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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: 1 = Valid length |
164 | * 0 = Invalid length |
165 | * |
166 | */ |
167 | static inline int |
168 | sctp_chunk_length_valid(struct sctp_chunk *chunk, |
169 | __u16 required_length) |
170 | { |
171 | __u16 chunk_length = ntohs(chunk->chunk_hdr->length); |
172 | |
173 | if (unlikely(chunk_length < required_length)) |
174 | return 0; |
175 | |
176 | return 1; |
177 | } |
178 | |
179 | /********************************************************** |
180 | * These are the state functions for handling chunk events. |
181 | **********************************************************/ |
182 | |
183 | /* |
184 | * Process the final SHUTDOWN COMPLETE. |
185 | * |
186 | * Section: 4 (C) (diagram), 9.2 |
187 | * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify |
188 | * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be |
189 | * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint |
190 | * should stop the T2-shutdown timer and remove all knowledge of the |
191 | * association (and thus the association enters the CLOSED state). |
192 | * |
193 | * Verification Tag: 8.5.1(C), sctpimpguide 2.41. |
194 | * C) Rules for packet carrying SHUTDOWN COMPLETE: |
195 | * ... |
196 | * - The receiver of a SHUTDOWN COMPLETE shall accept the packet |
197 | * if the Verification Tag field of the packet matches its own tag and |
198 | * the T bit is not set |
199 | * OR |
200 | * it is set to its peer's tag and the T bit is set in the Chunk |
201 | * Flags. |
202 | * Otherwise, the receiver MUST silently discard the packet |
203 | * and take no further action. An endpoint MUST ignore the |
204 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. |
205 | * |
206 | * Inputs |
207 | * (endpoint, asoc, chunk) |
208 | * |
209 | * Outputs |
210 | * (asoc, reply_msg, msg_up, timers, counters) |
211 | * |
212 | * The return value is the disposition of the chunk. |
213 | */ |
214 | sctp_disposition_t sctp_sf_do_4_C(struct net *net, |
215 | const struct sctp_endpoint *ep, |
216 | const struct sctp_association *asoc, |
217 | const sctp_subtype_t type, |
218 | void *arg, |
219 | sctp_cmd_seq_t *commands) |
220 | { |
221 | struct sctp_chunk *chunk = arg; |
222 | struct sctp_ulpevent *ev; |
223 | |
224 | if (!sctp_vtag_verify_either(chunk, asoc)) |
225 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
226 | |
227 | /* RFC 2960 6.10 Bundling |
228 | * |
229 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
230 | * SHUTDOWN COMPLETE with any other chunks. |
231 | */ |
232 | if (!chunk->singleton) |
233 | return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); |
234 | |
235 | /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */ |
236 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
237 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
238 | commands); |
239 | |
240 | /* RFC 2960 10.2 SCTP-to-ULP |
241 | * |
242 | * H) SHUTDOWN COMPLETE notification |
243 | * |
244 | * When SCTP completes the shutdown procedures (section 9.2) this |
245 | * notification is passed to the upper layer. |
246 | */ |
247 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
248 | 0, 0, 0, NULL, GFP_ATOMIC); |
249 | if (ev) |
250 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
251 | SCTP_ULPEVENT(ev)); |
252 | |
253 | /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint |
254 | * will verify that it is in SHUTDOWN-ACK-SENT state, if it is |
255 | * not the chunk should be discarded. If the endpoint is in |
256 | * the SHUTDOWN-ACK-SENT state the endpoint should stop the |
257 | * T2-shutdown timer and remove all knowledge of the |
258 | * association (and thus the association enters the CLOSED |
259 | * state). |
260 | */ |
261 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
262 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
263 | |
264 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
265 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
266 | |
267 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
268 | SCTP_STATE(SCTP_STATE_CLOSED)); |
269 | |
270 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
271 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
272 | |
273 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
274 | |
275 | return SCTP_DISPOSITION_DELETE_TCB; |
276 | } |
277 | |
278 | /* |
279 | * Respond to a normal INIT chunk. |
280 | * We are the side that is being asked for an association. |
281 | * |
282 | * Section: 5.1 Normal Establishment of an Association, B |
283 | * B) "Z" shall respond immediately with an INIT ACK chunk. The |
284 | * destination IP address of the INIT ACK MUST be set to the source |
285 | * IP address of the INIT to which this INIT ACK is responding. In |
286 | * the response, besides filling in other parameters, "Z" must set the |
287 | * Verification Tag field to Tag_A, and also provide its own |
288 | * Verification Tag (Tag_Z) in the Initiate Tag field. |
289 | * |
290 | * Verification Tag: Must be 0. |
291 | * |
292 | * Inputs |
293 | * (endpoint, asoc, chunk) |
294 | * |
295 | * Outputs |
296 | * (asoc, reply_msg, msg_up, timers, counters) |
297 | * |
298 | * The return value is the disposition of the chunk. |
299 | */ |
300 | sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net, |
301 | const struct sctp_endpoint *ep, |
302 | const struct sctp_association *asoc, |
303 | const sctp_subtype_t type, |
304 | void *arg, |
305 | sctp_cmd_seq_t *commands) |
306 | { |
307 | struct sctp_chunk *chunk = arg; |
308 | struct sctp_chunk *repl; |
309 | struct sctp_association *new_asoc; |
310 | struct sctp_chunk *err_chunk; |
311 | struct sctp_packet *packet; |
312 | sctp_unrecognized_param_t *unk_param; |
313 | int len; |
314 | |
315 | /* 6.10 Bundling |
316 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
317 | * SHUTDOWN COMPLETE with any other chunks. |
318 | * |
319 | * IG Section 2.11.2 |
320 | * Furthermore, we require that the receiver of an INIT chunk MUST |
321 | * enforce these rules by silently discarding an arriving packet |
322 | * with an INIT chunk that is bundled with other chunks. |
323 | */ |
324 | if (!chunk->singleton) |
325 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
326 | |
327 | /* If the packet is an OOTB packet which is temporarily on the |
328 | * control endpoint, respond with an ABORT. |
329 | */ |
330 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { |
331 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
332 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
333 | } |
334 | |
335 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
336 | * Tag. |
337 | */ |
338 | if (chunk->sctp_hdr->vtag != 0) |
339 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
340 | |
341 | /* Make sure that the INIT chunk has a valid length. |
342 | * Normally, this would cause an ABORT with a Protocol Violation |
343 | * error, but since we don't have an association, we'll |
344 | * just discard the packet. |
345 | */ |
346 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
347 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
348 | |
349 | /* If the INIT is coming toward a closing socket, we'll send back |
350 | * and ABORT. Essentially, this catches the race of INIT being |
351 | * backloged to the socket at the same time as the user isses close(). |
352 | * Since the socket and all its associations are going away, we |
353 | * can treat this OOTB |
354 | */ |
355 | if (sctp_sstate(ep->base.sk, CLOSING)) |
356 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
357 | |
358 | /* Verify the INIT chunk before processing it. */ |
359 | err_chunk = NULL; |
360 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
361 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
362 | &err_chunk)) { |
363 | /* This chunk contains fatal error. It is to be discarded. |
364 | * Send an ABORT, with causes if there is any. |
365 | */ |
366 | if (err_chunk) { |
367 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
368 | (__u8 *)(err_chunk->chunk_hdr) + |
369 | sizeof(sctp_chunkhdr_t), |
370 | ntohs(err_chunk->chunk_hdr->length) - |
371 | sizeof(sctp_chunkhdr_t)); |
372 | |
373 | sctp_chunk_free(err_chunk); |
374 | |
375 | if (packet) { |
376 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
377 | SCTP_PACKET(packet)); |
378 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
379 | return SCTP_DISPOSITION_CONSUME; |
380 | } else { |
381 | return SCTP_DISPOSITION_NOMEM; |
382 | } |
383 | } else { |
384 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, |
385 | commands); |
386 | } |
387 | } |
388 | |
389 | /* Grab the INIT header. */ |
390 | chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data; |
391 | |
392 | /* Tag the variable length parameters. */ |
393 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
394 | |
395 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
396 | if (!new_asoc) |
397 | goto nomem; |
398 | |
399 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, |
400 | sctp_scope(sctp_source(chunk)), |
401 | GFP_ATOMIC) < 0) |
402 | goto nomem_init; |
403 | |
404 | /* The call, sctp_process_init(), can fail on memory allocation. */ |
405 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), |
406 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
407 | GFP_ATOMIC)) |
408 | goto nomem_init; |
409 | |
410 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
411 | |
412 | /* If there are errors need to be reported for unknown parameters, |
413 | * make sure to reserve enough room in the INIT ACK for them. |
414 | */ |
415 | len = 0; |
416 | if (err_chunk) |
417 | len = ntohs(err_chunk->chunk_hdr->length) - |
418 | sizeof(sctp_chunkhdr_t); |
419 | |
420 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
421 | if (!repl) |
422 | goto nomem_init; |
423 | |
424 | /* If there are errors need to be reported for unknown parameters, |
425 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
426 | * parameter. |
427 | */ |
428 | if (err_chunk) { |
429 | /* Get the "Unrecognized parameter" parameter(s) out of the |
430 | * ERROR chunk generated by sctp_verify_init(). Since the |
431 | * error cause code for "unknown parameter" and the |
432 | * "Unrecognized parameter" type is the same, we can |
433 | * construct the parameters in INIT ACK by copying the |
434 | * ERROR causes over. |
435 | */ |
436 | unk_param = (sctp_unrecognized_param_t *) |
437 | ((__u8 *)(err_chunk->chunk_hdr) + |
438 | sizeof(sctp_chunkhdr_t)); |
439 | /* Replace the cause code with the "Unrecognized parameter" |
440 | * parameter type. |
441 | */ |
442 | sctp_addto_chunk(repl, len, unk_param); |
443 | sctp_chunk_free(err_chunk); |
444 | } |
445 | |
446 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
447 | |
448 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
449 | |
450 | /* |
451 | * Note: After sending out INIT ACK with the State Cookie parameter, |
452 | * "Z" MUST NOT allocate any resources, nor keep any states for the |
453 | * new association. Otherwise, "Z" will be vulnerable to resource |
454 | * attacks. |
455 | */ |
456 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
457 | |
458 | return SCTP_DISPOSITION_DELETE_TCB; |
459 | |
460 | nomem_init: |
461 | sctp_association_free(new_asoc); |
462 | nomem: |
463 | if (err_chunk) |
464 | sctp_chunk_free(err_chunk); |
465 | return SCTP_DISPOSITION_NOMEM; |
466 | } |
467 | |
468 | /* |
469 | * Respond to a normal INIT ACK chunk. |
470 | * We are the side that is initiating the association. |
471 | * |
472 | * Section: 5.1 Normal Establishment of an Association, C |
473 | * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init |
474 | * timer and leave COOKIE-WAIT state. "A" shall then send the State |
475 | * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start |
476 | * the T1-cookie timer, and enter the COOKIE-ECHOED state. |
477 | * |
478 | * Note: The COOKIE ECHO chunk can be bundled with any pending outbound |
479 | * DATA chunks, but it MUST be the first chunk in the packet and |
480 | * until the COOKIE ACK is returned the sender MUST NOT send any |
481 | * other packets to the peer. |
482 | * |
483 | * Verification Tag: 3.3.3 |
484 | * If the value of the Initiate Tag in a received INIT ACK chunk is |
485 | * found to be 0, the receiver MUST treat it as an error and close the |
486 | * association by transmitting an ABORT. |
487 | * |
488 | * Inputs |
489 | * (endpoint, asoc, chunk) |
490 | * |
491 | * Outputs |
492 | * (asoc, reply_msg, msg_up, timers, counters) |
493 | * |
494 | * The return value is the disposition of the chunk. |
495 | */ |
496 | sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net, |
497 | const struct sctp_endpoint *ep, |
498 | const struct sctp_association *asoc, |
499 | const sctp_subtype_t type, |
500 | void *arg, |
501 | sctp_cmd_seq_t *commands) |
502 | { |
503 | struct sctp_chunk *chunk = arg; |
504 | sctp_init_chunk_t *initchunk; |
505 | struct sctp_chunk *err_chunk; |
506 | struct sctp_packet *packet; |
507 | |
508 | if (!sctp_vtag_verify(chunk, asoc)) |
509 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
510 | |
511 | /* 6.10 Bundling |
512 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
513 | * SHUTDOWN COMPLETE with any other chunks. |
514 | */ |
515 | if (!chunk->singleton) |
516 | return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); |
517 | |
518 | /* Make sure that the INIT-ACK chunk has a valid length */ |
519 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t))) |
520 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
521 | commands); |
522 | /* Grab the INIT header. */ |
523 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
524 | |
525 | /* Verify the INIT chunk before processing it. */ |
526 | err_chunk = NULL; |
527 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
528 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
529 | &err_chunk)) { |
530 | |
531 | sctp_error_t error = SCTP_ERROR_NO_RESOURCE; |
532 | |
533 | /* This chunk contains fatal error. It is to be discarded. |
534 | * Send an ABORT, with causes. If there are no causes, |
535 | * then there wasn't enough memory. Just terminate |
536 | * the association. |
537 | */ |
538 | if (err_chunk) { |
539 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
540 | (__u8 *)(err_chunk->chunk_hdr) + |
541 | sizeof(sctp_chunkhdr_t), |
542 | ntohs(err_chunk->chunk_hdr->length) - |
543 | sizeof(sctp_chunkhdr_t)); |
544 | |
545 | sctp_chunk_free(err_chunk); |
546 | |
547 | if (packet) { |
548 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
549 | SCTP_PACKET(packet)); |
550 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
551 | error = SCTP_ERROR_INV_PARAM; |
552 | } |
553 | } |
554 | |
555 | /* SCTP-AUTH, Section 6.3: |
556 | * It should be noted that if the receiver wants to tear |
557 | * down an association in an authenticated way only, the |
558 | * handling of malformed packets should not result in |
559 | * tearing down the association. |
560 | * |
561 | * This means that if we only want to abort associations |
562 | * in an authenticated way (i.e AUTH+ABORT), then we |
563 | * can't destroy this association just because the packet |
564 | * was malformed. |
565 | */ |
566 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
567 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
568 | |
569 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
570 | return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, |
571 | asoc, chunk->transport); |
572 | } |
573 | |
574 | /* Tag the variable length parameters. Note that we never |
575 | * convert the parameters in an INIT chunk. |
576 | */ |
577 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
578 | |
579 | initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr; |
580 | |
581 | sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, |
582 | SCTP_PEER_INIT(initchunk)); |
583 | |
584 | /* Reset init error count upon receipt of INIT-ACK. */ |
585 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
586 | |
587 | /* 5.1 C) "A" shall stop the T1-init timer and leave |
588 | * COOKIE-WAIT state. "A" shall then ... start the T1-cookie |
589 | * timer, and enter the COOKIE-ECHOED state. |
590 | */ |
591 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
592 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
593 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
594 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
595 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
596 | SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); |
597 | |
598 | /* SCTP-AUTH: genereate the assocition shared keys so that |
599 | * we can potentially signe the COOKIE-ECHO. |
600 | */ |
601 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL()); |
602 | |
603 | /* 5.1 C) "A" shall then send the State Cookie received in the |
604 | * INIT ACK chunk in a COOKIE ECHO chunk, ... |
605 | */ |
606 | /* If there is any errors to report, send the ERROR chunk generated |
607 | * for unknown parameters as well. |
608 | */ |
609 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, |
610 | SCTP_CHUNK(err_chunk)); |
611 | |
612 | return SCTP_DISPOSITION_CONSUME; |
613 | } |
614 | |
615 | /* |
616 | * Respond to a normal COOKIE ECHO chunk. |
617 | * We are the side that is being asked for an association. |
618 | * |
619 | * Section: 5.1 Normal Establishment of an Association, D |
620 | * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply |
621 | * with a COOKIE ACK chunk after building a TCB and moving to |
622 | * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with |
623 | * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK |
624 | * chunk MUST be the first chunk in the packet. |
625 | * |
626 | * IMPLEMENTATION NOTE: An implementation may choose to send the |
627 | * Communication Up notification to the SCTP user upon reception |
628 | * of a valid COOKIE ECHO chunk. |
629 | * |
630 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
631 | * D) Rules for packet carrying a COOKIE ECHO |
632 | * |
633 | * - When sending a COOKIE ECHO, the endpoint MUST use the value of the |
634 | * Initial Tag received in the INIT ACK. |
635 | * |
636 | * - The receiver of a COOKIE ECHO follows the procedures in Section 5. |
637 | * |
638 | * Inputs |
639 | * (endpoint, asoc, chunk) |
640 | * |
641 | * Outputs |
642 | * (asoc, reply_msg, msg_up, timers, counters) |
643 | * |
644 | * The return value is the disposition of the chunk. |
645 | */ |
646 | sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net, |
647 | const struct sctp_endpoint *ep, |
648 | const struct sctp_association *asoc, |
649 | const sctp_subtype_t type, void *arg, |
650 | sctp_cmd_seq_t *commands) |
651 | { |
652 | struct sctp_chunk *chunk = arg; |
653 | struct sctp_association *new_asoc; |
654 | sctp_init_chunk_t *peer_init; |
655 | struct sctp_chunk *repl; |
656 | struct sctp_ulpevent *ev, *ai_ev = NULL; |
657 | int error = 0; |
658 | struct sctp_chunk *err_chk_p; |
659 | struct sock *sk; |
660 | |
661 | /* If the packet is an OOTB packet which is temporarily on the |
662 | * control endpoint, respond with an ABORT. |
663 | */ |
664 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { |
665 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
666 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
667 | } |
668 | |
669 | /* Make sure that the COOKIE_ECHO chunk has a valid length. |
670 | * In this case, we check that we have enough for at least a |
671 | * chunk header. More detailed verification is done |
672 | * in sctp_unpack_cookie(). |
673 | */ |
674 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
675 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
676 | |
677 | /* If the endpoint is not listening or if the number of associations |
678 | * on the TCP-style socket exceed the max backlog, respond with an |
679 | * ABORT. |
680 | */ |
681 | sk = ep->base.sk; |
682 | if (!sctp_sstate(sk, LISTENING) || |
683 | (sctp_style(sk, TCP) && sk_acceptq_is_full(sk))) |
684 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
685 | |
686 | /* "Decode" the chunk. We have no optional parameters so we |
687 | * are in good shape. |
688 | */ |
689 | chunk->subh.cookie_hdr = |
690 | (struct sctp_signed_cookie *)chunk->skb->data; |
691 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
692 | sizeof(sctp_chunkhdr_t))) |
693 | goto nomem; |
694 | |
695 | /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint |
696 | * "Z" will reply with a COOKIE ACK chunk after building a TCB |
697 | * and moving to the ESTABLISHED state. |
698 | */ |
699 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
700 | &err_chk_p); |
701 | |
702 | /* FIXME: |
703 | * If the re-build failed, what is the proper error path |
704 | * from here? |
705 | * |
706 | * [We should abort the association. --piggy] |
707 | */ |
708 | if (!new_asoc) { |
709 | /* FIXME: Several errors are possible. A bad cookie should |
710 | * be silently discarded, but think about logging it too. |
711 | */ |
712 | switch (error) { |
713 | case -SCTP_IERROR_NOMEM: |
714 | goto nomem; |
715 | |
716 | case -SCTP_IERROR_STALE_COOKIE: |
717 | sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, |
718 | err_chk_p); |
719 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
720 | |
721 | case -SCTP_IERROR_BAD_SIG: |
722 | default: |
723 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
724 | } |
725 | } |
726 | |
727 | |
728 | /* Delay state machine commands until later. |
729 | * |
730 | * Re-build the bind address for the association is done in |
731 | * the sctp_unpack_cookie() already. |
732 | */ |
733 | /* This is a brand-new association, so these are not yet side |
734 | * effects--it is safe to run them here. |
735 | */ |
736 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
737 | |
738 | if (!sctp_process_init(new_asoc, chunk, |
739 | &chunk->subh.cookie_hdr->c.peer_addr, |
740 | peer_init, GFP_ATOMIC)) |
741 | goto nomem_init; |
742 | |
743 | /* SCTP-AUTH: Now that we've populate required fields in |
744 | * sctp_process_init, set up the assocaition shared keys as |
745 | * necessary so that we can potentially authenticate the ACK |
746 | */ |
747 | error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC); |
748 | if (error) |
749 | goto nomem_init; |
750 | |
751 | /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo |
752 | * is supposed to be authenticated and we have to do delayed |
753 | * authentication. We've just recreated the association using |
754 | * the information in the cookie and now it's much easier to |
755 | * do the authentication. |
756 | */ |
757 | if (chunk->auth_chunk) { |
758 | struct sctp_chunk auth; |
759 | sctp_ierror_t ret; |
760 | |
761 | /* Make sure that we and the peer are AUTH capable */ |
762 | if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) { |
763 | sctp_association_free(new_asoc); |
764 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
765 | } |
766 | |
767 | /* set-up our fake chunk so that we can process it */ |
768 | auth.skb = chunk->auth_chunk; |
769 | auth.asoc = chunk->asoc; |
770 | auth.sctp_hdr = chunk->sctp_hdr; |
771 | auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk, |
772 | sizeof(sctp_chunkhdr_t)); |
773 | skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t)); |
774 | auth.transport = chunk->transport; |
775 | |
776 | ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth); |
777 | if (ret != SCTP_IERROR_NO_ERROR) { |
778 | sctp_association_free(new_asoc); |
779 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
780 | } |
781 | } |
782 | |
783 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
784 | if (!repl) |
785 | goto nomem_init; |
786 | |
787 | /* RFC 2960 5.1 Normal Establishment of an Association |
788 | * |
789 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
790 | * send the Communication Up notification to the SCTP user |
791 | * upon reception of a valid COOKIE ECHO chunk. |
792 | */ |
793 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, |
794 | new_asoc->c.sinit_num_ostreams, |
795 | new_asoc->c.sinit_max_instreams, |
796 | NULL, GFP_ATOMIC); |
797 | if (!ev) |
798 | goto nomem_ev; |
799 | |
800 | /* Sockets API Draft Section 5.3.1.6 |
801 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
802 | * delivers this notification to inform the application that of the |
803 | * peers requested adaptation layer. |
804 | */ |
805 | if (new_asoc->peer.adaptation_ind) { |
806 | ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc, |
807 | GFP_ATOMIC); |
808 | if (!ai_ev) |
809 | goto nomem_aiev; |
810 | } |
811 | |
812 | /* Add all the state machine commands now since we've created |
813 | * everything. This way we don't introduce memory corruptions |
814 | * during side-effect processing and correclty count established |
815 | * associations. |
816 | */ |
817 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
818 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
819 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
820 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
821 | SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS); |
822 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
823 | |
824 | if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
825 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
826 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
827 | |
828 | /* This will send the COOKIE ACK */ |
829 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
830 | |
831 | /* Queue the ASSOC_CHANGE event */ |
832 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
833 | |
834 | /* Send up the Adaptation Layer Indication event */ |
835 | if (ai_ev) |
836 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
837 | SCTP_ULPEVENT(ai_ev)); |
838 | |
839 | return SCTP_DISPOSITION_CONSUME; |
840 | |
841 | nomem_aiev: |
842 | sctp_ulpevent_free(ev); |
843 | nomem_ev: |
844 | sctp_chunk_free(repl); |
845 | nomem_init: |
846 | sctp_association_free(new_asoc); |
847 | nomem: |
848 | return SCTP_DISPOSITION_NOMEM; |
849 | } |
850 | |
851 | /* |
852 | * Respond to a normal COOKIE ACK chunk. |
853 | * We are the side that is being asked for an association. |
854 | * |
855 | * RFC 2960 5.1 Normal Establishment of an Association |
856 | * |
857 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the |
858 | * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie |
859 | * timer. It may also notify its ULP about the successful |
860 | * establishment of the association with a Communication Up |
861 | * notification (see Section 10). |
862 | * |
863 | * Verification Tag: |
864 | * Inputs |
865 | * (endpoint, asoc, chunk) |
866 | * |
867 | * Outputs |
868 | * (asoc, reply_msg, msg_up, timers, counters) |
869 | * |
870 | * The return value is the disposition of the chunk. |
871 | */ |
872 | sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net, |
873 | const struct sctp_endpoint *ep, |
874 | const struct sctp_association *asoc, |
875 | const sctp_subtype_t type, void *arg, |
876 | sctp_cmd_seq_t *commands) |
877 | { |
878 | struct sctp_chunk *chunk = arg; |
879 | struct sctp_ulpevent *ev; |
880 | |
881 | if (!sctp_vtag_verify(chunk, asoc)) |
882 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
883 | |
884 | /* Verify that the chunk length for the COOKIE-ACK is OK. |
885 | * If we don't do this, any bundled chunks may be junked. |
886 | */ |
887 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
888 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
889 | commands); |
890 | |
891 | /* Reset init error count upon receipt of COOKIE-ACK, |
892 | * to avoid problems with the managemement of this |
893 | * counter in stale cookie situations when a transition back |
894 | * from the COOKIE-ECHOED state to the COOKIE-WAIT |
895 | * state is performed. |
896 | */ |
897 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
898 | |
899 | /* RFC 2960 5.1 Normal Establishment of an Association |
900 | * |
901 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move |
902 | * from the COOKIE-ECHOED state to the ESTABLISHED state, |
903 | * stopping the T1-cookie timer. |
904 | */ |
905 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
906 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
907 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
908 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
909 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
910 | SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS); |
911 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
912 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
913 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
914 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
915 | |
916 | /* It may also notify its ULP about the successful |
917 | * establishment of the association with a Communication Up |
918 | * notification (see Section 10). |
919 | */ |
920 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, |
921 | 0, asoc->c.sinit_num_ostreams, |
922 | asoc->c.sinit_max_instreams, |
923 | NULL, GFP_ATOMIC); |
924 | |
925 | if (!ev) |
926 | goto nomem; |
927 | |
928 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
