Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
20dcb110 | 2 | /* L2TP core. |
fd558d18 JC |
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) | |
fd558d18 JC |
15 | */ |
16 | ||
a4ca44fa JP |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | ||
fd558d18 JC |
19 | #include <linux/module.h> |
20 | #include <linux/string.h> | |
21 | #include <linux/list.h> | |
e02d494d | 22 | #include <linux/rculist.h> |
fd558d18 JC |
23 | #include <linux/uaccess.h> |
24 | ||
25 | #include <linux/kernel.h> | |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/kthread.h> | |
28 | #include <linux/sched.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/jiffies.h> | |
32 | ||
33 | #include <linux/netdevice.h> | |
34 | #include <linux/net.h> | |
35 | #include <linux/inetdevice.h> | |
36 | #include <linux/skbuff.h> | |
37 | #include <linux/init.h> | |
0d76751f | 38 | #include <linux/in.h> |
fd558d18 JC |
39 | #include <linux/ip.h> |
40 | #include <linux/udp.h> | |
0d76751f | 41 | #include <linux/l2tp.h> |
fd558d18 JC |
42 | #include <linux/hash.h> |
43 | #include <linux/sort.h> | |
44 | #include <linux/file.h> | |
45 | #include <linux/nsproxy.h> | |
46 | #include <net/net_namespace.h> | |
47 | #include <net/netns/generic.h> | |
48 | #include <net/dst.h> | |
49 | #include <net/ip.h> | |
50 | #include <net/udp.h> | |
85644b4d | 51 | #include <net/udp_tunnel.h> |
309795f4 | 52 | #include <net/inet_common.h> |
fd558d18 | 53 | #include <net/xfrm.h> |
0d76751f | 54 | #include <net/protocol.h> |
d2cf3361 BL |
55 | #include <net/inet6_connection_sock.h> |
56 | #include <net/inet_ecn.h> | |
57 | #include <net/ip6_route.h> | |
d499bd2e | 58 | #include <net/ip6_checksum.h> |
fd558d18 JC |
59 | |
60 | #include <asm/byteorder.h> | |
60063497 | 61 | #include <linux/atomic.h> |
fd558d18 JC |
62 | |
63 | #include "l2tp_core.h" | |
64 | ||
65 | #define L2TP_DRV_VERSION "V2.0" | |
66 | ||
67 | /* L2TP header constants */ | |
68 | #define L2TP_HDRFLAG_T 0x8000 | |
69 | #define L2TP_HDRFLAG_L 0x4000 | |
70 | #define L2TP_HDRFLAG_S 0x0800 | |
71 | #define L2TP_HDRFLAG_O 0x0200 | |
72 | #define L2TP_HDRFLAG_P 0x0100 | |
73 | ||
74 | #define L2TP_HDR_VER_MASK 0x000F | |
75 | #define L2TP_HDR_VER_2 0x0002 | |
f7faffa3 | 76 | #define L2TP_HDR_VER_3 0x0003 |
fd558d18 JC |
77 | |
78 | /* L2TPv3 default L2-specific sublayer */ | |
79 | #define L2TP_SLFLAG_S 0x40000000 | |
80 | #define L2TP_SL_SEQ_MASK 0x00ffffff | |
81 | ||
91c52470 | 82 | #define L2TP_HDR_SIZE_MAX 14 |
fd558d18 JC |
83 | |
84 | /* Default trace flags */ | |
85 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 | |
86 | ||
fd558d18 JC |
87 | /* Private data stored for received packets in the skb. |
88 | */ | |
89 | struct l2tp_skb_cb { | |
f7faffa3 | 90 | u32 ns; |
fd558d18 JC |
91 | u16 has_seq; |
92 | u16 length; | |
93 | unsigned long expires; | |
94 | }; | |
95 | ||
b71a61cc | 96 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&skb->cb[sizeof(struct inet_skb_parm)]) |
fd558d18 | 97 | |
f8ccac0e | 98 | static struct workqueue_struct *l2tp_wq; |
fd558d18 JC |
99 | |
100 | /* per-net private data for this module */ | |
101 | static unsigned int l2tp_net_id; | |
102 | struct l2tp_net { | |
103 | struct list_head l2tp_tunnel_list; | |
20dcb110 | 104 | /* Lock for write access to l2tp_tunnel_list */ |
e02d494d | 105 | spinlock_t l2tp_tunnel_list_lock; |
f7faffa3 | 106 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
20dcb110 | 107 | /* Lock for write access to l2tp_session_hlist */ |
e02d494d | 108 | spinlock_t l2tp_session_hlist_lock; |
fd558d18 JC |
109 | }; |
110 | ||
b954f940 PA |
111 | #if IS_ENABLED(CONFIG_IPV6) |
112 | static bool l2tp_sk_is_v6(struct sock *sk) | |
113 | { | |
114 | return sk->sk_family == PF_INET6 && | |
115 | !ipv6_addr_v4mapped(&sk->sk_v6_daddr); | |
116 | } | |
117 | #endif | |
fc130840 | 118 | |
8d8a51e2 DM |
119 | static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) |
120 | { | |
121 | return sk->sk_user_data; | |
122 | } | |
123 | ||
9aaef50c | 124 | static inline struct l2tp_net *l2tp_pernet(const struct net *net) |
fd558d18 | 125 | { |
fd558d18 JC |
126 | return net_generic(net, l2tp_net_id); |
127 | } | |
128 | ||
f7faffa3 JC |
129 | /* Session hash global list for L2TPv3. |
130 | * The session_id SHOULD be random according to RFC3931, but several | |
131 | * L2TP implementations use incrementing session_ids. So we do a real | |
132 | * hash on the session_id, rather than a simple bitmask. | |
133 | */ | |
134 | static inline struct hlist_head * | |
135 | l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) | |
136 | { | |
137 | return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; | |
f7faffa3 JC |
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 | |
0d0d9a38 RK |
323 | /* IP encap expects session IDs to be globally unique, while |
324 | * UDP encap doesn't. | |
325 | */ | |
dbdbc73b | 326 | hlist_for_each_entry(session_walk, g_head, global_hlist) |
0d0d9a38 RK |
327 | if (session_walk->session_id == session->session_id && |
328 | (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || | |
329 | tunnel->encap == L2TP_ENCAPTYPE_IP)) { | |
f3c66d4e GN |
330 | err = -EEXIST; |
331 | goto err_tlock_pnlock; | |
332 | } | |
dbdbc73b | 333 | |
f3c66d4e | 334 | l2tp_tunnel_inc_refcount(tunnel); |
dbdbc73b | 335 | hlist_add_head_rcu(&session->global_hlist, g_head); |
f3c66d4e | 336 | |
dbdbc73b | 337 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e GN |
338 | } else { |
339 | l2tp_tunnel_inc_refcount(tunnel); | |
dbdbc73b GN |
340 | } |
341 | ||
342 | hlist_add_head(&session->hlist, head); | |
343 | write_unlock_bh(&tunnel->hlist_lock); | |
344 | ||
345 | return 0; | |
346 | ||
f3c66d4e | 347 | err_tlock_pnlock: |
dbdbc73b | 348 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e | 349 | err_tlock: |
dbdbc73b GN |
350 | write_unlock_bh(&tunnel->hlist_lock); |
351 | ||
f3c66d4e | 352 | return err; |
dbdbc73b | 353 | } |
3953ae7b | 354 | EXPORT_SYMBOL_GPL(l2tp_session_register); |
dbdbc73b | 355 | |
fd558d18 JC |
356 | /***************************************************************************** |
357 | * Receive data handling | |
358 | *****************************************************************************/ | |
359 | ||
360 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence | |
361 | * number. | |
362 | */ | |
363 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
364 | { | |
365 | struct sk_buff *skbp; | |
366 | struct sk_buff *tmp; | |
f7faffa3 | 367 | u32 ns = L2TP_SKB_CB(skb)->ns; |
fd558d18 JC |
368 | |
369 | spin_lock_bh(&session->reorder_q.lock); | |
370 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { | |
371 | if (L2TP_SKB_CB(skbp)->ns > ns) { | |
372 | __skb_queue_before(&session->reorder_q, skbp, skb); | |
a4ca44fa JP |
373 | l2tp_dbg(session, L2TP_MSG_SEQ, |
374 | "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", | |
375 | session->name, ns, L2TP_SKB_CB(skbp)->ns, | |
376 | skb_queue_len(&session->reorder_q)); | |
7b7c0719 | 377 | atomic_long_inc(&session->stats.rx_oos_packets); |
fd558d18 JC |
378 | goto out; |
379 | } | |
380 | } | |
381 | ||
382 | __skb_queue_tail(&session->reorder_q, skb); | |
383 | ||
384 | out: | |
385 | spin_unlock_bh(&session->reorder_q.lock); | |
386 | } | |
387 | ||
388 | /* Dequeue a single skb. | |
389 | */ | |
390 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
391 | { | |
392 | struct l2tp_tunnel *tunnel = session->tunnel; | |
393 | int length = L2TP_SKB_CB(skb)->length; | |
394 | ||
395 | /* We're about to requeue the skb, so return resources | |
396 | * to its current owner (a socket receive buffer). | |
397 | */ | |
398 | skb_orphan(skb); | |
399 | ||
7b7c0719 TP |
