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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. */ | |
c4028958 | 64 | static void sctp_assoc_bh_rcv(struct work_struct *work); |
1da177e4 LT |
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, | |
dd0fc66f | 74 | gfp_t gfp) |
1da177e4 LT |
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; | |
1da177e4 LT |
113 | asoc->frag_point = 0; |
114 | ||
115 | /* Set the association max_retrans and RTO values from the | |
116 | * socket values. | |
117 | */ | |
118 | asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt; | |
119 | asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial); | |
120 | asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max); | |
121 | asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min); | |
122 | ||
123 | asoc->overall_error_count = 0; | |
124 | ||
52ccb8e9 FF |
125 | /* Initialize the association's heartbeat interval based on the |
126 | * sock configured value. | |
127 | */ | |
128 | asoc->hbinterval = msecs_to_jiffies(sp->hbinterval); | |
129 | ||
130 | /* Initialize path max retrans value. */ | |
131 | asoc->pathmaxrxt = sp->pathmaxrxt; | |
132 | ||
133 | /* Initialize default path MTU. */ | |
134 | asoc->pathmtu = sp->pathmtu; | |
135 | ||
136 | /* Set association default SACK delay */ | |
137 | asoc->sackdelay = msecs_to_jiffies(sp->sackdelay); | |
138 | ||
139 | /* Set the association default flags controlling | |
140 | * Heartbeat, SACK delay, and Path MTU Discovery. | |
141 | */ | |
142 | asoc->param_flags = sp->param_flags; | |
143 | ||
1da177e4 LT |
144 | /* Initialize the maximum mumber of new data packets that can be sent |
145 | * in a burst. | |
146 | */ | |
147 | asoc->max_burst = sctp_max_burst; | |
148 | ||
1e7d3d90 VY |
149 | /* initialize association timers */ |
150 | asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0; | |
151 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial; | |
152 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial; | |
153 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial; | |
154 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0; | |
155 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0; | |
156 | ||
157 | /* sctpimpguide Section 2.12.2 | |
158 | * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the | |
159 | * recommended value of 5 times 'RTO.Max'. | |
160 | */ | |
161 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] | |
162 | = 5 * asoc->rto_max; | |
163 | ||
164 | asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0; | |
52ccb8e9 | 165 | asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay; |
1e7d3d90 VY |
166 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = |
167 | sp->autoclose * HZ; | |
168 | ||
169 | /* Initilizes the timers */ | |
1da177e4 | 170 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { |
1da177e4 LT |
171 | init_timer(&asoc->timers[i]); |
172 | asoc->timers[i].function = sctp_timer_events[i]; | |
173 | asoc->timers[i].data = (unsigned long) asoc; | |
174 | } | |
175 | ||
176 | /* Pull default initialization values from the sock options. | |
177 | * Note: This assumes that the values have already been | |
178 | * validated in the sock. | |
179 | */ | |
180 | asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; | |
181 | asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; | |
182 | asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; | |
183 | ||
184 | asoc->max_init_timeo = | |
185 | msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo); | |
186 | ||
187 | /* Allocate storage for the ssnmap after the inbound and outbound | |
188 | * streams have been negotiated during Init. | |
189 | */ | |
190 | asoc->ssnmap = NULL; | |
191 | ||
192 | /* Set the local window size for receive. | |
193 | * This is also the rcvbuf space per association. | |
194 | * RFC 6 - A SCTP receiver MUST be able to receive a minimum of | |
195 | * 1500 bytes in one SCTP packet. | |
196 | */ | |
049b3ff5 | 197 | if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW) |
1da177e4 LT |
198 | asoc->rwnd = SCTP_DEFAULT_MINWINDOW; |
199 | else | |
049b3ff5 | 200 | asoc->rwnd = sk->sk_rcvbuf/2; |
1da177e4 LT |
201 | |
202 | asoc->a_rwnd = asoc->rwnd; | |
203 | ||
204 | asoc->rwnd_over = 0; | |
205 | ||
206 | /* Use my own max window until I learn something better. */ | |
207 | asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; | |
208 | ||
209 | /* Set the sndbuf size for transmit. */ | |
210 | asoc->sndbuf_used = 0; | |
211 | ||
049b3ff5 NH |
212 | /* Initialize the receive memory counter */ |
213 | atomic_set(&asoc->rmem_alloc, 0); | |
214 | ||
1da177e4 LT |
215 | init_waitqueue_head(&asoc->wait); |
216 | ||
217 | asoc->c.my_vtag = sctp_generate_tag(ep); | |
218 | asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */ | |
219 | asoc->c.peer_vtag = 0; | |
220 | asoc->c.my_ttag = 0; | |
221 | asoc->c.peer_ttag = 0; | |
222 | asoc->c.my_port = ep->base.bind_addr.port; | |
223 | ||
224 | asoc->c.initial_tsn = sctp_generate_tsn(ep); | |
225 | ||
226 | asoc->next_tsn = asoc->c.initial_tsn; | |
227 | ||
228 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
229 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
230 | asoc->highest_sacked = asoc->ctsn_ack_point; | |
231 | asoc->last_cwr_tsn = asoc->ctsn_ack_point; | |
232 | asoc->unack_data = 0; | |
233 | ||
1da177e4 LT |
234 | /* ADDIP Section 4.1 Asconf Chunk Procedures |
235 | * | |
236 | * When an endpoint has an ASCONF signaled change to be sent to the | |
237 | * remote endpoint it should do the following: | |
238 | * ... | |
239 | * A2) a serial number should be assigned to the chunk. The serial | |
240 | * number SHOULD be a monotonically increasing number. The serial | |
241 | * numbers SHOULD be initialized at the start of the | |
