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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) 2001-2002 Intel Corp. | |
6 | * Copyright (c) 2002 Nokia Corp. | |
7 | * | |
8 | * This file is part of the SCTP kernel reference Implementation | |
9 | * | |
10 | * This is part of the SCTP Linux Kernel Reference Implementation. | |
11 | * | |
12 | * These are the state functions for the state machine. | |
13 | * | |
14 | * The SCTP reference implementation is free software; | |
15 | * you can redistribute it and/or modify it under the terms of | |
16 | * the GNU General Public License as published by | |
17 | * the Free Software Foundation; either version 2, or (at your option) | |
18 | * any later version. | |
19 | * | |
20 | * The SCTP reference implementation is distributed in the hope that it | |
21 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied | |
22 | * ************************ | |
23 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
24 | * See the GNU General Public License for more details. | |
25 | * | |
26 | * You should have received a copy of the GNU General Public License | |
27 | * along with GNU CC; see the file COPYING. If not, write to | |
28 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
29 | * Boston, MA 02111-1307, USA. | |
30 | * | |
31 | * Please send any bug reports or fixes you make to the | |
32 | * email address(es): | |
33 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
34 | * | |
35 | * Or submit a bug report through the following website: | |
36 | * http://www.sf.net/projects/lksctp | |
37 | * | |
38 | * Written or modified by: | |
39 | * La Monte H.P. Yarroll <piggy@acm.org> | |
40 | * Karl Knutson <karl@athena.chicago.il.us> | |
41 | * Mathew Kotowsky <kotowsky@sctp.org> | |
42 | * Sridhar Samudrala <samudrala@us.ibm.com> | |
43 | * Jon Grimm <jgrimm@us.ibm.com> | |
44 | * Hui Huang <hui.huang@nokia.com> | |
45 | * Dajiang Zhang <dajiang.zhang@nokia.com> | |
46 | * Daisy Chang <daisyc@us.ibm.com> | |
47 | * Ardelle Fan <ardelle.fan@intel.com> | |
48 | * Ryan Layer <rmlayer@us.ibm.com> | |
49 | * Kevin Gao <kevin.gao@intel.com> | |
50 | * | |
51 | * Any bugs reported given to us we will try to fix... any fixes shared will | |
52 | * be incorporated into the next SCTP release. | |
53 | */ | |
54 | ||
55 | #include <linux/types.h> | |
56 | #include <linux/kernel.h> | |
57 | #include <linux/ip.h> | |
58 | #include <linux/ipv6.h> | |
59 | #include <linux/net.h> | |
60 | #include <linux/inet.h> | |
61 | #include <net/sock.h> | |
62 | #include <net/inet_ecn.h> | |
63 | #include <linux/skbuff.h> | |
64 | #include <net/sctp/sctp.h> | |
65 | #include <net/sctp/sm.h> | |
66 | #include <net/sctp/structs.h> | |
67 | ||
68 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, | |
69 | const struct sctp_association *asoc, | |
70 | struct sctp_chunk *chunk, | |
71 | const void *payload, | |
72 | size_t paylen); | |
73 | static int sctp_eat_data(const struct sctp_association *asoc, | |
74 | struct sctp_chunk *chunk, | |
75 | sctp_cmd_seq_t *commands); | |
76 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, | |
77 | const struct sctp_chunk *chunk); | |
78 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, | |
79 | const struct sctp_association *asoc, | |
80 | const struct sctp_chunk *chunk, | |
81 | sctp_cmd_seq_t *commands, | |
82 | struct sctp_chunk *err_chunk); | |
83 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, | |
84 | const struct sctp_association *asoc, | |
85 | const sctp_subtype_t type, | |
86 | void *arg, | |
87 | sctp_cmd_seq_t *commands); | |
88 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, | |
89 | const struct sctp_association *asoc, | |
90 | const sctp_subtype_t type, | |
91 | void *arg, | |
92 | sctp_cmd_seq_t *commands); | |
93 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk); | |
94 | ||
95 | ||
96 | /* Small helper function that checks if the chunk length | |
97 | * is of the appropriate length. The 'required_length' argument | |
98 | * is set to be the size of a specific chunk we are testing. | |
99 | * Return Values: 1 = Valid length | |
100 | * 0 = Invalid length | |
101 | * | |
102 | */ | |
103 | static inline int | |
104 | sctp_chunk_length_valid(struct sctp_chunk *chunk, | |
105 | __u16 required_length) | |
106 | { | |
107 | __u16 chunk_length = ntohs(chunk->chunk_hdr->length); | |
108 | ||
109 | if (unlikely(chunk_length < required_length)) | |
110 | return 0; | |
111 | ||
112 | return 1; | |
113 | } | |
114 | ||
115 | /********************************************************** | |
116 | * These are the state functions for handling chunk events. | |
117 | **********************************************************/ | |
118 | ||
119 | /* | |
120 | * Process the final SHUTDOWN COMPLETE. | |
121 | * | |
122 | * Section: 4 (C) (diagram), 9.2 | |
123 | * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify | |
124 | * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be | |
125 | * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint | |
126 | * should stop the T2-shutdown timer and remove all knowledge of the | |
127 | * association (and thus the association enters the CLOSED state). | |
128 | * | |
129 | * Verification Tag: 8.5.1(C) | |
130 | * C) Rules for packet carrying SHUTDOWN COMPLETE: | |
131 | * ... | |
132 | * - The receiver of a SHUTDOWN COMPLETE shall accept the packet if the | |
133 | * Verification Tag field of the packet matches its own tag OR it is | |
134 | * set to its peer's tag and the T bit is set in the Chunk Flags. | |
135 | * Otherwise, the receiver MUST silently discard the packet and take | |
136 | * no further action. An endpoint MUST ignore the SHUTDOWN COMPLETE if | |
137 | * it is not in the SHUTDOWN-ACK-SENT state. | |
138 | * | |
139 | * Inputs | |
140 | * (endpoint, asoc, chunk) | |
141 | * | |
142 | * Outputs | |
143 | * (asoc, reply_msg, msg_up, timers, counters) | |
144 | * | |
145 | * The return value is the disposition of the chunk. | |
146 | */ | |
147 | sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep, | |
148 | const struct sctp_association *asoc, | |
149 | const sctp_subtype_t type, | |
150 | void *arg, | |
151 | sctp_cmd_seq_t *commands) | |
152 | { | |
153 | struct sctp_chunk *chunk = arg; | |
154 | struct sctp_ulpevent *ev; | |
155 | ||
156 | /* RFC 2960 6.10 Bundling | |
157 | * | |
158 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
159 | * SHUTDOWN COMPLETE with any other chunks. | |
160 | */ | |
161 | if (!chunk->singleton) | |
162 | return SCTP_DISPOSITION_VIOLATION; | |
163 | ||
164 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
165 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
166 | ||
167 | /* RFC 2960 10.2 SCTP-to-ULP | |
168 | * | |
169 | * H) SHUTDOWN COMPLETE notification | |
170 | * | |
171 | * When SCTP completes the shutdown procedures (section 9.2) this | |
172 | * notification is passed to the upper layer. | |
173 | */ | |
174 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, | |
175 | 0, 0, 0, GFP_ATOMIC); | |
176 | if (!ev) | |
177 | goto nomem; | |
178 | ||
179 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
180 | ||
181 | /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint | |
182 | * will verify that it is in SHUTDOWN-ACK-SENT state, if it is | |
183 | * not the chunk should be discarded. If the endpoint is in | |
184 | * the SHUTDOWN-ACK-SENT state the endpoint should stop the | |
185 | * T2-shutdown timer and remove all knowledge of the | |
186 | * association (and thus the association enters the CLOSED | |
187 | * state). | |
188 | */ | |
189 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
190 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
191 | ||
192 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
193 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
194 | ||
195 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
196 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
197 | ||
198 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); | |
199 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
200 | ||
201 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
202 | ||
203 | return SCTP_DISPOSITION_DELETE_TCB; | |
204 | ||
205 | nomem: | |
206 | return SCTP_DISPOSITION_NOMEM; | |
207 | } | |
208 | ||
209 | /* | |
210 | * Respond to a normal INIT chunk. | |
211 | * We are the side that is being asked for an association. | |
212 | * | |
213 | * Section: 5.1 Normal Establishment of an Association, B | |
214 | * B) "Z" shall respond immediately with an INIT ACK chunk. The | |
215 | * destination IP address of the INIT ACK MUST be set to the source | |
216 | * IP address of the INIT to which this INIT ACK is responding. In | |
217 | * the response, besides filling in other parameters, "Z" must set the | |
218 | * Verification Tag field to Tag_A, and also provide its own | |
219 | * Verification Tag (Tag_Z) in the Initiate Tag field. | |
220 | * | |
221 | * Verification Tag: Must be 0. | |
222 | * | |
223 | * Inputs | |
224 | * (endpoint, asoc, chunk) | |
225 | * | |
226 | * Outputs | |
227 | * (asoc, reply_msg, msg_up, timers, counters) | |
228 | * | |
229 | * The return value is the disposition of the chunk. | |
230 | */ | |
231 | sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep, | |
232 | const struct sctp_association *asoc, | |
233 | const sctp_subtype_t type, | |
234 | void *arg, | |
235 | sctp_cmd_seq_t *commands) | |
236 | { | |
237 | struct sctp_chunk *chunk = arg; | |
238 | struct sctp_chunk *repl; | |
239 | struct sctp_association *new_asoc; | |
240 | struct sctp_chunk *err_chunk; | |
241 | struct sctp_packet *packet; | |
242 | sctp_unrecognized_param_t *unk_param; | |
243 | struct sock *sk; | |
244 | int len; | |
245 | ||
246 | /* 6.10 Bundling | |
247 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
248 | * SHUTDOWN COMPLETE with any other chunks. | |
249 | * | |
250 | * IG Section 2.11.2 | |
251 | * Furthermore, we require that the receiver of an INIT chunk MUST | |
252 | * enforce these rules by silently discarding an arriving packet | |
253 | * with an INIT chunk that is bundled with other chunks. | |
254 | */ | |
255 | if (!chunk->singleton) | |
256 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
257 | ||
258 | /* If the packet is an OOTB packet which is temporarily on the | |
259 | * control endpoint, respond with an ABORT. | |
260 | */ | |
261 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) | |
262 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); | |
263 | ||
264 | sk = ep->base.sk; | |
265 | /* If the endpoint is not listening or if the number of associations | |
266 | * on the TCP-style socket exceed the max backlog, respond with an | |
267 | * ABORT. | |
268 | */ | |
269 | if (!sctp_sstate(sk, LISTENING) || | |
270 | (sctp_style(sk, TCP) && | |
271 | sk_acceptq_is_full(sk))) | |
272 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); | |
273 | ||
274 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification | |
275 | * Tag. | |
276 | */ | |
277 | if (chunk->sctp_hdr->vtag != 0) | |
278 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); | |
279 | ||
280 | /* Make sure that the INIT chunk has a valid length. | |
281 | * Normally, this would cause an ABORT with a Protocol Violation | |
282 | * error, but since we don't have an association, we'll | |
283 | * just discard the packet. | |
284 | */ | |
285 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) | |
286 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
287 | ||
288 | /* Verify the INIT chunk before processing it. */ | |
289 | err_chunk = NULL; | |
290 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, | |
291 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, | |
292 | &err_chunk)) { | |
293 | /* This chunk contains fatal error. It is to be discarded. | |
294 | * Send an ABORT, with causes if there is any. | |
295 | */ | |
296 | if (err_chunk) { | |
297 | packet = sctp_abort_pkt_new(ep, asoc, arg, | |
298 | (__u8 *)(err_chunk->chunk_hdr) + | |
299 | sizeof(sctp_chunkhdr_t), | |
300 | ntohs(err_chunk->chunk_hdr->length) - | |
301 | sizeof(sctp_chunkhdr_t)); | |
302 | ||
303 | sctp_chunk_free(err_chunk); | |
304 | ||
305 | if (packet) { | |
306 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
307 | SCTP_PACKET(packet)); | |
308 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
309 | return SCTP_DISPOSITION_CONSUME; | |
310 | } else { | |
311 | return SCTP_DISPOSITION_NOMEM; | |
312 | } | |
313 | } else { | |
314 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, | |
315 | commands); | |
316 | } | |
317 | } | |
318 | ||
319 | /* Grab the INIT header. */ | |
320 | chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data; | |
321 | ||
322 | /* Tag the variable length parameters. */ | |
323 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); | |
324 | ||
325 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); | |
326 | if (!new_asoc) | |
327 | goto nomem; | |
328 | ||
329 | /* The call, sctp_process_init(), can fail on memory allocation. */ | |
330 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, | |
331 | sctp_source(chunk), | |
332 | (sctp_init_chunk_t *)chunk->chunk_hdr, | |
333 | GFP_ATOMIC)) | |
334 | goto nomem_init; | |
335 | ||
336 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
337 | ||
338 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ | |
339 | ||
340 | /* If there are errors need to be reported for unknown parameters, | |
341 | * make sure to reserve enough room in the INIT ACK for them. | |
342 | */ | |
343 | len = 0; | |
344 | if (err_chunk) | |
345 | len = ntohs(err_chunk->chunk_hdr->length) - | |
346 | sizeof(sctp_chunkhdr_t); | |
347 | ||
348 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) | |
349 | goto nomem_ack; | |
350 | ||
351 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); | |
352 | if (!repl) | |
353 | goto nomem_ack; | |
354 | ||
355 | /* If there are errors need to be reported for unknown parameters, | |
356 | * include them in the outgoing INIT ACK as "Unrecognized parameter" | |
357 | * parameter. | |
358 | */ | |
359 | if (err_chunk) { | |
360 | /* Get the "Unrecognized parameter" parameter(s) out of the | |
361 | * ERROR chunk generated by sctp_verify_init(). Since the | |
362 | * error cause code for "unknown parameter" and the | |
363 | * "Unrecognized parameter" type is the same, we can | |
364 | * construct the parameters in INIT ACK by copying the | |
365 | * ERROR causes over. | |
366 | */ | |
367 | unk_param = (sctp_unrecognized_param_t *) | |
368 | ((__u8 *)(err_chunk->chunk_hdr) + | |
369 | sizeof(sctp_chunkhdr_t)); | |
370 | /* Replace the cause code with the "Unrecognized parameter" | |
371 | * parameter type. | |
372 | */ | |
373 | sctp_addto_chunk(repl, len, unk_param); | |
374 | sctp_chunk_free(err_chunk); | |
375 | } | |
376 | ||
377 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
378 | ||
379 | /* | |
380 | * Note: After sending out INIT ACK with the State Cookie parameter, | |
381 | * "Z" MUST NOT allocate any resources, nor keep any states for the | |
382 | * new association. Otherwise, "Z" will be vulnerable to resource | |
383 | * attacks. | |
384 | */ | |
385 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
386 | ||
387 | return SCTP_DISPOSITION_DELETE_TCB; | |
388 | ||
389 | nomem_ack: | |
390 | if (err_chunk) | |
391 | sctp_chunk_free(err_chunk); | |
392 | nomem_init: | |
393 | sctp_association_free(new_asoc); | |
394 | nomem: | |
395 | return SCTP_DISPOSITION_NOMEM; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Respond to a normal INIT ACK chunk. | |
400 | * We are the side that is initiating the association. | |
401 | * | |
402 | * Section: 5.1 Normal Establishment of an Association, C | |
403 | * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init | |
404 | * timer and leave COOKIE-WAIT state. "A" shall then send the State | |
405 | * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start | |
406 | * the T1-cookie timer, and enter the COOKIE-ECHOED state. | |
407 | * | |
408 | * Note: The COOKIE ECHO chunk can be bundled with any pending outbound | |
409 | * DATA chunks, but it MUST be the first chunk in the packet and | |
410 | * until the COOKIE ACK is returned the sender MUST NOT send any | |
411 | * other packets to the peer. | |
412 | * | |
413 | * Verification Tag: 3.3.3 | |
414 | * If the value of the Initiate Tag in a received INIT ACK chunk is | |
415 | * found to be 0, the receiver MUST treat it as an error and close the | |
416 | * association by transmitting an ABORT. | |
417 | * | |
418 | * Inputs | |
419 | * (endpoint, asoc, chunk) | |
420 | * | |
421 | * Outputs | |
422 | * (asoc, reply_msg, msg_up, timers, counters) | |
423 | * | |
424 | * The return value is the disposition of the chunk. | |
425 | */ | |
426 | sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep, | |
427 | const struct sctp_association *asoc, | |
428 | const sctp_subtype_t type, | |
429 | void *arg, | |
430 | sctp_cmd_seq_t *commands) | |
431 | { | |
432 | struct sctp_chunk *chunk = arg; | |
433 | sctp_init_chunk_t *initchunk; | |
434 | __u32 init_tag; | |
435 | struct sctp_chunk *err_chunk; | |
436 | struct sctp_packet *packet; | |
437 | sctp_disposition_t ret; | |
438 | ||
439 | if (!sctp_vtag_verify(chunk, asoc)) | |
440 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
441 | ||
442 | /* Make sure that the INIT-ACK chunk has a valid length */ | |
443 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t))) | |
444 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
445 | commands); | |
446 | /* 6.10 Bundling | |
447 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
448 | * SHUTDOWN COMPLETE with any other chunks. | |
449 | */ | |
450 | if (!chunk->singleton) | |
451 | return SCTP_DISPOSITION_VIOLATION; | |
452 | ||
453 | /* Grab the INIT header. */ | |
454 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; | |
455 | ||
456 | init_tag = ntohl(chunk->subh.init_hdr->init_tag); | |
457 | ||
458 | /* Verification Tag: 3.3.3 | |
459 | * If the value of the Initiate Tag in a received INIT ACK | |
460 | * chunk is found to be 0, the receiver MUST treat it as an | |
461 | * error and close the association by transmitting an ABORT. | |
462 | */ | |
463 | if (!init_tag) { | |
464 | struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0); | |
465 | if (!reply) | |
466 | goto nomem; | |
467 | ||
468 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
469 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
470 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
471 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
472 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
473 | return SCTP_DISPOSITION_DELETE_TCB; | |
474 | } | |
475 | ||
476 | /* Verify the INIT chunk before processing it. */ | |
477 | err_chunk = NULL; | |
478 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, | |
479 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, | |
480 | &err_chunk)) { | |
481 | ||
482 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
483 | ||
484 | /* This chunk contains fatal error. It is to be discarded. | |
485 | * Send an ABORT, with causes if there is any. | |
486 | */ | |
487 | if (err_chunk) { | |
488 | packet = sctp_abort_pkt_new(ep, asoc, arg, | |
489 | (__u8 *)(err_chunk->chunk_hdr) + | |
490 | sizeof(sctp_chunkhdr_t), | |
491 | ntohs(err_chunk->chunk_hdr->length) - | |
492 | sizeof(sctp_chunkhdr_t)); | |
493 | ||
494 | sctp_chunk_free(err_chunk); | |
495 | ||
496 | if (packet) { | |
497 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
498 | SCTP_PACKET(packet)); | |
499 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
500 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
501 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
502 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, | |
503 | SCTP_NULL()); | |
504 | return SCTP_DISPOSITION_CONSUME; | |
505 | } else { | |
506 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
507 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
508 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, | |
509 | SCTP_NULL()); | |
510 | return SCTP_DISPOSITION_NOMEM; | |
511 | } | |
512 | } else { | |
513 | ret = sctp_sf_tabort_8_4_8(ep, asoc, type, arg, | |
514 | commands); | |
515 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
516 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
517 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, | |
518 | SCTP_NULL()); | |
519 | return ret; | |
520 | } | |
521 | } | |
522 | ||
523 | /* Tag the variable length parameters. Note that we never | |
524 | * convert the parameters in an INIT chunk. | |
525 | */ | |
526 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); | |
527 | ||
528 | initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr; | |
529 | ||
530 | sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, | |
531 | SCTP_PEER_INIT(initchunk)); | |
532 | ||
533 | /* 5.1 C) "A" shall stop the T1-init timer and leave | |
534 | * COOKIE-WAIT state. "A" shall then ... start the T1-cookie | |
535 | * timer, and enter the COOKIE-ECHOED state. | |
536 | */ | |
537 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
538 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
539 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
540 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
541 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
542 | SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); | |
543 | ||
544 | /* 5.1 C) "A" shall then send the State Cookie received in the | |
545 | * INIT ACK chunk in a COOKIE ECHO chunk, ... | |
546 | */ | |
547 | /* If there is any errors to report, send the ERROR chunk generated | |
548 | * for unknown parameters as well. | |
549 | */ | |
550 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, | |
551 | SCTP_CHUNK(err_chunk)); | |
552 | ||
553 | return SCTP_DISPOSITION_CONSUME; | |
554 | ||
555 | nomem: | |
556 | return SCTP_DISPOSITION_NOMEM; | |
557 | } | |
558 | ||
559 | /* | |
560 | * Respond to a normal COOKIE ECHO chunk. | |
561 | * We are the side that is being asked for an association. | |
562 | * | |
563 | * Section: 5.1 Normal Establishment of an Association, D | |
564 | * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply | |
565 | * with a COOKIE ACK chunk after building a TCB and moving to | |
566 | * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with | |
567 | * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK | |
568 | * chunk MUST be the first chunk in the packet. | |
569 | * | |
570 | * IMPLEMENTATION NOTE: An implementation may choose to send the | |
571 | * Communication Up notification to the SCTP user upon reception | |
572 | * of a valid COOKIE ECHO chunk. | |
573 | * | |
574 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules | |
575 | * D) Rules for packet carrying a COOKIE ECHO | |
576 | * | |
577 | * - When sending a COOKIE ECHO, the endpoint MUST use the value of the | |
578 | * Initial Tag received in the INIT ACK. | |
579 | * | |
580 | * - The receiver of a COOKIE ECHO follows the procedures in Section 5. | |
581 | * | |
582 | * Inputs | |
583 | * (endpoint, asoc, chunk) | |
584 | * | |
585 | * Outputs | |
586 | * (asoc, reply_msg, msg_up, timers, counters) | |
587 | * | |
588 | * The return value is the disposition of the chunk. | |
589 | */ | |
590 | sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep, | |
591 | const struct sctp_association *asoc, | |
592 | const sctp_subtype_t type, void *arg, | |
593 | sctp_cmd_seq_t *commands) | |
594 | { | |
595 | struct sctp_chunk *chunk = arg; | |
596 | struct sctp_association *new_asoc; | |
597 | sctp_init_chunk_t *peer_init; | |
598 | struct sctp_chunk *repl; | |
599 | struct sctp_ulpevent *ev; | |
600 | int error = 0; | |
601 | struct sctp_chunk *err_chk_p; | |
602 | ||
603 | /* If the packet is an OOTB packet which is temporarily on the | |
604 | * control endpoint, respond with an ABORT. | |
605 | */ | |
606 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) | |
607 | return sctp_sf_ootb(ep, asoc, type, arg, commands); | |
608 | ||
609 | /* Make sure that the COOKIE_ECHO chunk has a valid length. | |
610 | * In this case, we check that we have enough for at least a | |
611 | * chunk header. More detailed verification is done | |
612 | * in sctp_unpack_cookie(). | |
613 | */ | |
614 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) | |
615 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
616 | ||
617 | /* "Decode" the chunk. We have no optional parameters so we | |
618 | * are in good shape. | |
619 | */ | |
620 | chunk->subh.cookie_hdr = | |
621 | (struct sctp_signed_cookie *)chunk->skb->data; | |
622 | skb_pull(chunk->skb, | |
623 | ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t)); | |
624 | ||
625 | /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint | |
626 | * "Z" will reply with a COOKIE ACK chunk after building a TCB | |
627 | * and moving to the ESTABLISHED state. | |
628 | */ | |
629 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, | |
630 | &err_chk_p); | |
631 | ||
632 | /* FIXME: | |
633 | * If the re-build failed, what is the proper error path | |
634 | * from here? | |
635 | * | |
636 | * [We should abort the association. --piggy] | |
637 | */ | |
638 | if (!new_asoc) { | |
639 | /* FIXME: Several errors are possible. A bad cookie should | |
640 | * be silently discarded, but think about logging it too. | |
641 | */ | |
642 | switch (error) { | |
643 | case -SCTP_IERROR_NOMEM: | |
644 | goto nomem; | |
645 | ||
646 | case -SCTP_IERROR_STALE_COOKIE: | |
647 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, | |
648 | err_chk_p); | |
649 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
650 | ||
651 | case -SCTP_IERROR_BAD_SIG: | |
652 | default: | |
653 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
654 | }; | |
655 | } | |
656 | ||
657 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