400 | atomic_long_inc(&tunnel->stats.rx_packets); |
401 | atomic_long_add(length, &tunnel->stats.rx_bytes); | |
402 | atomic_long_inc(&session->stats.rx_packets); | |
403 | atomic_long_add(length, &session->stats.rx_bytes); | |
fd558d18 JC |
404 | |
405 | if (L2TP_SKB_CB(skb)->has_seq) { | |
406 | /* Bump our Nr */ | |
407 | session->nr++; | |
8a1631d5 | 408 | session->nr &= session->nr_max; |
f7faffa3 | 409 | |
a4ca44fa JP |
410 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", |
411 | session->name, session->nr); | |
fd558d18 JC |
412 | } |
413 | ||
414 | /* call private receive handler */ | |
415 | if (session->recv_skb != NULL) | |
416 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); | |
417 | else | |
418 | kfree_skb(skb); | |
fd558d18 JC |
419 | } |
420 | ||
421 | /* Dequeue skbs from the session's reorder_q, subject to packet order. | |
422 | * Skbs that have been in the queue for too long are simply discarded. | |
423 | */ | |
424 | static void l2tp_recv_dequeue(struct l2tp_session *session) | |
425 | { | |
426 | struct sk_buff *skb; | |
427 | struct sk_buff *tmp; | |
428 | ||
429 | /* If the pkt at the head of the queue has the nr that we | |
430 | * expect to send up next, dequeue it and any other | |
431 | * in-sequence packets behind it. | |
432 | */ | |
e2e210c0 | 433 | start: |
fd558d18 JC |
434 | spin_lock_bh(&session->reorder_q.lock); |
435 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { | |
436 | if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { | |
7b7c0719 TP |
437 | atomic_long_inc(&session->stats.rx_seq_discards); |
438 | atomic_long_inc(&session->stats.rx_errors); | |
a4ca44fa JP |
439 | l2tp_dbg(session, L2TP_MSG_SEQ, |
440 | "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", | |
441 | session->name, L2TP_SKB_CB(skb)->ns, | |
442 | L2TP_SKB_CB(skb)->length, session->nr, | |
443 | skb_queue_len(&session->reorder_q)); | |
38d40b3f | 444 | session->reorder_skip = 1; |
fd558d18 JC |
445 | __skb_unlink(skb, &session->reorder_q); |
446 | kfree_skb(skb); | |
fd558d18 JC |
447 | continue; |
448 | } | |
449 | ||
450 | if (L2TP_SKB_CB(skb)->has_seq) { | |
38d40b3f | 451 | if (session->reorder_skip) { |
a4ca44fa JP |
452 | l2tp_dbg(session, L2TP_MSG_SEQ, |
453 | "%s: advancing nr to next pkt: %u -> %u", | |
454 | session->name, session->nr, | |
455 | L2TP_SKB_CB(skb)->ns); | |
38d40b3f JC |
456 | session->reorder_skip = 0; |
457 | session->nr = L2TP_SKB_CB(skb)->ns; | |
458 | } | |
fd558d18 | 459 | if (L2TP_SKB_CB(skb)->ns != session->nr) { |
a4ca44fa JP |
460 | l2tp_dbg(session, L2TP_MSG_SEQ, |
461 | "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", | |
462 | session->name, L2TP_SKB_CB(skb)->ns, | |
463 | L2TP_SKB_CB(skb)->length, session->nr, | |
464 | skb_queue_len(&session->reorder_q)); | |
fd558d18 JC |
465 | goto out; |
466 | } | |
467 | } | |
468 | __skb_unlink(skb, &session->reorder_q); | |
469 | ||
470 | /* Process the skb. We release the queue lock while we | |
471 | * do so to let other contexts process the queue. | |
472 | */ | |
473 | spin_unlock_bh(&session->reorder_q.lock); | |
474 | l2tp_recv_dequeue_skb(session, skb); | |
e2e210c0 | 475 | goto start; |
fd558d18 JC |
476 | } |
477 | ||
478 | out: | |
479 | spin_unlock_bh(&session->reorder_q.lock); | |
480 | } | |
481 | ||
8a1631d5 JC |
482 | static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) |
483 | { | |
484 | u32 nws; | |
485 | ||
486 | if (nr >= session->nr) | |
487 | nws = nr - session->nr; | |
488 | else | |
489 | nws = (session->nr_max + 1) - (session->nr - nr); | |
490 | ||
491 | return nws < session->nr_window_size; | |
492 | } | |
493 | ||
b6dc01a4 JC |
494 | /* If packet has sequence numbers, queue it if acceptable. Returns 0 if |
495 | * acceptable, else non-zero. | |
496 | */ | |
497 | static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) | |
498 | { | |
8a1631d5 JC |
499 | if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { |
500 | /* Packet sequence number is outside allowed window. | |
501 | * Discard it. | |
502 | */ | |
503 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
504 | "%s: pkt %u len %d discarded, outside window, nr=%u\n", | |
505 | session->name, L2TP_SKB_CB(skb)->ns, | |
506 | L2TP_SKB_CB(skb)->length, session->nr); | |
507 | goto discard; | |
508 | } | |
509 | ||
b6dc01a4 JC |
510 | if (session->reorder_timeout != 0) { |
511 | /* Packet reordering enabled. Add skb to session's | |
512 | * reorder queue, in order of ns. | |
513 | */ | |
514 | l2tp_recv_queue_skb(session, skb); | |
a0dbd822 JC |
515 | goto out; |
516 | } | |
517 | ||
518 | /* Packet reordering disabled. Discard out-of-sequence packets, while | |
519 | * tracking the number if in-sequence packets after the first OOS packet | |
520 | * is seen. After nr_oos_count_max in-sequence packets, reset the | |
521 | * sequence number to re-enable packet reception. | |
522 | */ | |
523 | if (L2TP_SKB_CB(skb)->ns == session->nr) { | |
524 | skb_queue_tail(&session->reorder_q, skb); | |
b6dc01a4 | 525 | } else { |
a0dbd822 JC |
526 | u32 nr_oos = L2TP_SKB_CB(skb)->ns; |
527 | u32 nr_next = (session->nr_oos + 1) & session->nr_max; | |
528 | ||
529 | if (nr_oos == nr_next) | |
530 | session->nr_oos_count++; | |
531 | else | |
532 | session->nr_oos_count = 0; | |
533 | ||
534 | session->nr_oos = nr_oos; | |
535 | if (session->nr_oos_count > session->nr_oos_count_max) { | |
536 | session->reorder_skip = 1; | |
537 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
538 | "%s: %d oos packets received. Resetting sequence numbers\n", | |
539 | session->name, session->nr_oos_count); | |
540 | } | |
541 | if (!session->reorder_skip) { | |
b6dc01a4 JC |
542 | atomic_long_inc(&session->stats.rx_seq_discards); |
543 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
544 | "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", | |
545 | session->name, L2TP_SKB_CB(skb)->ns, | |
546 | L2TP_SKB_CB(skb)->length, session->nr, | |
547 | skb_queue_len(&session->reorder_q)); | |
548 | goto discard; | |
549 | } | |
550 | skb_queue_tail(&session->reorder_q, skb); | |
551 | } | |
552 | ||
a0dbd822 | 553 | out: |
b6dc01a4 JC |
554 | return 0; |
555 | ||
556 | discard: | |
557 | return 1; | |
558 | } | |
559 | ||
f7faffa3 JC |
560 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
561 | * and L2TPv3 data frames here. | |
562 | * | |
563 | * L2TPv2 Data Message Header | |
564 | * | |
565 | * 0 1 2 3 | |
566 | * 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 | |
567 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
568 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | | |
569 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
570 | * | Tunnel ID | Session ID | | |
571 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
572 | * | Ns (opt) | Nr (opt) | | |
573 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
574 | * | Offset Size (opt) | Offset pad... (opt) | |
575 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
576 | * | |
577 | * Data frames are marked by T=0. All other fields are the same as | |
578 | * those in L2TP control frames. | |
579 | * | |
580 | * L2TPv3 Data Message Header | |
581 | * | |
582 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
583 | * | L2TP Session Header | | |
584 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
585 | * | L2-Specific Sublayer | | |
586 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
587 | * | Tunnel Payload ... | |
588 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
589 | * | |
590 | * L2TPv3 Session Header Over IP | |
591 | * | |
592 | * 0 1 2 3 | |
593 | * 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 | |
594 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