242 | * association to the same value as the initial TSN. | |
243 | */ | |
244 | asoc->addip_serial = asoc->c.initial_tsn; | |
245 | ||
79af02c2 | 246 | INIT_LIST_HEAD(&asoc->addip_chunk_list); |
1da177e4 LT |
247 | |
248 | /* Make an empty list of remote transport addresses. */ | |
249 | INIT_LIST_HEAD(&asoc->peer.transport_addr_list); | |
3f7a87d2 | 250 | asoc->peer.transport_count = 0; |
1da177e4 LT |
251 | |
252 | /* RFC 2960 5.1 Normal Establishment of an Association | |
253 | * | |
254 | * After the reception of the first data chunk in an | |
255 | * association the endpoint must immediately respond with a | |
256 | * sack to acknowledge the data chunk. Subsequent | |
257 | * acknowledgements should be done as described in Section | |
258 | * 6.2. | |
259 | * | |
260 | * [We implement this by telling a new association that it | |
261 | * already received one packet.] | |
262 | */ | |
263 | asoc->peer.sack_needed = 1; | |
264 | ||
265 | /* Assume that the peer recongizes ASCONF until reported otherwise | |
266 | * via an ERROR chunk. | |
267 | */ | |
268 | asoc->peer.asconf_capable = 1; | |
269 | ||
270 | /* Create an input queue. */ | |
271 | sctp_inq_init(&asoc->base.inqueue); | |
c4028958 | 272 | sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv); |
1da177e4 LT |
273 | |
274 | /* Create an output queue. */ | |
275 | sctp_outq_init(asoc, &asoc->outqueue); | |
276 | ||
277 | if (!sctp_ulpq_init(&asoc->ulpq, asoc)) | |
278 | goto fail_init; | |
279 | ||
280 | /* Set up the tsn tracking. */ | |
281 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0); | |
282 | ||
283 | asoc->need_ecne = 0; | |
284 | ||
285 | asoc->assoc_id = 0; | |
286 | ||
287 | /* Assume that peer would support both address types unless we are | |
288 | * told otherwise. | |
289 | */ | |
290 | asoc->peer.ipv4_address = 1; | |
291 | asoc->peer.ipv6_address = 1; | |
292 | INIT_LIST_HEAD(&asoc->asocs); | |
293 | ||
294 | asoc->autoclose = sp->autoclose; | |
295 | ||
296 | asoc->default_stream = sp->default_stream; | |
297 | asoc->default_ppid = sp->default_ppid; | |
298 | asoc->default_flags = sp->default_flags; | |
299 | asoc->default_context = sp->default_context; | |
300 | asoc->default_timetolive = sp->default_timetolive; | |
301 | ||
302 | return asoc; | |
303 | ||
304 | fail_init: | |
305 | sctp_endpoint_put(asoc->ep); | |
306 | sock_put(asoc->base.sk); | |
307 | return NULL; | |
308 | } | |
309 | ||
310 | /* Allocate and initialize a new association */ | |
311 | struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep, | |
312 | const struct sock *sk, | |
3182cd84 | 313 | sctp_scope_t scope, |
dd0fc66f | 314 | gfp_t gfp) |
1da177e4 LT |
315 | { |
316 | struct sctp_association *asoc; | |
317 | ||
318 | asoc = t_new(struct sctp_association, gfp); | |
319 | if (!asoc) | |
320 | goto fail; | |
321 | ||
322 | if (!sctp_association_init(asoc, ep, sk, scope, gfp)) | |
323 | goto fail_init; | |
324 | ||
325 | asoc->base.malloced = 1; | |
326 | SCTP_DBG_OBJCNT_INC(assoc); | |
3f7a87d2 | 327 | SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc); |
1da177e4 LT |
328 | |
329 | return asoc; | |
330 | ||
331 | fail_init: | |
332 | kfree(asoc); | |
333 | fail: | |
334 | return NULL; | |
335 | } | |
336 | ||
337 | /* Free this association if possible. There may still be users, so | |
338 | * the actual deallocation may be delayed. | |
339 | */ | |
340 | void sctp_association_free(struct sctp_association *asoc) | |
341 | { | |
342 | struct sock *sk = asoc->base.sk; | |
343 | struct sctp_transport *transport; | |
344 | struct list_head *pos, *temp; | |
345 | int i; | |
346 | ||
de76e695 VY |
347 | /* Only real associations count against the endpoint, so |
348 | * don't bother for if this is a temporary association. | |
349 | */ | |
350 | if (!asoc->temp) { | |
351 | list_del(&asoc->asocs); | |
352 | ||
353 | /* Decrement the backlog value for a TCP-style listening | |
354 | * socket. | |
355 | */ | |
356 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
357 | sk->sk_ack_backlog--; | |
358 | } | |
1da177e4 LT |
359 | |
360 | /* Mark as dead, so other users can know this structure is | |
361 | * going away. | |
362 | */ | |
363 | asoc->base.dead = 1; | |
364 | ||
365 | /* Dispose of any data lying around in the outqueue. */ | |
366 | sctp_outq_free(&asoc->outqueue); | |
367 | ||
368 | /* Dispose of any pending messages for the upper layer. */ | |
369 | sctp_ulpq_free(&asoc->ulpq); | |
370 | ||
371 | /* Dispose of any pending chunks on the inqueue. */ | |
372 | sctp_inq_free(&asoc->base.inqueue); | |
373 | ||
374 | /* Free ssnmap storage. */ | |
375 | sctp_ssnmap_free(asoc->ssnmap); | |
376 | ||
377 | /* Clean up the bound address list. */ | |
378 | sctp_bind_addr_free(&asoc->base.bind_addr); | |
379 | ||
380 | /* Do we need to go through all of our timers and | |
381 | * delete them? To be safe we will try to delete all, but we | |
382 | * should be able to go through and make a guess based | |
383 | * on our state. | |
384 | */ | |
385 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { | |
386 | if (timer_pending(&asoc->timers[i]) && | |
387 | del_timer(&asoc->timers[i])) | |
388 | sctp_association_put(asoc); | |
389 | } | |
390 | ||
391 | /* Free peer's cached cookie. */ | |
a51482bd | 392 | kfree(asoc->peer.cookie); |
1da177e4 LT |
393 | |
394 | /* Release the transport structures. */ | |
395 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
396 | transport = list_entry(pos, struct sctp_transport, transports); | |
397 | list_del(pos); | |
398 | sctp_transport_free(transport); | |
399 | } | |
400 | ||
3f7a87d2 FF |
401 | asoc->peer.transport_count = 0; |
402 | ||
1da177e4 LT |
403 | /* Free any cached ASCONF_ACK chunk. */ |
404 | if (asoc->addip_last_asconf_ack) | |
405 | sctp_chunk_free(asoc->addip_last_asconf_ack); | |
