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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
2 | * (C) Copyright IBM Corp. 2001, 2004 |
3 | * Copyright (c) 1999-2000 Cisco, Inc. | |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001 Intel Corp. | |
6 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
7 | * | |
60c778b2 | 8 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
9 | * |
10 | * This module provides the abstraction for an SCTP association. | |
11 | * | |
60c778b2 | 12 | * This SCTP implementation is free software; |
1da177e4 LT |
13 | * you can redistribute it and/or modify it under the terms of |
14 | * the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2, or (at your option) | |
16 | * any later version. | |
17 | * | |
60c778b2 | 18 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
19 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
20 | * ************************ | |
21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
22 | * See the GNU General Public License for more details. | |
23 | * | |
24 | * You should have received a copy of the GNU General Public License | |
4b2f13a2 JK |
25 | * along with GNU CC; see the file COPYING. If not, see |
26 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
27 | * |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email address(es): | |
91705c61 | 30 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 31 | * |
1da177e4 LT |
32 | * Written or modified by: |
33 | * La Monte H.P. Yarroll <piggy@acm.org> | |
34 | * Karl Knutson <karl@athena.chicago.il.us> | |
35 | * Jon Grimm <jgrimm@us.ibm.com> | |
36 | * Xingang Guo <xingang.guo@intel.com> | |
37 | * Hui Huang <hui.huang@nokia.com> | |
38 | * Sridhar Samudrala <sri@us.ibm.com> | |
39 | * Daisy Chang <daisyc@us.ibm.com> | |
40 | * Ryan Layer <rmlayer@us.ibm.com> | |
41 | * Kevin Gao <kevin.gao@intel.com> | |
1da177e4 LT |
42 | */ |
43 | ||
145ce502 JP |
44 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
45 | ||
1da177e4 LT |
46 | #include <linux/types.h> |
47 | #include <linux/fcntl.h> | |
48 | #include <linux/poll.h> | |
49 | #include <linux/init.h> | |
1da177e4 LT |
50 | |
51 | #include <linux/slab.h> | |
52 | #include <linux/in.h> | |
53 | #include <net/ipv6.h> | |
54 | #include <net/sctp/sctp.h> | |
55 | #include <net/sctp/sm.h> | |
56 | ||
57 | /* Forward declarations for internal functions. */ | |
b82e8f31 | 58 | static void sctp_select_active_and_retran_path(struct sctp_association *asoc); |
c4028958 | 59 | static void sctp_assoc_bh_rcv(struct work_struct *work); |
a08de64d | 60 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); |
8b4472cc | 61 | static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc); |
1da177e4 | 62 | |
1da177e4 LT |
63 | /* 1st Level Abstractions. */ |
64 | ||
65 | /* Initialize a new association from provided memory. */ | |
66 | static struct sctp_association *sctp_association_init(struct sctp_association *asoc, | |
67 | const struct sctp_endpoint *ep, | |
68 | const struct sock *sk, | |
69 | sctp_scope_t scope, | |
dd0fc66f | 70 | gfp_t gfp) |
1da177e4 | 71 | { |
e1fc3b14 | 72 | struct net *net = sock_net(sk); |
1da177e4 LT |
73 | struct sctp_sock *sp; |
74 | int i; | |
a29a5bd4 VY |
75 | sctp_paramhdr_t *p; |
76 | int err; | |
1da177e4 LT |
77 | |
78 | /* Retrieve the SCTP per socket area. */ | |
79 | sp = sctp_sk((struct sock *)sk); | |
80 | ||
1da177e4 LT |
81 | /* Discarding const is appropriate here. */ |
82 | asoc->ep = (struct sctp_endpoint *)ep; | |
1da177e4 | 83 | asoc->base.sk = (struct sock *)sk; |
2e0c9e79 DB |
84 | |
85 | sctp_endpoint_hold(asoc->ep); | |
1da177e4 LT |
86 | sock_hold(asoc->base.sk); |
87 | ||
88 | /* Initialize the common base substructure. */ | |
89 | asoc->base.type = SCTP_EP_TYPE_ASSOCIATION; | |
90 | ||
91 | /* Initialize the object handling fields. */ | |
92 | atomic_set(&asoc->base.refcnt, 1); | |
1da177e4 LT |
93 | |
94 | /* Initialize the bind addr area. */ | |
95 | sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port); | |
1da177e4 LT |
96 | |
97 | asoc->state = SCTP_STATE_CLOSED; | |
52db882f | 98 | asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life); |
f68b2e05 | 99 | asoc->user_frag = sp->user_frag; |
1da177e4 LT |
100 | |
101 | /* Set the association max_retrans and RTO values from the | |
102 | * socket values. | |
103 | */ | |
104 | asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt; | |
e1fc3b14 | 105 | asoc->pf_retrans = net->sctp.pf_retrans; |
5aa93bcf | 106 | |
1da177e4 LT |
107 | asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial); |
108 | asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max); | |
109 | asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min); | |
110 | ||
52ccb8e9 FF |
111 | /* Initialize the association's heartbeat interval based on the |
112 | * sock configured value. | |
113 | */ | |
114 | asoc->hbinterval = msecs_to_jiffies(sp->hbinterval); | |
115 | ||
116 | /* Initialize path max retrans value. */ | |
117 | asoc->pathmaxrxt = sp->pathmaxrxt; | |
118 | ||
119 | /* Initialize default path MTU. */ | |
120 | asoc->pathmtu = sp->pathmtu; | |
121 | ||
122 | /* Set association default SACK delay */ | |
123 | asoc->sackdelay = msecs_to_jiffies(sp->sackdelay); | |
d364d927 | 124 | asoc->sackfreq = sp->sackfreq; |
52ccb8e9 FF |
125 | |
126 | /* Set the association default flags controlling | |
127 | * Heartbeat, SACK delay, and Path MTU Discovery. | |
128 | */ | |
129 | asoc->param_flags = sp->param_flags; | |
130 | ||
9d2c881a | 131 | /* Initialize the maximum number of new data packets that can be sent |
1da177e4 LT |
132 | * in a burst. |
133 | */ | |
70331571 | 134 | asoc->max_burst = sp->max_burst; |
1da177e4 | 135 | |
1e7d3d90 | 136 | /* initialize association timers */ |
1e7d3d90 VY |
137 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial; |
138 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial; | |
139 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial; | |
1e7d3d90 VY |
140 | |
141 | /* sctpimpguide Section 2.12.2 | |
142 | * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the | |
143 | * recommended value of 5 times 'RTO.Max'. | |
144 | */ | |
d808ad9a | 145 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] |
1e7d3d90 VY |
146 | = 5 * asoc->rto_max; |
147 | ||
52ccb8e9 | 148 | asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay; |
9f70f46b | 149 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ; |
d808ad9a | 150 | |
421f91d2 | 151 | /* Initializes the timers */ |
b24b8a24 PE |
152 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) |
153 | setup_timer(&asoc->timers[i], sctp_timer_events[i], | |
154 | (unsigned long)asoc); | |
1da177e4 LT |
155 | |
156 | /* Pull default initialization values from the sock options. | |
157 | * Note: This assumes that the values have already been | |
158 | * validated in the sock. | |
159 | */ | |
160 | asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; | |
161 | asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; | |
162 | asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; | |
163 | ||
164 | asoc->max_init_timeo = | |
165 | msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo); | |
166 | ||
1da177e4 LT |
167 | /* Set the local window size for receive. |
168 | * This is also the rcvbuf space per association. | |
169 | * RFC 6 - A SCTP receiver MUST be able to receive a minimum of | |
170 | * 1500 bytes in one SCTP packet. | |
171 | */ | |
049b3ff5 | 172 | if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW) |
1da177e4 LT |
173 | asoc->rwnd = SCTP_DEFAULT_MINWINDOW; |
174 | else | |
049b3ff5 | 175 | asoc->rwnd = sk->sk_rcvbuf/2; |
1da177e4 LT |
176 | |
177 | asoc->a_rwnd = asoc->rwnd; | |
178 | ||
1da177e4 LT |
179 | /* Use my own max window until I learn something better. */ |
180 | asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; | |
181 | ||
049b3ff5 NH |
182 | /* Initialize the receive memory counter */ |
183 | atomic_set(&asoc->rmem_alloc, 0); | |
184 | ||
1da177e4 LT |
185 | init_waitqueue_head(&asoc->wait); |
186 | ||
187 | asoc->c.my_vtag = sctp_generate_tag(ep); | |
1da177e4 LT |
188 | asoc->c.my_port = ep->base.bind_addr.port; |
189 | ||
190 | asoc->c.initial_tsn = sctp_generate_tsn(ep); | |
191 | ||
192 | asoc->next_tsn = asoc->c.initial_tsn; | |
193 | ||
194 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
195 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
196 | asoc->highest_sacked = asoc->ctsn_ack_point; | |
197 | asoc->last_cwr_tsn = asoc->ctsn_ack_point; | |
1da177e4 | 198 | |
1da177e4 LT |
199 | /* ADDIP Section 4.1 Asconf Chunk Procedures |