595 | * | Session ID | | |
596 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
597 | * | Cookie (optional, maximum 64 bits)... | |
598 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
599 | * | | |
600 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
601 | * | |
602 | * L2TPv3 L2-Specific Sublayer Format | |
603 | * | |
604 | * 0 1 2 3 | |
605 | * 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 | |
606 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
607 | * |x|S|x|x|x|x|x|x| Sequence Number | | |
608 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
609 | * | |
23fe846f GN |
610 | * Cookie value and sublayer format are negotiated with the peer when |
611 | * the session is set up. Unlike L2TPv2, we do not need to parse the | |
612 | * packet header to determine if optional fields are present. | |
f7faffa3 JC |
613 | * |
614 | * Caller must already have parsed the frame and determined that it is | |
615 | * a data (not control) frame before coming here. Fields up to the | |
616 | * session-id have already been parsed and ptr points to the data | |
617 | * after the session-id. | |
fd558d18 | 618 | */ |
f7faffa3 JC |
619 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
620 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, | |
2b139e6b | 621 | int length) |
fd558d18 | 622 | { |
f7faffa3 | 623 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 624 | int offset; |
f7faffa3 | 625 | u32 ns, nr; |
fd558d18 | 626 | |
f7faffa3 JC |
627 | /* Parse and check optional cookie */ |
628 | if (session->peer_cookie_len > 0) { | |
629 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { | |
a4ca44fa JP |
630 | l2tp_info(tunnel, L2TP_MSG_DATA, |
631 | "%s: cookie mismatch (%u/%u). Discarding.\n", | |
632 | tunnel->name, tunnel->tunnel_id, | |
633 | session->session_id); | |
7b7c0719 | 634 | atomic_long_inc(&session->stats.rx_cookie_discards); |
f7faffa3 JC |
635 | goto discard; |
636 | } | |
637 | ptr += session->peer_cookie_len; | |
638 | } | |
639 | ||
fd558d18 JC |
640 | /* Handle the optional sequence numbers. Sequence numbers are |
641 | * in different places for L2TPv2 and L2TPv3. | |
642 | * | |
643 | * If we are the LAC, enable/disable sequence numbers under | |
644 | * the control of the LNS. If no sequence numbers present but | |
645 | * we were expecting them, discard frame. | |
646 | */ | |
647 | ns = nr = 0; | |
648 | L2TP_SKB_CB(skb)->has_seq = 0; | |
f7faffa3 JC |
649 | if (tunnel->version == L2TP_HDR_VER_2) { |
650 | if (hdrflags & L2TP_HDRFLAG_S) { | |
b71a61cc | 651 | ns = ntohs(*(__be16 *)ptr); |
f7faffa3 | 652 | ptr += 2; |
b71a61cc | 653 | nr = ntohs(*(__be16 *)ptr); |
f7faffa3 | 654 | ptr += 2; |
fd558d18 | 655 | |
f7faffa3 JC |
656 | /* Store L2TP info in the skb */ |
657 | L2TP_SKB_CB(skb)->ns = ns; | |
658 | L2TP_SKB_CB(skb)->has_seq = 1; | |
fd558d18 | 659 | |
a4ca44fa JP |
660 | l2tp_dbg(session, L2TP_MSG_SEQ, |
661 | "%s: recv data ns=%u, nr=%u, session nr=%u\n", | |
662 | session->name, ns, nr, session->nr); | |
f7faffa3 JC |
663 | } |
664 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
b71a61cc | 665 | u32 l2h = ntohl(*(__be32 *)ptr); |
f7faffa3 JC |
666 | |
667 | if (l2h & 0x40000000) { | |
668 | ns = l2h & 0x00ffffff; | |
669 | ||
670 | /* Store L2TP info in the skb */ | |
671 | L2TP_SKB_CB(skb)->ns = ns; | |
672 | L2TP_SKB_CB(skb)->has_seq = 1; | |
673 | ||
a4ca44fa JP |
674 | l2tp_dbg(session, L2TP_MSG_SEQ, |
675 | "%s: recv data ns=%u, session nr=%u\n", | |
676 | session->name, ns, session->nr); | |
f7faffa3 | 677 | } |
62e7b6a5 | 678 | ptr += 4; |
fd558d18 JC |
679 | } |
680 | ||
681 | if (L2TP_SKB_CB(skb)->has_seq) { | |
20dcb110 | 682 | /* Received a packet with sequence numbers. If we're the LAC, |
fd558d18 JC |
683 | * check if we sre sending sequence numbers and if not, |
684 | * configure it so. | |
685 | */ | |
686 | if ((!session->lns_mode) && (!session->send_seq)) { | |
a4ca44fa JP |
687 | l2tp_info(session, L2TP_MSG_SEQ, |
688 | "%s: requested to enable seq numbers by LNS\n", | |
689 | session->name); | |
3f9b9770 | 690 | session->send_seq = 1; |
f7faffa3 | 691 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
692 | } |
693 | } else { | |
694 | /* No sequence numbers. | |
695 | * If user has configured mandatory sequence numbers, discard. | |
696 | */ | |
697 | if (session->recv_seq) { | |
a4ca44fa JP |
698 | l2tp_warn(session, L2TP_MSG_SEQ, |
699 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
700 | session->name); | |
7b7c0719 | 701 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
702 | goto discard; |
703 | } | |
704 | ||
705 | /* If we're the LAC and we're sending sequence numbers, the | |
706 | * LNS has requested that we no longer send sequence numbers. | |
707 | * If we're the LNS and we're sending sequence numbers, the | |
708 | * LAC is broken. Discard the frame. | |
709 | */ | |
710 | if ((!session->lns_mode) && (session->send_seq)) { | |
a4ca44fa JP |
711 | l2tp_info(session, L2TP_MSG_SEQ, |
712 | "%s: requested to disable seq numbers by LNS\n", | |
713 | session->name); | |
fd558d18 | 714 | session->send_seq = 0; |
f7faffa3 | 715 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 | 716 | } else if (session->send_seq) { |
a4ca44fa JP |
717 | l2tp_warn(session, L2TP_MSG_SEQ, |
718 | "%s: recv data has no seq numbers when required. Discarding.\n", | |
719 | session->name); | |
7b7c0719 | 720 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
721 | goto discard; |
722 | } | |
723 | } | |
724 | ||
900631ee JC |
725 | /* Session data offset is defined only for L2TPv2 and is |
726 | * indicated by an optional 16-bit value in the header. | |
f7faffa3 JC |
727 | */ |
728 | if (tunnel->version == L2TP_HDR_VER_2) { | |
729 | /* If offset bit set, skip it. */ | |
730 | if (hdrflags & L2TP_HDRFLAG_O) { | |
731 | offset = ntohs(*(__be16 *)ptr); | |
732 | ptr += 2 + offset; | |
733 | } | |
900631ee | 734 | } |
fd558d18 JC |
735 | |
736 | offset = ptr - optr; | |
737 | if (!pskb_may_pull(skb, offset)) | |
738 | goto discard; | |
739 | ||
740 | __skb_pull(skb, offset); | |
741 | ||
fd558d18 JC |
742 | /* Prepare skb for adding to the session's reorder_q. Hold |
743 | * packets for max reorder_timeout or 1 second if not | |
744 | * reordering. | |
745 | */ | |
746 | L2TP_SKB_CB(skb)->length = length; | |
747 | L2TP_SKB_CB(skb)->expires = jiffies + | |
748 | (session->reorder_timeout ? session->reorder_timeout : HZ); | |
749 | ||
750 | /* Add packet to the session's receive queue. Reordering is done here, if | |
751 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. | |
752 | */ | |
753 | if (L2TP_SKB_CB(skb)->has_seq) { | |
b6dc01a4 JC |
754 | if (l2tp_recv_data_seq(session, skb)) |
755 | goto discard; | |
fd558d18 JC |
756 | } else { |
757 | /* No sequence numbers. Add the skb to the tail of the | |
758 | * reorder queue. This ensures that it will be | |
759 | * delivered after all previous sequenced skbs. | |
760 | */ | |
761 | skb_queue_tail(&session->reorder_q, skb); | |
762 | } | |
763 | ||
764 | /* Try to dequeue as many skbs from reorder_q as we can. */ | |
765 | l2tp_recv_dequeue(session); | |
766 | ||
f7faffa3 | 767 | return; |
fd558d18 JC |
768 | |
769 | discard: | |
7b7c0719 | 770 | atomic_long_inc(&session->stats.rx_errors); |
fd558d18 | 771 | kfree_skb(skb); |
f7faffa3 JC |
772 | } |
773 | EXPORT_SYMBOL(l2tp_recv_common); | |
774 | ||
48f72f92 TP |
775 | /* Drop skbs from the session's reorder_q |
776 | */ | |
2e67560e | 777 | static int l2tp_session_queue_purge(struct l2tp_session *session) |
48f72f92 TP |
778 | { |
779 | struct sk_buff *skb = NULL; | |
b71a61cc | 780 | |
48f72f92 TP |
781 | BUG_ON(!session); |
