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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" | |
6b7bdcd7 | 64 | #include "trace.h" |
fd558d18 | 65 | |
3f117d6f TP |
66 | #define CREATE_TRACE_POINTS |
67 | #include "trace.h" | |
68 | ||
fd558d18 JC |
69 | #define L2TP_DRV_VERSION "V2.0" |
70 | ||
71 | /* L2TP header constants */ | |
72 | #define L2TP_HDRFLAG_T 0x8000 | |
73 | #define L2TP_HDRFLAG_L 0x4000 | |
74 | #define L2TP_HDRFLAG_S 0x0800 | |
75 | #define L2TP_HDRFLAG_O 0x0200 | |
76 | #define L2TP_HDRFLAG_P 0x0100 | |
77 | ||
78 | #define L2TP_HDR_VER_MASK 0x000F | |
79 | #define L2TP_HDR_VER_2 0x0002 | |
f7faffa3 | 80 | #define L2TP_HDR_VER_3 0x0003 |
fd558d18 JC |
81 | |
82 | /* L2TPv3 default L2-specific sublayer */ | |
83 | #define L2TP_SLFLAG_S 0x40000000 | |
84 | #define L2TP_SL_SEQ_MASK 0x00ffffff | |
85 | ||
91c52470 | 86 | #define L2TP_HDR_SIZE_MAX 14 |
fd558d18 JC |
87 | |
88 | /* Default trace flags */ | |
89 | #define L2TP_DEFAULT_DEBUG_FLAGS 0 | |
90 | ||
fd558d18 JC |
91 | /* Private data stored for received packets in the skb. |
92 | */ | |
93 | struct l2tp_skb_cb { | |
f7faffa3 | 94 | u32 ns; |
fd558d18 JC |
95 | u16 has_seq; |
96 | u16 length; | |
97 | unsigned long expires; | |
98 | }; | |
99 | ||
efcd8c85 | 100 | #define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)]) |
fd558d18 | 101 | |
f8ccac0e | 102 | static struct workqueue_struct *l2tp_wq; |
fd558d18 JC |
103 | |
104 | /* per-net private data for this module */ | |
105 | static unsigned int l2tp_net_id; | |
106 | struct l2tp_net { | |
c4d48a58 CW |
107 | /* Lock for write access to l2tp_tunnel_idr */ |
108 | spinlock_t l2tp_tunnel_idr_lock; | |
109 | struct idr l2tp_tunnel_idr; | |
f7faffa3 | 110 | struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; |
20dcb110 | 111 | /* Lock for write access to l2tp_session_hlist */ |
e02d494d | 112 | spinlock_t l2tp_session_hlist_lock; |
fd558d18 JC |
113 | }; |
114 | ||
b954f940 PA |
115 | #if IS_ENABLED(CONFIG_IPV6) |
116 | static bool l2tp_sk_is_v6(struct sock *sk) | |
117 | { | |
118 | return sk->sk_family == PF_INET6 && | |
119 | !ipv6_addr_v4mapped(&sk->sk_v6_daddr); | |
120 | } | |
121 | #endif | |
fc130840 | 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)]; | |
f7faffa3 JC |
137 | } |
138 | ||
fd558d18 JC |
139 | /* Session hash list. |
140 | * The session_id SHOULD be random according to RFC2661, but several | |
141 | * L2TP implementations (Cisco and Microsoft) use incrementing | |
142 | * session_ids. So we do a real hash on the session_id, rather than a | |
143 | * simple bitmask. | |
144 | */ | |
145 | static inline struct hlist_head * | |
146 | l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) | |
147 | { | |
148 | return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; | |
149 | } | |
150 | ||
52016e25 | 151 | static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) |
d00fa9ad | 152 | { |
6b7bdcd7 | 153 | trace_free_tunnel(tunnel); |
d00fa9ad JC |
154 | sock_put(tunnel->sock); |
155 | /* the tunnel is freed in the socket destructor */ | |
156 | } | |
52016e25 TP |
157 | |
158 | static void l2tp_session_free(struct l2tp_session *session) | |
159 | { | |
6b7bdcd7 | 160 | trace_free_session(session); |
45faeff1 TP |
161 | if (session->tunnel) |
162 | l2tp_tunnel_dec_refcount(session->tunnel); | |
163 | kfree(session); | |
164 | } | |
6b7bdcd7 | 165 | |
45faeff1 TP |
166 | struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk) |
167 | { | |
168 | struct l2tp_tunnel *tunnel = sk->sk_user_data; | |
169 | ||
170 | if (tunnel) | |
52016e25 | 171 | if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) |
45faeff1 | 172 | return NULL; |
52016e25 | 173 | |
45faeff1 | 174 | return tunnel; |
52016e25 | 175 | } |
45faeff1 | 176 | EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel); |
52016e25 TP |
177 | |
178 | void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) | |
179 | { | |
180 | refcount_inc(&tunnel->ref_count); | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount); | |
183 | ||
184 | void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) | |
185 | { | |
186 | if (refcount_dec_and_test(&tunnel->ref_count)) | |
187 | l2tp_tunnel_free(tunnel); | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount); | |
190 | ||
191 | void l2tp_session_inc_refcount(struct l2tp_session *session) | |
192 | { | |
193 | refcount_inc(&session->ref_count); | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount); | |
196 | ||
197 | void l2tp_session_dec_refcount(struct l2tp_session *session) | |
198 | { | |
199 | if (refcount_dec_and_test(&session->ref_count)) | |
200 | l2tp_session_free(session); | |
201 | } | |
202 | EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount); | |
d00fa9ad | 203 | |
54652eb1 GN |
204 | /* Lookup a tunnel. A new reference is held on the returned tunnel. */ |
205 | struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) | |
206 | { | |
207 | const struct l2tp_net *pn = l2tp_pernet(net); | |
208 | struct l2tp_tunnel *tunnel; | |
209 | ||
210 | rcu_read_lock_bh(); | |
c4d48a58 CW |
211 | tunnel = idr_find(&pn->l2tp_tunnel_idr, tunnel_id); |
212 | if (tunnel && refcount_inc_not_zero(&tunnel->ref_count)) { | |
213 | rcu_read_unlock_bh(); | |
214 | return tunnel; | |
54652eb1 GN |
215 | } |
216 | rcu_read_unlock_bh(); | |
217 | ||
218 | return NULL; | |
219 | } | |
220 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get); | |
221 | ||
5846c131 GN |
222 | struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth) |
223 | { | |
c4d48a58 CW |
224 | struct l2tp_net *pn = l2tp_pernet(net); |
225 | unsigned long tunnel_id, tmp; | |
5846c131 GN |
226 | struct l2tp_tunnel *tunnel; |
227 | int count = 0; | |
228 | ||
229 | rcu_read_lock_bh(); | |
c4d48a58 CW |
230 | idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { |
231 | if (tunnel && ++count > nth && | |
a622b400 | 232 | refcount_inc_not_zero(&tunnel->ref_count)) { |
5846c131 GN |
233 | rcu_read_unlock_bh(); |
234 | return tunnel; | |
235 | } | |
236 | } | |
237 | rcu_read_unlock_bh(); | |
238 | ||
239 | return NULL; | |
240 | } | |
241 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth); | |
242 | ||
01e28b92 GN |
243 | struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, |
244 | u32 session_id) | |
61b9a047 GN |
245 | { |
246 | struct hlist_head *session_list; | |
247 | struct l2tp_session *session; | |
248 | ||
01e28b92 | 249 | session_list = l2tp_session_id_hash(tunnel, session_id); |
61b9a047 | 250 | |
07b8ca37 TP |
251 | rcu_read_lock_bh(); |
252 | hlist_for_each_entry_rcu(session, session_list, hlist) | |
01e28b92 GN |
253 | if (session->session_id == session_id) { |
254 | l2tp_session_inc_refcount(session); | |
07b8ca37 | 255 | rcu_read_unlock_bh(); |
61b9a047 | 256 | |
01e28b92 | 257 | return session; |
61b9a047 | 258 | } |
07b8ca37 | 259 | rcu_read_unlock_bh(); |
61b9a047 | 260 | |
01e28b92 GN |
261 | return NULL; |
262 | } | |
263 | EXPORT_SYMBOL_GPL(l2tp_tunnel_get_session); | |
61b9a047 | 264 | |
01e28b92 GN |
265 | struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id) |
266 | { | |
267 | struct hlist_head *session_list; | |
268 | struct l2tp_session *session; | |
269 | ||
270 | session_list = l2tp_session_id_hash_2(l2tp_pernet(net), session_id); | |
271 | ||
272 | rcu_read_lock_bh(); | |
273 | hlist_for_each_entry_rcu(session, session_list, global_hlist) | |
61b9a047 GN |
274 | if (session->session_id == session_id) { |
275 | l2tp_session_inc_refcount(session); | |
01e28b92 | 276 | rcu_read_unlock_bh(); |
61b9a047 GN |
277 | |
278 | return session; | |
279 | } | |
01e28b92 | 280 | rcu_read_unlock_bh(); |
61b9a047 GN |
281 | |
282 | return NULL; | |
283 | } | |
284 | EXPORT_SYMBOL_GPL(l2tp_session_get); | |
285 | ||
a4346210 | 286 | struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth) |
fd558d18 JC |
287 | { |
288 | int hash; | |
fd558d18 JC |
289 | struct l2tp_session *session; |
290 | int count = 0; | |
291 | ||
07b8ca37 | 292 | rcu_read_lock_bh(); |
fd558d18 | 293 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
07b8ca37 | 294 | hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { |
fd558d18 | 295 | if (++count > nth) { |
e08293a4 | 296 | l2tp_session_inc_refcount(session); |
07b8ca37 | 297 | rcu_read_unlock_bh(); |
fd558d18 JC |
298 | return session; |
299 | } | |
300 | } | |
301 | } | |
302 | ||
07b8ca37 | 303 | rcu_read_unlock_bh(); |
fd558d18 JC |
304 | |
305 | return NULL; | |
306 | } | |
e08293a4 | 307 | EXPORT_SYMBOL_GPL(l2tp_session_get_nth); |
fd558d18 | 308 | |
309795f4 JC |
309 | /* Lookup a session by interface name. |
310 | * This is very inefficient but is only used by management interfaces. | |
311 | */ | |
9aaef50c | 312 | struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, |
a4346210 | 313 | const char *ifname) |
309795f4 JC |
314 | { |
315 | struct l2tp_net *pn = l2tp_pernet(net); | |
316 | int hash; | |
309795f4 JC |
317 | struct l2tp_session *session; |
318 | ||
e02d494d | 319 | rcu_read_lock_bh(); |
309795f4 | 320 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { |
b67bfe0d | 321 | hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) { |
309795f4 | 322 | if (!strcmp(session->ifname, ifname)) { |
2777e2ab | 323 | l2tp_session_inc_refcount(session); |
e02d494d | 324 | rcu_read_unlock_bh(); |
2777e2ab | 325 | |
309795f4 JC |
326 | return session; |
327 | } | |
328 | } | |
329 | } | |
330 | ||
e02d494d | 331 | rcu_read_unlock_bh(); |
309795f4 JC |
332 | |
333 | return NULL; | |
334 | } | |
2777e2ab | 335 | EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); |
309795f4 | 336 | |
3953ae7b GN |
337 | int l2tp_session_register(struct l2tp_session *session, |
338 | struct l2tp_tunnel *tunnel) | |
dbdbc73b GN |
339 | { |
340 | struct l2tp_session *session_walk; | |
341 | struct hlist_head *g_head; | |
342 | struct hlist_head *head; | |
343 | struct l2tp_net *pn; | |
f3c66d4e | 344 | int err; |
dbdbc73b GN |
345 | |
346 | head = l2tp_session_id_hash(tunnel, session->session_id); | |
347 | ||
07b8ca37 | 348 | spin_lock_bh(&tunnel->hlist_lock); |
f3c66d4e GN |
349 | if (!tunnel->acpt_newsess) { |
350 | err = -ENODEV; | |
351 | goto err_tlock; | |
352 | } | |
353 | ||
dbdbc73b | 354 | hlist_for_each_entry(session_walk, head, hlist) |
f3c66d4e GN |
355 | if (session_walk->session_id == session->session_id) { |
356 | err = -EEXIST; | |
357 | goto err_tlock; | |
358 | } | |
dbdbc73b GN |
359 | |
360 | if (tunnel->version == L2TP_HDR_VER_3) { | |
361 | pn = l2tp_pernet(tunnel->l2tp_net); | |
363a341d | 362 | g_head = l2tp_session_id_hash_2(pn, session->session_id); |
dbdbc73b GN |
363 | |
364 | spin_lock_bh(&pn->l2tp_session_hlist_lock); | |
f3c66d4e | 365 | |
0d0d9a38 RK |
366 | /* IP encap expects session IDs to be globally unique, while |
367 | * UDP encap doesn't. | |
368 | */ | |
dbdbc73b | 369 | hlist_for_each_entry(session_walk, g_head, global_hlist) |
0d0d9a38 RK |
370 | if (session_walk->session_id == session->session_id && |
371 | (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || | |
372 | tunnel->encap == L2TP_ENCAPTYPE_IP)) { | |
f3c66d4e GN |
373 | err = -EEXIST; |
374 | goto err_tlock_pnlock; | |
375 | } | |
dbdbc73b | 376 | |
f3c66d4e | 377 | l2tp_tunnel_inc_refcount(tunnel); |
dbdbc73b | 378 | hlist_add_head_rcu(&session->global_hlist, g_head); |
f3c66d4e | 379 | |
dbdbc73b | 380 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e GN |
381 | } else { |
382 | l2tp_tunnel_inc_refcount(tunnel); | |
dbdbc73b GN |
383 | } |
384 | ||
07b8ca37 TP |
385 | hlist_add_head_rcu(&session->hlist, head); |
386 | spin_unlock_bh(&tunnel->hlist_lock); | |
dbdbc73b | 387 | |
6b7bdcd7 TP |
388 | trace_register_session(session); |
389 | ||
dbdbc73b GN |
390 | return 0; |
391 | ||
f3c66d4e | 392 | err_tlock_pnlock: |
dbdbc73b | 393 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); |
f3c66d4e | 394 | err_tlock: |
07b8ca37 | 395 | spin_unlock_bh(&tunnel->hlist_lock); |
dbdbc73b | 396 | |
f3c66d4e | 397 | return err; |
dbdbc73b | 398 | } |
3953ae7b | 399 | EXPORT_SYMBOL_GPL(l2tp_session_register); |
dbdbc73b | 400 | |
fd558d18 JC |
401 | /***************************************************************************** |
402 | * Receive data handling | |
403 | *****************************************************************************/ | |
404 | ||
405 | /* Queue a skb in order. We come here only if the skb has an L2TP sequence | |
406 | * number. | |
407 | */ | |
408 | static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
409 | { | |
410 | struct sk_buff *skbp; | |
411 | struct sk_buff *tmp; | |
f7faffa3 | 412 | u32 ns = L2TP_SKB_CB(skb)->ns; |
fd558d18 JC |
413 | |
414 | spin_lock_bh(&session->reorder_q.lock); | |
415 | skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { | |
416 | if (L2TP_SKB_CB(skbp)->ns > ns) { | |
417 | __skb_queue_before(&session->reorder_q, skbp, skb); | |
7b7c0719 | 418 | atomic_long_inc(&session->stats.rx_oos_packets); |
fd558d18 JC |
419 | goto out; |
420 | } | |
421 | } | |
422 | ||
423 | __skb_queue_tail(&session->reorder_q, skb); | |
424 | ||
425 | out: | |
426 | spin_unlock_bh(&session->reorder_q.lock); | |
427 | } | |
428 | ||
429 | /* Dequeue a single skb. | |
430 | */ | |
431 | static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) | |
432 | { | |
433 | struct l2tp_tunnel *tunnel = session->tunnel; | |
434 | int length = L2TP_SKB_CB(skb)->length; | |
435 | ||
436 | /* We're about to requeue the skb, so return resources | |
437 | * to its current owner (a socket receive buffer). | |
438 | */ | |
439 | skb_orphan(skb); | |
440 | ||
7b7c0719 TP |
441 | atomic_long_inc(&tunnel->stats.rx_packets); |
442 | atomic_long_add(length, &tunnel->stats.rx_bytes); | |
443 | atomic_long_inc(&session->stats.rx_packets); | |
444 | atomic_long_add(length, &session->stats.rx_bytes); | |
fd558d18 JC |
445 | |
446 | if (L2TP_SKB_CB(skb)->has_seq) { | |
447 | /* Bump our Nr */ | |
448 | session->nr++; | |
8a1631d5 | 449 | session->nr &= session->nr_max; |
6b7bdcd7 | 450 | trace_session_seqnum_update(session); |
fd558d18 JC |
451 | } |
452 | ||
453 | /* call private receive handler */ | |
0febc7b3 | 454 | if (session->recv_skb) |
fd558d18 JC |
455 | (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); |
456 | else | |
457 | kfree_skb(skb); | |
fd558d18 JC |
458 | } |
459 | ||
460 | /* Dequeue skbs from the session's reorder_q, subject to packet order. | |
461 | * Skbs that have been in the queue for too long are simply discarded. | |
462 | */ | |
463 | static void l2tp_recv_dequeue(struct l2tp_session *session) | |
464 | { | |
465 | struct sk_buff *skb; | |
466 | struct sk_buff *tmp; | |
467 | ||
468 | /* If the pkt at the head of the queue has the nr that we | |
469 | * expect to send up next, dequeue it and any other | |
470 | * in-sequence packets behind it. | |
471 | */ | |
e2e210c0 | 472 | start: |
fd558d18 JC |
473 | spin_lock_bh(&session->reorder_q.lock); |
474 | skb_queue_walk_safe(&session->reorder_q, skb, tmp) { | |
6b7bdcd7 TP |
475 | struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); |
476 | ||
477 | /* If the packet has been pending on the queue for too long, discard it */ | |
478 | if (time_after(jiffies, cb->expires)) { | |
7b7c0719 TP |
479 | atomic_long_inc(&session->stats.rx_seq_discards); |
480 | atomic_long_inc(&session->stats.rx_errors); | |
6b7bdcd7 | 481 | trace_session_pkt_expired(session, cb->ns); |
38d40b3f | 482 | session->reorder_skip = 1; |
fd558d18 JC |
483 | __skb_unlink(skb, &session->reorder_q); |
484 | kfree_skb(skb); | |
fd558d18 JC |
485 | continue; |
486 | } | |
487 | ||
6b7bdcd7 | 488 | if (cb->has_seq) { |
38d40b3f | 489 | if (session->reorder_skip) { |
38d40b3f | 490 | session->reorder_skip = 0; |
6b7bdcd7 TP |
491 | session->nr = cb->ns; |
492 | trace_session_seqnum_reset(session); | |
38d40b3f | 493 | } |
6b7bdcd7 | 494 | if (cb->ns != session->nr) |
fd558d18 | 495 | goto out; |
fd558d18 JC |
496 | } |
497 | __skb_unlink(skb, &session->reorder_q); | |
498 | ||
499 | /* Process the skb. We release the queue lock while we | |
500 | * do so to let other contexts process the queue. | |
501 | */ | |
502 | spin_unlock_bh(&session->reorder_q.lock); | |
503 | l2tp_recv_dequeue_skb(session, skb); | |
e2e210c0 | 504 | goto start; |
fd558d18 JC |
505 | } |
506 | ||
507 | out: | |