200 | * | |
201 | * When an endpoint has an ASCONF signaled change to be sent to the | |
202 | * remote endpoint it should do the following: | |
203 | * ... | |
204 | * A2) a serial number should be assigned to the chunk. The serial | |
205 | * number SHOULD be a monotonically increasing number. The serial | |
206 | * numbers SHOULD be initialized at the start of the | |
207 | * association to the same value as the initial TSN. | |
208 | */ | |
209 | asoc->addip_serial = asoc->c.initial_tsn; | |
cc16f00f | 210 | asoc->strreset_outseq = asoc->c.initial_tsn; |
1da177e4 | 211 | |
79af02c2 | 212 | INIT_LIST_HEAD(&asoc->addip_chunk_list); |
a08de64d | 213 | INIT_LIST_HEAD(&asoc->asconf_ack_list); |
1da177e4 LT |
214 | |
215 | /* Make an empty list of remote transport addresses. */ | |
216 | INIT_LIST_HEAD(&asoc->peer.transport_addr_list); | |
217 | ||
218 | /* RFC 2960 5.1 Normal Establishment of an Association | |
219 | * | |
220 | * After the reception of the first data chunk in an | |
221 | * association the endpoint must immediately respond with a | |
222 | * sack to acknowledge the data chunk. Subsequent | |
223 | * acknowledgements should be done as described in Section | |
224 | * 6.2. | |
225 | * | |
226 | * [We implement this by telling a new association that it | |
227 | * already received one packet.] | |
228 | */ | |
229 | asoc->peer.sack_needed = 1; | |
4244854d | 230 | asoc->peer.sack_generation = 1; |
1da177e4 | 231 | |
73d9c4fd VY |
232 | /* Assume that the peer will tell us if he recognizes ASCONF |
233 | * as part of INIT exchange. | |
9d2c881a | 234 | * The sctp_addip_noauth option is there for backward compatibility |
73d9c4fd | 235 | * and will revert old behavior. |
1da177e4 | 236 | */ |
e1fc3b14 | 237 | if (net->sctp.addip_noauth) |
73d9c4fd | 238 | asoc->peer.asconf_capable = 1; |
1da177e4 LT |
239 | |
240 | /* Create an input queue. */ | |
241 | sctp_inq_init(&asoc->base.inqueue); | |
c4028958 | 242 | sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv); |
1da177e4 LT |
243 | |
244 | /* Create an output queue. */ | |
245 | sctp_outq_init(asoc, &asoc->outqueue); | |
246 | ||
247 | if (!sctp_ulpq_init(&asoc->ulpq, asoc)) | |
248 | goto fail_init; | |
249 | ||
1da177e4 LT |
250 | /* Assume that peer would support both address types unless we are |
251 | * told otherwise. | |
252 | */ | |
253 | asoc->peer.ipv4_address = 1; | |
a2c39584 WY |
254 | if (asoc->base.sk->sk_family == PF_INET6) |
255 | asoc->peer.ipv6_address = 1; | |
1da177e4 LT |
256 | INIT_LIST_HEAD(&asoc->asocs); |
257 | ||
1da177e4 LT |
258 | asoc->default_stream = sp->default_stream; |
259 | asoc->default_ppid = sp->default_ppid; | |
260 | asoc->default_flags = sp->default_flags; | |
261 | asoc->default_context = sp->default_context; | |
262 | asoc->default_timetolive = sp->default_timetolive; | |
6ab792f5 | 263 | asoc->default_rcv_context = sp->default_rcv_context; |
1da177e4 | 264 | |
a29a5bd4 VY |
265 | /* AUTH related initializations */ |
266 | INIT_LIST_HEAD(&asoc->endpoint_shared_keys); | |
267 | err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp); | |
268 | if (err) | |
269 | goto fail_init; | |
270 | ||
271 | asoc->active_key_id = ep->active_key_id; | |
28aa4c26 | 272 | asoc->prsctp_enable = ep->prsctp_enable; |
a29a5bd4 | 273 | |
a29a5bd4 VY |
274 | /* Save the hmacs and chunks list into this association */ |
275 | if (ep->auth_hmacs_list) | |
276 | memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list, | |
277 | ntohs(ep->auth_hmacs_list->param_hdr.length)); | |
278 | if (ep->auth_chunk_list) | |
279 | memcpy(asoc->c.auth_chunks, ep->auth_chunk_list, | |
280 | ntohs(ep->auth_chunk_list->param_hdr.length)); | |
281 | ||
282 | /* Get the AUTH random number for this association */ | |
283 | p = (sctp_paramhdr_t *)asoc->c.auth_random; | |
284 | p->type = SCTP_PARAM_RANDOM; | |
285 | p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH); | |
286 | get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH); | |
287 | ||
1da177e4 LT |
288 | return asoc; |
289 | ||
290 | fail_init: | |
1da177e4 | 291 | sock_put(asoc->base.sk); |
2e0c9e79 | 292 | sctp_endpoint_put(asoc->ep); |
1da177e4 LT |
293 | return NULL; |
294 | } | |
295 | ||
296 | /* Allocate and initialize a new association */ | |
297 | struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep, | |
298 | const struct sock *sk, | |
3182cd84 | 299 | sctp_scope_t scope, |
dd0fc66f | 300 | gfp_t gfp) |
1da177e4 LT |
301 | { |
302 | struct sctp_association *asoc; | |
303 | ||
939cfa75 | 304 | asoc = kzalloc(sizeof(*asoc), gfp); |
1da177e4 LT |
305 | if (!asoc) |
306 | goto fail; | |
307 | ||
308 | if (!sctp_association_init(asoc, ep, sk, scope, gfp)) | |
309 | goto fail_init; | |
310 | ||
1da177e4 | 311 | SCTP_DBG_OBJCNT_INC(assoc); |
bb33381d DB |
312 | |
313 | pr_debug("Created asoc %p\n", asoc); | |
1da177e4 LT |
314 | |
315 | return asoc; | |
316 | ||
317 | fail_init: | |
318 | kfree(asoc); | |
319 | fail: | |
320 | return NULL; | |
321 | } | |
322 | ||
323 | /* Free this association if possible. There may still be users, so | |
324 | * the actual deallocation may be delayed. | |
325 | */ | |
326 | void sctp_association_free(struct sctp_association *asoc) | |
327 | { | |
328 | struct sock *sk = asoc->base.sk; | |
329 | struct sctp_transport *transport; | |
330 | struct list_head *pos, *temp; | |
331 | int i; | |
332 | ||
de76e695 VY |
333 | /* Only real associations count against the endpoint, so |
334 | * don't bother for if this is a temporary association. | |
335 | */ | |
d3217b15 | 336 | if (!list_empty(&asoc->asocs)) { |
de76e695 VY |
337 | list_del(&asoc->asocs); |
338 | ||
339 | /* Decrement the backlog value for a TCP-style listening | |
340 | * socket. | |
341 | */ | |
342 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
343 | sk->sk_ack_backlog--; | |
344 | } | |
1da177e4 LT |
345 | |
346 | /* Mark as dead, so other users can know this structure is | |
347 | * going away. | |
348 | */ | |
0022d2dd | 349 | asoc->base.dead = true; |
1da177e4 LT |
350 | |
351 | /* Dispose of any data lying around in the outqueue. */ | |
352 | sctp_outq_free(&asoc->outqueue); | |
353 | ||
354 | /* Dispose of any pending messages for the upper layer. */ | |
355 | sctp_ulpq_free(&asoc->ulpq); | |
356 | ||
357 | /* Dispose of any pending chunks on the inqueue. */ | |
358 | sctp_inq_free(&asoc->base.inqueue); | |
359 | ||
8e1ee18c VY |
360 | sctp_tsnmap_free(&asoc->peer.tsn_map); |
361 | ||
a8386317 XL |
362 | /* Free stream information. */ |
363 | sctp_stream_free(asoc->stream); | |
1da177e4 | 364 | |
7b9438de XL |
365 | if (asoc->strreset_chunk) |
366 | sctp_chunk_free(asoc->strreset_chunk); | |
367 | ||
1da177e4 LT |
368 | /* Clean up the bound address list. */ |
369 | sctp_bind_addr_free(&asoc->base.bind_addr); | |
370 | ||
371 | /* Do we need to go through all of our timers and | |
372 | * delete them? To be safe we will try to delete all, but we | |
373 | * should be able to go through and make a guess based | |
374 | * on our state. | |
375 | */ | |
376 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { | |
25cc4ae9 | 377 | if (del_timer(&asoc->timers[i])) |
1da177e4 LT |
378 | sctp_association_put(asoc); |
379 | } | |
380 | ||
381 | /* Free peer's cached cookie. */ | |
a51482bd | 382 | kfree(asoc->peer.cookie); |
730fc3d0 VY |
383 | kfree(asoc->peer.peer_random); |
384 | kfree(asoc->peer.peer_chunks); | |
385 | kfree(asoc->peer.peer_hmacs); | |
1da177e4 LT |
386 | |
387 | /* Release the transport structures. */ | |
388 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
389 | transport = list_entry(pos, struct sctp_transport, transports); | |
45122ca2 | 390 | list_del_rcu(pos); |
4f008781 | 391 | sctp_unhash_transport(transport); |
1da177e4 LT |
392 | sctp_transport_free(transport); |
393 | } | |
394 | ||
3f7a87d2 FF |
395 | asoc->peer.transport_count = 0; |
396 | ||
a000c01e | 397 | sctp_asconf_queue_teardown(asoc); |
1da177e4 | 398 | |
8a07eb0a | 399 | /* Free pending address space being deleted */ |
7d37d0c1 | 400 | kfree(asoc->asconf_addr_del_pending); |
8a07eb0a | 401 | |
a29a5bd4 VY |
402 | /* AUTH - Free the endpoint shared keys */ |
403 | sctp_auth_destroy_keys(&asoc->endpoint_shared_keys); | |
404 | ||
405 | /* AUTH - Free the association shared key */ | |
406 | sctp_auth_key_put(asoc->asoc_shared_key); | |
407 | ||
1da177e4 LT |
408 | sctp_association_put(asoc); |
409 | } | |
410 | ||
411 | /* Cleanup and free up an association. */ | |
412 | static void sctp_association_destroy(struct sctp_association *asoc) | |
413 | { | |
bb33381d DB |
414 | if (unlikely(!asoc->base.dead)) { |