929 | |
930 | /* Sockets API Draft Section 5.3.1.6 |
931 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
932 | * delivers this notification to inform the application that of the |
933 | * peers requested adaptation layer. |
934 | */ |
935 | if (asoc->peer.adaptation_ind) { |
936 | ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); |
937 | if (!ev) |
938 | goto nomem; |
939 | |
940 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
941 | SCTP_ULPEVENT(ev)); |
942 | } |
943 | |
944 | return SCTP_DISPOSITION_CONSUME; |
945 | nomem: |
946 | return SCTP_DISPOSITION_NOMEM; |
947 | } |
948 | |
949 | /* Generate and sendout a heartbeat packet. */ |
950 | static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep, |
951 | const struct sctp_association *asoc, |
952 | const sctp_subtype_t type, |
953 | void *arg, |
954 | sctp_cmd_seq_t *commands) |
955 | { |
956 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
957 | struct sctp_chunk *reply; |
958 | |
959 | /* Send a heartbeat to our peer. */ |
960 | reply = sctp_make_heartbeat(asoc, transport); |
961 | if (!reply) |
962 | return SCTP_DISPOSITION_NOMEM; |
963 | |
964 | /* Set rto_pending indicating that an RTT measurement |
965 | * is started with this heartbeat chunk. |
966 | */ |
967 | sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, |
968 | SCTP_TRANSPORT(transport)); |
969 | |
970 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
971 | return SCTP_DISPOSITION_CONSUME; |
972 | } |
973 | |
974 | /* Generate a HEARTBEAT packet on the given transport. */ |
975 | sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net, |
976 | const struct sctp_endpoint *ep, |
977 | const struct sctp_association *asoc, |
978 | const sctp_subtype_t type, |
979 | void *arg, |
980 | sctp_cmd_seq_t *commands) |
981 | { |
982 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
983 | |
984 | if (asoc->overall_error_count >= asoc->max_retrans) { |
985 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
986 | SCTP_ERROR(ETIMEDOUT)); |
987 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
988 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
989 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
990 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
991 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
992 | return SCTP_DISPOSITION_DELETE_TCB; |
993 | } |
994 | |
995 | /* Section 3.3.5. |
996 | * The Sender-specific Heartbeat Info field should normally include |
997 | * information about the sender's current time when this HEARTBEAT |
998 | * chunk is sent and the destination transport address to which this |
999 | * HEARTBEAT is sent (see Section 8.3). |
1000 | */ |
1001 | |
1002 | if (transport->param_flags & SPP_HB_ENABLE) { |
1003 | if (SCTP_DISPOSITION_NOMEM == |
1004 | sctp_sf_heartbeat(ep, asoc, type, arg, |
1005 | commands)) |
1006 | return SCTP_DISPOSITION_NOMEM; |
1007 | |
1008 | /* Set transport error counter and association error counter |
1009 | * when sending heartbeat. |
1010 | */ |
1011 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, |
1012 | SCTP_TRANSPORT(transport)); |
1013 | } |
1014 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE, |
1015 | SCTP_TRANSPORT(transport)); |
1016 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, |
1017 | SCTP_TRANSPORT(transport)); |
1018 | |
1019 | return SCTP_DISPOSITION_CONSUME; |
1020 | } |
1021 | |
1022 | /* |
1023 | * Process an heartbeat request. |
1024 | * |
1025 | * Section: 8.3 Path Heartbeat |
1026 | * The receiver of the HEARTBEAT should immediately respond with a |
1027 | * HEARTBEAT ACK that contains the Heartbeat Information field copied |
1028 | * from the received HEARTBEAT chunk. |
1029 | * |
1030 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
1031 | * When receiving an SCTP packet, the endpoint MUST ensure that the |
1032 | * value in the Verification Tag field of the received SCTP packet |
1033 | * matches its own Tag. If the received Verification Tag value does not |
1034 | * match the receiver's own tag value, the receiver shall silently |
1035 | * discard the packet and shall not process it any further except for |
1036 | * those cases listed in Section 8.5.1 below. |
1037 | * |
1038 | * Inputs |
1039 | * (endpoint, asoc, chunk) |
1040 | * |
1041 | * Outputs |
1042 | * (asoc, reply_msg, msg_up, timers, counters) |
1043 | * |
1044 | * The return value is the disposition of the chunk. |
1045 | */ |
1046 | sctp_disposition_t sctp_sf_beat_8_3(struct net *net, |
1047 | const struct sctp_endpoint *ep, |
1048 | const struct sctp_association *asoc, |
1049 | const sctp_subtype_t type, |
1050 | void *arg, |
1051 | sctp_cmd_seq_t *commands) |
1052 | { |
1053 | sctp_paramhdr_t *param_hdr; |
1054 | struct sctp_chunk *chunk = arg; |
1055 | struct sctp_chunk *reply; |
1056 | size_t paylen = 0; |
1057 | |
1058 | if (!sctp_vtag_verify(chunk, asoc)) |
1059 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
1060 | |
1061 | /* Make sure that the HEARTBEAT chunk has a valid length. */ |
1062 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) |
1063 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
1064 | commands); |
1065 | |
1066 | /* 8.3 The receiver of the HEARTBEAT should immediately |
1067 | * respond with a HEARTBEAT ACK that contains the Heartbeat |
1068 | * Information field copied from the received HEARTBEAT chunk. |
1069 | */ |
1070 | chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data; |
1071 | param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr; |
1072 | paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); |
1073 | |
1074 | if (ntohs(param_hdr->length) > paylen) |
1075 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
1076 | param_hdr, commands); |
1077 | |
1078 | if (!pskb_pull(chunk->skb, paylen)) |
1079 | goto nomem; |
1080 | |
1081 | reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen); |
1082 | if (!reply) |
1083 | goto nomem; |
1084 | |
1085 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
1086 | return SCTP_DISPOSITION_CONSUME; |
1087 | |
1088 | nomem: |
1089 | return SCTP_DISPOSITION_NOMEM; |
1090 | } |
1091 | |
1092 | /* |
1093 | * Process the returning HEARTBEAT ACK. |
1094 | * |
1095 | * Section: 8.3 Path Heartbeat |
1096 | * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT |
1097 | * should clear the error counter of the destination transport |
1098 | * address to which the HEARTBEAT was sent, and mark the destination |
1099 | * transport address as active if it is not so marked. The endpoint may |
1100 | * optionally report to the upper layer when an inactive destination |
1101 | * address is marked as active due to the reception of the latest |
1102 | * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also |
1103 | * clear the association overall error count as well (as defined |
1104 | * in section 8.1). |
1105 | * |
1106 | * The receiver of the HEARTBEAT ACK should also perform an RTT |
1107 | * measurement for that destination transport address using the time |
1108 | * value carried in the HEARTBEAT ACK chunk. |
1109 | * |
1110 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
1111 | * |
1112 | * Inputs |
1113 | * (endpoint, asoc, chunk) |
1114 | * |
1115 | * Outputs |
1116 | * (asoc, reply_msg, msg_up, timers, counters) |
1117 | * |
1118 | * The return value is the disposition of the chunk. |
1119 | */ |
1120 | sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net, |
1121 | const struct sctp_endpoint *ep, |
1122 | const struct sctp_association *asoc, |
1123 | const sctp_subtype_t type, |
1124 | void *arg, |
1125 | sctp_cmd_seq_t *commands) |
1126 | { |
1127 | struct sctp_chunk *chunk = arg; |
1128 | union sctp_addr from_addr; |
1129 | struct sctp_transport *link; |
1130 | sctp_sender_hb_info_t *hbinfo; |
1131 | unsigned long max_interval; |
1132 | |
1133 | if (!sctp_vtag_verify(chunk, asoc)) |
1134 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
1135 | |
1136 | /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ |
1137 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) + |
1138 | sizeof(sctp_sender_hb_info_t))) |
1139 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
1140 | commands); |
1141 | |
1142 | hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; |
1143 | /* Make sure that the length of the parameter is what we expect */ |
1144 | if (ntohs(hbinfo->param_hdr.length) != |
1145 | sizeof(sctp_sender_hb_info_t)) { |
1146 | return SCTP_DISPOSITION_DISCARD; |
1147 | } |
1148 | |
1149 | from_addr = hbinfo->daddr; |
1150 | link = sctp_assoc_lookup_paddr(asoc, &from_addr); |
1151 | |
1152 | /* This should never happen, but lets log it if so. */ |
1153 | if (unlikely(!link)) { |
1154 | if (from_addr.sa.sa_family == AF_INET6) { |
1155 | net_warn_ratelimited("%s association %p could not find address %pI6\n", |
1156 | __func__, |
1157 | asoc, |
1158 | &from_addr.v6.sin6_addr); |
1159 | } else { |
1160 | net_warn_ratelimited("%s association %p could not find address %pI4\n", |
1161 | __func__, |
1162 | asoc, |
1163 | &from_addr.v4.sin_addr.s_addr); |
1164 | } |
1165 | return SCTP_DISPOSITION_DISCARD; |
1166 | } |
1167 | |
1168 | /* Validate the 64-bit random nonce. */ |
1169 | if (hbinfo->hb_nonce != link->hb_nonce) |
1170 | return SCTP_DISPOSITION_DISCARD; |
1171 | |
1172 | max_interval = link->hbinterval + link->rto; |
1173 | |
1174 | /* Check if the timestamp looks valid. */ |
1175 | if (time_after(hbinfo->sent_at, jiffies) || |
1176 | time_after(jiffies, hbinfo->sent_at + max_interval)) { |
1177 | pr_debug("%s: HEARTBEAT ACK with invalid timestamp received " |
1178 | "for transport:%p\n", __func__, link); |
1179 | |
1180 | return SCTP_DISPOSITION_DISCARD; |
1181 | } |
1182 | |
1183 | /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of |
1184 | * the HEARTBEAT should clear the error counter of the |
1185 | * destination transport address to which the HEARTBEAT was |
1186 | * sent and mark the destination transport address as active if |
1187 | * it is not so marked. |
1188 | */ |
1189 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); |
1190 | |
1191 | return SCTP_DISPOSITION_CONSUME; |
1192 | } |
1193 | |
1194 | /* Helper function to send out an abort for the restart |
1195 | * condition. |
1196 | */ |
1197 | static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa, |
1198 | struct sctp_chunk *init, |
1199 | sctp_cmd_seq_t *commands) |
1200 | { |
1201 | int len; |
1202 | struct sctp_packet *pkt; |
1203 | union sctp_addr_param *addrparm; |
1204 | struct sctp_errhdr *errhdr; |
1205 | struct sctp_endpoint *ep; |
1206 | char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)]; |
1207 | struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); |
1208 | |
1209 | /* Build the error on the stack. We are way to malloc crazy |
1210 | * throughout the code today. |
1211 | */ |
1212 | errhdr = (struct sctp_errhdr *)buffer; |
1213 | addrparm = (union sctp_addr_param *)errhdr->variable; |
1214 | |
1215 | /* Copy into a parm format. */ |
1216 | len = af->to_addr_param(ssa, addrparm); |
1217 | len += sizeof(sctp_errhdr_t); |
1218 | |
1219 | errhdr->cause = SCTP_ERROR_RESTART; |
1220 | errhdr->length = htons(len); |
1221 | |
1222 | /* Assign to the control socket. */ |
1223 | ep = sctp_sk(net->sctp.ctl_sock)->ep; |
1224 | |
1225 | /* Association is NULL since this may be a restart attack and we |
1226 | * want to send back the attacker's vtag. |
1227 | */ |
1228 | pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len); |
1229 | |
1230 | if (!pkt) |
1231 | goto out; |
1232 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); |
1233 | |
1234 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1235 | |
1236 | /* Discard the rest of the inbound packet. */ |
1237 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
1238 | |
1239 | out: |
1240 | /* Even if there is no memory, treat as a failure so |
1241 | * the packet will get dropped. |
1242 | */ |
1243 | return 0; |
1244 | } |
1245 | |
1246 | static bool list_has_sctp_addr(const struct list_head *list, |
1247 | union sctp_addr *ipaddr) |
1248 | { |
1249 | struct sctp_transport *addr; |
1250 | |
1251 | list_for_each_entry(addr, list, transports) { |
1252 | if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr)) |
1253 | return true; |
1254 | } |
1255 | |
1256 | return false; |
1257 | } |
1258 | /* A restart is occurring, check to make sure no new addresses |
1259 | * are being added as we may be under a takeover attack. |
1260 | */ |
1261 | static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, |
1262 | const struct sctp_association *asoc, |
1263 | struct sctp_chunk *init, |
1264 | sctp_cmd_seq_t *commands) |
1265 | { |
1266 | struct net *net = sock_net(new_asoc->base.sk); |
1267 | struct sctp_transport *new_addr; |
1268 | int ret = 1; |
1269 | |
1270 | /* Implementor's Guide - Section 5.2.2 |
1271 | * ... |
1272 | * Before responding the endpoint MUST check to see if the |
1273 | * unexpected INIT adds new addresses to the association. If new |
1274 | * addresses are added to the association, the endpoint MUST respond |
1275 | * with an ABORT.. |
1276 | */ |
1277 | |
1278 | /* Search through all current addresses and make sure |
1279 | * we aren't adding any new ones. |
1280 | */ |
1281 | list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list, |
1282 | transports) { |
1283 | if (!list_has_sctp_addr(&asoc->peer.transport_addr_list, |
1284 | &new_addr->ipaddr)) { |
1285 | sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init, |
1286 | commands); |
1287 | ret = 0; |
1288 | break; |
1289 | } |
1290 | } |
1291 | |
1292 | /* Return success if all addresses were found. */ |
1293 | return ret; |
1294 | } |
1295 | |
1296 | /* Populate the verification/tie tags based on overlapping INIT |
1297 | * scenario. |
1298 | * |
1299 | * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. |
1300 | */ |
1301 | static void sctp_tietags_populate(struct sctp_association *new_asoc, |
1302 | const struct sctp_association *asoc) |
1303 | { |
1304 | switch (asoc->state) { |
1305 | |
1306 | /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ |
1307 | |
1308 | case SCTP_STATE_COOKIE_WAIT: |
1309 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
1310 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1311 | new_asoc->c.peer_ttag = 0; |
1312 | break; |
1313 | |
1314 | case SCTP_STATE_COOKIE_ECHOED: |
1315 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
1316 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1317 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
1318 | break; |
1319 | |
1320 | /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, |
1321 | * COOKIE-WAIT and SHUTDOWN-ACK-SENT |
1322 | */ |
1323 | default: |
1324 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1325 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
1326 | break; |
1327 | } |
1328 | |
1329 | /* Other parameters for the endpoint SHOULD be copied from the |
1330 | * existing parameters of the association (e.g. number of |
1331 | * outbound streams) into the INIT ACK and cookie. |
1332 | */ |
1333 | new_asoc->rwnd = asoc->rwnd; |
1334 | new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; |
1335 | new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; |
1336 | new_asoc->c.initial_tsn = asoc->c.initial_tsn; |
1337 | } |
1338 | |
1339 | /* |
1340 | * Compare vtag/tietag values to determine unexpected COOKIE-ECHO |
1341 | * handling action. |
1342 | * |
1343 | * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. |
1344 | * |
1345 | * Returns value representing action to be taken. These action values |
1346 | * correspond to Action/Description values in RFC 2960, Table 2. |
1347 | */ |
1348 | static char sctp_tietags_compare(struct sctp_association *new_asoc, |
1349 | const struct sctp_association *asoc) |
1350 | { |
1351 | /* In this case, the peer may have restarted. */ |
1352 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
1353 | (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && |
1354 | (asoc->c.my_vtag == new_asoc->c.my_ttag) && |
1355 | (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) |
1356 | return 'A'; |
1357 | |
1358 | /* Collision case B. */ |
1359 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
1360 | ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || |
1361 | (0 == asoc->c.peer_vtag))) { |
1362 | return 'B'; |
1363 | } |
1364 | |
1365 | /* Collision case D. */ |
1366 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
1367 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) |
1368 | return 'D'; |
1369 | |
1370 | /* Collision case C. */ |
1371 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
1372 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && |
1373 | (0 == new_asoc->c.my_ttag) && |
1374 | (0 == new_asoc->c.peer_ttag)) |
1375 | return 'C'; |
1376 | |
1377 | /* No match to any of the special cases; discard this packet. */ |
1378 | return 'E'; |
1379 | } |
1380 | |
1381 | /* Common helper routine for both duplicate and simulataneous INIT |
1382 | * chunk handling. |
1383 | */ |
1384 | static sctp_disposition_t sctp_sf_do_unexpected_init( |
1385 | struct net *net, |
1386 | const struct sctp_endpoint *ep, |
1387 | const struct sctp_association *asoc, |
1388 | const sctp_subtype_t type, |
1389 | void *arg, sctp_cmd_seq_t *commands) |
1390 | { |
1391 | sctp_disposition_t retval; |
1392 | struct sctp_chunk *chunk = arg; |
1393 | struct sctp_chunk *repl; |
1394 | struct sctp_association *new_asoc; |
1395 | struct sctp_chunk *err_chunk; |
1396 | struct sctp_packet *packet; |
1397 | sctp_unrecognized_param_t *unk_param; |
1398 | int len; |
1399 | |
1400 | /* 6.10 Bundling |
1401 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
1402 | * SHUTDOWN COMPLETE with any other chunks. |
1403 | * |
1404 | * IG Section 2.11.2 |
1405 | * Furthermore, we require that the receiver of an INIT chunk MUST |
1406 | * enforce these rules by silently discarding an arriving packet |
1407 | * with an INIT chunk that is bundled with other chunks. |
1408 | */ |
1409 | if (!chunk->singleton) |
1410 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
1411 | |
1412 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
1413 | * Tag. |
1414 | */ |
1415 | if (chunk->sctp_hdr->vtag != 0) |
1416 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
1417 | |
1418 | /* Make sure that the INIT chunk has a valid length. |
1419 | * In this case, we generate a protocol violation since we have |
1420 | * an association established. |
1421 | */ |
1422 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
1423 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
1424 | commands); |
1425 | /* Grab the INIT header. */ |
1426 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
1427 | |
1428 | /* Tag the variable length parameters. */ |
1429 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
1430 | |
1431 | /* Verify the INIT chunk before processing it. */ |
1432 | err_chunk = NULL; |
1433 | if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
1434 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
1435 | &err_chunk)) { |
1436 | /* This chunk contains fatal error. It is to be discarded. |
1437 | * Send an ABORT, with causes if there is any. |
1438 | */ |
1439 | if (err_chunk) { |
1440 | packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
1441 | (__u8 *)(err_chunk->chunk_hdr) + |
1442 | sizeof(sctp_chunkhdr_t), |
1443 | ntohs(err_chunk->chunk_hdr->length) - |
1444 | sizeof(sctp_chunkhdr_t)); |
1445 | |
1446 | if (packet) { |
1447 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
1448 | SCTP_PACKET(packet)); |
1449 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
1450 | retval = SCTP_DISPOSITION_CONSUME; |
1451 | } else { |
1452 | retval = SCTP_DISPOSITION_NOMEM; |
1453 | } |
1454 | goto cleanup; |
1455 | } else { |
1456 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, |
1457 | commands); |
1458 | } |
1459 | } |
1460 | |
1461 | /* |
1462 | * Other parameters for the endpoint SHOULD be copied from the |
1463 | * existing parameters of the association (e.g. number of |
1464 | * outbound streams) into the INIT ACK and cookie. |
1465 | * FIXME: We are copying parameters from the endpoint not the |
1466 | * association. |
1467 | */ |
1468 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
1469 | if (!new_asoc) |
1470 | goto nomem; |
1471 | |
1472 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, |
1473 | sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) |
1474 | goto nomem; |
1475 | |
1476 | /* In the outbound INIT ACK the endpoint MUST copy its current |
1477 | * Verification Tag and Peers Verification tag into a reserved |
1478 | * place (local tie-tag and per tie-tag) within the state cookie. |
1479 | */ |
1480 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), |
1481 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
1482 | GFP_ATOMIC)) |
1483 | goto nomem; |
1484 | |
1485 | /* Make sure no new addresses are being added during the |
1486 | * restart. Do not do this check for COOKIE-WAIT state, |
1487 | * since there are no peer addresses to check against. |
1488 | * Upon return an ABORT will have been sent if needed. |
1489 | */ |
1490 | if (!sctp_state(asoc, COOKIE_WAIT)) { |
1491 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, |
1492 | commands)) { |
1493 | retval = SCTP_DISPOSITION_CONSUME; |
1494 | goto nomem_retval; |
1495 | } |
1496 | } |
1497 | |
1498 | sctp_tietags_populate(new_asoc, asoc); |
1499 | |
1500 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
1501 | |
1502 | /* If there are errors need to be reported for unknown parameters, |
1503 | * make sure to reserve enough room in the INIT ACK for them. |
1504 | */ |
1505 | len = 0; |
1506 | if (err_chunk) { |
1507 | len = ntohs(err_chunk->chunk_hdr->length) - |
1508 | sizeof(sctp_chunkhdr_t); |
1509 | } |
1510 | |
1511 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
1512 | if (!repl) |
1513 | goto nomem; |
1514 | |
1515 | /* If there are errors need to be reported for unknown parameters, |
1516 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
1517 | * parameter. |
1518 | */ |
1519 | if (err_chunk) { |
1520 | /* Get the "Unrecognized parameter" parameter(s) out of the |
1521 | * ERROR chunk generated by sctp_verify_init(). Since the |
1522 | * error cause code for "unknown parameter" and the |
1523 | * "Unrecognized parameter" type is the same, we can |
1524 | * construct the parameters in INIT ACK by copying the |
1525 | * ERROR causes over. |
1526 | */ |
1527 | unk_param = (sctp_unrecognized_param_t *) |
1528 | ((__u8 *)(err_chunk->chunk_hdr) + |
1529 | sizeof(sctp_chunkhdr_t)); |
1530 | /* Replace the cause code with the "Unrecognized parameter" |
1531 | * parameter type. |
1532 | */ |
1533 | sctp_addto_chunk(repl, len, unk_param); |
1534 | } |
1535 | |
1536 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
1537 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1538 | |
1539 | /* |
1540 | * Note: After sending out INIT ACK with the State Cookie parameter, |
1541 | * "Z" MUST NOT allocate any resources for this new association. |
1542 | * Otherwise, "Z" will be vulnerable to resource attacks. |
1543 | */ |
1544 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
1545 | retval = SCTP_DISPOSITION_CONSUME; |
1546 | |
1547 | return retval; |
1548 | |
1549 | nomem: |
1550 | retval = SCTP_DISPOSITION_NOMEM; |
1551 | nomem_retval: |
1552 | if (new_asoc) |
1553 | sctp_association_free(new_asoc); |
1554 | cleanup: |
1555 | if (err_chunk) |
1556 | sctp_chunk_free(err_chunk); |
1557 | return retval; |
1558 | } |
1559 | |
1560 | /* |
1561 | * Handle simultaneous INIT. |
1562 | * This means we started an INIT and then we got an INIT request from |
1563 | * our peer. |
1564 | * |
1565 | * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) |
1566 | * This usually indicates an initialization collision, i.e., each |
1567 | * endpoint is attempting, at about the same time, to establish an |
1568 | * association with the other endpoint. |
1569 | * |
1570 | * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an |
1571 | * endpoint MUST respond with an INIT ACK using the same parameters it |
1572 | * sent in its original INIT chunk (including its Verification Tag, |
1573 | * unchanged). These original parameters are combined with those from the |
1574 | * newly received INIT chunk. The endpoint shall also generate a State |
1575 | * Cookie with the INIT ACK. The endpoint uses the parameters sent in its |
1576 | * INIT to calculate the State Cookie. |
1577 | * |
1578 | * After that, the endpoint MUST NOT change its state, the T1-init |
1579 | * timer shall be left running and the corresponding TCB MUST NOT be |
1580 | * destroyed. The normal procedures for handling State Cookies when |
1581 | * a TCB exists will resolve the duplicate INITs to a single association. |
1582 | * |
1583 | * For an endpoint that is in the COOKIE-ECHOED state it MUST populate |
1584 | * its Tie-Tags with the Tag information of itself and its peer (see |
1585 | * section 5.2.2 for a description of the Tie-Tags). |
1586 | * |
1587 | * Verification Tag: Not explicit, but an INIT can not have a valid |
1588 | * verification tag, so we skip the check. |
1589 | * |
1590 | * Inputs |
1591 | * (endpoint, asoc, chunk) |
1592 | * |
1593 | * Outputs |
1594 | * (asoc, reply_msg, msg_up, timers, counters) |
1595 | * |
1596 | * The return value is the disposition of the chunk. |
1597 | */ |
1598 | sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net, |
1599 | const struct sctp_endpoint *ep, |
1600 | const struct sctp_association *asoc, |
1601 | const sctp_subtype_t type, |
1602 | void *arg, |
1603 | sctp_cmd_seq_t *commands) |
1604 | { |
1605 | /* Call helper to do the real work for both simulataneous and |
1606 | * duplicate INIT chunk handling. |
1607 | */ |
1608 | return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); |
1609 | } |
1610 | |
1611 | /* |
1612 | * Handle duplicated INIT messages. These are usually delayed |
1613 | * restransmissions. |
1614 | * |
1615 | * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, |
1616 | * COOKIE-ECHOED and COOKIE-WAIT |
1617 | * |
1618 | * Unless otherwise stated, upon reception of an unexpected INIT for |
1619 | * this association, the endpoint shall generate an INIT ACK with a |
1620 | * State Cookie. In the outbound INIT ACK the endpoint MUST copy its |
1621 | * current Verification Tag and peer's Verification Tag into a reserved |
1622 | * place within the state cookie. We shall refer to these locations as |
1623 | * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet |
1624 | * containing this INIT ACK MUST carry a Verification Tag value equal to |
1625 | * the Initiation Tag found in the unexpected INIT. And the INIT ACK |
1626 | * MUST contain a new Initiation Tag (randomly generated see Section |
1627 | * 5.3.1). Other parameters for the endpoint SHOULD be copied from the |
1628 | * existing parameters of the association (e.g. number of outbound |
1629 | * streams) into the INIT ACK and cookie. |
1630 | * |
1631 | * After sending out the INIT ACK, the endpoint shall take no further |
1632 | * actions, i.e., the existing association, including its current state, |
1633 | * and the corresponding TCB MUST NOT be changed. |
1634 | * |
1635 | * Note: Only when a TCB exists and the association is not in a COOKIE- |
1636 | * WAIT state are the Tie-Tags populated. For a normal association INIT |
1637 | * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be |
1638 | * set to 0 (indicating that no previous TCB existed). The INIT ACK and |
1639 | * State Cookie are populated as specified in section 5.2.1. |
1640 | * |
1641 | * Verification Tag: Not specified, but an INIT has no way of knowing |
1642 | * what the verification tag could be, so we ignore it. |
1643 | * |
1644 | * Inputs |
1645 | * (endpoint, asoc, chunk) |
1646 | * |
1647 | * Outputs |
1648 | * (asoc, reply_msg, msg_up, timers, counters) |
1649 | * |
1650 | * The return value is the disposition of the chunk. |
1651 | */ |
1652 | sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net, |
1653 | const struct sctp_endpoint *ep, |
1654 | const struct sctp_association *asoc, |
1655 | const sctp_subtype_t type, |
1656 | void *arg, |
1657 | sctp_cmd_seq_t *commands) |
1658 | { |
1659 | /* Call helper to do the real work for both simulataneous and |
1660 | * duplicate INIT chunk handling. |
1661 | */ |
1662 | return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); |
1663 | } |
1664 | |
1665 | |
1666 | /* |
1667 | * Unexpected INIT-ACK handler. |
1668 | * |
1669 | * Section 5.2.3 |
1670 | * If an INIT ACK received by an endpoint in any state other than the |
1671 | * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk. |
1672 | * An unexpected INIT ACK usually indicates the processing of an old or |
1673 | * duplicated INIT chunk. |
1674 | */ |
1675 | sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net, |
1676 | const struct sctp_endpoint *ep, |
1677 | const struct sctp_association *asoc, |
1678 | const sctp_subtype_t type, |
1679 | void *arg, sctp_cmd_seq_t *commands) |
1680 | { |
1681 | /* Per the above section, we'll discard the chunk if we have an |
