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1da177e4 LT |
1 | /* SCTP kernel reference 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 reference Implementation | |
9 | * | |
10 | * This module provides the abstraction for an SCTP association. | |
11 | * | |
12 | * The SCTP reference 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 | * The SCTP reference 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 | #include <linux/sched.h> | |
56 | ||
57 | #include <linux/slab.h> | |
58 | #include <linux/in.h> | |
59 | #include <net/ipv6.h> | |
60 | #include <net/sctp/sctp.h> | |
61 | #include <net/sctp/sm.h> | |
62 | ||
63 | /* Forward declarations for internal functions. */ | |
64 | static void sctp_assoc_bh_rcv(struct sctp_association *asoc); | |
65 | ||
66 | ||
67 | /* 1st Level Abstractions. */ | |
68 | ||
69 | /* Initialize a new association from provided memory. */ | |
70 | static struct sctp_association *sctp_association_init(struct sctp_association *asoc, | |
71 | const struct sctp_endpoint *ep, | |
72 | const struct sock *sk, | |
73 | sctp_scope_t scope, | |
74 | int gfp) | |
75 | { | |
76 | struct sctp_sock *sp; | |
77 | int i; | |
78 | ||
79 | /* Retrieve the SCTP per socket area. */ | |
80 | sp = sctp_sk((struct sock *)sk); | |
81 | ||
82 | /* Init all variables to a known value. */ | |
83 | memset(asoc, 0, sizeof(struct sctp_association)); | |
84 | ||
85 | /* Discarding const is appropriate here. */ | |
86 | asoc->ep = (struct sctp_endpoint *)ep; | |
87 | sctp_endpoint_hold(asoc->ep); | |
88 | ||
89 | /* Hold the sock. */ | |
90 | asoc->base.sk = (struct sock *)sk; | |
91 | sock_hold(asoc->base.sk); | |
92 | ||
93 | /* Initialize the common base substructure. */ | |
94 | asoc->base.type = SCTP_EP_TYPE_ASSOCIATION; | |
95 | ||
96 | /* Initialize the object handling fields. */ | |
97 | atomic_set(&asoc->base.refcnt, 1); | |
98 | asoc->base.dead = 0; | |
99 | asoc->base.malloced = 0; | |
100 | ||
101 | /* Initialize the bind addr area. */ | |
102 | sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port); | |
103 | rwlock_init(&asoc->base.addr_lock); | |
104 | ||
105 | asoc->state = SCTP_STATE_CLOSED; | |
106 | ||
107 | /* Set these values from the socket values, a conversion between | |
108 | * millsecons to seconds/microseconds must also be done. | |
109 | */ | |
110 | asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000; | |
111 | asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000) | |
112 | * 1000; | |
113 | asoc->pmtu = 0; | |
114 | asoc->frag_point = 0; | |
115 | ||
116 | /* Set the association max_retrans and RTO values from the | |
117 | * socket values. | |
118 | */ | |
119 | asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt; | |
120 | asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial); | |
121 | asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max); | |
122 | asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min); | |
123 | ||
124 | asoc->overall_error_count = 0; | |
125 | ||
126 | /* Initialize the maximum mumber of new data packets that can be sent | |
127 | * in a burst. | |
128 | */ | |
129 | asoc->max_burst = sctp_max_burst; | |
130 | ||
131 | /* Copy things from the endpoint. */ | |
132 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { | |
133 | asoc->timeouts[i] = ep->timeouts[i]; | |
134 | init_timer(&asoc->timers[i]); | |
135 | asoc->timers[i].function = sctp_timer_events[i]; | |
136 | asoc->timers[i].data = (unsigned long) asoc; | |
137 | } | |
138 | ||
139 | /* Pull default initialization values from the sock options. | |
140 | * Note: This assumes that the values have already been | |
141 | * validated in the sock. | |
142 | */ | |
143 | asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; | |
144 | asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; | |
145 | asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; | |
146 | ||
147 | asoc->max_init_timeo = | |
148 | msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo); | |
149 | ||
150 | /* Allocate storage for the ssnmap after the inbound and outbound | |
151 | * streams have been negotiated during Init. | |
152 | */ | |
153 | asoc->ssnmap = NULL; | |
154 | ||
155 | /* Set the local window size for receive. | |
156 | * This is also the rcvbuf space per association. | |
157 | * RFC 6 - A SCTP receiver MUST be able to receive a minimum of | |
158 | * 1500 bytes in one SCTP packet. | |
159 | */ | |
160 | if (sk->sk_rcvbuf < SCTP_DEFAULT_MINWINDOW) | |
161 | asoc->rwnd = SCTP_DEFAULT_MINWINDOW; | |
162 | else | |
163 | asoc->rwnd = sk->sk_rcvbuf; | |
164 | ||
165 | asoc->a_rwnd = asoc->rwnd; | |
166 | ||
167 | asoc->rwnd_over = 0; | |
168 | ||
169 | /* Use my own max window until I learn something better. */ | |
170 | asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; | |
171 | ||
172 | /* Set the sndbuf size for transmit. */ | |
173 | asoc->sndbuf_used = 0; | |
174 | ||
175 | init_waitqueue_head(&asoc->wait); | |
176 | ||
177 | asoc->c.my_vtag = sctp_generate_tag(ep); | |
178 | asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */ | |
179 | asoc->c.peer_vtag = 0; | |
180 | asoc->c.my_ttag = 0; | |
181 | asoc->c.peer_ttag = 0; | |
182 | asoc->c.my_port = ep->base.bind_addr.port; | |
183 | ||
184 | asoc->c.initial_tsn = sctp_generate_tsn(ep); | |
185 | ||
186 | asoc->next_tsn = asoc->c.initial_tsn; | |
187 | ||
188 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
189 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
190 | asoc->highest_sacked = asoc->ctsn_ack_point; | |
191 | asoc->last_cwr_tsn = asoc->ctsn_ack_point; | |