415 | WARN(1, "Attempt to destroy undead association %p!\n", asoc); | |
416 | return; | |
417 | } | |
1da177e4 LT |
418 | |
419 | sctp_endpoint_put(asoc->ep); | |
420 | sock_put(asoc->base.sk); | |
421 | ||
422 | if (asoc->assoc_id != 0) { | |
423 | spin_lock_bh(&sctp_assocs_id_lock); | |
424 | idr_remove(&sctp_assocs_id, asoc->assoc_id); | |
425 | spin_unlock_bh(&sctp_assocs_id_lock); | |
426 | } | |
427 | ||
547b792c | 428 | WARN_ON(atomic_read(&asoc->rmem_alloc)); |
049b3ff5 | 429 | |
ff2266cd DB |
430 | kfree(asoc); |
431 | SCTP_DBG_OBJCNT_DEC(assoc); | |
1da177e4 LT |
432 | } |
433 | ||
434 | /* Change the primary destination address for the peer. */ | |
435 | void sctp_assoc_set_primary(struct sctp_association *asoc, | |
436 | struct sctp_transport *transport) | |
437 | { | |
319fa2a2 VY |
438 | int changeover = 0; |
439 | ||
440 | /* it's a changeover only if we already have a primary path | |
441 | * that we are changing | |
442 | */ | |
443 | if (asoc->peer.primary_path != NULL && | |
444 | asoc->peer.primary_path != transport) | |
445 | changeover = 1 ; | |
446 | ||
1da177e4 LT |
447 | asoc->peer.primary_path = transport; |
448 | ||
449 | /* Set a default msg_name for events. */ | |
450 | memcpy(&asoc->peer.primary_addr, &transport->ipaddr, | |
451 | sizeof(union sctp_addr)); | |
452 | ||
453 | /* If the primary path is changing, assume that the | |
454 | * user wants to use this new path. | |
455 | */ | |
ad8fec17 SS |
456 | if ((transport->state == SCTP_ACTIVE) || |
457 | (transport->state == SCTP_UNKNOWN)) | |
1da177e4 LT |
458 | asoc->peer.active_path = transport; |
459 | ||
460 | /* | |
461 | * SFR-CACC algorithm: | |
462 | * Upon the receipt of a request to change the primary | |
463 | * destination address, on the data structure for the new | |
464 | * primary destination, the sender MUST do the following: | |
465 | * | |
466 | * 1) If CHANGEOVER_ACTIVE is set, then there was a switch | |
467 | * to this destination address earlier. The sender MUST set | |
468 | * CYCLING_CHANGEOVER to indicate that this switch is a | |
469 | * double switch to the same destination address. | |
e0e9db17 VY |
470 | * |
471 | * Really, only bother is we have data queued or outstanding on | |
472 | * the association. | |
1da177e4 | 473 | */ |
e0e9db17 VY |
474 | if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen) |
475 | return; | |
476 | ||
1da177e4 | 477 | if (transport->cacc.changeover_active) |
319fa2a2 | 478 | transport->cacc.cycling_changeover = changeover; |
1da177e4 LT |
479 | |
480 | /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that | |
481 | * a changeover has occurred. | |
482 | */ | |
319fa2a2 | 483 | transport->cacc.changeover_active = changeover; |
1da177e4 LT |
484 | |
485 | /* 3) The sender MUST store the next TSN to be sent in | |
486 | * next_tsn_at_change. | |
487 | */ | |
488 | transport->cacc.next_tsn_at_change = asoc->next_tsn; | |
489 | } | |
490 | ||
3f7a87d2 FF |
491 | /* Remove a transport from an association. */ |
492 | void sctp_assoc_rm_peer(struct sctp_association *asoc, | |
493 | struct sctp_transport *peer) | |
494 | { | |
495 | struct list_head *pos; | |
496 | struct sctp_transport *transport; | |
497 | ||
bb33381d DB |
498 | pr_debug("%s: association:%p addr:%pISpc\n", |
499 | __func__, asoc, &peer->ipaddr.sa); | |
3f7a87d2 FF |
500 | |
501 | /* If we are to remove the current retran_path, update it | |
502 | * to the next peer before removing this peer from the list. | |
503 | */ | |
504 | if (asoc->peer.retran_path == peer) | |
505 | sctp_assoc_update_retran_path(asoc); | |
506 | ||
507 | /* Remove this peer from the list. */ | |
45122ca2 | 508 | list_del_rcu(&peer->transports); |
4f008781 XL |
509 | /* Remove this peer from the transport hashtable */ |
510 | sctp_unhash_transport(peer); | |
3f7a87d2 FF |
511 | |
512 | /* Get the first transport of asoc. */ | |
513 | pos = asoc->peer.transport_addr_list.next; | |
514 | transport = list_entry(pos, struct sctp_transport, transports); | |
515 | ||
516 | /* Update any entries that match the peer to be deleted. */ | |
517 | if (asoc->peer.primary_path == peer) | |
518 | sctp_assoc_set_primary(asoc, transport); | |
519 | if (asoc->peer.active_path == peer) | |
520 | asoc->peer.active_path = transport; | |
9494c7c5 WY |
521 | if (asoc->peer.retran_path == peer) |
522 | asoc->peer.retran_path = transport; | |
3f7a87d2 FF |
523 | if (asoc->peer.last_data_from == peer) |
524 | asoc->peer.last_data_from = transport; | |
525 | ||
7b9438de XL |
526 | if (asoc->strreset_chunk && |
527 | asoc->strreset_chunk->transport == peer) { | |
528 | asoc->strreset_chunk->transport = transport; | |
529 | sctp_transport_reset_reconf_timer(transport); | |
530 | } | |
531 | ||
3f7a87d2 FF |
532 | /* If we remove the transport an INIT was last sent to, set it to |
533 | * NULL. Combined with the update of the retran path above, this | |
534 | * will cause the next INIT to be sent to the next available | |
535 | * transport, maintaining the cycle. | |
536 | */ | |
537 | if (asoc->init_last_sent_to == peer) | |
538 | asoc->init_last_sent_to = NULL; | |
539 | ||
6345b199 WY |
540 | /* If we remove the transport an SHUTDOWN was last sent to, set it |
541 | * to NULL. Combined with the update of the retran path above, this | |
542 | * will cause the next SHUTDOWN to be sent to the next available | |
543 | * transport, maintaining the cycle. | |
544 | */ | |
545 | if (asoc->shutdown_last_sent_to == peer) | |
546 | asoc->shutdown_last_sent_to = NULL; | |
547 | ||
10a43cea WY |
548 | /* If we remove the transport an ASCONF was last sent to, set it to |
549 | * NULL. | |
550 | */ | |
551 | if (asoc->addip_last_asconf && | |
552 | asoc->addip_last_asconf->transport == peer) | |
553 | asoc->addip_last_asconf->transport = NULL; | |
554 | ||
31b02e15 VY |
555 | /* If we have something on the transmitted list, we have to |
556 | * save it off. The best place is the active path. | |
557 | */ | |
558 | if (!list_empty(&peer->transmitted)) { | |
559 | struct sctp_transport *active = asoc->peer.active_path; | |
560 | struct sctp_chunk *ch; | |
561 | ||
562 | /* Reset the transport of each chunk on this list */ | |
563 | list_for_each_entry(ch, &peer->transmitted, | |
564 | transmitted_list) { | |
565 | ch->transport = NULL; | |
566 | ch->rtt_in_progress = 0; | |
567 | } | |
568 | ||
569 | list_splice_tail_init(&peer->transmitted, | |
570 | &active->transmitted); | |
571 | ||
572 | /* Start a T3 timer here in case it wasn't running so | |
573 | * that these migrated packets have a chance to get | |
2bccbadf | 574 | * retransmitted. |
31b02e15 VY |
575 | */ |
576 | if (!timer_pending(&active->T3_rtx_timer)) | |
577 | if (!mod_timer(&active->T3_rtx_timer, | |
578 | jiffies + active->rto)) | |
579 | sctp_transport_hold(active); | |
580 | } | |
581 | ||
3f7a87d2 FF |
582 | asoc->peer.transport_count--; |
583 | ||
584 | sctp_transport_free(peer); | |
585 | } | |
586 | ||
1da177e4 LT |
587 | /* Add a transport address to an association. */ |
588 | struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, | |
589 | const union sctp_addr *addr, | |
dd0fc66f | 590 | const gfp_t gfp, |
3f7a87d2 | 591 | const int peer_state) |
1da177e4 | 592 | { |
89bf3450 | 593 | struct net *net = sock_net(asoc->base.sk); |
1da177e4 LT |
594 | struct sctp_transport *peer; |
595 | struct sctp_sock *sp; | |
596 | unsigned short port; | |
597 | ||
598 | sp = sctp_sk(asoc->base.sk); | |
599 | ||
600 | /* AF_INET and AF_INET6 share common port field. */ | |
4bdf4b5f | 601 | port = ntohs(addr->v4.sin_port); |
1da177e4 | 602 | |
bb33381d DB |
603 | pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__, |
604 | asoc, &addr->sa, peer_state); | |
3f7a87d2 | 605 | |
1da177e4 LT |
606 | /* Set the port if it has not been set yet. */ |
607 | if (0 == asoc->peer.port) | |
608 | asoc->peer.port = port; | |
609 | ||
610 | /* Check to see if this is a duplicate. */ | |
611 | peer = sctp_assoc_lookup_paddr(asoc, addr); | |
3f7a87d2 | 612 | if (peer) { |
add52379 VY |
613 | /* An UNKNOWN state is only set on transports added by |
614 | * user in sctp_connectx() call. Such transports should be | |
615 | * considered CONFIRMED per RFC 4960, Section 5.4. | |
616 | */ | |
ad8fec17 | 617 | if (peer->state == SCTP_UNKNOWN) { |
add52379 | 618 | peer->state = SCTP_ACTIVE; |
ad8fec17 | 619 | } |
1da177e4 | 620 | return peer; |
3f7a87d2 | 621 | } |
1da177e4 | 622 | |
89bf3450 | 623 | peer = sctp_transport_new(net, addr, gfp); |
1da177e4 LT |
624 | if (!peer) |
625 | return NULL; | |
626 | ||
627 | sctp_transport_set_owner(peer, asoc); | |
