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1 | /* SCTP kernel implementation |
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 | * |
8 | * This file is part of the SCTP kernel implementation |
9 | * |
10 | * This module provides the abstraction for an SCTP association. |
11 | * |
12 | * This SCTP implementation is free software; |
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 | * |
18 | * This SCTP implementation is distributed in the hope that it |
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 |
25 | * along with GNU CC; see the file COPYING. If not, write to |
26 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
27 | * Boston, MA 02111-1307, USA. |
28 | * |
29 | * Please send any bug reports or fixes you make to the |
30 | * email address(es): |
31 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
32 | * |
33 | * Or submit a bug report through the following website: |
34 | * http://www.sf.net/projects/lksctp |
35 | * |
36 | * Written or modified by: |
37 | * La Monte H.P. Yarroll <piggy@acm.org> |
38 | * Karl Knutson <karl@athena.chicago.il.us> |
39 | * Jon Grimm <jgrimm@us.ibm.com> |
40 | * Xingang Guo <xingang.guo@intel.com> |
41 | * Hui Huang <hui.huang@nokia.com> |
42 | * Sridhar Samudrala <sri@us.ibm.com> |
43 | * Daisy Chang <daisyc@us.ibm.com> |
44 | * Ryan Layer <rmlayer@us.ibm.com> |
45 | * Kevin Gao <kevin.gao@intel.com> |
46 | * |
47 | * Any bugs reported given to us we will try to fix... any fixes shared will |
48 | * be incorporated into the next SCTP release. |
49 | */ |
50 | |
51 | #include <linux/types.h> |
52 | #include <linux/fcntl.h> |
53 | #include <linux/poll.h> |
54 | #include <linux/init.h> |
55 | |
56 | #include <linux/slab.h> |
57 | #include <linux/in.h> |
58 | #include <net/ipv6.h> |
59 | #include <net/sctp/sctp.h> |
60 | #include <net/sctp/sm.h> |
61 | |
62 | /* Forward declarations for internal functions. */ |
63 | static void sctp_assoc_bh_rcv(struct work_struct *work); |
64 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); |
65 | |
66 | /* Keep track of the new idr low so that we don't re-use association id |
67 | * numbers too fast. It is protected by they idr spin lock is in the |
68 | * range of 1 - INT_MAX. |
69 | */ |
70 | static u32 idr_low = 1; |
71 | |
72 | |
73 | /* 1st Level Abstractions. */ |
74 | |
75 | /* Initialize a new association from provided memory. */ |
76 | static struct sctp_association *sctp_association_init(struct sctp_association *asoc, |
77 | const struct sctp_endpoint *ep, |
78 | const struct sock *sk, |
79 | sctp_scope_t scope, |
80 | gfp_t gfp) |
81 | { |
82 | struct sctp_sock *sp; |
83 | int i; |
84 | sctp_paramhdr_t *p; |
85 | int err; |
86 | |
87 | /* Retrieve the SCTP per socket area. */ |
88 | sp = sctp_sk((struct sock *)sk); |
89 | |
90 | /* Init all variables to a known value. */ |
91 | memset(asoc, 0, sizeof(struct sctp_association)); |
92 | |
93 | /* Discarding const is appropriate here. */ |
94 | asoc->ep = (struct sctp_endpoint *)ep; |
95 | sctp_endpoint_hold(asoc->ep); |
96 | |
97 | /* Hold the sock. */ |
98 | asoc->base.sk = (struct sock *)sk; |
99 | sock_hold(asoc->base.sk); |
100 | |
101 | /* Initialize the common base substructure. */ |
102 | asoc->base.type = SCTP_EP_TYPE_ASSOCIATION; |
103 | |
104 | /* Initialize the object handling fields. */ |
105 | atomic_set(&asoc->base.refcnt, 1); |
106 | asoc->base.dead = 0; |
107 | asoc->base.malloced = 0; |
108 | |
109 | /* Initialize the bind addr area. */ |
110 | sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port); |
111 | |
112 | asoc->state = SCTP_STATE_CLOSED; |
113 | |
114 | /* Set these values from the socket values, a conversion between |
115 | * millsecons to seconds/microseconds must also be done. |
116 | */ |
117 | asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000; |
118 | asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000) |
119 | * 1000; |
120 | asoc->frag_point = 0; |
121 | asoc->user_frag = sp->user_frag; |
122 | |
123 | /* Set the association max_retrans and RTO values from the |
124 | * socket values. |
125 | */ |
126 | asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt; |
127 | asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial); |
128 | asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max); |
129 | asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min); |
130 | |
131 | asoc->overall_error_count = 0; |
132 | |
133 | /* Initialize the association's heartbeat interval based on the |
134 | * sock configured value. |
135 | */ |
136 | asoc->hbinterval = msecs_to_jiffies(sp->hbinterval); |
137 | |
138 | /* Initialize path max retrans value. */ |
139 | asoc->pathmaxrxt = sp->pathmaxrxt; |
140 | |
141 | /* Initialize default path MTU. */ |
142 | asoc->pathmtu = sp->pathmtu; |
143 | |
144 | /* Set association default SACK delay */ |
145 | asoc->sackdelay = msecs_to_jiffies(sp->sackdelay); |
146 | asoc->sackfreq = sp->sackfreq; |
147 | |
148 | /* Set the association default flags controlling |
149 | * Heartbeat, SACK delay, and Path MTU Discovery. |
150 | */ |
151 | asoc->param_flags = sp->param_flags; |
152 | |
153 | /* Initialize the maximum mumber of new data packets that can be sent |
154 | * in a burst. |
155 | */ |
156 | asoc->max_burst = sp->max_burst; |
157 | |
158 | /* initialize association timers */ |
159 | asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0; |
160 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial; |
161 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial; |
162 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial; |
163 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0; |
164 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0; |
165 | |
166 | /* sctpimpguide Section 2.12.2 |
167 | * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the |
168 | * recommended value of 5 times 'RTO.Max'. |
169 | */ |
170 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] |
171 | = 5 * asoc->rto_max; |
172 | |
173 | asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0; |
174 | asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay; |
175 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = |
176 | (unsigned long)sp->autoclose * HZ; |
177 | |
178 | /* Initilizes the timers */ |
179 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) |
180 | setup_timer(&asoc->timers[i], sctp_timer_events[i], |
181 | (unsigned long)asoc); |
182 | |
183 | /* Pull default initialization values from the sock options. |
184 | * Note: This assumes that the values have already been |
185 | * validated in the sock. |
186 | */ |
187 | asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; |
188 | asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; |
189 | asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; |
190 | |
191 | asoc->max_init_timeo = |
192 | msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo); |
193 | |
194 | /* Allocate storage for the ssnmap after the inbound and outbound |
195 | * streams have been negotiated during Init. |
