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1da177e4 LT |
1 | /* SCTP kernel reference Implementation |
2 | * (C) Copyright IBM Corp. 2001, 2004 | |
3 | * Copyright (c) 1999-2000 Cisco, Inc. | |
4 | * Copyright (c) 1999-2001 Motorola, Inc. | |
5 | * Copyright (c) 2001 Intel Corp. | |
6 | * Copyright (c) 2001 Nokia, Inc. | |
7 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
8 | * | |
9 | * This abstraction carries sctp events to the ULP (sockets). | |
10 | * | |
11 | * The SCTP reference implementation is free software; | |
12 | * you can redistribute it and/or modify it under the terms of | |
13 | * the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2, or (at your option) | |
15 | * any later version. | |
16 | * | |
17 | * The SCTP reference implementation is distributed in the hope that it | |
18 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied | |
19 | * ************************ | |
20 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
21 | * See the GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with GNU CC; see the file COPYING. If not, write to | |
25 | * the Free Software Foundation, 59 Temple Place - Suite 330, | |
26 | * Boston, MA 02111-1307, USA. | |
27 | * | |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email address(es): | |
30 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
31 | * | |
32 | * Or submit a bug report through the following website: | |
33 | * http://www.sf.net/projects/lksctp | |
34 | * | |
35 | * Written or modified by: | |
36 | * Jon Grimm <jgrimm@us.ibm.com> | |
37 | * La Monte H.P. Yarroll <piggy@acm.org> | |
38 | * Sridhar Samudrala <sri@us.ibm.com> | |
39 | * | |
40 | * Any bugs reported given to us we will try to fix... any fixes shared will | |
41 | * be incorporated into the next SCTP release. | |
42 | */ | |
43 | ||
44 | #include <linux/types.h> | |
45 | #include <linux/skbuff.h> | |
46 | #include <net/sock.h> | |
47 | #include <net/sctp/structs.h> | |
48 | #include <net/sctp/sctp.h> | |
49 | #include <net/sctp/sm.h> | |
50 | ||
51 | /* Forward declarations for internal helpers. */ | |
52 | static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
53 | struct sctp_ulpevent *); | |
54 | static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *, | |
55 | struct sctp_ulpevent *); | |
56 | ||
57 | /* 1st Level Abstractions */ | |
58 | ||
59 | /* Initialize a ULP queue from a block of memory. */ | |
60 | struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, | |
61 | struct sctp_association *asoc) | |
62 | { | |
63 | memset(ulpq, 0, sizeof(struct sctp_ulpq)); | |
64 | ||
65 | ulpq->asoc = asoc; | |
66 | skb_queue_head_init(&ulpq->reasm); | |
67 | skb_queue_head_init(&ulpq->lobby); | |
68 | ulpq->pd_mode = 0; | |
69 | ulpq->malloced = 0; | |
70 | ||
71 | return ulpq; | |
72 | } | |
73 | ||
74 | ||
75 | /* Flush the reassembly and ordering queues. */ | |
76 | static void sctp_ulpq_flush(struct sctp_ulpq *ulpq) | |
77 | { | |
78 | struct sk_buff *skb; | |
79 | struct sctp_ulpevent *event; | |
80 | ||
81 | while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { | |
82 | event = sctp_skb2event(skb); | |
83 | sctp_ulpevent_free(event); | |
84 | } | |
85 | ||
86 | while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { | |
87 | event = sctp_skb2event(skb); | |
88 | sctp_ulpevent_free(event); | |
89 | } | |
90 | ||
91 | } | |
92 | ||
93 | /* Dispose of a ulpqueue. */ | |
94 | void sctp_ulpq_free(struct sctp_ulpq *ulpq) | |
95 | { | |
96 | sctp_ulpq_flush(ulpq); | |
97 | if (ulpq->malloced) | |
98 | kfree(ulpq); | |
99 | } | |
100 | ||
101 | /* Process an incoming DATA chunk. */ | |
102 | int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
3182cd84 | 103 | unsigned int __nocast gfp) |
1da177e4 LT |
104 | { |
105 | struct sk_buff_head temp; | |
106 | sctp_data_chunk_t *hdr; | |
107 | struct sctp_ulpevent *event; | |
108 | ||
109 | hdr = (sctp_data_chunk_t *) chunk->chunk_hdr; | |
110 | ||
111 | /* Create an event from the incoming chunk. */ | |