628 | ||
52ccb8e9 FF |
629 | /* Initialize the peer's heartbeat interval based on the |
630 | * association configured value. | |
631 | */ | |
632 | peer->hbinterval = asoc->hbinterval; | |
633 | ||
634 | /* Set the path max_retrans. */ | |
635 | peer->pathmaxrxt = asoc->pathmaxrxt; | |
636 | ||
2bccbadf | 637 | /* And the partial failure retrans threshold */ |
5aa93bcf NH |
638 | peer->pf_retrans = asoc->pf_retrans; |
639 | ||
52ccb8e9 FF |
640 | /* Initialize the peer's SACK delay timeout based on the |
641 | * association configured value. | |
642 | */ | |
643 | peer->sackdelay = asoc->sackdelay; | |
d364d927 | 644 | peer->sackfreq = asoc->sackfreq; |
52ccb8e9 FF |
645 | |
646 | /* Enable/disable heartbeat, SACK delay, and path MTU discovery | |
647 | * based on association setting. | |
648 | */ | |
649 | peer->param_flags = asoc->param_flags; | |
650 | ||
8da645e1 VY |
651 | sctp_transport_route(peer, NULL, sp); |
652 | ||
1da177e4 | 653 | /* Initialize the pmtu of the transport. */ |
8da645e1 VY |
654 | if (peer->param_flags & SPP_PMTUD_DISABLE) { |
655 | if (asoc->pathmtu) | |
656 | peer->pathmtu = asoc->pathmtu; | |
657 | else | |
658 | peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT; | |
659 | } | |
1da177e4 LT |
660 | |
661 | /* If this is the first transport addr on this association, | |
662 | * initialize the association PMTU to the peer's PMTU. | |
663 | * If not and the current association PMTU is higher than the new | |
664 | * peer's PMTU, reset the association PMTU to the new peer's PMTU. | |
665 | */ | |
52ccb8e9 FF |
666 | if (asoc->pathmtu) |
667 | asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu); | |
1da177e4 | 668 | else |
52ccb8e9 | 669 | asoc->pathmtu = peer->pathmtu; |
1da177e4 | 670 | |
bb33381d DB |
671 | pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc, |
672 | asoc->pathmtu); | |
673 | ||
6d0ccbac | 674 | peer->pmtu_pending = 0; |
1da177e4 | 675 | |
f68b2e05 | 676 | asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); |
1da177e4 LT |
677 | |
678 | /* The asoc->peer.port might not be meaningful yet, but | |
679 | * initialize the packet structure anyway. | |
680 | */ | |
681 | sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port, | |
682 | asoc->peer.port); | |
683 | ||
684 | /* 7.2.1 Slow-Start | |
685 | * | |
686 | * o The initial cwnd before DATA transmission or after a sufficiently | |
687 | * long idle period MUST be set to | |
688 | * min(4*MTU, max(2*MTU, 4380 bytes)) | |
689 | * | |
690 | * o The initial value of ssthresh MAY be arbitrarily high | |
691 | * (for example, implementations MAY use the size of the | |
692 | * receiver advertised window). | |
693 | */ | |
52ccb8e9 | 694 | peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); |
1da177e4 LT |
695 | |
696 | /* At this point, we may not have the receiver's advertised window, | |
697 | * so initialize ssthresh to the default value and it will be set | |
698 | * later when we process the INIT. | |
699 | */ | |
700 | peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; | |
701 | ||
702 | peer->partial_bytes_acked = 0; | |
703 | peer->flight_size = 0; | |
46d5a808 | 704 | peer->burst_limited = 0; |
1da177e4 | 705 | |
1da177e4 LT |
706 | /* Set the transport's RTO.initial value */ |
707 | peer->rto = asoc->rto_initial; | |
196d6759 | 708 | sctp_max_rto(asoc, peer); |
1da177e4 | 709 | |
3f7a87d2 FF |
710 | /* Set the peer's active state. */ |
711 | peer->state = peer_state; | |
712 | ||
7fda702f XL |
713 | /* Add this peer into the transport hashtable */ |
714 | if (sctp_hash_transport(peer)) { | |
715 | sctp_transport_free(peer); | |
716 | return NULL; | |
717 | } | |
718 | ||
1da177e4 | 719 | /* Attach the remote transport to our asoc. */ |
45122ca2 | 720 | list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list); |
3f7a87d2 | 721 | asoc->peer.transport_count++; |
1da177e4 LT |
722 | |
723 | /* If we do not yet have a primary path, set one. */ | |
724 | if (!asoc->peer.primary_path) { | |
725 | sctp_assoc_set_primary(asoc, peer); | |
726 | asoc->peer.retran_path = peer; | |
727 | } | |
728 | ||
fbdf501c VY |
729 | if (asoc->peer.active_path == asoc->peer.retran_path && |
730 | peer->state != SCTP_UNCONFIRMED) { | |
1da177e4 | 731 | asoc->peer.retran_path = peer; |
3f7a87d2 | 732 | } |
1da177e4 LT |
733 | |
734 | return peer; | |
735 | } | |
736 | ||
737 | /* Delete a transport address from an association. */ | |
738 | void sctp_assoc_del_peer(struct sctp_association *asoc, | |
739 | const union sctp_addr *addr) | |
740 | { | |
741 | struct list_head *pos; | |
742 | struct list_head *temp; | |
1da177e4 LT |
743 | struct sctp_transport *transport; |
744 | ||
745 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
746 | transport = list_entry(pos, struct sctp_transport, transports); | |
747 | if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) { | |
3f7a87d2 FF |
748 | /* Do book keeping for removing the peer and free it. */ |
749 | sctp_assoc_rm_peer(asoc, transport); | |
1da177e4 LT |
750 | break; |
751 | } | |
752 | } | |
1da177e4 LT |
753 | } |
754 | ||
755 | /* Lookup a transport by address. */ | |
756 | struct sctp_transport *sctp_assoc_lookup_paddr( | |
757 | const struct sctp_association *asoc, | |
758 | const union sctp_addr *address) | |
759 | { | |
760 | struct sctp_transport *t; | |
1da177e4 LT |
761 | |
762 | /* Cycle through all transports searching for a peer address. */ | |
763 | ||
9dbc15f0 RD |
764 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
765 | transports) { | |
1da177e4 LT |
766 | if (sctp_cmp_addr_exact(address, &t->ipaddr)) |
767 | return t; | |
768 | } | |
769 | ||
770 | return NULL; | |
771 | } | |
772 | ||
42e30bf3 VY |
773 | /* Remove all transports except a give one */ |
774 | void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc, | |
775 | struct sctp_transport *primary) | |
776 | { | |
777 | struct sctp_transport *temp; | |
778 | struct sctp_transport *t; | |
779 | ||
780 | list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list, | |
781 | transports) { | |
782 | /* if the current transport is not the primary one, delete it */ | |
783 | if (t != primary) | |
784 | sctp_assoc_rm_peer(asoc, t); | |
785 | } | |
42e30bf3 VY |
786 | } |
787 | ||
1da177e4 LT |
788 | /* Engage in transport control operations. |
789 | * Mark the transport up or down and send a notification to the user. | |
790 | * Select and update the new active and retran paths. | |
791 | */ | |
792 | void sctp_assoc_control_transport(struct sctp_association *asoc, | |
793 | struct sctp_transport *transport, | |
794 | sctp_transport_cmd_t command, | |
795 | sctp_sn_error_t error) | |
796 | { | |
1da177e4 | 797 | struct sctp_ulpevent *event; |
0906e20f | 798 | struct sockaddr_storage addr; |
1da177e4 | 799 | int spc_state = 0; |
5aa93bcf | 800 | bool ulp_notify = true; |
1da177e4 LT |
801 | |
802 | /* Record the transition on the transport. */ | |
803 | switch (command) { | |
804 | case SCTP_TRANSPORT_UP: | |
1ae4114d VY |
805 | /* If we are moving from UNCONFIRMED state due |
806 | * to heartbeat success, report the SCTP_ADDR_CONFIRMED | |
807 | * state to the user, otherwise report SCTP_ADDR_AVAILABLE. | |
808 | */ | |
809 | if (SCTP_UNCONFIRMED == transport->state && | |
810 | SCTP_HEARTBEAT_SUCCESS == error) | |
811 | spc_state = SCTP_ADDR_CONFIRMED; | |
812 | else | |
813 | spc_state = SCTP_ADDR_AVAILABLE; | |
5aa93bcf | 814 | /* Don't inform ULP about transition from PF to |
ac4f9599 | 815 | * active state and set cwnd to 1 MTU, see SCTP |
5aa93bcf NH |
816 | * Quick failover draft section 5.1, point 5 |
817 | */ | |
818 | if (transport->state == SCTP_PF) { | |
819 | ulp_notify = false; | |
ac4f9599 | 820 | transport->cwnd = asoc->pathmtu; |
5aa93bcf | 821 | } |
3f7a87d2 | 822 | transport->state = SCTP_ACTIVE; |
1da177e4 LT |
823 | break; |
824 | ||
825 | case SCTP_TRANSPORT_DOWN: | |
40187886 VY |
826 | /* If the transport was never confirmed, do not transition it |
827 | * to inactive state. Also, release the cached route since | |
828 | * there may be a better route next time. | |
cc75689a VY |
829 | */ |
830 | if (transport->state != SCTP_UNCONFIRMED) | |
831 | transport->state = SCTP_INACTIVE; | |
40187886 VY |
832 | else { |
833 | dst_release(transport->dst); | |
834 | transport->dst = NULL; | |
061079ac | 835 | ulp_notify = false; |
40187886 | 836 | } |
cc75689a | 837 | |
1da177e4 LT |
838 | spc_state = SCTP_ADDR_UNREACHABLE; |
839 | break; | |
840 | ||
5aa93bcf NH |
841 | case SCTP_TRANSPORT_PF: |
842 | transport->state = SCTP_PF; | |
843 | ulp_notify = false; | |
844 | break; | |
845 | ||