196 | */ |
197 | asoc->ssnmap = NULL; |
198 | |
199 | /* Set the local window size for receive. |
200 | * This is also the rcvbuf space per association. |
201 | * RFC 6 - A SCTP receiver MUST be able to receive a minimum of |
202 | * 1500 bytes in one SCTP packet. |
203 | */ |
204 | if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW) |
205 | asoc->rwnd = SCTP_DEFAULT_MINWINDOW; |
206 | else |
207 | asoc->rwnd = sk->sk_rcvbuf/2; |
208 | |
209 | asoc->a_rwnd = asoc->rwnd; |
210 | |
211 | asoc->rwnd_over = 0; |
212 | asoc->rwnd_press = 0; |
213 | |
214 | /* Use my own max window until I learn something better. */ |
215 | asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; |
216 | |
217 | /* Set the sndbuf size for transmit. */ |
218 | asoc->sndbuf_used = 0; |
219 | |
220 | /* Initialize the receive memory counter */ |
221 | atomic_set(&asoc->rmem_alloc, 0); |
222 | |
223 | init_waitqueue_head(&asoc->wait); |
224 | |
225 | asoc->c.my_vtag = sctp_generate_tag(ep); |
226 | asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */ |
227 | asoc->c.peer_vtag = 0; |
228 | asoc->c.my_ttag = 0; |
229 | asoc->c.peer_ttag = 0; |
230 | asoc->c.my_port = ep->base.bind_addr.port; |
231 | |
232 | asoc->c.initial_tsn = sctp_generate_tsn(ep); |
233 | |
234 | asoc->next_tsn = asoc->c.initial_tsn; |
235 | |
236 | asoc->ctsn_ack_point = asoc->next_tsn - 1; |
237 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; |
238 | asoc->highest_sacked = asoc->ctsn_ack_point; |
239 | asoc->last_cwr_tsn = asoc->ctsn_ack_point; |
240 | asoc->unack_data = 0; |
241 | |
242 | /* ADDIP Section 4.1 Asconf Chunk Procedures |
243 | * |
244 | * When an endpoint has an ASCONF signaled change to be sent to the |
245 | * remote endpoint it should do the following: |
246 | * ... |
247 | * A2) a serial number should be assigned to the chunk. The serial |
248 | * number SHOULD be a monotonically increasing number. The serial |
249 | * numbers SHOULD be initialized at the start of the |
250 | * association to the same value as the initial TSN. |
251 | */ |
252 | asoc->addip_serial = asoc->c.initial_tsn; |
253 | |
254 | INIT_LIST_HEAD(&asoc->addip_chunk_list); |
255 | INIT_LIST_HEAD(&asoc->asconf_ack_list); |
256 | |
257 | /* Make an empty list of remote transport addresses. */ |
258 | INIT_LIST_HEAD(&asoc->peer.transport_addr_list); |
259 | asoc->peer.transport_count = 0; |
260 | |
261 | /* RFC 2960 5.1 Normal Establishment of an Association |
262 | * |
263 | * After the reception of the first data chunk in an |
264 | * association the endpoint must immediately respond with a |
265 | * sack to acknowledge the data chunk. Subsequent |
266 | * acknowledgements should be done as described in Section |
267 | * 6.2. |
268 | * |
269 | * [We implement this by telling a new association that it |
270 | * already received one packet.] |
271 | */ |
272 | asoc->peer.sack_needed = 1; |
273 | asoc->peer.sack_cnt = 0; |
274 | |
275 | /* Assume that the peer will tell us if he recognizes ASCONF |
276 | * as part of INIT exchange. |
277 | * The sctp_addip_noauth option is there for backward compatibilty |
278 | * and will revert old behavior. |
279 | */ |
280 | asoc->peer.asconf_capable = 0; |
281 | if (sctp_addip_noauth) |
282 | asoc->peer.asconf_capable = 1; |
283 | |
284 | /* Create an input queue. */ |
285 | sctp_inq_init(&asoc->base.inqueue); |
286 | sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv); |
287 | |
288 | /* Create an output queue. */ |
289 | sctp_outq_init(asoc, &asoc->outqueue); |
290 | |
291 | if (!sctp_ulpq_init(&asoc->ulpq, asoc)) |
292 | goto fail_init; |
293 | |
294 | memset(&asoc->peer.tsn_map, 0, sizeof(struct sctp_tsnmap)); |
295 | |
296 | asoc->need_ecne = 0; |
297 | |
298 | asoc->assoc_id = 0; |
299 | |
300 | /* Assume that peer would support both address types unless we are |
301 | * told otherwise. |
302 | */ |
303 | asoc->peer.ipv4_address = 1; |
304 | if (asoc->base.sk->sk_family == PF_INET6) |
305 | asoc->peer.ipv6_address = 1; |
306 | INIT_LIST_HEAD(&asoc->asocs); |
307 | |
308 | asoc->autoclose = sp->autoclose; |
309 | |
310 | asoc->default_stream = sp->default_stream; |
311 | asoc->default_ppid = sp->default_ppid; |
312 | asoc->default_flags = sp->default_flags; |
313 | asoc->default_context = sp->default_context; |
314 | asoc->default_timetolive = sp->default_timetolive; |
315 | asoc->default_rcv_context = sp->default_rcv_context; |
316 | |
317 | /* AUTH related initializations */ |
318 | INIT_LIST_HEAD(&asoc->endpoint_shared_keys); |
319 | err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp); |
320 | if (err) |
321 | goto fail_init; |
322 | |
323 | asoc->active_key_id = ep->active_key_id; |
324 | asoc->asoc_shared_key = NULL; |
325 | |
326 | asoc->default_hmac_id = 0; |
327 | /* Save the hmacs and chunks list into this association */ |
328 | if (ep->auth_hmacs_list) |
329 | memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list, |
330 | ntohs(ep->auth_hmacs_list->param_hdr.length)); |
331 | if (ep->auth_chunk_list) |
332 | memcpy(asoc->c.auth_chunks, ep->auth_chunk_list, |
333 | ntohs(ep->auth_chunk_list->param_hdr.length)); |
334 | |
335 | /* Get the AUTH random number for this association */ |
336 | p = (sctp_paramhdr_t *)asoc->c.auth_random; |
337 | p->type = SCTP_PARAM_RANDOM; |
338 | p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH); |
339 | get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH); |
340 | |
341 | return asoc; |
342 | |
343 | fail_init: |
344 | sctp_endpoint_put(asoc->ep); |
345 | sock_put(asoc->base.sk); |
346 | return NULL; |
347 | } |
348 | |
349 | /* Allocate and initialize a new association */ |
350 | struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep, |
351 | const struct sock *sk, |
352 | sctp_scope_t scope, |
353 | gfp_t gfp) |
354 | { |
355 | struct sctp_association *asoc; |
356 | |
357 | asoc = t_new(struct sctp_association, gfp); |
358 | if (!asoc) |
359 | goto fail; |
360 | |
361 | if (!sctp_association_init(asoc, ep, sk, scope, gfp)) |
362 | goto fail_init; |
363 | |
364 | asoc->base.malloced = 1; |
365 | SCTP_DBG_OBJCNT_INC(assoc); |
366 | SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc); |
367 | |
368 | return asoc; |
369 | |
370 | fail_init: |
371 | kfree(asoc); |
372 | fail: |
373 | return NULL; |
374 | } |
375 | |
376 | /* Free this association if possible. There may still be users, so |
377 | * the actual deallocation may be delayed. |
378 | */ |
379 | void sctp_association_free(struct sctp_association *asoc) |
380 | { |
381 | struct sock *sk = asoc->base.sk; |
382 | struct sctp_transport *transport; |
383 | struct list_head *pos, *temp; |
384 | int i; |
385 | |
386 | /* Only real associations count against the endpoint, so |
387 | * don't bother for if this is a temporary association. |
388 | */ |
389 | if (!asoc->temp) { |
390 | list_del(&asoc->asocs); |
391 | |
392 | /* Decrement the backlog value for a TCP-style listening |
393 | * socket. |
394 | */ |
395 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) |
396 | sk->sk_ack_backlog--; |