508 | spin_unlock_bh(&session->reorder_q.lock); | |
509 | } | |
510 | ||
8a1631d5 JC |
511 | static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) |
512 | { | |
513 | u32 nws; | |
514 | ||
515 | if (nr >= session->nr) | |
516 | nws = nr - session->nr; | |
517 | else | |
518 | nws = (session->nr_max + 1) - (session->nr - nr); | |
519 | ||
520 | return nws < session->nr_window_size; | |
521 | } | |
522 | ||
b6dc01a4 JC |
523 | /* If packet has sequence numbers, queue it if acceptable. Returns 0 if |
524 | * acceptable, else non-zero. | |
525 | */ | |
526 | static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) | |
527 | { | |
6b7bdcd7 TP |
528 | struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); |
529 | ||
530 | if (!l2tp_seq_check_rx_window(session, cb->ns)) { | |
8a1631d5 JC |
531 | /* Packet sequence number is outside allowed window. |
532 | * Discard it. | |
533 | */ | |
6b7bdcd7 | 534 | trace_session_pkt_outside_rx_window(session, cb->ns); |
8a1631d5 JC |
535 | goto discard; |
536 | } | |
537 | ||
b6dc01a4 JC |
538 | if (session->reorder_timeout != 0) { |
539 | /* Packet reordering enabled. Add skb to session's | |
540 | * reorder queue, in order of ns. | |
541 | */ | |
542 | l2tp_recv_queue_skb(session, skb); | |
a0dbd822 JC |
543 | goto out; |
544 | } | |
545 | ||
546 | /* Packet reordering disabled. Discard out-of-sequence packets, while | |
547 | * tracking the number if in-sequence packets after the first OOS packet | |
548 | * is seen. After nr_oos_count_max in-sequence packets, reset the | |
549 | * sequence number to re-enable packet reception. | |
550 | */ | |
6b7bdcd7 | 551 | if (cb->ns == session->nr) { |
a0dbd822 | 552 | skb_queue_tail(&session->reorder_q, skb); |
b6dc01a4 | 553 | } else { |
6b7bdcd7 | 554 | u32 nr_oos = cb->ns; |
a0dbd822 JC |
555 | u32 nr_next = (session->nr_oos + 1) & session->nr_max; |
556 | ||
557 | if (nr_oos == nr_next) | |
558 | session->nr_oos_count++; | |
559 | else | |
560 | session->nr_oos_count = 0; | |
561 | ||
562 | session->nr_oos = nr_oos; | |
563 | if (session->nr_oos_count > session->nr_oos_count_max) { | |
564 | session->reorder_skip = 1; | |
a0dbd822 JC |
565 | } |
566 | if (!session->reorder_skip) { | |
b6dc01a4 | 567 | atomic_long_inc(&session->stats.rx_seq_discards); |
6b7bdcd7 | 568 | trace_session_pkt_oos(session, cb->ns); |
b6dc01a4 JC |
569 | goto discard; |
570 | } | |
571 | skb_queue_tail(&session->reorder_q, skb); | |
572 | } | |
573 | ||
a0dbd822 | 574 | out: |
b6dc01a4 JC |
575 | return 0; |
576 | ||
577 | discard: | |
578 | return 1; | |
579 | } | |
580 | ||
f7faffa3 JC |
581 | /* Do receive processing of L2TP data frames. We handle both L2TPv2 |
582 | * and L2TPv3 data frames here. | |
583 | * | |
584 | * L2TPv2 Data Message Header | |
585 | * | |
586 | * 0 1 2 3 | |
587 | * 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 | |
588 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
589 | * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | | |
590 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
591 | * | Tunnel ID | Session ID | | |
592 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
593 | * | Ns (opt) | Nr (opt) | | |
594 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
595 | * | Offset Size (opt) | Offset pad... (opt) | |
596 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
597 | * | |
598 | * Data frames are marked by T=0. All other fields are the same as | |
599 | * those in L2TP control frames. | |
600 | * | |
601 | * L2TPv3 Data Message Header | |
602 | * | |
603 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
604 | * | L2TP Session Header | | |
605 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
606 | * | L2-Specific Sublayer | | |
607 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
608 | * | Tunnel Payload ... | |
609 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
610 | * | |
611 | * L2TPv3 Session Header Over IP | |
612 | * | |
613 | * 0 1 2 3 | |
614 | * 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 | |
615 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
616 | * | Session ID | | |
617 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
618 | * | Cookie (optional, maximum 64 bits)... | |
619 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
620 | * | | |
621 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
622 | * | |
623 | * L2TPv3 L2-Specific Sublayer Format | |
624 | * | |
625 | * 0 1 2 3 | |
626 | * 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 | |
627 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
628 | * |x|S|x|x|x|x|x|x| Sequence Number | | |
629 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |
630 | * | |
23fe846f GN |
631 | * Cookie value and sublayer format are negotiated with the peer when |
632 | * the session is set up. Unlike L2TPv2, we do not need to parse the | |
633 | * packet header to determine if optional fields are present. | |
f7faffa3 JC |
634 | * |
635 | * Caller must already have parsed the frame and determined that it is | |
636 | * a data (not control) frame before coming here. Fields up to the | |
637 | * session-id have already been parsed and ptr points to the data | |
638 | * after the session-id. | |
fd558d18 | 639 | */ |
f7faffa3 JC |
640 | void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
641 | unsigned char *ptr, unsigned char *optr, u16 hdrflags, | |
2b139e6b | 642 | int length) |
fd558d18 | 643 | { |
f7faffa3 | 644 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 645 | int offset; |
fd558d18 | 646 | |
f7faffa3 JC |
647 | /* Parse and check optional cookie */ |
648 | if (session->peer_cookie_len > 0) { | |
649 | if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { | |
3e59e885 MS |
650 | pr_debug_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n", |
651 | tunnel->name, tunnel->tunnel_id, | |
652 | session->session_id); | |
7b7c0719 | 653 | atomic_long_inc(&session->stats.rx_cookie_discards); |
f7faffa3 JC |
654 | goto discard; |
655 | } | |
656 | ptr += session->peer_cookie_len; | |
657 | } | |
658 | ||
fd558d18 JC |
659 | /* Handle the optional sequence numbers. Sequence numbers are |
660 | * in different places for L2TPv2 and L2TPv3. | |
661 | * | |
662 | * If we are the LAC, enable/disable sequence numbers under | |
663 | * the control of the LNS. If no sequence numbers present but | |
664 | * we were expecting them, discard frame. | |
665 | */ | |
fd558d18 | 666 | L2TP_SKB_CB(skb)->has_seq = 0; |
f7faffa3 JC |
667 | if (tunnel->version == L2TP_HDR_VER_2) { |
668 | if (hdrflags & L2TP_HDRFLAG_S) { | |
f7faffa3 | 669 | /* Store L2TP info in the skb */ |
12923365 | 670 | L2TP_SKB_CB(skb)->ns = ntohs(*(__be16 *)ptr); |
f7faffa3 | 671 | L2TP_SKB_CB(skb)->has_seq = 1; |
12923365 TP |
672 | ptr += 2; |
673 | /* Skip past nr in the header */ | |
674 | ptr += 2; | |
fd558d18 | 675 | |
f7faffa3 JC |
676 | } |
677 | } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { | |
b71a61cc | 678 | u32 l2h = ntohl(*(__be32 *)ptr); |
f7faffa3 JC |
679 | |
680 | if (l2h & 0x40000000) { | |
f7faffa3 | 681 | /* Store L2TP info in the skb */ |
12923365 | 682 | L2TP_SKB_CB(skb)->ns = l2h & 0x00ffffff; |
f7faffa3 | 683 | L2TP_SKB_CB(skb)->has_seq = 1; |
f7faffa3 | 684 | } |
62e7b6a5 | 685 | ptr += 4; |
fd558d18 JC |
686 | } |
687 | ||
688 | if (L2TP_SKB_CB(skb)->has_seq) { | |
20dcb110 | 689 | /* Received a packet with sequence numbers. If we're the LAC, |
fd558d18 JC |
690 | * check if we sre sending sequence numbers and if not, |
691 | * configure it so. | |
692 | */ | |
6c0ec37b | 693 | if (!session->lns_mode && !session->send_seq) { |
6b7bdcd7 | 694 | trace_session_seqnum_lns_enable(session); |
3f9b9770 | 695 | session->send_seq = 1; |
f7faffa3 | 696 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 JC |
697 | } |
698 | } else { | |
699 | /* No sequence numbers. | |
700 | * If user has configured mandatory sequence numbers, discard. | |
701 | */ | |
702 | if (session->recv_seq) { | |
3e59e885 MS |
703 | pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", |
704 | session->name); | |
7b7c0719 | 705 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
