(ip6_addr.l2tp_addr)); | |
1340 | ip6_addr.l2tp_conn_id = tunnel_id; | |
1341 | err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, | |
1342 | sizeof(ip6_addr)); | |
1343 | if (err < 0) | |
1344 | goto out; | |
789a4a2c | 1345 | |
5dac94e1 JC |
1346 | ip6_addr.l2tp_family = AF_INET6; |
1347 | memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, | |
1348 | sizeof(ip6_addr.l2tp_addr)); | |
1349 | ip6_addr.l2tp_conn_id = peer_tunnel_id; | |
1350 | err = kernel_connect(sock, | |
1351 | (struct sockaddr *) &ip6_addr, | |
1352 | sizeof(ip6_addr), 0); | |
1353 | if (err < 0) | |
1354 | goto out; | |
1355 | } else | |
1356 | #endif | |
1357 | { | |
85644b4d TH |
1358 | struct sockaddr_l2tpip ip_addr = {0}; |
1359 | ||
26abe143 | 1360 | err = sock_create_kern(net, AF_INET, SOCK_DGRAM, |
167eb17e | 1361 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1362 | if (err < 0) |
1363 | goto out; | |
789a4a2c | 1364 | |
5dac94e1 JC |
1365 | ip_addr.l2tp_family = AF_INET; |
1366 | ip_addr.l2tp_addr = cfg->local_ip; | |
1367 | ip_addr.l2tp_conn_id = tunnel_id; | |
1368 | err = kernel_bind(sock, (struct sockaddr *) &ip_addr, | |
1369 | sizeof(ip_addr)); | |
1370 | if (err < 0) | |
1371 | goto out; | |
1372 | ||
1373 | ip_addr.l2tp_family = AF_INET; | |
1374 | ip_addr.l2tp_addr = cfg->peer_ip; | |
1375 | ip_addr.l2tp_conn_id = peer_tunnel_id; | |
1376 | err = kernel_connect(sock, (struct sockaddr *) &ip_addr, | |
1377 | sizeof(ip_addr), 0); | |
1378 | if (err < 0) | |
1379 | goto out; | |
1380 | } | |
789a4a2c JC |
1381 | break; |
1382 | ||
1383 | default: | |
1384 | goto out; | |
1385 | } | |
1386 | ||
1387 | out: | |
167eb17e | 1388 | *sockp = sock; |
789a4a2c | 1389 | if ((err < 0) && sock) { |
167eb17e | 1390 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 | 1391 | sock_release(sock); |
789a4a2c JC |
1392 | *sockp = NULL; |
1393 | } | |
1394 | ||
1395 | return err; | |
1396 | } | |
1397 | ||
37159ef2 ED |
1398 | static struct lock_class_key l2tp_socket_class; |
1399 | ||
fd558d18 JC |
1400 | 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) |
1401 | { | |
1402 | struct l2tp_tunnel *tunnel = NULL; | |
1403 | int err; | |
0d76751f | 1404 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
fd558d18 | 1405 | |
0d76751f JC |
1406 | if (cfg != NULL) |
1407 | encap = cfg->encap; | |
1408 | ||
fd558d18 JC |
1409 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
1410 | if (tunnel == NULL) { | |
1411 | err = -ENOMEM; | |
1412 | goto err; | |
1413 | } | |
1414 | ||
1415 | tunnel->version = version; | |
1416 | tunnel->tunnel_id = tunnel_id; | |
1417 | tunnel->peer_tunnel_id = peer_tunnel_id; | |
1418 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; | |
1419 | ||
1420 | tunnel->magic = L2TP_TUNNEL_MAGIC; | |
1421 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); | |
1422 | rwlock_init(&tunnel->hlist_lock); | |
f3c66d4e | 1423 | tunnel->acpt_newsess = true; |
fd558d18 | 1424 | |
0d76751f | 1425 | if (cfg != NULL) |
fd558d18 JC |
1426 | tunnel->debug = cfg->debug; |
1427 | ||
0d76751f | 1428 | tunnel->encap = encap; |
fd558d18 | 1429 | |
d00fa9ad | 1430 | refcount_set(&tunnel->ref_count, 1); |
d00fa9ad JC |
1431 | tunnel->fd = fd; |
1432 | ||
f8ccac0e TP |
1433 | /* Init delete workqueue struct */ |