782 | BUG_ON(session->magic != L2TP_SESSION_MAGIC); | |
783 | while ((skb = skb_dequeue(&session->reorder_q))) { | |
784 | atomic_long_inc(&session->stats.rx_errors); | |
785 | kfree_skb(skb); | |
48f72f92 TP |
786 | } |
787 | return 0; | |
788 | } | |
48f72f92 | 789 | |
f7faffa3 JC |
790 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
791 | * here. The skb is not on a list when we get here. | |
792 | * Returns 0 if the packet was a data packet and was successfully passed on. | |
793 | * Returns 1 if the packet was not a good data packet and could not be | |
794 | * forwarded. All such packets are passed up to userspace to deal with. | |
795 | */ | |
2b139e6b | 796 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) |
f7faffa3 JC |
797 | { |
798 | struct l2tp_session *session = NULL; | |
799 | unsigned char *ptr, *optr; | |
800 | u16 hdrflags; | |
801 | u32 tunnel_id, session_id; | |
f7faffa3 JC |
802 | u16 version; |
803 | int length; | |
804 | ||
58d6085c | 805 | /* UDP has verifed checksum */ |
f7faffa3 JC |
806 | |
807 | /* UDP always verifies the packet length. */ | |
808 | __skb_pull(skb, sizeof(struct udphdr)); | |
809 | ||
810 | /* Short packet? */ | |
91c52470 | 811 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { |
a4ca44fa JP |
812 | l2tp_info(tunnel, L2TP_MSG_DATA, |
813 | "%s: recv short packet (len=%d)\n", | |
814 | tunnel->name, skb->len); | |
f7faffa3 JC |
815 | goto error; |
816 | } | |
817 | ||
f7faffa3 JC |
818 | /* Trace packet contents, if enabled */ |
819 | if (tunnel->debug & L2TP_MSG_DATA) { | |
820 | length = min(32u, skb->len); | |
821 | if (!pskb_may_pull(skb, length)) | |
822 | goto error; | |
823 | ||
a4ca44fa JP |
824 | pr_debug("%s: recv\n", tunnel->name); |
825 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); | |
f7faffa3 JC |
826 | } |
827 | ||
e50e705c ED |
828 | /* Point to L2TP header */ |
829 | optr = ptr = skb->data; | |
830 | ||
f7faffa3 | 831 | /* Get L2TP header flags */ |
b71a61cc | 832 | hdrflags = ntohs(*(__be16 *)ptr); |
f7faffa3 JC |
833 | |
834 | /* Check protocol version */ | |
835 | version = hdrflags & L2TP_HDR_VER_MASK; | |
836 | if (version != tunnel->version) { | |
a4ca44fa JP |
837 | l2tp_info(tunnel, L2TP_MSG_DATA, |
838 | "%s: recv protocol version mismatch: got %d expected %d\n", | |
839 | tunnel->name, version, tunnel->version); | |
f7faffa3 JC |
840 | goto error; |
841 | } | |
842 | ||
843 | /* Get length of L2TP packet */ | |
844 | length = skb->len; | |
845 | ||
846 | /* If type is control packet, it is handled by userspace. */ | |
847 | if (hdrflags & L2TP_HDRFLAG_T) { | |
a4ca44fa JP |
848 | l2tp_dbg(tunnel, L2TP_MSG_DATA, |
849 | "%s: recv control packet, len=%d\n", | |
850 | tunnel->name, length); | |
f7faffa3 JC |
851 | goto error; |
852 | } | |
853 | ||
854 | /* Skip flags */ | |
855 | ptr += 2; | |
856 | ||
857 | if (tunnel->version == L2TP_HDR_VER_2) { | |
858 | /* If length is present, skip it */ | |
859 | if (hdrflags & L2TP_HDRFLAG_L) | |
860 | ptr += 2; | |
861 | ||
862 | /* Extract tunnel and session ID */ | |
b71a61cc | 863 | tunnel_id = ntohs(*(__be16 *)ptr); |
f7faffa3 | 864 | ptr += 2; |
b71a61cc | 865 | session_id = ntohs(*(__be16 *)ptr); |
f7faffa3 JC |
866 | ptr += 2; |
867 | } else { | |
868 | ptr += 2; /* skip reserved bits */ | |
869 | tunnel_id = tunnel->tunnel_id; | |
b71a61cc | 870 | session_id = ntohl(*(__be32 *)ptr); |
f7faffa3 JC |
871 | ptr += 4; |
872 | } | |
873 | ||
874 | /* Find the session context */ | |
01e28b92 | 875 | session = l2tp_tunnel_get_session(tunnel, session_id); |
309795f4 | 876 | if (!session || !session->recv_skb) { |
a4346210 | 877 | if (session) |
61b9a047 | 878 | l2tp_session_dec_refcount(session); |
61b9a047 | 879 | |
f7faffa3 | 880 | /* Not found? Pass to userspace to deal with */ |
a4ca44fa JP |
881 | l2tp_info(tunnel, L2TP_MSG_DATA, |
882 | "%s: no session found (%u/%u). Passing up.\n", | |
883 | tunnel->name, tunnel_id, session_id); | |
f7faffa3 JC |
884 | goto error; |
885 | } | |
886 | ||
4522a70d JW |
887 | if (tunnel->version == L2TP_HDR_VER_3 && |
888 | l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) | |
889 | goto error; | |
890 | ||
2b139e6b | 891 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); |
61b9a047 | 892 | l2tp_session_dec_refcount(session); |
fd558d18 JC |
893 | |
894 | return 0; | |
895 | ||
fd558d18 JC |
896 | error: |
897 | /* Put UDP header back */ | |
898 | __skb_push(skb, sizeof(struct udphdr)); | |
899 | ||
900 | return 1; | |
901 | } | |
fd558d18 JC |
902 | |
903 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. | |
904 | * Return codes: | |
905 | * 0 : success. | |
906 | * <0: error | |
907 | * >0: skb should be passed up to userspace as UDP. | |
908 | */ | |
909 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) | |
910 | { | |
911 | struct l2tp_tunnel *tunnel; | |
912 | ||
c1c47721 | 913 | tunnel = rcu_dereference_sk_user_data(sk); |
fd558d18 JC |
914 | if (tunnel == NULL) |
915 | goto pass_up; | |
916 | ||
a4ca44fa JP |
917 | l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", |
918 | tunnel->name, skb->len); | |
fd558d18 | 919 | |
2b139e6b | 920 | if (l2tp_udp_recv_core(tunnel, skb)) |
d00fa9ad | 921 | goto pass_up; |
fd558d18 | 922 | |
fd558d18 JC |
923 | return 0; |
924 | ||
fd558d18 JC |
925 | pass_up: |
926 | return 1; | |
927 | } | |
928 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); | |
929 | ||
930 | /************************************************************************ | |
931 | * Transmit handling | |
932 | ***********************************************************************/ | |
933 | ||
934 | /* Build an L2TP header for the session into the buffer provided. | |
935 | */ | |
f7faffa3 | 936 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
fd558d18 | 937 | { |
f7faffa3 | 938 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 939 | __be16 *bufp = buf; |
f7faffa3 | 940 | __be16 *optr = buf; |
fd558d18 JC |
941 | u16 flags = L2TP_HDR_VER_2; |
942 | u32 tunnel_id = tunnel->peer_tunnel_id; | |
943 | u32 session_id = session->peer_session_id; | |
944 | ||
945 | if (session->send_seq) | |
946 | flags |= L2TP_HDRFLAG_S; | |
947 | ||
948 | /* Setup L2TP header. */ | |
949 | *bufp++ = htons(flags); | |
950 | *bufp++ = htons(tunnel_id); | |
951 | *bufp++ = htons(session_id); | |
952 | if (session->send_seq) { | |
953 | *bufp++ = htons(session->ns); | |
954 | *bufp++ = 0; | |
955 | session->ns++; | |
f7faffa3 | 956 | session->ns &= 0xffff; |
a4ca44fa JP |
957 | l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", |
958 | session->name, session->ns); | |
fd558d18 | 959 | } |
f7faffa3 JC |
960 | |
961 | return bufp - optr; | |
fd558d18 JC |
962 | } |
963 | ||
f7faffa3 | 964 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
fd558d18 | 965 | { |
0d76751f | 966 | struct l2tp_tunnel *tunnel = session->tunnel; |
f7faffa3 JC |
967 | char *bufp = buf; |
968 | char *optr = bufp; | |
f7faffa3 | 969 | |
0d76751f JC |
970 | /* Setup L2TP header. The header differs slightly for UDP and |
971 | * IP encapsulations. For UDP, there is 4 bytes of flags. | |
972 | */ | |
973 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
974 | u16 flags = L2TP_HDR_VER_3; | |
b71a61cc | 975 | *((__be16 *)bufp) = htons(flags); |
0d76751f | 976 | bufp += 2; |
b71a61cc | 977 | *((__be16 *)bufp) = 0; |
0d76751f JC |
978 | bufp += 2; |
979 | } | |
980 | ||
b71a61cc | 981 | *((__be32 *)bufp) = htonl(session->peer_session_id); |
f7faffa3 JC |
982 | bufp += 4; |
983 | if (session->cookie_len) { | |
984 | memcpy(bufp, &session->cookie[0], session->cookie_len); | |
985 | bufp += session->cookie_len; | |
986 | } | |
62e7b6a5 LB |
987 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