1682 | * endpoint. If this is an OOTB INIT-ACK, treat it as such. |
1683 | */ |
1684 | if (ep == sctp_sk(net->sctp.ctl_sock)->ep) |
1685 | return sctp_sf_ootb(net, ep, asoc, type, arg, commands); |
1686 | else |
1687 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
1688 | } |
1689 | |
1690 | /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') |
1691 | * |
1692 | * Section 5.2.4 |
1693 | * A) In this case, the peer may have restarted. |
1694 | */ |
1695 | static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net, |
1696 | const struct sctp_endpoint *ep, |
1697 | const struct sctp_association *asoc, |
1698 | struct sctp_chunk *chunk, |
1699 | sctp_cmd_seq_t *commands, |
1700 | struct sctp_association *new_asoc) |
1701 | { |
1702 | sctp_init_chunk_t *peer_init; |
1703 | struct sctp_ulpevent *ev; |
1704 | struct sctp_chunk *repl; |
1705 | struct sctp_chunk *err; |
1706 | sctp_disposition_t disposition; |
1707 | |
1708 | /* new_asoc is a brand-new association, so these are not yet |
1709 | * side effects--it is safe to run them here. |
1710 | */ |
1711 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
1712 | |
1713 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, |
1714 | GFP_ATOMIC)) |
1715 | goto nomem; |
1716 | |
1717 | /* Make sure no new addresses are being added during the |
1718 | * restart. Though this is a pretty complicated attack |
1719 | * since you'd have to get inside the cookie. |
1720 | */ |
1721 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) { |
1722 | return SCTP_DISPOSITION_CONSUME; |
1723 | } |
1724 | |
1725 | /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes |
1726 | * the peer has restarted (Action A), it MUST NOT setup a new |
1727 | * association but instead resend the SHUTDOWN ACK and send an ERROR |
1728 | * chunk with a "Cookie Received while Shutting Down" error cause to |
1729 | * its peer. |
1730 | */ |
1731 | if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { |
1732 | disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc, |
1733 | SCTP_ST_CHUNK(chunk->chunk_hdr->type), |
1734 | chunk, commands); |
1735 | if (SCTP_DISPOSITION_NOMEM == disposition) |
1736 | goto nomem; |
1737 | |
1738 | err = sctp_make_op_error(asoc, chunk, |
1739 | SCTP_ERROR_COOKIE_IN_SHUTDOWN, |
1740 | NULL, 0, 0); |
1741 | if (err) |
1742 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
1743 | SCTP_CHUNK(err)); |
1744 | |
1745 | return SCTP_DISPOSITION_CONSUME; |
1746 | } |
1747 | |
1748 | /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked |
1749 | * data. Consider the optional choice of resending of this data. |
1750 | */ |
1751 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
1752 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1753 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); |
1754 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); |
1755 | |
1756 | /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue |
1757 | * and ASCONF-ACK cache. |
1758 | */ |
1759 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1760 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
1761 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL()); |
1762 | |
1763 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1764 | if (!repl) |
1765 | goto nomem; |
1766 | |
1767 | /* Report association restart to upper layer. */ |
1768 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, |
1769 | new_asoc->c.sinit_num_ostreams, |
1770 | new_asoc->c.sinit_max_instreams, |
1771 | NULL, GFP_ATOMIC); |
1772 | if (!ev) |
1773 | goto nomem_ev; |
1774 | |
1775 | /* Update the content of current association. */ |
1776 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
1777 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
1778 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
1779 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
1780 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1781 | return SCTP_DISPOSITION_CONSUME; |
1782 | |
1783 | nomem_ev: |
1784 | sctp_chunk_free(repl); |
1785 | nomem: |
1786 | return SCTP_DISPOSITION_NOMEM; |
1787 | } |
1788 | |
1789 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') |
1790 | * |
1791 | * Section 5.2.4 |
1792 | * B) In this case, both sides may be attempting to start an association |
1793 | * at about the same time but the peer endpoint started its INIT |
1794 | * after responding to the local endpoint's INIT |
1795 | */ |
1796 | /* This case represents an initialization collision. */ |
1797 | static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net, |
1798 | const struct sctp_endpoint *ep, |
1799 | const struct sctp_association *asoc, |
1800 | struct sctp_chunk *chunk, |
1801 | sctp_cmd_seq_t *commands, |
1802 | struct sctp_association *new_asoc) |
1803 | { |
1804 | sctp_init_chunk_t *peer_init; |
1805 | struct sctp_chunk *repl; |
1806 | |
1807 | /* new_asoc is a brand-new association, so these are not yet |
1808 | * side effects--it is safe to run them here. |
1809 | */ |
1810 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
1811 | if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, |
1812 | GFP_ATOMIC)) |
1813 | goto nomem; |
1814 | |
1815 | /* Update the content of current association. */ |
1816 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
1817 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
1818 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
1819 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
1820 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
1821 | |
1822 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1823 | if (!repl) |
1824 | goto nomem; |
1825 | |
1826 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1827 | |
1828 | /* RFC 2960 5.1 Normal Establishment of an Association |
1829 | * |
1830 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
1831 | * send the Communication Up notification to the SCTP user |
1832 | * upon reception of a valid COOKIE ECHO chunk. |
1833 | * |
1834 | * Sadly, this needs to be implemented as a side-effect, because |
1835 | * we are not guaranteed to have set the association id of the real |
1836 | * association and so these notifications need to be delayed until |
1837 | * the association id is allocated. |
1838 | */ |
1839 | |
1840 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP)); |
1841 | |
1842 | /* Sockets API Draft Section 5.3.1.6 |
1843 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
1844 | * delivers this notification to inform the application that of the |
1845 | * peers requested adaptation layer. |
1846 | * |
1847 | * This also needs to be done as a side effect for the same reason as |
1848 | * above. |
1849 | */ |
1850 | if (asoc->peer.adaptation_ind) |
1851 | sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL()); |
1852 | |
1853 | return SCTP_DISPOSITION_CONSUME; |
1854 | |
1855 | nomem: |
1856 | return SCTP_DISPOSITION_NOMEM; |
1857 | } |
1858 | |
1859 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') |
1860 | * |
1861 | * Section 5.2.4 |
1862 | * C) In this case, the local endpoint's cookie has arrived late. |
1863 | * Before it arrived, the local endpoint sent an INIT and received an |
1864 | * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag |
1865 | * but a new tag of its own. |
1866 | */ |
1867 | /* This case represents an initialization collision. */ |
1868 | static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net, |
1869 | const struct sctp_endpoint *ep, |
1870 | const struct sctp_association *asoc, |
1871 | struct sctp_chunk *chunk, |
1872 | sctp_cmd_seq_t *commands, |
1873 | struct sctp_association *new_asoc) |
1874 | { |
1875 | /* The cookie should be silently discarded. |
1876 | * The endpoint SHOULD NOT change states and should leave |
1877 | * any timers running. |
1878 | */ |
1879 | return SCTP_DISPOSITION_DISCARD; |
1880 | } |
1881 | |
1882 | /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') |
1883 | * |
1884 | * Section 5.2.4 |
1885 | * |
1886 | * D) When both local and remote tags match the endpoint should always |
1887 | * enter the ESTABLISHED state, if it has not already done so. |
1888 | */ |
1889 | /* This case represents an initialization collision. */ |
1890 | static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net, |
1891 | const struct sctp_endpoint *ep, |
1892 | const struct sctp_association *asoc, |
1893 | struct sctp_chunk *chunk, |
1894 | sctp_cmd_seq_t *commands, |
1895 | struct sctp_association *new_asoc) |
1896 | { |
1897 | struct sctp_ulpevent *ev = NULL, *ai_ev = NULL; |
1898 | struct sctp_chunk *repl; |
1899 | |
1900 | /* Clarification from Implementor's Guide: |
1901 | * D) When both local and remote tags match the endpoint should |
1902 | * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. |
1903 | * It should stop any cookie timer that may be running and send |
1904 | * a COOKIE ACK. |
1905 | */ |
1906 | |
1907 | /* Don't accidentally move back into established state. */ |
1908 | if (asoc->state < SCTP_STATE_ESTABLISHED) { |
1909 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1910 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
1911 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
1912 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
1913 | SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
1914 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, |
1915 | SCTP_NULL()); |
1916 | |
1917 | /* RFC 2960 5.1 Normal Establishment of an Association |
1918 | * |
1919 | * D) IMPLEMENTATION NOTE: An implementation may choose |
1920 | * to send the Communication Up notification to the |
1921 | * SCTP user upon reception of a valid COOKIE |
1922 | * ECHO chunk. |
1923 | */ |
1924 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, |
1925 | SCTP_COMM_UP, 0, |
1926 | asoc->c.sinit_num_ostreams, |
1927 | asoc->c.sinit_max_instreams, |
1928 | NULL, GFP_ATOMIC); |
1929 | if (!ev) |
1930 | goto nomem; |
1931 | |
1932 | /* Sockets API Draft Section 5.3.1.6 |
1933 | * When a peer sends a Adaptation Layer Indication parameter, |
1934 | * SCTP delivers this notification to inform the application |
1935 | * that of the peers requested adaptation layer. |
1936 | */ |
1937 | if (asoc->peer.adaptation_ind) { |
1938 | ai_ev = sctp_ulpevent_make_adaptation_indication(asoc, |
1939 | GFP_ATOMIC); |
1940 | if (!ai_ev) |
1941 | goto nomem; |
1942 | |
1943 | } |
1944 | } |
1945 | |
1946 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1947 | if (!repl) |
1948 | goto nomem; |
1949 | |
1950 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1951 | |
1952 | if (ev) |
1953 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
1954 | SCTP_ULPEVENT(ev)); |
1955 | if (ai_ev) |
1956 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
1957 | SCTP_ULPEVENT(ai_ev)); |
1958 | |
1959 | return SCTP_DISPOSITION_CONSUME; |
1960 | |
1961 | nomem: |
1962 | if (ai_ev) |
1963 | sctp_ulpevent_free(ai_ev); |
1964 | if (ev) |
1965 | sctp_ulpevent_free(ev); |
1966 | return SCTP_DISPOSITION_NOMEM; |
1967 | } |
1968 | |
1969 | /* |
1970 | * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying |
1971 | * chunk was retransmitted and then delayed in the network. |
1972 | * |
1973 | * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists |
1974 | * |
1975 | * Verification Tag: None. Do cookie validation. |
1976 | * |
1977 | * Inputs |
1978 | * (endpoint, asoc, chunk) |
1979 | * |
1980 | * Outputs |
1981 | * (asoc, reply_msg, msg_up, timers, counters) |
1982 | * |
1983 | * The return value is the disposition of the chunk. |
1984 | */ |
1985 | sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net, |
1986 | const struct sctp_endpoint *ep, |
1987 | const struct sctp_association *asoc, |
1988 | const sctp_subtype_t type, |
1989 | void *arg, |
1990 | sctp_cmd_seq_t *commands) |
1991 | { |
1992 | sctp_disposition_t retval; |
1993 | struct sctp_chunk *chunk = arg; |
1994 | struct sctp_association *new_asoc; |
1995 | int error = 0; |
1996 | char action; |
1997 | struct sctp_chunk *err_chk_p; |
1998 | |
1999 | /* Make sure that the chunk has a valid length from the protocol |
2000 | * perspective. In this case check to make sure we have at least |
2001 | * enough for the chunk header. Cookie length verification is |
2002 | * done later. |
2003 | */ |
2004 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
2005 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2006 | commands); |
2007 | |
2008 | /* "Decode" the chunk. We have no optional parameters so we |
2009 | * are in good shape. |
2010 | */ |
2011 | chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; |
2012 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
2013 | sizeof(sctp_chunkhdr_t))) |
2014 | goto nomem; |
2015 | |
2016 | /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie |
2017 | * of a duplicate COOKIE ECHO match the Verification Tags of the |
2018 | * current association, consider the State Cookie valid even if |
2019 | * the lifespan is exceeded. |
2020 | */ |
2021 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
2022 | &err_chk_p); |
2023 | |
2024 | /* FIXME: |
2025 | * If the re-build failed, what is the proper error path |
2026 | * from here? |
2027 | * |
2028 | * [We should abort the association. --piggy] |
2029 | */ |
2030 | if (!new_asoc) { |
2031 | /* FIXME: Several errors are possible. A bad cookie should |
2032 | * be silently discarded, but think about logging it too. |
2033 | */ |
2034 | switch (error) { |
2035 | case -SCTP_IERROR_NOMEM: |
2036 | goto nomem; |
2037 | |
2038 | case -SCTP_IERROR_STALE_COOKIE: |
2039 | sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, |
2040 | err_chk_p); |
2041 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2042 | case -SCTP_IERROR_BAD_SIG: |
2043 | default: |
2044 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2045 | } |
2046 | } |
2047 | |
2048 | /* Compare the tie_tag in cookie with the verification tag of |
2049 | * current association. |
2050 | */ |
2051 | action = sctp_tietags_compare(new_asoc, asoc); |
2052 | |
2053 | switch (action) { |
2054 | case 'A': /* Association restart. */ |
2055 | retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands, |
2056 | new_asoc); |
2057 | break; |
2058 | |
2059 | case 'B': /* Collision case B. */ |
2060 | retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands, |
2061 | new_asoc); |
2062 | break; |
2063 | |
2064 | case 'C': /* Collision case C. */ |
2065 | retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands, |
2066 | new_asoc); |
2067 | break; |
2068 | |
2069 | case 'D': /* Collision case D. */ |
2070 | retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands, |
2071 | new_asoc); |
2072 | break; |
2073 | |
2074 | default: /* Discard packet for all others. */ |
2075 | retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2076 | break; |
2077 | } |
2078 | |
2079 | /* Delete the tempory new association. */ |
2080 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc)); |
2081 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
2082 | |
2083 | /* Restore association pointer to provide SCTP command interpeter |
2084 | * with a valid context in case it needs to manipulate |
2085 | * the queues */ |
2086 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, |
2087 | SCTP_ASOC((struct sctp_association *)asoc)); |
2088 | |
2089 | return retval; |
2090 | |
2091 | nomem: |
2092 | return SCTP_DISPOSITION_NOMEM; |
2093 | } |
2094 | |
2095 | /* |
2096 | * Process an ABORT. (SHUTDOWN-PENDING state) |
2097 | * |
2098 | * See sctp_sf_do_9_1_abort(). |
2099 | */ |
2100 | sctp_disposition_t sctp_sf_shutdown_pending_abort( |
2101 | struct net *net, |
2102 | const struct sctp_endpoint *ep, |
2103 | const struct sctp_association *asoc, |
2104 | const sctp_subtype_t type, |
2105 | void *arg, |
2106 | sctp_cmd_seq_t *commands) |
2107 | { |
2108 | struct sctp_chunk *chunk = arg; |
2109 | |
2110 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2111 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2112 | |
2113 | /* Make sure that the ABORT chunk has a valid length. |
2114 | * Since this is an ABORT chunk, we have to discard it |
2115 | * because of the following text: |
2116 | * RFC 2960, Section 3.3.7 |
2117 | * If an endpoint receives an ABORT with a format error or for an |
2118 | * association that doesn't exist, it MUST silently discard it. |
2119 | * Because the length is "invalid", we can't really discard just |
2120 | * as we do not know its true length. So, to be safe, discard the |
2121 | * packet. |
2122 | */ |
2123 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2124 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2125 | |
2126 | /* ADD-IP: Special case for ABORT chunks |
2127 | * F4) One special consideration is that ABORT Chunks arriving |
2128 | * destined to the IP address being deleted MUST be |
2129 | * ignored (see Section 5.3.1 for further details). |
2130 | */ |
2131 | if (SCTP_ADDR_DEL == |
2132 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
2133 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
2134 | |
2135 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
2136 | } |
2137 | |
2138 | /* |
2139 | * Process an ABORT. (SHUTDOWN-SENT state) |
2140 | * |
2141 | * See sctp_sf_do_9_1_abort(). |
2142 | */ |
2143 | sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net, |
2144 | const struct sctp_endpoint *ep, |
2145 | const struct sctp_association *asoc, |
2146 | const sctp_subtype_t type, |
2147 | void *arg, |
2148 | sctp_cmd_seq_t *commands) |
2149 | { |
2150 | struct sctp_chunk *chunk = arg; |
2151 | |
2152 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2153 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2154 | |
2155 | /* Make sure that the ABORT chunk has a valid length. |
2156 | * Since this is an ABORT chunk, we have to discard it |
2157 | * because of the following text: |
2158 | * RFC 2960, Section 3.3.7 |
2159 | * If an endpoint receives an ABORT with a format error or for an |
2160 | * association that doesn't exist, it MUST silently discard it. |
2161 | * Because the length is "invalid", we can't really discard just |
2162 | * as we do not know its true length. So, to be safe, discard the |
2163 | * packet. |
2164 | */ |
2165 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2166 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2167 | |
2168 | /* ADD-IP: Special case for ABORT chunks |
2169 | * F4) One special consideration is that ABORT Chunks arriving |
2170 | * destined to the IP address being deleted MUST be |
2171 | * ignored (see Section 5.3.1 for further details). |
2172 | */ |
2173 | if (SCTP_ADDR_DEL == |
2174 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
2175 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
2176 | |
2177 | /* Stop the T2-shutdown timer. */ |
2178 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2179 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
2180 | |
2181 | /* Stop the T5-shutdown guard timer. */ |
2182 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2183 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
2184 | |
2185 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
2186 | } |
2187 | |
2188 | /* |
2189 | * Process an ABORT. (SHUTDOWN-ACK-SENT state) |
2190 | * |
2191 | * See sctp_sf_do_9_1_abort(). |
2192 | */ |
2193 | sctp_disposition_t sctp_sf_shutdown_ack_sent_abort( |
2194 | struct net *net, |
2195 | const struct sctp_endpoint *ep, |
2196 | const struct sctp_association *asoc, |
2197 | const sctp_subtype_t type, |
2198 | void *arg, |
2199 | sctp_cmd_seq_t *commands) |
2200 | { |
2201 | /* The same T2 timer, so we should be able to use |
2202 | * common function with the SHUTDOWN-SENT state. |
2203 | */ |
2204 | return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands); |
2205 | } |
2206 | |
2207 | /* |
2208 | * Handle an Error received in COOKIE_ECHOED state. |
2209 | * |
2210 | * Only handle the error type of stale COOKIE Error, the other errors will |
2211 | * be ignored. |
2212 | * |
2213 | * Inputs |
2214 | * (endpoint, asoc, chunk) |
2215 | * |
2216 | * Outputs |
2217 | * (asoc, reply_msg, msg_up, timers, counters) |
2218 | * |
2219 | * The return value is the disposition of the chunk. |
2220 | */ |
2221 | sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net, |
2222 | const struct sctp_endpoint *ep, |
2223 | const struct sctp_association *asoc, |
2224 | const sctp_subtype_t type, |
2225 | void *arg, |
2226 | sctp_cmd_seq_t *commands) |
2227 | { |
2228 | struct sctp_chunk *chunk = arg; |
2229 | sctp_errhdr_t *err; |
2230 | |
2231 | if (!sctp_vtag_verify(chunk, asoc)) |
2232 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2233 | |
2234 | /* Make sure that the ERROR chunk has a valid length. |
2235 | * The parameter walking depends on this as well. |
2236 | */ |
2237 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
2238 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2239 | commands); |
2240 | |
2241 | /* Process the error here */ |
2242 | /* FUTURE FIXME: When PR-SCTP related and other optional |
2243 | * parms are emitted, this will have to change to handle multiple |
2244 | * errors. |
2245 | */ |
2246 | sctp_walk_errors(err, chunk->chunk_hdr) { |
2247 | if (SCTP_ERROR_STALE_COOKIE == err->cause) |
2248 | return sctp_sf_do_5_2_6_stale(net, ep, asoc, type, |
2249 | arg, commands); |
2250 | } |
2251 | |
2252 | /* It is possible to have malformed error causes, and that |
2253 | * will cause us to end the walk early. However, since |
2254 | * we are discarding the packet, there should be no adverse |
2255 | * affects. |
2256 | */ |
2257 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2258 | } |
2259 | |
2260 | /* |
2261 | * Handle a Stale COOKIE Error |
2262 | * |
2263 | * Section: 5.2.6 Handle Stale COOKIE Error |
2264 | * If the association is in the COOKIE-ECHOED state, the endpoint may elect |
2265 | * one of the following three alternatives. |
2266 | * ... |
2267 | * 3) Send a new INIT chunk to the endpoint, adding a Cookie |
2268 | * Preservative parameter requesting an extension to the lifetime of |
2269 | * the State Cookie. When calculating the time extension, an |
2270 | * implementation SHOULD use the RTT information measured based on the |
2271 | * previous COOKIE ECHO / ERROR exchange, and should add no more |
2272 | * than 1 second beyond the measured RTT, due to long State Cookie |
2273 | * lifetimes making the endpoint more subject to a replay attack. |
2274 | * |
2275 | * Verification Tag: Not explicit, but safe to ignore. |
2276 | * |
2277 | * Inputs |
2278 | * (endpoint, asoc, chunk) |
2279 | * |
2280 | * Outputs |
2281 | * (asoc, reply_msg, msg_up, timers, counters) |
2282 | * |
2283 | * The return value is the disposition of the chunk. |
2284 | */ |
2285 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net, |
2286 | const struct sctp_endpoint *ep, |
2287 | const struct sctp_association *asoc, |
2288 | const sctp_subtype_t type, |
2289 | void *arg, |
2290 | sctp_cmd_seq_t *commands) |
2291 | { |
2292 | struct sctp_chunk *chunk = arg; |
2293 | time_t stale; |
2294 | sctp_cookie_preserve_param_t bht; |
2295 | sctp_errhdr_t *err; |
2296 | struct sctp_chunk *reply; |
2297 | struct sctp_bind_addr *bp; |
2298 | int attempts = asoc->init_err_counter + 1; |
2299 | |
2300 | if (attempts > asoc->max_init_attempts) { |
2301 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
2302 | SCTP_ERROR(ETIMEDOUT)); |
2303 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
2304 | SCTP_PERR(SCTP_ERROR_STALE_COOKIE)); |
2305 | return SCTP_DISPOSITION_DELETE_TCB; |
2306 | } |
2307 | |
2308 | err = (sctp_errhdr_t *)(chunk->skb->data); |
2309 | |
2310 | /* When calculating the time extension, an implementation |
2311 | * SHOULD use the RTT information measured based on the |
2312 | * previous COOKIE ECHO / ERROR exchange, and should add no |
2313 | * more than 1 second beyond the measured RTT, due to long |
2314 | * State Cookie lifetimes making the endpoint more subject to |
2315 | * a replay attack. |
2316 | * Measure of Staleness's unit is usec. (1/1000000 sec) |
2317 | * Suggested Cookie Life-span Increment's unit is msec. |
2318 | * (1/1000 sec) |
2319 | * In general, if you use the suggested cookie life, the value |
2320 | * found in the field of measure of staleness should be doubled |
2321 | * to give ample time to retransmit the new cookie and thus |
2322 | * yield a higher probability of success on the reattempt. |
2323 | */ |
2324 | stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t))); |
2325 | stale = (stale * 2) / 1000; |
2326 | |
2327 | bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; |
2328 | bht.param_hdr.length = htons(sizeof(bht)); |
2329 | bht.lifespan_increment = htonl(stale); |
2330 | |
2331 | /* Build that new INIT chunk. */ |
2332 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
2333 | reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); |
2334 | if (!reply) |
2335 | goto nomem; |
2336 | |
2337 | sctp_addto_chunk(reply, sizeof(bht), &bht); |
2338 | |
2339 | /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ |
2340 | sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); |
2341 | |
2342 | /* Stop pending T3-rtx and heartbeat timers */ |
2343 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
2344 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
2345 | |
2346 | /* Delete non-primary peer ip addresses since we are transitioning |
2347 | * back to the COOKIE-WAIT state |
2348 | */ |
2349 | sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); |
2350 | |
2351 | /* If we've sent any data bundled with COOKIE-ECHO we will need to |
2352 | * resend |
2353 | */ |
2354 | sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN, |
2355 | SCTP_TRANSPORT(asoc->peer.primary_path)); |
2356 | |
2357 | /* Cast away the const modifier, as we want to just |
2358 | * rerun it through as a sideffect. |
2359 | */ |
2360 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL()); |
2361 | |
2362 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2363 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
2364 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2365 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
2366 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
2367 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
2368 | |
2369 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
2370 | |
2371 | return SCTP_DISPOSITION_CONSUME; |
2372 | |
2373 | nomem: |
2374 | return SCTP_DISPOSITION_NOMEM; |
2375 | } |
2376 | |
2377 | /* |
2378 | * Process an ABORT. |
2379 | * |
2380 | * Section: 9.1 |
2381 | * After checking the Verification Tag, the receiving endpoint shall |
2382 | * remove the association from its record, and shall report the |
2383 | * termination to its upper layer. |
2384 | * |
2385 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
2386 | * B) Rules for packet carrying ABORT: |
2387 | * |
2388 | * - The endpoint shall always fill in the Verification Tag field of the |
2389 | * outbound packet with the destination endpoint's tag value if it |
2390 | * is known. |
2391 | * |
2392 | * - If the ABORT is sent in response to an OOTB packet, the endpoint |
2393 | * MUST follow the procedure described in Section 8.4. |
2394 | * |
2395 | * - The receiver MUST accept the packet if the Verification Tag |
2396 | * matches either its own tag, OR the tag of its peer. Otherwise, the |
2397 | * receiver MUST silently discard the packet and take no further |
2398 | * action. |
2399 | * |
2400 | * Inputs |
2401 | * (endpoint, asoc, chunk) |
2402 | * |
2403 | * Outputs |
2404 | * (asoc, reply_msg, msg_up, timers, counters) |
2405 | * |
2406 | * The return value is the disposition of the chunk. |
2407 | */ |
2408 | sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net, |
2409 | const struct sctp_endpoint *ep, |
2410 | const struct sctp_association *asoc, |
2411 | const sctp_subtype_t type, |
2412 | void *arg, |
2413 | sctp_cmd_seq_t *commands) |
2414 | { |
2415 | struct sctp_chunk *chunk = arg; |
2416 | |
2417 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2418 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2419 | |
2420 | /* Make sure that the ABORT chunk has a valid length. |
2421 | * Since this is an ABORT chunk, we have to discard it |
2422 | * because of the following text: |
2423 | * RFC 2960, Section 3.3.7 |
2424 | * If an endpoint receives an ABORT with a format error or for an |
2425 | * association that doesn't exist, it MUST silently discard it. |
2426 | * Because the length is "invalid", we can't really discard just |
2427 | * as we do not know its true length. So, to be safe, discard the |
2428 | * packet. |
2429 | */ |
2430 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2431 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2432 | |
2433 | /* ADD-IP: Special case for ABORT chunks |
2434 | * F4) One special consideration is that ABORT Chunks arriving |
2435 | * destined to the IP address being deleted MUST be |
2436 | * ignored (see Section 5.3.1 for further details). |
2437 | */ |
2438 | if (SCTP_ADDR_DEL == |
2439 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
2440 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
2441 | |