192 | asoc->unack_data = 0; | |
193 | ||
1da177e4 LT |
194 | /* ADDIP Section 4.1 Asconf Chunk Procedures |
195 | * | |
196 | * When an endpoint has an ASCONF signaled change to be sent to the | |
197 | * remote endpoint it should do the following: | |
198 | * ... | |
199 | * A2) a serial number should be assigned to the chunk. The serial | |
200 | * number SHOULD be a monotonically increasing number. The serial | |
201 | * numbers SHOULD be initialized at the start of the | |
202 | * association to the same value as the initial TSN. | |
203 | */ | |
204 | asoc->addip_serial = asoc->c.initial_tsn; | |
205 | ||
206 | skb_queue_head_init(&asoc->addip_chunks); | |
207 | ||
208 | /* Make an empty list of remote transport addresses. */ | |
209 | INIT_LIST_HEAD(&asoc->peer.transport_addr_list); | |
3f7a87d2 | 210 | asoc->peer.transport_count = 0; |
1da177e4 LT |
211 | |
212 | /* RFC 2960 5.1 Normal Establishment of an Association | |
213 | * | |
214 | * After the reception of the first data chunk in an | |
215 | * association the endpoint must immediately respond with a | |
216 | * sack to acknowledge the data chunk. Subsequent | |
217 | * acknowledgements should be done as described in Section | |
218 | * 6.2. | |
219 | * | |
220 | * [We implement this by telling a new association that it | |
221 | * already received one packet.] | |
222 | */ | |
223 | asoc->peer.sack_needed = 1; | |
224 | ||
225 | /* Assume that the peer recongizes ASCONF until reported otherwise | |
226 | * via an ERROR chunk. | |
227 | */ | |
228 | asoc->peer.asconf_capable = 1; | |
229 | ||
230 | /* Create an input queue. */ | |
231 | sctp_inq_init(&asoc->base.inqueue); | |
232 | sctp_inq_set_th_handler(&asoc->base.inqueue, | |
233 | (void (*)(void *))sctp_assoc_bh_rcv, | |
234 | asoc); | |
235 | ||
236 | /* Create an output queue. */ | |
237 | sctp_outq_init(asoc, &asoc->outqueue); | |
238 | ||
239 | if (!sctp_ulpq_init(&asoc->ulpq, asoc)) | |
240 | goto fail_init; | |
241 | ||
242 | /* Set up the tsn tracking. */ | |
243 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0); | |
244 | ||
245 | asoc->need_ecne = 0; | |
246 | ||
247 | asoc->assoc_id = 0; | |
248 | ||
249 | /* Assume that peer would support both address types unless we are | |
250 | * told otherwise. | |
251 | */ | |
252 | asoc->peer.ipv4_address = 1; | |
253 | asoc->peer.ipv6_address = 1; | |
254 | INIT_LIST_HEAD(&asoc->asocs); | |
255 | ||
256 | asoc->autoclose = sp->autoclose; | |
257 | ||
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; | |
263 | ||
264 | return asoc; | |
265 | ||
266 | fail_init: | |
267 | sctp_endpoint_put(asoc->ep); | |
268 | sock_put(asoc->base.sk); | |
269 | return NULL; | |
270 | } | |
271 | ||
272 | /* Allocate and initialize a new association */ | |
273 | struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep, | |
274 | const struct sock *sk, | |
275 | sctp_scope_t scope, int gfp) | |
276 | { | |
277 | struct sctp_association *asoc; | |
278 | ||
279 | asoc = t_new(struct sctp_association, gfp); | |
280 | if (!asoc) | |
281 | goto fail; | |
282 | ||
283 | if (!sctp_association_init(asoc, ep, sk, scope, gfp)) | |
284 | goto fail_init; | |
285 | ||
286 | asoc->base.malloced = 1; | |
287 | SCTP_DBG_OBJCNT_INC(assoc); | |
3f7a87d2 | 288 | SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc); |
1da177e4 LT |
289 | |
290 | return asoc; | |
291 | ||
292 | fail_init: | |
293 | kfree(asoc); | |
294 | fail: | |
295 | return NULL; | |
296 | } | |
297 | ||
298 | /* Free this association if possible. There may still be users, so | |
299 | * the actual deallocation may be delayed. | |
300 | */ | |
301 | void sctp_association_free(struct sctp_association *asoc) | |
302 | { | |
303 | struct sock *sk = asoc->base.sk; | |
304 | struct sctp_transport *transport; | |
305 | struct list_head *pos, *temp; | |
306 | int i; | |
307 | ||
308 | list_del(&asoc->asocs); | |
309 | ||
310 | /* Decrement the backlog value for a TCP-style listening socket. */ | |
311 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
312 | sk->sk_ack_backlog--; | |
313 | ||
314 | /* Mark as dead, so other users can know this structure is | |
315 | * going away. | |
316 | */ | |
317 | asoc->base.dead = 1; | |
318 | ||
319 | /* Dispose of any data lying around in the outqueue. */ | |
320 | sctp_outq_free(&asoc->outqueue); | |
321 | ||
322 | /* Dispose of any pending messages for the upper layer. */ | |
323 | sctp_ulpq_free(&asoc->ulpq); | |
324 | ||
325 | /* Dispose of any pending chunks on the inqueue. */ | |
326 | sctp_inq_free(&asoc->base.inqueue); | |
327 | ||
328 | /* Free ssnmap storage. */ | |
329 | sctp_ssnmap_free(asoc->ssnmap); | |
330 | ||
331 | /* Clean up the bound address list. */ | |
332 | sctp_bind_addr_free(&asoc->base.bind_addr); | |
333 | ||
334 | /* Do we need to go through all of our timers and | |
335 | * delete them? To be safe we will try to delete all, but we | |
336 | * should be able to go through and make a guess based | |
337 | * on our state. | |
338 | */ | |
339 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { | |
340 | if (timer_pending(&asoc->timers[i]) && | |
341 | del_timer(&asoc->timers[i])) | |
342 | sctp_association_put(asoc); | |
343 | } | |
344 | ||
345 | /* Free peer's cached cookie. */ | |
346 | if (asoc->peer.cookie) { | |
347 | kfree(asoc->peer.cookie); | |
348 | } | |
349 | ||
350 | /* Release the transport structures. */ | |
351 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
352 | transport = list_entry(pos, struct sctp_transport, transports); | |
353 | list_del(pos); | |
354 | sctp_transport_free(transport); | |