988 | u32 l2h = 0; | |
f7faffa3 | 989 | |
62e7b6a5 LB |
990 | if (session->send_seq) { |
991 | l2h = 0x40000000 | session->ns; | |
992 | session->ns++; | |
993 | session->ns &= 0xffffff; | |
994 | l2tp_dbg(session, L2TP_MSG_SEQ, | |
995 | "%s: updated ns to %u\n", | |
996 | session->name, session->ns); | |
f7faffa3 | 997 | } |
62e7b6a5 LB |
998 | |
999 | *((__be32 *)bufp) = htonl(l2h); | |
1000 | bufp += 4; | |
f7faffa3 | 1001 | } |
fd558d18 | 1002 | |
f7faffa3 | 1003 | return bufp - optr; |
fd558d18 | 1004 | } |
fd558d18 | 1005 | |
2685fbb8 GN |
1006 | static void l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, |
1007 | struct flowi *fl, size_t data_len) | |
fd558d18 JC |
1008 | { |
1009 | struct l2tp_tunnel *tunnel = session->tunnel; | |
1010 | unsigned int len = skb->len; | |
1011 | int error; | |
1012 | ||
1013 | /* Debug */ | |
1014 | if (session->send_seq) | |
5b5e0928 | 1015 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes, ns=%u\n", |
a4ca44fa | 1016 | session->name, data_len, session->ns - 1); |
fd558d18 | 1017 | else |
5b5e0928 | 1018 | l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes\n", |
a4ca44fa | 1019 | session->name, data_len); |
fd558d18 JC |
1020 | |
1021 | if (session->debug & L2TP_MSG_DATA) { | |
0d76751f JC |
1022 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1023 | unsigned char *datap = skb->data + uhlen; | |
fd558d18 | 1024 | |
a4ca44fa JP |
1025 | pr_debug("%s: xmit\n", session->name); |
1026 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, | |
1027 | datap, min_t(size_t, 32, len - uhlen)); | |
fd558d18 JC |
1028 | } |
1029 | ||
1030 | /* Queue the packet to IP for output */ | |
60ff7467 | 1031 | skb->ignore_df = 1; |
27d53323 | 1032 | skb_dst_drop(skb); |
d2cf3361 | 1033 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1034 | if (l2tp_sk_is_v6(tunnel->sock)) |
b0270e91 | 1035 | error = inet6_csk_xmit(tunnel->sock, skb, NULL); |
d2cf3361 BL |
1036 | else |
1037 | #endif | |
b0270e91 | 1038 | error = ip_queue_xmit(tunnel->sock, skb, fl); |
fd558d18 JC |
1039 | |
1040 | /* Update stats */ | |
1041 | if (error >= 0) { | |
7b7c0719 TP |
1042 | atomic_long_inc(&tunnel->stats.tx_packets); |
1043 | atomic_long_add(len, &tunnel->stats.tx_bytes); | |
1044 | atomic_long_inc(&session->stats.tx_packets); | |
1045 | atomic_long_add(len, &session->stats.tx_bytes); | |
fd558d18 | 1046 | } else { |
7b7c0719 TP |
1047 | atomic_long_inc(&tunnel->stats.tx_errors); |
1048 | atomic_long_inc(&session->stats.tx_errors); | |
fd558d18 | 1049 | } |
fd558d18 | 1050 | } |
fd558d18 | 1051 | |
fd558d18 JC |
1052 | /* If caller requires the skb to have a ppp header, the header must be |
1053 | * inserted in the skb data before calling this function. | |
1054 | */ | |
1055 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) | |
1056 | { | |
1057 | int data_len = skb->len; | |
0d76751f JC |
1058 | struct l2tp_tunnel *tunnel = session->tunnel; |
1059 | struct sock *sk = tunnel->sock; | |
d9d8da80 | 1060 | struct flowi *fl; |
fd558d18 | 1061 | struct udphdr *uh; |
fd558d18 | 1062 | struct inet_sock *inet; |
fd558d18 | 1063 | int headroom; |
0d76751f JC |
1064 | int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; |
1065 | int udp_len; | |
b8c84307 | 1066 | int ret = NET_XMIT_SUCCESS; |
fd558d18 JC |
1067 | |
1068 | /* Check that there's enough headroom in the skb to insert IP, | |
1069 | * UDP and L2TP headers. If not enough, expand it to | |
1070 | * make room. Adjust truesize. | |
1071 | */ | |
1072 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + | |
0d76751f | 1073 | uhlen + hdr_len; |
835acf5d | 1074 | if (skb_cow_head(skb, headroom)) { |
b8c84307 ED |
1075 | kfree_skb(skb); |
1076 | return NET_XMIT_DROP; | |
835acf5d | 1077 | } |
fd558d18 | 1078 | |
fd558d18 | 1079 | /* Setup L2TP header */ |
f7faffa3 | 1080 | session->build_header(session, __skb_push(skb, hdr_len)); |
fd558d18 | 1081 | |
0d76751f | 1082 | /* Reset skb netfilter state */ |
fd558d18 JC |
1083 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
1084 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | | |
1085 | IPSKB_REROUTED); | |
895b5c9f | 1086 | nf_reset_ct(skb); |
fd558d18 | 1087 | |
6af88da1 DM |
1088 | bh_lock_sock(sk); |
1089 | if (sock_owned_by_user(sk)) { | |
b8c84307 ED |
1090 | kfree_skb(skb); |
1091 | ret = NET_XMIT_DROP; | |
6af88da1 DM |
1092 | goto out_unlock; |
1093 | } | |
1094 | ||
b954f940 PA |
1095 | /* The user-space may change the connection status for the user-space |
1096 | * provided socket at run time: we must check it under the socket lock | |
1097 | */ | |
1098 | if (tunnel->fd >= 0 && sk->sk_state != TCP_ESTABLISHED) { | |
1099 | kfree_skb(skb); | |
1100 | ret = NET_XMIT_DROP; | |
1101 | goto out_unlock; | |
1102 | } | |
1103 | ||
d9d8da80 DM |
1104 | inet = inet_sk(sk); |
1105 | fl = &inet->cork.fl; | |
0d76751f JC |
1106 | switch (tunnel->encap) { |
1107 | case L2TP_ENCAPTYPE_UDP: | |
1108 | /* Setup UDP header */ | |
0d76751f JC |
1109 | __skb_push(skb, sizeof(*uh)); |
1110 | skb_reset_transport_header(skb); | |
1111 | uh = udp_hdr(skb); | |
1112 | uh->source = inet->inet_sport; | |
1113 | uh->dest = inet->inet_dport; | |
1114 | udp_len = uhlen + hdr_len + data_len; | |
1115 | uh->len = htons(udp_len); | |
0d76751f JC |
1116 | |
1117 | /* Calculate UDP checksum if configured to do so */ | |
d2cf3361 | 1118 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1119 | if (l2tp_sk_is_v6(sk)) |
77157e19 TH |
1120 | udp6_set_csum(udp_get_no_check6_tx(sk), |
1121 | skb, &inet6_sk(sk)->saddr, | |
1122 | &sk->sk_v6_daddr, udp_len); | |
d2cf3361 BL |
1123 | else |
1124 | #endif | |
0864e331 TP |
1125 | udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, |
1126 | inet->inet_daddr, udp_len); | |
0d76751f JC |
1127 | break; |
1128 | ||
1129 | case L2TP_ENCAPTYPE_IP: | |
1130 | break; | |
fd558d18 JC |
1131 | } |
1132 | ||
d9d8da80 | 1133 | l2tp_xmit_core(session, skb, fl, data_len); |
6af88da1 DM |
1134 | out_unlock: |
1135 | bh_unlock_sock(sk); | |
fd558d18 | 1136 | |
b8c84307 | 1137 | return ret; |
fd558d18 JC |
1138 | } |
1139 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); | |
1140 | ||
1141 | /***************************************************************************** | |
1142 | * Tinnel and session create/destroy. | |
1143 | *****************************************************************************/ | |
1144 | ||
1145 | /* Tunnel socket destruct hook. | |
1146 | * The tunnel context is deleted only when all session sockets have been | |
1147 | * closed. | |
1148 | */ | |
fc130840 | 1149 | static void l2tp_tunnel_destruct(struct sock *sk) |
fd558d18 | 1150 | { |
8d8a51e2 | 1151 | struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); |
fd558d18 | 1152 | |
fd558d18 JC |
1153 | if (tunnel == NULL) |
1154 | goto end; | |
1155 | ||
a4ca44fa | 1156 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); |
fd558d18 | 1157 | |
f8ccac0e | 1158 | /* Disable udp encapsulation */ |
0d76751f JC |
1159 | switch (tunnel->encap) { |
1160 | case L2TP_ENCAPTYPE_UDP: | |
1161 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ | |
1162 | (udp_sk(sk))->encap_type = 0; | |
1163 | (udp_sk(sk))->encap_rcv = NULL; | |
9980d001 | 1164 | (udp_sk(sk))->encap_destroy = NULL; |
0d76751f JC |
1165 | break; |
1166 | case L2TP_ENCAPTYPE_IP: | |
1167 | break; | |
1168 | } | |
fd558d18 JC |
1169 | |
1170 | /* Remove hooks into tunnel socket */ | |
fd558d18 JC |
1171 | sk->sk_destruct = tunnel->old_sk_destruct; |
1172 | sk->sk_user_data = NULL; | |
1173 | ||
f8ccac0e TP |
1174 | /* Call the original destructor */ |
1175 | if (sk->sk_destruct) | |
1176 | (*sk->sk_destruct)(sk); | |
d00fa9ad JC |
1177 | |
1178 | kfree_rcu(tunnel, rcu); | |
