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1 | /* SCTP kernel implementation | |
2 | * (C) Copyright IBM Corp. 2001, 2004 | |
3 | * Copyright (c) 1999-2000 Cisco, Inc. | |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001-2002 Intel Corp. | |
6 | * Copyright (c) 2002 Nokia Corp. | |
7 | * | |
8 | * This is part of the SCTP Linux Kernel Implementation. | |
9 | * | |
10 | * These are the state functions for the state machine. | |
11 | * | |
12 | * This SCTP implementation is free software; | |
13 | * you can redistribute it and/or modify it under the terms of | |
14 | * the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2, or (at your option) | |
16 | * any later version. | |
17 | * | |
18 | * This SCTP implementation is distributed in the hope that it | |
19 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied | |
20 | * ************************ | |
21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
22 | * See the GNU General Public License for more details. | |
23 | * | |
24 | * You should have received a copy of the GNU General Public License | |
25 | * along with GNU CC; see the file COPYING. If not, see | |
26 | * <http://www.gnu.org/licenses/>. | |
27 | * | |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email address(es): | |
30 | * lksctp developers <linux-sctp@vger.kernel.org> | |
31 | * | |
32 | * Written or modified by: | |
33 | * La Monte H.P. Yarroll <piggy@acm.org> | |
34 | * Karl Knutson <karl@athena.chicago.il.us> | |
35 | * Mathew Kotowsky <kotowsky@sctp.org> | |
36 | * Sridhar Samudrala <samudrala@us.ibm.com> | |
37 | * Jon Grimm <jgrimm@us.ibm.com> | |
38 | * Hui Huang <hui.huang@nokia.com> | |
39 | * Dajiang Zhang <dajiang.zhang@nokia.com> | |
40 | * Daisy Chang <daisyc@us.ibm.com> | |
41 | * Ardelle Fan <ardelle.fan@intel.com> | |
42 | * Ryan Layer <rmlayer@us.ibm.com> | |
43 | * Kevin Gao <kevin.gao@intel.com> | |
44 | */ | |
45 | ||
46 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
47 | ||
48 | #include <linux/types.h> | |
49 | #include <linux/kernel.h> | |
50 | #include <linux/ip.h> | |
51 | #include <linux/ipv6.h> | |
52 | #include <linux/net.h> | |
53 | #include <linux/inet.h> | |
54 | #include <linux/slab.h> | |
55 | #include <net/sock.h> | |
56 | #include <net/inet_ecn.h> | |
57 | #include <linux/skbuff.h> | |
58 | #include <net/sctp/sctp.h> | |
59 | #include <net/sctp/sm.h> | |
60 | #include <net/sctp/structs.h> | |
61 | ||
62 | static struct sctp_packet *sctp_abort_pkt_new(struct net *net, | |
63 | const struct sctp_endpoint *ep, | |
64 | const struct sctp_association *asoc, | |
65 | struct sctp_chunk *chunk, | |
66 | const void *payload, | |
67 | size_t paylen); | |
68 | static int sctp_eat_data(const struct sctp_association *asoc, | |
69 | struct sctp_chunk *chunk, | |
70 | sctp_cmd_seq_t *commands); | |
71 | static struct sctp_packet *sctp_ootb_pkt_new(struct net *net, | |
72 | const struct sctp_association *asoc, | |
73 | const struct sctp_chunk *chunk); | |
74 | static void sctp_send_stale_cookie_err(struct net *net, | |
75 | const struct sctp_endpoint *ep, | |
76 | const struct sctp_association *asoc, | |
77 | const struct sctp_chunk *chunk, | |
78 | sctp_cmd_seq_t *commands, | |
79 | struct sctp_chunk *err_chunk); | |
80 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net, | |
81 | const struct sctp_endpoint *ep, | |
82 | const struct sctp_association *asoc, | |
83 | const sctp_subtype_t type, | |
84 | void *arg, | |
85 | sctp_cmd_seq_t *commands); | |
86 | static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net, | |
87 | const struct sctp_endpoint *ep, | |
88 | const struct sctp_association *asoc, | |
89 | const sctp_subtype_t type, | |
90 | void *arg, | |
91 | sctp_cmd_seq_t *commands); | |
92 | static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net, | |
93 | const struct sctp_endpoint *ep, | |
94 | const struct sctp_association *asoc, | |
95 | const sctp_subtype_t type, | |
96 | void *arg, | |
97 | sctp_cmd_seq_t *commands); | |
98 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk); | |
99 | ||
100 | static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net, | |
101 | sctp_cmd_seq_t *commands, | |
102 | __be16 error, int sk_err, | |
103 | const struct sctp_association *asoc, | |
104 | struct sctp_transport *transport); | |
105 | ||
106 | static sctp_disposition_t sctp_sf_abort_violation( | |
107 | struct net *net, | |
108 | const struct sctp_endpoint *ep, | |
109 | const struct sctp_association *asoc, | |
110 | void *arg, | |
111 | sctp_cmd_seq_t *commands, | |
112 | const __u8 *payload, | |
113 | const size_t paylen); | |
114 | ||
115 | static sctp_disposition_t sctp_sf_violation_chunklen( | |
116 | struct net *net, | |
117 | const struct sctp_endpoint *ep, | |
118 | const struct sctp_association *asoc, | |
119 | const sctp_subtype_t type, | |
120 | void *arg, | |
121 | sctp_cmd_seq_t *commands); | |
122 | ||
123 | static sctp_disposition_t sctp_sf_violation_paramlen( | |
124 | struct net *net, | |
125 | const struct sctp_endpoint *ep, | |
126 | const struct sctp_association *asoc, | |
127 | const sctp_subtype_t type, | |
128 | void *arg, void *ext, | |
129 | sctp_cmd_seq_t *commands); | |
130 | ||
131 | static sctp_disposition_t sctp_sf_violation_ctsn( | |
132 | struct net *net, | |
133 | const struct sctp_endpoint *ep, | |
134 | const struct sctp_association *asoc, | |
135 | const sctp_subtype_t type, | |
136 | void *arg, | |
137 | sctp_cmd_seq_t *commands); | |
138 | ||
139 | static sctp_disposition_t sctp_sf_violation_chunk( | |
140 | struct net *net, | |
141 | const struct sctp_endpoint *ep, | |
142 | const struct sctp_association *asoc, | |
143 | const sctp_subtype_t type, | |
144 | void *arg, | |
145 | sctp_cmd_seq_t *commands); | |
146 | ||
147 | static sctp_ierror_t sctp_sf_authenticate(struct net *net, | |
148 | const struct sctp_endpoint *ep, | |
149 | const struct sctp_association *asoc, | |
150 | const sctp_subtype_t type, | |
151 | struct sctp_chunk *chunk); | |
152 | ||
153 | static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net, | |
154 | const struct sctp_endpoint *ep, | |
155 | const struct sctp_association *asoc, | |
156 | const sctp_subtype_t type, | |
157 | void *arg, | |
158 | sctp_cmd_seq_t *commands); | |
159 | ||
160 | /* Small helper function that checks if the chunk length | |
161 | * is of the appropriate length. The 'required_length' argument | |
162 | * is set to be the size of a specific chunk we are testing. | |
163 | * Return Values: true = Valid length | |
164 | * false = Invalid length | |
165 | * | |
166 | */ | |
167 | static inline bool | |
168 | sctp_chunk_length_valid(struct sctp_chunk *chunk, __u16 required_length) | |
169 | { | |
170 | __u16 chunk_length = ntohs(chunk->chunk_hdr->length); | |
171 | ||
172 | /* Previously already marked? */ | |
173 | if (unlikely(chunk->pdiscard)) | |
174 | return false; | |
175 | if (unlikely(chunk_length < required_length)) | |
176 | return false; | |
177 | ||
178 | return true; | |
179 | } | |
180 | ||
181 | /********************************************************** | |
182 | * These are the state functions for handling chunk events. | |
183 | **********************************************************/ | |
184 | ||
185 | /* | |
186 | * Process the final SHUTDOWN COMPLETE. | |
187 | * | |
188 | * Section: 4 (C) (diagram), 9.2 | |
189 | * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify | |
190 | * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be | |
191 | * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint | |
192 | * should stop the T2-shutdown timer and remove all knowledge of the | |
193 | * association (and thus the association enters the CLOSED state). | |
194 | * | |
195 | * Verification Tag: 8.5.1(C), sctpimpguide 2.41. | |
196 | * C) Rules for packet carrying SHUTDOWN COMPLETE: | |
197 | * ... | |
198 | * - The receiver of a SHUTDOWN COMPLETE shall accept the packet | |
199 | * if the Verification Tag field of the packet matches its own tag and | |
200 | * the T bit is not set | |
201 | * OR | |
202 | * it is set to its peer's tag and the T bit is set in the Chunk | |
203 | * Flags. | |
204 | * Otherwise, the receiver MUST silently discard the packet | |
205 | * and take no further action. An endpoint MUST ignore the | |
206 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. | |
207 | * | |
208 | * Inputs | |
209 | * (endpoint, asoc, chunk) | |
210 | * | |
211 | * Outputs | |
212 | * (asoc, reply_msg, msg_up, timers, counters) | |
213 | * | |
214 | * The return value is the disposition of the chunk. | |
215 | */ | |
216 | sctp_disposition_t sctp_sf_do_4_C(struct net *net, | |
217 | const struct sctp_endpoint *ep, | |
218 | const struct sctp_association *asoc, | |
219 | const sctp_subtype_t type, | |
220 | void *arg, | |
221 | sctp_cmd_seq_t *commands) | |
222 | { | |
223 | struct sctp_chunk *chunk = arg; | |
224 | struct sctp_ulpevent *ev; | |
225 | ||
226 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
227 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
228 | ||
229 | /* RFC 2960 6.10 Bundling | |
230 | * | |
231 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
232 | * SHUTDOWN COMPLETE with any other chunks. | |
233 | */ | |
234 | if (!chunk->singleton) | |
235 | return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); | |
236 | ||
237 | /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */ | |
238 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
239 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
240 | commands); | |
241 | ||
242 | /* RFC 2960 10.2 SCTP-to-ULP | |
243 | * | |
244 | * H) SHUTDOWN COMPLETE notification | |
245 | * | |
246 | * When SCTP completes the shutdown procedures (section 9.2) this | |
247 | * notification is passed to the upper layer. | |
248 | */ | |
249 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, | |
250 | 0, 0, 0, NULL, GFP_ATOMIC); | |
251 | if (ev) | |
252 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
253 | SCTP_ULPEVENT(ev)); | |
254 | ||
255 | /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint | |
256 | * will verify that it is in SHUTDOWN-ACK-SENT state, if it is | |
257 | * not the chunk should be discarded. If the endpoint is in | |
258 | * the SHUTDOWN-ACK-SENT state the endpoint should stop the | |
259 | * T2-shutdown timer and remove all knowledge of the | |
260 | * association (and thus the association enters the CLOSED | |
261 | * state). | |
262 | */ | |
263 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
264 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
265 | ||
266 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
267 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
268 | ||
269 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
270 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
271 | ||
272 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); | |
273 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
274 | ||
275 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
276 | ||
277 | return SCTP_DISPOSITION_DELETE_TCB; | |
278 | } | |
279 | ||
280 | /* | |
281 | * Respond to a normal INIT chunk. | |
282 | * We are the side that is being asked for an association. | |
283 | * | |
284 | * Section: 5.1 Normal Establishment of an Association, B | |
285 | * B) "Z" shall respond immediately with an INIT ACK chunk. The | |
286 | * destination IP address of the INIT ACK MUST be set to the source | |
287 | * IP address of the INIT to which this INIT ACK is responding. In | |
288 | * the response, besides filling in other parameters, "Z" must set the | |
289 | * Verification Tag field to Tag_A, and also provide its own | |
290 | * Verification Tag (Tag_Z) in the Initiate Tag field. | |
291 | * | |
292 | * Verification Tag: Must be 0. | |
293 | * | |
294 | * Inputs | |
295 | * (endpoint, asoc, chunk) | |
296 | * | |
297 | * Outputs | |
298 | * (asoc, reply_msg, msg_up, timers, counters) | |
299 | * | |
300 | * The return value is the disposition of the chunk. | |
301 | */ | |
302 | sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net, | |
303 | const struct sctp_endpoint *ep, | |
304 | const struct sctp_association *asoc, | |
305 | const sctp_subtype_t type, | |
306 | void *arg, | |
307 | sctp_cmd_seq_t *commands) | |
308 | { | |
309 | struct sctp_chunk *chunk = arg; | |
310 | struct sctp_chunk *repl; | |
311 | struct sctp_association *new_asoc; | |
312 | struct sctp_chunk *err_chunk; | |
313 | struct sctp_packet *packet; | |
314 | sctp_unrecognized_param_t *unk_param; | |
315 | int len; | |
316 | ||
317 | /* 6.10 Bundling | |
318 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
319 | * SHUTDOWN COMPLETE with any other chunks. | |
320 | * | |
321 | * IG Section 2.11.2 | |
322 | * Furthermore, we require that the receiver of an INIT chunk MUST | |
323 | * enforce these rules by silently discarding an arriving packet | |
324 | * with an INIT chunk that is bundled with other chunks. | |
325 | */ | |
326 | if (!chunk->singleton) | |
327 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
328 | ||
329 | /* If the packet is an OOTB packet which is temporarily on the | |
330 | * control endpoint, respond with an ABORT. | |
331 | */ | |
332 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { | |
333 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); | |
334 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
335 | } | |
336 | ||
337 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification | |
338 | * Tag. | |
339 | */ | |
340 | if (chunk->sctp_hdr->vtag != 0) | |
341 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
342 | ||
343 | /* Make sure that the INIT chunk has a valid length. | |
344 | * Normally, this would cause an ABORT with a Protocol Violation | |
345 | * error, but since we don't have an association, we'll | |
346 | * just discard the packet. | |
347 | */ | |
348 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk))) | |
349 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
350 | ||
351 | /* If the INIT is coming toward a closing socket, we'll send back | |
352 | * and ABORT. Essentially, this catches the race of INIT being | |
353 | * backloged to the socket at the same time as the user isses close(). | |
354 | * Since the socket and all its associations are going away, we | |
355 | * can treat this OOTB | |
356 | */ | |
357 | if (sctp_sstate(ep->base.sk, CLOSING)) | |
358 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
359 | ||
360 | /* Verify the INIT chunk before processing it. */ | |
361 | err_chunk = NULL; | |
362 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, | |
363 | (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, | |
364 | &err_chunk)) { | |
365 | /* This chunk contains fatal error. It is to be discarded. | |
366 | * Send an ABORT, with causes if there is any. | |
367 | */ | |
368 | if (err_chunk) { | |
369 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, | |
370 | (__u8 *)(err_chunk->chunk_hdr) + | |
371 | sizeof(struct sctp_chunkhdr), | |
372 | ntohs(err_chunk->chunk_hdr->length) - | |
373 | sizeof(struct sctp_chunkhdr)); | |
374 | ||
375 | sctp_chunk_free(err_chunk); | |
376 | ||
377 | if (packet) { | |
378 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
379 | SCTP_PACKET(packet)); | |
380 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
381 | return SCTP_DISPOSITION_CONSUME; | |
382 | } else { | |
383 | return SCTP_DISPOSITION_NOMEM; | |
384 | } | |
385 | } else { | |
386 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, | |
387 | commands); | |
388 | } | |
389 | } | |
390 | ||
391 | /* Grab the INIT header. */ | |
392 | chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; | |
393 | ||
394 | /* Tag the variable length parameters. */ | |
395 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); | |
396 | ||
397 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); | |
398 | if (!new_asoc) | |
399 | goto nomem; | |
400 | ||
401 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, | |
402 | sctp_scope(sctp_source(chunk)), | |
403 | GFP_ATOMIC) < 0) | |
404 | goto nomem_init; | |
405 | ||
406 | /* The call, sctp_process_init(), can fail on memory allocation. */ | |
407 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), | |
408 | (struct sctp_init_chunk *)chunk->chunk_hdr, | |
409 | GFP_ATOMIC)) | |
410 | goto nomem_init; | |
411 | ||
412 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ | |
413 | ||
414 | /* If there are errors need to be reported for unknown parameters, | |
415 | * make sure to reserve enough room in the INIT ACK for them. | |
416 | */ | |
417 | len = 0; | |
418 | if (err_chunk) | |
419 | len = ntohs(err_chunk->chunk_hdr->length) - | |
420 | sizeof(struct sctp_chunkhdr); | |
421 | ||
422 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); | |
423 | if (!repl) | |
424 | goto nomem_init; | |
425 | ||
426 | /* If there are errors need to be reported for unknown parameters, | |
427 | * include them in the outgoing INIT ACK as "Unrecognized parameter" | |
428 | * parameter. | |
429 | */ | |
430 | if (err_chunk) { | |
431 | /* Get the "Unrecognized parameter" parameter(s) out of the | |
432 | * ERROR chunk generated by sctp_verify_init(). Since the | |
433 | * error cause code for "unknown parameter" and the | |
434 | * "Unrecognized parameter" type is the same, we can | |
435 | * construct the parameters in INIT ACK by copying the | |
436 | * ERROR causes over. | |
437 | */ | |
438 | unk_param = (sctp_unrecognized_param_t *) | |
439 | ((__u8 *)(err_chunk->chunk_hdr) + | |
440 | sizeof(struct sctp_chunkhdr)); | |
441 | /* Replace the cause code with the "Unrecognized parameter" | |
442 | * parameter type. | |
443 | */ | |
444 | sctp_addto_chunk(repl, len, unk_param); | |
445 | sctp_chunk_free(err_chunk); | |
446 | } | |
447 | ||
448 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
449 | ||
450 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
451 | ||
452 | /* | |
453 | * Note: After sending out INIT ACK with the State Cookie parameter, | |
454 | * "Z" MUST NOT allocate any resources, nor keep any states for the | |
455 | * new association. Otherwise, "Z" will be vulnerable to resource | |
456 | * attacks. | |
457 | */ | |
458 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
459 | ||
460 | return SCTP_DISPOSITION_DELETE_TCB; | |
461 | ||
462 | nomem_init: | |
463 | sctp_association_free(new_asoc); | |
464 | nomem: | |
465 | if (err_chunk) | |
466 | sctp_chunk_free(err_chunk); | |
467 | return SCTP_DISPOSITION_NOMEM; | |
468 | } | |
469 | ||
470 | /* | |
471 | * Respond to a normal INIT ACK chunk. | |
472 | * We are the side that is initiating the association. | |
473 | * | |
474 | * Section: 5.1 Normal Establishment of an Association, C | |
475 | * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init | |
476 | * timer and leave COOKIE-WAIT state. "A" shall then send the State | |
477 | * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start | |
478 | * the T1-cookie timer, and enter the COOKIE-ECHOED state. | |
479 | * | |
480 | * Note: The COOKIE ECHO chunk can be bundled with any pending outbound | |
481 | * DATA chunks, but it MUST be the first chunk in the packet and | |
482 | * until the COOKIE ACK is returned the sender MUST NOT send any | |
483 | * other packets to the peer. | |
484 | * | |
485 | * Verification Tag: 3.3.3 | |
486 | * If the value of the Initiate Tag in a received INIT ACK chunk is | |
487 | * found to be 0, the receiver MUST treat it as an error and close the | |
488 | * association by transmitting an ABORT. | |
489 | * | |
490 | * Inputs | |
491 | * (endpoint, asoc, chunk) | |
492 | * | |
493 | * Outputs | |
494 | * (asoc, reply_msg, msg_up, timers, counters) | |
495 | * | |
496 | * The return value is the disposition of the chunk. | |
497 | */ | |
498 | sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net, | |
499 | const struct sctp_endpoint *ep, | |
500 | const struct sctp_association *asoc, | |
501 | const sctp_subtype_t type, | |
502 | void *arg, | |
503 | sctp_cmd_seq_t *commands) | |
504 | { | |
505 | struct sctp_chunk *chunk = arg; | |
506 | struct sctp_init_chunk *initchunk; | |
507 | struct sctp_chunk *err_chunk; | |
508 | struct sctp_packet *packet; | |
509 | ||
510 | if (!sctp_vtag_verify(chunk, asoc)) | |
511 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
512 | ||
513 | /* 6.10 Bundling | |
514 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
515 | * SHUTDOWN COMPLETE with any other chunks. | |
516 | */ | |
517 | if (!chunk->singleton) | |
518 | return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); | |
519 | ||
520 | /* Make sure that the INIT-ACK chunk has a valid length */ | |
521 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t))) | |
522 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
523 | commands); | |
524 | /* Grab the INIT header. */ | |
525 | chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; | |
526 | ||
527 | /* Verify the INIT chunk before processing it. */ | |
528 | err_chunk = NULL; | |
529 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, | |
530 | (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, | |
531 | &err_chunk)) { | |
532 | ||
533 | sctp_error_t error = SCTP_ERROR_NO_RESOURCE; | |
534 | ||
535 | /* This chunk contains fatal error. It is to be discarded. | |
536 | * Send an ABORT, with causes. If there are no causes, | |
537 | * then there wasn't enough memory. Just terminate | |
538 | * the association. | |
539 | */ | |
540 | if (err_chunk) { | |
541 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, | |
542 | (__u8 *)(err_chunk->chunk_hdr) + | |
543 | sizeof(struct sctp_chunkhdr), | |
544 | ntohs(err_chunk->chunk_hdr->length) - | |
545 | sizeof(struct sctp_chunkhdr)); | |
546 | ||
547 | sctp_chunk_free(err_chunk); | |
548 | ||
549 | if (packet) { | |
550 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
551 | SCTP_PACKET(packet)); | |
552 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
553 | error = SCTP_ERROR_INV_PARAM; | |
554 | } | |
555 | } | |
556 | ||
557 | /* SCTP-AUTH, Section 6.3: | |
558 | * It should be noted that if the receiver wants to tear | |
559 | * down an association in an authenticated way only, the | |
560 | * handling of malformed packets should not result in | |
561 | * tearing down the association. | |
562 | * | |
563 | * This means that if we only want to abort associations | |
564 | * in an authenticated way (i.e AUTH+ABORT), then we | |
565 | * can't destroy this association just because the packet | |
566 | * was malformed. | |
567 | */ | |
568 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) | |
569 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
570 | ||
571 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
572 | return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, | |
573 | asoc, chunk->transport); | |
574 | } | |
575 | ||
576 | /* Tag the variable length parameters. Note that we never | |
577 | * convert the parameters in an INIT chunk. | |
578 | */ | |
579 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); | |
580 | ||
581 | initchunk = (struct sctp_init_chunk *)chunk->chunk_hdr; | |
582 | ||
583 | sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, | |
584 | SCTP_PEER_INIT(initchunk)); | |
585 | ||
586 | /* Reset init error count upon receipt of INIT-ACK. */ | |
587 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); | |
588 | ||
589 | /* 5.1 C) "A" shall stop the T1-init timer and leave | |
590 | * COOKIE-WAIT state. "A" shall then ... start the T1-cookie | |
591 | * timer, and enter the COOKIE-ECHOED state. | |
592 | */ | |
593 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
594 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
595 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
596 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
597 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
598 | SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); | |
599 | ||
600 | /* SCTP-AUTH: genereate the assocition shared keys so that | |
601 | * we can potentially signe the COOKIE-ECHO. | |
602 | */ | |
603 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL()); | |
604 | ||
605 | /* 5.1 C) "A" shall then send the State Cookie received in the | |
606 | * INIT ACK chunk in a COOKIE ECHO chunk, ... | |
607 | */ | |
608 | /* If there is any errors to report, send the ERROR chunk generated | |
609 | * for unknown parameters as well. | |
610 | */ | |
611 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, | |
612 | SCTP_CHUNK(err_chunk)); | |
613 | ||
614 | return SCTP_DISPOSITION_CONSUME; | |
615 | } | |
616 | ||
617 | /* | |
618 | * Respond to a normal COOKIE ECHO chunk. | |
619 | * We are the side that is being asked for an association. | |
620 | * | |
621 | * Section: 5.1 Normal Establishment of an Association, D | |
622 | * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply | |
623 | * with a COOKIE ACK chunk after building a TCB and moving to | |
624 | * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with | |
625 | * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK | |
626 | * chunk MUST be the first chunk in the packet. | |
627 | * | |
628 | * IMPLEMENTATION NOTE: An implementation may choose to send the | |
629 | * Communication Up notification to the SCTP user upon reception | |
630 | * of a valid COOKIE ECHO chunk. | |
631 | * | |
632 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules | |
633 | * D) Rules for packet carrying a COOKIE ECHO | |
634 | * | |
635 | * - When sending a COOKIE ECHO, the endpoint MUST use the value of the | |
636 | * Initial Tag received in the INIT ACK. | |
637 | * | |
638 | * - The receiver of a COOKIE ECHO follows the procedures in Section 5. | |
639 | * | |
640 | * Inputs | |
641 | * (endpoint, asoc, chunk) | |
642 | * | |
643 | * Outputs | |
644 | * (asoc, reply_msg, msg_up, timers, counters) | |
645 | * | |
646 | * The return value is the disposition of the chunk. | |
647 | */ | |
648 | sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net, | |
649 | const struct sctp_endpoint *ep, | |
650 | const struct sctp_association *asoc, | |
651 | const sctp_subtype_t type, void *arg, | |
652 | sctp_cmd_seq_t *commands) | |
653 | { | |
654 | struct sctp_chunk *chunk = arg; | |
655 | struct sctp_association *new_asoc; | |
656 | struct sctp_init_chunk *peer_init; | |
657 | struct sctp_chunk *repl; | |
658 | struct sctp_ulpevent *ev, *ai_ev = NULL; | |
659 | int error = 0; | |
660 | struct sctp_chunk *err_chk_p; | |
661 | struct sock *sk; | |
662 | ||
663 | /* If the packet is an OOTB packet which is temporarily on the | |
664 | * control endpoint, respond with an ABORT. | |
665 | */ | |
666 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { | |
667 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); | |
668 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
669 | } | |
670 | ||
671 | /* Make sure that the COOKIE_ECHO chunk has a valid length. | |
672 | * In this case, we check that we have enough for at least a | |
673 | * chunk header. More detailed verification is done | |
674 | * in sctp_unpack_cookie(). | |
675 | */ | |
676 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
677 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
678 | ||
679 | /* If the endpoint is not listening or if the number of associations | |
680 | * on the TCP-style socket exceed the max backlog, respond with an | |
681 | * ABORT. | |
682 | */ | |
683 | sk = ep->base.sk; | |
684 | if (!sctp_sstate(sk, LISTENING) || | |
685 | (sctp_style(sk, TCP) && sk_acceptq_is_full(sk))) | |
686 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
687 | ||
688 | /* "Decode" the chunk. We have no optional parameters so we | |
689 | * are in good shape. | |
690 | */ | |
691 | chunk->subh.cookie_hdr = | |
692 | (struct sctp_signed_cookie *)chunk->skb->data; | |
693 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - | |
694 | sizeof(struct sctp_chunkhdr))) | |
695 | goto nomem; | |
696 | ||
697 | /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint | |
698 | * "Z" will reply with a COOKIE ACK chunk after building a TCB | |
699 | * and moving to the ESTABLISHED state. | |
700 | */ | |
701 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, | |
702 | &err_chk_p); | |
703 | ||
704 | /* FIXME: | |
705 | * If the re-build failed, what is the proper error path | |
706 | * from here? | |
707 | * | |
708 | * [We should abort the association. --piggy] | |
709 | */ | |
710 | if (!new_asoc) { | |
711 | /* FIXME: Several errors are possible. A bad cookie should | |
712 | * be silently discarded, but think about logging it too. | |
713 | */ | |
714 | switch (error) { | |
715 | case -SCTP_IERROR_NOMEM: | |
716 | goto nomem; | |
717 | ||
718 | case -SCTP_IERROR_STALE_COOKIE: | |
719 | sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, | |
720 | err_chk_p); | |
721 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
722 | ||
723 | case -SCTP_IERROR_BAD_SIG: | |
724 | default: | |
725 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
726 | } | |
727 | } | |
728 | ||
729 | ||
730 | /* Delay state machine commands until later. | |
731 | * | |
732 | * Re-build the bind address for the association is done in | |
733 | * the sctp_unpack_cookie() already. | |
734 | */ | |
735 | /* This is a brand-new association, so these are not yet side | |
736 | * effects--it is safe to run them here. | |
737 | */ | |
738 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
739 | ||
740 | if (!sctp_process_init(new_asoc, chunk, | |
741 | &chunk->subh.cookie_hdr->c.peer_addr, | |
742 | peer_init, GFP_ATOMIC)) | |
743 | goto nomem_init; | |
744 | ||
745 | /* SCTP-AUTH: Now that we've populate required fields in | |
746 | * sctp_process_init, set up the assocaition shared keys as | |
747 | * necessary so that we can potentially authenticate the ACK | |
748 | */ | |
749 | error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC); | |
750 | if (error) | |
751 | goto nomem_init; | |
752 | ||
753 | /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo | |
754 | * is supposed to be authenticated and we have to do delayed | |
755 | * authentication. We've just recreated the association using | |
756 | * the information in the cookie and now it's much easier to | |
757 | * do the authentication. | |
758 | */ | |
759 | if (chunk->auth_chunk) { | |
760 | struct sctp_chunk auth; | |
761 | sctp_ierror_t ret; | |
762 | ||
763 | /* Make sure that we and the peer are AUTH capable */ | |
764 | if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) { | |
765 | sctp_association_free(new_asoc); | |
766 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
767 | } | |
768 | ||
769 | /* set-up our fake chunk so that we can process it */ | |
770 | auth.skb = chunk->auth_chunk; | |
771 | auth.asoc = chunk->asoc; | |
772 | auth.sctp_hdr = chunk->sctp_hdr; | |
773 | auth.chunk_hdr = (struct sctp_chunkhdr *) | |
774 | skb_push(chunk->auth_chunk, | |
775 | sizeof(struct sctp_chunkhdr)); | |
776 | skb_pull(chunk->auth_chunk, sizeof(struct sctp_chunkhdr)); | |
777 | auth.transport = chunk->transport; | |
778 | ||
779 | ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth); | |
780 | if (ret != SCTP_IERROR_NO_ERROR) { | |
781 | sctp_association_free(new_asoc); | |
782 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
783 | } | |
784 | } | |
785 | ||
786 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
787 | if (!repl) | |
788 | goto nomem_init; | |
789 | ||
790 | /* RFC 2960 5.1 Normal Establishment of an Association | |
791 | * | |
792 | * D) IMPLEMENTATION NOTE: An implementation may choose to | |
793 | * send the Communication Up notification to the SCTP user | |
794 | * upon reception of a valid COOKIE ECHO chunk. | |
795 | */ | |
796 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, | |
797 | new_asoc->c.sinit_num_ostreams, | |
798 | new_asoc->c.sinit_max_instreams, | |
799 | NULL, GFP_ATOMIC); | |
800 | if (!ev) | |
801 | goto nomem_ev; | |
802 | ||
803 | /* Sockets API Draft Section 5.3.1.6 | |
