Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/net/sctp/sm_statefuns.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 166484 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* SCTP kernel reference Implementation |
2 | * (C) Copyright IBM Corp. 2001, 2004 |
3 | * Copyright (c) 1999-2000 Cisco, Inc. |
4 | * Copyright (c) 1999-2001 Motorola, Inc. |
5 | * Copyright (c) 2001-2002 Intel Corp. |
6 | * Copyright (c) 2002 Nokia Corp. |
7 | * |
8 | * This file is part of the SCTP kernel reference Implementation |
9 | * |
10 | * This is part of the SCTP Linux Kernel Reference Implementation. |
11 | * |
12 | * These are the state functions for the state machine. |
13 | * |
14 | * The SCTP reference implementation is free software; |
15 | * you can redistribute it and/or modify it under the terms of |
16 | * the GNU General Public License as published by |
17 | * the Free Software Foundation; either version 2, or (at your option) |
18 | * any later version. |
19 | * |
20 | * The SCTP reference implementation is distributed in the hope that it |
21 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
22 | * ************************ |
23 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
24 | * See the GNU General Public License for more details. |
25 | * |
26 | * You should have received a copy of the GNU General Public License |
27 | * along with GNU CC; see the file COPYING. If not, write to |
28 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
29 | * Boston, MA 02111-1307, USA. |
30 | * |
31 | * Please send any bug reports or fixes you make to the |
32 | * email address(es): |
33 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
34 | * |
35 | * Or submit a bug report through the following website: |
36 | * http://www.sf.net/projects/lksctp |
37 | * |
38 | * Written or modified by: |
39 | * La Monte H.P. Yarroll <piggy@acm.org> |
40 | * Karl Knutson <karl@athena.chicago.il.us> |
41 | * Mathew Kotowsky <kotowsky@sctp.org> |
42 | * Sridhar Samudrala <samudrala@us.ibm.com> |
43 | * Jon Grimm <jgrimm@us.ibm.com> |
44 | * Hui Huang <hui.huang@nokia.com> |
45 | * Dajiang Zhang <dajiang.zhang@nokia.com> |
46 | * Daisy Chang <daisyc@us.ibm.com> |
47 | * Ardelle Fan <ardelle.fan@intel.com> |
48 | * Ryan Layer <rmlayer@us.ibm.com> |
49 | * Kevin Gao <kevin.gao@intel.com> |
50 | * |
51 | * Any bugs reported given to us we will try to fix... any fixes shared will |
52 | * be incorporated into the next SCTP release. |
53 | */ |
54 | |
55 | #include <linux/types.h> |
56 | #include <linux/kernel.h> |
57 | #include <linux/ip.h> |
58 | #include <linux/ipv6.h> |
59 | #include <linux/net.h> |
60 | #include <linux/inet.h> |
61 | #include <net/sock.h> |
62 | #include <net/inet_ecn.h> |
63 | #include <linux/skbuff.h> |
64 | #include <net/sctp/sctp.h> |
65 | #include <net/sctp/sm.h> |
66 | #include <net/sctp/structs.h> |
67 | |
68 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, |
69 | const struct sctp_association *asoc, |
70 | struct sctp_chunk *chunk, |
71 | const void *payload, |
72 | size_t paylen); |
73 | static int sctp_eat_data(const struct sctp_association *asoc, |
74 | struct sctp_chunk *chunk, |
75 | sctp_cmd_seq_t *commands); |
76 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, |
77 | const struct sctp_chunk *chunk); |
78 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, |
79 | const struct sctp_association *asoc, |
80 | const struct sctp_chunk *chunk, |
81 | sctp_cmd_seq_t *commands, |
82 | struct sctp_chunk *err_chunk); |
83 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, |
84 | const struct sctp_association *asoc, |
85 | const sctp_subtype_t type, |
86 | void *arg, |
87 | sctp_cmd_seq_t *commands); |
88 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, |
89 | const struct sctp_association *asoc, |
90 | const sctp_subtype_t type, |
91 | void *arg, |
92 | sctp_cmd_seq_t *commands); |
93 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk); |
94 | |
95 | |
96 | /* Small helper function that checks if the chunk length |
97 | * is of the appropriate length. The 'required_length' argument |
98 | * is set to be the size of a specific chunk we are testing. |
99 | * Return Values: 1 = Valid length |
100 | * 0 = Invalid length |
101 | * |
102 | */ |
103 | static inline int |
104 | sctp_chunk_length_valid(struct sctp_chunk *chunk, |
105 | __u16 required_length) |
106 | { |
107 | __u16 chunk_length = ntohs(chunk->chunk_hdr->length); |
108 | |
109 | if (unlikely(chunk_length < required_length)) |
110 | return 0; |
111 | |
112 | return 1; |
113 | } |
114 | |
115 | /********************************************************** |
116 | * These are the state functions for handling chunk events. |
117 | **********************************************************/ |
118 | |
119 | /* |
120 | * Process the final SHUTDOWN COMPLETE. |
121 | * |
122 | * Section: 4 (C) (diagram), 9.2 |
123 | * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify |
124 | * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be |
125 | * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint |
126 | * should stop the T2-shutdown timer and remove all knowledge of the |
127 | * association (and thus the association enters the CLOSED state). |
128 | * |
129 | * Verification Tag: 8.5.1(C), sctpimpguide 2.41. |
130 | * C) Rules for packet carrying SHUTDOWN COMPLETE: |
131 | * ... |
132 | * - The receiver of a SHUTDOWN COMPLETE shall accept the packet |
133 | * if the Verification Tag field of the packet matches its own tag and |
134 | * the T bit is not set |
135 | * OR |
136 | * it is set to its peer's tag and the T bit is set in the Chunk |
137 | * Flags. |
138 | * Otherwise, the receiver MUST silently discard the packet |
139 | * and take no further action. An endpoint MUST ignore the |
140 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. |
141 | * |
142 | * Inputs |
143 | * (endpoint, asoc, chunk) |
144 | * |
145 | * Outputs |
146 | * (asoc, reply_msg, msg_up, timers, counters) |
147 | * |
148 | * The return value is the disposition of the chunk. |
149 | */ |
150 | sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep, |
151 | const struct sctp_association *asoc, |
152 | const sctp_subtype_t type, |
153 | void *arg, |
154 | sctp_cmd_seq_t *commands) |
155 | { |
156 | struct sctp_chunk *chunk = arg; |
157 | struct sctp_ulpevent *ev; |
158 | |
159 | /* RFC 2960 6.10 Bundling |
160 | * |
161 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
162 | * SHUTDOWN COMPLETE with any other chunks. |
163 | */ |
164 | if (!chunk->singleton) |
165 | return SCTP_DISPOSITION_VIOLATION; |
166 | |
167 | if (!sctp_vtag_verify_either(chunk, asoc)) |
168 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
169 | |
170 | /* RFC 2960 10.2 SCTP-to-ULP |
171 | * |
172 | * H) SHUTDOWN COMPLETE notification |
173 | * |
174 | * When SCTP completes the shutdown procedures (section 9.2) this |
175 | * notification is passed to the upper layer. |
176 | */ |
177 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
178 | 0, 0, 0, GFP_ATOMIC); |
179 | if (!ev) |
180 | goto nomem; |
181 | |
182 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
183 | |
184 | /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint |
185 | * will verify that it is in SHUTDOWN-ACK-SENT state, if it is |
186 | * not the chunk should be discarded. If the endpoint is in |
187 | * the SHUTDOWN-ACK-SENT state the endpoint should stop the |
188 | * T2-shutdown timer and remove all knowledge of the |
189 | * association (and thus the association enters the CLOSED |
190 | * state). |
191 | */ |
192 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
193 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
194 | |
195 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
196 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
197 | |
198 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
199 | SCTP_STATE(SCTP_STATE_CLOSED)); |
200 | |
201 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
202 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
203 | |
204 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
205 | |
206 | return SCTP_DISPOSITION_DELETE_TCB; |
207 | |
208 | nomem: |
209 | return SCTP_DISPOSITION_NOMEM; |
210 | } |
211 | |
212 | /* |
213 | * Respond to a normal INIT chunk. |
214 | * We are the side that is being asked for an association. |
215 | * |
216 | * Section: 5.1 Normal Establishment of an Association, B |
217 | * B) "Z" shall respond immediately with an INIT ACK chunk. The |
218 | * destination IP address of the INIT ACK MUST be set to the source |
219 | * IP address of the INIT to which this INIT ACK is responding. In |
220 | * the response, besides filling in other parameters, "Z" must set the |
221 | * Verification Tag field to Tag_A, and also provide its own |
222 | * Verification Tag (Tag_Z) in the Initiate Tag field. |
223 | * |
224 | * Verification Tag: Must be 0. |
225 | * |
226 | * Inputs |
227 | * (endpoint, asoc, chunk) |
228 | * |
229 | * Outputs |
230 | * (asoc, reply_msg, msg_up, timers, counters) |
231 | * |
232 | * The return value is the disposition of the chunk. |
233 | */ |
234 | sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep, |
235 | const struct sctp_association *asoc, |
236 | const sctp_subtype_t type, |
237 | void *arg, |
238 | sctp_cmd_seq_t *commands) |
239 | { |
240 | struct sctp_chunk *chunk = arg; |
241 | struct sctp_chunk *repl; |
242 | struct sctp_association *new_asoc; |
243 | struct sctp_chunk *err_chunk; |
244 | struct sctp_packet *packet; |
245 | sctp_unrecognized_param_t *unk_param; |
246 | struct sock *sk; |
247 | int len; |
248 | |
249 | /* 6.10 Bundling |
250 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
251 | * SHUTDOWN COMPLETE with any other chunks. |
252 | * |
253 | * IG Section 2.11.2 |
254 | * Furthermore, we require that the receiver of an INIT chunk MUST |
255 | * enforce these rules by silently discarding an arriving packet |
256 | * with an INIT chunk that is bundled with other chunks. |
257 | */ |
258 | if (!chunk->singleton) |
259 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
260 | |
261 | /* If the packet is an OOTB packet which is temporarily on the |
262 | * control endpoint, respond with an ABORT. |
263 | */ |
264 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) |
265 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
266 | |
267 | sk = ep->base.sk; |
268 | /* If the endpoint is not listening or if the number of associations |
269 | * on the TCP-style socket exceed the max backlog, respond with an |
270 | * ABORT. |
271 | */ |
272 | if (!sctp_sstate(sk, LISTENING) || |
273 | (sctp_style(sk, TCP) && |
274 | sk_acceptq_is_full(sk))) |
275 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
276 | |
277 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
278 | * Tag. |
279 | */ |
280 | if (chunk->sctp_hdr->vtag != 0) |
281 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
282 | |
283 | /* Make sure that the INIT chunk has a valid length. |
284 | * Normally, this would cause an ABORT with a Protocol Violation |
285 | * error, but since we don't have an association, we'll |
286 | * just discard the packet. |
287 | */ |
288 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
289 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
290 | |
291 | /* Verify the INIT chunk before processing it. */ |
292 | err_chunk = NULL; |
293 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
294 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
295 | &err_chunk)) { |
296 | /* This chunk contains fatal error. It is to be discarded. |
297 | * Send an ABORT, with causes if there is any. |
298 | */ |
299 | if (err_chunk) { |
300 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
301 | (__u8 *)(err_chunk->chunk_hdr) + |
302 | sizeof(sctp_chunkhdr_t), |
303 | ntohs(err_chunk->chunk_hdr->length) - |
304 | sizeof(sctp_chunkhdr_t)); |
305 | |
306 | sctp_chunk_free(err_chunk); |
307 | |
308 | if (packet) { |
309 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
310 | SCTP_PACKET(packet)); |
311 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
312 | return SCTP_DISPOSITION_CONSUME; |
313 | } else { |
314 | return SCTP_DISPOSITION_NOMEM; |
315 | } |
316 | } else { |
317 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, |
318 | commands); |
319 | } |
320 | } |
321 | |
322 | /* Grab the INIT header. */ |
323 | chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data; |
324 | |
325 | /* Tag the variable length parameters. */ |
326 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
327 | |
328 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
329 | if (!new_asoc) |
330 | goto nomem; |
331 | |
332 | /* The call, sctp_process_init(), can fail on memory allocation. */ |
333 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
334 | sctp_source(chunk), |
335 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
336 | GFP_ATOMIC)) |
337 | goto nomem_init; |
338 | |
339 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
340 | |
341 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
342 | |
343 | /* If there are errors need to be reported for unknown parameters, |
344 | * make sure to reserve enough room in the INIT ACK for them. |
345 | */ |
346 | len = 0; |
347 | if (err_chunk) |
348 | len = ntohs(err_chunk->chunk_hdr->length) - |
349 | sizeof(sctp_chunkhdr_t); |
350 | |
351 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) |
352 | goto nomem_ack; |
353 | |
354 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
355 | if (!repl) |
356 | goto nomem_ack; |
357 | |
358 | /* If there are errors need to be reported for unknown parameters, |
359 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
360 | * parameter. |
361 | */ |
362 | if (err_chunk) { |
363 | /* Get the "Unrecognized parameter" parameter(s) out of the |
364 | * ERROR chunk generated by sctp_verify_init(). Since the |
365 | * error cause code for "unknown parameter" and the |
366 | * "Unrecognized parameter" type is the same, we can |
367 | * construct the parameters in INIT ACK by copying the |
368 | * ERROR causes over. |
369 | */ |
370 | unk_param = (sctp_unrecognized_param_t *) |
371 | ((__u8 *)(err_chunk->chunk_hdr) + |
372 | sizeof(sctp_chunkhdr_t)); |
373 | /* Replace the cause code with the "Unrecognized parameter" |
374 | * parameter type. |
375 | */ |
376 | sctp_addto_chunk(repl, len, unk_param); |
377 | sctp_chunk_free(err_chunk); |
378 | } |
379 | |
380 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
381 | |
382 | /* |
383 | * Note: After sending out INIT ACK with the State Cookie parameter, |
384 | * "Z" MUST NOT allocate any resources, nor keep any states for the |
385 | * new association. Otherwise, "Z" will be vulnerable to resource |
386 | * attacks. |
387 | */ |
388 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
389 | |
390 | return SCTP_DISPOSITION_DELETE_TCB; |
391 | |
392 | nomem_ack: |
393 | if (err_chunk) |
394 | sctp_chunk_free(err_chunk); |
395 | nomem_init: |
396 | sctp_association_free(new_asoc); |
397 | nomem: |
398 | return SCTP_DISPOSITION_NOMEM; |
399 | } |
400 | |
401 | /* |
402 | * Respond to a normal INIT ACK chunk. |
403 | * We are the side that is initiating the association. |
404 | * |
405 | * Section: 5.1 Normal Establishment of an Association, C |
406 | * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init |
407 | * timer and leave COOKIE-WAIT state. "A" shall then send the State |
408 | * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start |
409 | * the T1-cookie timer, and enter the COOKIE-ECHOED state. |
410 | * |
411 | * Note: The COOKIE ECHO chunk can be bundled with any pending outbound |
412 | * DATA chunks, but it MUST be the first chunk in the packet and |
413 | * until the COOKIE ACK is returned the sender MUST NOT send any |
414 | * other packets to the peer. |
415 | * |
416 | * Verification Tag: 3.3.3 |
417 | * If the value of the Initiate Tag in a received INIT ACK chunk is |
418 | * found to be 0, the receiver MUST treat it as an error and close the |
419 | * association by transmitting an ABORT. |
420 | * |
421 | * Inputs |
422 | * (endpoint, asoc, chunk) |
423 | * |
424 | * Outputs |
425 | * (asoc, reply_msg, msg_up, timers, counters) |
426 | * |
427 | * The return value is the disposition of the chunk. |
428 | */ |
429 | sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep, |
430 | const struct sctp_association *asoc, |
431 | const sctp_subtype_t type, |
432 | void *arg, |
433 | sctp_cmd_seq_t *commands) |
434 | { |
435 | struct sctp_chunk *chunk = arg; |
436 | sctp_init_chunk_t *initchunk; |
437 | __u32 init_tag; |
438 | struct sctp_chunk *err_chunk; |
439 | struct sctp_packet *packet; |
440 | sctp_disposition_t ret; |
441 | |
442 | if (!sctp_vtag_verify(chunk, asoc)) |
443 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
444 | |
445 | /* Make sure that the INIT-ACK chunk has a valid length */ |
446 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t))) |
447 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
448 | commands); |
449 | /* 6.10 Bundling |
450 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
451 | * SHUTDOWN COMPLETE with any other chunks. |
452 | */ |
453 | if (!chunk->singleton) |
454 | return SCTP_DISPOSITION_VIOLATION; |
455 | |
456 | /* Grab the INIT header. */ |
457 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
458 | |
459 | init_tag = ntohl(chunk->subh.init_hdr->init_tag); |
460 | |
461 | /* Verification Tag: 3.3.3 |
462 | * If the value of the Initiate Tag in a received INIT ACK |
463 | * chunk is found to be 0, the receiver MUST treat it as an |
464 | * error and close the association by transmitting an ABORT. |
465 | */ |
466 | if (!init_tag) { |
467 | struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0); |
468 | if (!reply) |
469 | goto nomem; |
470 | |
471 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
472 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
473 | SCTP_STATE(SCTP_STATE_CLOSED)); |
474 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
475 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
476 | return SCTP_DISPOSITION_DELETE_TCB; |
477 | } |
478 | |
479 | /* Verify the INIT chunk before processing it. */ |
480 | err_chunk = NULL; |
481 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
482 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
483 | &err_chunk)) { |
484 | |
485 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
486 | |
487 | /* This chunk contains fatal error. It is to be discarded. |
488 | * Send an ABORT, with causes if there is any. |
489 | */ |
490 | if (err_chunk) { |
491 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
492 | (__u8 *)(err_chunk->chunk_hdr) + |
493 | sizeof(sctp_chunkhdr_t), |
494 | ntohs(err_chunk->chunk_hdr->length) - |
495 | sizeof(sctp_chunkhdr_t)); |
496 | |
497 | sctp_chunk_free(err_chunk); |
498 | |
499 | if (packet) { |
500 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
501 | SCTP_PACKET(packet)); |
502 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
503 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
504 | SCTP_STATE(SCTP_STATE_CLOSED)); |
505 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, |
506 | SCTP_NULL()); |
507 | return SCTP_DISPOSITION_CONSUME; |
508 | } else { |
509 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
510 | SCTP_STATE(SCTP_STATE_CLOSED)); |
511 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, |
512 | SCTP_NULL()); |
513 | return SCTP_DISPOSITION_NOMEM; |
514 | } |
515 | } else { |
516 | ret = sctp_sf_tabort_8_4_8(ep, asoc, type, arg, |
517 | commands); |
518 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
519 | SCTP_STATE(SCTP_STATE_CLOSED)); |
520 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, |
521 | SCTP_NULL()); |
522 | return ret; |
523 | } |
524 | } |
525 | |
526 | /* Tag the variable length parameters. Note that we never |
527 | * convert the parameters in an INIT chunk. |
528 | */ |
529 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
530 | |
531 | initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr; |
532 | |
533 | sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, |
534 | SCTP_PEER_INIT(initchunk)); |
535 | |
536 | /* 5.1 C) "A" shall stop the T1-init timer and leave |
537 | * COOKIE-WAIT state. "A" shall then ... start the T1-cookie |
538 | * timer, and enter the COOKIE-ECHOED state. |
539 | */ |
540 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
541 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
542 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
543 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
544 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
545 | SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); |
546 | |
547 | /* 5.1 C) "A" shall then send the State Cookie received in the |
548 | * INIT ACK chunk in a COOKIE ECHO chunk, ... |
549 | */ |
550 | /* If there is any errors to report, send the ERROR chunk generated |
551 | * for unknown parameters as well. |
552 | */ |
553 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, |
554 | SCTP_CHUNK(err_chunk)); |
555 | |
556 | return SCTP_DISPOSITION_CONSUME; |
557 | |
558 | nomem: |
559 | return SCTP_DISPOSITION_NOMEM; |
560 | } |
561 | |
562 | /* |
563 | * Respond to a normal COOKIE ECHO chunk. |
564 | * We are the side that is being asked for an association. |
565 | * |
566 | * Section: 5.1 Normal Establishment of an Association, D |
567 | * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply |
568 | * with a COOKIE ACK chunk after building a TCB and moving to |
569 | * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with |
570 | * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK |
571 | * chunk MUST be the first chunk in the packet. |
572 | * |
573 | * IMPLEMENTATION NOTE: An implementation may choose to send the |
574 | * Communication Up notification to the SCTP user upon reception |
575 | * of a valid COOKIE ECHO chunk. |
576 | * |
577 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
578 | * D) Rules for packet carrying a COOKIE ECHO |
579 | * |
580 | * - When sending a COOKIE ECHO, the endpoint MUST use the value of the |
581 | * Initial Tag received in the INIT ACK. |
582 | * |
583 | * - The receiver of a COOKIE ECHO follows the procedures in Section 5. |
584 | * |
585 | * Inputs |
586 | * (endpoint, asoc, chunk) |
587 | * |
588 | * Outputs |
589 | * (asoc, reply_msg, msg_up, timers, counters) |
590 | * |
591 | * The return value is the disposition of the chunk. |
592 | */ |
593 | sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep, |
594 | const struct sctp_association *asoc, |
595 | const sctp_subtype_t type, void *arg, |
596 | sctp_cmd_seq_t *commands) |
597 | { |
598 | struct sctp_chunk *chunk = arg; |
599 | struct sctp_association *new_asoc; |
600 | sctp_init_chunk_t *peer_init; |
601 | struct sctp_chunk *repl; |
602 | struct sctp_ulpevent *ev; |
603 | int error = 0; |
604 | struct sctp_chunk *err_chk_p; |
605 | |
606 | /* If the packet is an OOTB packet which is temporarily on the |
607 | * control endpoint, respond with an ABORT. |
608 | */ |
609 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) |
610 | return sctp_sf_ootb(ep, asoc, type, arg, commands); |
611 | |
612 | /* Make sure that the COOKIE_ECHO chunk has a valid length. |
613 | * In this case, we check that we have enough for at least a |
614 | * chunk header. More detailed verification is done |
615 | * in sctp_unpack_cookie(). |
616 | */ |
617 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
618 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
619 | |
620 | /* "Decode" the chunk. We have no optional parameters so we |
621 | * are in good shape. |
622 | */ |
623 | chunk->subh.cookie_hdr = |
624 | (struct sctp_signed_cookie *)chunk->skb->data; |
625 | skb_pull(chunk->skb, |
626 | ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t)); |
627 | |
628 | /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint |
629 | * "Z" will reply with a COOKIE ACK chunk after building a TCB |
630 | * and moving to the ESTABLISHED state. |
631 | */ |
632 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
633 | &err_chk_p); |
634 | |
635 | /* FIXME: |
636 | * If the re-build failed, what is the proper error path |
637 | * from here? |
638 | * |
639 | * [We should abort the association. --piggy] |
640 | */ |
641 | if (!new_asoc) { |
642 | /* FIXME: Several errors are possible. A bad cookie should |
643 | * be silently discarded, but think about logging it too. |
644 | */ |
645 | switch (error) { |
646 | case -SCTP_IERROR_NOMEM: |
647 | goto nomem; |
648 | |
649 | case -SCTP_IERROR_STALE_COOKIE: |
650 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, |
651 | err_chk_p); |
652 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
653 | |
654 | case -SCTP_IERROR_BAD_SIG: |