658 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
659 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
660 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); | |
661 | SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS); | |
662 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
663 | ||
664 | if (new_asoc->autoclose) | |
665 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
666 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
667 | ||
668 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); | |
669 | ||
670 | /* Re-build the bind address for the association is done in | |
671 | * the sctp_unpack_cookie() already. | |
672 | */ | |
673 | /* This is a brand-new association, so these are not yet side | |
674 | * effects--it is safe to run them here. | |
675 | */ | |
676 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
677 | ||
678 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, | |
679 | &chunk->subh.cookie_hdr->c.peer_addr, | |
680 | peer_init, GFP_ATOMIC)) | |
681 | goto nomem_init; | |
682 | ||
683 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
684 | if (!repl) | |
685 | goto nomem_repl; | |
686 | ||
687 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
688 | ||
689 | /* RFC 2960 5.1 Normal Establishment of an Association | |
690 | * | |
691 | * D) IMPLEMENTATION NOTE: An implementation may choose to | |
692 | * send the Communication Up notification to the SCTP user | |
693 | * upon reception of a valid COOKIE ECHO chunk. | |
694 | */ | |
695 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, | |
696 | new_asoc->c.sinit_num_ostreams, | |
697 | new_asoc->c.sinit_max_instreams, | |
698 | GFP_ATOMIC); | |
699 | if (!ev) | |
700 | goto nomem_ev; | |
701 | ||
702 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
703 | ||
704 | /* Sockets API Draft Section 5.3.1.6 | |
705 | * When a peer sends a Adaption Layer Indication parameter , SCTP | |
706 | * delivers this notification to inform the application that of the | |
707 | * peers requested adaption layer. | |
708 | */ | |
709 | if (new_asoc->peer.adaption_ind) { | |
710 | ev = sctp_ulpevent_make_adaption_indication(new_asoc, | |
711 | GFP_ATOMIC); | |
712 | if (!ev) | |
713 | goto nomem_ev; | |
714 | ||
715 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
716 | SCTP_ULPEVENT(ev)); | |
717 | } | |
718 | ||
719 | return SCTP_DISPOSITION_CONSUME; | |
720 | ||
721 | nomem_ev: | |
722 | sctp_chunk_free(repl); | |
723 | nomem_repl: | |
724 | nomem_init: | |
725 | sctp_association_free(new_asoc); | |
726 | nomem: | |
727 | return SCTP_DISPOSITION_NOMEM; | |
728 | } | |
729 | ||
730 | /* | |
731 | * Respond to a normal COOKIE ACK chunk. | |
732 | * We are the side that is being asked for an association. | |
733 | * | |
734 | * RFC 2960 5.1 Normal Establishment of an Association | |
735 | * | |
736 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the | |
737 | * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie | |
738 | * timer. It may also notify its ULP about the successful | |
739 | * establishment of the association with a Communication Up | |
740 | * notification (see Section 10). | |
741 | * | |
742 | * Verification Tag: | |
743 | * Inputs | |
744 | * (endpoint, asoc, chunk) | |
745 | * | |
746 | * Outputs | |
747 | * (asoc, reply_msg, msg_up, timers, counters) | |
748 | * | |
749 | * The return value is the disposition of the chunk. | |
750 | */ | |
751 | sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep, | |
752 | const struct sctp_association *asoc, | |
753 | const sctp_subtype_t type, void *arg, | |
754 | sctp_cmd_seq_t *commands) | |
755 | { | |
756 | struct sctp_chunk *chunk = arg; | |
757 | struct sctp_ulpevent *ev; | |
758 | ||
759 | if (!sctp_vtag_verify(chunk, asoc)) | |
760 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
761 | ||
762 | /* Verify that the chunk length for the COOKIE-ACK is OK. | |
763 | * If we don't do this, any bundled chunks may be junked. | |
764 | */ | |
765 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) | |
766 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
767 | commands); | |
768 | ||
769 | /* Reset init error count upon receipt of COOKIE-ACK, | |
770 | * to avoid problems with the managemement of this | |
771 | * counter in stale cookie situations when a transition back | |
772 | * from the COOKIE-ECHOED state to the COOKIE-WAIT | |
773 | * state is performed. | |
774 | */ | |
775 | sctp_add_cmd_sf(commands, SCTP_CMD_COUNTER_RESET, | |
776 | SCTP_COUNTER(SCTP_COUNTER_INIT_ERROR)); | |
777 | ||
778 | /* RFC 2960 5.1 Normal Establishment of an Association | |
779 | * | |
780 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move | |
781 | * from the COOKIE-ECHOED state to the ESTABLISHED state, | |
782 | * stopping the T1-cookie timer. | |
783 | */ | |
784 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
785 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
786 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
787 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
788 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); | |
789 | SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS); | |
790 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
791 | if (asoc->autoclose) | |
792 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
793 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
794 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); | |
795 | ||
796 | /* It may also notify its ULP about the successful | |
797 | * establishment of the association with a Communication Up | |
798 | * notification (see Section 10). | |
799 | */ | |
800 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, | |
801 | 0, asoc->c.sinit_num_ostreams, | |
802 | asoc->c.sinit_max_instreams, | |
803 | GFP_ATOMIC); | |
804 | ||
805 | if (!ev) | |
806 | goto nomem; | |
807 | ||
808 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
809 | ||
810 | /* Sockets API Draft Section 5.3.1.6 | |
811 | * When a peer sends a Adaption Layer Indication parameter , SCTP | |
812 | * delivers this notification to inform the application that of the | |
813 | * peers requested adaption layer. | |
814 | */ | |
815 | if (asoc->peer.adaption_ind) { | |
816 | ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC); | |
817 | if (!ev) | |
818 | goto nomem; | |
819 | ||
820 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
821 | SCTP_ULPEVENT(ev)); | |
822 | } | |
823 | ||
824 | return SCTP_DISPOSITION_CONSUME; | |
825 | nomem: | |
826 | return SCTP_DISPOSITION_NOMEM; | |
827 | } | |
828 | ||
829 | /* Generate and sendout a heartbeat packet. */ | |
830 | static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep, | |
831 | const struct sctp_association *asoc, | |
832 | const sctp_subtype_t type, | |
833 | void *arg, | |
834 | sctp_cmd_seq_t *commands) | |
835 | { | |
836 | struct sctp_transport *transport = (struct sctp_transport *) arg; | |
837 | struct sctp_chunk *reply; | |
838 | sctp_sender_hb_info_t hbinfo; | |
839 | size_t paylen = 0; | |
840 | ||
841 | hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; | |
842 | hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); | |
843 | hbinfo.daddr = transport->ipaddr; | |
844 | hbinfo.sent_at = jiffies; | |
845 | ||
846 | /* Send a heartbeat to our peer. */ | |
847 | paylen = sizeof(sctp_sender_hb_info_t); | |
848 | reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen); | |
849 | if (!reply) | |
850 | return SCTP_DISPOSITION_NOMEM; | |
851 | ||
852 | /* Set rto_pending indicating that an RTT measurement | |
853 | * is started with this heartbeat chunk. | |
854 | */ | |
855 | sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, | |
856 | SCTP_TRANSPORT(transport)); | |
857 | ||
858 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
859 | return SCTP_DISPOSITION_CONSUME; | |
860 | } | |
861 | ||
862 | /* Generate a HEARTBEAT packet on the given transport. */ | |
863 | sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep, | |
864 | const struct sctp_association *asoc, | |
865 | const sctp_subtype_t type, | |
866 | void *arg, | |
867 | sctp_cmd_seq_t *commands) | |
868 | { | |
869 | struct sctp_transport *transport = (struct sctp_transport *) arg; | |
870 | ||
871 | if (asoc->overall_error_count > asoc->max_retrans) { | |
872 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
873 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
874 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
875 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
876 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
877 | return SCTP_DISPOSITION_DELETE_TCB; | |
878 | } | |
879 | ||
880 | /* Section 3.3.5. | |
881 | * The Sender-specific Heartbeat Info field should normally include | |
882 | * information about the sender's current time when this HEARTBEAT | |
883 | * chunk is sent and the destination transport address to which this | |
884 | * HEARTBEAT is sent (see Section 8.3). | |
885 | */ | |
886 | ||
887 | if (transport->hb_allowed) { | |
888 | if (SCTP_DISPOSITION_NOMEM == | |
889 | sctp_sf_heartbeat(ep, asoc, type, arg, | |
890 | commands)) | |
891 | return SCTP_DISPOSITION_NOMEM; | |
892 | /* Set transport error counter and association error counter | |
893 | * when sending heartbeat. | |
894 | */ | |
895 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET, | |
896 | SCTP_TRANSPORT(transport)); | |
897 | } | |
898 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, | |
899 | SCTP_TRANSPORT(transport)); | |
900 | ||
901 | return SCTP_DISPOSITION_CONSUME; | |
902 | } | |
903 | ||
904 | /* | |
905 | * Process an heartbeat request. | |
906 | * | |
907 | * Section: 8.3 Path Heartbeat | |
908 | * The receiver of the HEARTBEAT should immediately respond with a | |
909 | * HEARTBEAT ACK that contains the Heartbeat Information field copied | |
910 | * from the received HEARTBEAT chunk. | |
911 | * | |
912 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
913 | * When receiving an SCTP packet, the endpoint MUST ensure that the | |
914 | * value in the Verification Tag field of the received SCTP packet | |
915 | * matches its own Tag. If the received Verification Tag value does not | |
916 | * match the receiver's own tag value, the receiver shall silently | |
917 | * discard the packet and shall not process it any further except for | |
918 | * those cases listed in Section 8.5.1 below. | |
919 | * | |
920 | * Inputs | |
921 | * (endpoint, asoc, chunk) | |
922 | * | |
923 | * Outputs | |
924 | * (asoc, reply_msg, msg_up, timers, counters) | |
925 | * | |
926 | * The return value is the disposition of the chunk. | |
927 | */ | |
928 | sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep, | |
929 | const struct sctp_association *asoc, | |
930 | const sctp_subtype_t type, | |
931 | void *arg, | |
932 | sctp_cmd_seq_t *commands) | |
933 | { | |
934 | struct sctp_chunk *chunk = arg; | |
935 | struct sctp_chunk *reply; | |
936 | size_t paylen = 0; | |
937 | ||
938 | if (!sctp_vtag_verify(chunk, asoc)) | |
939 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
940 | ||
941 | /* Make sure that the HEARTBEAT chunk has a valid length. */ | |
942 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) | |
943 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
944 | commands); | |
945 | ||
946 | /* 8.3 The receiver of the HEARTBEAT should immediately | |
947 | * respond with a HEARTBEAT ACK that contains the Heartbeat | |
948 | * Information field copied from the received HEARTBEAT chunk. | |
949 | */ | |
950 | chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data; | |
951 | paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); | |
952 | skb_pull(chunk->skb, paylen); | |
953 | ||
954 | reply = sctp_make_heartbeat_ack(asoc, chunk, | |
955 | chunk->subh.hb_hdr, paylen); | |
956 | if (!reply) | |
957 | goto nomem; | |
958 | ||
959 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
960 | return SCTP_DISPOSITION_CONSUME; | |
961 | ||
962 | nomem: | |
963 | return SCTP_DISPOSITION_NOMEM; | |
964 | } | |
965 | ||
966 | /* | |
967 | * Process the returning HEARTBEAT ACK. | |
968 | * | |
969 | * Section: 8.3 Path Heartbeat | |
970 | * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT | |
971 | * should clear the error counter of the destination transport | |
972 | * address to which the HEARTBEAT was sent, and mark the destination | |
973 | * transport address as active if it is not so marked. The endpoint may | |
974 | * optionally report to the upper layer when an inactive destination | |
975 | * address is marked as active due to the reception of the latest | |
976 | * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also | |
977 | * clear the association overall error count as well (as defined | |
978 | * in section 8.1). | |
979 | * | |
980 | * The receiver of the HEARTBEAT ACK should also perform an RTT | |
981 | * measurement for that destination transport address using the time | |
982 | * value carried in the HEARTBEAT ACK chunk. | |
983 | * | |
984 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
985 | * | |
986 | * Inputs | |
987 | * (endpoint, asoc, chunk) | |
988 | * | |
989 | * Outputs | |
990 | * (asoc, reply_msg, msg_up, timers, counters) | |
991 | * | |
992 | * The return value is the disposition of the chunk. | |
993 | */ | |
994 | sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep, | |
995 | const struct sctp_association *asoc, | |
996 | const sctp_subtype_t type, | |
997 | void *arg, | |
998 | sctp_cmd_seq_t *commands) | |
999 | { | |
1000 | struct sctp_chunk *chunk = arg; | |
1001 | union sctp_addr from_addr; | |
1002 | struct sctp_transport *link; | |
1003 | sctp_sender_hb_info_t *hbinfo; | |
1004 | unsigned long max_interval; | |
1005 | ||
1006 | if (!sctp_vtag_verify(chunk, asoc)) | |
1007 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1008 | ||
1009 | /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ | |
1010 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) | |
1011 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
1012 | commands); | |
1013 | ||
1014 | hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; | |
1015 | from_addr = hbinfo->daddr; | |
1016 | link = sctp_assoc_lookup_paddr(asoc, &from_addr); | |
1017 | ||
1018 | /* This should never happen, but lets log it if so. */ | |
1019 | if (!link) { | |
1020 | printk(KERN_WARNING | |
1021 | "%s: Could not find address %d.%d.%d.%d\n", | |
1022 | __FUNCTION__, NIPQUAD(from_addr.v4.sin_addr)); | |
1023 | return SCTP_DISPOSITION_DISCARD; | |
1024 | } | |
1025 | ||
1026 | max_interval = link->hb_interval + link->rto; | |
1027 | ||
1028 | /* Check if the timestamp looks valid. */ | |
1029 | if (time_after(hbinfo->sent_at, jiffies) || | |
1030 | time_after(jiffies, hbinfo->sent_at + max_interval)) { | |
1031 | SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp" | |
1032 | "received for transport: %p\n", | |
1033 | __FUNCTION__, link); | |
1034 | return SCTP_DISPOSITION_DISCARD; | |
1035 | } | |
1036 | ||
1037 | /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of | |
1038 | * the HEARTBEAT should clear the error counter of the | |
1039 | * destination transport address to which the HEARTBEAT was | |
1040 | * sent and mark the destination transport address as active if | |
1041 | * it is not so marked. | |
1042 | */ | |
1043 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); | |
1044 | ||
1045 | return SCTP_DISPOSITION_CONSUME; | |
1046 | } | |
1047 | ||
1048 | /* Helper function to send out an abort for the restart | |
1049 | * condition. | |
1050 | */ | |
1051 | static int sctp_sf_send_restart_abort(union sctp_addr *ssa, | |
1052 | struct sctp_chunk *init, | |
1053 | sctp_cmd_seq_t *commands) | |
1054 | { | |
1055 | int len; | |
1056 | struct sctp_packet *pkt; | |
1057 | union sctp_addr_param *addrparm; | |
1058 | struct sctp_errhdr *errhdr; | |
1059 | struct sctp_endpoint *ep; | |
1060 | char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)]; | |
1061 | struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); | |
1062 | ||
1063 | /* Build the error on the stack. We are way to malloc crazy | |
1064 | * throughout the code today. | |
1065 | */ | |
1066 | errhdr = (struct sctp_errhdr *)buffer; | |
1067 | addrparm = (union sctp_addr_param *)errhdr->variable; | |
1068 | ||
1069 | /* Copy into a parm format. */ | |
1070 | len = af->to_addr_param(ssa, addrparm); | |
1071 | len += sizeof(sctp_errhdr_t); | |
1072 | ||
1073 | errhdr->cause = SCTP_ERROR_RESTART; | |
1074 | errhdr->length = htons(len); | |
1075 | ||
1076 | /* Assign to the control socket. */ | |
1077 | ep = sctp_sk((sctp_get_ctl_sock()))->ep; | |
1078 | ||
1079 | /* Association is NULL since this may be a restart attack and we | |
1080 | * want to send back the attacker's vtag. | |
1081 | */ | |
1082 | pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len); | |
1083 | ||
1084 | if (!pkt) | |
1085 | goto out; | |
1086 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); | |
1087 | ||
1088 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
1089 | ||
1090 | /* Discard the rest of the inbound packet. */ | |
1091 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
1092 | ||
1093 | out: | |
1094 | /* Even if there is no memory, treat as a failure so | |
1095 | * the packet will get dropped. | |
1096 | */ | |
1097 | return 0; | |
1098 | } | |
1099 | ||
1100 | /* A restart is occurring, check to make sure no new addresses | |
1101 | * are being added as we may be under a takeover attack. | |
1102 | */ | |
1103 | static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, | |
1104 | const struct sctp_association *asoc, | |
1105 | struct sctp_chunk *init, | |
1106 | sctp_cmd_seq_t *commands) | |
1107 | { | |
1108 | struct sctp_transport *new_addr, *addr; | |
1109 | struct list_head *pos, *pos2; | |
1110 | int found; | |
1111 | ||
1112 | /* Implementor's Guide - Sectin 5.2.2 | |
1113 | * ... | |
1114 | * Before responding the endpoint MUST check to see if the | |
1115 | * unexpected INIT adds new addresses to the association. If new | |
1116 | * addresses are added to the association, the endpoint MUST respond | |
1117 | * with an ABORT.. | |
1118 | */ | |
1119 | ||
1120 | /* Search through all current addresses and make sure | |
1121 | * we aren't adding any new ones. | |
1122 | */ | |
1123 | new_addr = NULL; | |
1124 | found = 0; | |
1125 | ||
1126 | list_for_each(pos, &new_asoc->peer.transport_addr_list) { | |
1127 | new_addr = list_entry(pos, struct sctp_transport, transports); | |
1128 | found = 0; | |
1129 | list_for_each(pos2, &asoc->peer.transport_addr_list) { | |
1130 | addr = list_entry(pos2, struct sctp_transport, | |
1131 | transports); | |
1132 | if (sctp_cmp_addr_exact(&new_addr->ipaddr, | |
1133 | &addr->ipaddr)) { | |
1134 | found = 1; | |
1135 | break; | |
1136 | } | |
1137 | } | |
1138 | if (!found) | |
1139 | break; | |
1140 | } | |
1141 | ||
1142 | /* If a new address was added, ABORT the sender. */ | |
1143 | if (!found && new_addr) { | |
1144 | sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands); | |
1145 | } | |
1146 | ||
1147 | /* Return success if all addresses were found. */ | |
1148 | return found; | |
1149 | } | |
1150 | ||
1151 | /* Populate the verification/tie tags based on overlapping INIT | |
1152 | * scenario. | |
1153 | * | |
1154 | * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. | |
1155 | */ | |
1156 | static void sctp_tietags_populate(struct sctp_association *new_asoc, | |
1157 | const struct sctp_association *asoc) | |
1158 | { | |
1159 | switch (asoc->state) { | |
1160 | ||
1161 | /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ | |
1162 | ||
1163 | case SCTP_STATE_COOKIE_WAIT: | |
1164 | new_asoc->c.my_vtag = asoc->c.my_vtag; | |
1165 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1166 | new_asoc->c.peer_ttag = 0; | |
1167 | break; | |
1168 | ||
1169 | case SCTP_STATE_COOKIE_ECHOED: | |
1170 | new_asoc->c.my_vtag = asoc->c.my_vtag; | |
1171 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1172 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; | |
1173 | break; | |
1174 | ||
1175 | /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, | |
1176 | * COOKIE-WAIT and SHUTDOWN-ACK-SENT | |
1177 | */ | |
1178 | default: | |
1179 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1180 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; | |
1181 | break; | |
1182 | }; | |
1183 | ||
1184 | /* Other parameters for the endpoint SHOULD be copied from the | |
1185 | * existing parameters of the association (e.g. number of | |
1186 | * outbound streams) into the INIT ACK and cookie. | |
1187 | */ | |
1188 | new_asoc->rwnd = asoc->rwnd; | |
1189 | new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; | |
1190 | new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; | |
1191 | new_asoc->c.initial_tsn = asoc->c.initial_tsn; | |
1192 | } | |
1193 | ||
1194 | /* | |
1195 | * Compare vtag/tietag values to determine unexpected COOKIE-ECHO | |
1196 | * handling action. | |
1197 | * | |
1198 | * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. | |
1199 | * | |
1200 | * Returns value representing action to be taken. These action values | |
1201 | * correspond to Action/Description values in RFC 2960, Table 2. | |
1202 | */ | |
1203 | static char sctp_tietags_compare(struct sctp_association *new_asoc, | |
1204 | const struct sctp_association *asoc) | |
1205 | { | |
1206 | /* In this case, the peer may have restarted. */ | |
1207 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && | |
1208 | (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && | |
1209 | (asoc->c.my_vtag == new_asoc->c.my_ttag) && | |
1210 | (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) | |
1211 | return 'A'; | |
1212 | ||
1213 | /* Collision case B. */ | |
1214 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && | |
1215 | ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || | |
1216 | (0 == asoc->c.peer_vtag))) { | |
1217 | return 'B'; | |
1218 | } | |
1219 | ||
1220 | /* Collision case D. */ | |
1221 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && | |
1222 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) | |
1223 | return 'D'; | |
1224 | ||
1225 | /* Collision case C. */ | |
1226 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && | |
1227 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && | |
1228 | (0 == new_asoc->c.my_ttag) && | |
1229 | (0 == new_asoc->c.peer_ttag)) | |
1230 | return 'C'; | |
1231 | ||
1232 | /* No match to any of the special cases; discard this packet. */ | |
1233 | return 'E'; | |
1234 | } | |
1235 | ||
1236 | /* Common helper routine for both duplicate and simulataneous INIT | |
1237 | * chunk handling. | |
1238 | */ | |
1239 | static sctp_disposition_t sctp_sf_do_unexpected_init( | |
1240 | const struct sctp_endpoint *ep, | |
1241 | const struct sctp_association *asoc, | |
1242 | const sctp_subtype_t type, | |
1243 | void *arg, sctp_cmd_seq_t *commands) | |
1244 | { | |
1245 | sctp_disposition_t retval; | |
1246 | struct sctp_chunk *chunk = arg; | |
1247 | struct sctp_chunk *repl; | |
1248 | struct sctp_association *new_asoc; | |
1249 | struct sctp_chunk *err_chunk; | |
1250 | struct sctp_packet *packet; | |
1251 | sctp_unrecognized_param_t *unk_param; | |
1252 | int len; | |
1253 | ||
1254 | /* 6.10 Bundling | |
1255 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
1256 | * SHUTDOWN COMPLETE with any other chunks. | |
1257 | * | |
1258 | * IG Section 2.11.2 | |
1259 | * Furthermore, we require that the receiver of an INIT chunk MUST | |
1260 | * enforce these rules by silently discarding an arriving packet | |
1261 | * with an INIT chunk that is bundled with other chunks. | |
1262 | */ | |
1263 | if (!chunk->singleton) | |
1264 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1265 | ||
1266 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification | |
1267 | * Tag. | |
1268 | */ | |
1269 | if (chunk->sctp_hdr->vtag != 0) | |
1270 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); | |
1271 | ||
1272 | /* Make sure that the INIT chunk has a valid length. | |
1273 | * In this case, we generate a protocol violation since we have | |
1274 | * an association established. | |
1275 | */ | |
1276 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) | |
1277 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
1278 | commands); | |
1279 | /* Grab the INIT header. */ | |
1280 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; | |
1281 | ||
1282 | /* Tag the variable length parameters. */ | |
1283 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); | |
1284 | ||
1285 | /* Verify the INIT chunk before processing it. */ | |
1286 | err_chunk = NULL; | |
1287 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, | |
1288 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, | |
1289 | &err_chunk)) { | |
1290 | /* This chunk contains fatal error. It is to be discarded. | |
1291 | * Send an ABORT, with causes if there is any. | |
1292 | */ | |
1293 | if (err_chunk) { | |
1294 | packet = sctp_abort_pkt_new(ep, asoc, arg, | |
1295 | (__u8 *)(err_chunk->chunk_hdr) + | |
1296 | sizeof(sctp_chunkhdr_t), | |
1297 | ntohs(err_chunk->chunk_hdr->length) - | |
1298 | sizeof(sctp_chunkhdr_t)); | |
1299 | ||
1300 | if (packet) { | |
1301 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
1302 | SCTP_PACKET(packet)); | |
1303 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
1304 | retval = SCTP_DISPOSITION_CONSUME; | |
1305 | } else { | |
1306 | retval = SCTP_DISPOSITION_NOMEM; | |
1307 | } | |
1308 | goto cleanup; | |
1309 | } else { | |
1310 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, | |
1311 | commands); | |
1312 | } | |
1313 | } | |
1314 | ||
1315 | /* | |
1316 | * Other parameters for the endpoint SHOULD be copied from the | |
1317 | * existing parameters of the association (e.g. number of | |
1318 | * outbound streams) into the INIT ACK and cookie. | |
1319 | * FIXME: We are copying parameters from the endpoint not the | |