804 | * When a peer sends a Adaptation Layer Indication parameter , SCTP | |
805 | * delivers this notification to inform the application that of the | |
806 | * peers requested adaptation layer. | |
807 | */ | |
808 | if (new_asoc->peer.adaptation_ind) { | |
809 | ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc, | |
810 | GFP_ATOMIC); | |
811 | if (!ai_ev) | |
812 | goto nomem_aiev; | |
813 | } | |
814 | ||
815 | /* Add all the state machine commands now since we've created | |
816 | * everything. This way we don't introduce memory corruptions | |
817 | * during side-effect processing and correclty count established | |
818 | * associations. | |
819 | */ | |
820 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
821 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
822 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
823 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); | |
824 | SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS); | |
825 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
826 | ||
827 | if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) | |
828 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
829 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
830 | ||
831 | /* This will send the COOKIE ACK */ | |
832 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
833 | ||
834 | /* Queue the ASSOC_CHANGE event */ | |
835 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
836 | ||
837 | /* Send up the Adaptation Layer Indication event */ | |
838 | if (ai_ev) | |
839 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
840 | SCTP_ULPEVENT(ai_ev)); | |
841 | ||
842 | return SCTP_DISPOSITION_CONSUME; | |
843 | ||
844 | nomem_aiev: | |
845 | sctp_ulpevent_free(ev); | |
846 | nomem_ev: | |
847 | sctp_chunk_free(repl); | |
848 | nomem_init: | |
849 | sctp_association_free(new_asoc); | |
850 | nomem: | |
851 | return SCTP_DISPOSITION_NOMEM; | |
852 | } | |
853 | ||
854 | /* | |
855 | * Respond to a normal COOKIE ACK chunk. | |
856 | * We are the side that is asking for an association. | |
857 | * | |
858 | * RFC 2960 5.1 Normal Establishment of an Association | |
859 | * | |
860 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the | |
861 | * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie | |
862 | * timer. It may also notify its ULP about the successful | |
863 | * establishment of the association with a Communication Up | |
864 | * notification (see Section 10). | |
865 | * | |
866 | * Verification Tag: | |
867 | * Inputs | |
868 | * (endpoint, asoc, chunk) | |
869 | * | |
870 | * Outputs | |
871 | * (asoc, reply_msg, msg_up, timers, counters) | |
872 | * | |
873 | * The return value is the disposition of the chunk. | |
874 | */ | |
875 | sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net, | |
876 | const struct sctp_endpoint *ep, | |
877 | const struct sctp_association *asoc, | |
878 | const sctp_subtype_t type, void *arg, | |
879 | sctp_cmd_seq_t *commands) | |
880 | { | |
881 | struct sctp_chunk *chunk = arg; | |
882 | struct sctp_ulpevent *ev; | |
883 | ||
884 | if (!sctp_vtag_verify(chunk, asoc)) | |
885 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
886 | ||
887 | /* Verify that the chunk length for the COOKIE-ACK is OK. | |
888 | * If we don't do this, any bundled chunks may be junked. | |
889 | */ | |
890 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
891 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
892 | commands); | |
893 | ||
894 | /* Reset init error count upon receipt of COOKIE-ACK, | |
895 | * to avoid problems with the managemement of this | |
896 | * counter in stale cookie situations when a transition back | |
897 | * from the COOKIE-ECHOED state to the COOKIE-WAIT | |
898 | * state is performed. | |
899 | */ | |
900 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); | |
901 | ||
902 | /* RFC 2960 5.1 Normal Establishment of an Association | |
903 | * | |
904 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move | |
905 | * from the COOKIE-ECHOED state to the ESTABLISHED state, | |
906 | * stopping the T1-cookie timer. | |
907 | */ | |
908 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
909 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
910 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
911 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
912 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); | |
913 | SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS); | |
914 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
915 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) | |
916 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
917 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
918 | ||
919 | /* It may also notify its ULP about the successful | |
920 | * establishment of the association with a Communication Up | |
921 | * notification (see Section 10). | |
922 | */ | |
923 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, | |
924 | 0, asoc->c.sinit_num_ostreams, | |
925 | asoc->c.sinit_max_instreams, | |
926 | NULL, GFP_ATOMIC); | |
927 | ||
928 | if (!ev) | |
929 | goto nomem; | |
930 | ||
931 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
932 | ||
933 | /* Sockets API Draft Section 5.3.1.6 | |
934 | * When a peer sends a Adaptation Layer Indication parameter , SCTP | |
935 | * delivers this notification to inform the application that of the | |
936 | * peers requested adaptation layer. | |
937 | */ | |
938 | if (asoc->peer.adaptation_ind) { | |
939 | ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); | |
940 | if (!ev) | |
941 | goto nomem; | |
942 | ||
943 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
944 | SCTP_ULPEVENT(ev)); | |
945 | } | |
946 | ||
947 | return SCTP_DISPOSITION_CONSUME; | |
948 | nomem: | |
949 | return SCTP_DISPOSITION_NOMEM; | |
950 | } | |
951 | ||
952 | /* Generate and sendout a heartbeat packet. */ | |
953 | static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep, | |
954 | const struct sctp_association *asoc, | |
955 | const sctp_subtype_t type, | |
956 | void *arg, | |
957 | sctp_cmd_seq_t *commands) | |
958 | { | |
959 | struct sctp_transport *transport = (struct sctp_transport *) arg; | |
960 | struct sctp_chunk *reply; | |
961 | ||
962 | /* Send a heartbeat to our peer. */ | |
963 | reply = sctp_make_heartbeat(asoc, transport); | |
964 | if (!reply) | |
965 | return SCTP_DISPOSITION_NOMEM; | |
966 | ||
967 | /* Set rto_pending indicating that an RTT measurement | |
968 | * is started with this heartbeat chunk. | |
969 | */ | |
970 | sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, | |
971 | SCTP_TRANSPORT(transport)); | |
972 | ||
973 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
974 | return SCTP_DISPOSITION_CONSUME; | |
975 | } | |
976 | ||
977 | /* Generate a HEARTBEAT packet on the given transport. */ | |
978 | sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net, | |
979 | const struct sctp_endpoint *ep, | |
980 | const struct sctp_association *asoc, | |
981 | const sctp_subtype_t type, | |
982 | void *arg, | |
983 | sctp_cmd_seq_t *commands) | |
984 | { | |
985 | struct sctp_transport *transport = (struct sctp_transport *) arg; | |
986 | ||
987 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
988 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
989 | SCTP_ERROR(ETIMEDOUT)); | |
990 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
991 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
992 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
993 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
994 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
995 | return SCTP_DISPOSITION_DELETE_TCB; | |
996 | } | |
997 | ||
998 | /* Section 3.3.5. | |
999 | * The Sender-specific Heartbeat Info field should normally include | |
1000 | * information about the sender's current time when this HEARTBEAT | |
1001 | * chunk is sent and the destination transport address to which this | |
1002 | * HEARTBEAT is sent (see Section 8.3). | |
1003 | */ | |
1004 | ||
1005 | if (transport->param_flags & SPP_HB_ENABLE) { | |
1006 | if (SCTP_DISPOSITION_NOMEM == | |
1007 | sctp_sf_heartbeat(ep, asoc, type, arg, | |
1008 | commands)) | |
1009 | return SCTP_DISPOSITION_NOMEM; | |
1010 | ||
1011 | /* Set transport error counter and association error counter | |
1012 | * when sending heartbeat. | |
1013 | */ | |
1014 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, | |
1015 | SCTP_TRANSPORT(transport)); | |
1016 | } | |
1017 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE, | |
1018 | SCTP_TRANSPORT(transport)); | |
1019 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, | |
1020 | SCTP_TRANSPORT(transport)); | |
1021 | ||
1022 | return SCTP_DISPOSITION_CONSUME; | |
1023 | } | |
1024 | ||
1025 | /* resend asoc strreset_chunk. */ | |
1026 | sctp_disposition_t sctp_sf_send_reconf(struct net *net, | |
1027 | const struct sctp_endpoint *ep, | |
1028 | const struct sctp_association *asoc, | |
1029 | const sctp_subtype_t type, void *arg, | |
1030 | sctp_cmd_seq_t *commands) | |
1031 | { | |
1032 | struct sctp_transport *transport = arg; | |
1033 | ||
1034 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
1035 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
1036 | SCTP_ERROR(ETIMEDOUT)); | |
1037 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
1038 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
1039 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
1040 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
1041 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
1042 | return SCTP_DISPOSITION_DELETE_TCB; | |
1043 | } | |
1044 | ||
1045 | sctp_chunk_hold(asoc->strreset_chunk); | |
1046 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
1047 | SCTP_CHUNK(asoc->strreset_chunk)); | |
1048 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); | |
1049 | ||
1050 | return SCTP_DISPOSITION_CONSUME; | |
1051 | } | |
1052 | ||
1053 | /* | |
1054 | * Process an heartbeat request. | |
1055 | * | |
1056 | * Section: 8.3 Path Heartbeat | |
1057 | * The receiver of the HEARTBEAT should immediately respond with a | |
1058 | * HEARTBEAT ACK that contains the Heartbeat Information field copied | |
1059 | * from the received HEARTBEAT chunk. | |
1060 | * | |
1061 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
1062 | * When receiving an SCTP packet, the endpoint MUST ensure that the | |
1063 | * value in the Verification Tag field of the received SCTP packet | |
1064 | * matches its own Tag. If the received Verification Tag value does not | |
1065 | * match the receiver's own tag value, the receiver shall silently | |
1066 | * discard the packet and shall not process it any further except for | |
1067 | * those cases listed in Section 8.5.1 below. | |
1068 | * | |
1069 | * Inputs | |
1070 | * (endpoint, asoc, chunk) | |
1071 | * | |
1072 | * Outputs | |
1073 | * (asoc, reply_msg, msg_up, timers, counters) | |
1074 | * | |
1075 | * The return value is the disposition of the chunk. | |
1076 | */ | |
1077 | sctp_disposition_t sctp_sf_beat_8_3(struct net *net, | |
1078 | const struct sctp_endpoint *ep, | |
1079 | const struct sctp_association *asoc, | |
1080 | const sctp_subtype_t type, | |
1081 | void *arg, | |
1082 | sctp_cmd_seq_t *commands) | |
1083 | { | |
1084 | struct sctp_paramhdr *param_hdr; | |
1085 | struct sctp_chunk *chunk = arg; | |
1086 | struct sctp_chunk *reply; | |
1087 | size_t paylen = 0; | |
1088 | ||
1089 | if (!sctp_vtag_verify(chunk, asoc)) | |
1090 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
1091 | ||
1092 | /* Make sure that the HEARTBEAT chunk has a valid length. */ | |
1093 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) | |
1094 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
1095 | commands); | |
1096 | ||
1097 | /* 8.3 The receiver of the HEARTBEAT should immediately | |
1098 | * respond with a HEARTBEAT ACK that contains the Heartbeat | |
1099 | * Information field copied from the received HEARTBEAT chunk. | |
1100 | */ | |
1101 | chunk->subh.hb_hdr = (sctp_heartbeathdr_t *)chunk->skb->data; | |
1102 | param_hdr = (struct sctp_paramhdr *)chunk->subh.hb_hdr; | |
1103 | paylen = ntohs(chunk->chunk_hdr->length) - sizeof(struct sctp_chunkhdr); | |
1104 | ||
1105 | if (ntohs(param_hdr->length) > paylen) | |
1106 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, | |
1107 | param_hdr, commands); | |
1108 | ||
1109 | if (!pskb_pull(chunk->skb, paylen)) | |
1110 | goto nomem; | |
1111 | ||
1112 | reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen); | |
1113 | if (!reply) | |
1114 | goto nomem; | |
1115 | ||
1116 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
1117 | return SCTP_DISPOSITION_CONSUME; | |
1118 | ||
1119 | nomem: | |
1120 | return SCTP_DISPOSITION_NOMEM; | |
1121 | } | |
1122 | ||
1123 | /* | |
1124 | * Process the returning HEARTBEAT ACK. | |
1125 | * | |
1126 | * Section: 8.3 Path Heartbeat | |
1127 | * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT | |
1128 | * should clear the error counter of the destination transport | |
1129 | * address to which the HEARTBEAT was sent, and mark the destination | |
1130 | * transport address as active if it is not so marked. The endpoint may | |
1131 | * optionally report to the upper layer when an inactive destination | |
1132 | * address is marked as active due to the reception of the latest | |
1133 | * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also | |
1134 | * clear the association overall error count as well (as defined | |
1135 | * in section 8.1). | |
1136 | * | |
1137 | * The receiver of the HEARTBEAT ACK should also perform an RTT | |
1138 | * measurement for that destination transport address using the time | |
1139 | * value carried in the HEARTBEAT ACK chunk. | |
1140 | * | |
1141 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
1142 | * | |
1143 | * Inputs | |
1144 | * (endpoint, asoc, chunk) | |
1145 | * | |
1146 | * Outputs | |
1147 | * (asoc, reply_msg, msg_up, timers, counters) | |
1148 | * | |
1149 | * The return value is the disposition of the chunk. | |
1150 | */ | |
1151 | sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net, | |
1152 | const struct sctp_endpoint *ep, | |
1153 | const struct sctp_association *asoc, | |
1154 | const sctp_subtype_t type, | |
1155 | void *arg, | |
1156 | sctp_cmd_seq_t *commands) | |
1157 | { | |
1158 | struct sctp_chunk *chunk = arg; | |
1159 | union sctp_addr from_addr; | |
1160 | struct sctp_transport *link; | |
1161 | sctp_sender_hb_info_t *hbinfo; | |
1162 | unsigned long max_interval; | |
1163 | ||
1164 | if (!sctp_vtag_verify(chunk, asoc)) | |
1165 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
1166 | ||
1167 | /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ | |
1168 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr) + | |
1169 | sizeof(sctp_sender_hb_info_t))) | |
1170 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
1171 | commands); | |
1172 | ||
1173 | hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; | |
1174 | /* Make sure that the length of the parameter is what we expect */ | |
1175 | if (ntohs(hbinfo->param_hdr.length) != | |
1176 | sizeof(sctp_sender_hb_info_t)) { | |
1177 | return SCTP_DISPOSITION_DISCARD; | |
1178 | } | |
1179 | ||
1180 | from_addr = hbinfo->daddr; | |
1181 | link = sctp_assoc_lookup_paddr(asoc, &from_addr); | |
1182 | ||
1183 | /* This should never happen, but lets log it if so. */ | |
1184 | if (unlikely(!link)) { | |
1185 | if (from_addr.sa.sa_family == AF_INET6) { | |
1186 | net_warn_ratelimited("%s association %p could not find address %pI6\n", | |
1187 | __func__, | |
1188 | asoc, | |
1189 | &from_addr.v6.sin6_addr); | |
1190 | } else { | |
1191 | net_warn_ratelimited("%s association %p could not find address %pI4\n", | |
1192 | __func__, | |
1193 | asoc, | |
1194 | &from_addr.v4.sin_addr.s_addr); | |
1195 | } | |
1196 | return SCTP_DISPOSITION_DISCARD; | |
1197 | } | |
1198 | ||
1199 | /* Validate the 64-bit random nonce. */ | |
1200 | if (hbinfo->hb_nonce != link->hb_nonce) | |
1201 | return SCTP_DISPOSITION_DISCARD; | |
1202 | ||
1203 | max_interval = link->hbinterval + link->rto; | |
1204 | ||
1205 | /* Check if the timestamp looks valid. */ | |
1206 | if (time_after(hbinfo->sent_at, jiffies) || | |
1207 | time_after(jiffies, hbinfo->sent_at + max_interval)) { | |
1208 | pr_debug("%s: HEARTBEAT ACK with invalid timestamp received " | |
1209 | "for transport:%p\n", __func__, link); | |
1210 | ||
1211 | return SCTP_DISPOSITION_DISCARD; | |
1212 | } | |
1213 | ||
1214 | /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of | |
1215 | * the HEARTBEAT should clear the error counter of the | |
1216 | * destination transport address to which the HEARTBEAT was | |
1217 | * sent and mark the destination transport address as active if | |
1218 | * it is not so marked. | |
1219 | */ | |
1220 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); | |
1221 | ||
1222 | return SCTP_DISPOSITION_CONSUME; | |
1223 | } | |
1224 | ||
1225 | /* Helper function to send out an abort for the restart | |
1226 | * condition. | |
1227 | */ | |
1228 | static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa, | |
1229 | struct sctp_chunk *init, | |
1230 | sctp_cmd_seq_t *commands) | |
1231 | { | |
1232 | int len; | |
1233 | struct sctp_packet *pkt; | |
1234 | union sctp_addr_param *addrparm; | |
1235 | struct sctp_errhdr *errhdr; | |
1236 | struct sctp_endpoint *ep; | |
1237 | char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)]; | |
1238 | struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); | |
1239 | ||
1240 | /* Build the error on the stack. We are way to malloc crazy | |
1241 | * throughout the code today. | |
1242 | */ | |
1243 | errhdr = (struct sctp_errhdr *)buffer; | |
1244 | addrparm = (union sctp_addr_param *)errhdr->variable; | |
1245 | ||
1246 | /* Copy into a parm format. */ | |
1247 | len = af->to_addr_param(ssa, addrparm); | |
1248 | len += sizeof(sctp_errhdr_t); | |
1249 | ||
1250 | errhdr->cause = SCTP_ERROR_RESTART; | |
1251 | errhdr->length = htons(len); | |
1252 | ||
1253 | /* Assign to the control socket. */ | |
1254 | ep = sctp_sk(net->sctp.ctl_sock)->ep; | |
1255 | ||
1256 | /* Association is NULL since this may be a restart attack and we | |
1257 | * want to send back the attacker's vtag. | |
1258 | */ | |
1259 | pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len); | |
1260 | ||
1261 | if (!pkt) | |
1262 | goto out; | |
1263 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); | |
1264 | ||
1265 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
1266 | ||
1267 | /* Discard the rest of the inbound packet. */ | |
1268 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
1269 | ||
1270 | out: | |
1271 | /* Even if there is no memory, treat as a failure so | |
1272 | * the packet will get dropped. | |
1273 | */ | |
1274 | return 0; | |
1275 | } | |
1276 | ||
1277 | static bool list_has_sctp_addr(const struct list_head *list, | |
1278 | union sctp_addr *ipaddr) | |
1279 | { | |
1280 | struct sctp_transport *addr; | |
1281 | ||
1282 | list_for_each_entry(addr, list, transports) { | |
1283 | if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr)) | |
1284 | return true; | |
1285 | } | |
1286 | ||
1287 | return false; | |
1288 | } | |
1289 | /* A restart is occurring, check to make sure no new addresses | |
1290 | * are being added as we may be under a takeover attack. | |
1291 | */ | |
1292 | static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, | |
1293 | const struct sctp_association *asoc, | |
1294 | struct sctp_chunk *init, | |
1295 | sctp_cmd_seq_t *commands) | |
1296 | { | |
1297 | struct net *net = sock_net(new_asoc->base.sk); | |
1298 | struct sctp_transport *new_addr; | |
1299 | int ret = 1; | |
1300 | ||
1301 | /* Implementor's Guide - Section 5.2.2 | |
1302 | * ... | |
1303 | * Before responding the endpoint MUST check to see if the | |
1304 | * unexpected INIT adds new addresses to the association. If new | |
1305 | * addresses are added to the association, the endpoint MUST respond | |
1306 | * with an ABORT.. | |
1307 | */ | |
1308 | ||
1309 | /* Search through all current addresses and make sure | |
1310 | * we aren't adding any new ones. | |
1311 | */ | |
1312 | list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list, | |
1313 | transports) { | |
1314 | if (!list_has_sctp_addr(&asoc->peer.transport_addr_list, | |
1315 | &new_addr->ipaddr)) { | |
1316 | sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init, | |
1317 | commands); | |
1318 | ret = 0; | |
1319 | break; | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | /* Return success if all addresses were found. */ | |
1324 | return ret; | |
1325 | } | |
1326 | ||
1327 | /* Populate the verification/tie tags based on overlapping INIT | |
1328 | * scenario. | |
1329 | * | |
1330 | * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. | |
1331 | */ | |
1332 | static void sctp_tietags_populate(struct sctp_association *new_asoc, | |
1333 | const struct sctp_association *asoc) | |
1334 | { | |
1335 | switch (asoc->state) { | |
1336 | ||
1337 | /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ | |
1338 | ||
1339 | case SCTP_STATE_COOKIE_WAIT: | |
1340 | new_asoc->c.my_vtag = asoc->c.my_vtag; | |
1341 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1342 | new_asoc->c.peer_ttag = 0; | |
1343 | break; | |
1344 | ||
1345 | case SCTP_STATE_COOKIE_ECHOED: | |
1346 | new_asoc->c.my_vtag = asoc->c.my_vtag; | |
1347 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1348 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; | |
1349 | break; | |
1350 | ||
1351 | /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, | |
1352 | * COOKIE-WAIT and SHUTDOWN-ACK-SENT | |
1353 | */ | |
1354 | default: | |
1355 | new_asoc->c.my_ttag = asoc->c.my_vtag; | |
1356 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; | |
1357 | break; | |
1358 | } | |
1359 | ||
1360 | /* Other parameters for the endpoint SHOULD be copied from the | |
1361 | * existing parameters of the association (e.g. number of | |
1362 | * outbound streams) into the INIT ACK and cookie. | |
1363 | */ | |
1364 | new_asoc->rwnd = asoc->rwnd; | |
1365 | new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; | |
1366 | new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; | |
1367 | new_asoc->c.initial_tsn = asoc->c.initial_tsn; | |
1368 | } | |
1369 | ||
1370 | /* | |
1371 | * Compare vtag/tietag values to determine unexpected COOKIE-ECHO | |
1372 | * handling action. | |
1373 | * | |
1374 | * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. | |
1375 | * | |
1376 | * Returns value representing action to be taken. These action values | |
1377 | * correspond to Action/Description values in RFC 2960, Table 2. | |
1378 | */ | |
1379 | static char sctp_tietags_compare(struct sctp_association *new_asoc, | |
1380 | const struct sctp_association *asoc) | |
1381 | { | |
1382 | /* In this case, the peer may have restarted. */ | |
1383 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && | |
1384 | (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && | |
1385 | (asoc->c.my_vtag == new_asoc->c.my_ttag) && | |
1386 | (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) | |
1387 | return 'A'; | |
1388 | ||
1389 | /* Collision case B. */ | |
1390 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && | |
1391 | ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || | |
1392 | (0 == asoc->c.peer_vtag))) { | |
1393 | return 'B'; | |
1394 | } | |
1395 | ||
1396 | /* Collision case D. */ | |
1397 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && | |
1398 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) | |
1399 | return 'D'; | |
1400 | ||
1401 | /* Collision case C. */ | |
1402 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && | |
1403 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && | |
1404 | (0 == new_asoc->c.my_ttag) && | |
1405 | (0 == new_asoc->c.peer_ttag)) | |
1406 | return 'C'; | |
1407 | ||
1408 | /* No match to any of the special cases; discard this packet. */ | |
1409 | return 'E'; | |
1410 | } | |
1411 | ||
1412 | /* Common helper routine for both duplicate and simulataneous INIT | |
1413 | * chunk handling. | |
1414 | */ | |
1415 | static sctp_disposition_t sctp_sf_do_unexpected_init( | |
1416 | struct net *net, | |
1417 | const struct sctp_endpoint *ep, | |
1418 | const struct sctp_association *asoc, | |
1419 | const sctp_subtype_t type, | |
1420 | void *arg, sctp_cmd_seq_t *commands) | |
1421 | { | |
1422 | sctp_disposition_t retval; | |
1423 | struct sctp_chunk *chunk = arg; | |
1424 | struct sctp_chunk *repl; | |
1425 | struct sctp_association *new_asoc; | |
1426 | struct sctp_chunk *err_chunk; | |
1427 | struct sctp_packet *packet; | |
1428 | sctp_unrecognized_param_t *unk_param; | |
1429 | int len; | |
1430 | ||
1431 | /* 6.10 Bundling | |
1432 | * An endpoint MUST NOT bundle INIT, INIT ACK or | |
1433 | * SHUTDOWN COMPLETE with any other chunks. | |
1434 | * | |
1435 | * IG Section 2.11.2 | |
1436 | * Furthermore, we require that the receiver of an INIT chunk MUST | |
1437 | * enforce these rules by silently discarding an arriving packet | |
1438 | * with an INIT chunk that is bundled with other chunks. | |
1439 | */ | |
1440 | if (!chunk->singleton) | |
1441 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
1442 | ||
1443 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification | |
1444 | * Tag. | |
1445 | */ | |
1446 | if (chunk->sctp_hdr->vtag != 0) | |
1447 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
1448 | ||
1449 | /* Make sure that the INIT chunk has a valid length. | |
1450 | * In this case, we generate a protocol violation since we have | |
1451 | * an association established. | |
1452 | */ | |
1453 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk))) | |
1454 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
1455 | commands); | |
1456 | /* Grab the INIT header. */ | |
1457 | chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; | |
1458 | ||
1459 | /* Tag the variable length parameters. */ | |
1460 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); | |
1461 | ||
1462 | /* Verify the INIT chunk before processing it. */ | |
1463 | err_chunk = NULL; | |
1464 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, | |
1465 | (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, | |
1466 | &err_chunk)) { | |
1467 | /* This chunk contains fatal error. It is to be discarded. | |
1468 | * Send an ABORT, with causes if there is any. | |
1469 | */ | |
1470 | if (err_chunk) { | |
1471 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, | |
1472 | (__u8 *)(err_chunk->chunk_hdr) + | |
1473 | sizeof(struct sctp_chunkhdr), | |
1474 | ntohs(err_chunk->chunk_hdr->length) - | |
1475 | sizeof(struct sctp_chunkhdr)); | |
1476 | ||
1477 | if (packet) { | |
1478 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
1479 | SCTP_PACKET(packet)); | |
1480 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
1481 | retval = SCTP_DISPOSITION_CONSUME; | |
1482 | } else { | |
1483 | retval = SCTP_DISPOSITION_NOMEM; | |
1484 | } | |
1485 | goto cleanup; | |
1486 | } else { | |
1487 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, | |
1488 | commands); | |
1489 | } | |
1490 | } | |
1491 | ||
1492 | /* | |
1493 | * Other parameters for the endpoint SHOULD be copied from the | |
1494 | * existing parameters of the association (e.g. number of | |
1495 | * outbound streams) into the INIT ACK and cookie. | |
1496 | * FIXME: We are copying parameters from the endpoint not the | |
1497 | * association. | |
1498 | */ | |
1499 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); | |
1500 | if (!new_asoc) | |
1501 | goto nomem; | |
1502 | ||
1503 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, | |
1504 | sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) | |
1505 | goto nomem; | |
1506 | ||
1507 | /* In the outbound INIT ACK the endpoint MUST copy its current | |
1508 | * Verification Tag and Peers Verification tag into a reserved | |
1509 | * place (local tie-tag and per tie-tag) within the state cookie. | |
1510 | */ | |
1511 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), | |
1512 | (struct sctp_init_chunk *)chunk->chunk_hdr, | |
1513 | GFP_ATOMIC)) | |
1514 | goto nomem; | |
1515 | ||
1516 | /* Make sure no new addresses are being added during the | |
1517 | * restart. Do not do this check for COOKIE-WAIT state, | |
1518 | * since there are no peer addresses to check against. | |
1519 | * Upon return an ABORT will have been sent if needed. | |
1520 | */ | |
1521 | if (!sctp_state(asoc, COOKIE_WAIT)) { | |
1522 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, | |
1523 | commands)) { | |
1524 | retval = SCTP_DISPOSITION_CONSUME; | |
1525 | goto nomem_retval; | |
1526 | } | |
1527 | } | |
1528 | ||
1529 | sctp_tietags_populate(new_asoc, asoc); | |
1530 | ||
1531 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ | |
1532 | ||
1533 | /* If there are errors need to be reported for unknown parameters, | |
1534 | * make sure to reserve enough room in the INIT ACK for them. | |
1535 | */ | |
1536 | len = 0; | |
1537 | if (err_chunk) { | |
1538 | len = ntohs(err_chunk->chunk_hdr->length) - | |
1539 | sizeof(struct sctp_chunkhdr); | |
1540 | } | |
1541 | ||
1542 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); | |
1543 | if (!repl) | |
1544 | goto nomem; | |
1545 | ||
1546 | /* If there are errors need to be reported for unknown parameters, | |
1547 | * include them in the outgoing INIT ACK as "Unrecognized parameter" | |
1548 | * parameter. | |
1549 | */ | |
1550 | if (err_chunk) { | |
1551 | /* Get the "Unrecognized parameter" parameter(s) out of the | |
1552 | * ERROR chunk generated by sctp_verify_init(). Since the | |
1553 | * error cause code for "unknown parameter" and the | |
1554 | * "Unrecognized parameter" type is the same, we can | |
1555 | * construct the parameters in INIT ACK by copying the | |
1556 | * ERROR causes over. | |
1557 | */ | |
1558 | unk_param = (sctp_unrecognized_param_t *) | |
1559 | ((__u8 *)(err_chunk->chunk_hdr) + | |
1560 | sizeof(struct sctp_chunkhdr)); | |
1561 | /* Replace the cause code with the "Unrecognized parameter" | |
1562 | * parameter type. | |
1563 | */ | |
1564 | sctp_addto_chunk(repl, len, unk_param); | |
1565 | } | |
1566 | ||
1567 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); | |
1568 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1569 | ||
1570 | /* | |
1571 | * Note: After sending out INIT ACK with the State Cookie parameter, | |
1572 | * "Z" MUST NOT allocate any resources for this new association. | |
1573 | * Otherwise, "Z" will be vulnerable to resource attacks. | |
1574 | */ | |
1575 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
1576 | retval = SCTP_DISPOSITION_CONSUME; | |
1577 | ||
1578 | return retval; | |
1579 | ||
1580 | nomem: | |
1581 | retval = SCTP_DISPOSITION_NOMEM; | |
1582 | nomem_retval: | |
1583 | if (new_asoc) | |
1584 | sctp_association_free(new_asoc); | |
1585 | cleanup: | |
1586 | if (err_chunk) | |
1587 | sctp_chunk_free(err_chunk); | |
1588 | return retval; | |
1589 | } | |
1590 | ||
1591 | /* | |
1592 | * Handle simultaneous INIT. | |
1593 | * This means we started an INIT and then we got an INIT request from | |
1594 | * our peer. | |
1595 | * | |
1596 | * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) | |
1597 | * This usually indicates an initialization collision, i.e., each | |
1598 | * endpoint is attempting, at about the same time, to establish an | |
1599 | * association with the other endpoint. | |
1600 | * | |
1601 | * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an | |
1602 | * endpoint MUST respond with an INIT ACK using the same parameters it | |
1603 | * sent in its original INIT chunk (including its Verification Tag, | |
1604 | * unchanged). These original parameters are combined with those from the | |
1605 | * newly received INIT chunk. The endpoint shall also generate a State | |
1606 | * Cookie with the INIT ACK. The endpoint uses the parameters sent in its | |
