Commit | Line | Data |
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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
2 | * Copyright (c) 1999-2000 Cisco, Inc. |
3 | * Copyright (c) 1999-2001 Motorola, Inc. | |
4 | * Copyright (c) 2001-2003 International Business Machines, Corp. | |
5 | * Copyright (c) 2001 Intel Corp. | |
6 | * Copyright (c) 2001 Nokia, Inc. | |
7 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
8 | * | |
60c778b2 | 9 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
10 | * |
11 | * These functions handle all input from the IP layer into SCTP. | |
12 | * | |
60c778b2 | 13 | * This SCTP implementation is free software; |
1da177e4 LT |
14 | * you can redistribute it and/or modify it under the terms of |
15 | * the GNU General Public License as published by | |
16 | * the Free Software Foundation; either version 2, or (at your option) | |
17 | * any later version. | |
18 | * | |
60c778b2 | 19 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
20 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
21 | * ************************ | |
22 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
23 | * See the GNU General Public License for more details. | |
24 | * | |
25 | * You should have received a copy of the GNU General Public License | |
4b2f13a2 JK |
26 | * along with GNU CC; see the file COPYING. If not, see |
27 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
28 | * |
29 | * Please send any bug reports or fixes you make to the | |
30 | * email address(es): | |
91705c61 | 31 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 32 | * |
1da177e4 LT |
33 | * Written or modified by: |
34 | * La Monte H.P. Yarroll <piggy@acm.org> | |
35 | * Karl Knutson <karl@athena.chicago.il.us> | |
36 | * Xingang Guo <xingang.guo@intel.com> | |
37 | * Jon Grimm <jgrimm@us.ibm.com> | |
38 | * Hui Huang <hui.huang@nokia.com> | |
39 | * Daisy Chang <daisyc@us.ibm.com> | |
40 | * Sridhar Samudrala <sri@us.ibm.com> | |
41 | * Ardelle Fan <ardelle.fan@intel.com> | |
1da177e4 LT |
42 | */ |
43 | ||
44 | #include <linux/types.h> | |
45 | #include <linux/list.h> /* For struct list_head */ | |
46 | #include <linux/socket.h> | |
47 | #include <linux/ip.h> | |
48 | #include <linux/time.h> /* For struct timeval */ | |
5a0e3ad6 | 49 | #include <linux/slab.h> |
1da177e4 LT |
50 | #include <net/ip.h> |
51 | #include <net/icmp.h> | |
52 | #include <net/snmp.h> | |
53 | #include <net/sock.h> | |
54 | #include <net/xfrm.h> | |
55 | #include <net/sctp/sctp.h> | |
56 | #include <net/sctp/sm.h> | |
9ad0977f | 57 | #include <net/sctp/checksum.h> |
dcfc23ca | 58 | #include <net/net_namespace.h> |
1da177e4 LT |
59 | |
60 | /* Forward declarations for internal helpers. */ | |
61 | static int sctp_rcv_ootb(struct sk_buff *); | |
4110cc25 EB |
62 | static struct sctp_association *__sctp_rcv_lookup(struct net *net, |
63 | struct sk_buff *skb, | |
1da177e4 | 64 | const union sctp_addr *paddr, |
57565993 | 65 | const union sctp_addr *laddr, |
1da177e4 | 66 | struct sctp_transport **transportp); |
4cdadcbc EB |
67 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, |
68 | const union sctp_addr *laddr); | |
1da177e4 | 69 | static struct sctp_association *__sctp_lookup_association( |
4110cc25 | 70 | struct net *net, |
1da177e4 LT |
71 | const union sctp_addr *local, |
72 | const union sctp_addr *peer, | |
73 | struct sctp_transport **pt); | |
74 | ||
50b1a782 | 75 | static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb); |
61c9fed4 | 76 | |
1da177e4 LT |
77 | |
78 | /* Calculate the SCTP checksum of an SCTP packet. */ | |
b01a2407 | 79 | static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb) |
1da177e4 | 80 | { |
2c0fd387 | 81 | struct sctphdr *sh = sctp_hdr(skb); |
4458f04c | 82 | __le32 cmp = sh->checksum; |
024ec3de | 83 | __le32 val = sctp_compute_cksum(skb, 0); |
1da177e4 LT |
84 | |
85 | if (val != cmp) { | |
86 | /* CRC failure, dump it. */ | |
08e3baef | 87 | __SCTP_INC_STATS(net, SCTP_MIB_CHECKSUMERRORS); |
1da177e4 LT |
88 | return -1; |
89 | } | |
90 | return 0; | |
91 | } | |
92 | ||
1da177e4 LT |
93 | /* |
94 | * This is the routine which IP calls when receiving an SCTP packet. | |
95 | */ | |
96 | int sctp_rcv(struct sk_buff *skb) | |
97 | { | |
98 | struct sock *sk; | |
99 | struct sctp_association *asoc; | |
100 | struct sctp_endpoint *ep = NULL; | |
101 | struct sctp_ep_common *rcvr; | |
102 | struct sctp_transport *transport = NULL; | |
103 | struct sctp_chunk *chunk; | |
1da177e4 LT |
104 | union sctp_addr src; |
105 | union sctp_addr dest; | |
106 | int family; | |
107 | struct sctp_af *af; | |
4cdadcbc | 108 | struct net *net = dev_net(skb->dev); |
1da177e4 | 109 | |
cb3f837b | 110 | if (skb->pkt_type != PACKET_HOST) |
1da177e4 LT |
111 | goto discard_it; |
112 | ||
08e3baef | 113 | __SCTP_INC_STATS(net, SCTP_MIB_INSCTPPACKS); |
1da177e4 | 114 | |
3acb50c1 MRL |
115 | /* If packet is too small to contain a single chunk, let's not |
116 | * waste time on it anymore. | |
117 | */ | |
118 | if (skb->len < sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + | |
119 | skb_transport_offset(skb)) | |
28cd7752 HX |
120 | goto discard_it; |
121 | ||
4c2f2454 MRL |
122 | /* If the packet is fragmented and we need to do crc checking, |
123 | * it's better to just linearize it otherwise crc computing | |
124 | * takes longer. | |
125 | */ | |
126 | if ((!(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) && | |
127 | skb_linearize(skb)) || | |
128 | !pskb_may_pull(skb, sizeof(struct sctphdr))) | |
3acb50c1 | 129 | goto discard_it; |
1da177e4 | 130 | |
3acb50c1 | 131 | /* Pull up the IP header. */ |
ea2ae17d | 132 | __skb_pull(skb, skb_transport_offset(skb)); |
202863fe TH |
133 | |
134 | skb->csum_valid = 0; /* Previous value not applicable */ | |
135 | if (skb_csum_unnecessary(skb)) | |
136 | __skb_decr_checksum_unnecessary(skb); | |
90017acc MRL |
137 | else if (!sctp_checksum_disable && |
138 | !(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) && | |
139 | sctp_rcv_checksum(net, skb) < 0) | |
1da177e4 | 140 | goto discard_it; |
202863fe | 141 | skb->csum_valid = 1; |
1da177e4 | 142 | |
3acb50c1 | 143 | __skb_pull(skb, sizeof(struct sctphdr)); |
1da177e4 | 144 | |
eddc9ec5 | 145 | family = ipver2af(ip_hdr(skb)->version); |
1da177e4 LT |
146 | af = sctp_get_af_specific(family); |
147 | if (unlikely(!af)) | |