355 | } | |
356 | ||
3f7a87d2 FF |
357 | asoc->peer.transport_count = 0; |
358 | ||
1da177e4 LT |
359 | /* Free any cached ASCONF_ACK chunk. */ |
360 | if (asoc->addip_last_asconf_ack) | |
361 | sctp_chunk_free(asoc->addip_last_asconf_ack); | |
362 | ||
363 | /* Free any cached ASCONF chunk. */ | |
364 | if (asoc->addip_last_asconf) | |
365 | sctp_chunk_free(asoc->addip_last_asconf); | |
366 | ||
367 | sctp_association_put(asoc); | |
368 | } | |
369 | ||
370 | /* Cleanup and free up an association. */ | |
371 | static void sctp_association_destroy(struct sctp_association *asoc) | |
372 | { | |
373 | SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return); | |
374 | ||
375 | sctp_endpoint_put(asoc->ep); | |
376 | sock_put(asoc->base.sk); | |
377 | ||
378 | if (asoc->assoc_id != 0) { | |
379 | spin_lock_bh(&sctp_assocs_id_lock); | |
380 | idr_remove(&sctp_assocs_id, asoc->assoc_id); | |
381 | spin_unlock_bh(&sctp_assocs_id_lock); | |
382 | } | |
383 | ||
384 | if (asoc->base.malloced) { | |
385 | kfree(asoc); | |
386 | SCTP_DBG_OBJCNT_DEC(assoc); | |
387 | } | |
388 | } | |
389 | ||
390 | /* Change the primary destination address for the peer. */ | |
391 | void sctp_assoc_set_primary(struct sctp_association *asoc, | |
392 | struct sctp_transport *transport) | |
393 | { | |
394 | asoc->peer.primary_path = transport; | |
395 | ||
396 | /* Set a default msg_name for events. */ | |
397 | memcpy(&asoc->peer.primary_addr, &transport->ipaddr, | |
398 | sizeof(union sctp_addr)); | |
399 | ||
400 | /* If the primary path is changing, assume that the | |
401 | * user wants to use this new path. | |
402 | */ | |
3f7a87d2 | 403 | if (transport->state != SCTP_INACTIVE) |
1da177e4 LT |
404 | asoc->peer.active_path = transport; |
405 | ||
406 | /* | |
407 | * SFR-CACC algorithm: | |
408 | * Upon the receipt of a request to change the primary | |
409 | * destination address, on the data structure for the new | |
410 | * primary destination, the sender MUST do the following: | |
411 | * | |
412 | * 1) If CHANGEOVER_ACTIVE is set, then there was a switch | |
413 | * to this destination address earlier. The sender MUST set | |
414 | * CYCLING_CHANGEOVER to indicate that this switch is a | |
415 | * double switch to the same destination address. | |
416 | */ | |
417 | if (transport->cacc.changeover_active) | |
418 | transport->cacc.cycling_changeover = 1; | |
419 | ||
420 | /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that | |
421 | * a changeover has occurred. | |
422 | */ | |
423 | transport->cacc.changeover_active = 1; | |
424 | ||
425 | /* 3) The sender MUST store the next TSN to be sent in | |
426 | * next_tsn_at_change. | |
427 | */ | |
428 | transport->cacc.next_tsn_at_change = asoc->next_tsn; | |
429 | } | |
430 | ||
3f7a87d2 FF |
431 | /* Remove a transport from an association. */ |
432 | void sctp_assoc_rm_peer(struct sctp_association *asoc, | |
433 | struct sctp_transport *peer) | |
434 | { | |
435 | struct list_head *pos; | |
436 | struct sctp_transport *transport; | |
437 | ||
438 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ", | |
439 | " port: %d\n", | |
440 | asoc, | |
441 | (&peer->ipaddr), | |
442 | peer->ipaddr.v4.sin_port); | |
443 | ||
444 | /* If we are to remove the current retran_path, update it | |
445 | * to the next peer before removing this peer from the list. | |
446 | */ | |
447 | if (asoc->peer.retran_path == peer) | |
448 | sctp_assoc_update_retran_path(asoc); | |
449 | ||
450 | /* Remove this peer from the list. */ | |
451 | list_del(&peer->transports); | |
452 | ||
453 | /* Get the first transport of asoc. */ | |
454 | pos = asoc->peer.transport_addr_list.next; | |
455 | transport = list_entry(pos, struct sctp_transport, transports); | |
456 | ||
457 | /* Update any entries that match the peer to be deleted. */ | |
458 | if (asoc->peer.primary_path == peer) | |
459 | sctp_assoc_set_primary(asoc, transport); | |
460 | if (asoc->peer.active_path == peer) | |
461 | asoc->peer.active_path = transport; | |
462 | if (asoc->peer.last_data_from == peer) | |
463 | asoc->peer.last_data_from = transport; | |
464 | ||
465 | /* If we remove the transport an INIT was last sent to, set it to | |
466 | * NULL. Combined with the update of the retran path above, this | |
467 | * will cause the next INIT to be sent to the next available | |
468 | * transport, maintaining the cycle. | |
469 | */ | |
470 | if (asoc->init_last_sent_to == peer) | |
471 | asoc->init_last_sent_to = NULL; | |
472 | ||
473 | asoc->peer.transport_count--; | |
474 | ||
475 | sctp_transport_free(peer); | |
476 | } | |
477 | ||
1da177e4 LT |
478 | /* Add a transport address to an association. */ |
479 | struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, | |
480 | const union sctp_addr *addr, | |
3f7a87d2 FF |
481 | const int gfp, |
482 | const int peer_state) | |
1da177e4 LT |
483 | { |
484 | struct sctp_transport *peer; | |
485 | struct sctp_sock *sp; | |
486 | unsigned short port; | |
487 | ||
488 | sp = sctp_sk(asoc->base.sk); | |
489 | ||
490 | /* AF_INET and AF_INET6 share common port field. */ | |
491 | port = addr->v4.sin_port; | |
492 | ||
3f7a87d2 FF |
493 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ", |
494 | " port: %d state:%s\n", | |
495 | asoc, | |
496 | addr, | |
497 | addr->v4.sin_port, | |
498 | peer_state == SCTP_UNKNOWN?"UNKNOWN":"ACTIVE"); | |
499 | ||
1da177e4 LT |
500 | /* Set the port if it has not been set yet. */ |
501 | if (0 == asoc->peer.port) | |
502 | asoc->peer.port = port; | |
503 | ||
504 | /* Check to see if this is a duplicate. */ | |