1607 | * INIT to calculate the State Cookie. | |
1608 | * | |
1609 | * After that, the endpoint MUST NOT change its state, the T1-init | |
1610 | * timer shall be left running and the corresponding TCB MUST NOT be | |
1611 | * destroyed. The normal procedures for handling State Cookies when | |
1612 | * a TCB exists will resolve the duplicate INITs to a single association. | |
1613 | * | |
1614 | * For an endpoint that is in the COOKIE-ECHOED state it MUST populate | |
1615 | * its Tie-Tags with the Tag information of itself and its peer (see | |
1616 | * section 5.2.2 for a description of the Tie-Tags). | |
1617 | * | |
1618 | * Verification Tag: Not explicit, but an INIT can not have a valid | |
1619 | * verification tag, so we skip the check. | |
1620 | * | |
1621 | * Inputs | |
1622 | * (endpoint, asoc, chunk) | |
1623 | * | |
1624 | * Outputs | |
1625 | * (asoc, reply_msg, msg_up, timers, counters) | |
1626 | * | |
1627 | * The return value is the disposition of the chunk. | |
1628 | */ | |
1629 | sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net, | |
1630 | const struct sctp_endpoint *ep, | |
1631 | const struct sctp_association *asoc, | |
1632 | const sctp_subtype_t type, | |
1633 | void *arg, | |
1634 | sctp_cmd_seq_t *commands) | |
1635 | { | |
1636 | /* Call helper to do the real work for both simulataneous and | |
1637 | * duplicate INIT chunk handling. | |
1638 | */ | |
1639 | return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); | |
1640 | } | |
1641 | ||
1642 | /* | |
1643 | * Handle duplicated INIT messages. These are usually delayed | |
1644 | * restransmissions. | |
1645 | * | |
1646 | * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, | |
1647 | * COOKIE-ECHOED and COOKIE-WAIT | |
1648 | * | |
1649 | * Unless otherwise stated, upon reception of an unexpected INIT for | |
1650 | * this association, the endpoint shall generate an INIT ACK with a | |
1651 | * State Cookie. In the outbound INIT ACK the endpoint MUST copy its | |
1652 | * current Verification Tag and peer's Verification Tag into a reserved | |
1653 | * place within the state cookie. We shall refer to these locations as | |
1654 | * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet | |
1655 | * containing this INIT ACK MUST carry a Verification Tag value equal to | |
1656 | * the Initiation Tag found in the unexpected INIT. And the INIT ACK | |
1657 | * MUST contain a new Initiation Tag (randomly generated see Section | |
1658 | * 5.3.1). Other parameters for the endpoint SHOULD be copied from the | |
1659 | * existing parameters of the association (e.g. number of outbound | |
1660 | * streams) into the INIT ACK and cookie. | |
1661 | * | |
1662 | * After sending out the INIT ACK, the endpoint shall take no further | |
1663 | * actions, i.e., the existing association, including its current state, | |
1664 | * and the corresponding TCB MUST NOT be changed. | |
1665 | * | |
1666 | * Note: Only when a TCB exists and the association is not in a COOKIE- | |
1667 | * WAIT state are the Tie-Tags populated. For a normal association INIT | |
1668 | * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be | |
1669 | * set to 0 (indicating that no previous TCB existed). The INIT ACK and | |
1670 | * State Cookie are populated as specified in section 5.2.1. | |
1671 | * | |
1672 | * Verification Tag: Not specified, but an INIT has no way of knowing | |
1673 | * what the verification tag could be, so we ignore it. | |
1674 | * | |
1675 | * Inputs | |
1676 | * (endpoint, asoc, chunk) | |
1677 | * | |
1678 | * Outputs | |
1679 | * (asoc, reply_msg, msg_up, timers, counters) | |
1680 | * | |
1681 | * The return value is the disposition of the chunk. | |
1682 | */ | |
1683 | sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net, | |
1684 | const struct sctp_endpoint *ep, | |
1685 | const struct sctp_association *asoc, | |
1686 | const sctp_subtype_t type, | |
1687 | void *arg, | |
1688 | sctp_cmd_seq_t *commands) | |
1689 | { | |
1690 | /* Call helper to do the real work for both simulataneous and | |
1691 | * duplicate INIT chunk handling. | |
1692 | */ | |
1693 | return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); | |
1694 | } | |
1695 | ||
1696 | ||
1697 | /* | |
1698 | * Unexpected INIT-ACK handler. | |
1699 | * | |
1700 | * Section 5.2.3 | |
1701 | * If an INIT ACK received by an endpoint in any state other than the | |
1702 | * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk. | |
1703 | * An unexpected INIT ACK usually indicates the processing of an old or | |
1704 | * duplicated INIT chunk. | |
1705 | */ | |
1706 | sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net, | |
1707 | const struct sctp_endpoint *ep, | |
1708 | const struct sctp_association *asoc, | |
1709 | const sctp_subtype_t type, | |
1710 | void *arg, sctp_cmd_seq_t *commands) | |
1711 | { | |
1712 | /* Per the above section, we'll discard the chunk if we have an | |
1713 | * endpoint. If this is an OOTB INIT-ACK, treat it as such. | |
1714 | */ | |
1715 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) | |
1716 | return sctp_sf_ootb(net, ep, asoc, type, arg, commands); | |
1717 | else | |
1718 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
1719 | } | |
1720 | ||
1721 | /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') | |
1722 | * | |
1723 | * Section 5.2.4 | |
1724 | * A) In this case, the peer may have restarted. | |
1725 | */ | |
1726 | static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net, | |
1727 | const struct sctp_endpoint *ep, | |
1728 | const struct sctp_association *asoc, | |
1729 | struct sctp_chunk *chunk, | |
1730 | sctp_cmd_seq_t *commands, | |
1731 | struct sctp_association *new_asoc) | |
1732 | { | |
1733 | struct sctp_init_chunk *peer_init; | |
1734 | struct sctp_ulpevent *ev; | |
1735 | struct sctp_chunk *repl; | |
1736 | struct sctp_chunk *err; | |
1737 | sctp_disposition_t disposition; | |
1738 | ||
1739 | /* new_asoc is a brand-new association, so these are not yet | |
1740 | * side effects--it is safe to run them here. | |
1741 | */ | |
1742 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
1743 | ||
1744 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, | |
1745 | GFP_ATOMIC)) | |
1746 | goto nomem; | |
1747 | ||
1748 | /* Make sure no new addresses are being added during the | |
1749 | * restart. Though this is a pretty complicated attack | |
1750 | * since you'd have to get inside the cookie. | |
1751 | */ | |
1752 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) { | |
1753 | return SCTP_DISPOSITION_CONSUME; | |
1754 | } | |
1755 | ||
1756 | /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes | |
1757 | * the peer has restarted (Action A), it MUST NOT setup a new | |
1758 | * association but instead resend the SHUTDOWN ACK and send an ERROR | |
1759 | * chunk with a "Cookie Received while Shutting Down" error cause to | |
1760 | * its peer. | |
1761 | */ | |
1762 | if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { | |
1763 | disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc, | |
1764 | SCTP_ST_CHUNK(chunk->chunk_hdr->type), | |
1765 | chunk, commands); | |
1766 | if (SCTP_DISPOSITION_NOMEM == disposition) | |
1767 | goto nomem; | |
1768 | ||
1769 | err = sctp_make_op_error(asoc, chunk, | |
1770 | SCTP_ERROR_COOKIE_IN_SHUTDOWN, | |
1771 | NULL, 0, 0); | |
1772 | if (err) | |
1773 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
1774 | SCTP_CHUNK(err)); | |
1775 | ||
1776 | return SCTP_DISPOSITION_CONSUME; | |
1777 | } | |
1778 | ||
1779 | /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked | |
1780 | * data. Consider the optional choice of resending of this data. | |
1781 | */ | |
1782 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); | |
1783 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1784 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); | |
1785 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); | |
1786 | ||
1787 | /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue | |
1788 | * and ASCONF-ACK cache. | |
1789 | */ | |
1790 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1791 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
1792 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL()); | |
1793 | ||
1794 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1795 | if (!repl) | |
1796 | goto nomem; | |
1797 | ||
1798 | /* Report association restart to upper layer. */ | |
1799 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, | |
1800 | new_asoc->c.sinit_num_ostreams, | |
1801 | new_asoc->c.sinit_max_instreams, | |
1802 | NULL, GFP_ATOMIC); | |
1803 | if (!ev) | |
1804 | goto nomem_ev; | |
1805 | ||
1806 | /* Update the content of current association. */ | |
1807 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); | |
1808 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
1809 | if (sctp_state(asoc, SHUTDOWN_PENDING) && | |
1810 | (sctp_sstate(asoc->base.sk, CLOSING) || | |
1811 | sock_flag(asoc->base.sk, SOCK_DEAD))) { | |
1812 | /* if were currently in SHUTDOWN_PENDING, but the socket | |
1813 | * has been closed by user, don't transition to ESTABLISHED. | |
1814 | * Instead trigger SHUTDOWN bundled with COOKIE_ACK. | |
1815 | */ | |
1816 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1817 | return sctp_sf_do_9_2_start_shutdown(net, ep, asoc, | |
1818 | SCTP_ST_CHUNK(0), NULL, | |
1819 | commands); | |
1820 | } else { | |
1821 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
1822 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
1823 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1824 | } | |
1825 | return SCTP_DISPOSITION_CONSUME; | |
1826 | ||
1827 | nomem_ev: | |
1828 | sctp_chunk_free(repl); | |
1829 | nomem: | |
1830 | return SCTP_DISPOSITION_NOMEM; | |
1831 | } | |
1832 | ||
1833 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') | |
1834 | * | |
1835 | * Section 5.2.4 | |
1836 | * B) In this case, both sides may be attempting to start an association | |
1837 | * at about the same time but the peer endpoint started its INIT | |
1838 | * after responding to the local endpoint's INIT | |
1839 | */ | |
1840 | /* This case represents an initialization collision. */ | |
1841 | static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net, | |
1842 | const struct sctp_endpoint *ep, | |
1843 | const struct sctp_association *asoc, | |
1844 | struct sctp_chunk *chunk, | |
1845 | sctp_cmd_seq_t *commands, | |
1846 | struct sctp_association *new_asoc) | |
1847 | { | |
1848 | struct sctp_init_chunk *peer_init; | |
1849 | struct sctp_chunk *repl; | |
1850 | ||
1851 | /* new_asoc is a brand-new association, so these are not yet | |
1852 | * side effects--it is safe to run them here. | |
1853 | */ | |
1854 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; | |
1855 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, | |
1856 | GFP_ATOMIC)) | |
1857 | goto nomem; | |
1858 | ||
1859 | /* Update the content of current association. */ | |
1860 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); | |
1861 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
1862 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
1863 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); | |
1864 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); | |
1865 | ||
1866 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1867 | if (!repl) | |
1868 | goto nomem; | |
1869 | ||
1870 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1871 | ||
1872 | /* RFC 2960 5.1 Normal Establishment of an Association | |
1873 | * | |
1874 | * D) IMPLEMENTATION NOTE: An implementation may choose to | |
1875 | * send the Communication Up notification to the SCTP user | |
1876 | * upon reception of a valid COOKIE ECHO chunk. | |
1877 | * | |
1878 | * Sadly, this needs to be implemented as a side-effect, because | |
1879 | * we are not guaranteed to have set the association id of the real | |
1880 | * association and so these notifications need to be delayed until | |
1881 | * the association id is allocated. | |
1882 | */ | |
1883 | ||
1884 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP)); | |
1885 | ||
1886 | /* Sockets API Draft Section 5.3.1.6 | |
1887 | * When a peer sends a Adaptation Layer Indication parameter , SCTP | |
1888 | * delivers this notification to inform the application that of the | |
1889 | * peers requested adaptation layer. | |
1890 | * | |
1891 | * This also needs to be done as a side effect for the same reason as | |
1892 | * above. | |
1893 | */ | |
1894 | if (asoc->peer.adaptation_ind) | |
1895 | sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL()); | |
1896 | ||
1897 | return SCTP_DISPOSITION_CONSUME; | |
1898 | ||
1899 | nomem: | |
1900 | return SCTP_DISPOSITION_NOMEM; | |
1901 | } | |
1902 | ||
1903 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') | |
1904 | * | |
1905 | * Section 5.2.4 | |
1906 | * C) In this case, the local endpoint's cookie has arrived late. | |
1907 | * Before it arrived, the local endpoint sent an INIT and received an | |
1908 | * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag | |
1909 | * but a new tag of its own. | |
1910 | */ | |
1911 | /* This case represents an initialization collision. */ | |
1912 | static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net, | |
1913 | const struct sctp_endpoint *ep, | |
1914 | const struct sctp_association *asoc, | |
1915 | struct sctp_chunk *chunk, | |
1916 | sctp_cmd_seq_t *commands, | |
1917 | struct sctp_association *new_asoc) | |
1918 | { | |
1919 | /* The cookie should be silently discarded. | |
1920 | * The endpoint SHOULD NOT change states and should leave | |
1921 | * any timers running. | |
1922 | */ | |
1923 | return SCTP_DISPOSITION_DISCARD; | |
1924 | } | |
1925 | ||
1926 | /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') | |
1927 | * | |
1928 | * Section 5.2.4 | |
1929 | * | |
1930 | * D) When both local and remote tags match the endpoint should always | |
1931 | * enter the ESTABLISHED state, if it has not already done so. | |
1932 | */ | |
1933 | /* This case represents an initialization collision. */ | |
1934 | static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net, | |
1935 | const struct sctp_endpoint *ep, | |
1936 | const struct sctp_association *asoc, | |
1937 | struct sctp_chunk *chunk, | |
1938 | sctp_cmd_seq_t *commands, | |
1939 | struct sctp_association *new_asoc) | |
1940 | { | |
1941 | struct sctp_ulpevent *ev = NULL, *ai_ev = NULL; | |
1942 | struct sctp_chunk *repl; | |
1943 | ||
1944 | /* Clarification from Implementor's Guide: | |
1945 | * D) When both local and remote tags match the endpoint should | |
1946 | * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. | |
1947 | * It should stop any cookie timer that may be running and send | |
1948 | * a COOKIE ACK. | |
1949 | */ | |
1950 | ||
1951 | /* Don't accidentally move back into established state. */ | |
1952 | if (asoc->state < SCTP_STATE_ESTABLISHED) { | |
1953 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
1954 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
1955 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
1956 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); | |
1957 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); | |
1958 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, | |
1959 | SCTP_NULL()); | |
1960 | ||
1961 | /* RFC 2960 5.1 Normal Establishment of an Association | |
1962 | * | |
1963 | * D) IMPLEMENTATION NOTE: An implementation may choose | |
1964 | * to send the Communication Up notification to the | |
1965 | * SCTP user upon reception of a valid COOKIE | |
1966 | * ECHO chunk. | |
1967 | */ | |
1968 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, | |
1969 | SCTP_COMM_UP, 0, | |
1970 | asoc->c.sinit_num_ostreams, | |
1971 | asoc->c.sinit_max_instreams, | |
1972 | NULL, GFP_ATOMIC); | |
1973 | if (!ev) | |
1974 | goto nomem; | |
1975 | ||
1976 | /* Sockets API Draft Section 5.3.1.6 | |
1977 | * When a peer sends a Adaptation Layer Indication parameter, | |
1978 | * SCTP delivers this notification to inform the application | |
1979 | * that of the peers requested adaptation layer. | |
1980 | */ | |
1981 | if (asoc->peer.adaptation_ind) { | |
1982 | ai_ev = sctp_ulpevent_make_adaptation_indication(asoc, | |
1983 | GFP_ATOMIC); | |
1984 | if (!ai_ev) | |
1985 | goto nomem; | |
1986 | ||
1987 | } | |
1988 | } | |
1989 | ||
1990 | repl = sctp_make_cookie_ack(new_asoc, chunk); | |
1991 | if (!repl) | |
1992 | goto nomem; | |
1993 | ||
1994 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
1995 | ||
1996 | if (ev) | |
1997 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
1998 | SCTP_ULPEVENT(ev)); | |
1999 | if (ai_ev) | |
2000 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
2001 | SCTP_ULPEVENT(ai_ev)); | |
2002 | ||
2003 | return SCTP_DISPOSITION_CONSUME; | |
2004 | ||
2005 | nomem: | |
2006 | if (ai_ev) | |
2007 | sctp_ulpevent_free(ai_ev); | |
2008 | if (ev) | |
2009 | sctp_ulpevent_free(ev); | |
2010 | return SCTP_DISPOSITION_NOMEM; | |
2011 | } | |
2012 | ||
2013 | /* | |
2014 | * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying | |
2015 | * chunk was retransmitted and then delayed in the network. | |
2016 | * | |
2017 | * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists | |
2018 | * | |
2019 | * Verification Tag: None. Do cookie validation. | |
2020 | * | |
2021 | * Inputs | |
2022 | * (endpoint, asoc, chunk) | |
2023 | * | |
2024 | * Outputs | |
2025 | * (asoc, reply_msg, msg_up, timers, counters) | |
2026 | * | |
2027 | * The return value is the disposition of the chunk. | |
2028 | */ | |
2029 | sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net, | |
2030 | const struct sctp_endpoint *ep, | |
2031 | const struct sctp_association *asoc, | |
2032 | const sctp_subtype_t type, | |
2033 | void *arg, | |
2034 | sctp_cmd_seq_t *commands) | |
2035 | { | |
2036 | sctp_disposition_t retval; | |
2037 | struct sctp_chunk *chunk = arg; | |
2038 | struct sctp_association *new_asoc; | |
2039 | int error = 0; | |
2040 | char action; | |
2041 | struct sctp_chunk *err_chk_p; | |
2042 | ||
2043 | /* Make sure that the chunk has a valid length from the protocol | |
2044 | * perspective. In this case check to make sure we have at least | |
2045 | * enough for the chunk header. Cookie length verification is | |
2046 | * done later. | |
2047 | */ | |
2048 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
2049 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2050 | commands); | |
2051 | ||
2052 | /* "Decode" the chunk. We have no optional parameters so we | |
2053 | * are in good shape. | |
2054 | */ | |
2055 | chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; | |
2056 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - | |
2057 | sizeof(struct sctp_chunkhdr))) | |
2058 | goto nomem; | |
2059 | ||
2060 | /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie | |
2061 | * of a duplicate COOKIE ECHO match the Verification Tags of the | |
2062 | * current association, consider the State Cookie valid even if | |
2063 | * the lifespan is exceeded. | |
2064 | */ | |
2065 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, | |
2066 | &err_chk_p); | |
2067 | ||
2068 | /* FIXME: | |
2069 | * If the re-build failed, what is the proper error path | |
2070 | * from here? | |
2071 | * | |
2072 | * [We should abort the association. --piggy] | |
2073 | */ | |
2074 | if (!new_asoc) { | |
2075 | /* FIXME: Several errors are possible. A bad cookie should | |
2076 | * be silently discarded, but think about logging it too. | |
2077 | */ | |
2078 | switch (error) { | |
2079 | case -SCTP_IERROR_NOMEM: | |
2080 | goto nomem; | |
2081 | ||
2082 | case -SCTP_IERROR_STALE_COOKIE: | |
2083 | sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, | |
2084 | err_chk_p); | |
2085 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2086 | case -SCTP_IERROR_BAD_SIG: | |
2087 | default: | |
2088 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2089 | } | |
2090 | } | |
2091 | ||
2092 | /* Set temp so that it won't be added into hashtable */ | |
2093 | new_asoc->temp = 1; | |
2094 | ||
2095 | /* Compare the tie_tag in cookie with the verification tag of | |
2096 | * current association. | |
2097 | */ | |
2098 | action = sctp_tietags_compare(new_asoc, asoc); | |
2099 | ||
2100 | switch (action) { | |
2101 | case 'A': /* Association restart. */ | |
2102 | retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands, | |
2103 | new_asoc); | |
2104 | break; | |
2105 | ||
2106 | case 'B': /* Collision case B. */ | |
2107 | retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands, | |
2108 | new_asoc); | |
2109 | break; | |
2110 | ||
2111 | case 'C': /* Collision case C. */ | |
2112 | retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands, | |
2113 | new_asoc); | |
2114 | break; | |
2115 | ||
2116 | case 'D': /* Collision case D. */ | |
2117 | retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands, | |
2118 | new_asoc); | |
2119 | break; | |
2120 | ||
2121 | default: /* Discard packet for all others. */ | |
2122 | retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2123 | break; | |
2124 | } | |
2125 | ||
2126 | /* Delete the tempory new association. */ | |
2127 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc)); | |
2128 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
2129 | ||
2130 | /* Restore association pointer to provide SCTP command interpeter | |
2131 | * with a valid context in case it needs to manipulate | |
2132 | * the queues */ | |
2133 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, | |
2134 | SCTP_ASOC((struct sctp_association *)asoc)); | |
2135 | ||
2136 | return retval; | |
2137 | ||
2138 | nomem: | |
2139 | return SCTP_DISPOSITION_NOMEM; | |
2140 | } | |
2141 | ||
2142 | /* | |
2143 | * Process an ABORT. (SHUTDOWN-PENDING state) | |
2144 | * | |
2145 | * See sctp_sf_do_9_1_abort(). | |
2146 | */ | |
2147 | sctp_disposition_t sctp_sf_shutdown_pending_abort( | |
2148 | struct net *net, | |
2149 | const struct sctp_endpoint *ep, | |
2150 | const struct sctp_association *asoc, | |
2151 | const sctp_subtype_t type, | |
2152 | void *arg, | |
2153 | sctp_cmd_seq_t *commands) | |
2154 | { | |
2155 | struct sctp_chunk *chunk = arg; | |
2156 | ||
2157 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2158 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2159 | ||
2160 | /* Make sure that the ABORT chunk has a valid length. | |
2161 | * Since this is an ABORT chunk, we have to discard it | |
2162 | * because of the following text: | |
2163 | * RFC 2960, Section 3.3.7 | |
2164 | * If an endpoint receives an ABORT with a format error or for an | |
2165 | * association that doesn't exist, it MUST silently discard it. | |
2166 | * Because the length is "invalid", we can't really discard just | |
2167 | * as we do not know its true length. So, to be safe, discard the | |
2168 | * packet. | |
2169 | */ | |
2170 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2171 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2172 | ||
2173 | /* ADD-IP: Special case for ABORT chunks | |
2174 | * F4) One special consideration is that ABORT Chunks arriving | |
2175 | * destined to the IP address being deleted MUST be | |
2176 | * ignored (see Section 5.3.1 for further details). | |
2177 | */ | |
2178 | if (SCTP_ADDR_DEL == | |
2179 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) | |
2180 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
2181 | ||
2182 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); | |
2183 | } | |
2184 | ||
2185 | /* | |
2186 | * Process an ABORT. (SHUTDOWN-SENT state) | |
2187 | * | |
2188 | * See sctp_sf_do_9_1_abort(). | |
2189 | */ | |
2190 | sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net, | |
2191 | const struct sctp_endpoint *ep, | |
2192 | const struct sctp_association *asoc, | |
2193 | const sctp_subtype_t type, | |
2194 | void *arg, | |
2195 | sctp_cmd_seq_t *commands) | |
2196 | { | |
2197 | struct sctp_chunk *chunk = arg; | |
2198 | ||
2199 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2200 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2201 | ||
2202 | /* Make sure that the ABORT chunk has a valid length. | |
2203 | * Since this is an ABORT chunk, we have to discard it | |
2204 | * because of the following text: | |
2205 | * RFC 2960, Section 3.3.7 | |
2206 | * If an endpoint receives an ABORT with a format error or for an | |
2207 | * association that doesn't exist, it MUST silently discard it. | |
2208 | * Because the length is "invalid", we can't really discard just | |
2209 | * as we do not know its true length. So, to be safe, discard the | |
2210 | * packet. | |
2211 | */ | |
2212 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2213 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2214 | ||
2215 | /* ADD-IP: Special case for ABORT chunks | |
2216 | * F4) One special consideration is that ABORT Chunks arriving | |
2217 | * destined to the IP address being deleted MUST be | |
2218 | * ignored (see Section 5.3.1 for further details). | |
2219 | */ | |
2220 | if (SCTP_ADDR_DEL == | |
2221 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) | |
2222 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
2223 | ||
2224 | /* Stop the T2-shutdown timer. */ | |
2225 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2226 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
2227 | ||
2228 | /* Stop the T5-shutdown guard timer. */ | |
2229 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2230 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
2231 | ||
2232 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); | |
2233 | } | |
2234 | ||
2235 | /* | |
2236 | * Process an ABORT. (SHUTDOWN-ACK-SENT state) | |
2237 | * | |
2238 | * See sctp_sf_do_9_1_abort(). | |
2239 | */ | |
2240 | sctp_disposition_t sctp_sf_shutdown_ack_sent_abort( | |
2241 | struct net *net, | |
2242 | const struct sctp_endpoint *ep, | |
2243 | const struct sctp_association *asoc, | |
2244 | const sctp_subtype_t type, | |
2245 | void *arg, | |
2246 | sctp_cmd_seq_t *commands) | |
2247 | { | |
2248 | /* The same T2 timer, so we should be able to use | |
2249 | * common function with the SHUTDOWN-SENT state. | |
2250 | */ | |
2251 | return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands); | |
2252 | } | |
2253 | ||
2254 | /* | |
2255 | * Handle an Error received in COOKIE_ECHOED state. | |
2256 | * | |
2257 | * Only handle the error type of stale COOKIE Error, the other errors will | |
2258 | * be ignored. | |
2259 | * | |
2260 | * Inputs | |
2261 | * (endpoint, asoc, chunk) | |
2262 | * | |
2263 | * Outputs | |
2264 | * (asoc, reply_msg, msg_up, timers, counters) | |
2265 | * | |
2266 | * The return value is the disposition of the chunk. | |
2267 | */ | |
2268 | sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net, | |
2269 | const struct sctp_endpoint *ep, | |
2270 | const struct sctp_association *asoc, | |
2271 | const sctp_subtype_t type, | |
2272 | void *arg, | |
2273 | sctp_cmd_seq_t *commands) | |
2274 | { | |
2275 | struct sctp_chunk *chunk = arg; | |
2276 | sctp_errhdr_t *err; | |
2277 | ||
2278 | if (!sctp_vtag_verify(chunk, asoc)) | |
2279 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2280 | ||
2281 | /* Make sure that the ERROR chunk has a valid length. | |
2282 | * The parameter walking depends on this as well. | |
2283 | */ | |
2284 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) | |
2285 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2286 | commands); | |
2287 | ||
2288 | /* Process the error here */ | |
2289 | /* FUTURE FIXME: When PR-SCTP related and other optional | |
2290 | * parms are emitted, this will have to change to handle multiple | |
2291 | * errors. | |
2292 | */ | |
2293 | sctp_walk_errors(err, chunk->chunk_hdr) { | |
2294 | if (SCTP_ERROR_STALE_COOKIE == err->cause) | |
2295 | return sctp_sf_do_5_2_6_stale(net, ep, asoc, type, | |
2296 | arg, commands); | |
2297 | } | |
2298 | ||
2299 | /* It is possible to have malformed error causes, and that | |
2300 | * will cause us to end the walk early. However, since | |
2301 | * we are discarding the packet, there should be no adverse | |
2302 | * affects. | |
2303 | */ | |
2304 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2305 | } | |
2306 | ||
2307 | /* | |
2308 | * Handle a Stale COOKIE Error | |
2309 | * | |
2310 | * Section: 5.2.6 Handle Stale COOKIE Error | |
2311 | * If the association is in the COOKIE-ECHOED state, the endpoint may elect | |
2312 | * one of the following three alternatives. | |
2313 | * ... | |
2314 | * 3) Send a new INIT chunk to the endpoint, adding a Cookie | |
2315 | * Preservative parameter requesting an extension to the lifetime of | |
2316 | * the State Cookie. When calculating the time extension, an | |
2317 | * implementation SHOULD use the RTT information measured based on the | |
2318 | * previous COOKIE ECHO / ERROR exchange, and should add no more | |
2319 | * than 1 second beyond the measured RTT, due to long State Cookie | |
2320 | * lifetimes making the endpoint more subject to a replay attack. | |
2321 | * | |
2322 | * Verification Tag: Not explicit, but safe to ignore. | |
2323 | * | |
2324 | * Inputs | |
2325 | * (endpoint, asoc, chunk) | |
2326 | * | |
2327 | * Outputs | |
2328 | * (asoc, reply_msg, msg_up, timers, counters) | |
2329 | * | |
2330 | * The return value is the disposition of the chunk. | |
2331 | */ | |
2332 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net, | |
2333 | const struct sctp_endpoint *ep, | |
2334 | const struct sctp_association *asoc, | |
2335 | const sctp_subtype_t type, | |
2336 | void *arg, | |
2337 | sctp_cmd_seq_t *commands) | |
2338 | { | |
2339 | struct sctp_chunk *chunk = arg; | |
2340 | u32 stale; | |
2341 | sctp_cookie_preserve_param_t bht; | |
2342 | sctp_errhdr_t *err; | |
2343 | struct sctp_chunk *reply; | |
2344 | struct sctp_bind_addr *bp; | |
2345 | int attempts = asoc->init_err_counter + 1; | |
2346 | ||
2347 | if (attempts > asoc->max_init_attempts) { | |
2348 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
2349 | SCTP_ERROR(ETIMEDOUT)); | |
2350 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
2351 | SCTP_PERR(SCTP_ERROR_STALE_COOKIE)); | |
2352 | return SCTP_DISPOSITION_DELETE_TCB; | |
2353 | } | |
2354 | ||
2355 | err = (sctp_errhdr_t *)(chunk->skb->data); | |
2356 | ||
2357 | /* When calculating the time extension, an implementation | |
2358 | * SHOULD use the RTT information measured based on the | |
2359 | * previous COOKIE ECHO / ERROR exchange, and should add no | |
2360 | * more than 1 second beyond the measured RTT, due to long | |
2361 | * State Cookie lifetimes making the endpoint more subject to | |
2362 | * a replay attack. | |
2363 | * Measure of Staleness's unit is usec. (1/1000000 sec) | |
2364 | * Suggested Cookie Life-span Increment's unit is msec. | |
2365 | * (1/1000 sec) | |
2366 | * In general, if you use the suggested cookie life, the value | |
2367 | * found in the field of measure of staleness should be doubled | |
2368 | * to give ample time to retransmit the new cookie and thus | |
2369 | * yield a higher probability of success on the reattempt. | |
2370 | */ | |
2371 | stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t))); | |
2372 | stale = (stale * 2) / 1000; | |
2373 | ||
2374 | bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; | |
2375 | bht.param_hdr.length = htons(sizeof(bht)); | |
2376 | bht.lifespan_increment = htonl(stale); | |
2377 | ||
2378 | /* Build that new INIT chunk. */ | |
2379 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; | |
2380 | reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); | |
2381 | if (!reply) | |
2382 | goto nomem; | |
2383 | ||
2384 | sctp_addto_chunk(reply, sizeof(bht), &bht); | |
2385 | ||
2386 | /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ | |
2387 | sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); | |
2388 | ||
2389 | /* Stop pending T3-rtx and heartbeat timers */ | |
2390 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); | |