112 | event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); | |
113 | if (!event) | |
114 | return -ENOMEM; | |
115 | ||
116 | /* Do reassembly if needed. */ | |
117 | event = sctp_ulpq_reasm(ulpq, event); | |
118 | ||
119 | /* Do ordering if needed. */ | |
120 | if ((event) && (event->msg_flags & MSG_EOR)){ | |
121 | /* Create a temporary list to collect chunks on. */ | |
122 | skb_queue_head_init(&temp); | |
123 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
124 | ||
125 | event = sctp_ulpq_order(ulpq, event); | |
126 | } | |
127 | ||
128 | /* Send event to the ULP. */ | |
129 | if (event) | |
130 | sctp_ulpq_tail_event(ulpq, event); | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | /* Add a new event for propagation to the ULP. */ | |
136 | /* Clear the partial delivery mode for this socket. Note: This | |
137 | * assumes that no association is currently in partial delivery mode. | |
138 | */ | |
139 | int sctp_clear_pd(struct sock *sk) | |
140 | { | |
141 | struct sctp_sock *sp = sctp_sk(sk); | |
142 | ||
143 | sp->pd_mode = 0; | |
144 | if (!skb_queue_empty(&sp->pd_lobby)) { | |
145 | struct list_head *list; | |
146 | sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue); | |
147 | list = (struct list_head *)&sctp_sk(sk)->pd_lobby; | |
148 | INIT_LIST_HEAD(list); | |
149 | return 1; | |
150 | } | |
151 | return 0; | |
152 | } | |
153 | ||
154 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ | |
155 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) | |
156 | { | |
157 | ulpq->pd_mode = 0; | |
158 | return sctp_clear_pd(ulpq->asoc->base.sk); | |
159 | } | |
160 | ||
161 | ||
162 | ||
163 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) | |
164 | { | |
165 | struct sock *sk = ulpq->asoc->base.sk; | |
166 | struct sk_buff_head *queue; | |
167 | int clear_pd = 0; | |
168 | ||
169 | /* If the socket is just going to throw this away, do not | |
170 | * even try to deliver it. | |
171 | */ | |
172 | if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
173 | goto out_free; | |
174 | ||
175 | /* Check if the user wishes to receive this event. */ | |
176 | if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) | |
177 | goto out_free; | |
178 | ||
179 | /* If we are in partial delivery mode, post to the lobby until | |
180 | * partial delivery is cleared, unless, of course _this_ is | |
181 | * the association the cause of the partial delivery. | |
182 | */ | |
183 | ||
184 | if (!sctp_sk(sk)->pd_mode) { | |
185 | queue = &sk->sk_receive_queue; | |
186 | } else if (ulpq->pd_mode) { | |
187 | if (event->msg_flags & MSG_NOTIFICATION) | |
188 | queue = &sctp_sk(sk)->pd_lobby; | |
189 | else { | |
190 | clear_pd = event->msg_flags & MSG_EOR; | |
191 | queue = &sk->sk_receive_queue; | |
192 | } | |
193 | } else | |
194 | queue = &sctp_sk(sk)->pd_lobby; | |
195 | ||
196 | ||
197 | /* If we are harvesting multiple skbs they will be | |
198 | * collected on a list. | |
199 | */ | |
200 | if (sctp_event2skb(event)->list) | |
201 | sctp_skb_list_tail(sctp_event2skb(event)->list, queue); | |
202 | else | |
203 | __skb_queue_tail(queue, sctp_event2skb(event)); | |
204 | ||
205 | /* Did we just complete partial delivery and need to get | |
206 | * rolling again? Move pending data to the receive | |
207 | * queue. | |
208 | */ | |
209 | if (clear_pd) | |
210 | sctp_ulpq_clear_pd(ulpq); | |
211 | ||
212 | if (queue == &sk->sk_receive_queue) | |
213 | sk->sk_data_ready(sk, 0); | |
214 | return 1; | |
215 | ||
216 | out_free: | |
217 | if (sctp_event2skb(event)->list) | |
218 | sctp_queue_purge_ulpevents(sctp_event2skb(event)->list); | |
219 | else | |
220 | sctp_ulpevent_free(event); | |
221 | return 0; | |
222 | } | |
223 | ||
224 | /* 2nd Level Abstractions */ | |
225 | ||
226 | /* Helper function to store chunks that need to be reassembled. */ | |
227 | static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, | |
228 | struct sctp_ulpevent *event) | |
229 | { | |
230 | struct sk_buff *pos; | |
231 | struct sctp_ulpevent *cevent; | |
232 | __u32 tsn, ctsn; | |