406 | ||
407 | /* Free any cached ASCONF chunk. */ | |
408 | if (asoc->addip_last_asconf) | |
409 | sctp_chunk_free(asoc->addip_last_asconf); | |
410 | ||
411 | sctp_association_put(asoc); | |
412 | } | |
413 | ||
414 | /* Cleanup and free up an association. */ | |
415 | static void sctp_association_destroy(struct sctp_association *asoc) | |
416 | { | |
417 | SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return); | |
418 | ||
419 | sctp_endpoint_put(asoc->ep); | |
420 | sock_put(asoc->base.sk); | |
421 | ||
422 | if (asoc->assoc_id != 0) { | |
423 | spin_lock_bh(&sctp_assocs_id_lock); | |
424 | idr_remove(&sctp_assocs_id, asoc->assoc_id); | |
425 | spin_unlock_bh(&sctp_assocs_id_lock); | |
426 | } | |
427 | ||
049b3ff5 NH |
428 | BUG_TRAP(!atomic_read(&asoc->rmem_alloc)); |
429 | ||
1da177e4 LT |
430 | if (asoc->base.malloced) { |
431 | kfree(asoc); | |
432 | SCTP_DBG_OBJCNT_DEC(assoc); | |
433 | } | |
434 | } | |
435 | ||
436 | /* Change the primary destination address for the peer. */ | |
437 | void sctp_assoc_set_primary(struct sctp_association *asoc, | |
438 | struct sctp_transport *transport) | |
439 | { | |
440 | asoc->peer.primary_path = transport; | |
441 | ||
442 | /* Set a default msg_name for events. */ | |
443 | memcpy(&asoc->peer.primary_addr, &transport->ipaddr, | |
444 | sizeof(union sctp_addr)); | |
445 | ||
446 | /* If the primary path is changing, assume that the | |
447 | * user wants to use this new path. | |
448 | */ | |
ad8fec17 SS |
449 | if ((transport->state == SCTP_ACTIVE) || |
450 | (transport->state == SCTP_UNKNOWN)) | |
1da177e4 LT |
451 | asoc->peer.active_path = transport; |
452 | ||
453 | /* | |
454 | * SFR-CACC algorithm: | |
455 | * Upon the receipt of a request to change the primary | |
456 | * destination address, on the data structure for the new | |
457 | * primary destination, the sender MUST do the following: | |
458 | * | |
459 | * 1) If CHANGEOVER_ACTIVE is set, then there was a switch | |
460 | * to this destination address earlier. The sender MUST set | |
461 | * CYCLING_CHANGEOVER to indicate that this switch is a | |
462 | * double switch to the same destination address. | |
463 | */ | |
464 | if (transport->cacc.changeover_active) | |
465 | transport->cacc.cycling_changeover = 1; | |
466 | ||
467 | /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that | |
468 | * a changeover has occurred. | |
469 | */ | |
470 | transport->cacc.changeover_active = 1; | |
471 | ||
472 | /* 3) The sender MUST store the next TSN to be sent in | |
473 | * next_tsn_at_change. | |
474 | */ | |
475 | transport->cacc.next_tsn_at_change = asoc->next_tsn; | |
476 | } | |
477 | ||
3f7a87d2 FF |
478 | /* Remove a transport from an association. */ |
479 | void sctp_assoc_rm_peer(struct sctp_association *asoc, | |
480 | struct sctp_transport *peer) | |
481 | { | |
482 | struct list_head *pos; | |
483 | struct sctp_transport *transport; | |
484 | ||
485 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ", | |
486 | " port: %d\n", | |
487 | asoc, | |
488 | (&peer->ipaddr), | |
489 | peer->ipaddr.v4.sin_port); | |
490 | ||
491 | /* If we are to remove the current retran_path, update it | |
492 | * to the next peer before removing this peer from the list. | |
493 | */ | |
494 | if (asoc->peer.retran_path == peer) | |
495 | sctp_assoc_update_retran_path(asoc); | |
496 | ||
497 | /* Remove this peer from the list. */ | |
498 | list_del(&peer->transports); | |
499 | ||
500 | /* Get the first transport of asoc. */ | |
501 | pos = asoc->peer.transport_addr_list.next; | |
502 | transport = list_entry(pos, struct sctp_transport, transports); | |
503 | ||
504 | /* Update any entries that match the peer to be deleted. */ | |
505 | if (asoc->peer.primary_path == peer) | |
506 | sctp_assoc_set_primary(asoc, transport); | |
507 | if (asoc->peer.active_path == peer) | |
508 | asoc->peer.active_path = transport; | |
509 | if (asoc->peer.last_data_from == peer) | |
510 | asoc->peer.last_data_from = transport; | |
511 | ||
512 | /* If we remove the transport an INIT was last sent to, set it to | |
513 | * NULL. Combined with the update of the retran path above, this | |
514 | * will cause the next INIT to be sent to the next available | |
515 | * transport, maintaining the cycle. | |
516 | */ | |
517 | if (asoc->init_last_sent_to == peer) | |
518 | asoc->init_last_sent_to = NULL; | |
519 | ||
520 | asoc->peer.transport_count--; | |
521 | ||
522 | sctp_transport_free(peer); | |
523 | } | |
524 | ||
1da177e4 LT |
525 | /* Add a transport address to an association. */ |
526 | struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, | |
527 | const union sctp_addr *addr, | |
dd0fc66f | 528 | const gfp_t gfp, |
3f7a87d2 | 529 | const int peer_state) |
1da177e4 LT |
530 | { |
531 | struct sctp_transport *peer; | |
532 | struct sctp_sock *sp; | |
533 | unsigned short port; | |
534 | ||
535 | sp = sctp_sk(asoc->base.sk); | |
536 | ||
537 | /* AF_INET and AF_INET6 share common port field. */ | |
538 | port = addr->v4.sin_port; | |
539 | ||
3f7a87d2 | 540 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ", |
ad8fec17 | 541 | " port: %d state:%d\n", |
3f7a87d2 FF |
542 | asoc, |
543 | addr, | |
544 | addr->v4.sin_port, | |
ad8fec17 | 545 | peer_state); |
3f7a87d2 | 546 | |
1da177e4 LT |
547 | /* Set the port if it has not been set yet. */ |
548 | if (0 == asoc->peer.port) | |
549 | asoc->peer.port = port; | |
550 | ||
551 | /* Check to see if this is a duplicate. */ | |
552 | peer = sctp_assoc_lookup_paddr(asoc, addr); | |
3f7a87d2 | 553 | if (peer) { |
ad8fec17 SS |
554 | if (peer->state == SCTP_UNKNOWN) { |
555 | if (peer_state == SCTP_ACTIVE) | |
556 | peer->state = SCTP_ACTIVE; | |
557 | if (peer_state == SCTP_UNCONFIRMED) | |
558 | peer->state = SCTP_UNCONFIRMED; | |