397 | } |
398 | |
399 | /* Mark as dead, so other users can know this structure is |
400 | * going away. |
401 | */ |
402 | asoc->base.dead = 1; |
403 | |
404 | /* Dispose of any data lying around in the outqueue. */ |
405 | sctp_outq_free(&asoc->outqueue); |
406 | |
407 | /* Dispose of any pending messages for the upper layer. */ |
408 | sctp_ulpq_free(&asoc->ulpq); |
409 | |
410 | /* Dispose of any pending chunks on the inqueue. */ |
411 | sctp_inq_free(&asoc->base.inqueue); |
412 | |
413 | sctp_tsnmap_free(&asoc->peer.tsn_map); |
414 | |
415 | /* Free ssnmap storage. */ |
416 | sctp_ssnmap_free(asoc->ssnmap); |
417 | |
418 | /* Clean up the bound address list. */ |
419 | sctp_bind_addr_free(&asoc->base.bind_addr); |
420 | |
421 | /* Do we need to go through all of our timers and |
422 | * delete them? To be safe we will try to delete all, but we |
423 | * should be able to go through and make a guess based |
424 | * on our state. |
425 | */ |
426 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { |
427 | if (timer_pending(&asoc->timers[i]) && |
428 | del_timer(&asoc->timers[i])) |
429 | sctp_association_put(asoc); |
430 | } |
431 | |
432 | /* Free peer's cached cookie. */ |
433 | kfree(asoc->peer.cookie); |
434 | kfree(asoc->peer.peer_random); |
435 | kfree(asoc->peer.peer_chunks); |
436 | kfree(asoc->peer.peer_hmacs); |
437 | |
438 | /* Release the transport structures. */ |
439 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { |
440 | transport = list_entry(pos, struct sctp_transport, transports); |
441 | list_del(pos); |
442 | sctp_transport_free(transport); |
443 | } |
444 | |
445 | asoc->peer.transport_count = 0; |
446 | |
447 | /* Free any cached ASCONF_ACK chunk. */ |
448 | sctp_assoc_free_asconf_acks(asoc); |
449 | |
450 | /* Free any cached ASCONF chunk. */ |
451 | if (asoc->addip_last_asconf) |
452 | sctp_chunk_free(asoc->addip_last_asconf); |
453 | |
454 | /* AUTH - Free the endpoint shared keys */ |
455 | sctp_auth_destroy_keys(&asoc->endpoint_shared_keys); |
456 | |
457 | /* AUTH - Free the association shared key */ |
458 | sctp_auth_key_put(asoc->asoc_shared_key); |
459 | |
460 | sctp_association_put(asoc); |
461 | } |
462 | |
463 | /* Cleanup and free up an association. */ |
464 | static void sctp_association_destroy(struct sctp_association *asoc) |
465 | { |
466 | SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return); |
467 | |
468 | sctp_endpoint_put(asoc->ep); |
469 | sock_put(asoc->base.sk); |
470 | |
471 | if (asoc->assoc_id != 0) { |
472 | spin_lock_bh(&sctp_assocs_id_lock); |
473 | idr_remove(&sctp_assocs_id, asoc->assoc_id); |
474 | spin_unlock_bh(&sctp_assocs_id_lock); |
475 | } |
476 | |
477 | WARN_ON(atomic_read(&asoc->rmem_alloc)); |
478 | |
479 | if (asoc->base.malloced) { |
480 | kfree(asoc); |
481 | SCTP_DBG_OBJCNT_DEC(assoc); |
482 | } |
483 | } |
484 | |
485 | /* Change the primary destination address for the peer. */ |
486 | void sctp_assoc_set_primary(struct sctp_association *asoc, |
487 | struct sctp_transport *transport) |
488 | { |
489 | int changeover = 0; |
490 | |
491 | /* it's a changeover only if we already have a primary path |
492 | * that we are changing |
493 | */ |
494 | if (asoc->peer.primary_path != NULL && |
495 | asoc->peer.primary_path != transport) |
496 | changeover = 1 ; |
497 | |
498 | asoc->peer.primary_path = transport; |
499 | |
500 | /* Set a default msg_name for events. */ |
501 | memcpy(&asoc->peer.primary_addr, &transport->ipaddr, |
502 | sizeof(union sctp_addr)); |
503 | |
504 | /* If the primary path is changing, assume that the |
505 | * user wants to use this new path. |
506 | */ |
507 | if ((transport->state == SCTP_ACTIVE) || |
508 | (transport->state == SCTP_UNKNOWN)) |
509 | asoc->peer.active_path = transport; |
510 | |
511 | /* |
512 | * SFR-CACC algorithm: |
513 | * Upon the receipt of a request to change the primary |
514 | * destination address, on the data structure for the new |
515 | * primary destination, the sender MUST do the following: |
516 | * |
517 | * 1) If CHANGEOVER_ACTIVE is set, then there was a switch |
518 | * to this destination address earlier. The sender MUST set |
519 | * CYCLING_CHANGEOVER to indicate that this switch is a |
520 | * double switch to the same destination address. |
521 | * |
522 | * Really, only bother is we have data queued or outstanding on |
523 | * the association. |
524 | */ |
525 | if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen) |
526 | return; |
527 | |
528 | if (transport->cacc.changeover_active) |
529 | transport->cacc.cycling_changeover = changeover; |
530 | |
531 | /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that |
532 | * a changeover has occurred. |
533 | */ |
534 | transport->cacc.changeover_active = changeover; |
535 | |
536 | /* 3) The sender MUST store the next TSN to be sent in |
537 | * next_tsn_at_change. |
538 | */ |
539 | transport->cacc.next_tsn_at_change = asoc->next_tsn; |
540 | } |
541 | |
542 | /* Remove a transport from an association. */ |
543 | void sctp_assoc_rm_peer(struct sctp_association *asoc, |
544 | struct sctp_transport *peer) |
545 | { |
546 | struct list_head *pos; |
547 | struct sctp_transport *transport; |
548 | |
549 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ", |
550 | " port: %d\n", |
551 | asoc, |
552 | (&peer->ipaddr), |
553 | ntohs(peer->ipaddr.v4.sin_port)); |
554 | |
555 | /* If we are to remove the current retran_path, update it |
556 | * to the next peer before removing this peer from the list. |
557 | */ |
558 | if (asoc->peer.retran_path == peer) |
559 | sctp_assoc_update_retran_path(asoc); |
560 | |
561 | /* Remove this peer from the list. */ |
562 | list_del(&peer->transports); |
563 | |
564 | /* Get the first transport of asoc. */ |
565 | pos = asoc->peer.transport_addr_list.next; |
566 | transport = list_entry(pos, struct sctp_transport, transports); |
567 | |
568 | /* Update any entries that match the peer to be deleted. */ |
569 | if (asoc->peer.primary_path == peer) |
570 | sctp_assoc_set_primary(asoc, transport); |
571 | if (asoc->peer.active_path == peer) |
572 | asoc->peer.active_path = transport; |
573 | if (asoc->peer.last_data_from == peer) |
574 | asoc->peer.last_data_from = transport; |
575 | |
576 | /* If we remove the transport an INIT was last sent to, set it to |
577 | * NULL. Combined with the update of the retran path above, this |
578 | * will cause the next INIT to be sent to the next available |
579 | * transport, maintaining the cycle. |
580 | */ |
581 | if (asoc->init_last_sent_to == peer) |
582 | asoc->init_last_sent_to = NULL; |
583 | |
584 | /* If we remove the transport an SHUTDOWN was last sent to, set it |
585 | * to NULL. Combined with the update of the retran path above, this |
586 | * will cause the next SHUTDOWN to be sent to the next available |
587 | * transport, maintaining the cycle. |
588 | */ |
589 | if (asoc->shutdown_last_sent_to == peer) |
590 | asoc->shutdown_last_sent_to = NULL; |
591 | |
592 | /* If we remove the transport an ASCONF was last sent to, set it to |