505 | peer = sctp_assoc_lookup_paddr(asoc, addr); | |
3f7a87d2 FF |
506 | if (peer) { |
507 | if (peer_state == SCTP_ACTIVE && | |
508 | peer->state == SCTP_UNKNOWN) | |
509 | peer->state = SCTP_ACTIVE; | |
1da177e4 | 510 | return peer; |
3f7a87d2 | 511 | } |
1da177e4 LT |
512 | |
513 | peer = sctp_transport_new(addr, gfp); | |
514 | if (!peer) | |
515 | return NULL; | |
516 | ||
517 | sctp_transport_set_owner(peer, asoc); | |
518 | ||
519 | /* Initialize the pmtu of the transport. */ | |
520 | sctp_transport_pmtu(peer); | |
521 | ||
522 | /* If this is the first transport addr on this association, | |
523 | * initialize the association PMTU to the peer's PMTU. | |
524 | * If not and the current association PMTU is higher than the new | |
525 | * peer's PMTU, reset the association PMTU to the new peer's PMTU. | |
526 | */ | |
527 | if (asoc->pmtu) | |
528 | asoc->pmtu = min_t(int, peer->pmtu, asoc->pmtu); | |
529 | else | |
530 | asoc->pmtu = peer->pmtu; | |
531 | ||
532 | SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to " | |
533 | "%d\n", asoc, asoc->pmtu); | |
534 | ||
535 | asoc->frag_point = sctp_frag_point(sp, asoc->pmtu); | |
536 | ||
537 | /* The asoc->peer.port might not be meaningful yet, but | |
538 | * initialize the packet structure anyway. | |
539 | */ | |
540 | sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port, | |
541 | asoc->peer.port); | |
542 | ||
543 | /* 7.2.1 Slow-Start | |
544 | * | |
545 | * o The initial cwnd before DATA transmission or after a sufficiently | |
546 | * long idle period MUST be set to | |
547 | * min(4*MTU, max(2*MTU, 4380 bytes)) | |
548 | * | |
549 | * o The initial value of ssthresh MAY be arbitrarily high | |
550 | * (for example, implementations MAY use the size of the | |
551 | * receiver advertised window). | |
552 | */ | |
553 | peer->cwnd = min(4*asoc->pmtu, max_t(__u32, 2*asoc->pmtu, 4380)); | |
554 | ||
555 | /* At this point, we may not have the receiver's advertised window, | |
556 | * so initialize ssthresh to the default value and it will be set | |
557 | * later when we process the INIT. | |
558 | */ | |
559 | peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; | |
560 | ||
561 | peer->partial_bytes_acked = 0; | |
562 | peer->flight_size = 0; | |
563 | ||
564 | /* By default, enable heartbeat for peer address. */ | |
565 | peer->hb_allowed = 1; | |
566 | ||
567 | /* Initialize the peer's heartbeat interval based on the | |
568 | * sock configured value. | |
569 | */ | |
570 | peer->hb_interval = msecs_to_jiffies(sp->paddrparam.spp_hbinterval); | |
571 | ||
572 | /* Set the path max_retrans. */ | |
573 | peer->max_retrans = sp->paddrparam.spp_pathmaxrxt; | |
574 | ||
575 | /* Set the transport's RTO.initial value */ | |
576 | peer->rto = asoc->rto_initial; | |
577 | ||
3f7a87d2 FF |
578 | /* Set the peer's active state. */ |
579 | peer->state = peer_state; | |
580 | ||
1da177e4 LT |
581 | /* Attach the remote transport to our asoc. */ |
582 | list_add_tail(&peer->transports, &asoc->peer.transport_addr_list); | |
3f7a87d2 | 583 | asoc->peer.transport_count++; |
1da177e4 LT |
584 | |
585 | /* If we do not yet have a primary path, set one. */ | |
586 | if (!asoc->peer.primary_path) { | |
587 | sctp_assoc_set_primary(asoc, peer); | |
588 | asoc->peer.retran_path = peer; | |
589 | } | |
590 | ||
3f7a87d2 | 591 | if (asoc->peer.active_path == asoc->peer.retran_path) { |
1da177e4 | 592 | asoc->peer.retran_path = peer; |
3f7a87d2 | 593 | } |
1da177e4 LT |
594 | |
595 | return peer; | |
596 | } | |
597 | ||
598 | /* Delete a transport address from an association. */ | |
599 | void sctp_assoc_del_peer(struct sctp_association *asoc, | |
600 | const union sctp_addr *addr) | |
601 | { | |
602 | struct list_head *pos; | |
603 | struct list_head *temp; | |
1da177e4 LT |
604 | struct sctp_transport *transport; |
605 | ||
606 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
607 | transport = list_entry(pos, struct sctp_transport, transports); | |
608 | if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) { | |
3f7a87d2 FF |
609 | /* Do book keeping for removing the peer and free it. */ |
610 | sctp_assoc_rm_peer(asoc, transport); | |
1da177e4 LT |
611 | break; |
612 | } | |
613 | } | |
1da177e4 LT |
614 | } |
615 | ||
616 | /* Lookup a transport by address. */ | |
617 | struct sctp_transport *sctp_assoc_lookup_paddr( | |
618 | const struct sctp_association *asoc, | |
619 | const union sctp_addr *address) | |
620 | { | |
621 | struct sctp_transport *t; | |
622 | struct list_head *pos; | |
623 | ||
624 | /* Cycle through all transports searching for a peer address. */ | |
625 | ||
626 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
627 | t = list_entry(pos, struct sctp_transport, transports); | |
628 | if (sctp_cmp_addr_exact(address, &t->ipaddr)) | |
629 | return t; | |
630 | } | |
631 | ||
632 | return NULL; | |
633 | } | |
634 | ||
635 | /* Engage in transport control operations. | |
636 | * Mark the transport up or down and send a notification to the user. | |
637 | * Select and update the new active and retran paths. | |
638 | */ | |
639 | void sctp_assoc_control_transport(struct sctp_association *asoc, | |
640 | struct sctp_transport *transport, | |
641 | sctp_transport_cmd_t command, | |
642 | sctp_sn_error_t error) | |
643 | { | |
644 | struct sctp_transport *t = NULL; | |
645 | struct sctp_transport *first; | |
646 | struct sctp_transport *second; | |
647 | struct sctp_ulpevent *event; | |
648 | struct list_head *pos; | |
649 | int spc_state = 0; | |
650 | ||
651 | /* Record the transition on the transport. */ | |