2391 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
2392 | ||
2393 | /* Delete non-primary peer ip addresses since we are transitioning | |
2394 | * back to the COOKIE-WAIT state | |
2395 | */ | |
2396 | sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); | |
2397 | ||
2398 | /* If we've sent any data bundled with COOKIE-ECHO we will need to | |
2399 | * resend | |
2400 | */ | |
2401 | sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN, | |
2402 | SCTP_TRANSPORT(asoc->peer.primary_path)); | |
2403 | ||
2404 | /* Cast away the const modifier, as we want to just | |
2405 | * rerun it through as a sideffect. | |
2406 | */ | |
2407 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL()); | |
2408 | ||
2409 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2410 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
2411 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2412 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); | |
2413 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
2414 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
2415 | ||
2416 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
2417 | ||
2418 | return SCTP_DISPOSITION_CONSUME; | |
2419 | ||
2420 | nomem: | |
2421 | return SCTP_DISPOSITION_NOMEM; | |
2422 | } | |
2423 | ||
2424 | /* | |
2425 | * Process an ABORT. | |
2426 | * | |
2427 | * Section: 9.1 | |
2428 | * After checking the Verification Tag, the receiving endpoint shall | |
2429 | * remove the association from its record, and shall report the | |
2430 | * termination to its upper layer. | |
2431 | * | |
2432 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules | |
2433 | * B) Rules for packet carrying ABORT: | |
2434 | * | |
2435 | * - The endpoint shall always fill in the Verification Tag field of the | |
2436 | * outbound packet with the destination endpoint's tag value if it | |
2437 | * is known. | |
2438 | * | |
2439 | * - If the ABORT is sent in response to an OOTB packet, the endpoint | |
2440 | * MUST follow the procedure described in Section 8.4. | |
2441 | * | |
2442 | * - The receiver MUST accept the packet if the Verification Tag | |
2443 | * matches either its own tag, OR the tag of its peer. Otherwise, the | |
2444 | * receiver MUST silently discard the packet and take no further | |
2445 | * action. | |
2446 | * | |
2447 | * Inputs | |
2448 | * (endpoint, asoc, chunk) | |
2449 | * | |
2450 | * Outputs | |
2451 | * (asoc, reply_msg, msg_up, timers, counters) | |
2452 | * | |
2453 | * The return value is the disposition of the chunk. | |
2454 | */ | |
2455 | sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net, | |
2456 | const struct sctp_endpoint *ep, | |
2457 | const struct sctp_association *asoc, | |
2458 | const sctp_subtype_t type, | |
2459 | void *arg, | |
2460 | sctp_cmd_seq_t *commands) | |
2461 | { | |
2462 | struct sctp_chunk *chunk = arg; | |
2463 | ||
2464 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2465 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2466 | ||
2467 | /* Make sure that the ABORT chunk has a valid length. | |
2468 | * Since this is an ABORT chunk, we have to discard it | |
2469 | * because of the following text: | |
2470 | * RFC 2960, Section 3.3.7 | |
2471 | * If an endpoint receives an ABORT with a format error or for an | |
2472 | * association that doesn't exist, it MUST silently discard it. | |
2473 | * Because the length is "invalid", we can't really discard just | |
2474 | * as we do not know its true length. So, to be safe, discard the | |
2475 | * packet. | |
2476 | */ | |
2477 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2478 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2479 | ||
2480 | /* ADD-IP: Special case for ABORT chunks | |
2481 | * F4) One special consideration is that ABORT Chunks arriving | |
2482 | * destined to the IP address being deleted MUST be | |
2483 | * ignored (see Section 5.3.1 for further details). | |
2484 | */ | |
2485 | if (SCTP_ADDR_DEL == | |
2486 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) | |
2487 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
2488 | ||
2489 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); | |
2490 | } | |
2491 | ||
2492 | static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net, | |
2493 | 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 | struct sctp_chunk *chunk = arg; | |
2500 | unsigned int len; | |
2501 | __be16 error = SCTP_ERROR_NO_ERROR; | |
2502 | ||
2503 | /* See if we have an error cause code in the chunk. */ | |
2504 | len = ntohs(chunk->chunk_hdr->length); | |
2505 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) { | |
2506 | ||
2507 | sctp_errhdr_t *err; | |
2508 | sctp_walk_errors(err, chunk->chunk_hdr); | |
2509 | if ((void *)err != (void *)chunk->chunk_end) | |
2510 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2511 | ||
2512 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; | |
2513 | } | |
2514 | ||
2515 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET)); | |
2516 | /* ASSOC_FAILED will DELETE_TCB. */ | |
2517 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error)); | |
2518 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
2519 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
2520 | ||
2521 | return SCTP_DISPOSITION_ABORT; | |
2522 | } | |
2523 | ||
2524 | /* | |
2525 | * Process an ABORT. (COOKIE-WAIT state) | |
2526 | * | |
2527 | * See sctp_sf_do_9_1_abort() above. | |
2528 | */ | |
2529 | sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net, | |
2530 | const struct sctp_endpoint *ep, | |
2531 | const struct sctp_association *asoc, | |
2532 | const sctp_subtype_t type, | |
2533 | void *arg, | |
2534 | sctp_cmd_seq_t *commands) | |
2535 | { | |
2536 | struct sctp_chunk *chunk = arg; | |
2537 | unsigned int len; | |
2538 | __be16 error = SCTP_ERROR_NO_ERROR; | |
2539 | ||
2540 | if (!sctp_vtag_verify_either(chunk, asoc)) | |
2541 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2542 | ||
2543 | /* Make sure that the ABORT chunk has a valid length. | |
2544 | * Since this is an ABORT chunk, we have to discard it | |
2545 | * because of the following text: | |
2546 | * RFC 2960, Section 3.3.7 | |
2547 | * If an endpoint receives an ABORT with a format error or for an | |
2548 | * association that doesn't exist, it MUST silently discard it. | |
2549 | * Because the length is "invalid", we can't really discard just | |
2550 | * as we do not know its true length. So, to be safe, discard the | |
2551 | * packet. | |
2552 | */ | |
2553 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) | |
2554 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2555 | ||
2556 | /* See if we have an error cause code in the chunk. */ | |
2557 | len = ntohs(chunk->chunk_hdr->length); | |
2558 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) | |
2559 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; | |
2560 | ||
2561 | return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc, | |
2562 | chunk->transport); | |
2563 | } | |
2564 | ||
2565 | /* | |
2566 | * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) | |
2567 | */ | |
2568 | sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net, | |
2569 | const struct sctp_endpoint *ep, | |
2570 | const struct sctp_association *asoc, | |
2571 | const sctp_subtype_t type, | |
2572 | void *arg, | |
2573 | sctp_cmd_seq_t *commands) | |
2574 | { | |
2575 | return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR, | |
2576 | ENOPROTOOPT, asoc, | |
2577 | (struct sctp_transport *)arg); | |
2578 | } | |
2579 | ||
2580 | /* | |
2581 | * Process an ABORT. (COOKIE-ECHOED state) | |
2582 | */ | |
2583 | sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net, | |
2584 | const struct sctp_endpoint *ep, | |
2585 | const struct sctp_association *asoc, | |
2586 | const sctp_subtype_t type, | |
2587 | void *arg, | |
2588 | sctp_cmd_seq_t *commands) | |
2589 | { | |
2590 | /* There is a single T1 timer, so we should be able to use | |
2591 | * common function with the COOKIE-WAIT state. | |
2592 | */ | |
2593 | return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands); | |
2594 | } | |
2595 | ||
2596 | /* | |
2597 | * Stop T1 timer and abort association with "INIT failed". | |
2598 | * | |
2599 | * This is common code called by several sctp_sf_*_abort() functions above. | |
2600 | */ | |
2601 | static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net, | |
2602 | sctp_cmd_seq_t *commands, | |
2603 | __be16 error, int sk_err, | |
2604 | const struct sctp_association *asoc, | |
2605 | struct sctp_transport *transport) | |
2606 | { | |
2607 | pr_debug("%s: ABORT received (INIT)\n", __func__); | |
2608 | ||
2609 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2610 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
2611 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
2612 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
2613 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
2614 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err)); | |
2615 | /* CMD_INIT_FAILED will DELETE_TCB. */ | |
2616 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
2617 | SCTP_PERR(error)); | |
2618 | ||
2619 | return SCTP_DISPOSITION_ABORT; | |
2620 | } | |
2621 | ||
2622 | /* | |
2623 | * sctp_sf_do_9_2_shut | |
2624 | * | |
2625 | * Section: 9.2 | |
2626 | * Upon the reception of the SHUTDOWN, the peer endpoint shall | |
2627 | * - enter the SHUTDOWN-RECEIVED state, | |
2628 | * | |
2629 | * - stop accepting new data from its SCTP user | |
2630 | * | |
2631 | * - verify, by checking the Cumulative TSN Ack field of the chunk, | |
2632 | * that all its outstanding DATA chunks have been received by the | |
2633 | * SHUTDOWN sender. | |
2634 | * | |
2635 | * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT | |
2636 | * send a SHUTDOWN in response to a ULP request. And should discard | |
2637 | * subsequent SHUTDOWN chunks. | |
2638 | * | |
2639 | * If there are still outstanding DATA chunks left, the SHUTDOWN | |
2640 | * receiver shall continue to follow normal data transmission | |
2641 | * procedures defined in Section 6 until all outstanding DATA chunks | |
2642 | * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept | |
2643 | * new data from its SCTP user. | |
2644 | * | |
2645 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2646 | * | |
2647 | * Inputs | |
2648 | * (endpoint, asoc, chunk) | |
2649 | * | |
2650 | * Outputs | |
2651 | * (asoc, reply_msg, msg_up, timers, counters) | |
2652 | * | |
2653 | * The return value is the disposition of the chunk. | |
2654 | */ | |
2655 | sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net, | |
2656 | const struct sctp_endpoint *ep, | |
2657 | const struct sctp_association *asoc, | |
2658 | const sctp_subtype_t type, | |
2659 | void *arg, | |
2660 | sctp_cmd_seq_t *commands) | |
2661 | { | |
2662 | struct sctp_chunk *chunk = arg; | |
2663 | sctp_shutdownhdr_t *sdh; | |
2664 | sctp_disposition_t disposition; | |
2665 | struct sctp_ulpevent *ev; | |
2666 | __u32 ctsn; | |
2667 | ||
2668 | if (!sctp_vtag_verify(chunk, asoc)) | |
2669 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2670 | ||
2671 | /* Make sure that the SHUTDOWN chunk has a valid length. */ | |
2672 | if (!sctp_chunk_length_valid(chunk, | |
2673 | sizeof(struct sctp_shutdown_chunk_t))) | |
2674 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2675 | commands); | |
2676 | ||
2677 | /* Convert the elaborate header. */ | |
2678 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; | |
2679 | skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); | |
2680 | chunk->subh.shutdown_hdr = sdh; | |
2681 | ctsn = ntohl(sdh->cum_tsn_ack); | |
2682 | ||
2683 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { | |
2684 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, | |
2685 | asoc->ctsn_ack_point); | |
2686 | ||
2687 | return SCTP_DISPOSITION_DISCARD; | |
2688 | } | |
2689 | ||
2690 | /* If Cumulative TSN Ack beyond the max tsn currently | |
2691 | * send, terminating the association and respond to the | |
2692 | * sender with an ABORT. | |
2693 | */ | |
2694 | if (!TSN_lt(ctsn, asoc->next_tsn)) | |
2695 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); | |
2696 | ||
2697 | /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT | |
2698 | * When a peer sends a SHUTDOWN, SCTP delivers this notification to | |
2699 | * inform the application that it should cease sending data. | |
2700 | */ | |
2701 | ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); | |
2702 | if (!ev) { | |
2703 | disposition = SCTP_DISPOSITION_NOMEM; | |
2704 | goto out; | |
2705 | } | |
2706 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
2707 | ||
2708 | /* Upon the reception of the SHUTDOWN, the peer endpoint shall | |
2709 | * - enter the SHUTDOWN-RECEIVED state, | |
2710 | * - stop accepting new data from its SCTP user | |
2711 | * | |
2712 | * [This is implicit in the new state.] | |
2713 | */ | |
2714 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
2715 | SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); | |
2716 | disposition = SCTP_DISPOSITION_CONSUME; | |
2717 | ||
2718 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
2719 | disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type, | |
2720 | arg, commands); | |
2721 | } | |
2722 | ||
2723 | if (SCTP_DISPOSITION_NOMEM == disposition) | |
2724 | goto out; | |
2725 | ||
2726 | /* - verify, by checking the Cumulative TSN Ack field of the | |
2727 | * chunk, that all its outstanding DATA chunks have been | |
2728 | * received by the SHUTDOWN sender. | |
2729 | */ | |
2730 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, | |
2731 | SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack)); | |
2732 | ||
2733 | out: | |
2734 | return disposition; | |
2735 | } | |
2736 | ||
2737 | /* | |
2738 | * sctp_sf_do_9_2_shut_ctsn | |
2739 | * | |
2740 | * Once an endpoint has reached the SHUTDOWN-RECEIVED state, | |
2741 | * it MUST NOT send a SHUTDOWN in response to a ULP request. | |
2742 | * The Cumulative TSN Ack of the received SHUTDOWN chunk | |
2743 | * MUST be processed. | |
2744 | */ | |
2745 | sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net, | |
2746 | const struct sctp_endpoint *ep, | |
2747 | const struct sctp_association *asoc, | |
2748 | const sctp_subtype_t type, | |
2749 | void *arg, | |
2750 | sctp_cmd_seq_t *commands) | |
2751 | { | |
2752 | struct sctp_chunk *chunk = arg; | |
2753 | sctp_shutdownhdr_t *sdh; | |
2754 | __u32 ctsn; | |
2755 | ||
2756 | if (!sctp_vtag_verify(chunk, asoc)) | |
2757 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2758 | ||
2759 | /* Make sure that the SHUTDOWN chunk has a valid length. */ | |
2760 | if (!sctp_chunk_length_valid(chunk, | |
2761 | sizeof(struct sctp_shutdown_chunk_t))) | |
2762 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2763 | commands); | |
2764 | ||
2765 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; | |
2766 | ctsn = ntohl(sdh->cum_tsn_ack); | |
2767 | ||
2768 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { | |
2769 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, | |
2770 | asoc->ctsn_ack_point); | |
2771 | ||
2772 | return SCTP_DISPOSITION_DISCARD; | |
2773 | } | |
2774 | ||
2775 | /* If Cumulative TSN Ack beyond the max tsn currently | |
2776 | * send, terminating the association and respond to the | |
2777 | * sender with an ABORT. | |
2778 | */ | |
2779 | if (!TSN_lt(ctsn, asoc->next_tsn)) | |
2780 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); | |
2781 | ||
2782 | /* verify, by checking the Cumulative TSN Ack field of the | |
2783 | * chunk, that all its outstanding DATA chunks have been | |
2784 | * received by the SHUTDOWN sender. | |
2785 | */ | |
2786 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, | |
2787 | SCTP_BE32(sdh->cum_tsn_ack)); | |
2788 | ||
2789 | return SCTP_DISPOSITION_CONSUME; | |
2790 | } | |
2791 | ||
2792 | /* RFC 2960 9.2 | |
2793 | * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk | |
2794 | * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination | |
2795 | * transport addresses (either in the IP addresses or in the INIT chunk) | |
2796 | * that belong to this association, it should discard the INIT chunk and | |
2797 | * retransmit the SHUTDOWN ACK chunk. | |
2798 | */ | |
2799 | sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net, | |
2800 | const struct sctp_endpoint *ep, | |
2801 | const struct sctp_association *asoc, | |
2802 | const sctp_subtype_t type, | |
2803 | void *arg, | |
2804 | sctp_cmd_seq_t *commands) | |
2805 | { | |
2806 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; | |
2807 | struct sctp_chunk *reply; | |
2808 | ||
2809 | /* Make sure that the chunk has a valid length */ | |
2810 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
2811 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2812 | commands); | |
2813 | ||
2814 | /* Since we are not going to really process this INIT, there | |
2815 | * is no point in verifying chunk boundries. Just generate | |
2816 | * the SHUTDOWN ACK. | |
2817 | */ | |
2818 | reply = sctp_make_shutdown_ack(asoc, chunk); | |
2819 | if (NULL == reply) | |
2820 | goto nomem; | |
2821 | ||
2822 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for | |
2823 | * the T2-SHUTDOWN timer. | |
2824 | */ | |
2825 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
2826 | ||
2827 | /* and restart the T2-shutdown timer. */ | |
2828 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
2829 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
2830 | ||
2831 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
2832 | ||
2833 | return SCTP_DISPOSITION_CONSUME; | |
2834 | nomem: | |
2835 | return SCTP_DISPOSITION_NOMEM; | |
2836 | } | |
2837 | ||
2838 | /* | |
2839 | * sctp_sf_do_ecn_cwr | |
2840 | * | |
2841 | * Section: Appendix A: Explicit Congestion Notification | |
2842 | * | |
2843 | * CWR: | |
2844 | * | |
2845 | * RFC 2481 details a specific bit for a sender to send in the header of | |
2846 | * its next outbound TCP segment to indicate to its peer that it has | |
2847 | * reduced its congestion window. This is termed the CWR bit. For | |
2848 | * SCTP the same indication is made by including the CWR chunk. | |
2849 | * This chunk contains one data element, i.e. the TSN number that | |
2850 | * was sent in the ECNE chunk. This element represents the lowest | |
2851 | * TSN number in the datagram that was originally marked with the | |
2852 | * CE bit. | |
2853 | * | |
2854 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2855 | * Inputs | |
2856 | * (endpoint, asoc, chunk) | |
2857 | * | |
2858 | * Outputs | |
2859 | * (asoc, reply_msg, msg_up, timers, counters) | |
2860 | * | |
2861 | * The return value is the disposition of the chunk. | |
2862 | */ | |
2863 | sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net, | |
2864 | const struct sctp_endpoint *ep, | |
2865 | const struct sctp_association *asoc, | |
2866 | const sctp_subtype_t type, | |
2867 | void *arg, | |
2868 | sctp_cmd_seq_t *commands) | |
2869 | { | |
2870 | sctp_cwrhdr_t *cwr; | |
2871 | struct sctp_chunk *chunk = arg; | |
2872 | u32 lowest_tsn; | |
2873 | ||
2874 | if (!sctp_vtag_verify(chunk, asoc)) | |
2875 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2876 | ||
2877 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) | |
2878 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2879 | commands); | |
2880 | ||
2881 | cwr = (sctp_cwrhdr_t *) chunk->skb->data; | |
2882 | skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t)); | |
2883 | ||
2884 | lowest_tsn = ntohl(cwr->lowest_tsn); | |
2885 | ||
2886 | /* Does this CWR ack the last sent congestion notification? */ | |
2887 | if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) { | |
2888 | /* Stop sending ECNE. */ | |
2889 | sctp_add_cmd_sf(commands, | |
2890 | SCTP_CMD_ECN_CWR, | |
2891 | SCTP_U32(lowest_tsn)); | |
2892 | } | |
2893 | return SCTP_DISPOSITION_CONSUME; | |
2894 | } | |
2895 | ||
2896 | /* | |
2897 | * sctp_sf_do_ecne | |
2898 | * | |
2899 | * Section: Appendix A: Explicit Congestion Notification | |
2900 | * | |
2901 | * ECN-Echo | |
2902 | * | |
2903 | * RFC 2481 details a specific bit for a receiver to send back in its | |
2904 | * TCP acknowledgements to notify the sender of the Congestion | |
2905 | * Experienced (CE) bit having arrived from the network. For SCTP this | |
2906 | * same indication is made by including the ECNE chunk. This chunk | |
2907 | * contains one data element, i.e. the lowest TSN associated with the IP | |
2908 | * datagram marked with the CE bit..... | |
2909 | * | |
2910 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2911 | * Inputs | |
2912 | * (endpoint, asoc, chunk) | |
2913 | * | |
2914 | * Outputs | |
2915 | * (asoc, reply_msg, msg_up, timers, counters) | |
2916 | * | |
2917 | * The return value is the disposition of the chunk. | |
2918 | */ | |
2919 | sctp_disposition_t sctp_sf_do_ecne(struct net *net, | |
2920 | const struct sctp_endpoint *ep, | |
2921 | const struct sctp_association *asoc, | |
2922 | const sctp_subtype_t type, | |
2923 | void *arg, | |
2924 | sctp_cmd_seq_t *commands) | |
2925 | { | |
2926 | sctp_ecnehdr_t *ecne; | |
2927 | struct sctp_chunk *chunk = arg; | |
2928 | ||
2929 | if (!sctp_vtag_verify(chunk, asoc)) | |
2930 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2931 | ||
2932 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) | |
2933 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2934 | commands); | |
2935 | ||
2936 | ecne = (sctp_ecnehdr_t *) chunk->skb->data; | |
2937 | skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t)); | |
2938 | ||
2939 | /* If this is a newer ECNE than the last CWR packet we sent out */ | |
2940 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, | |
2941 | SCTP_U32(ntohl(ecne->lowest_tsn))); | |
2942 | ||
2943 | return SCTP_DISPOSITION_CONSUME; | |
2944 | } | |
2945 | ||
2946 | /* | |
2947 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks | |
2948 | * | |
2949 | * The SCTP endpoint MUST always acknowledge the reception of each valid | |
2950 | * DATA chunk. | |
2951 | * | |
2952 | * The guidelines on delayed acknowledgement algorithm specified in | |
2953 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an | |
2954 | * acknowledgement SHOULD be generated for at least every second packet | |
2955 | * (not every second DATA chunk) received, and SHOULD be generated within | |
2956 | * 200 ms of the arrival of any unacknowledged DATA chunk. In some | |
2957 | * situations it may be beneficial for an SCTP transmitter to be more | |
2958 | * conservative than the algorithms detailed in this document allow. | |
2959 | * However, an SCTP transmitter MUST NOT be more aggressive than the | |
2960 | * following algorithms allow. | |
2961 | * | |
2962 | * A SCTP receiver MUST NOT generate more than one SACK for every | |
2963 | * incoming packet, other than to update the offered window as the | |
2964 | * receiving application consumes new data. | |
2965 | * | |
2966 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
2967 | * | |
2968 | * Inputs | |
2969 | * (endpoint, asoc, chunk) | |
2970 | * | |
2971 | * Outputs | |
2972 | * (asoc, reply_msg, msg_up, timers, counters) | |
2973 | * | |
2974 | * The return value is the disposition of the chunk. | |
2975 | */ | |
2976 | sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net, | |
2977 | const struct sctp_endpoint *ep, | |
2978 | const struct sctp_association *asoc, | |
2979 | const sctp_subtype_t type, | |
2980 | void *arg, | |
2981 | sctp_cmd_seq_t *commands) | |
2982 | { | |
2983 | struct sctp_chunk *chunk = arg; | |
2984 | sctp_arg_t force = SCTP_NOFORCE(); | |
2985 | int error; | |
2986 | ||
2987 | if (!sctp_vtag_verify(chunk, asoc)) { | |
2988 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
2989 | SCTP_NULL()); | |
2990 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
2991 | } | |
2992 | ||
2993 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_data_chunk))) | |
2994 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
2995 | commands); | |
2996 | ||
2997 | error = sctp_eat_data(asoc, chunk, commands); | |
2998 | switch (error) { | |
2999 | case SCTP_IERROR_NO_ERROR: | |
3000 | break; | |
3001 | case SCTP_IERROR_HIGH_TSN: | |
3002 | case SCTP_IERROR_BAD_STREAM: | |
3003 | SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); | |
3004 | goto discard_noforce; | |
3005 | case SCTP_IERROR_DUP_TSN: | |
3006 | case SCTP_IERROR_IGNORE_TSN: | |
3007 | SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); | |
3008 | goto discard_force; | |
3009 | case SCTP_IERROR_NO_DATA: | |
3010 | return SCTP_DISPOSITION_ABORT; | |
3011 | case SCTP_IERROR_PROTO_VIOLATION: | |
3012 | return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, | |
3013 | (u8 *)chunk->subh.data_hdr, | |
3014 | sizeof(struct sctp_datahdr)); | |
3015 | default: | |
3016 | BUG(); | |
3017 | } | |
3018 | ||
3019 | if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM) | |
3020 | force = SCTP_FORCE(); | |
3021 | ||
3022 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { | |
3023 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3024 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
3025 | } | |
3026 | ||
3027 | /* If this is the last chunk in a packet, we need to count it | |
3028 | * toward sack generation. Note that we need to SACK every | |
3029 | * OTHER packet containing data chunks, EVEN IF WE DISCARD | |
3030 | * THEM. We elect to NOT generate SACK's if the chunk fails | |
3031 | * the verification tag test. | |
3032 | * | |
3033 | * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks | |
3034 | * | |
3035 | * The SCTP endpoint MUST always acknowledge the reception of | |
3036 | * each valid DATA chunk. | |
3037 | * | |
3038 | * The guidelines on delayed acknowledgement algorithm | |
3039 | * specified in Section 4.2 of [RFC2581] SHOULD be followed. | |
3040 | * Specifically, an acknowledgement SHOULD be generated for at | |
3041 | * least every second packet (not every second DATA chunk) | |
3042 | * received, and SHOULD be generated within 200 ms of the | |
3043 | * arrival of any unacknowledged DATA chunk. In some | |
3044 | * situations it may be beneficial for an SCTP transmitter to | |
3045 | * be more conservative than the algorithms detailed in this | |
3046 | * document allow. However, an SCTP transmitter MUST NOT be | |
3047 | * more aggressive than the following algorithms allow. | |
3048 | */ | |
3049 | if (chunk->end_of_packet) | |
3050 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); | |
3051 | ||
3052 | return SCTP_DISPOSITION_CONSUME; | |
3053 | ||
3054 | discard_force: | |
3055 | /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks | |
3056 | * | |
3057 | * When a packet arrives with duplicate DATA chunk(s) and with | |
3058 | * no new DATA chunk(s), the endpoint MUST immediately send a | |
3059 | * SACK with no delay. If a packet arrives with duplicate | |
3060 | * DATA chunk(s) bundled with new DATA chunks, the endpoint | |
3061 | * MAY immediately send a SACK. Normally receipt of duplicate | |
3062 | * DATA chunks will occur when the original SACK chunk was lost | |
3063 | * and the peer's RTO has expired. The duplicate TSN number(s) | |
3064 | * SHOULD be reported in the SACK as duplicate. | |
3065 | */ | |
3066 | /* In our case, we split the MAY SACK advice up whether or not | |
3067 | * the last chunk is a duplicate.' | |
3068 | */ | |
3069 | if (chunk->end_of_packet) | |
3070 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
3071 | return SCTP_DISPOSITION_DISCARD; | |
3072 | ||
3073 | discard_noforce: | |
3074 | if (chunk->end_of_packet) | |
3075 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); | |
3076 | ||
3077 | return SCTP_DISPOSITION_DISCARD; | |
3078 | } | |
3079 | ||
3080 | /* | |
3081 | * sctp_sf_eat_data_fast_4_4 | |
3082 | * | |
3083 | * Section: 4 (4) | |
3084 | * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received | |
3085 | * DATA chunks without delay. | |
3086 | * | |
3087 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
3088 | * Inputs | |
3089 | * (endpoint, asoc, chunk) | |
3090 | * | |
3091 | * Outputs | |
3092 | * (asoc, reply_msg, msg_up, timers, counters) | |
3093 | * | |
3094 | * The return value is the disposition of the chunk. | |
3095 | */ | |
3096 | sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net, | |
3097 | const struct sctp_endpoint *ep, | |
3098 | const struct sctp_association *asoc, | |
3099 | const sctp_subtype_t type, | |
3100 | void *arg, | |
3101 | sctp_cmd_seq_t *commands) | |
3102 | { | |
3103 | struct sctp_chunk *chunk = arg; | |
3104 | int error; | |
3105 | ||
3106 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3107 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3108 | SCTP_NULL()); | |
3109 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3110 | } | |
3111 | ||
3112 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_data_chunk))) | |
3113 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3114 | commands); | |
3115 | ||
3116 | error = sctp_eat_data(asoc, chunk, commands); | |
3117 | switch (error) { | |
3118 | case SCTP_IERROR_NO_ERROR: | |
3119 | case SCTP_IERROR_HIGH_TSN: | |
3120 | case SCTP_IERROR_DUP_TSN: | |
3121 | case SCTP_IERROR_IGNORE_TSN: | |
3122 | case SCTP_IERROR_BAD_STREAM: | |
3123 | break; | |
3124 | case SCTP_IERROR_NO_DATA: | |
3125 | return SCTP_DISPOSITION_ABORT; | |
3126 | case SCTP_IERROR_PROTO_VIOLATION: | |
3127 | return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, | |
3128 | (u8 *)chunk->subh.data_hdr, | |
3129 | sizeof(struct sctp_datahdr)); | |
3130 | default: | |
3131 | BUG(); | |
3132 | } | |
3133 | ||
3134 | /* Go a head and force a SACK, since we are shutting down. */ | |
3135 | ||
3136 | /* Implementor's Guide. | |
3137 | * | |
3138 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately | |
3139 | * respond to each received packet containing one or more DATA chunk(s) | |
3140 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer | |
3141 | */ | |
3142 | if (chunk->end_of_packet) { | |
3143 | /* We must delay the chunk creation since the cumulative | |
3144 | * TSN has not been updated yet. | |
3145 | */ | |
3146 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); | |
3147 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
3148 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3149 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
3150 | } | |
3151 | ||
3152 | return SCTP_DISPOSITION_CONSUME; | |
3153 | } | |
3154 | ||
3155 | /* | |
3156 | * Section: 6.2 Processing a Received SACK | |
3157 | * D) Any time a SACK arrives, the endpoint performs the following: | |
3158 | * | |
3159 | * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, | |
3160 | * then drop the SACK. Since Cumulative TSN Ack is monotonically | |
3161 | * increasing, a SACK whose Cumulative TSN Ack is less than the | |
3162 | * Cumulative TSN Ack Point indicates an out-of-order SACK. | |
3163 | * | |
3164 | * ii) Set rwnd equal to the newly received a_rwnd minus the number | |
3165 | * of bytes still outstanding after processing the Cumulative TSN Ack | |
3166 | * and the Gap Ack Blocks. | |
3167 | * | |
3168 | * iii) If the SACK is missing a TSN that was previously | |
3169 | * acknowledged via a Gap Ack Block (e.g., the data receiver | |
3170 | * reneged on the data), then mark the corresponding DATA chunk | |
3171 | * as available for retransmit: Mark it as missing for fast | |
3172 | * retransmit as described in Section 7.2.4 and if no retransmit | |
3173 | * timer is running for the destination address to which the DATA | |
3174 | * chunk was originally transmitted, then T3-rtx is started for | |
3175 | * that destination address. | |
3176 | * | |
3177 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
3178 | * | |
3179 | * Inputs | |
3180 | * (endpoint, asoc, chunk) | |
3181 | * | |
3182 | * Outputs | |
3183 | * (asoc, reply_msg, msg_up, timers, counters) | |
3184 | * | |