1320 | * association. | |
1321 | */ | |
1322 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); | |
1323 | if (!new_asoc) | |
1324 | goto nomem; | |
1325 | ||
1326 | /* In the outbound INIT ACK the endpoint MUST copy its current | |
1327 | * Verification Tag and Peers Verification tag into a reserved | |
1328 | * place (local tie-tag and per tie-tag) within the state cookie. | |
1329 | */ | |
1330 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, | |
1331 | sctp_source(chunk), | |
1332 | (sctp_init_chunk_t *)chunk->chunk_hdr, | |
1333 | GFP_ATOMIC)) { | |
1334 | retval = SCTP_DISPOSITION_NOMEM; | |
1335 | goto nomem_init; | |
1336 | } | |
1337 | ||
1338 | /* Make sure no new addresses are being added during the | |
1339 | * restart. Do not do this check for COOKIE-WAIT state, | |
1340 | * since there are no peer addresses to check against. | |
1341 | * Upon return an ABORT will have been sent if needed. | |
1342 | */ | |
1343 | if (!sctp_state(asoc, COOKIE_WAIT)) { | |
1344 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, | |
1345 | commands)) { | |
1346 | retval = SCTP_DISPOSITION_CONSUME; | |
1347 | goto cleanup_asoc; | |
1348 | } | |
1349 | } | |
1350 | ||
1351 | sctp_tietags_populate(new_asoc, asoc); | |
1352 | ||
1353 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ | |
1354 | ||
1355 | /* If there are errors need to be reported for unknown parameters, | |
1356 | * make sure to reserve enough room in the INIT ACK for them. | |
1357 | */ | |
1358 | len = 0; | |
1359 | if (err_chunk) { | |
1360 | len = ntohs(err_chunk->chunk_hdr->length) - | |
1361 | sizeof(sctp_chunkhdr_t); | |
1362 | } | |
1363 | ||
1364 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) | |
1365 | goto nomem; | |
1366 | ||
1367 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); | |
1368 | if (!repl) | |
1369 | goto nomem; | |
1370 | ||
1371 | /* If there are errors need to be reported for unknown parameters, | |
1372 | * include them in the outgoing INIT ACK as "Unrecognized parameter" | |
1373 | * parameter. | |
1374 | */ | |
1375 | if (err_chunk) { | |
1376 | /* Get the "Unrecognized parameter" parameter(s) out of the | |
1377 | * ERROR chunk generated by sctp_verify_init(). Since the | |
1378 | * error cause code for "unknown parameter" and the | |
1379 | * "Unrecognized parameter" type is the same, we can | |
1380 | * construct the parameters in INIT ACK by copying the | |
1381 | * ERROR causes over. | |
1382 | */ | |
1383 | unk_param = (sctp_unrecognized_param_t *) | |
1384 | ((__u8 *)(err_chunk->chunk_hdr) + | |
1385 | sizeof(sctp_chunkhdr_t)); | |
1386 | /* Replace the cause code with the "Unrecognized parameter" | |
1387 | * parameter type. | |
1388 | */ | |
1389 | sctp_addto_chunk(repl, len, unk_param); | |
1390 | } | |
1391 | ||
1392 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
1393 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1394 | ||
1395 | /* | |
1396 | * Note: After sending out INIT ACK with the State Cookie parameter, | |
1397 | * "Z" MUST NOT allocate any resources for this new association. | |
1398 | * Otherwise, "Z" will be vulnerable to resource attacks. | |
1399 | */ | |
1400 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
1401 | retval = SCTP_DISPOSITION_CONSUME; | |
1402 | ||
1403 | cleanup: | |
1404 | if (err_chunk) | |
1405 | sctp_chunk_free(err_chunk); | |
1406 | return retval; | |
1407 | nomem: | |
1408 | retval = SCTP_DISPOSITION_NOMEM; | |
1409 | goto cleanup; | |
1410 | nomem_init: | |
1411 | cleanup_asoc: | |
1412 | sctp_association_free(new_asoc); | |
1413 | goto cleanup; | |
1414 | } | |
1415 | ||
1416 | /* | |
1417 | * Handle simultanous INIT. | |
1418 | * This means we started an INIT and then we got an INIT request from | |
1419 | * our peer. | |
1420 | * | |
1421 | * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) | |
1422 | * This usually indicates an initialization collision, i.e., each | |
1423 | * endpoint is attempting, at about the same time, to establish an | |
1424 | * association with the other endpoint. | |
1425 | * | |
1426 | * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an | |
1427 | * endpoint MUST respond with an INIT ACK using the same parameters it | |
1428 | * sent in its original INIT chunk (including its Verification Tag, | |
1429 | * unchanged). These original parameters are combined with those from the | |
1430 | * newly received INIT chunk. The endpoint shall also generate a State | |
1431 | * Cookie with the INIT ACK. The endpoint uses the parameters sent in its | |
1432 | * INIT to calculate the State Cookie. | |
1433 | * | |
1434 | * After that, the endpoint MUST NOT change its state, the T1-init | |
1435 | * timer shall be left running and the corresponding TCB MUST NOT be | |
1436 | * destroyed. The normal procedures for handling State Cookies when | |
1437 | * a TCB exists will resolve the duplicate INITs to a single association. | |
1438 | * | |
1439 | * For an endpoint that is in the COOKIE-ECHOED state it MUST populate | |
1440 | * its Tie-Tags with the Tag information of itself and its peer (see | |
1441 | * section 5.2.2 for a description of the Tie-Tags). | |
1442 | * | |
1443 | * Verification Tag: Not explicit, but an INIT can not have a valid | |
1444 | * verification tag, so we skip the check. | |
1445 | * | |
1446 | * Inputs | |
1447 | * (endpoint, asoc, chunk) | |
1448 | * | |
1449 | * Outputs | |
1450 | * (asoc, reply_msg, msg_up, timers, counters) | |
1451 | * | |
1452 | * The return value is the disposition of the chunk. | |
1453 | */ | |
1454 | sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep, | |
1455 | const struct sctp_association *asoc, | |
1456 | const sctp_subtype_t type, | |
1457 | void *arg, | |
1458 | sctp_cmd_seq_t *commands) | |
1459 | { | |
1460 | /* Call helper to do the real work for both simulataneous and | |
1461 | * duplicate INIT chunk handling. | |
1462 | */ | |
1463 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); | |
1464 | } | |
1465 | ||
1466 | /* | |
1467 | * Handle duplicated INIT messages. These are usually delayed | |
1468 | * restransmissions. | |
1469 | * | |
1470 | * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, | |
1471 | * COOKIE-ECHOED and COOKIE-WAIT | |
1472 | * | |
1473 | * Unless otherwise stated, upon reception of an unexpected INIT for | |
1474 | * this association, the endpoint shall generate an INIT ACK with a | |
1475 | * State Cookie. In the outbound INIT ACK the endpoint MUST copy its | |
1476 | * current Verification Tag and peer's Verification Tag into a reserved | |
1477 | * place within the state cookie. We shall refer to these locations as | |
1478 | * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet | |
1479 | * containing this INIT ACK MUST carry a Verification Tag value equal to | |
1480 | * the Initiation Tag found in the unexpected INIT. And the INIT ACK | |
1481 | * MUST contain a new Initiation Tag (randomly generated see Section | |
1482 | * 5.3.1). Other parameters for the endpoint SHOULD be copied from the | |
1483 | * existing parameters of the association (e.g. number of outbound | |
1484 | * streams) into the INIT ACK and cookie. | |
1485 | * | |
1486 | * After sending out the INIT ACK, the endpoint shall take no further | |
1487 | * actions, i.e., the existing association, including its current state, | |
1488 | * and the corresponding TCB MUST NOT be changed. | |
1489 | * | |
1490 | * Note: Only when a TCB exists and the association is not in a COOKIE- | |
1491 | * WAIT state are the Tie-Tags populated. For a normal association INIT | |
1492 | * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be | |
1493 | * set to 0 (indicating that no previous TCB existed). The INIT ACK and | |
1494 | * State Cookie are populated as specified in section 5.2.1. | |
1495 | * | |
1496 | * Verification Tag: Not specified, but an INIT has no way of knowing | |
1497 | * what the verification tag could be, so we ignore it. | |
1498 | * | |
1499 | * Inputs | |
1500 | * (endpoint, asoc, chunk) | |
1501 | * | |
1502 | * Outputs | |
1503 | * (asoc, reply_msg, msg_up, timers, counters) | |
1504 | * | |
1505 | * The return value is the disposition of the chunk. | |
1506 | */ | |
1507 | sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep, | |
1508 | const struct sctp_association *asoc, | |
1509 | const sctp_subtype_t type, | |
1510 | void *arg, | |
1511 | sctp_cmd_seq_t *commands) | |
1512 | { | |
1513 | /* Call helper to do the real work for both simulataneous and | |
1514 | * duplicate INIT chunk handling. | |
1515 | */ | |
1516 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); | |
1517 | } | |
1518 | ||
1519 | ||
1520 | ||
1521 | /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') | |
1522 | * | |
1523 | * Section 5.2.4 | |
1524 | * A) In this case, the peer may have restarted. | |
1525 | */ | |
1526 | static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep, | |
1527 | const struct sctp_association *asoc, | |
1528 | struct sctp_chunk *chunk, | |
1529 | sctp_cmd_seq_t *commands, | |
1530 | struct sctp_association *new_asoc) | |
1531 | { | |
1532 | sctp_init_chunk_t *peer_init; | |
1533 | struct sctp_ulpevent *ev; | |
1534 | struct sctp_chunk *repl; | |
1535 | struct sctp_chunk *err; | |
1536 | sctp_disposition_t disposition; | |
1537 | ||
1538 | /* new_asoc is a brand-new association, so these are not yet | |
1539 | * side effects--it is safe to run them here. | |
1540 | */ | |
1541 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
1542 | ||
1543 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, | |
1544 | sctp_source(chunk), peer_init, | |
1545 | GFP_ATOMIC)) | |
1546 | goto nomem; | |
1547 | ||
1548 | /* Make sure no new addresses are being added during the | |
1549 | * restart. Though this is a pretty complicated attack | |
1550 | * since you'd have to get inside the cookie. | |
1551 | */ | |
1552 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) { | |
1553 | return SCTP_DISPOSITION_CONSUME; | |
1554 | } | |
1555 | ||
1556 | /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes | |
1557 | * the peer has restarted (Action A), it MUST NOT setup a new | |
1558 | * association but instead resend the SHUTDOWN ACK and send an ERROR | |
1559 | * chunk with a "Cookie Received while Shutting Down" error cause to | |
1560 | * its peer. | |
1561 | */ | |
1562 | if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { | |
1563 | disposition = sctp_sf_do_9_2_reshutack(ep, asoc, | |
1564 | SCTP_ST_CHUNK(chunk->chunk_hdr->type), | |
1565 | chunk, commands); | |
1566 | if (SCTP_DISPOSITION_NOMEM == disposition) | |
1567 | goto nomem; | |
1568 | ||
1569 | err = sctp_make_op_error(asoc, chunk, | |
1570 | SCTP_ERROR_COOKIE_IN_SHUTDOWN, | |
1571 | NULL, 0); | |
1572 | if (err) | |
1573 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
1574 | SCTP_CHUNK(err)); | |
1575 | ||
1576 | return SCTP_DISPOSITION_CONSUME; | |
1577 | } | |
1578 | ||
1579 | /* For now, fail any unsent/unacked data. Consider the optional | |
1580 | * choice of resending of this data. | |
1581 | */ | |
1582 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); | |
1583 | ||
1584 | /* Update the content of current association. */ | |
1585 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); | |
1586 | ||
1587 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1588 | if (!repl) | |
1589 | goto nomem; | |
1590 | ||
1591 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1592 | ||
1593 | /* Report association restart to upper layer. */ | |
1594 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, | |
1595 | new_asoc->c.sinit_num_ostreams, | |
1596 | new_asoc->c.sinit_max_instreams, | |
1597 | GFP_ATOMIC); | |
1598 | if (!ev) | |
1599 | goto nomem_ev; | |
1600 | ||
1601 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
1602 | return SCTP_DISPOSITION_CONSUME; | |
1603 | ||
1604 | nomem_ev: | |
1605 | sctp_chunk_free(repl); | |
1606 | nomem: | |
1607 | return SCTP_DISPOSITION_NOMEM; | |
1608 | } | |
1609 | ||
1610 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') | |
1611 | * | |
1612 | * Section 5.2.4 | |
1613 | * B) In this case, both sides may be attempting to start an association | |
1614 | * at about the same time but the peer endpoint started its INIT | |
1615 | * after responding to the local endpoint's INIT | |
1616 | */ | |
1617 | /* This case represents an initialization collision. */ | |
1618 | static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep, | |
1619 | const struct sctp_association *asoc, | |
1620 | struct sctp_chunk *chunk, | |
1621 | sctp_cmd_seq_t *commands, | |
1622 | struct sctp_association *new_asoc) | |
1623 | { | |
1624 | sctp_init_chunk_t *peer_init; | |
1625 | struct sctp_ulpevent *ev; | |
1626 | struct sctp_chunk *repl; | |
1627 | ||
1628 | /* new_asoc is a brand-new association, so these are not yet | |
1629 | * side effects--it is safe to run them here. | |
1630 | */ | |
1631 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
1632 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, | |
1633 | sctp_source(chunk), peer_init, | |
1634 | GFP_ATOMIC)) | |
1635 | goto nomem; | |
1636 | ||
1637 | /* Update the content of current association. */ | |
1638 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); | |
1639 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
1640 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
1641 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); | |
1642 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
1643 | ||
1644 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1645 | if (!repl) | |
1646 | goto nomem; | |
1647 | ||
1648 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1649 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); | |
1650 | ||
1651 | /* RFC 2960 5.1 Normal Establishment of an Association | |
1652 | * | |
1653 | * D) IMPLEMENTATION NOTE: An implementation may choose to | |
1654 | * send the Communication Up notification to the SCTP user | |
1655 | * upon reception of a valid COOKIE ECHO chunk. | |
1656 | */ | |
1657 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0, | |
1658 | new_asoc->c.sinit_num_ostreams, | |
1659 | new_asoc->c.sinit_max_instreams, | |
1660 | GFP_ATOMIC); | |
1661 | if (!ev) | |
1662 | goto nomem_ev; | |
1663 | ||
1664 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
1665 | ||
1666 | /* Sockets API Draft Section 5.3.1.6 | |
1667 | * When a peer sends a Adaption Layer Indication parameter , SCTP | |
1668 | * delivers this notification to inform the application that of the | |
1669 | * peers requested adaption layer. | |
1670 | */ | |
1671 | if (asoc->peer.adaption_ind) { | |
1672 | ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC); | |
1673 | if (!ev) | |
1674 | goto nomem_ev; | |
1675 | ||
1676 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
1677 | SCTP_ULPEVENT(ev)); | |
1678 | } | |
1679 | ||
1680 | return SCTP_DISPOSITION_CONSUME; | |
1681 | ||
1682 | nomem_ev: | |
1683 | sctp_chunk_free(repl); | |
1684 | nomem: | |
1685 | return SCTP_DISPOSITION_NOMEM; | |
1686 | } | |
1687 | ||
1688 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') | |
1689 | * | |
1690 | * Section 5.2.4 | |
1691 | * C) In this case, the local endpoint's cookie has arrived late. | |
1692 | * Before it arrived, the local endpoint sent an INIT and received an | |
1693 | * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag | |
1694 | * but a new tag of its own. | |
1695 | */ | |
1696 | /* This case represents an initialization collision. */ | |
1697 | static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep, | |
1698 | const struct sctp_association *asoc, | |
1699 | struct sctp_chunk *chunk, | |
1700 | sctp_cmd_seq_t *commands, | |
1701 | struct sctp_association *new_asoc) | |
1702 | { | |
1703 | /* The cookie should be silently discarded. | |
1704 | * The endpoint SHOULD NOT change states and should leave | |
1705 | * any timers running. | |
1706 | */ | |
1707 | return SCTP_DISPOSITION_DISCARD; | |
1708 | } | |
1709 | ||
1710 | /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') | |
1711 | * | |
1712 | * Section 5.2.4 | |
1713 | * | |
1714 | * D) When both local and remote tags match the endpoint should always | |
1715 | * enter the ESTABLISHED state, if it has not already done so. | |
1716 | */ | |
1717 | /* This case represents an initialization collision. */ | |
1718 | static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep, | |
1719 | const struct sctp_association *asoc, | |
1720 | struct sctp_chunk *chunk, | |
1721 | sctp_cmd_seq_t *commands, | |
1722 | struct sctp_association *new_asoc) | |
1723 | { | |
1724 | struct sctp_ulpevent *ev = NULL; | |
1725 | struct sctp_chunk *repl; | |
1726 | ||
1727 | /* Clarification from Implementor's Guide: | |
1728 | * D) When both local and remote tags match the endpoint should | |
1729 | * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. | |
1730 | * It should stop any cookie timer that may be running and send | |
1731 | * a COOKIE ACK. | |
1732 | */ | |
1733 | ||
1734 | /* Don't accidentally move back into established state. */ | |
1735 | if (asoc->state < SCTP_STATE_ESTABLISHED) { | |
1736 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1737 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
1738 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
1739 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
1740 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); | |
1741 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, | |
1742 | SCTP_NULL()); | |
1743 | ||
1744 | /* RFC 2960 5.1 Normal Establishment of an Association | |
1745 | * | |
1746 | * D) IMPLEMENTATION NOTE: An implementation may choose | |
1747 | * to send the Communication Up notification to the | |
1748 | * SCTP user upon reception of a valid COOKIE | |
1749 | * ECHO chunk. | |
1750 | */ | |
1751 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, | |
1752 | SCTP_COMM_UP, 0, | |
1753 | new_asoc->c.sinit_num_ostreams, | |
1754 | new_asoc->c.sinit_max_instreams, | |
1755 | GFP_ATOMIC); | |
1756 | if (!ev) | |
1757 | goto nomem; | |
1758 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
1759 | SCTP_ULPEVENT(ev)); | |
1760 | ||
1761 | /* Sockets API Draft Section 5.3.1.6 | |
1762 | * When a peer sends a Adaption Layer Indication parameter, | |
1763 | * SCTP delivers this notification to inform the application | |
1764 | * that of the peers requested adaption layer. | |
1765 | */ | |
1766 | if (new_asoc->peer.adaption_ind) { | |
1767 | ev = sctp_ulpevent_make_adaption_indication(new_asoc, | |
1768 | GFP_ATOMIC); | |
1769 | if (!ev) | |
1770 | goto nomem; | |
1771 | ||
1772 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
1773 | SCTP_ULPEVENT(ev)); | |
1774 | } | |
1775 | } | |
1776 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); | |
1777 | ||
1778 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1779 | if (!repl) | |
1780 | goto nomem; | |
1781 | ||
1782 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1783 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); | |
1784 | ||
1785 | return SCTP_DISPOSITION_CONSUME; | |
1786 | ||
1787 | nomem: | |
1788 | if (ev) | |
1789 | sctp_ulpevent_free(ev); | |
1790 | return SCTP_DISPOSITION_NOMEM; | |
1791 | } | |
1792 | ||
1793 | /* | |
1794 | * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying | |
1795 | * chunk was retransmitted and then delayed in the network. | |
1796 | * | |
1797 | * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists | |
1798 | * | |
1799 | * Verification Tag: None. Do cookie validation. | |
1800 | * | |
1801 | * Inputs | |
1802 | * (endpoint, asoc, chunk) | |
1803 | * | |
1804 | * Outputs | |
1805 | * (asoc, reply_msg, msg_up, timers, counters) | |
1806 | * | |
1807 | * The return value is the disposition of the chunk. | |
1808 | */ | |
1809 | sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep, | |
1810 | const struct sctp_association *asoc, | |
1811 | const sctp_subtype_t type, | |
1812 | void *arg, | |
1813 | sctp_cmd_seq_t *commands) | |
1814 | { | |
1815 | sctp_disposition_t retval; | |
1816 | struct sctp_chunk *chunk = arg; | |
1817 | struct sctp_association *new_asoc; | |
1818 | int error = 0; | |
1819 | char action; | |
1820 | struct sctp_chunk *err_chk_p; | |
1821 | ||
1822 | /* Make sure that the chunk has a valid length from the protocol | |
1823 | * perspective. In this case check to make sure we have at least | |
1824 | * enough for the chunk header. Cookie length verification is | |
1825 | * done later. | |
1826 | */ | |
1827 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) | |
1828 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
1829 | commands); | |
1830 | ||
1831 | /* "Decode" the chunk. We have no optional parameters so we | |
1832 | * are in good shape. | |
1833 | */ | |
1834 | chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; | |
1835 | skb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - | |
1836 | sizeof(sctp_chunkhdr_t)); | |
1837 | ||
1838 | /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie | |
1839 | * of a duplicate COOKIE ECHO match the Verification Tags of the | |
1840 | * current association, consider the State Cookie valid even if | |
1841 | * the lifespan is exceeded. | |
1842 | */ | |
1843 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, | |
1844 | &err_chk_p); | |
1845 | ||
1846 | /* FIXME: | |
1847 | * If the re-build failed, what is the proper error path | |
1848 | * from here? | |
1849 | * | |
1850 | * [We should abort the association. --piggy] | |
1851 | */ | |
1852 | if (!new_asoc) { | |
1853 | /* FIXME: Several errors are possible. A bad cookie should | |
1854 | * be silently discarded, but think about logging it too. | |
1855 | */ | |
1856 | switch (error) { | |
1857 | case -SCTP_IERROR_NOMEM: | |
1858 | goto nomem; | |
1859 | ||
1860 | case -SCTP_IERROR_STALE_COOKIE: | |
1861 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, | |
1862 | err_chk_p); | |
1863 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1864 | case -SCTP_IERROR_BAD_SIG: | |
1865 | default: | |
1866 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1867 | }; | |
1868 | } | |
1869 | ||
1870 | /* Compare the tie_tag in cookie with the verification tag of | |
1871 | * current association. | |
1872 | */ | |
1873 | action = sctp_tietags_compare(new_asoc, asoc); | |
1874 | ||
1875 | switch (action) { | |
1876 | case 'A': /* Association restart. */ | |
1877 | retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands, | |
1878 | new_asoc); | |
1879 | break; | |
1880 | ||
1881 | case 'B': /* Collision case B. */ | |
1882 | retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands, | |
1883 | new_asoc); | |
1884 | break; | |
1885 | ||
1886 | case 'C': /* Collision case C. */ | |
1887 | retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands, | |
1888 | new_asoc); | |
1889 | break; | |
1890 | ||
1891 | case 'D': /* Collision case D. */ | |
1892 | retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands, | |
1893 | new_asoc); | |
1894 | break; | |
1895 | ||
1896 | default: /* Discard packet for all others. */ | |
1897 | retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1898 | break; | |
1899 | }; | |
1900 | ||
1901 | /* Delete the tempory new association. */ | |
1902 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
1903 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
1904 | ||
1905 | return retval; | |
1906 | ||
1907 | nomem: | |
1908 | return SCTP_DISPOSITION_NOMEM; | |
1909 | } | |
1910 | ||
1911 | /* | |
1912 | * Process an ABORT. (SHUTDOWN-PENDING state) | |
1913 | * | |
1914 | * See sctp_sf_do_9_1_abort(). | |
1915 | */ | |
1916 | sctp_disposition_t sctp_sf_shutdown_pending_abort( | |
1917 | const struct sctp_endpoint *ep, | |
1918 | const struct sctp_association *asoc, | |
1919 | const sctp_subtype_t type, | |
1920 | void *arg, | |
1921 | sctp_cmd_seq_t *commands) | |
1922 | { | |
1923 | struct sctp_chunk *chunk = arg; | |
1924 | ||
1925 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
1926 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1927 | ||
1928 | /* Make sure that the ABORT chunk has a valid length. | |
1929 | * Since this is an ABORT chunk, we have to discard it | |
1930 | * because of the following text: | |
1931 | * RFC 2960, Section 3.3.7 | |
1932 | * If an endpoint receives an ABORT with a format error or for an | |
1933 | * association that doesn't exist, it MUST silently discard it. | |
1934 | * Becasue the length is "invalid", we can't really discard just | |
1935 | * as we do not know its true length. So, to be safe, discard the | |
1936 | * packet. | |
1937 | */ | |
1938 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
1939 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1940 | ||
1941 | /* Stop the T5-shutdown guard timer. */ | |
1942 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1943 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
1944 | ||
1945 | return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); | |
1946 | } | |
1947 | ||
1948 | /* | |
1949 | * Process an ABORT. (SHUTDOWN-SENT state) | |
1950 | * | |
1951 | * See sctp_sf_do_9_1_abort(). | |
1952 | */ | |
1953 | sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep, | |
1954 | const struct sctp_association *asoc, | |
1955 | const sctp_subtype_t type, | |
1956 | void *arg, | |
1957 | sctp_cmd_seq_t *commands) | |
1958 | { | |
1959 | struct sctp_chunk *chunk = arg; | |
1960 | ||
1961 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
1962 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1963 | ||
1964 | /* Make sure that the ABORT chunk has a valid length. | |
1965 | * Since this is an ABORT chunk, we have to discard it | |
1966 | * because of the following text: | |
1967 | * RFC 2960, Section 3.3.7 | |
1968 | * If an endpoint receives an ABORT with a format error or for an | |
1969 | * association that doesn't exist, it MUST silently discard it. | |
