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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * (C) Copyright IBM Corp. 2001, 2004 |
4 | * Copyright (c) 1999-2000 Cisco, Inc. | |
5 | * Copyright (c) 1999-2001 Motorola, Inc. | |
6 | * Copyright (c) 2001 Intel Corp. | |
7 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
8 | * | |
60c778b2 | 9 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
10 | * |
11 | * This module provides the abstraction for an SCTP association. | |
12 | * | |
1da177e4 LT |
13 | * Please send any bug reports or fixes you make to the |
14 | * email address(es): | |
91705c61 | 15 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 16 | * |
1da177e4 LT |
17 | * Written or modified by: |
18 | * La Monte H.P. Yarroll <piggy@acm.org> | |
19 | * Karl Knutson <karl@athena.chicago.il.us> | |
20 | * Jon Grimm <jgrimm@us.ibm.com> | |
21 | * Xingang Guo <xingang.guo@intel.com> | |
22 | * Hui Huang <hui.huang@nokia.com> | |
23 | * Sridhar Samudrala <sri@us.ibm.com> | |
24 | * Daisy Chang <daisyc@us.ibm.com> | |
25 | * Ryan Layer <rmlayer@us.ibm.com> | |
26 | * Kevin Gao <kevin.gao@intel.com> | |
1da177e4 LT |
27 | */ |
28 | ||
145ce502 JP |
29 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
30 | ||
1da177e4 LT |
31 | #include <linux/types.h> |
32 | #include <linux/fcntl.h> | |
33 | #include <linux/poll.h> | |
34 | #include <linux/init.h> | |
1da177e4 LT |
35 | |
36 | #include <linux/slab.h> | |
37 | #include <linux/in.h> | |
38 | #include <net/ipv6.h> | |
39 | #include <net/sctp/sctp.h> | |
40 | #include <net/sctp/sm.h> | |
41 | ||
42 | /* Forward declarations for internal functions. */ | |
b82e8f31 | 43 | static void sctp_select_active_and_retran_path(struct sctp_association *asoc); |
c4028958 | 44 | static void sctp_assoc_bh_rcv(struct work_struct *work); |
a08de64d | 45 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc); |
8b4472cc | 46 | static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc); |
1da177e4 | 47 | |
1da177e4 LT |
48 | /* 1st Level Abstractions. */ |
49 | ||
50 | /* Initialize a new association from provided memory. */ | |
1c662018 XL |
51 | static struct sctp_association *sctp_association_init( |
52 | struct sctp_association *asoc, | |
53 | const struct sctp_endpoint *ep, | |
54 | const struct sock *sk, | |
55 | enum sctp_scope scope, gfp_t gfp) | |
1da177e4 LT |
56 | { |
57 | struct sctp_sock *sp; | |
3c918704 | 58 | struct sctp_paramhdr *p; |
58194778 | 59 | int i; |
1da177e4 LT |
60 | |
61 | /* Retrieve the SCTP per socket area. */ | |
62 | sp = sctp_sk((struct sock *)sk); | |
63 | ||
1da177e4 LT |
64 | /* Discarding const is appropriate here. */ |
65 | asoc->ep = (struct sctp_endpoint *)ep; | |
1da177e4 | 66 | asoc->base.sk = (struct sock *)sk; |
31243461 | 67 | asoc->base.net = sock_net(sk); |
2e0c9e79 DB |
68 | |
69 | sctp_endpoint_hold(asoc->ep); | |
1da177e4 LT |
70 | sock_hold(asoc->base.sk); |
71 | ||
72 | /* Initialize the common base substructure. */ | |
73 | asoc->base.type = SCTP_EP_TYPE_ASSOCIATION; | |
74 | ||
75 | /* Initialize the object handling fields. */ | |
c638457a | 76 | refcount_set(&asoc->base.refcnt, 1); |
1da177e4 LT |
77 | |
78 | /* Initialize the bind addr area. */ | |
79 | sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port); | |
1da177e4 LT |
80 | |
81 | asoc->state = SCTP_STATE_CLOSED; | |
52db882f | 82 | asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life); |
f68b2e05 | 83 | asoc->user_frag = sp->user_frag; |
1da177e4 LT |
84 | |
85 | /* Set the association max_retrans and RTO values from the | |
86 | * socket values. | |
87 | */ | |
88 | asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt; | |
8add543e | 89 | asoc->pf_retrans = sp->pf_retrans; |
34515e94 | 90 | asoc->ps_retrans = sp->ps_retrans; |
aef587be | 91 | asoc->pf_expose = sp->pf_expose; |
5aa93bcf | 92 | |
1da177e4 LT |
93 | asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial); |
94 | asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max); | |
95 | asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min); | |
96 | ||
52ccb8e9 FF |
97 | /* Initialize the association's heartbeat interval based on the |
98 | * sock configured value. | |
99 | */ | |
100 | asoc->hbinterval = msecs_to_jiffies(sp->hbinterval); | |
101 | ||
102 | /* Initialize path max retrans value. */ | |
103 | asoc->pathmaxrxt = sp->pathmaxrxt; | |
104 | ||
8a9c58d2 XL |
105 | asoc->flowlabel = sp->flowlabel; |
106 | asoc->dscp = sp->dscp; | |
107 | ||
52ccb8e9 FF |
108 | /* Set association default SACK delay */ |
109 | asoc->sackdelay = msecs_to_jiffies(sp->sackdelay); | |
d364d927 | 110 | asoc->sackfreq = sp->sackfreq; |
52ccb8e9 FF |
111 | |
112 | /* Set the association default flags controlling | |
113 | * Heartbeat, SACK delay, and Path MTU Discovery. | |
114 | */ | |
115 | asoc->param_flags = sp->param_flags; | |
116 | ||
9d2c881a | 117 | /* Initialize the maximum number of new data packets that can be sent |
1da177e4 LT |
118 | * in a burst. |
119 | */ | |
70331571 | 120 | asoc->max_burst = sp->max_burst; |
1da177e4 | 121 | |
a1e3a059 XL |
122 | asoc->subscribe = sp->subscribe; |
123 | ||
1e7d3d90 | 124 | /* initialize association timers */ |
1e7d3d90 VY |
125 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial; |
126 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial; | |
127 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial; | |
1e7d3d90 VY |
128 | |
129 | /* sctpimpguide Section 2.12.2 | |
130 | * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the | |
131 | * recommended value of 5 times 'RTO.Max'. | |
132 | */ | |
d808ad9a | 133 | asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] |
1e7d3d90 VY |
134 | = 5 * asoc->rto_max; |
135 | ||
52ccb8e9 | 136 | asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay; |
9f70f46b | 137 | asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ; |
d808ad9a | 138 | |
421f91d2 | 139 | /* Initializes the timers */ |
b24b8a24 | 140 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) |
9c3b5751 | 141 | timer_setup(&asoc->timers[i], sctp_timer_events[i], 0); |
1da177e4 LT |
142 | |
143 | /* Pull default initialization values from the sock options. | |
144 | * Note: This assumes that the values have already been | |
145 | * validated in the sock. | |
146 | */ | |
147 | asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; | |
148 | asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; | |
149 | asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; | |
150 | ||
151 | asoc->max_init_timeo = | |
152 | msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo); | |
153 | ||
1da177e4 LT |
154 | /* Set the local window size for receive. |
155 | * This is also the rcvbuf space per association. | |
156 | * RFC 6 - A SCTP receiver MUST be able to receive a minimum of | |
157 | * 1500 bytes in one SCTP packet. | |
158 | */ | |
049b3ff5 | 159 | if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW) |
1da177e4 LT |
160 | asoc->rwnd = SCTP_DEFAULT_MINWINDOW; |
161 | else | |
049b3ff5 | 162 | asoc->rwnd = sk->sk_rcvbuf/2; |
1da177e4 LT |
163 | |
164 | asoc->a_rwnd = asoc->rwnd; | |
165 | ||
1da177e4 LT |
166 | /* Use my own max window until I learn something better. */ |
167 | asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; | |
168 | ||
049b3ff5 NH |
169 | /* Initialize the receive memory counter */ |
170 | atomic_set(&asoc->rmem_alloc, 0); | |
171 | ||
1da177e4 LT |
172 | init_waitqueue_head(&asoc->wait); |
173 | ||
174 | asoc->c.my_vtag = sctp_generate_tag(ep); | |
1da177e4 LT |
175 | asoc->c.my_port = ep->base.bind_addr.port; |
176 | ||
177 | asoc->c.initial_tsn = sctp_generate_tsn(ep); | |
178 | ||
179 | asoc->next_tsn = asoc->c.initial_tsn; | |
180 | ||
181 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
182 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
183 | asoc->highest_sacked = asoc->ctsn_ack_point; | |
184 | asoc->last_cwr_tsn = asoc->ctsn_ack_point; | |
1da177e4 | 185 | |
1da177e4 LT |
186 | /* ADDIP Section 4.1 Asconf Chunk Procedures |
187 | * | |
188 | * When an endpoint has an ASCONF signaled change to be sent to the | |
189 | * remote endpoint it should do the following: | |
190 | * ... | |
191 | * A2) a serial number should be assigned to the chunk. The serial | |
192 | * number SHOULD be a monotonically increasing number. The serial | |
193 | * numbers SHOULD be initialized at the start of the | |
194 | * association to the same value as the initial TSN. | |
195 | */ | |
196 | asoc->addip_serial = asoc->c.initial_tsn; | |
cc16f00f | 197 | asoc->strreset_outseq = asoc->c.initial_tsn; |
1da177e4 | 198 | |
79af02c2 | 199 | INIT_LIST_HEAD(&asoc->addip_chunk_list); |
