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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * Copyright (c) 1999-2000 Cisco, Inc. |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001-2003 International Business Machines, Corp. | |
6 | * Copyright (c) 2001 Intel Corp. | |
7 | * Copyright (c) 2001 Nokia, Inc. | |
8 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
9 | * | |
60c778b2 | 10 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
11 | * |
12 | * These functions handle all input from the IP layer into SCTP. | |
13 | * | |
1da177e4 LT |
14 | * Please send any bug reports or fixes you make to the |
15 | * email address(es): | |
91705c61 | 16 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 17 | * |
1da177e4 LT |
18 | * Written or modified by: |
19 | * La Monte H.P. Yarroll <piggy@acm.org> | |
20 | * Karl Knutson <karl@athena.chicago.il.us> | |
21 | * Xingang Guo <xingang.guo@intel.com> | |
22 | * Jon Grimm <jgrimm@us.ibm.com> | |
23 | * Hui Huang <hui.huang@nokia.com> | |
24 | * Daisy Chang <daisyc@us.ibm.com> | |
25 | * Sridhar Samudrala <sri@us.ibm.com> | |
26 | * Ardelle Fan <ardelle.fan@intel.com> | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/types.h> | |
30 | #include <linux/list.h> /* For struct list_head */ | |
31 | #include <linux/socket.h> | |
32 | #include <linux/ip.h> | |
33 | #include <linux/time.h> /* For struct timeval */ | |
5a0e3ad6 | 34 | #include <linux/slab.h> |
1da177e4 LT |
35 | #include <net/ip.h> |
36 | #include <net/icmp.h> | |
37 | #include <net/snmp.h> | |
38 | #include <net/sock.h> | |
39 | #include <net/xfrm.h> | |
40 | #include <net/sctp/sctp.h> | |
41 | #include <net/sctp/sm.h> | |
9ad0977f | 42 | #include <net/sctp/checksum.h> |
dcfc23ca | 43 | #include <net/net_namespace.h> |
0eb71a9d | 44 | #include <linux/rhashtable.h> |
532ae2f1 | 45 | #include <net/sock_reuseport.h> |
1da177e4 LT |
46 | |
47 | /* Forward declarations for internal helpers. */ | |
48 | static int sctp_rcv_ootb(struct sk_buff *); | |
4110cc25 EB |
49 | static struct sctp_association *__sctp_rcv_lookup(struct net *net, |
50 | struct sk_buff *skb, | |
1da177e4 | 51 | const union sctp_addr *paddr, |
57565993 | 52 | const union sctp_addr *laddr, |
0af03170 XL |
53 | struct sctp_transport **transportp, |
54 | int dif, int sdif); | |
532ae2f1 XL |
55 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint( |
56 | struct net *net, struct sk_buff *skb, | |
57 | const union sctp_addr *laddr, | |
0af03170 XL |
58 | const union sctp_addr *daddr, |
59 | int dif, int sdif); | |
1da177e4 | 60 | static struct sctp_association *__sctp_lookup_association( |
4110cc25 | 61 | struct net *net, |
1da177e4 LT |
62 | const union sctp_addr *local, |
63 | const union sctp_addr *peer, | |
0af03170 XL |
64 | struct sctp_transport **pt, |
65 | int dif, int sdif); | |
1da177e4 | 66 | |
50b1a782 | 67 | static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb); |
61c9fed4 | 68 | |
1da177e4 LT |
69 | |
70 | /* Calculate the SCTP checksum of an SCTP packet. */ | |
b01a2407 | 71 | static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb) |
1da177e4 | 72 | { |
2c0fd387 | 73 | struct sctphdr *sh = sctp_hdr(skb); |
4458f04c | 74 | __le32 cmp = sh->checksum; |
024ec3de | 75 | __le32 val = sctp_compute_cksum(skb, 0); |
1da177e4 LT |
76 | |
77 | if (val != cmp) { | |
78 | /* CRC failure, dump it. */ | |
08e3baef | 79 | __SCTP_INC_STATS(net, SCTP_MIB_CHECKSUMERRORS); |
1da177e4 LT |
80 | return -1; |
81 | } | |
82 | return 0; | |
83 | } | |
84 | ||
1da177e4 LT |
85 | /* |
86 | * This is the routine which IP calls when receiving an SCTP packet. | |
87 | */ | |
88 | int sctp_rcv(struct sk_buff *skb) | |
89 | { | |
90 | struct sock *sk; | |
91 | struct sctp_association *asoc; | |
92 | struct sctp_endpoint *ep = NULL; | |
93 | struct sctp_ep_common *rcvr; | |
94 | struct sctp_transport *transport = NULL; | |
95 | struct sctp_chunk *chunk; | |
1da177e4 LT |
96 | union sctp_addr src; |
97 | union sctp_addr dest; | |
98 | int family; | |
99 | struct sctp_af *af; | |
4cdadcbc | 100 | struct net *net = dev_net(skb->dev); |
1dd27cde | 101 | bool is_gso = skb_is_gso(skb) && skb_is_gso_sctp(skb); |
0af03170 | 102 | int dif, sdif; |
1da177e4 | 103 | |
cb3f837b | 104 | if (skb->pkt_type != PACKET_HOST) |
1da177e4 LT |
105 | goto discard_it; |
106 | ||
08e3baef | 107 | __SCTP_INC_STATS(net, SCTP_MIB_INSCTPPACKS); |
1da177e4 | 108 | |
3acb50c1 MRL |
109 | /* If packet is too small to contain a single chunk, let's not |
110 | * waste time on it anymore. | |
111 | */ | |
112 | if (skb->len < sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + | |
113 | skb_transport_offset(skb)) | |
28cd7752 HX |
114 | goto discard_it; |
115 | ||
4c2f2454 MRL |
116 | /* If the packet is fragmented and we need to do crc checking, |
117 | * it's better to just linearize it otherwise crc computing | |
118 | * takes longer. | |
119 | */ | |
1dd27cde | 120 | if ((!is_gso && skb_linearize(skb)) || |
4c2f2454 | 121 | !pskb_may_pull(skb, sizeof(struct sctphdr))) |
3acb50c1 | 122 | goto discard_it; |
1da177e4 | 123 | |
3acb50c1 | 124 | /* Pull up the IP header. */ |
ea2ae17d | 125 | __skb_pull(skb, skb_transport_offset(skb)); |
202863fe TH |
126 | |
127 | skb->csum_valid = 0; /* Previous value not applicable */ | |
128 | if (skb_csum_unnecessary(skb)) | |
129 | __skb_decr_checksum_unnecessary(skb); | |
90017acc | 130 | else if (!sctp_checksum_disable && |
1dd27cde | 131 | !is_gso && |
90017acc | 132 | sctp_rcv_checksum(net, skb) < 0) |
1da177e4 | 133 | goto discard_it; |
202863fe | 134 | skb->csum_valid = 1; |
1da177e4 | 135 | |
3acb50c1 | 136 | __skb_pull(skb, sizeof(struct sctphdr)); |
1da177e4 | 137 | |
eddc9ec5 | 138 | family = ipver2af(ip_hdr(skb)->version); |
1da177e4 LT |
139 | af = sctp_get_af_specific(family); |
140 | if (unlikely(!af)) | |
141 | goto discard_it; | |
e7487c86 | 142 | SCTP_INPUT_CB(skb)->af = af; |
1da177e4 LT |
143 | |
144 | /* Initialize local addresses for lookups. */ | |
145 | af->from_skb(&src, skb, 1); | |
146 | af->from_skb(&dest, skb, 0); | |
0af03170 XL |
147 | dif = af->skb_iif(skb); |
148 | sdif = af->skb_sdif(skb); | |
1da177e4 LT |
149 | |
150 | /* If the packet is to or from a non-unicast address, | |
151 | * silently discard the packet. | |
152 | * | |
153 | * This is not clearly defined in the RFC except in section | |
154 | * 8.4 - OOTB handling. However, based on the book "Stream Control | |
155 | * Transmission Protocol" 2.1, "It is important to note that the | |
156 | * IP address of an SCTP transport address must be a routable | |
157 | * unicast address. In other words, IP multicast addresses and | |
158 | * IP broadcast addresses cannot be used in an SCTP transport | |
159 | * address." | |
160 | */ | |
5636bef7 VY |