655 | default: |
656 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
657 | }; |
658 | } |
659 | |
660 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
661 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
662 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
663 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
664 | SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS); |
665 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
666 | |
667 | if (new_asoc->autoclose) |
668 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
669 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
670 | |
671 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
672 | |
673 | /* Re-build the bind address for the association is done in |
674 | * the sctp_unpack_cookie() already. |
675 | */ |
676 | /* This is a brand-new association, so these are not yet side |
677 | * effects--it is safe to run them here. |
678 | */ |
679 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
680 | |
681 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
682 | &chunk->subh.cookie_hdr->c.peer_addr, |
683 | peer_init, GFP_ATOMIC)) |
684 | goto nomem_init; |
685 | |
686 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
687 | if (!repl) |
688 | goto nomem_repl; |
689 | |
690 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
691 | |
692 | /* RFC 2960 5.1 Normal Establishment of an Association |
693 | * |
694 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
695 | * send the Communication Up notification to the SCTP user |
696 | * upon reception of a valid COOKIE ECHO chunk. |
697 | */ |
698 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, |
699 | new_asoc->c.sinit_num_ostreams, |
700 | new_asoc->c.sinit_max_instreams, |
701 | GFP_ATOMIC); |
702 | if (!ev) |
703 | goto nomem_ev; |
704 | |
705 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
706 | |
707 | /* Sockets API Draft Section 5.3.1.6 |
708 | * When a peer sends a Adaption Layer Indication parameter , SCTP |
709 | * delivers this notification to inform the application that of the |
710 | * peers requested adaption layer. |
711 | */ |
712 | if (new_asoc->peer.adaption_ind) { |
713 | ev = sctp_ulpevent_make_adaption_indication(new_asoc, |
714 | GFP_ATOMIC); |
715 | if (!ev) |
716 | goto nomem_ev; |
717 | |
718 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
719 | SCTP_ULPEVENT(ev)); |
720 | } |
721 | |
722 | return SCTP_DISPOSITION_CONSUME; |
723 | |
724 | nomem_ev: |
725 | sctp_chunk_free(repl); |
726 | nomem_repl: |
727 | nomem_init: |
728 | sctp_association_free(new_asoc); |
729 | nomem: |
730 | return SCTP_DISPOSITION_NOMEM; |
731 | } |
732 | |
733 | /* |
734 | * Respond to a normal COOKIE ACK chunk. |
735 | * We are the side that is being asked for an association. |
736 | * |
737 | * RFC 2960 5.1 Normal Establishment of an Association |
738 | * |
739 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the |
740 | * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie |
741 | * timer. It may also notify its ULP about the successful |
742 | * establishment of the association with a Communication Up |
743 | * notification (see Section 10). |
744 | * |
745 | * Verification Tag: |
746 | * Inputs |
747 | * (endpoint, asoc, chunk) |
748 | * |
749 | * Outputs |
750 | * (asoc, reply_msg, msg_up, timers, counters) |
751 | * |
752 | * The return value is the disposition of the chunk. |
753 | */ |
754 | sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep, |
755 | const struct sctp_association *asoc, |
756 | const sctp_subtype_t type, void *arg, |
757 | sctp_cmd_seq_t *commands) |
758 | { |
759 | struct sctp_chunk *chunk = arg; |
760 | struct sctp_ulpevent *ev; |
761 | |
762 | if (!sctp_vtag_verify(chunk, asoc)) |
763 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
764 | |
765 | /* Verify that the chunk length for the COOKIE-ACK is OK. |
766 | * If we don't do this, any bundled chunks may be junked. |
767 | */ |
768 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
769 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
770 | commands); |
771 | |
772 | /* Reset init error count upon receipt of COOKIE-ACK, |
773 | * to avoid problems with the managemement of this |
774 | * counter in stale cookie situations when a transition back |
775 | * from the COOKIE-ECHOED state to the COOKIE-WAIT |
776 | * state is performed. |
777 | */ |
778 | sctp_add_cmd_sf(commands, SCTP_CMD_COUNTER_RESET, |
779 | SCTP_COUNTER(SCTP_COUNTER_INIT_ERROR)); |
780 | |
781 | /* RFC 2960 5.1 Normal Establishment of an Association |
782 | * |
783 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move |
784 | * from the COOKIE-ECHOED state to the ESTABLISHED state, |
785 | * stopping the T1-cookie timer. |
786 | */ |
787 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
788 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
789 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
790 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
791 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
792 | SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS); |
793 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
794 | if (asoc->autoclose) |
795 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
796 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
797 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
798 | |
799 | /* It may also notify its ULP about the successful |
800 | * establishment of the association with a Communication Up |
801 | * notification (see Section 10). |
802 | */ |
803 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, |
804 | 0, asoc->c.sinit_num_ostreams, |
805 | asoc->c.sinit_max_instreams, |
806 | GFP_ATOMIC); |
807 | |
808 | if (!ev) |
809 | goto nomem; |
810 | |
811 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
812 | |
813 | /* Sockets API Draft Section 5.3.1.6 |
814 | * When a peer sends a Adaption Layer Indication parameter , SCTP |
815 | * delivers this notification to inform the application that of the |
816 | * peers requested adaption layer. |
817 | */ |
818 | if (asoc->peer.adaption_ind) { |
819 | ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC); |
820 | if (!ev) |
821 | goto nomem; |
822 | |
823 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
824 | SCTP_ULPEVENT(ev)); |
825 | } |
826 | |
827 | return SCTP_DISPOSITION_CONSUME; |
828 | nomem: |
829 | return SCTP_DISPOSITION_NOMEM; |
830 | } |
831 | |
832 | /* Generate and sendout a heartbeat packet. */ |
833 | static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep, |
834 | const struct sctp_association *asoc, |
835 | const sctp_subtype_t type, |
836 | void *arg, |
837 | sctp_cmd_seq_t *commands) |
838 | { |
839 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
840 | struct sctp_chunk *reply; |
841 | sctp_sender_hb_info_t hbinfo; |
842 | size_t paylen = 0; |
843 | |
844 | hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; |
845 | hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); |
846 | hbinfo.daddr = transport->ipaddr; |
847 | hbinfo.sent_at = jiffies; |
848 | |
849 | /* Send a heartbeat to our peer. */ |
850 | paylen = sizeof(sctp_sender_hb_info_t); |
851 | reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen); |
852 | if (!reply) |
853 | return SCTP_DISPOSITION_NOMEM; |
854 | |
855 | /* Set rto_pending indicating that an RTT measurement |
856 | * is started with this heartbeat chunk. |
857 | */ |
858 | sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, |
859 | SCTP_TRANSPORT(transport)); |
860 | |
861 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
862 | return SCTP_DISPOSITION_CONSUME; |
863 | } |
864 | |
865 | /* Generate a HEARTBEAT packet on the given transport. */ |
866 | sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep, |
867 | const struct sctp_association *asoc, |
868 | const sctp_subtype_t type, |
869 | void *arg, |
870 | sctp_cmd_seq_t *commands) |
871 | { |
872 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
873 | |
874 | if (asoc->overall_error_count > asoc->max_retrans) { |
875 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
876 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
877 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
878 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
879 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
880 | return SCTP_DISPOSITION_DELETE_TCB; |
881 | } |
882 | |
883 | /* Section 3.3.5. |
884 | * The Sender-specific Heartbeat Info field should normally include |
885 | * information about the sender's current time when this HEARTBEAT |
886 | * chunk is sent and the destination transport address to which this |
887 | * HEARTBEAT is sent (see Section 8.3). |
888 | */ |
889 | |
890 | if (transport->hb_allowed) { |
891 | if (SCTP_DISPOSITION_NOMEM == |
892 | sctp_sf_heartbeat(ep, asoc, type, arg, |
893 | commands)) |
894 | return SCTP_DISPOSITION_NOMEM; |
895 | /* Set transport error counter and association error counter |
896 | * when sending heartbeat. |
897 | */ |
898 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET, |
899 | SCTP_TRANSPORT(transport)); |
900 | } |
901 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, |
902 | SCTP_TRANSPORT(transport)); |
903 | |
904 | return SCTP_DISPOSITION_CONSUME; |
905 | } |
906 | |
907 | /* |
908 | * Process an heartbeat request. |
909 | * |
910 | * Section: 8.3 Path Heartbeat |
911 | * The receiver of the HEARTBEAT should immediately respond with a |
912 | * HEARTBEAT ACK that contains the Heartbeat Information field copied |
913 | * from the received HEARTBEAT chunk. |
914 | * |
915 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
916 | * When receiving an SCTP packet, the endpoint MUST ensure that the |
917 | * value in the Verification Tag field of the received SCTP packet |
918 | * matches its own Tag. If the received Verification Tag value does not |
919 | * match the receiver's own tag value, the receiver shall silently |
920 | * discard the packet and shall not process it any further except for |
921 | * those cases listed in Section 8.5.1 below. |
922 | * |
923 | * Inputs |
924 | * (endpoint, asoc, chunk) |
925 | * |
926 | * Outputs |
927 | * (asoc, reply_msg, msg_up, timers, counters) |
928 | * |
929 | * The return value is the disposition of the chunk. |
930 | */ |
931 | sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep, |
932 | const struct sctp_association *asoc, |
933 | const sctp_subtype_t type, |
934 | void *arg, |
935 | sctp_cmd_seq_t *commands) |
936 | { |
937 | struct sctp_chunk *chunk = arg; |
938 | struct sctp_chunk *reply; |
939 | size_t paylen = 0; |
940 | |
941 | if (!sctp_vtag_verify(chunk, asoc)) |
942 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
943 | |
944 | /* Make sure that the HEARTBEAT chunk has a valid length. */ |
945 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) |
946 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
947 | commands); |
948 | |
949 | /* 8.3 The receiver of the HEARTBEAT should immediately |
950 | * respond with a HEARTBEAT ACK that contains the Heartbeat |
951 | * Information field copied from the received HEARTBEAT chunk. |
952 | */ |
953 | chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data; |
954 | paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); |
955 | skb_pull(chunk->skb, paylen); |
956 | |
957 | reply = sctp_make_heartbeat_ack(asoc, chunk, |
958 | chunk->subh.hb_hdr, paylen); |
959 | if (!reply) |
960 | goto nomem; |
961 | |
962 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
963 | return SCTP_DISPOSITION_CONSUME; |
964 | |
965 | nomem: |
966 | return SCTP_DISPOSITION_NOMEM; |
967 | } |
968 | |
969 | /* |
970 | * Process the returning HEARTBEAT ACK. |
971 | * |
972 | * Section: 8.3 Path Heartbeat |
973 | * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT |
974 | * should clear the error counter of the destination transport |
975 | * address to which the HEARTBEAT was sent, and mark the destination |
976 | * transport address as active if it is not so marked. The endpoint may |
977 | * optionally report to the upper layer when an inactive destination |
978 | * address is marked as active due to the reception of the latest |
979 | * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also |
980 | * clear the association overall error count as well (as defined |
981 | * in section 8.1). |
982 | * |
983 | * The receiver of the HEARTBEAT ACK should also perform an RTT |
984 | * measurement for that destination transport address using the time |
985 | * value carried in the HEARTBEAT ACK chunk. |
986 | * |
987 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
988 | * |
989 | * Inputs |
990 | * (endpoint, asoc, chunk) |
991 | * |
992 | * Outputs |
993 | * (asoc, reply_msg, msg_up, timers, counters) |
994 | * |
995 | * The return value is the disposition of the chunk. |
996 | */ |
997 | sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep, |
998 | const struct sctp_association *asoc, |
999 | const sctp_subtype_t type, |
1000 | void *arg, |
1001 | sctp_cmd_seq_t *commands) |
1002 | { |
1003 | struct sctp_chunk *chunk = arg; |
1004 | union sctp_addr from_addr; |
1005 | struct sctp_transport *link; |
1006 | sctp_sender_hb_info_t *hbinfo; |
1007 | unsigned long max_interval; |
1008 | |
1009 | if (!sctp_vtag_verify(chunk, asoc)) |
1010 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1011 | |
1012 | /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ |
1013 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) |
1014 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
1015 | commands); |
1016 | |
1017 | hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; |
1018 | from_addr = hbinfo->daddr; |
1019 | link = sctp_assoc_lookup_paddr(asoc, &from_addr); |
1020 | |
1021 | /* This should never happen, but lets log it if so. */ |
1022 | if (!link) { |
1023 | printk(KERN_WARNING |
1024 | "%s: Could not find address %d.%d.%d.%d\n", |
1025 | __FUNCTION__, NIPQUAD(from_addr.v4.sin_addr)); |
1026 | return SCTP_DISPOSITION_DISCARD; |
1027 | } |
1028 | |
1029 | max_interval = link->hb_interval + link->rto; |
1030 | |
1031 | /* Check if the timestamp looks valid. */ |
1032 | if (time_after(hbinfo->sent_at, jiffies) || |
1033 | time_after(jiffies, hbinfo->sent_at + max_interval)) { |
1034 | SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp" |
1035 | "received for transport: %p\n", |
1036 | __FUNCTION__, link); |
1037 | return SCTP_DISPOSITION_DISCARD; |
1038 | } |
1039 | |
1040 | /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of |
1041 | * the HEARTBEAT should clear the error counter of the |
1042 | * destination transport address to which the HEARTBEAT was |
1043 | * sent and mark the destination transport address as active if |
1044 | * it is not so marked. |
1045 | */ |
1046 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); |
1047 | |
1048 | return SCTP_DISPOSITION_CONSUME; |
1049 | } |
1050 | |
1051 | /* Helper function to send out an abort for the restart |
1052 | * condition. |
1053 | */ |
1054 | static int sctp_sf_send_restart_abort(union sctp_addr *ssa, |
1055 | struct sctp_chunk *init, |
1056 | sctp_cmd_seq_t *commands) |
1057 | { |
1058 | int len; |
1059 | struct sctp_packet *pkt; |
1060 | union sctp_addr_param *addrparm; |
1061 | struct sctp_errhdr *errhdr; |
1062 | struct sctp_endpoint *ep; |
1063 | char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)]; |
1064 | struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); |
1065 | |
1066 | /* Build the error on the stack. We are way to malloc crazy |
1067 | * throughout the code today. |
1068 | */ |
1069 | errhdr = (struct sctp_errhdr *)buffer; |
1070 | addrparm = (union sctp_addr_param *)errhdr->variable; |
1071 | |
1072 | /* Copy into a parm format. */ |
1073 | len = af->to_addr_param(ssa, addrparm); |
1074 | len += sizeof(sctp_errhdr_t); |
1075 | |
1076 | errhdr->cause = SCTP_ERROR_RESTART; |
1077 | errhdr->length = htons(len); |
1078 | |
1079 | /* Assign to the control socket. */ |
1080 | ep = sctp_sk((sctp_get_ctl_sock()))->ep; |
1081 | |
1082 | /* Association is NULL since this may be a restart attack and we |
1083 | * want to send back the attacker's vtag. |
1084 | */ |
1085 | pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len); |
1086 | |
1087 | if (!pkt) |
1088 | goto out; |
1089 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); |
1090 | |
1091 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1092 | |
1093 | /* Discard the rest of the inbound packet. */ |
1094 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
1095 | |
1096 | out: |
1097 | /* Even if there is no memory, treat as a failure so |
1098 | * the packet will get dropped. |
1099 | */ |
1100 | return 0; |
1101 | } |
1102 | |
1103 | /* A restart is occurring, check to make sure no new addresses |
1104 | * are being added as we may be under a takeover attack. |
1105 | */ |
1106 | static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, |
1107 | const struct sctp_association *asoc, |
1108 | struct sctp_chunk *init, |
1109 | sctp_cmd_seq_t *commands) |
1110 | { |
1111 | struct sctp_transport *new_addr, *addr; |
1112 | struct list_head *pos, *pos2; |
1113 | int found; |
1114 | |
1115 | /* Implementor's Guide - Sectin 5.2.2 |
1116 | * ... |
1117 | * Before responding the endpoint MUST check to see if the |
1118 | * unexpected INIT adds new addresses to the association. If new |
1119 | * addresses are added to the association, the endpoint MUST respond |
1120 | * with an ABORT.. |
1121 | */ |
1122 | |
1123 | /* Search through all current addresses and make sure |
1124 | * we aren't adding any new ones. |
1125 | */ |
1126 | new_addr = NULL; |
1127 | found = 0; |
1128 | |
1129 | list_for_each(pos, &new_asoc->peer.transport_addr_list) { |
1130 | new_addr = list_entry(pos, struct sctp_transport, transports); |
1131 | found = 0; |
1132 | list_for_each(pos2, &asoc->peer.transport_addr_list) { |
1133 | addr = list_entry(pos2, struct sctp_transport, |
1134 | transports); |
1135 | if (sctp_cmp_addr_exact(&new_addr->ipaddr, |
1136 | &addr->ipaddr)) { |
1137 | found = 1; |
1138 | break; |
1139 | } |
1140 | } |
1141 | if (!found) |
1142 | break; |
1143 | } |
1144 | |
1145 | /* If a new address was added, ABORT the sender. */ |
1146 | if (!found && new_addr) { |
1147 | sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands); |
1148 | } |
1149 | |
1150 | /* Return success if all addresses were found. */ |
1151 | return found; |
1152 | } |
1153 | |
1154 | /* Populate the verification/tie tags based on overlapping INIT |
1155 | * scenario. |
1156 | * |
1157 | * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. |
1158 | */ |
1159 | static void sctp_tietags_populate(struct sctp_association *new_asoc, |
1160 | const struct sctp_association *asoc) |
1161 | { |
1162 | switch (asoc->state) { |
1163 | |
1164 | /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ |
1165 | |
1166 | case SCTP_STATE_COOKIE_WAIT: |
1167 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
1168 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1169 | new_asoc->c.peer_ttag = 0; |
1170 | break; |
1171 | |
1172 | case SCTP_STATE_COOKIE_ECHOED: |
1173 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
1174 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1175 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
1176 | break; |
1177 | |
1178 | /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, |
1179 | * COOKIE-WAIT and SHUTDOWN-ACK-SENT |
1180 | */ |
1181 | default: |
1182 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
1183 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
1184 | break; |
1185 | }; |
1186 | |
1187 | /* Other parameters for the endpoint SHOULD be copied from the |
1188 | * existing parameters of the association (e.g. number of |
1189 | * outbound streams) into the INIT ACK and cookie. |
1190 | */ |
1191 | new_asoc->rwnd = asoc->rwnd; |
1192 | new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; |
1193 | new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; |
1194 | new_asoc->c.initial_tsn = asoc->c.initial_tsn; |
1195 | } |
1196 | |
1197 | /* |
1198 | * Compare vtag/tietag values to determine unexpected COOKIE-ECHO |
1199 | * handling action. |
1200 | * |
1201 | * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. |
1202 | * |
1203 | * Returns value representing action to be taken. These action values |
1204 | * correspond to Action/Description values in RFC 2960, Table 2. |
1205 | */ |
1206 | static char sctp_tietags_compare(struct sctp_association *new_asoc, |
1207 | const struct sctp_association *asoc) |
1208 | { |
1209 | /* In this case, the peer may have restarted. */ |
1210 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
1211 | (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && |
1212 | (asoc->c.my_vtag == new_asoc->c.my_ttag) && |
1213 | (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) |
1214 | return 'A'; |
1215 | |
1216 | /* Collision case B. */ |
1217 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
1218 | ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || |
1219 | (0 == asoc->c.peer_vtag))) { |
1220 | return 'B'; |
1221 | } |
1222 | |
1223 | /* Collision case D. */ |
1224 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
1225 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) |
1226 | return 'D'; |
1227 | |
1228 | /* Collision case C. */ |
1229 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
1230 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && |
1231 | (0 == new_asoc->c.my_ttag) && |
1232 | (0 == new_asoc->c.peer_ttag)) |
1233 | return 'C'; |
1234 | |
1235 | /* No match to any of the special cases; discard this packet. */ |
1236 | return 'E'; |
1237 | } |
1238 | |
1239 | /* Common helper routine for both duplicate and simulataneous INIT |
1240 | * chunk handling. |
1241 | */ |
1242 | static sctp_disposition_t sctp_sf_do_unexpected_init( |
1243 | const struct sctp_endpoint *ep, |
1244 | const struct sctp_association *asoc, |
1245 | const sctp_subtype_t type, |
1246 | void *arg, sctp_cmd_seq_t *commands) |
1247 | { |
1248 | sctp_disposition_t retval; |
1249 | struct sctp_chunk *chunk = arg; |
1250 | struct sctp_chunk *repl; |
1251 | struct sctp_association *new_asoc; |
1252 | struct sctp_chunk *err_chunk; |
1253 | struct sctp_packet *packet; |
1254 | sctp_unrecognized_param_t *unk_param; |
1255 | int len; |
1256 | |
1257 | /* 6.10 Bundling |
1258 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
1259 | * SHUTDOWN COMPLETE with any other chunks. |
1260 | * |
1261 | * IG Section 2.11.2 |
1262 | * Furthermore, we require that the receiver of an INIT chunk MUST |
1263 | * enforce these rules by silently discarding an arriving packet |
1264 | * with an INIT chunk that is bundled with other chunks. |
1265 | */ |
1266 | if (!chunk->singleton) |
1267 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1268 | |
1269 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
1270 | * Tag. |
1271 | */ |
1272 | if (chunk->sctp_hdr->vtag != 0) |
1273 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
1274 | |
1275 | /* Make sure that the INIT chunk has a valid length. |
1276 | * In this case, we generate a protocol violation since we have |
1277 | * an association established. |
1278 | */ |
1279 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
1280 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
1281 | commands); |
1282 | /* Grab the INIT header. */ |
1283 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
1284 | |
1285 | /* Tag the variable length parameters. */ |
1286 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
1287 | |
1288 | /* Verify the INIT chunk before processing it. */ |
1289 | err_chunk = NULL; |
1290 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
1291 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
1292 | &err_chunk)) { |
1293 | /* This chunk contains fatal error. It is to be discarded. |
1294 | * Send an ABORT, with causes if there is any. |
1295 | */ |
1296 | if (err_chunk) { |
1297 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
1298 | (__u8 *)(err_chunk->chunk_hdr) + |
1299 | sizeof(sctp_chunkhdr_t), |
1300 | ntohs(err_chunk->chunk_hdr->length) - |
1301 | sizeof(sctp_chunkhdr_t)); |
1302 | |
1303 | if (packet) { |
1304 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
1305 | SCTP_PACKET(packet)); |
1306 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
1307 | retval = SCTP_DISPOSITION_CONSUME; |
1308 | } else { |
1309 | retval = SCTP_DISPOSITION_NOMEM; |
1310 | } |
1311 | goto cleanup; |
1312 | } else { |
1313 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, |
1314 | commands); |
1315 | } |
1316 | } |
1317 | |
1318 | /* |
1319 | * Other parameters for the endpoint SHOULD be copied from the |
1320 | * existing parameters of the association (e.g. number of |