652 | switch (command) { | |
653 | case SCTP_TRANSPORT_UP: | |
3f7a87d2 | 654 | transport->state = SCTP_ACTIVE; |
1da177e4 LT |
655 | spc_state = SCTP_ADDR_AVAILABLE; |
656 | break; | |
657 | ||
658 | case SCTP_TRANSPORT_DOWN: | |
3f7a87d2 | 659 | transport->state = SCTP_INACTIVE; |
1da177e4 LT |
660 | spc_state = SCTP_ADDR_UNREACHABLE; |
661 | break; | |
662 | ||
663 | default: | |
664 | return; | |
665 | }; | |
666 | ||
667 | /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the | |
668 | * user. | |
669 | */ | |
670 | event = sctp_ulpevent_make_peer_addr_change(asoc, | |
671 | (struct sockaddr_storage *) &transport->ipaddr, | |
672 | 0, spc_state, error, GFP_ATOMIC); | |
673 | if (event) | |
674 | sctp_ulpq_tail_event(&asoc->ulpq, event); | |
675 | ||
676 | /* Select new active and retran paths. */ | |
677 | ||
678 | /* Look for the two most recently used active transports. | |
679 | * | |
680 | * This code produces the wrong ordering whenever jiffies | |
681 | * rolls over, but we still get usable transports, so we don't | |
682 | * worry about it. | |
683 | */ | |
684 | first = NULL; second = NULL; | |
685 | ||
686 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
687 | t = list_entry(pos, struct sctp_transport, transports); | |
688 | ||
3f7a87d2 | 689 | if (t->state == SCTP_INACTIVE) |
1da177e4 LT |
690 | continue; |
691 | if (!first || t->last_time_heard > first->last_time_heard) { | |
692 | second = first; | |
693 | first = t; | |
694 | } | |
695 | if (!second || t->last_time_heard > second->last_time_heard) | |
696 | second = t; | |
697 | } | |
698 | ||
699 | /* RFC 2960 6.4 Multi-Homed SCTP Endpoints | |
700 | * | |
701 | * By default, an endpoint should always transmit to the | |
702 | * primary path, unless the SCTP user explicitly specifies the | |
703 | * destination transport address (and possibly source | |
704 | * transport address) to use. | |
705 | * | |
706 | * [If the primary is active but not most recent, bump the most | |
707 | * recently used transport.] | |
708 | */ | |
3f7a87d2 | 709 | if (asoc->peer.primary_path->state != SCTP_INACTIVE && |
1da177e4 LT |
710 | first != asoc->peer.primary_path) { |
711 | second = first; | |
712 | first = asoc->peer.primary_path; | |
713 | } | |
714 | ||
715 | /* If we failed to find a usable transport, just camp on the | |
716 | * primary, even if it is inactive. | |
717 | */ | |
718 | if (!first) { | |
719 | first = asoc->peer.primary_path; | |
720 | second = asoc->peer.primary_path; | |
721 | } | |
722 | ||
723 | /* Set the active and retran transports. */ | |
724 | asoc->peer.active_path = first; | |
725 | asoc->peer.retran_path = second; | |
726 | } | |
727 | ||
728 | /* Hold a reference to an association. */ | |
729 | void sctp_association_hold(struct sctp_association *asoc) | |
730 | { | |
731 | atomic_inc(&asoc->base.refcnt); | |
732 | } | |
733 | ||
734 | /* Release a reference to an association and cleanup | |
735 | * if there are no more references. | |
736 | */ | |
737 | void sctp_association_put(struct sctp_association *asoc) | |
738 | { | |
739 | if (atomic_dec_and_test(&asoc->base.refcnt)) | |
740 | sctp_association_destroy(asoc); | |
741 | } | |
742 | ||
743 | /* Allocate the next TSN, Transmission Sequence Number, for the given | |
744 | * association. | |
745 | */ | |
746 | __u32 sctp_association_get_next_tsn(struct sctp_association *asoc) | |
747 | { | |
748 | /* From Section 1.6 Serial Number Arithmetic: | |
749 | * Transmission Sequence Numbers wrap around when they reach | |
750 | * 2**32 - 1. That is, the next TSN a DATA chunk MUST use | |
751 | * after transmitting TSN = 2*32 - 1 is TSN = 0. | |
752 | */ | |
753 | __u32 retval = asoc->next_tsn; | |
754 | asoc->next_tsn++; | |
755 | asoc->unack_data++; | |
756 | ||
757 | return retval; | |
758 | } | |
759 | ||
760 | /* Compare two addresses to see if they match. Wildcard addresses | |
761 | * only match themselves. | |
762 | */ | |
763 | int sctp_cmp_addr_exact(const union sctp_addr *ss1, | |
764 | const union sctp_addr *ss2) | |
765 | { | |
766 | struct sctp_af *af; | |
767 | ||
768 | af = sctp_get_af_specific(ss1->sa.sa_family); | |
769 | if (unlikely(!af)) | |
770 | return 0; | |
771 | ||
772 | return af->cmp_addr(ss1, ss2); | |
773 | } | |
774 | ||
775 | /* Return an ecne chunk to get prepended to a packet. | |
776 | * Note: We are sly and return a shared, prealloced chunk. FIXME: | |
777 | * No we don't, but we could/should. | |
778 | */ | |
779 | struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc) | |
780 | { | |
781 | struct sctp_chunk *chunk; | |
782 | ||
783 | /* Send ECNE if needed. | |
784 | * Not being able to allocate a chunk here is not deadly. | |
785 | */ | |
786 | if (asoc->need_ecne) | |
787 | chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn); | |
788 | else | |
789 | chunk = NULL; | |
790 | ||
791 | return chunk; | |
792 | } | |
793 | ||
794 | /* | |
795 | * Find which transport this TSN was sent on. | |
796 | */ | |
797 | struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc, | |
798 | __u32 tsn) | |
799 | { | |
800 | struct sctp_transport *active; | |
801 | struct sctp_transport *match; | |
802 | struct list_head *entry, *pos; | |
803 | struct sctp_transport *transport; | |
804 | struct sctp_chunk *chunk; | |
805 | __u32 key = htonl(tsn); | |
806 | ||
807 | match = NULL; | |
808 | ||
809 | /* | |
810 | * FIXME: In general, find a more efficient data structure for | |
811 | * searching. | |
812 | */ | |
813 | ||
814 | /* | |
815 | * The general strategy is to search each transport's transmitted | |
816 | * list. Return which transport this TSN lives on. | |