161 | if (!af->addr_valid(&src, NULL, skb) || |
162 | !af->addr_valid(&dest, NULL, skb)) | |
1da177e4 LT |
163 | goto discard_it; |
164 | ||
0af03170 | 165 | asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport, dif, sdif); |
1c7d1fc1 | 166 | |
0fd9a65a | 167 | if (!asoc) |
0af03170 | 168 | ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src, dif, sdif); |
0fd9a65a NH |
169 | |
170 | /* Retrieve the common input handling substructure. */ | |
171 | rcvr = asoc ? &asoc->base : &ep->base; | |
172 | sk = rcvr->sk; | |
173 | ||
1da177e4 LT |
174 | /* |
175 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. | |
176 | * An SCTP packet is called an "out of the blue" (OOTB) | |
177 | * packet if it is correctly formed, i.e., passed the | |
178 | * receiver's checksum check, but the receiver is not | |
179 | * able to identify the association to which this | |
180 | * packet belongs. | |
181 | */ | |
182 | if (!asoc) { | |
1da177e4 | 183 | if (sctp_rcv_ootb(skb)) { |
08e3baef | 184 | __SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
1da177e4 LT |
185 | goto discard_release; |
186 | } | |
187 | } | |
188 | ||
1da177e4 LT |
189 | if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family)) |
190 | goto discard_release; | |
895b5c9f | 191 | nf_reset_ct(skb); |
1da177e4 | 192 | |
fda9ef5d | 193 | if (sk_filter(sk, skb)) |
d808ad9a | 194 | goto discard_release; |
1da177e4 LT |
195 | |
196 | /* Create an SCTP packet structure. */ | |
cea8768f | 197 | chunk = sctp_chunkify(skb, asoc, sk, GFP_ATOMIC); |
2babf9da | 198 | if (!chunk) |
1da177e4 | 199 | goto discard_release; |
79af02c2 | 200 | SCTP_INPUT_CB(skb)->chunk = chunk; |
1da177e4 | 201 | |
1da177e4 LT |
202 | /* Remember what endpoint is to handle this packet. */ |
203 | chunk->rcvr = rcvr; | |
204 | ||
205 | /* Remember the SCTP header. */ | |
3acb50c1 | 206 | chunk->sctp_hdr = sctp_hdr(skb); |
1da177e4 LT |
207 | |
208 | /* Set the source and destination addresses of the incoming chunk. */ | |
d55c41b1 | 209 | sctp_init_addrs(chunk, &src, &dest); |
1da177e4 LT |
210 | |
211 | /* Remember where we came from. */ | |
212 | chunk->transport = transport; | |
213 | ||
214 | /* Acquire access to the sock lock. Note: We are safe from other | |
215 | * bottom halves on this lock, but a user may be in the lock too, | |
216 | * so check if it is busy. | |
217 | */ | |
5bc1d1b4 | 218 | bh_lock_sock(sk); |
1da177e4 | 219 | |
ae53b5bd VY |
220 | if (sk != rcvr->sk) { |
221 | /* Our cached sk is different from the rcvr->sk. This is | |
222 | * because migrate()/accept() may have moved the association | |
223 | * to a new socket and released all the sockets. So now we | |
224 | * are holding a lock on the old socket while the user may | |
225 | * be doing something with the new socket. Switch our veiw | |
226 | * of the current sk. | |
227 | */ | |
5bc1d1b4 | 228 | bh_unlock_sock(sk); |
ae53b5bd | 229 | sk = rcvr->sk; |
5bc1d1b4 | 230 | bh_lock_sock(sk); |
ae53b5bd VY |
231 | } |
232 | ||
819be810 | 233 | if (sock_owned_by_user(sk) || !sctp_newsk_ready(sk)) { |
50b1a782 | 234 | if (sctp_add_backlog(sk, skb)) { |
5bc1d1b4 | 235 | bh_unlock_sock(sk); |
50b1a782 ZY |
236 | sctp_chunk_free(chunk); |
237 | skb = NULL; /* sctp_chunk_free already freed the skb */ | |
238 | goto discard_release; | |
239 | } | |
08e3baef | 240 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_BACKLOG); |
ac0b0462 | 241 | } else { |
08e3baef | 242 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_SOFTIRQ); |
61c9fed4 | 243 | sctp_inq_push(&chunk->rcvr->inqueue, chunk); |
ac0b0462 | 244 | } |
1da177e4 | 245 | |
5bc1d1b4 | 246 | bh_unlock_sock(sk); |
61c9fed4 VY |
247 | |
248 | /* Release the asoc/ep ref we took in the lookup calls. */ | |
dae399d7 XL |
249 | if (transport) |
250 | sctp_transport_put(transport); | |
61c9fed4 VY |
251 | else |
252 | sctp_endpoint_put(ep); | |
7a48f923 | 253 | |
2babf9da | 254 | return 0; |
1da177e4 LT |
255 | |
256 | discard_it: | |
08e3baef | 257 | __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS); |
1da177e4 | 258 | kfree_skb(skb); |
2babf9da | 259 | return 0; |
1da177e4 LT |
260 | |
261 | discard_release: | |
61c9fed4 | 262 | /* Release the asoc/ep ref we took in the lookup calls. */ |
dae399d7 XL |
263 | if (transport) |
264 | sctp_transport_put(transport); | |
0fd9a65a | 265 | else |
1da177e4 | 266 | sctp_endpoint_put(ep); |
1da177e4 LT |
267 | |
268 | goto discard_it; | |
269 | } | |
270 | ||
61c9fed4 VY |
271 | /* Process the backlog queue of the socket. Every skb on |
272 | * the backlog holds a ref on an association or endpoint. | |
273 | * We hold this ref throughout the state machine to make | |
274 | * sure that the structure we need is still around. | |
1da177e4 LT |
275 | */ |
276 | int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
277 | { | |
79af02c2 | 278 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
d808ad9a | 279 | struct sctp_inq *inqueue = &chunk->rcvr->inqueue; |
dae399d7 | 280 | struct sctp_transport *t = chunk->transport; |
d808ad9a | 281 | struct sctp_ep_common *rcvr = NULL; |
61c9fed4 | 282 | int backloged = 0; |
7a48f923 | 283 | |
d808ad9a | 284 | rcvr = chunk->rcvr; |
c4d2444e | 285 | |
61c9fed4 VY |
286 | /* If the rcvr is dead then the association or endpoint |
287 | * has been deleted and we can safely drop the chunk | |
288 | * and refs that we are holding. | |
289 | */ | |
290 | if (rcvr->dead) { | |
291 | sctp_chunk_free(chunk); | |
292 | goto done; | |
293 | } | |
294 | ||
295 | if (unlikely(rcvr->sk != sk)) { | |
296 | /* In this case, the association moved from one socket to | |
297 | * another. We are currently sitting on the backlog of the | |
298 | * old socket, so we need to move. | |
299 | * However, since we are here in the process context we | |
300 | * need to take make sure that the user doesn't own | |
301 | * the new socket when we process the packet. | |
302 | * If the new socket is user-owned, queue the chunk to the | |
303 | * backlog of the new socket without dropping any refs. | |
304 | * Otherwise, we can safely push the chunk on the inqueue. | |
305 | */ | |
306 | ||
307 | sk = rcvr->sk; | |
eefc1b1d | 308 | local_bh_disable(); |
5bc1d1b4 | 309 | bh_lock_sock(sk); |
61c9fed4 | 310 | |
819be810 | 311 | if (sock_owned_by_user(sk) || !sctp_newsk_ready(sk)) { |
8265792b | 312 | if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) |
50b1a782 ZY |
313 | sctp_chunk_free(chunk); |
314 | else | |
315 | backloged = 1; | |
61c9fed4 VY |
316 | } else |
317 | sctp_inq_push(inqueue, chunk); | |
318 | ||
5bc1d1b4 | 319 | bh_unlock_sock(sk); |
eefc1b1d | 320 | local_bh_enable(); |
61c9fed4 VY |
321 | |
322 | /* If the chunk was backloged again, don't drop refs */ | |
323 | if (backloged) | |
324 | return 0; | |
325 | } else { | |
819be810 | 326 | if (!sctp_newsk_ready(sk)) { |