a08de64d | 200 | INIT_LIST_HEAD(&asoc->asconf_ack_list); |
1da177e4 LT |
201 | |
202 | /* Make an empty list of remote transport addresses. */ | |
203 | INIT_LIST_HEAD(&asoc->peer.transport_addr_list); | |
204 | ||
205 | /* RFC 2960 5.1 Normal Establishment of an Association | |
206 | * | |
207 | * After the reception of the first data chunk in an | |
208 | * association the endpoint must immediately respond with a | |
209 | * sack to acknowledge the data chunk. Subsequent | |
210 | * acknowledgements should be done as described in Section | |
211 | * 6.2. | |
212 | * | |
213 | * [We implement this by telling a new association that it | |
214 | * already received one packet.] | |
215 | */ | |
216 | asoc->peer.sack_needed = 1; | |
4244854d | 217 | asoc->peer.sack_generation = 1; |
1da177e4 | 218 | |
1da177e4 LT |
219 | /* Create an input queue. */ |
220 | sctp_inq_init(&asoc->base.inqueue); | |
c4028958 | 221 | sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv); |
1da177e4 LT |
222 | |
223 | /* Create an output queue. */ | |
224 | sctp_outq_init(asoc, &asoc->outqueue); | |
225 | ||
226 | if (!sctp_ulpq_init(&asoc->ulpq, asoc)) | |
227 | goto fail_init; | |
228 | ||
ff356414 XL |
229 | if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, |
230 | 0, gfp)) | |
3dbcc105 XL |
231 | goto fail_init; |
232 | ||
4135cce7 XL |
233 | /* Initialize default path MTU. */ |
234 | asoc->pathmtu = sp->pathmtu; | |
235 | sctp_assoc_update_frag_point(asoc); | |
236 | ||
1da177e4 LT |
237 | /* Assume that peer would support both address types unless we are |
238 | * told otherwise. | |
239 | */ | |
240 | asoc->peer.ipv4_address = 1; | |
a2c39584 WY |
241 | if (asoc->base.sk->sk_family == PF_INET6) |
242 | asoc->peer.ipv6_address = 1; | |
1da177e4 LT |
243 | INIT_LIST_HEAD(&asoc->asocs); |
244 | ||
1da177e4 LT |
245 | asoc->default_stream = sp->default_stream; |
246 | asoc->default_ppid = sp->default_ppid; | |
247 | asoc->default_flags = sp->default_flags; | |
248 | asoc->default_context = sp->default_context; | |
249 | asoc->default_timetolive = sp->default_timetolive; | |
6ab792f5 | 250 | asoc->default_rcv_context = sp->default_rcv_context; |
1da177e4 | 251 | |
a29a5bd4 VY |
252 | /* AUTH related initializations */ |
253 | INIT_LIST_HEAD(&asoc->endpoint_shared_keys); | |
58194778 | 254 | if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp)) |
3dbcc105 | 255 | goto stream_free; |
a29a5bd4 VY |
256 | |
257 | asoc->active_key_id = ep->active_key_id; | |
9fb657ae | 258 | asoc->strreset_enable = ep->strreset_enable; |
a29a5bd4 | 259 | |
a29a5bd4 VY |
260 | /* Save the hmacs and chunks list into this association */ |
261 | if (ep->auth_hmacs_list) | |
262 | memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list, | |
263 | ntohs(ep->auth_hmacs_list->param_hdr.length)); | |
264 | if (ep->auth_chunk_list) | |
265 | memcpy(asoc->c.auth_chunks, ep->auth_chunk_list, | |
266 | ntohs(ep->auth_chunk_list->param_hdr.length)); | |
267 | ||
268 | /* Get the AUTH random number for this association */ | |
3c918704 | 269 | p = (struct sctp_paramhdr *)asoc->c.auth_random; |
a29a5bd4 | 270 | p->type = SCTP_PARAM_RANDOM; |
3c918704 | 271 | p->length = htons(sizeof(*p) + SCTP_AUTH_RANDOM_LENGTH); |
a29a5bd4 VY |
272 | get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH); |
273 | ||
1da177e4 LT |
274 | return asoc; |
275 | ||
3dbcc105 | 276 | stream_free: |
cee360ab | 277 | sctp_stream_free(&asoc->stream); |
1da177e4 | 278 | fail_init: |
1da177e4 | 279 | sock_put(asoc->base.sk); |
2e0c9e79 | 280 | sctp_endpoint_put(asoc->ep); |
1da177e4 LT |
281 | return NULL; |
282 | } | |
283 | ||
284 | /* Allocate and initialize a new association */ | |
285 | struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep, | |
1c662018 XL |
286 | const struct sock *sk, |
287 | enum sctp_scope scope, gfp_t gfp) | |
1da177e4 LT |
288 | { |
289 | struct sctp_association *asoc; | |
290 | ||
939cfa75 | 291 | asoc = kzalloc(sizeof(*asoc), gfp); |
1da177e4 LT |
292 | if (!asoc) |
293 | goto fail; | |
294 | ||
295 | if (!sctp_association_init(asoc, ep, sk, scope, gfp)) | |
296 | goto fail_init; | |
297 | ||
1da177e4 | 298 | SCTP_DBG_OBJCNT_INC(assoc); |
bb33381d DB |
299 | |
300 | pr_debug("Created asoc %p\n", asoc); | |
1da177e4 LT |
301 | |
302 | return asoc; | |
303 | ||
304 | fail_init: | |
305 | kfree(asoc); | |
306 | fail: | |
307 | return NULL; | |
308 | } | |
309 | ||
310 | /* Free this association if possible. There may still be users, so | |
311 | * the actual deallocation may be delayed. | |
312 | */ | |
313 | void sctp_association_free(struct sctp_association *asoc) | |
314 | { | |
315 | struct sock *sk = asoc->base.sk; | |
316 | struct sctp_transport *transport; | |
317 | struct list_head *pos, *temp; | |
318 | int i; | |
319 | ||
de76e695 VY |
320 | /* Only real associations count against the endpoint, so |
321 | * don't bother for if this is a temporary association. | |
322 | */ | |
d3217b15 | 323 | if (!list_empty(&asoc->asocs)) { |
de76e695 VY |
324 | list_del(&asoc->asocs); |
325 | ||
326 | /* Decrement the backlog value for a TCP-style listening | |
327 | * socket. | |
328 | */ | |
329 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
7976a11b | 330 | sk_acceptq_removed(sk); |
de76e695 | 331 | } |
1da177e4 LT |
332 | |
333 | /* Mark as dead, so other users can know this structure is | |
334 | * going away. | |
335 | */ | |
0022d2dd | 336 | asoc->base.dead = true; |
1da177e4 LT |
337 | |
338 | /* Dispose of any data lying around in the outqueue. */ | |
339 | sctp_outq_free(&asoc->outqueue); | |
340 | ||
341 | /* Dispose of any pending messages for the upper layer. */ | |
342 | sctp_ulpq_free(&asoc->ulpq); | |
343 | ||
344 | /* Dispose of any pending chunks on the inqueue. */ | |
345 | sctp_inq_free(&asoc->base.inqueue); | |
346 | ||
8e1ee18c VY |
347 | sctp_tsnmap_free(&asoc->peer.tsn_map); |
348 | ||
a8386317 | 349 | /* Free stream information. */ |
cee360ab | 350 | sctp_stream_free(&asoc->stream); |
1da177e4 | 351 | |
7b9438de XL |
352 | if (asoc->strreset_chunk) |
353 | sctp_chunk_free(asoc->strreset_chunk); | |
354 | ||
1da177e4 LT |
355 | /* Clean up the bound address list. */ |
356 | sctp_bind_addr_free(&asoc->base.bind_addr); | |
357 | ||
358 | /* Do we need to go through all of our timers and | |
359 | * delete them? To be safe we will try to delete all, but we | |
360 | * should be able to go through and make a guess based | |
361 | * on our state. | |
362 | */ | |
363 | for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { | |
25cc4ae9 | 364 | if (del_timer(&asoc->timers[i])) |
1da177e4 LT |
365 | sctp_association_put(asoc); |
366 | } | |
367 | ||
368 | /* Free peer's cached cookie. */ | |
a51482bd | 369 | kfree(asoc->peer.cookie); |
730fc3d0 VY |
370 | kfree(asoc->peer.peer_random); |
371 | kfree(asoc->peer.peer_chunks); | |
372 | kfree(asoc->peer.peer_hmacs); | |
1da177e4 LT |
373 | |
374 | /* Release the transport structures. */ | |
375 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
376 | transport = list_entry(pos, struct sctp_transport, transports); | |
45122ca2 | 377 | list_del_rcu(pos); |
4f008781 | 378 | sctp_unhash_transport(transport); |
1da177e4 LT |
379 | sctp_transport_free(transport); |
380 | } | |
381 | ||
3f7a87d2 FF |
382 | asoc->peer.transport_count = 0; |
383 | ||
a000c01e | 384 | sctp_asconf_queue_teardown(asoc); |
1da177e4 | 385 | |
8a07eb0a | 386 | /* Free pending address space being deleted */ |
7d37d0c1 | 387 | kfree(asoc->asconf_addr_del_pending); |
8a07eb0a | 388 | |
a29a5bd4 VY |
389 | /* AUTH - Free the endpoint shared keys */ |
390 | sctp_auth_destroy_keys(&asoc->endpoint_shared_keys); | |
391 | ||
392 | /* AUTH - Free the association shared key */ | |
393 | sctp_auth_key_put(asoc->asoc_shared_key); | |
394 | ||
1da177e4 LT |
395 | sctp_association_put(asoc); |
396 | } | |
397 | ||
398 | /* Cleanup and free up an association. */ | |
399 | static void sctp_association_destroy(struct sctp_association *asoc) | |
400 | { | |
bb33381d DB |
401 | if (unlikely(!asoc->base.dead)) { |
402 | WARN(1, "Attempt to destroy undead association %p!\n", asoc); | |
403 | return; | |
404 | } | |
1da177e4 LT |
405 | |
406 | sctp_endpoint_put(asoc->ep); | |
407 | sock_put(asoc->base.sk); | |
408 | ||
409 | if (asoc->assoc_id != 0) { | |
410 | spin_lock_bh(&sctp_assocs_id_lock); | |
411 | idr_remove(&sctp_assocs_id, asoc->assoc_id); | |
412 | spin_unlock_bh(&sctp_assocs_id_lock); | |
413 | } | |
414 | ||
547b792c | 415 | WARN_ON(atomic_read(&asoc->rmem_alloc)); |
049b3ff5 | 416 | |
fb6df5a6 | 417 | kfree_rcu(asoc, rcu); |
ff2266cd | 418 | SCTP_DBG_OBJCNT_DEC(assoc); |
1da177e4 LT |
419 | } |
420 | ||