817 | * | |
818 | * Let's be hopeful and check the active_path first. | |
819 | * Another optimization would be to know if there is only one | |
820 | * outbound path and not have to look for the TSN at all. | |
821 | * | |
822 | */ | |
823 | ||
824 | active = asoc->peer.active_path; | |
825 | ||
826 | list_for_each(entry, &active->transmitted) { | |
827 | chunk = list_entry(entry, struct sctp_chunk, transmitted_list); | |
828 | ||
829 | if (key == chunk->subh.data_hdr->tsn) { | |
830 | match = active; | |
831 | goto out; | |
832 | } | |
833 | } | |
834 | ||
835 | /* If not found, go search all the other transports. */ | |
836 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
837 | transport = list_entry(pos, struct sctp_transport, transports); | |
838 | ||
839 | if (transport == active) | |
840 | break; | |
841 | list_for_each(entry, &transport->transmitted) { | |
842 | chunk = list_entry(entry, struct sctp_chunk, | |
843 | transmitted_list); | |
844 | if (key == chunk->subh.data_hdr->tsn) { | |
845 | match = transport; | |
846 | goto out; | |
847 | } | |
848 | } | |
849 | } | |
850 | out: | |
851 | return match; | |
852 | } | |
853 | ||
854 | /* Is this the association we are looking for? */ | |
855 | struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc, | |
856 | const union sctp_addr *laddr, | |
857 | const union sctp_addr *paddr) | |
858 | { | |
859 | struct sctp_transport *transport; | |
860 | ||
861 | sctp_read_lock(&asoc->base.addr_lock); | |
862 | ||
863 | if ((asoc->base.bind_addr.port == laddr->v4.sin_port) && | |
864 | (asoc->peer.port == paddr->v4.sin_port)) { | |
865 | transport = sctp_assoc_lookup_paddr(asoc, paddr); | |
866 | if (!transport) | |
867 | goto out; | |
868 | ||
869 | if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
870 | sctp_sk(asoc->base.sk))) | |
871 | goto out; | |
872 | } | |
873 | transport = NULL; | |
874 | ||
875 | out: | |
876 | sctp_read_unlock(&asoc->base.addr_lock); | |
877 | return transport; | |
878 | } | |
879 | ||
880 | /* Do delayed input processing. This is scheduled by sctp_rcv(). */ | |
881 | static void sctp_assoc_bh_rcv(struct sctp_association *asoc) | |
882 | { | |
883 | struct sctp_endpoint *ep; | |
884 | struct sctp_chunk *chunk; | |
885 | struct sock *sk; | |
886 | struct sctp_inq *inqueue; | |
887 | int state; | |
888 | sctp_subtype_t subtype; | |
889 | int error = 0; | |
890 | ||
891 | /* The association should be held so we should be safe. */ | |
892 | ep = asoc->ep; | |
893 | sk = asoc->base.sk; | |
894 | ||
895 | inqueue = &asoc->base.inqueue; | |
896 | sctp_association_hold(asoc); | |
897 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
898 | state = asoc->state; | |
899 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
900 | ||
901 | /* Remember where the last DATA chunk came from so we | |
902 | * know where to send the SACK. | |
903 | */ | |
904 | if (sctp_chunk_is_data(chunk)) | |
905 | asoc->peer.last_data_from = chunk->transport; | |
906 | else | |
907 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); | |
908 | ||
909 | if (chunk->transport) | |
910 | chunk->transport->last_time_heard = jiffies; | |
911 | ||
912 | /* Run through the state machine. */ | |
913 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, | |
914 | state, ep, asoc, chunk, GFP_ATOMIC); | |
915 | ||
916 | /* Check to see if the association is freed in response to | |
917 | * the incoming chunk. If so, get out of the while loop. | |
918 | */ | |
919 | if (asoc->base.dead) | |
920 | break; | |
921 | ||
922 | /* If there is an error on chunk, discard this packet. */ | |
923 | if (error && chunk) | |
924 | chunk->pdiscard = 1; | |
925 | } | |
926 | sctp_association_put(asoc); | |
927 | } | |
928 | ||
929 | /* This routine moves an association from its old sk to a new sk. */ | |
930 | void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk) | |
931 | { | |
932 | struct sctp_sock *newsp = sctp_sk(newsk); | |
933 | struct sock *oldsk = assoc->base.sk; | |
934 | ||
935 | /* Delete the association from the old endpoint's list of | |
936 | * associations. | |
937 | */ | |
938 | list_del_init(&assoc->asocs); | |
939 | ||
940 | /* Decrement the backlog value for a TCP-style socket. */ | |
941 | if (sctp_style(oldsk, TCP)) | |
942 | oldsk->sk_ack_backlog--; | |
943 | ||
944 | /* Release references to the old endpoint and the sock. */ | |
945 | sctp_endpoint_put(assoc->ep); | |
946 | sock_put(assoc->base.sk); | |
947 | ||
948 | /* Get a reference to the new endpoint. */ | |
949 | assoc->ep = newsp->ep; | |
950 | sctp_endpoint_hold(assoc->ep); | |
951 | ||
952 | /* Get a reference to the new sock. */ | |
953 | assoc->base.sk = newsk; | |
954 | sock_hold(assoc->base.sk); | |
955 | ||
956 | /* Add the association to the new endpoint's list of associations. */ | |
957 | sctp_endpoint_add_asoc(newsp->ep, assoc); | |
958 | } | |
959 | ||
960 | /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ | |
961 | void sctp_assoc_update(struct sctp_association *asoc, | |
962 | struct sctp_association *new) | |
963 | { | |
964 | struct sctp_transport *trans; | |
965 | struct list_head *pos, *temp; | |
966 | ||
967 | /* Copy in new parameters of peer. */ | |
968 | asoc->c = new->c; | |
969 | asoc->peer.rwnd = new->peer.rwnd; | |
970 | asoc->peer.sack_needed = new->peer.sack_needed; | |
971 | asoc->peer.i = new->peer.i; | |
972 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, | |
973 | asoc->peer.i.initial_tsn); | |
974 | ||
975 | /* Remove any peer addresses not present in the new association. */ | |