148 | goto discard_it; | |
e7487c86 | 149 | SCTP_INPUT_CB(skb)->af = af; |
1da177e4 LT |
150 | |
151 | /* Initialize local addresses for lookups. */ | |
152 | af->from_skb(&src, skb, 1); | |
153 | af->from_skb(&dest, skb, 0); | |
154 | ||
155 | /* If the packet is to or from a non-unicast address, | |
156 | * silently discard the packet. | |
157 | * | |
158 | * This is not clearly defined in the RFC except in section | |
159 | * 8.4 - OOTB handling. However, based on the book "Stream Control | |
160 | * Transmission Protocol" 2.1, "It is important to note that the | |
161 | * IP address of an SCTP transport address must be a routable | |
162 | * unicast address. In other words, IP multicast addresses and | |
163 | * IP broadcast addresses cannot be used in an SCTP transport | |
164 | * address." | |
165 | */ | |
5636bef7 VY |
166 | if (!af->addr_valid(&src, NULL, skb) || |
167 | !af->addr_valid(&dest, NULL, skb)) | |
1da177e4 LT |
168 | goto discard_it; |
169 | ||
4110cc25 | 170 | asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport); |
1c7d1fc1 | 171 | |
0fd9a65a | 172 | if (!asoc) |
4cdadcbc | 173 | ep = __sctp_rcv_lookup_endpoint(net, &dest); |
0fd9a65a NH |
174 | |
175 | /* Retrieve the common input handling substructure. */ | |
176 | rcvr = asoc ? &asoc->base : &ep->base; | |
177 | sk = rcvr->sk; | |
178 | ||
179 | /* | |
180 | * If a frame arrives on an interface and the receiving socket is | |
181 | * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB | |
182 | */ | |
8d72651d | 183 | if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) { |
dae399d7 XL |
184 | if (transport) { |
185 | sctp_transport_put(transport); | |
0fd9a65a | 186 | asoc = NULL; |
dae399d7 | 187 | transport = NULL; |
0fd9a65a NH |
188 | } else { |
189 | sctp_endpoint_put(ep); | |
190 | ep = NULL; | |
191 | } | |
2ce95503 | 192 | sk = net->sctp.ctl_sock; |
0fd9a65a NH |
193 | ep = sctp_sk(sk)->ep; |
194 | sctp_endpoint_hold(ep); | |
0fd9a65a NH |
195 | rcvr = &ep->base; |
196 | } | |
197 | ||
1da177e4 LT |
198 | /* |
199 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. | |
200 | * An SCTP packet is called an "out of the blue" (OOTB) | |
201 | * packet if it is correctly formed, i.e., passed the | |
202 | * receiver's checksum check, but the receiver is not | |
203 | * able to identify the association to which this | |
204 | * packet belongs. | |
205 | */ | |
206 | if (!asoc) { | |
1da177e4 | 207 | if (sctp_rcv_ootb(skb)) { |
08e3baef | 208 | __SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
1da177e4 LT |
209 | goto discard_release; |
210 | } | |
211 | } | |
212 | ||
1da177e4 LT |
213 | if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) |
214 | goto discard_release; | |
b59c2701 | 215 | nf_reset(skb); |
1da177e4 | 216 | |
fda9ef5d | 217 | if (sk_filter(sk, skb)) |
d808ad9a | 218 | goto discard_release; |
1da177e4 LT |
219 | |
220 | /* Create an SCTP packet structure. */ | |
cea8768f | 221 | chunk = sctp_chunkify(skb, asoc, sk, GFP_ATOMIC); |
2babf9da | 222 | if (!chunk) |
1da177e4 | 223 | goto discard_release; |
79af02c2 | 224 | SCTP_INPUT_CB(skb)->chunk = chunk; |
1da177e4 | 225 | |
1da177e4 LT |
226 | /* Remember what endpoint is to handle this packet. */ |
227 | chunk->rcvr = rcvr; | |
228 | ||
229 | /* Remember the SCTP header. */ | |
3acb50c1 | 230 | chunk->sctp_hdr = sctp_hdr(skb); |
1da177e4 LT |
231 | |
232 | /* Set the source and destination addresses of the incoming chunk. */ | |
d55c41b1 | 233 | sctp_init_addrs(chunk, &src, &dest); |
1da177e4 LT |
234 | |
235 | /* Remember where we came from. */ | |
236 | chunk->transport = transport; | |
237 | ||
238 | /* Acquire access to the sock lock. Note: We are safe from other | |
239 | * bottom halves on this lock, but a user may be in the lock too, | |
240 | * so check if it is busy. | |
241 | */ | |
5bc1d1b4 | 242 | bh_lock_sock(sk); |
1da177e4 | 243 | |
ae53b5bd VY |
244 | if (sk != rcvr->sk) { |
245 | /* Our cached sk is different from the rcvr->sk. This is | |
246 | * because migrate()/accept() may have moved the association | |
247 | * to a new socket and released all the sockets. So now we | |
248 | * are holding a lock on the old socket while the user may | |
249 | * be doing something with the new socket. Switch our veiw | |
250 | * of the current sk. | |
251 | */ | |
5bc1d1b4 | 252 | bh_unlock_sock(sk); |
ae53b5bd | 253 | sk = rcvr->sk; |
5bc1d1b4 | 254 | bh_lock_sock(sk); |
ae53b5bd VY |
255 | } |
256 | ||
ac0b0462 | 257 | if (sock_owned_by_user(sk)) { |
50b1a782 | 258 | if (sctp_add_backlog(sk, skb)) { |
5bc1d1b4 | 259 | bh_unlock_sock(sk); |
50b1a782 ZY |
260 | sctp_chunk_free(chunk); |
261 | skb = NULL; /* sctp_chunk_free already freed the skb */ | |
262 | goto discard_release; | |
263 | } | |
08e3baef | 264 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_BACKLOG); |
ac0b0462 | 265 | } else { |
08e3baef | 266 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_SOFTIRQ); |
61c9fed4 | 267 | sctp_inq_push(&chunk->rcvr->inqueue, chunk); |
ac0b0462 | 268 | } |
1da177e4 | 269 | |
5bc1d1b4 | 270 | bh_unlock_sock(sk); |
61c9fed4 VY |
271 | |
272 | /* Release the asoc/ep ref we took in the lookup calls. */ | |
dae399d7 XL |
273 | if (transport) |
274 | sctp_transport_put(transport); | |
61c9fed4 VY |
275 | else |
276 | sctp_endpoint_put(ep); | |
7a48f923 | 277 | |
2babf9da | 278 | return 0; |
1da177e4 LT |
279 | |
280 | discard_it: | |
08e3baef | 281 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS); |
1da177e4 | 282 | kfree_skb(skb); |
2babf9da | 283 | return 0; |
1da177e4 LT |
284 | |
285 | discard_release: | |
61c9fed4 | 286 | /* Release the asoc/ep ref we took in the lookup calls. */ |
dae399d7 XL |
287 | if (transport) |
288 | sctp_transport_put(transport); | |
0fd9a65a | 289 | else |
1da177e4 | 290 | sctp_endpoint_put(ep); |
1da177e4 LT |
291 | |
292 | goto discard_it; | |
293 | } | |
294 | ||
61c9fed4 VY |
295 | /* Process the backlog queue of the socket. Every skb on |
296 | * the backlog holds a ref on an association or endpoint. | |
297 | * We hold this ref throughout the state machine to make | |
298 | * sure that the structure we need is still around. | |
1da177e4 LT |
299 | */ |
300 | int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
301 | { | |
79af02c2 | 302 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