1970 | * Becasue the length is "invalid", we can't really discard just | |
1971 | * as we do not know its true length. So, to be safe, discard the | |
1972 | * packet. | |
1973 | */ | |
1974 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
1975 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
1976 | ||
1977 | /* Stop the T2-shutdown timer. */ | |
1978 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1979 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
1980 | ||
1981 | /* Stop the T5-shutdown guard timer. */ | |
1982 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1983 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
1984 | ||
1985 | return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); | |
1986 | } | |
1987 | ||
1988 | /* | |
1989 | * Process an ABORT. (SHUTDOWN-ACK-SENT state) | |
1990 | * | |
1991 | * See sctp_sf_do_9_1_abort(). | |
1992 | */ | |
1993 | sctp_disposition_t sctp_sf_shutdown_ack_sent_abort( | |
1994 | const struct sctp_endpoint *ep, | |
1995 | const struct sctp_association *asoc, | |
1996 | const sctp_subtype_t type, | |
1997 | void *arg, | |
1998 | sctp_cmd_seq_t *commands) | |
1999 | { | |
2000 | /* The same T2 timer, so we should be able to use | |
2001 | * common function with the SHUTDOWN-SENT state. | |
2002 | */ | |
2003 | return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands); | |
2004 | } | |
2005 | ||
2006 | /* | |
2007 | * Handle an Error received in COOKIE_ECHOED state. | |
2008 | * | |
2009 | * Only handle the error type of stale COOKIE Error, the other errors will | |
2010 | * be ignored. | |
2011 | * | |
2012 | * Inputs | |
2013 | * (endpoint, asoc, chunk) | |
2014 | * | |
2015 | * Outputs | |
2016 | * (asoc, reply_msg, msg_up, timers, counters) | |
2017 | * | |
2018 | * The return value is the disposition of the chunk. | |
2019 | */ | |
2020 | sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep, | |
2021 | const struct sctp_association *asoc, | |
2022 | const sctp_subtype_t type, | |
2023 | void *arg, | |
2024 | sctp_cmd_seq_t *commands) | |
2025 | { | |
2026 | struct sctp_chunk *chunk = arg; | |
2027 | sctp_errhdr_t *err; | |
2028 | ||
2029 | if (!sctp_vtag_verify(chunk, asoc)) | |
2030 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2031 | ||
2032 | /* Make sure that the ERROR chunk has a valid length. | |
2033 | * The parameter walking depends on this as well. | |
2034 | */ | |
2035 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) | |
2036 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2037 | commands); | |
2038 | ||
2039 | /* Process the error here */ | |
2040 | /* FUTURE FIXME: When PR-SCTP related and other optional | |
2041 | * parms are emitted, this will have to change to handle multiple | |
2042 | * errors. | |
2043 | */ | |
2044 | sctp_walk_errors(err, chunk->chunk_hdr) { | |
2045 | if (SCTP_ERROR_STALE_COOKIE == err->cause) | |
2046 | return sctp_sf_do_5_2_6_stale(ep, asoc, type, | |
2047 | arg, commands); | |
2048 | } | |
2049 | ||
2050 | /* It is possible to have malformed error causes, and that | |
2051 | * will cause us to end the walk early. However, since | |
2052 | * we are discarding the packet, there should be no adverse | |
2053 | * affects. | |
2054 | */ | |
2055 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2056 | } | |
2057 | ||
2058 | /* | |
2059 | * Handle a Stale COOKIE Error | |
2060 | * | |
2061 | * Section: 5.2.6 Handle Stale COOKIE Error | |
2062 | * If the association is in the COOKIE-ECHOED state, the endpoint may elect | |
2063 | * one of the following three alternatives. | |
2064 | * ... | |
2065 | * 3) Send a new INIT chunk to the endpoint, adding a Cookie | |
2066 | * Preservative parameter requesting an extension to the lifetime of | |
2067 | * the State Cookie. When calculating the time extension, an | |
2068 | * implementation SHOULD use the RTT information measured based on the | |
2069 | * previous COOKIE ECHO / ERROR exchange, and should add no more | |
2070 | * than 1 second beyond the measured RTT, due to long State Cookie | |
2071 | * lifetimes making the endpoint more subject to a replay attack. | |
2072 | * | |
2073 | * Verification Tag: Not explicit, but safe to ignore. | |
2074 | * | |
2075 | * Inputs | |
2076 | * (endpoint, asoc, chunk) | |
2077 | * | |
2078 | * Outputs | |
2079 | * (asoc, reply_msg, msg_up, timers, counters) | |
2080 | * | |
2081 | * The return value is the disposition of the chunk. | |
2082 | */ | |
2083 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, | |
2084 | const struct sctp_association *asoc, | |
2085 | const sctp_subtype_t type, | |
2086 | void *arg, | |
2087 | sctp_cmd_seq_t *commands) | |
2088 | { | |
2089 | struct sctp_chunk *chunk = arg; | |
2090 | time_t stale; | |
2091 | sctp_cookie_preserve_param_t bht; | |
2092 | sctp_errhdr_t *err; | |
2093 | struct sctp_chunk *reply; | |
2094 | struct sctp_bind_addr *bp; | |
2095 | int attempts; | |
2096 | ||
2097 | attempts = asoc->counters[SCTP_COUNTER_INIT_ERROR] + 1; | |
2098 | ||
2099 | if (attempts >= asoc->max_init_attempts) { | |
2100 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
2101 | SCTP_U32(SCTP_ERROR_STALE_COOKIE)); | |
2102 | return SCTP_DISPOSITION_DELETE_TCB; | |
2103 | } | |
2104 | ||
2105 | err = (sctp_errhdr_t *)(chunk->skb->data); | |
2106 | ||
2107 | /* When calculating the time extension, an implementation | |
2108 | * SHOULD use the RTT information measured based on the | |
2109 | * previous COOKIE ECHO / ERROR exchange, and should add no | |
2110 | * more than 1 second beyond the measured RTT, due to long | |
2111 | * State Cookie lifetimes making the endpoint more subject to | |
2112 | * a replay attack. | |
2113 | * Measure of Staleness's unit is usec. (1/1000000 sec) | |
2114 | * Suggested Cookie Life-span Increment's unit is msec. | |
2115 | * (1/1000 sec) | |
2116 | * In general, if you use the suggested cookie life, the value | |
2117 | * found in the field of measure of staleness should be doubled | |
2118 | * to give ample time to retransmit the new cookie and thus | |
2119 | * yield a higher probability of success on the reattempt. | |
2120 | */ | |
2121 | stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t))); | |
2122 | stale = (stale * 2) / 1000; | |
2123 | ||
2124 | bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; | |
2125 | bht.param_hdr.length = htons(sizeof(bht)); | |
2126 | bht.lifespan_increment = htonl(stale); | |
2127 | ||
2128 | /* Build that new INIT chunk. */ | |
2129 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; | |
2130 | reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); | |
2131 | if (!reply) | |
2132 | goto nomem; | |
2133 | ||
2134 | sctp_addto_chunk(reply, sizeof(bht), &bht); | |
2135 | ||
2136 | /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ | |
2137 | sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); | |
2138 | ||
2139 | /* Stop pending T3-rtx and heartbeat timers */ | |
2140 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); | |
2141 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
2142 | ||
2143 | /* Delete non-primary peer ip addresses since we are transitioning | |
2144 | * back to the COOKIE-WAIT state | |
2145 | */ | |
2146 | sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); | |
2147 | ||
2148 | /* If we've sent any data bundled with COOKIE-ECHO we will need to | |
2149 | * resend | |
2150 | */ | |
2151 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, | |
2152 | SCTP_TRANSPORT(asoc->peer.primary_path)); | |
2153 | ||
2154 | /* Cast away the const modifier, as we want to just | |
2155 | * rerun it through as a sideffect. | |
2156 | */ | |
2157 | sctp_add_cmd_sf(commands, SCTP_CMD_COUNTER_INC, | |
2158 | SCTP_COUNTER(SCTP_COUNTER_INIT_ERROR)); | |
2159 | ||
2160 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2161 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
2162 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2163 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); | |
2164 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
2165 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
2166 | ||
2167 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
2168 | ||
2169 | return SCTP_DISPOSITION_CONSUME; | |
2170 | ||
2171 | nomem: | |
2172 | return SCTP_DISPOSITION_NOMEM; | |
2173 | } | |
2174 | ||
2175 | /* | |
2176 | * Process an ABORT. | |
2177 | * | |
2178 | * Section: 9.1 | |
2179 | * After checking the Verification Tag, the receiving endpoint shall | |
2180 | * remove the association from its record, and shall report the | |
2181 | * termination to its upper layer. | |
2182 | * | |
2183 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules | |
2184 | * B) Rules for packet carrying ABORT: | |
2185 | * | |
2186 | * - The endpoint shall always fill in the Verification Tag field of the | |
2187 | * outbound packet with the destination endpoint's tag value if it | |
2188 | * is known. | |
2189 | * | |
2190 | * - If the ABORT is sent in response to an OOTB packet, the endpoint | |
2191 | * MUST follow the procedure described in Section 8.4. | |
2192 | * | |
2193 | * - The receiver MUST accept the packet if the Verification Tag | |
2194 | * matches either its own tag, OR the tag of its peer. Otherwise, the | |
2195 | * receiver MUST silently discard the packet and take no further | |
2196 | * action. | |
2197 | * | |
2198 | * Inputs | |
2199 | * (endpoint, asoc, chunk) | |
2200 | * | |
2201 | * Outputs | |
2202 | * (asoc, reply_msg, msg_up, timers, counters) | |
2203 | * | |
2204 | * The return value is the disposition of the chunk. | |
2205 | */ | |
2206 | sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep, | |
2207 | const struct sctp_association *asoc, | |
2208 | const sctp_subtype_t type, | |
2209 | void *arg, | |
2210 | sctp_cmd_seq_t *commands) | |
2211 | { | |
2212 | struct sctp_chunk *chunk = arg; | |
2213 | unsigned len; | |
2214 | __u16 error = SCTP_ERROR_NO_ERROR; | |
2215 | ||
2216 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2217 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2218 | ||
2219 | /* Make sure that the ABORT chunk has a valid length. | |
2220 | * Since this is an ABORT chunk, we have to discard it | |
2221 | * because of the following text: | |
2222 | * RFC 2960, Section 3.3.7 | |
2223 | * If an endpoint receives an ABORT with a format error or for an | |
2224 | * association that doesn't exist, it MUST silently discard it. | |
2225 | * Becasue the length is "invalid", we can't really discard just | |
2226 | * as we do not know its true length. So, to be safe, discard the | |
2227 | * packet. | |
2228 | */ | |
2229 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2230 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2231 | ||
2232 | /* See if we have an error cause code in the chunk. */ | |
2233 | len = ntohs(chunk->chunk_hdr->length); | |
2234 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) | |
2235 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; | |
2236 | ||
2237 | /* ASSOC_FAILED will DELETE_TCB. */ | |
2238 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error)); | |
2239 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
2240 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
2241 | ||
2242 | return SCTP_DISPOSITION_ABORT; | |
2243 | } | |
2244 | ||
2245 | /* | |
2246 | * Process an ABORT. (COOKIE-WAIT state) | |
2247 | * | |
2248 | * See sctp_sf_do_9_1_abort() above. | |
2249 | */ | |
2250 | sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep, | |
2251 | const struct sctp_association *asoc, | |
2252 | const sctp_subtype_t type, | |
2253 | void *arg, | |
2254 | sctp_cmd_seq_t *commands) | |
2255 | { | |
2256 | struct sctp_chunk *chunk = arg; | |
2257 | unsigned len; | |
2258 | __u16 error = SCTP_ERROR_NO_ERROR; | |
2259 | ||
2260 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2261 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2262 | ||
2263 | /* Make sure that the ABORT chunk has a valid length. | |
2264 | * Since this is an ABORT chunk, we have to discard it | |
2265 | * because of the following text: | |
2266 | * RFC 2960, Section 3.3.7 | |
2267 | * If an endpoint receives an ABORT with a format error or for an | |
2268 | * association that doesn't exist, it MUST silently discard it. | |
2269 | * Becasue the length is "invalid", we can't really discard just | |
2270 | * as we do not know its true length. So, to be safe, discard the | |
2271 | * packet. | |
2272 | */ | |
2273 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2274 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2275 | ||
2276 | /* See if we have an error cause code in the chunk. */ | |
2277 | len = ntohs(chunk->chunk_hdr->length); | |
2278 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) | |
2279 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; | |
2280 | ||
2281 | sctp_stop_t1_and_abort(commands, error); | |
2282 | return SCTP_DISPOSITION_ABORT; | |
2283 | } | |
2284 | ||
2285 | /* | |
2286 | * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) | |
2287 | */ | |
2288 | sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep, | |
2289 | const struct sctp_association *asoc, | |
2290 | const sctp_subtype_t type, | |
2291 | void *arg, | |
2292 | sctp_cmd_seq_t *commands) | |
2293 | { | |
2294 | sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR); | |
2295 | return SCTP_DISPOSITION_ABORT; | |
2296 | } | |
2297 | ||
2298 | /* | |
2299 | * Process an ABORT. (COOKIE-ECHOED state) | |
2300 | */ | |
2301 | sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep, | |
2302 | const struct sctp_association *asoc, | |
2303 | const sctp_subtype_t type, | |
2304 | void *arg, | |
2305 | sctp_cmd_seq_t *commands) | |
2306 | { | |
2307 | /* There is a single T1 timer, so we should be able to use | |
2308 | * common function with the COOKIE-WAIT state. | |
2309 | */ | |
2310 | return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands); | |
2311 | } | |
2312 | ||
2313 | /* | |
2314 | * Stop T1 timer and abort association with "INIT failed". | |
2315 | * | |
2316 | * This is common code called by several sctp_sf_*_abort() functions above. | |
2317 | */ | |
2318 | void sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands, __u16 error) | |
2319 | { | |
2320 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2321 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
2322 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
2323 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2324 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
2325 | /* CMD_INIT_FAILED will DELETE_TCB. */ | |
2326 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
2327 | SCTP_U32(error)); | |
2328 | } | |
2329 | ||
2330 | /* | |
2331 | * sctp_sf_do_9_2_shut | |
2332 | * | |
2333 | * Section: 9.2 | |
2334 | * Upon the reception of the SHUTDOWN, the peer endpoint shall | |
2335 | * - enter the SHUTDOWN-RECEIVED state, | |
2336 | * | |
2337 | * - stop accepting new data from its SCTP user | |
2338 | * | |
2339 | * - verify, by checking the Cumulative TSN Ack field of the chunk, | |
2340 | * that all its outstanding DATA chunks have been received by the | |
2341 | * SHUTDOWN sender. | |
2342 | * | |
2343 | * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT | |
2344 | * send a SHUTDOWN in response to a ULP request. And should discard | |
2345 | * subsequent SHUTDOWN chunks. | |
2346 | * | |
2347 | * If there are still outstanding DATA chunks left, the SHUTDOWN | |
2348 | * receiver shall continue to follow normal data transmission | |
2349 | * procedures defined in Section 6 until all outstanding DATA chunks | |
2350 | * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept | |
2351 | * new data from its SCTP user. | |
2352 | * | |
2353 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2354 | * | |
2355 | * Inputs | |
2356 | * (endpoint, asoc, chunk) | |
2357 | * | |
2358 | * Outputs | |
2359 | * (asoc, reply_msg, msg_up, timers, counters) | |
2360 | * | |
2361 | * The return value is the disposition of the chunk. | |
2362 | */ | |
2363 | sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep, | |
2364 | const struct sctp_association *asoc, | |
2365 | const sctp_subtype_t type, | |
2366 | void *arg, | |
2367 | sctp_cmd_seq_t *commands) | |
2368 | { | |
2369 | struct sctp_chunk *chunk = arg; | |
2370 | sctp_shutdownhdr_t *sdh; | |
2371 | sctp_disposition_t disposition; | |
2372 | struct sctp_ulpevent *ev; | |
2373 | ||
2374 | if (!sctp_vtag_verify(chunk, asoc)) | |
2375 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2376 | ||
2377 | /* Make sure that the SHUTDOWN chunk has a valid length. */ | |
2378 | if (!sctp_chunk_length_valid(chunk, | |
2379 | sizeof(struct sctp_shutdown_chunk_t))) | |
2380 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2381 | commands); | |
2382 | ||
2383 | /* Convert the elaborate header. */ | |
2384 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; | |
2385 | skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); | |
2386 | chunk->subh.shutdown_hdr = sdh; | |
2387 | ||
2388 | /* Upon the reception of the SHUTDOWN, the peer endpoint shall | |
2389 | * - enter the SHUTDOWN-RECEIVED state, | |
2390 | * - stop accepting new data from its SCTP user | |
2391 | * | |
2392 | * [This is implicit in the new state.] | |
2393 | */ | |
2394 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2395 | SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); | |
2396 | disposition = SCTP_DISPOSITION_CONSUME; | |
2397 | ||
2398 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
2399 | disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type, | |
2400 | arg, commands); | |
2401 | } | |
2402 | ||
2403 | if (SCTP_DISPOSITION_NOMEM == disposition) | |
2404 | goto out; | |
2405 | ||
2406 | /* - verify, by checking the Cumulative TSN Ack field of the | |
2407 | * chunk, that all its outstanding DATA chunks have been | |
2408 | * received by the SHUTDOWN sender. | |
2409 | */ | |
2410 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, | |
2411 | SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack)); | |
2412 | ||
2413 | /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT | |
2414 | * When a peer sends a SHUTDOWN, SCTP delivers this notification to | |
2415 | * inform the application that it should cease sending data. | |
2416 | */ | |
2417 | ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); | |
2418 | if (!ev) { | |
2419 | disposition = SCTP_DISPOSITION_NOMEM; | |
2420 | goto out; | |
2421 | } | |
2422 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
2423 | ||
2424 | out: | |
2425 | return disposition; | |
2426 | } | |
2427 | ||
2428 | /* RFC 2960 9.2 | |
2429 | * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk | |
2430 | * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination | |
2431 | * transport addresses (either in the IP addresses or in the INIT chunk) | |
2432 | * that belong to this association, it should discard the INIT chunk and | |
2433 | * retransmit the SHUTDOWN ACK chunk. | |
2434 | */ | |
2435 | sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep, | |
2436 | const struct sctp_association *asoc, | |
2437 | const sctp_subtype_t type, | |
2438 | void *arg, | |
2439 | sctp_cmd_seq_t *commands) | |
2440 | { | |
2441 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; | |
2442 | struct sctp_chunk *reply; | |
2443 | ||
2444 | /* Since we are not going to really process this INIT, there | |
2445 | * is no point in verifying chunk boundries. Just generate | |
2446 | * the SHUTDOWN ACK. | |
2447 | */ | |
2448 | reply = sctp_make_shutdown_ack(asoc, chunk); | |
2449 | if (NULL == reply) | |
2450 | goto nomem; | |
2451 | ||
2452 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for | |
2453 | * the T2-SHUTDOWN timer. | |
2454 | */ | |
2455 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
2456 | ||
2457 | /* and restart the T2-shutdown timer. */ | |
2458 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2459 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
2460 | ||
2461 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
2462 | ||
2463 | return SCTP_DISPOSITION_CONSUME; | |
2464 | nomem: | |
2465 | return SCTP_DISPOSITION_NOMEM; | |
2466 | } | |
2467 | ||
2468 | /* | |
2469 | * sctp_sf_do_ecn_cwr | |
2470 | * | |
2471 | * Section: Appendix A: Explicit Congestion Notification | |
2472 | * | |
2473 | * CWR: | |
2474 | * | |
2475 | * RFC 2481 details a specific bit for a sender to send in the header of | |
2476 | * its next outbound TCP segment to indicate to its peer that it has | |
2477 | * reduced its congestion window. This is termed the CWR bit. For | |
2478 | * SCTP the same indication is made by including the CWR chunk. | |
2479 | * This chunk contains one data element, i.e. the TSN number that | |
2480 | * was sent in the ECNE chunk. This element represents the lowest | |
2481 | * TSN number in the datagram that was originally marked with the | |
2482 | * CE bit. | |
2483 | * | |
2484 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2485 | * Inputs | |
2486 | * (endpoint, asoc, chunk) | |
2487 | * | |
2488 | * Outputs | |
2489 | * (asoc, reply_msg, msg_up, timers, counters) | |
2490 | * | |
2491 | * The return value is the disposition of the chunk. | |
2492 | */ | |
2493 | sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep, | |
2494 | const struct sctp_association *asoc, | |
2495 | const sctp_subtype_t type, | |
2496 | void *arg, | |
2497 | sctp_cmd_seq_t *commands) | |
2498 | { | |
2499 | sctp_cwrhdr_t *cwr; | |
2500 | struct sctp_chunk *chunk = arg; | |
2501 | ||
2502 | if (!sctp_vtag_verify(chunk, asoc)) | |
2503 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2504 | ||
2505 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) | |
2506 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2507 | commands); | |
2508 | ||
2509 | cwr = (sctp_cwrhdr_t *) chunk->skb->data; | |
2510 | skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t)); | |
2511 | ||
2512 | cwr->lowest_tsn = ntohl(cwr->lowest_tsn); | |
2513 | ||
2514 | /* Does this CWR ack the last sent congestion notification? */ | |
2515 | if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) { | |
2516 | /* Stop sending ECNE. */ | |
2517 | sctp_add_cmd_sf(commands, | |
2518 | SCTP_CMD_ECN_CWR, | |
2519 | SCTP_U32(cwr->lowest_tsn)); | |
2520 | } | |
2521 | return SCTP_DISPOSITION_CONSUME; | |
2522 | } | |
2523 | ||
2524 | /* | |
2525 | * sctp_sf_do_ecne | |
2526 | * | |
2527 | * Section: Appendix A: Explicit Congestion Notification | |
2528 | * | |
2529 | * ECN-Echo | |
2530 | * | |
2531 | * RFC 2481 details a specific bit for a receiver to send back in its | |
2532 | * TCP acknowledgements to notify the sender of the Congestion | |
2533 | * Experienced (CE) bit having arrived from the network. For SCTP this | |
2534 | * same indication is made by including the ECNE chunk. This chunk | |
2535 | * contains one data element, i.e. the lowest TSN associated with the IP | |
2536 | * datagram marked with the CE bit..... | |
2537 | * | |
2538 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2539 | * Inputs | |
2540 | * (endpoint, asoc, chunk) | |
2541 | * | |
2542 | * Outputs | |
2543 | * (asoc, reply_msg, msg_up, timers, counters) | |
2544 | * | |
2545 | * The return value is the disposition of the chunk. | |
2546 | */ | |
2547 | sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep, | |
2548 | const struct sctp_association *asoc, | |
2549 | const sctp_subtype_t type, | |
2550 | void *arg, | |
2551 | sctp_cmd_seq_t *commands) | |
2552 | { | |
2553 | sctp_ecnehdr_t *ecne; | |
2554 | struct sctp_chunk *chunk = arg; | |
2555 | ||
2556 | if (!sctp_vtag_verify(chunk, asoc)) | |
2557 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2558 | ||
2559 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) | |
2560 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2561 | commands); | |
2562 | ||
2563 | ecne = (sctp_ecnehdr_t *) chunk->skb->data; | |
2564 | skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t)); | |
2565 | ||
2566 | /* If this is a newer ECNE than the last CWR packet we sent out */ | |
2567 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, | |
2568 | SCTP_U32(ntohl(ecne->lowest_tsn))); | |
2569 | ||
2570 | return SCTP_DISPOSITION_CONSUME; | |
2571 | } | |
2572 | ||
2573 | /* | |
2574 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks | |
2575 | * | |
2576 | * The SCTP endpoint MUST always acknowledge the reception of each valid | |
2577 | * DATA chunk. | |
2578 | * | |
2579 | * The guidelines on delayed acknowledgement algorithm specified in | |
2580 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an | |
2581 | * acknowledgement SHOULD be generated for at least every second packet | |
2582 | * (not every second DATA chunk) received, and SHOULD be generated within | |
2583 | * 200 ms of the arrival of any unacknowledged DATA chunk. In some | |
2584 | * situations it may be beneficial for an SCTP transmitter to be more | |
2585 | * conservative than the algorithms detailed in this document allow. | |
2586 | * However, an SCTP transmitter MUST NOT be more aggressive than the | |
2587 | * following algorithms allow. | |
2588 | * | |
2589 | * A SCTP receiver MUST NOT generate more than one SACK for every | |
2590 | * incoming packet, other than to update the offered window as the | |
2591 | * receiving application consumes new data. | |
2592 | * | |
2593 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2594 | * | |
2595 | * Inputs | |
2596 | * (endpoint, asoc, chunk) | |
2597 | * | |
2598 | * Outputs | |
2599 | * (asoc, reply_msg, msg_up, timers, counters) | |
2600 | * | |
2601 | * The return value is the disposition of the chunk. | |
2602 | */ | |
2603 | sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep, | |
2604 | const struct sctp_association *asoc, | |
2605 | const sctp_subtype_t type, | |
2606 | void *arg, | |
2607 | sctp_cmd_seq_t *commands) | |
2608 | { | |
2609 | struct sctp_chunk *chunk = arg; | |