fd558d18 JC |
1179 | end: |
1180 | return; | |
1181 | } | |
fd558d18 JC |
1182 | |
1183 | /* When the tunnel is closed, all the attached sessions need to go too. | |
1184 | */ | |
d08532bb | 1185 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
fd558d18 JC |
1186 | { |
1187 | int hash; | |
1188 | struct hlist_node *walk; | |
1189 | struct hlist_node *tmp; | |
1190 | struct l2tp_session *session; | |
1191 | ||
1192 | BUG_ON(tunnel == NULL); | |
1193 | ||
a4ca44fa JP |
1194 | l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", |
1195 | tunnel->name); | |
fd558d18 JC |
1196 | |
1197 | write_lock_bh(&tunnel->hlist_lock); | |
f3c66d4e | 1198 | tunnel->acpt_newsess = false; |
fd558d18 JC |
1199 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
1200 | again: | |
1201 | hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { | |
1202 | session = hlist_entry(walk, struct l2tp_session, hlist); | |
1203 | ||
a4ca44fa JP |
1204 | l2tp_info(session, L2TP_MSG_CONTROL, |
1205 | "%s: closing session\n", session->name); | |
fd558d18 JC |
1206 | |
1207 | hlist_del_init(&session->hlist); | |
1208 | ||
b228a940 GN |
1209 | if (test_and_set_bit(0, &session->dead)) |
1210 | goto again; | |
1211 | ||
fd558d18 JC |
1212 | write_unlock_bh(&tunnel->hlist_lock); |
1213 | ||
f6e16b29 | 1214 | __l2tp_session_unhash(session); |
4c6e2fd3 TP |
1215 | l2tp_session_queue_purge(session); |
1216 | ||
fd558d18 JC |
1217 | if (session->session_close != NULL) |
1218 | (*session->session_close)(session); | |
1219 | ||
9980d001 TP |
1220 | l2tp_session_dec_refcount(session); |
1221 | ||
fd558d18 JC |
1222 | write_lock_bh(&tunnel->hlist_lock); |
1223 | ||
1224 | /* Now restart from the beginning of this hash | |
1225 | * chain. We always remove a session from the | |
1226 | * list so we are guaranteed to make forward | |
1227 | * progress. | |
1228 | */ | |
1229 | goto again; | |
1230 | } | |
1231 | } | |
1232 | write_unlock_bh(&tunnel->hlist_lock); | |
1233 | } | |
fd558d18 | 1234 | |
9980d001 TP |
1235 | /* Tunnel socket destroy hook for UDP encapsulation */ |
1236 | static void l2tp_udp_encap_destroy(struct sock *sk) | |
1237 | { | |
d00fa9ad JC |
1238 | struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); |
1239 | ||
1240 | if (tunnel) | |
1241 | l2tp_tunnel_delete(tunnel); | |
9980d001 TP |
1242 | } |
1243 | ||
f8ccac0e TP |
1244 | /* Workqueue tunnel deletion function */ |
1245 | static void l2tp_tunnel_del_work(struct work_struct *work) | |
1246 | { | |
d00fa9ad JC |
1247 | struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, |
1248 | del_work); | |
1249 | struct sock *sk = tunnel->sock; | |
1250 | struct socket *sock = sk->sk_socket; | |
28f5bfb8 | 1251 | struct l2tp_net *pn; |
12d656af RK |
1252 | |
1253 | l2tp_tunnel_closeall(tunnel); | |
1254 | ||
76a6abdb | 1255 | /* If the tunnel socket was created within the kernel, use |
02d13ed5 | 1256 | * the sk API to release it here. |
f8ccac0e | 1257 | */ |
76a6abdb | 1258 | if (tunnel->fd < 0) { |
26abe143 | 1259 | if (sock) { |
02d13ed5 | 1260 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 EB |
1261 | sock_release(sock); |
1262 | } | |
167eb17e | 1263 | } |
f8ccac0e | 1264 | |
28f5bfb8 JC |
1265 | /* Remove the tunnel struct from the tunnel list */ |
1266 | pn = l2tp_pernet(tunnel->l2tp_net); | |
1267 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); | |
1268 | list_del_rcu(&tunnel->list); | |
1269 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1270 | ||
d00fa9ad JC |
1271 | /* drop initial ref */ |
1272 | l2tp_tunnel_dec_refcount(tunnel); | |
1273 | ||
1274 | /* drop workqueue ref */ | |
06a15f51 | 1275 | l2tp_tunnel_dec_refcount(tunnel); |
fd558d18 | 1276 | } |
fd558d18 | 1277 | |
789a4a2c JC |
1278 | /* Create a socket for the tunnel, if one isn't set up by |
1279 | * userspace. This is used for static tunnels where there is no | |
1280 | * managing L2TP daemon. | |
167eb17e TP |
1281 | * |
1282 | * Since we don't want these sockets to keep a namespace alive by | |
1283 | * themselves, we drop the socket's namespace refcount after creation. | |
1284 | * These sockets are freed when the namespace exits using the pernet | |
1285 | * exit hook. | |
789a4a2c | 1286 | */ |
167eb17e | 1287 | static int l2tp_tunnel_sock_create(struct net *net, |
8ce9825a TP |
1288 | u32 tunnel_id, |
1289 | u32 peer_tunnel_id, | |
1290 | struct l2tp_tunnel_cfg *cfg, | |
1291 | struct socket **sockp) | |
789a4a2c JC |
1292 | { |
1293 | int err = -EINVAL; | |
167eb17e | 1294 | struct socket *sock = NULL; |
85644b4d | 1295 | struct udp_port_cfg udp_conf; |
789a4a2c JC |
1296 | |
1297 | switch (cfg->encap) { | |
1298 | case L2TP_ENCAPTYPE_UDP: | |
85644b4d TH |
1299 | memset(&udp_conf, 0, sizeof(udp_conf)); |
1300 | ||
f9bac8df CE |
1301 | #if IS_ENABLED(CONFIG_IPV6) |
1302 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1303 | udp_conf.family = AF_INET6; |
1304 | memcpy(&udp_conf.local_ip6, cfg->local_ip6, | |
1305 | sizeof(udp_conf.local_ip6)); | |
1306 | memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, | |
1307 | sizeof(udp_conf.peer_ip6)); | |
1308 | udp_conf.use_udp6_tx_checksums = | |
b71a61cc | 1309 | !cfg->udp6_zero_tx_checksums; |
85644b4d | 1310 | udp_conf.use_udp6_rx_checksums = |
b71a61cc | 1311 | !cfg->udp6_zero_rx_checksums; |
f9bac8df CE |
1312 | } else |
1313 | #endif | |
1314 | { | |
85644b4d TH |
1315 | udp_conf.family = AF_INET; |
1316 | udp_conf.local_ip = cfg->local_ip; | |
1317 | udp_conf.peer_ip = cfg->peer_ip; | |
1318 | udp_conf.use_udp_checksums = cfg->use_udp_checksums; | |
f9bac8df | 1319 | } |
789a4a2c | 1320 | |
85644b4d TH |
1321 | udp_conf.local_udp_port = htons(cfg->local_udp_port); |
1322 | udp_conf.peer_udp_port = htons(cfg->peer_udp_port); | |
1323 | ||
1324 | err = udp_sock_create(net, &udp_conf, &sock); | |
1325 | if (err < 0) | |
1326 | goto out; | |
789a4a2c JC |
1327 | |
1328 | break; | |
1329 | ||
1330 | case L2TP_ENCAPTYPE_IP: | |
f9bac8df CE |
1331 | #if IS_ENABLED(CONFIG_IPV6) |
1332 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1333 | struct sockaddr_l2tpip6 ip6_addr = {0}; |
1334 | ||
26abe143 | 1335 | err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, |
8ce9825a | 1336 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1337 | if (err < 0) |
1338 | goto out; | |
789a4a2c | 1339 | |
5dac94e1 JC |
1340 | ip6_addr.l2tp_family = AF_INET6; |
1341 | memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, | |
1342 | sizeof(ip6_addr.l2tp_addr)); | |
1343 | ip6_addr.l2tp_conn_id = tunnel_id; | |
b71a61cc | 1344 | err = kernel_bind(sock, (struct sockaddr *)&ip6_addr, |
5dac94e1 JC |
1345 | sizeof(ip6_addr)); |
1346 | if (err < 0) | |
1347 | goto out; | |
789a4a2c | 1348 | |
5dac94e1 JC |
1349 | ip6_addr.l2tp_family = AF_INET6; |
1350 | memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, | |
1351 | sizeof(ip6_addr.l2tp_addr)); | |
1352 | ip6_addr.l2tp_conn_id = peer_tunnel_id; | |
1353 | err = kernel_connect(sock, | |
b71a61cc | 1354 | (struct sockaddr *)&ip6_addr, |
5dac94e1 JC |
1355 | sizeof(ip6_addr), 0); |
1356 | if (err < 0) | |
1357 | goto out; | |
1358 | } else | |
1359 | #endif | |
1360 | { | |
85644b4d TH |
1361 | struct sockaddr_l2tpip ip_addr = {0}; |
1362 | ||
26abe143 | 1363 | err = sock_create_kern(net, AF_INET, SOCK_DGRAM, |
8ce9825a | 1364 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1365 | if (err < 0) |
1366 | goto out; | |
789a4a2c | 1367 | |
5dac94e1 JC |
1368 | ip_addr.l2tp_family = AF_INET; |
1369 | ip_addr.l2tp_addr = cfg->local_ip; | |
1370 | ip_addr.l2tp_conn_id = tunnel_id; | |
b71a61cc | 1371 | err = kernel_bind(sock, (struct sockaddr *)&ip_addr, |
5dac94e1 JC |
1372 | sizeof(ip_addr)); |
1373 | if (err < 0) | |