d808ad9a | 303 | struct sctp_inq *inqueue = &chunk->rcvr->inqueue; |
dae399d7 | 304 | struct sctp_transport *t = chunk->transport; |
d808ad9a | 305 | struct sctp_ep_common *rcvr = NULL; |
61c9fed4 | 306 | int backloged = 0; |
7a48f923 | 307 | |
d808ad9a | 308 | rcvr = chunk->rcvr; |
c4d2444e | 309 | |
61c9fed4 VY |
310 | /* If the rcvr is dead then the association or endpoint |
311 | * has been deleted and we can safely drop the chunk | |
312 | * and refs that we are holding. | |
313 | */ | |
314 | if (rcvr->dead) { | |
315 | sctp_chunk_free(chunk); | |
316 | goto done; | |
317 | } | |
318 | ||
319 | if (unlikely(rcvr->sk != sk)) { | |
320 | /* In this case, the association moved from one socket to | |
321 | * another. We are currently sitting on the backlog of the | |
322 | * old socket, so we need to move. | |
323 | * However, since we are here in the process context we | |
324 | * need to take make sure that the user doesn't own | |
325 | * the new socket when we process the packet. | |
326 | * If the new socket is user-owned, queue the chunk to the | |
327 | * backlog of the new socket without dropping any refs. | |
328 | * Otherwise, we can safely push the chunk on the inqueue. | |
329 | */ | |
330 | ||
331 | sk = rcvr->sk; | |
eefc1b1d | 332 | local_bh_disable(); |
5bc1d1b4 | 333 | bh_lock_sock(sk); |
61c9fed4 VY |
334 | |
335 | if (sock_owned_by_user(sk)) { | |
f545a38f | 336 | if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) |
50b1a782 ZY |
337 | sctp_chunk_free(chunk); |
338 | else | |
339 | backloged = 1; | |
61c9fed4 VY |
340 | } else |
341 | sctp_inq_push(inqueue, chunk); | |
342 | ||
5bc1d1b4 | 343 | bh_unlock_sock(sk); |
eefc1b1d | 344 | local_bh_enable(); |
61c9fed4 VY |
345 | |
346 | /* If the chunk was backloged again, don't drop refs */ | |
347 | if (backloged) | |
348 | return 0; | |
349 | } else { | |
350 | sctp_inq_push(inqueue, chunk); | |
351 | } | |
352 | ||
353 | done: | |
354 | /* Release the refs we took in sctp_add_backlog */ | |
355 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) | |
dae399d7 | 356 | sctp_transport_put(t); |
61c9fed4 VY |
357 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
358 | sctp_endpoint_put(sctp_ep(rcvr)); | |
359 | else | |
360 | BUG(); | |
361 | ||
d808ad9a | 362 | return 0; |
1da177e4 LT |
363 | } |
364 | ||
50b1a782 | 365 | static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb) |
c4d2444e | 366 | { |
61c9fed4 | 367 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
dae399d7 | 368 | struct sctp_transport *t = chunk->transport; |
61c9fed4 | 369 | struct sctp_ep_common *rcvr = chunk->rcvr; |
50b1a782 | 370 | int ret; |
c4d2444e | 371 | |
f545a38f | 372 | ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf); |
50b1a782 ZY |
373 | if (!ret) { |
374 | /* Hold the assoc/ep while hanging on the backlog queue. | |
375 | * This way, we know structures we need will not disappear | |
376 | * from us | |
377 | */ | |
378 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) | |
dae399d7 | 379 | sctp_transport_hold(t); |
50b1a782 ZY |
380 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
381 | sctp_endpoint_hold(sctp_ep(rcvr)); | |
382 | else | |
383 | BUG(); | |
384 | } | |
385 | return ret; | |
61c9fed4 | 386 | |
c4d2444e SS |
387 | } |
388 | ||
1da177e4 LT |
389 | /* Handle icmp frag needed error. */ |
390 | void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, | |
391 | struct sctp_transport *t, __u32 pmtu) | |
392 | { | |
91bd6b1e | 393 | if (!t || (t->pathmtu <= pmtu)) |
52ccb8e9 FF |
394 | return; |
395 | ||
8a479491 VY |
396 | if (sock_owned_by_user(sk)) { |
397 | asoc->pmtu_pending = 1; | |
398 | t->pmtu_pending = 1; | |
399 | return; | |
400 | } | |
401 | ||
b4bab946 MRL |
402 | if (!(t->param_flags & SPP_PMTUD_ENABLE)) |
403 | /* We can't allow retransmitting in such case, as the | |
404 | * retransmission would be sized just as before, and thus we | |
405 | * would get another icmp, and retransmit again. | |
406 | */ | |
407 | return; | |
1da177e4 | 408 | |
d47da4eb MRL |
409 | /* Update transports view of the MTU. Return if no update was needed. |
410 | * If an update wasn't needed/possible, it also doesn't make sense to | |
411 | * try to retransmit now. | |
412 | */ | |
413 | if (!sctp_transport_update_pmtu(t, pmtu)) | |
414 | return; | |
52ccb8e9 | 415 | |
b4bab946 MRL |
416 | /* Update association pmtu. */ |
417 | sctp_assoc_sync_pmtu(asoc); | |
418 | ||
419 | /* Retransmit with the new pmtu setting. */ | |
52ccb8e9 | 420 | sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); |
1da177e4 LT |
421 | } |
422 | ||
ec18d9a2 DM |
423 | void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t, |
424 | struct sk_buff *skb) | |
55be7a9c DM |
425 | { |
426 | struct dst_entry *dst; | |
427 | ||
1cc276ce | 428 | if (sock_owned_by_user(sk) || !t) |
55be7a9c DM |
429 | return; |
430 | dst = sctp_transport_dst_check(t); | |
1ed5c48f | 431 | if (dst) |
6700c270 | 432 | dst->ops->redirect(dst, sk, skb); |
55be7a9c DM |
433 | } |
434 | ||
1da177e4 LT |
435 | /* |
436 | * SCTP Implementer's Guide, 2.37 ICMP handling procedures | |
437 | * | |
438 | * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" | |
439 | * or a "Protocol Unreachable" treat this message as an abort | |
440 | * with the T bit set. | |
441 | * | |
442 | * This function sends an event to the state machine, which will abort the | |
443 | * association. | |
444 | * | |
445 | */ | |
446 | void sctp_icmp_proto_unreachable(struct sock *sk, | |
d808ad9a YH |
447 | struct sctp_association *asoc, |
448 | struct sctp_transport *t) | |
1da177e4 | 449 | { |
50b5d6ad VY |
450 | if (sock_owned_by_user(sk)) { |
451 | if (timer_pending(&t->proto_unreach_timer)) | |
452 | return; | |
453 | else { | |
454 | if (!mod_timer(&t->proto_unreach_timer, | |
455 | jiffies + (HZ/20))) | |
456 | sctp_association_hold(asoc); | |
457 | } | |
50b5d6ad | 458 | } else { |
55e26eb9 EB |
459 | struct net *net = sock_net(sk); |
460 | ||
bb33381d DB |
461 | pr_debug("%s: unrecognized next header type " |
462 | "encountered!\n", __func__); | |
463 | ||
25cc4ae9 | 464 | if (del_timer(&t->proto_unreach_timer)) |
50b5d6ad | 465 | sctp_association_put(asoc); |
1da177e4 | 466 | |
55e26eb9 | 467 | sctp_do_sm(net, SCTP_EVENT_T_OTHER, |
50b5d6ad VY |
468 | SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), |
469 | asoc->state, asoc->ep, asoc, t, | |