559 | } | |
1da177e4 | 560 | return peer; |
3f7a87d2 | 561 | } |
1da177e4 LT |
562 | |
563 | peer = sctp_transport_new(addr, gfp); | |
564 | if (!peer) | |
565 | return NULL; | |
566 | ||
567 | sctp_transport_set_owner(peer, asoc); | |
568 | ||
52ccb8e9 FF |
569 | /* Initialize the peer's heartbeat interval based on the |
570 | * association configured value. | |
571 | */ | |
572 | peer->hbinterval = asoc->hbinterval; | |
573 | ||
574 | /* Set the path max_retrans. */ | |
575 | peer->pathmaxrxt = asoc->pathmaxrxt; | |
576 | ||
577 | /* Initialize the peer's SACK delay timeout based on the | |
578 | * association configured value. | |
579 | */ | |
580 | peer->sackdelay = asoc->sackdelay; | |
581 | ||
582 | /* Enable/disable heartbeat, SACK delay, and path MTU discovery | |
583 | * based on association setting. | |
584 | */ | |
585 | peer->param_flags = asoc->param_flags; | |
586 | ||
1da177e4 | 587 | /* Initialize the pmtu of the transport. */ |
52ccb8e9 FF |
588 | if (peer->param_flags & SPP_PMTUD_ENABLE) |
589 | sctp_transport_pmtu(peer); | |
590 | else if (asoc->pathmtu) | |
591 | peer->pathmtu = asoc->pathmtu; | |
592 | else | |
593 | peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT; | |
1da177e4 LT |
594 | |
595 | /* If this is the first transport addr on this association, | |
596 | * initialize the association PMTU to the peer's PMTU. | |
597 | * If not and the current association PMTU is higher than the new | |
598 | * peer's PMTU, reset the association PMTU to the new peer's PMTU. | |
599 | */ | |
52ccb8e9 FF |
600 | if (asoc->pathmtu) |
601 | asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu); | |
1da177e4 | 602 | else |
52ccb8e9 | 603 | asoc->pathmtu = peer->pathmtu; |
1da177e4 LT |
604 | |
605 | SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to " | |
52ccb8e9 | 606 | "%d\n", asoc, asoc->pathmtu); |
1da177e4 | 607 | |
52ccb8e9 | 608 | asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu); |
1da177e4 LT |
609 | |
610 | /* The asoc->peer.port might not be meaningful yet, but | |
611 | * initialize the packet structure anyway. | |
612 | */ | |
613 | sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port, | |
614 | asoc->peer.port); | |
615 | ||
616 | /* 7.2.1 Slow-Start | |
617 | * | |
618 | * o The initial cwnd before DATA transmission or after a sufficiently | |
619 | * long idle period MUST be set to | |
620 | * min(4*MTU, max(2*MTU, 4380 bytes)) | |
621 | * | |
622 | * o The initial value of ssthresh MAY be arbitrarily high | |
623 | * (for example, implementations MAY use the size of the | |
624 | * receiver advertised window). | |
625 | */ | |
52ccb8e9 | 626 | peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); |
1da177e4 LT |
627 | |
628 | /* At this point, we may not have the receiver's advertised window, | |
629 | * so initialize ssthresh to the default value and it will be set | |
630 | * later when we process the INIT. | |
631 | */ | |
632 | peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; | |
633 | ||
634 | peer->partial_bytes_acked = 0; | |
635 | peer->flight_size = 0; | |
636 | ||
1da177e4 LT |
637 | /* Set the transport's RTO.initial value */ |
638 | peer->rto = asoc->rto_initial; | |
639 | ||
3f7a87d2 FF |
640 | /* Set the peer's active state. */ |
641 | peer->state = peer_state; | |
642 | ||
1da177e4 LT |
643 | /* Attach the remote transport to our asoc. */ |
644 | list_add_tail(&peer->transports, &asoc->peer.transport_addr_list); | |
3f7a87d2 | 645 | asoc->peer.transport_count++; |
1da177e4 LT |
646 | |
647 | /* If we do not yet have a primary path, set one. */ | |
648 | if (!asoc->peer.primary_path) { | |
649 | sctp_assoc_set_primary(asoc, peer); | |
650 | asoc->peer.retran_path = peer; | |
651 | } | |
652 | ||
3f7a87d2 | 653 | if (asoc->peer.active_path == asoc->peer.retran_path) { |
1da177e4 | 654 | asoc->peer.retran_path = peer; |
3f7a87d2 | 655 | } |
1da177e4 LT |
656 | |
657 | return peer; | |
658 | } | |
659 | ||
660 | /* Delete a transport address from an association. */ | |
661 | void sctp_assoc_del_peer(struct sctp_association *asoc, | |
662 | const union sctp_addr *addr) | |
663 | { | |
664 | struct list_head *pos; | |
665 | struct list_head *temp; | |
1da177e4 LT |
666 | struct sctp_transport *transport; |
667 | ||
668 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
669 | transport = list_entry(pos, struct sctp_transport, transports); | |
670 | if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) { | |
3f7a87d2 FF |
671 | /* Do book keeping for removing the peer and free it. */ |
672 | sctp_assoc_rm_peer(asoc, transport); | |
1da177e4 LT |
673 | break; |
674 | } | |
675 | } | |
1da177e4 LT |
676 | } |
677 | ||
678 | /* Lookup a transport by address. */ | |
679 | struct sctp_transport *sctp_assoc_lookup_paddr( | |
680 | const struct sctp_association *asoc, | |
681 | const union sctp_addr *address) | |
682 | { | |
683 | struct sctp_transport *t; | |
684 | struct list_head *pos; | |
685 | ||
686 | /* Cycle through all transports searching for a peer address. */ | |
687 | ||
688 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
689 | t = list_entry(pos, struct sctp_transport, transports); | |
690 | if (sctp_cmp_addr_exact(address, &t->ipaddr)) | |
691 | return t; | |
692 | } | |
693 | ||
694 | return NULL; | |
695 | } | |
696 | ||
697 | /* Engage in transport control operations. | |
698 | * Mark the transport up or down and send a notification to the user. | |
699 | * Select and update the new active and retran paths. | |
700 | */ | |
701 | void sctp_assoc_control_transport(struct sctp_association *asoc, | |
702 | struct sctp_transport *transport, | |
703 | sctp_transport_cmd_t command, | |
704 | sctp_sn_error_t error) | |
705 | { | |
706 | struct sctp_transport *t = NULL; | |
707 | struct sctp_transport *first; | |