1321 | * outbound streams) into the INIT ACK and cookie. |
1322 | * FIXME: We are copying parameters from the endpoint not the |
1323 | * association. |
1324 | */ |
1325 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
1326 | if (!new_asoc) |
1327 | goto nomem; |
1328 | |
1329 | /* In the outbound INIT ACK the endpoint MUST copy its current |
1330 | * Verification Tag and Peers Verification tag into a reserved |
1331 | * place (local tie-tag and per tie-tag) within the state cookie. |
1332 | */ |
1333 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
1334 | sctp_source(chunk), |
1335 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
1336 | GFP_ATOMIC)) { |
1337 | retval = SCTP_DISPOSITION_NOMEM; |
1338 | goto nomem_init; |
1339 | } |
1340 | |
1341 | /* Make sure no new addresses are being added during the |
1342 | * restart. Do not do this check for COOKIE-WAIT state, |
1343 | * since there are no peer addresses to check against. |
1344 | * Upon return an ABORT will have been sent if needed. |
1345 | */ |
1346 | if (!sctp_state(asoc, COOKIE_WAIT)) { |
1347 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, |
1348 | commands)) { |
1349 | retval = SCTP_DISPOSITION_CONSUME; |
1350 | goto cleanup_asoc; |
1351 | } |
1352 | } |
1353 | |
1354 | sctp_tietags_populate(new_asoc, asoc); |
1355 | |
1356 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
1357 | |
1358 | /* If there are errors need to be reported for unknown parameters, |
1359 | * make sure to reserve enough room in the INIT ACK for them. |
1360 | */ |
1361 | len = 0; |
1362 | if (err_chunk) { |
1363 | len = ntohs(err_chunk->chunk_hdr->length) - |
1364 | sizeof(sctp_chunkhdr_t); |
1365 | } |
1366 | |
1367 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) |
1368 | goto nomem; |
1369 | |
1370 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
1371 | if (!repl) |
1372 | goto nomem; |
1373 | |
1374 | /* If there are errors need to be reported for unknown parameters, |
1375 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
1376 | * parameter. |
1377 | */ |
1378 | if (err_chunk) { |
1379 | /* Get the "Unrecognized parameter" parameter(s) out of the |
1380 | * ERROR chunk generated by sctp_verify_init(). Since the |
1381 | * error cause code for "unknown parameter" and the |
1382 | * "Unrecognized parameter" type is the same, we can |
1383 | * construct the parameters in INIT ACK by copying the |
1384 | * ERROR causes over. |
1385 | */ |
1386 | unk_param = (sctp_unrecognized_param_t *) |
1387 | ((__u8 *)(err_chunk->chunk_hdr) + |
1388 | sizeof(sctp_chunkhdr_t)); |
1389 | /* Replace the cause code with the "Unrecognized parameter" |
1390 | * parameter type. |
1391 | */ |
1392 | sctp_addto_chunk(repl, len, unk_param); |
1393 | } |
1394 | |
1395 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
1396 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1397 | |
1398 | /* |
1399 | * Note: After sending out INIT ACK with the State Cookie parameter, |
1400 | * "Z" MUST NOT allocate any resources for this new association. |
1401 | * Otherwise, "Z" will be vulnerable to resource attacks. |
1402 | */ |
1403 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
1404 | retval = SCTP_DISPOSITION_CONSUME; |
1405 | |
1406 | cleanup: |
1407 | if (err_chunk) |
1408 | sctp_chunk_free(err_chunk); |
1409 | return retval; |
1410 | nomem: |
1411 | retval = SCTP_DISPOSITION_NOMEM; |
1412 | goto cleanup; |
1413 | nomem_init: |
1414 | cleanup_asoc: |
1415 | sctp_association_free(new_asoc); |
1416 | goto cleanup; |
1417 | } |
1418 | |
1419 | /* |
1420 | * Handle simultanous INIT. |
1421 | * This means we started an INIT and then we got an INIT request from |
1422 | * our peer. |
1423 | * |
1424 | * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) |
1425 | * This usually indicates an initialization collision, i.e., each |
1426 | * endpoint is attempting, at about the same time, to establish an |
1427 | * association with the other endpoint. |
1428 | * |
1429 | * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an |
1430 | * endpoint MUST respond with an INIT ACK using the same parameters it |
1431 | * sent in its original INIT chunk (including its Verification Tag, |
1432 | * unchanged). These original parameters are combined with those from the |
1433 | * newly received INIT chunk. The endpoint shall also generate a State |
1434 | * Cookie with the INIT ACK. The endpoint uses the parameters sent in its |
1435 | * INIT to calculate the State Cookie. |
1436 | * |
1437 | * After that, the endpoint MUST NOT change its state, the T1-init |
1438 | * timer shall be left running and the corresponding TCB MUST NOT be |
1439 | * destroyed. The normal procedures for handling State Cookies when |
1440 | * a TCB exists will resolve the duplicate INITs to a single association. |
1441 | * |
1442 | * For an endpoint that is in the COOKIE-ECHOED state it MUST populate |
1443 | * its Tie-Tags with the Tag information of itself and its peer (see |
1444 | * section 5.2.2 for a description of the Tie-Tags). |
1445 | * |
1446 | * Verification Tag: Not explicit, but an INIT can not have a valid |
1447 | * verification tag, so we skip the check. |
1448 | * |
1449 | * Inputs |
1450 | * (endpoint, asoc, chunk) |
1451 | * |
1452 | * Outputs |
1453 | * (asoc, reply_msg, msg_up, timers, counters) |
1454 | * |
1455 | * The return value is the disposition of the chunk. |
1456 | */ |
1457 | sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep, |
1458 | const struct sctp_association *asoc, |
1459 | const sctp_subtype_t type, |
1460 | void *arg, |
1461 | sctp_cmd_seq_t *commands) |
1462 | { |
1463 | /* Call helper to do the real work for both simulataneous and |
1464 | * duplicate INIT chunk handling. |
1465 | */ |
1466 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); |
1467 | } |
1468 | |
1469 | /* |
1470 | * Handle duplicated INIT messages. These are usually delayed |
1471 | * restransmissions. |
1472 | * |
1473 | * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, |
1474 | * COOKIE-ECHOED and COOKIE-WAIT |
1475 | * |
1476 | * Unless otherwise stated, upon reception of an unexpected INIT for |
1477 | * this association, the endpoint shall generate an INIT ACK with a |
1478 | * State Cookie. In the outbound INIT ACK the endpoint MUST copy its |
1479 | * current Verification Tag and peer's Verification Tag into a reserved |
1480 | * place within the state cookie. We shall refer to these locations as |
1481 | * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet |
1482 | * containing this INIT ACK MUST carry a Verification Tag value equal to |
1483 | * the Initiation Tag found in the unexpected INIT. And the INIT ACK |
1484 | * MUST contain a new Initiation Tag (randomly generated see Section |
1485 | * 5.3.1). Other parameters for the endpoint SHOULD be copied from the |
1486 | * existing parameters of the association (e.g. number of outbound |
1487 | * streams) into the INIT ACK and cookie. |
1488 | * |
1489 | * After sending out the INIT ACK, the endpoint shall take no further |
1490 | * actions, i.e., the existing association, including its current state, |
1491 | * and the corresponding TCB MUST NOT be changed. |
1492 | * |
1493 | * Note: Only when a TCB exists and the association is not in a COOKIE- |
1494 | * WAIT state are the Tie-Tags populated. For a normal association INIT |
1495 | * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be |
1496 | * set to 0 (indicating that no previous TCB existed). The INIT ACK and |
1497 | * State Cookie are populated as specified in section 5.2.1. |
1498 | * |
1499 | * Verification Tag: Not specified, but an INIT has no way of knowing |
1500 | * what the verification tag could be, so we ignore it. |
1501 | * |
1502 | * Inputs |
1503 | * (endpoint, asoc, chunk) |
1504 | * |
1505 | * Outputs |
1506 | * (asoc, reply_msg, msg_up, timers, counters) |
1507 | * |
1508 | * The return value is the disposition of the chunk. |
1509 | */ |
1510 | sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep, |
1511 | const struct sctp_association *asoc, |
1512 | const sctp_subtype_t type, |
1513 | void *arg, |
1514 | sctp_cmd_seq_t *commands) |
1515 | { |
1516 | /* Call helper to do the real work for both simulataneous and |
1517 | * duplicate INIT chunk handling. |
1518 | */ |
1519 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); |
1520 | } |
1521 | |
1522 | |
1523 | |
1524 | /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') |
1525 | * |
1526 | * Section 5.2.4 |
1527 | * A) In this case, the peer may have restarted. |
1528 | */ |
1529 | static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep, |
1530 | const struct sctp_association *asoc, |
1531 | struct sctp_chunk *chunk, |
1532 | sctp_cmd_seq_t *commands, |
1533 | struct sctp_association *new_asoc) |
1534 | { |
1535 | sctp_init_chunk_t *peer_init; |
1536 | struct sctp_ulpevent *ev; |
1537 | struct sctp_chunk *repl; |
1538 | struct sctp_chunk *err; |
1539 | sctp_disposition_t disposition; |
1540 | |
1541 | /* new_asoc is a brand-new association, so these are not yet |
1542 | * side effects--it is safe to run them here. |
1543 | */ |
1544 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
1545 | |
1546 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
1547 | sctp_source(chunk), peer_init, |
1548 | GFP_ATOMIC)) |
1549 | goto nomem; |
1550 | |
1551 | /* Make sure no new addresses are being added during the |
1552 | * restart. Though this is a pretty complicated attack |
1553 | * since you'd have to get inside the cookie. |
1554 | */ |
1555 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) { |
1556 | return SCTP_DISPOSITION_CONSUME; |
1557 | } |
1558 | |
1559 | /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes |
1560 | * the peer has restarted (Action A), it MUST NOT setup a new |
1561 | * association but instead resend the SHUTDOWN ACK and send an ERROR |
1562 | * chunk with a "Cookie Received while Shutting Down" error cause to |
1563 | * its peer. |
1564 | */ |
1565 | if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { |
1566 | disposition = sctp_sf_do_9_2_reshutack(ep, asoc, |
1567 | SCTP_ST_CHUNK(chunk->chunk_hdr->type), |
1568 | chunk, commands); |
1569 | if (SCTP_DISPOSITION_NOMEM == disposition) |
1570 | goto nomem; |
1571 | |
1572 | err = sctp_make_op_error(asoc, chunk, |
1573 | SCTP_ERROR_COOKIE_IN_SHUTDOWN, |
1574 | NULL, 0); |
1575 | if (err) |
1576 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
1577 | SCTP_CHUNK(err)); |
1578 | |
1579 | return SCTP_DISPOSITION_CONSUME; |
1580 | } |
1581 | |
1582 | /* For now, fail any unsent/unacked data. Consider the optional |
1583 | * choice of resending of this data. |
1584 | */ |
1585 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); |
1586 | |
1587 | /* Update the content of current association. */ |
1588 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
1589 | |
1590 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1591 | if (!repl) |
1592 | goto nomem; |
1593 | |
1594 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1595 | |
1596 | /* Report association restart to upper layer. */ |
1597 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, |
1598 | new_asoc->c.sinit_num_ostreams, |
1599 | new_asoc->c.sinit_max_instreams, |
1600 | GFP_ATOMIC); |
1601 | if (!ev) |
1602 | goto nomem_ev; |
1603 | |
1604 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
1605 | return SCTP_DISPOSITION_CONSUME; |
1606 | |
1607 | nomem_ev: |
1608 | sctp_chunk_free(repl); |
1609 | nomem: |
1610 | return SCTP_DISPOSITION_NOMEM; |
1611 | } |
1612 | |
1613 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') |
1614 | * |
1615 | * Section 5.2.4 |
1616 | * B) In this case, both sides may be attempting to start an association |
1617 | * at about the same time but the peer endpoint started its INIT |
1618 | * after responding to the local endpoint's INIT |
1619 | */ |
1620 | /* This case represents an initialization collision. */ |
1621 | static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep, |
1622 | const struct sctp_association *asoc, |
1623 | struct sctp_chunk *chunk, |
1624 | sctp_cmd_seq_t *commands, |
1625 | struct sctp_association *new_asoc) |
1626 | { |
1627 | sctp_init_chunk_t *peer_init; |
1628 | struct sctp_ulpevent *ev; |
1629 | struct sctp_chunk *repl; |
1630 | |
1631 | /* new_asoc is a brand-new association, so these are not yet |
1632 | * side effects--it is safe to run them here. |
1633 | */ |
1634 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
1635 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
1636 | sctp_source(chunk), peer_init, |
1637 | GFP_ATOMIC)) |
1638 | goto nomem; |
1639 | |
1640 | /* Update the content of current association. */ |
1641 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
1642 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
1643 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
1644 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
1645 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
1646 | |
1647 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1648 | if (!repl) |
1649 | goto nomem; |
1650 | |
1651 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1652 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
1653 | |
1654 | /* RFC 2960 5.1 Normal Establishment of an Association |
1655 | * |
1656 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
1657 | * send the Communication Up notification to the SCTP user |
1658 | * upon reception of a valid COOKIE ECHO chunk. |
1659 | */ |
1660 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0, |
1661 | new_asoc->c.sinit_num_ostreams, |
1662 | new_asoc->c.sinit_max_instreams, |
1663 | GFP_ATOMIC); |
1664 | if (!ev) |
1665 | goto nomem_ev; |
1666 | |
1667 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
1668 | |
1669 | /* Sockets API Draft Section 5.3.1.6 |
1670 | * When a peer sends a Adaption Layer Indication parameter , SCTP |
1671 | * delivers this notification to inform the application that of the |
1672 | * peers requested adaption layer. |
1673 | */ |
1674 | if (asoc->peer.adaption_ind) { |
1675 | ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC); |
1676 | if (!ev) |
1677 | goto nomem_ev; |
1678 | |
1679 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
1680 | SCTP_ULPEVENT(ev)); |
1681 | } |
1682 | |
1683 | return SCTP_DISPOSITION_CONSUME; |
1684 | |
1685 | nomem_ev: |
1686 | sctp_chunk_free(repl); |
1687 | nomem: |
1688 | return SCTP_DISPOSITION_NOMEM; |
1689 | } |
1690 | |
1691 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') |
1692 | * |
1693 | * Section 5.2.4 |
1694 | * C) In this case, the local endpoint's cookie has arrived late. |
1695 | * Before it arrived, the local endpoint sent an INIT and received an |
1696 | * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag |
1697 | * but a new tag of its own. |
1698 | */ |
1699 | /* This case represents an initialization collision. */ |
1700 | static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep, |
1701 | const struct sctp_association *asoc, |
1702 | struct sctp_chunk *chunk, |
1703 | sctp_cmd_seq_t *commands, |
1704 | struct sctp_association *new_asoc) |
1705 | { |
1706 | /* The cookie should be silently discarded. |
1707 | * The endpoint SHOULD NOT change states and should leave |
1708 | * any timers running. |
1709 | */ |
1710 | return SCTP_DISPOSITION_DISCARD; |
1711 | } |
1712 | |
1713 | /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') |
1714 | * |
1715 | * Section 5.2.4 |
1716 | * |
1717 | * D) When both local and remote tags match the endpoint should always |
1718 | * enter the ESTABLISHED state, if it has not already done so. |
1719 | */ |
1720 | /* This case represents an initialization collision. */ |
1721 | static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep, |
1722 | const struct sctp_association *asoc, |
1723 | struct sctp_chunk *chunk, |
1724 | sctp_cmd_seq_t *commands, |
1725 | struct sctp_association *new_asoc) |
1726 | { |
1727 | struct sctp_ulpevent *ev = NULL; |
1728 | struct sctp_chunk *repl; |
1729 | |
1730 | /* Clarification from Implementor's Guide: |
1731 | * D) When both local and remote tags match the endpoint should |
1732 | * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. |
1733 | * It should stop any cookie timer that may be running and send |
1734 | * a COOKIE ACK. |
1735 | */ |
1736 | |
1737 | /* Don't accidentally move back into established state. */ |
1738 | if (asoc->state < SCTP_STATE_ESTABLISHED) { |
1739 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1740 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
1741 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
1742 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
1743 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
1744 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, |
1745 | SCTP_NULL()); |
1746 | |
1747 | /* RFC 2960 5.1 Normal Establishment of an Association |
1748 | * |
1749 | * D) IMPLEMENTATION NOTE: An implementation may choose |
1750 | * to send the Communication Up notification to the |
1751 | * SCTP user upon reception of a valid COOKIE |
1752 | * ECHO chunk. |
1753 | */ |
1754 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, |
1755 | SCTP_COMM_UP, 0, |
1756 | new_asoc->c.sinit_num_ostreams, |
1757 | new_asoc->c.sinit_max_instreams, |
1758 | GFP_ATOMIC); |
1759 | if (!ev) |
1760 | goto nomem; |
1761 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
1762 | SCTP_ULPEVENT(ev)); |
1763 | |
1764 | /* Sockets API Draft Section 5.3.1.6 |
1765 | * When a peer sends a Adaption Layer Indication parameter, |
1766 | * SCTP delivers this notification to inform the application |
1767 | * that of the peers requested adaption layer. |
1768 | */ |
1769 | if (new_asoc->peer.adaption_ind) { |
1770 | ev = sctp_ulpevent_make_adaption_indication(new_asoc, |
1771 | GFP_ATOMIC); |
1772 | if (!ev) |
1773 | goto nomem; |
1774 | |
1775 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
1776 | SCTP_ULPEVENT(ev)); |
1777 | } |
1778 | } |
1779 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
1780 | |
1781 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
1782 | if (!repl) |
1783 | goto nomem; |
1784 | |
1785 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
1786 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
1787 | |
1788 | return SCTP_DISPOSITION_CONSUME; |
1789 | |
1790 | nomem: |
1791 | if (ev) |
1792 | sctp_ulpevent_free(ev); |
1793 | return SCTP_DISPOSITION_NOMEM; |
1794 | } |
1795 | |
1796 | /* |
1797 | * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying |
1798 | * chunk was retransmitted and then delayed in the network. |
1799 | * |
1800 | * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists |
1801 | * |
1802 | * Verification Tag: None. Do cookie validation. |
1803 | * |
1804 | * Inputs |
1805 | * (endpoint, asoc, chunk) |
1806 | * |
1807 | * Outputs |
1808 | * (asoc, reply_msg, msg_up, timers, counters) |
1809 | * |
1810 | * The return value is the disposition of the chunk. |
1811 | */ |
1812 | sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep, |
1813 | const struct sctp_association *asoc, |
1814 | const sctp_subtype_t type, |
1815 | void *arg, |
1816 | sctp_cmd_seq_t *commands) |
1817 | { |
1818 | sctp_disposition_t retval; |
1819 | struct sctp_chunk *chunk = arg; |
1820 | struct sctp_association *new_asoc; |
1821 | int error = 0; |
1822 | char action; |
1823 | struct sctp_chunk *err_chk_p; |
1824 | |
1825 | /* Make sure that the chunk has a valid length from the protocol |
1826 | * perspective. In this case check to make sure we have at least |
1827 | * enough for the chunk header. Cookie length verification is |
1828 | * done later. |
1829 | */ |
1830 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
1831 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
1832 | commands); |
1833 | |
1834 | /* "Decode" the chunk. We have no optional parameters so we |
1835 | * are in good shape. |
1836 | */ |
1837 | chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; |
1838 | skb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
1839 | sizeof(sctp_chunkhdr_t)); |
1840 | |
1841 | /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie |
1842 | * of a duplicate COOKIE ECHO match the Verification Tags of the |
1843 | * current association, consider the State Cookie valid even if |
1844 | * the lifespan is exceeded. |
1845 | */ |
1846 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
1847 | &err_chk_p); |
1848 | |
1849 | /* FIXME: |
1850 | * If the re-build failed, what is the proper error path |
1851 | * from here? |
1852 | * |
1853 | * [We should abort the association. --piggy] |
1854 | */ |
1855 | if (!new_asoc) { |
1856 | /* FIXME: Several errors are possible. A bad cookie should |
1857 | * be silently discarded, but think about logging it too. |
1858 | */ |
1859 | switch (error) { |
1860 | case -SCTP_IERROR_NOMEM: |
1861 | goto nomem; |
1862 | |
1863 | case -SCTP_IERROR_STALE_COOKIE: |
1864 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, |
1865 | err_chk_p); |
1866 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1867 | case -SCTP_IERROR_BAD_SIG: |
1868 | default: |
1869 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1870 | }; |
1871 | } |
1872 | |
1873 | /* Compare the tie_tag in cookie with the verification tag of |
1874 | * current association. |
1875 | */ |
1876 | action = sctp_tietags_compare(new_asoc, asoc); |
1877 | |
1878 | switch (action) { |
1879 | case 'A': /* Association restart. */ |
1880 | retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands, |
1881 | new_asoc); |
1882 | break; |
1883 | |
1884 | case 'B': /* Collision case B. */ |
1885 | retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands, |
1886 | new_asoc); |
1887 | break; |
1888 | |
1889 | case 'C': /* Collision case C. */ |
1890 | retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands, |
1891 | new_asoc); |
1892 | break; |
1893 | |
1894 | case 'D': /* Collision case D. */ |
1895 | retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands, |
1896 | new_asoc); |
1897 | break; |
1898 | |
1899 | default: /* Discard packet for all others. */ |
1900 | retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1901 | break; |
1902 | }; |
1903 | |
1904 | /* Delete the tempory new association. */ |
1905 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
1906 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
1907 | |
1908 | return retval; |
1909 | |
1910 | nomem: |
1911 | return SCTP_DISPOSITION_NOMEM; |
1912 | } |
1913 | |
1914 | /* |
1915 | * Process an ABORT. (SHUTDOWN-PENDING state) |
1916 | * |
1917 | * See sctp_sf_do_9_1_abort(). |
1918 | */ |
1919 | sctp_disposition_t sctp_sf_shutdown_pending_abort( |
1920 | const struct sctp_endpoint *ep, |
1921 | const struct sctp_association *asoc, |
1922 | const sctp_subtype_t type, |
1923 | void *arg, |
1924 | sctp_cmd_seq_t *commands) |
1925 | { |
1926 | struct sctp_chunk *chunk = arg; |
1927 | |
1928 | if (!sctp_vtag_verify_either(chunk, asoc)) |
1929 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1930 | |
1931 | /* Make sure that the ABORT chunk has a valid length. |
1932 | * Since this is an ABORT chunk, we have to discard it |
1933 | * because of the following text: |
1934 | * RFC 2960, Section 3.3.7 |
1935 | * If an endpoint receives an ABORT with a format error or for an |
1936 | * association that doesn't exist, it MUST silently discard it. |
1937 | * Becasue the length is "invalid", we can't really discard just |
1938 | * as we do not know its true length. So, to be safe, discard the |
1939 | * packet. |
1940 | */ |
1941 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
1942 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1943 | |
1944 | /* Stop the T5-shutdown guard timer. */ |
1945 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1946 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
1947 | |
1948 | return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); |
1949 | } |
1950 | |
1951 | /* |
1952 | * Process an ABORT. (SHUTDOWN-SENT state) |
1953 | * |
1954 | * See sctp_sf_do_9_1_abort(). |
1955 | */ |
1956 | sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep, |
1957 | const struct sctp_association *asoc, |
1958 | const sctp_subtype_t type, |
1959 | void *arg, |
1960 | sctp_cmd_seq_t *commands) |
1961 | { |
1962 | struct sctp_chunk *chunk = arg; |
1963 | |
1964 | if (!sctp_vtag_verify_either(chunk, asoc)) |
1965 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1966 | |
1967 | /* Make sure that the ABORT chunk has a valid length. |
1968 | * Since this is an ABORT chunk, we have to discard it |
1969 | * because of the following text: |
1970 | * RFC 2960, Section 3.3.7 |
1971 | * If an endpoint receives an ABORT with a format error or for an |
1972 | * association that doesn't exist, it MUST silently discard it. |