8265792b | 327 | if (!sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) |
819be810 XL |
328 | return 0; |
329 | sctp_chunk_free(chunk); | |
330 | } else { | |
331 | sctp_inq_push(inqueue, chunk); | |
332 | } | |
61c9fed4 VY |
333 | } |
334 | ||
335 | done: | |
336 | /* Release the refs we took in sctp_add_backlog */ | |
337 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) | |
dae399d7 | 338 | sctp_transport_put(t); |
61c9fed4 VY |
339 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
340 | sctp_endpoint_put(sctp_ep(rcvr)); | |
341 | else | |
342 | BUG(); | |
343 | ||
d808ad9a | 344 | return 0; |
1da177e4 LT |
345 | } |
346 | ||
50b1a782 | 347 | static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb) |
c4d2444e | 348 | { |
61c9fed4 | 349 | struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; |
dae399d7 | 350 | struct sctp_transport *t = chunk->transport; |
61c9fed4 | 351 | struct sctp_ep_common *rcvr = chunk->rcvr; |
50b1a782 | 352 | int ret; |
c4d2444e | 353 | |
8265792b | 354 | ret = sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf)); |
50b1a782 ZY |
355 | if (!ret) { |
356 | /* Hold the assoc/ep while hanging on the backlog queue. | |
357 | * This way, we know structures we need will not disappear | |
358 | * from us | |
359 | */ | |
360 | if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type) | |
dae399d7 | 361 | sctp_transport_hold(t); |
50b1a782 ZY |
362 | else if (SCTP_EP_TYPE_SOCKET == rcvr->type) |
363 | sctp_endpoint_hold(sctp_ep(rcvr)); | |
364 | else | |
365 | BUG(); | |
366 | } | |
367 | return ret; | |
61c9fed4 | 368 | |
c4d2444e SS |
369 | } |
370 | ||
1da177e4 LT |
371 | /* Handle icmp frag needed error. */ |
372 | void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc, | |
373 | struct sctp_transport *t, __u32 pmtu) | |
374 | { | |
83696408 XL |
375 | if (!t || |
376 | (t->pathmtu <= pmtu && | |
377 | t->pl.probe_size + sctp_transport_pl_hlen(t) <= pmtu)) | |
52ccb8e9 FF |
378 | return; |
379 | ||
8a479491 | 380 | if (sock_owned_by_user(sk)) { |
d805397c | 381 | atomic_set(&t->mtu_info, pmtu); |
8a479491 VY |
382 | asoc->pmtu_pending = 1; |
383 | t->pmtu_pending = 1; | |
384 | return; | |
385 | } | |
386 | ||
cc35c3d1 MRL |
387 | if (!(t->param_flags & SPP_PMTUD_ENABLE)) |
388 | /* We can't allow retransmitting in such case, as the | |
389 | * retransmission would be sized just as before, and thus we | |
390 | * would get another icmp, and retransmit again. | |
391 | */ | |
392 | return; | |
1da177e4 | 393 | |
b6c5734d MRL |
394 | /* Update transports view of the MTU. Return if no update was needed. |
395 | * If an update wasn't needed/possible, it also doesn't make sense to | |
396 | * try to retransmit now. | |
397 | */ | |
398 | if (!sctp_transport_update_pmtu(t, pmtu)) | |
399 | return; | |
52ccb8e9 | 400 | |
cc35c3d1 MRL |
401 | /* Update association pmtu. */ |
402 | sctp_assoc_sync_pmtu(asoc); | |
403 | ||
404 | /* Retransmit with the new pmtu setting. */ | |
52ccb8e9 | 405 | sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD); |
1da177e4 LT |
406 | } |
407 | ||
ec18d9a2 DM |
408 | void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t, |
409 | struct sk_buff *skb) | |
55be7a9c DM |
410 | { |
411 | struct dst_entry *dst; | |
412 | ||
1cc276ce | 413 | if (sock_owned_by_user(sk) || !t) |
55be7a9c DM |
414 | return; |
415 | dst = sctp_transport_dst_check(t); | |
1ed5c48f | 416 | if (dst) |
6700c270 | 417 | dst->ops->redirect(dst, sk, skb); |
55be7a9c DM |
418 | } |
419 | ||
1da177e4 LT |
420 | /* |
421 | * SCTP Implementer's Guide, 2.37 ICMP handling procedures | |
422 | * | |
423 | * ICMP8) If the ICMP code is a "Unrecognized next header type encountered" | |
424 | * or a "Protocol Unreachable" treat this message as an abort | |
425 | * with the T bit set. | |
426 | * | |
427 | * This function sends an event to the state machine, which will abort the | |
428 | * association. | |
429 | * | |
430 | */ | |
431 | void sctp_icmp_proto_unreachable(struct sock *sk, | |
d808ad9a YH |
432 | struct sctp_association *asoc, |
433 | struct sctp_transport *t) | |
1da177e4 | 434 | { |
50b5d6ad VY |
435 | if (sock_owned_by_user(sk)) { |
436 | if (timer_pending(&t->proto_unreach_timer)) | |
437 | return; | |
438 | else { | |
439 | if (!mod_timer(&t->proto_unreach_timer, | |
440 | jiffies + (HZ/20))) | |
057a10fa | 441 | sctp_transport_hold(t); |
50b5d6ad | 442 | } |
50b5d6ad | 443 | } else { |
55e26eb9 EB |
444 | struct net *net = sock_net(sk); |
445 | ||
bb33381d DB |
446 | pr_debug("%s: unrecognized next header type " |
447 | "encountered!\n", __func__); | |
448 | ||
25cc4ae9 | 449 | if (del_timer(&t->proto_unreach_timer)) |
057a10fa | 450 | sctp_transport_put(t); |
1da177e4 | 451 | |
55e26eb9 | 452 | sctp_do_sm(net, SCTP_EVENT_T_OTHER, |
50b5d6ad VY |
453 | SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), |
454 | asoc->state, asoc->ep, asoc, t, | |
455 | GFP_ATOMIC); | |
456 | } | |
1da177e4 LT |
457 | } |
458 | ||
459 | /* Common lookup code for icmp/icmpv6 error handler. */ | |
4110cc25 | 460 | struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb, |
1da177e4 | 461 | struct sctphdr *sctphdr, |
1da177e4 LT |
462 | struct sctp_association **app, |
463 | struct sctp_transport **tpp) | |
464 | { | |
804ec7eb | 465 | struct sctp_init_chunk *chunkhdr, _chunkhdr; |
1da177e4 LT |
466 | union sctp_addr saddr; |
467 | union sctp_addr daddr; | |
468 | struct sctp_af *af; | |
469 | struct sock *sk = NULL; | |
8de8c873 | 470 | struct sctp_association *asoc; |
1da177e4 | 471 | struct sctp_transport *transport = NULL; |
7115e632 | 472 | __u32 vtag = ntohl(sctphdr->vtag); |
0af03170 XL |
473 | int sdif = inet_sdif(skb); |
474 | int dif = inet_iif(skb); | |
1da177e4 | 475 | |
d1ad1ff2 | 476 | *app = NULL; *tpp = NULL; |
1da177e4 LT |
477 | |
478 | af = sctp_get_af_specific(family); | |
479 | if (unlikely(!af)) { | |
480 | return NULL; | |
481 | } | |
482 | ||
483 | /* Initialize local addresses for lookups. */ | |
484 | af->from_skb(&saddr, skb, 1); | |
485 | af->from_skb(&daddr, skb, 0); | |
486 | ||
487 | /* Look for an association that matches the incoming ICMP error | |
488 | * packet. | |
489 | */ | |
0af03170 | 490 | asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport, dif, sdif); |
d1ad1ff2 SS |
491 | if (!asoc) |
492 | return NULL; | |
1da177e4 | 493 | |
d1ad1ff2 | 494 | sk = asoc->base.sk; |
1da177e4 | 495 | |
7115e632 WY |
496 | /* RFC 4960, Appendix C. ICMP Handling |
497 | * | |
498 | * ICMP6) An implementation MUST validate that the Verification Tag | |
499 | * contained in the ICMP message matches the Verification Tag of | |
500 | * the peer. If the Verification Tag is not 0 and does NOT | |
501 | * match, discard the ICMP message. If it is 0 and the ICMP | |