1434 | INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); | |
1435 | ||
fd558d18 | 1436 | INIT_LIST_HEAD(&tunnel->list); |
fd558d18 JC |
1437 | |
1438 | err = 0; | |
1439 | err: | |
1440 | if (tunnelp) | |
1441 | *tunnelp = tunnel; | |
1442 | ||
fd558d18 JC |
1443 | return err; |
1444 | } | |
1445 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); | |
1446 | ||
6b9f3423 GN |
1447 | static int l2tp_validate_socket(const struct sock *sk, const struct net *net, |
1448 | enum l2tp_encap_type encap) | |
1449 | { | |
1450 | if (!net_eq(sock_net(sk), net)) | |
1451 | return -EINVAL; | |
1452 | ||
1453 | if (sk->sk_type != SOCK_DGRAM) | |
1454 | return -EPROTONOSUPPORT; | |
1455 | ||
1456 | if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || | |
1457 | (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) | |
1458 | return -EPROTONOSUPPORT; | |
1459 | ||
1460 | if (sk->sk_user_data) | |
1461 | return -EBUSY; | |
1462 | ||
1463 | return 0; | |
1464 | } | |
1465 | ||
1466 | int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, | |
1467 | struct l2tp_tunnel_cfg *cfg) | |
1468 | { | |
f6cd651b | 1469 | struct l2tp_tunnel *tunnel_walk; |
6b9f3423 GN |
1470 | struct l2tp_net *pn; |
1471 | struct socket *sock; | |
1472 | struct sock *sk; | |
1473 | int ret; | |
1474 | ||
1475 | if (tunnel->fd < 0) { | |
1476 | ret = l2tp_tunnel_sock_create(net, tunnel->tunnel_id, | |
1477 | tunnel->peer_tunnel_id, cfg, | |
1478 | &sock); | |
1479 | if (ret < 0) | |
1480 | goto err; | |
1481 | } else { | |
1482 | sock = sockfd_lookup(tunnel->fd, &ret); | |
1483 | if (!sock) | |
1484 | goto err; | |
1485 | ||
1486 | ret = l2tp_validate_socket(sock->sk, net, tunnel->encap); | |
1487 | if (ret < 0) | |
1488 | goto err_sock; | |
1489 | } | |
1490 | ||
6b9f3423 | 1491 | tunnel->l2tp_net = net; |
6b9f3423 | 1492 | pn = l2tp_pernet(net); |
f6cd651b | 1493 | |
6b9f3423 | 1494 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
f6cd651b GN |
1495 | list_for_each_entry(tunnel_walk, &pn->l2tp_tunnel_list, list) { |
1496 | if (tunnel_walk->tunnel_id == tunnel->tunnel_id) { | |
1497 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1498 | ||
1499 | ret = -EEXIST; | |
1500 | goto err_sock; | |
1501 | } | |
1502 | } | |
6b9f3423 GN |
1503 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); |
1504 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1505 | ||
f8504f4c XL |
1506 | sk = sock->sk; |
1507 | sock_hold(sk); | |
1508 | tunnel->sock = sk; | |
1509 | ||
6b9f3423 GN |
1510 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
1511 | struct udp_tunnel_sock_cfg udp_cfg = { | |
1512 | .sk_user_data = tunnel, | |
1513 | .encap_type = UDP_ENCAP_L2TPINUDP, | |
1514 | .encap_rcv = l2tp_udp_encap_recv, | |
1515 | .encap_destroy = l2tp_udp_encap_destroy, | |
1516 | }; | |
1517 | ||
1518 | setup_udp_tunnel_sock(net, sock, &udp_cfg); | |
1519 | } else { | |
1520 | sk->sk_user_data = tunnel; | |
1521 | } | |
1522 | ||
1523 | tunnel->old_sk_destruct = sk->sk_destruct; | |
1524 | sk->sk_destruct = &l2tp_tunnel_destruct; | |
1525 | lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, | |
1526 | "l2tp_sock"); | |
1527 | sk->sk_allocation = GFP_ATOMIC; | |
1528 | ||
1529 | if (tunnel->fd >= 0) | |
1530 | sockfd_put(sock); | |
1531 | ||
1532 | return 0; | |