593 | * NULL. |
594 | */ |
595 | if (asoc->addip_last_asconf && |
596 | asoc->addip_last_asconf->transport == peer) |
597 | asoc->addip_last_asconf->transport = NULL; |
598 | |
599 | /* If we have something on the transmitted list, we have to |
600 | * save it off. The best place is the active path. |
601 | */ |
602 | if (!list_empty(&peer->transmitted)) { |
603 | struct sctp_transport *active = asoc->peer.active_path; |
604 | struct sctp_chunk *ch; |
605 | |
606 | /* Reset the transport of each chunk on this list */ |
607 | list_for_each_entry(ch, &peer->transmitted, |
608 | transmitted_list) { |
609 | ch->transport = NULL; |
610 | ch->rtt_in_progress = 0; |
611 | } |
612 | |
613 | list_splice_tail_init(&peer->transmitted, |
614 | &active->transmitted); |
615 | |
616 | /* Start a T3 timer here in case it wasn't running so |
617 | * that these migrated packets have a chance to get |
618 | * retrnasmitted. |
619 | */ |
620 | if (!timer_pending(&active->T3_rtx_timer)) |
621 | if (!mod_timer(&active->T3_rtx_timer, |
622 | jiffies + active->rto)) |
623 | sctp_transport_hold(active); |
624 | } |
625 | |
626 | asoc->peer.transport_count--; |
627 | |
628 | sctp_transport_free(peer); |
629 | } |
630 | |
631 | /* Add a transport address to an association. */ |
632 | struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, |
633 | const union sctp_addr *addr, |
634 | const gfp_t gfp, |
635 | const int peer_state) |
636 | { |
637 | struct sctp_transport *peer; |
638 | struct sctp_sock *sp; |
639 | unsigned short port; |
640 | |
641 | sp = sctp_sk(asoc->base.sk); |
642 | |
643 | /* AF_INET and AF_INET6 share common port field. */ |
644 | port = ntohs(addr->v4.sin_port); |
645 | |
646 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ", |
647 | " port: %d state:%d\n", |
648 | asoc, |
649 | addr, |
650 | port, |
651 | peer_state); |
652 | |
653 | /* Set the port if it has not been set yet. */ |
654 | if (0 == asoc->peer.port) |
655 | asoc->peer.port = port; |
656 | |
657 | /* Check to see if this is a duplicate. */ |
658 | peer = sctp_assoc_lookup_paddr(asoc, addr); |
659 | if (peer) { |
660 | /* An UNKNOWN state is only set on transports added by |
661 | * user in sctp_connectx() call. Such transports should be |
662 | * considered CONFIRMED per RFC 4960, Section 5.4. |
663 | */ |
664 | if (peer->state == SCTP_UNKNOWN) { |
665 | peer->state = SCTP_ACTIVE; |
666 | } |
667 | return peer; |
668 | } |
669 | |
670 | peer = sctp_transport_new(addr, gfp); |
671 | if (!peer) |
672 | return NULL; |
673 | |
674 | sctp_transport_set_owner(peer, asoc); |
675 | |
676 | /* Initialize the peer's heartbeat interval based on the |
677 | * association configured value. |
678 | */ |
679 | peer->hbinterval = asoc->hbinterval; |
680 | |
681 | /* Set the path max_retrans. */ |
682 | peer->pathmaxrxt = asoc->pathmaxrxt; |
683 | |
684 | /* Initialize the peer's SACK delay timeout based on the |
685 | * association configured value. |
686 | */ |
687 | peer->sackdelay = asoc->sackdelay; |
688 | peer->sackfreq = asoc->sackfreq; |
689 | |
690 | /* Enable/disable heartbeat, SACK delay, and path MTU discovery |
691 | * based on association setting. |
692 | */ |
693 | peer->param_flags = asoc->param_flags; |
694 | |
695 | sctp_transport_route(peer, NULL, sp); |
696 | |
697 | /* Initialize the pmtu of the transport. */ |
698 | if (peer->param_flags & SPP_PMTUD_DISABLE) { |
699 | if (asoc->pathmtu) |
700 | peer->pathmtu = asoc->pathmtu; |
701 | else |
702 | peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT; |
703 | } |
704 | |
705 | /* If this is the first transport addr on this association, |
706 | * initialize the association PMTU to the peer's PMTU. |
707 | * If not and the current association PMTU is higher than the new |
708 | * peer's PMTU, reset the association PMTU to the new peer's PMTU. |
709 | */ |
710 | if (asoc->pathmtu) |
711 | asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu); |
712 | else |
713 | asoc->pathmtu = peer->pathmtu; |
714 | |
715 | SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to " |
716 | "%d\n", asoc, asoc->pathmtu); |
717 | peer->pmtu_pending = 0; |
718 | |
719 | asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu); |
720 | |
721 | /* The asoc->peer.port might not be meaningful yet, but |
722 | * initialize the packet structure anyway. |
723 | */ |
724 | sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port, |
725 | asoc->peer.port); |
726 | |
727 | /* 7.2.1 Slow-Start |
728 | * |
729 | * o The initial cwnd before DATA transmission or after a sufficiently |
730 | * long idle period MUST be set to |
731 | * min(4*MTU, max(2*MTU, 4380 bytes)) |
732 | * |
733 | * o The initial value of ssthresh MAY be arbitrarily high |
734 | * (for example, implementations MAY use the size of the |
735 | * receiver advertised window). |
736 | */ |
737 | peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); |
738 | |
739 | /* At this point, we may not have the receiver's advertised window, |
740 | * so initialize ssthresh to the default value and it will be set |
741 | * later when we process the INIT. |
742 | */ |
743 | peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; |
744 | |
745 | peer->partial_bytes_acked = 0; |
746 | peer->flight_size = 0; |
747 | peer->burst_limited = 0; |
748 | |
749 | /* Set the transport's RTO.initial value */ |
750 | peer->rto = asoc->rto_initial; |
751 | |
752 | /* Set the peer's active state. */ |
753 | peer->state = peer_state; |
754 | |
755 | /* Attach the remote transport to our asoc. */ |
756 | list_add_tail(&peer->transports, &asoc->peer.transport_addr_list); |
757 | asoc->peer.transport_count++; |
758 | |
759 | /* If we do not yet have a primary path, set one. */ |
760 | if (!asoc->peer.primary_path) { |
761 | sctp_assoc_set_primary(asoc, peer); |
762 | asoc->peer.retran_path = peer; |
763 | } |
764 | |
765 | if (asoc->peer.active_path == asoc->peer.retran_path) { |
766 | asoc->peer.retran_path = peer; |
767 | } |
768 | |
769 | return peer; |
770 | } |
771 | |
772 | /* Delete a transport address from an association. */ |
773 | void sctp_assoc_del_peer(struct sctp_association *asoc, |
774 | const union sctp_addr *addr) |
775 | { |
776 | struct list_head *pos; |
777 | struct list_head *temp; |
778 | struct sctp_transport *transport; |
779 | |
780 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { |
781 | transport = list_entry(pos, struct sctp_transport, transports); |
782 | if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) { |
783 | /* Do book keeping for removing the peer and free it. */ |
784 | sctp_assoc_rm_peer(asoc, transport); |
785 | break; |
786 | } |
787 | } |
788 | } |
789 | |
790 | /* Lookup a transport by address. */ |
791 | struct sctp_transport *sctp_assoc_lookup_paddr( |
792 | const struct sctp_association *asoc, |
793 | const union sctp_addr *address) |
794 | { |
795 | struct sctp_transport *t; |
796 | |
797 | /* Cycle through all transports searching for a peer address. */ |
798 | |