421 | /* Change the primary destination address for the peer. */ | |
422 | void sctp_assoc_set_primary(struct sctp_association *asoc, | |
423 | struct sctp_transport *transport) | |
424 | { | |
319fa2a2 VY |
425 | int changeover = 0; |
426 | ||
427 | /* it's a changeover only if we already have a primary path | |
428 | * that we are changing | |
429 | */ | |
430 | if (asoc->peer.primary_path != NULL && | |
431 | asoc->peer.primary_path != transport) | |
432 | changeover = 1 ; | |
433 | ||
1da177e4 | 434 | asoc->peer.primary_path = transport; |
5cd0b917 XL |
435 | sctp_ulpevent_nofity_peer_addr_change(transport, |
436 | SCTP_ADDR_MADE_PRIM, 0); | |
1da177e4 LT |
437 | |
438 | /* Set a default msg_name for events. */ | |
439 | memcpy(&asoc->peer.primary_addr, &transport->ipaddr, | |
440 | sizeof(union sctp_addr)); | |
441 | ||
442 | /* If the primary path is changing, assume that the | |
443 | * user wants to use this new path. | |
444 | */ | |
ad8fec17 SS |
445 | if ((transport->state == SCTP_ACTIVE) || |
446 | (transport->state == SCTP_UNKNOWN)) | |
1da177e4 LT |
447 | asoc->peer.active_path = transport; |
448 | ||
449 | /* | |
450 | * SFR-CACC algorithm: | |
451 | * Upon the receipt of a request to change the primary | |
452 | * destination address, on the data structure for the new | |
453 | * primary destination, the sender MUST do the following: | |
454 | * | |
455 | * 1) If CHANGEOVER_ACTIVE is set, then there was a switch | |
456 | * to this destination address earlier. The sender MUST set | |
457 | * CYCLING_CHANGEOVER to indicate that this switch is a | |
458 | * double switch to the same destination address. | |
e0e9db17 VY |
459 | * |
460 | * Really, only bother is we have data queued or outstanding on | |
461 | * the association. | |
1da177e4 | 462 | */ |
e0e9db17 VY |
463 | if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen) |
464 | return; | |
465 | ||
1da177e4 | 466 | if (transport->cacc.changeover_active) |
319fa2a2 | 467 | transport->cacc.cycling_changeover = changeover; |
1da177e4 LT |
468 | |
469 | /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that | |
470 | * a changeover has occurred. | |
471 | */ | |
319fa2a2 | 472 | transport->cacc.changeover_active = changeover; |
1da177e4 LT |
473 | |
474 | /* 3) The sender MUST store the next TSN to be sent in | |
475 | * next_tsn_at_change. | |
476 | */ | |
477 | transport->cacc.next_tsn_at_change = asoc->next_tsn; | |
478 | } | |
479 | ||
3f7a87d2 FF |
480 | /* Remove a transport from an association. */ |
481 | void sctp_assoc_rm_peer(struct sctp_association *asoc, | |
482 | struct sctp_transport *peer) | |
483 | { | |
df132eff XL |
484 | struct sctp_transport *transport; |
485 | struct list_head *pos; | |
486 | struct sctp_chunk *ch; | |
3f7a87d2 | 487 | |
bb33381d DB |
488 | pr_debug("%s: association:%p addr:%pISpc\n", |
489 | __func__, asoc, &peer->ipaddr.sa); | |
3f7a87d2 FF |
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. */ | |
45122ca2 | 498 | list_del_rcu(&peer->transports); |
4f008781 XL |
499 | /* Remove this peer from the transport hashtable */ |
500 | sctp_unhash_transport(peer); | |
3f7a87d2 FF |
501 | |
502 | /* Get the first transport of asoc. */ | |
503 | pos = asoc->peer.transport_addr_list.next; | |
504 | transport = list_entry(pos, struct sctp_transport, transports); | |
505 | ||
506 | /* Update any entries that match the peer to be deleted. */ | |
507 | if (asoc->peer.primary_path == peer) | |
508 | sctp_assoc_set_primary(asoc, transport); | |
509 | if (asoc->peer.active_path == peer) | |
510 | asoc->peer.active_path = transport; | |
9494c7c5 WY |
511 | if (asoc->peer.retran_path == peer) |
512 | asoc->peer.retran_path = transport; | |
3f7a87d2 FF |
513 | if (asoc->peer.last_data_from == peer) |
514 | asoc->peer.last_data_from = transport; | |
515 | ||
7b9438de XL |
516 | if (asoc->strreset_chunk && |
517 | asoc->strreset_chunk->transport == peer) { | |
518 | asoc->strreset_chunk->transport = transport; | |
519 | sctp_transport_reset_reconf_timer(transport); | |
520 | } | |
521 | ||
3f7a87d2 FF |
522 | /* If we remove the transport an INIT was last sent to, set it to |
523 | * NULL. Combined with the update of the retran path above, this | |
524 | * will cause the next INIT to be sent to the next available | |
525 | * transport, maintaining the cycle. | |
526 | */ | |
527 | if (asoc->init_last_sent_to == peer) | |
528 | asoc->init_last_sent_to = NULL; | |
529 | ||
6345b199 WY |
530 | /* If we remove the transport an SHUTDOWN was last sent to, set it |
531 | * to NULL. Combined with the update of the retran path above, this | |
532 | * will cause the next SHUTDOWN to be sent to the next available | |
533 | * transport, maintaining the cycle. | |
534 | */ | |
535 | if (asoc->shutdown_last_sent_to == peer) | |
536 | asoc->shutdown_last_sent_to = NULL; | |
537 | ||
10a43cea WY |
538 | /* If we remove the transport an ASCONF was last sent to, set it to |
539 | * NULL. | |
540 | */ | |
541 | if (asoc->addip_last_asconf && | |
542 | asoc->addip_last_asconf->transport == peer) | |
543 | asoc->addip_last_asconf->transport = NULL; | |
544 | ||
31b02e15 VY |
545 | /* If we have something on the transmitted list, we have to |
546 | * save it off. The best place is the active path. | |
547 | */ | |
548 | if (!list_empty(&peer->transmitted)) { | |
549 | struct sctp_transport *active = asoc->peer.active_path; | |
31b02e15 VY |
550 | |
551 | /* Reset the transport of each chunk on this list */ | |
552 | list_for_each_entry(ch, &peer->transmitted, | |
553 | transmitted_list) { | |
554 | ch->transport = NULL; | |
555 | ch->rtt_in_progress = 0; | |
556 | } | |
557 | ||
558 | list_splice_tail_init(&peer->transmitted, | |
559 | &active->transmitted); | |
560 | ||
561 | /* Start a T3 timer here in case it wasn't running so | |
562 | * that these migrated packets have a chance to get | |
2bccbadf | 563 | * retransmitted. |
31b02e15 VY |
564 | */ |
565 | if (!timer_pending(&active->T3_rtx_timer)) | |
566 | if (!mod_timer(&active->T3_rtx_timer, | |
567 | jiffies + active->rto)) | |
568 | sctp_transport_hold(active); | |
569 | } | |
570 | ||
df132eff XL |
571 | list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) |
572 | if (ch->transport == peer) | |
573 | ch->transport = NULL; | |
574 | ||
3f7a87d2 FF |
575 | asoc->peer.transport_count--; |
576 | ||
c446f50c | 577 | sctp_ulpevent_nofity_peer_addr_change(peer, SCTP_ADDR_REMOVED, 0); |
3f7a87d2 FF |
578 | sctp_transport_free(peer); |
579 | } | |
580 | ||
1da177e4 LT |
581 | /* Add a transport address to an association. */ |
582 | struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc, | |
583 | const union sctp_addr *addr, | |
dd0fc66f | 584 | const gfp_t gfp, |
3f7a87d2 | 585 | const int peer_state) |
1da177e4 | 586 | { |
89bf3450 | 587 | struct net *net = sock_net(asoc->base.sk); |
1da177e4 LT |
588 | struct sctp_transport *peer; |
589 | struct sctp_sock *sp; | |
590 | unsigned short port; | |
591 | ||
592 | sp = sctp_sk(asoc->base.sk); | |
593 | ||
594 | /* AF_INET and AF_INET6 share common port field. */ | |
4bdf4b5f | 595 | port = ntohs(addr->v4.sin_port); |
1da177e4 | 596 | |
bb33381d DB |
597 | pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__, |
598 | asoc, &addr->sa, peer_state); | |
3f7a87d2 | 599 | |
1da177e4 LT |
600 | /* Set the port if it has not been set yet. */ |
601 | if (0 == asoc->peer.port) | |
602 | asoc->peer.port = port; | |
603 | ||
604 | /* Check to see if this is a duplicate. */ | |
605 | peer = sctp_assoc_lookup_paddr(asoc, addr); | |
3f7a87d2 | 606 | if (peer) { |
add52379 VY |
607 | /* An UNKNOWN state is only set on transports added by |
608 | * user in sctp_connectx() call. Such transports should be | |
609 | * considered CONFIRMED per RFC 4960, Section 5.4. | |
610 | */ | |
ad8fec17 | 611 | if (peer->state == SCTP_UNKNOWN) { |
add52379 | 612 | peer->state = SCTP_ACTIVE; |
ad8fec17 | 613 | } |
1da177e4 | 614 | return peer; |
3f7a87d2 | 615 | } |
1da177e4 | 616 | |
89bf3450 | 617 | peer = sctp_transport_new(net, addr, gfp); |
1da177e4 LT |
618 | if (!peer) |
619 | return NULL; | |
620 | ||
621 | sctp_transport_set_owner(peer, asoc); | |
622 | ||
52ccb8e9 FF |
623 | /* Initialize the peer's heartbeat interval based on the |
624 | * association configured value. | |
625 | */ | |
626 | peer->hbinterval = asoc->hbinterval; | |
627 | ||
628 | /* Set the path max_retrans. */ | |
629 | peer->pathmaxrxt = asoc->pathmaxrxt; | |
630 | ||
2bccbadf | 631 | /* And the partial failure retrans threshold */ |
5aa93bcf | 632 | peer->pf_retrans = asoc->pf_retrans; |
34515e94 XL |
633 | /* And the primary path switchover retrans threshold */ |