1533 | ||
1534 | err_sock: | |
f6cd651b GN |
1535 | if (tunnel->fd < 0) |
1536 | sock_release(sock); | |
1537 | else | |
1538 | sockfd_put(sock); | |
6b9f3423 GN |
1539 | err: |
1540 | return ret; | |
1541 | } | |
1542 | EXPORT_SYMBOL_GPL(l2tp_tunnel_register); | |
1543 | ||
309795f4 JC |
1544 | /* This function is used by the netlink TUNNEL_DELETE command. |
1545 | */ | |
62b982ee | 1546 | void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) |
309795f4 | 1547 | { |
62b982ee SD |
1548 | if (!test_and_set_bit(0, &tunnel->dead)) { |
1549 | l2tp_tunnel_inc_refcount(tunnel); | |
1550 | queue_work(l2tp_wq, &tunnel->del_work); | |
06a15f51 | 1551 | } |
309795f4 JC |
1552 | } |
1553 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); | |
1554 | ||
fd558d18 JC |
1555 | /* Really kill the session. |
1556 | */ | |
1557 | void l2tp_session_free(struct l2tp_session *session) | |
1558 | { | |
f6e16b29 | 1559 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 1560 | |
fbea9e07 | 1561 | BUG_ON(refcount_read(&session->ref_count) != 0); |
fd558d18 | 1562 | |
f6e16b29 | 1563 | if (tunnel) { |
fd558d18 | 1564 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
f6e16b29 TP |
1565 | l2tp_tunnel_dec_refcount(tunnel); |
1566 | } | |
1567 | ||
1568 | kfree(session); | |
f6e16b29 TP |
1569 | } |
1570 | EXPORT_SYMBOL_GPL(l2tp_session_free); | |
1571 | ||
1572 | /* Remove an l2tp session from l2tp_core's hash lists. | |
1573 | * Provides a tidyup interface for pseudowire code which can't just route all | |
1574 | * shutdown via. l2tp_session_delete and a pseudowire-specific session_close | |
1575 | * callback. | |
1576 | */ | |
1577 | void __l2tp_session_unhash(struct l2tp_session *session) | |
1578 | { | |
1579 | struct l2tp_tunnel *tunnel = session->tunnel; | |
fd558d18 | 1580 | |
f6e16b29 TP |
1581 | /* Remove the session from core hashes */ |
1582 | if (tunnel) { | |
1583 | /* Remove from the per-tunnel hash */ | |
fd558d18 JC |
1584 | write_lock_bh(&tunnel->hlist_lock); |
1585 | hlist_del_init(&session->hlist); | |
1586 | write_unlock_bh(&tunnel->hlist_lock); | |
1587 | ||
f6e16b29 | 1588 | /* For L2TPv3 we have a per-net hash: remove from there, too */ |
f7faffa3 JC |
1589 | if (tunnel->version != L2TP_HDR_VER_2) { |
1590 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
e02d494d JC |
1591 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1592 | hlist_del_init_rcu(&session->global_hlist); | |
1593 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
1594 | synchronize_rcu(); | |
f7faffa3 | 1595 | } |
fd558d18 | 1596 | } |
fd558d18 | 1597 | } |
f6e16b29 | 1598 | EXPORT_SYMBOL_GPL(__l2tp_session_unhash); |
fd558d18 | 1599 | |
309795f4 JC |
1600 | /* This function is used by the netlink SESSION_DELETE command and by |
1601 | pseudowire modules. | |
1602 | */ | |
1603 | int l2tp_session_delete(struct l2tp_session *session) | |
1604 | { | |
b228a940 GN |
1605 | if (test_and_set_bit(0, &session->dead)) |
1606 | return 0; | |
1607 | ||
f6e16b29 | 1608 | __l2tp_session_unhash(session); |
4c6e2fd3 | 1609 | l2tp_session_queue_purge(session); |
309795f4 JC |
1610 | if (session->session_close != NULL) |
1611 | (*session->session_close)(session); | |
a4346210 | 1612 | |
309795f4 | 1613 | l2tp_session_dec_refcount(session); |