1973 | * Becasue the length is "invalid", we can't really discard just |
1974 | * as we do not know its true length. So, to be safe, discard the |
1975 | * packet. |
1976 | */ |
1977 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
1978 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
1979 | |
1980 | /* Stop the T2-shutdown timer. */ |
1981 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1982 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
1983 | |
1984 | /* Stop the T5-shutdown guard timer. */ |
1985 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
1986 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
1987 | |
1988 | return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); |
1989 | } |
1990 | |
1991 | /* |
1992 | * Process an ABORT. (SHUTDOWN-ACK-SENT state) |
1993 | * |
1994 | * See sctp_sf_do_9_1_abort(). |
1995 | */ |
1996 | sctp_disposition_t sctp_sf_shutdown_ack_sent_abort( |
1997 | const struct sctp_endpoint *ep, |
1998 | const struct sctp_association *asoc, |
1999 | const sctp_subtype_t type, |
2000 | void *arg, |
2001 | sctp_cmd_seq_t *commands) |
2002 | { |
2003 | /* The same T2 timer, so we should be able to use |
2004 | * common function with the SHUTDOWN-SENT state. |
2005 | */ |
2006 | return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands); |
2007 | } |
2008 | |
2009 | /* |
2010 | * Handle an Error received in COOKIE_ECHOED state. |
2011 | * |
2012 | * Only handle the error type of stale COOKIE Error, the other errors will |
2013 | * be ignored. |
2014 | * |
2015 | * Inputs |
2016 | * (endpoint, asoc, chunk) |
2017 | * |
2018 | * Outputs |
2019 | * (asoc, reply_msg, msg_up, timers, counters) |
2020 | * |
2021 | * The return value is the disposition of the chunk. |
2022 | */ |
2023 | sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep, |
2024 | const struct sctp_association *asoc, |
2025 | const sctp_subtype_t type, |
2026 | void *arg, |
2027 | sctp_cmd_seq_t *commands) |
2028 | { |
2029 | struct sctp_chunk *chunk = arg; |
2030 | sctp_errhdr_t *err; |
2031 | |
2032 | if (!sctp_vtag_verify(chunk, asoc)) |
2033 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2034 | |
2035 | /* Make sure that the ERROR chunk has a valid length. |
2036 | * The parameter walking depends on this as well. |
2037 | */ |
2038 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
2039 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2040 | commands); |
2041 | |
2042 | /* Process the error here */ |
2043 | /* FUTURE FIXME: When PR-SCTP related and other optional |
2044 | * parms are emitted, this will have to change to handle multiple |
2045 | * errors. |
2046 | */ |
2047 | sctp_walk_errors(err, chunk->chunk_hdr) { |
2048 | if (SCTP_ERROR_STALE_COOKIE == err->cause) |
2049 | return sctp_sf_do_5_2_6_stale(ep, asoc, type, |
2050 | arg, commands); |
2051 | } |
2052 | |
2053 | /* It is possible to have malformed error causes, and that |
2054 | * will cause us to end the walk early. However, since |
2055 | * we are discarding the packet, there should be no adverse |
2056 | * affects. |
2057 | */ |
2058 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2059 | } |
2060 | |
2061 | /* |
2062 | * Handle a Stale COOKIE Error |
2063 | * |
2064 | * Section: 5.2.6 Handle Stale COOKIE Error |
2065 | * If the association is in the COOKIE-ECHOED state, the endpoint may elect |
2066 | * one of the following three alternatives. |
2067 | * ... |
2068 | * 3) Send a new INIT chunk to the endpoint, adding a Cookie |
2069 | * Preservative parameter requesting an extension to the lifetime of |
2070 | * the State Cookie. When calculating the time extension, an |
2071 | * implementation SHOULD use the RTT information measured based on the |
2072 | * previous COOKIE ECHO / ERROR exchange, and should add no more |
2073 | * than 1 second beyond the measured RTT, due to long State Cookie |
2074 | * lifetimes making the endpoint more subject to a replay attack. |
2075 | * |
2076 | * Verification Tag: Not explicit, but safe to ignore. |
2077 | * |
2078 | * Inputs |
2079 | * (endpoint, asoc, chunk) |
2080 | * |
2081 | * Outputs |
2082 | * (asoc, reply_msg, msg_up, timers, counters) |
2083 | * |
2084 | * The return value is the disposition of the chunk. |
2085 | */ |
2086 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, |
2087 | const struct sctp_association *asoc, |
2088 | const sctp_subtype_t type, |
2089 | void *arg, |
2090 | sctp_cmd_seq_t *commands) |
2091 | { |
2092 | struct sctp_chunk *chunk = arg; |
2093 | time_t stale; |
2094 | sctp_cookie_preserve_param_t bht; |
2095 | sctp_errhdr_t *err; |
2096 | struct sctp_chunk *reply; |
2097 | struct sctp_bind_addr *bp; |
2098 | int attempts; |
2099 | |
2100 | attempts = asoc->counters[SCTP_COUNTER_INIT_ERROR] + 1; |
2101 | |
2102 | if (attempts >= asoc->max_init_attempts) { |
2103 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
2104 | SCTP_U32(SCTP_ERROR_STALE_COOKIE)); |
2105 | return SCTP_DISPOSITION_DELETE_TCB; |
2106 | } |
2107 | |
2108 | err = (sctp_errhdr_t *)(chunk->skb->data); |
2109 | |
2110 | /* When calculating the time extension, an implementation |
2111 | * SHOULD use the RTT information measured based on the |
2112 | * previous COOKIE ECHO / ERROR exchange, and should add no |
2113 | * more than 1 second beyond the measured RTT, due to long |
2114 | * State Cookie lifetimes making the endpoint more subject to |
2115 | * a replay attack. |
2116 | * Measure of Staleness's unit is usec. (1/1000000 sec) |
2117 | * Suggested Cookie Life-span Increment's unit is msec. |
2118 | * (1/1000 sec) |
2119 | * In general, if you use the suggested cookie life, the value |
2120 | * found in the field of measure of staleness should be doubled |
2121 | * to give ample time to retransmit the new cookie and thus |
2122 | * yield a higher probability of success on the reattempt. |
2123 | */ |
2124 | stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t))); |
2125 | stale = (stale * 2) / 1000; |
2126 | |
2127 | bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; |
2128 | bht.param_hdr.length = htons(sizeof(bht)); |
2129 | bht.lifespan_increment = htonl(stale); |
2130 | |
2131 | /* Build that new INIT chunk. */ |
2132 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
2133 | reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); |
2134 | if (!reply) |
2135 | goto nomem; |
2136 | |
2137 | sctp_addto_chunk(reply, sizeof(bht), &bht); |
2138 | |
2139 | /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ |
2140 | sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); |
2141 | |
2142 | /* Stop pending T3-rtx and heartbeat timers */ |
2143 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
2144 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
2145 | |
2146 | /* Delete non-primary peer ip addresses since we are transitioning |
2147 | * back to the COOKIE-WAIT state |
2148 | */ |
2149 | sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); |
2150 | |
2151 | /* If we've sent any data bundled with COOKIE-ECHO we will need to |
2152 | * resend |
2153 | */ |
2154 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, |
2155 | SCTP_TRANSPORT(asoc->peer.primary_path)); |
2156 | |
2157 | /* Cast away the const modifier, as we want to just |
2158 | * rerun it through as a sideffect. |
2159 | */ |
2160 | sctp_add_cmd_sf(commands, SCTP_CMD_COUNTER_INC, |
2161 | SCTP_COUNTER(SCTP_COUNTER_INIT_ERROR)); |
2162 | |
2163 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2164 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
2165 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2166 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
2167 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
2168 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
2169 | |
2170 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
2171 | |
2172 | return SCTP_DISPOSITION_CONSUME; |
2173 | |
2174 | nomem: |
2175 | return SCTP_DISPOSITION_NOMEM; |
2176 | } |
2177 | |
2178 | /* |
2179 | * Process an ABORT. |
2180 | * |
2181 | * Section: 9.1 |
2182 | * After checking the Verification Tag, the receiving endpoint shall |
2183 | * remove the association from its record, and shall report the |
2184 | * termination to its upper layer. |
2185 | * |
2186 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
2187 | * B) Rules for packet carrying ABORT: |
2188 | * |
2189 | * - The endpoint shall always fill in the Verification Tag field of the |
2190 | * outbound packet with the destination endpoint's tag value if it |
2191 | * is known. |
2192 | * |
2193 | * - If the ABORT is sent in response to an OOTB packet, the endpoint |
2194 | * MUST follow the procedure described in Section 8.4. |
2195 | * |
2196 | * - The receiver MUST accept the packet if the Verification Tag |
2197 | * matches either its own tag, OR the tag of its peer. Otherwise, the |
2198 | * receiver MUST silently discard the packet and take no further |
2199 | * action. |
2200 | * |
2201 | * Inputs |
2202 | * (endpoint, asoc, chunk) |
2203 | * |
2204 | * Outputs |
2205 | * (asoc, reply_msg, msg_up, timers, counters) |
2206 | * |
2207 | * The return value is the disposition of the chunk. |
2208 | */ |
2209 | sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep, |
2210 | const struct sctp_association *asoc, |
2211 | const sctp_subtype_t type, |
2212 | void *arg, |
2213 | sctp_cmd_seq_t *commands) |
2214 | { |
2215 | struct sctp_chunk *chunk = arg; |
2216 | unsigned len; |
2217 | __u16 error = SCTP_ERROR_NO_ERROR; |
2218 | |
2219 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2220 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2221 | |
2222 | /* Make sure that the ABORT chunk has a valid length. |
2223 | * Since this is an ABORT chunk, we have to discard it |
2224 | * because of the following text: |
2225 | * RFC 2960, Section 3.3.7 |
2226 | * If an endpoint receives an ABORT with a format error or for an |
2227 | * association that doesn't exist, it MUST silently discard it. |
2228 | * Becasue the length is "invalid", we can't really discard just |
2229 | * as we do not know its true length. So, to be safe, discard the |
2230 | * packet. |
2231 | */ |
2232 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2233 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2234 | |
2235 | /* See if we have an error cause code in the chunk. */ |
2236 | len = ntohs(chunk->chunk_hdr->length); |
2237 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
2238 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
2239 | |
2240 | /* ASSOC_FAILED will DELETE_TCB. */ |
2241 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error)); |
2242 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
2243 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
2244 | |
2245 | return SCTP_DISPOSITION_ABORT; |
2246 | } |
2247 | |
2248 | /* |
2249 | * Process an ABORT. (COOKIE-WAIT state) |
2250 | * |
2251 | * See sctp_sf_do_9_1_abort() above. |
2252 | */ |
2253 | sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep, |
2254 | const struct sctp_association *asoc, |
2255 | const sctp_subtype_t type, |
2256 | void *arg, |
2257 | sctp_cmd_seq_t *commands) |
2258 | { |
2259 | struct sctp_chunk *chunk = arg; |
2260 | unsigned len; |
2261 | __u16 error = SCTP_ERROR_NO_ERROR; |
2262 | |
2263 | if (!sctp_vtag_verify_either(chunk, asoc)) |
2264 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2265 | |
2266 | /* Make sure that the ABORT chunk has a valid length. |
2267 | * Since this is an ABORT chunk, we have to discard it |
2268 | * because of the following text: |
2269 | * RFC 2960, Section 3.3.7 |
2270 | * If an endpoint receives an ABORT with a format error or for an |
2271 | * association that doesn't exist, it MUST silently discard it. |
2272 | * Becasue the length is "invalid", we can't really discard just |
2273 | * as we do not know its true length. So, to be safe, discard the |
2274 | * packet. |
2275 | */ |
2276 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
2277 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2278 | |
2279 | /* See if we have an error cause code in the chunk. */ |
2280 | len = ntohs(chunk->chunk_hdr->length); |
2281 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
2282 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
2283 | |
2284 | sctp_stop_t1_and_abort(commands, error); |
2285 | return SCTP_DISPOSITION_ABORT; |
2286 | } |
2287 | |
2288 | /* |
2289 | * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) |
2290 | */ |
2291 | sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep, |
2292 | const struct sctp_association *asoc, |
2293 | const sctp_subtype_t type, |
2294 | void *arg, |
2295 | sctp_cmd_seq_t *commands) |
2296 | { |
2297 | sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR); |
2298 | return SCTP_DISPOSITION_ABORT; |
2299 | } |
2300 | |
2301 | /* |
2302 | * Process an ABORT. (COOKIE-ECHOED state) |
2303 | */ |
2304 | sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep, |
2305 | const struct sctp_association *asoc, |
2306 | const sctp_subtype_t type, |
2307 | void *arg, |
2308 | sctp_cmd_seq_t *commands) |
2309 | { |
2310 | /* There is a single T1 timer, so we should be able to use |
2311 | * common function with the COOKIE-WAIT state. |
2312 | */ |
2313 | return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands); |
2314 | } |
2315 | |
2316 | /* |
2317 | * Stop T1 timer and abort association with "INIT failed". |
2318 | * |
2319 | * This is common code called by several sctp_sf_*_abort() functions above. |
2320 | */ |
2321 | void sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands, __u16 error) |
2322 | { |
2323 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2324 | SCTP_STATE(SCTP_STATE_CLOSED)); |
2325 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
2326 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
2327 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
2328 | /* CMD_INIT_FAILED will DELETE_TCB. */ |
2329 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
2330 | SCTP_U32(error)); |
2331 | } |
2332 | |
2333 | /* |
2334 | * sctp_sf_do_9_2_shut |
2335 | * |
2336 | * Section: 9.2 |
2337 | * Upon the reception of the SHUTDOWN, the peer endpoint shall |
2338 | * - enter the SHUTDOWN-RECEIVED state, |
2339 | * |
2340 | * - stop accepting new data from its SCTP user |
2341 | * |
2342 | * - verify, by checking the Cumulative TSN Ack field of the chunk, |
2343 | * that all its outstanding DATA chunks have been received by the |
2344 | * SHUTDOWN sender. |
2345 | * |
2346 | * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT |
2347 | * send a SHUTDOWN in response to a ULP request. And should discard |
2348 | * subsequent SHUTDOWN chunks. |
2349 | * |
2350 | * If there are still outstanding DATA chunks left, the SHUTDOWN |
2351 | * receiver shall continue to follow normal data transmission |
2352 | * procedures defined in Section 6 until all outstanding DATA chunks |
2353 | * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept |
2354 | * new data from its SCTP user. |
2355 | * |
2356 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2357 | * |
2358 | * Inputs |
2359 | * (endpoint, asoc, chunk) |
2360 | * |
2361 | * Outputs |
2362 | * (asoc, reply_msg, msg_up, timers, counters) |
2363 | * |
2364 | * The return value is the disposition of the chunk. |
2365 | */ |
2366 | sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep, |
2367 | const struct sctp_association *asoc, |
2368 | const sctp_subtype_t type, |
2369 | void *arg, |
2370 | sctp_cmd_seq_t *commands) |
2371 | { |
2372 | struct sctp_chunk *chunk = arg; |
2373 | sctp_shutdownhdr_t *sdh; |
2374 | sctp_disposition_t disposition; |
2375 | struct sctp_ulpevent *ev; |
2376 | |
2377 | if (!sctp_vtag_verify(chunk, asoc)) |
2378 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2379 | |
2380 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
2381 | if (!sctp_chunk_length_valid(chunk, |
2382 | sizeof(struct sctp_shutdown_chunk_t))) |
2383 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2384 | commands); |
2385 | |
2386 | /* Convert the elaborate header. */ |
2387 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; |
2388 | skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); |
2389 | chunk->subh.shutdown_hdr = sdh; |
2390 | |
2391 | /* Upon the reception of the SHUTDOWN, the peer endpoint shall |
2392 | * - enter the SHUTDOWN-RECEIVED state, |
2393 | * - stop accepting new data from its SCTP user |
2394 | * |
2395 | * [This is implicit in the new state.] |
2396 | */ |
2397 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
2398 | SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); |
2399 | disposition = SCTP_DISPOSITION_CONSUME; |
2400 | |
2401 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
2402 | disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type, |
2403 | arg, commands); |
2404 | } |
2405 | |
2406 | if (SCTP_DISPOSITION_NOMEM == disposition) |
2407 | goto out; |
2408 | |
2409 | /* - verify, by checking the Cumulative TSN Ack field of the |
2410 | * chunk, that all its outstanding DATA chunks have been |
2411 | * received by the SHUTDOWN sender. |
2412 | */ |
2413 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
2414 | SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack)); |
2415 | |
2416 | /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT |
2417 | * When a peer sends a SHUTDOWN, SCTP delivers this notification to |
2418 | * inform the application that it should cease sending data. |
2419 | */ |
2420 | ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); |
2421 | if (!ev) { |
2422 | disposition = SCTP_DISPOSITION_NOMEM; |
2423 | goto out; |
2424 | } |
2425 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
2426 | |
2427 | out: |
2428 | return disposition; |
2429 | } |
2430 | |
2431 | /* RFC 2960 9.2 |
2432 | * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk |
2433 | * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination |
2434 | * transport addresses (either in the IP addresses or in the INIT chunk) |
2435 | * that belong to this association, it should discard the INIT chunk and |
2436 | * retransmit the SHUTDOWN ACK chunk. |
2437 | */ |
2438 | sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep, |
2439 | const struct sctp_association *asoc, |
2440 | const sctp_subtype_t type, |
2441 | void *arg, |
2442 | sctp_cmd_seq_t *commands) |
2443 | { |
2444 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; |
2445 | struct sctp_chunk *reply; |
2446 | |
2447 | /* Since we are not going to really process this INIT, there |
2448 | * is no point in verifying chunk boundries. Just generate |
2449 | * the SHUTDOWN ACK. |
2450 | */ |
2451 | reply = sctp_make_shutdown_ack(asoc, chunk); |
2452 | if (NULL == reply) |
2453 | goto nomem; |
2454 | |
2455 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
2456 | * the T2-SHUTDOWN timer. |
2457 | */ |
2458 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
2459 | |
2460 | /* and restart the T2-shutdown timer. */ |
2461 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2462 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
2463 | |
2464 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
2465 | |
2466 | return SCTP_DISPOSITION_CONSUME; |
2467 | nomem: |
2468 | return SCTP_DISPOSITION_NOMEM; |
2469 | } |
2470 | |
2471 | /* |
2472 | * sctp_sf_do_ecn_cwr |
2473 | * |
2474 | * Section: Appendix A: Explicit Congestion Notification |
2475 | * |
2476 | * CWR: |
2477 | * |
2478 | * RFC 2481 details a specific bit for a sender to send in the header of |
2479 | * its next outbound TCP segment to indicate to its peer that it has |
2480 | * reduced its congestion window. This is termed the CWR bit. For |
2481 | * SCTP the same indication is made by including the CWR chunk. |
2482 | * This chunk contains one data element, i.e. the TSN number that |
2483 | * was sent in the ECNE chunk. This element represents the lowest |
2484 | * TSN number in the datagram that was originally marked with the |
2485 | * CE bit. |
2486 | * |
2487 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2488 | * Inputs |
2489 | * (endpoint, asoc, chunk) |
2490 | * |
2491 | * Outputs |
2492 | * (asoc, reply_msg, msg_up, timers, counters) |
2493 | * |
2494 | * The return value is the disposition of the chunk. |
2495 | */ |
2496 | sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep, |
2497 | const struct sctp_association *asoc, |
2498 | const sctp_subtype_t type, |
2499 | void *arg, |
2500 | sctp_cmd_seq_t *commands) |
2501 | { |
2502 | sctp_cwrhdr_t *cwr; |
2503 | struct sctp_chunk *chunk = arg; |
2504 | |
2505 | if (!sctp_vtag_verify(chunk, asoc)) |
2506 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2507 | |
2508 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
2509 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2510 | commands); |
2511 | |
2512 | cwr = (sctp_cwrhdr_t *) chunk->skb->data; |
2513 | skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t)); |
2514 | |
2515 | cwr->lowest_tsn = ntohl(cwr->lowest_tsn); |
2516 | |
2517 | /* Does this CWR ack the last sent congestion notification? */ |
2518 | if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) { |
2519 | /* Stop sending ECNE. */ |
2520 | sctp_add_cmd_sf(commands, |
2521 | SCTP_CMD_ECN_CWR, |
2522 | SCTP_U32(cwr->lowest_tsn)); |
2523 | } |
2524 | return SCTP_DISPOSITION_CONSUME; |
2525 | } |
2526 | |
2527 | /* |
2528 | * sctp_sf_do_ecne |
2529 | * |
2530 | * Section: Appendix A: Explicit Congestion Notification |
2531 | * |
2532 | * ECN-Echo |
2533 | * |
2534 | * RFC 2481 details a specific bit for a receiver to send back in its |
2535 | * TCP acknowledgements to notify the sender of the Congestion |
2536 | * Experienced (CE) bit having arrived from the network. For SCTP this |
2537 | * same indication is made by including the ECNE chunk. This chunk |
2538 | * contains one data element, i.e. the lowest TSN associated with the IP |
2539 | * datagram marked with the CE bit..... |
2540 | * |
2541 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2542 | * Inputs |
2543 | * (endpoint, asoc, chunk) |
2544 | * |
2545 | * Outputs |
2546 | * (asoc, reply_msg, msg_up, timers, counters) |
2547 | * |
2548 | * The return value is the disposition of the chunk. |
2549 | */ |
2550 | sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep, |
2551 | const struct sctp_association *asoc, |
2552 | const sctp_subtype_t type, |
2553 | void *arg, |
2554 | sctp_cmd_seq_t *commands) |
2555 | { |
2556 | sctp_ecnehdr_t *ecne; |
2557 | struct sctp_chunk *chunk = arg; |
2558 | |
2559 | if (!sctp_vtag_verify(chunk, asoc)) |
2560 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2561 | |
2562 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
2563 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2564 | commands); |
2565 | |
2566 | ecne = (sctp_ecnehdr_t *) chunk->skb->data; |
2567 | skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t)); |
2568 | |
2569 | /* If this is a newer ECNE than the last CWR packet we sent out */ |
2570 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, |
2571 | SCTP_U32(ntohl(ecne->lowest_tsn))); |
2572 | |
2573 | return SCTP_DISPOSITION_CONSUME; |
2574 | } |
2575 | |
2576 | /* |
2577 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
2578 | * |
2579 | * The SCTP endpoint MUST always acknowledge the reception of each valid |
2580 | * DATA chunk. |
2581 | * |
2582 | * The guidelines on delayed acknowledgement algorithm specified in |
2583 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
2584 | * acknowledgement SHOULD be generated for at least every second packet |
2585 | * (not every second DATA chunk) received, and SHOULD be generated within |
2586 | * 200 ms of the arrival of any unacknowledged DATA chunk. In some |
2587 | * situations it may be beneficial for an SCTP transmitter to be more |
2588 | * conservative than the algorithms detailed in this document allow. |
2589 | * However, an SCTP transmitter MUST NOT be more aggressive than the |
2590 | * following algorithms allow. |
2591 | * |
2592 | * A SCTP receiver MUST NOT generate more than one SACK for every |
2593 | * incoming packet, other than to update the offered window as the |
2594 | * receiving application consumes new data. |
2595 | * |
2596 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2597 | * |
2598 | * Inputs |
2599 | * (endpoint, asoc, chunk) |
2600 | * |
2601 | * Outputs |
2602 | * (asoc, reply_msg, msg_up, timers, counters) |
2603 | * |
2604 | * The return value is the disposition of the chunk. |
2605 | */ |
2606 | sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep, |
2607 | const struct sctp_association *asoc, |
2608 | const sctp_subtype_t type, |
2609 | void *arg, |
2610 | sctp_cmd_seq_t *commands) |
2611 | { |
2612 | struct sctp_chunk *chunk = arg; |
2613 | int error; |