470 | GFP_ATOMIC); | |
471 | } | |
1da177e4 LT |
472 | } |
473 | ||
474 | /* Common lookup code for icmp/icmpv6 error handler. */ | |
4110cc25 | 475 | struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb, |
1da177e4 | 476 | struct sctphdr *sctphdr, |
1da177e4 LT |
477 | struct sctp_association **app, |
478 | struct sctp_transport **tpp) | |
479 | { | |
804ec7eb | 480 | struct sctp_init_chunk *chunkhdr, _chunkhdr; |
1da177e4 LT |
481 | union sctp_addr saddr; |
482 | union sctp_addr daddr; | |
483 | struct sctp_af *af; | |
484 | struct sock *sk = NULL; | |
8de8c873 | 485 | struct sctp_association *asoc; |
1da177e4 | 486 | struct sctp_transport *transport = NULL; |
7115e632 | 487 | __u32 vtag = ntohl(sctphdr->vtag); |
1da177e4 | 488 | |
d1ad1ff2 | 489 | *app = NULL; *tpp = NULL; |
1da177e4 LT |
490 | |
491 | af = sctp_get_af_specific(family); | |
492 | if (unlikely(!af)) { | |
493 | return NULL; | |
494 | } | |
495 | ||
496 | /* Initialize local addresses for lookups. */ | |
497 | af->from_skb(&saddr, skb, 1); | |
498 | af->from_skb(&daddr, skb, 0); | |
499 | ||
500 | /* Look for an association that matches the incoming ICMP error | |
501 | * packet. | |
502 | */ | |
4110cc25 | 503 | asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport); |
d1ad1ff2 SS |
504 | if (!asoc) |
505 | return NULL; | |
1da177e4 | 506 | |
d1ad1ff2 | 507 | sk = asoc->base.sk; |
1da177e4 | 508 | |
7115e632 WY |
509 | /* RFC 4960, Appendix C. ICMP Handling |
510 | * | |
511 | * ICMP6) An implementation MUST validate that the Verification Tag | |
512 | * contained in the ICMP message matches the Verification Tag of | |
513 | * the peer. If the Verification Tag is not 0 and does NOT | |
514 | * match, discard the ICMP message. If it is 0 and the ICMP | |
515 | * message contains enough bytes to verify that the chunk type is | |
516 | * an INIT chunk and that the Initiate Tag matches the tag of the | |
517 | * peer, continue with ICMP7. If the ICMP message is too short | |
518 | * or the chunk type or the Initiate Tag does not match, silently | |
519 | * discard the packet. | |
520 | */ | |
521 | if (vtag == 0) { | |
804ec7eb DC |
522 | /* chunk header + first 4 octects of init header */ |
523 | chunkhdr = skb_header_pointer(skb, skb_transport_offset(skb) + | |
524 | sizeof(struct sctphdr), | |
525 | sizeof(struct sctp_chunkhdr) + | |
526 | sizeof(__be32), &_chunkhdr); | |
527 | if (!chunkhdr || | |
7115e632 | 528 | chunkhdr->chunk_hdr.type != SCTP_CID_INIT || |
804ec7eb | 529 | ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) |
7115e632 | 530 | goto out; |
804ec7eb | 531 | |
7115e632 | 532 | } else if (vtag != asoc->c.peer_vtag) { |
d1ad1ff2 SS |
533 | goto out; |
534 | } | |
1da177e4 | 535 | |
5bc1d1b4 | 536 | bh_lock_sock(sk); |
1da177e4 LT |
537 | |
538 | /* If too many ICMPs get dropped on busy | |
539 | * servers this needs to be solved differently. | |
540 | */ | |
541 | if (sock_owned_by_user(sk)) | |
02a1d6e7 | 542 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
1da177e4 | 543 | |
1da177e4 LT |
544 | *app = asoc; |
545 | *tpp = transport; | |
546 | return sk; | |
547 | ||
548 | out: | |
dae399d7 | 549 | sctp_transport_put(transport); |
1da177e4 LT |
550 | return NULL; |
551 | } | |
552 | ||
553 | /* Common cleanup code for icmp/icmpv6 error handler. */ | |
dae399d7 | 554 | void sctp_err_finish(struct sock *sk, struct sctp_transport *t) |
1da177e4 | 555 | { |
5bc1d1b4 | 556 | bh_unlock_sock(sk); |
dae399d7 | 557 | sctp_transport_put(t); |
1da177e4 LT |
558 | } |
559 | ||
560 | /* | |
561 | * This routine is called by the ICMP module when it gets some | |
562 | * sort of error condition. If err < 0 then the socket should | |
563 | * be closed and the error returned to the user. If err > 0 | |
564 | * it's just the icmp type << 8 | icmp code. After adjustment | |
565 | * header points to the first 8 bytes of the sctp header. We need | |
566 | * to find the appropriate port. | |
567 | * | |
568 | * The locking strategy used here is very "optimistic". When | |
569 | * someone else accesses the socket the ICMP is just dropped | |
570 | * and for some paths there is no check at all. | |
571 | * A more general error queue to queue errors for later handling | |
572 | * is probably better. | |
573 | * | |
574 | */ | |
575 | void sctp_v4_err(struct sk_buff *skb, __u32 info) | |
576 | { | |
b71d1d42 | 577 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
a27ef749 | 578 | const int ihlen = iph->ihl * 4; |
88c7664f ACM |
579 | const int type = icmp_hdr(skb)->type; |
580 | const int code = icmp_hdr(skb)->code; | |
1da177e4 | 581 | struct sock *sk; |
8de8c873 | 582 | struct sctp_association *asoc = NULL; |
1da177e4 LT |
583 | struct sctp_transport *transport; |
584 | struct inet_sock *inet; | |
aef6de51 | 585 | __u16 saveip, savesctp; |
1da177e4 | 586 | int err; |
4110cc25 | 587 | struct net *net = dev_net(skb->dev); |
1da177e4 | 588 | |
1da177e4 | 589 | /* Fix up skb to look at the embedded net header. */ |
b0e380b1 ACM |
590 | saveip = skb->network_header; |
591 | savesctp = skb->transport_header; | |
31c7711b | 592 | skb_reset_network_header(skb); |
a27ef749 | 593 | skb_set_transport_header(skb, ihlen); |
4110cc25 | 594 | sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport); |
2e07fa9c | 595 | /* Put back, the original values. */ |
b0e380b1 ACM |
596 | skb->network_header = saveip; |
597 | skb->transport_header = savesctp; | |
1da177e4 | 598 | if (!sk) { |
5d3848bc | 599 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
600 | return; |
601 | } | |
602 | /* Warning: The sock lock is held. Remember to call | |
603 | * sctp_err_finish! | |
604 | */ | |
605 | ||
606 | switch (type) { | |
607 | case ICMP_PARAMETERPROB: | |
608 | err = EPROTO; | |
609 | break; | |
610 | case ICMP_DEST_UNREACH: | |
611 | if (code > NR_ICMP_UNREACH) | |
612 | goto out_unlock; | |
613 | ||
614 | /* PMTU discovery (RFC1191) */ | |
615 | if (ICMP_FRAG_NEEDED == code) { | |
3822a5ff | 616 | sctp_icmp_frag_needed(sk, asoc, transport, |
e2f036a9 | 617 | SCTP_TRUNC4(info)); |
1da177e4 | 618 | goto out_unlock; |
8d72651d | 619 | } else { |
1da177e4 | 620 | if (ICMP_PROT_UNREACH == code) { |
d1ad1ff2 | 621 | sctp_icmp_proto_unreachable(sk, asoc, |
1da177e4 LT |
622 | transport); |
623 | goto out_unlock; | |
624 | } | |
625 | } | |