3185 | * The return value is the disposition of the chunk. | |
3186 | */ | |
3187 | sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net, | |
3188 | const struct sctp_endpoint *ep, | |
3189 | const struct sctp_association *asoc, | |
3190 | const sctp_subtype_t type, | |
3191 | void *arg, | |
3192 | sctp_cmd_seq_t *commands) | |
3193 | { | |
3194 | struct sctp_chunk *chunk = arg; | |
3195 | sctp_sackhdr_t *sackh; | |
3196 | __u32 ctsn; | |
3197 | ||
3198 | if (!sctp_vtag_verify(chunk, asoc)) | |
3199 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3200 | ||
3201 | /* Make sure that the SACK chunk has a valid length. */ | |
3202 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t))) | |
3203 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3204 | commands); | |
3205 | ||
3206 | /* Pull the SACK chunk from the data buffer */ | |
3207 | sackh = sctp_sm_pull_sack(chunk); | |
3208 | /* Was this a bogus SACK? */ | |
3209 | if (!sackh) | |
3210 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3211 | chunk->subh.sack_hdr = sackh; | |
3212 | ctsn = ntohl(sackh->cum_tsn_ack); | |
3213 | ||
3214 | /* i) If Cumulative TSN Ack is less than the Cumulative TSN | |
3215 | * Ack Point, then drop the SACK. Since Cumulative TSN | |
3216 | * Ack is monotonically increasing, a SACK whose | |
3217 | * Cumulative TSN Ack is less than the Cumulative TSN Ack | |
3218 | * Point indicates an out-of-order SACK. | |
3219 | */ | |
3220 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { | |
3221 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, | |
3222 | asoc->ctsn_ack_point); | |
3223 | ||
3224 | return SCTP_DISPOSITION_DISCARD; | |
3225 | } | |
3226 | ||
3227 | /* If Cumulative TSN Ack beyond the max tsn currently | |
3228 | * send, terminating the association and respond to the | |
3229 | * sender with an ABORT. | |
3230 | */ | |
3231 | if (!TSN_lt(ctsn, asoc->next_tsn)) | |
3232 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); | |
3233 | ||
3234 | /* Return this SACK for further processing. */ | |
3235 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk)); | |
3236 | ||
3237 | /* Note: We do the rest of the work on the PROCESS_SACK | |
3238 | * sideeffect. | |
3239 | */ | |
3240 | return SCTP_DISPOSITION_CONSUME; | |
3241 | } | |
3242 | ||
3243 | /* | |
3244 | * Generate an ABORT in response to a packet. | |
3245 | * | |
3246 | * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41 | |
3247 | * | |
3248 | * 8) The receiver should respond to the sender of the OOTB packet with | |
3249 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet | |
3250 | * MUST fill in the Verification Tag field of the outbound packet | |
3251 | * with the value found in the Verification Tag field of the OOTB | |
3252 | * packet and set the T-bit in the Chunk Flags to indicate that the | |
3253 | * Verification Tag is reflected. After sending this ABORT, the | |
3254 | * receiver of the OOTB packet shall discard the OOTB packet and take | |
3255 | * no further action. | |
3256 | * | |
3257 | * Verification Tag: | |
3258 | * | |
3259 | * The return value is the disposition of the chunk. | |
3260 | */ | |
3261 | static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net, | |
3262 | const struct sctp_endpoint *ep, | |
3263 | const struct sctp_association *asoc, | |
3264 | const sctp_subtype_t type, | |
3265 | void *arg, | |
3266 | sctp_cmd_seq_t *commands) | |
3267 | { | |
3268 | struct sctp_packet *packet = NULL; | |
3269 | struct sctp_chunk *chunk = arg; | |
3270 | struct sctp_chunk *abort; | |
3271 | ||
3272 | packet = sctp_ootb_pkt_new(net, asoc, chunk); | |
3273 | if (!packet) | |
3274 | return SCTP_DISPOSITION_NOMEM; | |
3275 | ||
3276 | /* Make an ABORT. The T bit will be set if the asoc | |
3277 | * is NULL. | |
3278 | */ | |
3279 | abort = sctp_make_abort(asoc, chunk, 0); | |
3280 | if (!abort) { | |
3281 | sctp_ootb_pkt_free(packet); | |
3282 | return SCTP_DISPOSITION_NOMEM; | |
3283 | } | |
3284 | ||
3285 | /* Reflect vtag if T-Bit is set */ | |
3286 | if (sctp_test_T_bit(abort)) | |
3287 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); | |
3288 | ||
3289 | /* Set the skb to the belonging sock for accounting. */ | |
3290 | abort->skb->sk = ep->base.sk; | |
3291 | ||
3292 | sctp_packet_append_chunk(packet, abort); | |
3293 | ||
3294 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
3295 | SCTP_PACKET(packet)); | |
3296 | ||
3297 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
3298 | ||
3299 | sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3300 | return SCTP_DISPOSITION_CONSUME; | |
3301 | } | |
3302 | ||
3303 | /* | |
3304 | * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR | |
3305 | * event as ULP notification for each cause included in the chunk. | |
3306 | * | |
3307 | * API 5.3.1.3 - SCTP_REMOTE_ERROR | |
3308 | * | |
3309 | * The return value is the disposition of the chunk. | |
3310 | */ | |
3311 | sctp_disposition_t sctp_sf_operr_notify(struct net *net, | |
3312 | const struct sctp_endpoint *ep, | |
3313 | const struct sctp_association *asoc, | |
3314 | const sctp_subtype_t type, | |
3315 | void *arg, | |
3316 | sctp_cmd_seq_t *commands) | |
3317 | { | |
3318 | struct sctp_chunk *chunk = arg; | |
3319 | sctp_errhdr_t *err; | |
3320 | ||
3321 | if (!sctp_vtag_verify(chunk, asoc)) | |
3322 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3323 | ||
3324 | /* Make sure that the ERROR chunk has a valid length. */ | |
3325 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) | |
3326 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3327 | commands); | |
3328 | sctp_walk_errors(err, chunk->chunk_hdr); | |
3329 | if ((void *)err != (void *)chunk->chunk_end) | |
3330 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, | |
3331 | (void *)err, commands); | |
3332 | ||
3333 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, | |
3334 | SCTP_CHUNK(chunk)); | |
3335 | ||
3336 | return SCTP_DISPOSITION_CONSUME; | |
3337 | } | |
3338 | ||
3339 | /* | |
3340 | * Process an inbound SHUTDOWN ACK. | |
3341 | * | |
3342 | * From Section 9.2: | |
3343 | * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall | |
3344 | * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its | |
3345 | * peer, and remove all record of the association. | |
3346 | * | |
3347 | * The return value is the disposition. | |
3348 | */ | |
3349 | sctp_disposition_t sctp_sf_do_9_2_final(struct net *net, | |
3350 | const struct sctp_endpoint *ep, | |
3351 | const struct sctp_association *asoc, | |
3352 | const sctp_subtype_t type, | |
3353 | void *arg, | |
3354 | sctp_cmd_seq_t *commands) | |
3355 | { | |
3356 | struct sctp_chunk *chunk = arg; | |
3357 | struct sctp_chunk *reply; | |
3358 | struct sctp_ulpevent *ev; | |
3359 | ||
3360 | if (!sctp_vtag_verify(chunk, asoc)) | |
3361 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3362 | ||
3363 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ | |
3364 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
3365 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3366 | commands); | |
3367 | /* 10.2 H) SHUTDOWN COMPLETE notification | |
3368 | * | |
3369 | * When SCTP completes the shutdown procedures (section 9.2) this | |
3370 | * notification is passed to the upper layer. | |
3371 | */ | |
3372 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, | |
3373 | 0, 0, 0, NULL, GFP_ATOMIC); | |
3374 | if (!ev) | |
3375 | goto nomem; | |
3376 | ||
3377 | /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ | |
3378 | reply = sctp_make_shutdown_complete(asoc, chunk); | |
3379 | if (!reply) | |
3380 | goto nomem_chunk; | |
3381 | ||
3382 | /* Do all the commands now (after allocation), so that we | |
3383 | * have consistent state if memory allocation failes | |
3384 | */ | |
3385 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); | |
3386 | ||
3387 | /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall | |
3388 | * stop the T2-shutdown timer, | |
3389 | */ | |
3390 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3391 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
3392 | ||
3393 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3394 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
3395 | ||
3396 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
3397 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
3398 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); | |
3399 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
3400 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
3401 | ||
3402 | /* ...and remove all record of the association. */ | |
3403 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
3404 | return SCTP_DISPOSITION_DELETE_TCB; | |
3405 | ||
3406 | nomem_chunk: | |
3407 | sctp_ulpevent_free(ev); | |
3408 | nomem: | |
3409 | return SCTP_DISPOSITION_NOMEM; | |
3410 | } | |
3411 | ||
3412 | /* | |
3413 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41. | |
3414 | * | |
3415 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should | |
3416 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. | |
3417 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB | |
3418 | * packet must fill in the Verification Tag field of the outbound | |
3419 | * packet with the Verification Tag received in the SHUTDOWN ACK and | |
3420 | * set the T-bit in the Chunk Flags to indicate that the Verification | |
3421 | * Tag is reflected. | |
3422 | * | |
3423 | * 8) The receiver should respond to the sender of the OOTB packet with | |
3424 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet | |
3425 | * MUST fill in the Verification Tag field of the outbound packet | |
3426 | * with the value found in the Verification Tag field of the OOTB | |
3427 | * packet and set the T-bit in the Chunk Flags to indicate that the | |
3428 | * Verification Tag is reflected. After sending this ABORT, the | |
3429 | * receiver of the OOTB packet shall discard the OOTB packet and take | |
3430 | * no further action. | |
3431 | */ | |
3432 | sctp_disposition_t sctp_sf_ootb(struct net *net, | |
3433 | const struct sctp_endpoint *ep, | |
3434 | const struct sctp_association *asoc, | |
3435 | const sctp_subtype_t type, | |
3436 | void *arg, | |
3437 | sctp_cmd_seq_t *commands) | |
3438 | { | |
3439 | struct sctp_chunk *chunk = arg; | |
3440 | struct sk_buff *skb = chunk->skb; | |
3441 | struct sctp_chunkhdr *ch; | |
3442 | sctp_errhdr_t *err; | |
3443 | __u8 *ch_end; | |
3444 | int ootb_shut_ack = 0; | |
3445 | int ootb_cookie_ack = 0; | |
3446 | ||
3447 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); | |
3448 | ||
3449 | ch = (struct sctp_chunkhdr *)chunk->chunk_hdr; | |
3450 | do { | |
3451 | /* Report violation if the chunk is less then minimal */ | |
3452 | if (ntohs(ch->length) < sizeof(*ch)) | |
3453 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3454 | commands); | |
3455 | ||
3456 | /* Report violation if chunk len overflows */ | |
3457 | ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length)); | |
3458 | if (ch_end > skb_tail_pointer(skb)) | |
3459 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3460 | commands); | |
3461 | ||
3462 | /* Now that we know we at least have a chunk header, | |
3463 | * do things that are type appropriate. | |
3464 | */ | |
3465 | if (SCTP_CID_SHUTDOWN_ACK == ch->type) | |
3466 | ootb_shut_ack = 1; | |
3467 | ||
3468 | /* RFC 2960, Section 3.3.7 | |
3469 | * Moreover, under any circumstances, an endpoint that | |
3470 | * receives an ABORT MUST NOT respond to that ABORT by | |
3471 | * sending an ABORT of its own. | |
3472 | */ | |
3473 | if (SCTP_CID_ABORT == ch->type) | |
3474 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3475 | ||
3476 | /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR | |
3477 | * or a COOKIE ACK the SCTP Packet should be silently | |
3478 | * discarded. | |
3479 | */ | |
3480 | ||
3481 | if (SCTP_CID_COOKIE_ACK == ch->type) | |
3482 | ootb_cookie_ack = 1; | |
3483 | ||
3484 | if (SCTP_CID_ERROR == ch->type) { | |
3485 | sctp_walk_errors(err, ch) { | |
3486 | if (SCTP_ERROR_STALE_COOKIE == err->cause) { | |
3487 | ootb_cookie_ack = 1; | |
3488 | break; | |
3489 | } | |
3490 | } | |
3491 | } | |
3492 | ||
3493 | ch = (struct sctp_chunkhdr *)ch_end; | |
3494 | } while (ch_end < skb_tail_pointer(skb)); | |
3495 | ||
3496 | if (ootb_shut_ack) | |
3497 | return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands); | |
3498 | else if (ootb_cookie_ack) | |
3499 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3500 | else | |
3501 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); | |
3502 | } | |
3503 | ||
3504 | /* | |
3505 | * Handle an "Out of the blue" SHUTDOWN ACK. | |
3506 | * | |
3507 | * Section: 8.4 5, sctpimpguide 2.41. | |
3508 | * | |
3509 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should | |
3510 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. | |
3511 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB | |
3512 | * packet must fill in the Verification Tag field of the outbound | |
3513 | * packet with the Verification Tag received in the SHUTDOWN ACK and | |
3514 | * set the T-bit in the Chunk Flags to indicate that the Verification | |
3515 | * Tag is reflected. | |
3516 | * | |
3517 | * Inputs | |
3518 | * (endpoint, asoc, type, arg, commands) | |
3519 | * | |
3520 | * Outputs | |
3521 | * (sctp_disposition_t) | |
3522 | * | |
3523 | * The return value is the disposition of the chunk. | |
3524 | */ | |
3525 | static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net, | |
3526 | const struct sctp_endpoint *ep, | |
3527 | const struct sctp_association *asoc, | |
3528 | const sctp_subtype_t type, | |
3529 | void *arg, | |
3530 | sctp_cmd_seq_t *commands) | |
3531 | { | |
3532 | struct sctp_packet *packet = NULL; | |
3533 | struct sctp_chunk *chunk = arg; | |
3534 | struct sctp_chunk *shut; | |
3535 | ||
3536 | packet = sctp_ootb_pkt_new(net, asoc, chunk); | |
3537 | if (!packet) | |
3538 | return SCTP_DISPOSITION_NOMEM; | |
3539 | ||
3540 | /* Make an SHUTDOWN_COMPLETE. | |
3541 | * The T bit will be set if the asoc is NULL. | |
3542 | */ | |
3543 | shut = sctp_make_shutdown_complete(asoc, chunk); | |
3544 | if (!shut) { | |
3545 | sctp_ootb_pkt_free(packet); | |
3546 | return SCTP_DISPOSITION_NOMEM; | |
3547 | } | |
3548 | ||
3549 | /* Reflect vtag if T-Bit is set */ | |
3550 | if (sctp_test_T_bit(shut)) | |
3551 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); | |
3552 | ||
3553 | /* Set the skb to the belonging sock for accounting. */ | |
3554 | shut->skb->sk = ep->base.sk; | |
3555 | ||
3556 | sctp_packet_append_chunk(packet, shut); | |
3557 | ||
3558 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
3559 | SCTP_PACKET(packet)); | |
3560 | ||
3561 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
3562 | ||
3563 | /* If the chunk length is invalid, we don't want to process | |
3564 | * the reset of the packet. | |
3565 | */ | |
3566 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
3567 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3568 | ||
3569 | /* We need to discard the rest of the packet to prevent | |
3570 | * potential bomming attacks from additional bundled chunks. | |
3571 | * This is documented in SCTP Threats ID. | |
3572 | */ | |
3573 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3574 | } | |
3575 | ||
3576 | /* | |
3577 | * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. | |
3578 | * | |
3579 | * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK | |
3580 | * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the | |
3581 | * procedures in section 8.4 SHOULD be followed, in other words it | |
3582 | * should be treated as an Out Of The Blue packet. | |
3583 | * [This means that we do NOT check the Verification Tag on these | |
3584 | * chunks. --piggy ] | |
3585 | * | |
3586 | */ | |
3587 | sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net, | |
3588 | const struct sctp_endpoint *ep, | |
3589 | const struct sctp_association *asoc, | |
3590 | const sctp_subtype_t type, | |
3591 | void *arg, | |
3592 | sctp_cmd_seq_t *commands) | |
3593 | { | |
3594 | struct sctp_chunk *chunk = arg; | |
3595 | ||
3596 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ | |
3597 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
3598 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3599 | commands); | |
3600 | ||
3601 | /* Although we do have an association in this case, it corresponds | |
3602 | * to a restarted association. So the packet is treated as an OOTB | |
3603 | * packet and the state function that handles OOTB SHUTDOWN_ACK is | |
3604 | * called with a NULL association. | |
3605 | */ | |
3606 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); | |
3607 | ||
3608 | return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands); | |
3609 | } | |
3610 | ||
3611 | /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ | |
3612 | sctp_disposition_t sctp_sf_do_asconf(struct net *net, | |
3613 | const struct sctp_endpoint *ep, | |
3614 | const struct sctp_association *asoc, | |
3615 | const sctp_subtype_t type, void *arg, | |
3616 | sctp_cmd_seq_t *commands) | |
3617 | { | |
3618 | struct sctp_chunk *chunk = arg; | |
3619 | struct sctp_chunk *asconf_ack = NULL; | |
3620 | struct sctp_paramhdr *err_param = NULL; | |
3621 | sctp_addiphdr_t *hdr; | |
3622 | __u32 serial; | |
3623 | ||
3624 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3625 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3626 | SCTP_NULL()); | |
3627 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3628 | } | |
3629 | ||
3630 | /* ADD-IP: Section 4.1.1 | |
3631 | * This chunk MUST be sent in an authenticated way by using | |
3632 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk | |
3633 | * is received unauthenticated it MUST be silently discarded as | |
3634 | * described in [I-D.ietf-tsvwg-sctp-auth]. | |
3635 | */ | |
3636 | if (!net->sctp.addip_noauth && !chunk->auth) | |
3637 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
3638 | ||
3639 | /* Make sure that the ASCONF ADDIP chunk has a valid length. */ | |
3640 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t))) | |
3641 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3642 | commands); | |
3643 | ||
3644 | hdr = (sctp_addiphdr_t *)chunk->skb->data; | |
3645 | serial = ntohl(hdr->serial); | |
3646 | ||
3647 | /* Verify the ASCONF chunk before processing it. */ | |
3648 | if (!sctp_verify_asconf(asoc, chunk, true, &err_param)) | |
3649 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, | |
3650 | (void *)err_param, commands); | |
3651 | ||
3652 | /* ADDIP 5.2 E1) Compare the value of the serial number to the value | |
3653 | * the endpoint stored in a new association variable | |
3654 | * 'Peer-Serial-Number'. | |
3655 | */ | |
3656 | if (serial == asoc->peer.addip_serial + 1) { | |
3657 | /* If this is the first instance of ASCONF in the packet, | |
3658 | * we can clean our old ASCONF-ACKs. | |
3659 | */ | |
3660 | if (!chunk->has_asconf) | |
3661 | sctp_assoc_clean_asconf_ack_cache(asoc); | |
3662 | ||
3663 | /* ADDIP 5.2 E4) When the Sequence Number matches the next one | |
3664 | * expected, process the ASCONF as described below and after | |
3665 | * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to | |
3666 | * the response packet and cache a copy of it (in the event it | |
3667 | * later needs to be retransmitted). | |
3668 | * | |
3669 | * Essentially, do V1-V5. | |
3670 | */ | |
3671 | asconf_ack = sctp_process_asconf((struct sctp_association *) | |
3672 | asoc, chunk); | |
3673 | if (!asconf_ack) | |
3674 | return SCTP_DISPOSITION_NOMEM; | |
3675 | } else if (serial < asoc->peer.addip_serial + 1) { | |
3676 | /* ADDIP 5.2 E2) | |
3677 | * If the value found in the Sequence Number is less than the | |
3678 | * ('Peer- Sequence-Number' + 1), simply skip to the next | |
3679 | * ASCONF, and include in the outbound response packet | |
3680 | * any previously cached ASCONF-ACK response that was | |
3681 | * sent and saved that matches the Sequence Number of the | |
3682 | * ASCONF. Note: It is possible that no cached ASCONF-ACK | |
3683 | * Chunk exists. This will occur when an older ASCONF | |
3684 | * arrives out of order. In such a case, the receiver | |
3685 | * should skip the ASCONF Chunk and not include ASCONF-ACK | |
3686 | * Chunk for that chunk. | |
3687 | */ | |
3688 | asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial); | |
3689 | if (!asconf_ack) | |
3690 | return SCTP_DISPOSITION_DISCARD; | |
3691 | ||
3692 | /* Reset the transport so that we select the correct one | |
3693 | * this time around. This is to make sure that we don't | |
3694 | * accidentally use a stale transport that's been removed. | |
3695 | */ | |
3696 | asconf_ack->transport = NULL; | |
3697 | } else { | |
3698 | /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since | |
3699 | * it must be either a stale packet or from an attacker. | |
3700 | */ | |
3701 | return SCTP_DISPOSITION_DISCARD; | |
3702 | } | |
3703 | ||
3704 | /* ADDIP 5.2 E6) The destination address of the SCTP packet | |
3705 | * containing the ASCONF-ACK Chunks MUST be the source address of | |
3706 | * the SCTP packet that held the ASCONF Chunks. | |
3707 | * | |
3708 | * To do this properly, we'll set the destination address of the chunk | |
3709 | * and at the transmit time, will try look up the transport to use. | |
3710 | * Since ASCONFs may be bundled, the correct transport may not be | |
3711 | * created until we process the entire packet, thus this workaround. | |
3712 | */ | |
3713 | asconf_ack->dest = chunk->source; | |
3714 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); | |
3715 | if (asoc->new_transport) { | |
3716 | sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands); | |
3717 | ((struct sctp_association *)asoc)->new_transport = NULL; | |
3718 | } | |
3719 | ||
3720 | return SCTP_DISPOSITION_CONSUME; | |
3721 | } | |
3722 | ||
3723 | /* | |
3724 | * ADDIP Section 4.3 General rules for address manipulation | |
3725 | * When building TLV parameters for the ASCONF Chunk that will add or | |
3726 | * delete IP addresses the D0 to D13 rules should be applied: | |
3727 | */ | |
3728 | sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net, | |
3729 | const struct sctp_endpoint *ep, | |
3730 | const struct sctp_association *asoc, | |
3731 | const sctp_subtype_t type, void *arg, | |
3732 | sctp_cmd_seq_t *commands) | |
3733 | { | |
3734 | struct sctp_chunk *asconf_ack = arg; | |
3735 | struct sctp_chunk *last_asconf = asoc->addip_last_asconf; | |
3736 | struct sctp_chunk *abort; | |
3737 | struct sctp_paramhdr *err_param = NULL; | |
3738 | sctp_addiphdr_t *addip_hdr; | |
3739 | __u32 sent_serial, rcvd_serial; | |
3740 | ||
3741 | if (!sctp_vtag_verify(asconf_ack, asoc)) { | |
3742 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3743 | SCTP_NULL()); | |
3744 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3745 | } | |
3746 | ||
3747 | /* ADD-IP, Section 4.1.2: | |
3748 | * This chunk MUST be sent in an authenticated way by using | |
3749 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk | |
3750 | * is received unauthenticated it MUST be silently discarded as | |
3751 | * described in [I-D.ietf-tsvwg-sctp-auth]. | |
3752 | */ | |
3753 | if (!net->sctp.addip_noauth && !asconf_ack->auth) | |
3754 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); | |
3755 | ||
3756 | /* Make sure that the ADDIP chunk has a valid length. */ | |
3757 | if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t))) | |
3758 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3759 | commands); | |
3760 | ||
3761 | addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data; | |
3762 | rcvd_serial = ntohl(addip_hdr->serial); | |
3763 | ||
3764 | /* Verify the ASCONF-ACK chunk before processing it. */ | |
3765 | if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param)) | |
3766 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, | |
3767 | (void *)err_param, commands); | |
3768 | ||
3769 | if (last_asconf) { | |
3770 | addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr; | |
3771 | sent_serial = ntohl(addip_hdr->serial); | |
3772 | } else { | |
3773 | sent_serial = asoc->addip_serial - 1; | |
3774 | } | |
3775 | ||
3776 | /* D0) If an endpoint receives an ASCONF-ACK that is greater than or | |
3777 | * equal to the next serial number to be used but no ASCONF chunk is | |
3778 | * outstanding the endpoint MUST ABORT the association. Note that a | |
3779 | * sequence number is greater than if it is no more than 2^^31-1 | |
3780 | * larger than the current sequence number (using serial arithmetic). | |
3781 | */ | |
3782 | if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && | |
3783 | !(asoc->addip_last_asconf)) { | |
3784 | abort = sctp_make_abort(asoc, asconf_ack, | |
3785 | sizeof(sctp_errhdr_t)); | |
3786 | if (abort) { | |
3787 | sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0); | |
3788 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3789 | SCTP_CHUNK(abort)); | |
3790 | } | |
3791 | /* We are going to ABORT, so we might as well stop | |
3792 | * processing the rest of the chunks in the packet. | |
3793 | */ | |
3794 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3795 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
3796 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
3797 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
3798 | SCTP_ERROR(ECONNABORTED)); | |
3799 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
3800 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); | |
3801 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
3802 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
3803 | return SCTP_DISPOSITION_ABORT; | |
3804 | } | |
3805 | ||
3806 | if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { | |
3807 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
3808 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
3809 | ||
3810 | if (!sctp_process_asconf_ack((struct sctp_association *)asoc, | |
3811 | asconf_ack)) { | |
3812 | /* Successfully processed ASCONF_ACK. We can | |
3813 | * release the next asconf if we have one. | |
3814 | */ | |
3815 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF, | |
3816 | SCTP_NULL()); | |
3817 | return SCTP_DISPOSITION_CONSUME; | |
3818 | } | |
3819 | ||
3820 | abort = sctp_make_abort(asoc, asconf_ack, | |
3821 | sizeof(sctp_errhdr_t)); | |
3822 | if (abort) { | |
3823 | sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); | |
3824 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3825 | SCTP_CHUNK(abort)); | |
3826 | } | |
3827 | /* We are going to ABORT, so we might as well stop | |
3828 | * processing the rest of the chunks in the packet. | |
3829 | */ | |
3830 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
3831 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
3832 | SCTP_ERROR(ECONNABORTED)); | |
3833 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
3834 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); | |
3835 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
3836 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
3837 | return SCTP_DISPOSITION_ABORT; | |
3838 | } | |
3839 | ||
3840 | return SCTP_DISPOSITION_DISCARD; | |
3841 | } | |
3842 | ||
3843 | /* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */ | |
3844 | sctp_disposition_t sctp_sf_do_reconf(struct net *net, | |
3845 | const struct sctp_endpoint *ep, | |
3846 | const struct sctp_association *asoc, | |
3847 | const sctp_subtype_t type, void *arg, | |
3848 | sctp_cmd_seq_t *commands) | |
3849 | { | |
3850 | struct sctp_paramhdr *err_param = NULL; | |
3851 | struct sctp_chunk *chunk = arg; | |
3852 | struct sctp_reconf_chunk *hdr; | |
3853 | union sctp_params param; | |
3854 | ||
3855 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3856 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3857 | SCTP_NULL()); | |
3858 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3859 | } | |
3860 | ||
3861 | /* Make sure that the RECONF chunk has a valid length. */ | |
3862 | if (!sctp_chunk_length_valid(chunk, sizeof(*hdr))) | |
3863 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3864 | commands); | |
3865 | ||
3866 | if (!sctp_verify_reconf(asoc, chunk, &err_param)) | |
3867 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, | |
3868 | (void *)err_param, commands); | |
3869 | ||
3870 | hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; | |
3871 | sctp_walk_params(param, hdr, params) { | |
3872 | struct sctp_chunk *reply = NULL; | |
3873 | struct sctp_ulpevent *ev = NULL; | |
3874 | ||
3875 | if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST) | |
3876 | reply = sctp_process_strreset_outreq( | |
3877 | (struct sctp_association *)asoc, param, &ev); | |
3878 | else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST) | |
3879 | reply = sctp_process_strreset_inreq( | |
3880 | (struct sctp_association *)asoc, param, &ev); | |
3881 | else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST) | |
3882 | reply = sctp_process_strreset_tsnreq( | |
3883 | (struct sctp_association *)asoc, param, &ev); | |
3884 | else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) | |
3885 | reply = sctp_process_strreset_addstrm_out( | |
3886 | (struct sctp_association *)asoc, param, &ev); | |
3887 | else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) | |
3888 | reply = sctp_process_strreset_addstrm_in( | |
3889 | (struct sctp_association *)asoc, param, &ev); | |
3890 | else if (param.p->type == SCTP_PARAM_RESET_RESPONSE) | |
3891 | reply = sctp_process_strreset_resp( | |
3892 | (struct sctp_association *)asoc, param, &ev); | |
3893 | ||
3894 | if (ev) | |
3895 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
3896 | SCTP_ULPEVENT(ev)); | |
3897 | ||
3898 | if (reply) | |
3899 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
3900 | SCTP_CHUNK(reply)); | |
3901 | } | |
3902 | ||
3903 | return SCTP_DISPOSITION_CONSUME; | |
3904 | } | |
3905 | ||
3906 | /* | |
3907 | * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP | |
3908 | * | |
3909 | * When a FORWARD TSN chunk arrives, the data receiver MUST first update | |
3910 | * its cumulative TSN point to the value carried in the FORWARD TSN | |
3911 | * chunk, and then MUST further advance its cumulative TSN point locally | |
3912 | * if possible. | |
3913 | * After the above processing, the data receiver MUST stop reporting any | |
3914 | * missing TSNs earlier than or equal to the new cumulative TSN point. | |
3915 | * | |
3916 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
3917 | * | |
3918 | * The return value is the disposition of the chunk. | |
3919 | */ | |
3920 | sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net, | |
3921 | const struct sctp_endpoint *ep, | |
3922 | const struct sctp_association *asoc, | |
3923 | const sctp_subtype_t type, | |
3924 | void *arg, | |
3925 | sctp_cmd_seq_t *commands) | |
3926 | { | |
3927 | struct sctp_chunk *chunk = arg; | |
3928 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; | |
3929 | struct sctp_fwdtsn_skip *skip; | |
3930 | __u16 len; | |
3931 | __u32 tsn; | |
3932 | ||
3933 | if (!sctp_vtag_verify(chunk, asoc)) { | |
3934 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
3935 | SCTP_NULL()); | |
3936 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
3937 | } | |
3938 | ||
3939 | if (!asoc->peer.prsctp_capable) | |
3940 | return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); | |
3941 | ||
3942 | /* Make sure that the FORWARD_TSN chunk has valid length. */ | |
3943 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) | |
3944 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
3945 | commands); | |
3946 | ||
3947 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; | |
3948 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; | |
3949 | len = ntohs(chunk->chunk_hdr->length); | |
3950 | len -= sizeof(struct sctp_chunkhdr); | |
3951 | skb_pull(chunk->skb, len); | |
3952 | ||
3953 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); | |