706 | goto discard; |
707 | } | |
708 | ||
709 | /* If we're the LAC and we're sending sequence numbers, the | |
710 | * LNS has requested that we no longer send sequence numbers. | |
711 | * If we're the LNS and we're sending sequence numbers, the | |
712 | * LAC is broken. Discard the frame. | |
713 | */ | |
6c0ec37b | 714 | if (!session->lns_mode && session->send_seq) { |
6b7bdcd7 | 715 | trace_session_seqnum_lns_disable(session); |
fd558d18 | 716 | session->send_seq = 0; |
f7faffa3 | 717 | l2tp_session_set_header_len(session, tunnel->version); |
fd558d18 | 718 | } else if (session->send_seq) { |
3e59e885 MS |
719 | pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", |
720 | session->name); | |
7b7c0719 | 721 | atomic_long_inc(&session->stats.rx_seq_discards); |
fd558d18 JC |
722 | goto discard; |
723 | } | |
724 | } | |
725 | ||
900631ee JC |
726 | /* Session data offset is defined only for L2TPv2 and is |
727 | * indicated by an optional 16-bit value in the header. | |
f7faffa3 JC |
728 | */ |
729 | if (tunnel->version == L2TP_HDR_VER_2) { | |
730 | /* If offset bit set, skip it. */ | |
731 | if (hdrflags & L2TP_HDRFLAG_O) { | |
732 | offset = ntohs(*(__be16 *)ptr); | |
733 | ptr += 2 + offset; | |
734 | } | |
900631ee | 735 | } |
fd558d18 JC |
736 | |
737 | offset = ptr - optr; | |
738 | if (!pskb_may_pull(skb, offset)) | |
739 | goto discard; | |
740 | ||
741 | __skb_pull(skb, offset); | |
742 | ||
fd558d18 JC |
743 | /* Prepare skb for adding to the session's reorder_q. Hold |
744 | * packets for max reorder_timeout or 1 second if not | |
745 | * reordering. | |
746 | */ | |
747 | L2TP_SKB_CB(skb)->length = length; | |
748 | L2TP_SKB_CB(skb)->expires = jiffies + | |
749 | (session->reorder_timeout ? session->reorder_timeout : HZ); | |
750 | ||
751 | /* Add packet to the session's receive queue. Reordering is done here, if | |
752 | * enabled. Saved L2TP protocol info is stored in skb->sb[]. | |
753 | */ | |
754 | if (L2TP_SKB_CB(skb)->has_seq) { | |
b6dc01a4 JC |
755 | if (l2tp_recv_data_seq(session, skb)) |
756 | goto discard; | |
fd558d18 JC |
757 | } else { |
758 | /* No sequence numbers. Add the skb to the tail of the | |
759 | * reorder queue. This ensures that it will be | |
760 | * delivered after all previous sequenced skbs. | |
761 | */ | |
762 | skb_queue_tail(&session->reorder_q, skb); | |
763 | } | |
764 | ||
765 | /* Try to dequeue as many skbs from reorder_q as we can. */ | |
766 | l2tp_recv_dequeue(session); | |
767 | ||
f7faffa3 | 768 | return; |
fd558d18 JC |
769 | |
770 | discard: | |
7b7c0719 | 771 | atomic_long_inc(&session->stats.rx_errors); |
fd558d18 | 772 | kfree_skb(skb); |
f7faffa3 | 773 | } |
ca7885db | 774 | EXPORT_SYMBOL_GPL(l2tp_recv_common); |
f7faffa3 | 775 | |
48f72f92 TP |
776 | /* Drop skbs from the session's reorder_q |
777 | */ | |
493048f5 | 778 | static void l2tp_session_queue_purge(struct l2tp_session *session) |
48f72f92 TP |
779 | { |
780 | struct sk_buff *skb = NULL; | |
b71a61cc | 781 | |
48f72f92 TP |
782 | while ((skb = skb_dequeue(&session->reorder_q))) { |
783 | atomic_long_inc(&session->stats.rx_errors); | |
784 | kfree_skb(skb); | |
48f72f92 | 785 | } |
48f72f92 | 786 | } |
48f72f92 | 787 | |
f7faffa3 JC |
788 | /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame |
789 | * here. The skb is not on a list when we get here. | |
790 | * Returns 0 if the packet was a data packet and was successfully passed on. | |
791 | * Returns 1 if the packet was not a good data packet and could not be | |
792 | * forwarded. All such packets are passed up to userspace to deal with. | |
793 | */ | |
2b139e6b | 794 | static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) |
f7faffa3 JC |
795 | { |
796 | struct l2tp_session *session = NULL; | |
628bc3e5 | 797 | struct l2tp_tunnel *orig_tunnel = tunnel; |
f7faffa3 JC |
798 | unsigned char *ptr, *optr; |
799 | u16 hdrflags; | |
800 | u32 tunnel_id, session_id; | |
f7faffa3 JC |
801 | u16 version; |
802 | int length; | |
803 | ||
aa785f93 | 804 | /* UDP has verified checksum */ |
f7faffa3 JC |
805 | |
806 | /* UDP always verifies the packet length. */ | |
807 | __skb_pull(skb, sizeof(struct udphdr)); | |
808 | ||
809 | /* Short packet? */ | |
91c52470 | 810 | if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { |
3e59e885 MS |
811 | pr_debug_ratelimited("%s: recv short packet (len=%d)\n", |
812 | tunnel->name, skb->len); | |
813 | goto invalid; | |
f7faffa3 JC |
814 | } |
815 | ||
e50e705c | 816 | /* Point to L2TP header */ |
95075150 TP |
817 | optr = skb->data; |
818 | ptr = skb->data; | |
e50e705c | 819 | |
f7faffa3 | 820 | /* Get L2TP header flags */ |
b71a61cc | 821 | hdrflags = ntohs(*(__be16 *)ptr); |
f7faffa3 JC |
822 | |
823 | /* Check protocol version */ | |
824 | version = hdrflags & L2TP_HDR_VER_MASK; | |
825 | if (version != tunnel->version) { | |
3e59e885 MS |
826 | pr_debug_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n", |
827 | tunnel->name, version, tunnel->version); | |
828 | goto invalid; | |
f7faffa3 JC |
829 | } |
830 | ||
831 | /* Get length of L2TP packet */ | |
832 | length = skb->len; | |
833 | ||
834 | /* If type is control packet, it is handled by userspace. */ | |
12923365 | 835 | if (hdrflags & L2TP_HDRFLAG_T) |
3e59e885 | 836 | goto pass; |
f7faffa3 JC |
837 | |
838 | /* Skip flags */ | |
839 | ptr += 2; | |
840 | ||
841 | if (tunnel->version == L2TP_HDR_VER_2) { | |
842 | /* If length is present, skip it */ | |
843 | if (hdrflags & L2TP_HDRFLAG_L) | |
844 | ptr += 2; | |
845 | ||
846 | /* Extract tunnel and session ID */ | |
b71a61cc | 847 | tunnel_id = ntohs(*(__be16 *)ptr); |
f7faffa3 | 848 | ptr += 2; |
628bc3e5 ST |
849 | |
850 | if (tunnel_id != tunnel->tunnel_id) { | |
851 | /* We are receiving trafic for another tunnel, probably | |
852 | * because we have several tunnels between the same | |
853 | * IP/port quadruple, look it up. | |
854 | */ | |
855 | struct l2tp_tunnel *alt_tunnel; | |
856 | ||
857 | alt_tunnel = l2tp_tunnel_get(tunnel->l2tp_net, tunnel_id); | |
858 | if (!alt_tunnel || alt_tunnel->version != L2TP_HDR_VER_2) | |
859 | goto pass; | |
860 | tunnel = alt_tunnel; | |
861 | } | |
862 | ||
b71a61cc | 863 | session_id = ntohs(*(__be16 *)ptr); |
f7faffa3 JC |
864 | ptr += 2; |
865 | } else { | |
866 | ptr += 2; /* skip reserved bits */ | |
867 | tunnel_id = tunnel->tunnel_id; | |
b71a61cc | 868 | session_id = ntohl(*(__be32 *)ptr); |
f7faffa3 JC |
869 | ptr += 4; |
870 | } | |
871 | ||
872 | /* Find the session context */ | |
01e28b92 | 873 | session = l2tp_tunnel_get_session(tunnel, session_id); |
309795f4 | 874 | if (!session || !session->recv_skb) { |
a4346210 | 875 | if (session) |
61b9a047 | 876 | l2tp_session_dec_refcount(session); |
61b9a047 | 877 | |
f7faffa3 | 878 | /* Not found? Pass to userspace to deal with */ |
3e59e885 MS |
879 | pr_debug_ratelimited("%s: no session found (%u/%u). Passing up.\n", |
880 | tunnel->name, tunnel_id, session_id); | |
881 | goto pass; | |
f7faffa3 JC |
882 | } |
883 | ||
4522a70d | 884 | if (tunnel->version == L2TP_HDR_VER_3 && |
9b6ff7eb XY |
885 | l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) { |
886 | l2tp_session_dec_refcount(session); | |
3e59e885 | 887 | goto invalid; |
9b6ff7eb | 888 | } |
4522a70d | 889 | |
2b139e6b | 890 | l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); |
61b9a047 | 891 | l2tp_session_dec_refcount(session); |
fd558d18 | 892 | |
628bc3e5 ST |
893 | if (tunnel != orig_tunnel) |
894 | l2tp_tunnel_dec_refcount(tunnel); | |
895 | ||
fd558d18 JC |
896 | return 0; |
897 | ||
3e59e885 MS |
898 | invalid: |
899 | atomic_long_inc(&tunnel->stats.rx_invalid); | |
900 | ||
901 | pass: | |
fd558d18 JC |
902 | /* Put UDP header back */ |
903 | __skb_push(skb, sizeof(struct udphdr)); | |
904 | ||
628bc3e5 ST |
905 | if (tunnel != orig_tunnel) |
906 | l2tp_tunnel_dec_refcount(tunnel); | |
907 | ||
fd558d18 JC |
908 | return 1; |
909 | } | |
fd558d18 JC |
910 | |
911 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. | |
912 | * Return codes: | |
913 | * 0 : success. | |
914 | * <0: error | |
915 | * >0: skb should be passed up to userspace as UDP. | |
916 | */ | |