626 | err = icmp_err_convert[code].errno; | |
627 | break; | |
628 | case ICMP_TIME_EXCEEDED: | |
629 | /* Ignore any time exceeded errors due to fragment reassembly | |
630 | * timeouts. | |
631 | */ | |
632 | if (ICMP_EXC_FRAGTIME == code) | |
633 | goto out_unlock; | |
634 | ||
635 | err = EHOSTUNREACH; | |
636 | break; | |
55be7a9c DM |
637 | case ICMP_REDIRECT: |
638 | sctp_icmp_redirect(sk, transport, skb); | |
3f96a532 | 639 | /* Fall through to out_unlock. */ |
1da177e4 LT |
640 | default: |
641 | goto out_unlock; | |
642 | } | |
643 | ||
644 | inet = inet_sk(sk); | |
645 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
646 | sk->sk_err = err; | |
647 | sk->sk_error_report(sk); | |
648 | } else { /* Only an error on timeout */ | |
649 | sk->sk_err_soft = err; | |
650 | } | |
651 | ||
652 | out_unlock: | |
dae399d7 | 653 | sctp_err_finish(sk, transport); |
1da177e4 LT |
654 | } |
655 | ||
656 | /* | |
657 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. | |
658 | * | |
659 | * This function scans all the chunks in the OOTB packet to determine if | |
660 | * the packet should be discarded right away. If a response might be needed | |
661 | * for this packet, or, if further processing is possible, the packet will | |
662 | * be queued to a proper inqueue for the next phase of handling. | |
663 | * | |
664 | * Output: | |
665 | * Return 0 - If further processing is needed. | |
666 | * Return 1 - If the packet can be discarded right away. | |
667 | */ | |
04675210 | 668 | static int sctp_rcv_ootb(struct sk_buff *skb) |
1da177e4 | 669 | { |
922dbc5b | 670 | struct sctp_chunkhdr *ch, _ch; |
3acb50c1 | 671 | int ch_end, offset = 0; |
1da177e4 LT |
672 | |
673 | /* Scan through all the chunks in the packet. */ | |
a7d1f1b6 | 674 | do { |
3acb50c1 | 675 | /* Make sure we have at least the header there */ |
922dbc5b | 676 | if (offset + sizeof(_ch) > skb->len) |
3acb50c1 MRL |
677 | break; |
678 | ||
679 | ch = skb_header_pointer(skb, offset, sizeof(*ch), &_ch); | |
680 | ||
a7d1f1b6 | 681 | /* Break out if chunk length is less then minimal. */ |
922dbc5b | 682 | if (ntohs(ch->length) < sizeof(_ch)) |
a7d1f1b6 TF |
683 | break; |
684 | ||
e2f036a9 | 685 | ch_end = offset + SCTP_PAD4(ntohs(ch->length)); |
3acb50c1 | 686 | if (ch_end > skb->len) |
a7d1f1b6 | 687 | break; |
1da177e4 LT |
688 | |
689 | /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the | |
690 | * receiver MUST silently discard the OOTB packet and take no | |
691 | * further action. | |
692 | */ | |
693 | if (SCTP_CID_ABORT == ch->type) | |
694 | goto discard; | |
695 | ||
696 | /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE | |
697 | * chunk, the receiver should silently discard the packet | |
698 | * and take no further action. | |
699 | */ | |
700 | if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) | |
701 | goto discard; | |
702 | ||
3c77f961 VY |
703 | /* RFC 4460, 2.11.2 |
704 | * This will discard packets with INIT chunk bundled as | |
705 | * subsequent chunks in the packet. When INIT is first, | |
706 | * the normal INIT processing will discard the chunk. | |
707 | */ | |
708 | if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) | |
709 | goto discard; | |
710 | ||
3acb50c1 MRL |
711 | offset = ch_end; |
712 | } while (ch_end < skb->len); | |
1da177e4 LT |
713 | |
714 | return 0; | |
715 | ||
716 | discard: | |
717 | return 1; | |
718 | } | |
719 | ||
720 | /* Insert endpoint into the hash table. */ | |
721 | static void __sctp_hash_endpoint(struct sctp_endpoint *ep) | |
722 | { | |
4cdadcbc | 723 | struct net *net = sock_net(ep->base.sk); |
1da177e4 LT |
724 | struct sctp_ep_common *epb; |
725 | struct sctp_hashbucket *head; | |
726 | ||
727 | epb = &ep->base; | |
728 | ||
4cdadcbc | 729 | epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); |
1da177e4 LT |
730 | head = &sctp_ep_hashtable[epb->hashent]; |
731 | ||
387602df | 732 | write_lock(&head->lock); |
d970dbf8 | 733 | hlist_add_head(&epb->node, &head->chain); |
387602df | 734 | write_unlock(&head->lock); |
1da177e4 LT |
735 | } |
736 | ||
737 | /* Add an endpoint to the hash. Local BH-safe. */ | |
738 | void sctp_hash_endpoint(struct sctp_endpoint *ep) | |
739 | { | |
79b91130 | 740 | local_bh_disable(); |
1da177e4 | 741 | __sctp_hash_endpoint(ep); |
79b91130 | 742 | local_bh_enable(); |
1da177e4 LT |
743 | } |
744 | ||
745 | /* Remove endpoint from the hash table. */ | |
746 | static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) | |
747 | { | |
4cdadcbc | 748 | struct net *net = sock_net(ep->base.sk); |
1da177e4 LT |
749 | struct sctp_hashbucket *head; |
750 | struct sctp_ep_common *epb; | |
751 | ||
752 | epb = &ep->base; | |
753 | ||
4cdadcbc | 754 | epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port); |
1da177e4 LT |
755 | |
756 | head = &sctp_ep_hashtable[epb->hashent]; | |
757 | ||
387602df | 758 | write_lock(&head->lock); |
2eebc1e1 | 759 | hlist_del_init(&epb->node); |
387602df | 760 | write_unlock(&head->lock); |
1da177e4 LT |
761 | } |
762 | ||
763 | /* Remove endpoint from the hash. Local BH-safe. */ | |
764 | void sctp_unhash_endpoint(struct sctp_endpoint *ep) | |
765 | { | |
79b91130 | 766 | local_bh_disable(); |
1da177e4 | 767 | __sctp_unhash_endpoint(ep); |
79b91130 | 768 | local_bh_enable(); |
1da177e4 LT |
769 | } |
770 | ||
771 | /* Look up an endpoint. */ | |
4cdadcbc EB |
772 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net, |
773 | const union sctp_addr *laddr) | |
1da177e4 LT |
774 | { |
775 | struct sctp_hashbucket *head; | |
776 | struct sctp_ep_common *epb; | |
777 | struct sctp_endpoint *ep; | |
778 | int hash; | |
779 | ||
4cdadcbc | 780 | hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port)); |
1da177e4 LT |
781 | head = &sctp_ep_hashtable[hash]; |
782 | read_lock(&head->lock); | |
b67bfe0d | 783 | sctp_for_each_hentry(epb, &head->chain) { |
1da177e4 | 784 | ep = sctp_ep(epb); |
4cdadcbc | 785 | if (sctp_endpoint_is_match(ep, net, laddr)) |
1da177e4 LT |
786 | goto hit; |
787 | } | |
788 | ||
2ce95503 | 789 | ep = sctp_sk(net->sctp.ctl_sock)->ep; |
1da177e4 LT |
790 | |
791 | hit: | |
792 | sctp_endpoint_hold(ep); | |
1da177e4 LT |
793 | read_unlock(&head->lock); |
794 | return ep; | |
795 | } | |
796 | ||
d6c0256a XL |
797 | /* rhashtable for transport */ |
798 | struct sctp_hash_cmp_arg { | |
7fda702f XL |