a4346210 | 1614 | |
309795f4 JC |
1615 | return 0; |
1616 | } | |
1617 | EXPORT_SYMBOL_GPL(l2tp_session_delete); | |
1618 | ||
f7faffa3 | 1619 | /* We come here whenever a session's send_seq, cookie_len or |
62e7b6a5 | 1620 | * l2specific_type parameters are set. |
f7faffa3 | 1621 | */ |
bb5016ea | 1622 | void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
f7faffa3 JC |
1623 | { |
1624 | if (version == L2TP_HDR_VER_2) { | |
1625 | session->hdr_len = 6; | |
1626 | if (session->send_seq) | |
1627 | session->hdr_len += 4; | |
1628 | } else { | |
62e7b6a5 LB |
1629 | session->hdr_len = 4 + session->cookie_len; |
1630 | session->hdr_len += l2tp_get_l2specific_len(session); | |
0d76751f JC |
1631 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) |
1632 | session->hdr_len += 4; | |
f7faffa3 JC |
1633 | } |
1634 | ||
1635 | } | |
bb5016ea | 1636 | EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); |
f7faffa3 | 1637 | |
fd558d18 JC |
1638 | 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) |
1639 | { | |
1640 | struct l2tp_session *session; | |
1641 | ||
1642 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); | |
1643 | if (session != NULL) { | |
1644 | session->magic = L2TP_SESSION_MAGIC; | |
1645 | session->tunnel = tunnel; | |
1646 | ||
1647 | session->session_id = session_id; | |
1648 | session->peer_session_id = peer_session_id; | |
d301e325 | 1649 | session->nr = 0; |
8a1631d5 JC |
1650 | if (tunnel->version == L2TP_HDR_VER_2) |
1651 | session->nr_max = 0xffff; | |
1652 | else | |
1653 | session->nr_max = 0xffffff; | |
1654 | session->nr_window_size = session->nr_max / 2; | |
a0dbd822 JC |
1655 | session->nr_oos_count_max = 4; |
1656 | ||
1657 | /* Use NR of first received packet */ | |
1658 | session->reorder_skip = 1; | |
fd558d18 JC |
1659 | |
1660 | sprintf(&session->name[0], "sess %u/%u", | |
1661 | tunnel->tunnel_id, session->session_id); | |
1662 | ||
1663 | skb_queue_head_init(&session->reorder_q); | |
1664 | ||
1665 | INIT_HLIST_NODE(&session->hlist); | |
f7faffa3 | 1666 | INIT_HLIST_NODE(&session->global_hlist); |
fd558d18 JC |
1667 | |
1668 | /* Inherit debug options from tunnel */ | |
1669 | session->debug = tunnel->debug; | |
1670 | ||
1671 | if (cfg) { | |
f7faffa3 | 1672 | session->pwtype = cfg->pw_type; |
fd558d18 | 1673 | session->debug = cfg->debug; |
fd558d18 JC |
1674 | session->send_seq = cfg->send_seq; |
1675 | session->recv_seq = cfg->recv_seq; | |
1676 | session->lns_mode = cfg->lns_mode; | |
f7faffa3 | 1677 | session->reorder_timeout = cfg->reorder_timeout; |
f7faffa3 | 1678 | session->l2specific_type = cfg->l2specific_type; |
f7faffa3 JC |
1679 | session->cookie_len = cfg->cookie_len; |
1680 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); | |
1681 | session->peer_cookie_len = cfg->peer_cookie_len; | |
1682 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); | |
fd558d18 JC |
1683 | } |
1684 | ||
f7faffa3 JC |
1685 | if (tunnel->version == L2TP_HDR_VER_2) |
1686 | session->build_header = l2tp_build_l2tpv2_header; | |
1687 | else | |
1688 | session->build_header = l2tp_build_l2tpv3_header; | |
1689 | ||
1690 | l2tp_session_set_header_len(session, tunnel->version); | |
1691 | ||
9ee369a4 GN |
1692 | refcount_set(&session->ref_count, 1); |
1693 | ||