634 | peer->ps_retrans = asoc->ps_retrans; | |
5aa93bcf | 635 | |
52ccb8e9 FF |
636 | /* Initialize the peer's SACK delay timeout based on the |
637 | * association configured value. | |
638 | */ | |
639 | peer->sackdelay = asoc->sackdelay; | |
d364d927 | 640 | peer->sackfreq = asoc->sackfreq; |
52ccb8e9 | 641 | |
4be4139f XL |
642 | if (addr->sa.sa_family == AF_INET6) { |
643 | __be32 info = addr->v6.sin6_flowinfo; | |
644 | ||
645 | if (info) { | |
646 | peer->flowlabel = ntohl(info & IPV6_FLOWLABEL_MASK); | |
647 | peer->flowlabel |= SCTP_FLOWLABEL_SET_MASK; | |
648 | } else { | |
649 | peer->flowlabel = asoc->flowlabel; | |
650 | } | |
651 | } | |
8a9c58d2 XL |
652 | peer->dscp = asoc->dscp; |
653 | ||
52ccb8e9 FF |
654 | /* Enable/disable heartbeat, SACK delay, and path MTU discovery |
655 | * based on association setting. | |
656 | */ | |
657 | peer->param_flags = asoc->param_flags; | |
658 | ||
1da177e4 | 659 | /* Initialize the pmtu of the transport. */ |
800e00c1 | 660 | sctp_transport_route(peer, NULL, sp); |
1da177e4 LT |
661 | |
662 | /* If this is the first transport addr on this association, | |
663 | * initialize the association PMTU to the peer's PMTU. | |
664 | * If not and the current association PMTU is higher than the new | |
665 | * peer's PMTU, reset the association PMTU to the new peer's PMTU. | |
666 | */ | |
c4b2893d MRL |
667 | sctp_assoc_set_pmtu(asoc, asoc->pathmtu ? |
668 | min_t(int, peer->pathmtu, asoc->pathmtu) : | |
669 | peer->pathmtu); | |
bb33381d | 670 | |
6d0ccbac | 671 | peer->pmtu_pending = 0; |
1da177e4 | 672 | |
1da177e4 LT |
673 | /* The asoc->peer.port might not be meaningful yet, but |
674 | * initialize the packet structure anyway. | |
675 | */ | |
676 | sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port, | |
677 | asoc->peer.port); | |
678 | ||
679 | /* 7.2.1 Slow-Start | |
680 | * | |
681 | * o The initial cwnd before DATA transmission or after a sufficiently | |
682 | * long idle period MUST be set to | |
683 | * min(4*MTU, max(2*MTU, 4380 bytes)) | |
684 | * | |
685 | * o The initial value of ssthresh MAY be arbitrarily high | |
686 | * (for example, implementations MAY use the size of the | |
687 | * receiver advertised window). | |
688 | */ | |
52ccb8e9 | 689 | peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380)); |
1da177e4 LT |
690 | |
691 | /* At this point, we may not have the receiver's advertised window, | |
692 | * so initialize ssthresh to the default value and it will be set | |
693 | * later when we process the INIT. | |
694 | */ | |
695 | peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; | |
696 | ||
697 | peer->partial_bytes_acked = 0; | |
698 | peer->flight_size = 0; | |
46d5a808 | 699 | peer->burst_limited = 0; |
1da177e4 | 700 | |
1da177e4 LT |
701 | /* Set the transport's RTO.initial value */ |
702 | peer->rto = asoc->rto_initial; | |
196d6759 | 703 | sctp_max_rto(asoc, peer); |
1da177e4 | 704 | |
3f7a87d2 FF |
705 | /* Set the peer's active state. */ |
706 | peer->state = peer_state; | |
707 | ||
7fda702f XL |
708 | /* Add this peer into the transport hashtable */ |
709 | if (sctp_hash_transport(peer)) { | |
710 | sctp_transport_free(peer); | |
711 | return NULL; | |
712 | } | |
713 | ||
1da177e4 | 714 | /* Attach the remote transport to our asoc. */ |
45122ca2 | 715 | list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list); |
3f7a87d2 | 716 | asoc->peer.transport_count++; |
1da177e4 | 717 | |
4b774032 XL |
718 | sctp_ulpevent_nofity_peer_addr_change(peer, SCTP_ADDR_ADDED, 0); |
719 | ||
1da177e4 LT |
720 | /* If we do not yet have a primary path, set one. */ |
721 | if (!asoc->peer.primary_path) { | |
722 | sctp_assoc_set_primary(asoc, peer); | |
723 | asoc->peer.retran_path = peer; | |
724 | } | |
725 | ||
fbdf501c VY |
726 | if (asoc->peer.active_path == asoc->peer.retran_path && |
727 | peer->state != SCTP_UNCONFIRMED) { | |
1da177e4 | 728 | asoc->peer.retran_path = peer; |
3f7a87d2 | 729 | } |
1da177e4 LT |
730 | |
731 | return peer; | |
732 | } | |
733 | ||
734 | /* Delete a transport address from an association. */ | |
735 | void sctp_assoc_del_peer(struct sctp_association *asoc, | |
736 | const union sctp_addr *addr) | |
737 | { | |
738 | struct list_head *pos; | |
739 | struct list_head *temp; | |
1da177e4 LT |
740 | struct sctp_transport *transport; |
741 | ||
742 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
743 | transport = list_entry(pos, struct sctp_transport, transports); | |
744 | if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) { | |
3f7a87d2 FF |
745 | /* Do book keeping for removing the peer and free it. */ |
746 | sctp_assoc_rm_peer(asoc, transport); | |
1da177e4 LT |
747 | break; |
748 | } | |
749 | } | |
1da177e4 LT |
750 | } |
751 | ||
752 | /* Lookup a transport by address. */ | |
753 | struct sctp_transport *sctp_assoc_lookup_paddr( | |
754 | const struct sctp_association *asoc, | |
755 | const union sctp_addr *address) | |
756 | { | |
757 | struct sctp_transport *t; | |
1da177e4 LT |
758 | |
759 | /* Cycle through all transports searching for a peer address. */ | |
760 | ||
9dbc15f0 RD |
761 | list_for_each_entry(t, &asoc->peer.transport_addr_list, |
762 | transports) { | |
1da177e4 LT |
763 | if (sctp_cmp_addr_exact(address, &t->ipaddr)) |
764 | return t; | |
765 | } | |
766 | ||
767 | return NULL; | |
768 | } | |
769 | ||
42e30bf3 VY |
770 | /* Remove all transports except a give one */ |
771 | void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc, | |
772 | struct sctp_transport *primary) | |
773 | { | |
774 | struct sctp_transport *temp; | |
775 | struct sctp_transport *t; | |
776 | ||
777 | list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list, | |
778 | transports) { | |
779 | /* if the current transport is not the primary one, delete it */ | |
780 | if (t != primary) | |
781 | sctp_assoc_rm_peer(asoc, t); | |
782 | } | |
42e30bf3 VY |
783 | } |
784 | ||
1da177e4 LT |
785 | /* Engage in transport control operations. |
786 | * Mark the transport up or down and send a notification to the user. | |
787 | * Select and update the new active and retran paths. | |
788 | */ | |
789 | void sctp_assoc_control_transport(struct sctp_association *asoc, | |
790 | struct sctp_transport *transport, | |
0ceaeebe | 791 | enum sctp_transport_cmd command, |
1da177e4 LT |
792 | sctp_sn_error_t error) |
793 | { | |
768e1518 | 794 | int spc_state = SCTP_ADDR_AVAILABLE; |
5aa93bcf | 795 | bool ulp_notify = true; |
1da177e4 LT |
796 | |
797 | /* Record the transition on the transport. */ | |
798 | switch (command) { | |
799 | case SCTP_TRANSPORT_UP: | |
1ae4114d VY |
800 | /* If we are moving from UNCONFIRMED state due |
801 | * to heartbeat success, report the SCTP_ADDR_CONFIRMED | |
802 | * state to the user, otherwise report SCTP_ADDR_AVAILABLE. | |
803 | */ | |
768e1518 XL |
804 | if (transport->state == SCTP_PF && |
805 | asoc->pf_expose != SCTP_PF_EXPOSE_ENABLE) | |
5aa93bcf | 806 | ulp_notify = false; |
768e1518 XL |
807 | else if (transport->state == SCTP_UNCONFIRMED && |
808 | error == SCTP_HEARTBEAT_SUCCESS) | |
809 | spc_state = SCTP_ADDR_CONFIRMED; | |
810 | ||
3f7a87d2 | 811 | transport->state = SCTP_ACTIVE; |
1da177e4 LT |
812 | break; |
813 | ||
814 | case SCTP_TRANSPORT_DOWN: | |
40187886 VY |
815 | /* If the transport was never confirmed, do not transition it |
816 | * to inactive state. Also, release the cached route since | |
817 | * there may be a better route next time. | |
cc75689a | 818 | */ |
768e1518 | 819 | if (transport->state != SCTP_UNCONFIRMED) { |
cc75689a | 820 | transport->state = SCTP_INACTIVE; |
768e1518 XL |
821 | spc_state = SCTP_ADDR_UNREACHABLE; |
822 | } else { | |
c86a773c | 823 | sctp_transport_dst_release(transport); |
061079ac | 824 | ulp_notify = false; |
40187886 | 825 | } |
1da177e4 LT |
826 | break; |
827 | ||
5aa93bcf NH |
828 | case SCTP_TRANSPORT_PF: |
829 | transport->state = SCTP_PF; | |
768e1518 XL |
830 | if (asoc->pf_expose != SCTP_PF_EXPOSE_ENABLE) |
831 | ulp_notify = false; | |
832 | else | |
833 | spc_state = SCTP_ADDR_POTENTIALLY_FAILED; | |
5aa93bcf NH |
834 | break; |
835 | ||
1da177e4 LT |
836 | default: |
837 | return; | |
3ff50b79 | 838 | } |
1da177e4 | 839 | |
b82e8f31 DB |
840 | /* Generate and send a SCTP_PEER_ADDR_CHANGE notification |
841 | * to the user. | |
1da177e4 | 842 | */ |
4b774032 XL |
843 | if (ulp_notify) |
844 | sctp_ulpevent_nofity_peer_addr_change(transport, | |
845 | spc_state, error); | |
1da177e4 LT |
846 | |
847 | /* Select new active and retran paths. */ | |
b82e8f31 | 848 | sctp_select_active_and_retran_path(asoc); |
1da177e4 LT |
849 | } |
850 | ||
851 | /* Hold a reference to an association. */ | |