917 | int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) | |
918 | { | |
919 | struct l2tp_tunnel *tunnel; | |
920 | ||
45faeff1 TP |
921 | /* Note that this is called from the encap_rcv hook inside an |
922 | * RCU-protected region, but without the socket being locked. | |
923 | * Hence we use rcu_dereference_sk_user_data to access the | |
924 | * tunnel data structure rather the usual l2tp_sk_to_tunnel | |
925 | * accessor function. | |
926 | */ | |
c1c47721 | 927 | tunnel = rcu_dereference_sk_user_data(sk); |
0febc7b3 | 928 | if (!tunnel) |
fd558d18 | 929 | goto pass_up; |
45faeff1 TP |
930 | if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) |
931 | goto pass_up; | |
fd558d18 | 932 | |
2b139e6b | 933 | if (l2tp_udp_recv_core(tunnel, skb)) |
d00fa9ad | 934 | goto pass_up; |
fd558d18 | 935 | |
fd558d18 JC |
936 | return 0; |
937 | ||
fd558d18 JC |
938 | pass_up: |
939 | return 1; | |
940 | } | |
941 | EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); | |
942 | ||
943 | /************************************************************************ | |
944 | * Transmit handling | |
945 | ***********************************************************************/ | |
946 | ||
947 | /* Build an L2TP header for the session into the buffer provided. | |
948 | */ | |
f7faffa3 | 949 | static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) |
fd558d18 | 950 | { |
f7faffa3 | 951 | struct l2tp_tunnel *tunnel = session->tunnel; |
fd558d18 | 952 | __be16 *bufp = buf; |
f7faffa3 | 953 | __be16 *optr = buf; |
fd558d18 JC |
954 | u16 flags = L2TP_HDR_VER_2; |
955 | u32 tunnel_id = tunnel->peer_tunnel_id; | |
956 | u32 session_id = session->peer_session_id; | |
957 | ||
958 | if (session->send_seq) | |
959 | flags |= L2TP_HDRFLAG_S; | |
960 | ||
961 | /* Setup L2TP header. */ | |
962 | *bufp++ = htons(flags); | |
963 | *bufp++ = htons(tunnel_id); | |
964 | *bufp++ = htons(session_id); | |
965 | if (session->send_seq) { | |
966 | *bufp++ = htons(session->ns); | |
967 | *bufp++ = 0; | |
968 | session->ns++; | |
f7faffa3 | 969 | session->ns &= 0xffff; |
6b7bdcd7 | 970 | trace_session_seqnum_update(session); |
fd558d18 | 971 | } |
f7faffa3 JC |
972 | |
973 | return bufp - optr; | |
fd558d18 JC |
974 | } |
975 | ||
f7faffa3 | 976 | static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) |
fd558d18 | 977 | { |
0d76751f | 978 | struct l2tp_tunnel *tunnel = session->tunnel; |
f7faffa3 JC |
979 | char *bufp = buf; |
980 | char *optr = bufp; | |
f7faffa3 | 981 | |
0d76751f JC |
982 | /* Setup L2TP header. The header differs slightly for UDP and |
983 | * IP encapsulations. For UDP, there is 4 bytes of flags. | |
984 | */ | |
985 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { | |
986 | u16 flags = L2TP_HDR_VER_3; | |
b71a61cc | 987 | *((__be16 *)bufp) = htons(flags); |
0d76751f | 988 | bufp += 2; |
b71a61cc | 989 | *((__be16 *)bufp) = 0; |
0d76751f JC |
990 | bufp += 2; |
991 | } | |
992 | ||
b71a61cc | 993 | *((__be32 *)bufp) = htonl(session->peer_session_id); |
f7faffa3 JC |
994 | bufp += 4; |
995 | if (session->cookie_len) { | |
996 | memcpy(bufp, &session->cookie[0], session->cookie_len); | |
997 | bufp += session->cookie_len; | |
998 | } | |
62e7b6a5 LB |
999 | if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { |
1000 | u32 l2h = 0; | |
f7faffa3 | 1001 | |
62e7b6a5 LB |
1002 | if (session->send_seq) { |
1003 | l2h = 0x40000000 | session->ns; | |
1004 | session->ns++; | |
1005 | session->ns &= 0xffffff; | |
6b7bdcd7 | 1006 | trace_session_seqnum_update(session); |
f7faffa3 | 1007 | } |
62e7b6a5 LB |
1008 | |
1009 | *((__be32 *)bufp) = htonl(l2h); | |
1010 | bufp += 4; | |
f7faffa3 | 1011 | } |
fd558d18 | 1012 | |
f7faffa3 | 1013 | return bufp - optr; |
fd558d18 | 1014 | } |
fd558d18 | 1015 | |
de68b039 TP |
1016 | /* Queue the packet to IP for output: tunnel socket lock must be held */ |
1017 | static int l2tp_xmit_queue(struct l2tp_tunnel *tunnel, struct sk_buff *skb, struct flowi *fl) | |
fd558d18 | 1018 | { |
de68b039 | 1019 | int err; |
fd558d18 | 1020 | |
60ff7467 | 1021 | skb->ignore_df = 1; |
27d53323 | 1022 | skb_dst_drop(skb); |
d2cf3361 | 1023 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1024 | if (l2tp_sk_is_v6(tunnel->sock)) |
de68b039 | 1025 | err = inet6_csk_xmit(tunnel->sock, skb, NULL); |
d2cf3361 BL |
1026 | else |
1027 | #endif | |
de68b039 | 1028 | err = ip_queue_xmit(tunnel->sock, skb, fl); |
fd558d18 | 1029 | |
de68b039 | 1030 | return err >= 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP; |
fd558d18 | 1031 | } |
fd558d18 | 1032 | |
f52e4b27 | 1033 | static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, unsigned int *len) |
fd558d18 | 1034 | { |
0d76751f | 1035 | struct l2tp_tunnel *tunnel = session->tunnel; |
de68b039 | 1036 | unsigned int data_len = skb->len; |
0d76751f | 1037 | struct sock *sk = tunnel->sock; |
de68b039 | 1038 | int headroom, uhlen, udp_len; |
b8c84307 | 1039 | int ret = NET_XMIT_SUCCESS; |
de68b039 TP |
1040 | struct inet_sock *inet; |
1041 | struct udphdr *uh; | |
fd558d18 JC |
1042 | |
1043 | /* Check that there's enough headroom in the skb to insert IP, | |
1044 | * UDP and L2TP headers. If not enough, expand it to | |
1045 | * make room. Adjust truesize. | |
1046 | */ | |
de68b039 TP |
1047 | uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(*uh) : 0; |
1048 | headroom = NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len; | |
835acf5d | 1049 | if (skb_cow_head(skb, headroom)) { |
b8c84307 ED |
1050 | kfree_skb(skb); |
1051 | return NET_XMIT_DROP; | |
835acf5d | 1052 | } |
fd558d18 | 1053 | |
fd558d18 | 1054 | /* Setup L2TP header */ |
2dedab6f | 1055 | if (tunnel->version == L2TP_HDR_VER_2) |
efe05278 | 1056 | l2tp_build_l2tpv2_header(session, __skb_push(skb, session->hdr_len)); |
2dedab6f | 1057 | else |
efe05278 | 1058 | l2tp_build_l2tpv3_header(session, __skb_push(skb, session->hdr_len)); |
fd558d18 | 1059 | |
0d76751f | 1060 | /* Reset skb netfilter state */ |
fd558d18 | 1061 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
de68b039 | 1062 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); |
895b5c9f | 1063 | nf_reset_ct(skb); |
fd558d18 | 1064 | |
0b2c5972 | 1065 | bh_lock_sock_nested(sk); |
6af88da1 | 1066 | if (sock_owned_by_user(sk)) { |
b8c84307 ED |
1067 | kfree_skb(skb); |
1068 | ret = NET_XMIT_DROP; | |
6af88da1 DM |
1069 | goto out_unlock; |
1070 | } | |
1071 | ||
b954f940 PA |
1072 | /* The user-space may change the connection status for the user-space |
1073 | * provided socket at run time: we must check it under the socket lock | |
1074 | */ | |
1075 | if (tunnel->fd >= 0 && sk->sk_state != TCP_ESTABLISHED) { | |
1076 | kfree_skb(skb); | |
1077 | ret = NET_XMIT_DROP; | |
1078 | goto out_unlock; | |
1079 | } | |
1080 | ||
f52e4b27 TP |
1081 | /* Report transmitted length before we add encap header, which keeps |
1082 | * statistics consistent for both UDP and IP encap tx/rx paths. | |
1083 | */ | |
1084 | *len = skb->len; | |
1085 | ||
d9d8da80 | 1086 | inet = inet_sk(sk); |
0d76751f JC |
1087 | switch (tunnel->encap) { |
1088 | case L2TP_ENCAPTYPE_UDP: | |
1089 | /* Setup UDP header */ | |
0d76751f JC |
1090 | __skb_push(skb, sizeof(*uh)); |
1091 | skb_reset_transport_header(skb); | |
1092 | uh = udp_hdr(skb); | |
1093 | uh->source = inet->inet_sport; | |
1094 | uh->dest = inet->inet_dport; | |
efe05278 | 1095 | udp_len = uhlen + session->hdr_len + data_len; |
0d76751f | 1096 | uh->len = htons(udp_len); |
0d76751f JC |
1097 | |
1098 | /* Calculate UDP checksum if configured to do so */ | |
d2cf3361 | 1099 | #if IS_ENABLED(CONFIG_IPV6) |
b954f940 | 1100 | if (l2tp_sk_is_v6(sk)) |
77157e19 TH |
1101 | udp6_set_csum(udp_get_no_check6_tx(sk), |
1102 | skb, &inet6_sk(sk)->saddr, | |
1103 | &sk->sk_v6_daddr, udp_len); | |
d2cf3361 BL |
1104 | else |
1105 | #endif | |
0864e331 TP |
1106 | udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, |
1107 | inet->inet_daddr, udp_len); | |
0d76751f JC |
1108 | break; |
1109 | ||
1110 | case L2TP_ENCAPTYPE_IP: | |
1111 | break; | |
fd558d18 JC |
1112 | } |
1113 | ||
de68b039 TP |
1114 | ret = l2tp_xmit_queue(tunnel, skb, &inet->cork.fl); |
1115 | ||