dbdbc73b | 1694 | return session; |
fd558d18 JC |
1695 | } |
1696 | ||
dbdbc73b | 1697 | return ERR_PTR(-ENOMEM); |
fd558d18 JC |
1698 | } |
1699 | EXPORT_SYMBOL_GPL(l2tp_session_create); | |
1700 | ||
1701 | /***************************************************************************** | |
1702 | * Init and cleanup | |
1703 | *****************************************************************************/ | |
1704 | ||
1705 | static __net_init int l2tp_init_net(struct net *net) | |
1706 | { | |
e773aaff | 1707 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
f7faffa3 | 1708 | int hash; |
fd558d18 | 1709 | |
fd558d18 | 1710 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
e02d494d | 1711 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
fd558d18 | 1712 | |
f7faffa3 JC |
1713 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
1714 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); | |
1715 | ||
e02d494d | 1716 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
f7faffa3 | 1717 | |
fd558d18 | 1718 | return 0; |
fd558d18 JC |
1719 | } |
1720 | ||
167eb17e TP |
1721 | static __net_exit void l2tp_exit_net(struct net *net) |
1722 | { | |
1723 | struct l2tp_net *pn = l2tp_pernet(net); | |
1724 | struct l2tp_tunnel *tunnel = NULL; | |
1e7af3b2 | 1725 | int hash; |
167eb17e TP |
1726 | |
1727 | rcu_read_lock_bh(); | |
1728 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
4dc12ffe | 1729 | l2tp_tunnel_delete(tunnel); |
167eb17e TP |
1730 | } |
1731 | rcu_read_unlock_bh(); | |
2f86953e | 1732 | |
638a3a1e Y |
1733 | if (l2tp_wq) |
1734 | flush_workqueue(l2tp_wq); | |
2f86953e | 1735 | rcu_barrier(); |
1e7af3b2 VA |
1736 | |
1737 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) | |
1738 | WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash])); | |
167eb17e TP |
1739 | } |
1740 | ||
fd558d18 JC |
1741 | static struct pernet_operations l2tp_net_ops = { |
1742 | .init = l2tp_init_net, | |
167eb17e | 1743 | .exit = l2tp_exit_net, |
fd558d18 JC |
1744 | .id = &l2tp_net_id, |
1745 | .size = sizeof(struct l2tp_net), | |
1746 | }; | |
1747 | ||
1748 | static int __init l2tp_init(void) | |
1749 | { | |
1750 | int rc = 0; | |
1751 | ||
1752 | rc = register_pernet_device(&l2tp_net_ops); | |
1753 | if (rc) | |
1754 | goto out; | |
1755 | ||
59ff3eb6 | 1756 | l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); |
f8ccac0e TP |
1757 | if (!l2tp_wq) { |
1758 | pr_err("alloc_workqueue failed\n"); | |
67e04c29 | 1759 | unregister_pernet_device(&l2tp_net_ops); |
f8ccac0e TP |
1760 | rc = -ENOMEM; |
1761 | goto out; | |
1762 | } | |
1763 | ||
a4ca44fa | 1764 | pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); |
fd558d18 JC |
1765 | |
1766 | out: | |
1767 | return rc; | |
1768 | } | |
1769 | ||
1770 | static void __exit l2tp_exit(void) | |
1771 | { | |
1772 | unregister_pernet_device(&l2tp_net_ops); | |
f8ccac0e TP |
1773 | if (l2tp_wq) { |
1774 | destroy_workqueue(l2tp_wq); | |
1775 | l2tp_wq = NULL; | |
1776 | } | |
fd558d18 JC |
1777 | } |
1778 | ||
1779 | module_init(l2tp_init); | |
1780 | module_exit(l2tp_exit); | |
1781 | ||
1782 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
1783 | MODULE_DESCRIPTION("L2TP core"); | |
1784 | MODULE_LICENSE("GPL"); | |
1785 | MODULE_VERSION(L2TP_DRV_VERSION); |