799 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
800 | transports) { |
801 | if (sctp_cmp_addr_exact(address, &t->ipaddr)) |
802 | return t; |
803 | } |
804 | |
805 | return NULL; |
806 | } |
807 | |
808 | /* Remove all transports except a give one */ |
809 | void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc, |
810 | struct sctp_transport *primary) |
811 | { |
812 | struct sctp_transport *temp; |
813 | struct sctp_transport *t; |
814 | |
815 | list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list, |
816 | transports) { |
817 | /* if the current transport is not the primary one, delete it */ |
818 | if (t != primary) |
819 | sctp_assoc_rm_peer(asoc, t); |
820 | } |
821 | |
822 | return; |
823 | } |
824 | |
825 | /* Engage in transport control operations. |
826 | * Mark the transport up or down and send a notification to the user. |
827 | * Select and update the new active and retran paths. |
828 | */ |
829 | void sctp_assoc_control_transport(struct sctp_association *asoc, |
830 | struct sctp_transport *transport, |
831 | sctp_transport_cmd_t command, |
832 | sctp_sn_error_t error) |
833 | { |
834 | struct sctp_transport *t = NULL; |
835 | struct sctp_transport *first; |
836 | struct sctp_transport *second; |
837 | struct sctp_ulpevent *event; |
838 | struct sockaddr_storage addr; |
839 | int spc_state = 0; |
840 | |
841 | /* Record the transition on the transport. */ |
842 | switch (command) { |
843 | case SCTP_TRANSPORT_UP: |
844 | /* If we are moving from UNCONFIRMED state due |
845 | * to heartbeat success, report the SCTP_ADDR_CONFIRMED |
846 | * state to the user, otherwise report SCTP_ADDR_AVAILABLE. |
847 | */ |
848 | if (SCTP_UNCONFIRMED == transport->state && |
849 | SCTP_HEARTBEAT_SUCCESS == error) |
850 | spc_state = SCTP_ADDR_CONFIRMED; |
851 | else |
852 | spc_state = SCTP_ADDR_AVAILABLE; |
853 | transport->state = SCTP_ACTIVE; |
854 | break; |
855 | |
856 | case SCTP_TRANSPORT_DOWN: |
857 | /* If the transport was never confirmed, do not transition it |
858 | * to inactive state. Also, release the cached route since |
859 | * there may be a better route next time. |
860 | */ |
861 | if (transport->state != SCTP_UNCONFIRMED) |
862 | transport->state = SCTP_INACTIVE; |
863 | else { |
864 | dst_release(transport->dst); |
865 | transport->dst = NULL; |
866 | } |
867 | |
868 | spc_state = SCTP_ADDR_UNREACHABLE; |
869 | break; |
870 | |
871 | default: |
872 | return; |
873 | } |
874 | |
875 | /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the |
876 | * user. |
877 | */ |
878 | memset(&addr, 0, sizeof(struct sockaddr_storage)); |
879 | memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len); |
880 | event = sctp_ulpevent_make_peer_addr_change(asoc, &addr, |
881 | 0, spc_state, error, GFP_ATOMIC); |
882 | if (event) |
883 | sctp_ulpq_tail_event(&asoc->ulpq, event); |
884 | |
885 | /* Select new active and retran paths. */ |
886 | |
887 | /* Look for the two most recently used active transports. |
888 | * |
889 | * This code produces the wrong ordering whenever jiffies |
890 | * rolls over, but we still get usable transports, so we don't |
891 | * worry about it. |
892 | */ |
893 | first = NULL; second = NULL; |
894 | |
895 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
896 | transports) { |
897 | |
898 | if ((t->state == SCTP_INACTIVE) || |
899 | (t->state == SCTP_UNCONFIRMED)) |
900 | continue; |
901 | if (!first || t->last_time_heard > first->last_time_heard) { |
902 | second = first; |
903 | first = t; |
904 | } |
905 | if (!second || t->last_time_heard > second->last_time_heard) |
906 | second = t; |
907 | } |
908 | |
909 | /* RFC 2960 6.4 Multi-Homed SCTP Endpoints |
910 | * |
911 | * By default, an endpoint should always transmit to the |
912 | * primary path, unless the SCTP user explicitly specifies the |
913 | * destination transport address (and possibly source |
914 | * transport address) to use. |
915 | * |
916 | * [If the primary is active but not most recent, bump the most |
917 | * recently used transport.] |
918 | */ |
919 | if (((asoc->peer.primary_path->state == SCTP_ACTIVE) || |
920 | (asoc->peer.primary_path->state == SCTP_UNKNOWN)) && |
921 | first != asoc->peer.primary_path) { |
922 | second = first; |
923 | first = asoc->peer.primary_path; |
924 | } |
925 | |
926 | /* If we failed to find a usable transport, just camp on the |
927 | * primary, even if it is inactive. |
928 | */ |
929 | if (!first) { |
930 | first = asoc->peer.primary_path; |
931 | second = asoc->peer.primary_path; |
932 | } |
933 | |
934 | /* Set the active and retran transports. */ |
935 | asoc->peer.active_path = first; |
936 | asoc->peer.retran_path = second; |
937 | } |
938 | |
939 | /* Hold a reference to an association. */ |
940 | void sctp_association_hold(struct sctp_association *asoc) |
941 | { |
942 | atomic_inc(&asoc->base.refcnt); |
943 | } |
944 | |
945 | /* Release a reference to an association and cleanup |
946 | * if there are no more references. |
947 | */ |
948 | void sctp_association_put(struct sctp_association *asoc) |
949 | { |
950 | if (atomic_dec_and_test(&asoc->base.refcnt)) |
951 | sctp_association_destroy(asoc); |
952 | } |
953 | |
954 | /* Allocate the next TSN, Transmission Sequence Number, for the given |
955 | * association. |
956 | */ |
957 | __u32 sctp_association_get_next_tsn(struct sctp_association *asoc) |
958 | { |
959 | /* From Section 1.6 Serial Number Arithmetic: |
960 | * Transmission Sequence Numbers wrap around when they reach |
961 | * 2**32 - 1. That is, the next TSN a DATA chunk MUST use |
962 | * after transmitting TSN = 2*32 - 1 is TSN = 0. |
963 | */ |
964 | __u32 retval = asoc->next_tsn; |
965 | asoc->next_tsn++; |
966 | asoc->unack_data++; |
967 | |
968 | return retval; |
969 | } |
970 | |
971 | /* Compare two addresses to see if they match. Wildcard addresses |
972 | * only match themselves. |
973 | */ |
974 | int sctp_cmp_addr_exact(const union sctp_addr *ss1, |
975 | const union sctp_addr *ss2) |
976 | { |
977 | struct sctp_af *af; |
978 | |
979 | af = sctp_get_af_specific(ss1->sa.sa_family); |
980 | if (unlikely(!af)) |
981 | return 0; |
982 | |
983 | return af->cmp_addr(ss1, ss2); |
984 | } |
985 | |
986 | /* Return an ecne chunk to get prepended to a packet. |
987 | * Note: We are sly and return a shared, prealloced chunk. FIXME: |
988 | * No we don't, but we could/should. |
989 | */ |
990 | struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc) |
991 | { |
992 | struct sctp_chunk *chunk; |
993 | |
994 | /* Send ECNE if needed. |
995 | * Not being able to allocate a chunk here is not deadly. |
996 | */ |
997 | if (asoc->need_ecne) |
998 | chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn); |
999 | else |
1000 | chunk = NULL; |
1001 | |
1002 | return chunk; |
1003 | } |
1004 | |
1005 | /* |
1006 | * Find which transport this TSN was sent on. |
1007 | */ |
1008 | struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc, |
1009 | __u32 tsn) |
1010 | { |
1011 | struct sctp_transport *active; |