502 | * message contains enough bytes to verify that the chunk type is | |
503 | * an INIT chunk and that the Initiate Tag matches the tag of the | |
504 | * peer, continue with ICMP7. If the ICMP message is too short | |
505 | * or the chunk type or the Initiate Tag does not match, silently | |
506 | * discard the packet. | |
507 | */ | |
508 | if (vtag == 0) { | |
804ec7eb DC |
509 | /* chunk header + first 4 octects of init header */ |
510 | chunkhdr = skb_header_pointer(skb, skb_transport_offset(skb) + | |
511 | sizeof(struct sctphdr), | |
512 | sizeof(struct sctp_chunkhdr) + | |
513 | sizeof(__be32), &_chunkhdr); | |
514 | if (!chunkhdr || | |
7115e632 | 515 | chunkhdr->chunk_hdr.type != SCTP_CID_INIT || |
804ec7eb | 516 | ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) |
7115e632 | 517 | goto out; |
804ec7eb | 518 | |
7115e632 | 519 | } else if (vtag != asoc->c.peer_vtag) { |
d1ad1ff2 SS |
520 | goto out; |
521 | } | |
1da177e4 | 522 | |
5bc1d1b4 | 523 | bh_lock_sock(sk); |
1da177e4 LT |
524 | |
525 | /* If too many ICMPs get dropped on busy | |
526 | * servers this needs to be solved differently. | |
527 | */ | |
528 | if (sock_owned_by_user(sk)) | |
02a1d6e7 | 529 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
1da177e4 | 530 | |
1da177e4 LT |
531 | *app = asoc; |
532 | *tpp = transport; | |
533 | return sk; | |
534 | ||
535 | out: | |
dae399d7 | 536 | sctp_transport_put(transport); |
1da177e4 LT |
537 | return NULL; |
538 | } | |
539 | ||
540 | /* Common cleanup code for icmp/icmpv6 error handler. */ | |
dae399d7 | 541 | void sctp_err_finish(struct sock *sk, struct sctp_transport *t) |
887cf3d1 | 542 | __releases(&((__sk)->sk_lock.slock)) |
1da177e4 | 543 | { |
5bc1d1b4 | 544 | bh_unlock_sock(sk); |
dae399d7 | 545 | sctp_transport_put(t); |
1da177e4 LT |
546 | } |
547 | ||
d8306075 XL |
548 | static void sctp_v4_err_handle(struct sctp_transport *t, struct sk_buff *skb, |
549 | __u8 type, __u8 code, __u32 info) | |
550 | { | |
551 | struct sctp_association *asoc = t->asoc; | |
552 | struct sock *sk = asoc->base.sk; | |
553 | int err = 0; | |
554 | ||
555 | switch (type) { | |
556 | case ICMP_PARAMETERPROB: | |
557 | err = EPROTO; | |
558 | break; | |
559 | case ICMP_DEST_UNREACH: | |
560 | if (code > NR_ICMP_UNREACH) | |
561 | return; | |
562 | if (code == ICMP_FRAG_NEEDED) { | |
563 | sctp_icmp_frag_needed(sk, asoc, t, SCTP_TRUNC4(info)); | |
564 | return; | |
565 | } | |
566 | if (code == ICMP_PROT_UNREACH) { | |
567 | sctp_icmp_proto_unreachable(sk, asoc, t); | |
568 | return; | |
569 | } | |
570 | err = icmp_err_convert[code].errno; | |
571 | break; | |
572 | case ICMP_TIME_EXCEEDED: | |
573 | if (code == ICMP_EXC_FRAGTIME) | |
574 | return; | |
575 | ||
576 | err = EHOSTUNREACH; | |
577 | break; | |
578 | case ICMP_REDIRECT: | |
579 | sctp_icmp_redirect(sk, t, skb); | |
dbe69e43 | 580 | return; |
d8306075 XL |
581 | default: |
582 | return; | |
583 | } | |
584 | if (!sock_owned_by_user(sk) && inet_sk(sk)->recverr) { | |
585 | sk->sk_err = err; | |
e3ae2365 | 586 | sk_error_report(sk); |
d8306075 XL |
587 | } else { /* Only an error on timeout */ |
588 | sk->sk_err_soft = err; | |
589 | } | |
590 | } | |
591 | ||
1da177e4 LT |
592 | /* |
593 | * This routine is called by the ICMP module when it gets some | |
594 | * sort of error condition. If err < 0 then the socket should | |
595 | * be closed and the error returned to the user. If err > 0 | |
596 | * it's just the icmp type << 8 | icmp code. After adjustment | |
597 | * header points to the first 8 bytes of the sctp header. We need | |
598 | * to find the appropriate port. | |
599 | * | |
600 | * The locking strategy used here is very "optimistic". When | |
601 | * someone else accesses the socket the ICMP is just dropped | |
602 | * and for some paths there is no check at all. | |
603 | * A more general error queue to queue errors for later handling | |
604 | * is probably better. | |
605 | * | |
606 | */ | |
32bbd879 | 607 | int sctp_v4_err(struct sk_buff *skb, __u32 info) |
1da177e4 | 608 | { |
b71d1d42 | 609 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
88c7664f ACM |
610 | const int type = icmp_hdr(skb)->type; |
611 | const int code = icmp_hdr(skb)->code; | |
d8306075 | 612 | struct net *net = dev_net(skb->dev); |
1da177e4 | 613 | struct sctp_transport *transport; |
d8306075 | 614 | struct sctp_association *asoc; |
aef6de51 | 615 | __u16 saveip, savesctp; |
d8306075 | 616 | struct sock *sk; |
1da177e4 | 617 | |
1da177e4 | 618 | /* Fix up skb to look at the embedded net header. */ |
b0e380b1 ACM |
619 | saveip = skb->network_header; |
620 | savesctp = skb->transport_header; | |
31c7711b | 621 | skb_reset_network_header(skb); |
d8306075 | 622 | skb_set_transport_header(skb, iph->ihl * 4); |
4110cc25 | 623 | sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport); |
2e07fa9c | 624 | /* Put back, the original values. */ |
b0e380b1 ACM |
625 | skb->network_header = saveip; |
626 | skb->transport_header = savesctp; | |
1da177e4 | 627 | if (!sk) { |
5d3848bc | 628 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
32bbd879 | 629 | return -ENOENT; |
1da177e4 | 630 | } |
1da177e4 | 631 | |
d8306075 | 632 | sctp_v4_err_handle(transport, skb, type, code, info); |
dae399d7 | 633 | sctp_err_finish(sk, transport); |
1da177e4 | 634 | |
32bbd879 | 635 | return 0; |
1da177e4 | 636 | } |
1da177e4 | 637 | |
9e47df00 XL |
638 | int sctp_udp_v4_err(struct sock *sk, struct sk_buff *skb) |
639 | { | |
640 | struct net *net = dev_net(skb->dev); | |
641 | struct sctp_association *asoc; | |
642 | struct sctp_transport *t; | |
643 | struct icmphdr *hdr; | |
644 | __u32 info = 0; | |
645 | ||
646 | skb->transport_header += sizeof(struct udphdr); | |
647 | sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &t); | |
648 | if (!sk) { | |
649 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); | |
650 | return -ENOENT; | |
1da177e4 LT |
651 | } |
652 | ||
9e47df00 XL |
653 | skb->transport_header -= sizeof(struct udphdr); |
654 | hdr = (struct icmphdr *)(skb_network_header(skb) - sizeof(struct icmphdr)); | |
655 | if (hdr->type == ICMP_REDIRECT) { | |
656 | /* can't be handled without outer iphdr known, leave it to udp_err */ | |
657 | sctp_err_finish(sk, t); | |
658 | return 0; | |
1da177e4 | 659 | } |
9e47df00 XL |
660 | if (hdr->type == ICMP_DEST_UNREACH && hdr->code == ICMP_FRAG_NEEDED) |
661 | info = ntohs(hdr->un.frag.mtu); | |
662 | sctp_v4_err_handle(t, skb, hdr->type, hdr->code, info); | |
1da177e4 | 663 | |
9e47df00 XL |
664 | sctp_err_finish(sk, t); |
665 | return 1; | |
1da177e4 LT |
666 | } |
667 | ||
668 | /* | |
669 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets. | |
670 | * | |
671 | * This function scans all the chunks in the OOTB packet to determine if | |