2442 | return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
2443 | } |
2444 | |
2445 | static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net, |
2446 | const struct sctp_endpoint *ep, |
2447 | const struct sctp_association *asoc, |
2448 | const sctp_subtype_t type, |
2449 | void *arg, |
2450 | sctp_cmd_seq_t *commands) |
2451 | { |
2452 | struct sctp_chunk *chunk = arg; |
2453 | unsigned int len; |
2454 | __be16 error = SCTP_ERROR_NO_ERROR; |
2455 | |
2456 | /* See if we have an error cause code in the chunk. */ |
2457 | len = ntohs(chunk->chunk_hdr->length); |
2458 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) { |
2459 | |
2460 | sctp_errhdr_t *err; |
2461 | sctp_walk_errors(err, chunk->chunk_hdr); |
2462 | if ((void *)err != (void *)chunk->chunk_end) |
2463 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2464 | |
2465 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
2466 | } |
2467 | |
2468 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET)); |
2469 | /* ASSOC_FAILED will DELETE_TCB. */ |
2470 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error)); |
2471 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
2472 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
2473 | |
2474 | return SCTP_DISPOSITION_ABORT; |
2475 | } |
2476 | |
2477 | /* |
2478 | * Process an ABORT. (COOKIE-WAIT state) |
2479 | * |
2480 | * See sctp_sf_do_9_1_abort() above. |
2481 | */ |
2482 | sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net, |
2483 | const struct sctp_endpoint *ep, |
2484 | const struct sctp_association *asoc, |
2485 | const sctp_subtype_t type, |
2486 | void *arg, |
2487 | sctp_cmd_seq_t *commands) |
2488 | { |
2489 | struct sctp_chunk *chunk = arg; |
2490 | unsigned int len; |
2491 | __be16 error = SCTP_ERROR_NO_ERROR; |
2492 | |
2493 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2494 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2495 | |
2496 | /* Make sure that the ABORT chunk has a valid length. |
2497 | * Since this is an ABORT chunk, we have to discard it |
2498 | * because of the following text: |
2499 | * RFC 2960, Section 3.3.7 |
2500 | * If an endpoint receives an ABORT with a format error or for an |
2501 | * association that doesn't exist, it MUST silently discard it. |
2502 | * Because the length is "invalid", we can't really discard just |
2503 | * as we do not know its true length. So, to be safe, discard the |
2504 | * packet. |
2505 | */ |
2506 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2507 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2508 | |
2509 | /* See if we have an error cause code in the chunk. */ |
2510 | len = ntohs(chunk->chunk_hdr->length); |
2511 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
2512 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
2513 | |
2514 | return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc, |
2515 | chunk->transport); |
2516 | } |
2517 | |
2518 | /* |
2519 | * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) |
2520 | */ |
2521 | sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net, |
2522 | const struct sctp_endpoint *ep, |
2523 | const struct sctp_association *asoc, |
2524 | const sctp_subtype_t type, |
2525 | void *arg, |
2526 | sctp_cmd_seq_t *commands) |
2527 | { |
2528 | return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR, |
2529 | ENOPROTOOPT, asoc, |
2530 | (struct sctp_transport *)arg); |
2531 | } |
2532 | |
2533 | /* |
2534 | * Process an ABORT. (COOKIE-ECHOED state) |
2535 | */ |
2536 | sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net, |
2537 | const struct sctp_endpoint *ep, |
2538 | const struct sctp_association *asoc, |
2539 | const sctp_subtype_t type, |
2540 | void *arg, |
2541 | sctp_cmd_seq_t *commands) |
2542 | { |
2543 | /* There is a single T1 timer, so we should be able to use |
2544 | * common function with the COOKIE-WAIT state. |
2545 | */ |
2546 | return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands); |
2547 | } |
2548 | |
2549 | /* |
2550 | * Stop T1 timer and abort association with "INIT failed". |
2551 | * |
2552 | * This is common code called by several sctp_sf_*_abort() functions above. |
2553 | */ |
2554 | static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net, |
2555 | sctp_cmd_seq_t *commands, |
2556 | __be16 error, int sk_err, |
2557 | const struct sctp_association *asoc, |
2558 | struct sctp_transport *transport) |
2559 | { |
2560 | pr_debug("%s: ABORT received (INIT)\n", __func__); |
2561 | |
2562 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2563 | SCTP_STATE(SCTP_STATE_CLOSED)); |
2564 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
2565 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2566 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
2567 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err)); |
2568 | /* CMD_INIT_FAILED will DELETE_TCB. */ |
2569 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
2570 | SCTP_PERR(error)); |
2571 | |
2572 | return SCTP_DISPOSITION_ABORT; |
2573 | } |
2574 | |
2575 | /* |
2576 | * sctp_sf_do_9_2_shut |
2577 | * |
2578 | * Section: 9.2 |
2579 | * Upon the reception of the SHUTDOWN, the peer endpoint shall |
2580 | * - enter the SHUTDOWN-RECEIVED state, |
2581 | * |
2582 | * - stop accepting new data from its SCTP user |
2583 | * |
2584 | * - verify, by checking the Cumulative TSN Ack field of the chunk, |
2585 | * that all its outstanding DATA chunks have been received by the |
2586 | * SHUTDOWN sender. |
2587 | * |
2588 | * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT |
2589 | * send a SHUTDOWN in response to a ULP request. And should discard |
2590 | * subsequent SHUTDOWN chunks. |
2591 | * |
2592 | * If there are still outstanding DATA chunks left, the SHUTDOWN |
2593 | * receiver shall continue to follow normal data transmission |
2594 | * procedures defined in Section 6 until all outstanding DATA chunks |
2595 | * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept |
2596 | * new data from its SCTP user. |
2597 | * |
2598 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2599 | * |
2600 | * Inputs |
2601 | * (endpoint, asoc, chunk) |
2602 | * |
2603 | * Outputs |
2604 | * (asoc, reply_msg, msg_up, timers, counters) |
2605 | * |
2606 | * The return value is the disposition of the chunk. |
2607 | */ |
2608 | sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net, |
2609 | const struct sctp_endpoint *ep, |
2610 | const struct sctp_association *asoc, |
2611 | const sctp_subtype_t type, |
2612 | void *arg, |
2613 | sctp_cmd_seq_t *commands) |
2614 | { |
2615 | struct sctp_chunk *chunk = arg; |
2616 | sctp_shutdownhdr_t *sdh; |
2617 | sctp_disposition_t disposition; |
2618 | struct sctp_ulpevent *ev; |
2619 | __u32 ctsn; |
2620 | |
2621 | if (!sctp_vtag_verify(chunk, asoc)) |
2622 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2623 | |
2624 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
2625 | if (!sctp_chunk_length_valid(chunk, |
2626 | sizeof(struct sctp_shutdown_chunk_t))) |
2627 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2628 | commands); |
2629 | |
2630 | /* Convert the elaborate header. */ |
2631 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; |
2632 | skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); |
2633 | chunk->subh.shutdown_hdr = sdh; |
2634 | ctsn = ntohl(sdh->cum_tsn_ack); |
2635 | |
2636 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
2637 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
2638 | asoc->ctsn_ack_point); |
2639 | |
2640 | return SCTP_DISPOSITION_DISCARD; |
2641 | } |
2642 | |
2643 | /* If Cumulative TSN Ack beyond the max tsn currently |
2644 | * send, terminating the association and respond to the |
2645 | * sender with an ABORT. |
2646 | */ |
2647 | if (!TSN_lt(ctsn, asoc->next_tsn)) |
2648 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
2649 | |
2650 | /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT |
2651 | * When a peer sends a SHUTDOWN, SCTP delivers this notification to |
2652 | * inform the application that it should cease sending data. |
2653 | */ |
2654 | ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); |
2655 | if (!ev) { |
2656 | disposition = SCTP_DISPOSITION_NOMEM; |
2657 | goto out; |
2658 | } |
2659 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
2660 | |
2661 | /* Upon the reception of the SHUTDOWN, the peer endpoint shall |
2662 | * - enter the SHUTDOWN-RECEIVED state, |
2663 | * - stop accepting new data from its SCTP user |
2664 | * |
2665 | * [This is implicit in the new state.] |
2666 | */ |
2667 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2668 | SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); |
2669 | disposition = SCTP_DISPOSITION_CONSUME; |
2670 | |
2671 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
2672 | disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type, |
2673 | arg, commands); |
2674 | } |
2675 | |
2676 | if (SCTP_DISPOSITION_NOMEM == disposition) |
2677 | goto out; |
2678 | |
2679 | /* - verify, by checking the Cumulative TSN Ack field of the |
2680 | * chunk, that all its outstanding DATA chunks have been |
2681 | * received by the SHUTDOWN sender. |
2682 | */ |
2683 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
2684 | SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack)); |
2685 | |
2686 | out: |
2687 | return disposition; |
2688 | } |
2689 | |
2690 | /* |
2691 | * sctp_sf_do_9_2_shut_ctsn |
2692 | * |
2693 | * Once an endpoint has reached the SHUTDOWN-RECEIVED state, |
2694 | * it MUST NOT send a SHUTDOWN in response to a ULP request. |
2695 | * The Cumulative TSN Ack of the received SHUTDOWN chunk |
2696 | * MUST be processed. |
2697 | */ |
2698 | sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net, |
2699 | const struct sctp_endpoint *ep, |
2700 | const struct sctp_association *asoc, |
2701 | const sctp_subtype_t type, |
2702 | void *arg, |
2703 | sctp_cmd_seq_t *commands) |
2704 | { |
2705 | struct sctp_chunk *chunk = arg; |
2706 | sctp_shutdownhdr_t *sdh; |
2707 | __u32 ctsn; |
2708 | |
2709 | if (!sctp_vtag_verify(chunk, asoc)) |
2710 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2711 | |
2712 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
2713 | if (!sctp_chunk_length_valid(chunk, |
2714 | sizeof(struct sctp_shutdown_chunk_t))) |
2715 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2716 | commands); |
2717 | |
2718 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; |
2719 | ctsn = ntohl(sdh->cum_tsn_ack); |
2720 | |
2721 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
2722 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
2723 | asoc->ctsn_ack_point); |
2724 | |
2725 | return SCTP_DISPOSITION_DISCARD; |
2726 | } |
2727 | |
2728 | /* If Cumulative TSN Ack beyond the max tsn currently |
2729 | * send, terminating the association and respond to the |
2730 | * sender with an ABORT. |
2731 | */ |
2732 | if (!TSN_lt(ctsn, asoc->next_tsn)) |
2733 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
2734 | |
2735 | /* verify, by checking the Cumulative TSN Ack field of the |
2736 | * chunk, that all its outstanding DATA chunks have been |
2737 | * received by the SHUTDOWN sender. |
2738 | */ |
2739 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
2740 | SCTP_BE32(sdh->cum_tsn_ack)); |
2741 | |
2742 | return SCTP_DISPOSITION_CONSUME; |
2743 | } |
2744 | |
2745 | /* RFC 2960 9.2 |
2746 | * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk |
2747 | * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination |
2748 | * transport addresses (either in the IP addresses or in the INIT chunk) |
2749 | * that belong to this association, it should discard the INIT chunk and |
2750 | * retransmit the SHUTDOWN ACK chunk. |
2751 | */ |
2752 | sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net, |
2753 | const struct sctp_endpoint *ep, |
2754 | const struct sctp_association *asoc, |
2755 | const sctp_subtype_t type, |
2756 | void *arg, |
2757 | sctp_cmd_seq_t *commands) |
2758 | { |
2759 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; |
2760 | struct sctp_chunk *reply; |
2761 | |
2762 | /* Make sure that the chunk has a valid length */ |
2763 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
2764 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2765 | commands); |
2766 | |
2767 | /* Since we are not going to really process this INIT, there |
2768 | * is no point in verifying chunk boundries. Just generate |
2769 | * the SHUTDOWN ACK. |
2770 | */ |
2771 | reply = sctp_make_shutdown_ack(asoc, chunk); |
2772 | if (NULL == reply) |
2773 | goto nomem; |
2774 | |
2775 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
2776 | * the T2-SHUTDOWN timer. |
2777 | */ |
2778 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
2779 | |
2780 | /* and restart the T2-shutdown timer. */ |
2781 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2782 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
2783 | |
2784 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
2785 | |
2786 | return SCTP_DISPOSITION_CONSUME; |
2787 | nomem: |
2788 | return SCTP_DISPOSITION_NOMEM; |
2789 | } |
2790 | |
2791 | /* |
2792 | * sctp_sf_do_ecn_cwr |
2793 | * |
2794 | * Section: Appendix A: Explicit Congestion Notification |
2795 | * |
2796 | * CWR: |
2797 | * |
2798 | * RFC 2481 details a specific bit for a sender to send in the header of |
2799 | * its next outbound TCP segment to indicate to its peer that it has |
2800 | * reduced its congestion window. This is termed the CWR bit. For |
2801 | * SCTP the same indication is made by including the CWR chunk. |
2802 | * This chunk contains one data element, i.e. the TSN number that |
2803 | * was sent in the ECNE chunk. This element represents the lowest |
2804 | * TSN number in the datagram that was originally marked with the |
2805 | * CE bit. |
2806 | * |
2807 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2808 | * Inputs |
2809 | * (endpoint, asoc, chunk) |
2810 | * |
2811 | * Outputs |
2812 | * (asoc, reply_msg, msg_up, timers, counters) |
2813 | * |
2814 | * The return value is the disposition of the chunk. |
2815 | */ |
2816 | sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net, |
2817 | const struct sctp_endpoint *ep, |
2818 | const struct sctp_association *asoc, |
2819 | const sctp_subtype_t type, |
2820 | void *arg, |
2821 | sctp_cmd_seq_t *commands) |
2822 | { |
2823 | sctp_cwrhdr_t *cwr; |
2824 | struct sctp_chunk *chunk = arg; |
2825 | u32 lowest_tsn; |
2826 | |
2827 | if (!sctp_vtag_verify(chunk, asoc)) |
2828 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2829 | |
2830 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
2831 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2832 | commands); |
2833 | |
2834 | cwr = (sctp_cwrhdr_t *) chunk->skb->data; |
2835 | skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t)); |
2836 | |
2837 | lowest_tsn = ntohl(cwr->lowest_tsn); |
2838 | |
2839 | /* Does this CWR ack the last sent congestion notification? */ |
2840 | if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) { |
2841 | /* Stop sending ECNE. */ |
2842 | sctp_add_cmd_sf(commands, |
2843 | SCTP_CMD_ECN_CWR, |
2844 | SCTP_U32(lowest_tsn)); |
2845 | } |
2846 | return SCTP_DISPOSITION_CONSUME; |
2847 | } |
2848 | |
2849 | /* |
2850 | * sctp_sf_do_ecne |
2851 | * |
2852 | * Section: Appendix A: Explicit Congestion Notification |
2853 | * |
2854 | * ECN-Echo |
2855 | * |
2856 | * RFC 2481 details a specific bit for a receiver to send back in its |
2857 | * TCP acknowledgements to notify the sender of the Congestion |
2858 | * Experienced (CE) bit having arrived from the network. For SCTP this |
2859 | * same indication is made by including the ECNE chunk. This chunk |
2860 | * contains one data element, i.e. the lowest TSN associated with the IP |
2861 | * datagram marked with the CE bit..... |
2862 | * |
2863 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2864 | * Inputs |
2865 | * (endpoint, asoc, chunk) |
2866 | * |
2867 | * Outputs |
2868 | * (asoc, reply_msg, msg_up, timers, counters) |
2869 | * |
2870 | * The return value is the disposition of the chunk. |
2871 | */ |
2872 | sctp_disposition_t sctp_sf_do_ecne(struct net *net, |
2873 | const struct sctp_endpoint *ep, |
2874 | const struct sctp_association *asoc, |
2875 | const sctp_subtype_t type, |
2876 | void *arg, |
2877 | sctp_cmd_seq_t *commands) |
2878 | { |
2879 | sctp_ecnehdr_t *ecne; |
2880 | struct sctp_chunk *chunk = arg; |
2881 | |
2882 | if (!sctp_vtag_verify(chunk, asoc)) |
2883 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2884 | |
2885 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
2886 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2887 | commands); |
2888 | |
2889 | ecne = (sctp_ecnehdr_t *) chunk->skb->data; |
2890 | skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t)); |
2891 | |
2892 | /* If this is a newer ECNE than the last CWR packet we sent out */ |
2893 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, |
2894 | SCTP_U32(ntohl(ecne->lowest_tsn))); |
2895 | |
2896 | return SCTP_DISPOSITION_CONSUME; |
2897 | } |
2898 | |
2899 | /* |
2900 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
2901 | * |
2902 | * The SCTP endpoint MUST always acknowledge the reception of each valid |
2903 | * DATA chunk. |
2904 | * |
2905 | * The guidelines on delayed acknowledgement algorithm specified in |
2906 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
2907 | * acknowledgement SHOULD be generated for at least every second packet |
2908 | * (not every second DATA chunk) received, and SHOULD be generated within |
2909 | * 200 ms of the arrival of any unacknowledged DATA chunk. In some |
2910 | * situations it may be beneficial for an SCTP transmitter to be more |
2911 | * conservative than the algorithms detailed in this document allow. |
2912 | * However, an SCTP transmitter MUST NOT be more aggressive than the |
2913 | * following algorithms allow. |
2914 | * |
2915 | * A SCTP receiver MUST NOT generate more than one SACK for every |
2916 | * incoming packet, other than to update the offered window as the |
2917 | * receiving application consumes new data. |
2918 | * |
2919 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2920 | * |
2921 | * Inputs |
2922 | * (endpoint, asoc, chunk) |
2923 | * |
2924 | * Outputs |
2925 | * (asoc, reply_msg, msg_up, timers, counters) |
2926 | * |
2927 | * The return value is the disposition of the chunk. |
2928 | */ |
2929 | sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net, |
2930 | const struct sctp_endpoint *ep, |
2931 | const struct sctp_association *asoc, |
2932 | const sctp_subtype_t type, |
2933 | void *arg, |
2934 | sctp_cmd_seq_t *commands) |
2935 | { |
2936 | struct sctp_chunk *chunk = arg; |
2937 | sctp_arg_t force = SCTP_NOFORCE(); |
2938 | int error; |
2939 | |
2940 | if (!sctp_vtag_verify(chunk, asoc)) { |
2941 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
2942 | SCTP_NULL()); |
2943 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
2944 | } |
2945 | |
2946 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
2947 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
2948 | commands); |
2949 | |
2950 | error = sctp_eat_data(asoc, chunk, commands); |
2951 | switch (error) { |
2952 | case SCTP_IERROR_NO_ERROR: |
2953 | break; |
2954 | case SCTP_IERROR_HIGH_TSN: |
2955 | case SCTP_IERROR_BAD_STREAM: |
2956 | SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
2957 | goto discard_noforce; |
2958 | case SCTP_IERROR_DUP_TSN: |
2959 | case SCTP_IERROR_IGNORE_TSN: |
2960 | SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
2961 | goto discard_force; |
2962 | case SCTP_IERROR_NO_DATA: |
2963 | goto consume; |
2964 | case SCTP_IERROR_PROTO_VIOLATION: |
2965 | return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, |
2966 | (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t)); |
2967 | default: |
2968 | BUG(); |
2969 | } |
2970 | |
2971 | if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM) |
2972 | force = SCTP_FORCE(); |
2973 | |
2974 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { |
2975 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2976 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
2977 | } |
2978 | |
2979 | /* If this is the last chunk in a packet, we need to count it |
2980 | * toward sack generation. Note that we need to SACK every |
2981 | * OTHER packet containing data chunks, EVEN IF WE DISCARD |
2982 | * THEM. We elect to NOT generate SACK's if the chunk fails |
2983 | * the verification tag test. |
2984 | * |
2985 | * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
2986 | * |
2987 | * The SCTP endpoint MUST always acknowledge the reception of |
2988 | * each valid DATA chunk. |
2989 | * |
2990 | * The guidelines on delayed acknowledgement algorithm |
2991 | * specified in Section 4.2 of [RFC2581] SHOULD be followed. |
2992 | * Specifically, an acknowledgement SHOULD be generated for at |
2993 | * least every second packet (not every second DATA chunk) |
2994 | * received, and SHOULD be generated within 200 ms of the |
2995 | * arrival of any unacknowledged DATA chunk. In some |
2996 | * situations it may be beneficial for an SCTP transmitter to |
2997 | * be more conservative than the algorithms detailed in this |
2998 | * document allow. However, an SCTP transmitter MUST NOT be |
2999 | * more aggressive than the following algorithms allow. |
3000 | */ |
3001 | if (chunk->end_of_packet) |
3002 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); |
3003 | |
3004 | return SCTP_DISPOSITION_CONSUME; |
3005 | |
3006 | discard_force: |
3007 | /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
3008 | * |
3009 | * When a packet arrives with duplicate DATA chunk(s) and with |
3010 | * no new DATA chunk(s), the endpoint MUST immediately send a |
3011 | * SACK with no delay. If a packet arrives with duplicate |
3012 | * DATA chunk(s) bundled with new DATA chunks, the endpoint |
3013 | * MAY immediately send a SACK. Normally receipt of duplicate |
3014 | * DATA chunks will occur when the original SACK chunk was lost |
3015 | * and the peer's RTO has expired. The duplicate TSN number(s) |
3016 | * SHOULD be reported in the SACK as duplicate. |
3017 | */ |
3018 | /* In our case, we split the MAY SACK advice up whether or not |
3019 | * the last chunk is a duplicate.' |
3020 | */ |
3021 | if (chunk->end_of_packet) |
3022 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
3023 | return SCTP_DISPOSITION_DISCARD; |
3024 | |
3025 | discard_noforce: |
3026 | if (chunk->end_of_packet) |
3027 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); |
3028 | |
3029 | return SCTP_DISPOSITION_DISCARD; |
3030 | consume: |
3031 | return SCTP_DISPOSITION_CONSUME; |
3032 | |
3033 | } |
3034 | |
3035 | /* |
3036 | * sctp_sf_eat_data_fast_4_4 |
3037 | * |
3038 | * Section: 4 (4) |
3039 | * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received |
3040 | * DATA chunks without delay. |
3041 | * |
3042 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
3043 | * Inputs |
3044 | * (endpoint, asoc, chunk) |
3045 | * |
3046 | * Outputs |
3047 | * (asoc, reply_msg, msg_up, timers, counters) |
3048 | * |
3049 | * The return value is the disposition of the chunk. |
3050 | */ |
3051 | sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net, |
3052 | const struct sctp_endpoint *ep, |
3053 | const struct sctp_association *asoc, |
3054 | const sctp_subtype_t type, |
3055 | void *arg, |
3056 | sctp_cmd_seq_t *commands) |
3057 | { |
3058 | struct sctp_chunk *chunk = arg; |
3059 | int error; |
3060 | |
3061 | if (!sctp_vtag_verify(chunk, asoc)) { |
3062 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3063 | SCTP_NULL()); |
3064 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3065 | } |
3066 | |
3067 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
3068 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3069 | commands); |
3070 | |
3071 | error = sctp_eat_data(asoc, chunk, commands); |
3072 | switch (error) { |
3073 | case SCTP_IERROR_NO_ERROR: |
3074 | case SCTP_IERROR_HIGH_TSN: |
3075 | case SCTP_IERROR_DUP_TSN: |
3076 | case SCTP_IERROR_IGNORE_TSN: |
3077 | case SCTP_IERROR_BAD_STREAM: |
3078 | break; |
3079 | case SCTP_IERROR_NO_DATA: |
3080 | goto consume; |
3081 | case SCTP_IERROR_PROTO_VIOLATION: |
3082 | return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, |
3083 | (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t)); |
3084 | default: |
3085 | BUG(); |
3086 | } |
3087 | |
3088 | /* Go a head and force a SACK, since we are shutting down. */ |
3089 | |
3090 | /* Implementor's Guide. |
3091 | * |
3092 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
3093 | * respond to each received packet containing one or more DATA chunk(s) |
3094 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
3095 | */ |
3096 | if (chunk->end_of_packet) { |
3097 | /* We must delay the chunk creation since the cumulative |
3098 | * TSN has not been updated yet. |
3099 | */ |
3100 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
3101 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
3102 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3103 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
3104 | } |
3105 | |
3106 | consume: |
3107 | return SCTP_DISPOSITION_CONSUME; |
3108 | } |
3109 | |
3110 | /* |
3111 | * Section: 6.2 Processing a Received SACK |
3112 | * D) Any time a SACK arrives, the endpoint performs the following: |
3113 | * |
3114 | * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, |
3115 | * then drop the SACK. Since Cumulative TSN Ack is monotonically |
3116 | * increasing, a SACK whose Cumulative TSN Ack is less than the |
3117 | * Cumulative TSN Ack Point indicates an out-of-order SACK. |
3118 | * |
3119 | * ii) Set rwnd equal to the newly received a_rwnd minus the number |
3120 | * of bytes still outstanding after processing the Cumulative TSN Ack |
3121 | * and the Gap Ack Blocks. |
3122 | * |
3123 | * iii) If the SACK is missing a TSN that was previously |
3124 | * acknowledged via a Gap Ack Block (e.g., the data receiver |
3125 | * reneged on the data), then mark the corresponding DATA chunk |
3126 | * as available for retransmit: Mark it as missing for fast |
3127 | * retransmit as described in Section 7.2.4 and if no retransmit |
3128 | * timer is running for the destination address to which the DATA |
3129 | * chunk was originally transmitted, then T3-rtx is started for |
3130 | * that destination address. |
3131 | * |
3132 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
3133 | * |
3134 | * Inputs |
3135 | * (endpoint, asoc, chunk) |
3136 | * |
3137 | * Outputs |
3138 | * (asoc, reply_msg, msg_up, timers, counters) |
3139 | * |
3140 | * The return value is the disposition of the chunk. |
3141 | */ |
3142 | sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net, |
3143 | const struct sctp_endpoint *ep, |
3144 | const struct sctp_association *asoc, |
3145 | const sctp_subtype_t type, |
3146 | void *arg, |
3147 | sctp_cmd_seq_t *commands) |
3148 | { |
3149 | struct sctp_chunk *chunk = arg; |
3150 | sctp_sackhdr_t *sackh; |
3151 | __u32 ctsn; |
3152 | |
3153 | if (!sctp_vtag_verify(chunk, asoc)) |
3154 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3155 | |
3156 | /* Make sure that the SACK chunk has a valid length. */ |
3157 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t))) |
3158 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3159 | commands); |
3160 | |
3161 | /* Pull the SACK chunk from the data buffer */ |
3162 | sackh = sctp_sm_pull_sack(chunk); |
3163 | /* Was this a bogus SACK? */ |
3164 | if (!sackh) |
3165 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3166 | chunk->subh.sack_hdr = sackh; |
3167 | ctsn = ntohl(sackh->cum_tsn_ack); |
3168 | |
3169 | /* i) If Cumulative TSN Ack is less than the Cumulative TSN |
3170 | * Ack Point, then drop the SACK. Since Cumulative TSN |
3171 | * Ack is monotonically increasing, a SACK whose |
3172 | * Cumulative TSN Ack is less than the Cumulative TSN Ack |
3173 | * Point indicates an out-of-order SACK. |
3174 | */ |
3175 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
3176 | pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
3177 | asoc->ctsn_ack_point); |
3178 | |
3179 | return SCTP_DISPOSITION_DISCARD; |
3180 | } |
3181 | |
3182 | /* If Cumulative TSN Ack beyond the max tsn currently |
3183 | * send, terminating the association and respond to the |
3184 | * sender with an ABORT. |
3185 | */ |
3186 | if (!TSN_lt(ctsn, asoc->next_tsn)) |
3187 | return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
3188 | |
3189 | /* Return this SACK for further processing. */ |
3190 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk)); |
3191 | |
3192 | /* Note: We do the rest of the work on the PROCESS_SACK |
3193 | * sideeffect. |
3194 | */ |
3195 | return SCTP_DISPOSITION_CONSUME; |
3196 | } |
3197 | |
3198 | /* |
3199 | * Generate an ABORT in response to a packet. |
3200 | * |
3201 | * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41 |
3202 | * |
3203 | * 8) The receiver should respond to the sender of the OOTB packet with |
3204 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