2614 | |
2615 | if (!sctp_vtag_verify(chunk, asoc)) { |
2616 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
2617 | SCTP_NULL()); |
2618 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2619 | } |
2620 | |
2621 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
2622 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2623 | commands); |
2624 | |
2625 | error = sctp_eat_data(asoc, chunk, commands ); |
2626 | switch (error) { |
2627 | case SCTP_IERROR_NO_ERROR: |
2628 | break; |
2629 | case SCTP_IERROR_HIGH_TSN: |
2630 | case SCTP_IERROR_BAD_STREAM: |
2631 | goto discard_noforce; |
2632 | case SCTP_IERROR_DUP_TSN: |
2633 | case SCTP_IERROR_IGNORE_TSN: |
2634 | goto discard_force; |
2635 | case SCTP_IERROR_NO_DATA: |
2636 | goto consume; |
2637 | default: |
2638 | BUG(); |
2639 | } |
2640 | |
2641 | if (asoc->autoclose) { |
2642 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2643 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
2644 | } |
2645 | |
2646 | /* If this is the last chunk in a packet, we need to count it |
2647 | * toward sack generation. Note that we need to SACK every |
2648 | * OTHER packet containing data chunks, EVEN IF WE DISCARD |
2649 | * THEM. We elect to NOT generate SACK's if the chunk fails |
2650 | * the verification tag test. |
2651 | * |
2652 | * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
2653 | * |
2654 | * The SCTP endpoint MUST always acknowledge the reception of |
2655 | * each valid DATA chunk. |
2656 | * |
2657 | * The guidelines on delayed acknowledgement algorithm |
2658 | * specified in Section 4.2 of [RFC2581] SHOULD be followed. |
2659 | * Specifically, an acknowledgement SHOULD be generated for at |
2660 | * least every second packet (not every second DATA chunk) |
2661 | * received, and SHOULD be generated within 200 ms of the |
2662 | * arrival of any unacknowledged DATA chunk. In some |
2663 | * situations it may be beneficial for an SCTP transmitter to |
2664 | * be more conservative than the algorithms detailed in this |
2665 | * document allow. However, an SCTP transmitter MUST NOT be |
2666 | * more aggressive than the following algorithms allow. |
2667 | */ |
2668 | if (chunk->end_of_packet) { |
2669 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
2670 | |
2671 | /* Start the SACK timer. */ |
2672 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2673 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); |
2674 | } |
2675 | |
2676 | return SCTP_DISPOSITION_CONSUME; |
2677 | |
2678 | discard_force: |
2679 | /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
2680 | * |
2681 | * When a packet arrives with duplicate DATA chunk(s) and with |
2682 | * no new DATA chunk(s), the endpoint MUST immediately send a |
2683 | * SACK with no delay. If a packet arrives with duplicate |
2684 | * DATA chunk(s) bundled with new DATA chunks, the endpoint |
2685 | * MAY immediately send a SACK. Normally receipt of duplicate |
2686 | * DATA chunks will occur when the original SACK chunk was lost |
2687 | * and the peer's RTO has expired. The duplicate TSN number(s) |
2688 | * SHOULD be reported in the SACK as duplicate. |
2689 | */ |
2690 | /* In our case, we split the MAY SACK advice up whether or not |
2691 | * the last chunk is a duplicate.' |
2692 | */ |
2693 | if (chunk->end_of_packet) |
2694 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
2695 | return SCTP_DISPOSITION_DISCARD; |
2696 | |
2697 | discard_noforce: |
2698 | if (chunk->end_of_packet) { |
2699 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
2700 | |
2701 | /* Start the SACK timer. */ |
2702 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2703 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); |
2704 | } |
2705 | return SCTP_DISPOSITION_DISCARD; |
2706 | consume: |
2707 | return SCTP_DISPOSITION_CONSUME; |
2708 | |
2709 | } |
2710 | |
2711 | /* |
2712 | * sctp_sf_eat_data_fast_4_4 |
2713 | * |
2714 | * Section: 4 (4) |
2715 | * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received |
2716 | * DATA chunks without delay. |
2717 | * |
2718 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2719 | * Inputs |
2720 | * (endpoint, asoc, chunk) |
2721 | * |
2722 | * Outputs |
2723 | * (asoc, reply_msg, msg_up, timers, counters) |
2724 | * |
2725 | * The return value is the disposition of the chunk. |
2726 | */ |
2727 | sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep, |
2728 | const struct sctp_association *asoc, |
2729 | const sctp_subtype_t type, |
2730 | void *arg, |
2731 | sctp_cmd_seq_t *commands) |
2732 | { |
2733 | struct sctp_chunk *chunk = arg; |
2734 | int error; |
2735 | |
2736 | if (!sctp_vtag_verify(chunk, asoc)) { |
2737 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
2738 | SCTP_NULL()); |
2739 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2740 | } |
2741 | |
2742 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
2743 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2744 | commands); |
2745 | |
2746 | error = sctp_eat_data(asoc, chunk, commands ); |
2747 | switch (error) { |
2748 | case SCTP_IERROR_NO_ERROR: |
2749 | case SCTP_IERROR_HIGH_TSN: |
2750 | case SCTP_IERROR_DUP_TSN: |
2751 | case SCTP_IERROR_IGNORE_TSN: |
2752 | case SCTP_IERROR_BAD_STREAM: |
2753 | break; |
2754 | case SCTP_IERROR_NO_DATA: |
2755 | goto consume; |
2756 | default: |
2757 | BUG(); |
2758 | } |
2759 | |
2760 | /* Go a head and force a SACK, since we are shutting down. */ |
2761 | |
2762 | /* Implementor's Guide. |
2763 | * |
2764 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
2765 | * respond to each received packet containing one or more DATA chunk(s) |
2766 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
2767 | */ |
2768 | if (chunk->end_of_packet) { |
2769 | /* We must delay the chunk creation since the cumulative |
2770 | * TSN has not been updated yet. |
2771 | */ |
2772 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
2773 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
2774 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
2775 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
2776 | } |
2777 | |
2778 | consume: |
2779 | return SCTP_DISPOSITION_CONSUME; |
2780 | } |
2781 | |
2782 | /* |
2783 | * Section: 6.2 Processing a Received SACK |
2784 | * D) Any time a SACK arrives, the endpoint performs the following: |
2785 | * |
2786 | * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, |
2787 | * then drop the SACK. Since Cumulative TSN Ack is monotonically |
2788 | * increasing, a SACK whose Cumulative TSN Ack is less than the |
2789 | * Cumulative TSN Ack Point indicates an out-of-order SACK. |
2790 | * |
2791 | * ii) Set rwnd equal to the newly received a_rwnd minus the number |
2792 | * of bytes still outstanding after processing the Cumulative TSN Ack |
2793 | * and the Gap Ack Blocks. |
2794 | * |
2795 | * iii) If the SACK is missing a TSN that was previously |
2796 | * acknowledged via a Gap Ack Block (e.g., the data receiver |
2797 | * reneged on the data), then mark the corresponding DATA chunk |
2798 | * as available for retransmit: Mark it as missing for fast |
2799 | * retransmit as described in Section 7.2.4 and if no retransmit |
2800 | * timer is running for the destination address to which the DATA |
2801 | * chunk was originally transmitted, then T3-rtx is started for |
2802 | * that destination address. |
2803 | * |
2804 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
2805 | * |
2806 | * Inputs |
2807 | * (endpoint, asoc, chunk) |
2808 | * |
2809 | * Outputs |
2810 | * (asoc, reply_msg, msg_up, timers, counters) |
2811 | * |
2812 | * The return value is the disposition of the chunk. |
2813 | */ |
2814 | sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep, |
2815 | const struct sctp_association *asoc, |
2816 | const sctp_subtype_t type, |
2817 | void *arg, |
2818 | sctp_cmd_seq_t *commands) |
2819 | { |
2820 | struct sctp_chunk *chunk = arg; |
2821 | sctp_sackhdr_t *sackh; |
2822 | __u32 ctsn; |
2823 | |
2824 | if (!sctp_vtag_verify(chunk, asoc)) |
2825 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2826 | |
2827 | /* Make sure that the SACK chunk has a valid length. */ |
2828 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t))) |
2829 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2830 | commands); |
2831 | |
2832 | /* Pull the SACK chunk from the data buffer */ |
2833 | sackh = sctp_sm_pull_sack(chunk); |
2834 | /* Was this a bogus SACK? */ |
2835 | if (!sackh) |
2836 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2837 | chunk->subh.sack_hdr = sackh; |
2838 | ctsn = ntohl(sackh->cum_tsn_ack); |
2839 | |
2840 | /* i) If Cumulative TSN Ack is less than the Cumulative TSN |
2841 | * Ack Point, then drop the SACK. Since Cumulative TSN |
2842 | * Ack is monotonically increasing, a SACK whose |
2843 | * Cumulative TSN Ack is less than the Cumulative TSN Ack |
2844 | * Point indicates an out-of-order SACK. |
2845 | */ |
2846 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
2847 | SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn); |
2848 | SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point); |
2849 | return SCTP_DISPOSITION_DISCARD; |
2850 | } |
2851 | |
2852 | /* Return this SACK for further processing. */ |
2853 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh)); |
2854 | |
2855 | /* Note: We do the rest of the work on the PROCESS_SACK |
2856 | * sideeffect. |
2857 | */ |
2858 | return SCTP_DISPOSITION_CONSUME; |
2859 | } |
2860 | |
2861 | /* |
2862 | * Generate an ABORT in response to a packet. |
2863 | * |
2864 | * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41 |
2865 | * |
2866 | * 8) The receiver should respond to the sender of the OOTB packet with |
2867 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
2868 | * MUST fill in the Verification Tag field of the outbound packet |
2869 | * with the value found in the Verification Tag field of the OOTB |
2870 | * packet and set the T-bit in the Chunk Flags to indicate that the |
2871 | * Verification Tag is reflected. After sending this ABORT, the |
2872 | * receiver of the OOTB packet shall discard the OOTB packet and take |
2873 | * no further action. |
2874 | * |
2875 | * Verification Tag: |
2876 | * |
2877 | * The return value is the disposition of the chunk. |
2878 | */ |
2879 | sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep, |
2880 | const struct sctp_association *asoc, |
2881 | const sctp_subtype_t type, |
2882 | void *arg, |
2883 | sctp_cmd_seq_t *commands) |
2884 | { |
2885 | struct sctp_packet *packet = NULL; |
2886 | struct sctp_chunk *chunk = arg; |
2887 | struct sctp_chunk *abort; |
2888 | |
2889 | packet = sctp_ootb_pkt_new(asoc, chunk); |
2890 | |
2891 | if (packet) { |
2892 | /* Make an ABORT. The T bit will be set if the asoc |
2893 | * is NULL. |
2894 | */ |
2895 | abort = sctp_make_abort(asoc, chunk, 0); |
2896 | if (!abort) { |
2897 | sctp_ootb_pkt_free(packet); |
2898 | return SCTP_DISPOSITION_NOMEM; |
2899 | } |
2900 | |
2901 | /* Reflect vtag if T-Bit is set */ |
2902 | if (sctp_test_T_bit(abort)) |
2903 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
2904 | |
2905 | /* Set the skb to the belonging sock for accounting. */ |
2906 | abort->skb->sk = ep->base.sk; |
2907 | |
2908 | sctp_packet_append_chunk(packet, abort); |
2909 | |
2910 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
2911 | SCTP_PACKET(packet)); |
2912 | |
2913 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
2914 | |
2915 | return SCTP_DISPOSITION_CONSUME; |
2916 | } |
2917 | |
2918 | return SCTP_DISPOSITION_NOMEM; |
2919 | } |
2920 | |
2921 | /* |
2922 | * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR |
2923 | * event as ULP notification for each cause included in the chunk. |
2924 | * |
2925 | * API 5.3.1.3 - SCTP_REMOTE_ERROR |
2926 | * |
2927 | * The return value is the disposition of the chunk. |
2928 | */ |
2929 | sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep, |
2930 | const struct sctp_association *asoc, |
2931 | const sctp_subtype_t type, |
2932 | void *arg, |
2933 | sctp_cmd_seq_t *commands) |
2934 | { |
2935 | struct sctp_chunk *chunk = arg; |
2936 | struct sctp_ulpevent *ev; |
2937 | |
2938 | if (!sctp_vtag_verify(chunk, asoc)) |
2939 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2940 | |
2941 | /* Make sure that the ERROR chunk has a valid length. */ |
2942 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
2943 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2944 | commands); |
2945 | |
2946 | while (chunk->chunk_end > chunk->skb->data) { |
2947 | ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, |
2948 | GFP_ATOMIC); |
2949 | if (!ev) |
2950 | goto nomem; |
2951 | |
2952 | if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP, |
2953 | SCTP_ULPEVENT(ev))) { |
2954 | sctp_ulpevent_free(ev); |
2955 | goto nomem; |
2956 | } |
2957 | |
2958 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, |
2959 | SCTP_CHUNK(chunk)); |
2960 | } |
2961 | return SCTP_DISPOSITION_CONSUME; |
2962 | |
2963 | nomem: |
2964 | return SCTP_DISPOSITION_NOMEM; |
2965 | } |
2966 | |
2967 | /* |
2968 | * Process an inbound SHUTDOWN ACK. |
2969 | * |
2970 | * From Section 9.2: |
2971 | * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
2972 | * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its |
2973 | * peer, and remove all record of the association. |
2974 | * |
2975 | * The return value is the disposition. |
2976 | */ |
2977 | sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep, |
2978 | const struct sctp_association *asoc, |
2979 | const sctp_subtype_t type, |
2980 | void *arg, |
2981 | sctp_cmd_seq_t *commands) |
2982 | { |
2983 | struct sctp_chunk *chunk = arg; |
2984 | struct sctp_chunk *reply; |
2985 | struct sctp_ulpevent *ev; |
2986 | |
2987 | if (!sctp_vtag_verify(chunk, asoc)) |
2988 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
2989 | |
2990 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
2991 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
2992 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
2993 | commands); |
2994 | |
2995 | /* 10.2 H) SHUTDOWN COMPLETE notification |
2996 | * |
2997 | * When SCTP completes the shutdown procedures (section 9.2) this |
2998 | * notification is passed to the upper layer. |
2999 | */ |
3000 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
3001 | 0, 0, 0, GFP_ATOMIC); |
3002 | if (!ev) |
3003 | goto nomem; |
3004 | |
3005 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
3006 | |
3007 | /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
3008 | * stop the T2-shutdown timer, |
3009 | */ |
3010 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3011 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
3012 | |
3013 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3014 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
3015 | |
3016 | /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ |
3017 | reply = sctp_make_shutdown_complete(asoc, chunk); |
3018 | if (!reply) |
3019 | goto nomem; |
3020 | |
3021 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
3022 | SCTP_STATE(SCTP_STATE_CLOSED)); |
3023 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
3024 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
3025 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
3026 | |
3027 | /* ...and remove all record of the association. */ |
3028 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
3029 | return SCTP_DISPOSITION_DELETE_TCB; |
3030 | |
3031 | nomem: |
3032 | return SCTP_DISPOSITION_NOMEM; |
3033 | } |
3034 | |
3035 | /* |
3036 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41. |
3037 | * |
3038 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
3039 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
3040 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
3041 | * packet must fill in the Verification Tag field of the outbound |
3042 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
3043 | * set the T-bit in the Chunk Flags to indicate that the Verification |
3044 | * Tag is reflected. |
3045 | * |
3046 | * 8) The receiver should respond to the sender of the OOTB packet with |
3047 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
3048 | * MUST fill in the Verification Tag field of the outbound packet |
3049 | * with the value found in the Verification Tag field of the OOTB |
3050 | * packet and set the T-bit in the Chunk Flags to indicate that the |
3051 | * Verification Tag is reflected. After sending this ABORT, the |
3052 | * receiver of the OOTB packet shall discard the OOTB packet and take |
3053 | * no further action. |
3054 | */ |
3055 | sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep, |
3056 | const struct sctp_association *asoc, |
3057 | const sctp_subtype_t type, |
3058 | void *arg, |
3059 | sctp_cmd_seq_t *commands) |
3060 | { |
3061 | struct sctp_chunk *chunk = arg; |
3062 | struct sk_buff *skb = chunk->skb; |
3063 | sctp_chunkhdr_t *ch; |
3064 | __u8 *ch_end; |
3065 | int ootb_shut_ack = 0; |
3066 | |
3067 | SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES); |
3068 | |
3069 | ch = (sctp_chunkhdr_t *) chunk->chunk_hdr; |
3070 | do { |
3071 | /* Break out if chunk length is less then minimal. */ |
3072 | if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) |
3073 | break; |
3074 | |
3075 | ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); |
3076 | |
3077 | if (SCTP_CID_SHUTDOWN_ACK == ch->type) |
3078 | ootb_shut_ack = 1; |
3079 | |
3080 | /* RFC 2960, Section 3.3.7 |
3081 | * Moreover, under any circumstances, an endpoint that |
3082 | * receives an ABORT MUST NOT respond to that ABORT by |
3083 | * sending an ABORT of its own. |
3084 | */ |
3085 | if (SCTP_CID_ABORT == ch->type) |
3086 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3087 | |
3088 | ch = (sctp_chunkhdr_t *) ch_end; |
3089 | } while (ch_end < skb->tail); |
3090 | |
3091 | if (ootb_shut_ack) |
3092 | sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands); |
3093 | else |
3094 | sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
3095 | |
3096 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3097 | } |
3098 | |
3099 | /* |
3100 | * Handle an "Out of the blue" SHUTDOWN ACK. |
3101 | * |
3102 | * Section: 8.4 5, sctpimpguide 2.41. |
3103 | * |
3104 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
3105 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
3106 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
3107 | * packet must fill in the Verification Tag field of the outbound |
3108 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
3109 | * set the T-bit in the Chunk Flags to indicate that the Verification |
3110 | * Tag is reflected. |
3111 | * |
3112 | * Inputs |
3113 | * (endpoint, asoc, type, arg, commands) |
3114 | * |
3115 | * Outputs |
3116 | * (sctp_disposition_t) |
3117 | * |
3118 | * The return value is the disposition of the chunk. |
3119 | */ |
3120 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, |
3121 | const struct sctp_association *asoc, |
3122 | const sctp_subtype_t type, |
3123 | void *arg, |
3124 | sctp_cmd_seq_t *commands) |
3125 | { |
3126 | struct sctp_packet *packet = NULL; |
3127 | struct sctp_chunk *chunk = arg; |
3128 | struct sctp_chunk *shut; |
3129 | |
3130 | packet = sctp_ootb_pkt_new(asoc, chunk); |
3131 | |
3132 | if (packet) { |
3133 | /* Make an SHUTDOWN_COMPLETE. |
3134 | * The T bit will be set if the asoc is NULL. |
3135 | */ |
3136 | shut = sctp_make_shutdown_complete(asoc, chunk); |
3137 | if (!shut) { |
3138 | sctp_ootb_pkt_free(packet); |
3139 | return SCTP_DISPOSITION_NOMEM; |
3140 | } |
3141 | |
3142 | /* Reflect vtag if T-Bit is set */ |
3143 | if (sctp_test_T_bit(shut)) |
3144 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
3145 | |
3146 | /* Set the skb to the belonging sock for accounting. */ |
3147 | shut->skb->sk = ep->base.sk; |
3148 | |
3149 | sctp_packet_append_chunk(packet, shut); |
3150 | |
3151 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
3152 | SCTP_PACKET(packet)); |
3153 | |
3154 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
3155 | |
3156 | /* If the chunk length is invalid, we don't want to process |
3157 | * the reset of the packet. |
3158 | */ |
3159 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
3160 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3161 | |
3162 | return SCTP_DISPOSITION_CONSUME; |
3163 | } |
3164 | |
3165 | return SCTP_DISPOSITION_NOMEM; |
3166 | } |
3167 | |
3168 | /* |
3169 | * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. |
3170 | * |
3171 | * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK |
3172 | * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the |
3173 | * procedures in section 8.4 SHOULD be followed, in other words it |
3174 | * should be treated as an Out Of The Blue packet. |
3175 | * [This means that we do NOT check the Verification Tag on these |
3176 | * chunks. --piggy ] |
3177 | * |
3178 | */ |
3179 | sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep, |
3180 | const struct sctp_association *asoc, |
3181 | const sctp_subtype_t type, |
3182 | void *arg, |
3183 | sctp_cmd_seq_t *commands) |
3184 | { |
3185 | /* Although we do have an association in this case, it corresponds |
3186 | * to a restarted association. So the packet is treated as an OOTB |
3187 | * packet and the state function that handles OOTB SHUTDOWN_ACK is |
3188 | * called with a NULL association. |
3189 | */ |
3190 | return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands); |
3191 | } |
3192 | |
3193 | /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ |
3194 | sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep, |
3195 | const struct sctp_association *asoc, |
3196 | const sctp_subtype_t type, void *arg, |
3197 | sctp_cmd_seq_t *commands) |
3198 | { |
3199 | struct sctp_chunk *chunk = arg; |
3200 | struct sctp_chunk *asconf_ack = NULL; |
3201 | sctp_addiphdr_t *hdr; |
3202 | __u32 serial; |
3203 | |
3204 | if (!sctp_vtag_verify(chunk, asoc)) { |
3205 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3206 | SCTP_NULL()); |
3207 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3208 | } |
3209 | |
3210 | /* Make sure that the ASCONF ADDIP chunk has a valid length. */ |
3211 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t))) |
3212 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
3213 | commands); |
3214 | |
3215 | hdr = (sctp_addiphdr_t *)chunk->skb->data; |
3216 | serial = ntohl(hdr->serial); |
3217 | |
3218 | /* ADDIP 4.2 C1) Compare the value of the serial number to the value |
3219 | * the endpoint stored in a new association variable |
3220 | * 'Peer-Serial-Number'. |
3221 | */ |
3222 | if (serial == asoc->peer.addip_serial + 1) { |
3223 | /* ADDIP 4.2 C2) If the value found in the serial number is |
3224 | * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST |
3225 | * do V1-V5. |
3226 | */ |
3227 | asconf_ack = sctp_process_asconf((struct sctp_association *) |
3228 | asoc, chunk); |
3229 | if (!asconf_ack) |
3230 | return SCTP_DISPOSITION_NOMEM; |
3231 | } else if (serial == asoc->peer.addip_serial) { |
3232 | /* ADDIP 4.2 C3) If the value found in the serial number is |
3233 | * equal to the value stored in the 'Peer-Serial-Number' |
3234 | * IMPLEMENTATION NOTE: As an optimization a receiver may wish |
3235 | * to save the last ASCONF-ACK for some predetermined period of |
3236 | * time and instead of re-processing the ASCONF (with the same |
3237 | * serial number) it may just re-transmit the ASCONF-ACK. |
3238 | */ |
3239 | if (asoc->addip_last_asconf_ack) |
3240 | asconf_ack = asoc->addip_last_asconf_ack; |
3241 | else |
3242 | return SCTP_DISPOSITION_DISCARD; |
3243 | } else { |
3244 | /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since |
3245 | * it must be either a stale packet or from an attacker. |
3246 | */ |
3247 | return SCTP_DISPOSITION_DISCARD; |
3248 | } |
3249 | |
3250 | /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent |
3251 | * back to the source address contained in the IP header of the ASCONF |
3252 | * being responded to. |
3253 | */ |
3254 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); |
3255 | |
3256 | return SCTP_DISPOSITION_CONSUME; |
3257 | } |
3258 | |
3259 | /* |
3260 | * ADDIP Section 4.3 General rules for address manipulation |
3261 | * When building TLV parameters for the ASCONF Chunk that will add or |
3262 | * delete IP addresses the D0 to D13 rules should be applied: |
3263 | */ |
3264 | sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep, |
3265 | const struct sctp_association *asoc, |
3266 | const sctp_subtype_t type, void *arg, |
3267 | sctp_cmd_seq_t *commands) |
3268 | { |
3269 | struct sctp_chunk *asconf_ack = arg; |
3270 | struct sctp_chunk *last_asconf = asoc->addip_last_asconf; |
3271 | struct sctp_chunk *abort; |