2610 | int error; | |
2611 | ||
2612 | if (!sctp_vtag_verify(chunk, asoc)) { | |
2613 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
2614 | SCTP_NULL()); | |
2615 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2616 | } | |
2617 | ||
2618 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) | |
2619 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2620 | commands); | |
2621 | ||
2622 | error = sctp_eat_data(asoc, chunk, commands ); | |
2623 | switch (error) { | |
2624 | case SCTP_IERROR_NO_ERROR: | |
2625 | break; | |
2626 | case SCTP_IERROR_HIGH_TSN: | |
2627 | case SCTP_IERROR_BAD_STREAM: | |
2628 | goto discard_noforce; | |
2629 | case SCTP_IERROR_DUP_TSN: | |
2630 | case SCTP_IERROR_IGNORE_TSN: | |
2631 | goto discard_force; | |
2632 | case SCTP_IERROR_NO_DATA: | |
2633 | goto consume; | |
2634 | default: | |
2635 | BUG(); | |
2636 | } | |
2637 | ||
2638 | if (asoc->autoclose) { | |
2639 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2640 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
2641 | } | |
2642 | ||
2643 | /* If this is the last chunk in a packet, we need to count it | |
2644 | * toward sack generation. Note that we need to SACK every | |
2645 | * OTHER packet containing data chunks, EVEN IF WE DISCARD | |
2646 | * THEM. We elect to NOT generate SACK's if the chunk fails | |
2647 | * the verification tag test. | |
2648 | * | |
2649 | * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks | |
2650 | * | |
2651 | * The SCTP endpoint MUST always acknowledge the reception of | |
2652 | * each valid DATA chunk. | |
2653 | * | |
2654 | * The guidelines on delayed acknowledgement algorithm | |
2655 | * specified in Section 4.2 of [RFC2581] SHOULD be followed. | |
2656 | * Specifically, an acknowledgement SHOULD be generated for at | |
2657 | * least every second packet (not every second DATA chunk) | |
2658 | * received, and SHOULD be generated within 200 ms of the | |
2659 | * arrival of any unacknowledged DATA chunk. In some | |
2660 | * situations it may be beneficial for an SCTP transmitter to | |
2661 | * be more conservative than the algorithms detailed in this | |
2662 | * document allow. However, an SCTP transmitter MUST NOT be | |
2663 | * more aggressive than the following algorithms allow. | |
2664 | */ | |
2665 | if (chunk->end_of_packet) { | |
2666 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); | |
2667 | ||
2668 | /* Start the SACK timer. */ | |
2669 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2670 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); | |
2671 | } | |
2672 | ||
2673 | return SCTP_DISPOSITION_CONSUME; | |
2674 | ||
2675 | discard_force: | |
2676 | /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks | |
2677 | * | |
2678 | * When a packet arrives with duplicate DATA chunk(s) and with | |
2679 | * no new DATA chunk(s), the endpoint MUST immediately send a | |
2680 | * SACK with no delay. If a packet arrives with duplicate | |
2681 | * DATA chunk(s) bundled with new DATA chunks, the endpoint | |
2682 | * MAY immediately send a SACK. Normally receipt of duplicate | |
2683 | * DATA chunks will occur when the original SACK chunk was lost | |
2684 | * and the peer's RTO has expired. The duplicate TSN number(s) | |
2685 | * SHOULD be reported in the SACK as duplicate. | |
2686 | */ | |
2687 | /* In our case, we split the MAY SACK advice up whether or not | |
2688 | * the last chunk is a duplicate.' | |
2689 | */ | |
2690 | if (chunk->end_of_packet) | |
2691 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
2692 | return SCTP_DISPOSITION_DISCARD; | |
2693 | ||
2694 | discard_noforce: | |
2695 | if (chunk->end_of_packet) { | |
2696 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); | |
2697 | ||
2698 | /* Start the SACK timer. */ | |
2699 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2700 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); | |
2701 | } | |
2702 | return SCTP_DISPOSITION_DISCARD; | |
2703 | consume: | |
2704 | return SCTP_DISPOSITION_CONSUME; | |
2705 | ||
2706 | } | |
2707 | ||
2708 | /* | |
2709 | * sctp_sf_eat_data_fast_4_4 | |
2710 | * | |
2711 | * Section: 4 (4) | |
2712 | * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received | |
2713 | * DATA chunks without delay. | |
2714 | * | |
2715 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2716 | * Inputs | |
2717 | * (endpoint, asoc, chunk) | |
2718 | * | |
2719 | * Outputs | |
2720 | * (asoc, reply_msg, msg_up, timers, counters) | |
2721 | * | |
2722 | * The return value is the disposition of the chunk. | |
2723 | */ | |
2724 | sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep, | |
2725 | const struct sctp_association *asoc, | |
2726 | const sctp_subtype_t type, | |
2727 | void *arg, | |
2728 | sctp_cmd_seq_t *commands) | |
2729 | { | |
2730 | struct sctp_chunk *chunk = arg; | |
2731 | int error; | |
2732 | ||
2733 | if (!sctp_vtag_verify(chunk, asoc)) { | |
2734 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
2735 | SCTP_NULL()); | |
2736 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2737 | } | |
2738 | ||
2739 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) | |
2740 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2741 | commands); | |
2742 | ||
2743 | error = sctp_eat_data(asoc, chunk, commands ); | |
2744 | switch (error) { | |
2745 | case SCTP_IERROR_NO_ERROR: | |
2746 | case SCTP_IERROR_HIGH_TSN: | |
2747 | case SCTP_IERROR_DUP_TSN: | |
2748 | case SCTP_IERROR_IGNORE_TSN: | |
2749 | case SCTP_IERROR_BAD_STREAM: | |
2750 | break; | |
2751 | case SCTP_IERROR_NO_DATA: | |
2752 | goto consume; | |
2753 | default: | |
2754 | BUG(); | |
2755 | } | |
2756 | ||
2757 | /* Go a head and force a SACK, since we are shutting down. */ | |
2758 | ||
2759 | /* Implementor's Guide. | |
2760 | * | |
2761 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately | |
2762 | * respond to each received packet containing one or more DATA chunk(s) | |
2763 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer | |
2764 | */ | |
2765 | if (chunk->end_of_packet) { | |
2766 | /* We must delay the chunk creation since the cumulative | |
2767 | * TSN has not been updated yet. | |
2768 | */ | |
2769 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); | |
2770 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
2771 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2772 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
2773 | } | |
2774 | ||
2775 | consume: | |
2776 | return SCTP_DISPOSITION_CONSUME; | |
2777 | } | |
2778 | ||
2779 | /* | |
2780 | * Section: 6.2 Processing a Received SACK | |
2781 | * D) Any time a SACK arrives, the endpoint performs the following: | |
2782 | * | |
2783 | * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, | |
2784 | * then drop the SACK. Since Cumulative TSN Ack is monotonically | |
2785 | * increasing, a SACK whose Cumulative TSN Ack is less than the | |
2786 | * Cumulative TSN Ack Point indicates an out-of-order SACK. | |
2787 | * | |
2788 | * ii) Set rwnd equal to the newly received a_rwnd minus the number | |
2789 | * of bytes still outstanding after processing the Cumulative TSN Ack | |
2790 | * and the Gap Ack Blocks. | |
2791 | * | |
2792 | * iii) If the SACK is missing a TSN that was previously | |
2793 | * acknowledged via a Gap Ack Block (e.g., the data receiver | |
2794 | * reneged on the data), then mark the corresponding DATA chunk | |
2795 | * as available for retransmit: Mark it as missing for fast | |
2796 | * retransmit as described in Section 7.2.4 and if no retransmit | |
2797 | * timer is running for the destination address to which the DATA | |
2798 | * chunk was originally transmitted, then T3-rtx is started for | |
2799 | * that destination address. | |
2800 | * | |
2801 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2802 | * | |
2803 | * Inputs | |
2804 | * (endpoint, asoc, chunk) | |
2805 | * | |
2806 | * Outputs | |
2807 | * (asoc, reply_msg, msg_up, timers, counters) | |
2808 | * | |
2809 | * The return value is the disposition of the chunk. | |
2810 | */ | |
2811 | sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep, | |
2812 | const struct sctp_association *asoc, | |
2813 | const sctp_subtype_t type, | |
2814 | void *arg, | |
2815 | sctp_cmd_seq_t *commands) | |
2816 | { | |
2817 | struct sctp_chunk *chunk = arg; | |
2818 | sctp_sackhdr_t *sackh; | |
2819 | __u32 ctsn; | |
2820 | ||
2821 | if (!sctp_vtag_verify(chunk, asoc)) | |
2822 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2823 | ||
2824 | /* Make sure that the SACK chunk has a valid length. */ | |
2825 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t))) | |
2826 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2827 | commands); | |
2828 | ||
2829 | /* Pull the SACK chunk from the data buffer */ | |
2830 | sackh = sctp_sm_pull_sack(chunk); | |
2831 | /* Was this a bogus SACK? */ | |
2832 | if (!sackh) | |
2833 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2834 | chunk->subh.sack_hdr = sackh; | |
2835 | ctsn = ntohl(sackh->cum_tsn_ack); | |
2836 | ||
2837 | /* i) If Cumulative TSN Ack is less than the Cumulative TSN | |
2838 | * Ack Point, then drop the SACK. Since Cumulative TSN | |
2839 | * Ack is monotonically increasing, a SACK whose | |
2840 | * Cumulative TSN Ack is less than the Cumulative TSN Ack | |
2841 | * Point indicates an out-of-order SACK. | |
2842 | */ | |
2843 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { | |
2844 | SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn); | |
2845 | SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point); | |
2846 | return SCTP_DISPOSITION_DISCARD; | |
2847 | } | |
2848 | ||
2849 | /* Return this SACK for further processing. */ | |
2850 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh)); | |
2851 | ||
2852 | /* Note: We do the rest of the work on the PROCESS_SACK | |
2853 | * sideeffect. | |
2854 | */ | |
2855 | return SCTP_DISPOSITION_CONSUME; | |
2856 | } | |
2857 | ||
2858 | /* | |
2859 | * Generate an ABORT in response to a packet. | |
2860 | * | |
2861 | * Section: 8.4 Handle "Out of the blue" Packets | |
2862 | * | |
2863 | * 8) The receiver should respond to the sender of the OOTB packet | |
2864 | * with an ABORT. When sending the ABORT, the receiver of the | |
2865 | * OOTB packet MUST fill in the Verification Tag field of the | |
2866 | * outbound packet with the value found in the Verification Tag | |
2867 | * field of the OOTB packet and set the T-bit in the Chunk Flags | |
2868 | * to indicate that no TCB was found. After sending this ABORT, | |
2869 | * the receiver of the OOTB packet shall discard the OOTB packet | |
2870 | * and take no further action. | |
2871 | * | |
2872 | * Verification Tag: | |
2873 | * | |
2874 | * The return value is the disposition of the chunk. | |
2875 | */ | |
2876 | sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep, | |
2877 | const struct sctp_association *asoc, | |
2878 | const sctp_subtype_t type, | |
2879 | void *arg, | |
2880 | sctp_cmd_seq_t *commands) | |
2881 | { | |
2882 | struct sctp_packet *packet = NULL; | |
2883 | struct sctp_chunk *chunk = arg; | |
2884 | struct sctp_chunk *abort; | |
2885 | ||
2886 | packet = sctp_ootb_pkt_new(asoc, chunk); | |
2887 | ||
2888 | if (packet) { | |
2889 | /* Make an ABORT. The T bit will be set if the asoc | |
2890 | * is NULL. | |
2891 | */ | |
2892 | abort = sctp_make_abort(asoc, chunk, 0); | |
2893 | if (!abort) { | |
2894 | sctp_ootb_pkt_free(packet); | |
2895 | return SCTP_DISPOSITION_NOMEM; | |
2896 | } | |
2897 | ||
2898 | /* Set the skb to the belonging sock for accounting. */ | |
2899 | abort->skb->sk = ep->base.sk; | |
2900 | ||
2901 | sctp_packet_append_chunk(packet, abort); | |
2902 | ||
2903 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
2904 | SCTP_PACKET(packet)); | |
2905 | ||
2906 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
2907 | ||
2908 | return SCTP_DISPOSITION_CONSUME; | |
2909 | } | |
2910 | ||
2911 | return SCTP_DISPOSITION_NOMEM; | |
2912 | } | |
2913 | ||
2914 | /* | |
2915 | * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR | |
2916 | * event as ULP notification for each cause included in the chunk. | |
2917 | * | |
2918 | * API 5.3.1.3 - SCTP_REMOTE_ERROR | |
2919 | * | |
2920 | * The return value is the disposition of the chunk. | |
2921 | */ | |
2922 | sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep, | |
2923 | const struct sctp_association *asoc, | |
2924 | const sctp_subtype_t type, | |
2925 | void *arg, | |
2926 | sctp_cmd_seq_t *commands) | |
2927 | { | |
2928 | struct sctp_chunk *chunk = arg; | |
2929 | struct sctp_ulpevent *ev; | |
2930 | ||
2931 | if (!sctp_vtag_verify(chunk, asoc)) | |
2932 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2933 | ||
2934 | /* Make sure that the ERROR chunk has a valid length. */ | |
2935 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) | |
2936 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2937 | commands); | |
2938 | ||
2939 | while (chunk->chunk_end > chunk->skb->data) { | |
2940 | ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, | |
2941 | GFP_ATOMIC); | |
2942 | if (!ev) | |
2943 | goto nomem; | |
2944 | ||
2945 | if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP, | |
2946 | SCTP_ULPEVENT(ev))) { | |
2947 | sctp_ulpevent_free(ev); | |
2948 | goto nomem; | |
2949 | } | |
2950 | ||
2951 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, | |
2952 | SCTP_CHUNK(chunk)); | |
2953 | } | |
2954 | return SCTP_DISPOSITION_CONSUME; | |
2955 | ||
2956 | nomem: | |
2957 | return SCTP_DISPOSITION_NOMEM; | |
2958 | } | |
2959 | ||
2960 | /* | |
2961 | * Process an inbound SHUTDOWN ACK. | |
2962 | * | |
2963 | * From Section 9.2: | |
2964 | * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall | |
2965 | * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its | |
2966 | * peer, and remove all record of the association. | |
2967 | * | |
2968 | * The return value is the disposition. | |
2969 | */ | |
2970 | sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep, | |
2971 | const struct sctp_association *asoc, | |
2972 | const sctp_subtype_t type, | |
2973 | void *arg, | |
2974 | sctp_cmd_seq_t *commands) | |
2975 | { | |
2976 | struct sctp_chunk *chunk = arg; | |
2977 | struct sctp_chunk *reply; | |
2978 | struct sctp_ulpevent *ev; | |
2979 | ||
2980 | if (!sctp_vtag_verify(chunk, asoc)) | |
2981 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
2982 | ||
2983 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ | |
2984 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) | |
2985 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
2986 | commands); | |
2987 | ||
2988 | /* 10.2 H) SHUTDOWN COMPLETE notification | |
2989 | * | |
2990 | * When SCTP completes the shutdown procedures (section 9.2) this | |
2991 | * notification is passed to the upper layer. | |
2992 | */ | |
2993 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, | |
2994 | 0, 0, 0, GFP_ATOMIC); | |
2995 | if (!ev) | |
2996 | goto nomem; | |
2997 | ||
2998 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
2999 | ||
3000 | /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall | |
3001 | * stop the T2-shutdown timer, | |
3002 | */ | |
3003 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3004 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
3005 | ||
3006 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3007 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
3008 | ||
3009 | /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ | |
3010 | reply = sctp_make_shutdown_complete(asoc, chunk); | |
3011 | if (!reply) | |
3012 | goto nomem; | |
3013 | ||
3014 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
3015 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
3016 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); | |
3017 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
3018 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
3019 | ||
3020 | /* ...and remove all record of the association. */ | |
3021 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
3022 | return SCTP_DISPOSITION_DELETE_TCB; | |
3023 | ||
3024 | nomem: | |
3025 | return SCTP_DISPOSITION_NOMEM; | |
3026 | } | |
3027 | ||
3028 | /* | |
3029 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets | |
3030 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should | |
3031 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. | |
3032 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB | |
3033 | * packet must fill in the Verification Tag field of the outbound | |
3034 | * packet with the Verification Tag received in the SHUTDOWN ACK and | |
3035 | * set the T-bit in the Chunk Flags to indicate that no TCB was | |
3036 | * found. Otherwise, | |
3037 | * | |
3038 | * 8) The receiver should respond to the sender of the OOTB packet with | |
3039 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet | |
3040 | * MUST fill in the Verification Tag field of the outbound packet | |
3041 | * with the value found in the Verification Tag field of the OOTB | |
3042 | * packet and set the T-bit in the Chunk Flags to indicate that no | |
3043 | * TCB was found. After sending this ABORT, the receiver of the OOTB | |
3044 | * packet shall discard the OOTB packet and take no further action. | |
3045 | */ | |
3046 | sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep, | |
3047 | const struct sctp_association *asoc, | |
3048 | const sctp_subtype_t type, | |
3049 | void *arg, | |
3050 | sctp_cmd_seq_t *commands) | |
3051 | { | |
3052 | struct sctp_chunk *chunk = arg; | |
3053 | struct sk_buff *skb = chunk->skb; | |
3054 | sctp_chunkhdr_t *ch; | |
3055 | __u8 *ch_end; | |
3056 | int ootb_shut_ack = 0; | |
3057 | ||
3058 | SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES); | |
3059 | ||
3060 | ch = (sctp_chunkhdr_t *) chunk->chunk_hdr; | |
3061 | do { | |
3062 | /* Break out if chunk length is less then minimal. */ | |
3063 | if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) | |
3064 | break; | |
3065 | ||
3066 | ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); | |
3067 | ||
3068 | if (SCTP_CID_SHUTDOWN_ACK == ch->type) | |
3069 | ootb_shut_ack = 1; | |
3070 | ||
3071 | /* RFC 2960, Section 3.3.7 | |
3072 | * Moreover, under any circumstances, an endpoint that | |
3073 | * receives an ABORT MUST NOT respond to that ABORT by | |
3074 | * sending an ABORT of its own. | |
3075 | */ | |
3076 | if (SCTP_CID_ABORT == ch->type) | |
3077 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3078 | ||
3079 | ch = (sctp_chunkhdr_t *) ch_end; | |
3080 | } while (ch_end < skb->tail); | |
3081 | ||
3082 | if (ootb_shut_ack) | |
3083 | sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands); | |
3084 | else | |
3085 | sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); | |
3086 | ||
3087 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3088 | } | |
3089 | ||
3090 | /* | |
3091 | * Handle an "Out of the blue" SHUTDOWN ACK. | |
3092 | * | |
3093 | * Section: 8.4 5) | |
3094 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should | |
3095 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. | |
3096 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB packet | |
3097 | * must fill in the Verification Tag field of the outbound packet with | |
3098 | * the Verification Tag received in the SHUTDOWN ACK and set the | |
3099 | * T-bit in the Chunk Flags to indicate that no TCB was found. | |
3100 | * | |
3101 | * Inputs | |
3102 | * (endpoint, asoc, type, arg, commands) | |
3103 | * | |
3104 | * Outputs | |
3105 | * (sctp_disposition_t) | |
3106 | * | |
3107 | * The return value is the disposition of the chunk. | |
3108 | */ | |
3109 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, | |
3110 | const struct sctp_association *asoc, | |
3111 | const sctp_subtype_t type, | |
3112 | void *arg, | |
3113 | sctp_cmd_seq_t *commands) | |
3114 | { | |
3115 | struct sctp_packet *packet = NULL; | |
3116 | struct sctp_chunk *chunk = arg; | |
3117 | struct sctp_chunk *shut; | |
3118 | ||
3119 | packet = sctp_ootb_pkt_new(asoc, chunk); | |
3120 | ||
3121 | if (packet) { | |
3122 | /* Make an SHUTDOWN_COMPLETE. | |
3123 | * The T bit will be set if the asoc is NULL. | |
3124 | */ | |
3125 | shut = sctp_make_shutdown_complete(asoc, chunk); | |
3126 | if (!shut) { | |
3127 | sctp_ootb_pkt_free(packet); | |
3128 | return SCTP_DISPOSITION_NOMEM; | |
3129 | } | |
3130 | ||
3131 | /* Set the skb to the belonging sock for accounting. */ | |
3132 | shut->skb->sk = ep->base.sk; | |
3133 | ||
3134 | sctp_packet_append_chunk(packet, shut); | |
3135 | ||
3136 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
3137 | SCTP_PACKET(packet)); | |
3138 | ||
3139 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
3140 | ||
3141 | /* If the chunk length is invalid, we don't want to process | |
3142 | * the reset of the packet. | |
3143 | */ | |
3144 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) | |
3145 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3146 | ||
3147 | return SCTP_DISPOSITION_CONSUME; | |
3148 | } | |
3149 | ||
3150 | return SCTP_DISPOSITION_NOMEM; | |
3151 | } | |
3152 | ||
3153 | /* | |
3154 | * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. | |
3155 | * | |
3156 | * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK | |
3157 | * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the | |
3158 | * procedures in section 8.4 SHOULD be followed, in other words it | |
3159 | * should be treated as an Out Of The Blue packet. | |
3160 | * [This means that we do NOT check the Verification Tag on these | |
3161 | * chunks. --piggy ] | |
3162 | * | |
3163 | */ | |
3164 | sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep, | |
3165 | const struct sctp_association *asoc, | |
3166 | const sctp_subtype_t type, | |
3167 | void *arg, | |
3168 | sctp_cmd_seq_t *commands) | |
3169 | { | |
3170 | /* Although we do have an association in this case, it corresponds | |
3171 | * to a restarted association. So the packet is treated as an OOTB | |
3172 | * packet and the state function that handles OOTB SHUTDOWN_ACK is | |
3173 | * called with a NULL association. | |
3174 | */ | |
3175 | return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands); | |
3176 | } | |
3177 | ||
3178 | /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ | |
3179 | sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep, | |
3180 | const struct sctp_association *asoc, | |
3181 | const sctp_subtype_t type, void *arg, | |
3182 | sctp_cmd_seq_t *commands) | |
3183 | { | |
3184 | struct sctp_chunk *chunk = arg; | |
3185 | struct sctp_chunk *asconf_ack = NULL; | |
3186 | sctp_addiphdr_t *hdr; | |
3187 | __u32 serial; | |
3188 | ||
3189 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3190 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3191 | SCTP_NULL()); | |
3192 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3193 | } | |
3194 | ||
3195 | /* Make sure that the ASCONF ADDIP chunk has a valid length. */ | |
3196 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t))) | |
3197 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
3198 | commands); | |
3199 | ||
3200 | hdr = (sctp_addiphdr_t *)chunk->skb->data; | |
3201 | serial = ntohl(hdr->serial); | |
3202 | ||
3203 | /* ADDIP 4.2 C1) Compare the value of the serial number to the value | |
3204 | * the endpoint stored in a new association variable | |
3205 | * 'Peer-Serial-Number'. | |
3206 | */ | |
3207 | if (serial == asoc->peer.addip_serial + 1) { | |
3208 | /* ADDIP 4.2 C2) If the value found in the serial number is | |
3209 | * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST | |
3210 | * do V1-V5. | |
3211 | */ | |
3212 | asconf_ack = sctp_process_asconf((struct sctp_association *) | |
3213 | asoc, chunk); | |
3214 | if (!asconf_ack) | |
3215 | return SCTP_DISPOSITION_NOMEM; | |
3216 | } else if (serial == asoc->peer.addip_serial) { | |
3217 | /* ADDIP 4.2 C3) If the value found in the serial number is | |
3218 | * equal to the value stored in the 'Peer-Serial-Number' | |
3219 | * IMPLEMENTATION NOTE: As an optimization a receiver may wish | |
3220 | * to save the last ASCONF-ACK for some predetermined period of | |
3221 | * time and instead of re-processing the ASCONF (with the same | |
3222 | * serial number) it may just re-transmit the ASCONF-ACK. | |
3223 | */ | |
3224 | if (asoc->addip_last_asconf_ack) | |
3225 | asconf_ack = asoc->addip_last_asconf_ack; | |
3226 | else | |
3227 | return SCTP_DISPOSITION_DISCARD; | |
3228 | } else { | |
3229 | /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since | |
3230 | * it must be either a stale packet or from an attacker. | |
3231 | */ | |
3232 | return SCTP_DISPOSITION_DISCARD; | |
3233 | } | |
3234 | ||
3235 | /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent | |
3236 | * back to the source address contained in the IP header of the ASCONF | |
3237 | * being responded to. | |
3238 | */ | |
3239 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); | |
3240 | ||
3241 | return SCTP_DISPOSITION_CONSUME; | |
3242 | } | |
3243 | ||
3244 | /* | |
3245 | * ADDIP Section 4.3 General rules for address manipulation | |
3246 | * When building TLV parameters for the ASCONF Chunk that will add or | |
3247 | * delete IP addresses the D0 to D13 rules should be applied: | |
3248 | */ | |
3249 | sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep, | |
3250 | const struct sctp_association *asoc, | |
3251 | const sctp_subtype_t type, void *arg, | |
3252 | sctp_cmd_seq_t *commands) | |
3253 | { | |
3254 | struct sctp_chunk *asconf_ack = arg; | |
3255 | struct sctp_chunk *last_asconf = asoc->addip_last_asconf; | |
3256 | struct sctp_chunk *abort; | |
3257 | sctp_addiphdr_t *addip_hdr; | |
3258 | __u32 sent_serial, rcvd_serial; | |
3259 | ||
3260 | if (!sctp_vtag_verify(asconf_ack, asoc)) { | |
3261 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3262 | SCTP_NULL()); | |