6af88da1 DM |
1116 | out_unlock: |
1117 | bh_unlock_sock(sk); | |
fd558d18 | 1118 | |
b8c84307 | 1119 | return ret; |
fd558d18 | 1120 | } |
de68b039 TP |
1121 | |
1122 | /* If caller requires the skb to have a ppp header, the header must be | |
1123 | * inserted in the skb data before calling this function. | |
1124 | */ | |
1125 | int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb) | |
1126 | { | |
f52e4b27 | 1127 | unsigned int len = 0; |
de68b039 TP |
1128 | int ret; |
1129 | ||
f52e4b27 | 1130 | ret = l2tp_xmit_core(session, skb, &len); |
de68b039 TP |
1131 | if (ret == NET_XMIT_SUCCESS) { |
1132 | atomic_long_inc(&session->tunnel->stats.tx_packets); | |
1133 | atomic_long_add(len, &session->tunnel->stats.tx_bytes); | |
1134 | atomic_long_inc(&session->stats.tx_packets); | |
1135 | atomic_long_add(len, &session->stats.tx_bytes); | |
1136 | } else { | |
1137 | atomic_long_inc(&session->tunnel->stats.tx_errors); | |
1138 | atomic_long_inc(&session->stats.tx_errors); | |
1139 | } | |
1140 | return ret; | |
1141 | } | |
fd558d18 JC |
1142 | EXPORT_SYMBOL_GPL(l2tp_xmit_skb); |
1143 | ||
1144 | /***************************************************************************** | |
1145 | * Tinnel and session create/destroy. | |
1146 | *****************************************************************************/ | |
1147 | ||
1148 | /* Tunnel socket destruct hook. | |
1149 | * The tunnel context is deleted only when all session sockets have been | |
1150 | * closed. | |
1151 | */ | |
fc130840 | 1152 | static void l2tp_tunnel_destruct(struct sock *sk) |
fd558d18 | 1153 | { |
45faeff1 | 1154 | struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); |
fd558d18 | 1155 | |
0febc7b3 | 1156 | if (!tunnel) |
fd558d18 JC |
1157 | goto end; |
1158 | ||
f8ccac0e | 1159 | /* Disable udp encapsulation */ |
0d76751f JC |
1160 | switch (tunnel->encap) { |
1161 | case L2TP_ENCAPTYPE_UDP: | |
1162 | /* No longer an encapsulation socket. See net/ipv4/udp.c */ | |
70a36f57 ED |
1163 | WRITE_ONCE(udp_sk(sk)->encap_type, 0); |
1164 | udp_sk(sk)->encap_rcv = NULL; | |
1165 | udp_sk(sk)->encap_destroy = NULL; | |
0d76751f JC |
1166 | break; |
1167 | case L2TP_ENCAPTYPE_IP: | |
1168 | break; | |
1169 | } | |
fd558d18 JC |
1170 | |
1171 | /* Remove hooks into tunnel socket */ | |
b68777d5 | 1172 | write_lock_bh(&sk->sk_callback_lock); |
fd558d18 JC |
1173 | sk->sk_destruct = tunnel->old_sk_destruct; |
1174 | sk->sk_user_data = NULL; | |
b68777d5 | 1175 | write_unlock_bh(&sk->sk_callback_lock); |
fd558d18 | 1176 | |
f8ccac0e TP |
1177 | /* Call the original destructor */ |
1178 | if (sk->sk_destruct) | |
1179 | (*sk->sk_destruct)(sk); | |
d00fa9ad JC |
1180 | |
1181 | kfree_rcu(tunnel, rcu); | |
fd558d18 JC |
1182 | end: |
1183 | return; | |
1184 | } | |
fd558d18 | 1185 | |
b2aecfe8 TP |
1186 | /* Remove an l2tp session from l2tp_core's hash lists. */ |
1187 | static void l2tp_session_unhash(struct l2tp_session *session) | |
1188 | { | |
1189 | struct l2tp_tunnel *tunnel = session->tunnel; | |
1190 | ||
1191 | /* Remove the session from core hashes */ | |
1192 | if (tunnel) { | |
1193 | /* Remove from the per-tunnel hash */ | |
07b8ca37 TP |
1194 | spin_lock_bh(&tunnel->hlist_lock); |
1195 | hlist_del_init_rcu(&session->hlist); | |
1196 | spin_unlock_bh(&tunnel->hlist_lock); | |
b2aecfe8 TP |
1197 | |
1198 | /* For L2TPv3 we have a per-net hash: remove from there, too */ | |
1199 | if (tunnel->version != L2TP_HDR_VER_2) { | |
1200 | struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); | |
1201 | ||
1202 | spin_lock_bh(&pn->l2tp_session_hlist_lock); | |
1203 | hlist_del_init_rcu(&session->global_hlist); | |
1204 | spin_unlock_bh(&pn->l2tp_session_hlist_lock); | |
b2aecfe8 | 1205 | } |
07b8ca37 TP |
1206 | |
1207 | synchronize_rcu(); | |
b2aecfe8 TP |
1208 | } |
1209 | } | |
1210 | ||
fd558d18 JC |
1211 | /* When the tunnel is closed, all the attached sessions need to go too. |
1212 | */ | |
d08532bb | 1213 | static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) |
fd558d18 | 1214 | { |
fd558d18 | 1215 | struct l2tp_session *session; |
07b8ca37 | 1216 | int hash; |
fd558d18 | 1217 | |
07b8ca37 | 1218 | spin_lock_bh(&tunnel->hlist_lock); |
f3c66d4e | 1219 | tunnel->acpt_newsess = false; |
fd558d18 JC |
1220 | for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { |
1221 | again: | |
07b8ca37 TP |
1222 | hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { |
1223 | hlist_del_init_rcu(&session->hlist); | |
fd558d18 | 1224 | |
07b8ca37 | 1225 | spin_unlock_bh(&tunnel->hlist_lock); |
9d319a8e | 1226 | l2tp_session_delete(session); |
07b8ca37 | 1227 | spin_lock_bh(&tunnel->hlist_lock); |
fd558d18 JC |
1228 | |
1229 | /* Now restart from the beginning of this hash | |
1230 | * chain. We always remove a session from the | |
1231 | * list so we are guaranteed to make forward | |
1232 | * progress. | |
1233 | */ | |
1234 | goto again; | |
1235 | } | |
1236 | } | |
07b8ca37 | 1237 | spin_unlock_bh(&tunnel->hlist_lock); |
fd558d18 | 1238 | } |
fd558d18 | 1239 | |
9980d001 TP |
1240 | /* Tunnel socket destroy hook for UDP encapsulation */ |
1241 | static void l2tp_udp_encap_destroy(struct sock *sk) | |
1242 | { | |
45faeff1 | 1243 | struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); |
d00fa9ad JC |
1244 | |
1245 | if (tunnel) | |
1246 | l2tp_tunnel_delete(tunnel); | |
9980d001 TP |
1247 | } |
1248 | ||
c4d48a58 CW |
1249 | static void l2tp_tunnel_remove(struct net *net, struct l2tp_tunnel *tunnel) |
1250 | { | |
1251 | struct l2tp_net *pn = l2tp_pernet(net); | |
1252 | ||
1253 | spin_lock_bh(&pn->l2tp_tunnel_idr_lock); | |
1254 | idr_remove(&pn->l2tp_tunnel_idr, tunnel->tunnel_id); | |
1255 | spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); | |
1256 | } | |
1257 | ||
f8ccac0e TP |
1258 | /* Workqueue tunnel deletion function */ |
1259 | static void l2tp_tunnel_del_work(struct work_struct *work) | |
1260 | { | |
d00fa9ad JC |
1261 | struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, |
1262 | del_work); | |
1263 | struct sock *sk = tunnel->sock; | |
1264 | struct socket *sock = sk->sk_socket; | |
12d656af RK |
1265 | |
1266 | l2tp_tunnel_closeall(tunnel); | |
1267 | ||
76a6abdb | 1268 | /* If the tunnel socket was created within the kernel, use |
02d13ed5 | 1269 | * the sk API to release it here. |
f8ccac0e | 1270 | */ |
76a6abdb | 1271 | if (tunnel->fd < 0) { |
26abe143 | 1272 | if (sock) { |
02d13ed5 | 1273 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 EB |
1274 | sock_release(sock); |
1275 | } | |
167eb17e | 1276 | } |
f8ccac0e | 1277 | |
c4d48a58 | 1278 | l2tp_tunnel_remove(tunnel->l2tp_net, tunnel); |
d00fa9ad JC |
1279 | /* drop initial ref */ |
1280 | l2tp_tunnel_dec_refcount(tunnel); | |
1281 | ||
1282 | /* drop workqueue ref */ | |
06a15f51 | 1283 | l2tp_tunnel_dec_refcount(tunnel); |
fd558d18 | 1284 | } |
fd558d18 | 1285 | |
789a4a2c JC |
1286 | /* Create a socket for the tunnel, if one isn't set up by |
1287 | * userspace. This is used for static tunnels where there is no | |
1288 | * managing L2TP daemon. | |
167eb17e TP |
1289 | * |
1290 | * Since we don't want these sockets to keep a namespace alive by | |
1291 | * themselves, we drop the socket's namespace refcount after creation. | |
1292 | * These sockets are freed when the namespace exits using the pernet | |
1293 | * exit hook. | |
789a4a2c | 1294 | */ |
167eb17e | 1295 | static int l2tp_tunnel_sock_create(struct net *net, |
8ce9825a TP |
1296 | u32 tunnel_id, |
1297 | u32 peer_tunnel_id, | |
1298 | struct l2tp_tunnel_cfg *cfg, | |
1299 | struct socket **sockp) | |
789a4a2c JC |
1300 | { |
1301 | int err = -EINVAL; | |
167eb17e | 1302 | struct socket *sock = NULL; |
85644b4d | 1303 | struct udp_port_cfg udp_conf; |
789a4a2c JC |
1304 | |
1305 | switch (cfg->encap) { | |
1306 | case L2TP_ENCAPTYPE_UDP: | |
85644b4d TH |
1307 | memset(&udp_conf, 0, sizeof(udp_conf)); |
1308 | ||
f9bac8df CE |
1309 | #if IS_ENABLED(CONFIG_IPV6) |
1310 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1311 | udp_conf.family = AF_INET6; |
1312 | memcpy(&udp_conf.local_ip6, cfg->local_ip6, | |
1313 | sizeof(udp_conf.local_ip6)); | |