3205 | * MUST fill in the Verification Tag field of the outbound packet |
3206 | * with the value found in the Verification Tag field of the OOTB |
3207 | * packet and set the T-bit in the Chunk Flags to indicate that the |
3208 | * Verification Tag is reflected. After sending this ABORT, the |
3209 | * receiver of the OOTB packet shall discard the OOTB packet and take |
3210 | * no further action. |
3211 | * |
3212 | * Verification Tag: |
3213 | * |
3214 | * The return value is the disposition of the chunk. |
3215 | */ |
3216 | static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net, |
3217 | const struct sctp_endpoint *ep, |
3218 | const struct sctp_association *asoc, |
3219 | const sctp_subtype_t type, |
3220 | void *arg, |
3221 | sctp_cmd_seq_t *commands) |
3222 | { |
3223 | struct sctp_packet *packet = NULL; |
3224 | struct sctp_chunk *chunk = arg; |
3225 | struct sctp_chunk *abort; |
3226 | |
3227 | packet = sctp_ootb_pkt_new(net, asoc, chunk); |
3228 | |
3229 | if (packet) { |
3230 | /* Make an ABORT. The T bit will be set if the asoc |
3231 | * is NULL. |
3232 | */ |
3233 | abort = sctp_make_abort(asoc, chunk, 0); |
3234 | if (!abort) { |
3235 | sctp_ootb_pkt_free(packet); |
3236 | return SCTP_DISPOSITION_NOMEM; |
3237 | } |
3238 | |
3239 | /* Reflect vtag if T-Bit is set */ |
3240 | if (sctp_test_T_bit(abort)) |
3241 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
3242 | |
3243 | /* Set the skb to the belonging sock for accounting. */ |
3244 | abort->skb->sk = ep->base.sk; |
3245 | |
3246 | sctp_packet_append_chunk(packet, abort); |
3247 | |
3248 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
3249 | SCTP_PACKET(packet)); |
3250 | |
3251 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
3252 | |
3253 | sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3254 | return SCTP_DISPOSITION_CONSUME; |
3255 | } |
3256 | |
3257 | return SCTP_DISPOSITION_NOMEM; |
3258 | } |
3259 | |
3260 | /* |
3261 | * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR |
3262 | * event as ULP notification for each cause included in the chunk. |
3263 | * |
3264 | * API 5.3.1.3 - SCTP_REMOTE_ERROR |
3265 | * |
3266 | * The return value is the disposition of the chunk. |
3267 | */ |
3268 | sctp_disposition_t sctp_sf_operr_notify(struct net *net, |
3269 | const struct sctp_endpoint *ep, |
3270 | const struct sctp_association *asoc, |
3271 | const sctp_subtype_t type, |
3272 | void *arg, |
3273 | sctp_cmd_seq_t *commands) |
3274 | { |
3275 | struct sctp_chunk *chunk = arg; |
3276 | sctp_errhdr_t *err; |
3277 | |
3278 | if (!sctp_vtag_verify(chunk, asoc)) |
3279 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3280 | |
3281 | /* Make sure that the ERROR chunk has a valid length. */ |
3282 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
3283 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3284 | commands); |
3285 | sctp_walk_errors(err, chunk->chunk_hdr); |
3286 | if ((void *)err != (void *)chunk->chunk_end) |
3287 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
3288 | (void *)err, commands); |
3289 | |
3290 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, |
3291 | SCTP_CHUNK(chunk)); |
3292 | |
3293 | return SCTP_DISPOSITION_CONSUME; |
3294 | } |
3295 | |
3296 | /* |
3297 | * Process an inbound SHUTDOWN ACK. |
3298 | * |
3299 | * From Section 9.2: |
3300 | * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
3301 | * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its |
3302 | * peer, and remove all record of the association. |
3303 | * |
3304 | * The return value is the disposition. |
3305 | */ |
3306 | sctp_disposition_t sctp_sf_do_9_2_final(struct net *net, |
3307 | const struct sctp_endpoint *ep, |
3308 | const struct sctp_association *asoc, |
3309 | const sctp_subtype_t type, |
3310 | void *arg, |
3311 | sctp_cmd_seq_t *commands) |
3312 | { |
3313 | struct sctp_chunk *chunk = arg; |
3314 | struct sctp_chunk *reply; |
3315 | struct sctp_ulpevent *ev; |
3316 | |
3317 | if (!sctp_vtag_verify(chunk, asoc)) |
3318 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3319 | |
3320 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
3321 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
3322 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3323 | commands); |
3324 | /* 10.2 H) SHUTDOWN COMPLETE notification |
3325 | * |
3326 | * When SCTP completes the shutdown procedures (section 9.2) this |
3327 | * notification is passed to the upper layer. |
3328 | */ |
3329 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
3330 | 0, 0, 0, NULL, GFP_ATOMIC); |
3331 | if (!ev) |
3332 | goto nomem; |
3333 | |
3334 | /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ |
3335 | reply = sctp_make_shutdown_complete(asoc, chunk); |
3336 | if (!reply) |
3337 | goto nomem_chunk; |
3338 | |
3339 | /* Do all the commands now (after allocation), so that we |
3340 | * have consistent state if memory allocation failes |
3341 | */ |
3342 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
3343 | |
3344 | /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
3345 | * stop the T2-shutdown timer, |
3346 | */ |
3347 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3348 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
3349 | |
3350 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3351 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
3352 | |
3353 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
3354 | SCTP_STATE(SCTP_STATE_CLOSED)); |
3355 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
3356 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
3357 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
3358 | |
3359 | /* ...and remove all record of the association. */ |
3360 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
3361 | return SCTP_DISPOSITION_DELETE_TCB; |
3362 | |
3363 | nomem_chunk: |
3364 | sctp_ulpevent_free(ev); |
3365 | nomem: |
3366 | return SCTP_DISPOSITION_NOMEM; |
3367 | } |
3368 | |
3369 | /* |
3370 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41. |
3371 | * |
3372 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
3373 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
3374 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
3375 | * packet must fill in the Verification Tag field of the outbound |
3376 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
3377 | * set the T-bit in the Chunk Flags to indicate that the Verification |
3378 | * Tag is reflected. |
3379 | * |
3380 | * 8) The receiver should respond to the sender of the OOTB packet with |
3381 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
3382 | * MUST fill in the Verification Tag field of the outbound packet |
3383 | * with the value found in the Verification Tag field of the OOTB |
3384 | * packet and set the T-bit in the Chunk Flags to indicate that the |
3385 | * Verification Tag is reflected. After sending this ABORT, the |
3386 | * receiver of the OOTB packet shall discard the OOTB packet and take |
3387 | * no further action. |
3388 | */ |
3389 | sctp_disposition_t sctp_sf_ootb(struct net *net, |
3390 | const struct sctp_endpoint *ep, |
3391 | const struct sctp_association *asoc, |
3392 | const sctp_subtype_t type, |
3393 | void *arg, |
3394 | sctp_cmd_seq_t *commands) |
3395 | { |
3396 | struct sctp_chunk *chunk = arg; |
3397 | struct sk_buff *skb = chunk->skb; |
3398 | sctp_chunkhdr_t *ch; |
3399 | sctp_errhdr_t *err; |
3400 | __u8 *ch_end; |
3401 | int ootb_shut_ack = 0; |
3402 | int ootb_cookie_ack = 0; |
3403 | |
3404 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
3405 | |
3406 | ch = (sctp_chunkhdr_t *) chunk->chunk_hdr; |
3407 | do { |
3408 | /* Report violation if the chunk is less then minimal */ |
3409 | if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) |
3410 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3411 | commands); |
3412 | |
3413 | /* Now that we know we at least have a chunk header, |
3414 | * do things that are type appropriate. |
3415 | */ |
3416 | if (SCTP_CID_SHUTDOWN_ACK == ch->type) |
3417 | ootb_shut_ack = 1; |
3418 | |
3419 | /* RFC 2960, Section 3.3.7 |
3420 | * Moreover, under any circumstances, an endpoint that |
3421 | * receives an ABORT MUST NOT respond to that ABORT by |
3422 | * sending an ABORT of its own. |
3423 | */ |
3424 | if (SCTP_CID_ABORT == ch->type) |
3425 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3426 | |
3427 | /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR |
3428 | * or a COOKIE ACK the SCTP Packet should be silently |
3429 | * discarded. |
3430 | */ |
3431 | |
3432 | if (SCTP_CID_COOKIE_ACK == ch->type) |
3433 | ootb_cookie_ack = 1; |
3434 | |
3435 | if (SCTP_CID_ERROR == ch->type) { |
3436 | sctp_walk_errors(err, ch) { |
3437 | if (SCTP_ERROR_STALE_COOKIE == err->cause) { |
3438 | ootb_cookie_ack = 1; |
3439 | break; |
3440 | } |
3441 | } |
3442 | } |
3443 | |
3444 | /* Report violation if chunk len overflows */ |
3445 | ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); |
3446 | if (ch_end > skb_tail_pointer(skb)) |
3447 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3448 | commands); |
3449 | |
3450 | ch = (sctp_chunkhdr_t *) ch_end; |
3451 | } while (ch_end < skb_tail_pointer(skb)); |
3452 | |
3453 | if (ootb_shut_ack) |
3454 | return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands); |
3455 | else if (ootb_cookie_ack) |
3456 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3457 | else |
3458 | return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
3459 | } |
3460 | |
3461 | /* |
3462 | * Handle an "Out of the blue" SHUTDOWN ACK. |
3463 | * |
3464 | * Section: 8.4 5, sctpimpguide 2.41. |
3465 | * |
3466 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
3467 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
3468 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
3469 | * packet must fill in the Verification Tag field of the outbound |
3470 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
3471 | * set the T-bit in the Chunk Flags to indicate that the Verification |
3472 | * Tag is reflected. |
3473 | * |
3474 | * Inputs |
3475 | * (endpoint, asoc, type, arg, commands) |
3476 | * |
3477 | * Outputs |
3478 | * (sctp_disposition_t) |
3479 | * |
3480 | * The return value is the disposition of the chunk. |
3481 | */ |
3482 | static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net, |
3483 | const struct sctp_endpoint *ep, |
3484 | const struct sctp_association *asoc, |
3485 | const sctp_subtype_t type, |
3486 | void *arg, |
3487 | sctp_cmd_seq_t *commands) |
3488 | { |
3489 | struct sctp_packet *packet = NULL; |
3490 | struct sctp_chunk *chunk = arg; |
3491 | struct sctp_chunk *shut; |
3492 | |
3493 | packet = sctp_ootb_pkt_new(net, asoc, chunk); |
3494 | |
3495 | if (packet) { |
3496 | /* Make an SHUTDOWN_COMPLETE. |
3497 | * The T bit will be set if the asoc is NULL. |
3498 | */ |
3499 | shut = sctp_make_shutdown_complete(asoc, chunk); |
3500 | if (!shut) { |
3501 | sctp_ootb_pkt_free(packet); |
3502 | return SCTP_DISPOSITION_NOMEM; |
3503 | } |
3504 | |
3505 | /* Reflect vtag if T-Bit is set */ |
3506 | if (sctp_test_T_bit(shut)) |
3507 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
3508 | |
3509 | /* Set the skb to the belonging sock for accounting. */ |
3510 | shut->skb->sk = ep->base.sk; |
3511 | |
3512 | sctp_packet_append_chunk(packet, shut); |
3513 | |
3514 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
3515 | SCTP_PACKET(packet)); |
3516 | |
3517 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
3518 | |
3519 | /* If the chunk length is invalid, we don't want to process |
3520 | * the reset of the packet. |
3521 | */ |
3522 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
3523 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3524 | |
3525 | /* We need to discard the rest of the packet to prevent |
3526 | * potential bomming attacks from additional bundled chunks. |
3527 | * This is documented in SCTP Threats ID. |
3528 | */ |
3529 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3530 | } |
3531 | |
3532 | return SCTP_DISPOSITION_NOMEM; |
3533 | } |
3534 | |
3535 | /* |
3536 | * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. |
3537 | * |
3538 | * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK |
3539 | * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the |
3540 | * procedures in section 8.4 SHOULD be followed, in other words it |
3541 | * should be treated as an Out Of The Blue packet. |
3542 | * [This means that we do NOT check the Verification Tag on these |
3543 | * chunks. --piggy ] |
3544 | * |
3545 | */ |
3546 | sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net, |
3547 | const struct sctp_endpoint *ep, |
3548 | const struct sctp_association *asoc, |
3549 | const sctp_subtype_t type, |
3550 | void *arg, |
3551 | sctp_cmd_seq_t *commands) |
3552 | { |
3553 | struct sctp_chunk *chunk = arg; |
3554 | |
3555 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
3556 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
3557 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3558 | commands); |
3559 | |
3560 | /* Although we do have an association in this case, it corresponds |
3561 | * to a restarted association. So the packet is treated as an OOTB |
3562 | * packet and the state function that handles OOTB SHUTDOWN_ACK is |
3563 | * called with a NULL association. |
3564 | */ |
3565 | SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
3566 | |
3567 | return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands); |
3568 | } |
3569 | |
3570 | /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ |
3571 | sctp_disposition_t sctp_sf_do_asconf(struct net *net, |
3572 | const struct sctp_endpoint *ep, |
3573 | const struct sctp_association *asoc, |
3574 | const sctp_subtype_t type, void *arg, |
3575 | sctp_cmd_seq_t *commands) |
3576 | { |
3577 | struct sctp_chunk *chunk = arg; |
3578 | struct sctp_chunk *asconf_ack = NULL; |
3579 | struct sctp_paramhdr *err_param = NULL; |
3580 | sctp_addiphdr_t *hdr; |
3581 | union sctp_addr_param *addr_param; |
3582 | __u32 serial; |
3583 | int length; |
3584 | |
3585 | if (!sctp_vtag_verify(chunk, asoc)) { |
3586 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3587 | SCTP_NULL()); |
3588 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3589 | } |
3590 | |
3591 | /* ADD-IP: Section 4.1.1 |
3592 | * This chunk MUST be sent in an authenticated way by using |
3593 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
3594 | * is received unauthenticated it MUST be silently discarded as |
3595 | * described in [I-D.ietf-tsvwg-sctp-auth]. |
3596 | */ |
3597 | if (!net->sctp.addip_noauth && !chunk->auth) |
3598 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
3599 | |
3600 | /* Make sure that the ASCONF ADDIP chunk has a valid length. */ |
3601 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t))) |
3602 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3603 | commands); |
3604 | |
3605 | hdr = (sctp_addiphdr_t *)chunk->skb->data; |
3606 | serial = ntohl(hdr->serial); |
3607 | |
3608 | addr_param = (union sctp_addr_param *)hdr->params; |
3609 | length = ntohs(addr_param->p.length); |
3610 | if (length < sizeof(sctp_paramhdr_t)) |
3611 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
3612 | (void *)addr_param, commands); |
3613 | |
3614 | /* Verify the ASCONF chunk before processing it. */ |
3615 | if (!sctp_verify_asconf(asoc, |
3616 | (sctp_paramhdr_t *)((void *)addr_param + length), |
3617 | (void *)chunk->chunk_end, |
3618 | &err_param)) |
3619 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
3620 | (void *)err_param, commands); |
3621 | |
3622 | /* ADDIP 5.2 E1) Compare the value of the serial number to the value |
3623 | * the endpoint stored in a new association variable |
3624 | * 'Peer-Serial-Number'. |
3625 | */ |
3626 | if (serial == asoc->peer.addip_serial + 1) { |
3627 | /* If this is the first instance of ASCONF in the packet, |
3628 | * we can clean our old ASCONF-ACKs. |
3629 | */ |
3630 | if (!chunk->has_asconf) |
3631 | sctp_assoc_clean_asconf_ack_cache(asoc); |
3632 | |
3633 | /* ADDIP 5.2 E4) When the Sequence Number matches the next one |
3634 | * expected, process the ASCONF as described below and after |
3635 | * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to |
3636 | * the response packet and cache a copy of it (in the event it |
3637 | * later needs to be retransmitted). |
3638 | * |
3639 | * Essentially, do V1-V5. |
3640 | */ |
3641 | asconf_ack = sctp_process_asconf((struct sctp_association *) |
3642 | asoc, chunk); |
3643 | if (!asconf_ack) |
3644 | return SCTP_DISPOSITION_NOMEM; |
3645 | } else if (serial < asoc->peer.addip_serial + 1) { |
3646 | /* ADDIP 5.2 E2) |
3647 | * If the value found in the Sequence Number is less than the |
3648 | * ('Peer- Sequence-Number' + 1), simply skip to the next |
3649 | * ASCONF, and include in the outbound response packet |
3650 | * any previously cached ASCONF-ACK response that was |
3651 | * sent and saved that matches the Sequence Number of the |
3652 | * ASCONF. Note: It is possible that no cached ASCONF-ACK |
3653 | * Chunk exists. This will occur when an older ASCONF |
3654 | * arrives out of order. In such a case, the receiver |
3655 | * should skip the ASCONF Chunk and not include ASCONF-ACK |
3656 | * Chunk for that chunk. |
3657 | */ |
3658 | asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial); |
3659 | if (!asconf_ack) |
3660 | return SCTP_DISPOSITION_DISCARD; |
3661 | |
3662 | /* Reset the transport so that we select the correct one |
3663 | * this time around. This is to make sure that we don't |
3664 | * accidentally use a stale transport that's been removed. |
3665 | */ |
3666 | asconf_ack->transport = NULL; |
3667 | } else { |
3668 | /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since |
3669 | * it must be either a stale packet or from an attacker. |
3670 | */ |
3671 | return SCTP_DISPOSITION_DISCARD; |
3672 | } |
3673 | |
3674 | /* ADDIP 5.2 E6) The destination address of the SCTP packet |
3675 | * containing the ASCONF-ACK Chunks MUST be the source address of |
3676 | * the SCTP packet that held the ASCONF Chunks. |
3677 | * |
3678 | * To do this properly, we'll set the destination address of the chunk |
3679 | * and at the transmit time, will try look up the transport to use. |
3680 | * Since ASCONFs may be bundled, the correct transport may not be |
3681 | * created until we process the entire packet, thus this workaround. |
3682 | */ |
3683 | asconf_ack->dest = chunk->source; |
3684 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); |
3685 | if (asoc->new_transport) { |
3686 | sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands); |
3687 | ((struct sctp_association *)asoc)->new_transport = NULL; |
3688 | } |
3689 | |
3690 | return SCTP_DISPOSITION_CONSUME; |
3691 | } |
3692 | |
3693 | /* |
3694 | * ADDIP Section 4.3 General rules for address manipulation |
3695 | * When building TLV parameters for the ASCONF Chunk that will add or |
3696 | * delete IP addresses the D0 to D13 rules should be applied: |
3697 | */ |
3698 | sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net, |
3699 | const struct sctp_endpoint *ep, |
3700 | const struct sctp_association *asoc, |
3701 | const sctp_subtype_t type, void *arg, |
3702 | sctp_cmd_seq_t *commands) |
3703 | { |
3704 | struct sctp_chunk *asconf_ack = arg; |
3705 | struct sctp_chunk *last_asconf = asoc->addip_last_asconf; |
3706 | struct sctp_chunk *abort; |
3707 | struct sctp_paramhdr *err_param = NULL; |
3708 | sctp_addiphdr_t *addip_hdr; |
3709 | __u32 sent_serial, rcvd_serial; |
3710 | |
3711 | if (!sctp_vtag_verify(asconf_ack, asoc)) { |
3712 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3713 | SCTP_NULL()); |
3714 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3715 | } |
3716 | |
3717 | /* ADD-IP, Section 4.1.2: |
3718 | * This chunk MUST be sent in an authenticated way by using |
3719 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
3720 | * is received unauthenticated it MUST be silently discarded as |
3721 | * described in [I-D.ietf-tsvwg-sctp-auth]. |
3722 | */ |
3723 | if (!net->sctp.addip_noauth && !asconf_ack->auth) |
3724 | return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
3725 | |
3726 | /* Make sure that the ADDIP chunk has a valid length. */ |
3727 | if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t))) |
3728 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3729 | commands); |
3730 | |
3731 | addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data; |
3732 | rcvd_serial = ntohl(addip_hdr->serial); |
3733 | |
3734 | /* Verify the ASCONF-ACK chunk before processing it. */ |
3735 | if (!sctp_verify_asconf(asoc, |
3736 | (sctp_paramhdr_t *)addip_hdr->params, |
3737 | (void *)asconf_ack->chunk_end, |
3738 | &err_param)) |
3739 | return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
3740 | (void *)err_param, commands); |
3741 | |
3742 | if (last_asconf) { |
3743 | addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr; |
3744 | sent_serial = ntohl(addip_hdr->serial); |
3745 | } else { |
3746 | sent_serial = asoc->addip_serial - 1; |
3747 | } |
3748 | |
3749 | /* D0) If an endpoint receives an ASCONF-ACK that is greater than or |
3750 | * equal to the next serial number to be used but no ASCONF chunk is |
3751 | * outstanding the endpoint MUST ABORT the association. Note that a |
3752 | * sequence number is greater than if it is no more than 2^^31-1 |
3753 | * larger than the current sequence number (using serial arithmetic). |
3754 | */ |
3755 | if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && |
3756 | !(asoc->addip_last_asconf)) { |
3757 | abort = sctp_make_abort(asoc, asconf_ack, |
3758 | sizeof(sctp_errhdr_t)); |
3759 | if (abort) { |
3760 | sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0); |
3761 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3762 | SCTP_CHUNK(abort)); |
3763 | } |
3764 | /* We are going to ABORT, so we might as well stop |
3765 | * processing the rest of the chunks in the packet. |
3766 | */ |
3767 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3768 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
3769 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
3770 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
3771 | SCTP_ERROR(ECONNABORTED)); |
3772 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
3773 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
3774 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
3775 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
3776 | return SCTP_DISPOSITION_ABORT; |
3777 | } |
3778 | |
3779 | if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { |
3780 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3781 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
3782 | |
3783 | if (!sctp_process_asconf_ack((struct sctp_association *)asoc, |
3784 | asconf_ack)) { |
3785 | /* Successfully processed ASCONF_ACK. We can |
3786 | * release the next asconf if we have one. |
3787 | */ |
3788 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF, |
3789 | SCTP_NULL()); |
3790 | return SCTP_DISPOSITION_CONSUME; |
3791 | } |
3792 | |
3793 | abort = sctp_make_abort(asoc, asconf_ack, |
3794 | sizeof(sctp_errhdr_t)); |
3795 | if (abort) { |
3796 | sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); |
3797 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3798 | SCTP_CHUNK(abort)); |
3799 | } |
3800 | /* We are going to ABORT, so we might as well stop |
3801 | * processing the rest of the chunks in the packet. |
3802 | */ |
3803 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
3804 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
3805 | SCTP_ERROR(ECONNABORTED)); |
3806 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
3807 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
3808 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
3809 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
3810 | return SCTP_DISPOSITION_ABORT; |
3811 | } |
3812 | |
3813 | return SCTP_DISPOSITION_DISCARD; |
3814 | } |
3815 | |
3816 | /* |
3817 | * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP |
3818 | * |
3819 | * When a FORWARD TSN chunk arrives, the data receiver MUST first update |
3820 | * its cumulative TSN point to the value carried in the FORWARD TSN |
3821 | * chunk, and then MUST further advance its cumulative TSN point locally |
3822 | * if possible. |
3823 | * After the above processing, the data receiver MUST stop reporting any |
3824 | * missing TSNs earlier than or equal to the new cumulative TSN point. |
3825 | * |
3826 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
3827 | * |
3828 | * The return value is the disposition of the chunk. |
3829 | */ |
3830 | sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net, |
3831 | const struct sctp_endpoint *ep, |
3832 | const struct sctp_association *asoc, |
3833 | const sctp_subtype_t type, |
3834 | void *arg, |
3835 | sctp_cmd_seq_t *commands) |
3836 | { |
3837 | struct sctp_chunk *chunk = arg; |
3838 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
3839 | struct sctp_fwdtsn_skip *skip; |
3840 | __u16 len; |
3841 | __u32 tsn; |
3842 | |
3843 | if (!sctp_vtag_verify(chunk, asoc)) { |
3844 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3845 | SCTP_NULL()); |
3846 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3847 | } |
3848 | |
3849 | /* Make sure that the FORWARD_TSN chunk has valid length. */ |
3850 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
3851 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3852 | commands); |
3853 | |
3854 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
3855 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
3856 | len = ntohs(chunk->chunk_hdr->length); |
3857 | len -= sizeof(struct sctp_chunkhdr); |
3858 | skb_pull(chunk->skb, len); |
3859 | |
3860 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
3861 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
3862 | |
3863 | /* The TSN is too high--silently discard the chunk and count on it |
3864 | * getting retransmitted later. |
3865 | */ |
3866 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
3867 | goto discard_noforce; |
3868 | |
3869 | /* Silently discard the chunk if stream-id is not valid */ |
3870 | sctp_walk_fwdtsn(skip, chunk) { |
3871 | if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams) |
3872 | goto discard_noforce; |
3873 | } |
3874 | |
3875 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
3876 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
3877 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
3878 | SCTP_CHUNK(chunk)); |
3879 | |
3880 | /* Count this as receiving DATA. */ |
3881 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { |
3882 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3883 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
3884 | } |
3885 | |
3886 | /* FIXME: For now send a SACK, but DATA processing may |
3887 | * send another. |
3888 | */ |
3889 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
3890 | |
3891 | return SCTP_DISPOSITION_CONSUME; |
3892 | |
3893 | discard_noforce: |
3894 | return SCTP_DISPOSITION_DISCARD; |
3895 | } |
3896 | |
3897 | sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( |
3898 | struct net *net, |
3899 | const struct sctp_endpoint *ep, |
3900 | const struct sctp_association *asoc, |
3901 | const sctp_subtype_t type, |
3902 | void *arg, |
3903 | sctp_cmd_seq_t *commands) |
3904 | { |
3905 | struct sctp_chunk *chunk = arg; |
3906 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
3907 | struct sctp_fwdtsn_skip *skip; |
3908 | __u16 len; |
3909 | __u32 tsn; |
3910 | |
3911 | if (!sctp_vtag_verify(chunk, asoc)) { |
3912 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3913 | SCTP_NULL()); |
3914 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
3915 | } |
3916 | |
3917 | /* Make sure that the FORWARD_TSN chunk has a valid length. */ |
3918 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
3919 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
3920 | commands); |
3921 | |
3922 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
3923 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
3924 | len = ntohs(chunk->chunk_hdr->length); |
3925 | len -= sizeof(struct sctp_chunkhdr); |
3926 | skb_pull(chunk->skb, len); |
3927 | |
3928 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
3929 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
3930 | |
3931 | /* The TSN is too high--silently discard the chunk and count on it |
3932 | * getting retransmitted later. |
3933 | */ |
3934 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
3935 | goto gen_shutdown; |
3936 | |
3937 | /* Silently discard the chunk if stream-id is not valid */ |
3938 | sctp_walk_fwdtsn(skip, chunk) { |
3939 | if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams) |
3940 | goto gen_shutdown; |
3941 | } |
3942 | |
3943 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
3944 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
3945 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
3946 | SCTP_CHUNK(chunk)); |
3947 | |
3948 | /* Go a head and force a SACK, since we are shutting down. */ |