3954 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); | |
3955 | ||
3956 | /* The TSN is too high--silently discard the chunk and count on it | |
3957 | * getting retransmitted later. | |
3958 | */ | |
3959 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) | |
3960 | goto discard_noforce; | |
3961 | ||
3962 | /* Silently discard the chunk if stream-id is not valid */ | |
3963 | sctp_walk_fwdtsn(skip, chunk) { | |
3964 | if (ntohs(skip->stream) >= asoc->stream.incnt) | |
3965 | goto discard_noforce; | |
3966 | } | |
3967 | ||
3968 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); | |
3969 | if (len > sizeof(struct sctp_fwdtsn_hdr)) | |
3970 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, | |
3971 | SCTP_CHUNK(chunk)); | |
3972 | ||
3973 | /* Count this as receiving DATA. */ | |
3974 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { | |
3975 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
3976 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
3977 | } | |
3978 | ||
3979 | /* FIXME: For now send a SACK, but DATA processing may | |
3980 | * send another. | |
3981 | */ | |
3982 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); | |
3983 | ||
3984 | return SCTP_DISPOSITION_CONSUME; | |
3985 | ||
3986 | discard_noforce: | |
3987 | return SCTP_DISPOSITION_DISCARD; | |
3988 | } | |
3989 | ||
3990 | sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( | |
3991 | struct net *net, | |
3992 | const struct sctp_endpoint *ep, | |
3993 | const struct sctp_association *asoc, | |
3994 | const sctp_subtype_t type, | |
3995 | void *arg, | |
3996 | sctp_cmd_seq_t *commands) | |
3997 | { | |
3998 | struct sctp_chunk *chunk = arg; | |
3999 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; | |
4000 | struct sctp_fwdtsn_skip *skip; | |
4001 | __u16 len; | |
4002 | __u32 tsn; | |
4003 | ||
4004 | if (!sctp_vtag_verify(chunk, asoc)) { | |
4005 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
4006 | SCTP_NULL()); | |
4007 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4008 | } | |
4009 | ||
4010 | if (!asoc->peer.prsctp_capable) | |
4011 | return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); | |
4012 | ||
4013 | /* Make sure that the FORWARD_TSN chunk has a valid length. */ | |
4014 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) | |
4015 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4016 | commands); | |
4017 | ||
4018 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; | |
4019 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; | |
4020 | len = ntohs(chunk->chunk_hdr->length); | |
4021 | len -= sizeof(struct sctp_chunkhdr); | |
4022 | skb_pull(chunk->skb, len); | |
4023 | ||
4024 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); | |
4025 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); | |
4026 | ||
4027 | /* The TSN is too high--silently discard the chunk and count on it | |
4028 | * getting retransmitted later. | |
4029 | */ | |
4030 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) | |
4031 | goto gen_shutdown; | |
4032 | ||
4033 | /* Silently discard the chunk if stream-id is not valid */ | |
4034 | sctp_walk_fwdtsn(skip, chunk) { | |
4035 | if (ntohs(skip->stream) >= asoc->stream.incnt) | |
4036 | goto gen_shutdown; | |
4037 | } | |
4038 | ||
4039 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); | |
4040 | if (len > sizeof(struct sctp_fwdtsn_hdr)) | |
4041 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, | |
4042 | SCTP_CHUNK(chunk)); | |
4043 | ||
4044 | /* Go a head and force a SACK, since we are shutting down. */ | |
4045 | gen_shutdown: | |
4046 | /* Implementor's Guide. | |
4047 | * | |
4048 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately | |
4049 | * respond to each received packet containing one or more DATA chunk(s) | |
4050 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer | |
4051 | */ | |
4052 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); | |
4053 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
4054 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
4055 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
4056 | ||
4057 | return SCTP_DISPOSITION_CONSUME; | |
4058 | } | |
4059 | ||
4060 | /* | |
4061 | * SCTP-AUTH Section 6.3 Receiving authenticated chukns | |
4062 | * | |
4063 | * The receiver MUST use the HMAC algorithm indicated in the HMAC | |
4064 | * Identifier field. If this algorithm was not specified by the | |
4065 | * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk | |
4066 | * during association setup, the AUTH chunk and all chunks after it MUST | |
4067 | * be discarded and an ERROR chunk SHOULD be sent with the error cause | |
4068 | * defined in Section 4.1. | |
4069 | * | |
4070 | * If an endpoint with no shared key receives a Shared Key Identifier | |
4071 | * other than 0, it MUST silently discard all authenticated chunks. If | |
4072 | * the endpoint has at least one endpoint pair shared key for the peer, | |
4073 | * it MUST use the key specified by the Shared Key Identifier if a | |
4074 | * key has been configured for that Shared Key Identifier. If no | |
4075 | * endpoint pair shared key has been configured for that Shared Key | |
4076 | * Identifier, all authenticated chunks MUST be silently discarded. | |
4077 | * | |
4078 | * Verification Tag: 8.5 Verification Tag [Normal verification] | |
4079 | * | |
4080 | * The return value is the disposition of the chunk. | |
4081 | */ | |
4082 | static sctp_ierror_t sctp_sf_authenticate(struct net *net, | |
4083 | const struct sctp_endpoint *ep, | |
4084 | const struct sctp_association *asoc, | |
4085 | const sctp_subtype_t type, | |
4086 | struct sctp_chunk *chunk) | |
4087 | { | |
4088 | struct sctp_authhdr *auth_hdr; | |
4089 | struct sctp_hmac *hmac; | |
4090 | unsigned int sig_len; | |
4091 | __u16 key_id; | |
4092 | __u8 *save_digest; | |
4093 | __u8 *digest; | |
4094 | ||
4095 | /* Pull in the auth header, so we can do some more verification */ | |
4096 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; | |
4097 | chunk->subh.auth_hdr = auth_hdr; | |
4098 | skb_pull(chunk->skb, sizeof(struct sctp_authhdr)); | |
4099 | ||
4100 | /* Make sure that we support the HMAC algorithm from the auth | |
4101 | * chunk. | |
4102 | */ | |
4103 | if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id)) | |
4104 | return SCTP_IERROR_AUTH_BAD_HMAC; | |
4105 | ||
4106 | /* Make sure that the provided shared key identifier has been | |
4107 | * configured | |
4108 | */ | |
4109 | key_id = ntohs(auth_hdr->shkey_id); | |
4110 | if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id)) | |
4111 | return SCTP_IERROR_AUTH_BAD_KEYID; | |
4112 | ||
4113 | ||
4114 | /* Make sure that the length of the signature matches what | |
4115 | * we expect. | |
4116 | */ | |
4117 | sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t); | |
4118 | hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id)); | |
4119 | if (sig_len != hmac->hmac_len) | |
4120 | return SCTP_IERROR_PROTO_VIOLATION; | |
4121 | ||
4122 | /* Now that we've done validation checks, we can compute and | |
4123 | * verify the hmac. The steps involved are: | |
4124 | * 1. Save the digest from the chunk. | |
4125 | * 2. Zero out the digest in the chunk. | |
4126 | * 3. Compute the new digest | |
4127 | * 4. Compare saved and new digests. | |
4128 | */ | |
4129 | digest = auth_hdr->hmac; | |
4130 | skb_pull(chunk->skb, sig_len); | |
4131 | ||
4132 | save_digest = kmemdup(digest, sig_len, GFP_ATOMIC); | |
4133 | if (!save_digest) | |
4134 | goto nomem; | |
4135 | ||
4136 | memset(digest, 0, sig_len); | |
4137 | ||
4138 | sctp_auth_calculate_hmac(asoc, chunk->skb, | |
4139 | (struct sctp_auth_chunk *)chunk->chunk_hdr, | |
4140 | GFP_ATOMIC); | |
4141 | ||
4142 | /* Discard the packet if the digests do not match */ | |
4143 | if (memcmp(save_digest, digest, sig_len)) { | |
4144 | kfree(save_digest); | |
4145 | return SCTP_IERROR_BAD_SIG; | |
4146 | } | |
4147 | ||
4148 | kfree(save_digest); | |
4149 | chunk->auth = 1; | |
4150 | ||
4151 | return SCTP_IERROR_NO_ERROR; | |
4152 | nomem: | |
4153 | return SCTP_IERROR_NOMEM; | |
4154 | } | |
4155 | ||
4156 | sctp_disposition_t sctp_sf_eat_auth(struct net *net, | |
4157 | const struct sctp_endpoint *ep, | |
4158 | const struct sctp_association *asoc, | |
4159 | const sctp_subtype_t type, | |
4160 | void *arg, | |
4161 | sctp_cmd_seq_t *commands) | |
4162 | { | |
4163 | struct sctp_authhdr *auth_hdr; | |
4164 | struct sctp_chunk *chunk = arg; | |
4165 | struct sctp_chunk *err_chunk; | |
4166 | sctp_ierror_t error; | |
4167 | ||
4168 | /* Make sure that the peer has AUTH capable */ | |
4169 | if (!asoc->peer.auth_capable) | |
4170 | return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); | |
4171 | ||
4172 | if (!sctp_vtag_verify(chunk, asoc)) { | |
4173 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, | |
4174 | SCTP_NULL()); | |
4175 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4176 | } | |
4177 | ||
4178 | /* Make sure that the AUTH chunk has valid length. */ | |
4179 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk))) | |
4180 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4181 | commands); | |
4182 | ||
4183 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; | |
4184 | error = sctp_sf_authenticate(net, ep, asoc, type, chunk); | |
4185 | switch (error) { | |
4186 | case SCTP_IERROR_AUTH_BAD_HMAC: | |
4187 | /* Generate the ERROR chunk and discard the rest | |
4188 | * of the packet | |
4189 | */ | |
4190 | err_chunk = sctp_make_op_error(asoc, chunk, | |
4191 | SCTP_ERROR_UNSUP_HMAC, | |
4192 | &auth_hdr->hmac_id, | |
4193 | sizeof(__u16), 0); | |
4194 | if (err_chunk) { | |
4195 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
4196 | SCTP_CHUNK(err_chunk)); | |
4197 | } | |
4198 | /* Fall Through */ | |
4199 | case SCTP_IERROR_AUTH_BAD_KEYID: | |
4200 | case SCTP_IERROR_BAD_SIG: | |
4201 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4202 | ||
4203 | case SCTP_IERROR_PROTO_VIOLATION: | |
4204 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4205 | commands); | |
4206 | ||
4207 | case SCTP_IERROR_NOMEM: | |
4208 | return SCTP_DISPOSITION_NOMEM; | |
4209 | ||
4210 | default: /* Prevent gcc warnings */ | |
4211 | break; | |
4212 | } | |
4213 | ||
4214 | if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) { | |
4215 | struct sctp_ulpevent *ev; | |
4216 | ||
4217 | ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id), | |
4218 | SCTP_AUTH_NEWKEY, GFP_ATOMIC); | |
4219 | ||
4220 | if (!ev) | |
4221 | return -ENOMEM; | |
4222 | ||
4223 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, | |
4224 | SCTP_ULPEVENT(ev)); | |
4225 | } | |
4226 | ||
4227 | return SCTP_DISPOSITION_CONSUME; | |
4228 | } | |
4229 | ||
4230 | /* | |
4231 | * Process an unknown chunk. | |
4232 | * | |
4233 | * Section: 3.2. Also, 2.1 in the implementor's guide. | |
4234 | * | |
4235 | * Chunk Types are encoded such that the highest-order two bits specify | |
4236 | * the action that must be taken if the processing endpoint does not | |
4237 | * recognize the Chunk Type. | |
4238 | * | |
4239 | * 00 - Stop processing this SCTP packet and discard it, do not process | |
4240 | * any further chunks within it. | |
4241 | * | |
4242 | * 01 - Stop processing this SCTP packet and discard it, do not process | |
4243 | * any further chunks within it, and report the unrecognized | |
4244 | * chunk in an 'Unrecognized Chunk Type'. | |
4245 | * | |
4246 | * 10 - Skip this chunk and continue processing. | |
4247 | * | |
4248 | * 11 - Skip this chunk and continue processing, but report in an ERROR | |
4249 | * Chunk using the 'Unrecognized Chunk Type' cause of error. | |
4250 | * | |
4251 | * The return value is the disposition of the chunk. | |
4252 | */ | |
4253 | sctp_disposition_t sctp_sf_unk_chunk(struct net *net, | |
4254 | const struct sctp_endpoint *ep, | |
4255 | const struct sctp_association *asoc, | |
4256 | const sctp_subtype_t type, | |
4257 | void *arg, | |
4258 | sctp_cmd_seq_t *commands) | |
4259 | { | |
4260 | struct sctp_chunk *unk_chunk = arg; | |
4261 | struct sctp_chunk *err_chunk; | |
4262 | struct sctp_chunkhdr *hdr; | |
4263 | ||
4264 | pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk); | |
4265 | ||
4266 | if (!sctp_vtag_verify(unk_chunk, asoc)) | |
4267 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4268 | ||
4269 | /* Make sure that the chunk has a valid length. | |
4270 | * Since we don't know the chunk type, we use a general | |
4271 | * chunkhdr structure to make a comparison. | |
4272 | */ | |
4273 | if (!sctp_chunk_length_valid(unk_chunk, sizeof(*hdr))) | |
4274 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4275 | commands); | |
4276 | ||
4277 | switch (type.chunk & SCTP_CID_ACTION_MASK) { | |
4278 | case SCTP_CID_ACTION_DISCARD: | |
4279 | /* Discard the packet. */ | |
4280 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4281 | case SCTP_CID_ACTION_DISCARD_ERR: | |
4282 | /* Generate an ERROR chunk as response. */ | |
4283 | hdr = unk_chunk->chunk_hdr; | |
4284 | err_chunk = sctp_make_op_error(asoc, unk_chunk, | |
4285 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, | |
4286 | SCTP_PAD4(ntohs(hdr->length)), | |
4287 | 0); | |
4288 | if (err_chunk) { | |
4289 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
4290 | SCTP_CHUNK(err_chunk)); | |
4291 | } | |
4292 | ||
4293 | /* Discard the packet. */ | |
4294 | sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
4295 | return SCTP_DISPOSITION_CONSUME; | |
4296 | case SCTP_CID_ACTION_SKIP: | |
4297 | /* Skip the chunk. */ | |
4298 | return SCTP_DISPOSITION_DISCARD; | |
4299 | case SCTP_CID_ACTION_SKIP_ERR: | |
4300 | /* Generate an ERROR chunk as response. */ | |
4301 | hdr = unk_chunk->chunk_hdr; | |
4302 | err_chunk = sctp_make_op_error(asoc, unk_chunk, | |
4303 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, | |
4304 | SCTP_PAD4(ntohs(hdr->length)), | |
4305 | 0); | |
4306 | if (err_chunk) { | |
4307 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
4308 | SCTP_CHUNK(err_chunk)); | |
4309 | } | |
4310 | /* Skip the chunk. */ | |
4311 | return SCTP_DISPOSITION_CONSUME; | |
4312 | default: | |
4313 | break; | |
4314 | } | |
4315 | ||
4316 | return SCTP_DISPOSITION_DISCARD; | |
4317 | } | |
4318 | ||
4319 | /* | |
4320 | * Discard the chunk. | |
4321 | * | |
4322 | * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 | |
4323 | * [Too numerous to mention...] | |
4324 | * Verification Tag: No verification needed. | |
4325 | * Inputs | |
4326 | * (endpoint, asoc, chunk) | |
4327 | * | |
4328 | * Outputs | |
4329 | * (asoc, reply_msg, msg_up, timers, counters) | |
4330 | * | |
4331 | * The return value is the disposition of the chunk. | |
4332 | */ | |
4333 | sctp_disposition_t sctp_sf_discard_chunk(struct net *net, | |
4334 | const struct sctp_endpoint *ep, | |
4335 | const struct sctp_association *asoc, | |
4336 | const sctp_subtype_t type, | |
4337 | void *arg, | |
4338 | sctp_cmd_seq_t *commands) | |
4339 | { | |
4340 | struct sctp_chunk *chunk = arg; | |
4341 | ||
4342 | /* Make sure that the chunk has a valid length. | |
4343 | * Since we don't know the chunk type, we use a general | |
4344 | * chunkhdr structure to make a comparison. | |
4345 | */ | |
4346 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
4347 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4348 | commands); | |
4349 | ||
4350 | pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk); | |
4351 | ||
4352 | return SCTP_DISPOSITION_DISCARD; | |
4353 | } | |
4354 | ||
4355 | /* | |
4356 | * Discard the whole packet. | |
4357 | * | |
4358 | * Section: 8.4 2) | |
4359 | * | |
4360 | * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST | |
4361 | * silently discard the OOTB packet and take no further action. | |
4362 | * | |
4363 | * Verification Tag: No verification necessary | |
4364 | * | |
4365 | * Inputs | |
4366 | * (endpoint, asoc, chunk) | |
4367 | * | |
4368 | * Outputs | |
4369 | * (asoc, reply_msg, msg_up, timers, counters) | |
4370 | * | |
4371 | * The return value is the disposition of the chunk. | |
4372 | */ | |
4373 | sctp_disposition_t sctp_sf_pdiscard(struct net *net, | |
4374 | const struct sctp_endpoint *ep, | |
4375 | const struct sctp_association *asoc, | |
4376 | const sctp_subtype_t type, | |
4377 | void *arg, | |
4378 | sctp_cmd_seq_t *commands) | |
4379 | { | |
4380 | SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS); | |
4381 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
4382 | ||
4383 | return SCTP_DISPOSITION_CONSUME; | |
4384 | } | |
4385 | ||
4386 | ||
4387 | /* | |
4388 | * The other end is violating protocol. | |
4389 | * | |
4390 | * Section: Not specified | |
4391 | * Verification Tag: Not specified | |
4392 | * Inputs | |
4393 | * (endpoint, asoc, chunk) | |
4394 | * | |
4395 | * Outputs | |
4396 | * (asoc, reply_msg, msg_up, timers, counters) | |
4397 | * | |
4398 | * We simply tag the chunk as a violation. The state machine will log | |
4399 | * the violation and continue. | |
4400 | */ | |
4401 | sctp_disposition_t sctp_sf_violation(struct net *net, | |
4402 | const struct sctp_endpoint *ep, | |
4403 | const struct sctp_association *asoc, | |
4404 | const sctp_subtype_t type, | |
4405 | void *arg, | |
4406 | sctp_cmd_seq_t *commands) | |
4407 | { | |
4408 | struct sctp_chunk *chunk = arg; | |
4409 | ||
4410 | /* Make sure that the chunk has a valid length. */ | |
4411 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) | |
4412 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
4413 | commands); | |
4414 | ||
4415 | return SCTP_DISPOSITION_VIOLATION; | |
4416 | } | |
4417 | ||
4418 | /* | |
4419 | * Common function to handle a protocol violation. | |
4420 | */ | |
4421 | static sctp_disposition_t sctp_sf_abort_violation( | |
4422 | struct net *net, | |
4423 | const struct sctp_endpoint *ep, | |
4424 | const struct sctp_association *asoc, | |
4425 | void *arg, | |
4426 | sctp_cmd_seq_t *commands, | |
4427 | const __u8 *payload, | |
4428 | const size_t paylen) | |
4429 | { | |
4430 | struct sctp_packet *packet = NULL; | |
4431 | struct sctp_chunk *chunk = arg; | |
4432 | struct sctp_chunk *abort = NULL; | |
4433 | ||
4434 | /* SCTP-AUTH, Section 6.3: | |
4435 | * It should be noted that if the receiver wants to tear | |
4436 | * down an association in an authenticated way only, the | |
4437 | * handling of malformed packets should not result in | |
4438 | * tearing down the association. | |
4439 | * | |
4440 | * This means that if we only want to abort associations | |
4441 | * in an authenticated way (i.e AUTH+ABORT), then we | |
4442 | * can't destroy this association just because the packet | |
4443 | * was malformed. | |
4444 | */ | |
4445 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) | |
4446 | goto discard; | |
4447 | ||
4448 | /* Make the abort chunk. */ | |
4449 | abort = sctp_make_abort_violation(asoc, chunk, payload, paylen); | |
4450 | if (!abort) | |
4451 | goto nomem; | |
4452 | ||
4453 | if (asoc) { | |
4454 | /* Treat INIT-ACK as a special case during COOKIE-WAIT. */ | |
4455 | if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK && | |
4456 | !asoc->peer.i.init_tag) { | |
4457 | sctp_initack_chunk_t *initack; | |
4458 | ||
4459 | initack = (sctp_initack_chunk_t *)chunk->chunk_hdr; | |
4460 | if (!sctp_chunk_length_valid(chunk, | |
4461 | sizeof(sctp_initack_chunk_t))) | |
4462 | abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T; | |
4463 | else { | |
4464 | unsigned int inittag; | |
4465 | ||
4466 | inittag = ntohl(initack->init_hdr.init_tag); | |
4467 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG, | |
4468 | SCTP_U32(inittag)); | |
4469 | } | |
4470 | } | |
4471 | ||
4472 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
4473 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
4474 | ||
4475 | if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { | |
4476 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4477 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
4478 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
4479 | SCTP_ERROR(ECONNREFUSED)); | |
4480 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
4481 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); | |
4482 | } else { | |
4483 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
4484 | SCTP_ERROR(ECONNABORTED)); | |
4485 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4486 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); | |
4487 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
4488 | } | |
4489 | } else { | |
4490 | packet = sctp_ootb_pkt_new(net, asoc, chunk); | |
4491 | ||
4492 | if (!packet) | |
4493 | goto nomem_pkt; | |
4494 | ||
4495 | if (sctp_test_T_bit(abort)) | |
4496 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); | |
4497 | ||
4498 | abort->skb->sk = ep->base.sk; | |
4499 | ||
4500 | sctp_packet_append_chunk(packet, abort); | |
4501 | ||
4502 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
4503 | SCTP_PACKET(packet)); | |
4504 | ||
4505 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
4506 | } | |
4507 | ||
4508 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
4509 | ||
4510 | discard: | |
4511 | sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); | |
4512 | return SCTP_DISPOSITION_ABORT; | |
4513 | ||
4514 | nomem_pkt: | |
4515 | sctp_chunk_free(abort); | |
4516 | nomem: | |
4517 | return SCTP_DISPOSITION_NOMEM; | |
4518 | } | |
4519 | ||
4520 | /* | |
4521 | * Handle a protocol violation when the chunk length is invalid. | |
4522 | * "Invalid" length is identified as smaller than the minimal length a | |
4523 | * given chunk can be. For example, a SACK chunk has invalid length | |
4524 | * if its length is set to be smaller than the size of sctp_sack_chunk_t. | |
4525 | * | |
4526 | * We inform the other end by sending an ABORT with a Protocol Violation | |
4527 | * error code. | |
4528 | * | |
4529 | * Section: Not specified | |
4530 | * Verification Tag: Nothing to do | |
4531 | * Inputs | |
4532 | * (endpoint, asoc, chunk) | |
4533 | * | |
4534 | * Outputs | |
4535 | * (reply_msg, msg_up, counters) | |
4536 | * | |
4537 | * Generate an ABORT chunk and terminate the association. | |
4538 | */ | |
4539 | static sctp_disposition_t sctp_sf_violation_chunklen( | |
4540 | struct net *net, | |
4541 | const struct sctp_endpoint *ep, | |
4542 | const struct sctp_association *asoc, | |
4543 | const sctp_subtype_t type, | |
4544 | void *arg, | |
4545 | sctp_cmd_seq_t *commands) | |
4546 | { | |
4547 | static const char err_str[] = "The following chunk had invalid length:"; | |
4548 | ||
4549 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, | |
4550 | sizeof(err_str)); | |
4551 | } | |
4552 | ||
4553 | /* | |
4554 | * Handle a protocol violation when the parameter length is invalid. | |
4555 | * If the length is smaller than the minimum length of a given parameter, | |
4556 | * or accumulated length in multi parameters exceeds the end of the chunk, | |
4557 | * the length is considered as invalid. | |
4558 | */ | |
4559 | static sctp_disposition_t sctp_sf_violation_paramlen( | |
4560 | struct net *net, | |
4561 | const struct sctp_endpoint *ep, | |
4562 | const struct sctp_association *asoc, | |
4563 | const sctp_subtype_t type, | |
4564 | void *arg, void *ext, | |
4565 | sctp_cmd_seq_t *commands) | |
4566 | { | |
4567 | struct sctp_chunk *chunk = arg; | |
4568 | struct sctp_paramhdr *param = ext; | |
4569 | struct sctp_chunk *abort = NULL; | |
4570 | ||
4571 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) | |
4572 | goto discard; | |
4573 | ||
4574 | /* Make the abort chunk. */ | |
4575 | abort = sctp_make_violation_paramlen(asoc, chunk, param); | |
4576 | if (!abort) | |
4577 | goto nomem; | |
4578 | ||
4579 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
4580 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
4581 | ||
4582 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
4583 | SCTP_ERROR(ECONNABORTED)); | |
4584 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4585 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); | |
4586 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
4587 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
4588 | ||
4589 | discard: | |
4590 | sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); | |
4591 | return SCTP_DISPOSITION_ABORT; | |
4592 | nomem: | |
4593 | return SCTP_DISPOSITION_NOMEM; | |
4594 | } | |
4595 | ||
4596 | /* Handle a protocol violation when the peer trying to advance the | |
4597 | * cumulative tsn ack to a point beyond the max tsn currently sent. | |
4598 | * | |
4599 | * We inform the other end by sending an ABORT with a Protocol Violation | |
4600 | * error code. | |
4601 | */ | |
4602 | static sctp_disposition_t sctp_sf_violation_ctsn( | |
4603 | struct net *net, | |
4604 | const struct sctp_endpoint *ep, | |
4605 | const struct sctp_association *asoc, | |
4606 | const sctp_subtype_t type, | |
4607 | void *arg, | |
4608 | sctp_cmd_seq_t *commands) | |
4609 | { | |
4610 | static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:"; | |
4611 | ||
4612 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, | |
4613 | sizeof(err_str)); | |
4614 | } | |
4615 | ||
4616 | /* Handle protocol violation of an invalid chunk bundling. For example, | |
4617 | * when we have an association and we receive bundled INIT-ACK, or | |
4618 | * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle" | |
4619 | * statement from the specs. Additionally, there might be an attacker | |
4620 | * on the path and we may not want to continue this communication. | |
4621 | */ | |
4622 | static sctp_disposition_t sctp_sf_violation_chunk( | |
4623 | struct net *net, | |
4624 | const struct sctp_endpoint *ep, | |
4625 | const struct sctp_association *asoc, | |
4626 | const sctp_subtype_t type, | |
4627 | void *arg, | |
4628 | sctp_cmd_seq_t *commands) | |
4629 | { | |
4630 | static const char err_str[] = "The following chunk violates protocol:"; | |
4631 | ||
4632 | if (!asoc) | |
4633 | return sctp_sf_violation(net, ep, asoc, type, arg, commands); | |
4634 | ||
4635 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, | |
4636 | sizeof(err_str)); | |
4637 | } | |
4638 | /*************************************************************************** | |
4639 | * These are the state functions for handling primitive (Section 10) events. | |
4640 | ***************************************************************************/ | |
4641 | /* | |
4642 | * sctp_sf_do_prm_asoc | |
4643 | * | |
4644 | * Section: 10.1 ULP-to-SCTP | |
4645 | * B) Associate | |
4646 | * | |
4647 | * Format: ASSOCIATE(local SCTP instance name, destination transport addr, | |
4648 | * outbound stream count) | |
4649 | * -> association id [,destination transport addr list] [,outbound stream | |
4650 | * count] | |
4651 | * | |
4652 | * This primitive allows the upper layer to initiate an association to a | |
4653 | * specific peer endpoint. | |
4654 | * | |
4655 | * The peer endpoint shall be specified by one of the transport addresses | |
4656 | * which defines the endpoint (see Section 1.4). If the local SCTP | |
4657 | * instance has not been initialized, the ASSOCIATE is considered an | |
4658 | * error. | |
4659 | * [This is not relevant for the kernel implementation since we do all | |
4660 | * initialization at boot time. It we hadn't initialized we wouldn't | |
4661 | * get anywhere near this code.] | |
4662 | * | |
4663 | * An association id, which is a local handle to the SCTP association, | |
4664 | * will be returned on successful establishment of the association. If | |
4665 | * SCTP is not able to open an SCTP association with the peer endpoint, | |
4666 | * an error is returned. | |
4667 | * [In the kernel implementation, the struct sctp_association needs to | |
4668 | * be created BEFORE causing this primitive to run.] | |
4669 | * | |
4670 | * Other association parameters may be returned, including the | |
4671 | * complete destination transport addresses of the peer as well as the | |
4672 | * outbound stream count of the local endpoint. One of the transport | |
4673 | * address from the returned destination addresses will be selected by | |
4674 | * the local endpoint as default primary path for sending SCTP packets | |
4675 | * to this peer. The returned "destination transport addr list" can | |
4676 | * be used by the ULP to change the default primary path or to force | |
4677 | * sending a packet to a specific transport address. [All of this | |
4678 | * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING | |
4679 | * function.] | |
4680 | * | |
4681 | * Mandatory attributes: | |
4682 | * | |
4683 | * o local SCTP instance name - obtained from the INITIALIZE operation. | |
4684 | * [This is the argument asoc.] | |
4685 | * o destination transport addr - specified as one of the transport | |
4686 | * addresses of the peer endpoint with which the association is to be | |
4687 | * established. | |
4688 | * [This is asoc->peer.active_path.] | |
4689 | * o outbound stream count - the number of outbound streams the ULP | |
4690 | * would like to open towards this peer endpoint. | |
4691 | * [BUG: This is not currently implemented.] | |
4692 | * Optional attributes: | |
4693 | * | |
4694 | * None. | |
4695 | * | |
4696 | * The return value is a disposition. | |
4697 | */ | |
4698 | sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net, | |
4699 | const struct sctp_endpoint *ep, | |
4700 | const struct sctp_association *asoc, | |
4701 | const sctp_subtype_t type, | |
4702 | void *arg, | |
4703 | sctp_cmd_seq_t *commands) | |
4704 | { | |
4705 | struct sctp_chunk *repl; | |
4706 | struct sctp_association *my_asoc; | |
4707 | ||
4708 | /* The comment below says that we enter COOKIE-WAIT AFTER | |
4709 | * sending the INIT, but that doesn't actually work in our | |
4710 | * implementation... | |
4711 | */ | |
4712 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4713 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); | |
4714 | ||
4715 | /* RFC 2960 5.1 Normal Establishment of an Association | |
4716 | * | |
4717 | * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" | |
4718 | * must provide its Verification Tag (Tag_A) in the Initiate | |
4719 | * Tag field. Tag_A SHOULD be a random number in the range of | |
4720 | * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... | |
4721 | */ | |
4722 | ||
4723 | repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); | |
4724 | if (!repl) | |
4725 | goto nomem; | |
4726 | ||
4727 | /* Choose transport for INIT. */ | |
4728 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, | |
4729 | SCTP_CHUNK(repl)); | |
4730 | ||
4731 | /* Cast away the const modifier, as we want to just | |
4732 | * rerun it through as a sideffect. | |
4733 | */ | |
4734 | my_asoc = (struct sctp_association *)asoc; | |
4735 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc)); | |
4736 | ||
4737 | /* After sending the INIT, "A" starts the T1-init timer and | |
4738 | * enters the COOKIE-WAIT state. | |
4739 | */ | |
4740 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
4741 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
4742 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
4743 | return SCTP_DISPOSITION_CONSUME; | |
4744 | ||
4745 | nomem: | |
4746 | return SCTP_DISPOSITION_NOMEM; | |
4747 | } | |
4748 | ||
4749 | /* | |
4750 | * Process the SEND primitive. | |
4751 | * | |
4752 | * Section: 10.1 ULP-to-SCTP | |
4753 | * E) Send | |
4754 | * | |
4755 | * Format: SEND(association id, buffer address, byte count [,context] | |
4756 | * [,stream id] [,life time] [,destination transport address] | |
4757 | * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) | |
4758 | * -> result | |
4759 | * | |
4760 | * This is the main method to send user data via SCTP. | |
4761 | * | |
4762 | * Mandatory attributes: | |
4763 | * | |
4764 | * o association id - local handle to the SCTP association | |
4765 | * | |
4766 | * o buffer address - the location where the user message to be | |
4767 | * transmitted is stored; | |