852 | void sctp_association_hold(struct sctp_association *asoc) | |
853 | { | |
c638457a | 854 | refcount_inc(&asoc->base.refcnt); |
1da177e4 LT |
855 | } |
856 | ||
857 | /* Release a reference to an association and cleanup | |
858 | * if there are no more references. | |
859 | */ | |
860 | void sctp_association_put(struct sctp_association *asoc) | |
861 | { | |
c638457a | 862 | if (refcount_dec_and_test(&asoc->base.refcnt)) |
1da177e4 LT |
863 | sctp_association_destroy(asoc); |
864 | } | |
865 | ||
866 | /* Allocate the next TSN, Transmission Sequence Number, for the given | |
867 | * association. | |
868 | */ | |
869 | __u32 sctp_association_get_next_tsn(struct sctp_association *asoc) | |
870 | { | |
871 | /* From Section 1.6 Serial Number Arithmetic: | |
872 | * Transmission Sequence Numbers wrap around when they reach | |
873 | * 2**32 - 1. That is, the next TSN a DATA chunk MUST use | |
874 | * after transmitting TSN = 2*32 - 1 is TSN = 0. | |
875 | */ | |
876 | __u32 retval = asoc->next_tsn; | |
877 | asoc->next_tsn++; | |
878 | asoc->unack_data++; | |
879 | ||
880 | return retval; | |
881 | } | |
882 | ||
883 | /* Compare two addresses to see if they match. Wildcard addresses | |
884 | * only match themselves. | |
885 | */ | |
886 | int sctp_cmp_addr_exact(const union sctp_addr *ss1, | |
887 | const union sctp_addr *ss2) | |
888 | { | |
889 | struct sctp_af *af; | |
890 | ||
891 | af = sctp_get_af_specific(ss1->sa.sa_family); | |
892 | if (unlikely(!af)) | |
893 | return 0; | |
894 | ||
895 | return af->cmp_addr(ss1, ss2); | |
896 | } | |
897 | ||
898 | /* Return an ecne chunk to get prepended to a packet. | |
899 | * Note: We are sly and return a shared, prealloced chunk. FIXME: | |
900 | * No we don't, but we could/should. | |
901 | */ | |
902 | struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc) | |
903 | { | |
8b7318d3 | 904 | if (!asoc->need_ecne) |
905 | return NULL; | |
1da177e4 LT |
906 | |
907 | /* Send ECNE if needed. | |
908 | * Not being able to allocate a chunk here is not deadly. | |
909 | */ | |
8b7318d3 | 910 | return sctp_make_ecne(asoc, asoc->last_ecne_tsn); |
1da177e4 LT |
911 | } |
912 | ||
913 | /* | |
914 | * Find which transport this TSN was sent on. | |
915 | */ | |
916 | struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc, | |
917 | __u32 tsn) | |
918 | { | |
919 | struct sctp_transport *active; | |
920 | struct sctp_transport *match; | |
1da177e4 LT |
921 | struct sctp_transport *transport; |
922 | struct sctp_chunk *chunk; | |
dbc16db1 | 923 | __be32 key = htonl(tsn); |
1da177e4 LT |
924 | |
925 | match = NULL; | |
926 | ||
927 | /* | |
928 | * FIXME: In general, find a more efficient data structure for | |
929 | * searching. | |
930 | */ | |
931 | ||
932 | /* | |
933 | * The general strategy is to search each transport's transmitted | |
934 | * list. Return which transport this TSN lives on. | |
935 | * | |
936 | * Let's be hopeful and check the active_path first. | |
937 | * Another optimization would be to know if there is only one | |
938 | * outbound path and not have to look for the TSN at all. | |
939 | * | |
940 | */ | |
941 | ||
942 | active = asoc->peer.active_path; | |
943 | ||
9dbc15f0 RD |
944 | list_for_each_entry(chunk, &active->transmitted, |
945 | transmitted_list) { | |
1da177e4 LT |
946 | |
947 | if (key == chunk->subh.data_hdr->tsn) { | |
948 | match = active; | |
949 | goto out; | |
950 | } | |
951 | } | |
952 | ||
953 | /* If not found, go search all the other transports. */ | |
9dbc15f0 RD |
954 | list_for_each_entry(transport, &asoc->peer.transport_addr_list, |
955 | transports) { | |
1da177e4 LT |
956 | |
957 | if (transport == active) | |
2317f449 | 958 | continue; |
9dbc15f0 RD |
959 | list_for_each_entry(chunk, &transport->transmitted, |
960 | transmitted_list) { | |
1da177e4 LT |
961 | if (key == chunk->subh.data_hdr->tsn) { |
962 | match = transport; | |
963 | goto out; | |
964 | } | |
965 | } | |
966 | } | |
967 | out: | |
968 | return match; | |
969 | } | |
970 | ||
1da177e4 | 971 | /* Do delayed input processing. This is scheduled by sctp_rcv(). */ |
c4028958 | 972 | static void sctp_assoc_bh_rcv(struct work_struct *work) |
1da177e4 | 973 | { |
c4028958 DH |
974 | struct sctp_association *asoc = |
975 | container_of(work, struct sctp_association, | |
976 | base.inqueue.immediate); | |
55e26eb9 | 977 | struct net *net = sock_net(asoc->base.sk); |
bfc6f827 | 978 | union sctp_subtype subtype; |
1da177e4 LT |
979 | struct sctp_endpoint *ep; |
980 | struct sctp_chunk *chunk; | |
1da177e4 | 981 | struct sctp_inq *inqueue; |
59d8d443 | 982 | int first_time = 1; /* is this the first time through the loop */ |
1da177e4 | 983 | int error = 0; |
59d8d443 | 984 | int state; |
1da177e4 LT |
985 | |
986 | /* The association should be held so we should be safe. */ | |
987 | ep = asoc->ep; | |
1da177e4 LT |
988 | |
989 | inqueue = &asoc->base.inqueue; | |
990 | sctp_association_hold(asoc); | |
991 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
992 | state = asoc->state; | |
993 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
994 | ||
59d8d443 XL |
995 | /* If the first chunk in the packet is AUTH, do special |
996 | * processing specified in Section 6.3 of SCTP-AUTH spec | |
997 | */ | |
998 | if (first_time && subtype.chunk == SCTP_CID_AUTH) { | |
999 | struct sctp_chunkhdr *next_hdr; | |
1000 | ||
1001 | next_hdr = sctp_inq_peek(inqueue); | |
1002 | if (!next_hdr) | |
1003 | goto normal; | |
1004 | ||
1005 | /* If the next chunk is COOKIE-ECHO, skip the AUTH | |
1006 | * chunk while saving a pointer to it so we can do | |
1007 | * Authentication later (during cookie-echo | |
1008 | * processing). | |
1009 | */ | |
1010 | if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { | |
1011 | chunk->auth_chunk = skb_clone(chunk->skb, | |
1012 | GFP_ATOMIC); | |
1013 | chunk->auth = 1; | |
1014 | continue; | |
1015 | } | |
1016 | } | |
1017 | ||
1018 | normal: | |
bbd0d598 VY |
1019 | /* SCTP-AUTH, Section 6.3: |
1020 | * The receiver has a list of chunk types which it expects | |
1021 | * to be received only after an AUTH-chunk. This list has | |
1022 | * been sent to the peer during the association setup. It | |
1023 | * MUST silently discard these chunks if they are not placed | |
1024 | * after an AUTH chunk in the packet. | |
1025 | */ | |
1026 | if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) | |
1027 | continue; | |
1028 | ||
1da177e4 LT |
1029 | /* Remember where the last DATA chunk came from so we |
1030 | * know where to send the SACK. | |
1031 | */ | |
1032 | if (sctp_chunk_is_data(chunk)) | |
1033 | asoc->peer.last_data_from = chunk->transport; | |
196d6759 | 1034 | else { |
55e26eb9 | 1035 | SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS); |
196d6759 MB |
1036 | asoc->stats.ictrlchunks++; |
1037 | if (chunk->chunk_hdr->type == SCTP_CID_SACK) | |
1038 | asoc->stats.isacks++; | |
1039 | } | |
1da177e4 LT |
1040 | |
1041 | if (chunk->transport) | |
e575235f | 1042 | chunk->transport->last_time_heard = ktime_get(); |
1da177e4 LT |
1043 | |
1044 | /* Run through the state machine. */ | |
55e26eb9 | 1045 | error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, |
1da177e4 LT |
1046 | state, ep, asoc, chunk, GFP_ATOMIC); |
1047 | ||
1048 | /* Check to see if the association is freed in response to | |
1049 | * the incoming chunk. If so, get out of the while loop. | |
1050 | */ | |
1051 | if (asoc->base.dead) | |
1052 | break; | |
1053 | ||
1054 | /* If there is an error on chunk, discard this packet. */ | |
1055 | if (error && chunk) | |
1056 | chunk->pdiscard = 1; | |
59d8d443 XL |
1057 | |
1058 | if (first_time) | |
1059 | first_time = 0; | |
1da177e4 LT |
1060 | } |
1061 | sctp_association_put(asoc); | |
1062 | } | |
1063 | ||
1064 | /* This routine moves an association from its old sk to a new sk. */ | |
1065 | void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk) | |
1066 | { | |
1067 | struct sctp_sock *newsp = sctp_sk(newsk); | |
1068 | struct sock *oldsk = assoc->base.sk; | |
1069 | ||
1070 | /* Delete the association from the old endpoint's list of | |
1071 | * associations. | |
1072 | */ | |
1073 | list_del_init(&assoc->asocs); | |
1074 | ||
1075 | /* Decrement the backlog value for a TCP-style socket. */ | |
1076 | if (sctp_style(oldsk, TCP)) | |
7976a11b | 1077 | sk_acceptq_removed(oldsk); |
1da177e4 LT |
1078 | |
1079 | /* Release references to the old endpoint and the sock. */ | |
1080 | sctp_endpoint_put(assoc->ep); | |
1081 | sock_put(assoc->base.sk); | |
1082 | ||
1083 | /* Get a reference to the new endpoint. */ | |
1084 | assoc->ep = newsp->ep; | |
1085 | sctp_endpoint_hold(assoc->ep); | |
1086 | ||