3949 | gen_shutdown: |
3950 | /* Implementor's Guide. |
3951 | * |
3952 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
3953 | * respond to each received packet containing one or more DATA chunk(s) |
3954 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
3955 | */ |
3956 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
3957 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
3958 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3959 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
3960 | |
3961 | return SCTP_DISPOSITION_CONSUME; |
3962 | } |
3963 | |
3964 | /* |
3965 | * SCTP-AUTH Section 6.3 Receiving authenticated chukns |
3966 | * |
3967 | * The receiver MUST use the HMAC algorithm indicated in the HMAC |
3968 | * Identifier field. If this algorithm was not specified by the |
3969 | * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk |
3970 | * during association setup, the AUTH chunk and all chunks after it MUST |
3971 | * be discarded and an ERROR chunk SHOULD be sent with the error cause |
3972 | * defined in Section 4.1. |
3973 | * |
3974 | * If an endpoint with no shared key receives a Shared Key Identifier |
3975 | * other than 0, it MUST silently discard all authenticated chunks. If |
3976 | * the endpoint has at least one endpoint pair shared key for the peer, |
3977 | * it MUST use the key specified by the Shared Key Identifier if a |
3978 | * key has been configured for that Shared Key Identifier. If no |
3979 | * endpoint pair shared key has been configured for that Shared Key |
3980 | * Identifier, all authenticated chunks MUST be silently discarded. |
3981 | * |
3982 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
3983 | * |
3984 | * The return value is the disposition of the chunk. |
3985 | */ |
3986 | static sctp_ierror_t sctp_sf_authenticate(struct net *net, |
3987 | const struct sctp_endpoint *ep, |
3988 | const struct sctp_association *asoc, |
3989 | const sctp_subtype_t type, |
3990 | struct sctp_chunk *chunk) |
3991 | { |
3992 | struct sctp_authhdr *auth_hdr; |
3993 | struct sctp_hmac *hmac; |
3994 | unsigned int sig_len; |
3995 | __u16 key_id; |
3996 | __u8 *save_digest; |
3997 | __u8 *digest; |
3998 | |
3999 | /* Pull in the auth header, so we can do some more verification */ |
4000 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
4001 | chunk->subh.auth_hdr = auth_hdr; |
4002 | skb_pull(chunk->skb, sizeof(struct sctp_authhdr)); |
4003 | |
4004 | /* Make sure that we support the HMAC algorithm from the auth |
4005 | * chunk. |
4006 | */ |
4007 | if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id)) |
4008 | return SCTP_IERROR_AUTH_BAD_HMAC; |
4009 | |
4010 | /* Make sure that the provided shared key identifier has been |
4011 | * configured |
4012 | */ |
4013 | key_id = ntohs(auth_hdr->shkey_id); |
4014 | if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id)) |
4015 | return SCTP_IERROR_AUTH_BAD_KEYID; |
4016 | |
4017 | |
4018 | /* Make sure that the length of the signature matches what |
4019 | * we expect. |
4020 | */ |
4021 | sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t); |
4022 | hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id)); |
4023 | if (sig_len != hmac->hmac_len) |
4024 | return SCTP_IERROR_PROTO_VIOLATION; |
4025 | |
4026 | /* Now that we've done validation checks, we can compute and |
4027 | * verify the hmac. The steps involved are: |
4028 | * 1. Save the digest from the chunk. |
4029 | * 2. Zero out the digest in the chunk. |
4030 | * 3. Compute the new digest |
4031 | * 4. Compare saved and new digests. |
4032 | */ |
4033 | digest = auth_hdr->hmac; |
4034 | skb_pull(chunk->skb, sig_len); |
4035 | |
4036 | save_digest = kmemdup(digest, sig_len, GFP_ATOMIC); |
4037 | if (!save_digest) |
4038 | goto nomem; |
4039 | |
4040 | memset(digest, 0, sig_len); |
4041 | |
4042 | sctp_auth_calculate_hmac(asoc, chunk->skb, |
4043 | (struct sctp_auth_chunk *)chunk->chunk_hdr, |
4044 | GFP_ATOMIC); |
4045 | |
4046 | /* Discard the packet if the digests do not match */ |
4047 | if (memcmp(save_digest, digest, sig_len)) { |
4048 | kfree(save_digest); |
4049 | return SCTP_IERROR_BAD_SIG; |
4050 | } |
4051 | |
4052 | kfree(save_digest); |
4053 | chunk->auth = 1; |
4054 | |
4055 | return SCTP_IERROR_NO_ERROR; |
4056 | nomem: |
4057 | return SCTP_IERROR_NOMEM; |
4058 | } |
4059 | |
4060 | sctp_disposition_t sctp_sf_eat_auth(struct net *net, |
4061 | const struct sctp_endpoint *ep, |
4062 | const struct sctp_association *asoc, |
4063 | const sctp_subtype_t type, |
4064 | void *arg, |
4065 | sctp_cmd_seq_t *commands) |
4066 | { |
4067 | struct sctp_authhdr *auth_hdr; |
4068 | struct sctp_chunk *chunk = arg; |
4069 | struct sctp_chunk *err_chunk; |
4070 | sctp_ierror_t error; |
4071 | |
4072 | /* Make sure that the peer has AUTH capable */ |
4073 | if (!asoc->peer.auth_capable) |
4074 | return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); |
4075 | |
4076 | if (!sctp_vtag_verify(chunk, asoc)) { |
4077 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
4078 | SCTP_NULL()); |
4079 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
4080 | } |
4081 | |
4082 | /* Make sure that the AUTH chunk has valid length. */ |
4083 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk))) |
4084 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
4085 | commands); |
4086 | |
4087 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
4088 | error = sctp_sf_authenticate(net, ep, asoc, type, chunk); |
4089 | switch (error) { |
4090 | case SCTP_IERROR_AUTH_BAD_HMAC: |
4091 | /* Generate the ERROR chunk and discard the rest |
4092 | * of the packet |
4093 | */ |
4094 | err_chunk = sctp_make_op_error(asoc, chunk, |
4095 | SCTP_ERROR_UNSUP_HMAC, |
4096 | &auth_hdr->hmac_id, |
4097 | sizeof(__u16), 0); |
4098 | if (err_chunk) { |
4099 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
4100 | SCTP_CHUNK(err_chunk)); |
4101 | } |
4102 | /* Fall Through */ |
4103 | case SCTP_IERROR_AUTH_BAD_KEYID: |
4104 | case SCTP_IERROR_BAD_SIG: |
4105 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
4106 | |
4107 | case SCTP_IERROR_PROTO_VIOLATION: |
4108 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
4109 | commands); |
4110 | |
4111 | case SCTP_IERROR_NOMEM: |
4112 | return SCTP_DISPOSITION_NOMEM; |
4113 | |
4114 | default: /* Prevent gcc warnings */ |
4115 | break; |
4116 | } |
4117 | |
4118 | if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) { |
4119 | struct sctp_ulpevent *ev; |
4120 | |
4121 | ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id), |
4122 | SCTP_AUTH_NEWKEY, GFP_ATOMIC); |
4123 | |
4124 | if (!ev) |
4125 | return -ENOMEM; |
4126 | |
4127 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
4128 | SCTP_ULPEVENT(ev)); |
4129 | } |
4130 | |
4131 | return SCTP_DISPOSITION_CONSUME; |
4132 | } |
4133 | |
4134 | /* |
4135 | * Process an unknown chunk. |
4136 | * |
4137 | * Section: 3.2. Also, 2.1 in the implementor's guide. |
4138 | * |
4139 | * Chunk Types are encoded such that the highest-order two bits specify |
4140 | * the action that must be taken if the processing endpoint does not |
4141 | * recognize the Chunk Type. |
4142 | * |
4143 | * 00 - Stop processing this SCTP packet and discard it, do not process |
4144 | * any further chunks within it. |
4145 | * |
4146 | * 01 - Stop processing this SCTP packet and discard it, do not process |
4147 | * any further chunks within it, and report the unrecognized |
4148 | * chunk in an 'Unrecognized Chunk Type'. |
4149 | * |
4150 | * 10 - Skip this chunk and continue processing. |
4151 | * |
4152 | * 11 - Skip this chunk and continue processing, but report in an ERROR |
4153 | * Chunk using the 'Unrecognized Chunk Type' cause of error. |
4154 | * |
4155 | * The return value is the disposition of the chunk. |
4156 | */ |
4157 | sctp_disposition_t sctp_sf_unk_chunk(struct net *net, |
4158 | const struct sctp_endpoint *ep, |
4159 | const struct sctp_association *asoc, |
4160 | const sctp_subtype_t type, |
4161 | void *arg, |
4162 | sctp_cmd_seq_t *commands) |
4163 | { |
4164 | struct sctp_chunk *unk_chunk = arg; |
4165 | struct sctp_chunk *err_chunk; |
4166 | sctp_chunkhdr_t *hdr; |
4167 | |
4168 | pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk); |
4169 | |
4170 | if (!sctp_vtag_verify(unk_chunk, asoc)) |
4171 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
4172 | |
4173 | /* Make sure that the chunk has a valid length. |
4174 | * Since we don't know the chunk type, we use a general |
4175 | * chunkhdr structure to make a comparison. |
4176 | */ |
4177 | if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t))) |
4178 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
4179 | commands); |
4180 | |
4181 | switch (type.chunk & SCTP_CID_ACTION_MASK) { |
4182 | case SCTP_CID_ACTION_DISCARD: |
4183 | /* Discard the packet. */ |
4184 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
4185 | break; |
4186 | case SCTP_CID_ACTION_DISCARD_ERR: |
4187 | /* Generate an ERROR chunk as response. */ |
4188 | hdr = unk_chunk->chunk_hdr; |
4189 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
4190 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
4191 | WORD_ROUND(ntohs(hdr->length)), |
4192 | 0); |
4193 | if (err_chunk) { |
4194 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
4195 | SCTP_CHUNK(err_chunk)); |
4196 | } |
4197 | |
4198 | /* Discard the packet. */ |
4199 | sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
4200 | return SCTP_DISPOSITION_CONSUME; |
4201 | break; |
4202 | case SCTP_CID_ACTION_SKIP: |
4203 | /* Skip the chunk. */ |
4204 | return SCTP_DISPOSITION_DISCARD; |
4205 | break; |
4206 | case SCTP_CID_ACTION_SKIP_ERR: |
4207 | /* Generate an ERROR chunk as response. */ |
4208 | hdr = unk_chunk->chunk_hdr; |
4209 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
4210 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
4211 | WORD_ROUND(ntohs(hdr->length)), |
4212 | 0); |
4213 | if (err_chunk) { |
4214 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
4215 | SCTP_CHUNK(err_chunk)); |
4216 | } |
4217 | /* Skip the chunk. */ |
4218 | return SCTP_DISPOSITION_CONSUME; |
4219 | break; |
4220 | default: |
4221 | break; |
4222 | } |
4223 | |
4224 | return SCTP_DISPOSITION_DISCARD; |
4225 | } |
4226 | |
4227 | /* |
4228 | * Discard the chunk. |
4229 | * |
4230 | * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 |
4231 | * [Too numerous to mention...] |
4232 | * Verification Tag: No verification needed. |
4233 | * Inputs |
4234 | * (endpoint, asoc, chunk) |
4235 | * |
4236 | * Outputs |
4237 | * (asoc, reply_msg, msg_up, timers, counters) |
4238 | * |
4239 | * The return value is the disposition of the chunk. |
4240 | */ |
4241 | sctp_disposition_t sctp_sf_discard_chunk(struct net *net, |
4242 | const struct sctp_endpoint *ep, |
4243 | const struct sctp_association *asoc, |
4244 | const sctp_subtype_t type, |
4245 | void *arg, |
4246 | sctp_cmd_seq_t *commands) |
4247 | { |
4248 | struct sctp_chunk *chunk = arg; |
4249 | |
4250 | /* Make sure that the chunk has a valid length. |
4251 | * Since we don't know the chunk type, we use a general |
4252 | * chunkhdr structure to make a comparison. |
4253 | */ |
4254 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
4255 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
4256 | commands); |
4257 | |
4258 | pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk); |
4259 | |
4260 | return SCTP_DISPOSITION_DISCARD; |
4261 | } |
4262 | |
4263 | /* |
4264 | * Discard the whole packet. |
4265 | * |
4266 | * Section: 8.4 2) |
4267 | * |
4268 | * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST |
4269 | * silently discard the OOTB packet and take no further action. |
4270 | * |
4271 | * Verification Tag: No verification necessary |
4272 | * |
4273 | * Inputs |
4274 | * (endpoint, asoc, chunk) |
4275 | * |
4276 | * Outputs |
4277 | * (asoc, reply_msg, msg_up, timers, counters) |
4278 | * |
4279 | * The return value is the disposition of the chunk. |
4280 | */ |
4281 | sctp_disposition_t sctp_sf_pdiscard(struct net *net, |
4282 | const struct sctp_endpoint *ep, |
4283 | const struct sctp_association *asoc, |
4284 | const sctp_subtype_t type, |
4285 | void *arg, |
4286 | sctp_cmd_seq_t *commands) |
4287 | { |
4288 | SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS); |
4289 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
4290 | |
4291 | return SCTP_DISPOSITION_CONSUME; |
4292 | } |
4293 | |
4294 | |
4295 | /* |
4296 | * The other end is violating protocol. |
4297 | * |
4298 | * Section: Not specified |
4299 | * Verification Tag: Not specified |
4300 | * Inputs |
4301 | * (endpoint, asoc, chunk) |
4302 | * |
4303 | * Outputs |
4304 | * (asoc, reply_msg, msg_up, timers, counters) |
4305 | * |
4306 | * We simply tag the chunk as a violation. The state machine will log |
4307 | * the violation and continue. |
4308 | */ |
4309 | sctp_disposition_t sctp_sf_violation(struct net *net, |
4310 | const struct sctp_endpoint *ep, |
4311 | const struct sctp_association *asoc, |
4312 | const sctp_subtype_t type, |
4313 | void *arg, |
4314 | sctp_cmd_seq_t *commands) |
4315 | { |
4316 | struct sctp_chunk *chunk = arg; |
4317 | |
4318 | /* Make sure that the chunk has a valid length. */ |
4319 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
4320 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
4321 | commands); |
4322 | |
4323 | return SCTP_DISPOSITION_VIOLATION; |
4324 | } |
4325 | |
4326 | /* |
4327 | * Common function to handle a protocol violation. |
4328 | */ |
4329 | static sctp_disposition_t sctp_sf_abort_violation( |
4330 | struct net *net, |
4331 | const struct sctp_endpoint *ep, |
4332 | const struct sctp_association *asoc, |
4333 | void *arg, |
4334 | sctp_cmd_seq_t *commands, |
4335 | const __u8 *payload, |
4336 | const size_t paylen) |
4337 | { |
4338 | struct sctp_packet *packet = NULL; |
4339 | struct sctp_chunk *chunk = arg; |
4340 | struct sctp_chunk *abort = NULL; |
4341 | |
4342 | /* SCTP-AUTH, Section 6.3: |
4343 | * It should be noted that if the receiver wants to tear |
4344 | * down an association in an authenticated way only, the |
4345 | * handling of malformed packets should not result in |
4346 | * tearing down the association. |
4347 | * |
4348 | * This means that if we only want to abort associations |
4349 | * in an authenticated way (i.e AUTH+ABORT), then we |
4350 | * can't destroy this association just because the packet |
4351 | * was malformed. |
4352 | */ |
4353 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
4354 | goto discard; |
4355 | |
4356 | /* Make the abort chunk. */ |
4357 | abort = sctp_make_abort_violation(asoc, chunk, payload, paylen); |
4358 | if (!abort) |
4359 | goto nomem; |
4360 | |
4361 | if (asoc) { |
4362 | /* Treat INIT-ACK as a special case during COOKIE-WAIT. */ |
4363 | if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK && |
4364 | !asoc->peer.i.init_tag) { |
4365 | sctp_initack_chunk_t *initack; |
4366 | |
4367 | initack = (sctp_initack_chunk_t *)chunk->chunk_hdr; |
4368 | if (!sctp_chunk_length_valid(chunk, |
4369 | sizeof(sctp_initack_chunk_t))) |
4370 | abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T; |
4371 | else { |
4372 | unsigned int inittag; |
4373 | |
4374 | inittag = ntohl(initack->init_hdr.init_tag); |
4375 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG, |
4376 | SCTP_U32(inittag)); |
4377 | } |
4378 | } |
4379 | |
4380 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4381 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
4382 | |
4383 | if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { |
4384 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4385 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4386 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
4387 | SCTP_ERROR(ECONNREFUSED)); |
4388 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
4389 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
4390 | } else { |
4391 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
4392 | SCTP_ERROR(ECONNABORTED)); |
4393 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4394 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
4395 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
4396 | } |
4397 | } else { |
4398 | packet = sctp_ootb_pkt_new(net, asoc, chunk); |
4399 | |
4400 | if (!packet) |
4401 | goto nomem_pkt; |
4402 | |
4403 | if (sctp_test_T_bit(abort)) |
4404 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
4405 | |
4406 | abort->skb->sk = ep->base.sk; |
4407 | |
4408 | sctp_packet_append_chunk(packet, abort); |
4409 | |
4410 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
4411 | SCTP_PACKET(packet)); |
4412 | |
4413 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
4414 | } |
4415 | |
4416 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
4417 | |
4418 | discard: |
4419 | sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); |
4420 | return SCTP_DISPOSITION_ABORT; |
4421 | |
4422 | nomem_pkt: |
4423 | sctp_chunk_free(abort); |
4424 | nomem: |
4425 | return SCTP_DISPOSITION_NOMEM; |
4426 | } |
4427 | |
4428 | /* |
4429 | * Handle a protocol violation when the chunk length is invalid. |
4430 | * "Invalid" length is identified as smaller than the minimal length a |
4431 | * given chunk can be. For example, a SACK chunk has invalid length |
4432 | * if its length is set to be smaller than the size of sctp_sack_chunk_t. |
4433 | * |
4434 | * We inform the other end by sending an ABORT with a Protocol Violation |
4435 | * error code. |
4436 | * |
4437 | * Section: Not specified |
4438 | * Verification Tag: Nothing to do |
4439 | * Inputs |
4440 | * (endpoint, asoc, chunk) |
4441 | * |
4442 | * Outputs |
4443 | * (reply_msg, msg_up, counters) |
4444 | * |
4445 | * Generate an ABORT chunk and terminate the association. |
4446 | */ |
4447 | static sctp_disposition_t sctp_sf_violation_chunklen( |
4448 | struct net *net, |
4449 | const struct sctp_endpoint *ep, |
4450 | const struct sctp_association *asoc, |
4451 | const sctp_subtype_t type, |
4452 | void *arg, |
4453 | sctp_cmd_seq_t *commands) |
4454 | { |
4455 | static const char err_str[] = "The following chunk had invalid length:"; |
4456 | |
4457 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
4458 | sizeof(err_str)); |
4459 | } |
4460 | |
4461 | /* |
4462 | * Handle a protocol violation when the parameter length is invalid. |
4463 | * If the length is smaller than the minimum length of a given parameter, |
4464 | * or accumulated length in multi parameters exceeds the end of the chunk, |
4465 | * the length is considered as invalid. |
4466 | */ |
4467 | static sctp_disposition_t sctp_sf_violation_paramlen( |
4468 | struct net *net, |
4469 | const struct sctp_endpoint *ep, |
4470 | const struct sctp_association *asoc, |
4471 | const sctp_subtype_t type, |
4472 | void *arg, void *ext, |
4473 | sctp_cmd_seq_t *commands) |
4474 | { |
4475 | struct sctp_chunk *chunk = arg; |
4476 | struct sctp_paramhdr *param = ext; |
4477 | struct sctp_chunk *abort = NULL; |
4478 | |
4479 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
4480 | goto discard; |
4481 | |
4482 | /* Make the abort chunk. */ |
4483 | abort = sctp_make_violation_paramlen(asoc, chunk, param); |
4484 | if (!abort) |
4485 | goto nomem; |
4486 | |
4487 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4488 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
4489 | |
4490 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
4491 | SCTP_ERROR(ECONNABORTED)); |
4492 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4493 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
4494 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
4495 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
4496 | |
4497 | discard: |
4498 | sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); |
4499 | return SCTP_DISPOSITION_ABORT; |
4500 | nomem: |
4501 | return SCTP_DISPOSITION_NOMEM; |
4502 | } |
4503 | |
4504 | /* Handle a protocol violation when the peer trying to advance the |
4505 | * cumulative tsn ack to a point beyond the max tsn currently sent. |
4506 | * |
4507 | * We inform the other end by sending an ABORT with a Protocol Violation |
4508 | * error code. |
4509 | */ |
4510 | static sctp_disposition_t sctp_sf_violation_ctsn( |
4511 | struct net *net, |
4512 | const struct sctp_endpoint *ep, |
4513 | const struct sctp_association *asoc, |
4514 | const sctp_subtype_t type, |
4515 | void *arg, |
4516 | sctp_cmd_seq_t *commands) |
4517 | { |
4518 | static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:"; |
4519 | |
4520 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
4521 | sizeof(err_str)); |
4522 | } |
4523 | |
4524 | /* Handle protocol violation of an invalid chunk bundling. For example, |
4525 | * when we have an association and we receive bundled INIT-ACK, or |
4526 | * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle" |
4527 | * statement from the specs. Additionally, there might be an attacker |
4528 | * on the path and we may not want to continue this communication. |
4529 | */ |
4530 | static sctp_disposition_t sctp_sf_violation_chunk( |
4531 | struct net *net, |
4532 | const struct sctp_endpoint *ep, |
4533 | const struct sctp_association *asoc, |
4534 | const sctp_subtype_t type, |
4535 | void *arg, |
4536 | sctp_cmd_seq_t *commands) |
4537 | { |
4538 | static const char err_str[] = "The following chunk violates protocol:"; |
4539 | |
4540 | if (!asoc) |
4541 | return sctp_sf_violation(net, ep, asoc, type, arg, commands); |
4542 | |
4543 | return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
4544 | sizeof(err_str)); |
4545 | } |
4546 | /*************************************************************************** |
4547 | * These are the state functions for handling primitive (Section 10) events. |
4548 | ***************************************************************************/ |
4549 | /* |
4550 | * sctp_sf_do_prm_asoc |
4551 | * |
4552 | * Section: 10.1 ULP-to-SCTP |
4553 | * B) Associate |
4554 | * |
4555 | * Format: ASSOCIATE(local SCTP instance name, destination transport addr, |
4556 | * outbound stream count) |
4557 | * -> association id [,destination transport addr list] [,outbound stream |
4558 | * count] |
4559 | * |
4560 | * This primitive allows the upper layer to initiate an association to a |
4561 | * specific peer endpoint. |
4562 | * |
4563 | * The peer endpoint shall be specified by one of the transport addresses |
4564 | * which defines the endpoint (see Section 1.4). If the local SCTP |
4565 | * instance has not been initialized, the ASSOCIATE is considered an |
4566 | * error. |
4567 | * [This is not relevant for the kernel implementation since we do all |
4568 | * initialization at boot time. It we hadn't initialized we wouldn't |
4569 | * get anywhere near this code.] |
4570 | * |
4571 | * An association id, which is a local handle to the SCTP association, |
4572 | * will be returned on successful establishment of the association. If |
4573 | * SCTP is not able to open an SCTP association with the peer endpoint, |
4574 | * an error is returned. |
4575 | * [In the kernel implementation, the struct sctp_association needs to |
4576 | * be created BEFORE causing this primitive to run.] |
4577 | * |
4578 | * Other association parameters may be returned, including the |
4579 | * complete destination transport addresses of the peer as well as the |
4580 | * outbound stream count of the local endpoint. One of the transport |
4581 | * address from the returned destination addresses will be selected by |
4582 | * the local endpoint as default primary path for sending SCTP packets |
4583 | * to this peer. The returned "destination transport addr list" can |
4584 | * be used by the ULP to change the default primary path or to force |
4585 | * sending a packet to a specific transport address. [All of this |
4586 | * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING |
4587 | * function.] |
4588 | * |
4589 | * Mandatory attributes: |
4590 | * |
4591 | * o local SCTP instance name - obtained from the INITIALIZE operation. |
4592 | * [This is the argument asoc.] |
4593 | * o destination transport addr - specified as one of the transport |
4594 | * addresses of the peer endpoint with which the association is to be |
4595 | * established. |
4596 | * [This is asoc->peer.active_path.] |
4597 | * o outbound stream count - the number of outbound streams the ULP |
4598 | * would like to open towards this peer endpoint. |
4599 | * [BUG: This is not currently implemented.] |
4600 | * Optional attributes: |
4601 | * |
4602 | * None. |
4603 | * |
4604 | * The return value is a disposition. |
4605 | */ |
4606 | sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net, |
4607 | const struct sctp_endpoint *ep, |
4608 | const struct sctp_association *asoc, |
4609 | const sctp_subtype_t type, |
4610 | void *arg, |
4611 | sctp_cmd_seq_t *commands) |
4612 | { |
4613 | struct sctp_chunk *repl; |
4614 | struct sctp_association *my_asoc; |
4615 | |
4616 | /* The comment below says that we enter COOKIE-WAIT AFTER |
4617 | * sending the INIT, but that doesn't actually work in our |
4618 | * implementation... |
4619 | */ |
4620 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4621 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
4622 | |
4623 | /* RFC 2960 5.1 Normal Establishment of an Association |
4624 | * |
4625 | * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" |
4626 | * must provide its Verification Tag (Tag_A) in the Initiate |
4627 | * Tag field. Tag_A SHOULD be a random number in the range of |
4628 | * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... |
4629 | */ |
4630 | |
4631 | repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); |
4632 | if (!repl) |
4633 | goto nomem; |
4634 | |
4635 | /* Choose transport for INIT. */ |
4636 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
4637 | SCTP_CHUNK(repl)); |
4638 | |
4639 | /* Cast away the const modifier, as we want to just |
4640 | * rerun it through as a sideffect. |
4641 | */ |
4642 | my_asoc = (struct sctp_association *)asoc; |
4643 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc)); |
4644 | |
4645 | /* After sending the INIT, "A" starts the T1-init timer and |
4646 | * enters the COOKIE-WAIT state. |
4647 | */ |
4648 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
4649 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4650 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
4651 | return SCTP_DISPOSITION_CONSUME; |
4652 | |
4653 | nomem: |
4654 | return SCTP_DISPOSITION_NOMEM; |
4655 | } |
4656 | |
4657 | /* |
4658 | * Process the SEND primitive. |
4659 | * |
4660 | * Section: 10.1 ULP-to-SCTP |
4661 | * E) Send |
4662 | * |
4663 | * Format: SEND(association id, buffer address, byte count [,context] |
4664 | * [,stream id] [,life time] [,destination transport address] |
4665 | * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) |
4666 | * -> result |
4667 | * |
4668 | * This is the main method to send user data via SCTP. |
4669 | * |
4670 | * Mandatory attributes: |
4671 | * |
4672 | * o association id - local handle to the SCTP association |
4673 | * |
4674 | * o buffer address - the location where the user message to be |
4675 | * transmitted is stored; |
4676 | * |
4677 | * o byte count - The size of the user data in number of bytes; |
4678 | * |
4679 | * Optional attributes: |
4680 | * |
4681 | * o context - an optional 32 bit integer that will be carried in the |
4682 | * sending failure notification to the ULP if the transportation of |
4683 | * this User Message fails. |
4684 | * |
4685 | * o stream id - to indicate which stream to send the data on. If not |
4686 | * specified, stream 0 will be used. |
4687 | * |
4688 | * o life time - specifies the life time of the user data. The user data |
4689 | * will not be sent by SCTP after the life time expires. This |
4690 | * parameter can be used to avoid efforts to transmit stale |
4691 | * user messages. SCTP notifies the ULP if the data cannot be |
4692 | * initiated to transport (i.e. sent to the destination via SCTP's |
4693 | * send primitive) within the life time variable. However, the |
4694 | * user data will be transmitted if SCTP has attempted to transmit a |
4695 | * chunk before the life time expired. |
4696 | * |
4697 | * o destination transport address - specified as one of the destination |
4698 | * transport addresses of the peer endpoint to which this packet |
4699 | * should be sent. Whenever possible, SCTP should use this destination |
4700 | * transport address for sending the packets, instead of the current |
4701 | * primary path. |
4702 | * |
4703 | * o unorder flag - this flag, if present, indicates that the user |
4704 | * would like the data delivered in an unordered fashion to the peer |
4705 | * (i.e., the U flag is set to 1 on all DATA chunks carrying this |
4706 | * message). |
4707 | * |
4708 | * o no-bundle flag - instructs SCTP not to bundle this user data with |
4709 | * other outbound DATA chunks. SCTP MAY still bundle even when |
4710 | * this flag is present, when faced with network congestion. |
4711 | * |
4712 | * o payload protocol-id - A 32 bit unsigned integer that is to be |