3263 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3264 | } | |
3265 | ||
3266 | /* Make sure that the ADDIP chunk has a valid length. */ | |
3267 | if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t))) | |
3268 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
3269 | commands); | |
3270 | ||
3271 | addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data; | |
3272 | rcvd_serial = ntohl(addip_hdr->serial); | |
3273 | ||
3274 | if (last_asconf) { | |
3275 | addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr; | |
3276 | sent_serial = ntohl(addip_hdr->serial); | |
3277 | } else { | |
3278 | sent_serial = asoc->addip_serial - 1; | |
3279 | } | |
3280 | ||
3281 | /* D0) If an endpoint receives an ASCONF-ACK that is greater than or | |
3282 | * equal to the next serial number to be used but no ASCONF chunk is | |
3283 | * outstanding the endpoint MUST ABORT the association. Note that a | |
3284 | * sequence number is greater than if it is no more than 2^^31-1 | |
3285 | * larger than the current sequence number (using serial arithmetic). | |
3286 | */ | |
3287 | if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && | |
3288 | !(asoc->addip_last_asconf)) { | |
3289 | abort = sctp_make_abort(asoc, asconf_ack, | |
3290 | sizeof(sctp_errhdr_t)); | |
3291 | if (abort) { | |
3292 | sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0); | |
3293 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3294 | SCTP_CHUNK(abort)); | |
3295 | } | |
3296 | /* We are going to ABORT, so we might as well stop | |
3297 | * processing the rest of the chunks in the packet. | |
3298 | */ | |
3299 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3300 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
3301 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); | |
3302 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
3303 | SCTP_U32(SCTP_ERROR_ASCONF_ACK)); | |
3304 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
3305 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
3306 | return SCTP_DISPOSITION_ABORT; | |
3307 | } | |
3308 | ||
3309 | if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { | |
3310 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3311 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
3312 | ||
3313 | if (!sctp_process_asconf_ack((struct sctp_association *)asoc, | |
3314 | asconf_ack)) | |
3315 | return SCTP_DISPOSITION_CONSUME; | |
3316 | ||
3317 | abort = sctp_make_abort(asoc, asconf_ack, | |
3318 | sizeof(sctp_errhdr_t)); | |
3319 | if (abort) { | |
3320 | sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0); | |
3321 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3322 | SCTP_CHUNK(abort)); | |
3323 | } | |
3324 | /* We are going to ABORT, so we might as well stop | |
3325 | * processing the rest of the chunks in the packet. | |
3326 | */ | |
3327 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); | |
3328 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
3329 | SCTP_U32(SCTP_ERROR_ASCONF_ACK)); | |
3330 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
3331 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
3332 | return SCTP_DISPOSITION_ABORT; | |
3333 | } | |
3334 | ||
3335 | return SCTP_DISPOSITION_DISCARD; | |
3336 | } | |
3337 | ||
3338 | /* | |
3339 | * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP | |
3340 | * | |
3341 | * When a FORWARD TSN chunk arrives, the data receiver MUST first update | |
3342 | * its cumulative TSN point to the value carried in the FORWARD TSN | |
3343 | * chunk, and then MUST further advance its cumulative TSN point locally | |
3344 | * if possible. | |
3345 | * After the above processing, the data receiver MUST stop reporting any | |
3346 | * missing TSNs earlier than or equal to the new cumulative TSN point. | |
3347 | * | |
3348 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
3349 | * | |
3350 | * The return value is the disposition of the chunk. | |
3351 | */ | |
3352 | sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep, | |
3353 | const struct sctp_association *asoc, | |
3354 | const sctp_subtype_t type, | |
3355 | void *arg, | |
3356 | sctp_cmd_seq_t *commands) | |
3357 | { | |
3358 | struct sctp_chunk *chunk = arg; | |
3359 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; | |
3360 | __u16 len; | |
3361 | __u32 tsn; | |
3362 | ||
3363 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3364 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3365 | SCTP_NULL()); | |
3366 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3367 | } | |
3368 | ||
3369 | /* Make sure that the FORWARD_TSN chunk has valid length. */ | |
3370 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) | |
3371 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
3372 | commands); | |
3373 | ||
3374 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; | |
3375 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; | |
3376 | len = ntohs(chunk->chunk_hdr->length); | |
3377 | len -= sizeof(struct sctp_chunkhdr); | |
3378 | skb_pull(chunk->skb, len); | |
3379 | ||
3380 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); | |
3381 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn); | |
3382 | ||
3383 | /* The TSN is too high--silently discard the chunk and count on it | |
3384 | * getting retransmitted later. | |
3385 | */ | |
3386 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) | |
3387 | goto discard_noforce; | |
3388 | ||
3389 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); | |
3390 | if (len > sizeof(struct sctp_fwdtsn_hdr)) | |
3391 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, | |
3392 | SCTP_CHUNK(chunk)); | |
3393 | ||
3394 | /* Count this as receiving DATA. */ | |
3395 | if (asoc->autoclose) { | |
3396 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3397 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
3398 | } | |
3399 | ||
3400 | /* FIXME: For now send a SACK, but DATA processing may | |
3401 | * send another. | |
3402 | */ | |
3403 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); | |
3404 | /* Start the SACK timer. */ | |
3405 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3406 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); | |
3407 | ||
3408 | return SCTP_DISPOSITION_CONSUME; | |
3409 | ||
3410 | discard_noforce: | |
3411 | return SCTP_DISPOSITION_DISCARD; | |
3412 | } | |
3413 | ||
3414 | sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( | |
3415 | const struct sctp_endpoint *ep, | |
3416 | const struct sctp_association *asoc, | |
3417 | const sctp_subtype_t type, | |
3418 | void *arg, | |
3419 | sctp_cmd_seq_t *commands) | |
3420 | { | |
3421 | struct sctp_chunk *chunk = arg; | |
3422 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; | |
3423 | __u16 len; | |
3424 | __u32 tsn; | |
3425 | ||
3426 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3427 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3428 | SCTP_NULL()); | |
3429 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3430 | } | |
3431 | ||
3432 | /* Make sure that the FORWARD_TSN chunk has a valid length. */ | |
3433 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) | |
3434 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
3435 | commands); | |
3436 | ||
3437 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; | |
3438 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; | |
3439 | len = ntohs(chunk->chunk_hdr->length); | |
3440 | len -= sizeof(struct sctp_chunkhdr); | |
3441 | skb_pull(chunk->skb, len); | |
3442 | ||
3443 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); | |
3444 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn); | |
3445 | ||
3446 | /* The TSN is too high--silently discard the chunk and count on it | |
3447 | * getting retransmitted later. | |
3448 | */ | |
3449 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) | |
3450 | goto gen_shutdown; | |
3451 | ||
3452 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); | |
3453 | if (len > sizeof(struct sctp_fwdtsn_hdr)) | |
3454 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, | |
3455 | SCTP_CHUNK(chunk)); | |
3456 | ||
3457 | /* Go a head and force a SACK, since we are shutting down. */ | |
3458 | gen_shutdown: | |
3459 | /* Implementor's Guide. | |
3460 | * | |
3461 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately | |
3462 | * respond to each received packet containing one or more DATA chunk(s) | |
3463 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer | |
3464 | */ | |
3465 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); | |
3466 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
3467 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3468 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
3469 | ||
3470 | return SCTP_DISPOSITION_CONSUME; | |
3471 | } | |
3472 | ||
3473 | /* | |
3474 | * Process an unknown chunk. | |
3475 | * | |
3476 | * Section: 3.2. Also, 2.1 in the implementor's guide. | |
3477 | * | |
3478 | * Chunk Types are encoded such that the highest-order two bits specify | |
3479 | * the action that must be taken if the processing endpoint does not | |
3480 | * recognize the Chunk Type. | |
3481 | * | |
3482 | * 00 - Stop processing this SCTP packet and discard it, do not process | |
3483 | * any further chunks within it. | |
3484 | * | |
3485 | * 01 - Stop processing this SCTP packet and discard it, do not process | |
3486 | * any further chunks within it, and report the unrecognized | |
3487 | * chunk in an 'Unrecognized Chunk Type'. | |
3488 | * | |
3489 | * 10 - Skip this chunk and continue processing. | |
3490 | * | |
3491 | * 11 - Skip this chunk and continue processing, but report in an ERROR | |
3492 | * Chunk using the 'Unrecognized Chunk Type' cause of error. | |
3493 | * | |
3494 | * The return value is the disposition of the chunk. | |
3495 | */ | |
3496 | sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep, | |
3497 | const struct sctp_association *asoc, | |
3498 | const sctp_subtype_t type, | |
3499 | void *arg, | |
3500 | sctp_cmd_seq_t *commands) | |
3501 | { | |
3502 | struct sctp_chunk *unk_chunk = arg; | |
3503 | struct sctp_chunk *err_chunk; | |
3504 | sctp_chunkhdr_t *hdr; | |
3505 | ||
3506 | SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk); | |
3507 | ||
3508 | if (!sctp_vtag_verify(unk_chunk, asoc)) | |
3509 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3510 | ||
3511 | /* Make sure that the chunk has a valid length. | |
3512 | * Since we don't know the chunk type, we use a general | |
3513 | * chunkhdr structure to make a comparison. | |
3514 | */ | |
3515 | if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t))) | |
3516 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
3517 | commands); | |
3518 | ||
3519 | switch (type.chunk & SCTP_CID_ACTION_MASK) { | |
3520 | case SCTP_CID_ACTION_DISCARD: | |
3521 | /* Discard the packet. */ | |
3522 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3523 | break; | |
3524 | case SCTP_CID_ACTION_DISCARD_ERR: | |
3525 | /* Discard the packet. */ | |
3526 | sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
3527 | ||
3528 | /* Generate an ERROR chunk as response. */ | |
3529 | hdr = unk_chunk->chunk_hdr; | |
3530 | err_chunk = sctp_make_op_error(asoc, unk_chunk, | |
3531 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, | |
3532 | WORD_ROUND(ntohs(hdr->length))); | |
3533 | if (err_chunk) { | |
3534 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3535 | SCTP_CHUNK(err_chunk)); | |
3536 | } | |
3537 | return SCTP_DISPOSITION_CONSUME; | |
3538 | break; | |
3539 | case SCTP_CID_ACTION_SKIP: | |
3540 | /* Skip the chunk. */ | |
3541 | return SCTP_DISPOSITION_DISCARD; | |
3542 | break; | |
3543 | case SCTP_CID_ACTION_SKIP_ERR: | |
3544 | /* Generate an ERROR chunk as response. */ | |
3545 | hdr = unk_chunk->chunk_hdr; | |
3546 | err_chunk = sctp_make_op_error(asoc, unk_chunk, | |
3547 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, | |
3548 | WORD_ROUND(ntohs(hdr->length))); | |
3549 | if (err_chunk) { | |
3550 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3551 | SCTP_CHUNK(err_chunk)); | |
3552 | } | |
3553 | /* Skip the chunk. */ | |
3554 | return SCTP_DISPOSITION_CONSUME; | |
3555 | break; | |
3556 | default: | |
3557 | break; | |
3558 | } | |
3559 | ||
3560 | return SCTP_DISPOSITION_DISCARD; | |
3561 | } | |
3562 | ||
3563 | /* | |
3564 | * Discard the chunk. | |
3565 | * | |
3566 | * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 | |
3567 | * [Too numerous to mention...] | |
3568 | * Verification Tag: No verification needed. | |
3569 | * Inputs | |
3570 | * (endpoint, asoc, chunk) | |
3571 | * | |
3572 | * Outputs | |
3573 | * (asoc, reply_msg, msg_up, timers, counters) | |
3574 | * | |
3575 | * The return value is the disposition of the chunk. | |
3576 | */ | |
3577 | sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep, | |
3578 | const struct sctp_association *asoc, | |
3579 | const sctp_subtype_t type, | |
3580 | void *arg, | |
3581 | sctp_cmd_seq_t *commands) | |
3582 | { | |
3583 | SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk); | |
3584 | return SCTP_DISPOSITION_DISCARD; | |
3585 | } | |
3586 | ||
3587 | /* | |
3588 | * Discard the whole packet. | |
3589 | * | |
3590 | * Section: 8.4 2) | |
3591 | * | |
3592 | * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST | |
3593 | * silently discard the OOTB packet and take no further action. | |
3594 | * Otherwise, | |
3595 | * | |
3596 | * Verification Tag: No verification necessary | |
3597 | * | |
3598 | * Inputs | |
3599 | * (endpoint, asoc, chunk) | |
3600 | * | |
3601 | * Outputs | |
3602 | * (asoc, reply_msg, msg_up, timers, counters) | |
3603 | * | |
3604 | * The return value is the disposition of the chunk. | |
3605 | */ | |
3606 | sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep, | |
3607 | const struct sctp_association *asoc, | |
3608 | const sctp_subtype_t type, | |
3609 | void *arg, | |
3610 | sctp_cmd_seq_t *commands) | |
3611 | { | |
3612 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
3613 | ||
3614 | return SCTP_DISPOSITION_CONSUME; | |
3615 | } | |
3616 | ||
3617 | ||
3618 | /* | |
3619 | * The other end is violating protocol. | |
3620 | * | |
3621 | * Section: Not specified | |
3622 | * Verification Tag: Not specified | |
3623 | * Inputs | |
3624 | * (endpoint, asoc, chunk) | |
3625 | * | |
3626 | * Outputs | |
3627 | * (asoc, reply_msg, msg_up, timers, counters) | |
3628 | * | |
3629 | * We simply tag the chunk as a violation. The state machine will log | |
3630 | * the violation and continue. | |
3631 | */ | |
3632 | sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep, | |
3633 | const struct sctp_association *asoc, | |
3634 | const sctp_subtype_t type, | |
3635 | void *arg, | |
3636 | sctp_cmd_seq_t *commands) | |
3637 | { | |
3638 | return SCTP_DISPOSITION_VIOLATION; | |
3639 | } | |
3640 | ||
3641 | ||
3642 | /* | |
3643 | * Handle a protocol violation when the chunk length is invalid. | |
3644 | * "Invalid" length is identified as smaller then the minimal length a | |
3645 | * given chunk can be. For example, a SACK chunk has invalid length | |
3646 | * if it's length is set to be smaller then the size of sctp_sack_chunk_t. | |
3647 | * | |
3648 | * We inform the other end by sending an ABORT with a Protocol Violation | |
3649 | * error code. | |
3650 | * | |
3651 | * Section: Not specified | |
3652 | * Verification Tag: Nothing to do | |
3653 | * Inputs | |
3654 | * (endpoint, asoc, chunk) | |
3655 | * | |
3656 | * Outputs | |
3657 | * (reply_msg, msg_up, counters) | |
3658 | * | |
3659 | * Generate an ABORT chunk and terminate the association. | |
3660 | */ | |
3661 | sctp_disposition_t sctp_sf_violation_chunklen(const struct sctp_endpoint *ep, | |
3662 | const struct sctp_association *asoc, | |
3663 | const sctp_subtype_t type, | |
3664 | void *arg, | |
3665 | sctp_cmd_seq_t *commands) | |
3666 | { | |
3667 | struct sctp_chunk *chunk = arg; | |
3668 | struct sctp_chunk *abort = NULL; | |
3669 | char err_str[]="The following chunk had invalid length:"; | |
3670 | ||
3671 | /* Make the abort chunk. */ | |
3672 | abort = sctp_make_abort_violation(asoc, chunk, err_str, | |
3673 | sizeof(err_str)); | |
3674 | if (!abort) | |
3675 | goto nomem; | |
3676 | ||
3677 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
3678 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
3679 | ||
3680 | if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { | |
3681 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3682 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
3683 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
3684 | SCTP_U32(SCTP_ERROR_PROTO_VIOLATION)); | |
3685 | } else { | |
3686 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
3687 | SCTP_U32(SCTP_ERROR_PROTO_VIOLATION)); | |
3688 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
3689 | } | |
3690 | ||
3691 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
3692 | ||
3693 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
3694 | ||
3695 | return SCTP_DISPOSITION_ABORT; | |
3696 | ||
3697 | nomem: | |
3698 | return SCTP_DISPOSITION_NOMEM; | |
3699 | } | |
3700 | ||
3701 | /*************************************************************************** | |
3702 | * These are the state functions for handling primitive (Section 10) events. | |
3703 | ***************************************************************************/ | |
3704 | /* | |
3705 | * sctp_sf_do_prm_asoc | |
3706 | * | |
3707 | * Section: 10.1 ULP-to-SCTP | |
3708 | * B) Associate | |
3709 | * | |
3710 | * Format: ASSOCIATE(local SCTP instance name, destination transport addr, | |
3711 | * outbound stream count) | |
3712 | * -> association id [,destination transport addr list] [,outbound stream | |
3713 | * count] | |
3714 | * | |
3715 | * This primitive allows the upper layer to initiate an association to a | |
3716 | * specific peer endpoint. | |
3717 | * | |
3718 | * The peer endpoint shall be specified by one of the transport addresses | |
3719 | * which defines the endpoint (see Section 1.4). If the local SCTP | |
3720 | * instance has not been initialized, the ASSOCIATE is considered an | |
3721 | * error. | |
3722 | * [This is not relevant for the kernel implementation since we do all | |
3723 | * initialization at boot time. It we hadn't initialized we wouldn't | |
3724 | * get anywhere near this code.] | |
3725 | * | |
3726 | * An association id, which is a local handle to the SCTP association, | |
3727 | * will be returned on successful establishment of the association. If | |
3728 | * SCTP is not able to open an SCTP association with the peer endpoint, | |
3729 | * an error is returned. | |
3730 | * [In the kernel implementation, the struct sctp_association needs to | |
3731 | * be created BEFORE causing this primitive to run.] | |
3732 | * | |
3733 | * Other association parameters may be returned, including the | |
3734 | * complete destination transport addresses of the peer as well as the | |
3735 | * outbound stream count of the local endpoint. One of the transport | |
3736 | * address from the returned destination addresses will be selected by | |
3737 | * the local endpoint as default primary path for sending SCTP packets | |
3738 | * to this peer. The returned "destination transport addr list" can | |
3739 | * be used by the ULP to change the default primary path or to force | |
3740 | * sending a packet to a specific transport address. [All of this | |
3741 | * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING | |
3742 | * function.] | |
3743 | * | |
3744 | * Mandatory attributes: | |
3745 | * | |
3746 | * o local SCTP instance name - obtained from the INITIALIZE operation. | |
3747 | * [This is the argument asoc.] | |
3748 | * o destination transport addr - specified as one of the transport | |
3749 | * addresses of the peer endpoint with which the association is to be | |
3750 | * established. | |
3751 | * [This is asoc->peer.active_path.] | |
3752 | * o outbound stream count - the number of outbound streams the ULP | |
3753 | * would like to open towards this peer endpoint. | |
3754 | * [BUG: This is not currently implemented.] | |
3755 | * Optional attributes: | |
3756 | * | |
3757 | * None. | |
3758 | * | |
3759 | * The return value is a disposition. | |
3760 | */ | |
3761 | sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep, | |
3762 | const struct sctp_association *asoc, | |
3763 | const sctp_subtype_t type, | |
3764 | void *arg, | |
3765 | sctp_cmd_seq_t *commands) | |
3766 | { | |
3767 | struct sctp_chunk *repl; | |
3768 | ||
3769 | /* The comment below says that we enter COOKIE-WAIT AFTER | |
3770 | * sending the INIT, but that doesn't actually work in our | |
3771 | * implementation... | |
3772 | */ | |
3773 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
3774 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); | |
3775 | ||
3776 | /* RFC 2960 5.1 Normal Establishment of an Association | |
3777 | * | |
3778 | * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" | |
3779 | * must provide its Verification Tag (Tag_A) in the Initiate | |
3780 | * Tag field. Tag_A SHOULD be a random number in the range of | |
3781 | * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... | |
3782 | */ | |
3783 | ||
3784 | repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); | |
3785 | if (!repl) | |
3786 | goto nomem; | |
3787 | ||
3788 | /* Cast away the const modifier, as we want to just | |
3789 | * rerun it through as a sideffect. | |
3790 | */ | |
3791 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, | |
3792 | SCTP_ASOC((struct sctp_association *) asoc)); | |
3793 | ||
3794 | /* After sending the INIT, "A" starts the T1-init timer and | |
3795 | * enters the COOKIE-WAIT state. | |
3796 | */ | |
3797 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
3798 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
3799 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
3800 | return SCTP_DISPOSITION_CONSUME; | |
3801 | ||
3802 | nomem: | |
3803 | return SCTP_DISPOSITION_NOMEM; | |
3804 | } | |
3805 | ||
3806 | /* | |
3807 | * Process the SEND primitive. | |
3808 | * | |
3809 | * Section: 10.1 ULP-to-SCTP | |
3810 | * E) Send | |
3811 | * | |
3812 | * Format: SEND(association id, buffer address, byte count [,context] | |
3813 | * [,stream id] [,life time] [,destination transport address] | |
3814 | * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) | |
3815 | * -> result | |
3816 | * | |
3817 | * This is the main method to send user data via SCTP. | |
3818 | * | |
3819 | * Mandatory attributes: | |
3820 | * | |
3821 | * o association id - local handle to the SCTP association | |
3822 | * | |
3823 | * o buffer address - the location where the user message to be | |
3824 | * transmitted is stored; | |
3825 | * | |
3826 | * o byte count - The size of the user data in number of bytes; | |
3827 | * | |
3828 | * Optional attributes: | |
3829 | * | |
3830 | * o context - an optional 32 bit integer that will be carried in the | |
3831 | * sending failure notification to the ULP if the transportation of | |
3832 | * this User Message fails. | |
3833 | * | |
3834 | * o stream id - to indicate which stream to send the data on. If not | |
3835 | * specified, stream 0 will be used. | |
3836 | * | |
3837 | * o life time - specifies the life time of the user data. The user data | |
3838 | * will not be sent by SCTP after the life time expires. This | |
3839 | * parameter can be used to avoid efforts to transmit stale | |
3840 | * user messages. SCTP notifies the ULP if the data cannot be | |
3841 | * initiated to transport (i.e. sent to the destination via SCTP's | |
3842 | * send primitive) within the life time variable. However, the | |
3843 | * user data will be transmitted if SCTP has attempted to transmit a | |
3844 | * chunk before the life time expired. | |
3845 | * | |
3846 | * o destination transport address - specified as one of the destination | |
3847 | * transport addresses of the peer endpoint to which this packet | |
3848 | * should be sent. Whenever possible, SCTP should use this destination | |
3849 | * transport address for sending the packets, instead of the current | |
3850 | * primary path. | |
3851 | * | |
3852 | * o unorder flag - this flag, if present, indicates that the user | |
3853 | * would like the data delivered in an unordered fashion to the peer | |
3854 | * (i.e., the U flag is set to 1 on all DATA chunks carrying this | |
3855 | * message). | |
3856 | * | |
3857 | * o no-bundle flag - instructs SCTP not to bundle this user data with | |
3858 | * other outbound DATA chunks. SCTP MAY still bundle even when | |
3859 | * this flag is present, when faced with network congestion. | |
3860 | * | |
3861 | * o payload protocol-id - A 32 bit unsigned integer that is to be | |
3862 | * passed to the peer indicating the type of payload protocol data | |
3863 | * being transmitted. This value is passed as opaque data by SCTP. | |
3864 | * | |
3865 | * The return value is the disposition. | |
3866 | */ | |
3867 | sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep, | |
3868 | const struct sctp_association *asoc, | |
3869 | const sctp_subtype_t type, | |
3870 | void *arg, | |
3871 | sctp_cmd_seq_t *commands) | |
3872 | { | |
3873 | struct sctp_chunk *chunk = arg; | |
3874 | ||
3875 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); | |
3876 | return SCTP_DISPOSITION_CONSUME; | |
3877 | } | |
3878 | ||
3879 | /* | |
3880 | * Process the SHUTDOWN primitive. | |
3881 | * | |
3882 | * Section: 10.1: | |
3883 | * C) Shutdown | |
3884 | * | |
3885 | * Format: SHUTDOWN(association id) | |
3886 | * -> result | |
3887 | * | |
3888 | * Gracefully closes an association. Any locally queued user data | |
3889 | * will be delivered to the peer. The association will be terminated only | |
3890 | * after the peer acknowledges all the SCTP packets sent. A success code | |
3891 | * will be returned on successful termination of the association. If | |