708 | struct sctp_transport *second; | |
709 | struct sctp_ulpevent *event; | |
710 | struct list_head *pos; | |
711 | int spc_state = 0; | |
712 | ||
713 | /* Record the transition on the transport. */ | |
714 | switch (command) { | |
715 | case SCTP_TRANSPORT_UP: | |
3f7a87d2 | 716 | transport->state = SCTP_ACTIVE; |
1da177e4 LT |
717 | spc_state = SCTP_ADDR_AVAILABLE; |
718 | break; | |
719 | ||
720 | case SCTP_TRANSPORT_DOWN: | |
3f7a87d2 | 721 | transport->state = SCTP_INACTIVE; |
1da177e4 LT |
722 | spc_state = SCTP_ADDR_UNREACHABLE; |
723 | break; | |
724 | ||
725 | default: | |
726 | return; | |
727 | }; | |
728 | ||
729 | /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the | |
730 | * user. | |
731 | */ | |
732 | event = sctp_ulpevent_make_peer_addr_change(asoc, | |
733 | (struct sockaddr_storage *) &transport->ipaddr, | |
734 | 0, spc_state, error, GFP_ATOMIC); | |
735 | if (event) | |
736 | sctp_ulpq_tail_event(&asoc->ulpq, event); | |
737 | ||
738 | /* Select new active and retran paths. */ | |
739 | ||
740 | /* Look for the two most recently used active transports. | |
741 | * | |
742 | * This code produces the wrong ordering whenever jiffies | |
743 | * rolls over, but we still get usable transports, so we don't | |
744 | * worry about it. | |
745 | */ | |
746 | first = NULL; second = NULL; | |
747 | ||
748 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
749 | t = list_entry(pos, struct sctp_transport, transports); | |
750 | ||
ad8fec17 SS |
751 | if ((t->state == SCTP_INACTIVE) || |
752 | (t->state == SCTP_UNCONFIRMED)) | |
1da177e4 LT |
753 | continue; |
754 | if (!first || t->last_time_heard > first->last_time_heard) { | |
755 | second = first; | |
756 | first = t; | |
757 | } | |
758 | if (!second || t->last_time_heard > second->last_time_heard) | |
759 | second = t; | |
760 | } | |
761 | ||
762 | /* RFC 2960 6.4 Multi-Homed SCTP Endpoints | |
763 | * | |
764 | * By default, an endpoint should always transmit to the | |
765 | * primary path, unless the SCTP user explicitly specifies the | |
766 | * destination transport address (and possibly source | |
767 | * transport address) to use. | |
768 | * | |
769 | * [If the primary is active but not most recent, bump the most | |
770 | * recently used transport.] | |
771 | */ | |
ad8fec17 SS |
772 | if (((asoc->peer.primary_path->state == SCTP_ACTIVE) || |
773 | (asoc->peer.primary_path->state == SCTP_UNKNOWN)) && | |
1da177e4 LT |
774 | first != asoc->peer.primary_path) { |
775 | second = first; | |
776 | first = asoc->peer.primary_path; | |
777 | } | |
778 | ||
779 | /* If we failed to find a usable transport, just camp on the | |
780 | * primary, even if it is inactive. | |
781 | */ | |
782 | if (!first) { | |
783 | first = asoc->peer.primary_path; | |
784 | second = asoc->peer.primary_path; | |
785 | } | |
786 | ||
787 | /* Set the active and retran transports. */ | |
788 | asoc->peer.active_path = first; | |
789 | asoc->peer.retran_path = second; | |
790 | } | |
791 | ||
792 | /* Hold a reference to an association. */ | |
793 | void sctp_association_hold(struct sctp_association *asoc) | |
794 | { | |
795 | atomic_inc(&asoc->base.refcnt); | |
796 | } | |
797 | ||
798 | /* Release a reference to an association and cleanup | |
799 | * if there are no more references. | |
800 | */ | |
801 | void sctp_association_put(struct sctp_association *asoc) | |
802 | { | |
803 | if (atomic_dec_and_test(&asoc->base.refcnt)) | |
804 | sctp_association_destroy(asoc); | |
805 | } | |
806 | ||
807 | /* Allocate the next TSN, Transmission Sequence Number, for the given | |
808 | * association. | |
809 | */ | |
810 | __u32 sctp_association_get_next_tsn(struct sctp_association *asoc) | |
811 | { | |
812 | /* From Section 1.6 Serial Number Arithmetic: | |
813 | * Transmission Sequence Numbers wrap around when they reach | |
814 | * 2**32 - 1. That is, the next TSN a DATA chunk MUST use | |
815 | * after transmitting TSN = 2*32 - 1 is TSN = 0. | |
816 | */ | |
817 | __u32 retval = asoc->next_tsn; | |
818 | asoc->next_tsn++; | |
819 | asoc->unack_data++; | |
820 | ||
821 | return retval; | |
822 | } | |
823 | ||
824 | /* Compare two addresses to see if they match. Wildcard addresses | |
825 | * only match themselves. | |
826 | */ | |
827 | int sctp_cmp_addr_exact(const union sctp_addr *ss1, | |
828 | const union sctp_addr *ss2) | |
829 | { | |
830 | struct sctp_af *af; | |
831 | ||
832 | af = sctp_get_af_specific(ss1->sa.sa_family); | |
833 | if (unlikely(!af)) | |
834 | return 0; | |
835 | ||
836 | return af->cmp_addr(ss1, ss2); | |
837 | } | |
838 | ||
839 | /* Return an ecne chunk to get prepended to a packet. | |
840 | * Note: We are sly and return a shared, prealloced chunk. FIXME: | |
841 | * No we don't, but we could/should. | |
842 | */ | |
843 | struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc) | |
844 | { | |
845 | struct sctp_chunk *chunk; | |
846 | ||
847 | /* Send ECNE if needed. | |
848 | * Not being able to allocate a chunk here is not deadly. | |
849 | */ | |
850 | if (asoc->need_ecne) | |
851 | chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn); | |
852 | else | |
853 | chunk = NULL; | |
854 | ||
855 | return chunk; | |
856 | } | |
857 | ||
858 | /* | |
859 | * Find which transport this TSN was sent on. | |
860 | */ | |
861 | struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc, | |
862 | __u32 tsn) | |
863 | { | |
864 | struct sctp_transport *active; | |
865 | struct sctp_transport *match; | |
866 | struct list_head *entry, *pos; | |
867 | struct sctp_transport *transport; | |
868 | struct sctp_chunk *chunk; | |
869 | __u32 key = htonl(tsn); | |
870 | ||
871 | match = NULL; | |
872 | ||
873 | /* | |
874 | * FIXME: In general, find a more efficient data structure for | |
875 | * searching. | |
876 | */ | |