1da177e4 LT |
846 | default: |
847 | return; | |
3ff50b79 | 848 | } |
1da177e4 | 849 | |
b82e8f31 DB |
850 | /* Generate and send a SCTP_PEER_ADDR_CHANGE notification |
851 | * to the user. | |
1da177e4 | 852 | */ |
5aa93bcf NH |
853 | if (ulp_notify) { |
854 | memset(&addr, 0, sizeof(struct sockaddr_storage)); | |
855 | memcpy(&addr, &transport->ipaddr, | |
856 | transport->af_specific->sockaddr_len); | |
b82e8f31 | 857 | |
5aa93bcf NH |
858 | event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, |
859 | 0, spc_state, error, GFP_ATOMIC); | |
860 | if (event) | |
861 | sctp_ulpq_tail_event(&asoc->ulpq, event); | |
862 | } | |
1da177e4 LT |
863 | |
864 | /* Select new active and retran paths. */ | |
b82e8f31 | 865 | sctp_select_active_and_retran_path(asoc); |
1da177e4 LT |
866 | } |
867 | ||
868 | /* Hold a reference to an association. */ | |
869 | void sctp_association_hold(struct sctp_association *asoc) | |
870 | { | |
871 | atomic_inc(&asoc->base.refcnt); | |
872 | } | |
873 | ||
874 | /* Release a reference to an association and cleanup | |
875 | * if there are no more references. | |
876 | */ | |
877 | void sctp_association_put(struct sctp_association *asoc) | |
878 | { | |
879 | if (atomic_dec_and_test(&asoc->base.refcnt)) | |
880 | sctp_association_destroy(asoc); | |
881 | } | |
882 | ||
883 | /* Allocate the next TSN, Transmission Sequence Number, for the given | |
884 | * association. | |
885 | */ | |
886 | __u32 sctp_association_get_next_tsn(struct sctp_association *asoc) | |
887 | { | |
888 | /* From Section 1.6 Serial Number Arithmetic: | |
889 | * Transmission Sequence Numbers wrap around when they reach | |
890 | * 2**32 - 1. That is, the next TSN a DATA chunk MUST use | |
891 | * after transmitting TSN = 2*32 - 1 is TSN = 0. | |
892 | */ | |
893 | __u32 retval = asoc->next_tsn; | |
894 | asoc->next_tsn++; | |
895 | asoc->unack_data++; | |
896 | ||
897 | return retval; | |
898 | } | |
899 | ||
900 | /* Compare two addresses to see if they match. Wildcard addresses | |
901 | * only match themselves. | |
902 | */ | |
903 | int sctp_cmp_addr_exact(const union sctp_addr *ss1, | |
904 | const union sctp_addr *ss2) | |
905 | { | |
906 | struct sctp_af *af; | |
907 | ||
908 | af = sctp_get_af_specific(ss1->sa.sa_family); | |
909 | if (unlikely(!af)) | |
910 | return 0; | |
911 | ||
912 | return af->cmp_addr(ss1, ss2); | |
913 | } | |
914 | ||
915 | /* Return an ecne chunk to get prepended to a packet. | |
916 | * Note: We are sly and return a shared, prealloced chunk. FIXME: | |
917 | * No we don't, but we could/should. | |
918 | */ | |
919 | struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc) | |
920 | { | |
8b7318d3 | 921 | if (!asoc->need_ecne) |
922 | return NULL; | |
1da177e4 LT |
923 | |
924 | /* Send ECNE if needed. | |
925 | * Not being able to allocate a chunk here is not deadly. | |
926 | */ | |
8b7318d3 | 927 | return sctp_make_ecne(asoc, asoc->last_ecne_tsn); |
1da177e4 LT |
928 | } |
929 | ||
930 | /* | |
931 | * Find which transport this TSN was sent on. | |
932 | */ | |
933 | struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc, | |
934 | __u32 tsn) | |
935 | { | |
936 | struct sctp_transport *active; | |
937 | struct sctp_transport *match; | |
1da177e4 LT |
938 | struct sctp_transport *transport; |
939 | struct sctp_chunk *chunk; | |
dbc16db1 | 940 | __be32 key = htonl(tsn); |
1da177e4 LT |
941 | |
942 | match = NULL; | |
943 | ||
944 | /* | |
945 | * FIXME: In general, find a more efficient data structure for | |
946 | * searching. | |
947 | */ | |
948 | ||
949 | /* | |
950 | * The general strategy is to search each transport's transmitted | |
951 | * list. Return which transport this TSN lives on. | |
952 | * | |
953 | * Let's be hopeful and check the active_path first. | |
954 | * Another optimization would be to know if there is only one | |
955 | * outbound path and not have to look for the TSN at all. | |
956 | * | |
957 | */ | |
958 | ||
959 | active = asoc->peer.active_path; | |
960 | ||
9dbc15f0 RD |
961 | list_for_each_entry(chunk, &active->transmitted, |
962 | transmitted_list) { | |
1da177e4 LT |
963 | |
964 | if (key == chunk->subh.data_hdr->tsn) { | |
965 | match = active; | |
966 | goto out; | |
967 | } | |
968 | } | |
969 | ||
970 | /* If not found, go search all the other transports. */ | |
9dbc15f0 RD |
971 | list_for_each_entry(transport, &asoc->peer.transport_addr_list, |
972 | transports) { | |
1da177e4 LT |
973 | |
974 | if (transport == active) | |
2317f449 | 975 | continue; |
9dbc15f0 RD |
976 | list_for_each_entry(chunk, &transport->transmitted, |
977 | transmitted_list) { | |
1da177e4 LT |
978 | if (key == chunk->subh.data_hdr->tsn) { |
979 | match = transport; | |
980 | goto out; | |
981 | } | |
982 | } | |
983 | } | |
984 | out: | |
985 | return match; | |
986 | } | |
987 | ||
988 | /* Is this the association we are looking for? */ | |
989 | struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc, | |
4110cc25 | 990 | struct net *net, |
1da177e4 LT |
991 | const union sctp_addr *laddr, |
992 | const union sctp_addr *paddr) | |
993 | { | |
994 | struct sctp_transport *transport; | |
995 | ||
e2fccedb | 996 | if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) && |
4110cc25 EB |
997 | (htons(asoc->peer.port) == paddr->v4.sin_port) && |
998 | net_eq(sock_net(asoc->base.sk), net)) { | |
1da177e4 LT |
999 | transport = sctp_assoc_lookup_paddr(asoc, paddr); |
1000 | if (!transport) | |
1001 | goto out; | |
1002 | ||
1003 | if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
1004 | sctp_sk(asoc->base.sk))) | |
1005 | goto out; | |
1006 | } | |
1007 | transport = NULL; | |
1008 | ||
1009 | out: | |
1da177e4 LT |
1010 | return transport; |
1011 | } | |
1012 | ||
1013 | /* Do delayed input processing. This is scheduled by sctp_rcv(). */ | |
c4028958 | 1014 | static void sctp_assoc_bh_rcv(struct work_struct *work) |
1da177e4 | 1015 | { |
c4028958 DH |
1016 | struct sctp_association *asoc = |
1017 | container_of(work, struct sctp_association, | |
1018 | base.inqueue.immediate); | |
55e26eb9 | 1019 | struct net *net = sock_net(asoc->base.sk); |
1da177e4 LT |
1020 | struct sctp_endpoint *ep; |
1021 | struct sctp_chunk *chunk; | |
1da177e4 LT |
1022 | struct sctp_inq *inqueue; |
1023 | int state; | |
1024 | sctp_subtype_t subtype; | |
1025 | int error = 0; | |
1026 | ||
1027 | /* The association should be held so we should be safe. */ | |
1028 | ep = asoc->ep; | |
1da177e4 LT |
1029 | |
1030 | inqueue = &asoc->base.inqueue; | |
1031 | sctp_association_hold(asoc); | |
1032 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
1033 | state = asoc->state; | |
1034 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
1035 | ||
bbd0d598 VY |
1036 | /* SCTP-AUTH, Section 6.3: |
1037 | * The receiver has a list of chunk types which it expects | |
1038 | * to be received only after an AUTH-chunk. This list has | |
1039 | * been sent to the peer during the association setup. It | |
1040 | * MUST silently discard these chunks if they are not placed | |
1041 | * after an AUTH chunk in the packet. | |
1042 | */ | |
1043 | if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) | |
1044 | continue; | |
1045 | ||
1da177e4 LT |
1046 | /* Remember where the last DATA chunk came from so we |
1047 | * know where to send the SACK. | |
1048 | */ | |
1049 | if (sctp_chunk_is_data(chunk)) | |
1050 | asoc->peer.last_data_from = chunk->transport; | |
196d6759 | 1051 | else { |
55e26eb9 | 1052 | SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS); |
196d6759 MB |
1053 | asoc->stats.ictrlchunks++; |
1054 | if (chunk->chunk_hdr->type == SCTP_CID_SACK) | |
1055 | asoc->stats.isacks++; | |
1056 | } | |
1da177e4 LT |
1057 | |
1058 | if (chunk->transport) | |
e575235f | 1059 | chunk->transport->last_time_heard = ktime_get(); |
1da177e4 LT |
1060 | |
1061 | /* Run through the state machine. */ | |
55e26eb9 | 1062 | error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, |
1da177e4 LT |
1063 | state, ep, asoc, chunk, GFP_ATOMIC); |
1064 | ||
1065 | /* Check to see if the association is freed in response to | |
1066 | * the incoming chunk. If so, get out of the while loop. | |
1067 | */ | |
1068 | if (asoc->base.dead) | |
1069 | break; | |
1070 | ||
1071 | /* If there is an error on chunk, discard this packet. */ | |
1072 | if (error && chunk) | |
1073 | chunk->pdiscard = 1; | |
1074 | } | |
1075 | sctp_association_put(asoc); | |
1076 | } | |
1077 | ||
1078 | /* This routine moves an association from its old sk to a new sk. */ | |
1079 | void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk) | |
1080 | { | |