4768 | * | |
4769 | * o byte count - The size of the user data in number of bytes; | |
4770 | * | |
4771 | * Optional attributes: | |
4772 | * | |
4773 | * o context - an optional 32 bit integer that will be carried in the | |
4774 | * sending failure notification to the ULP if the transportation of | |
4775 | * this User Message fails. | |
4776 | * | |
4777 | * o stream id - to indicate which stream to send the data on. If not | |
4778 | * specified, stream 0 will be used. | |
4779 | * | |
4780 | * o life time - specifies the life time of the user data. The user data | |
4781 | * will not be sent by SCTP after the life time expires. This | |
4782 | * parameter can be used to avoid efforts to transmit stale | |
4783 | * user messages. SCTP notifies the ULP if the data cannot be | |
4784 | * initiated to transport (i.e. sent to the destination via SCTP's | |
4785 | * send primitive) within the life time variable. However, the | |
4786 | * user data will be transmitted if SCTP has attempted to transmit a | |
4787 | * chunk before the life time expired. | |
4788 | * | |
4789 | * o destination transport address - specified as one of the destination | |
4790 | * transport addresses of the peer endpoint to which this packet | |
4791 | * should be sent. Whenever possible, SCTP should use this destination | |
4792 | * transport address for sending the packets, instead of the current | |
4793 | * primary path. | |
4794 | * | |
4795 | * o unorder flag - this flag, if present, indicates that the user | |
4796 | * would like the data delivered in an unordered fashion to the peer | |
4797 | * (i.e., the U flag is set to 1 on all DATA chunks carrying this | |
4798 | * message). | |
4799 | * | |
4800 | * o no-bundle flag - instructs SCTP not to bundle this user data with | |
4801 | * other outbound DATA chunks. SCTP MAY still bundle even when | |
4802 | * this flag is present, when faced with network congestion. | |
4803 | * | |
4804 | * o payload protocol-id - A 32 bit unsigned integer that is to be | |
4805 | * passed to the peer indicating the type of payload protocol data | |
4806 | * being transmitted. This value is passed as opaque data by SCTP. | |
4807 | * | |
4808 | * The return value is the disposition. | |
4809 | */ | |
4810 | sctp_disposition_t sctp_sf_do_prm_send(struct net *net, | |
4811 | const struct sctp_endpoint *ep, | |
4812 | const struct sctp_association *asoc, | |
4813 | const sctp_subtype_t type, | |
4814 | void *arg, | |
4815 | sctp_cmd_seq_t *commands) | |
4816 | { | |
4817 | struct sctp_datamsg *msg = arg; | |
4818 | ||
4819 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg)); | |
4820 | return SCTP_DISPOSITION_CONSUME; | |
4821 | } | |
4822 | ||
4823 | /* | |
4824 | * Process the SHUTDOWN primitive. | |
4825 | * | |
4826 | * Section: 10.1: | |
4827 | * C) Shutdown | |
4828 | * | |
4829 | * Format: SHUTDOWN(association id) | |
4830 | * -> result | |
4831 | * | |
4832 | * Gracefully closes an association. Any locally queued user data | |
4833 | * will be delivered to the peer. The association will be terminated only | |
4834 | * after the peer acknowledges all the SCTP packets sent. A success code | |
4835 | * will be returned on successful termination of the association. If | |
4836 | * attempting to terminate the association results in a failure, an error | |
4837 | * code shall be returned. | |
4838 | * | |
4839 | * Mandatory attributes: | |
4840 | * | |
4841 | * o association id - local handle to the SCTP association | |
4842 | * | |
4843 | * Optional attributes: | |
4844 | * | |
4845 | * None. | |
4846 | * | |
4847 | * The return value is the disposition. | |
4848 | */ | |
4849 | sctp_disposition_t sctp_sf_do_9_2_prm_shutdown( | |
4850 | struct net *net, | |
4851 | const struct sctp_endpoint *ep, | |
4852 | const struct sctp_association *asoc, | |
4853 | const sctp_subtype_t type, | |
4854 | void *arg, | |
4855 | sctp_cmd_seq_t *commands) | |
4856 | { | |
4857 | int disposition; | |
4858 | ||
4859 | /* From 9.2 Shutdown of an Association | |
4860 | * Upon receipt of the SHUTDOWN primitive from its upper | |
4861 | * layer, the endpoint enters SHUTDOWN-PENDING state and | |
4862 | * remains there until all outstanding data has been | |
4863 | * acknowledged by its peer. The endpoint accepts no new data | |
4864 | * from its upper layer, but retransmits data to the far end | |
4865 | * if necessary to fill gaps. | |
4866 | */ | |
4867 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4868 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); | |
4869 | ||
4870 | disposition = SCTP_DISPOSITION_CONSUME; | |
4871 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
4872 | disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, | |
4873 | arg, commands); | |
4874 | } | |
4875 | return disposition; | |
4876 | } | |
4877 | ||
4878 | /* | |
4879 | * Process the ABORT primitive. | |
4880 | * | |
4881 | * Section: 10.1: | |
4882 | * C) Abort | |
4883 | * | |
4884 | * Format: Abort(association id [, cause code]) | |
4885 | * -> result | |
4886 | * | |
4887 | * Ungracefully closes an association. Any locally queued user data | |
4888 | * will be discarded and an ABORT chunk is sent to the peer. A success code | |
4889 | * will be returned on successful abortion of the association. If | |
4890 | * attempting to abort the association results in a failure, an error | |
4891 | * code shall be returned. | |
4892 | * | |
4893 | * Mandatory attributes: | |
4894 | * | |
4895 | * o association id - local handle to the SCTP association | |
4896 | * | |
4897 | * Optional attributes: | |
4898 | * | |
4899 | * o cause code - reason of the abort to be passed to the peer | |
4900 | * | |
4901 | * None. | |
4902 | * | |
4903 | * The return value is the disposition. | |
4904 | */ | |
4905 | sctp_disposition_t sctp_sf_do_9_1_prm_abort( | |
4906 | struct net *net, | |
4907 | const struct sctp_endpoint *ep, | |
4908 | const struct sctp_association *asoc, | |
4909 | const sctp_subtype_t type, | |
4910 | void *arg, | |
4911 | sctp_cmd_seq_t *commands) | |
4912 | { | |
4913 | /* From 9.1 Abort of an Association | |
4914 | * Upon receipt of the ABORT primitive from its upper | |
4915 | * layer, the endpoint enters CLOSED state and | |
4916 | * discard all outstanding data has been | |
4917 | * acknowledged by its peer. The endpoint accepts no new data | |
4918 | * from its upper layer, but retransmits data to the far end | |
4919 | * if necessary to fill gaps. | |
4920 | */ | |
4921 | struct sctp_chunk *abort = arg; | |
4922 | ||
4923 | if (abort) | |
4924 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
4925 | ||
4926 | /* Even if we can't send the ABORT due to low memory delete the | |
4927 | * TCB. This is a departure from our typical NOMEM handling. | |
4928 | */ | |
4929 | ||
4930 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
4931 | SCTP_ERROR(ECONNABORTED)); | |
4932 | /* Delete the established association. */ | |
4933 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
4934 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); | |
4935 | ||
4936 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
4937 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
4938 | ||
4939 | return SCTP_DISPOSITION_ABORT; | |
4940 | } | |
4941 | ||
4942 | /* We tried an illegal operation on an association which is closed. */ | |
4943 | sctp_disposition_t sctp_sf_error_closed(struct net *net, | |
4944 | const struct sctp_endpoint *ep, | |
4945 | const struct sctp_association *asoc, | |
4946 | const sctp_subtype_t type, | |
4947 | void *arg, | |
4948 | sctp_cmd_seq_t *commands) | |
4949 | { | |
4950 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); | |
4951 | return SCTP_DISPOSITION_CONSUME; | |
4952 | } | |
4953 | ||
4954 | /* We tried an illegal operation on an association which is shutting | |
4955 | * down. | |
4956 | */ | |
4957 | sctp_disposition_t sctp_sf_error_shutdown(struct net *net, | |
4958 | const struct sctp_endpoint *ep, | |
4959 | const struct sctp_association *asoc, | |
4960 | const sctp_subtype_t type, | |
4961 | void *arg, | |
4962 | sctp_cmd_seq_t *commands) | |
4963 | { | |
4964 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, | |
4965 | SCTP_ERROR(-ESHUTDOWN)); | |
4966 | return SCTP_DISPOSITION_CONSUME; | |
4967 | } | |
4968 | ||
4969 | /* | |
4970 | * sctp_cookie_wait_prm_shutdown | |
4971 | * | |
4972 | * Section: 4 Note: 2 | |
4973 | * Verification Tag: | |
4974 | * Inputs | |
4975 | * (endpoint, asoc) | |
4976 | * | |
4977 | * The RFC does not explicitly address this issue, but is the route through the | |
4978 | * state table when someone issues a shutdown while in COOKIE_WAIT state. | |
4979 | * | |
4980 | * Outputs | |
4981 | * (timers) | |
4982 | */ | |
4983 | sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown( | |
4984 | struct net *net, | |
4985 | const struct sctp_endpoint *ep, | |
4986 | const struct sctp_association *asoc, | |
4987 | const sctp_subtype_t type, | |
4988 | void *arg, | |
4989 | sctp_cmd_seq_t *commands) | |
4990 | { | |
4991 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
4992 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
4993 | ||
4994 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
4995 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
4996 | ||
4997 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); | |
4998 | ||
4999 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); | |
5000 | ||
5001 | return SCTP_DISPOSITION_DELETE_TCB; | |
5002 | } | |
5003 | ||
5004 | /* | |
5005 | * sctp_cookie_echoed_prm_shutdown | |
5006 | * | |
5007 | * Section: 4 Note: 2 | |
5008 | * Verification Tag: | |
5009 | * Inputs | |
5010 | * (endpoint, asoc) | |
5011 | * | |
5012 | * The RFC does not explcitly address this issue, but is the route through the | |
5013 | * state table when someone issues a shutdown while in COOKIE_ECHOED state. | |
5014 | * | |
5015 | * Outputs | |
5016 | * (timers) | |
5017 | */ | |
5018 | sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown( | |
5019 | struct net *net, | |
5020 | const struct sctp_endpoint *ep, | |
5021 | const struct sctp_association *asoc, | |
5022 | const sctp_subtype_t type, | |
5023 | void *arg, sctp_cmd_seq_t *commands) | |
5024 | { | |
5025 | /* There is a single T1 timer, so we should be able to use | |
5026 | * common function with the COOKIE-WAIT state. | |
5027 | */ | |
5028 | return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands); | |
5029 | } | |
5030 | ||
5031 | /* | |
5032 | * sctp_sf_cookie_wait_prm_abort | |
5033 | * | |
5034 | * Section: 4 Note: 2 | |
5035 | * Verification Tag: | |
5036 | * Inputs | |
5037 | * (endpoint, asoc) | |
5038 | * | |
5039 | * The RFC does not explicitly address this issue, but is the route through the | |
5040 | * state table when someone issues an abort while in COOKIE_WAIT state. | |
5041 | * | |
5042 | * Outputs | |
5043 | * (timers) | |
5044 | */ | |
5045 | sctp_disposition_t sctp_sf_cookie_wait_prm_abort( | |
5046 | struct net *net, | |
5047 | const struct sctp_endpoint *ep, | |
5048 | const struct sctp_association *asoc, | |
5049 | const sctp_subtype_t type, | |
5050 | void *arg, | |
5051 | sctp_cmd_seq_t *commands) | |
5052 | { | |
5053 | struct sctp_chunk *abort = arg; | |
5054 | ||
5055 | /* Stop T1-init timer */ | |
5056 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5057 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
5058 | ||
5059 | if (abort) | |
5060 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); | |
5061 | ||
5062 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
5063 | SCTP_STATE(SCTP_STATE_CLOSED)); | |
5064 | ||
5065 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
5066 | ||
5067 | /* Even if we can't send the ABORT due to low memory delete the | |
5068 | * TCB. This is a departure from our typical NOMEM handling. | |
5069 | */ | |
5070 | ||
5071 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5072 | SCTP_ERROR(ECONNREFUSED)); | |
5073 | /* Delete the established association. */ | |
5074 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
5075 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); | |
5076 | ||
5077 | return SCTP_DISPOSITION_ABORT; | |
5078 | } | |
5079 | ||
5080 | /* | |
5081 | * sctp_sf_cookie_echoed_prm_abort | |
5082 | * | |
5083 | * Section: 4 Note: 3 | |
5084 | * Verification Tag: | |
5085 | * Inputs | |
5086 | * (endpoint, asoc) | |
5087 | * | |
5088 | * The RFC does not explcitly address this issue, but is the route through the | |
5089 | * state table when someone issues an abort while in COOKIE_ECHOED state. | |
5090 | * | |
5091 | * Outputs | |
5092 | * (timers) | |
5093 | */ | |
5094 | sctp_disposition_t sctp_sf_cookie_echoed_prm_abort( | |
5095 | struct net *net, | |
5096 | const struct sctp_endpoint *ep, | |
5097 | const struct sctp_association *asoc, | |
5098 | const sctp_subtype_t type, | |
5099 | void *arg, | |
5100 | sctp_cmd_seq_t *commands) | |
5101 | { | |
5102 | /* There is a single T1 timer, so we should be able to use | |
5103 | * common function with the COOKIE-WAIT state. | |
5104 | */ | |
5105 | return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands); | |
5106 | } | |
5107 | ||
5108 | /* | |
5109 | * sctp_sf_shutdown_pending_prm_abort | |
5110 | * | |
5111 | * Inputs | |
5112 | * (endpoint, asoc) | |
5113 | * | |
5114 | * The RFC does not explicitly address this issue, but is the route through the | |
5115 | * state table when someone issues an abort while in SHUTDOWN-PENDING state. | |
5116 | * | |
5117 | * Outputs | |
5118 | * (timers) | |
5119 | */ | |
5120 | sctp_disposition_t sctp_sf_shutdown_pending_prm_abort( | |
5121 | struct net *net, | |
5122 | const struct sctp_endpoint *ep, | |
5123 | const struct sctp_association *asoc, | |
5124 | const sctp_subtype_t type, | |
5125 | void *arg, | |
5126 | sctp_cmd_seq_t *commands) | |
5127 | { | |
5128 | /* Stop the T5-shutdown guard timer. */ | |
5129 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5130 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
5131 | ||
5132 | return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); | |
5133 | } | |
5134 | ||
5135 | /* | |
5136 | * sctp_sf_shutdown_sent_prm_abort | |
5137 | * | |
5138 | * Inputs | |
5139 | * (endpoint, asoc) | |
5140 | * | |
5141 | * The RFC does not explicitly address this issue, but is the route through the | |
5142 | * state table when someone issues an abort while in SHUTDOWN-SENT state. | |
5143 | * | |
5144 | * Outputs | |
5145 | * (timers) | |
5146 | */ | |
5147 | sctp_disposition_t sctp_sf_shutdown_sent_prm_abort( | |
5148 | struct net *net, | |
5149 | const struct sctp_endpoint *ep, | |
5150 | const struct sctp_association *asoc, | |
5151 | const sctp_subtype_t type, | |
5152 | void *arg, | |
5153 | sctp_cmd_seq_t *commands) | |
5154 | { | |
5155 | /* Stop the T2-shutdown timer. */ | |
5156 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5157 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
5158 | ||
5159 | /* Stop the T5-shutdown guard timer. */ | |
5160 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5161 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
5162 | ||
5163 | return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); | |
5164 | } | |
5165 | ||
5166 | /* | |
5167 | * sctp_sf_cookie_echoed_prm_abort | |
5168 | * | |
5169 | * Inputs | |
5170 | * (endpoint, asoc) | |
5171 | * | |
5172 | * The RFC does not explcitly address this issue, but is the route through the | |
5173 | * state table when someone issues an abort while in COOKIE_ECHOED state. | |
5174 | * | |
5175 | * Outputs | |
5176 | * (timers) | |
5177 | */ | |
5178 | sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort( | |
5179 | struct net *net, | |
5180 | const struct sctp_endpoint *ep, | |
5181 | const struct sctp_association *asoc, | |
5182 | const sctp_subtype_t type, | |
5183 | void *arg, | |
5184 | sctp_cmd_seq_t *commands) | |
5185 | { | |
5186 | /* The same T2 timer, so we should be able to use | |
5187 | * common function with the SHUTDOWN-SENT state. | |
5188 | */ | |
5189 | return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands); | |
5190 | } | |
5191 | ||
5192 | /* | |
5193 | * Process the REQUESTHEARTBEAT primitive | |
5194 | * | |
5195 | * 10.1 ULP-to-SCTP | |
5196 | * J) Request Heartbeat | |
5197 | * | |
5198 | * Format: REQUESTHEARTBEAT(association id, destination transport address) | |
5199 | * | |
5200 | * -> result | |
5201 | * | |
5202 | * Instructs the local endpoint to perform a HeartBeat on the specified | |
5203 | * destination transport address of the given association. The returned | |
5204 | * result should indicate whether the transmission of the HEARTBEAT | |
5205 | * chunk to the destination address is successful. | |
5206 | * | |
5207 | * Mandatory attributes: | |
5208 | * | |
5209 | * o association id - local handle to the SCTP association | |
5210 | * | |
5211 | * o destination transport address - the transport address of the | |
5212 | * association on which a heartbeat should be issued. | |
5213 | */ | |
5214 | sctp_disposition_t sctp_sf_do_prm_requestheartbeat( | |
5215 | struct net *net, | |
5216 | const struct sctp_endpoint *ep, | |
5217 | const struct sctp_association *asoc, | |
5218 | const sctp_subtype_t type, | |
5219 | void *arg, | |
5220 | sctp_cmd_seq_t *commands) | |
5221 | { | |
5222 | if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type, | |
5223 | (struct sctp_transport *)arg, commands)) | |
5224 | return SCTP_DISPOSITION_NOMEM; | |
5225 | ||
5226 | /* | |
5227 | * RFC 2960 (bis), section 8.3 | |
5228 | * | |
5229 | * D) Request an on-demand HEARTBEAT on a specific destination | |
5230 | * transport address of a given association. | |
5231 | * | |
5232 | * The endpoint should increment the respective error counter of | |
5233 | * the destination transport address each time a HEARTBEAT is sent | |
5234 | * to that address and not acknowledged within one RTO. | |
5235 | * | |
5236 | */ | |
5237 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, | |
5238 | SCTP_TRANSPORT(arg)); | |
5239 | return SCTP_DISPOSITION_CONSUME; | |
5240 | } | |
5241 | ||
5242 | /* | |
5243 | * ADDIP Section 4.1 ASCONF Chunk Procedures | |
5244 | * When an endpoint has an ASCONF signaled change to be sent to the | |
5245 | * remote endpoint it should do A1 to A9 | |
5246 | */ | |
5247 | sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net, | |
5248 | const struct sctp_endpoint *ep, | |
5249 | const struct sctp_association *asoc, | |
5250 | const sctp_subtype_t type, | |
5251 | void *arg, | |
5252 | sctp_cmd_seq_t *commands) | |
5253 | { | |
5254 | struct sctp_chunk *chunk = arg; | |
5255 | ||
5256 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); | |
5257 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
5258 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
5259 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); | |
5260 | return SCTP_DISPOSITION_CONSUME; | |
5261 | } | |
5262 | ||
5263 | /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */ | |
5264 | sctp_disposition_t sctp_sf_do_prm_reconf(struct net *net, | |
5265 | const struct sctp_endpoint *ep, | |
5266 | const struct sctp_association *asoc, | |
5267 | const sctp_subtype_t type, | |
5268 | void *arg, sctp_cmd_seq_t *commands) | |
5269 | { | |
5270 | struct sctp_chunk *chunk = arg; | |
5271 | ||
5272 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); | |
5273 | return SCTP_DISPOSITION_CONSUME; | |
5274 | } | |
5275 | ||
5276 | /* | |
5277 | * Ignore the primitive event | |
5278 | * | |
5279 | * The return value is the disposition of the primitive. | |
5280 | */ | |
5281 | sctp_disposition_t sctp_sf_ignore_primitive( | |
5282 | struct net *net, | |
5283 | const struct sctp_endpoint *ep, | |
5284 | const struct sctp_association *asoc, | |
5285 | const sctp_subtype_t type, | |
5286 | void *arg, | |
5287 | sctp_cmd_seq_t *commands) | |
5288 | { | |
5289 | pr_debug("%s: primitive type:%d is ignored\n", __func__, | |
5290 | type.primitive); | |
5291 | ||
5292 | return SCTP_DISPOSITION_DISCARD; | |
5293 | } | |
5294 | ||
5295 | /*************************************************************************** | |
5296 | * These are the state functions for the OTHER events. | |
5297 | ***************************************************************************/ | |
5298 | ||
5299 | /* | |
5300 | * When the SCTP stack has no more user data to send or retransmit, this | |
5301 | * notification is given to the user. Also, at the time when a user app | |
5302 | * subscribes to this event, if there is no data to be sent or | |
5303 | * retransmit, the stack will immediately send up this notification. | |
5304 | */ | |
5305 | sctp_disposition_t sctp_sf_do_no_pending_tsn( | |
5306 | struct net *net, | |
5307 | const struct sctp_endpoint *ep, | |
5308 | const struct sctp_association *asoc, | |
5309 | const sctp_subtype_t type, | |
5310 | void *arg, | |
5311 | sctp_cmd_seq_t *commands) | |
5312 | { | |
5313 | struct sctp_ulpevent *event; | |
5314 | ||
5315 | event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC); | |
5316 | if (!event) | |
5317 | return SCTP_DISPOSITION_NOMEM; | |
5318 | ||
5319 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event)); | |
5320 | ||
5321 | return SCTP_DISPOSITION_CONSUME; | |
5322 | } | |
5323 | ||
5324 | /* | |
5325 | * Start the shutdown negotiation. | |
5326 | * | |
5327 | * From Section 9.2: | |
5328 | * Once all its outstanding data has been acknowledged, the endpoint | |
5329 | * shall send a SHUTDOWN chunk to its peer including in the Cumulative | |
5330 | * TSN Ack field the last sequential TSN it has received from the peer. | |
5331 | * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT | |
5332 | * state. If the timer expires, the endpoint must re-send the SHUTDOWN | |
5333 | * with the updated last sequential TSN received from its peer. | |
5334 | * | |
5335 | * The return value is the disposition. | |
5336 | */ | |
5337 | sctp_disposition_t sctp_sf_do_9_2_start_shutdown( | |
5338 | struct net *net, | |
5339 | const struct sctp_endpoint *ep, | |
5340 | const struct sctp_association *asoc, | |
5341 | const sctp_subtype_t type, | |
5342 | void *arg, | |
5343 | sctp_cmd_seq_t *commands) | |
5344 | { | |
5345 | struct sctp_chunk *reply; | |
5346 | ||
5347 | /* Once all its outstanding data has been acknowledged, the | |
5348 | * endpoint shall send a SHUTDOWN chunk to its peer including | |
5349 | * in the Cumulative TSN Ack field the last sequential TSN it | |
5350 | * has received from the peer. | |
5351 | */ | |
5352 | reply = sctp_make_shutdown(asoc, NULL); | |
5353 | if (!reply) | |
5354 | goto nomem; | |
5355 | ||
5356 | /* Set the transport for the SHUTDOWN chunk and the timeout for the | |
5357 | * T2-shutdown timer. | |
5358 | */ | |
5359 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
5360 | ||
5361 | /* It shall then start the T2-shutdown timer */ | |
5362 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, | |
5363 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
5364 | ||
5365 | /* RFC 4960 Section 9.2 | |
5366 | * The sender of the SHUTDOWN MAY also start an overall guard timer | |
5367 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. | |
5368 | */ | |
5369 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
5370 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
5371 | ||
5372 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) | |
5373 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5374 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
5375 | ||
5376 | /* and enter the SHUTDOWN-SENT state. */ | |
5377 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
5378 | SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); | |
5379 | ||
5380 | /* sctp-implguide 2.10 Issues with Heartbeating and failover | |
5381 | * | |
5382 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN | |
5383 | * or SHUTDOWN-ACK. | |
5384 | */ | |
5385 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
5386 | ||
5387 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
5388 | ||
5389 | return SCTP_DISPOSITION_CONSUME; | |
5390 | ||
5391 | nomem: | |
5392 | return SCTP_DISPOSITION_NOMEM; | |
5393 | } | |
5394 | ||
5395 | /* | |
5396 | * Generate a SHUTDOWN ACK now that everything is SACK'd. | |
5397 | * | |
5398 | * From Section 9.2: | |
5399 | * | |
5400 | * If it has no more outstanding DATA chunks, the SHUTDOWN receiver | |
5401 | * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, | |
5402 | * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the | |
5403 | * endpoint must re-send the SHUTDOWN ACK. | |
5404 | * | |
5405 | * The return value is the disposition. | |
5406 | */ | |
5407 | sctp_disposition_t sctp_sf_do_9_2_shutdown_ack( | |
5408 | struct net *net, | |
5409 | const struct sctp_endpoint *ep, | |
5410 | const struct sctp_association *asoc, | |
5411 | const sctp_subtype_t type, | |
5412 | void *arg, | |
5413 | sctp_cmd_seq_t *commands) | |
5414 | { | |
5415 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; | |
5416 | struct sctp_chunk *reply; | |
5417 | ||
5418 | /* There are 2 ways of getting here: | |
5419 | * 1) called in response to a SHUTDOWN chunk | |
5420 | * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. | |
5421 | * | |
5422 | * For the case (2), the arg parameter is set to NULL. We need | |
5423 | * to check that we have a chunk before accessing it's fields. | |
5424 | */ | |
5425 | if (chunk) { | |
5426 | if (!sctp_vtag_verify(chunk, asoc)) | |
5427 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); | |
5428 | ||
5429 | /* Make sure that the SHUTDOWN chunk has a valid length. */ | |
5430 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t))) | |
5431 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, | |
5432 | commands); | |
5433 | } | |
5434 | ||
5435 | /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver | |
5436 | * shall send a SHUTDOWN ACK ... | |
5437 | */ | |
5438 | reply = sctp_make_shutdown_ack(asoc, chunk); | |
5439 | if (!reply) | |
5440 | goto nomem; | |
5441 | ||
5442 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for | |
5443 | * the T2-shutdown timer. | |
5444 | */ | |
5445 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
5446 | ||
5447 | /* and start/restart a T2-shutdown timer of its own, */ | |
5448 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
5449 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
5450 | ||
5451 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) | |
5452 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5453 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); | |
5454 | ||
5455 | /* Enter the SHUTDOWN-ACK-SENT state. */ | |
5456 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
5457 | SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); | |
5458 | ||
5459 | /* sctp-implguide 2.10 Issues with Heartbeating and failover | |
5460 | * | |
5461 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN | |
5462 | * or SHUTDOWN-ACK. | |
5463 | */ | |
5464 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); | |
5465 | ||
5466 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
5467 | ||
5468 | return SCTP_DISPOSITION_CONSUME; | |
5469 | ||
5470 | nomem: | |
5471 | return SCTP_DISPOSITION_NOMEM; | |
5472 | } | |
5473 | ||
5474 | /* | |
5475 | * Ignore the event defined as other | |
5476 | * | |
5477 | * The return value is the disposition of the event. | |
5478 | */ | |
5479 | sctp_disposition_t sctp_sf_ignore_other(struct net *net, | |
5480 | const struct sctp_endpoint *ep, | |
5481 | const struct sctp_association *asoc, | |
5482 | const sctp_subtype_t type, | |
5483 | void *arg, | |
5484 | sctp_cmd_seq_t *commands) | |
5485 | { | |
5486 | pr_debug("%s: the event other type:%d is ignored\n", | |
5487 | __func__, type.other); | |
5488 | ||
5489 | return SCTP_DISPOSITION_DISCARD; | |
5490 | } | |
5491 | ||
5492 | /************************************************************ | |
5493 | * These are the state functions for handling timeout events. | |
5494 | ************************************************************/ | |
5495 | ||
5496 | /* | |
5497 | * RTX Timeout | |
5498 | * | |
5499 | * Section: 6.3.3 Handle T3-rtx Expiration | |
5500 | * | |
5501 | * Whenever the retransmission timer T3-rtx expires for a destination | |
5502 | * address, do the following: | |
5503 | * [See below] | |
5504 | * | |
5505 | * The return value is the disposition of the chunk. | |
5506 | */ | |
5507 | sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net, | |
5508 | const struct sctp_endpoint *ep, | |
5509 | const struct sctp_association *asoc, | |
5510 | const sctp_subtype_t type, | |
5511 | void *arg, | |
5512 | sctp_cmd_seq_t *commands) | |
5513 | { | |
5514 | struct sctp_transport *transport = arg; | |
5515 | ||
5516 | SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS); | |
5517 | ||
5518 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
5519 | if (asoc->peer.zero_window_announced && | |
5520 | asoc->state == SCTP_STATE_SHUTDOWN_PENDING) { | |
5521 | /* | |
5522 | * We are here likely because the receiver had its rwnd | |
5523 | * closed for a while and we have not been able to | |
5524 | * transmit the locally queued data within the maximum | |
5525 | * retransmission attempts limit. Start the T5 | |
5526 | * shutdown guard timer to give the receiver one last | |
5527 | * chance and some additional time to recover before | |
5528 | * aborting. | |
5529 | */ | |
5530 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE, | |
5531 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); | |
5532 | } else { | |
5533 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5534 | SCTP_ERROR(ETIMEDOUT)); | |
5535 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
5536 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
5537 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5538 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
5539 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
5540 | return SCTP_DISPOSITION_DELETE_TCB; | |
5541 | } | |
5542 | } | |
5543 | ||
5544 | /* E1) For the destination address for which the timer | |
5545 | * expires, adjust its ssthresh with rules defined in Section | |
5546 | * 7.2.3 and set the cwnd <- MTU. | |
5547 | */ | |
5548 | ||
5549 | /* E2) For the destination address for which the timer | |
5550 | * expires, set RTO <- RTO * 2 ("back off the timer"). The | |
5551 | * maximum value discussed in rule C7 above (RTO.max) may be | |
5552 | * used to provide an upper bound to this doubling operation. | |
5553 | */ | |
5554 | ||
5555 | /* E3) Determine how many of the earliest (i.e., lowest TSN) | |
5556 | * outstanding DATA chunks for the address for which the | |
5557 | * T3-rtx has expired will fit into a single packet, subject | |
5558 | * to the MTU constraint for the path corresponding to the | |
5559 | * destination transport address to which the retransmission | |
5560 | * is being sent (this may be different from the address for | |
5561 | * which the timer expires [see Section 6.4]). Call this | |
5562 | * value K. Bundle and retransmit those K DATA chunks in a | |
5563 | * single packet to the destination endpoint. | |
5564 | * | |
5565 | * Note: Any DATA chunks that were sent to the address for | |
5566 | * which the T3-rtx timer expired but did not fit in one MTU | |
5567 | * (rule E3 above), should be marked for retransmission and | |
5568 | * sent as soon as cwnd allows (normally when a SACK arrives). | |
5569 | */ | |
5570 | ||
5571 | /* Do some failure management (Section 8.2). */ | |
5572 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); | |
5573 | ||
5574 | /* NB: Rules E4 and F1 are implicit in R1. */ | |
5575 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); | |
5576 | ||
5577 | return SCTP_DISPOSITION_CONSUME; | |
5578 | } | |
5579 | ||
5580 | /* | |
5581 | * Generate delayed SACK on timeout | |
5582 | * | |
5583 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks | |
5584 | * | |
5585 | * The guidelines on delayed acknowledgement algorithm specified in | |