1374 | goto out; | |
1375 | ||
1376 | ip_addr.l2tp_family = AF_INET; | |
1377 | ip_addr.l2tp_addr = cfg->peer_ip; | |
1378 | ip_addr.l2tp_conn_id = peer_tunnel_id; | |
b71a61cc | 1379 | err = kernel_connect(sock, (struct sockaddr *)&ip_addr, |
5dac94e1 JC |
1380 | sizeof(ip_addr), 0); |
1381 | if (err < 0) | |
1382 | goto out; | |
1383 | } | |
789a4a2c JC |
1384 | break; |
1385 | ||
1386 | default: | |
1387 | goto out; | |
1388 | } | |
1389 | ||
1390 | out: | |
167eb17e | 1391 | *sockp = sock; |
789a4a2c | 1392 | if ((err < 0) && sock) { |
167eb17e | 1393 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 | 1394 | sock_release(sock); |
789a4a2c JC |
1395 | *sockp = NULL; |
1396 | } | |
1397 | ||
1398 | return err; | |
1399 | } | |
1400 | ||
37159ef2 ED |
1401 | static struct lock_class_key l2tp_socket_class; |
1402 | ||
fd558d18 JC |
1403 | 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) |
1404 | { | |
1405 | struct l2tp_tunnel *tunnel = NULL; | |
1406 | int err; | |
0d76751f | 1407 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
fd558d18 | 1408 | |
0d76751f JC |
1409 | if (cfg != NULL) |
1410 | encap = cfg->encap; | |
1411 | ||
fd558d18 JC |
1412 | tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); |
1413 | if (tunnel == NULL) { | |
1414 | err = -ENOMEM; | |
1415 | goto err; | |
1416 | } | |
1417 | ||
1418 | tunnel->version = version; | |
1419 | tunnel->tunnel_id = tunnel_id; | |
1420 | tunnel->peer_tunnel_id = peer_tunnel_id; | |
1421 | tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; | |
1422 | ||
1423 | tunnel->magic = L2TP_TUNNEL_MAGIC; | |
1424 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); | |
1425 | rwlock_init(&tunnel->hlist_lock); | |
f3c66d4e | 1426 | tunnel->acpt_newsess = true; |
fd558d18 | 1427 | |
0d76751f | 1428 | if (cfg != NULL) |
fd558d18 JC |
1429 | tunnel->debug = cfg->debug; |
1430 | ||
0d76751f | 1431 | tunnel->encap = encap; |
fd558d18 | 1432 | |
d00fa9ad | 1433 | refcount_set(&tunnel->ref_count, 1); |
d00fa9ad JC |
1434 | tunnel->fd = fd; |
1435 | ||
f8ccac0e TP |
1436 | /* Init delete workqueue struct */ |
1437 | INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); | |
1438 | ||
fd558d18 | 1439 | INIT_LIST_HEAD(&tunnel->list); |
fd558d18 JC |
1440 | |
1441 | err = 0; | |
1442 | err: | |
1443 | if (tunnelp) | |
1444 | *tunnelp = tunnel; | |
1445 | ||
fd558d18 JC |
1446 | return err; |
1447 | } | |
1448 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); | |
1449 | ||
6b9f3423 GN |
1450 | static int l2tp_validate_socket(const struct sock *sk, const struct net *net, |
1451 | enum l2tp_encap_type encap) | |
1452 | { | |
1453 | if (!net_eq(sock_net(sk), net)) | |
1454 | return -EINVAL; | |
1455 | ||
1456 | if (sk->sk_type != SOCK_DGRAM) | |
1457 | return -EPROTONOSUPPORT; | |
1458 | ||
d9a81a22 ED |
1459 | if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) |
1460 | return -EPROTONOSUPPORT; | |
1461 | ||
6b9f3423 GN |
1462 | if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || |
1463 | (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) | |
1464 | return -EPROTONOSUPPORT; | |
1465 | ||
1466 | if (sk->sk_user_data) | |
1467 | return -EBUSY; | |
1468 | ||
1469 | return 0; | |
1470 | } | |
1471 | ||
1472 | int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, | |
1473 | struct l2tp_tunnel_cfg *cfg) | |
1474 | { | |
f6cd651b | 1475 | struct l2tp_tunnel *tunnel_walk; |
6b9f3423 GN |
1476 | struct l2tp_net *pn; |
1477 | struct socket *sock; | |
1478 | struct sock *sk; | |
1479 | int ret; | |
1480 | ||
1481 | if (tunnel->fd < 0) { | |
1482 | ret = l2tp_tunnel_sock_create(net, tunnel->tunnel_id, | |
1483 | tunnel->peer_tunnel_id, cfg, | |
1484 | &sock); | |
1485 | if (ret < 0) | |
1486 | goto err; | |
1487 | } else { | |
1488 | sock = sockfd_lookup(tunnel->fd, &ret); | |
1489 | if (!sock) | |
1490 | goto err; | |
1491 | ||
1492 | ret = l2tp_validate_socket(sock->sk, net, tunnel->encap); | |
1493 | if (ret < 0) | |
1494 | goto err_sock; | |
1495 | } | |
1496 | ||
6b9f3423 | 1497 | tunnel->l2tp_net = net; |
6b9f3423 | 1498 | pn = l2tp_pernet(net); |
f6cd651b | 1499 | |
6b9f3423 | 1500 | spin_lock_bh(&pn->l2tp_tunnel_list_lock); |
f6cd651b GN |
1501 | list_for_each_entry(tunnel_walk, &pn->l2tp_tunnel_list, list) { |
1502 | if (tunnel_walk->tunnel_id == tunnel->tunnel_id) { | |
1503 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1504 | ||
1505 | ret = -EEXIST; | |
1506 | goto err_sock; | |
1507 | } | |
1508 | } | |
6b9f3423 GN |
1509 | list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); |
1510 | spin_unlock_bh(&pn->l2tp_tunnel_list_lock); | |
1511 | ||
f8504f4c XL |
1512 | sk = sock->sk; |
1513 | sock_hold(sk); | |
1514 | tunnel->sock = sk; | |
1515 | ||
6b9f3423 GN |
1516 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
1517 | struct udp_tunnel_sock_cfg udp_cfg = { | |
1518 | .sk_user_data = tunnel, | |
1519 | .encap_type = UDP_ENCAP_L2TPINUDP, | |
1520 | .encap_rcv = l2tp_udp_encap_recv, | |
1521 | .encap_destroy = l2tp_udp_encap_destroy, | |
1522 | }; | |
1523 | ||
1524 | setup_udp_tunnel_sock(net, sock, &udp_cfg); | |
1525 | } else { | |
1526 | sk->sk_user_data = tunnel; | |
1527 | } | |
1528 | ||
1529 | tunnel->old_sk_destruct = sk->sk_destruct; | |
1530 | sk->sk_destruct = &l2tp_tunnel_destruct; | |
1531 | lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, | |
1532 | "l2tp_sock"); | |
1533 | sk->sk_allocation = GFP_ATOMIC; | |
1534 | ||
1535 | if (tunnel->fd >= 0) | |
1536 | sockfd_put(sock); | |
1537 | ||
1538 | return 0; | |
1539 | ||
1540 | err_sock: | |
f6cd651b GN |
1541 | if (tunnel->fd < 0) |
1542 | sock_release(sock); | |
1543 | else | |
1544 | sockfd_put(sock); | |
6b9f3423 GN |
1545 | err: |
1546 | return ret; | |
1547 | } | |
1548 | EXPORT_SYMBOL_GPL(l2tp_tunnel_register); | |
1549 | ||
309795f4 JC |
1550 | /* This function is used by the netlink TUNNEL_DELETE command. |
1551 | */ | |
62b982ee | 1552 | void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) |
309795f4 | 1553 | { |
62b982ee SD |
1554 | if (!test_and_set_bit(0, &tunnel->dead)) { |
1555 | l2tp_tunnel_inc_refcount(tunnel); | |
1556 | queue_work(l2tp_wq, &tunnel->del_work); | |
06a15f51 | 1557 | } |
309795f4 JC |
1558 | } |
1559 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); | |
1560 | ||
fd558d18 JC |
1561 | /* Really kill the session. |
1562 | */ | |
1563 | void l2tp_session_free(struct l2tp_session *session) | |
1564 | { | |
f6e16b29 | 1565 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 1566 | |
fbea9e07 | 1567 | BUG_ON(refcount_read(&session->ref_count) != 0); |
fd558d18 | 1568 | |
f6e16b29 | 1569 | if (tunnel) { |
fd558d18 | 1570 | BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
f6e16b29 TP |
1571 | l2tp_tunnel_dec_refcount(tunnel); |
1572 | } | |
1573 | ||
1574 | kfree(session); | |
f6e16b29 TP |
1575 | } |
1576 | EXPORT_SYMBOL_GPL(l2tp_session_free); | |
1577 | ||
1578 | /* Remove an l2tp session from l2tp_core's hash lists. | |
1579 | * Provides a tidyup interface for pseudowire code which can't just route all | |
1580 | * shutdown via. l2tp_session_delete and a pseudowire-specific session_close | |
1581 | * callback. | |
1582 | */ | |
1583 | void __l2tp_session_unhash(struct l2tp_session *session) | |
1584 | { | |
1585 | struct l2tp_tunnel *tunnel = session->tunnel; | |
fd558d18 | 1586 | |
f6e16b29 TP |
1587 | /* Remove the session from core hashes */ |
1588 | if (tunnel) { | |
1589 | /* Remove from the per-tunnel hash */ | |
fd558d18 JC |
1590 | write_lock_bh(&tunnel->hlist_lock); |
1591 | hlist_del_init(&session->hlist); | |
1592 | write_unlock_bh(&tunnel->hlist_lock); | |
1593 | ||
f6e16b29 | 1594 | /* For L2TPv3 we have a per-net hash: remove from there, too */ |