877 | ||
878 | /* | |
879 | * The general strategy is to search each transport's transmitted | |
880 | * list. Return which transport this TSN lives on. | |
881 | * | |
882 | * Let's be hopeful and check the active_path first. | |
883 | * Another optimization would be to know if there is only one | |
884 | * outbound path and not have to look for the TSN at all. | |
885 | * | |
886 | */ | |
887 | ||
888 | active = asoc->peer.active_path; | |
889 | ||
890 | list_for_each(entry, &active->transmitted) { | |
891 | chunk = list_entry(entry, struct sctp_chunk, transmitted_list); | |
892 | ||
893 | if (key == chunk->subh.data_hdr->tsn) { | |
894 | match = active; | |
895 | goto out; | |
896 | } | |
897 | } | |
898 | ||
899 | /* If not found, go search all the other transports. */ | |
900 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
901 | transport = list_entry(pos, struct sctp_transport, transports); | |
902 | ||
903 | if (transport == active) | |
904 | break; | |
905 | list_for_each(entry, &transport->transmitted) { | |
906 | chunk = list_entry(entry, struct sctp_chunk, | |
907 | transmitted_list); | |
908 | if (key == chunk->subh.data_hdr->tsn) { | |
909 | match = transport; | |
910 | goto out; | |
911 | } | |
912 | } | |
913 | } | |
914 | out: | |
915 | return match; | |
916 | } | |
917 | ||
918 | /* Is this the association we are looking for? */ | |
919 | struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc, | |
920 | const union sctp_addr *laddr, | |
921 | const union sctp_addr *paddr) | |
922 | { | |
923 | struct sctp_transport *transport; | |
924 | ||
925 | sctp_read_lock(&asoc->base.addr_lock); | |
926 | ||
927 | if ((asoc->base.bind_addr.port == laddr->v4.sin_port) && | |
928 | (asoc->peer.port == paddr->v4.sin_port)) { | |
929 | transport = sctp_assoc_lookup_paddr(asoc, paddr); | |
930 | if (!transport) | |
931 | goto out; | |
932 | ||
933 | if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
934 | sctp_sk(asoc->base.sk))) | |
935 | goto out; | |
936 | } | |
937 | transport = NULL; | |
938 | ||
939 | out: | |
940 | sctp_read_unlock(&asoc->base.addr_lock); | |
941 | return transport; | |
942 | } | |
943 | ||
944 | /* Do delayed input processing. This is scheduled by sctp_rcv(). */ | |
c4028958 | 945 | static void sctp_assoc_bh_rcv(struct work_struct *work) |
1da177e4 | 946 | { |
c4028958 DH |
947 | struct sctp_association *asoc = |
948 | container_of(work, struct sctp_association, | |
949 | base.inqueue.immediate); | |
1da177e4 LT |
950 | struct sctp_endpoint *ep; |
951 | struct sctp_chunk *chunk; | |
952 | struct sock *sk; | |
953 | struct sctp_inq *inqueue; | |
954 | int state; | |
955 | sctp_subtype_t subtype; | |
956 | int error = 0; | |
957 | ||
958 | /* The association should be held so we should be safe. */ | |
959 | ep = asoc->ep; | |
960 | sk = asoc->base.sk; | |
961 | ||
962 | inqueue = &asoc->base.inqueue; | |
963 | sctp_association_hold(asoc); | |
964 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
965 | state = asoc->state; | |
966 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
967 | ||
968 | /* Remember where the last DATA chunk came from so we | |
969 | * know where to send the SACK. | |
970 | */ | |
971 | if (sctp_chunk_is_data(chunk)) | |
972 | asoc->peer.last_data_from = chunk->transport; | |
973 | else | |
974 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); | |
975 | ||
976 | if (chunk->transport) | |
977 | chunk->transport->last_time_heard = jiffies; | |
978 | ||
979 | /* Run through the state machine. */ | |
980 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, | |
981 | state, ep, asoc, chunk, GFP_ATOMIC); | |
982 | ||
983 | /* Check to see if the association is freed in response to | |
984 | * the incoming chunk. If so, get out of the while loop. | |
985 | */ | |
986 | if (asoc->base.dead) | |
987 | break; | |
988 | ||
989 | /* If there is an error on chunk, discard this packet. */ | |
990 | if (error && chunk) | |
991 | chunk->pdiscard = 1; | |
992 | } | |
993 | sctp_association_put(asoc); | |
994 | } | |
995 | ||
996 | /* This routine moves an association from its old sk to a new sk. */ | |
997 | void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk) | |
998 | { | |
999 | struct sctp_sock *newsp = sctp_sk(newsk); | |
1000 | struct sock *oldsk = assoc->base.sk; | |
1001 | ||
1002 | /* Delete the association from the old endpoint's list of | |
1003 | * associations. | |
1004 | */ | |
1005 | list_del_init(&assoc->asocs); | |
1006 | ||
1007 | /* Decrement the backlog value for a TCP-style socket. */ | |
1008 | if (sctp_style(oldsk, TCP)) | |
1009 | oldsk->sk_ack_backlog--; | |
1010 | ||
1011 | /* Release references to the old endpoint and the sock. */ | |
1012 | sctp_endpoint_put(assoc->ep); | |
1013 | sock_put(assoc->base.sk); | |
1014 | ||
1015 | /* Get a reference to the new endpoint. */ | |
1016 | assoc->ep = newsp->ep; | |
1017 | sctp_endpoint_hold(assoc->ep); | |
1018 | ||
1019 | /* Get a reference to the new sock. */ | |
1020 | assoc->base.sk = newsk; | |
1021 | sock_hold(assoc->base.sk); | |
1022 | ||
1023 | /* Add the association to the new endpoint's list of associations. */ | |
1024 | sctp_endpoint_add_asoc(newsp->ep, assoc); | |
1025 | } | |
1026 | ||
1027 | /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ | |
1028 | void sctp_assoc_update(struct sctp_association *asoc, | |
1029 | struct sctp_association *new) | |
1030 | { | |
1031 | struct sctp_transport *trans; | |
1032 | struct list_head *pos, *temp; | |
1033 | ||
1034 | /* Copy in new parameters of peer. */ | |
1035 | asoc->c = new->c; | |
1036 | asoc->peer.rwnd = new->peer.rwnd; | |
1037 | asoc->peer.sack_needed = new->peer.sack_needed; | |
1038 | asoc->peer.i = new->peer.i; | |
1039 | sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, | |