4713 | * passed to the peer indicating the type of payload protocol data |
4714 | * being transmitted. This value is passed as opaque data by SCTP. |
4715 | * |
4716 | * The return value is the disposition. |
4717 | */ |
4718 | sctp_disposition_t sctp_sf_do_prm_send(struct net *net, |
4719 | const struct sctp_endpoint *ep, |
4720 | const struct sctp_association *asoc, |
4721 | const sctp_subtype_t type, |
4722 | void *arg, |
4723 | sctp_cmd_seq_t *commands) |
4724 | { |
4725 | struct sctp_datamsg *msg = arg; |
4726 | |
4727 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg)); |
4728 | return SCTP_DISPOSITION_CONSUME; |
4729 | } |
4730 | |
4731 | /* |
4732 | * Process the SHUTDOWN primitive. |
4733 | * |
4734 | * Section: 10.1: |
4735 | * C) Shutdown |
4736 | * |
4737 | * Format: SHUTDOWN(association id) |
4738 | * -> result |
4739 | * |
4740 | * Gracefully closes an association. Any locally queued user data |
4741 | * will be delivered to the peer. The association will be terminated only |
4742 | * after the peer acknowledges all the SCTP packets sent. A success code |
4743 | * will be returned on successful termination of the association. If |
4744 | * attempting to terminate the association results in a failure, an error |
4745 | * code shall be returned. |
4746 | * |
4747 | * Mandatory attributes: |
4748 | * |
4749 | * o association id - local handle to the SCTP association |
4750 | * |
4751 | * Optional attributes: |
4752 | * |
4753 | * None. |
4754 | * |
4755 | * The return value is the disposition. |
4756 | */ |
4757 | sctp_disposition_t sctp_sf_do_9_2_prm_shutdown( |
4758 | struct net *net, |
4759 | const struct sctp_endpoint *ep, |
4760 | const struct sctp_association *asoc, |
4761 | const sctp_subtype_t type, |
4762 | void *arg, |
4763 | sctp_cmd_seq_t *commands) |
4764 | { |
4765 | int disposition; |
4766 | |
4767 | /* From 9.2 Shutdown of an Association |
4768 | * Upon receipt of the SHUTDOWN primitive from its upper |
4769 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
4770 | * remains there until all outstanding data has been |
4771 | * acknowledged by its peer. The endpoint accepts no new data |
4772 | * from its upper layer, but retransmits data to the far end |
4773 | * if necessary to fill gaps. |
4774 | */ |
4775 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4776 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
4777 | |
4778 | disposition = SCTP_DISPOSITION_CONSUME; |
4779 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
4780 | disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, |
4781 | arg, commands); |
4782 | } |
4783 | return disposition; |
4784 | } |
4785 | |
4786 | /* |
4787 | * Process the ABORT primitive. |
4788 | * |
4789 | * Section: 10.1: |
4790 | * C) Abort |
4791 | * |
4792 | * Format: Abort(association id [, cause code]) |
4793 | * -> result |
4794 | * |
4795 | * Ungracefully closes an association. Any locally queued user data |
4796 | * will be discarded and an ABORT chunk is sent to the peer. A success code |
4797 | * will be returned on successful abortion of the association. If |
4798 | * attempting to abort the association results in a failure, an error |
4799 | * code shall be returned. |
4800 | * |
4801 | * Mandatory attributes: |
4802 | * |
4803 | * o association id - local handle to the SCTP association |
4804 | * |
4805 | * Optional attributes: |
4806 | * |
4807 | * o cause code - reason of the abort to be passed to the peer |
4808 | * |
4809 | * None. |
4810 | * |
4811 | * The return value is the disposition. |
4812 | */ |
4813 | sctp_disposition_t sctp_sf_do_9_1_prm_abort( |
4814 | struct net *net, |
4815 | const struct sctp_endpoint *ep, |
4816 | const struct sctp_association *asoc, |
4817 | const sctp_subtype_t type, |
4818 | void *arg, |
4819 | sctp_cmd_seq_t *commands) |
4820 | { |
4821 | /* From 9.1 Abort of an Association |
4822 | * Upon receipt of the ABORT primitive from its upper |
4823 | * layer, the endpoint enters CLOSED state and |
4824 | * discard all outstanding data has been |
4825 | * acknowledged by its peer. The endpoint accepts no new data |
4826 | * from its upper layer, but retransmits data to the far end |
4827 | * if necessary to fill gaps. |
4828 | */ |
4829 | struct sctp_chunk *abort = arg; |
4830 | sctp_disposition_t retval; |
4831 | |
4832 | retval = SCTP_DISPOSITION_CONSUME; |
4833 | |
4834 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4835 | |
4836 | /* Even if we can't send the ABORT due to low memory delete the |
4837 | * TCB. This is a departure from our typical NOMEM handling. |
4838 | */ |
4839 | |
4840 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
4841 | SCTP_ERROR(ECONNABORTED)); |
4842 | /* Delete the established association. */ |
4843 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4844 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
4845 | |
4846 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
4847 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
4848 | |
4849 | return retval; |
4850 | } |
4851 | |
4852 | /* We tried an illegal operation on an association which is closed. */ |
4853 | sctp_disposition_t sctp_sf_error_closed(struct net *net, |
4854 | const struct sctp_endpoint *ep, |
4855 | const struct sctp_association *asoc, |
4856 | const sctp_subtype_t type, |
4857 | void *arg, |
4858 | sctp_cmd_seq_t *commands) |
4859 | { |
4860 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); |
4861 | return SCTP_DISPOSITION_CONSUME; |
4862 | } |
4863 | |
4864 | /* We tried an illegal operation on an association which is shutting |
4865 | * down. |
4866 | */ |
4867 | sctp_disposition_t sctp_sf_error_shutdown(struct net *net, |
4868 | const struct sctp_endpoint *ep, |
4869 | const struct sctp_association *asoc, |
4870 | const sctp_subtype_t type, |
4871 | void *arg, |
4872 | sctp_cmd_seq_t *commands) |
4873 | { |
4874 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, |
4875 | SCTP_ERROR(-ESHUTDOWN)); |
4876 | return SCTP_DISPOSITION_CONSUME; |
4877 | } |
4878 | |
4879 | /* |
4880 | * sctp_cookie_wait_prm_shutdown |
4881 | * |
4882 | * Section: 4 Note: 2 |
4883 | * Verification Tag: |
4884 | * Inputs |
4885 | * (endpoint, asoc) |
4886 | * |
4887 | * The RFC does not explicitly address this issue, but is the route through the |
4888 | * state table when someone issues a shutdown while in COOKIE_WAIT state. |
4889 | * |
4890 | * Outputs |
4891 | * (timers) |
4892 | */ |
4893 | sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown( |
4894 | struct net *net, |
4895 | const struct sctp_endpoint *ep, |
4896 | const struct sctp_association *asoc, |
4897 | const sctp_subtype_t type, |
4898 | void *arg, |
4899 | sctp_cmd_seq_t *commands) |
4900 | { |
4901 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4902 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4903 | |
4904 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4905 | SCTP_STATE(SCTP_STATE_CLOSED)); |
4906 | |
4907 | SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
4908 | |
4909 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
4910 | |
4911 | return SCTP_DISPOSITION_DELETE_TCB; |
4912 | } |
4913 | |
4914 | /* |
4915 | * sctp_cookie_echoed_prm_shutdown |
4916 | * |
4917 | * Section: 4 Note: 2 |
4918 | * Verification Tag: |
4919 | * Inputs |
4920 | * (endpoint, asoc) |
4921 | * |
4922 | * The RFC does not explcitly address this issue, but is the route through the |
4923 | * state table when someone issues a shutdown while in COOKIE_ECHOED state. |
4924 | * |
4925 | * Outputs |
4926 | * (timers) |
4927 | */ |
4928 | sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown( |
4929 | struct net *net, |
4930 | const struct sctp_endpoint *ep, |
4931 | const struct sctp_association *asoc, |
4932 | const sctp_subtype_t type, |
4933 | void *arg, sctp_cmd_seq_t *commands) |
4934 | { |
4935 | /* There is a single T1 timer, so we should be able to use |
4936 | * common function with the COOKIE-WAIT state. |
4937 | */ |
4938 | return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands); |
4939 | } |
4940 | |
4941 | /* |
4942 | * sctp_sf_cookie_wait_prm_abort |
4943 | * |
4944 | * Section: 4 Note: 2 |
4945 | * Verification Tag: |
4946 | * Inputs |
4947 | * (endpoint, asoc) |
4948 | * |
4949 | * The RFC does not explicitly address this issue, but is the route through the |
4950 | * state table when someone issues an abort while in COOKIE_WAIT state. |
4951 | * |
4952 | * Outputs |
4953 | * (timers) |
4954 | */ |
4955 | sctp_disposition_t sctp_sf_cookie_wait_prm_abort( |
4956 | struct net *net, |
4957 | const struct sctp_endpoint *ep, |
4958 | const struct sctp_association *asoc, |
4959 | const sctp_subtype_t type, |
4960 | void *arg, |
4961 | sctp_cmd_seq_t *commands) |
4962 | { |
4963 | struct sctp_chunk *abort = arg; |
4964 | sctp_disposition_t retval; |
4965 | |
4966 | /* Stop T1-init timer */ |
4967 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4968 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4969 | retval = SCTP_DISPOSITION_CONSUME; |
4970 | |
4971 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4972 | |
4973 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4974 | SCTP_STATE(SCTP_STATE_CLOSED)); |
4975 | |
4976 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
4977 | |
4978 | /* Even if we can't send the ABORT due to low memory delete the |
4979 | * TCB. This is a departure from our typical NOMEM handling. |
4980 | */ |
4981 | |
4982 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
4983 | SCTP_ERROR(ECONNREFUSED)); |
4984 | /* Delete the established association. */ |
4985 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
4986 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
4987 | |
4988 | return retval; |
4989 | } |
4990 | |
4991 | /* |
4992 | * sctp_sf_cookie_echoed_prm_abort |
4993 | * |
4994 | * Section: 4 Note: 3 |
4995 | * Verification Tag: |
4996 | * Inputs |
4997 | * (endpoint, asoc) |
4998 | * |
4999 | * The RFC does not explcitly address this issue, but is the route through the |
5000 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
5001 | * |
5002 | * Outputs |
5003 | * (timers) |
5004 | */ |
5005 | sctp_disposition_t sctp_sf_cookie_echoed_prm_abort( |
5006 | struct net *net, |
5007 | const struct sctp_endpoint *ep, |
5008 | const struct sctp_association *asoc, |
5009 | const sctp_subtype_t type, |
5010 | void *arg, |
5011 | sctp_cmd_seq_t *commands) |
5012 | { |
5013 | /* There is a single T1 timer, so we should be able to use |
5014 | * common function with the COOKIE-WAIT state. |
5015 | */ |
5016 | return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands); |
5017 | } |
5018 | |
5019 | /* |
5020 | * sctp_sf_shutdown_pending_prm_abort |
5021 | * |
5022 | * Inputs |
5023 | * (endpoint, asoc) |
5024 | * |
5025 | * The RFC does not explicitly address this issue, but is the route through the |
5026 | * state table when someone issues an abort while in SHUTDOWN-PENDING state. |
5027 | * |
5028 | * Outputs |
5029 | * (timers) |
5030 | */ |
5031 | sctp_disposition_t sctp_sf_shutdown_pending_prm_abort( |
5032 | struct net *net, |
5033 | const struct sctp_endpoint *ep, |
5034 | const struct sctp_association *asoc, |
5035 | const sctp_subtype_t type, |
5036 | void *arg, |
5037 | sctp_cmd_seq_t *commands) |
5038 | { |
5039 | /* Stop the T5-shutdown guard timer. */ |
5040 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5041 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
5042 | |
5043 | return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); |
5044 | } |
5045 | |
5046 | /* |
5047 | * sctp_sf_shutdown_sent_prm_abort |
5048 | * |
5049 | * Inputs |
5050 | * (endpoint, asoc) |
5051 | * |
5052 | * The RFC does not explicitly address this issue, but is the route through the |
5053 | * state table when someone issues an abort while in SHUTDOWN-SENT state. |
5054 | * |
5055 | * Outputs |
5056 | * (timers) |
5057 | */ |
5058 | sctp_disposition_t sctp_sf_shutdown_sent_prm_abort( |
5059 | struct net *net, |
5060 | const struct sctp_endpoint *ep, |
5061 | const struct sctp_association *asoc, |
5062 | const sctp_subtype_t type, |
5063 | void *arg, |
5064 | sctp_cmd_seq_t *commands) |
5065 | { |
5066 | /* Stop the T2-shutdown timer. */ |
5067 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5068 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
5069 | |
5070 | /* Stop the T5-shutdown guard timer. */ |
5071 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5072 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
5073 | |
5074 | return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); |
5075 | } |
5076 | |
5077 | /* |
5078 | * sctp_sf_cookie_echoed_prm_abort |
5079 | * |
5080 | * Inputs |
5081 | * (endpoint, asoc) |
5082 | * |
5083 | * The RFC does not explcitly address this issue, but is the route through the |
5084 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
5085 | * |
5086 | * Outputs |
5087 | * (timers) |
5088 | */ |
5089 | sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort( |
5090 | struct net *net, |
5091 | const struct sctp_endpoint *ep, |
5092 | const struct sctp_association *asoc, |
5093 | const sctp_subtype_t type, |
5094 | void *arg, |
5095 | sctp_cmd_seq_t *commands) |
5096 | { |
5097 | /* The same T2 timer, so we should be able to use |
5098 | * common function with the SHUTDOWN-SENT state. |
5099 | */ |
5100 | return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands); |
5101 | } |
5102 | |
5103 | /* |
5104 | * Process the REQUESTHEARTBEAT primitive |
5105 | * |
5106 | * 10.1 ULP-to-SCTP |
5107 | * J) Request Heartbeat |
5108 | * |
5109 | * Format: REQUESTHEARTBEAT(association id, destination transport address) |
5110 | * |
5111 | * -> result |
5112 | * |
5113 | * Instructs the local endpoint to perform a HeartBeat on the specified |
5114 | * destination transport address of the given association. The returned |
5115 | * result should indicate whether the transmission of the HEARTBEAT |
5116 | * chunk to the destination address is successful. |
5117 | * |
5118 | * Mandatory attributes: |
5119 | * |
5120 | * o association id - local handle to the SCTP association |
5121 | * |
5122 | * o destination transport address - the transport address of the |
5123 | * association on which a heartbeat should be issued. |
5124 | */ |
5125 | sctp_disposition_t sctp_sf_do_prm_requestheartbeat( |
5126 | struct net *net, |
5127 | const struct sctp_endpoint *ep, |
5128 | const struct sctp_association *asoc, |
5129 | const sctp_subtype_t type, |
5130 | void *arg, |
5131 | sctp_cmd_seq_t *commands) |
5132 | { |
5133 | if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type, |
5134 | (struct sctp_transport *)arg, commands)) |
5135 | return SCTP_DISPOSITION_NOMEM; |
5136 | |
5137 | /* |
5138 | * RFC 2960 (bis), section 8.3 |
5139 | * |
5140 | * D) Request an on-demand HEARTBEAT on a specific destination |
5141 | * transport address of a given association. |
5142 | * |
5143 | * The endpoint should increment the respective error counter of |
5144 | * the destination transport address each time a HEARTBEAT is sent |
5145 | * to that address and not acknowledged within one RTO. |
5146 | * |
5147 | */ |
5148 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, |
5149 | SCTP_TRANSPORT(arg)); |
5150 | return SCTP_DISPOSITION_CONSUME; |
5151 | } |
5152 | |
5153 | /* |
5154 | * ADDIP Section 4.1 ASCONF Chunk Procedures |
5155 | * When an endpoint has an ASCONF signaled change to be sent to the |
5156 | * remote endpoint it should do A1 to A9 |
5157 | */ |
5158 | sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net, |
5159 | const struct sctp_endpoint *ep, |
5160 | const struct sctp_association *asoc, |
5161 | const sctp_subtype_t type, |
5162 | void *arg, |
5163 | sctp_cmd_seq_t *commands) |
5164 | { |
5165 | struct sctp_chunk *chunk = arg; |
5166 | |
5167 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
5168 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
5169 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
5170 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
5171 | return SCTP_DISPOSITION_CONSUME; |
5172 | } |
5173 | |
5174 | /* |
5175 | * Ignore the primitive event |
5176 | * |
5177 | * The return value is the disposition of the primitive. |
5178 | */ |
5179 | sctp_disposition_t sctp_sf_ignore_primitive( |
5180 | struct net *net, |
5181 | const struct sctp_endpoint *ep, |
5182 | const struct sctp_association *asoc, |
5183 | const sctp_subtype_t type, |
5184 | void *arg, |
5185 | sctp_cmd_seq_t *commands) |
5186 | { |
5187 | pr_debug("%s: primitive type:%d is ignored\n", __func__, |
5188 | type.primitive); |
5189 | |
5190 | return SCTP_DISPOSITION_DISCARD; |
5191 | } |
5192 | |
5193 | /*************************************************************************** |
5194 | * These are the state functions for the OTHER events. |
5195 | ***************************************************************************/ |
5196 | |
5197 | /* |
5198 | * When the SCTP stack has no more user data to send or retransmit, this |
5199 | * notification is given to the user. Also, at the time when a user app |
5200 | * subscribes to this event, if there is no data to be sent or |
5201 | * retransmit, the stack will immediately send up this notification. |
5202 | */ |
5203 | sctp_disposition_t sctp_sf_do_no_pending_tsn( |
5204 | struct net *net, |
5205 | const struct sctp_endpoint *ep, |
5206 | const struct sctp_association *asoc, |
5207 | const sctp_subtype_t type, |
5208 | void *arg, |
5209 | sctp_cmd_seq_t *commands) |
5210 | { |
5211 | struct sctp_ulpevent *event; |
5212 | |
5213 | event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC); |
5214 | if (!event) |
5215 | return SCTP_DISPOSITION_NOMEM; |
5216 | |
5217 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event)); |
5218 | |
5219 | return SCTP_DISPOSITION_CONSUME; |
5220 | } |
5221 | |
5222 | /* |
5223 | * Start the shutdown negotiation. |
5224 | * |
5225 | * From Section 9.2: |
5226 | * Once all its outstanding data has been acknowledged, the endpoint |
5227 | * shall send a SHUTDOWN chunk to its peer including in the Cumulative |
5228 | * TSN Ack field the last sequential TSN it has received from the peer. |
5229 | * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT |
5230 | * state. If the timer expires, the endpoint must re-send the SHUTDOWN |
5231 | * with the updated last sequential TSN received from its peer. |
5232 | * |
5233 | * The return value is the disposition. |
5234 | */ |
5235 | sctp_disposition_t sctp_sf_do_9_2_start_shutdown( |
5236 | struct net *net, |
5237 | const struct sctp_endpoint *ep, |
5238 | const struct sctp_association *asoc, |
5239 | const sctp_subtype_t type, |
5240 | void *arg, |
5241 | sctp_cmd_seq_t *commands) |
5242 | { |
5243 | struct sctp_chunk *reply; |
5244 | |
5245 | /* Once all its outstanding data has been acknowledged, the |
5246 | * endpoint shall send a SHUTDOWN chunk to its peer including |
5247 | * in the Cumulative TSN Ack field the last sequential TSN it |
5248 | * has received from the peer. |
5249 | */ |
5250 | reply = sctp_make_shutdown(asoc, NULL); |
5251 | if (!reply) |
5252 | goto nomem; |
5253 | |
5254 | /* Set the transport for the SHUTDOWN chunk and the timeout for the |
5255 | * T2-shutdown timer. |
5256 | */ |
5257 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
5258 | |
5259 | /* It shall then start the T2-shutdown timer */ |
5260 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
5261 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
5262 | |
5263 | /* RFC 4960 Section 9.2 |
5264 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
5265 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
5266 | */ |
5267 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
5268 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
5269 | |
5270 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
5271 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5272 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
5273 | |
5274 | /* and enter the SHUTDOWN-SENT state. */ |
5275 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
5276 | SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); |
5277 | |
5278 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
5279 | * |
5280 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
5281 | * or SHUTDOWN-ACK. |
5282 | */ |
5283 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
5284 | |
5285 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
5286 | |
5287 | return SCTP_DISPOSITION_CONSUME; |
5288 | |
5289 | nomem: |
5290 | return SCTP_DISPOSITION_NOMEM; |
5291 | } |
5292 | |
5293 | /* |
5294 | * Generate a SHUTDOWN ACK now that everything is SACK'd. |
5295 | * |
5296 | * From Section 9.2: |
5297 | * |
5298 | * If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
5299 | * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, |
5300 | * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the |
5301 | * endpoint must re-send the SHUTDOWN ACK. |
5302 | * |
5303 | * The return value is the disposition. |
5304 | */ |
5305 | sctp_disposition_t sctp_sf_do_9_2_shutdown_ack( |
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_chunk *chunk = (struct sctp_chunk *) arg; |
5314 | struct sctp_chunk *reply; |
5315 | |
5316 | /* There are 2 ways of getting here: |
5317 | * 1) called in response to a SHUTDOWN chunk |
5318 | * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. |
5319 | * |
5320 | * For the case (2), the arg parameter is set to NULL. We need |
5321 | * to check that we have a chunk before accessing it's fields. |
5322 | */ |
5323 | if (chunk) { |
5324 | if (!sctp_vtag_verify(chunk, asoc)) |
5325 | return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
5326 | |
5327 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
5328 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t))) |
5329 | return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
5330 | commands); |
5331 | } |
5332 | |
5333 | /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
5334 | * shall send a SHUTDOWN ACK ... |
5335 | */ |
5336 | reply = sctp_make_shutdown_ack(asoc, chunk); |
5337 | if (!reply) |
5338 | goto nomem; |
5339 | |
5340 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
5341 | * the T2-shutdown timer. |
5342 | */ |
5343 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
5344 | |
5345 | /* and start/restart a T2-shutdown timer of its own, */ |
5346 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
5347 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
5348 | |
5349 | if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
5350 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5351 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
5352 | |
5353 | /* Enter the SHUTDOWN-ACK-SENT state. */ |
5354 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
5355 | SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); |
5356 | |
5357 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
5358 | * |
5359 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
5360 | * or SHUTDOWN-ACK. |
5361 | */ |
5362 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
5363 | |
5364 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
5365 | |
5366 | return SCTP_DISPOSITION_CONSUME; |
5367 | |
5368 | nomem: |
5369 | return SCTP_DISPOSITION_NOMEM; |
5370 | } |
5371 | |
5372 | /* |
5373 | * Ignore the event defined as other |
5374 | * |
5375 | * The return value is the disposition of the event. |
5376 | */ |
5377 | sctp_disposition_t sctp_sf_ignore_other(struct net *net, |
5378 | const struct sctp_endpoint *ep, |
5379 | const struct sctp_association *asoc, |
5380 | const sctp_subtype_t type, |
5381 | void *arg, |
5382 | sctp_cmd_seq_t *commands) |
5383 | { |
5384 | pr_debug("%s: the event other type:%d is ignored\n", |
5385 | __func__, type.other); |
5386 | |
5387 | return SCTP_DISPOSITION_DISCARD; |
5388 | } |
5389 | |
5390 | /************************************************************ |
5391 | * These are the state functions for handling timeout events. |
5392 | ************************************************************/ |
5393 | |
5394 | /* |
5395 | * RTX Timeout |
5396 | * |
5397 | * Section: 6.3.3 Handle T3-rtx Expiration |
5398 | * |
5399 | * Whenever the retransmission timer T3-rtx expires for a destination |
5400 | * address, do the following: |
5401 | * [See below] |
5402 | * |
5403 | * The return value is the disposition of the chunk. |
5404 | */ |
5405 | sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net, |
5406 | const struct sctp_endpoint *ep, |
5407 | const struct sctp_association *asoc, |
5408 | const sctp_subtype_t type, |
5409 | void *arg, |
5410 | sctp_cmd_seq_t *commands) |
5411 | { |
5412 | struct sctp_transport *transport = arg; |
5413 | |
5414 | SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS); |
5415 | |
5416 | if (asoc->overall_error_count >= asoc->max_retrans) { |
5417 | if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) { |
5418 | /* |
5419 | * We are here likely because the receiver had its rwnd |
5420 | * closed for a while and we have not been able to |
5421 | * transmit the locally queued data within the maximum |
5422 | * retransmission attempts limit. Start the T5 |
5423 | * shutdown guard timer to give the receiver one last |
5424 | * chance and some additional time to recover before |
5425 | * aborting. |
5426 | */ |
5427 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE, |
5428 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
5429 | } else { |
5430 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5431 | SCTP_ERROR(ETIMEDOUT)); |
5432 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
5433 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
5434 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5435 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
5436 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
5437 | return SCTP_DISPOSITION_DELETE_TCB; |
5438 | } |
5439 | } |
5440 | |
5441 | /* E1) For the destination address for which the timer |
5442 | * expires, adjust its ssthresh with rules defined in Section |
5443 | * 7.2.3 and set the cwnd <- MTU. |
5444 | */ |
5445 | |
5446 | /* E2) For the destination address for which the timer |
5447 | * expires, set RTO <- RTO * 2 ("back off the timer"). The |
5448 | * maximum value discussed in rule C7 above (RTO.max) may be |
5449 | * used to provide an upper bound to this doubling operation. |
5450 | */ |
5451 | |
5452 | /* E3) Determine how many of the earliest (i.e., lowest TSN) |
5453 | * outstanding DATA chunks for the address for which the |
5454 | * T3-rtx has expired will fit into a single packet, subject |
5455 | * to the MTU constraint for the path corresponding to the |
5456 | * destination transport address to which the retransmission |
5457 | * is being sent (this may be different from the address for |
5458 | * which the timer expires [see Section 6.4]). Call this |
5459 | * value K. Bundle and retransmit those K DATA chunks in a |
5460 | * single packet to the destination endpoint. |
5461 | * |
5462 | * Note: Any DATA chunks that were sent to the address for |
5463 | * which the T3-rtx timer expired but did not fit in one MTU |
5464 | * (rule E3 above), should be marked for retransmission and |
5465 | * sent as soon as cwnd allows (normally when a SACK arrives). |
5466 | */ |
5467 | |
5468 | /* Do some failure management (Section 8.2). */ |
5469 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
5470 | |
5471 | /* NB: Rules E4 and F1 are implicit in R1. */ |
5472 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); |
5473 | |
5474 | return SCTP_DISPOSITION_CONSUME; |
5475 | } |
5476 | |
5477 | /* |
5478 | * Generate delayed SACK on timeout |
5479 | * |
5480 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
5481 | * |
5482 | * The guidelines on delayed acknowledgement algorithm specified in |
5483 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
5484 | * acknowledgement SHOULD be generated for at least every second packet |
5485 | * (not every second DATA chunk) received, and SHOULD be generated |
5486 | * within 200 ms of the arrival of any unacknowledged DATA chunk. In |
5487 | * some situations it may be beneficial for an SCTP transmitter to be |
5488 | * more conservative than the algorithms detailed in this document |
5489 | * allow. However, an SCTP transmitter MUST NOT be more aggressive than |
5490 | * the following algorithms allow. |
5491 | */ |
5492 | sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net, |
5493 | const struct sctp_endpoint *ep, |
5494 | const struct sctp_association *asoc, |
5495 | const sctp_subtype_t type, |
5496 | void *arg, |
5497 | sctp_cmd_seq_t *commands) |
5498 | { |
5499 | SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS); |
5500 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
5501 | return SCTP_DISPOSITION_CONSUME; |
5502 | } |
5503 | |
5504 | /* |
5505 | * sctp_sf_t1_init_timer_expire |
5506 | * |
5507 | * Section: 4 Note: 2 |
5508 | * Verification Tag: |
5509 | * Inputs |
5510 | * (endpoint, asoc) |
5511 | * |
5512 | * RFC 2960 Section 4 Notes |
5513 | * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT |
5514 | * and re-start the T1-init timer without changing state. This MUST |
5515 | * be repeated up to 'Max.Init.Retransmits' times. After that, the |
5516 | * endpoint MUST abort the initialization process and report the |
5517 | * error to SCTP user. |
5518 | * |
5519 | * Outputs |
5520 | * (timers, events) |
5521 | * |
5522 | */ |
5523 | sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net, |
5524 | const struct sctp_endpoint *ep, |
5525 | const struct sctp_association *asoc, |
5526 | const sctp_subtype_t type, |
5527 | void *arg, |
5528 | sctp_cmd_seq_t *commands) |
5529 | { |
5530 | struct sctp_chunk *repl = NULL; |
5531 | struct sctp_bind_addr *bp; |
5532 | int attempts = asoc->init_err_counter + 1; |
5533 | |
5534 | pr_debug("%s: timer T1 expired (INIT)\n", __func__); |
5535 | |
5536 | SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS); |
5537 | |
5538 | if (attempts <= asoc->max_init_attempts) { |
5539 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
5540 | repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); |
5541 | if (!repl) |
5542 | return SCTP_DISPOSITION_NOMEM; |
5543 | |
5544 | /* Choose transport for INIT. */ |
5545 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
5546 | SCTP_CHUNK(repl)); |
5547 | |
5548 | /* Issue a sideeffect to do the needed accounting. */ |
5549 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, |
5550 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
5551 | |
5552 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
5553 | } else { |
5554 | pr_debug("%s: giving up on INIT, attempts:%d " |
5555 | "max_init_attempts:%d\n", __func__, attempts, |
5556 | asoc->max_init_attempts); |
5557 | |
5558 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5559 | SCTP_ERROR(ETIMEDOUT)); |
5560 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
5561 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5562 | return SCTP_DISPOSITION_DELETE_TCB; |
5563 | } |
5564 | |
5565 | return SCTP_DISPOSITION_CONSUME; |
5566 | } |
5567 | |
5568 | /* |
5569 | * sctp_sf_t1_cookie_timer_expire |
5570 | * |
5571 | * Section: 4 Note: 2 |
5572 | * Verification Tag: |
5573 | * Inputs |
5574 | * (endpoint, asoc) |
5575 | * |
5576 | * RFC 2960 Section 4 Notes |
5577 | * 3) If the T1-cookie timer expires, the endpoint MUST retransmit |
5578 | * COOKIE ECHO and re-start the T1-cookie timer without changing |
5579 | * state. This MUST be repeated up to 'Max.Init.Retransmits' times. |
5580 | * After that, the endpoint MUST abort the initialization process and |
5581 | * report the error to SCTP user. |
5582 | * |
5583 | * Outputs |
5584 | * (timers, events) |
5585 | * |
5586 | */ |
5587 | sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net, |
5588 | const struct sctp_endpoint *ep, |
5589 | const struct sctp_association *asoc, |
5590 | const sctp_subtype_t type, |
5591 | void *arg, |
5592 | sctp_cmd_seq_t *commands) |
5593 | { |
5594 | struct sctp_chunk *repl = NULL; |
5595 | int attempts = asoc->init_err_counter + 1; |
5596 | |
5597 | pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__); |
5598 | |
5599 | SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS); |
5600 | |
5601 | if (attempts <= asoc->max_init_attempts) { |
5602 | repl = sctp_make_cookie_echo(asoc, NULL); |
5603 | if (!repl) |
5604 | return SCTP_DISPOSITION_NOMEM; |
5605 | |
5606 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
5607 | SCTP_CHUNK(repl)); |
5608 | /* Issue a sideeffect to do the needed accounting. */ |
5609 | sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART, |
5610 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
5611 | |
5612 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
5613 | } else { |
5614 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5615 | SCTP_ERROR(ETIMEDOUT)); |
5616 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
5617 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5618 | return SCTP_DISPOSITION_DELETE_TCB; |
5619 | } |
5620 | |
5621 | return SCTP_DISPOSITION_CONSUME; |
5622 | } |
5623 | |
5624 | /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN |
5625 | * with the updated last sequential TSN received from its peer. |
5626 | * |
5627 | * An endpoint should limit the number of retransmissions of the |
5628 | * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. |
5629 | * If this threshold is exceeded the endpoint should destroy the TCB and |
5630 | * MUST report the peer endpoint unreachable to the upper layer (and |
5631 | * thus the association enters the CLOSED state). The reception of any |
5632 | * packet from its peer (i.e. as the peer sends all of its queued DATA |
5633 | * chunks) should clear the endpoint's retransmission count and restart |
5634 | * the T2-Shutdown timer, giving its peer ample opportunity to transmit |
5635 | * all of its queued DATA chunks that have not yet been sent. |
5636 | */ |
5637 | sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net, |
5638 | const struct sctp_endpoint *ep, |
5639 | const struct sctp_association *asoc, |
5640 | const sctp_subtype_t type, |
5641 | void *arg, |
5642 | sctp_cmd_seq_t *commands) |
5643 | { |
5644 | struct sctp_chunk *reply = NULL; |
5645 | |
5646 | pr_debug("%s: timer T2 expired\n", __func__); |
5647 | |
5648 | SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS); |
5649 | |
5650 | ((struct sctp_association *)asoc)->shutdown_retries++; |
5651 | |
5652 | if (asoc->overall_error_count >= asoc->max_retrans) { |
5653 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5654 | SCTP_ERROR(ETIMEDOUT)); |
5655 | /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
5656 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
5657 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5658 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
5659 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
5660 | return SCTP_DISPOSITION_DELETE_TCB; |
5661 | } |
5662 | |
5663 | switch (asoc->state) { |
5664 | case SCTP_STATE_SHUTDOWN_SENT: |
5665 | reply = sctp_make_shutdown(asoc, NULL); |
5666 | break; |
5667 | |
5668 | case SCTP_STATE_SHUTDOWN_ACK_SENT: |
5669 | reply = sctp_make_shutdown_ack(asoc, NULL); |
5670 | break; |
5671 | |
5672 | default: |
5673 | BUG(); |
5674 | break; |
5675 | } |
5676 | |
5677 | if (!reply) |
5678 | goto nomem; |
5679 | |
5680 | /* Do some failure management (Section 8.2). |
5681 | * If we remove the transport an SHUTDOWN was last sent to, don't |
5682 | * do failure management. |
5683 | */ |
5684 | if (asoc->shutdown_last_sent_to) |
5685 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
5686 | SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); |
5687 | |
5688 | /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for |
5689 | * the T2-shutdown timer. |
5690 | */ |
5691 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
5692 | |
5693 | /* Restart the T2-shutdown timer. */ |
5694 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
5695 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
5696 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
5697 | return SCTP_DISPOSITION_CONSUME; |
5698 | |
5699 | nomem: |
5700 | return SCTP_DISPOSITION_NOMEM; |
5701 | } |
5702 | |
5703 | /* |
5704 | * ADDIP Section 4.1 ASCONF CHunk Procedures |
5705 | * If the T4 RTO timer expires the endpoint should do B1 to B5 |
5706 | */ |
5707 | sctp_disposition_t sctp_sf_t4_timer_expire( |
5708 | struct net *net, |
5709 | const struct sctp_endpoint *ep, |
5710 | const struct sctp_association *asoc, |
5711 | const sctp_subtype_t type, |
5712 | void *arg, |
5713 | sctp_cmd_seq_t *commands) |
5714 | { |
5715 | struct sctp_chunk *chunk = asoc->addip_last_asconf; |
5716 | struct sctp_transport *transport = chunk->transport; |
5717 | |
5718 | SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS); |
5719 | |
5720 | /* ADDIP 4.1 B1) Increment the error counters and perform path failure |
5721 | * detection on the appropriate destination address as defined in |
5722 | * RFC2960 [5] section 8.1 and 8.2. |
5723 | */ |
5724 | if (transport) |
5725 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
5726 | SCTP_TRANSPORT(transport)); |
5727 | |
5728 | /* Reconfig T4 timer and transport. */ |
5729 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
5730 | |
5731 | /* ADDIP 4.1 B2) Increment the association error counters and perform |
5732 | * endpoint failure detection on the association as defined in |
5733 | * RFC2960 [5] section 8.1 and 8.2. |
5734 | * association error counter is incremented in SCTP_CMD_STRIKE. |
5735 | */ |
5736 | if (asoc->overall_error_count >= asoc->max_retrans) { |
5737 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
5738 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
5739 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5740 | SCTP_ERROR(ETIMEDOUT)); |
5741 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
5742 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5743 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
5744 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
5745 | return SCTP_DISPOSITION_ABORT; |
5746 | } |
5747 | |
5748 | /* ADDIP 4.1 B3) Back-off the destination address RTO value to which |
5749 | * the ASCONF chunk was sent by doubling the RTO timer value. |
5750 | * This is done in SCTP_CMD_STRIKE. |
5751 | */ |
5752 | |
5753 | /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible |
5754 | * choose an alternate destination address (please refer to RFC2960 |
5755 | * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this |
5756 | * chunk, it MUST be the same (including its serial number) as the last |
5757 | * ASCONF sent. |
5758 | */ |
5759 | sctp_chunk_hold(asoc->addip_last_asconf); |
5760 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
5761 | SCTP_CHUNK(asoc->addip_last_asconf)); |
5762 | |
5763 | /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different |
5764 | * destination is selected, then the RTO used will be that of the new |
5765 | * destination address. |
5766 | */ |
5767 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
5768 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
5769 | |
5770 | return SCTP_DISPOSITION_CONSUME; |
5771 | } |
5772 | |
5773 | /* sctpimpguide-05 Section 2.12.2 |
5774 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
5775 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
5776 | * At the expiration of this timer the sender SHOULD abort the association |
5777 | * by sending an ABORT chunk. |
5778 | */ |
5779 | sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net, |
5780 | const struct sctp_endpoint *ep, |
5781 | const struct sctp_association *asoc, |
5782 | const sctp_subtype_t type, |
5783 | void *arg, |
5784 | sctp_cmd_seq_t *commands) |
5785 | { |
5786 | struct sctp_chunk *reply = NULL; |
5787 | |
5788 | pr_debug("%s: timer T5 expired\n", __func__); |
5789 | |
5790 | SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS); |
5791 | |
5792 | reply = sctp_make_abort(asoc, NULL, 0); |
5793 | if (!reply) |
5794 | goto nomem; |
5795 | |
5796 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
5797 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
5798 | SCTP_ERROR(ETIMEDOUT)); |
5799 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
5800 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
5801 | |
5802 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
5803 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
5804 | |
5805 | return SCTP_DISPOSITION_DELETE_TCB; |
5806 | nomem: |
5807 | return SCTP_DISPOSITION_NOMEM; |
5808 | } |
5809 | |
5810 | /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, |
5811 | * the association is automatically closed by starting the shutdown process. |
5812 | * The work that needs to be done is same as when SHUTDOWN is initiated by |
5813 | * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). |
5814 | */ |
5815 | sctp_disposition_t sctp_sf_autoclose_timer_expire( |
5816 | struct net *net, |
5817 | const struct sctp_endpoint *ep, |
5818 | const struct sctp_association *asoc, |
5819 | const sctp_subtype_t type, |
5820 | void *arg, |
5821 | sctp_cmd_seq_t *commands) |
5822 | { |
5823 | int disposition; |
5824 | |
5825 | SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS); |
5826 | |
5827 | /* From 9.2 Shutdown of an Association |
5828 | * Upon receipt of the SHUTDOWN primitive from its upper |
5829 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
5830 | * remains there until all outstanding data has been |
5831 | * acknowledged by its peer. The endpoint accepts no new data |
5832 | * from its upper layer, but retransmits data to the far end |
5833 | * if necessary to fill gaps. |
5834 | */ |
5835 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
5836 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
5837 | |
5838 | disposition = SCTP_DISPOSITION_CONSUME; |
5839 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
5840 | disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, |
5841 | arg, commands); |
5842 | } |
5843 | return disposition; |
5844 | } |
5845 | |
5846 | /***************************************************************************** |
5847 | * These are sa state functions which could apply to all types of events. |
5848 | ****************************************************************************/ |
5849 | |
5850 | /* |
5851 | * This table entry is not implemented. |
5852 | * |
5853 | * Inputs |
5854 | * (endpoint, asoc, chunk) |
5855 | * |
5856 | * The return value is the disposition of the chunk. |
5857 | */ |
5858 | sctp_disposition_t sctp_sf_not_impl(struct net *net, |
5859 | const struct sctp_endpoint *ep, |
5860 | const struct sctp_association *asoc, |
5861 | const sctp_subtype_t type, |
5862 | void *arg, |
5863 | sctp_cmd_seq_t *commands) |
5864 | { |
5865 | return SCTP_DISPOSITION_NOT_IMPL; |
5866 | } |
5867 | |
5868 | /* |
5869 | * This table entry represents a bug. |
5870 | * |
5871 | * Inputs |
5872 | * (endpoint, asoc, chunk) |
5873 | * |
5874 | * The return value is the disposition of the chunk. |
5875 | */ |
5876 | sctp_disposition_t sctp_sf_bug(struct net *net, |
5877 | const struct sctp_endpoint *ep, |
5878 | const struct sctp_association *asoc, |
5879 | const sctp_subtype_t type, |
5880 | void *arg, |
5881 | sctp_cmd_seq_t *commands) |
5882 | { |
5883 | return SCTP_DISPOSITION_BUG; |
5884 | } |
5885 | |
5886 | /* |
5887 | * This table entry represents the firing of a timer in the wrong state. |
5888 | * Since timer deletion cannot be guaranteed a timer 'may' end up firing |
5889 | * when the association is in the wrong state. This event should |
5890 | * be ignored, so as to prevent any rearming of the timer. |
5891 | * |
5892 | * Inputs |
5893 | * (endpoint, asoc, chunk) |
5894 | * |
5895 | * The return value is the disposition of the chunk. |
5896 | */ |
5897 | sctp_disposition_t sctp_sf_timer_ignore(struct net *net, |
5898 | const struct sctp_endpoint *ep, |
5899 | const struct sctp_association *asoc, |
5900 | const sctp_subtype_t type, |
5901 | void *arg, |
5902 | sctp_cmd_seq_t *commands) |
5903 | { |
5904 | pr_debug("%s: timer %d ignored\n", __func__, type.chunk); |
5905 | |
5906 | return SCTP_DISPOSITION_CONSUME; |
5907 | } |
5908 | |
5909 | /******************************************************************** |
5910 | * 2nd Level Abstractions |
5911 | ********************************************************************/ |
5912 | |
5913 | /* Pull the SACK chunk based on the SACK header. */ |
5914 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) |
5915 | { |
5916 | struct sctp_sackhdr *sack; |
5917 | unsigned int len; |
5918 | __u16 num_blocks; |
5919 | __u16 num_dup_tsns; |
5920 | |
5921 | /* Protect ourselves from reading too far into |
5922 | * the skb from a bogus sender. |
5923 | */ |
5924 | sack = (struct sctp_sackhdr *) chunk->skb->data; |
5925 | |
5926 | num_blocks = ntohs(sack->num_gap_ack_blocks); |
5927 | num_dup_tsns = ntohs(sack->num_dup_tsns); |
5928 | len = sizeof(struct sctp_sackhdr); |
5929 | len += (num_blocks + num_dup_tsns) * sizeof(__u32); |
5930 | if (len > chunk->skb->len) |
5931 | return NULL; |
5932 | |
5933 | skb_pull(chunk->skb, len); |
5934 | |
5935 | return sack; |
5936 | } |
5937 | |
5938 | /* Create an ABORT packet to be sent as a response, with the specified |
5939 | * error causes. |
5940 | */ |
5941 | static struct sctp_packet *sctp_abort_pkt_new(struct net *net, |
5942 | const struct sctp_endpoint *ep, |
5943 | const struct sctp_association *asoc, |
5944 | struct sctp_chunk *chunk, |
5945 | const void *payload, |
5946 | size_t paylen) |
5947 | { |
5948 | struct sctp_packet *packet; |
5949 | struct sctp_chunk *abort; |
5950 | |
5951 | packet = sctp_ootb_pkt_new(net, asoc, chunk); |
5952 | |
5953 | if (packet) { |
5954 | /* Make an ABORT. |
5955 | * The T bit will be set if the asoc is NULL. |
5956 | */ |
5957 | abort = sctp_make_abort(asoc, chunk, paylen); |
5958 | if (!abort) { |
5959 | sctp_ootb_pkt_free(packet); |
5960 | return NULL; |
5961 | } |
5962 | |
5963 | /* Reflect vtag if T-Bit is set */ |
5964 | if (sctp_test_T_bit(abort)) |
5965 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
5966 | |
5967 | /* Add specified error causes, i.e., payload, to the |
5968 | * end of the chunk. |
5969 | */ |
5970 | sctp_addto_chunk(abort, paylen, payload); |
5971 | |
5972 | /* Set the skb to the belonging sock for accounting. */ |
5973 | abort->skb->sk = ep->base.sk; |
5974 | |
5975 | sctp_packet_append_chunk(packet, abort); |
5976 | |
5977 | } |
5978 | |
5979 | return packet; |
5980 | } |
5981 | |
5982 | /* Allocate a packet for responding in the OOTB conditions. */ |
5983 | static struct sctp_packet *sctp_ootb_pkt_new(struct net *net, |
5984 | const struct sctp_association *asoc, |
5985 | const struct sctp_chunk *chunk) |
5986 | { |
5987 | struct sctp_packet *packet; |
5988 | struct sctp_transport *transport; |
5989 | __u16 sport; |
5990 | __u16 dport; |
5991 | __u32 vtag; |
5992 | |
5993 | /* Get the source and destination port from the inbound packet. */ |
5994 | sport = ntohs(chunk->sctp_hdr->dest); |
5995 | dport = ntohs(chunk->sctp_hdr->source); |
5996 | |
5997 | /* The V-tag is going to be the same as the inbound packet if no |
5998 | * association exists, otherwise, use the peer's vtag. |
5999 | */ |
6000 | if (asoc) { |
6001 | /* Special case the INIT-ACK as there is no peer's vtag |
6002 | * yet. |
6003 | */ |
6004 | switch (chunk->chunk_hdr->type) { |
6005 | case SCTP_CID_INIT_ACK: |
6006 | { |
6007 | sctp_initack_chunk_t *initack; |
6008 | |
6009 | initack = (sctp_initack_chunk_t *)chunk->chunk_hdr; |
6010 | vtag = ntohl(initack->init_hdr.init_tag); |
6011 | break; |
6012 | } |
6013 | default: |
6014 | vtag = asoc->peer.i.init_tag; |
6015 | break; |
6016 | } |
6017 | } else { |
6018 | /* Special case the INIT and stale COOKIE_ECHO as there is no |
6019 | * vtag yet. |
6020 | */ |
6021 | switch (chunk->chunk_hdr->type) { |
6022 | case SCTP_CID_INIT: |
6023 | { |
6024 | sctp_init_chunk_t *init; |
6025 | |
6026 | init = (sctp_init_chunk_t *)chunk->chunk_hdr; |
6027 | vtag = ntohl(init->init_hdr.init_tag); |
6028 | break; |
6029 | } |
6030 | default: |
6031 | vtag = ntohl(chunk->sctp_hdr->vtag); |
6032 | break; |
6033 | } |
6034 | } |
6035 | |
6036 | /* Make a transport for the bucket, Eliza... */ |
6037 | transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC); |
6038 | if (!transport) |
6039 | goto nomem; |
6040 | |
6041 | /* Cache a route for the transport with the chunk's destination as |
6042 | * the source address. |
6043 | */ |
6044 | sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, |
6045 | sctp_sk(net->sctp.ctl_sock)); |
6046 | |
6047 | packet = sctp_packet_init(&transport->packet, transport, sport, dport); |
6048 | packet = sctp_packet_config(packet, vtag, 0); |
6049 | |
6050 | return packet; |
6051 | |
6052 | nomem: |
6053 | return NULL; |
6054 | } |
6055 | |
6056 | /* Free the packet allocated earlier for responding in the OOTB condition. */ |
6057 | void sctp_ootb_pkt_free(struct sctp_packet *packet) |
6058 | { |
6059 | sctp_transport_free(packet->transport); |
6060 | } |
6061 | |
6062 | /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ |
6063 | static void sctp_send_stale_cookie_err(struct net *net, |
6064 | const struct sctp_endpoint *ep, |
6065 | const struct sctp_association *asoc, |
6066 | const struct sctp_chunk *chunk, |
6067 | sctp_cmd_seq_t *commands, |
6068 | struct sctp_chunk *err_chunk) |
6069 | { |
6070 | struct sctp_packet *packet; |
6071 | |
6072 | if (err_chunk) { |
6073 | packet = sctp_ootb_pkt_new(net, asoc, chunk); |
6074 | if (packet) { |
6075 | struct sctp_signed_cookie *cookie; |
6076 | |
6077 | /* Override the OOTB vtag from the cookie. */ |
6078 | cookie = chunk->subh.cookie_hdr; |
6079 | packet->vtag = cookie->c.peer_vtag; |
6080 | |
6081 | /* Set the skb to the belonging sock for accounting. */ |
6082 | err_chunk->skb->sk = ep->base.sk; |
6083 | sctp_packet_append_chunk(packet, err_chunk); |
6084 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
6085 | SCTP_PACKET(packet)); |
6086 | SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
6087 | } else |
6088 | sctp_chunk_free (err_chunk); |
6089 | } |
6090 | } |
6091 | |
6092 | |
6093 | /* Process a data chunk */ |
6094 | static int sctp_eat_data(const struct sctp_association *asoc, |
6095 | struct sctp_chunk *chunk, |
6096 | sctp_cmd_seq_t *commands) |
6097 | { |
6098 | sctp_datahdr_t *data_hdr; |
6099 | struct sctp_chunk *err; |
6100 | size_t datalen; |
6101 | sctp_verb_t deliver; |
6102 | int tmp; |
6103 | __u32 tsn; |
6104 | struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; |
6105 | struct sock *sk = asoc->base.sk; |
6106 | struct net *net = sock_net(sk); |
6107 | u16 ssn; |
6108 | u16 sid; |
6109 | u8 ordered = 0; |
6110 | |
6111 | data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data; |
6112 | skb_pull(chunk->skb, sizeof(sctp_datahdr_t)); |
6113 | |
6114 | tsn = ntohl(data_hdr->tsn); |
6115 | pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
6116 | |
6117 | /* ASSERT: Now skb->data is really the user data. */ |
6118 | |
6119 | /* Process ECN based congestion. |
6120 | * |
6121 | * Since the chunk structure is reused for all chunks within |
6122 | * a packet, we use ecn_ce_done to track if we've already |
6123 | * done CE processing for this packet. |
6124 | * |
6125 | * We need to do ECN processing even if we plan to discard the |
6126 | * chunk later. |
6127 | */ |
6128 | |
6129 | if (!chunk->ecn_ce_done) { |
6130 | struct sctp_af *af; |
6131 | chunk->ecn_ce_done = 1; |
6132 | |
6133 | af = sctp_get_af_specific( |
6134 | ipver2af(ip_hdr(chunk->skb)->version)); |
6135 | |
6136 | if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) { |
6137 | /* Do real work as sideffect. */ |
6138 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, |
6139 | SCTP_U32(tsn)); |
6140 | } |
6141 | } |
6142 | |
6143 | tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); |
6144 | if (tmp < 0) { |
6145 | /* The TSN is too high--silently discard the chunk and |
6146 | * count on it getting retransmitted later. |
6147 | */ |
6148 | if (chunk->asoc) |
6149 | chunk->asoc->stats.outofseqtsns++; |
6150 | return SCTP_IERROR_HIGH_TSN; |
6151 | } else if (tmp > 0) { |
6152 | /* This is a duplicate. Record it. */ |
6153 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); |
6154 | return SCTP_IERROR_DUP_TSN; |
6155 | } |
6156 | |
6157 | /* This is a new TSN. */ |
6158 | |
6159 | /* Discard if there is no room in the receive window. |
6160 | * Actually, allow a little bit of overflow (up to a MTU). |
6161 | */ |
6162 | datalen = ntohs(chunk->chunk_hdr->length); |
6163 | datalen -= sizeof(sctp_data_chunk_t); |
6164 | |
6165 | deliver = SCTP_CMD_CHUNK_ULP; |
6166 | |
6167 | /* Think about partial delivery. */ |
6168 | if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { |
6169 | |
6170 | /* Even if we don't accept this chunk there is |
6171 | * memory pressure. |
6172 | */ |
6173 | sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); |
6174 | } |
6175 | |
6176 | /* Spill over rwnd a little bit. Note: While allowed, this spill over |
6177 | * seems a bit troublesome in that frag_point varies based on |
6178 | * PMTU. In cases, such as loopback, this might be a rather |
6179 | * large spill over. |
6180 | */ |
6181 | if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over || |
6182 | (datalen > asoc->rwnd + asoc->frag_point))) { |
6183 | |
6184 | /* If this is the next TSN, consider reneging to make |
6185 | * room. Note: Playing nice with a confused sender. A |
6186 | * malicious sender can still eat up all our buffer |
6187 | * space and in the future we may want to detect and |
6188 | * do more drastic reneging. |
6189 | */ |
6190 | if (sctp_tsnmap_has_gap(map) && |
6191 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
6192 | pr_debug("%s: reneging for tsn:%u\n", __func__, tsn); |
6193 | deliver = SCTP_CMD_RENEGE; |
6194 | } else { |
6195 | pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n", |
6196 | __func__, tsn, datalen, asoc->rwnd); |
6197 | |
6198 | return SCTP_IERROR_IGNORE_TSN; |
6199 | } |
6200 | } |
6201 | |
6202 | /* |
6203 | * Also try to renege to limit our memory usage in the event that |
6204 | * we are under memory pressure |
6205 | * If we can't renege, don't worry about it, the sk_rmem_schedule |
6206 | * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our |
6207 | * memory usage too much |
6208 | */ |
6209 | if (*sk->sk_prot_creator->memory_pressure) { |
6210 | if (sctp_tsnmap_has_gap(map) && |
6211 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
6212 | pr_debug("%s: under pressure, reneging for tsn:%u\n", |
6213 | __func__, tsn); |
6214 | deliver = SCTP_CMD_RENEGE; |
6215 | } |
6216 | } |
6217 | |
6218 | /* |
6219 | * Section 3.3.10.9 No User Data (9) |
6220 | * |
6221 | * Cause of error |
6222 | * --------------- |
6223 | * No User Data: This error cause is returned to the originator of a |
6224 | * DATA chunk if a received DATA chunk has no user data. |
6225 | */ |
6226 | if (unlikely(0 == datalen)) { |
6227 | err = sctp_make_abort_no_data(asoc, chunk, tsn); |
6228 | if (err) { |
6229 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
6230 | SCTP_CHUNK(err)); |
6231 | } |
6232 | /* We are going to ABORT, so we might as well stop |
6233 | * processing the rest of the chunks in the packet. |
6234 | */ |
6235 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
6236 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
6237 | SCTP_ERROR(ECONNABORTED)); |
6238 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
6239 | SCTP_PERR(SCTP_ERROR_NO_DATA)); |
6240 | SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
6241 | SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
6242 | return SCTP_IERROR_NO_DATA; |
6243 | } |
6244 | |
6245 | chunk->data_accepted = 1; |
6246 | |
6247 | /* Note: Some chunks may get overcounted (if we drop) or overcounted |
6248 | * if we renege and the chunk arrives again. |
6249 | */ |
6250 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { |
6251 | SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS); |
6252 | if (chunk->asoc) |
6253 | chunk->asoc->stats.iuodchunks++; |
6254 | } else { |
6255 | SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS); |
6256 | if (chunk->asoc) |
6257 | chunk->asoc->stats.iodchunks++; |
6258 | ordered = 1; |
6259 | } |
6260 | |
6261 | /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number |
6262 | * |
6263 | * If an endpoint receive a DATA chunk with an invalid stream |
6264 | * identifier, it shall acknowledge the reception of the DATA chunk |
6265 | * following the normal procedure, immediately send an ERROR chunk |
6266 | * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) |
6267 | * and discard the DATA chunk. |
6268 | */ |
6269 | sid = ntohs(data_hdr->stream); |
6270 | if (sid >= asoc->c.sinit_max_instreams) { |
6271 | /* Mark tsn as received even though we drop it */ |
6272 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); |
6273 | |
6274 | err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, |
6275 | &data_hdr->stream, |
6276 | sizeof(data_hdr->stream), |
6277 | sizeof(u16)); |
6278 | if (err) |
6279 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
6280 | SCTP_CHUNK(err)); |
6281 | return SCTP_IERROR_BAD_STREAM; |
6282 | } |
6283 | |
6284 | /* Check to see if the SSN is possible for this TSN. |
6285 | * The biggest gap we can record is 4K wide. Since SSNs wrap |
6286 | * at an unsigned short, there is no way that an SSN can |
6287 | * wrap and for a valid TSN. We can simply check if the current |
6288 | * SSN is smaller then the next expected one. If it is, it wrapped |
6289 | * and is invalid. |
6290 | */ |
6291 | ssn = ntohs(data_hdr->ssn); |
6292 | if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) { |
6293 | return SCTP_IERROR_PROTO_VIOLATION; |
6294 | } |
6295 | |
6296 | /* Send the data up to the user. Note: Schedule the |
6297 | * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK |
6298 | * chunk needs the updated rwnd. |
6299 | */ |
6300 | sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); |
6301 | |
6302 | return SCTP_IERROR_NO_ERROR; |
6303 | } |
6304 |
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