1081 | struct sctp_sock *newsp = sctp_sk(newsk); | |
1082 | struct sock *oldsk = assoc->base.sk; | |
1083 | ||
1084 | /* Delete the association from the old endpoint's list of | |
1085 | * associations. | |
1086 | */ | |
1087 | list_del_init(&assoc->asocs); | |
1088 | ||
1089 | /* Decrement the backlog value for a TCP-style socket. */ | |
1090 | if (sctp_style(oldsk, TCP)) | |
1091 | oldsk->sk_ack_backlog--; | |
1092 | ||
1093 | /* Release references to the old endpoint and the sock. */ | |
1094 | sctp_endpoint_put(assoc->ep); | |
1095 | sock_put(assoc->base.sk); | |
1096 | ||
1097 | /* Get a reference to the new endpoint. */ | |
1098 | assoc->ep = newsp->ep; | |
1099 | sctp_endpoint_hold(assoc->ep); | |
1100 | ||
1101 | /* Get a reference to the new sock. */ | |
1102 | assoc->base.sk = newsk; | |
1103 | sock_hold(assoc->base.sk); | |
1104 | ||
1105 | /* Add the association to the new endpoint's list of associations. */ | |
1106 | sctp_endpoint_add_asoc(newsp->ep, assoc); | |
1107 | } | |
1108 | ||
1109 | /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ | |
1110 | void sctp_assoc_update(struct sctp_association *asoc, | |
1111 | struct sctp_association *new) | |
1112 | { | |
1113 | struct sctp_transport *trans; | |
1114 | struct list_head *pos, *temp; | |
1115 | ||
1116 | /* Copy in new parameters of peer. */ | |
1117 | asoc->c = new->c; | |
1118 | asoc->peer.rwnd = new->peer.rwnd; | |
1119 | asoc->peer.sack_needed = new->peer.sack_needed; | |
1be9a950 | 1120 | asoc->peer.auth_capable = new->peer.auth_capable; |
1da177e4 | 1121 | asoc->peer.i = new->peer.i; |
8e1ee18c VY |
1122 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, |
1123 | asoc->peer.i.initial_tsn, GFP_ATOMIC); | |
1da177e4 LT |
1124 | |
1125 | /* Remove any peer addresses not present in the new association. */ | |
1126 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
1127 | trans = list_entry(pos, struct sctp_transport, transports); | |
0c42749c VY |
1128 | if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) { |
1129 | sctp_assoc_rm_peer(asoc, trans); | |
1130 | continue; | |
1131 | } | |
749bf921 VY |
1132 | |
1133 | if (asoc->state >= SCTP_STATE_ESTABLISHED) | |
1134 | sctp_transport_reset(trans); | |
1da177e4 LT |
1135 | } |
1136 | ||
1137 | /* If the case is A (association restart), use | |
1138 | * initial_tsn as next_tsn. If the case is B, use | |
1139 | * current next_tsn in case data sent to peer | |
1140 | * has been discarded and needs retransmission. | |
1141 | */ | |
1142 | if (asoc->state >= SCTP_STATE_ESTABLISHED) { | |
1143 | asoc->next_tsn = new->next_tsn; | |
1144 | asoc->ctsn_ack_point = new->ctsn_ack_point; | |
1145 | asoc->adv_peer_ack_point = new->adv_peer_ack_point; | |
1146 | ||
1147 | /* Reinitialize SSN for both local streams | |
1148 | * and peer's streams. | |
1149 | */ | |
a8386317 | 1150 | sctp_stream_clear(asoc->stream); |
1da177e4 | 1151 | |
0b58a811 VY |
1152 | /* Flush the ULP reassembly and ordered queue. |
1153 | * Any data there will now be stale and will | |
1154 | * cause problems. | |
1155 | */ | |
1156 | sctp_ulpq_flush(&asoc->ulpq); | |
1157 | ||
749bf921 VY |
1158 | /* reset the overall association error count so |
1159 | * that the restarted association doesn't get torn | |
1160 | * down on the next retransmission timer. | |
1161 | */ | |
1162 | asoc->overall_error_count = 0; | |
1163 | ||
1da177e4 LT |
1164 | } else { |
1165 | /* Add any peer addresses from the new association. */ | |
9dbc15f0 RD |
1166 | list_for_each_entry(trans, &new->peer.transport_addr_list, |
1167 | transports) { | |
1da177e4 LT |
1168 | if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr)) |
1169 | sctp_assoc_add_peer(asoc, &trans->ipaddr, | |
ad8fec17 | 1170 | GFP_ATOMIC, trans->state); |
1da177e4 LT |
1171 | } |
1172 | ||
1173 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
1174 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
a8386317 XL |
1175 | if (!asoc->stream) { |
1176 | asoc->stream = new->stream; | |
1177 | new->stream = NULL; | |
1da177e4 | 1178 | } |
07d93967 VY |
1179 | |
1180 | if (!asoc->assoc_id) { | |
1181 | /* get a new association id since we don't have one | |
1182 | * yet. | |
1183 | */ | |
1184 | sctp_assoc_set_id(asoc, GFP_ATOMIC); | |
1185 | } | |
1da177e4 | 1186 | } |
a29a5bd4 | 1187 | |
9d2c881a | 1188 | /* SCTP-AUTH: Save the peer parameters from the new associations |
730fc3d0 VY |
1189 | * and also move the association shared keys over |
1190 | */ | |
1191 | kfree(asoc->peer.peer_random); | |
1192 | asoc->peer.peer_random = new->peer.peer_random; | |
1193 | new->peer.peer_random = NULL; | |
1194 | ||
1195 | kfree(asoc->peer.peer_chunks); | |
1196 | asoc->peer.peer_chunks = new->peer.peer_chunks; | |
1197 | new->peer.peer_chunks = NULL; | |
1198 | ||
1199 | kfree(asoc->peer.peer_hmacs); | |
1200 | asoc->peer.peer_hmacs = new->peer.peer_hmacs; | |
1201 | new->peer.peer_hmacs = NULL; | |
1202 | ||
730fc3d0 | 1203 | sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC); |
1da177e4 LT |
1204 | } |
1205 | ||
1206 | /* Update the retran path for sending a retransmitted packet. | |
4c47af4d DB |
1207 | * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints: |
1208 | * | |
1209 | * When there is outbound data to send and the primary path | |
1210 | * becomes inactive (e.g., due to failures), or where the | |
1211 | * SCTP user explicitly requests to send data to an | |
1212 | * inactive destination transport address, before reporting | |
1213 | * an error to its ULP, the SCTP endpoint should try to send | |
1214 | * the data to an alternate active destination transport | |
1215 | * address if one exists. | |
1216 | * | |
1217 | * When retransmitting data that timed out, if the endpoint | |
1218 | * is multihomed, it should consider each source-destination | |
1219 | * address pair in its retransmission selection policy. | |
1220 | * When retransmitting timed-out data, the endpoint should | |
1221 | * attempt to pick the most divergent source-destination | |
1222 | * pair from the original source-destination pair to which | |
1223 | * the packet was transmitted. | |
1224 | * | |
1225 | * Note: Rules for picking the most divergent source-destination | |
1226 | * pair are an implementation decision and are not specified | |
1227 | * within this document. | |
1228 | * | |
1229 | * Our basic strategy is to round-robin transports in priorities | |
2103d6b8 | 1230 | * according to sctp_trans_score() e.g., if no such |
4c47af4d DB |
1231 | * transport with state SCTP_ACTIVE exists, round-robin through |
1232 | * SCTP_UNKNOWN, etc. You get the picture. | |
1da177e4 | 1233 | */ |
4c47af4d | 1234 | static u8 sctp_trans_score(const struct sctp_transport *trans) |
1da177e4 | 1235 | { |
2103d6b8 DV |
1236 | switch (trans->state) { |
1237 | case SCTP_ACTIVE: | |
1238 | return 3; /* best case */ | |
1239 | case SCTP_UNKNOWN: | |
1240 | return 2; | |
1241 | case SCTP_PF: | |
1242 | return 1; | |
1243 | default: /* case SCTP_INACTIVE */ | |
1244 | return 0; /* worst case */ | |
1245 | } | |
4c47af4d | 1246 | } |
1da177e4 | 1247 | |
a7288c4d DB |
1248 | static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1, |
1249 | struct sctp_transport *trans2) | |
1250 | { | |
1251 | if (trans1->error_count > trans2->error_count) { | |
1252 | return trans2; | |
1253 | } else if (trans1->error_count == trans2->error_count && | |
1254 | ktime_after(trans2->last_time_heard, | |
1255 | trans1->last_time_heard)) { | |
1256 | return trans2; | |
1257 | } else { | |
1258 | return trans1; | |
1259 | } | |
1260 | } | |
1261 | ||
4c47af4d DB |
1262 | static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr, |
1263 | struct sctp_transport *best) | |
1264 | { | |
a7288c4d DB |
1265 | u8 score_curr, score_best; |
1266 | ||
ea4f19c1 | 1267 | if (best == NULL || curr == best) |
4c47af4d | 1268 | return curr; |
4141ddc0 | 1269 | |
a7288c4d DB |
1270 | score_curr = sctp_trans_score(curr); |
1271 | score_best = sctp_trans_score(best); | |
1272 | ||
1273 | /* First, try a score-based selection if both transport states | |
1274 | * differ. If we're in a tie, lets try to make a more clever | |
1275 | * decision here based on error counts and last time heard. | |
1276 | */ | |
1277 | if (score_curr > score_best) | |
1278 | return curr; | |
1279 | else if (score_curr == score_best) | |
39d2adeb | 1280 | return sctp_trans_elect_tie(best, curr); |
a7288c4d DB |
1281 | else |
1282 | return best; | |
4c47af4d | 1283 | } |
1da177e4 | 1284 | |
4c47af4d DB |
1285 | void sctp_assoc_update_retran_path(struct sctp_association *asoc) |
1286 | { | |