672 | * the packet should be discarded right away. If a response might be needed | |
673 | * for this packet, or, if further processing is possible, the packet will | |
674 | * be queued to a proper inqueue for the next phase of handling. | |
675 | * | |
676 | * Output: | |
677 | * Return 0 - If further processing is needed. | |
678 | * Return 1 - If the packet can be discarded right away. | |
679 | */ | |
04675210 | 680 | static int sctp_rcv_ootb(struct sk_buff *skb) |
1da177e4 | 681 | { |
922dbc5b | 682 | struct sctp_chunkhdr *ch, _ch; |
3acb50c1 | 683 | int ch_end, offset = 0; |
1da177e4 LT |
684 | |
685 | /* Scan through all the chunks in the packet. */ | |
a7d1f1b6 | 686 | do { |
3acb50c1 | 687 | /* Make sure we have at least the header there */ |
922dbc5b | 688 | if (offset + sizeof(_ch) > skb->len) |
3acb50c1 MRL |
689 | break; |
690 | ||
691 | ch = skb_header_pointer(skb, offset, sizeof(*ch), &_ch); | |
692 | ||
a7d1f1b6 | 693 | /* Break out if chunk length is less then minimal. */ |
f7e745f8 | 694 | if (!ch || ntohs(ch->length) < sizeof(_ch)) |
a7d1f1b6 TF |
695 | break; |
696 | ||
e2f036a9 | 697 | ch_end = offset + SCTP_PAD4(ntohs(ch->length)); |
3acb50c1 | 698 | if (ch_end > skb->len) |
a7d1f1b6 | 699 | break; |
1da177e4 LT |
700 | |
701 | /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the | |
702 | * receiver MUST silently discard the OOTB packet and take no | |
703 | * further action. | |
704 | */ | |
705 | if (SCTP_CID_ABORT == ch->type) | |
706 | goto discard; | |
707 | ||
708 | /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE | |
709 | * chunk, the receiver should silently discard the packet | |
710 | * and take no further action. | |
711 | */ | |
712 | if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type) | |
713 | goto discard; | |
714 | ||
3c77f961 VY |
715 | /* RFC 4460, 2.11.2 |
716 | * This will discard packets with INIT chunk bundled as | |
717 | * subsequent chunks in the packet. When INIT is first, | |
718 | * the normal INIT processing will discard the chunk. | |
719 | */ | |
720 | if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data) | |
721 | goto discard; | |
722 | ||
3acb50c1 MRL |
723 | offset = ch_end; |
724 | } while (ch_end < skb->len); | |
1da177e4 LT |
725 | |
726 | return 0; | |
727 | ||
728 | discard: | |
729 | return 1; | |
730 | } | |
731 | ||
732 | /* Insert endpoint into the hash table. */ | |
76c6d988 | 733 | static int __sctp_hash_endpoint(struct sctp_endpoint *ep) |
1da177e4 | 734 | { |
76c6d988 XL |
735 | struct sock *sk = ep->base.sk; |
736 | struct net *net = sock_net(sk); | |
1da177e4 LT |
737 | struct sctp_hashbucket *head; |
738 | ||
3d3b2f57 XL |
739 | ep->hashent = sctp_ep_hashfn(net, ep->base.bind_addr.port); |
740 | head = &sctp_ep_hashtable[ep->hashent]; | |
1da177e4 | 741 | |
76c6d988 XL |
742 | if (sk->sk_reuseport) { |
743 | bool any = sctp_is_ep_boundall(sk); | |
3d3b2f57 | 744 | struct sctp_endpoint *ep2; |
76c6d988 XL |
745 | struct list_head *list; |
746 | int cnt = 0, err = 1; | |
747 | ||
748 | list_for_each(list, &ep->base.bind_addr.address_list) | |
749 | cnt++; | |
750 | ||
3d3b2f57 XL |
751 | sctp_for_each_hentry(ep2, &head->chain) { |
752 | struct sock *sk2 = ep2->base.sk; | |
76c6d988 XL |
753 | |
754 | if (!net_eq(sock_net(sk2), net) || sk2 == sk || | |
755 | !uid_eq(sock_i_uid(sk2), sock_i_uid(sk)) || | |
756 | !sk2->sk_reuseport) | |
757 | continue; | |
758 | ||
759 | err = sctp_bind_addrs_check(sctp_sk(sk2), | |
760 | sctp_sk(sk), cnt); | |
761 | if (!err) { | |
762 | err = reuseport_add_sock(sk, sk2, any); | |
763 | if (err) | |
764 | return err; | |
765 | break; | |
766 | } else if (err < 0) { | |
767 | return err; | |
768 | } | |
769 | } | |
770 | ||
771 | if (err) { | |
772 | err = reuseport_alloc(sk, any); | |
773 | if (err) | |
774 | return err; | |
775 | } | |
776 | } | |
777 | ||
387602df | 778 | write_lock(&head->lock); |
3d3b2f57 | 779 | hlist_add_head(&ep->node, &head->chain); |
387602df | 780 | write_unlock(&head->lock); |
76c6d988 | 781 | return 0; |
1da177e4 LT |
782 | } |
783 | ||
784 | /* Add an endpoint to the hash. Local BH-safe. */ | |
76c6d988 | 785 | int sctp_hash_endpoint(struct sctp_endpoint *ep) |
1da177e4 | 786 | { |
76c6d988 XL |
787 | int err; |
788 | ||
79b91130 | 789 | local_bh_disable(); |
76c6d988 | 790 | err = __sctp_hash_endpoint(ep); |
79b91130 | 791 | local_bh_enable(); |
76c6d988 XL |
792 | |
793 | return err; | |
1da177e4 LT |
794 | } |
795 | ||
796 | /* Remove endpoint from the hash table. */ | |
797 | static void __sctp_unhash_endpoint(struct sctp_endpoint *ep) | |
798 | { | |
76c6d988 | 799 | struct sock *sk = ep->base.sk; |
1da177e4 | 800 | struct sctp_hashbucket *head; |
1da177e4 | 801 | |
3d3b2f57 | 802 | ep->hashent = sctp_ep_hashfn(sock_net(sk), ep->base.bind_addr.port); |
1da177e4 | 803 | |
3d3b2f57 | 804 | head = &sctp_ep_hashtable[ep->hashent]; |
1da177e4 | 805 | |
76c6d988 XL |
806 | if (rcu_access_pointer(sk->sk_reuseport_cb)) |
807 | reuseport_detach_sock(sk); | |
808 | ||
387602df | 809 | write_lock(&head->lock); |
3d3b2f57 | 810 | hlist_del_init(&ep->node); |
387602df | 811 | write_unlock(&head->lock); |
1da177e4 LT |
812 | } |
813 | ||
814 | /* Remove endpoint from the hash. Local BH-safe. */ | |
815 | void sctp_unhash_endpoint(struct sctp_endpoint *ep) | |
816 | { | |
79b91130 | 817 | local_bh_disable(); |
1da177e4 | 818 | __sctp_unhash_endpoint(ep); |
79b91130 | 819 | local_bh_enable(); |
1da177e4 LT |
820 | } |
821 | ||
532ae2f1 XL |
822 | static inline __u32 sctp_hashfn(const struct net *net, __be16 lport, |
823 | const union sctp_addr *paddr, __u32 seed) | |
824 | { | |
825 | __u32 addr; | |
826 | ||
827 | if (paddr->sa.sa_family == AF_INET6) | |
828 | addr = jhash(&paddr->v6.sin6_addr, 16, seed); | |
829 | else | |
830 | addr = (__force __u32)paddr->v4.sin_addr.s_addr; | |
831 | ||
832 | return jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 | | |
833 | (__force __u32)lport, net_hash_mix(net), seed); | |
834 | } | |
835 | ||
1da177e4 | 836 | /* Look up an endpoint. */ |
532ae2f1 XL |
837 | static struct sctp_endpoint *__sctp_rcv_lookup_endpoint( |
838 | struct net *net, struct sk_buff *skb, | |
839 | const union sctp_addr *laddr, | |
0af03170 XL |
840 | const union sctp_addr *paddr, |
841 | int dif, int sdif) | |
1da177e4 LT |
842 | { |
843 | struct sctp_hashbucket *head; | |
1da177e4 | 844 | struct sctp_endpoint *ep; |
532ae2f1 XL |
845 | struct sock *sk; |
846 | __be16 lport; | |
1da177e4 LT |
847 | int hash; |
848 | ||
532ae2f1 XL |
849 | lport = laddr->v4.sin_port; |
850 | hash = sctp_ep_hashfn(net, ntohs(lport)); | |
1da177e4 LT |
851 | head = &sctp_ep_hashtable[hash]; |
852 | read_lock(&head->lock); | |
3d3b2f57 | 853 | sctp_for_each_hentry(ep, &head->chain) { |