3272 | sctp_addiphdr_t *addip_hdr; |
3273 | __u32 sent_serial, rcvd_serial; |
3274 | |
3275 | if (!sctp_vtag_verify(asconf_ack, asoc)) { |
3276 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3277 | SCTP_NULL()); |
3278 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3279 | } |
3280 | |
3281 | /* Make sure that the ADDIP chunk has a valid length. */ |
3282 | if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t))) |
3283 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
3284 | commands); |
3285 | |
3286 | addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data; |
3287 | rcvd_serial = ntohl(addip_hdr->serial); |
3288 | |
3289 | if (last_asconf) { |
3290 | addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr; |
3291 | sent_serial = ntohl(addip_hdr->serial); |
3292 | } else { |
3293 | sent_serial = asoc->addip_serial - 1; |
3294 | } |
3295 | |
3296 | /* D0) If an endpoint receives an ASCONF-ACK that is greater than or |
3297 | * equal to the next serial number to be used but no ASCONF chunk is |
3298 | * outstanding the endpoint MUST ABORT the association. Note that a |
3299 | * sequence number is greater than if it is no more than 2^^31-1 |
3300 | * larger than the current sequence number (using serial arithmetic). |
3301 | */ |
3302 | if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && |
3303 | !(asoc->addip_last_asconf)) { |
3304 | abort = sctp_make_abort(asoc, asconf_ack, |
3305 | sizeof(sctp_errhdr_t)); |
3306 | if (abort) { |
3307 | sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0); |
3308 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3309 | SCTP_CHUNK(abort)); |
3310 | } |
3311 | /* We are going to ABORT, so we might as well stop |
3312 | * processing the rest of the chunks in the packet. |
3313 | */ |
3314 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3315 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
3316 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
3317 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
3318 | SCTP_U32(SCTP_ERROR_ASCONF_ACK)); |
3319 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
3320 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
3321 | return SCTP_DISPOSITION_ABORT; |
3322 | } |
3323 | |
3324 | if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { |
3325 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3326 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
3327 | |
3328 | if (!sctp_process_asconf_ack((struct sctp_association *)asoc, |
3329 | asconf_ack)) |
3330 | return SCTP_DISPOSITION_CONSUME; |
3331 | |
3332 | abort = sctp_make_abort(asoc, asconf_ack, |
3333 | sizeof(sctp_errhdr_t)); |
3334 | if (abort) { |
3335 | sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0); |
3336 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3337 | SCTP_CHUNK(abort)); |
3338 | } |
3339 | /* We are going to ABORT, so we might as well stop |
3340 | * processing the rest of the chunks in the packet. |
3341 | */ |
3342 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
3343 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
3344 | SCTP_U32(SCTP_ERROR_ASCONF_ACK)); |
3345 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
3346 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
3347 | return SCTP_DISPOSITION_ABORT; |
3348 | } |
3349 | |
3350 | return SCTP_DISPOSITION_DISCARD; |
3351 | } |
3352 | |
3353 | /* |
3354 | * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP |
3355 | * |
3356 | * When a FORWARD TSN chunk arrives, the data receiver MUST first update |
3357 | * its cumulative TSN point to the value carried in the FORWARD TSN |
3358 | * chunk, and then MUST further advance its cumulative TSN point locally |
3359 | * if possible. |
3360 | * After the above processing, the data receiver MUST stop reporting any |
3361 | * missing TSNs earlier than or equal to the new cumulative TSN point. |
3362 | * |
3363 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
3364 | * |
3365 | * The return value is the disposition of the chunk. |
3366 | */ |
3367 | sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep, |
3368 | const struct sctp_association *asoc, |
3369 | const sctp_subtype_t type, |
3370 | void *arg, |
3371 | sctp_cmd_seq_t *commands) |
3372 | { |
3373 | struct sctp_chunk *chunk = arg; |
3374 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
3375 | __u16 len; |
3376 | __u32 tsn; |
3377 | |
3378 | if (!sctp_vtag_verify(chunk, asoc)) { |
3379 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3380 | SCTP_NULL()); |
3381 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3382 | } |
3383 | |
3384 | /* Make sure that the FORWARD_TSN chunk has valid length. */ |
3385 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
3386 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
3387 | commands); |
3388 | |
3389 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
3390 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
3391 | len = ntohs(chunk->chunk_hdr->length); |
3392 | len -= sizeof(struct sctp_chunkhdr); |
3393 | skb_pull(chunk->skb, len); |
3394 | |
3395 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
3396 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn); |
3397 | |
3398 | /* The TSN is too high--silently discard the chunk and count on it |
3399 | * getting retransmitted later. |
3400 | */ |
3401 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
3402 | goto discard_noforce; |
3403 | |
3404 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
3405 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
3406 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
3407 | SCTP_CHUNK(chunk)); |
3408 | |
3409 | /* Count this as receiving DATA. */ |
3410 | if (asoc->autoclose) { |
3411 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3412 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
3413 | } |
3414 | |
3415 | /* FIXME: For now send a SACK, but DATA processing may |
3416 | * send another. |
3417 | */ |
3418 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
3419 | /* Start the SACK timer. */ |
3420 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3421 | SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); |
3422 | |
3423 | return SCTP_DISPOSITION_CONSUME; |
3424 | |
3425 | discard_noforce: |
3426 | return SCTP_DISPOSITION_DISCARD; |
3427 | } |
3428 | |
3429 | sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( |
3430 | const struct sctp_endpoint *ep, |
3431 | const struct sctp_association *asoc, |
3432 | const sctp_subtype_t type, |
3433 | void *arg, |
3434 | sctp_cmd_seq_t *commands) |
3435 | { |
3436 | struct sctp_chunk *chunk = arg; |
3437 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
3438 | __u16 len; |
3439 | __u32 tsn; |
3440 | |
3441 | if (!sctp_vtag_verify(chunk, asoc)) { |
3442 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
3443 | SCTP_NULL()); |
3444 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3445 | } |
3446 | |
3447 | /* Make sure that the FORWARD_TSN chunk has a valid length. */ |
3448 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
3449 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
3450 | commands); |
3451 | |
3452 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
3453 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
3454 | len = ntohs(chunk->chunk_hdr->length); |
3455 | len -= sizeof(struct sctp_chunkhdr); |
3456 | skb_pull(chunk->skb, len); |
3457 | |
3458 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
3459 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn); |
3460 | |
3461 | /* The TSN is too high--silently discard the chunk and count on it |
3462 | * getting retransmitted later. |
3463 | */ |
3464 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
3465 | goto gen_shutdown; |
3466 | |
3467 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
3468 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
3469 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
3470 | SCTP_CHUNK(chunk)); |
3471 | |
3472 | /* Go a head and force a SACK, since we are shutting down. */ |
3473 | gen_shutdown: |
3474 | /* Implementor's Guide. |
3475 | * |
3476 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
3477 | * respond to each received packet containing one or more DATA chunk(s) |
3478 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
3479 | */ |
3480 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
3481 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
3482 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
3483 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
3484 | |
3485 | return SCTP_DISPOSITION_CONSUME; |
3486 | } |
3487 | |
3488 | /* |
3489 | * Process an unknown chunk. |
3490 | * |
3491 | * Section: 3.2. Also, 2.1 in the implementor's guide. |
3492 | * |
3493 | * Chunk Types are encoded such that the highest-order two bits specify |
3494 | * the action that must be taken if the processing endpoint does not |
3495 | * recognize the Chunk Type. |
3496 | * |
3497 | * 00 - Stop processing this SCTP packet and discard it, do not process |
3498 | * any further chunks within it. |
3499 | * |
3500 | * 01 - Stop processing this SCTP packet and discard it, do not process |
3501 | * any further chunks within it, and report the unrecognized |
3502 | * chunk in an 'Unrecognized Chunk Type'. |
3503 | * |
3504 | * 10 - Skip this chunk and continue processing. |
3505 | * |
3506 | * 11 - Skip this chunk and continue processing, but report in an ERROR |
3507 | * Chunk using the 'Unrecognized Chunk Type' cause of error. |
3508 | * |
3509 | * The return value is the disposition of the chunk. |
3510 | */ |
3511 | sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep, |
3512 | const struct sctp_association *asoc, |
3513 | const sctp_subtype_t type, |
3514 | void *arg, |
3515 | sctp_cmd_seq_t *commands) |
3516 | { |
3517 | struct sctp_chunk *unk_chunk = arg; |
3518 | struct sctp_chunk *err_chunk; |
3519 | sctp_chunkhdr_t *hdr; |
3520 | |
3521 | SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk); |
3522 | |
3523 | if (!sctp_vtag_verify(unk_chunk, asoc)) |
3524 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3525 | |
3526 | /* Make sure that the chunk has a valid length. |
3527 | * Since we don't know the chunk type, we use a general |
3528 | * chunkhdr structure to make a comparison. |
3529 | */ |
3530 | if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t))) |
3531 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
3532 | commands); |
3533 | |
3534 | switch (type.chunk & SCTP_CID_ACTION_MASK) { |
3535 | case SCTP_CID_ACTION_DISCARD: |
3536 | /* Discard the packet. */ |
3537 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3538 | break; |
3539 | case SCTP_CID_ACTION_DISCARD_ERR: |
3540 | /* Discard the packet. */ |
3541 | sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
3542 | |
3543 | /* Generate an ERROR chunk as response. */ |
3544 | hdr = unk_chunk->chunk_hdr; |
3545 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
3546 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
3547 | WORD_ROUND(ntohs(hdr->length))); |
3548 | if (err_chunk) { |
3549 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3550 | SCTP_CHUNK(err_chunk)); |
3551 | } |
3552 | return SCTP_DISPOSITION_CONSUME; |
3553 | break; |
3554 | case SCTP_CID_ACTION_SKIP: |
3555 | /* Skip the chunk. */ |
3556 | return SCTP_DISPOSITION_DISCARD; |
3557 | break; |
3558 | case SCTP_CID_ACTION_SKIP_ERR: |
3559 | /* Generate an ERROR chunk as response. */ |
3560 | hdr = unk_chunk->chunk_hdr; |
3561 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
3562 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
3563 | WORD_ROUND(ntohs(hdr->length))); |
3564 | if (err_chunk) { |
3565 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
3566 | SCTP_CHUNK(err_chunk)); |
3567 | } |
3568 | /* Skip the chunk. */ |
3569 | return SCTP_DISPOSITION_CONSUME; |
3570 | break; |
3571 | default: |
3572 | break; |
3573 | } |
3574 | |
3575 | return SCTP_DISPOSITION_DISCARD; |
3576 | } |
3577 | |
3578 | /* |
3579 | * Discard the chunk. |
3580 | * |
3581 | * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 |
3582 | * [Too numerous to mention...] |
3583 | * Verification Tag: No verification needed. |
3584 | * Inputs |
3585 | * (endpoint, asoc, chunk) |
3586 | * |
3587 | * Outputs |
3588 | * (asoc, reply_msg, msg_up, timers, counters) |
3589 | * |
3590 | * The return value is the disposition of the chunk. |
3591 | */ |
3592 | sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep, |
3593 | const struct sctp_association *asoc, |
3594 | const sctp_subtype_t type, |
3595 | void *arg, |
3596 | sctp_cmd_seq_t *commands) |
3597 | { |
3598 | SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk); |
3599 | return SCTP_DISPOSITION_DISCARD; |
3600 | } |
3601 | |
3602 | /* |
3603 | * Discard the whole packet. |
3604 | * |
3605 | * Section: 8.4 2) |
3606 | * |
3607 | * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST |
3608 | * silently discard the OOTB packet and take no further action. |
3609 | * |
3610 | * Verification Tag: No verification necessary |
3611 | * |
3612 | * Inputs |
3613 | * (endpoint, asoc, chunk) |
3614 | * |
3615 | * Outputs |
3616 | * (asoc, reply_msg, msg_up, timers, counters) |
3617 | * |
3618 | * The return value is the disposition of the chunk. |
3619 | */ |
3620 | sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep, |
3621 | const struct sctp_association *asoc, |
3622 | const sctp_subtype_t type, |
3623 | void *arg, |
3624 | sctp_cmd_seq_t *commands) |
3625 | { |
3626 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
3627 | |
3628 | return SCTP_DISPOSITION_CONSUME; |
3629 | } |
3630 | |
3631 | |
3632 | /* |
3633 | * The other end is violating protocol. |
3634 | * |
3635 | * Section: Not specified |
3636 | * Verification Tag: Not specified |
3637 | * Inputs |
3638 | * (endpoint, asoc, chunk) |
3639 | * |
3640 | * Outputs |
3641 | * (asoc, reply_msg, msg_up, timers, counters) |
3642 | * |
3643 | * We simply tag the chunk as a violation. The state machine will log |
3644 | * the violation and continue. |
3645 | */ |
3646 | sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep, |
3647 | const struct sctp_association *asoc, |
3648 | const sctp_subtype_t type, |
3649 | void *arg, |
3650 | sctp_cmd_seq_t *commands) |
3651 | { |
3652 | return SCTP_DISPOSITION_VIOLATION; |
3653 | } |
3654 | |
3655 | |
3656 | /* |
3657 | * Handle a protocol violation when the chunk length is invalid. |
3658 | * "Invalid" length is identified as smaller then the minimal length a |
3659 | * given chunk can be. For example, a SACK chunk has invalid length |
3660 | * if it's length is set to be smaller then the size of sctp_sack_chunk_t. |
3661 | * |
3662 | * We inform the other end by sending an ABORT with a Protocol Violation |
3663 | * error code. |
3664 | * |
3665 | * Section: Not specified |
3666 | * Verification Tag: Nothing to do |
3667 | * Inputs |
3668 | * (endpoint, asoc, chunk) |
3669 | * |
3670 | * Outputs |
3671 | * (reply_msg, msg_up, counters) |
3672 | * |
3673 | * Generate an ABORT chunk and terminate the association. |
3674 | */ |
3675 | sctp_disposition_t sctp_sf_violation_chunklen(const struct sctp_endpoint *ep, |
3676 | const struct sctp_association *asoc, |
3677 | const sctp_subtype_t type, |
3678 | void *arg, |
3679 | sctp_cmd_seq_t *commands) |
3680 | { |
3681 | struct sctp_chunk *chunk = arg; |
3682 | struct sctp_chunk *abort = NULL; |
3683 | char err_str[]="The following chunk had invalid length:"; |
3684 | |
3685 | /* Make the abort chunk. */ |
3686 | abort = sctp_make_abort_violation(asoc, chunk, err_str, |
3687 | sizeof(err_str)); |
3688 | if (!abort) |
3689 | goto nomem; |
3690 | |
3691 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
3692 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
3693 | |
3694 | if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { |
3695 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
3696 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
3697 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
3698 | SCTP_U32(SCTP_ERROR_PROTO_VIOLATION)); |
3699 | } else { |
3700 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
3701 | SCTP_U32(SCTP_ERROR_PROTO_VIOLATION)); |
3702 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
3703 | } |
3704 | |
3705 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
3706 | |
3707 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
3708 | |
3709 | return SCTP_DISPOSITION_ABORT; |
3710 | |
3711 | nomem: |
3712 | return SCTP_DISPOSITION_NOMEM; |
3713 | } |
3714 | |
3715 | /*************************************************************************** |
3716 | * These are the state functions for handling primitive (Section 10) events. |
3717 | ***************************************************************************/ |
3718 | /* |
3719 | * sctp_sf_do_prm_asoc |
3720 | * |
3721 | * Section: 10.1 ULP-to-SCTP |
3722 | * B) Associate |
3723 | * |
3724 | * Format: ASSOCIATE(local SCTP instance name, destination transport addr, |
3725 | * outbound stream count) |
3726 | * -> association id [,destination transport addr list] [,outbound stream |
3727 | * count] |
3728 | * |
3729 | * This primitive allows the upper layer to initiate an association to a |
3730 | * specific peer endpoint. |
3731 | * |
3732 | * The peer endpoint shall be specified by one of the transport addresses |
3733 | * which defines the endpoint (see Section 1.4). If the local SCTP |
3734 | * instance has not been initialized, the ASSOCIATE is considered an |
3735 | * error. |
3736 | * [This is not relevant for the kernel implementation since we do all |
3737 | * initialization at boot time. It we hadn't initialized we wouldn't |
3738 | * get anywhere near this code.] |
3739 | * |
3740 | * An association id, which is a local handle to the SCTP association, |
3741 | * will be returned on successful establishment of the association. If |
3742 | * SCTP is not able to open an SCTP association with the peer endpoint, |
3743 | * an error is returned. |
3744 | * [In the kernel implementation, the struct sctp_association needs to |
3745 | * be created BEFORE causing this primitive to run.] |
3746 | * |
3747 | * Other association parameters may be returned, including the |
3748 | * complete destination transport addresses of the peer as well as the |
3749 | * outbound stream count of the local endpoint. One of the transport |
3750 | * address from the returned destination addresses will be selected by |
3751 | * the local endpoint as default primary path for sending SCTP packets |
3752 | * to this peer. The returned "destination transport addr list" can |
3753 | * be used by the ULP to change the default primary path or to force |
3754 | * sending a packet to a specific transport address. [All of this |
3755 | * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING |
3756 | * function.] |
3757 | * |
3758 | * Mandatory attributes: |
3759 | * |
3760 | * o local SCTP instance name - obtained from the INITIALIZE operation. |
3761 | * [This is the argument asoc.] |
3762 | * o destination transport addr - specified as one of the transport |
3763 | * addresses of the peer endpoint with which the association is to be |
3764 | * established. |
3765 | * [This is asoc->peer.active_path.] |
3766 | * o outbound stream count - the number of outbound streams the ULP |
3767 | * would like to open towards this peer endpoint. |
3768 | * [BUG: This is not currently implemented.] |
3769 | * Optional attributes: |
3770 | * |
3771 | * None. |
3772 | * |
3773 | * The return value is a disposition. |
3774 | */ |
3775 | sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep, |
3776 | const struct sctp_association *asoc, |
3777 | const sctp_subtype_t type, |
3778 | void *arg, |
3779 | sctp_cmd_seq_t *commands) |
3780 | { |
3781 | struct sctp_chunk *repl; |
3782 | |
3783 | /* The comment below says that we enter COOKIE-WAIT AFTER |
3784 | * sending the INIT, but that doesn't actually work in our |
3785 | * implementation... |
3786 | */ |
3787 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
3788 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
3789 | |
3790 | /* RFC 2960 5.1 Normal Establishment of an Association |
3791 | * |
3792 | * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" |
3793 | * must provide its Verification Tag (Tag_A) in the Initiate |
3794 | * Tag field. Tag_A SHOULD be a random number in the range of |
3795 | * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... |
3796 | */ |
3797 | |
3798 | repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); |
3799 | if (!repl) |
3800 | goto nomem; |
3801 | |
3802 | /* Cast away the const modifier, as we want to just |
3803 | * rerun it through as a sideffect. |
3804 | */ |
3805 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, |
3806 | SCTP_ASOC((struct sctp_association *) asoc)); |
3807 | |
3808 | /* After sending the INIT, "A" starts the T1-init timer and |
3809 | * enters the COOKIE-WAIT state. |
3810 | */ |
3811 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
3812 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
3813 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
3814 | return SCTP_DISPOSITION_CONSUME; |
3815 | |
3816 | nomem: |
3817 | return SCTP_DISPOSITION_NOMEM; |
3818 | } |
3819 | |
3820 | /* |
3821 | * Process the SEND primitive. |
3822 | * |
3823 | * Section: 10.1 ULP-to-SCTP |
3824 | * E) Send |
3825 | * |
3826 | * Format: SEND(association id, buffer address, byte count [,context] |
3827 | * [,stream id] [,life time] [,destination transport address] |
3828 | * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) |
3829 | * -> result |
3830 | * |
3831 | * This is the main method to send user data via SCTP. |
3832 | * |
3833 | * Mandatory attributes: |
3834 | * |
3835 | * o association id - local handle to the SCTP association |
3836 | * |
3837 | * o buffer address - the location where the user message to be |
3838 | * transmitted is stored; |
3839 | * |
3840 | * o byte count - The size of the user data in number of bytes; |
3841 | * |
3842 | * Optional attributes: |
3843 | * |
3844 | * o context - an optional 32 bit integer that will be carried in the |
3845 | * sending failure notification to the ULP if the transportation of |
3846 | * this User Message fails. |
3847 | * |
3848 | * o stream id - to indicate which stream to send the data on. If not |
3849 | * specified, stream 0 will be used. |
3850 | * |
3851 | * o life time - specifies the life time of the user data. The user data |
3852 | * will not be sent by SCTP after the life time expires. This |
3853 | * parameter can be used to avoid efforts to transmit stale |
3854 | * user messages. SCTP notifies the ULP if the data cannot be |
3855 | * initiated to transport (i.e. sent to the destination via SCTP's |
3856 | * send primitive) within the life time variable. However, the |
3857 | * user data will be transmitted if SCTP has attempted to transmit a |
3858 | * chunk before the life time expired. |
3859 | * |
3860 | * o destination transport address - specified as one of the destination |
3861 | * transport addresses of the peer endpoint to which this packet |
3862 | * should be sent. Whenever possible, SCTP should use this destination |
3863 | * transport address for sending the packets, instead of the current |
3864 | * primary path. |
3865 | * |
3866 | * o unorder flag - this flag, if present, indicates that the user |
3867 | * would like the data delivered in an unordered fashion to the peer |
3868 | * (i.e., the U flag is set to 1 on all DATA chunks carrying this |
3869 | * message). |
3870 | * |
3871 | * o no-bundle flag - instructs SCTP not to bundle this user data with |
3872 | * other outbound DATA chunks. SCTP MAY still bundle even when |
3873 | * this flag is present, when faced with network congestion. |
3874 | * |
3875 | * o payload protocol-id - A 32 bit unsigned integer that is to be |
3876 | * passed to the peer indicating the type of payload protocol data |
3877 | * being transmitted. This value is passed as opaque data by SCTP. |
3878 | * |
3879 | * The return value is the disposition. |
3880 | */ |
3881 | sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep, |
3882 | const struct sctp_association *asoc, |
3883 | const sctp_subtype_t type, |
3884 | void *arg, |
3885 | sctp_cmd_seq_t *commands) |
3886 | { |
3887 | struct sctp_chunk *chunk = arg; |
3888 | |
3889 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
3890 | return SCTP_DISPOSITION_CONSUME; |
3891 | } |
3892 | |
3893 | /* |
3894 | * Process the SHUTDOWN primitive. |
3895 | * |
3896 | * Section: 10.1: |
3897 | * C) Shutdown |
3898 | * |
3899 | * Format: SHUTDOWN(association id) |
3900 | * -> result |
3901 | * |
3902 | * Gracefully closes an association. Any locally queued user data |