1287 | struct sctp_transport *trans = asoc->peer.retran_path; | |
1288 | struct sctp_transport *trans_next = NULL; | |
1da177e4 | 1289 | |
4c47af4d DB |
1290 | /* We're done as we only have the one and only path. */ |
1291 | if (asoc->peer.transport_count == 1) | |
1292 | return; | |
1293 | /* If active_path and retran_path are the same and active, | |
1294 | * then this is the only active path. Use it. | |
1295 | */ | |
1296 | if (asoc->peer.active_path == asoc->peer.retran_path && | |
1297 | asoc->peer.active_path->state == SCTP_ACTIVE) | |
1298 | return; | |
1da177e4 | 1299 | |
4c47af4d DB |
1300 | /* Iterate from retran_path's successor back to retran_path. */ |
1301 | for (trans = list_next_entry(trans, transports); 1; | |
1302 | trans = list_next_entry(trans, transports)) { | |
1303 | /* Manually skip the head element. */ | |
1304 | if (&trans->transports == &asoc->peer.transport_addr_list) | |
1305 | continue; | |
1306 | if (trans->state == SCTP_UNCONFIRMED) | |
1307 | continue; | |
1308 | trans_next = sctp_trans_elect_best(trans, trans_next); | |
1309 | /* Active is good enough for immediate return. */ | |
1310 | if (trans_next->state == SCTP_ACTIVE) | |
4141ddc0 | 1311 | break; |
4c47af4d DB |
1312 | /* We've reached the end, time to update path. */ |
1313 | if (trans == asoc->peer.retran_path) | |
1da177e4 | 1314 | break; |
1da177e4 LT |
1315 | } |
1316 | ||
433131ba | 1317 | asoc->peer.retran_path = trans_next; |
3f7a87d2 | 1318 | |
4c47af4d DB |
1319 | pr_debug("%s: association:%p updated new path to addr:%pISpc\n", |
1320 | __func__, asoc, &asoc->peer.retran_path->ipaddr.sa); | |
3f7a87d2 FF |
1321 | } |
1322 | ||
b82e8f31 DB |
1323 | static void sctp_select_active_and_retran_path(struct sctp_association *asoc) |
1324 | { | |
1325 | struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL; | |
a7288c4d | 1326 | struct sctp_transport *trans_pf = NULL; |
b82e8f31 DB |
1327 | |
1328 | /* Look for the two most recently used active transports. */ | |
1329 | list_for_each_entry(trans, &asoc->peer.transport_addr_list, | |
1330 | transports) { | |
a7288c4d | 1331 | /* Skip uninteresting transports. */ |
b82e8f31 | 1332 | if (trans->state == SCTP_INACTIVE || |
a7288c4d | 1333 | trans->state == SCTP_UNCONFIRMED) |
b82e8f31 | 1334 | continue; |
a7288c4d DB |
1335 | /* Keep track of the best PF transport from our |
1336 | * list in case we don't find an active one. | |
1337 | */ | |
1338 | if (trans->state == SCTP_PF) { | |
1339 | trans_pf = sctp_trans_elect_best(trans, trans_pf); | |
1340 | continue; | |
1341 | } | |
1342 | /* For active transports, pick the most recent ones. */ | |
b82e8f31 | 1343 | if (trans_pri == NULL || |
e575235f DB |
1344 | ktime_after(trans->last_time_heard, |
1345 | trans_pri->last_time_heard)) { | |
b82e8f31 DB |
1346 | trans_sec = trans_pri; |
1347 | trans_pri = trans; | |
1348 | } else if (trans_sec == NULL || | |
e575235f DB |
1349 | ktime_after(trans->last_time_heard, |
1350 | trans_sec->last_time_heard)) { | |
b82e8f31 DB |
1351 | trans_sec = trans; |
1352 | } | |
1353 | } | |
1354 | ||
1355 | /* RFC 2960 6.4 Multi-Homed SCTP Endpoints | |
1356 | * | |
1357 | * By default, an endpoint should always transmit to the primary | |
1358 | * path, unless the SCTP user explicitly specifies the | |
1359 | * destination transport address (and possibly source transport | |
1360 | * address) to use. [If the primary is active but not most recent, | |
1361 | * bump the most recently used transport.] | |
1362 | */ | |
1363 | if ((asoc->peer.primary_path->state == SCTP_ACTIVE || | |
1364 | asoc->peer.primary_path->state == SCTP_UNKNOWN) && | |
1365 | asoc->peer.primary_path != trans_pri) { | |
1366 | trans_sec = trans_pri; | |
1367 | trans_pri = asoc->peer.primary_path; | |
1368 | } | |
1369 | ||
1370 | /* We did not find anything useful for a possible retransmission | |
1371 | * path; either primary path that we found is the the same as | |
1372 | * the current one, or we didn't generally find an active one. | |
1373 | */ | |
1374 | if (trans_sec == NULL) | |
1375 | trans_sec = trans_pri; | |
1376 | ||
1377 | /* If we failed to find a usable transport, just camp on the | |
aa4a83ee | 1378 | * active or pick a PF iff it's the better choice. |
b82e8f31 DB |
1379 | */ |
1380 | if (trans_pri == NULL) { | |
aa4a83ee DB |
1381 | trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf); |
1382 | trans_sec = trans_pri; | |
b82e8f31 DB |
1383 | } |
1384 | ||
1385 | /* Set the active and retran transports. */ | |
1386 | asoc->peer.active_path = trans_pri; | |
1387 | asoc->peer.retran_path = trans_sec; | |
1388 | } | |
1389 | ||
4c47af4d DB |
1390 | struct sctp_transport * |
1391 | sctp_assoc_choose_alter_transport(struct sctp_association *asoc, | |
1392 | struct sctp_transport *last_sent_to) | |
3f7a87d2 | 1393 | { |
9919b455 WY |
1394 | /* If this is the first time packet is sent, use the active path, |
1395 | * else use the retran path. If the last packet was sent over the | |
3f7a87d2 FF |
1396 | * retran path, update the retran path and use it. |
1397 | */ | |
4c47af4d | 1398 | if (last_sent_to == NULL) { |
1da177e4 | 1399 | return asoc->peer.active_path; |
4c47af4d | 1400 | } else { |
9919b455 | 1401 | if (last_sent_to == asoc->peer.retran_path) |
1da177e4 | 1402 | sctp_assoc_update_retran_path(asoc); |
4c47af4d | 1403 | |
1da177e4 LT |
1404 | return asoc->peer.retran_path; |
1405 | } | |
1da177e4 LT |
1406 | } |
1407 | ||
1408 | /* Update the association's pmtu and frag_point by going through all the | |
1409 | * transports. This routine is called when a transport's PMTU has changed. | |
1410 | */ | |
02f3d4ce | 1411 | void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc) |
1da177e4 LT |
1412 | { |
1413 | struct sctp_transport *t; | |
1da177e4 LT |
1414 | __u32 pmtu = 0; |
1415 | ||
1416 | if (!asoc) | |
1417 | return; | |
1418 | ||
1419 | /* Get the lowest pmtu of all the transports. */ | |
9dbc15f0 RD |
1420 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
1421 | transports) { | |
8a479491 | 1422 | if (t->pmtu_pending && t->dst) { |
3822a5ff | 1423 | sctp_transport_update_pmtu(sk, t, |
e2f036a9 | 1424 | SCTP_TRUNC4(dst_mtu(t->dst))); |
8a479491 VY |
1425 | t->pmtu_pending = 0; |
1426 | } | |
52ccb8e9 FF |
1427 | if (!pmtu || (t->pathmtu < pmtu)) |
1428 | pmtu = t->pathmtu; | |
1da177e4 LT |
1429 | } |
1430 | ||
1431 | if (pmtu) { | |
52ccb8e9 | 1432 | asoc->pathmtu = pmtu; |
f68b2e05 | 1433 | asoc->frag_point = sctp_frag_point(asoc, pmtu); |
1da177e4 LT |
1434 | } |
1435 | ||
bb33381d DB |
1436 | pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, |
1437 | asoc->pathmtu, asoc->frag_point); | |
1da177e4 LT |
1438 | } |
1439 | ||
1440 | /* Should we send a SACK to update our peer? */ | |
ce4a03db | 1441 | static inline bool sctp_peer_needs_update(struct sctp_association *asoc) |
1da177e4 | 1442 | { |
e1fc3b14 | 1443 | struct net *net = sock_net(asoc->base.sk); |
1da177e4 LT |
1444 | switch (asoc->state) { |
1445 | case SCTP_STATE_ESTABLISHED: | |
1446 | case SCTP_STATE_SHUTDOWN_PENDING: | |
1447 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
1448 | case SCTP_STATE_SHUTDOWN_SENT: | |
1449 | if ((asoc->rwnd > asoc->a_rwnd) && | |
90f2f531 | 1450 | ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32, |
e1fc3b14 | 1451 | (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift), |
90f2f531 | 1452 | asoc->pathmtu))) |
ce4a03db | 1453 | return true; |
1da177e4 LT |
1454 | break; |
1455 | default: | |
1456 | break; | |
1457 | } | |
ce4a03db | 1458 | return false; |
1da177e4 LT |
1459 | } |
1460 | ||
362d5204 DB |
1461 | /* Increase asoc's rwnd by len and send any window update SACK if needed. */ |
1462 | void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len) | |
1da177e4 LT |
1463 | { |
1464 | struct sctp_chunk *sack; | |
1465 | struct timer_list *timer; | |
1466 | ||
362d5204 DB |
1467 | if (asoc->rwnd_over) { |
1468 | if (asoc->rwnd_over >= len) { | |
1469 | asoc->rwnd_over -= len; | |
1470 | } else { | |
1471 | asoc->rwnd += (len - asoc->rwnd_over); | |
1472 | asoc->rwnd_over = 0; | |
1473 | } | |
1474 | } else { | |
1475 | asoc->rwnd += len; | |
1476 | } | |
1da177e4 | 1477 | |
362d5204 DB |
1478 | /* If we had window pressure, start recovering it |
1479 | * once our rwnd had reached the accumulated pressure | |
1480 | * threshold. The idea is to recover slowly, but up | |
1481 | * to the initial advertised window. | |
1482 | */ | |
1636098c | 1483 | if (asoc->rwnd_press) { |
362d5204 DB |
1484 | int change = min(asoc->pathmtu, asoc->rwnd_press); |
1485 | asoc->rwnd += change; | |
1486 | asoc->rwnd_press -= change; | |
1487 | } | |