799 | const union sctp_addr *paddr; |
800 | const struct net *net; | |
8d32503e | 801 | __be16 lport; |
d6c0256a XL |
802 | }; |
803 | ||
804 | static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg, | |
805 | const void *ptr) | |
806 | { | |
715f5552 | 807 | struct sctp_transport *t = (struct sctp_transport *)ptr; |
d6c0256a | 808 | const struct sctp_hash_cmp_arg *x = arg->key; |
715f5552 | 809 | int err = 1; |
d6c0256a | 810 | |
d6c0256a | 811 | if (!sctp_cmp_addr_exact(&t->ipaddr, x->paddr)) |
715f5552 XL |
812 | return err; |
813 | if (!sctp_transport_hold(t)) | |
814 | return err; | |
815 | ||
7fda702f XL |
816 | if (!net_eq(sock_net(t->asoc->base.sk), x->net)) |
817 | goto out; | |
818 | if (x->lport != htons(t->asoc->base.bind_addr.port)) | |
715f5552 | 819 | goto out; |
d6c0256a | 820 | |
715f5552 XL |
821 | err = 0; |
822 | out: | |
823 | sctp_transport_put(t); | |
824 | return err; | |
d6c0256a XL |
825 | } |
826 | ||
8d32503e | 827 | static inline __u32 sctp_hash_obj(const void *data, u32 len, u32 seed) |
d6c0256a XL |
828 | { |
829 | const struct sctp_transport *t = data; | |
830 | const union sctp_addr *paddr = &t->ipaddr; | |
831 | const struct net *net = sock_net(t->asoc->base.sk); | |
8d32503e XL |
832 | __be16 lport = htons(t->asoc->base.bind_addr.port); |
833 | __u32 addr; | |
d6c0256a XL |
834 | |
835 | if (paddr->sa.sa_family == AF_INET6) | |
836 | addr = jhash(&paddr->v6.sin6_addr, 16, seed); | |
837 | else | |
8d32503e | 838 | addr = (__force __u32)paddr->v4.sin_addr.s_addr; |
d6c0256a | 839 | |
8d32503e | 840 | return jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 | |
d6c0256a XL |
841 | (__force __u32)lport, net_hash_mix(net), seed); |
842 | } | |
843 | ||
8d32503e | 844 | static inline __u32 sctp_hash_key(const void *data, u32 len, u32 seed) |
d6c0256a XL |
845 | { |
846 | const struct sctp_hash_cmp_arg *x = data; | |
847 | const union sctp_addr *paddr = x->paddr; | |
848 | const struct net *net = x->net; | |
8d32503e XL |
849 | __be16 lport = x->lport; |
850 | __u32 addr; | |
d6c0256a XL |
851 | |
852 | if (paddr->sa.sa_family == AF_INET6) | |
853 | addr = jhash(&paddr->v6.sin6_addr, 16, seed); | |
854 | else | |
8d32503e | 855 | addr = (__force __u32)paddr->v4.sin_addr.s_addr; |
d6c0256a | 856 | |
8d32503e | 857 | return jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 | |
d6c0256a XL |
858 | (__force __u32)lport, net_hash_mix(net), seed); |
859 | } | |
860 | ||
861 | static const struct rhashtable_params sctp_hash_params = { | |
862 | .head_offset = offsetof(struct sctp_transport, node), | |
863 | .hashfn = sctp_hash_key, | |
864 | .obj_hashfn = sctp_hash_obj, | |
865 | .obj_cmpfn = sctp_hash_cmp, | |
866 | .automatic_shrinking = true, | |
867 | }; | |
868 | ||
869 | int sctp_transport_hashtable_init(void) | |
870 | { | |
7fda702f | 871 | return rhltable_init(&sctp_transport_hashtable, &sctp_hash_params); |
d6c0256a XL |
872 | } |
873 | ||
874 | void sctp_transport_hashtable_destroy(void) | |
875 | { | |
7fda702f | 876 | rhltable_destroy(&sctp_transport_hashtable); |
d6c0256a XL |
877 | } |
878 | ||
7fda702f | 879 | int sctp_hash_transport(struct sctp_transport *t) |
d6c0256a | 880 | { |
cd2b7087 XL |
881 | struct sctp_transport *transport; |
882 | struct rhlist_head *tmp, *list; | |
d6c0256a | 883 | struct sctp_hash_cmp_arg arg; |
7fda702f | 884 | int err; |
d6c0256a | 885 | |
dd7445ad | 886 | if (t->asoc->temp) |
7fda702f | 887 | return 0; |
dd7445ad | 888 | |
d6c0256a | 889 | arg.net = sock_net(t->asoc->base.sk); |
7fda702f XL |
890 | arg.paddr = &t->ipaddr; |
891 | arg.lport = htons(t->asoc->base.bind_addr.port); | |
d6c0256a | 892 | |
5179b266 | 893 | rcu_read_lock(); |
cd2b7087 XL |
894 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
895 | sctp_hash_params); | |
896 | ||
897 | rhl_for_each_entry_rcu(transport, tmp, list, node) | |
898 | if (transport->asoc->ep == t->asoc->ep) { | |
5179b266 | 899 | rcu_read_unlock(); |
36728a6b | 900 | return -EEXIST; |
cd2b7087 | 901 | } |
5179b266 | 902 | rcu_read_unlock(); |
cd2b7087 | 903 | |
7fda702f XL |
904 | err = rhltable_insert_key(&sctp_transport_hashtable, &arg, |
905 | &t->node, sctp_hash_params); | |
906 | if (err) | |
907 | pr_err_once("insert transport fail, errno %d\n", err); | |
908 | ||
909 | return err; | |
d6c0256a XL |
910 | } |
911 | ||
912 | void sctp_unhash_transport(struct sctp_transport *t) | |
913 | { | |
dd7445ad XL |
914 | if (t->asoc->temp) |
915 | return; | |
916 | ||
7fda702f XL |
917 | rhltable_remove(&sctp_transport_hashtable, &t->node, |
918 | sctp_hash_params); | |
d6c0256a XL |
919 | } |
920 | ||
7fda702f | 921 | /* return a transport with holding it */ |
d6c0256a XL |
922 | struct sctp_transport *sctp_addrs_lookup_transport( |
923 | struct net *net, | |
924 | const union sctp_addr *laddr, | |
925 | const union sctp_addr *paddr) | |
926 | { | |
7fda702f XL |
927 | struct rhlist_head *tmp, *list; |
928 | struct sctp_transport *t; | |
d6c0256a | 929 | struct sctp_hash_cmp_arg arg = { |
d6c0256a XL |
930 | .paddr = paddr, |
931 | .net = net, | |
7fda702f | 932 | .lport = laddr->v4.sin_port, |
d6c0256a XL |
933 | }; |
934 | ||
7fda702f XL |
935 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
936 | sctp_hash_params); | |
937 | ||
938 | rhl_for_each_entry_rcu(t, tmp, list, node) { | |
939 | if (!sctp_transport_hold(t)) | |
940 | continue; | |
941 | ||
942 | if (sctp_bind_addr_match(&t->asoc->base.bind_addr, | |
943 | laddr, sctp_sk(t->asoc->base.sk))) | |
944 | return t; | |
945 | sctp_transport_put(t); | |
946 | } | |
947 | ||
948 | return NULL; | |
d6c0256a XL |
949 | } |
950 | ||
7fda702f | 951 | /* return a transport without holding it, as it's only used under sock lock */ |
d6c0256a XL |
952 | struct sctp_transport *sctp_epaddr_lookup_transport( |
953 | const struct sctp_endpoint *ep, | |
954 | const union sctp_addr *paddr) | |
955 | { | |
d6c0256a | 956 | struct net *net = sock_net(ep->base.sk); |
7fda702f XL |
957 | struct rhlist_head *tmp, *list; |
958 | struct sctp_transport *t; | |
65a5124a | 959 | struct sctp_hash_cmp_arg arg = { |
65a5124a XL |
960 | .paddr = paddr, |
961 | .net = net, | |
7fda702f | 962 | .lport = htons(ep->base.bind_addr.port), |
65a5124a | 963 | }; |
d6c0256a | 964 | |
7fda702f XL |
965 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
966 | sctp_hash_params); | |
967 | ||