976 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
977 | trans = list_entry(pos, struct sctp_transport, transports); | |
978 | if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) | |
979 | sctp_assoc_del_peer(asoc, &trans->ipaddr); | |
980 | } | |
981 | ||
982 | /* If the case is A (association restart), use | |
983 | * initial_tsn as next_tsn. If the case is B, use | |
984 | * current next_tsn in case data sent to peer | |
985 | * has been discarded and needs retransmission. | |
986 | */ | |
987 | if (asoc->state >= SCTP_STATE_ESTABLISHED) { | |
988 | asoc->next_tsn = new->next_tsn; | |
989 | asoc->ctsn_ack_point = new->ctsn_ack_point; | |
990 | asoc->adv_peer_ack_point = new->adv_peer_ack_point; | |
991 | ||
992 | /* Reinitialize SSN for both local streams | |
993 | * and peer's streams. | |
994 | */ | |
995 | sctp_ssnmap_clear(asoc->ssnmap); | |
996 | ||
997 | } else { | |
998 | /* Add any peer addresses from the new association. */ | |
999 | list_for_each(pos, &new->peer.transport_addr_list) { | |
1000 | trans = list_entry(pos, struct sctp_transport, | |
1001 | transports); | |
1002 | if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr)) | |
1003 | sctp_assoc_add_peer(asoc, &trans->ipaddr, | |
3f7a87d2 | 1004 | GFP_ATOMIC, SCTP_ACTIVE); |
1da177e4 LT |
1005 | } |
1006 | ||
1007 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
1008 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
1009 | if (!asoc->ssnmap) { | |
1010 | /* Move the ssnmap. */ | |
1011 | asoc->ssnmap = new->ssnmap; | |
1012 | new->ssnmap = NULL; | |
1013 | } | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | /* Update the retran path for sending a retransmitted packet. | |
1018 | * Round-robin through the active transports, else round-robin | |
1019 | * through the inactive transports as this is the next best thing | |
1020 | * we can try. | |
1021 | */ | |
1022 | void sctp_assoc_update_retran_path(struct sctp_association *asoc) | |
1023 | { | |
1024 | struct sctp_transport *t, *next; | |
1025 | struct list_head *head = &asoc->peer.transport_addr_list; | |
1026 | struct list_head *pos; | |
1027 | ||
1028 | /* Find the next transport in a round-robin fashion. */ | |
1029 | t = asoc->peer.retran_path; | |
1030 | pos = &t->transports; | |
1031 | next = NULL; | |
1032 | ||
1033 | while (1) { | |
1034 | /* Skip the head. */ | |
1035 | if (pos->next == head) | |
1036 | pos = head->next; | |
1037 | else | |
1038 | pos = pos->next; | |
1039 | ||
1040 | t = list_entry(pos, struct sctp_transport, transports); | |
1041 | ||
1042 | /* Try to find an active transport. */ | |
1043 | ||
3f7a87d2 | 1044 | if (t->state != SCTP_INACTIVE) { |
1da177e4 LT |
1045 | break; |
1046 | } else { | |
1047 | /* Keep track of the next transport in case | |
1048 | * we don't find any active transport. | |
1049 | */ | |
1050 | if (!next) | |
1051 | next = t; | |
1052 | } | |
1053 | ||
1054 | /* We have exhausted the list, but didn't find any | |
1055 | * other active transports. If so, use the next | |
1056 | * transport. | |
1057 | */ | |
1058 | if (t == asoc->peer.retran_path) { | |
1059 | t = next; | |
1060 | break; | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | asoc->peer.retran_path = t; | |
3f7a87d2 FF |
1065 | |
1066 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" | |
1067 | " %p addr: ", | |
1068 | " port: %d\n", | |
1069 | asoc, | |
1070 | (&t->ipaddr), | |
1071 | t->ipaddr.v4.sin_port); | |
1072 | } | |
1073 | ||
1074 | /* Choose the transport for sending a INIT packet. */ | |
1075 | struct sctp_transport *sctp_assoc_choose_init_transport( | |
1076 | struct sctp_association *asoc) | |
1077 | { | |
1078 | struct sctp_transport *t; | |
1079 | ||
1080 | /* Use the retran path. If the last INIT was sent over the | |
1081 | * retran path, update the retran path and use it. | |
1082 | */ | |
1083 | if (!asoc->init_last_sent_to) { | |
1084 | t = asoc->peer.active_path; | |
1085 | } else { | |
1086 | if (asoc->init_last_sent_to == asoc->peer.retran_path) | |
1087 | sctp_assoc_update_retran_path(asoc); | |
1088 | t = asoc->peer.retran_path; | |
1089 | } | |
1090 | ||
1091 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" | |
1092 | " %p addr: ", | |
1093 | " port: %d\n", | |
1094 | asoc, | |
1095 | (&t->ipaddr), | |
1096 | t->ipaddr.v4.sin_port); | |
1097 | ||
1098 | return t; | |
1da177e4 LT |
1099 | } |
1100 | ||
1101 | /* Choose the transport for sending a SHUTDOWN packet. */ | |
1102 | struct sctp_transport *sctp_assoc_choose_shutdown_transport( | |
1103 | struct sctp_association *asoc) | |
1104 | { | |
1105 | /* If this is the first time SHUTDOWN is sent, use the active path, | |
1106 | * else use the retran path. If the last SHUTDOWN was sent over the | |
1107 | * retran path, update the retran path and use it. | |
1108 | */ | |
1109 | if (!asoc->shutdown_last_sent_to) | |
1110 | return asoc->peer.active_path; | |
1111 | else { | |
1112 | if (asoc->shutdown_last_sent_to == asoc->peer.retran_path) | |
1113 | sctp_assoc_update_retran_path(asoc); | |
1114 | return asoc->peer.retran_path; | |
1115 | } | |
1116 | ||
1117 | } | |
1118 | ||
1119 | /* Update the association's pmtu and frag_point by going through all the | |
1120 | * transports. This routine is called when a transport's PMTU has changed. | |
1121 | */ | |
1122 | void sctp_assoc_sync_pmtu(struct sctp_association *asoc) | |
1123 | { | |
1124 | struct sctp_transport *t; | |
1125 | struct list_head *pos; | |
1126 | __u32 pmtu = 0; | |
1127 | ||
1128 | if (!asoc) | |
1129 | return; | |
1130 | ||
1131 | /* Get the lowest pmtu of all the transports. */ | |