5586 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an | |
5587 | * acknowledgement SHOULD be generated for at least every second packet | |
5588 | * (not every second DATA chunk) received, and SHOULD be generated | |
5589 | * within 200 ms of the arrival of any unacknowledged DATA chunk. In | |
5590 | * some situations it may be beneficial for an SCTP transmitter to be | |
5591 | * more conservative than the algorithms detailed in this document | |
5592 | * allow. However, an SCTP transmitter MUST NOT be more aggressive than | |
5593 | * the following algorithms allow. | |
5594 | */ | |
5595 | sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net, | |
5596 | const struct sctp_endpoint *ep, | |
5597 | const struct sctp_association *asoc, | |
5598 | const sctp_subtype_t type, | |
5599 | void *arg, | |
5600 | sctp_cmd_seq_t *commands) | |
5601 | { | |
5602 | SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS); | |
5603 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); | |
5604 | return SCTP_DISPOSITION_CONSUME; | |
5605 | } | |
5606 | ||
5607 | /* | |
5608 | * sctp_sf_t1_init_timer_expire | |
5609 | * | |
5610 | * Section: 4 Note: 2 | |
5611 | * Verification Tag: | |
5612 | * Inputs | |
5613 | * (endpoint, asoc) | |
5614 | * | |
5615 | * RFC 2960 Section 4 Notes | |
5616 | * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT | |
5617 | * and re-start the T1-init timer without changing state. This MUST | |
5618 | * be repeated up to 'Max.Init.Retransmits' times. After that, the | |
5619 | * endpoint MUST abort the initialization process and report the | |
5620 | * error to SCTP user. | |
5621 | * | |
5622 | * Outputs | |
5623 | * (timers, events) | |
5624 | * | |
5625 | */ | |
5626 | sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net, | |
5627 | const struct sctp_endpoint *ep, | |
5628 | const struct sctp_association *asoc, | |
5629 | const sctp_subtype_t type, | |
5630 | void *arg, | |
5631 | sctp_cmd_seq_t *commands) | |
5632 | { | |
5633 | struct sctp_chunk *repl = NULL; | |
5634 | struct sctp_bind_addr *bp; | |
5635 | int attempts = asoc->init_err_counter + 1; | |
5636 | ||
5637 | pr_debug("%s: timer T1 expired (INIT)\n", __func__); | |
5638 | ||
5639 | SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS); | |
5640 | ||
5641 | if (attempts <= asoc->max_init_attempts) { | |
5642 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; | |
5643 | repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); | |
5644 | if (!repl) | |
5645 | return SCTP_DISPOSITION_NOMEM; | |
5646 | ||
5647 | /* Choose transport for INIT. */ | |
5648 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, | |
5649 | SCTP_CHUNK(repl)); | |
5650 | ||
5651 | /* Issue a sideeffect to do the needed accounting. */ | |
5652 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, | |
5653 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); | |
5654 | ||
5655 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
5656 | } else { | |
5657 | pr_debug("%s: giving up on INIT, attempts:%d " | |
5658 | "max_init_attempts:%d\n", __func__, attempts, | |
5659 | asoc->max_init_attempts); | |
5660 | ||
5661 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5662 | SCTP_ERROR(ETIMEDOUT)); | |
5663 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
5664 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5665 | return SCTP_DISPOSITION_DELETE_TCB; | |
5666 | } | |
5667 | ||
5668 | return SCTP_DISPOSITION_CONSUME; | |
5669 | } | |
5670 | ||
5671 | /* | |
5672 | * sctp_sf_t1_cookie_timer_expire | |
5673 | * | |
5674 | * Section: 4 Note: 2 | |
5675 | * Verification Tag: | |
5676 | * Inputs | |
5677 | * (endpoint, asoc) | |
5678 | * | |
5679 | * RFC 2960 Section 4 Notes | |
5680 | * 3) If the T1-cookie timer expires, the endpoint MUST retransmit | |
5681 | * COOKIE ECHO and re-start the T1-cookie timer without changing | |
5682 | * state. This MUST be repeated up to 'Max.Init.Retransmits' times. | |
5683 | * After that, the endpoint MUST abort the initialization process and | |
5684 | * report the error to SCTP user. | |
5685 | * | |
5686 | * Outputs | |
5687 | * (timers, events) | |
5688 | * | |
5689 | */ | |
5690 | sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net, | |
5691 | const struct sctp_endpoint *ep, | |
5692 | const struct sctp_association *asoc, | |
5693 | const sctp_subtype_t type, | |
5694 | void *arg, | |
5695 | sctp_cmd_seq_t *commands) | |
5696 | { | |
5697 | struct sctp_chunk *repl = NULL; | |
5698 | int attempts = asoc->init_err_counter + 1; | |
5699 | ||
5700 | pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__); | |
5701 | ||
5702 | SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS); | |
5703 | ||
5704 | if (attempts <= asoc->max_init_attempts) { | |
5705 | repl = sctp_make_cookie_echo(asoc, NULL); | |
5706 | if (!repl) | |
5707 | return SCTP_DISPOSITION_NOMEM; | |
5708 | ||
5709 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, | |
5710 | SCTP_CHUNK(repl)); | |
5711 | /* Issue a sideeffect to do the needed accounting. */ | |
5712 | sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART, | |
5713 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); | |
5714 | ||
5715 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); | |
5716 | } else { | |
5717 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5718 | SCTP_ERROR(ETIMEDOUT)); | |
5719 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, | |
5720 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5721 | return SCTP_DISPOSITION_DELETE_TCB; | |
5722 | } | |
5723 | ||
5724 | return SCTP_DISPOSITION_CONSUME; | |
5725 | } | |
5726 | ||
5727 | /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN | |
5728 | * with the updated last sequential TSN received from its peer. | |
5729 | * | |
5730 | * An endpoint should limit the number of retransmissions of the | |
5731 | * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. | |
5732 | * If this threshold is exceeded the endpoint should destroy the TCB and | |
5733 | * MUST report the peer endpoint unreachable to the upper layer (and | |
5734 | * thus the association enters the CLOSED state). The reception of any | |
5735 | * packet from its peer (i.e. as the peer sends all of its queued DATA | |
5736 | * chunks) should clear the endpoint's retransmission count and restart | |
5737 | * the T2-Shutdown timer, giving its peer ample opportunity to transmit | |
5738 | * all of its queued DATA chunks that have not yet been sent. | |
5739 | */ | |
5740 | sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net, | |
5741 | const struct sctp_endpoint *ep, | |
5742 | const struct sctp_association *asoc, | |
5743 | const sctp_subtype_t type, | |
5744 | void *arg, | |
5745 | sctp_cmd_seq_t *commands) | |
5746 | { | |
5747 | struct sctp_chunk *reply = NULL; | |
5748 | ||
5749 | pr_debug("%s: timer T2 expired\n", __func__); | |
5750 | ||
5751 | SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS); | |
5752 | ||
5753 | ((struct sctp_association *)asoc)->shutdown_retries++; | |
5754 | ||
5755 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
5756 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5757 | SCTP_ERROR(ETIMEDOUT)); | |
5758 | /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ | |
5759 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
5760 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5761 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
5762 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
5763 | return SCTP_DISPOSITION_DELETE_TCB; | |
5764 | } | |
5765 | ||
5766 | switch (asoc->state) { | |
5767 | case SCTP_STATE_SHUTDOWN_SENT: | |
5768 | reply = sctp_make_shutdown(asoc, NULL); | |
5769 | break; | |
5770 | ||
5771 | case SCTP_STATE_SHUTDOWN_ACK_SENT: | |
5772 | reply = sctp_make_shutdown_ack(asoc, NULL); | |
5773 | break; | |
5774 | ||
5775 | default: | |
5776 | BUG(); | |
5777 | break; | |
5778 | } | |
5779 | ||
5780 | if (!reply) | |
5781 | goto nomem; | |
5782 | ||
5783 | /* Do some failure management (Section 8.2). | |
5784 | * If we remove the transport an SHUTDOWN was last sent to, don't | |
5785 | * do failure management. | |
5786 | */ | |
5787 | if (asoc->shutdown_last_sent_to) | |
5788 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, | |
5789 | SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); | |
5790 | ||
5791 | /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for | |
5792 | * the T2-shutdown timer. | |
5793 | */ | |
5794 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); | |
5795 | ||
5796 | /* Restart the T2-shutdown timer. */ | |
5797 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
5798 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); | |
5799 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
5800 | return SCTP_DISPOSITION_CONSUME; | |
5801 | ||
5802 | nomem: | |
5803 | return SCTP_DISPOSITION_NOMEM; | |
5804 | } | |
5805 | ||
5806 | /* | |
5807 | * ADDIP Section 4.1 ASCONF CHunk Procedures | |
5808 | * If the T4 RTO timer expires the endpoint should do B1 to B5 | |
5809 | */ | |
5810 | sctp_disposition_t sctp_sf_t4_timer_expire( | |
5811 | struct net *net, | |
5812 | const struct sctp_endpoint *ep, | |
5813 | const struct sctp_association *asoc, | |
5814 | const sctp_subtype_t type, | |
5815 | void *arg, | |
5816 | sctp_cmd_seq_t *commands) | |
5817 | { | |
5818 | struct sctp_chunk *chunk = asoc->addip_last_asconf; | |
5819 | struct sctp_transport *transport = chunk->transport; | |
5820 | ||
5821 | SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS); | |
5822 | ||
5823 | /* ADDIP 4.1 B1) Increment the error counters and perform path failure | |
5824 | * detection on the appropriate destination address as defined in | |
5825 | * RFC2960 [5] section 8.1 and 8.2. | |
5826 | */ | |
5827 | if (transport) | |
5828 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, | |
5829 | SCTP_TRANSPORT(transport)); | |
5830 | ||
5831 | /* Reconfig T4 timer and transport. */ | |
5832 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); | |
5833 | ||
5834 | /* ADDIP 4.1 B2) Increment the association error counters and perform | |
5835 | * endpoint failure detection on the association as defined in | |
5836 | * RFC2960 [5] section 8.1 and 8.2. | |
5837 | * association error counter is incremented in SCTP_CMD_STRIKE. | |
5838 | */ | |
5839 | if (asoc->overall_error_count >= asoc->max_retrans) { | |
5840 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, | |
5841 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
5842 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5843 | SCTP_ERROR(ETIMEDOUT)); | |
5844 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
5845 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5846 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
5847 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
5848 | return SCTP_DISPOSITION_ABORT; | |
5849 | } | |
5850 | ||
5851 | /* ADDIP 4.1 B3) Back-off the destination address RTO value to which | |
5852 | * the ASCONF chunk was sent by doubling the RTO timer value. | |
5853 | * This is done in SCTP_CMD_STRIKE. | |
5854 | */ | |
5855 | ||
5856 | /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible | |
5857 | * choose an alternate destination address (please refer to RFC2960 | |
5858 | * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this | |
5859 | * chunk, it MUST be the same (including its serial number) as the last | |
5860 | * ASCONF sent. | |
5861 | */ | |
5862 | sctp_chunk_hold(asoc->addip_last_asconf); | |
5863 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
5864 | SCTP_CHUNK(asoc->addip_last_asconf)); | |
5865 | ||
5866 | /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different | |
5867 | * destination is selected, then the RTO used will be that of the new | |
5868 | * destination address. | |
5869 | */ | |
5870 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, | |
5871 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); | |
5872 | ||
5873 | return SCTP_DISPOSITION_CONSUME; | |
5874 | } | |
5875 | ||
5876 | /* sctpimpguide-05 Section 2.12.2 | |
5877 | * The sender of the SHUTDOWN MAY also start an overall guard timer | |
5878 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. | |
5879 | * At the expiration of this timer the sender SHOULD abort the association | |
5880 | * by sending an ABORT chunk. | |
5881 | */ | |
5882 | sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net, | |
5883 | const struct sctp_endpoint *ep, | |
5884 | const struct sctp_association *asoc, | |
5885 | const sctp_subtype_t type, | |
5886 | void *arg, | |
5887 | sctp_cmd_seq_t *commands) | |
5888 | { | |
5889 | struct sctp_chunk *reply = NULL; | |
5890 | ||
5891 | pr_debug("%s: timer T5 expired\n", __func__); | |
5892 | ||
5893 | SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS); | |
5894 | ||
5895 | reply = sctp_make_abort(asoc, NULL, 0); | |
5896 | if (!reply) | |
5897 | goto nomem; | |
5898 | ||
5899 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); | |
5900 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
5901 | SCTP_ERROR(ETIMEDOUT)); | |
5902 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
5903 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); | |
5904 | ||
5905 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
5906 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
5907 | ||
5908 | return SCTP_DISPOSITION_DELETE_TCB; | |
5909 | nomem: | |
5910 | return SCTP_DISPOSITION_NOMEM; | |
5911 | } | |
5912 | ||
5913 | /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, | |
5914 | * the association is automatically closed by starting the shutdown process. | |
5915 | * The work that needs to be done is same as when SHUTDOWN is initiated by | |
5916 | * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). | |
5917 | */ | |
5918 | sctp_disposition_t sctp_sf_autoclose_timer_expire( | |
5919 | struct net *net, | |
5920 | const struct sctp_endpoint *ep, | |
5921 | const struct sctp_association *asoc, | |
5922 | const sctp_subtype_t type, | |
5923 | void *arg, | |
5924 | sctp_cmd_seq_t *commands) | |
5925 | { | |
5926 | int disposition; | |
5927 | ||
5928 | SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS); | |
5929 | ||
5930 | /* From 9.2 Shutdown of an Association | |
5931 | * Upon receipt of the SHUTDOWN primitive from its upper | |
5932 | * layer, the endpoint enters SHUTDOWN-PENDING state and | |
5933 | * remains there until all outstanding data has been | |
5934 | * acknowledged by its peer. The endpoint accepts no new data | |
5935 | * from its upper layer, but retransmits data to the far end | |
5936 | * if necessary to fill gaps. | |
5937 | */ | |
5938 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, | |
5939 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); | |
5940 | ||
5941 | disposition = SCTP_DISPOSITION_CONSUME; | |
5942 | if (sctp_outq_is_empty(&asoc->outqueue)) { | |
5943 | disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, | |
5944 | arg, commands); | |
5945 | } | |
5946 | return disposition; | |
5947 | } | |
5948 | ||
5949 | /***************************************************************************** | |
5950 | * These are sa state functions which could apply to all types of events. | |
5951 | ****************************************************************************/ | |
5952 | ||
5953 | /* | |
5954 | * This table entry is not implemented. | |
5955 | * | |
5956 | * Inputs | |
5957 | * (endpoint, asoc, chunk) | |
5958 | * | |
5959 | * The return value is the disposition of the chunk. | |
5960 | */ | |
5961 | sctp_disposition_t sctp_sf_not_impl(struct net *net, | |
5962 | const struct sctp_endpoint *ep, | |
5963 | const struct sctp_association *asoc, | |
5964 | const sctp_subtype_t type, | |
5965 | void *arg, | |
5966 | sctp_cmd_seq_t *commands) | |
5967 | { | |
5968 | return SCTP_DISPOSITION_NOT_IMPL; | |
5969 | } | |
5970 | ||
5971 | /* | |
5972 | * This table entry represents a bug. | |
5973 | * | |
5974 | * Inputs | |
5975 | * (endpoint, asoc, chunk) | |
5976 | * | |
5977 | * The return value is the disposition of the chunk. | |
5978 | */ | |
5979 | sctp_disposition_t sctp_sf_bug(struct net *net, | |
5980 | const struct sctp_endpoint *ep, | |
5981 | const struct sctp_association *asoc, | |
5982 | const sctp_subtype_t type, | |
5983 | void *arg, | |
5984 | sctp_cmd_seq_t *commands) | |
5985 | { | |
5986 | return SCTP_DISPOSITION_BUG; | |
5987 | } | |
5988 | ||
5989 | /* | |
5990 | * This table entry represents the firing of a timer in the wrong state. | |
5991 | * Since timer deletion cannot be guaranteed a timer 'may' end up firing | |
5992 | * when the association is in the wrong state. This event should | |
5993 | * be ignored, so as to prevent any rearming of the timer. | |
5994 | * | |
5995 | * Inputs | |
5996 | * (endpoint, asoc, chunk) | |
5997 | * | |
5998 | * The return value is the disposition of the chunk. | |
5999 | */ | |
6000 | sctp_disposition_t sctp_sf_timer_ignore(struct net *net, | |
6001 | const struct sctp_endpoint *ep, | |
6002 | const struct sctp_association *asoc, | |
6003 | const sctp_subtype_t type, | |
6004 | void *arg, | |
6005 | sctp_cmd_seq_t *commands) | |
6006 | { | |
6007 | pr_debug("%s: timer %d ignored\n", __func__, type.chunk); | |
6008 | ||
6009 | return SCTP_DISPOSITION_CONSUME; | |
6010 | } | |
6011 | ||
6012 | /******************************************************************** | |
6013 | * 2nd Level Abstractions | |
6014 | ********************************************************************/ | |
6015 | ||
6016 | /* Pull the SACK chunk based on the SACK header. */ | |
6017 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) | |
6018 | { | |
6019 | struct sctp_sackhdr *sack; | |
6020 | unsigned int len; | |
6021 | __u16 num_blocks; | |
6022 | __u16 num_dup_tsns; | |
6023 | ||
6024 | /* Protect ourselves from reading too far into | |
6025 | * the skb from a bogus sender. | |
6026 | */ | |
6027 | sack = (struct sctp_sackhdr *) chunk->skb->data; | |
6028 | ||
6029 | num_blocks = ntohs(sack->num_gap_ack_blocks); | |
6030 | num_dup_tsns = ntohs(sack->num_dup_tsns); | |
6031 | len = sizeof(struct sctp_sackhdr); | |
6032 | len += (num_blocks + num_dup_tsns) * sizeof(__u32); | |
6033 | if (len > chunk->skb->len) | |
6034 | return NULL; | |
6035 | ||
6036 | skb_pull(chunk->skb, len); | |
6037 | ||
6038 | return sack; | |
6039 | } | |
6040 | ||
6041 | /* Create an ABORT packet to be sent as a response, with the specified | |
6042 | * error causes. | |
6043 | */ | |
6044 | static struct sctp_packet *sctp_abort_pkt_new(struct net *net, | |
6045 | const struct sctp_endpoint *ep, | |
6046 | const struct sctp_association *asoc, | |
6047 | struct sctp_chunk *chunk, | |
6048 | const void *payload, | |
6049 | size_t paylen) | |
6050 | { | |
6051 | struct sctp_packet *packet; | |
6052 | struct sctp_chunk *abort; | |
6053 | ||
6054 | packet = sctp_ootb_pkt_new(net, asoc, chunk); | |
6055 | ||
6056 | if (packet) { | |
6057 | /* Make an ABORT. | |
6058 | * The T bit will be set if the asoc is NULL. | |
6059 | */ | |
6060 | abort = sctp_make_abort(asoc, chunk, paylen); | |
6061 | if (!abort) { | |
6062 | sctp_ootb_pkt_free(packet); | |
6063 | return NULL; | |
6064 | } | |
6065 | ||
6066 | /* Reflect vtag if T-Bit is set */ | |
6067 | if (sctp_test_T_bit(abort)) | |
6068 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); | |
6069 | ||
6070 | /* Add specified error causes, i.e., payload, to the | |
6071 | * end of the chunk. | |
6072 | */ | |
6073 | sctp_addto_chunk(abort, paylen, payload); | |
6074 | ||
6075 | /* Set the skb to the belonging sock for accounting. */ | |
6076 | abort->skb->sk = ep->base.sk; | |
6077 | ||
6078 | sctp_packet_append_chunk(packet, abort); | |
6079 | ||
6080 | } | |
6081 | ||
6082 | return packet; | |
6083 | } | |
6084 | ||
6085 | /* Allocate a packet for responding in the OOTB conditions. */ | |
6086 | static struct sctp_packet *sctp_ootb_pkt_new(struct net *net, | |
6087 | const struct sctp_association *asoc, | |
6088 | const struct sctp_chunk *chunk) | |
6089 | { | |
6090 | struct sctp_packet *packet; | |
6091 | struct sctp_transport *transport; | |
6092 | __u16 sport; | |
6093 | __u16 dport; | |
6094 | __u32 vtag; | |
6095 | ||
6096 | /* Get the source and destination port from the inbound packet. */ | |
6097 | sport = ntohs(chunk->sctp_hdr->dest); | |
6098 | dport = ntohs(chunk->sctp_hdr->source); | |
6099 | ||
6100 | /* The V-tag is going to be the same as the inbound packet if no | |
6101 | * association exists, otherwise, use the peer's vtag. | |
6102 | */ | |
6103 | if (asoc) { | |
6104 | /* Special case the INIT-ACK as there is no peer's vtag | |
6105 | * yet. | |
6106 | */ | |
6107 | switch (chunk->chunk_hdr->type) { | |
6108 | case SCTP_CID_INIT_ACK: | |
6109 | { | |
6110 | sctp_initack_chunk_t *initack; | |
6111 | ||
6112 | initack = (sctp_initack_chunk_t *)chunk->chunk_hdr; | |
6113 | vtag = ntohl(initack->init_hdr.init_tag); | |
6114 | break; | |
6115 | } | |
6116 | default: | |
6117 | vtag = asoc->peer.i.init_tag; | |
6118 | break; | |
6119 | } | |
6120 | } else { | |
6121 | /* Special case the INIT and stale COOKIE_ECHO as there is no | |
6122 | * vtag yet. | |
6123 | */ | |
6124 | switch (chunk->chunk_hdr->type) { | |
6125 | case SCTP_CID_INIT: | |
6126 | { | |
6127 | struct sctp_init_chunk *init; | |
6128 | ||
6129 | init = (struct sctp_init_chunk *)chunk->chunk_hdr; | |
6130 | vtag = ntohl(init->init_hdr.init_tag); | |
6131 | break; | |
6132 | } | |
6133 | default: | |
6134 | vtag = ntohl(chunk->sctp_hdr->vtag); | |
6135 | break; | |
6136 | } | |
6137 | } | |
6138 | ||
6139 | /* Make a transport for the bucket, Eliza... */ | |
6140 | transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC); | |
6141 | if (!transport) | |
6142 | goto nomem; | |
6143 | ||
6144 | /* Cache a route for the transport with the chunk's destination as | |
6145 | * the source address. | |
6146 | */ | |
6147 | sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, | |
6148 | sctp_sk(net->sctp.ctl_sock)); | |
6149 | ||
6150 | packet = &transport->packet; | |
6151 | sctp_packet_init(packet, transport, sport, dport); | |
6152 | sctp_packet_config(packet, vtag, 0); | |
6153 | ||
6154 | return packet; | |
6155 | ||
6156 | nomem: | |
6157 | return NULL; | |
6158 | } | |
6159 | ||
6160 | /* Free the packet allocated earlier for responding in the OOTB condition. */ | |
6161 | void sctp_ootb_pkt_free(struct sctp_packet *packet) | |
6162 | { | |
6163 | sctp_transport_free(packet->transport); | |
6164 | } | |
6165 | ||
6166 | /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ | |
6167 | static void sctp_send_stale_cookie_err(struct net *net, | |
6168 | const struct sctp_endpoint *ep, | |
6169 | const struct sctp_association *asoc, | |
6170 | const struct sctp_chunk *chunk, | |
6171 | sctp_cmd_seq_t *commands, | |
6172 | struct sctp_chunk *err_chunk) | |
6173 | { | |
6174 | struct sctp_packet *packet; | |
6175 | ||
6176 | if (err_chunk) { | |
6177 | packet = sctp_ootb_pkt_new(net, asoc, chunk); | |
6178 | if (packet) { | |
6179 | struct sctp_signed_cookie *cookie; | |
6180 | ||
6181 | /* Override the OOTB vtag from the cookie. */ | |
6182 | cookie = chunk->subh.cookie_hdr; | |
6183 | packet->vtag = cookie->c.peer_vtag; | |
6184 | ||
6185 | /* Set the skb to the belonging sock for accounting. */ | |
6186 | err_chunk->skb->sk = ep->base.sk; | |
6187 | sctp_packet_append_chunk(packet, err_chunk); | |
6188 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, | |
6189 | SCTP_PACKET(packet)); | |
6190 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); | |
6191 | } else | |
6192 | sctp_chunk_free (err_chunk); | |
6193 | } | |
6194 | } | |
6195 | ||
6196 | ||
6197 | /* Process a data chunk */ | |
6198 | static int sctp_eat_data(const struct sctp_association *asoc, | |
6199 | struct sctp_chunk *chunk, | |
6200 | sctp_cmd_seq_t *commands) | |
6201 | { | |
6202 | struct sctp_datahdr *data_hdr; | |
6203 | struct sctp_chunk *err; | |
6204 | size_t datalen; | |
6205 | sctp_verb_t deliver; | |
6206 | int tmp; | |
6207 | __u32 tsn; | |
6208 | struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; | |
6209 | struct sock *sk = asoc->base.sk; | |
6210 | struct net *net = sock_net(sk); | |
6211 | u16 ssn; | |
6212 | u16 sid; | |
6213 | u8 ordered = 0; | |
6214 | ||
6215 | data_hdr = (struct sctp_datahdr *)chunk->skb->data; | |
6216 | chunk->subh.data_hdr = data_hdr; | |
6217 | skb_pull(chunk->skb, sizeof(*data_hdr)); | |
6218 | ||
6219 | tsn = ntohl(data_hdr->tsn); | |
6220 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); | |
6221 | ||
6222 | /* ASSERT: Now skb->data is really the user data. */ | |
6223 | ||
6224 | /* Process ECN based congestion. | |
6225 | * | |
6226 | * Since the chunk structure is reused for all chunks within | |
6227 | * a packet, we use ecn_ce_done to track if we've already | |
6228 | * done CE processing for this packet. | |
6229 | * | |
6230 | * We need to do ECN processing even if we plan to discard the | |
6231 | * chunk later. | |
6232 | */ | |
6233 | ||
6234 | if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) { | |
6235 | struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af; | |
6236 | chunk->ecn_ce_done = 1; | |
6237 | ||
6238 | if (af->is_ce(sctp_gso_headskb(chunk->skb))) { | |
6239 | /* Do real work as sideffect. */ | |
6240 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, | |
6241 | SCTP_U32(tsn)); | |
6242 | } | |
6243 | } | |
6244 | ||
6245 | tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); | |
6246 | if (tmp < 0) { | |
6247 | /* The TSN is too high--silently discard the chunk and | |
6248 | * count on it getting retransmitted later. | |
6249 | */ | |
6250 | if (chunk->asoc) | |
6251 | chunk->asoc->stats.outofseqtsns++; | |
6252 | return SCTP_IERROR_HIGH_TSN; | |
6253 | } else if (tmp > 0) { | |
6254 | /* This is a duplicate. Record it. */ | |
6255 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); | |
6256 | return SCTP_IERROR_DUP_TSN; | |
6257 | } | |
6258 | ||
6259 | /* This is a new TSN. */ | |
6260 | ||
6261 | /* Discard if there is no room in the receive window. | |
6262 | * Actually, allow a little bit of overflow (up to a MTU). | |
6263 | */ | |
6264 | datalen = ntohs(chunk->chunk_hdr->length); | |
6265 | datalen -= sizeof(struct sctp_data_chunk); | |
6266 | ||
6267 | deliver = SCTP_CMD_CHUNK_ULP; | |
6268 | ||
6269 | /* Think about partial delivery. */ | |
6270 | if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { | |
6271 | ||
6272 | /* Even if we don't accept this chunk there is | |
6273 | * memory pressure. | |
6274 | */ | |
6275 | sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); | |
6276 | } | |
6277 | ||
6278 | /* Spill over rwnd a little bit. Note: While allowed, this spill over | |
6279 | * seems a bit troublesome in that frag_point varies based on | |
6280 | * PMTU. In cases, such as loopback, this might be a rather | |
6281 | * large spill over. | |
6282 | */ | |
6283 | if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over || | |
6284 | (datalen > asoc->rwnd + asoc->frag_point))) { | |
6285 | ||
6286 | /* If this is the next TSN, consider reneging to make | |
6287 | * room. Note: Playing nice with a confused sender. A | |
6288 | * malicious sender can still eat up all our buffer | |
6289 | * space and in the future we may want to detect and | |
6290 | * do more drastic reneging. | |
6291 | */ | |
6292 | if (sctp_tsnmap_has_gap(map) && | |
6293 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { | |
6294 | pr_debug("%s: reneging for tsn:%u\n", __func__, tsn); | |
6295 | deliver = SCTP_CMD_RENEGE; | |
6296 | } else { | |
6297 | pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n", | |
6298 | __func__, tsn, datalen, asoc->rwnd); | |
6299 | ||
6300 | return SCTP_IERROR_IGNORE_TSN; | |
6301 | } | |
6302 | } | |
6303 | ||
6304 | /* | |
6305 | * Also try to renege to limit our memory usage in the event that | |
6306 | * we are under memory pressure | |
6307 | * If we can't renege, don't worry about it, the sk_rmem_schedule | |
6308 | * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our | |
6309 | * memory usage too much | |
6310 | */ | |
6311 | if (*sk->sk_prot_creator->memory_pressure) { | |
6312 | if (sctp_tsnmap_has_gap(map) && | |
6313 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { | |
6314 | pr_debug("%s: under pressure, reneging for tsn:%u\n", | |
6315 | __func__, tsn); | |
6316 | deliver = SCTP_CMD_RENEGE; | |
6317 | } | |
6318 | } | |
6319 | ||
6320 | /* | |
6321 | * Section 3.3.10.9 No User Data (9) | |
6322 | * | |
6323 | * Cause of error | |
6324 | * --------------- | |
6325 | * No User Data: This error cause is returned to the originator of a | |
6326 | * DATA chunk if a received DATA chunk has no user data. | |
6327 | */ | |
6328 | if (unlikely(0 == datalen)) { | |
6329 | err = sctp_make_abort_no_data(asoc, chunk, tsn); | |
6330 | if (err) { | |
6331 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
6332 | SCTP_CHUNK(err)); | |
6333 | } | |
6334 | /* We are going to ABORT, so we might as well stop | |
6335 | * processing the rest of the chunks in the packet. | |
6336 | */ | |
6337 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); | |
6338 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, | |
6339 | SCTP_ERROR(ECONNABORTED)); | |
6340 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, | |
6341 | SCTP_PERR(SCTP_ERROR_NO_DATA)); | |
6342 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); | |
6343 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); | |
6344 | return SCTP_IERROR_NO_DATA; | |
6345 | } | |
6346 | ||
6347 | chunk->data_accepted = 1; | |
6348 | ||
6349 | /* Note: Some chunks may get overcounted (if we drop) or overcounted | |
6350 | * if we renege and the chunk arrives again. | |
6351 | */ | |
6352 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { | |
6353 | SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS); | |
6354 | if (chunk->asoc) | |
6355 | chunk->asoc->stats.iuodchunks++; | |
6356 | } else { | |
6357 | SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS); | |
6358 | if (chunk->asoc) | |
6359 | chunk->asoc->stats.iodchunks++; | |
6360 | ordered = 1; | |
6361 | } | |
6362 | ||
6363 | /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number | |
6364 | * | |
6365 | * If an endpoint receive a DATA chunk with an invalid stream | |
6366 | * identifier, it shall acknowledge the reception of the DATA chunk | |
6367 | * following the normal procedure, immediately send an ERROR chunk | |
6368 | * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) | |
6369 | * and discard the DATA chunk. | |
6370 | */ | |
6371 | sid = ntohs(data_hdr->stream); | |
6372 | if (sid >= asoc->stream.incnt) { | |
6373 | /* Mark tsn as received even though we drop it */ | |
6374 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); | |
6375 | ||
6376 | err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, | |
6377 | &data_hdr->stream, | |
6378 | sizeof(data_hdr->stream), | |
6379 | sizeof(u16)); | |
6380 | if (err) | |
6381 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, | |
6382 | SCTP_CHUNK(err)); | |
6383 | return SCTP_IERROR_BAD_STREAM; | |
6384 | } | |
6385 | ||
6386 | /* Check to see if the SSN is possible for this TSN. | |
6387 | * The biggest gap we can record is 4K wide. Since SSNs wrap | |
6388 | * at an unsigned short, there is no way that an SSN can | |
6389 | * wrap and for a valid TSN. We can simply check if the current | |
6390 | * SSN is smaller then the next expected one. If it is, it wrapped | |
6391 | * and is invalid. | |
6392 | */ | |
6393 | ssn = ntohs(data_hdr->ssn); | |
6394 | if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->stream, in, sid))) | |
6395 | return SCTP_IERROR_PROTO_VIOLATION; | |
6396 | ||
6397 | /* Send the data up to the user. Note: Schedule the | |
6398 | * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK | |
6399 | * chunk needs the updated rwnd. | |
6400 | */ | |
6401 | sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); | |
6402 | ||
6403 | return SCTP_IERROR_NO_ERROR; | |
6404 | } |