968 | rhl_for_each_entry_rcu(t, tmp, list, node) | |
969 | if (ep == t->asoc->ep) | |
970 | return t; | |
971 | ||
972 | return NULL; | |
d6c0256a XL |
973 | } |
974 | ||
1da177e4 LT |
975 | /* Look up an association. */ |
976 | static struct sctp_association *__sctp_lookup_association( | |
4110cc25 | 977 | struct net *net, |
1da177e4 LT |
978 | const union sctp_addr *local, |
979 | const union sctp_addr *peer, | |
980 | struct sctp_transport **pt) | |
981 | { | |
4f008781 | 982 | struct sctp_transport *t; |
1eed6779 | 983 | struct sctp_association *asoc = NULL; |
1da177e4 | 984 | |
4f008781 | 985 | t = sctp_addrs_lookup_transport(net, local, peer); |
7fda702f | 986 | if (!t) |
1eed6779 | 987 | goto out; |
1da177e4 | 988 | |
1eed6779 | 989 | asoc = t->asoc; |
4f008781 | 990 | *pt = t; |
1da177e4 | 991 | |
1eed6779 | 992 | out: |
1eed6779 | 993 | return asoc; |
1da177e4 LT |
994 | } |
995 | ||
4f008781 | 996 | /* Look up an association. protected by RCU read lock */ |
dda91928 | 997 | static |
4110cc25 EB |
998 | struct sctp_association *sctp_lookup_association(struct net *net, |
999 | const union sctp_addr *laddr, | |
1da177e4 | 1000 | const union sctp_addr *paddr, |
dda91928 | 1001 | struct sctp_transport **transportp) |
1da177e4 LT |
1002 | { |
1003 | struct sctp_association *asoc; | |
1004 | ||
f46c7011 | 1005 | rcu_read_lock(); |
4110cc25 | 1006 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp); |
f46c7011 | 1007 | rcu_read_unlock(); |
1da177e4 LT |
1008 | |
1009 | return asoc; | |
1010 | } | |
1011 | ||
1012 | /* Is there an association matching the given local and peer addresses? */ | |
4110cc25 EB |
1013 | int sctp_has_association(struct net *net, |
1014 | const union sctp_addr *laddr, | |
1da177e4 LT |
1015 | const union sctp_addr *paddr) |
1016 | { | |
1017 | struct sctp_association *asoc; | |
1018 | struct sctp_transport *transport; | |
1019 | ||
4110cc25 | 1020 | if ((asoc = sctp_lookup_association(net, laddr, paddr, &transport))) { |
dae399d7 | 1021 | sctp_transport_put(transport); |
1da177e4 LT |
1022 | return 1; |
1023 | } | |
1024 | ||
1025 | return 0; | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * SCTP Implementors Guide, 2.18 Handling of address | |
1030 | * parameters within the INIT or INIT-ACK. | |
1031 | * | |
1032 | * D) When searching for a matching TCB upon reception of an INIT | |
1033 | * or INIT-ACK chunk the receiver SHOULD use not only the | |
1034 | * source address of the packet (containing the INIT or | |
1035 | * INIT-ACK) but the receiver SHOULD also use all valid | |
1036 | * address parameters contained within the chunk. | |
1037 | * | |
1038 | * 2.18.3 Solution description | |
1039 | * | |
1040 | * This new text clearly specifies to an implementor the need | |
1041 | * to look within the INIT or INIT-ACK. Any implementation that | |
1042 | * does not do this, may not be able to establish associations | |
1043 | * in certain circumstances. | |
1044 | * | |
1045 | */ | |
4110cc25 EB |
1046 | static struct sctp_association *__sctp_rcv_init_lookup(struct net *net, |
1047 | struct sk_buff *skb, | |
1da177e4 LT |
1048 | const union sctp_addr *laddr, struct sctp_transport **transportp) |
1049 | { | |
1050 | struct sctp_association *asoc; | |
1051 | union sctp_addr addr; | |
1052 | union sctp_addr *paddr = &addr; | |
2c0fd387 | 1053 | struct sctphdr *sh = sctp_hdr(skb); |
1da177e4 | 1054 | union sctp_params params; |
01a992be | 1055 | struct sctp_init_chunk *init; |
1da177e4 LT |
1056 | struct sctp_af *af; |
1057 | ||
1da177e4 LT |
1058 | /* |
1059 | * This code will NOT touch anything inside the chunk--it is | |
1060 | * strictly READ-ONLY. | |
1061 | * | |
1062 | * RFC 2960 3 SCTP packet Format | |
1063 | * | |
1064 | * Multiple chunks can be bundled into one SCTP packet up to | |
1065 | * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN | |
1066 | * COMPLETE chunks. These chunks MUST NOT be bundled with any | |
1067 | * other chunk in a packet. See Section 6.10 for more details | |
1068 | * on chunk bundling. | |
1069 | */ | |
1070 | ||
1071 | /* Find the start of the TLVs and the end of the chunk. This is | |
1072 | * the region we search for address parameters. | |
1073 | */ | |
01a992be | 1074 | init = (struct sctp_init_chunk *)skb->data; |
1da177e4 LT |
1075 | |
1076 | /* Walk the parameters looking for embedded addresses. */ | |
1077 | sctp_walk_params(params, init, init_hdr.params) { | |
1078 | ||
1079 | /* Note: Ignoring hostname addresses. */ | |
1080 | af = sctp_get_af_specific(param_type2af(params.p->type)); | |
1081 | if (!af) | |
1082 | continue; | |
1083 | ||
dd86d136 | 1084 | af->from_addr_param(paddr, params.addr, sh->source, 0); |
1da177e4 | 1085 | |
7c17fcc7 | 1086 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp); |
1da177e4 LT |
1087 | if (asoc) |
1088 | return asoc; | |
1089 | } | |
1090 | ||
1091 | return NULL; | |
1092 | } | |
1093 | ||
df218577 VY |
1094 | /* ADD-IP, Section 5.2 |
1095 | * When an endpoint receives an ASCONF Chunk from the remote peer | |
1096 | * special procedures may be needed to identify the association the | |
1097 | * ASCONF Chunk is associated with. To properly find the association | |
1098 | * the following procedures SHOULD be followed: | |
1099 | * | |
1100 | * D2) If the association is not found, use the address found in the | |
1101 | * Address Parameter TLV combined with the port number found in the | |
1102 | * SCTP common header. If found proceed to rule D4. | |
1103 | * | |
1104 | * D2-ext) If more than one ASCONF Chunks are packed together, use the | |
1105 | * address found in the ASCONF Address Parameter TLV of each of the | |
1106 | * subsequent ASCONF Chunks. If found, proceed to rule D4. | |
1107 | */ | |
1108 | static struct sctp_association *__sctp_rcv_asconf_lookup( | |
4110cc25 | 1109 | struct net *net, |
922dbc5b | 1110 | struct sctp_chunkhdr *ch, |
df218577 | 1111 | const union sctp_addr *laddr, |
bc92dd19 | 1112 | __be16 peer_port, |
df218577 VY |
1113 | struct sctp_transport **transportp) |
1114 | { | |
68d75469 | 1115 | struct sctp_addip_chunk *asconf = (struct sctp_addip_chunk *)ch; |
df218577 VY |
1116 | struct sctp_af *af; |
1117 | union sctp_addr_param *param; | |
1118 | union sctp_addr paddr; | |
1119 | ||
1120 | /* Skip over the ADDIP header and find the Address parameter */ | |
1121 | param = (union sctp_addr_param *)(asconf + 1); | |