3903 | * will be delivered to the peer. The association will be terminated only |
3904 | * after the peer acknowledges all the SCTP packets sent. A success code |
3905 | * will be returned on successful termination of the association. If |
3906 | * attempting to terminate the association results in a failure, an error |
3907 | * code shall be returned. |
3908 | * |
3909 | * Mandatory attributes: |
3910 | * |
3911 | * o association id - local handle to the SCTP association |
3912 | * |
3913 | * Optional attributes: |
3914 | * |
3915 | * None. |
3916 | * |
3917 | * The return value is the disposition. |
3918 | */ |
3919 | sctp_disposition_t sctp_sf_do_9_2_prm_shutdown( |
3920 | const struct sctp_endpoint *ep, |
3921 | const struct sctp_association *asoc, |
3922 | const sctp_subtype_t type, |
3923 | void *arg, |
3924 | sctp_cmd_seq_t *commands) |
3925 | { |
3926 | int disposition; |
3927 | |
3928 | /* From 9.2 Shutdown of an Association |
3929 | * Upon receipt of the SHUTDOWN primitive from its upper |
3930 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
3931 | * remains there until all outstanding data has been |
3932 | * acknowledged by its peer. The endpoint accepts no new data |
3933 | * from its upper layer, but retransmits data to the far end |
3934 | * if necessary to fill gaps. |
3935 | */ |
3936 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
3937 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
3938 | |
3939 | /* sctpimpguide-05 Section 2.12.2 |
3940 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
3941 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
3942 | */ |
3943 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
3944 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
3945 | |
3946 | disposition = SCTP_DISPOSITION_CONSUME; |
3947 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
3948 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, |
3949 | arg, commands); |
3950 | } |
3951 | return disposition; |
3952 | } |
3953 | |
3954 | /* |
3955 | * Process the ABORT primitive. |
3956 | * |
3957 | * Section: 10.1: |
3958 | * C) Abort |
3959 | * |
3960 | * Format: Abort(association id [, cause code]) |
3961 | * -> result |
3962 | * |
3963 | * Ungracefully closes an association. Any locally queued user data |
3964 | * will be discarded and an ABORT chunk is sent to the peer. A success code |
3965 | * will be returned on successful abortion of the association. If |
3966 | * attempting to abort the association results in a failure, an error |
3967 | * code shall be returned. |
3968 | * |
3969 | * Mandatory attributes: |
3970 | * |
3971 | * o association id - local handle to the SCTP association |
3972 | * |
3973 | * Optional attributes: |
3974 | * |
3975 | * o cause code - reason of the abort to be passed to the peer |
3976 | * |
3977 | * None. |
3978 | * |
3979 | * The return value is the disposition. |
3980 | */ |
3981 | sctp_disposition_t sctp_sf_do_9_1_prm_abort( |
3982 | const struct sctp_endpoint *ep, |
3983 | const struct sctp_association *asoc, |
3984 | const sctp_subtype_t type, |
3985 | void *arg, |
3986 | sctp_cmd_seq_t *commands) |
3987 | { |
3988 | /* From 9.1 Abort of an Association |
3989 | * Upon receipt of the ABORT primitive from its upper |
3990 | * layer, the endpoint enters CLOSED state and |
3991 | * discard all outstanding data has been |
3992 | * acknowledged by its peer. The endpoint accepts no new data |
3993 | * from its upper layer, but retransmits data to the far end |
3994 | * if necessary to fill gaps. |
3995 | */ |
3996 | struct msghdr *msg = arg; |
3997 | struct sctp_chunk *abort; |
3998 | sctp_disposition_t retval; |
3999 | |
4000 | retval = SCTP_DISPOSITION_CONSUME; |
4001 | |
4002 | /* Generate ABORT chunk to send the peer. */ |
4003 | abort = sctp_make_abort_user(asoc, NULL, msg); |
4004 | if (!abort) |
4005 | retval = SCTP_DISPOSITION_NOMEM; |
4006 | else |
4007 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4008 | |
4009 | /* Even if we can't send the ABORT due to low memory delete the |
4010 | * TCB. This is a departure from our typical NOMEM handling. |
4011 | */ |
4012 | |
4013 | /* Delete the established association. */ |
4014 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4015 | SCTP_U32(SCTP_ERROR_USER_ABORT)); |
4016 | |
4017 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
4018 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
4019 | |
4020 | return retval; |
4021 | } |
4022 | |
4023 | /* We tried an illegal operation on an association which is closed. */ |
4024 | sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep, |
4025 | const struct sctp_association *asoc, |
4026 | const sctp_subtype_t type, |
4027 | void *arg, |
4028 | sctp_cmd_seq_t *commands) |
4029 | { |
4030 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); |
4031 | return SCTP_DISPOSITION_CONSUME; |
4032 | } |
4033 | |
4034 | /* We tried an illegal operation on an association which is shutting |
4035 | * down. |
4036 | */ |
4037 | sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep, |
4038 | const struct sctp_association *asoc, |
4039 | const sctp_subtype_t type, |
4040 | void *arg, |
4041 | sctp_cmd_seq_t *commands) |
4042 | { |
4043 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, |
4044 | SCTP_ERROR(-ESHUTDOWN)); |
4045 | return SCTP_DISPOSITION_CONSUME; |
4046 | } |
4047 | |
4048 | /* |
4049 | * sctp_cookie_wait_prm_shutdown |
4050 | * |
4051 | * Section: 4 Note: 2 |
4052 | * Verification Tag: |
4053 | * Inputs |
4054 | * (endpoint, asoc) |
4055 | * |
4056 | * The RFC does not explicitly address this issue, but is the route through the |
4057 | * state table when someone issues a shutdown while in COOKIE_WAIT state. |
4058 | * |
4059 | * Outputs |
4060 | * (timers) |
4061 | */ |
4062 | sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown( |
4063 | const struct sctp_endpoint *ep, |
4064 | const struct sctp_association *asoc, |
4065 | const sctp_subtype_t type, |
4066 | void *arg, |
4067 | sctp_cmd_seq_t *commands) |
4068 | { |
4069 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4070 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4071 | |
4072 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4073 | SCTP_STATE(SCTP_STATE_CLOSED)); |
4074 | |
4075 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
4076 | |
4077 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
4078 | |
4079 | return SCTP_DISPOSITION_DELETE_TCB; |
4080 | } |
4081 | |
4082 | /* |
4083 | * sctp_cookie_echoed_prm_shutdown |
4084 | * |
4085 | * Section: 4 Note: 2 |
4086 | * Verification Tag: |
4087 | * Inputs |
4088 | * (endpoint, asoc) |
4089 | * |
4090 | * The RFC does not explcitly address this issue, but is the route through the |
4091 | * state table when someone issues a shutdown while in COOKIE_ECHOED state. |
4092 | * |
4093 | * Outputs |
4094 | * (timers) |
4095 | */ |
4096 | sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown( |
4097 | const struct sctp_endpoint *ep, |
4098 | const struct sctp_association *asoc, |
4099 | const sctp_subtype_t type, |
4100 | void *arg, sctp_cmd_seq_t *commands) |
4101 | { |
4102 | /* There is a single T1 timer, so we should be able to use |
4103 | * common function with the COOKIE-WAIT state. |
4104 | */ |
4105 | return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands); |
4106 | } |
4107 | |
4108 | /* |
4109 | * sctp_sf_cookie_wait_prm_abort |
4110 | * |
4111 | * Section: 4 Note: 2 |
4112 | * Verification Tag: |
4113 | * Inputs |
4114 | * (endpoint, asoc) |
4115 | * |
4116 | * The RFC does not explicitly address this issue, but is the route through the |
4117 | * state table when someone issues an abort while in COOKIE_WAIT state. |
4118 | * |
4119 | * Outputs |
4120 | * (timers) |
4121 | */ |
4122 | sctp_disposition_t sctp_sf_cookie_wait_prm_abort( |
4123 | const struct sctp_endpoint *ep, |
4124 | const struct sctp_association *asoc, |
4125 | const sctp_subtype_t type, |
4126 | void *arg, |
4127 | sctp_cmd_seq_t *commands) |
4128 | { |
4129 | struct msghdr *msg = arg; |
4130 | struct sctp_chunk *abort; |
4131 | sctp_disposition_t retval; |
4132 | |
4133 | /* Stop T1-init timer */ |
4134 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4135 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
4136 | retval = SCTP_DISPOSITION_CONSUME; |
4137 | |
4138 | /* Generate ABORT chunk to send the peer */ |
4139 | abort = sctp_make_abort_user(asoc, NULL, msg); |
4140 | if (!abort) |
4141 | retval = SCTP_DISPOSITION_NOMEM; |
4142 | else |
4143 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
4144 | |
4145 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4146 | SCTP_STATE(SCTP_STATE_CLOSED)); |
4147 | |
4148 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
4149 | |
4150 | /* Even if we can't send the ABORT due to low memory delete the |
4151 | * TCB. This is a departure from our typical NOMEM handling. |
4152 | */ |
4153 | |
4154 | /* Delete the established association. */ |
4155 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
4156 | SCTP_U32(SCTP_ERROR_USER_ABORT)); |
4157 | |
4158 | return retval; |
4159 | } |
4160 | |
4161 | /* |
4162 | * sctp_sf_cookie_echoed_prm_abort |
4163 | * |
4164 | * Section: 4 Note: 3 |
4165 | * Verification Tag: |
4166 | * Inputs |
4167 | * (endpoint, asoc) |
4168 | * |
4169 | * The RFC does not explcitly address this issue, but is the route through the |
4170 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
4171 | * |
4172 | * Outputs |
4173 | * (timers) |
4174 | */ |
4175 | sctp_disposition_t sctp_sf_cookie_echoed_prm_abort( |
4176 | const struct sctp_endpoint *ep, |
4177 | const struct sctp_association *asoc, |
4178 | const sctp_subtype_t type, |
4179 | void *arg, |
4180 | sctp_cmd_seq_t *commands) |
4181 | { |
4182 | /* There is a single T1 timer, so we should be able to use |
4183 | * common function with the COOKIE-WAIT state. |
4184 | */ |
4185 | return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands); |
4186 | } |
4187 | |
4188 | /* |
4189 | * sctp_sf_shutdown_pending_prm_abort |
4190 | * |
4191 | * Inputs |
4192 | * (endpoint, asoc) |
4193 | * |
4194 | * The RFC does not explicitly address this issue, but is the route through the |
4195 | * state table when someone issues an abort while in SHUTDOWN-PENDING state. |
4196 | * |
4197 | * Outputs |
4198 | * (timers) |
4199 | */ |
4200 | sctp_disposition_t sctp_sf_shutdown_pending_prm_abort( |
4201 | const struct sctp_endpoint *ep, |
4202 | const struct sctp_association *asoc, |
4203 | const sctp_subtype_t type, |
4204 | void *arg, |
4205 | sctp_cmd_seq_t *commands) |
4206 | { |
4207 | /* Stop the T5-shutdown guard timer. */ |
4208 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4209 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
4210 | |
4211 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); |
4212 | } |
4213 | |
4214 | /* |
4215 | * sctp_sf_shutdown_sent_prm_abort |
4216 | * |
4217 | * Inputs |
4218 | * (endpoint, asoc) |
4219 | * |
4220 | * The RFC does not explicitly address this issue, but is the route through the |
4221 | * state table when someone issues an abort while in SHUTDOWN-SENT state. |
4222 | * |
4223 | * Outputs |
4224 | * (timers) |
4225 | */ |
4226 | sctp_disposition_t sctp_sf_shutdown_sent_prm_abort( |
4227 | const struct sctp_endpoint *ep, |
4228 | const struct sctp_association *asoc, |
4229 | const sctp_subtype_t type, |
4230 | void *arg, |
4231 | sctp_cmd_seq_t *commands) |
4232 | { |
4233 | /* Stop the T2-shutdown timer. */ |
4234 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4235 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
4236 | |
4237 | /* Stop the T5-shutdown guard timer. */ |
4238 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4239 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
4240 | |
4241 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); |
4242 | } |
4243 | |
4244 | /* |
4245 | * sctp_sf_cookie_echoed_prm_abort |
4246 | * |
4247 | * Inputs |
4248 | * (endpoint, asoc) |
4249 | * |
4250 | * The RFC does not explcitly address this issue, but is the route through the |
4251 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
4252 | * |
4253 | * Outputs |
4254 | * (timers) |
4255 | */ |
4256 | sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort( |
4257 | const struct sctp_endpoint *ep, |
4258 | const struct sctp_association *asoc, |
4259 | const sctp_subtype_t type, |
4260 | void *arg, |
4261 | sctp_cmd_seq_t *commands) |
4262 | { |
4263 | /* The same T2 timer, so we should be able to use |
4264 | * common function with the SHUTDOWN-SENT state. |
4265 | */ |
4266 | return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands); |
4267 | } |
4268 | |
4269 | /* |
4270 | * Process the REQUESTHEARTBEAT primitive |
4271 | * |
4272 | * 10.1 ULP-to-SCTP |
4273 | * J) Request Heartbeat |
4274 | * |
4275 | * Format: REQUESTHEARTBEAT(association id, destination transport address) |
4276 | * |
4277 | * -> result |
4278 | * |
4279 | * Instructs the local endpoint to perform a HeartBeat on the specified |
4280 | * destination transport address of the given association. The returned |
4281 | * result should indicate whether the transmission of the HEARTBEAT |
4282 | * chunk to the destination address is successful. |
4283 | * |
4284 | * Mandatory attributes: |
4285 | * |
4286 | * o association id - local handle to the SCTP association |
4287 | * |
4288 | * o destination transport address - the transport address of the |
4289 | * association on which a heartbeat should be issued. |
4290 | */ |
4291 | sctp_disposition_t sctp_sf_do_prm_requestheartbeat( |
4292 | const struct sctp_endpoint *ep, |
4293 | const struct sctp_association *asoc, |
4294 | const sctp_subtype_t type, |
4295 | void *arg, |
4296 | sctp_cmd_seq_t *commands) |
4297 | { |
4298 | return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg, |
4299 | commands); |
4300 | } |
4301 | |
4302 | /* |
4303 | * ADDIP Section 4.1 ASCONF Chunk Procedures |
4304 | * When an endpoint has an ASCONF signaled change to be sent to the |
4305 | * remote endpoint it should do A1 to A9 |
4306 | */ |
4307 | sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep, |
4308 | const struct sctp_association *asoc, |
4309 | const sctp_subtype_t type, |
4310 | void *arg, |
4311 | sctp_cmd_seq_t *commands) |
4312 | { |
4313 | struct sctp_chunk *chunk = arg; |
4314 | |
4315 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
4316 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
4317 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
4318 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
4319 | return SCTP_DISPOSITION_CONSUME; |
4320 | } |
4321 | |
4322 | /* |
4323 | * Ignore the primitive event |
4324 | * |
4325 | * The return value is the disposition of the primitive. |
4326 | */ |
4327 | sctp_disposition_t sctp_sf_ignore_primitive( |
4328 | const struct sctp_endpoint *ep, |
4329 | const struct sctp_association *asoc, |
4330 | const sctp_subtype_t type, |
4331 | void *arg, |
4332 | sctp_cmd_seq_t *commands) |
4333 | { |
4334 | SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive); |
4335 | return SCTP_DISPOSITION_DISCARD; |
4336 | } |
4337 | |
4338 | /*************************************************************************** |
4339 | * These are the state functions for the OTHER events. |
4340 | ***************************************************************************/ |
4341 | |
4342 | /* |
4343 | * Start the shutdown negotiation. |
4344 | * |
4345 | * From Section 9.2: |
4346 | * Once all its outstanding data has been acknowledged, the endpoint |
4347 | * shall send a SHUTDOWN chunk to its peer including in the Cumulative |
4348 | * TSN Ack field the last sequential TSN it has received from the peer. |
4349 | * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT |
4350 | * state. If the timer expires, the endpoint must re-send the SHUTDOWN |
4351 | * with the updated last sequential TSN received from its peer. |
4352 | * |
4353 | * The return value is the disposition. |
4354 | */ |
4355 | sctp_disposition_t sctp_sf_do_9_2_start_shutdown( |
4356 | const struct sctp_endpoint *ep, |
4357 | const struct sctp_association *asoc, |
4358 | const sctp_subtype_t type, |
4359 | void *arg, |
4360 | sctp_cmd_seq_t *commands) |
4361 | { |
4362 | struct sctp_chunk *reply; |
4363 | |
4364 | /* Once all its outstanding data has been acknowledged, the |
4365 | * endpoint shall send a SHUTDOWN chunk to its peer including |
4366 | * in the Cumulative TSN Ack field the last sequential TSN it |
4367 | * has received from the peer. |
4368 | */ |
4369 | reply = sctp_make_shutdown(asoc, NULL); |
4370 | if (!reply) |
4371 | goto nomem; |
4372 | |
4373 | /* Set the transport for the SHUTDOWN chunk and the timeout for the |
4374 | * T2-shutdown timer. |
4375 | */ |
4376 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
4377 | |
4378 | /* It shall then start the T2-shutdown timer */ |
4379 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
4380 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
4381 | |
4382 | if (asoc->autoclose) |
4383 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4384 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
4385 | |
4386 | /* and enter the SHUTDOWN-SENT state. */ |
4387 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4388 | SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); |
4389 | |
4390 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
4391 | * |
4392 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
4393 | * or SHUTDOWN-ACK. |
4394 | */ |
4395 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
4396 | |
4397 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
4398 | |
4399 | return SCTP_DISPOSITION_CONSUME; |
4400 | |
4401 | nomem: |
4402 | return SCTP_DISPOSITION_NOMEM; |
4403 | } |
4404 | |
4405 | /* |
4406 | * Generate a SHUTDOWN ACK now that everything is SACK'd. |
4407 | * |
4408 | * From Section 9.2: |
4409 | * |
4410 | * If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
4411 | * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, |
4412 | * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the |
4413 | * endpoint must re-send the SHUTDOWN ACK. |
4414 | * |
4415 | * The return value is the disposition. |
4416 | */ |
4417 | sctp_disposition_t sctp_sf_do_9_2_shutdown_ack( |
4418 | const struct sctp_endpoint *ep, |
4419 | const struct sctp_association *asoc, |
4420 | const sctp_subtype_t type, |
4421 | void *arg, |
4422 | sctp_cmd_seq_t *commands) |
4423 | { |
4424 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; |
4425 | struct sctp_chunk *reply; |
4426 | |
4427 | /* There are 2 ways of getting here: |
4428 | * 1) called in response to a SHUTDOWN chunk |
4429 | * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. |
4430 | * |
4431 | * For the case (2), the arg parameter is set to NULL. We need |
4432 | * to check that we have a chunk before accessing it's fields. |
4433 | */ |
4434 | if (chunk) { |
4435 | if (!sctp_vtag_verify(chunk, asoc)) |
4436 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
4437 | |
4438 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
4439 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t))) |
4440 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
4441 | commands); |
4442 | } |
4443 | |
4444 | /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
4445 | * shall send a SHUTDOWN ACK ... |
4446 | */ |
4447 | reply = sctp_make_shutdown_ack(asoc, chunk); |
4448 | if (!reply) |
4449 | goto nomem; |
4450 | |
4451 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
4452 | * the T2-shutdown timer. |
4453 | */ |
4454 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
4455 | |
4456 | /* and start/restart a T2-shutdown timer of its own, */ |
4457 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
4458 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
4459 | |
4460 | if (asoc->autoclose) |
4461 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4462 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
4463 | |
4464 | /* Enter the SHUTDOWN-ACK-SENT state. */ |
4465 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4466 | SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); |
4467 | |
4468 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
4469 | * |
4470 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
4471 | * or SHUTDOWN-ACK. |
4472 | */ |
4473 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
4474 | |
4475 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
4476 | |
4477 | return SCTP_DISPOSITION_CONSUME; |
4478 | |
4479 | nomem: |
4480 | return SCTP_DISPOSITION_NOMEM; |
4481 | } |
4482 | |
4483 | /* |
4484 | * Ignore the event defined as other |
4485 | * |
4486 | * The return value is the disposition of the event. |
4487 | */ |
4488 | sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep, |
4489 | const struct sctp_association *asoc, |
4490 | const sctp_subtype_t type, |
4491 | void *arg, |
4492 | sctp_cmd_seq_t *commands) |
4493 | { |
4494 | SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other); |
4495 | return SCTP_DISPOSITION_DISCARD; |
4496 | } |
4497 | |
4498 | /************************************************************ |
4499 | * These are the state functions for handling timeout events. |
4500 | ************************************************************/ |
4501 | |
4502 | /* |
4503 | * RTX Timeout |
4504 | * |
4505 | * Section: 6.3.3 Handle T3-rtx Expiration |
4506 | * |
4507 | * Whenever the retransmission timer T3-rtx expires for a destination |
4508 | * address, do the following: |
4509 | * [See below] |
4510 | * |
4511 | * The return value is the disposition of the chunk. |
4512 | */ |
4513 | sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep, |
4514 | const struct sctp_association *asoc, |
4515 | const sctp_subtype_t type, |
4516 | void *arg, |
4517 | sctp_cmd_seq_t *commands) |
4518 | { |
4519 | struct sctp_transport *transport = arg; |
4520 | |
4521 | if (asoc->overall_error_count >= asoc->max_retrans) { |
4522 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
4523 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4524 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
4525 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
4526 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
4527 | return SCTP_DISPOSITION_DELETE_TCB; |
4528 | } |
4529 | |
4530 | /* E1) For the destination address for which the timer |
4531 | * expires, adjust its ssthresh with rules defined in Section |
4532 | * 7.2.3 and set the cwnd <- MTU. |
4533 | */ |
4534 | |
4535 | /* E2) For the destination address for which the timer |
4536 | * expires, set RTO <- RTO * 2 ("back off the timer"). The |
4537 | * maximum value discussed in rule C7 above (RTO.max) may be |
4538 | * used to provide an upper bound to this doubling operation. |
4539 | */ |
4540 | |
4541 | /* E3) Determine how many of the earliest (i.e., lowest TSN) |
4542 | * outstanding DATA chunks for the address for which the |
4543 | * T3-rtx has expired will fit into a single packet, subject |
4544 | * to the MTU constraint for the path corresponding to the |
4545 | * destination transport address to which the retransmission |
4546 | * is being sent (this may be different from the address for |
4547 | * which the timer expires [see Section 6.4]). Call this |
4548 | * value K. Bundle and retransmit those K DATA chunks in a |
4549 | * single packet to the destination endpoint. |
4550 | * |
4551 | * Note: Any DATA chunks that were sent to the address for |
4552 | * which the T3-rtx timer expired but did not fit in one MTU |
4553 | * (rule E3 above), should be marked for retransmission and |
4554 | * sent as soon as cwnd allows (normally when a SACK arrives). |
4555 | */ |
4556 | |
4557 | /* NB: Rules E4 and F1 are implicit in R1. */ |
4558 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); |
4559 | |
4560 | /* Do some failure management (Section 8.2). */ |
4561 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
4562 | |
4563 | return SCTP_DISPOSITION_CONSUME; |
4564 | } |
4565 | |
4566 | /* |
4567 | * Generate delayed SACK on timeout |
4568 | * |
4569 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
4570 | * |
4571 | * The guidelines on delayed acknowledgement algorithm specified in |
4572 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
4573 | * acknowledgement SHOULD be generated for at least every second packet |
4574 | * (not every second DATA chunk) received, and SHOULD be generated |
4575 | * within 200 ms of the arrival of any unacknowledged DATA chunk. In |
4576 | * some situations it may be beneficial for an SCTP transmitter to be |
4577 | * more conservative than the algorithms detailed in this document |
4578 | * allow. However, an SCTP transmitter MUST NOT be more aggressive than |
4579 | * the following algorithms allow. |
4580 | */ |