1314 | memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, | |
1315 | sizeof(udp_conf.peer_ip6)); | |
1316 | udp_conf.use_udp6_tx_checksums = | |
b71a61cc | 1317 | !cfg->udp6_zero_tx_checksums; |
85644b4d | 1318 | udp_conf.use_udp6_rx_checksums = |
b71a61cc | 1319 | !cfg->udp6_zero_rx_checksums; |
f9bac8df CE |
1320 | } else |
1321 | #endif | |
1322 | { | |
85644b4d TH |
1323 | udp_conf.family = AF_INET; |
1324 | udp_conf.local_ip = cfg->local_ip; | |
1325 | udp_conf.peer_ip = cfg->peer_ip; | |
1326 | udp_conf.use_udp_checksums = cfg->use_udp_checksums; | |
f9bac8df | 1327 | } |
789a4a2c | 1328 | |
85644b4d TH |
1329 | udp_conf.local_udp_port = htons(cfg->local_udp_port); |
1330 | udp_conf.peer_udp_port = htons(cfg->peer_udp_port); | |
1331 | ||
1332 | err = udp_sock_create(net, &udp_conf, &sock); | |
1333 | if (err < 0) | |
1334 | goto out; | |
789a4a2c JC |
1335 | |
1336 | break; | |
1337 | ||
1338 | case L2TP_ENCAPTYPE_IP: | |
f9bac8df CE |
1339 | #if IS_ENABLED(CONFIG_IPV6) |
1340 | if (cfg->local_ip6 && cfg->peer_ip6) { | |
85644b4d TH |
1341 | struct sockaddr_l2tpip6 ip6_addr = {0}; |
1342 | ||
26abe143 | 1343 | err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, |
8ce9825a | 1344 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1345 | if (err < 0) |
1346 | goto out; | |
789a4a2c | 1347 | |
5dac94e1 JC |
1348 | ip6_addr.l2tp_family = AF_INET6; |
1349 | memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, | |
1350 | sizeof(ip6_addr.l2tp_addr)); | |
1351 | ip6_addr.l2tp_conn_id = tunnel_id; | |
b71a61cc | 1352 | err = kernel_bind(sock, (struct sockaddr *)&ip6_addr, |
5dac94e1 JC |
1353 | sizeof(ip6_addr)); |
1354 | if (err < 0) | |
1355 | goto out; | |
789a4a2c | 1356 | |
5dac94e1 JC |
1357 | ip6_addr.l2tp_family = AF_INET6; |
1358 | memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6, | |
1359 | sizeof(ip6_addr.l2tp_addr)); | |
1360 | ip6_addr.l2tp_conn_id = peer_tunnel_id; | |
1361 | err = kernel_connect(sock, | |
b71a61cc | 1362 | (struct sockaddr *)&ip6_addr, |
5dac94e1 JC |
1363 | sizeof(ip6_addr), 0); |
1364 | if (err < 0) | |
1365 | goto out; | |
1366 | } else | |
1367 | #endif | |
1368 | { | |
85644b4d TH |
1369 | struct sockaddr_l2tpip ip_addr = {0}; |
1370 | ||
26abe143 | 1371 | err = sock_create_kern(net, AF_INET, SOCK_DGRAM, |
8ce9825a | 1372 | IPPROTO_L2TP, &sock); |
5dac94e1 JC |
1373 | if (err < 0) |
1374 | goto out; | |
789a4a2c | 1375 | |
5dac94e1 JC |
1376 | ip_addr.l2tp_family = AF_INET; |
1377 | ip_addr.l2tp_addr = cfg->local_ip; | |
1378 | ip_addr.l2tp_conn_id = tunnel_id; | |
b71a61cc | 1379 | err = kernel_bind(sock, (struct sockaddr *)&ip_addr, |
5dac94e1 JC |
1380 | sizeof(ip_addr)); |
1381 | if (err < 0) | |
1382 | goto out; | |
1383 | ||
1384 | ip_addr.l2tp_family = AF_INET; | |
1385 | ip_addr.l2tp_addr = cfg->peer_ip; | |
1386 | ip_addr.l2tp_conn_id = peer_tunnel_id; | |
b71a61cc | 1387 | err = kernel_connect(sock, (struct sockaddr *)&ip_addr, |
5dac94e1 JC |
1388 | sizeof(ip_addr), 0); |
1389 | if (err < 0) | |
1390 | goto out; | |
1391 | } | |
789a4a2c JC |
1392 | break; |
1393 | ||
1394 | default: | |
1395 | goto out; | |
1396 | } | |
1397 | ||
1398 | out: | |
167eb17e | 1399 | *sockp = sock; |
6c0ec37b | 1400 | if (err < 0 && sock) { |
167eb17e | 1401 | kernel_sock_shutdown(sock, SHUT_RDWR); |
26abe143 | 1402 | sock_release(sock); |
789a4a2c JC |
1403 | *sockp = NULL; |
1404 | } | |
1405 | ||
1406 | return err; | |
1407 | } | |
1408 | ||
c9ccd4c6 | 1409 | int l2tp_tunnel_create(int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, |
c0235fb3 | 1410 | struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) |
fd558d18 JC |
1411 | { |
1412 | struct l2tp_tunnel *tunnel = NULL; | |
1413 | int err; | |
0d76751f | 1414 | enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; |
fd558d18 | 1415 | |
0febc7b3 | 1416 | if (cfg) |
0d76751f JC |
1417 | encap = cfg->encap; |
1418 | ||
70c05bfa | 1419 | tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); |
0febc7b3 | 1420 | if (!tunnel) { |
fd558d18 JC |
1421 | err = -ENOMEM; |
1422 | goto err; | |
1423 | } | |
1424 | ||
1425 | tunnel->version = version; | |
1426 | tunnel->tunnel_id = tunnel_id; | |
1427 | tunnel->peer_tunnel_id = peer_tunnel_id; | |
fd558d18 JC |
1428 | |
1429 | tunnel->magic = L2TP_TUNNEL_MAGIC; | |
1430 | sprintf(&tunnel->name[0], "tunl %u", tunnel_id); | |
07b8ca37 | 1431 | spin_lock_init(&tunnel->hlist_lock); |
f3c66d4e | 1432 | tunnel->acpt_newsess = true; |
fd558d18 | 1433 | |
0d76751f | 1434 | tunnel->encap = encap; |
fd558d18 | 1435 | |
d00fa9ad | 1436 | refcount_set(&tunnel->ref_count, 1); |
d00fa9ad JC |
1437 | tunnel->fd = fd; |
1438 | ||
f8ccac0e TP |
1439 | /* Init delete workqueue struct */ |
1440 | INIT_WORK(&tunnel->del_work, l2tp_tunnel_del_work); | |
1441 | ||
fd558d18 | 1442 | INIT_LIST_HEAD(&tunnel->list); |
fd558d18 JC |
1443 | |
1444 | err = 0; | |
1445 | err: | |
1446 | if (tunnelp) | |
1447 | *tunnelp = tunnel; | |
1448 | ||
fd558d18 JC |
1449 | return err; |
1450 | } | |
1451 | EXPORT_SYMBOL_GPL(l2tp_tunnel_create); | |
1452 | ||
6b9f3423 GN |
1453 | static int l2tp_validate_socket(const struct sock *sk, const struct net *net, |
1454 | enum l2tp_encap_type encap) | |
1455 | { | |
1456 | if (!net_eq(sock_net(sk), net)) | |
1457 | return -EINVAL; | |
1458 | ||
1459 | if (sk->sk_type != SOCK_DGRAM) | |
1460 | return -EPROTONOSUPPORT; | |
1461 | ||
d9a81a22 ED |
1462 | if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) |
1463 | return -EPROTONOSUPPORT; | |
1464 | ||
6b9f3423 GN |
1465 | if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || |
1466 | (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) | |
1467 | return -EPROTONOSUPPORT; | |
1468 | ||
1469 | if (sk->sk_user_data) | |
1470 | return -EBUSY; | |
1471 | ||
1472 | return 0; | |
1473 | } | |
1474 | ||
1475 | int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, | |
1476 | struct l2tp_tunnel_cfg *cfg) | |
1477 | { | |
c4d48a58 CW |
1478 | struct l2tp_net *pn = l2tp_pernet(net); |
1479 | u32 tunnel_id = tunnel->tunnel_id; | |
6b9f3423 GN |
1480 | struct socket *sock; |
1481 | struct sock *sk; | |
1482 | int ret; | |
1483 | ||
c4d48a58 CW |
1484 | spin_lock_bh(&pn->l2tp_tunnel_idr_lock); |
1485 | ret = idr_alloc_u32(&pn->l2tp_tunnel_idr, NULL, &tunnel_id, tunnel_id, | |
1486 | GFP_ATOMIC); | |
1487 | spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); | |
1488 | if (ret) | |
1489 | return ret == -ENOSPC ? -EEXIST : ret; | |
1490 | ||
6b9f3423 GN |
1491 | if (tunnel->fd < 0) { |
1492 | ret = l2tp_tunnel_sock_create(net, tunnel->tunnel_id, | |
1493 | tunnel->peer_tunnel_id, cfg, | |
1494 | &sock); | |
1495 | if (ret < 0) | |
1496 | goto err; | |
1497 | } else { | |
1498 | sock = sockfd_lookup(tunnel->fd, &ret); | |
1499 | if (!sock) | |
1500 | goto err; | |
6b9f3423 GN |
1501 | } |
1502 | ||
b68777d5 | 1503 | sk = sock->sk; |
0b2c5972 | 1504 | lock_sock(sk); |
af295e85 | 1505 | write_lock_bh(&sk->sk_callback_lock); |
b68777d5 | 1506 | ret = l2tp_validate_socket(sk, net, tunnel->encap); |
b9fb10d1 | 1507 | if (ret < 0) |
af295e85 JS |
1508 | goto err_inval_sock; |
1509 | rcu_assign_sk_user_data(sk, tunnel); | |
1510 | write_unlock_bh(&sk->sk_callback_lock); | |
b68777d5 | 1511 | |
6b9f3423 GN |
1512 | if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
1513 | struct udp_tunnel_sock_cfg udp_cfg = { | |
1514 | .sk_user_data = tunnel, | |
1515 | .encap_type = UDP_ENCAP_L2TPINUDP, | |
1516 | .encap_rcv = l2tp_udp_encap_recv, | |
1517 | .encap_destroy = l2tp_udp_encap_destroy, | |
1518 | }; | |
1519 | ||
1520 | setup_udp_tunnel_sock(net, sock, &udp_cfg); | |
6b9f3423 GN |
1521 | } |
1522 | ||
1523 | tunnel->old_sk_destruct = sk->sk_destruct; | |
1524 | sk->sk_destruct = &l2tp_tunnel_destruct; | |
6b9f3423 | 1525 | sk->sk_allocation = GFP_ATOMIC; |
0b2c5972 CW |
1526 | release_sock(sk); |
1527 | ||
1528 | sock_hold(sk); | |
1529 | tunnel->sock = sk; | |
1530 | tunnel->l2tp_net = net; | |
1531 | ||
1532 | spin_lock_bh(&pn->l2tp_tunnel_idr_lock); | |
1533 | idr_replace(&pn->l2tp_tunnel_idr, tunnel, tunnel->tunnel_id); | |
1534 | spin_unlock_bh(&pn->l2tp_tunnel_idr_lock); | |
6b9f3423 | 1535 | |