0af03170 | 854 | if (sctp_endpoint_is_match(ep, net, laddr, dif, sdif)) |
1da177e4 LT |
855 | goto hit; |
856 | } | |
857 | ||
2ce95503 | 858 | ep = sctp_sk(net->sctp.ctl_sock)->ep; |
1da177e4 LT |
859 | |
860 | hit: | |
532ae2f1 XL |
861 | sk = ep->base.sk; |
862 | if (sk->sk_reuseport) { | |
863 | __u32 phash = sctp_hashfn(net, lport, paddr, 0); | |
864 | ||
865 | sk = reuseport_select_sock(sk, phash, skb, | |
866 | sizeof(struct sctphdr)); | |
867 | if (sk) | |
868 | ep = sctp_sk(sk)->ep; | |
869 | } | |
1da177e4 | 870 | sctp_endpoint_hold(ep); |
1da177e4 LT |
871 | read_unlock(&head->lock); |
872 | return ep; | |
873 | } | |
874 | ||
d6c0256a XL |
875 | /* rhashtable for transport */ |
876 | struct sctp_hash_cmp_arg { | |
7fda702f XL |
877 | const union sctp_addr *paddr; |
878 | const struct net *net; | |
8d32503e | 879 | __be16 lport; |
d6c0256a XL |
880 | }; |
881 | ||
882 | static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg, | |
883 | const void *ptr) | |
884 | { | |
715f5552 | 885 | struct sctp_transport *t = (struct sctp_transport *)ptr; |
d6c0256a | 886 | const struct sctp_hash_cmp_arg *x = arg->key; |
715f5552 | 887 | int err = 1; |
d6c0256a | 888 | |
d6c0256a | 889 | if (!sctp_cmp_addr_exact(&t->ipaddr, x->paddr)) |
715f5552 XL |
890 | return err; |
891 | if (!sctp_transport_hold(t)) | |
892 | return err; | |
893 | ||
31243461 | 894 | if (!net_eq(t->asoc->base.net, x->net)) |
7fda702f XL |
895 | goto out; |
896 | if (x->lport != htons(t->asoc->base.bind_addr.port)) | |
715f5552 | 897 | goto out; |
d6c0256a | 898 | |
715f5552 XL |
899 | err = 0; |
900 | out: | |
901 | sctp_transport_put(t); | |
902 | return err; | |
d6c0256a XL |
903 | } |
904 | ||
8d32503e | 905 | static inline __u32 sctp_hash_obj(const void *data, u32 len, u32 seed) |
d6c0256a XL |
906 | { |
907 | const struct sctp_transport *t = data; | |
d6c0256a | 908 | |
31243461 | 909 | return sctp_hashfn(t->asoc->base.net, |
532ae2f1 XL |
910 | htons(t->asoc->base.bind_addr.port), |
911 | &t->ipaddr, seed); | |
d6c0256a XL |
912 | } |
913 | ||
8d32503e | 914 | static inline __u32 sctp_hash_key(const void *data, u32 len, u32 seed) |
d6c0256a XL |
915 | { |
916 | const struct sctp_hash_cmp_arg *x = data; | |
d6c0256a | 917 | |
532ae2f1 | 918 | return sctp_hashfn(x->net, x->lport, x->paddr, seed); |
d6c0256a XL |
919 | } |
920 | ||
921 | static const struct rhashtable_params sctp_hash_params = { | |
922 | .head_offset = offsetof(struct sctp_transport, node), | |
923 | .hashfn = sctp_hash_key, | |
924 | .obj_hashfn = sctp_hash_obj, | |
925 | .obj_cmpfn = sctp_hash_cmp, | |
926 | .automatic_shrinking = true, | |
927 | }; | |
928 | ||
929 | int sctp_transport_hashtable_init(void) | |
930 | { | |
7fda702f | 931 | return rhltable_init(&sctp_transport_hashtable, &sctp_hash_params); |
d6c0256a XL |
932 | } |
933 | ||
934 | void sctp_transport_hashtable_destroy(void) | |
935 | { | |
7fda702f | 936 | rhltable_destroy(&sctp_transport_hashtable); |
d6c0256a XL |
937 | } |
938 | ||
7fda702f | 939 | int sctp_hash_transport(struct sctp_transport *t) |
d6c0256a | 940 | { |
cd2b7087 XL |
941 | struct sctp_transport *transport; |
942 | struct rhlist_head *tmp, *list; | |
d6c0256a | 943 | struct sctp_hash_cmp_arg arg; |
7fda702f | 944 | int err; |
d6c0256a | 945 | |
dd7445ad | 946 | if (t->asoc->temp) |
7fda702f | 947 | return 0; |
dd7445ad | 948 | |
4e7696d9 | 949 | arg.net = t->asoc->base.net; |
7fda702f XL |
950 | arg.paddr = &t->ipaddr; |
951 | arg.lport = htons(t->asoc->base.bind_addr.port); | |
d6c0256a | 952 | |
5179b266 | 953 | rcu_read_lock(); |
cd2b7087 XL |
954 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
955 | sctp_hash_params); | |
956 | ||
957 | rhl_for_each_entry_rcu(transport, tmp, list, node) | |
958 | if (transport->asoc->ep == t->asoc->ep) { | |
5179b266 | 959 | rcu_read_unlock(); |
27af86bb | 960 | return -EEXIST; |
cd2b7087 | 961 | } |
5179b266 | 962 | rcu_read_unlock(); |
cd2b7087 | 963 | |
7fda702f XL |
964 | err = rhltable_insert_key(&sctp_transport_hashtable, &arg, |
965 | &t->node, sctp_hash_params); | |
966 | if (err) | |
967 | pr_err_once("insert transport fail, errno %d\n", err); | |
968 | ||
969 | return err; | |
d6c0256a XL |
970 | } |
971 | ||
972 | void sctp_unhash_transport(struct sctp_transport *t) | |
973 | { | |
dd7445ad XL |
974 | if (t->asoc->temp) |
975 | return; | |
976 | ||
7fda702f XL |
977 | rhltable_remove(&sctp_transport_hashtable, &t->node, |
978 | sctp_hash_params); | |
d6c0256a XL |
979 | } |
980 | ||
0af03170 XL |
981 | bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif) |
982 | { | |
983 | bool l3mdev_accept = true; | |
984 | ||
985 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
986 | l3mdev_accept = !!READ_ONCE(net->sctp.l3mdev_accept); | |
987 | #endif | |
988 | return inet_bound_dev_eq(l3mdev_accept, bound_dev_if, dif, sdif); | |
989 | } | |
990 | ||
7fda702f | 991 | /* return a transport with holding it */ |
d6c0256a XL |
992 | struct sctp_transport *sctp_addrs_lookup_transport( |
993 | struct net *net, | |
994 | const union sctp_addr *laddr, | |
0af03170 XL |
995 | const union sctp_addr *paddr, |
996 | int dif, int sdif) | |
d6c0256a | 997 | { |
7fda702f XL |
998 | struct rhlist_head *tmp, *list; |
999 | struct sctp_transport *t; | |
0af03170 | 1000 | int bound_dev_if; |
d6c0256a | 1001 | struct sctp_hash_cmp_arg arg = { |
d6c0256a XL |
1002 | .paddr = paddr, |
1003 | .net = net, | |
7fda702f | 1004 | .lport = laddr->v4.sin_port, |
d6c0256a XL |
1005 | }; |
1006 | ||
7fda702f XL |
1007 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
1008 | sctp_hash_params); | |
1009 | ||
1010 | rhl_for_each_entry_rcu(t, tmp, list, node) { | |
1011 | if (!sctp_transport_hold(t)) | |
1012 | continue; | |
1013 | ||
0af03170 XL |
1014 | bound_dev_if = READ_ONCE(t->asoc->base.sk->sk_bound_dev_if); |
1015 | if (sctp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif) && | |
1016 | sctp_bind_addr_match(&t->asoc->base.bind_addr, | |
7fda702f XL |
1017 | laddr, sctp_sk(t->asoc->base.sk))) |
1018 | return t; | |
1019 | sctp_transport_put(t); | |
1020 | } | |
1021 | ||
1022 | return NULL; | |
d6c0256a XL |
1023 | } |
1024 | ||
7fda702f | 1025 | /* return a transport without holding it, as it's only used under sock lock */ |
d6c0256a XL |
1026 | struct sctp_transport *sctp_epaddr_lookup_transport( |
1027 | const struct sctp_endpoint *ep, | |
1028 | const union sctp_addr *paddr) | |
1029 | { | |
7fda702f XL |
1030 | struct rhlist_head *tmp, *list; |
1031 | struct sctp_transport *t; | |
65a5124a | 1032 | struct sctp_hash_cmp_arg arg = { |
65a5124a | 1033 | .paddr = paddr, |
4e7696d9 | 1034 | .net = ep->base.net, |
7fda702f | 1035 | .lport = htons(ep->base.bind_addr.port), |
65a5124a | 1036 | }; |
d6c0256a | 1037 | |
7fda702f XL |