1122 | ||
6a435732 | 1123 | af = sctp_get_af_specific(param_type2af(param->p.type)); |
df218577 VY |
1124 | if (unlikely(!af)) |
1125 | return NULL; | |
1126 | ||
1127 | af->from_addr_param(&paddr, param, peer_port, 0); | |
1128 | ||
4110cc25 | 1129 | return __sctp_lookup_association(net, laddr, &paddr, transportp); |
df218577 VY |
1130 | } |
1131 | ||
1132 | ||
bbd0d598 VY |
1133 | /* SCTP-AUTH, Section 6.3: |
1134 | * If the receiver does not find a STCB for a packet containing an AUTH | |
1135 | * chunk as the first chunk and not a COOKIE-ECHO chunk as the second | |
1136 | * chunk, it MUST use the chunks after the AUTH chunk to look up an existing | |
1137 | * association. | |
1138 | * | |
1139 | * This means that any chunks that can help us identify the association need | |
25985edc | 1140 | * to be looked at to find this association. |
bbd0d598 | 1141 | */ |
4110cc25 EB |
1142 | static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, |
1143 | struct sk_buff *skb, | |
bbd0d598 VY |
1144 | const union sctp_addr *laddr, |
1145 | struct sctp_transport **transportp) | |
1146 | { | |
df218577 | 1147 | struct sctp_association *asoc = NULL; |
922dbc5b | 1148 | struct sctp_chunkhdr *ch; |
df218577 VY |
1149 | int have_auth = 0; |
1150 | unsigned int chunk_num = 1; | |
1151 | __u8 *ch_end; | |
1152 | ||
1153 | /* Walk through the chunks looking for AUTH or ASCONF chunks | |
1154 | * to help us find the association. | |
bbd0d598 | 1155 | */ |
922dbc5b | 1156 | ch = (struct sctp_chunkhdr *)skb->data; |
df218577 VY |
1157 | do { |
1158 | /* Break out if chunk length is less then minimal. */ | |
922dbc5b | 1159 | if (ntohs(ch->length) < sizeof(*ch)) |
df218577 VY |
1160 | break; |
1161 | ||
e2f036a9 | 1162 | ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length)); |
df218577 VY |
1163 | if (ch_end > skb_tail_pointer(skb)) |
1164 | break; | |
1165 | ||
cb3f837b | 1166 | switch (ch->type) { |
f7010e61 | 1167 | case SCTP_CID_AUTH: |
1168 | have_auth = chunk_num; | |
1169 | break; | |
1170 | ||
1171 | case SCTP_CID_COOKIE_ECHO: | |
1172 | /* If a packet arrives containing an AUTH chunk as | |
1173 | * a first chunk, a COOKIE-ECHO chunk as the second | |
1174 | * chunk, and possibly more chunks after them, and | |
1175 | * the receiver does not have an STCB for that | |
1176 | * packet, then authentication is based on | |
1177 | * the contents of the COOKIE- ECHO chunk. | |
1178 | */ | |
1179 | if (have_auth == 1 && chunk_num == 2) | |
1180 | return NULL; | |
1181 | break; | |
1182 | ||
1183 | case SCTP_CID_ASCONF: | |
1184 | if (have_auth || net->sctp.addip_noauth) | |
1185 | asoc = __sctp_rcv_asconf_lookup( | |
1186 | net, ch, laddr, | |
1187 | sctp_hdr(skb)->source, | |
1188 | transportp); | |
1189 | default: | |
1190 | break; | |
df218577 VY |
1191 | } |
1192 | ||
1193 | if (asoc) | |
1194 | break; | |
1195 | ||
922dbc5b | 1196 | ch = (struct sctp_chunkhdr *)ch_end; |
df218577 VY |
1197 | chunk_num++; |
1198 | } while (ch_end < skb_tail_pointer(skb)); | |
1199 | ||
1200 | return asoc; | |
bbd0d598 VY |
1201 | } |
1202 | ||
1203 | /* | |
1204 | * There are circumstances when we need to look inside the SCTP packet | |
1205 | * for information to help us find the association. Examples | |
1206 | * include looking inside of INIT/INIT-ACK chunks or after the AUTH | |
1207 | * chunks. | |
1208 | */ | |
4110cc25 EB |
1209 | static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net, |
1210 | struct sk_buff *skb, | |
bbd0d598 VY |
1211 | const union sctp_addr *laddr, |
1212 | struct sctp_transport **transportp) | |
1213 | { | |
922dbc5b | 1214 | struct sctp_chunkhdr *ch; |
bbd0d598 | 1215 | |
90017acc MRL |
1216 | /* We do not allow GSO frames here as we need to linearize and |
1217 | * then cannot guarantee frame boundaries. This shouldn't be an | |
1218 | * issue as packets hitting this are mostly INIT or INIT-ACK and | |
1219 | * those cannot be on GSO-style anyway. | |
1220 | */ | |
1221 | if ((skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) == SKB_GSO_SCTP) | |
1222 | return NULL; | |
1223 | ||
922dbc5b | 1224 | ch = (struct sctp_chunkhdr *)skb->data; |
bbd0d598 | 1225 | |
df218577 VY |
1226 | /* The code below will attempt to walk the chunk and extract |
1227 | * parameter information. Before we do that, we need to verify | |
1228 | * that the chunk length doesn't cause overflow. Otherwise, we'll | |
1229 | * walk off the end. | |
1230 | */ | |
e2f036a9 | 1231 | if (SCTP_PAD4(ntohs(ch->length)) > skb->len) |
df218577 VY |
1232 | return NULL; |
1233 | ||
bbd0d598 | 1234 | /* If this is INIT/INIT-ACK look inside the chunk too. */ |
f482f2fc | 1235 | if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK) |
4110cc25 | 1236 | return __sctp_rcv_init_lookup(net, skb, laddr, transportp); |
bbd0d598 | 1237 | |
f482f2fc | 1238 | return __sctp_rcv_walk_lookup(net, skb, laddr, transportp); |
bbd0d598 VY |
1239 | } |
1240 | ||
1da177e4 | 1241 | /* Lookup an association for an inbound skb. */ |
4110cc25 EB |
1242 | static struct sctp_association *__sctp_rcv_lookup(struct net *net, |
1243 | struct sk_buff *skb, | |
1da177e4 LT |
1244 | const union sctp_addr *paddr, |
1245 | const union sctp_addr *laddr, | |
1246 | struct sctp_transport **transportp) | |
1247 | { | |
1248 | struct sctp_association *asoc; | |
1249 | ||
4110cc25 | 1250 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp); |
b77b7565 MRL |
1251 | if (asoc) |
1252 | goto out; | |
1da177e4 LT |
1253 | |
1254 | /* Further lookup for INIT/INIT-ACK packets. | |
1255 | * SCTP Implementors Guide, 2.18 Handling of address | |
1256 | * parameters within the INIT or INIT-ACK. | |
1257 | */ | |
b77b7565 MRL |
1258 | asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp); |
1259 | if (asoc) | |
1260 | goto out; | |
1da177e4 | 1261 | |
b77b7565 MRL |
1262 | if (paddr->sa.sa_family == AF_INET) |
1263 | pr_debug("sctp: asoc not found for src:%pI4:%d dst:%pI4:%d\n", | |
1264 | &laddr->v4.sin_addr, ntohs(laddr->v4.sin_port), | |
1265 | &paddr->v4.sin_addr, ntohs(paddr->v4.sin_port)); | |
1266 | else | |
1267 | pr_debug("sctp: asoc not found for src:%pI6:%d dst:%pI6:%d\n", | |
1268 | &laddr->v6.sin6_addr, ntohs(laddr->v6.sin6_port), | |
1269 | &paddr->v6.sin6_addr, ntohs(paddr->v6.sin6_port)); | |
1270 | ||
1271 | out: | |
1da177e4 LT |
1272 | return asoc; |
1273 | } |