1087 | /* Get a reference to the new sock. */ | |
1088 | assoc->base.sk = newsk; | |
1089 | sock_hold(assoc->base.sk); | |
1090 | ||
1091 | /* Add the association to the new endpoint's list of associations. */ | |
1092 | sctp_endpoint_add_asoc(newsp->ep, assoc); | |
1093 | } | |
1094 | ||
1095 | /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ | |
5ee8aa68 XL |
1096 | int sctp_assoc_update(struct sctp_association *asoc, |
1097 | struct sctp_association *new) | |
1da177e4 LT |
1098 | { |
1099 | struct sctp_transport *trans; | |
1100 | struct list_head *pos, *temp; | |
1101 | ||
1102 | /* Copy in new parameters of peer. */ | |
1103 | asoc->c = new->c; | |
1104 | asoc->peer.rwnd = new->peer.rwnd; | |
1105 | asoc->peer.sack_needed = new->peer.sack_needed; | |
1be9a950 | 1106 | asoc->peer.auth_capable = new->peer.auth_capable; |
1da177e4 | 1107 | asoc->peer.i = new->peer.i; |
5ee8aa68 XL |
1108 | |
1109 | if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, | |
1110 | asoc->peer.i.initial_tsn, GFP_ATOMIC)) | |
1111 | return -ENOMEM; | |
1da177e4 LT |
1112 | |
1113 | /* Remove any peer addresses not present in the new association. */ | |
1114 | list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { | |
1115 | trans = list_entry(pos, struct sctp_transport, transports); | |
0c42749c VY |
1116 | if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) { |
1117 | sctp_assoc_rm_peer(asoc, trans); | |
1118 | continue; | |
1119 | } | |
749bf921 VY |
1120 | |
1121 | if (asoc->state >= SCTP_STATE_ESTABLISHED) | |
1122 | sctp_transport_reset(trans); | |
1da177e4 LT |
1123 | } |
1124 | ||
1125 | /* If the case is A (association restart), use | |
1126 | * initial_tsn as next_tsn. If the case is B, use | |
1127 | * current next_tsn in case data sent to peer | |
1128 | * has been discarded and needs retransmission. | |
1129 | */ | |
1130 | if (asoc->state >= SCTP_STATE_ESTABLISHED) { | |
1131 | asoc->next_tsn = new->next_tsn; | |
1132 | asoc->ctsn_ack_point = new->ctsn_ack_point; | |
1133 | asoc->adv_peer_ack_point = new->adv_peer_ack_point; | |
1134 | ||
1135 | /* Reinitialize SSN for both local streams | |
1136 | * and peer's streams. | |
1137 | */ | |
cee360ab | 1138 | sctp_stream_clear(&asoc->stream); |
1da177e4 | 1139 | |
0b58a811 VY |
1140 | /* Flush the ULP reassembly and ordered queue. |
1141 | * Any data there will now be stale and will | |
1142 | * cause problems. | |
1143 | */ | |
1144 | sctp_ulpq_flush(&asoc->ulpq); | |
1145 | ||
749bf921 VY |
1146 | /* reset the overall association error count so |
1147 | * that the restarted association doesn't get torn | |
1148 | * down on the next retransmission timer. | |
1149 | */ | |
1150 | asoc->overall_error_count = 0; | |
1151 | ||
1da177e4 LT |
1152 | } else { |
1153 | /* Add any peer addresses from the new association. */ | |
9dbc15f0 | 1154 | list_for_each_entry(trans, &new->peer.transport_addr_list, |
5ee8aa68 XL |
1155 | transports) |
1156 | if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr) && | |
1157 | !sctp_assoc_add_peer(asoc, &trans->ipaddr, | |
1158 | GFP_ATOMIC, trans->state)) | |
1159 | return -ENOMEM; | |
1da177e4 LT |
1160 | |
1161 | asoc->ctsn_ack_point = asoc->next_tsn - 1; | |
1162 | asoc->adv_peer_ack_point = asoc->ctsn_ack_point; | |
3ab21379 | 1163 | |
cee360ab XL |
1164 | if (sctp_state(asoc, COOKIE_WAIT)) |
1165 | sctp_stream_update(&asoc->stream, &new->stream); | |
07d93967 | 1166 | |
4abf5a65 | 1167 | /* get a new assoc id if we don't have one yet. */ |
5ee8aa68 XL |
1168 | if (sctp_assoc_set_id(asoc, GFP_ATOMIC)) |
1169 | return -ENOMEM; | |
1da177e4 | 1170 | } |
a29a5bd4 | 1171 | |
9d2c881a | 1172 | /* SCTP-AUTH: Save the peer parameters from the new associations |
730fc3d0 VY |
1173 | * and also move the association shared keys over |
1174 | */ | |
1175 | kfree(asoc->peer.peer_random); | |
1176 | asoc->peer.peer_random = new->peer.peer_random; | |
1177 | new->peer.peer_random = NULL; | |
1178 | ||
1179 | kfree(asoc->peer.peer_chunks); | |
1180 | asoc->peer.peer_chunks = new->peer.peer_chunks; | |
1181 | new->peer.peer_chunks = NULL; | |
1182 | ||
1183 | kfree(asoc->peer.peer_hmacs); | |
1184 | asoc->peer.peer_hmacs = new->peer.peer_hmacs; | |
1185 | new->peer.peer_hmacs = NULL; | |
1186 | ||
5ee8aa68 | 1187 | return sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC); |
1da177e4 LT |
1188 | } |
1189 | ||
1190 | /* Update the retran path for sending a retransmitted packet. | |
4c47af4d DB |
1191 | * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints: |
1192 | * | |
1193 | * When there is outbound data to send and the primary path | |
1194 | * becomes inactive (e.g., due to failures), or where the | |
1195 | * SCTP user explicitly requests to send data to an | |
1196 | * inactive destination transport address, before reporting | |
1197 | * an error to its ULP, the SCTP endpoint should try to send | |
1198 | * the data to an alternate active destination transport | |
1199 | * address if one exists. | |
1200 | * | |
1201 | * When retransmitting data that timed out, if the endpoint | |
1202 | * is multihomed, it should consider each source-destination | |
1203 | * address pair in its retransmission selection policy. | |
1204 | * When retransmitting timed-out data, the endpoint should | |
1205 | * attempt to pick the most divergent source-destination | |
1206 | * pair from the original source-destination pair to which | |
1207 | * the packet was transmitted. | |
1208 | * | |
1209 | * Note: Rules for picking the most divergent source-destination | |
1210 | * pair are an implementation decision and are not specified | |
1211 | * within this document. | |
1212 | * | |
1213 | * Our basic strategy is to round-robin transports in priorities | |
2103d6b8 | 1214 | * according to sctp_trans_score() e.g., if no such |
4c47af4d DB |
1215 | * transport with state SCTP_ACTIVE exists, round-robin through |
1216 | * SCTP_UNKNOWN, etc. You get the picture. | |
1da177e4 | 1217 | */ |
4c47af4d | 1218 | static u8 sctp_trans_score(const struct sctp_transport *trans) |
1da177e4 | 1219 | { |
2103d6b8 DV |
1220 | switch (trans->state) { |
1221 | case SCTP_ACTIVE: | |
1222 | return 3; /* best case */ | |
1223 | case SCTP_UNKNOWN: | |
1224 | return 2; | |
1225 | case SCTP_PF: | |
1226 | return 1; | |
1227 | default: /* case SCTP_INACTIVE */ | |
1228 | return 0; /* worst case */ | |
1229 | } | |
4c47af4d | 1230 | } |
1da177e4 | 1231 | |
a7288c4d DB |
1232 | static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1, |
1233 | struct sctp_transport *trans2) | |
1234 | { | |
1235 | if (trans1->error_count > trans2->error_count) { | |
1236 | return trans2; | |
1237 | } else if (trans1->error_count == trans2->error_count && | |
1238 | ktime_after(trans2->last_time_heard, | |
1239 | trans1->last_time_heard)) { | |
1240 | return trans2; | |
1241 | } else { | |
1242 | return trans1; | |
1243 | } | |
1244 | } | |
1245 | ||
4c47af4d DB |
1246 | static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr, |
1247 | struct sctp_transport *best) | |
1248 | { | |
a7288c4d DB |
1249 | u8 score_curr, score_best; |
1250 | ||
ea4f19c1 | 1251 | if (best == NULL || curr == best) |
4c47af4d | 1252 | return curr; |
4141ddc0 | 1253 | |
a7288c4d DB |
1254 | score_curr = sctp_trans_score(curr); |
1255 | score_best = sctp_trans_score(best); | |
1256 | ||
1257 | /* First, try a score-based selection if both transport states | |
1258 | * differ. If we're in a tie, lets try to make a more clever | |
1259 | * decision here based on error counts and last time heard. | |
1260 | */ | |
1261 | if (score_curr > score_best) | |
1262 | return curr; | |
1263 | else if (score_curr == score_best) | |
39d2adeb | 1264 | return sctp_trans_elect_tie(best, curr); |
a7288c4d DB |
1265 | else |
1266 | return best; | |
4c47af4d | 1267 | } |
1da177e4 | 1268 | |
4c47af4d DB |
1269 | void sctp_assoc_update_retran_path(struct sctp_association *asoc) |
1270 | { | |
1271 | struct sctp_transport *trans = asoc->peer.retran_path; | |
1272 | struct sctp_transport *trans_next = NULL; | |
1da177e4 | 1273 | |
4c47af4d DB |
1274 | /* We're done as we only have the one and only path. */ |
1275 | if (asoc->peer.transport_count == 1) | |
1276 | return; | |
1277 | /* If active_path and retran_path are the same and active, | |
1278 | * then this is the only active path. Use it. | |
1279 | */ | |
1280 | if (asoc->peer.active_path == asoc->peer.retran_path && | |
1281 | asoc->peer.active_path->state == SCTP_ACTIVE) | |
1282 | return; | |
1da177e4 | 1283 | |
4c47af4d DB |
1284 | /* Iterate from retran_path's successor back to retran_path. */ |
1285 | for (trans = list_next_entry(trans, transports); 1; | |