1012 | struct sctp_transport *match; |
1013 | struct sctp_transport *transport; |
1014 | struct sctp_chunk *chunk; |
1015 | __be32 key = htonl(tsn); |
1016 | |
1017 | match = NULL; |
1018 | |
1019 | /* |
1020 | * FIXME: In general, find a more efficient data structure for |
1021 | * searching. |
1022 | */ |
1023 | |
1024 | /* |
1025 | * The general strategy is to search each transport's transmitted |
1026 | * list. Return which transport this TSN lives on. |
1027 | * |
1028 | * Let's be hopeful and check the active_path first. |
1029 | * Another optimization would be to know if there is only one |
1030 | * outbound path and not have to look for the TSN at all. |
1031 | * |
1032 | */ |
1033 | |
1034 | active = asoc->peer.active_path; |
1035 | |
1036 | list_for_each_entry(chunk, &active->transmitted, |
1037 | transmitted_list) { |
1038 | |
1039 | if (key == chunk->subh.data_hdr->tsn) { |
1040 | match = active; |
1041 | goto out; |
1042 | } |
1043 | } |
1044 | |
1045 | /* If not found, go search all the other transports. */ |
1046 | list_for_each_entry(transport, &asoc->peer.transport_addr_list, |
1047 | transports) { |
1048 | |
1049 | if (transport == active) |
1050 | break; |
1051 | list_for_each_entry(chunk, &transport->transmitted, |
1052 | transmitted_list) { |
1053 | if (key == chunk->subh.data_hdr->tsn) { |
1054 | match = transport; |
1055 | goto out; |
1056 | } |
1057 | } |
1058 | } |
1059 | out: |
1060 | return match; |
1061 | } |
1062 | |
1063 | /* Is this the association we are looking for? */ |
1064 | struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc, |
1065 | const union sctp_addr *laddr, |
1066 | const union sctp_addr *paddr) |
1067 | { |
1068 | struct sctp_transport *transport; |
1069 | |
1070 | if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) && |
1071 | (htons(asoc->peer.port) == paddr->v4.sin_port)) { |
1072 | transport = sctp_assoc_lookup_paddr(asoc, paddr); |
1073 | if (!transport) |
1074 | goto out; |
1075 | |
1076 | if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr, |
1077 | sctp_sk(asoc->base.sk))) |
1078 | goto out; |
1079 | } |
1080 | transport = NULL; |
1081 | |
1082 | out: |
1083 | return transport; |
1084 | } |
1085 | |
1086 | /* Do delayed input processing. This is scheduled by sctp_rcv(). */ |
1087 | static void sctp_assoc_bh_rcv(struct work_struct *work) |
1088 | { |
1089 | struct sctp_association *asoc = |
1090 | container_of(work, struct sctp_association, |
1091 | base.inqueue.immediate); |
1092 | struct sctp_endpoint *ep; |
1093 | struct sctp_chunk *chunk; |
1094 | struct sock *sk; |
1095 | struct sctp_inq *inqueue; |
1096 | int state; |
1097 | sctp_subtype_t subtype; |
1098 | int error = 0; |
1099 | |
1100 | /* The association should be held so we should be safe. */ |
1101 | ep = asoc->ep; |
1102 | sk = asoc->base.sk; |
1103 | |
1104 | inqueue = &asoc->base.inqueue; |
1105 | sctp_association_hold(asoc); |
1106 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { |
1107 | state = asoc->state; |
1108 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); |
1109 | |
1110 | /* SCTP-AUTH, Section 6.3: |
1111 | * The receiver has a list of chunk types which it expects |
1112 | * to be received only after an AUTH-chunk. This list has |
1113 | * been sent to the peer during the association setup. It |
1114 | * MUST silently discard these chunks if they are not placed |
1115 | * after an AUTH chunk in the packet. |
1116 | */ |
1117 | if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) |
1118 | continue; |
1119 | |
1120 | /* Remember where the last DATA chunk came from so we |
1121 | * know where to send the SACK. |
1122 | */ |
1123 | if (sctp_chunk_is_data(chunk)) |
1124 | asoc->peer.last_data_from = chunk->transport; |
1125 | else |
1126 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); |
1127 | |
1128 | if (chunk->transport) |
1129 | chunk->transport->last_time_heard = jiffies; |
1130 | |
1131 | /* Run through the state machine. */ |
1132 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, |
1133 | state, ep, asoc, chunk, GFP_ATOMIC); |
1134 | |
1135 | /* Check to see if the association is freed in response to |
1136 | * the incoming chunk. If so, get out of the while loop. |
1137 | */ |
1138 | if (asoc->base.dead) |
1139 | break; |
1140 | |
1141 | /* If there is an error on chunk, discard this packet. */ |
1142 | if (error && chunk) |
1143 | chunk->pdiscard = 1; |
1144 | } |
1145 | sctp_association_put(asoc); |
1146 | } |
1147 | |
1148 | /* This routine moves an association from its old sk to a new sk. */ |
1149 | void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk) |
1150 | { |
1151 | struct sctp_sock *newsp = sctp_sk(newsk); |
1152 | struct sock *oldsk = assoc->base.sk; |
1153 | |
1154 | /* Delete the association from the old endpoint's list of |
1155 | * associations. |
1156 | */ |
1157 | list_del_init(&assoc->asocs); |
1158 | |
1159 | /* Decrement the backlog value for a TCP-style socket. */ |
1160 | if (sctp_style(oldsk, TCP)) |
1161 | oldsk->sk_ack_backlog--; |
1162 | |
1163 | /* Release references to the old endpoint and the sock. */ |
1164 | sctp_endpoint_put(assoc->ep); |
1165 | sock_put(assoc->base.sk); |
1166 | |
1167 | /* Get a reference to the new endpoint. */ |
1168 | assoc->ep = newsp->ep; |
1169 | sctp_endpoint_hold(assoc->ep); |
1170 | |
1171 | /* Get a reference to the new sock. */ |
1172 | assoc->base.sk = newsk; |
1173 | sock_hold(assoc->base.sk); |
1174 | |
1175 | /* Add the association to the new endpoint's list of associations. */ |
1176 | sctp_endpoint_add_asoc(newsp->ep, assoc); |
1177 | } |
1178 | |
1179 | /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ |
1180 | void sctp_assoc_update(struct sctp_association *asoc, |
1181 | struct sctp_association *new) |
1182 | { |
1183 | struct sctp_transport *trans; |
1184 | struct list_head *pos, *temp; |
1185 | |
1186 | /* Copy in new parameters of peer. */ |
1187 | asoc->c = new->c; |
1188 | asoc->peer.rwnd = new->peer.rwnd; |
1189 | asoc->peer.sack_needed = new->peer.sack_needed; |
1190 | asoc->peer.i = new->peer.i; |
1191 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, |
1192 | asoc->peer.i.initial_tsn, GFP_ATOMIC); |
1193 | |
1194 | /* Remove any peer addresses not present in the new association. */ |
1195 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { |
1196 | trans = list_entry(pos, struct sctp_transport, transports); |
1197 | if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) { |
1198 | sctp_assoc_rm_peer(asoc, trans); |
1199 | continue; |
1200 | } |
1201 | |
1202 | if (asoc->state >= SCTP_STATE_ESTABLISHED) |
1203 | sctp_transport_reset(trans); |
1204 | } |
1205 | |
1206 | /* If the case is A (association restart), use |
1207 | * initial_tsn as next_tsn. If the case is B, use |
1208 | * current next_tsn in case data sent to peer |
1209 | * has been discarded and needs retransmission. |
1210 | */ |
1211 | if (asoc->state >= SCTP_STATE_ESTABLISHED) { |
1212 | asoc->next_tsn = new->next_tsn; |
1213 | asoc->ctsn_ack_point = new->ctsn_ack_point; |