4d3c46e6 | 1488 | |
362d5204 DB |
1489 | pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n", |
1490 | __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, | |
1491 | asoc->a_rwnd); | |
1da177e4 LT |
1492 | |
1493 | /* Send a window update SACK if the rwnd has increased by at least the | |
1494 | * minimum of the association's PMTU and half of the receive buffer. | |
1495 | * The algorithm used is similar to the one described in | |
1496 | * Section 4.2.3.3 of RFC 1122. | |
1497 | */ | |
362d5204 | 1498 | if (sctp_peer_needs_update(asoc)) { |
1da177e4 | 1499 | asoc->a_rwnd = asoc->rwnd; |
bb33381d DB |
1500 | |
1501 | pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u " | |
1502 | "a_rwnd:%u\n", __func__, asoc, asoc->rwnd, | |
1503 | asoc->a_rwnd); | |
1504 | ||
1da177e4 LT |
1505 | sack = sctp_make_sack(asoc); |
1506 | if (!sack) | |
1507 | return; | |
1508 | ||
1509 | asoc->peer.sack_needed = 0; | |
1510 | ||
cea8768f | 1511 | sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC); |
1da177e4 LT |
1512 | |
1513 | /* Stop the SACK timer. */ | |
1514 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; | |
25cc4ae9 | 1515 | if (del_timer(timer)) |
1da177e4 LT |
1516 | sctp_association_put(asoc); |
1517 | } | |
1518 | } | |
1519 | ||
362d5204 DB |
1520 | /* Decrease asoc's rwnd by len. */ |
1521 | void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len) | |
1522 | { | |
1523 | int rx_count; | |
1524 | int over = 0; | |
1525 | ||
1526 | if (unlikely(!asoc->rwnd || asoc->rwnd_over)) | |
1527 | pr_debug("%s: association:%p has asoc->rwnd:%u, " | |
1528 | "asoc->rwnd_over:%u!\n", __func__, asoc, | |
1529 | asoc->rwnd, asoc->rwnd_over); | |
1530 | ||
1531 | if (asoc->ep->rcvbuf_policy) | |
1532 | rx_count = atomic_read(&asoc->rmem_alloc); | |
1533 | else | |
1534 | rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); | |
1535 | ||
1536 | /* If we've reached or overflowed our receive buffer, announce | |
1537 | * a 0 rwnd if rwnd would still be positive. Store the | |
1538 | * the potential pressure overflow so that the window can be restored | |
1539 | * back to original value. | |
1540 | */ | |
1541 | if (rx_count >= asoc->base.sk->sk_rcvbuf) | |
1542 | over = 1; | |
1543 | ||
1544 | if (asoc->rwnd >= len) { | |
1545 | asoc->rwnd -= len; | |
1546 | if (over) { | |
1547 | asoc->rwnd_press += asoc->rwnd; | |
1548 | asoc->rwnd = 0; | |
1549 | } | |
1550 | } else { | |
58b94d88 | 1551 | asoc->rwnd_over += len - asoc->rwnd; |
362d5204 DB |
1552 | asoc->rwnd = 0; |
1553 | } | |
1554 | ||
1555 | pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n", | |
1556 | __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, | |
1557 | asoc->rwnd_press); | |
1558 | } | |
1da177e4 LT |
1559 | |
1560 | /* Build the bind address list for the association based on info from the | |
1561 | * local endpoint and the remote peer. | |
1562 | */ | |
3182cd84 | 1563 | int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, |
409b95af | 1564 | sctp_scope_t scope, gfp_t gfp) |
1da177e4 | 1565 | { |
1da177e4 LT |
1566 | int flags; |
1567 | ||
1568 | /* Use scoping rules to determine the subset of addresses from | |
1569 | * the endpoint. | |
1570 | */ | |
1da177e4 LT |
1571 | flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; |
1572 | if (asoc->peer.ipv4_address) | |
1573 | flags |= SCTP_ADDR4_PEERSUPP; | |
1574 | if (asoc->peer.ipv6_address) | |
1575 | flags |= SCTP_ADDR6_PEERSUPP; | |
1576 | ||
4db67e80 EB |
1577 | return sctp_bind_addr_copy(sock_net(asoc->base.sk), |
1578 | &asoc->base.bind_addr, | |
1da177e4 LT |
1579 | &asoc->ep->base.bind_addr, |
1580 | scope, gfp, flags); | |
1581 | } | |
1582 | ||
1583 | /* Build the association's bind address list from the cookie. */ | |
1584 | int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc, | |
3182cd84 | 1585 | struct sctp_cookie *cookie, |
dd0fc66f | 1586 | gfp_t gfp) |
1da177e4 LT |
1587 | { |
1588 | int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); | |
1589 | int var_size3 = cookie->raw_addr_list_len; | |
1590 | __u8 *raw = (__u8 *)cookie->peer_init + var_size2; | |
1591 | ||
1592 | return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3, | |
1593 | asoc->ep->base.bind_addr.port, gfp); | |
1594 | } | |
1595 | ||
d808ad9a YH |
1596 | /* Lookup laddr in the bind address list of an association. */ |
1597 | int sctp_assoc_lookup_laddr(struct sctp_association *asoc, | |
1da177e4 LT |
1598 | const union sctp_addr *laddr) |
1599 | { | |
559cf710 | 1600 | int found = 0; |
1da177e4 | 1601 | |
1da177e4 LT |
1602 | if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) && |
1603 | sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
559cf710 | 1604 | sctp_sk(asoc->base.sk))) |
1da177e4 | 1605 | found = 1; |
1da177e4 | 1606 | |
1da177e4 LT |
1607 | return found; |
1608 | } | |
07d93967 VY |
1609 | |
1610 | /* Set an association id for a given association */ | |
1611 | int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp) | |
1612 | { | |
d0164adc | 1613 | bool preload = gfpflags_allow_blocking(gfp); |
94960e8c | 1614 | int ret; |
c6ba68a2 VY |
1615 | |
1616 | /* If the id is already assigned, keep it. */ | |
1617 | if (asoc->assoc_id) | |
94960e8c | 1618 | return 0; |
07d93967 | 1619 | |
94960e8c TH |
1620 | if (preload) |
1621 | idr_preload(gfp); | |
07d93967 | 1622 | spin_lock_bh(&sctp_assocs_id_lock); |
713e00a3 JL |
1623 | /* 0 is not a valid assoc_id, must be >= 1 */ |
1624 | ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT); | |
07d93967 | 1625 | spin_unlock_bh(&sctp_assocs_id_lock); |
94960e8c TH |
1626 | if (preload) |
1627 | idr_preload_end(); | |
1628 | if (ret < 0) | |
1629 | return ret; | |
07d93967 | 1630 | |
94960e8c TH |
1631 | asoc->assoc_id = (sctp_assoc_t)ret; |
1632 | return 0; | |
07d93967 | 1633 | } |
a08de64d | 1634 | |
8b4472cc WY |
1635 | /* Free the ASCONF queue */ |
1636 | static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc) | |
1637 | { | |
1638 | struct sctp_chunk *asconf; | |
1639 | struct sctp_chunk *tmp; | |
1640 | ||
1641 | list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) { | |
1642 | list_del_init(&asconf->list); | |
1643 | sctp_chunk_free(asconf); | |
1644 | } | |
1645 | } | |
1646 | ||
a08de64d VY |
1647 | /* Free asconf_ack cache */ |
1648 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc) | |
1649 | { | |
1650 | struct sctp_chunk *ack; | |
1651 | struct sctp_chunk *tmp; | |
1652 | ||
1653 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, | |
1654 | transmitted_list) { | |
1655 | list_del_init(&ack->transmitted_list); | |
1656 | sctp_chunk_free(ack); | |
1657 | } | |
1658 | } | |
1659 | ||
1660 | /* Clean up the ASCONF_ACK queue */ | |
1661 | void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc) | |
1662 | { | |
1663 | struct sctp_chunk *ack; | |
1664 | struct sctp_chunk *tmp; | |
1665 | ||
25985edc | 1666 | /* We can remove all the entries from the queue up to |
a08de64d VY |
1667 | * the "Peer-Sequence-Number". |
1668 | */ | |
1669 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, | |
1670 | transmitted_list) { | |
1671 | if (ack->subh.addip_hdr->serial == | |
1672 | htonl(asoc->peer.addip_serial)) | |
1673 | break; | |
1674 | ||
1675 | list_del_init(&ack->transmitted_list); | |
1676 | sctp_chunk_free(ack); | |
1677 | } | |
1678 | } | |
1679 | ||
1680 | /* Find the ASCONF_ACK whose serial number matches ASCONF */ | |
1681 | struct sctp_chunk *sctp_assoc_lookup_asconf_ack( | |
1682 | const struct sctp_association *asoc, | |
1683 | __be32 serial) | |
1684 | { | |
a8699814 | 1685 | struct sctp_chunk *ack; |
a08de64d VY |
1686 | |
1687 | /* Walk through the list of cached ASCONF-ACKs and find the | |
1688 | * ack chunk whose serial number matches that of the request. | |
1689 | */ | |
1690 | list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) { | |
b69040d8 DB |
1691 | if (sctp_chunk_pending(ack)) |
1692 | continue; | |
a08de64d VY |
1693 | if (ack->subh.addip_hdr->serial == serial) { |
1694 | sctp_chunk_hold(ack); | |
a8699814 | 1695 | return ack; |
a08de64d VY |
1696 | } |
1697 | } | |
1698 | ||
a8699814 | 1699 | return NULL; |
a08de64d | 1700 | } |
a000c01e WY |
1701 | |
1702 | void sctp_asconf_queue_teardown(struct sctp_association *asoc) | |
1703 | { | |
1704 | /* Free any cached ASCONF_ACK chunk. */ | |
1705 | sctp_assoc_free_asconf_acks(asoc); | |
1706 | ||
1707 | /* Free the ASCONF queue. */ | |
1708 | sctp_assoc_free_asconf_queue(asoc); | |
1709 | ||
1710 | /* Free any cached ASCONF chunk. */ | |
1711 | if (asoc->addip_last_asconf) | |
1712 | sctp_chunk_free(asoc->addip_last_asconf); | |
1713 | } |