1286 | trans = list_next_entry(trans, transports)) { | |
1287 | /* Manually skip the head element. */ | |
1288 | if (&trans->transports == &asoc->peer.transport_addr_list) | |
1289 | continue; | |
1290 | if (trans->state == SCTP_UNCONFIRMED) | |
1291 | continue; | |
1292 | trans_next = sctp_trans_elect_best(trans, trans_next); | |
1293 | /* Active is good enough for immediate return. */ | |
1294 | if (trans_next->state == SCTP_ACTIVE) | |
4141ddc0 | 1295 | break; |
4c47af4d DB |
1296 | /* We've reached the end, time to update path. */ |
1297 | if (trans == asoc->peer.retran_path) | |
1da177e4 | 1298 | break; |
1da177e4 LT |
1299 | } |
1300 | ||
433131ba | 1301 | asoc->peer.retran_path = trans_next; |
3f7a87d2 | 1302 | |
4c47af4d DB |
1303 | pr_debug("%s: association:%p updated new path to addr:%pISpc\n", |
1304 | __func__, asoc, &asoc->peer.retran_path->ipaddr.sa); | |
3f7a87d2 FF |
1305 | } |
1306 | ||
b82e8f31 DB |
1307 | static void sctp_select_active_and_retran_path(struct sctp_association *asoc) |
1308 | { | |
1309 | struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL; | |
a7288c4d | 1310 | struct sctp_transport *trans_pf = NULL; |
b82e8f31 DB |
1311 | |
1312 | /* Look for the two most recently used active transports. */ | |
1313 | list_for_each_entry(trans, &asoc->peer.transport_addr_list, | |
1314 | transports) { | |
a7288c4d | 1315 | /* Skip uninteresting transports. */ |
b82e8f31 | 1316 | if (trans->state == SCTP_INACTIVE || |
a7288c4d | 1317 | trans->state == SCTP_UNCONFIRMED) |
b82e8f31 | 1318 | continue; |
a7288c4d DB |
1319 | /* Keep track of the best PF transport from our |
1320 | * list in case we don't find an active one. | |
1321 | */ | |
1322 | if (trans->state == SCTP_PF) { | |
1323 | trans_pf = sctp_trans_elect_best(trans, trans_pf); | |
1324 | continue; | |
1325 | } | |
1326 | /* For active transports, pick the most recent ones. */ | |
b82e8f31 | 1327 | if (trans_pri == NULL || |
e575235f DB |
1328 | ktime_after(trans->last_time_heard, |
1329 | trans_pri->last_time_heard)) { | |
b82e8f31 DB |
1330 | trans_sec = trans_pri; |
1331 | trans_pri = trans; | |
1332 | } else if (trans_sec == NULL || | |
e575235f DB |
1333 | ktime_after(trans->last_time_heard, |
1334 | trans_sec->last_time_heard)) { | |
b82e8f31 DB |
1335 | trans_sec = trans; |
1336 | } | |
1337 | } | |
1338 | ||
1339 | /* RFC 2960 6.4 Multi-Homed SCTP Endpoints | |
1340 | * | |
1341 | * By default, an endpoint should always transmit to the primary | |
1342 | * path, unless the SCTP user explicitly specifies the | |
1343 | * destination transport address (and possibly source transport | |
1344 | * address) to use. [If the primary is active but not most recent, | |
1345 | * bump the most recently used transport.] | |
1346 | */ | |
1347 | if ((asoc->peer.primary_path->state == SCTP_ACTIVE || | |
1348 | asoc->peer.primary_path->state == SCTP_UNKNOWN) && | |
1349 | asoc->peer.primary_path != trans_pri) { | |
1350 | trans_sec = trans_pri; | |
1351 | trans_pri = asoc->peer.primary_path; | |
1352 | } | |
1353 | ||
1354 | /* We did not find anything useful for a possible retransmission | |
1355 | * path; either primary path that we found is the the same as | |
1356 | * the current one, or we didn't generally find an active one. | |
1357 | */ | |
1358 | if (trans_sec == NULL) | |
1359 | trans_sec = trans_pri; | |
1360 | ||
1361 | /* If we failed to find a usable transport, just camp on the | |
aa4a83ee | 1362 | * active or pick a PF iff it's the better choice. |
b82e8f31 DB |
1363 | */ |
1364 | if (trans_pri == NULL) { | |
aa4a83ee DB |
1365 | trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf); |
1366 | trans_sec = trans_pri; | |
b82e8f31 DB |
1367 | } |
1368 | ||
1369 | /* Set the active and retran transports. */ | |
1370 | asoc->peer.active_path = trans_pri; | |
1371 | asoc->peer.retran_path = trans_sec; | |
1372 | } | |
1373 | ||
4c47af4d DB |
1374 | struct sctp_transport * |
1375 | sctp_assoc_choose_alter_transport(struct sctp_association *asoc, | |
1376 | struct sctp_transport *last_sent_to) | |
3f7a87d2 | 1377 | { |
9919b455 WY |
1378 | /* If this is the first time packet is sent, use the active path, |
1379 | * else use the retran path. If the last packet was sent over the | |
3f7a87d2 FF |
1380 | * retran path, update the retran path and use it. |
1381 | */ | |
4c47af4d | 1382 | if (last_sent_to == NULL) { |
1da177e4 | 1383 | return asoc->peer.active_path; |
4c47af4d | 1384 | } else { |
9919b455 | 1385 | if (last_sent_to == asoc->peer.retran_path) |
1da177e4 | 1386 | sctp_assoc_update_retran_path(asoc); |
4c47af4d | 1387 | |
1da177e4 LT |
1388 | return asoc->peer.retran_path; |
1389 | } | |
1da177e4 LT |
1390 | } |
1391 | ||
2f5e3c9d MRL |
1392 | void sctp_assoc_update_frag_point(struct sctp_association *asoc) |
1393 | { | |
1394 | int frag = sctp_mtu_payload(sctp_sk(asoc->base.sk), asoc->pathmtu, | |
1395 | sctp_datachk_len(&asoc->stream)); | |
1396 | ||
1397 | if (asoc->user_frag) | |
1398 | frag = min_t(int, frag, asoc->user_frag); | |
1399 | ||
1400 | frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN - | |
1401 | sctp_datachk_len(&asoc->stream)); | |
1402 | ||
1403 | asoc->frag_point = SCTP_TRUNC4(frag); | |
1404 | } | |
1405 | ||
c4b2893d MRL |
1406 | void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu) |
1407 | { | |
2f5e3c9d | 1408 | if (asoc->pathmtu != pmtu) { |
c4b2893d | 1409 | asoc->pathmtu = pmtu; |
2f5e3c9d MRL |
1410 | sctp_assoc_update_frag_point(asoc); |
1411 | } | |
c4b2893d MRL |
1412 | |
1413 | pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc, | |
1414 | asoc->pathmtu, asoc->frag_point); | |
1415 | } | |
1416 | ||
1da177e4 LT |
1417 | /* Update the association's pmtu and frag_point by going through all the |
1418 | * transports. This routine is called when a transport's PMTU has changed. | |
1419 | */ | |
3ebfdf08 | 1420 | void sctp_assoc_sync_pmtu(struct sctp_association *asoc) |
1da177e4 LT |
1421 | { |
1422 | struct sctp_transport *t; | |
1da177e4 LT |
1423 | __u32 pmtu = 0; |
1424 | ||
1425 | if (!asoc) | |
1426 | return; | |
1427 | ||
1428 | /* Get the lowest pmtu of all the transports. */ | |
6ff0f871 | 1429 | list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { |
8a479491 | 1430 | if (t->pmtu_pending && t->dst) { |
d805397c XL |
1431 | sctp_transport_update_pmtu(t, |
1432 | atomic_read(&t->mtu_info)); | |
8a479491 VY |
1433 | t->pmtu_pending = 0; |
1434 | } | |
52ccb8e9 FF |
1435 | if (!pmtu || (t->pathmtu < pmtu)) |
1436 | pmtu = t->pathmtu; | |
1da177e4 LT |
1437 | } |
1438 | ||
c4b2893d | 1439 | sctp_assoc_set_pmtu(asoc, pmtu); |
1da177e4 LT |
1440 | } |
1441 | ||
1442 | /* Should we send a SACK to update our peer? */ | |
ce4a03db | 1443 | static inline bool sctp_peer_needs_update(struct sctp_association *asoc) |
1da177e4 | 1444 | { |
e1fc3b14 | 1445 | struct net *net = sock_net(asoc->base.sk); |
1da177e4 LT |
1446 | switch (asoc->state) { |
1447 | case SCTP_STATE_ESTABLISHED: | |
1448 | case SCTP_STATE_SHUTDOWN_PENDING: | |
1449 | case SCTP_STATE_SHUTDOWN_RECEIVED: | |
1450 | case SCTP_STATE_SHUTDOWN_SENT: | |
1451 | if ((asoc->rwnd > asoc->a_rwnd) && | |
90f2f531 | 1452 | ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32, |
e1fc3b14 | 1453 | (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift), |
90f2f531 | 1454 | asoc->pathmtu))) |
ce4a03db | 1455 | return true; |
1da177e4 LT |
1456 | break; |
1457 | default: | |
1458 | break; | |
1459 | } | |
ce4a03db | 1460 | return false; |
1da177e4 LT |
1461 | } |
1462 | ||
362d5204 DB |
1463 | /* Increase asoc's rwnd by len and send any window update SACK if needed. */ |
1464 | void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len) | |
1da177e4 LT |
1465 | { |
1466 | struct sctp_chunk *sack; | |
1467 | struct timer_list *timer; | |
1468 | ||
362d5204 DB |
1469 | if (asoc->rwnd_over) { |
1470 | if (asoc->rwnd_over >= len) { | |
1471 | asoc->rwnd_over -= len; | |
1472 | } else { | |
1473 | asoc->rwnd += (len - asoc->rwnd_over); | |
1474 | asoc->rwnd_over = 0; | |
1475 | } | |
1476 | } else { | |
1477 | asoc->rwnd += len; | |
1478 | } | |
1da177e4 | 1479 | |
362d5204 DB |
1480 | /* If we had window pressure, start recovering it |
1481 | * once our rwnd had reached the accumulated pressure | |
1482 | * threshold. The idea is to recover slowly, but up | |
1483 | * to the initial advertised window. | |
1484 | */ | |
1636098c | 1485 | if (asoc->rwnd_press) { |
362d5204 DB |
1486 | int change = min(asoc->pathmtu, asoc->rwnd_press); |
1487 | asoc->rwnd += change; | |
1488 | asoc->rwnd_press -= change; | |
1489 | } | |
4d3c46e6 | 1490 | |
362d5204 DB |
1491 | pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n", |