1038 | list = rhltable_lookup(&sctp_transport_hashtable, &arg, |
1039 | sctp_hash_params); | |
1040 | ||
1041 | rhl_for_each_entry_rcu(t, tmp, list, node) | |
1042 | if (ep == t->asoc->ep) | |
1043 | return t; | |
1044 | ||
1045 | return NULL; | |
d6c0256a XL |
1046 | } |
1047 | ||
1da177e4 LT |
1048 | /* Look up an association. */ |
1049 | static struct sctp_association *__sctp_lookup_association( | |
4110cc25 | 1050 | struct net *net, |
1da177e4 LT |
1051 | const union sctp_addr *local, |
1052 | const union sctp_addr *peer, | |
0af03170 XL |
1053 | struct sctp_transport **pt, |
1054 | int dif, int sdif) | |
1da177e4 | 1055 | { |
4f008781 | 1056 | struct sctp_transport *t; |
1eed6779 | 1057 | struct sctp_association *asoc = NULL; |
1da177e4 | 1058 | |
0af03170 | 1059 | t = sctp_addrs_lookup_transport(net, local, peer, dif, sdif); |
7fda702f | 1060 | if (!t) |
1eed6779 | 1061 | goto out; |
1da177e4 | 1062 | |
1eed6779 | 1063 | asoc = t->asoc; |
4f008781 | 1064 | *pt = t; |
1da177e4 | 1065 | |
1eed6779 | 1066 | out: |
1eed6779 | 1067 | return asoc; |
1da177e4 LT |
1068 | } |
1069 | ||
4f008781 | 1070 | /* Look up an association. protected by RCU read lock */ |
dda91928 | 1071 | static |
4110cc25 EB |
1072 | struct sctp_association *sctp_lookup_association(struct net *net, |
1073 | const union sctp_addr *laddr, | |
1da177e4 | 1074 | const union sctp_addr *paddr, |
0af03170 XL |
1075 | struct sctp_transport **transportp, |
1076 | int dif, int sdif) | |
1da177e4 LT |
1077 | { |
1078 | struct sctp_association *asoc; | |
1079 | ||
f46c7011 | 1080 | rcu_read_lock(); |
0af03170 | 1081 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif); |
f46c7011 | 1082 | rcu_read_unlock(); |
1da177e4 LT |
1083 | |
1084 | return asoc; | |
1085 | } | |
1086 | ||
1087 | /* Is there an association matching the given local and peer addresses? */ | |
53066538 XL |
1088 | bool sctp_has_association(struct net *net, |
1089 | const union sctp_addr *laddr, | |
0af03170 XL |
1090 | const union sctp_addr *paddr, |
1091 | int dif, int sdif) | |
1da177e4 | 1092 | { |
1da177e4 LT |
1093 | struct sctp_transport *transport; |
1094 | ||
0af03170 | 1095 | if (sctp_lookup_association(net, laddr, paddr, &transport, dif, sdif)) { |
dae399d7 | 1096 | sctp_transport_put(transport); |
53066538 | 1097 | return true; |
1da177e4 LT |
1098 | } |
1099 | ||
53066538 | 1100 | return false; |
1da177e4 LT |
1101 | } |
1102 | ||
1103 | /* | |
1104 | * SCTP Implementors Guide, 2.18 Handling of address | |
1105 | * parameters within the INIT or INIT-ACK. | |
1106 | * | |
1107 | * D) When searching for a matching TCB upon reception of an INIT | |
1108 | * or INIT-ACK chunk the receiver SHOULD use not only the | |
1109 | * source address of the packet (containing the INIT or | |
1110 | * INIT-ACK) but the receiver SHOULD also use all valid | |
1111 | * address parameters contained within the chunk. | |
1112 | * | |
1113 | * 2.18.3 Solution description | |
1114 | * | |
1115 | * This new text clearly specifies to an implementor the need | |
1116 | * to look within the INIT or INIT-ACK. Any implementation that | |
1117 | * does not do this, may not be able to establish associations | |
1118 | * in certain circumstances. | |
1119 | * | |
1120 | */ | |
4110cc25 EB |
1121 | static struct sctp_association *__sctp_rcv_init_lookup(struct net *net, |
1122 | struct sk_buff *skb, | |
0af03170 XL |
1123 | const union sctp_addr *laddr, struct sctp_transport **transportp, |
1124 | int dif, int sdif) | |
1da177e4 LT |
1125 | { |
1126 | struct sctp_association *asoc; | |
1127 | union sctp_addr addr; | |
1128 | union sctp_addr *paddr = &addr; | |
2c0fd387 | 1129 | struct sctphdr *sh = sctp_hdr(skb); |
1da177e4 | 1130 | union sctp_params params; |
01a992be | 1131 | struct sctp_init_chunk *init; |
1da177e4 LT |
1132 | struct sctp_af *af; |
1133 | ||
1da177e4 LT |
1134 | /* |
1135 | * This code will NOT touch anything inside the chunk--it is | |
1136 | * strictly READ-ONLY. | |
1137 | * | |
1138 | * RFC 2960 3 SCTP packet Format | |
1139 | * | |
1140 | * Multiple chunks can be bundled into one SCTP packet up to | |
1141 | * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN | |
1142 | * COMPLETE chunks. These chunks MUST NOT be bundled with any | |
1143 | * other chunk in a packet. See Section 6.10 for more details | |
1144 | * on chunk bundling. | |
1145 | */ | |
1146 | ||
1147 | /* Find the start of the TLVs and the end of the chunk. This is | |
1148 | * the region we search for address parameters. | |
1149 | */ | |
01a992be | 1150 | init = (struct sctp_init_chunk *)skb->data; |
1da177e4 LT |
1151 | |
1152 | /* Walk the parameters looking for embedded addresses. */ | |
1153 | sctp_walk_params(params, init, init_hdr.params) { | |
1154 | ||
1155 | /* Note: Ignoring hostname addresses. */ | |
1156 | af = sctp_get_af_specific(param_type2af(params.p->type)); | |
1157 | if (!af) | |
1158 | continue; | |
1159 | ||
0c5dc070 MRL |
1160 | if (!af->from_addr_param(paddr, params.addr, sh->source, 0)) |
1161 | continue; | |
1da177e4 | 1162 | |
0af03170 | 1163 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif); |
1da177e4 LT |
1164 | if (asoc) |
1165 | return asoc; | |
1166 | } | |
1167 | ||
1168 | return NULL; | |
1169 | } | |
1170 | ||
df218577 VY |
1171 | /* ADD-IP, Section 5.2 |
1172 | * When an endpoint receives an ASCONF Chunk from the remote peer | |
1173 | * special procedures may be needed to identify the association the | |
1174 | * ASCONF Chunk is associated with. To properly find the association | |
1175 | * the following procedures SHOULD be followed: | |
1176 | * | |
1177 | * D2) If the association is not found, use the address found in the | |
1178 | * Address Parameter TLV combined with the port number found in the | |
1179 | * SCTP common header. If found proceed to rule D4. | |
1180 | * | |
1181 | * D2-ext) If more than one ASCONF Chunks are packed together, use the | |
1182 | * address found in the ASCONF Address Parameter TLV of each of the | |
1183 | * subsequent ASCONF Chunks. If found, proceed to rule D4. | |
1184 | */ | |
1185 | static struct sctp_association *__sctp_rcv_asconf_lookup( | |
4110cc25 | 1186 | struct net *net, |
922dbc5b | 1187 | struct sctp_chunkhdr *ch, |
df218577 | 1188 | const union sctp_addr *laddr, |
bc92dd19 | 1189 | __be16 peer_port, |
0af03170 XL |
1190 | struct sctp_transport **transportp, |
1191 | int dif, int sdif) | |
df218577 | 1192 | { |
68d75469 | 1193 | struct sctp_addip_chunk *asconf = (struct sctp_addip_chunk *)ch; |
df218577 VY |
1194 | struct sctp_af *af; |
1195 | union sctp_addr_param *param; | |
1196 | union sctp_addr paddr; | |
1197 | ||
b6ffe767 MRL |
1198 | if (ntohs(ch->length) < sizeof(*asconf) + sizeof(struct sctp_paramhdr)) |
1199 | return NULL; | |
1200 | ||
df218577 VY |