1214 | asoc->adv_peer_ack_point = new->adv_peer_ack_point; |
1215 | |
1216 | /* Reinitialize SSN for both local streams |
1217 | * and peer's streams. |
1218 | */ |
1219 | sctp_ssnmap_clear(asoc->ssnmap); |
1220 | |
1221 | /* Flush the ULP reassembly and ordered queue. |
1222 | * Any data there will now be stale and will |
1223 | * cause problems. |
1224 | */ |
1225 | sctp_ulpq_flush(&asoc->ulpq); |
1226 | |
1227 | /* reset the overall association error count so |
1228 | * that the restarted association doesn't get torn |
1229 | * down on the next retransmission timer. |
1230 | */ |
1231 | asoc->overall_error_count = 0; |
1232 | |
1233 | } else { |
1234 | /* Add any peer addresses from the new association. */ |
1235 | list_for_each_entry(trans, &new->peer.transport_addr_list, |
1236 | transports) { |
1237 | if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr)) |
1238 | sctp_assoc_add_peer(asoc, &trans->ipaddr, |
1239 | GFP_ATOMIC, trans->state); |
1240 | } |
1241 | |
1242 | asoc->ctsn_ack_point = asoc->next_tsn - 1; |
1243 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; |
1244 | if (!asoc->ssnmap) { |
1245 | /* Move the ssnmap. */ |
1246 | asoc->ssnmap = new->ssnmap; |
1247 | new->ssnmap = NULL; |
1248 | } |
1249 | |
1250 | if (!asoc->assoc_id) { |
1251 | /* get a new association id since we don't have one |
1252 | * yet. |
1253 | */ |
1254 | sctp_assoc_set_id(asoc, GFP_ATOMIC); |
1255 | } |
1256 | } |
1257 | |
1258 | /* SCTP-AUTH: Save the peer parameters from the new assocaitions |
1259 | * and also move the association shared keys over |
1260 | */ |
1261 | kfree(asoc->peer.peer_random); |
1262 | asoc->peer.peer_random = new->peer.peer_random; |
1263 | new->peer.peer_random = NULL; |
1264 | |
1265 | kfree(asoc->peer.peer_chunks); |
1266 | asoc->peer.peer_chunks = new->peer.peer_chunks; |
1267 | new->peer.peer_chunks = NULL; |
1268 | |
1269 | kfree(asoc->peer.peer_hmacs); |
1270 | asoc->peer.peer_hmacs = new->peer.peer_hmacs; |
1271 | new->peer.peer_hmacs = NULL; |
1272 | |
1273 | sctp_auth_key_put(asoc->asoc_shared_key); |
1274 | sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC); |
1275 | } |
1276 | |
1277 | /* Update the retran path for sending a retransmitted packet. |
1278 | * Round-robin through the active transports, else round-robin |
1279 | * through the inactive transports as this is the next best thing |
1280 | * we can try. |
1281 | */ |
1282 | void sctp_assoc_update_retran_path(struct sctp_association *asoc) |
1283 | { |
1284 | struct sctp_transport *t, *next; |
1285 | struct list_head *head = &asoc->peer.transport_addr_list; |
1286 | struct list_head *pos; |
1287 | |
1288 | if (asoc->peer.transport_count == 1) |
1289 | return; |
1290 | |
1291 | /* Find the next transport in a round-robin fashion. */ |
1292 | t = asoc->peer.retran_path; |
1293 | pos = &t->transports; |
1294 | next = NULL; |
1295 | |
1296 | while (1) { |
1297 | /* Skip the head. */ |
1298 | if (pos->next == head) |
1299 | pos = head->next; |
1300 | else |
1301 | pos = pos->next; |
1302 | |
1303 | t = list_entry(pos, struct sctp_transport, transports); |
1304 | |
1305 | /* We have exhausted the list, but didn't find any |
1306 | * other active transports. If so, use the next |
1307 | * transport. |
1308 | */ |
1309 | if (t == asoc->peer.retran_path) { |
1310 | t = next; |
1311 | break; |
1312 | } |
1313 | |
1314 | /* Try to find an active transport. */ |
1315 | |
1316 | if ((t->state == SCTP_ACTIVE) || |
1317 | (t->state == SCTP_UNKNOWN)) { |
1318 | break; |
1319 | } else { |
1320 | /* Keep track of the next transport in case |
1321 | * we don't find any active transport. |
1322 | */ |
1323 | if (!next) |
1324 | next = t; |
1325 | } |
1326 | } |
1327 | |
1328 | asoc->peer.retran_path = t; |
1329 | |
1330 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" |
1331 | " %p addr: ", |
1332 | " port: %d\n", |
1333 | asoc, |
1334 | (&t->ipaddr), |
1335 | ntohs(t->ipaddr.v4.sin_port)); |
1336 | } |
1337 | |
1338 | /* Choose the transport for sending retransmit packet. */ |
1339 | struct sctp_transport *sctp_assoc_choose_alter_transport( |
1340 | struct sctp_association *asoc, struct sctp_transport *last_sent_to) |
1341 | { |
1342 | /* If this is the first time packet is sent, use the active path, |
1343 | * else use the retran path. If the last packet was sent over the |
1344 | * retran path, update the retran path and use it. |
1345 | */ |
1346 | if (!last_sent_to) |
1347 | return asoc->peer.active_path; |
1348 | else { |
1349 | if (last_sent_to == asoc->peer.retran_path) |
1350 | sctp_assoc_update_retran_path(asoc); |
1351 | return asoc->peer.retran_path; |
1352 | } |
1353 | } |
1354 | |
1355 | /* Update the association's pmtu and frag_point by going through all the |
1356 | * transports. This routine is called when a transport's PMTU has changed. |
1357 | */ |
1358 | void sctp_assoc_sync_pmtu(struct sctp_association *asoc) |
1359 | { |
1360 | struct sctp_transport *t; |
1361 | __u32 pmtu = 0; |
1362 | |
1363 | if (!asoc) |
1364 | return; |
1365 | |
1366 | /* Get the lowest pmtu of all the transports. */ |
1367 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
1368 | transports) { |
1369 | if (t->pmtu_pending && t->dst) { |
1370 | sctp_transport_update_pmtu(t, dst_mtu(t->dst)); |
1371 | t->pmtu_pending = 0; |
1372 | } |
1373 | if (!pmtu || (t->pathmtu < pmtu)) |
1374 | pmtu = t->pathmtu; |
1375 | } |
1376 | |
1377 | if (pmtu) { |
1378 | asoc->pathmtu = pmtu; |
1379 | asoc->frag_point = sctp_frag_point(asoc, pmtu); |
1380 | } |
1381 | |
1382 | SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n", |
1383 | __func__, asoc, asoc->pathmtu, asoc->frag_point); |
1384 | } |
1385 | |
1386 | /* Should we send a SACK to update our peer? */ |
1387 | static inline int sctp_peer_needs_update(struct sctp_association *asoc) |
1388 | { |
1389 | switch (asoc->state) { |
1390 | case SCTP_STATE_ESTABLISHED: |
1391 | case SCTP_STATE_SHUTDOWN_PENDING: |
1392 | case SCTP_STATE_SHUTDOWN_RECEIVED: |
1393 | case SCTP_STATE_SHUTDOWN_SENT: |
1394 | if ((asoc->rwnd > asoc->a_rwnd) && |
1395 | ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32, |
1396 | (asoc->base.sk->sk_rcvbuf >> sctp_rwnd_upd_shift), |
1397 | asoc->pathmtu))) |
1398 | return 1; |
1399 | break; |
1400 | default: |
1401 | break; |
1402 | } |
1403 | return 0; |
1404 | } |
1405 | |
1406 | /* Increase asoc's rwnd by len and send any window update SACK if needed. */ |
1407 | void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len) |
1408 | { |
1409 | struct sctp_chunk *sack; |
1410 | struct timer_list *timer; |
1411 | |
1412 | if (asoc->rwnd_over) { |
1413 | if (asoc->rwnd_over >= len) { |
1414 | asoc->rwnd_over -= len; |
1415 | } else { |
1416 | asoc->rwnd += (len - asoc->rwnd_over); |
1417 | asoc->rwnd_over = 0; |
1418 | } |
1419 | } else { |
1420 | asoc->rwnd += len; |
1421 | } |
1422 | |
1423 | /* If we had window pressure, start recovering it |
1424 | * once our rwnd had reached the accumulated pressure |
1425 | * threshold. The idea is to recover slowly, but up |