f7faffa3 JC |
1595 | if (tunnel->version != L2TP_HDR_VER_2) { |
1596 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
b71a61cc | 1597 | |
e02d494d JC |
1598 | spin_lock_bh(&pn->l2tp_session_hlist_lock); |
1599 | hlist_del_init_rcu(&session->global_hlist); | |
1600 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
1601 | synchronize_rcu(); | |
f7faffa3 | 1602 | } |
fd558d18 | 1603 | } |
fd558d18 | 1604 | } |
f6e16b29 | 1605 | EXPORT_SYMBOL_GPL(__l2tp_session_unhash); |
fd558d18 | 1606 | |
309795f4 | 1607 | /* This function is used by the netlink SESSION_DELETE command and by |
20dcb110 | 1608 | * pseudowire modules. |
309795f4 JC |
1609 | */ |
1610 | int l2tp_session_delete(struct l2tp_session *session) | |
1611 | { | |
b228a940 GN |
1612 | if (test_and_set_bit(0, &session->dead)) |
1613 | return 0; | |
1614 | ||
f6e16b29 | 1615 | __l2tp_session_unhash(session); |
4c6e2fd3 | 1616 | l2tp_session_queue_purge(session); |
309795f4 JC |
1617 | if (session->session_close != NULL) |
1618 | (*session->session_close)(session); | |
a4346210 | 1619 | |
309795f4 | 1620 | l2tp_session_dec_refcount(session); |
a4346210 | 1621 | |
309795f4 JC |
1622 | return 0; |
1623 | } | |
1624 | EXPORT_SYMBOL_GPL(l2tp_session_delete); | |
1625 | ||
f7faffa3 | 1626 | /* We come here whenever a session's send_seq, cookie_len or |
62e7b6a5 | 1627 | * l2specific_type parameters are set. |
f7faffa3 | 1628 | */ |
bb5016ea | 1629 | void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
f7faffa3 JC |
1630 | { |
1631 | if (version == L2TP_HDR_VER_2) { | |
1632 | session->hdr_len = 6; | |
1633 | if (session->send_seq) | |
1634 | session->hdr_len += 4; | |
1635 | } else { | |
62e7b6a5 LB |
1636 | session->hdr_len = 4 + session->cookie_len; |
1637 | session->hdr_len += l2tp_get_l2specific_len(session); | |
0d76751f JC |
1638 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) |
1639 | session->hdr_len += 4; | |
f7faffa3 | 1640 | } |
f7faffa3 | 1641 | } |
bb5016ea | 1642 | EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); |
f7faffa3 | 1643 | |
fd558d18 JC |
1644 | 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) |
1645 | { | |
1646 | struct l2tp_session *session; | |
1647 | ||
1648 | session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); | |
1649 | if (session != NULL) { | |
1650 | session->magic = L2TP_SESSION_MAGIC; | |
1651 | session->tunnel = tunnel; | |
1652 | ||
1653 | session->session_id = session_id; | |
1654 | session->peer_session_id = peer_session_id; | |
d301e325 | 1655 | session->nr = 0; |
8a1631d5 JC |
1656 | if (tunnel->version == L2TP_HDR_VER_2) |
1657 | session->nr_max = 0xffff; | |
1658 | else | |
1659 | session->nr_max = 0xffffff; | |
1660 | session->nr_window_size = session->nr_max / 2; | |
a0dbd822 JC |
1661 | session->nr_oos_count_max = 4; |
1662 | ||
1663 | /* Use NR of first received packet */ | |
1664 | session->reorder_skip = 1; | |
fd558d18 JC |
1665 | |
1666 | sprintf(&session->name[0], "sess %u/%u", | |
1667 | tunnel->tunnel_id, session->session_id); | |
1668 | ||
1669 | skb_queue_head_init(&session->reorder_q); | |
1670 | ||
1671 | INIT_HLIST_NODE(&session->hlist); | |
f7faffa3 | 1672 | INIT_HLIST_NODE(&session->global_hlist); |
fd558d18 JC |
1673 | |
1674 | /* Inherit debug options from tunnel */ | |
1675 | session->debug = tunnel->debug; | |
1676 | ||
1677 | if (cfg) { | |
f7faffa3 | 1678 | session->pwtype = cfg->pw_type; |
fd558d18 | 1679 | session->debug = cfg->debug; |
fd558d18 JC |
1680 | session->send_seq = cfg->send_seq; |
1681 | session->recv_seq = cfg->recv_seq; | |
1682 | session->lns_mode = cfg->lns_mode; | |
f7faffa3 | 1683 | session->reorder_timeout = cfg->reorder_timeout; |
f7faffa3 | 1684 | session->l2specific_type = cfg->l2specific_type; |
f7faffa3 JC |
1685 | session->cookie_len = cfg->cookie_len; |
1686 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); | |
1687 | session->peer_cookie_len = cfg->peer_cookie_len; | |
1688 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); | |
fd558d18 JC |
1689 | } |
1690 | ||
f7faffa3 JC |
1691 | if (tunnel->version == L2TP_HDR_VER_2) |
1692 | session->build_header = l2tp_build_l2tpv2_header; | |
1693 | else | |
1694 | session->build_header = l2tp_build_l2tpv3_header; | |
1695 | ||
1696 | l2tp_session_set_header_len(session, tunnel->version); | |
1697 | ||
9ee369a4 GN |
1698 | refcount_set(&session->ref_count, 1); |
1699 | ||
dbdbc73b | 1700 | return session; |
fd558d18 JC |
1701 | } |
1702 | ||
dbdbc73b | 1703 | return ERR_PTR(-ENOMEM); |
fd558d18 JC |
1704 | } |
1705 | EXPORT_SYMBOL_GPL(l2tp_session_create); | |
1706 | ||
1707 | /***************************************************************************** | |
1708 | * Init and cleanup | |
1709 | *****************************************************************************/ | |
1710 | ||
1711 | static __net_init int l2tp_init_net(struct net *net) | |
1712 | { | |
e773aaff | 1713 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
f7faffa3 | 1714 | int hash; |
fd558d18 | 1715 | |
fd558d18 | 1716 | INIT_LIST_HEAD(&pn->l2tp_tunnel_list); |
e02d494d | 1717 | spin_lock_init(&pn->l2tp_tunnel_list_lock); |
fd558d18 | 1718 | |
f7faffa3 JC |
1719 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
1720 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); | |
1721 | ||
e02d494d | 1722 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
f7faffa3 | 1723 | |
fd558d18 | 1724 | return 0; |
fd558d18 JC |
1725 | } |
1726 | ||
167eb17e TP |
1727 | static __net_exit void l2tp_exit_net(struct net *net) |
1728 | { | |
1729 | struct l2tp_net *pn = l2tp_pernet(net); | |
1730 | struct l2tp_tunnel *tunnel = NULL; | |
1e7af3b2 | 1731 | int hash; |
167eb17e TP |
1732 | |
1733 | rcu_read_lock_bh(); | |
1734 | list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { | |
4dc12ffe | 1735 | l2tp_tunnel_delete(tunnel); |
167eb17e TP |
1736 | } |
1737 | rcu_read_unlock_bh(); | |
2f86953e | 1738 | |
638a3a1e Y |
1739 | if (l2tp_wq) |
1740 | flush_workqueue(l2tp_wq); | |
2f86953e | 1741 | rcu_barrier(); |
1e7af3b2 VA |
1742 | |
1743 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) | |
1744 | WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash])); | |
167eb17e TP |
1745 | } |
1746 | ||
fd558d18 JC |
1747 | static struct pernet_operations l2tp_net_ops = { |
1748 | .init = l2tp_init_net, | |
167eb17e | 1749 | .exit = l2tp_exit_net, |
fd558d18 JC |
1750 | .id = &l2tp_net_id, |
1751 | .size = sizeof(struct l2tp_net), | |
1752 | }; | |
1753 | ||
1754 | static int __init l2tp_init(void) | |
1755 | { | |
1756 | int rc = 0; | |
1757 | ||
1758 | rc = register_pernet_device(&l2tp_net_ops); | |
1759 | if (rc) | |
1760 | goto out; | |
1761 | ||
59ff3eb6 | 1762 | l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); |
f8ccac0e TP |
1763 | if (!l2tp_wq) { |
1764 | pr_err("alloc_workqueue failed\n"); | |
67e04c29 | 1765 | unregister_pernet_device(&l2tp_net_ops); |
f8ccac0e TP |
1766 | rc = -ENOMEM; |
1767 | goto out; | |
1768 | } | |
1769 | ||
a4ca44fa | 1770 | pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); |
fd558d18 JC |
1771 | |
1772 | out: | |
1773 | return rc; | |
1774 | } | |
1775 | ||
1776 | static void __exit l2tp_exit(void) | |
1777 | { | |
1778 | unregister_pernet_device(&l2tp_net_ops); | |
f8ccac0e TP |
1779 | if (l2tp_wq) { |
1780 | destroy_workqueue(l2tp_wq); | |
1781 | l2tp_wq = NULL; | |
1782 | } | |
fd558d18 JC |
1783 | } |
1784 | ||
1785 | module_init(l2tp_init); | |
1786 | module_exit(l2tp_exit); | |
1787 | ||
1788 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
1789 | MODULE_DESCRIPTION("L2TP core"); | |
1790 | MODULE_LICENSE("GPL"); | |
1791 | MODULE_VERSION(L2TP_DRV_VERSION); |