1132 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
1133 | t = list_entry(pos, struct sctp_transport, transports); | |
1134 | if (!pmtu || (t->pmtu < pmtu)) | |
1135 | pmtu = t->pmtu; | |
1136 | } | |
1137 | ||
1138 | if (pmtu) { | |
1139 | struct sctp_sock *sp = sctp_sk(asoc->base.sk); | |
1140 | asoc->pmtu = pmtu; | |
1141 | asoc->frag_point = sctp_frag_point(sp, pmtu); | |
1142 | } | |
1143 | ||
1144 | SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n", | |
1145 | __FUNCTION__, asoc, asoc->pmtu, asoc->frag_point); | |
1146 | } | |
1147 | ||
1148 | /* Should we send a SACK to update our peer? */ | |
1149 | static inline int sctp_peer_needs_update(struct sctp_association *asoc) | |
1150 | { | |
1151 | switch (asoc->state) { | |
1152 | case SCTP_STATE_ESTABLISHED: | |
1153 | case SCTP_STATE_SHUTDOWN_PENDING: | |
1154 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
1155 | case SCTP_STATE_SHUTDOWN_SENT: | |
1156 | if ((asoc->rwnd > asoc->a_rwnd) && | |
1157 | ((asoc->rwnd - asoc->a_rwnd) >= | |
1158 | min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pmtu))) | |
1159 | return 1; | |
1160 | break; | |
1161 | default: | |
1162 | break; | |
1163 | } | |
1164 | return 0; | |
1165 | } | |
1166 | ||
1167 | /* Increase asoc's rwnd by len and send any window update SACK if needed. */ | |
1168 | void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len) | |
1169 | { | |
1170 | struct sctp_chunk *sack; | |
1171 | struct timer_list *timer; | |
1172 | ||
1173 | if (asoc->rwnd_over) { | |
1174 | if (asoc->rwnd_over >= len) { | |
1175 | asoc->rwnd_over -= len; | |
1176 | } else { | |
1177 | asoc->rwnd += (len - asoc->rwnd_over); | |
1178 | asoc->rwnd_over = 0; | |
1179 | } | |
1180 | } else { | |
1181 | asoc->rwnd += len; | |
1182 | } | |
1183 | ||
1184 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) " | |
1185 | "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd, | |
1186 | asoc->rwnd_over, asoc->a_rwnd); | |
1187 | ||
1188 | /* Send a window update SACK if the rwnd has increased by at least the | |
1189 | * minimum of the association's PMTU and half of the receive buffer. | |
1190 | * The algorithm used is similar to the one described in | |
1191 | * Section 4.2.3.3 of RFC 1122. | |
1192 | */ | |
1193 | if (sctp_peer_needs_update(asoc)) { | |
1194 | asoc->a_rwnd = asoc->rwnd; | |
1195 | SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p " | |
1196 | "rwnd: %u a_rwnd: %u\n", __FUNCTION__, | |
1197 | asoc, asoc->rwnd, asoc->a_rwnd); | |
1198 | sack = sctp_make_sack(asoc); | |
1199 | if (!sack) | |
1200 | return; | |
1201 | ||
1202 | asoc->peer.sack_needed = 0; | |
1203 | ||
1204 | sctp_outq_tail(&asoc->outqueue, sack); | |
1205 | ||
1206 | /* Stop the SACK timer. */ | |
1207 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; | |
1208 | if (timer_pending(timer) && del_timer(timer)) | |
1209 | sctp_association_put(asoc); | |
1210 | } | |
1211 | } | |
1212 | ||
1213 | /* Decrease asoc's rwnd by len. */ | |
1214 | void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len) | |
1215 | { | |
1216 | SCTP_ASSERT(asoc->rwnd, "rwnd zero", return); | |
1217 | SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return); | |
1218 | if (asoc->rwnd >= len) { | |
1219 | asoc->rwnd -= len; | |
1220 | } else { | |
1221 | asoc->rwnd_over = len - asoc->rwnd; | |
1222 | asoc->rwnd = 0; | |
1223 | } | |
1224 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n", | |
1225 | __FUNCTION__, asoc, len, asoc->rwnd, | |
1226 | asoc->rwnd_over); | |
1227 | } | |
1228 | ||
1229 | /* Build the bind address list for the association based on info from the | |
1230 | * local endpoint and the remote peer. | |
1231 | */ | |
1232 | int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, int gfp) | |
1233 | { | |
1234 | sctp_scope_t scope; | |
1235 | int flags; | |
1236 | ||
1237 | /* Use scoping rules to determine the subset of addresses from | |
1238 | * the endpoint. | |
1239 | */ | |
1240 | scope = sctp_scope(&asoc->peer.active_path->ipaddr); | |
1241 | flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; | |
1242 | if (asoc->peer.ipv4_address) | |
1243 | flags |= SCTP_ADDR4_PEERSUPP; | |
1244 | if (asoc->peer.ipv6_address) | |
1245 | flags |= SCTP_ADDR6_PEERSUPP; | |
1246 | ||
1247 | return sctp_bind_addr_copy(&asoc->base.bind_addr, | |
1248 | &asoc->ep->base.bind_addr, | |
1249 | scope, gfp, flags); | |
1250 | } | |
1251 | ||
1252 | /* Build the association's bind address list from the cookie. */ | |
1253 | int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc, | |
1254 | struct sctp_cookie *cookie, int gfp) | |
1255 | { | |
1256 | int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); | |
1257 | int var_size3 = cookie->raw_addr_list_len; | |
1258 | __u8 *raw = (__u8 *)cookie->peer_init + var_size2; | |
1259 | ||
1260 | return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3, | |
1261 | asoc->ep->base.bind_addr.port, gfp); | |
1262 | } | |
1263 | ||
1264 | /* Lookup laddr in the bind address list of an association. */ | |
1265 | int sctp_assoc_lookup_laddr(struct sctp_association *asoc, | |
1266 | const union sctp_addr *laddr) | |
1267 | { | |
1268 | int found; | |
1269 | ||
1270 | sctp_read_lock(&asoc->base.addr_lock); | |
1271 | if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) && | |
1272 | sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
1273 | sctp_sk(asoc->base.sk))) { | |
1274 | found = 1; | |
1275 | goto out; | |
1276 | } | |
1277 | ||
1278 | found = 0; | |
1279 | out: | |
1280 | sctp_read_unlock(&asoc->base.addr_lock); | |
1281 | return found; | |
1282 | } |