1040 | asoc->peer.i.initial_tsn); | |
1041 | ||
1042 | /* Remove any peer addresses not present in the new association. */ | |
1043 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
1044 | trans = list_entry(pos, struct sctp_transport, transports); | |
1045 | if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) | |
1046 | sctp_assoc_del_peer(asoc, &trans->ipaddr); | |
1047 | } | |
1048 | ||
1049 | /* If the case is A (association restart), use | |
1050 | * initial_tsn as next_tsn. If the case is B, use | |
1051 | * current next_tsn in case data sent to peer | |
1052 | * has been discarded and needs retransmission. | |
1053 | */ | |
1054 | if (asoc->state >= SCTP_STATE_ESTABLISHED) { | |
1055 | asoc->next_tsn = new->next_tsn; | |
1056 | asoc->ctsn_ack_point = new->ctsn_ack_point; | |
1057 | asoc->adv_peer_ack_point = new->adv_peer_ack_point; | |
1058 | ||
1059 | /* Reinitialize SSN for both local streams | |
1060 | * and peer's streams. | |
1061 | */ | |
1062 | sctp_ssnmap_clear(asoc->ssnmap); | |
1063 | ||
1064 | } else { | |
1065 | /* Add any peer addresses from the new association. */ | |
1066 | list_for_each(pos, &new->peer.transport_addr_list) { | |
1067 | trans = list_entry(pos, struct sctp_transport, | |
1068 | transports); | |
1069 | if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr)) | |
1070 | sctp_assoc_add_peer(asoc, &trans->ipaddr, | |
ad8fec17 | 1071 | GFP_ATOMIC, trans->state); |
1da177e4 LT |
1072 | } |
1073 | ||
1074 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
1075 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
1076 | if (!asoc->ssnmap) { | |
1077 | /* Move the ssnmap. */ | |
1078 | asoc->ssnmap = new->ssnmap; | |
1079 | new->ssnmap = NULL; | |
1080 | } | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | /* Update the retran path for sending a retransmitted packet. | |
1085 | * Round-robin through the active transports, else round-robin | |
1086 | * through the inactive transports as this is the next best thing | |
1087 | * we can try. | |
1088 | */ | |
1089 | void sctp_assoc_update_retran_path(struct sctp_association *asoc) | |
1090 | { | |
1091 | struct sctp_transport *t, *next; | |
1092 | struct list_head *head = &asoc->peer.transport_addr_list; | |
1093 | struct list_head *pos; | |
1094 | ||
1095 | /* Find the next transport in a round-robin fashion. */ | |
1096 | t = asoc->peer.retran_path; | |
1097 | pos = &t->transports; | |
1098 | next = NULL; | |
1099 | ||
1100 | while (1) { | |
1101 | /* Skip the head. */ | |
1102 | if (pos->next == head) | |
1103 | pos = head->next; | |
1104 | else | |
1105 | pos = pos->next; | |
1106 | ||
1107 | t = list_entry(pos, struct sctp_transport, transports); | |
1108 | ||
1109 | /* Try to find an active transport. */ | |
1110 | ||
ad8fec17 SS |
1111 | if ((t->state == SCTP_ACTIVE) || |
1112 | (t->state == SCTP_UNKNOWN)) { | |
1da177e4 LT |
1113 | break; |
1114 | } else { | |
1115 | /* Keep track of the next transport in case | |
1116 | * we don't find any active transport. | |
1117 | */ | |
1118 | if (!next) | |
1119 | next = t; | |
1120 | } | |
1121 | ||
1122 | /* We have exhausted the list, but didn't find any | |
1123 | * other active transports. If so, use the next | |
1124 | * transport. | |
1125 | */ | |
1126 | if (t == asoc->peer.retran_path) { | |
1127 | t = next; | |
1128 | break; | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | asoc->peer.retran_path = t; | |
3f7a87d2 FF |
1133 | |
1134 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" | |
1135 | " %p addr: ", | |
1136 | " port: %d\n", | |
1137 | asoc, | |
1138 | (&t->ipaddr), | |
1139 | t->ipaddr.v4.sin_port); | |
1140 | } | |
1141 | ||
1142 | /* Choose the transport for sending a INIT packet. */ | |
1143 | struct sctp_transport *sctp_assoc_choose_init_transport( | |
1144 | struct sctp_association *asoc) | |
1145 | { | |
1146 | struct sctp_transport *t; | |
1147 | ||
1148 | /* Use the retran path. If the last INIT was sent over the | |
1149 | * retran path, update the retran path and use it. | |
1150 | */ | |
1151 | if (!asoc->init_last_sent_to) { | |
1152 | t = asoc->peer.active_path; | |
1153 | } else { | |
1154 | if (asoc->init_last_sent_to == asoc->peer.retran_path) | |
1155 | sctp_assoc_update_retran_path(asoc); | |
1156 | t = asoc->peer.retran_path; | |
1157 | } | |
1158 | ||
1159 | SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" | |
1160 | " %p addr: ", | |
1161 | " port: %d\n", | |
1162 | asoc, | |
1163 | (&t->ipaddr), | |
1164 | t->ipaddr.v4.sin_port); | |
1165 | ||
1166 | return t; | |
1da177e4 LT |
1167 | } |
1168 | ||
1169 | /* Choose the transport for sending a SHUTDOWN packet. */ | |
1170 | struct sctp_transport *sctp_assoc_choose_shutdown_transport( | |
1171 | struct sctp_association *asoc) | |
1172 | { | |
1173 | /* If this is the first time SHUTDOWN is sent, use the active path, | |
1174 | * else use the retran path. If the last SHUTDOWN was sent over the | |
1175 | * retran path, update the retran path and use it. | |
1176 | */ | |
1177 | if (!asoc->shutdown_last_sent_to) | |
1178 | return asoc->peer.active_path; | |
1179 | else { | |
1180 | if (asoc->shutdown_last_sent_to == asoc->peer.retran_path) | |
1181 | sctp_assoc_update_retran_path(asoc); | |
1182 | return asoc->peer.retran_path; | |
1183 | } | |
1184 | ||
1185 | } | |
1186 | ||
1187 | /* Update the association's pmtu and frag_point by going through all the | |
1188 | * transports. This routine is called when a transport's PMTU has changed. | |
1189 | */ | |
1190 | void sctp_assoc_sync_pmtu(struct sctp_association *asoc) | |
1191 | { | |
1192 | struct sctp_transport *t; | |
1193 | struct list_head *pos; | |
1194 | __u32 pmtu = 0; | |
1195 | ||
1196 | if (!asoc) | |
1197 | return; | |
1198 | ||
1199 | /* Get the lowest pmtu of all the transports. */ | |