4581 | sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep, |
4582 | const struct sctp_association *asoc, |
4583 | const sctp_subtype_t type, |
4584 | void *arg, |
4585 | sctp_cmd_seq_t *commands) |
4586 | { |
4587 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
4588 | return SCTP_DISPOSITION_CONSUME; |
4589 | } |
4590 | |
4591 | /* |
4592 | * sctp_sf_t1_timer_expire |
4593 | * |
4594 | * Section: 4 Note: 2 |
4595 | * Verification Tag: |
4596 | * Inputs |
4597 | * (endpoint, asoc) |
4598 | * |
4599 | * RFC 2960 Section 4 Notes |
4600 | * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT |
4601 | * and re-start the T1-init timer without changing state. This MUST |
4602 | * be repeated up to 'Max.Init.Retransmits' times. After that, the |
4603 | * endpoint MUST abort the initialization process and report the |
4604 | * error to SCTP user. |
4605 | * |
4606 | * 3) If the T1-cookie timer expires, the endpoint MUST retransmit |
4607 | * COOKIE ECHO and re-start the T1-cookie timer without changing |
4608 | * state. This MUST be repeated up to 'Max.Init.Retransmits' times. |
4609 | * After that, the endpoint MUST abort the initialization process and |
4610 | * report the error to SCTP user. |
4611 | * |
4612 | * Outputs |
4613 | * (timers, events) |
4614 | * |
4615 | */ |
4616 | sctp_disposition_t sctp_sf_t1_timer_expire(const struct sctp_endpoint *ep, |
4617 | const struct sctp_association *asoc, |
4618 | const sctp_subtype_t type, |
4619 | void *arg, |
4620 | sctp_cmd_seq_t *commands) |
4621 | { |
4622 | struct sctp_chunk *repl; |
4623 | struct sctp_bind_addr *bp; |
4624 | sctp_event_timeout_t timer = (sctp_event_timeout_t) arg; |
4625 | int timeout; |
4626 | int attempts; |
4627 | |
4628 | timeout = asoc->timeouts[timer]; |
4629 | attempts = asoc->counters[SCTP_COUNTER_INIT_ERROR] + 1; |
4630 | repl = NULL; |
4631 | |
4632 | SCTP_DEBUG_PRINTK("Timer T1 expired.\n"); |
4633 | |
4634 | if (attempts < asoc->max_init_attempts) { |
4635 | switch (timer) { |
4636 | case SCTP_EVENT_TIMEOUT_T1_INIT: |
4637 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
4638 | repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); |
4639 | break; |
4640 | |
4641 | case SCTP_EVENT_TIMEOUT_T1_COOKIE: |
4642 | repl = sctp_make_cookie_echo(asoc, NULL); |
4643 | break; |
4644 | |
4645 | default: |
4646 | BUG(); |
4647 | break; |
4648 | }; |
4649 | |
4650 | if (!repl) |
4651 | goto nomem; |
4652 | |
4653 | /* Issue a sideeffect to do the needed accounting. */ |
4654 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, |
4655 | SCTP_TO(timer)); |
4656 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
4657 | } else { |
4658 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
4659 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
4660 | return SCTP_DISPOSITION_DELETE_TCB; |
4661 | } |
4662 | |
4663 | return SCTP_DISPOSITION_CONSUME; |
4664 | |
4665 | nomem: |
4666 | return SCTP_DISPOSITION_NOMEM; |
4667 | } |
4668 | |
4669 | /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN |
4670 | * with the updated last sequential TSN received from its peer. |
4671 | * |
4672 | * An endpoint should limit the number of retransmissions of the |
4673 | * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. |
4674 | * If this threshold is exceeded the endpoint should destroy the TCB and |
4675 | * MUST report the peer endpoint unreachable to the upper layer (and |
4676 | * thus the association enters the CLOSED state). The reception of any |
4677 | * packet from its peer (i.e. as the peer sends all of its queued DATA |
4678 | * chunks) should clear the endpoint's retransmission count and restart |
4679 | * the T2-Shutdown timer, giving its peer ample opportunity to transmit |
4680 | * all of its queued DATA chunks that have not yet been sent. |
4681 | */ |
4682 | sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep, |
4683 | const struct sctp_association *asoc, |
4684 | const sctp_subtype_t type, |
4685 | void *arg, |
4686 | sctp_cmd_seq_t *commands) |
4687 | { |
4688 | struct sctp_chunk *reply = NULL; |
4689 | |
4690 | SCTP_DEBUG_PRINTK("Timer T2 expired.\n"); |
4691 | if (asoc->overall_error_count >= asoc->max_retrans) { |
4692 | /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
4693 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4694 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
4695 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
4696 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
4697 | return SCTP_DISPOSITION_DELETE_TCB; |
4698 | } |
4699 | |
4700 | switch (asoc->state) { |
4701 | case SCTP_STATE_SHUTDOWN_SENT: |
4702 | reply = sctp_make_shutdown(asoc, NULL); |
4703 | break; |
4704 | |
4705 | case SCTP_STATE_SHUTDOWN_ACK_SENT: |
4706 | reply = sctp_make_shutdown_ack(asoc, NULL); |
4707 | break; |
4708 | |
4709 | default: |
4710 | BUG(); |
4711 | break; |
4712 | }; |
4713 | |
4714 | if (!reply) |
4715 | goto nomem; |
4716 | |
4717 | /* Do some failure management (Section 8.2). */ |
4718 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
4719 | SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); |
4720 | |
4721 | /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for |
4722 | * the T2-shutdown timer. |
4723 | */ |
4724 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
4725 | |
4726 | /* Restart the T2-shutdown timer. */ |
4727 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
4728 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
4729 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
4730 | return SCTP_DISPOSITION_CONSUME; |
4731 | |
4732 | nomem: |
4733 | return SCTP_DISPOSITION_NOMEM; |
4734 | } |
4735 | |
4736 | /* |
4737 | * ADDIP Section 4.1 ASCONF CHunk Procedures |
4738 | * If the T4 RTO timer expires the endpoint should do B1 to B5 |
4739 | */ |
4740 | sctp_disposition_t sctp_sf_t4_timer_expire( |
4741 | const struct sctp_endpoint *ep, |
4742 | const struct sctp_association *asoc, |
4743 | const sctp_subtype_t type, |
4744 | void *arg, |
4745 | sctp_cmd_seq_t *commands) |
4746 | { |
4747 | struct sctp_chunk *chunk = asoc->addip_last_asconf; |
4748 | struct sctp_transport *transport = chunk->transport; |
4749 | |
4750 | /* ADDIP 4.1 B1) Increment the error counters and perform path failure |
4751 | * detection on the appropriate destination address as defined in |
4752 | * RFC2960 [5] section 8.1 and 8.2. |
4753 | */ |
4754 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
4755 | |
4756 | /* Reconfig T4 timer and transport. */ |
4757 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
4758 | |
4759 | /* ADDIP 4.1 B2) Increment the association error counters and perform |
4760 | * endpoint failure detection on the association as defined in |
4761 | * RFC2960 [5] section 8.1 and 8.2. |
4762 | * association error counter is incremented in SCTP_CMD_STRIKE. |
4763 | */ |
4764 | if (asoc->overall_error_count >= asoc->max_retrans) { |
4765 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
4766 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
4767 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4768 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
4769 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
4770 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
4771 | return SCTP_DISPOSITION_ABORT; |
4772 | } |
4773 | |
4774 | /* ADDIP 4.1 B3) Back-off the destination address RTO value to which |
4775 | * the ASCONF chunk was sent by doubling the RTO timer value. |
4776 | * This is done in SCTP_CMD_STRIKE. |
4777 | */ |
4778 | |
4779 | /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible |
4780 | * choose an alternate destination address (please refer to RFC2960 |
4781 | * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this |
4782 | * chunk, it MUST be the same (including its serial number) as the last |
4783 | * ASCONF sent. |
4784 | */ |
4785 | sctp_chunk_hold(asoc->addip_last_asconf); |
4786 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
4787 | SCTP_CHUNK(asoc->addip_last_asconf)); |
4788 | |
4789 | /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different |
4790 | * destination is selected, then the RTO used will be that of the new |
4791 | * destination address. |
4792 | */ |
4793 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
4794 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
4795 | |
4796 | return SCTP_DISPOSITION_CONSUME; |
4797 | } |
4798 | |
4799 | /* sctpimpguide-05 Section 2.12.2 |
4800 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
4801 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
4802 | * At the expiration of this timer the sender SHOULD abort the association |
4803 | * by sending an ABORT chunk. |
4804 | */ |
4805 | sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep, |
4806 | const struct sctp_association *asoc, |
4807 | const sctp_subtype_t type, |
4808 | void *arg, |
4809 | sctp_cmd_seq_t *commands) |
4810 | { |
4811 | struct sctp_chunk *reply = NULL; |
4812 | |
4813 | SCTP_DEBUG_PRINTK("Timer T5 expired.\n"); |
4814 | |
4815 | reply = sctp_make_abort(asoc, NULL, 0); |
4816 | if (!reply) |
4817 | goto nomem; |
4818 | |
4819 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
4820 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
4821 | SCTP_U32(SCTP_ERROR_NO_ERROR)); |
4822 | |
4823 | return SCTP_DISPOSITION_DELETE_TCB; |
4824 | nomem: |
4825 | return SCTP_DISPOSITION_NOMEM; |
4826 | } |
4827 | |
4828 | /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, |
4829 | * the association is automatically closed by starting the shutdown process. |
4830 | * The work that needs to be done is same as when SHUTDOWN is initiated by |
4831 | * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). |
4832 | */ |
4833 | sctp_disposition_t sctp_sf_autoclose_timer_expire( |
4834 | const struct sctp_endpoint *ep, |
4835 | const struct sctp_association *asoc, |
4836 | const sctp_subtype_t type, |
4837 | void *arg, |
4838 | sctp_cmd_seq_t *commands) |
4839 | { |
4840 | int disposition; |
4841 | |
4842 | /* From 9.2 Shutdown of an Association |
4843 | * Upon receipt of the SHUTDOWN primitive from its upper |
4844 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
4845 | * remains there until all outstanding data has been |
4846 | * acknowledged by its peer. The endpoint accepts no new data |
4847 | * from its upper layer, but retransmits data to the far end |
4848 | * if necessary to fill gaps. |
4849 | */ |
4850 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
4851 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
4852 | |
4853 | /* sctpimpguide-05 Section 2.12.2 |
4854 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
4855 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
4856 | */ |
4857 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
4858 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
4859 | disposition = SCTP_DISPOSITION_CONSUME; |
4860 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
4861 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, |
4862 | arg, commands); |
4863 | } |
4864 | return disposition; |
4865 | } |
4866 | |
4867 | /***************************************************************************** |
4868 | * These are sa state functions which could apply to all types of events. |
4869 | ****************************************************************************/ |
4870 | |
4871 | /* |
4872 | * This table entry is not implemented. |
4873 | * |
4874 | * Inputs |
4875 | * (endpoint, asoc, chunk) |
4876 | * |
4877 | * The return value is the disposition of the chunk. |
4878 | */ |
4879 | sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep, |
4880 | const struct sctp_association *asoc, |
4881 | const sctp_subtype_t type, |
4882 | void *arg, |
4883 | sctp_cmd_seq_t *commands) |
4884 | { |
4885 | return SCTP_DISPOSITION_NOT_IMPL; |
4886 | } |
4887 | |
4888 | /* |
4889 | * This table entry represents a bug. |
4890 | * |
4891 | * Inputs |
4892 | * (endpoint, asoc, chunk) |
4893 | * |
4894 | * The return value is the disposition of the chunk. |
4895 | */ |
4896 | sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep, |
4897 | const struct sctp_association *asoc, |
4898 | const sctp_subtype_t type, |
4899 | void *arg, |
4900 | sctp_cmd_seq_t *commands) |
4901 | { |
4902 | return SCTP_DISPOSITION_BUG; |
4903 | } |
4904 | |
4905 | /* |
4906 | * This table entry represents the firing of a timer in the wrong state. |
4907 | * Since timer deletion cannot be guaranteed a timer 'may' end up firing |
4908 | * when the association is in the wrong state. This event should |
4909 | * be ignored, so as to prevent any rearming of the timer. |
4910 | * |
4911 | * Inputs |
4912 | * (endpoint, asoc, chunk) |
4913 | * |
4914 | * The return value is the disposition of the chunk. |
4915 | */ |
4916 | sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep, |
4917 | const struct sctp_association *asoc, |
4918 | const sctp_subtype_t type, |
4919 | void *arg, |
4920 | sctp_cmd_seq_t *commands) |
4921 | { |
4922 | SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk); |
4923 | return SCTP_DISPOSITION_CONSUME; |
4924 | } |
4925 | |
4926 | /******************************************************************** |
4927 | * 2nd Level Abstractions |
4928 | ********************************************************************/ |
4929 | |
4930 | /* Pull the SACK chunk based on the SACK header. */ |
4931 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) |
4932 | { |
4933 | struct sctp_sackhdr *sack; |
4934 | unsigned int len; |
4935 | __u16 num_blocks; |
4936 | __u16 num_dup_tsns; |
4937 | |
4938 | /* Protect ourselves from reading too far into |
4939 | * the skb from a bogus sender. |
4940 | */ |
4941 | sack = (struct sctp_sackhdr *) chunk->skb->data; |
4942 | |
4943 | num_blocks = ntohs(sack->num_gap_ack_blocks); |
4944 | num_dup_tsns = ntohs(sack->num_dup_tsns); |
4945 | len = sizeof(struct sctp_sackhdr); |
4946 | len += (num_blocks + num_dup_tsns) * sizeof(__u32); |
4947 | if (len > chunk->skb->len) |
4948 | return NULL; |
4949 | |
4950 | skb_pull(chunk->skb, len); |
4951 | |
4952 | return sack; |
4953 | } |
4954 | |
4955 | /* Create an ABORT packet to be sent as a response, with the specified |
4956 | * error causes. |
4957 | */ |
4958 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, |
4959 | const struct sctp_association *asoc, |
4960 | struct sctp_chunk *chunk, |
4961 | const void *payload, |
4962 | size_t paylen) |
4963 | { |
4964 | struct sctp_packet *packet; |
4965 | struct sctp_chunk *abort; |
4966 | |
4967 | packet = sctp_ootb_pkt_new(asoc, chunk); |
4968 | |
4969 | if (packet) { |
4970 | /* Make an ABORT. |
4971 | * The T bit will be set if the asoc is NULL. |
4972 | */ |
4973 | abort = sctp_make_abort(asoc, chunk, paylen); |
4974 | if (!abort) { |
4975 | sctp_ootb_pkt_free(packet); |
4976 | return NULL; |
4977 | } |
4978 | |
4979 | /* Reflect vtag if T-Bit is set */ |
4980 | if (sctp_test_T_bit(abort)) |
4981 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
4982 | |
4983 | /* Add specified error causes, i.e., payload, to the |
4984 | * end of the chunk. |
4985 | */ |
4986 | sctp_addto_chunk(abort, paylen, payload); |
4987 | |
4988 | /* Set the skb to the belonging sock for accounting. */ |
4989 | abort->skb->sk = ep->base.sk; |
4990 | |
4991 | sctp_packet_append_chunk(packet, abort); |
4992 | |
4993 | } |
4994 | |
4995 | return packet; |
4996 | } |
4997 | |
4998 | /* Allocate a packet for responding in the OOTB conditions. */ |
4999 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, |
5000 | const struct sctp_chunk *chunk) |
5001 | { |
5002 | struct sctp_packet *packet; |
5003 | struct sctp_transport *transport; |
5004 | __u16 sport; |
5005 | __u16 dport; |
5006 | __u32 vtag; |
5007 | |
5008 | /* Get the source and destination port from the inbound packet. */ |
5009 | sport = ntohs(chunk->sctp_hdr->dest); |
5010 | dport = ntohs(chunk->sctp_hdr->source); |
5011 | |
5012 | /* The V-tag is going to be the same as the inbound packet if no |
5013 | * association exists, otherwise, use the peer's vtag. |
5014 | */ |
5015 | if (asoc) { |
5016 | vtag = asoc->peer.i.init_tag; |
5017 | } else { |
5018 | /* Special case the INIT and stale COOKIE_ECHO as there is no |
5019 | * vtag yet. |
5020 | */ |
5021 | switch(chunk->chunk_hdr->type) { |
5022 | case SCTP_CID_INIT: |
5023 | { |
5024 | sctp_init_chunk_t *init; |
5025 | |
5026 | init = (sctp_init_chunk_t *)chunk->chunk_hdr; |
5027 | vtag = ntohl(init->init_hdr.init_tag); |
5028 | break; |
5029 | } |
5030 | default: |
5031 | vtag = ntohl(chunk->sctp_hdr->vtag); |
5032 | break; |
5033 | } |
5034 | } |
5035 | |
5036 | /* Make a transport for the bucket, Eliza... */ |
5037 | transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC); |
5038 | if (!transport) |
5039 | goto nomem; |
5040 | |
5041 | /* Cache a route for the transport with the chunk's destination as |
5042 | * the source address. |
5043 | */ |
5044 | sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, |
5045 | sctp_sk(sctp_get_ctl_sock())); |
5046 | |
5047 | packet = sctp_packet_init(&transport->packet, transport, sport, dport); |
5048 | packet = sctp_packet_config(packet, vtag, 0); |
5049 | |
5050 | return packet; |
5051 | |
5052 | nomem: |
5053 | return NULL; |
5054 | } |
5055 | |
5056 | /* Free the packet allocated earlier for responding in the OOTB condition. */ |
5057 | void sctp_ootb_pkt_free(struct sctp_packet *packet) |
5058 | { |
5059 | sctp_transport_free(packet->transport); |
5060 | } |
5061 | |
5062 | /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ |
5063 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, |
5064 | const struct sctp_association *asoc, |
5065 | const struct sctp_chunk *chunk, |
5066 | sctp_cmd_seq_t *commands, |
5067 | struct sctp_chunk *err_chunk) |
5068 | { |
5069 | struct sctp_packet *packet; |
5070 | |
5071 | if (err_chunk) { |
5072 | packet = sctp_ootb_pkt_new(asoc, chunk); |
5073 | if (packet) { |
5074 | struct sctp_signed_cookie *cookie; |
5075 | |
5076 | /* Override the OOTB vtag from the cookie. */ |
5077 | cookie = chunk->subh.cookie_hdr; |
5078 | packet->vtag = cookie->c.peer_vtag; |
5079 | |
5080 | /* Set the skb to the belonging sock for accounting. */ |
5081 | err_chunk->skb->sk = ep->base.sk; |
5082 | sctp_packet_append_chunk(packet, err_chunk); |
5083 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
5084 | SCTP_PACKET(packet)); |
5085 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
5086 | } else |
5087 | sctp_chunk_free (err_chunk); |
5088 | } |
5089 | } |
5090 | |
5091 | |
5092 | /* Process a data chunk */ |
5093 | static int sctp_eat_data(const struct sctp_association *asoc, |
5094 | struct sctp_chunk *chunk, |
5095 | sctp_cmd_seq_t *commands) |
5096 | { |
5097 | sctp_datahdr_t *data_hdr; |
5098 | struct sctp_chunk *err; |
5099 | size_t datalen; |
5100 | sctp_verb_t deliver; |
5101 | int tmp; |
5102 | __u32 tsn; |
5103 | |
5104 | data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data; |
5105 | skb_pull(chunk->skb, sizeof(sctp_datahdr_t)); |
5106 | |
5107 | tsn = ntohl(data_hdr->tsn); |
5108 | SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn); |
5109 | |
5110 | /* ASSERT: Now skb->data is really the user data. */ |
5111 | |
5112 | /* Process ECN based congestion. |
5113 | * |
5114 | * Since the chunk structure is reused for all chunks within |
5115 | * a packet, we use ecn_ce_done to track if we've already |
5116 | * done CE processing for this packet. |
5117 | * |
5118 | * We need to do ECN processing even if we plan to discard the |
5119 | * chunk later. |
5120 | */ |
5121 | |
5122 | if (!chunk->ecn_ce_done) { |
5123 | struct sctp_af *af; |
5124 | chunk->ecn_ce_done = 1; |
5125 | |
5126 | af = sctp_get_af_specific( |
5127 | ipver2af(chunk->skb->nh.iph->version)); |
5128 | |
5129 | if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) { |
5130 | /* Do real work as sideffect. */ |
5131 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, |
5132 | SCTP_U32(tsn)); |
5133 | } |
5134 | } |
5135 | |
5136 | tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); |
5137 | if (tmp < 0) { |
5138 | /* The TSN is too high--silently discard the chunk and |
5139 | * count on it getting retransmitted later. |
5140 | */ |
5141 | return SCTP_IERROR_HIGH_TSN; |
5142 | } else if (tmp > 0) { |
5143 | /* This is a duplicate. Record it. */ |
5144 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); |
5145 | return SCTP_IERROR_DUP_TSN; |
5146 | } |
5147 | |
5148 | /* This is a new TSN. */ |
5149 | |
5150 | /* Discard if there is no room in the receive window. |
5151 | * Actually, allow a little bit of overflow (up to a MTU). |
5152 | */ |
5153 | datalen = ntohs(chunk->chunk_hdr->length); |
5154 | datalen -= sizeof(sctp_data_chunk_t); |
5155 | |
5156 | deliver = SCTP_CMD_CHUNK_ULP; |
5157 | |
5158 | /* Think about partial delivery. */ |
5159 | if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { |
5160 | |
5161 | /* Even if we don't accept this chunk there is |
5162 | * memory pressure. |
5163 | */ |
5164 | sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); |
5165 | } |
5166 | |
5167 | /* Spill over rwnd a little bit. Note: While allowed, this spill over |
5168 | * seems a bit troublesome in that frag_point varies based on |
5169 | * PMTU. In cases, such as loopback, this might be a rather |
5170 | * large spill over. |
5171 | */ |
5172 | if (!asoc->rwnd || asoc->rwnd_over || |
5173 | (datalen > asoc->rwnd + asoc->frag_point)) { |
5174 | |
5175 | /* If this is the next TSN, consider reneging to make |
5176 | * room. Note: Playing nice with a confused sender. A |
5177 | * malicious sender can still eat up all our buffer |
5178 | * space and in the future we may want to detect and |
5179 | * do more drastic reneging. |
5180 | */ |
5181 | if (sctp_tsnmap_has_gap(&asoc->peer.tsn_map) && |
5182 | (sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1) == tsn) { |
5183 | SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn); |
5184 | deliver = SCTP_CMD_RENEGE; |
5185 | } else { |
5186 | SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, " |
5187 | "rwnd: %d\n", tsn, datalen, |
5188 | asoc->rwnd); |
5189 | return SCTP_IERROR_IGNORE_TSN; |
5190 | } |
5191 | } |
5192 | |
5193 | /* |
5194 | * Section 3.3.10.9 No User Data (9) |
5195 | * |
5196 | * Cause of error |
5197 | * --------------- |
5198 | * No User Data: This error cause is returned to the originator of a |
5199 | * DATA chunk if a received DATA chunk has no user data. |
5200 | */ |
5201 | if (unlikely(0 == datalen)) { |
5202 | err = sctp_make_abort_no_data(asoc, chunk, tsn); |
5203 | if (err) { |
5204 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
5205 | SCTP_CHUNK(err)); |
5206 | } |
5207 | /* We are going to ABORT, so we might as well stop |
5208 | * processing the rest of the chunks in the packet. |
5209 | */ |
5210 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
5211 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
5212 | SCTP_U32(SCTP_ERROR_NO_DATA)); |
5213 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
5214 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
5215 | return SCTP_IERROR_NO_DATA; |
5216 | } |
5217 | |
5218 | /* If definately accepting the DATA chunk, record its TSN, otherwise |
5219 | * wait for renege processing. |
5220 | */ |
5221 | if (SCTP_CMD_CHUNK_ULP == deliver) |
5222 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); |
5223 | |
5224 | /* Note: Some chunks may get overcounted (if we drop) or overcounted |
5225 | * if we renege and the chunk arrives again. |
5226 | */ |
5227 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
5228 | SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS); |
5229 | else |
5230 | SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS); |
5231 | |
5232 | /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number |
5233 | * |
5234 | * If an endpoint receive a DATA chunk with an invalid stream |
5235 | * identifier, it shall acknowledge the reception of the DATA chunk |
5236 | * following the normal procedure, immediately send an ERROR chunk |
5237 | * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) |
5238 | * and discard the DATA chunk. |
5239 | */ |
5240 | if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) { |
5241 | err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, |
5242 | &data_hdr->stream, |
5243 | sizeof(data_hdr->stream)); |
5244 | if (err) |
5245 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
5246 | SCTP_CHUNK(err)); |
5247 | return SCTP_IERROR_BAD_STREAM; |
5248 | } |
5249 | |
5250 | /* Send the data up to the user. Note: Schedule the |
5251 | * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK |
5252 | * chunk needs the updated rwnd. |
5253 | */ |
5254 | sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); |
5255 | |
5256 | return SCTP_IERROR_NO_ERROR; |
5257 | } |