1492 | __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, | |
1493 | asoc->a_rwnd); | |
1da177e4 LT |
1494 | |
1495 | /* Send a window update SACK if the rwnd has increased by at least the | |
1496 | * minimum of the association's PMTU and half of the receive buffer. | |
1497 | * The algorithm used is similar to the one described in | |
1498 | * Section 4.2.3.3 of RFC 1122. | |
1499 | */ | |
362d5204 | 1500 | if (sctp_peer_needs_update(asoc)) { |
1da177e4 | 1501 | asoc->a_rwnd = asoc->rwnd; |
bb33381d DB |
1502 | |
1503 | pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u " | |
1504 | "a_rwnd:%u\n", __func__, asoc, asoc->rwnd, | |
1505 | asoc->a_rwnd); | |
1506 | ||
1da177e4 LT |
1507 | sack = sctp_make_sack(asoc); |
1508 | if (!sack) | |
1509 | return; | |
1510 | ||
1511 | asoc->peer.sack_needed = 0; | |
1512 | ||
cea8768f | 1513 | sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC); |
1da177e4 LT |
1514 | |
1515 | /* Stop the SACK timer. */ | |
1516 | timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; | |
25cc4ae9 | 1517 | if (del_timer(timer)) |
1da177e4 LT |
1518 | sctp_association_put(asoc); |
1519 | } | |
1520 | } | |
1521 | ||
362d5204 DB |
1522 | /* Decrease asoc's rwnd by len. */ |
1523 | void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len) | |
1524 | { | |
1525 | int rx_count; | |
1526 | int over = 0; | |
1527 | ||
1528 | if (unlikely(!asoc->rwnd || asoc->rwnd_over)) | |
1529 | pr_debug("%s: association:%p has asoc->rwnd:%u, " | |
1530 | "asoc->rwnd_over:%u!\n", __func__, asoc, | |
1531 | asoc->rwnd, asoc->rwnd_over); | |
1532 | ||
1533 | if (asoc->ep->rcvbuf_policy) | |
1534 | rx_count = atomic_read(&asoc->rmem_alloc); | |
1535 | else | |
1536 | rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc); | |
1537 | ||
1538 | /* If we've reached or overflowed our receive buffer, announce | |
1539 | * a 0 rwnd if rwnd would still be positive. Store the | |
1540 | * the potential pressure overflow so that the window can be restored | |
1541 | * back to original value. | |
1542 | */ | |
1543 | if (rx_count >= asoc->base.sk->sk_rcvbuf) | |
1544 | over = 1; | |
1545 | ||
1546 | if (asoc->rwnd >= len) { | |
1547 | asoc->rwnd -= len; | |
1548 | if (over) { | |
1549 | asoc->rwnd_press += asoc->rwnd; | |
1550 | asoc->rwnd = 0; | |
1551 | } | |
1552 | } else { | |
58b94d88 | 1553 | asoc->rwnd_over += len - asoc->rwnd; |
362d5204 DB |
1554 | asoc->rwnd = 0; |
1555 | } | |
1556 | ||
1557 | pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n", | |
1558 | __func__, asoc, len, asoc->rwnd, asoc->rwnd_over, | |
1559 | asoc->rwnd_press); | |
1560 | } | |
1da177e4 LT |
1561 | |
1562 | /* Build the bind address list for the association based on info from the | |
1563 | * local endpoint and the remote peer. | |
1564 | */ | |
3182cd84 | 1565 | int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, |
1c662018 | 1566 | enum sctp_scope scope, gfp_t gfp) |
1da177e4 | 1567 | { |
1da177e4 LT |
1568 | int flags; |
1569 | ||
1570 | /* Use scoping rules to determine the subset of addresses from | |
1571 | * the endpoint. | |
1572 | */ | |
1da177e4 LT |
1573 | flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0; |
1574 | if (asoc->peer.ipv4_address) | |
1575 | flags |= SCTP_ADDR4_PEERSUPP; | |
1576 | if (asoc->peer.ipv6_address) | |
1577 | flags |= SCTP_ADDR6_PEERSUPP; | |
1578 | ||
4db67e80 EB |
1579 | return sctp_bind_addr_copy(sock_net(asoc->base.sk), |
1580 | &asoc->base.bind_addr, | |
1da177e4 LT |
1581 | &asoc->ep->base.bind_addr, |
1582 | scope, gfp, flags); | |
1583 | } | |
1584 | ||
1585 | /* Build the association's bind address list from the cookie. */ | |
1586 | int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc, | |
3182cd84 | 1587 | struct sctp_cookie *cookie, |
dd0fc66f | 1588 | gfp_t gfp) |
1da177e4 LT |
1589 | { |
1590 | int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); | |
1591 | int var_size3 = cookie->raw_addr_list_len; | |
1592 | __u8 *raw = (__u8 *)cookie->peer_init + var_size2; | |
1593 | ||
1594 | return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3, | |
1595 | asoc->ep->base.bind_addr.port, gfp); | |
1596 | } | |
1597 | ||
d808ad9a YH |
1598 | /* Lookup laddr in the bind address list of an association. */ |
1599 | int sctp_assoc_lookup_laddr(struct sctp_association *asoc, | |
1da177e4 LT |
1600 | const union sctp_addr *laddr) |
1601 | { | |
559cf710 | 1602 | int found = 0; |
1da177e4 | 1603 | |
1da177e4 LT |
1604 | if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) && |
1605 | sctp_bind_addr_match(&asoc->base.bind_addr, laddr, | |
559cf710 | 1606 | sctp_sk(asoc->base.sk))) |
1da177e4 | 1607 | found = 1; |
1da177e4 | 1608 | |
1da177e4 LT |
1609 | return found; |
1610 | } | |
07d93967 VY |
1611 | |
1612 | /* Set an association id for a given association */ | |
1613 | int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp) | |
1614 | { | |
d0164adc | 1615 | bool preload = gfpflags_allow_blocking(gfp); |
94960e8c | 1616 | int ret; |
c6ba68a2 VY |
1617 | |
1618 | /* If the id is already assigned, keep it. */ | |
1619 | if (asoc->assoc_id) | |
94960e8c | 1620 | return 0; |
07d93967 | 1621 | |
94960e8c TH |
1622 | if (preload) |
1623 | idr_preload(gfp); | |
07d93967 | 1624 | spin_lock_bh(&sctp_assocs_id_lock); |
80df2704 XL |
1625 | /* 0, 1, 2 are used as SCTP_FUTURE_ASSOC, SCTP_CURRENT_ASSOC and |
1626 | * SCTP_ALL_ASSOC, so an available id must be > SCTP_ALL_ASSOC. | |
1627 | */ | |
1628 | ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, SCTP_ALL_ASSOC + 1, 0, | |
1629 | GFP_NOWAIT); | |
07d93967 | 1630 | spin_unlock_bh(&sctp_assocs_id_lock); |
94960e8c TH |
1631 | if (preload) |
1632 | idr_preload_end(); | |
1633 | if (ret < 0) | |
1634 | return ret; | |
07d93967 | 1635 | |
94960e8c TH |
1636 | asoc->assoc_id = (sctp_assoc_t)ret; |
1637 | return 0; | |
07d93967 | 1638 | } |
a08de64d | 1639 | |
8b4472cc WY |
1640 | /* Free the ASCONF queue */ |
1641 | static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc) | |
1642 | { | |
1643 | struct sctp_chunk *asconf; | |
1644 | struct sctp_chunk *tmp; | |
1645 | ||
1646 | list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) { | |
1647 | list_del_init(&asconf->list); | |
1648 | sctp_chunk_free(asconf); | |
1649 | } | |
1650 | } | |
1651 | ||
a08de64d VY |
1652 | /* Free asconf_ack cache */ |
1653 | static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc) | |
1654 | { | |
1655 | struct sctp_chunk *ack; | |
1656 | struct sctp_chunk *tmp; | |
1657 | ||
1658 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, | |
1659 | transmitted_list) { | |
1660 | list_del_init(&ack->transmitted_list); | |
1661 | sctp_chunk_free(ack); | |
1662 | } | |
1663 | } | |
1664 | ||
1665 | /* Clean up the ASCONF_ACK queue */ | |
1666 | void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc) | |
1667 | { | |
1668 | struct sctp_chunk *ack; | |
1669 | struct sctp_chunk *tmp; | |
1670 | ||
25985edc | 1671 | /* We can remove all the entries from the queue up to |
a08de64d VY |
1672 | * the "Peer-Sequence-Number". |
1673 | */ | |
1674 | list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list, | |
1675 | transmitted_list) { | |
1676 | if (ack->subh.addip_hdr->serial == | |
1677 | htonl(asoc->peer.addip_serial)) | |
1678 | break; | |
1679 | ||
1680 | list_del_init(&ack->transmitted_list); | |
1681 | sctp_chunk_free(ack); | |
1682 | } | |
1683 | } | |
1684 | ||
1685 | /* Find the ASCONF_ACK whose serial number matches ASCONF */ | |
1686 | struct sctp_chunk *sctp_assoc_lookup_asconf_ack( | |
1687 | const struct sctp_association *asoc, | |
1688 | __be32 serial) | |
1689 | { | |
a8699814 | 1690 | struct sctp_chunk *ack; |
a08de64d VY |
1691 | |
1692 | /* Walk through the list of cached ASCONF-ACKs and find the | |
1693 | * ack chunk whose serial number matches that of the request. | |
1694 | */ | |
1695 | list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) { | |
b69040d8 DB |
1696 | if (sctp_chunk_pending(ack)) |
1697 | continue; | |
a08de64d VY |
1698 | if (ack->subh.addip_hdr->serial == serial) { |
1699 | sctp_chunk_hold(ack); | |
a8699814 | 1700 | return ack; |
a08de64d VY |
1701 | } |
1702 | } | |
1703 | ||
a8699814 | 1704 | return NULL; |
a08de64d | 1705 | } |
a000c01e WY |
1706 | |
1707 | void sctp_asconf_queue_teardown(struct sctp_association *asoc) | |
1708 | { | |
1709 | /* Free any cached ASCONF_ACK chunk. */ | |
1710 | sctp_assoc_free_asconf_acks(asoc); | |
1711 | ||
1712 | /* Free the ASCONF queue. */ | |
1713 | sctp_assoc_free_asconf_queue(asoc); | |
1714 | ||
1715 | /* Free any cached ASCONF chunk. */ | |
1716 | if (asoc->addip_last_asconf) | |
1717 | sctp_chunk_free(asoc->addip_last_asconf); | |
1718 | } |