3892 | * attempting to terminate the association results in a failure, an error | |
3893 | * code shall be returned. | |
3894 | * | |
3895 | * Mandatory attributes: | |
3896 | * | |
3897 | * o association id - local handle to the SCTP association | |
3898 | * | |
3899 | * Optional attributes: | |
3900 | * | |
3901 | * None. | |
3902 | * | |
3903 | * The return value is the disposition. | |
3904 | */ | |
3905 | sctp_disposition_t sctp_sf_do_9_2_prm_shutdown( | |
3906 | const struct sctp_endpoint *ep, | |
3907 | const struct sctp_association *asoc, | |
3908 | const sctp_subtype_t type, | |
3909 | void *arg, | |
3910 | sctp_cmd_seq_t *commands) | |
3911 | { | |
3912 | int disposition; | |
3913 | ||
3914 | /* From 9.2 Shutdown of an Association | |
3915 | * Upon receipt of the SHUTDOWN primitive from its upper | |
3916 | * layer, the endpoint enters SHUTDOWN-PENDING state and | |
3917 | * remains there until all outstanding data has been | |
3918 | * acknowledged by its peer. The endpoint accepts no new data | |
3919 | * from its upper layer, but retransmits data to the far end | |
3920 | * if necessary to fill gaps. | |
3921 | */ | |
3922 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
3923 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); | |
3924 | ||
3925 | /* sctpimpguide-05 Section 2.12.2 | |
3926 | * The sender of the SHUTDOWN MAY also start an overall guard timer | |
3927 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. | |
3928 | */ | |
3929 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
3930 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
3931 | ||
3932 | disposition = SCTP_DISPOSITION_CONSUME; | |
3933 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
3934 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, | |
3935 | arg, commands); | |
3936 | } | |
3937 | return disposition; | |
3938 | } | |
3939 | ||
3940 | /* | |
3941 | * Process the ABORT primitive. | |
3942 | * | |
3943 | * Section: 10.1: | |
3944 | * C) Abort | |
3945 | * | |
3946 | * Format: Abort(association id [, cause code]) | |
3947 | * -> result | |
3948 | * | |
3949 | * Ungracefully closes an association. Any locally queued user data | |
3950 | * will be discarded and an ABORT chunk is sent to the peer. A success code | |
3951 | * will be returned on successful abortion of the association. If | |
3952 | * attempting to abort the association results in a failure, an error | |
3953 | * code shall be returned. | |
3954 | * | |
3955 | * Mandatory attributes: | |
3956 | * | |
3957 | * o association id - local handle to the SCTP association | |
3958 | * | |
3959 | * Optional attributes: | |
3960 | * | |
3961 | * o cause code - reason of the abort to be passed to the peer | |
3962 | * | |
3963 | * None. | |
3964 | * | |
3965 | * The return value is the disposition. | |
3966 | */ | |
3967 | sctp_disposition_t sctp_sf_do_9_1_prm_abort( | |
3968 | const struct sctp_endpoint *ep, | |
3969 | const struct sctp_association *asoc, | |
3970 | const sctp_subtype_t type, | |
3971 | void *arg, | |
3972 | sctp_cmd_seq_t *commands) | |
3973 | { | |
3974 | /* From 9.1 Abort of an Association | |
3975 | * Upon receipt of the ABORT primitive from its upper | |
3976 | * layer, the endpoint enters CLOSED state and | |
3977 | * discard all outstanding data has been | |
3978 | * acknowledged by its peer. The endpoint accepts no new data | |
3979 | * from its upper layer, but retransmits data to the far end | |
3980 | * if necessary to fill gaps. | |
3981 | */ | |
3982 | struct msghdr *msg = arg; | |
3983 | struct sctp_chunk *abort; | |
3984 | sctp_disposition_t retval; | |
3985 | ||
3986 | retval = SCTP_DISPOSITION_CONSUME; | |
3987 | ||
3988 | /* Generate ABORT chunk to send the peer. */ | |
3989 | abort = sctp_make_abort_user(asoc, NULL, msg); | |
3990 | if (!abort) | |
3991 | retval = SCTP_DISPOSITION_NOMEM; | |
3992 | else | |
3993 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
3994 | ||
3995 | /* Even if we can't send the ABORT due to low memory delete the | |
3996 | * TCB. This is a departure from our typical NOMEM handling. | |
3997 | */ | |
3998 | ||
3999 | /* Delete the established association. */ | |
4000 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4001 | SCTP_U32(SCTP_ERROR_USER_ABORT)); | |
4002 | ||
4003 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
4004 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
4005 | ||
4006 | return retval; | |
4007 | } | |
4008 | ||
4009 | /* We tried an illegal operation on an association which is closed. */ | |
4010 | sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep, | |
4011 | const struct sctp_association *asoc, | |
4012 | const sctp_subtype_t type, | |
4013 | void *arg, | |
4014 | sctp_cmd_seq_t *commands) | |
4015 | { | |
4016 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); | |
4017 | return SCTP_DISPOSITION_CONSUME; | |
4018 | } | |
4019 | ||
4020 | /* We tried an illegal operation on an association which is shutting | |
4021 | * down. | |
4022 | */ | |
4023 | sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep, | |
4024 | const struct sctp_association *asoc, | |
4025 | const sctp_subtype_t type, | |
4026 | void *arg, | |
4027 | sctp_cmd_seq_t *commands) | |
4028 | { | |
4029 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, | |
4030 | SCTP_ERROR(-ESHUTDOWN)); | |
4031 | return SCTP_DISPOSITION_CONSUME; | |
4032 | } | |
4033 | ||
4034 | /* | |
4035 | * sctp_cookie_wait_prm_shutdown | |
4036 | * | |
4037 | * Section: 4 Note: 2 | |
4038 | * Verification Tag: | |
4039 | * Inputs | |
4040 | * (endpoint, asoc) | |
4041 | * | |
4042 | * The RFC does not explicitly address this issue, but is the route through the | |
4043 | * state table when someone issues a shutdown while in COOKIE_WAIT state. | |
4044 | * | |
4045 | * Outputs | |
4046 | * (timers) | |
4047 | */ | |
4048 | sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown( | |
4049 | const struct sctp_endpoint *ep, | |
4050 | const struct sctp_association *asoc, | |
4051 | const sctp_subtype_t type, | |
4052 | void *arg, | |
4053 | sctp_cmd_seq_t *commands) | |
4054 | { | |
4055 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4056 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
4057 | ||
4058 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4059 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
4060 | ||
4061 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); | |
4062 | ||
4063 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
4064 | ||
4065 | return SCTP_DISPOSITION_DELETE_TCB; | |
4066 | } | |
4067 | ||
4068 | /* | |
4069 | * sctp_cookie_echoed_prm_shutdown | |
4070 | * | |
4071 | * Section: 4 Note: 2 | |
4072 | * Verification Tag: | |
4073 | * Inputs | |
4074 | * (endpoint, asoc) | |
4075 | * | |
4076 | * The RFC does not explcitly address this issue, but is the route through the | |
4077 | * state table when someone issues a shutdown while in COOKIE_ECHOED state. | |
4078 | * | |
4079 | * Outputs | |
4080 | * (timers) | |
4081 | */ | |
4082 | sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown( | |
4083 | const struct sctp_endpoint *ep, | |
4084 | const struct sctp_association *asoc, | |
4085 | const sctp_subtype_t type, | |
4086 | void *arg, sctp_cmd_seq_t *commands) | |
4087 | { | |
4088 | /* There is a single T1 timer, so we should be able to use | |
4089 | * common function with the COOKIE-WAIT state. | |
4090 | */ | |
4091 | return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands); | |
4092 | } | |
4093 | ||
4094 | /* | |
4095 | * sctp_sf_cookie_wait_prm_abort | |
4096 | * | |
4097 | * Section: 4 Note: 2 | |
4098 | * Verification Tag: | |
4099 | * Inputs | |
4100 | * (endpoint, asoc) | |
4101 | * | |
4102 | * The RFC does not explicitly address this issue, but is the route through the | |
4103 | * state table when someone issues an abort while in COOKIE_WAIT state. | |
4104 | * | |
4105 | * Outputs | |
4106 | * (timers) | |
4107 | */ | |
4108 | sctp_disposition_t sctp_sf_cookie_wait_prm_abort( | |
4109 | const struct sctp_endpoint *ep, | |
4110 | const struct sctp_association *asoc, | |
4111 | const sctp_subtype_t type, | |
4112 | void *arg, | |
4113 | sctp_cmd_seq_t *commands) | |
4114 | { | |
4115 | struct msghdr *msg = arg; | |
4116 | struct sctp_chunk *abort; | |
4117 | sctp_disposition_t retval; | |
4118 | ||
4119 | /* Stop T1-init timer */ | |
4120 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4121 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
4122 | retval = SCTP_DISPOSITION_CONSUME; | |
4123 | ||
4124 | /* Generate ABORT chunk to send the peer */ | |
4125 | abort = sctp_make_abort_user(asoc, NULL, msg); | |
4126 | if (!abort) | |
4127 | retval = SCTP_DISPOSITION_NOMEM; | |
4128 | else | |
4129 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
4130 | ||
4131 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4132 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
4133 | ||
4134 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
4135 | ||
4136 | /* Even if we can't send the ABORT due to low memory delete the | |
4137 | * TCB. This is a departure from our typical NOMEM handling. | |
4138 | */ | |
4139 | ||
4140 | /* Delete the established association. */ | |
4141 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
4142 | SCTP_U32(SCTP_ERROR_USER_ABORT)); | |
4143 | ||
4144 | return retval; | |
4145 | } | |
4146 | ||
4147 | /* | |
4148 | * sctp_sf_cookie_echoed_prm_abort | |
4149 | * | |
4150 | * Section: 4 Note: 3 | |
4151 | * Verification Tag: | |
4152 | * Inputs | |
4153 | * (endpoint, asoc) | |
4154 | * | |
4155 | * The RFC does not explcitly address this issue, but is the route through the | |
4156 | * state table when someone issues an abort while in COOKIE_ECHOED state. | |
4157 | * | |
4158 | * Outputs | |
4159 | * (timers) | |
4160 | */ | |
4161 | sctp_disposition_t sctp_sf_cookie_echoed_prm_abort( | |
4162 | const struct sctp_endpoint *ep, | |
4163 | const struct sctp_association *asoc, | |
4164 | const sctp_subtype_t type, | |
4165 | void *arg, | |
4166 | sctp_cmd_seq_t *commands) | |
4167 | { | |
4168 | /* There is a single T1 timer, so we should be able to use | |
4169 | * common function with the COOKIE-WAIT state. | |
4170 | */ | |
4171 | return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands); | |
4172 | } | |
4173 | ||
4174 | /* | |
4175 | * sctp_sf_shutdown_pending_prm_abort | |
4176 | * | |
4177 | * Inputs | |
4178 | * (endpoint, asoc) | |
4179 | * | |
4180 | * The RFC does not explicitly address this issue, but is the route through the | |
4181 | * state table when someone issues an abort while in SHUTDOWN-PENDING state. | |
4182 | * | |
4183 | * Outputs | |
4184 | * (timers) | |
4185 | */ | |
4186 | sctp_disposition_t sctp_sf_shutdown_pending_prm_abort( | |
4187 | const struct sctp_endpoint *ep, | |
4188 | const struct sctp_association *asoc, | |
4189 | const sctp_subtype_t type, | |
4190 | void *arg, | |
4191 | sctp_cmd_seq_t *commands) | |
4192 | { | |
4193 | /* Stop the T5-shutdown guard timer. */ | |
4194 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4195 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
4196 | ||
4197 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); | |
4198 | } | |
4199 | ||
4200 | /* | |
4201 | * sctp_sf_shutdown_sent_prm_abort | |
4202 | * | |
4203 | * Inputs | |
4204 | * (endpoint, asoc) | |
4205 | * | |
4206 | * The RFC does not explicitly address this issue, but is the route through the | |
4207 | * state table when someone issues an abort while in SHUTDOWN-SENT state. | |
4208 | * | |
4209 | * Outputs | |
4210 | * (timers) | |
4211 | */ | |
4212 | sctp_disposition_t sctp_sf_shutdown_sent_prm_abort( | |
4213 | const struct sctp_endpoint *ep, | |
4214 | const struct sctp_association *asoc, | |
4215 | const sctp_subtype_t type, | |
4216 | void *arg, | |
4217 | sctp_cmd_seq_t *commands) | |
4218 | { | |
4219 | /* Stop the T2-shutdown timer. */ | |
4220 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4221 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
4222 | ||
4223 | /* Stop the T5-shutdown guard timer. */ | |
4224 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4225 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
4226 | ||
4227 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); | |
4228 | } | |
4229 | ||
4230 | /* | |
4231 | * sctp_sf_cookie_echoed_prm_abort | |
4232 | * | |
4233 | * Inputs | |
4234 | * (endpoint, asoc) | |
4235 | * | |
4236 | * The RFC does not explcitly address this issue, but is the route through the | |
4237 | * state table when someone issues an abort while in COOKIE_ECHOED state. | |
4238 | * | |
4239 | * Outputs | |
4240 | * (timers) | |
4241 | */ | |
4242 | sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort( | |
4243 | const struct sctp_endpoint *ep, | |
4244 | const struct sctp_association *asoc, | |
4245 | const sctp_subtype_t type, | |
4246 | void *arg, | |
4247 | sctp_cmd_seq_t *commands) | |
4248 | { | |
4249 | /* The same T2 timer, so we should be able to use | |
4250 | * common function with the SHUTDOWN-SENT state. | |
4251 | */ | |
4252 | return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands); | |
4253 | } | |
4254 | ||
4255 | /* | |
4256 | * Process the REQUESTHEARTBEAT primitive | |
4257 | * | |
4258 | * 10.1 ULP-to-SCTP | |
4259 | * J) Request Heartbeat | |
4260 | * | |
4261 | * Format: REQUESTHEARTBEAT(association id, destination transport address) | |
4262 | * | |
4263 | * -> result | |
4264 | * | |
4265 | * Instructs the local endpoint to perform a HeartBeat on the specified | |
4266 | * destination transport address of the given association. The returned | |
4267 | * result should indicate whether the transmission of the HEARTBEAT | |
4268 | * chunk to the destination address is successful. | |
4269 | * | |
4270 | * Mandatory attributes: | |
4271 | * | |
4272 | * o association id - local handle to the SCTP association | |
4273 | * | |
4274 | * o destination transport address - the transport address of the | |
4275 | * association on which a heartbeat should be issued. | |
4276 | */ | |
4277 | sctp_disposition_t sctp_sf_do_prm_requestheartbeat( | |
4278 | const struct sctp_endpoint *ep, | |
4279 | const struct sctp_association *asoc, | |
4280 | const sctp_subtype_t type, | |
4281 | void *arg, | |
4282 | sctp_cmd_seq_t *commands) | |
4283 | { | |
4284 | return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg, | |
4285 | commands); | |
4286 | } | |
4287 | ||
4288 | /* | |
4289 | * ADDIP Section 4.1 ASCONF Chunk Procedures | |
4290 | * When an endpoint has an ASCONF signaled change to be sent to the | |
4291 | * remote endpoint it should do A1 to A9 | |
4292 | */ | |
4293 | sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep, | |
4294 | const struct sctp_association *asoc, | |
4295 | const sctp_subtype_t type, | |
4296 | void *arg, | |
4297 | sctp_cmd_seq_t *commands) | |
4298 | { | |
4299 | struct sctp_chunk *chunk = arg; | |
4300 | ||
4301 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); | |
4302 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
4303 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
4304 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); | |
4305 | return SCTP_DISPOSITION_CONSUME; | |
4306 | } | |
4307 | ||
4308 | /* | |
4309 | * Ignore the primitive event | |
4310 | * | |
4311 | * The return value is the disposition of the primitive. | |
4312 | */ | |
4313 | sctp_disposition_t sctp_sf_ignore_primitive( | |
4314 | const struct sctp_endpoint *ep, | |
4315 | const struct sctp_association *asoc, | |
4316 | const sctp_subtype_t type, | |
4317 | void *arg, | |
4318 | sctp_cmd_seq_t *commands) | |
4319 | { | |
4320 | SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive); | |
4321 | return SCTP_DISPOSITION_DISCARD; | |
4322 | } | |
4323 | ||
4324 | /*************************************************************************** | |
4325 | * These are the state functions for the OTHER events. | |
4326 | ***************************************************************************/ | |
4327 | ||
4328 | /* | |
4329 | * Start the shutdown negotiation. | |
4330 | * | |
4331 | * From Section 9.2: | |
4332 | * Once all its outstanding data has been acknowledged, the endpoint | |
4333 | * shall send a SHUTDOWN chunk to its peer including in the Cumulative | |
4334 | * TSN Ack field the last sequential TSN it has received from the peer. | |
4335 | * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT | |
4336 | * state. If the timer expires, the endpoint must re-send the SHUTDOWN | |
4337 | * with the updated last sequential TSN received from its peer. | |
4338 | * | |
4339 | * The return value is the disposition. | |
4340 | */ | |
4341 | sctp_disposition_t sctp_sf_do_9_2_start_shutdown( | |
4342 | const struct sctp_endpoint *ep, | |
4343 | const struct sctp_association *asoc, | |
4344 | const sctp_subtype_t type, | |
4345 | void *arg, | |
4346 | sctp_cmd_seq_t *commands) | |
4347 | { | |
4348 | struct sctp_chunk *reply; | |
4349 | ||
4350 | /* Once all its outstanding data has been acknowledged, the | |
4351 | * endpoint shall send a SHUTDOWN chunk to its peer including | |
4352 | * in the Cumulative TSN Ack field the last sequential TSN it | |
4353 | * has received from the peer. | |
4354 | */ | |
4355 | reply = sctp_make_shutdown(asoc, NULL); | |
4356 | if (!reply) | |
4357 | goto nomem; | |
4358 | ||
4359 | /* Set the transport for the SHUTDOWN chunk and the timeout for the | |
4360 | * T2-shutdown timer. | |
4361 | */ | |
4362 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
4363 | ||
4364 | /* It shall then start the T2-shutdown timer */ | |
4365 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
4366 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
4367 | ||
4368 | if (asoc->autoclose) | |
4369 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4370 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
4371 | ||
4372 | /* and enter the SHUTDOWN-SENT state. */ | |
4373 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4374 | SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); | |
4375 | ||
4376 | /* sctp-implguide 2.10 Issues with Heartbeating and failover | |
4377 | * | |
4378 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN | |
4379 | * or SHUTDOWN-ACK. | |
4380 | */ | |
4381 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
4382 | ||
4383 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
4384 | ||
4385 | return SCTP_DISPOSITION_CONSUME; | |
4386 | ||
4387 | nomem: | |
4388 | return SCTP_DISPOSITION_NOMEM; | |
4389 | } | |
4390 | ||
4391 | /* | |
4392 | * Generate a SHUTDOWN ACK now that everything is SACK'd. | |
4393 | * | |
4394 | * From Section 9.2: | |
4395 | * | |
4396 | * If it has no more outstanding DATA chunks, the SHUTDOWN receiver | |
4397 | * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, | |
4398 | * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the | |
4399 | * endpoint must re-send the SHUTDOWN ACK. | |
4400 | * | |
4401 | * The return value is the disposition. | |
4402 | */ | |
4403 | sctp_disposition_t sctp_sf_do_9_2_shutdown_ack( | |
4404 | const struct sctp_endpoint *ep, | |
4405 | const struct sctp_association *asoc, | |
4406 | const sctp_subtype_t type, | |
4407 | void *arg, | |
4408 | sctp_cmd_seq_t *commands) | |
4409 | { | |
4410 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; | |
4411 | struct sctp_chunk *reply; | |
4412 | ||
4413 | /* There are 2 ways of getting here: | |
4414 | * 1) called in response to a SHUTDOWN chunk | |
4415 | * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. | |
4416 | * | |
4417 | * For the case (2), the arg parameter is set to NULL. We need | |
4418 | * to check that we have a chunk before accessing it's fields. | |
4419 | */ | |
4420 | if (chunk) { | |
4421 | if (!sctp_vtag_verify(chunk, asoc)) | |
4422 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); | |
4423 | ||
4424 | /* Make sure that the SHUTDOWN chunk has a valid length. */ | |
4425 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t))) | |
4426 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, | |
4427 | commands); | |
4428 | } | |
4429 | ||
4430 | /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver | |
4431 | * shall send a SHUTDOWN ACK ... | |
4432 | */ | |
4433 | reply = sctp_make_shutdown_ack(asoc, chunk); | |
4434 | if (!reply) | |
4435 | goto nomem; | |
4436 | ||
4437 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for | |
4438 | * the T2-shutdown timer. | |
4439 | */ | |
4440 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
4441 | ||
4442 | /* and start/restart a T2-shutdown timer of its own, */ | |
4443 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
4444 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
4445 | ||
4446 | if (asoc->autoclose) | |
4447 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4448 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
4449 | ||
4450 | /* Enter the SHUTDOWN-ACK-SENT state. */ | |
4451 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4452 | SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); | |
4453 | ||
4454 | /* sctp-implguide 2.10 Issues with Heartbeating and failover | |
4455 | * | |
4456 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN | |
4457 | * or SHUTDOWN-ACK. | |
4458 | */ | |
4459 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
4460 | ||
4461 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
4462 | ||
4463 | return SCTP_DISPOSITION_CONSUME; | |
4464 | ||
4465 | nomem: | |
4466 | return SCTP_DISPOSITION_NOMEM; | |
4467 | } | |
4468 | ||
4469 | /* | |
4470 | * Ignore the event defined as other | |
4471 | * | |
4472 | * The return value is the disposition of the event. | |
4473 | */ | |
4474 | sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep, | |
4475 | const struct sctp_association *asoc, | |
4476 | const sctp_subtype_t type, | |
4477 | void *arg, | |
4478 | sctp_cmd_seq_t *commands) | |
4479 | { | |
4480 | SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other); | |
4481 | return SCTP_DISPOSITION_DISCARD; | |
4482 | } | |
4483 | ||
4484 | /************************************************************ | |
4485 | * These are the state functions for handling timeout events. | |
4486 | ************************************************************/ | |
4487 | ||
4488 | /* | |
4489 | * RTX Timeout | |
4490 | * | |
4491 | * Section: 6.3.3 Handle T3-rtx Expiration | |
4492 | * | |
4493 | * Whenever the retransmission timer T3-rtx expires for a destination | |
4494 | * address, do the following: | |
4495 | * [See below] | |
4496 | * | |
4497 | * The return value is the disposition of the chunk. | |
4498 | */ | |
4499 | sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep, | |
4500 | const struct sctp_association *asoc, | |
4501 | const sctp_subtype_t type, | |
4502 | void *arg, | |
4503 | sctp_cmd_seq_t *commands) | |
4504 | { | |
4505 | struct sctp_transport *transport = arg; | |
4506 | ||
4507 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
4508 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
4509 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4510 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
4511 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
4512 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
4513 | return SCTP_DISPOSITION_DELETE_TCB; | |
4514 | } | |
4515 | ||
4516 | /* E1) For the destination address for which the timer | |
4517 | * expires, adjust its ssthresh with rules defined in Section | |
4518 | * 7.2.3 and set the cwnd <- MTU. | |
4519 | */ | |
4520 | ||
4521 | /* E2) For the destination address for which the timer | |
4522 | * expires, set RTO <- RTO * 2 ("back off the timer"). The | |
4523 | * maximum value discussed in rule C7 above (RTO.max) may be | |
4524 | * used to provide an upper bound to this doubling operation. | |
4525 | */ | |
4526 | ||
4527 | /* E3) Determine how many of the earliest (i.e., lowest TSN) | |
4528 | * outstanding DATA chunks for the address for which the | |
4529 | * T3-rtx has expired will fit into a single packet, subject | |
4530 | * to the MTU constraint for the path corresponding to the | |
4531 | * destination transport address to which the retransmission | |
4532 | * is being sent (this may be different from the address for | |
4533 | * which the timer expires [see Section 6.4]). Call this | |
4534 | * value K. Bundle and retransmit those K DATA chunks in a | |
4535 | * single packet to the destination endpoint. | |
4536 | * | |
4537 | * Note: Any DATA chunks that were sent to the address for | |
4538 | * which the T3-rtx timer expired but did not fit in one MTU | |
4539 | * (rule E3 above), should be marked for retransmission and | |
4540 | * sent as soon as cwnd allows (normally when a SACK arrives). | |
4541 | */ | |
4542 | ||
4543 | /* NB: Rules E4 and F1 are implicit in R1. */ | |
4544 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); | |
4545 | ||
4546 | /* Do some failure management (Section 8.2). */ | |
4547 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); | |
4548 | ||
4549 | return SCTP_DISPOSITION_CONSUME; | |
4550 | } | |
4551 | ||
4552 | /* | |
4553 | * Generate delayed SACK on timeout | |
4554 | * | |
4555 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks | |
4556 | * | |
4557 | * The guidelines on delayed acknowledgement algorithm specified in | |
4558 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an | |
4559 | * acknowledgement SHOULD be generated for at least every second packet | |
4560 | * (not every second DATA chunk) received, and SHOULD be generated | |
4561 | * within 200 ms of the arrival of any unacknowledged DATA chunk. In | |
4562 | * some situations it may be beneficial for an SCTP transmitter to be | |
4563 | * more conservative than the algorithms detailed in this document | |
4564 | * allow. However, an SCTP transmitter MUST NOT be more aggressive than | |
4565 | * the following algorithms allow. | |