1200 | list_for_each(pos, &asoc->peer.transport_addr_list) { | |
1201 | t = list_entry(pos, struct sctp_transport, transports); | |
52ccb8e9 FF |
1202 | if (!pmtu || (t->pathmtu < pmtu)) |
1203 | pmtu = t->pathmtu; | |
1da177e4 LT |
1204 | } |
1205 | ||
1206 | if (pmtu) { | |
1207 | struct sctp_sock *sp = sctp_sk(asoc->base.sk); | |
52ccb8e9 | 1208 | asoc->pathmtu = pmtu; |
1da177e4 LT |
1209 | asoc->frag_point = sctp_frag_point(sp, pmtu); |
1210 | } | |
1211 | ||
1212 | SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n", | |
52ccb8e9 | 1213 | __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point); |
1da177e4 LT |
1214 | } |
1215 | ||
1216 | /* Should we send a SACK to update our peer? */ | |
1217 | static inline int sctp_peer_needs_update(struct sctp_association *asoc) | |
1218 | { | |
1219 | switch (asoc->state) { | |
1220 | case SCTP_STATE_ESTABLISHED: | |
1221 | case SCTP_STATE_SHUTDOWN_PENDING: | |
1222 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
1223 | case SCTP_STATE_SHUTDOWN_SENT: | |
1224 | if ((asoc->rwnd > asoc->a_rwnd) && | |
1225 | ((asoc->rwnd - asoc->a_rwnd) >= | |
52ccb8e9 | 1226 | min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu))) |
1da177e4 LT |
1227 | return 1; |
1228 | break; | |
1229 | default: | |
1230 | break; | |
1231 | } | |
1232 | return 0; | |
1233 | } | |
1234 | ||
1235 | /* Increase asoc's rwnd by len and send any window update SACK if needed. */ | |
1236 | void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len) | |
1237 | { | |
1238 | struct sctp_chunk *sack; | |
1239 | struct timer_list *timer; | |
1240 | ||
1241 | if (asoc->rwnd_over) { | |
1242 | if (asoc->rwnd_over >= len) { | |
1243 | asoc->rwnd_over -= len; | |
1244 | } else { | |
1245 | asoc->rwnd += (len - asoc->rwnd_over); | |
1246 | asoc->rwnd_over = 0; | |
1247 | } | |
1248 | } else { | |
1249 | asoc->rwnd += len; | |
1250 | } | |
1251 | ||
1252 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) " | |
1253 | "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd, | |
1254 | asoc->rwnd_over, asoc->a_rwnd); | |
1255 | ||
1256 | /* Send a window update SACK if the rwnd has increased by at least the | |
1257 | * minimum of the association's PMTU and half of the receive buffer. | |
1258 | * The algorithm used is similar to the one described in | |
1259 | * Section 4.2.3.3 of RFC 1122. | |
1260 | */ | |
1261 | if (sctp_peer_needs_update(asoc)) { | |
1262 | asoc->a_rwnd = asoc->rwnd; | |
1263 | SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p " | |
1264 | "rwnd: %u a_rwnd: %u\n", __FUNCTION__, | |
1265 | asoc, asoc->rwnd, asoc->a_rwnd); | |
1266 | sack = sctp_make_sack(asoc); | |
1267 | if (!sack) | |
1268 | return; | |
1269 | ||
1270 | asoc->peer.sack_needed = 0; | |
1271 | ||
1272 | sctp_outq_tail(&asoc->outqueue, sack); | |
1273 | ||
1274 | /* Stop the SACK timer. */ | |
1275 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; | |
1276 | if (timer_pending(timer) && del_timer(timer)) | |
1277 | sctp_association_put(asoc); | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | /* Decrease asoc's rwnd by len. */ | |
1282 | void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len) | |
1283 | { | |
1284 | SCTP_ASSERT(asoc->rwnd, "rwnd zero", return); | |
1285 | SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return); | |
1286 | if (asoc->rwnd >= len) { | |
1287 | asoc->rwnd -= len; | |
1288 | } else { | |
1289 | asoc->rwnd_over = len - asoc->rwnd; | |
1290 | asoc->rwnd = 0; | |
1291 | } | |
1292 | SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n", | |
1293 | __FUNCTION__, asoc, len, asoc->rwnd, | |
1294 | asoc->rwnd_over); | |
1295 | } | |
1296 | ||
1297 | /* Build the bind address list for the association based on info from the | |
1298 | * local endpoint and the remote peer. | |
1299 | */ | |
3182cd84 | 1300 | int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, |
dd0fc66f | 1301 | gfp_t gfp) |
1da177e4 LT |
1302 | { |
1303 | sctp_scope_t scope; | |
1304 | int flags; | |
1305 | ||
1306 | /* Use scoping rules to determine the subset of addresses from | |
1307 | * the endpoint. | |
1308 | */ | |
1309 | scope = sctp_scope(&asoc->peer.active_path->ipaddr); | |
1310 | flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; | |
1311 | if (asoc->peer.ipv4_address) | |
1312 | flags |= SCTP_ADDR4_PEERSUPP; | |
1313 | if (asoc->peer.ipv6_address) | |
1314 | flags |= SCTP_ADDR6_PEERSUPP; | |
1315 | ||
1316 | return sctp_bind_addr_copy(&asoc->base.bind_addr, | |
1317 | &asoc->ep->base.bind_addr, | |
1318 | scope, gfp, flags); | |
1319 | } | |
1320 | ||
1321 | /* Build the association's bind address list from the cookie. */ | |
1322 | int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc, | |
3182cd84 | 1323 | struct sctp_cookie *cookie, |
dd0fc66f | 1324 | gfp_t gfp) |
1da177e4 LT |
1325 | { |
1326 | int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); | |
1327 | int var_size3 = cookie->raw_addr_list_len; | |
1328 | __u8 *raw = (__u8 *)cookie->peer_init + var_size2; | |
1329 | ||
1330 | return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3, | |
1331 | asoc->ep->base.bind_addr.port, gfp); | |
1332 | } | |
1333 | ||
1334 | /* Lookup laddr in the bind address list of an association. */ | |
1335 | int sctp_assoc_lookup_laddr(struct sctp_association *asoc, | |
1336 | const union sctp_addr *laddr) | |
1337 | { | |
1338 | int found; | |
1339 | ||
1340 | sctp_read_lock(&asoc->base.addr_lock); | |
1341 | if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) && | |
1342 | sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
1343 | sctp_sk(asoc->base.sk))) { | |
1344 | found = 1; | |
1345 | goto out; | |
1346 | } | |
1347 | ||
1348 | found = 0; | |
1349 | out: | |
1350 | sctp_read_unlock(&asoc->base.addr_lock); | |
1351 | return found; | |
1352 | } |