1426 | * to the initial advertised window. |
1427 | */ |
1428 | if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) { |
1429 | int change = min(asoc->pathmtu, asoc->rwnd_press); |
1430 | asoc->rwnd += change; |
1431 | asoc->rwnd_press -= change; |
1432 | } |
1433 | |
1434 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) " |
1435 | "- %u\n", __func__, asoc, len, asoc->rwnd, |
1436 | asoc->rwnd_over, asoc->a_rwnd); |
1437 | |
1438 | /* Send a window update SACK if the rwnd has increased by at least the |
1439 | * minimum of the association's PMTU and half of the receive buffer. |
1440 | * The algorithm used is similar to the one described in |
1441 | * Section 4.2.3.3 of RFC 1122. |
1442 | */ |
1443 | if (sctp_peer_needs_update(asoc)) { |
1444 | asoc->a_rwnd = asoc->rwnd; |
1445 | SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p " |
1446 | "rwnd: %u a_rwnd: %u\n", __func__, |
1447 | asoc, asoc->rwnd, asoc->a_rwnd); |
1448 | sack = sctp_make_sack(asoc); |
1449 | if (!sack) |
1450 | return; |
1451 | |
1452 | asoc->peer.sack_needed = 0; |
1453 | |
1454 | sctp_outq_tail(&asoc->outqueue, sack); |
1455 | |
1456 | /* Stop the SACK timer. */ |
1457 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
1458 | if (timer_pending(timer) && del_timer(timer)) |
1459 | sctp_association_put(asoc); |
1460 | } |
1461 | } |
1462 | |
1463 | /* Decrease asoc's rwnd by len. */ |
1464 | void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len) |
1465 | { |
1466 | int rx_count; |
1467 | int over = 0; |
1468 | |
1469 | SCTP_ASSERT(asoc->rwnd, "rwnd zero", return); |
1470 | SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return); |
1471 | |
1472 | if (asoc->ep->rcvbuf_policy) |
1473 | rx_count = atomic_read(&asoc->rmem_alloc); |
1474 | else |
1475 | rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); |
1476 | |
1477 | /* If we've reached or overflowed our receive buffer, announce |
1478 | * a 0 rwnd if rwnd would still be positive. Store the |
1479 | * the pottential pressure overflow so that the window can be restored |
1480 | * back to original value. |
1481 | */ |
1482 | if (rx_count >= asoc->base.sk->sk_rcvbuf) |
1483 | over = 1; |
1484 | |
1485 | if (asoc->rwnd >= len) { |
1486 | asoc->rwnd -= len; |
1487 | if (over) { |
1488 | asoc->rwnd_press = asoc->rwnd; |
1489 | asoc->rwnd = 0; |
1490 | } |
1491 | } else { |
1492 | asoc->rwnd_over = len - asoc->rwnd; |
1493 | asoc->rwnd = 0; |
1494 | } |
1495 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n", |
1496 | __func__, asoc, len, asoc->rwnd, |
1497 | asoc->rwnd_over, asoc->rwnd_press); |
1498 | } |
1499 | |
1500 | /* Build the bind address list for the association based on info from the |
1501 | * local endpoint and the remote peer. |
1502 | */ |
1503 | int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, |
1504 | sctp_scope_t scope, gfp_t gfp) |
1505 | { |
1506 | int flags; |
1507 | |
1508 | /* Use scoping rules to determine the subset of addresses from |
1509 | * the endpoint. |
1510 | */ |
1511 | flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; |
1512 | if (asoc->peer.ipv4_address) |
1513 | flags |= SCTP_ADDR4_PEERSUPP; |
1514 | if (asoc->peer.ipv6_address) |
1515 | flags |= SCTP_ADDR6_PEERSUPP; |
1516 | |
1517 | return sctp_bind_addr_copy(&asoc->base.bind_addr, |
1518 | &asoc->ep->base.bind_addr, |
1519 | scope, gfp, flags); |
1520 | } |
1521 | |
1522 | /* Build the association's bind address list from the cookie. */ |
1523 | int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc, |
1524 | struct sctp_cookie *cookie, |
1525 | gfp_t gfp) |
1526 | { |
1527 | int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); |
1528 | int var_size3 = cookie->raw_addr_list_len; |
1529 | __u8 *raw = (__u8 *)cookie->peer_init + var_size2; |
1530 | |
1531 | return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3, |
1532 | asoc->ep->base.bind_addr.port, gfp); |
1533 | } |
1534 | |
1535 | /* Lookup laddr in the bind address list of an association. */ |
1536 | int sctp_assoc_lookup_laddr(struct sctp_association *asoc, |
1537 | const union sctp_addr *laddr) |
1538 | { |
1539 | int found = 0; |
1540 | |
1541 | if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) && |
1542 | sctp_bind_addr_match(&asoc->base.bind_addr, laddr, |
1543 | sctp_sk(asoc->base.sk))) |
1544 | found = 1; |
1545 | |
1546 | return found; |
1547 | } |
1548 | |
1549 | /* Set an association id for a given association */ |
1550 | int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp) |
1551 | { |
1552 | int assoc_id; |
1553 | int error = 0; |
1554 | |
1555 | /* If the id is already assigned, keep it. */ |
1556 | if (asoc->assoc_id) |
1557 | return error; |
1558 | retry: |
1559 | if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp))) |
1560 | return -ENOMEM; |
1561 | |
1562 | spin_lock_bh(&sctp_assocs_id_lock); |
1563 | error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, |
1564 | idr_low, &assoc_id); |
1565 | if (!error) { |
1566 | idr_low = assoc_id + 1; |
1567 | if (idr_low == INT_MAX) |
1568 | idr_low = 1; |
1569 | } |
1570 | spin_unlock_bh(&sctp_assocs_id_lock); |
1571 | if (error == -EAGAIN) |
1572 | goto retry; |
1573 | else if (error) |
1574 | return error; |
1575 | |
1576 | asoc->assoc_id = (sctp_assoc_t) assoc_id; |
1577 | return error; |
1578 | } |
1579 | |
1580 | /* Free asconf_ack cache */ |
1581 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc) |
1582 | { |
1583 | struct sctp_chunk *ack; |
1584 | struct sctp_chunk *tmp; |
1585 | |
1586 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, |
1587 | transmitted_list) { |
1588 | list_del_init(&ack->transmitted_list); |
1589 | sctp_chunk_free(ack); |
1590 | } |
1591 | } |
1592 | |
1593 | /* Clean up the ASCONF_ACK queue */ |
1594 | void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc) |
1595 | { |
1596 | struct sctp_chunk *ack; |
1597 | struct sctp_chunk *tmp; |
1598 | |
1599 | /* We can remove all the entries from the queue upto |
1600 | * the "Peer-Sequence-Number". |
1601 | */ |
1602 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, |
1603 | transmitted_list) { |
1604 | if (ack->subh.addip_hdr->serial == |
1605 | htonl(asoc->peer.addip_serial)) |
1606 | break; |
1607 | |
1608 | list_del_init(&ack->transmitted_list); |
1609 | sctp_chunk_free(ack); |
1610 | } |
1611 | } |
1612 | |
1613 | /* Find the ASCONF_ACK whose serial number matches ASCONF */ |
1614 | struct sctp_chunk *sctp_assoc_lookup_asconf_ack( |
1615 | const struct sctp_association *asoc, |
1616 | __be32 serial) |
1617 | { |
1618 | struct sctp_chunk *ack; |
1619 | |
1620 | /* Walk through the list of cached ASCONF-ACKs and find the |
1621 | * ack chunk whose serial number matches that of the request. |
1622 | */ |
1623 | list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) { |
1624 | if (ack->subh.addip_hdr->serial == serial) { |
1625 | sctp_chunk_hold(ack); |
1626 | return ack; |
1627 | } |
1628 | } |
1629 | |
1630 | return NULL; |
1631 | } |
1632 |
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