4566 | */ | |
4567 | sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep, | |
4568 | const struct sctp_association *asoc, | |
4569 | const sctp_subtype_t type, | |
4570 | void *arg, | |
4571 | sctp_cmd_seq_t *commands) | |
4572 | { | |
4573 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
4574 | return SCTP_DISPOSITION_CONSUME; | |
4575 | } | |
4576 | ||
4577 | /* | |
4578 | * sctp_sf_t1_timer_expire | |
4579 | * | |
4580 | * Section: 4 Note: 2 | |
4581 | * Verification Tag: | |
4582 | * Inputs | |
4583 | * (endpoint, asoc) | |
4584 | * | |
4585 | * RFC 2960 Section 4 Notes | |
4586 | * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT | |
4587 | * and re-start the T1-init timer without changing state. This MUST | |
4588 | * be repeated up to 'Max.Init.Retransmits' times. After that, the | |
4589 | * endpoint MUST abort the initialization process and report the | |
4590 | * error to SCTP user. | |
4591 | * | |
4592 | * 3) If the T1-cookie timer expires, the endpoint MUST retransmit | |
4593 | * COOKIE ECHO and re-start the T1-cookie timer without changing | |
4594 | * state. This MUST be repeated up to 'Max.Init.Retransmits' times. | |
4595 | * After that, the endpoint MUST abort the initialization process and | |
4596 | * report the error to SCTP user. | |
4597 | * | |
4598 | * Outputs | |
4599 | * (timers, events) | |
4600 | * | |
4601 | */ | |
4602 | sctp_disposition_t sctp_sf_t1_timer_expire(const struct sctp_endpoint *ep, | |
4603 | const struct sctp_association *asoc, | |
4604 | const sctp_subtype_t type, | |
4605 | void *arg, | |
4606 | sctp_cmd_seq_t *commands) | |
4607 | { | |
4608 | struct sctp_chunk *repl; | |
4609 | struct sctp_bind_addr *bp; | |
4610 | sctp_event_timeout_t timer = (sctp_event_timeout_t) arg; | |
4611 | int timeout; | |
4612 | int attempts; | |
4613 | ||
4614 | timeout = asoc->timeouts[timer]; | |
4615 | attempts = asoc->counters[SCTP_COUNTER_INIT_ERROR] + 1; | |
4616 | repl = NULL; | |
4617 | ||
4618 | SCTP_DEBUG_PRINTK("Timer T1 expired.\n"); | |
4619 | ||
4620 | if (attempts < asoc->max_init_attempts) { | |
4621 | switch (timer) { | |
4622 | case SCTP_EVENT_TIMEOUT_T1_INIT: | |
4623 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; | |
4624 | repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); | |
4625 | break; | |
4626 | ||
4627 | case SCTP_EVENT_TIMEOUT_T1_COOKIE: | |
4628 | repl = sctp_make_cookie_echo(asoc, NULL); | |
4629 | break; | |
4630 | ||
4631 | default: | |
4632 | BUG(); | |
4633 | break; | |
4634 | }; | |
4635 | ||
4636 | if (!repl) | |
4637 | goto nomem; | |
4638 | ||
4639 | /* Issue a sideeffect to do the needed accounting. */ | |
4640 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, | |
4641 | SCTP_TO(timer)); | |
4642 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
4643 | } else { | |
4644 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
4645 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
4646 | return SCTP_DISPOSITION_DELETE_TCB; | |
4647 | } | |
4648 | ||
4649 | return SCTP_DISPOSITION_CONSUME; | |
4650 | ||
4651 | nomem: | |
4652 | return SCTP_DISPOSITION_NOMEM; | |
4653 | } | |
4654 | ||
4655 | /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN | |
4656 | * with the updated last sequential TSN received from its peer. | |
4657 | * | |
4658 | * An endpoint should limit the number of retransmissions of the | |
4659 | * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. | |
4660 | * If this threshold is exceeded the endpoint should destroy the TCB and | |
4661 | * MUST report the peer endpoint unreachable to the upper layer (and | |
4662 | * thus the association enters the CLOSED state). The reception of any | |
4663 | * packet from its peer (i.e. as the peer sends all of its queued DATA | |
4664 | * chunks) should clear the endpoint's retransmission count and restart | |
4665 | * the T2-Shutdown timer, giving its peer ample opportunity to transmit | |
4666 | * all of its queued DATA chunks that have not yet been sent. | |
4667 | */ | |
4668 | sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep, | |
4669 | const struct sctp_association *asoc, | |
4670 | const sctp_subtype_t type, | |
4671 | void *arg, | |
4672 | sctp_cmd_seq_t *commands) | |
4673 | { | |
4674 | struct sctp_chunk *reply = NULL; | |
4675 | ||
4676 | SCTP_DEBUG_PRINTK("Timer T2 expired.\n"); | |
4677 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
4678 | /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
4679 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4680 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
4681 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
4682 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
4683 | return SCTP_DISPOSITION_DELETE_TCB; | |
4684 | } | |
4685 | ||
4686 | switch (asoc->state) { | |
4687 | case SCTP_STATE_SHUTDOWN_SENT: | |
4688 | reply = sctp_make_shutdown(asoc, NULL); | |
4689 | break; | |
4690 | ||
4691 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
4692 | reply = sctp_make_shutdown_ack(asoc, NULL); | |
4693 | break; | |
4694 | ||
4695 | default: | |
4696 | BUG(); | |
4697 | break; | |
4698 | }; | |
4699 | ||
4700 | if (!reply) | |
4701 | goto nomem; | |
4702 | ||
4703 | /* Do some failure management (Section 8.2). */ | |
4704 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, | |
4705 | SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); | |
4706 | ||
4707 | /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for | |
4708 | * the T2-shutdown timer. | |
4709 | */ | |
4710 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
4711 | ||
4712 | /* Restart the T2-shutdown timer. */ | |
4713 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
4714 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
4715 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
4716 | return SCTP_DISPOSITION_CONSUME; | |
4717 | ||
4718 | nomem: | |
4719 | return SCTP_DISPOSITION_NOMEM; | |
4720 | } | |
4721 | ||
4722 | /* | |
4723 | * ADDIP Section 4.1 ASCONF CHunk Procedures | |
4724 | * If the T4 RTO timer expires the endpoint should do B1 to B5 | |
4725 | */ | |
4726 | sctp_disposition_t sctp_sf_t4_timer_expire( | |
4727 | const struct sctp_endpoint *ep, | |
4728 | const struct sctp_association *asoc, | |
4729 | const sctp_subtype_t type, | |
4730 | void *arg, | |
4731 | sctp_cmd_seq_t *commands) | |
4732 | { | |
4733 | struct sctp_chunk *chunk = asoc->addip_last_asconf; | |
4734 | struct sctp_transport *transport = chunk->transport; | |
4735 | ||
4736 | /* ADDIP 4.1 B1) Increment the error counters and perform path failure | |
4737 | * detection on the appropriate destination address as defined in | |
4738 | * RFC2960 [5] section 8.1 and 8.2. | |
4739 | */ | |
4740 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); | |
4741 | ||
4742 | /* Reconfig T4 timer and transport. */ | |
4743 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); | |
4744 | ||
4745 | /* ADDIP 4.1 B2) Increment the association error counters and perform | |
4746 | * endpoint failure detection on the association as defined in | |
4747 | * RFC2960 [5] section 8.1 and 8.2. | |
4748 | * association error counter is incremented in SCTP_CMD_STRIKE. | |
4749 | */ | |
4750 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
4751 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4752 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
4753 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4754 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
4755 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
4756 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); | |
4757 | return SCTP_DISPOSITION_ABORT; | |
4758 | } | |
4759 | ||
4760 | /* ADDIP 4.1 B3) Back-off the destination address RTO value to which | |
4761 | * the ASCONF chunk was sent by doubling the RTO timer value. | |
4762 | * This is done in SCTP_CMD_STRIKE. | |
4763 | */ | |
4764 | ||
4765 | /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible | |
4766 | * choose an alternate destination address (please refer to RFC2960 | |
4767 | * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this | |
4768 | * chunk, it MUST be the same (including its serial number) as the last | |
4769 | * ASCONF sent. | |
4770 | */ | |
4771 | sctp_chunk_hold(asoc->addip_last_asconf); | |
4772 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
4773 | SCTP_CHUNK(asoc->addip_last_asconf)); | |
4774 | ||
4775 | /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different | |
4776 | * destination is selected, then the RTO used will be that of the new | |
4777 | * destination address. | |
4778 | */ | |
4779 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
4780 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
4781 | ||
4782 | return SCTP_DISPOSITION_CONSUME; | |
4783 | } | |
4784 | ||
4785 | /* sctpimpguide-05 Section 2.12.2 | |
4786 | * The sender of the SHUTDOWN MAY also start an overall guard timer | |
4787 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. | |
4788 | * At the expiration of this timer the sender SHOULD abort the association | |
4789 | * by sending an ABORT chunk. | |
4790 | */ | |
4791 | sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep, | |
4792 | const struct sctp_association *asoc, | |
4793 | const sctp_subtype_t type, | |
4794 | void *arg, | |
4795 | sctp_cmd_seq_t *commands) | |
4796 | { | |
4797 | struct sctp_chunk *reply = NULL; | |
4798 | ||
4799 | SCTP_DEBUG_PRINTK("Timer T5 expired.\n"); | |
4800 | ||
4801 | reply = sctp_make_abort(asoc, NULL, 0); | |
4802 | if (!reply) | |
4803 | goto nomem; | |
4804 | ||
4805 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
4806 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4807 | SCTP_U32(SCTP_ERROR_NO_ERROR)); | |
4808 | ||
4809 | return SCTP_DISPOSITION_DELETE_TCB; | |
4810 | nomem: | |
4811 | return SCTP_DISPOSITION_NOMEM; | |
4812 | } | |
4813 | ||
4814 | /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, | |
4815 | * the association is automatically closed by starting the shutdown process. | |
4816 | * The work that needs to be done is same as when SHUTDOWN is initiated by | |
4817 | * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). | |
4818 | */ | |
4819 | sctp_disposition_t sctp_sf_autoclose_timer_expire( | |
4820 | const struct sctp_endpoint *ep, | |
4821 | const struct sctp_association *asoc, | |
4822 | const sctp_subtype_t type, | |
4823 | void *arg, | |
4824 | sctp_cmd_seq_t *commands) | |
4825 | { | |
4826 | int disposition; | |
4827 | ||
4828 | /* From 9.2 Shutdown of an Association | |
4829 | * Upon receipt of the SHUTDOWN primitive from its upper | |
4830 | * layer, the endpoint enters SHUTDOWN-PENDING state and | |
4831 | * remains there until all outstanding data has been | |
4832 | * acknowledged by its peer. The endpoint accepts no new data | |
4833 | * from its upper layer, but retransmits data to the far end | |
4834 | * if necessary to fill gaps. | |
4835 | */ | |
4836 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4837 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); | |
4838 | ||
4839 | /* sctpimpguide-05 Section 2.12.2 | |
4840 | * The sender of the SHUTDOWN MAY also start an overall guard timer | |
4841 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. | |
4842 | */ | |
4843 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
4844 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
4845 | disposition = SCTP_DISPOSITION_CONSUME; | |
4846 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
4847 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, | |
4848 | arg, commands); | |
4849 | } | |
4850 | return disposition; | |
4851 | } | |
4852 | ||
4853 | /***************************************************************************** | |
4854 | * These are sa state functions which could apply to all types of events. | |
4855 | ****************************************************************************/ | |
4856 | ||
4857 | /* | |
4858 | * This table entry is not implemented. | |
4859 | * | |
4860 | * Inputs | |
4861 | * (endpoint, asoc, chunk) | |
4862 | * | |
4863 | * The return value is the disposition of the chunk. | |
4864 | */ | |
4865 | sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep, | |
4866 | const struct sctp_association *asoc, | |
4867 | const sctp_subtype_t type, | |
4868 | void *arg, | |
4869 | sctp_cmd_seq_t *commands) | |
4870 | { | |
4871 | return SCTP_DISPOSITION_NOT_IMPL; | |
4872 | } | |
4873 | ||
4874 | /* | |
4875 | * This table entry represents a bug. | |
4876 | * | |
4877 | * Inputs | |
4878 | * (endpoint, asoc, chunk) | |
4879 | * | |
4880 | * The return value is the disposition of the chunk. | |
4881 | */ | |
4882 | sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep, | |
4883 | const struct sctp_association *asoc, | |
4884 | const sctp_subtype_t type, | |
4885 | void *arg, | |
4886 | sctp_cmd_seq_t *commands) | |
4887 | { | |
4888 | return SCTP_DISPOSITION_BUG; | |
4889 | } | |
4890 | ||
4891 | /* | |
4892 | * This table entry represents the firing of a timer in the wrong state. | |
4893 | * Since timer deletion cannot be guaranteed a timer 'may' end up firing | |
4894 | * when the association is in the wrong state. This event should | |
4895 | * be ignored, so as to prevent any rearming of the timer. | |
4896 | * | |
4897 | * Inputs | |
4898 | * (endpoint, asoc, chunk) | |
4899 | * | |
4900 | * The return value is the disposition of the chunk. | |
4901 | */ | |
4902 | sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep, | |
4903 | const struct sctp_association *asoc, | |
4904 | const sctp_subtype_t type, | |
4905 | void *arg, | |
4906 | sctp_cmd_seq_t *commands) | |
4907 | { | |
4908 | SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk); | |
4909 | return SCTP_DISPOSITION_CONSUME; | |
4910 | } | |
4911 | ||
4912 | /******************************************************************** | |
4913 | * 2nd Level Abstractions | |
4914 | ********************************************************************/ | |
4915 | ||
4916 | /* Pull the SACK chunk based on the SACK header. */ | |
4917 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) | |
4918 | { | |
4919 | struct sctp_sackhdr *sack; | |
4920 | unsigned int len; | |
4921 | __u16 num_blocks; | |
4922 | __u16 num_dup_tsns; | |
4923 | ||
4924 | /* Protect ourselves from reading too far into | |
4925 | * the skb from a bogus sender. | |
4926 | */ | |
4927 | sack = (struct sctp_sackhdr *) chunk->skb->data; | |
4928 | ||
4929 | num_blocks = ntohs(sack->num_gap_ack_blocks); | |
4930 | num_dup_tsns = ntohs(sack->num_dup_tsns); | |
4931 | len = sizeof(struct sctp_sackhdr); | |
4932 | len += (num_blocks + num_dup_tsns) * sizeof(__u32); | |
4933 | if (len > chunk->skb->len) | |
4934 | return NULL; | |
4935 | ||
4936 | skb_pull(chunk->skb, len); | |
4937 | ||
4938 | return sack; | |
4939 | } | |
4940 | ||
4941 | /* Create an ABORT packet to be sent as a response, with the specified | |
4942 | * error causes. | |
4943 | */ | |
4944 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, | |
4945 | const struct sctp_association *asoc, | |
4946 | struct sctp_chunk *chunk, | |
4947 | const void *payload, | |
4948 | size_t paylen) | |
4949 | { | |
4950 | struct sctp_packet *packet; | |
4951 | struct sctp_chunk *abort; | |
4952 | ||
4953 | packet = sctp_ootb_pkt_new(asoc, chunk); | |
4954 | ||
4955 | if (packet) { | |
4956 | /* Make an ABORT. | |
4957 | * The T bit will be set if the asoc is NULL. | |
4958 | */ | |
4959 | abort = sctp_make_abort(asoc, chunk, paylen); | |
4960 | if (!abort) { | |
4961 | sctp_ootb_pkt_free(packet); | |
4962 | return NULL; | |
4963 | } | |
4964 | /* Add specified error causes, i.e., payload, to the | |
4965 | * end of the chunk. | |
4966 | */ | |
4967 | sctp_addto_chunk(abort, paylen, payload); | |
4968 | ||
4969 | /* Set the skb to the belonging sock for accounting. */ | |
4970 | abort->skb->sk = ep->base.sk; | |
4971 | ||
4972 | sctp_packet_append_chunk(packet, abort); | |
4973 | ||
4974 | } | |
4975 | ||
4976 | return packet; | |
4977 | } | |
4978 | ||
4979 | /* Allocate a packet for responding in the OOTB conditions. */ | |
4980 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, | |
4981 | const struct sctp_chunk *chunk) | |
4982 | { | |
4983 | struct sctp_packet *packet; | |
4984 | struct sctp_transport *transport; | |
4985 | __u16 sport; | |
4986 | __u16 dport; | |
4987 | __u32 vtag; | |
4988 | ||
4989 | /* Get the source and destination port from the inbound packet. */ | |
4990 | sport = ntohs(chunk->sctp_hdr->dest); | |
4991 | dport = ntohs(chunk->sctp_hdr->source); | |
4992 | ||
4993 | /* The V-tag is going to be the same as the inbound packet if no | |
4994 | * association exists, otherwise, use the peer's vtag. | |
4995 | */ | |
4996 | if (asoc) { | |
4997 | vtag = asoc->peer.i.init_tag; | |
4998 | } else { | |
4999 | /* Special case the INIT and stale COOKIE_ECHO as there is no | |
5000 | * vtag yet. | |
5001 | */ | |
5002 | switch(chunk->chunk_hdr->type) { | |
5003 | case SCTP_CID_INIT: | |
5004 | { | |
5005 | sctp_init_chunk_t *init; | |
5006 | ||
5007 | init = (sctp_init_chunk_t *)chunk->chunk_hdr; | |
5008 | vtag = ntohl(init->init_hdr.init_tag); | |
5009 | break; | |
5010 | } | |
5011 | default: | |
5012 | vtag = ntohl(chunk->sctp_hdr->vtag); | |
5013 | break; | |
5014 | } | |
5015 | } | |
5016 | ||
5017 | /* Make a transport for the bucket, Eliza... */ | |
5018 | transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC); | |
5019 | if (!transport) | |
5020 | goto nomem; | |
5021 | ||
5022 | /* Cache a route for the transport with the chunk's destination as | |
5023 | * the source address. | |
5024 | */ | |
5025 | sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, | |
5026 | sctp_sk(sctp_get_ctl_sock())); | |
5027 | ||
5028 | packet = sctp_packet_init(&transport->packet, transport, sport, dport); | |
5029 | packet = sctp_packet_config(packet, vtag, 0); | |
5030 | ||
5031 | return packet; | |
5032 | ||
5033 | nomem: | |
5034 | return NULL; | |
5035 | } | |
5036 | ||
5037 | /* Free the packet allocated earlier for responding in the OOTB condition. */ | |
5038 | void sctp_ootb_pkt_free(struct sctp_packet *packet) | |
5039 | { | |
5040 | sctp_transport_free(packet->transport); | |
5041 | } | |
5042 | ||
5043 | /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ | |
5044 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, | |
5045 | const struct sctp_association *asoc, | |
5046 | const struct sctp_chunk *chunk, | |
5047 | sctp_cmd_seq_t *commands, | |
5048 | struct sctp_chunk *err_chunk) | |
5049 | { | |
5050 | struct sctp_packet *packet; | |
5051 | ||
5052 | if (err_chunk) { | |
5053 | packet = sctp_ootb_pkt_new(asoc, chunk); | |
5054 | if (packet) { | |
5055 | struct sctp_signed_cookie *cookie; | |
5056 | ||
5057 | /* Override the OOTB vtag from the cookie. */ | |
5058 | cookie = chunk->subh.cookie_hdr; | |
5059 | packet->vtag = cookie->c.peer_vtag; | |
5060 | ||
5061 | /* Set the skb to the belonging sock for accounting. */ | |
5062 | err_chunk->skb->sk = ep->base.sk; | |
5063 | sctp_packet_append_chunk(packet, err_chunk); | |
5064 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
5065 | SCTP_PACKET(packet)); | |
5066 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); | |
5067 | } else | |
5068 | sctp_chunk_free (err_chunk); | |
5069 | } | |
5070 | } | |
5071 | ||
5072 | ||
5073 | /* Process a data chunk */ | |
5074 | static int sctp_eat_data(const struct sctp_association *asoc, | |
5075 | struct sctp_chunk *chunk, | |
5076 | sctp_cmd_seq_t *commands) | |
5077 | { | |
5078 | sctp_datahdr_t *data_hdr; | |
5079 | struct sctp_chunk *err; | |
5080 | size_t datalen; | |
5081 | sctp_verb_t deliver; | |
5082 | int tmp; | |
5083 | __u32 tsn; | |
5084 | ||
5085 | data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data; | |
5086 | skb_pull(chunk->skb, sizeof(sctp_datahdr_t)); | |
5087 | ||
5088 | tsn = ntohl(data_hdr->tsn); | |
5089 | SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn); | |
5090 | ||
5091 | /* ASSERT: Now skb->data is really the user data. */ | |
5092 | ||
5093 | /* Process ECN based congestion. | |
5094 | * | |
5095 | * Since the chunk structure is reused for all chunks within | |
5096 | * a packet, we use ecn_ce_done to track if we've already | |
5097 | * done CE processing for this packet. | |
5098 | * | |
5099 | * We need to do ECN processing even if we plan to discard the | |
5100 | * chunk later. | |
5101 | */ | |
5102 | ||
5103 | if (!chunk->ecn_ce_done) { | |
5104 | struct sctp_af *af; | |
5105 | chunk->ecn_ce_done = 1; | |
5106 | ||
5107 | af = sctp_get_af_specific( | |
5108 | ipver2af(chunk->skb->nh.iph->version)); | |
5109 | ||
5110 | if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) { | |
5111 | /* Do real work as sideffect. */ | |
5112 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, | |
5113 | SCTP_U32(tsn)); | |
5114 | } | |
5115 | } | |
5116 | ||
5117 | tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); | |
5118 | if (tmp < 0) { | |
5119 | /* The TSN is too high--silently discard the chunk and | |
5120 | * count on it getting retransmitted later. | |
5121 | */ | |
5122 | return SCTP_IERROR_HIGH_TSN; | |
5123 | } else if (tmp > 0) { | |
5124 | /* This is a duplicate. Record it. */ | |
5125 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); | |
5126 | return SCTP_IERROR_DUP_TSN; | |
5127 | } | |
5128 | ||
5129 | /* This is a new TSN. */ | |
5130 | ||
5131 | /* Discard if there is no room in the receive window. | |
5132 | * Actually, allow a little bit of overflow (up to a MTU). | |
5133 | */ | |
5134 | datalen = ntohs(chunk->chunk_hdr->length); | |
5135 | datalen -= sizeof(sctp_data_chunk_t); | |
5136 | ||
5137 | deliver = SCTP_CMD_CHUNK_ULP; | |
5138 | ||
5139 | /* Think about partial delivery. */ | |
5140 | if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { | |
5141 | ||
5142 | /* Even if we don't accept this chunk there is | |
5143 | * memory pressure. | |
5144 | */ | |
5145 | sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); | |
5146 | } | |
5147 | ||
5148 | /* Spill over rwnd a little bit. Note: While allowed, this spill over | |
5149 | * seems a bit troublesome in that frag_point varies based on | |
5150 | * PMTU. In cases, such as loopback, this might be a rather | |
5151 | * large spill over. | |
5152 | */ | |
5153 | if (!asoc->rwnd || asoc->rwnd_over || | |
5154 | (datalen > asoc->rwnd + asoc->frag_point)) { | |
5155 | ||
5156 | /* If this is the next TSN, consider reneging to make | |
5157 | * room. Note: Playing nice with a confused sender. A | |
5158 | * malicious sender can still eat up all our buffer | |
5159 | * space and in the future we may want to detect and | |
5160 | * do more drastic reneging. | |
5161 | */ | |
5162 | if (sctp_tsnmap_has_gap(&asoc->peer.tsn_map) && | |
5163 | (sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1) == tsn) { | |
5164 | SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn); | |
5165 | deliver = SCTP_CMD_RENEGE; | |
5166 | } else { | |
5167 | SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, " | |
5168 | "rwnd: %d\n", tsn, datalen, | |
5169 | asoc->rwnd); | |
5170 | return SCTP_IERROR_IGNORE_TSN; | |
5171 | } | |
5172 | } | |
5173 | ||
5174 | /* | |
5175 | * Section 3.3.10.9 No User Data (9) | |
5176 | * | |
5177 | * Cause of error | |
5178 | * --------------- | |
5179 | * No User Data: This error cause is returned to the originator of a | |
5180 | * DATA chunk if a received DATA chunk has no user data. | |
5181 | */ | |
5182 | if (unlikely(0 == datalen)) { | |
5183 | err = sctp_make_abort_no_data(asoc, chunk, tsn); | |
5184 | if (err) { | |
5185 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
5186 | SCTP_CHUNK(err)); | |
5187 | } | |
5188 | /* We are going to ABORT, so we might as well stop | |
5189 | * processing the rest of the chunks in the packet. | |
5190 | */ | |
5191 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); | |
5192 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
5193 | SCTP_U32(SCTP_ERROR_NO_DATA)); | |
5194 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); | |
5195 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); | |
5196 | return SCTP_IERROR_NO_DATA; | |
5197 | } | |
5198 | ||
5199 | /* If definately accepting the DATA chunk, record its TSN, otherwise | |
5200 | * wait for renege processing. | |
5201 | */ | |
5202 | if (SCTP_CMD_CHUNK_ULP == deliver) | |
5203 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); | |
5204 | ||
5205 | /* Note: Some chunks may get overcounted (if we drop) or overcounted | |
5206 | * if we renege and the chunk arrives again. | |
5207 | */ | |
5208 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) | |
5209 | SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS); | |
5210 | else | |
5211 | SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS); | |
5212 | ||
5213 | /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number | |
5214 | * | |
5215 | * If an endpoint receive a DATA chunk with an invalid stream | |
5216 | * identifier, it shall acknowledge the reception of the DATA chunk | |
5217 | * following the normal procedure, immediately send an ERROR chunk | |
5218 | * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) | |
5219 | * and discard the DATA chunk. | |
5220 | */ | |
5221 | if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) { | |
5222 | err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, | |
5223 | &data_hdr->stream, | |
5224 | sizeof(data_hdr->stream)); | |
5225 | if (err) | |
5226 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
5227 | SCTP_CHUNK(err)); | |
5228 | return SCTP_IERROR_BAD_STREAM; | |
5229 | } | |
5230 | ||
5231 | /* Send the data up to the user. Note: Schedule the | |
5232 | * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK | |
5233 | * chunk needs the updated rwnd. | |
5234 | */ | |
5235 | sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); | |
5236 | ||
5237 | return SCTP_IERROR_NO_ERROR; | |
5238 | } |