6b7bdcd7 TP |
1536 | trace_register_tunnel(tunnel); |
1537 | ||
6b9f3423 GN |
1538 | if (tunnel->fd >= 0) |
1539 | sockfd_put(sock); | |
1540 | ||
1541 | return 0; | |
1542 | ||
af295e85 JS |
1543 | err_inval_sock: |
1544 | write_unlock_bh(&sk->sk_callback_lock); | |
b9fb10d1 | 1545 | release_sock(sk); |
af295e85 | 1546 | |
f6cd651b GN |
1547 | if (tunnel->fd < 0) |
1548 | sock_release(sock); | |
1549 | else | |
1550 | sockfd_put(sock); | |
6b9f3423 | 1551 | err: |
c4d48a58 | 1552 | l2tp_tunnel_remove(net, tunnel); |
6b9f3423 GN |
1553 | return ret; |
1554 | } | |
1555 | EXPORT_SYMBOL_GPL(l2tp_tunnel_register); | |
1556 | ||
309795f4 JC |
1557 | /* This function is used by the netlink TUNNEL_DELETE command. |
1558 | */ | |
62b982ee | 1559 | void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) |
309795f4 | 1560 | { |
62b982ee | 1561 | if (!test_and_set_bit(0, &tunnel->dead)) { |
6b7bdcd7 | 1562 | trace_delete_tunnel(tunnel); |
62b982ee SD |
1563 | l2tp_tunnel_inc_refcount(tunnel); |
1564 | queue_work(l2tp_wq, &tunnel->del_work); | |
06a15f51 | 1565 | } |
309795f4 JC |
1566 | } |
1567 | EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); | |
1568 | ||
628703f5 | 1569 | void l2tp_session_delete(struct l2tp_session *session) |
309795f4 | 1570 | { |
b228a940 | 1571 | if (test_and_set_bit(0, &session->dead)) |
628703f5 | 1572 | return; |
b228a940 | 1573 | |
6b7bdcd7 | 1574 | trace_delete_session(session); |
b2aecfe8 | 1575 | l2tp_session_unhash(session); |
4c6e2fd3 | 1576 | l2tp_session_queue_purge(session); |
0febc7b3 | 1577 | if (session->session_close) |
309795f4 | 1578 | (*session->session_close)(session); |
a4346210 | 1579 | |
309795f4 | 1580 | l2tp_session_dec_refcount(session); |
309795f4 JC |
1581 | } |
1582 | EXPORT_SYMBOL_GPL(l2tp_session_delete); | |
1583 | ||
f7faffa3 | 1584 | /* We come here whenever a session's send_seq, cookie_len or |
62e7b6a5 | 1585 | * l2specific_type parameters are set. |
f7faffa3 | 1586 | */ |
bb5016ea | 1587 | void l2tp_session_set_header_len(struct l2tp_session *session, int version) |
f7faffa3 JC |
1588 | { |
1589 | if (version == L2TP_HDR_VER_2) { | |
1590 | session->hdr_len = 6; | |
1591 | if (session->send_seq) | |
1592 | session->hdr_len += 4; | |
1593 | } else { | |
62e7b6a5 LB |
1594 | session->hdr_len = 4 + session->cookie_len; |
1595 | session->hdr_len += l2tp_get_l2specific_len(session); | |
0d76751f JC |
1596 | if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) |
1597 | session->hdr_len += 4; | |
f7faffa3 | 1598 | } |
f7faffa3 | 1599 | } |
bb5016ea | 1600 | EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); |
f7faffa3 | 1601 | |
c0235fb3 TP |
1602 | struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, |
1603 | u32 peer_session_id, struct l2tp_session_cfg *cfg) | |
fd558d18 JC |
1604 | { |
1605 | struct l2tp_session *session; | |
1606 | ||
70c05bfa | 1607 | session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL); |
0febc7b3 | 1608 | if (session) { |
fd558d18 JC |
1609 | session->magic = L2TP_SESSION_MAGIC; |
1610 | session->tunnel = tunnel; | |
1611 | ||
1612 | session->session_id = session_id; | |
1613 | session->peer_session_id = peer_session_id; | |
d301e325 | 1614 | session->nr = 0; |
8a1631d5 JC |
1615 | if (tunnel->version == L2TP_HDR_VER_2) |
1616 | session->nr_max = 0xffff; | |
1617 | else | |
1618 | session->nr_max = 0xffffff; | |
1619 | session->nr_window_size = session->nr_max / 2; | |
a0dbd822 JC |
1620 | session->nr_oos_count_max = 4; |
1621 | ||
1622 | /* Use NR of first received packet */ | |
1623 | session->reorder_skip = 1; | |
fd558d18 JC |
1624 | |
1625 | sprintf(&session->name[0], "sess %u/%u", | |
1626 | tunnel->tunnel_id, session->session_id); | |
1627 | ||
1628 | skb_queue_head_init(&session->reorder_q); | |
1629 | ||
1630 | INIT_HLIST_NODE(&session->hlist); | |
f7faffa3 | 1631 | INIT_HLIST_NODE(&session->global_hlist); |
fd558d18 | 1632 | |
fd558d18 | 1633 | if (cfg) { |
f7faffa3 | 1634 | session->pwtype = cfg->pw_type; |
fd558d18 JC |
1635 | session->send_seq = cfg->send_seq; |
1636 | session->recv_seq = cfg->recv_seq; | |
1637 | session->lns_mode = cfg->lns_mode; | |
f7faffa3 | 1638 | session->reorder_timeout = cfg->reorder_timeout; |
f7faffa3 | 1639 | session->l2specific_type = cfg->l2specific_type; |
f7faffa3 JC |
1640 | session->cookie_len = cfg->cookie_len; |
1641 | memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); | |
1642 | session->peer_cookie_len = cfg->peer_cookie_len; | |
1643 | memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); | |
fd558d18 JC |
1644 | } |
1645 | ||
f7faffa3 JC |
1646 | l2tp_session_set_header_len(session, tunnel->version); |
1647 | ||
9ee369a4 GN |
1648 | refcount_set(&session->ref_count, 1); |
1649 | ||
dbdbc73b | 1650 | return session; |
fd558d18 JC |
1651 | } |
1652 | ||
dbdbc73b | 1653 | return ERR_PTR(-ENOMEM); |
fd558d18 JC |
1654 | } |
1655 | EXPORT_SYMBOL_GPL(l2tp_session_create); | |
1656 | ||
1657 | /***************************************************************************** | |
1658 | * Init and cleanup | |
1659 | *****************************************************************************/ | |
1660 | ||
1661 | static __net_init int l2tp_init_net(struct net *net) | |
1662 | { | |
e773aaff | 1663 | struct l2tp_net *pn = net_generic(net, l2tp_net_id); |
f7faffa3 | 1664 | int hash; |
fd558d18 | 1665 | |
c4d48a58 CW |
1666 | idr_init(&pn->l2tp_tunnel_idr); |
1667 | spin_lock_init(&pn->l2tp_tunnel_idr_lock); | |
fd558d18 | 1668 | |
f7faffa3 JC |
1669 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) |
1670 | INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); | |
1671 | ||
e02d494d | 1672 | spin_lock_init(&pn->l2tp_session_hlist_lock); |
f7faffa3 | 1673 | |
fd558d18 | 1674 | return 0; |
fd558d18 JC |
1675 | } |
1676 | ||
167eb17e TP |
1677 | static __net_exit void l2tp_exit_net(struct net *net) |
1678 | { | |
1679 | struct l2tp_net *pn = l2tp_pernet(net); | |
1680 | struct l2tp_tunnel *tunnel = NULL; | |
c4d48a58 | 1681 | unsigned long tunnel_id, tmp; |
1e7af3b2 | 1682 | int hash; |
167eb17e TP |
1683 | |
1684 | rcu_read_lock_bh(); | |
c4d48a58 CW |
1685 | idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { |
1686 | if (tunnel) | |
1687 | l2tp_tunnel_delete(tunnel); | |
167eb17e TP |
1688 | } |
1689 | rcu_read_unlock_bh(); | |
2f86953e | 1690 | |
638a3a1e Y |
1691 | if (l2tp_wq) |
1692 | flush_workqueue(l2tp_wq); | |
2f86953e | 1693 | rcu_barrier(); |
1e7af3b2 VA |
1694 | |
1695 | for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) | |
1696 | WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash])); | |
c4d48a58 | 1697 | idr_destroy(&pn->l2tp_tunnel_idr); |
167eb17e TP |
1698 | } |
1699 | ||
fd558d18 JC |
1700 | static struct pernet_operations l2tp_net_ops = { |
1701 | .init = l2tp_init_net, | |
167eb17e | 1702 | .exit = l2tp_exit_net, |
fd558d18 JC |
1703 | .id = &l2tp_net_id, |
1704 | .size = sizeof(struct l2tp_net), | |
1705 | }; | |
1706 | ||
1707 | static int __init l2tp_init(void) | |
1708 | { | |
1709 | int rc = 0; | |
1710 | ||
1711 | rc = register_pernet_device(&l2tp_net_ops); | |
1712 | if (rc) | |
1713 | goto out; | |
1714 | ||
59ff3eb6 | 1715 | l2tp_wq = alloc_workqueue("l2tp", WQ_UNBOUND, 0); |
f8ccac0e TP |
1716 | if (!l2tp_wq) { |
1717 | pr_err("alloc_workqueue failed\n"); | |
67e04c29 | 1718 | unregister_pernet_device(&l2tp_net_ops); |
f8ccac0e TP |
1719 | rc = -ENOMEM; |
1720 | goto out; | |
1721 | } | |
1722 | ||
a4ca44fa | 1723 | pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION); |
fd558d18 JC |
1724 | |
1725 | out: | |
1726 | return rc; | |
1727 | } | |
1728 | ||
1729 | static void __exit l2tp_exit(void) | |
1730 | { | |
1731 | unregister_pernet_device(&l2tp_net_ops); | |
f8ccac0e TP |
1732 | if (l2tp_wq) { |
1733 | destroy_workqueue(l2tp_wq); | |
1734 | l2tp_wq = NULL; | |
1735 | } | |
fd558d18 JC |
1736 | } |
1737 | ||
1738 | module_init(l2tp_init); | |
1739 | module_exit(l2tp_exit); | |
1740 | ||
1741 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); | |
1742 | MODULE_DESCRIPTION("L2TP core"); | |
1743 | MODULE_LICENSE("GPL"); | |
1744 | MODULE_VERSION(L2TP_DRV_VERSION); |