1201 | /* Skip over the ADDIP header and find the Address parameter */ |
1202 | param = (union sctp_addr_param *)(asconf + 1); | |
1203 | ||
6a435732 | 1204 | af = sctp_get_af_specific(param_type2af(param->p.type)); |
df218577 VY |
1205 | if (unlikely(!af)) |
1206 | return NULL; | |
1207 | ||
557fb586 | 1208 | if (!af->from_addr_param(&paddr, param, peer_port, 0)) |
0c5dc070 | 1209 | return NULL; |
df218577 | 1210 | |
0af03170 | 1211 | return __sctp_lookup_association(net, laddr, &paddr, transportp, dif, sdif); |
df218577 VY |
1212 | } |
1213 | ||
1214 | ||
bbd0d598 VY |
1215 | /* SCTP-AUTH, Section 6.3: |
1216 | * If the receiver does not find a STCB for a packet containing an AUTH | |
1217 | * chunk as the first chunk and not a COOKIE-ECHO chunk as the second | |
1218 | * chunk, it MUST use the chunks after the AUTH chunk to look up an existing | |
1219 | * association. | |
1220 | * | |
1221 | * This means that any chunks that can help us identify the association need | |
25985edc | 1222 | * to be looked at to find this association. |
bbd0d598 | 1223 | */ |
4110cc25 EB |
1224 | static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net, |
1225 | struct sk_buff *skb, | |
bbd0d598 | 1226 | const union sctp_addr *laddr, |
0af03170 XL |
1227 | struct sctp_transport **transportp, |
1228 | int dif, int sdif) | |
bbd0d598 | 1229 | { |
df218577 | 1230 | struct sctp_association *asoc = NULL; |
922dbc5b | 1231 | struct sctp_chunkhdr *ch; |
df218577 VY |
1232 | int have_auth = 0; |
1233 | unsigned int chunk_num = 1; | |
1234 | __u8 *ch_end; | |
1235 | ||
1236 | /* Walk through the chunks looking for AUTH or ASCONF chunks | |
1237 | * to help us find the association. | |
bbd0d598 | 1238 | */ |
922dbc5b | 1239 | ch = (struct sctp_chunkhdr *)skb->data; |
df218577 VY |
1240 | do { |
1241 | /* Break out if chunk length is less then minimal. */ | |
922dbc5b | 1242 | if (ntohs(ch->length) < sizeof(*ch)) |
df218577 VY |
1243 | break; |
1244 | ||
e2f036a9 | 1245 | ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length)); |
df218577 VY |
1246 | if (ch_end > skb_tail_pointer(skb)) |
1247 | break; | |
1248 | ||
cb3f837b | 1249 | switch (ch->type) { |
f7010e61 | 1250 | case SCTP_CID_AUTH: |
1251 | have_auth = chunk_num; | |
1252 | break; | |
1253 | ||
1254 | case SCTP_CID_COOKIE_ECHO: | |
1255 | /* If a packet arrives containing an AUTH chunk as | |
1256 | * a first chunk, a COOKIE-ECHO chunk as the second | |
1257 | * chunk, and possibly more chunks after them, and | |
1258 | * the receiver does not have an STCB for that | |
1259 | * packet, then authentication is based on | |
1260 | * the contents of the COOKIE- ECHO chunk. | |
1261 | */ | |
1262 | if (have_auth == 1 && chunk_num == 2) | |
1263 | return NULL; | |
1264 | break; | |
1265 | ||
1266 | case SCTP_CID_ASCONF: | |
1267 | if (have_auth || net->sctp.addip_noauth) | |
1268 | asoc = __sctp_rcv_asconf_lookup( | |
1269 | net, ch, laddr, | |
1270 | sctp_hdr(skb)->source, | |
0af03170 | 1271 | transportp, dif, sdif); |
0572b37b | 1272 | break; |
f7010e61 | 1273 | default: |
1274 | break; | |
df218577 VY |
1275 | } |
1276 | ||
1277 | if (asoc) | |
1278 | break; | |
1279 | ||
922dbc5b | 1280 | ch = (struct sctp_chunkhdr *)ch_end; |
df218577 | 1281 | chunk_num++; |
50619dbf | 1282 | } while (ch_end + sizeof(*ch) < skb_tail_pointer(skb)); |
df218577 VY |
1283 | |
1284 | return asoc; | |
bbd0d598 VY |
1285 | } |
1286 | ||
1287 | /* | |
1288 | * There are circumstances when we need to look inside the SCTP packet | |
1289 | * for information to help us find the association. Examples | |
1290 | * include looking inside of INIT/INIT-ACK chunks or after the AUTH | |
1291 | * chunks. | |
1292 | */ | |
4110cc25 EB |
1293 | static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net, |
1294 | struct sk_buff *skb, | |
bbd0d598 | 1295 | const union sctp_addr *laddr, |
0af03170 XL |
1296 | struct sctp_transport **transportp, |
1297 | int dif, int sdif) | |
bbd0d598 | 1298 | { |
922dbc5b | 1299 | struct sctp_chunkhdr *ch; |
bbd0d598 | 1300 | |
90017acc MRL |
1301 | /* We do not allow GSO frames here as we need to linearize and |
1302 | * then cannot guarantee frame boundaries. This shouldn't be an | |
1303 | * issue as packets hitting this are mostly INIT or INIT-ACK and | |
1304 | * those cannot be on GSO-style anyway. | |
1305 | */ | |
1dd27cde | 1306 | if (skb_is_gso(skb) && skb_is_gso_sctp(skb)) |
90017acc MRL |
1307 | return NULL; |
1308 | ||
922dbc5b | 1309 | ch = (struct sctp_chunkhdr *)skb->data; |
bbd0d598 | 1310 | |
df218577 VY |
1311 | /* The code below will attempt to walk the chunk and extract |
1312 | * parameter information. Before we do that, we need to verify | |
1313 | * that the chunk length doesn't cause overflow. Otherwise, we'll | |
1314 | * walk off the end. | |
1315 | */ | |
e2f036a9 | 1316 | if (SCTP_PAD4(ntohs(ch->length)) > skb->len) |
df218577 VY |
1317 | return NULL; |
1318 | ||
bbd0d598 | 1319 | /* If this is INIT/INIT-ACK look inside the chunk too. */ |
f482f2fc | 1320 | if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK) |
0af03170 | 1321 | return __sctp_rcv_init_lookup(net, skb, laddr, transportp, dif, sdif); |
bbd0d598 | 1322 | |
0af03170 | 1323 | return __sctp_rcv_walk_lookup(net, skb, laddr, transportp, dif, sdif); |
bbd0d598 VY |
1324 | } |
1325 | ||
1da177e4 | 1326 | /* Lookup an association for an inbound skb. */ |
4110cc25 EB |
1327 | static struct sctp_association *__sctp_rcv_lookup(struct net *net, |
1328 | struct sk_buff *skb, | |
1da177e4 LT |
1329 | const union sctp_addr *paddr, |
1330 | const union sctp_addr *laddr, | |
0af03170 XL |
1331 | struct sctp_transport **transportp, |
1332 | int dif, int sdif) | |
1da177e4 LT |
1333 | { |
1334 | struct sctp_association *asoc; | |
1335 | ||
0af03170 | 1336 | asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif); |
b77b7565 MRL |
1337 | if (asoc) |
1338 | goto out; | |
1da177e4 LT |
1339 | |
1340 | /* Further lookup for INIT/INIT-ACK packets. | |
1341 | * SCTP Implementors Guide, 2.18 Handling of address | |
1342 | * parameters within the INIT or INIT-ACK. | |
1343 | */ | |
0af03170 | 1344 | asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp, dif, sdif); |
b77b7565 MRL |
1345 | if (asoc) |
1346 | goto out; | |
1da177e4 | 1347 | |
b77b7565 MRL |
1348 | if (paddr->sa.sa_family == AF_INET) |
1349 | pr_debug("sctp: asoc not found for src:%pI4:%d dst:%pI4:%d\n", | |
1350 | &laddr->v4.sin_addr, ntohs(laddr->v4.sin_port), | |
1351 | &paddr->v4.sin_addr, ntohs(paddr->v4.sin_port)); | |
1352 | else | |
1353 | pr_debug("sctp: asoc not found for src:%pI6:%d dst:%pI6:%d\n", | |
1354 | &laddr->v6.sin6_addr, ntohs(laddr->v6.sin6_port), | |
1355 | &paddr->v6.sin6_addr, ntohs(paddr->v6.sin6_port)); | |
1356 | ||
1357 | out: | |
1da177e4 LT |
1358 | return asoc; |
1359 | } |