233 | ||
234 | tsn = event->tsn; | |
235 | ||
236 | /* See if it belongs at the end. */ | |
237 | pos = skb_peek_tail(&ulpq->reasm); | |
238 | if (!pos) { | |
239 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
240 | return; | |
241 | } | |
242 | ||
243 | /* Short circuit just dropping it at the end. */ | |
244 | cevent = sctp_skb2event(pos); | |
245 | ctsn = cevent->tsn; | |
246 | if (TSN_lt(ctsn, tsn)) { | |
247 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
248 | return; | |
249 | } | |
250 | ||
251 | /* Find the right place in this list. We store them by TSN. */ | |
252 | skb_queue_walk(&ulpq->reasm, pos) { | |
253 | cevent = sctp_skb2event(pos); | |
254 | ctsn = cevent->tsn; | |
255 | ||
256 | if (TSN_lt(tsn, ctsn)) | |
257 | break; | |
258 | } | |
259 | ||
260 | /* Insert before pos. */ | |
261 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm); | |
262 | ||
263 | } | |
264 | ||
265 | /* Helper function to return an event corresponding to the reassembled | |
266 | * datagram. | |
267 | * This routine creates a re-assembled skb given the first and last skb's | |
268 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
269 | * payload was fragmented on the way and ip had to reassemble them. | |
270 | * We add the rest of skb's to the first skb's fraglist. | |
271 | */ | |
272 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff *f_frag, struct sk_buff *l_frag) | |
273 | { | |
274 | struct sk_buff *pos; | |
275 | struct sctp_ulpevent *event; | |
276 | struct sk_buff *pnext, *last; | |
277 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
278 | ||
279 | /* Store the pointer to the 2nd skb */ | |
280 | if (f_frag == l_frag) | |
281 | pos = NULL; | |
282 | else | |
283 | pos = f_frag->next; | |
284 | ||
285 | /* Get the last skb in the f_frag's frag_list if present. */ | |
286 | for (last = list; list; last = list, list = list->next); | |
287 | ||
288 | /* Add the list of remaining fragments to the first fragments | |
289 | * frag_list. | |
290 | */ | |
291 | if (last) | |
292 | last->next = pos; | |
293 | else | |
294 | skb_shinfo(f_frag)->frag_list = pos; | |
295 | ||
296 | /* Remove the first fragment from the reassembly queue. */ | |
297 | __skb_unlink(f_frag, f_frag->list); | |
298 | while (pos) { | |
299 | ||
300 | pnext = pos->next; | |
301 | ||
302 | /* Update the len and data_len fields of the first fragment. */ | |
303 | f_frag->len += pos->len; | |
304 | f_frag->data_len += pos->len; | |
305 | ||
306 | /* Remove the fragment from the reassembly queue. */ | |
307 | __skb_unlink(pos, pos->list); | |
308 | ||
309 | /* Break if we have reached the last fragment. */ | |
310 | if (pos == l_frag) | |
311 | break; | |
312 | pos->next = pnext; | |
313 | pos = pnext; | |
314 | }; | |
315 | ||
316 | event = sctp_skb2event(f_frag); | |
317 | SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS); | |
318 | ||
319 | return event; | |
320 | } | |
321 | ||
322 | ||
323 | /* Helper function to check if an incoming chunk has filled up the last | |
324 | * missing fragment in a SCTP datagram and return the corresponding event. | |
325 | */ | |
326 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) | |
327 | { | |
328 | struct sk_buff *pos; | |
329 | struct sctp_ulpevent *cevent; | |
330 | struct sk_buff *first_frag = NULL; | |
331 | __u32 ctsn, next_tsn; | |
332 | struct sctp_ulpevent *retval = NULL; | |
333 | ||
334 | /* Initialized to 0 just to avoid compiler warning message. Will | |
335 | * never be used with this value. It is referenced only after it | |
336 | * is set when we find the first fragment of a message. | |
337 | */ | |
338 | next_tsn = 0; | |
339 | ||
340 | /* The chunks are held in the reasm queue sorted by TSN. | |
341 | * Walk through the queue sequentially and look for a sequence of | |
342 | * fragmented chunks that complete a datagram. | |
343 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
344 | * is the first fragment of a datagram. Once these 2 fields are set | |
345 | * we expect to find the remaining middle fragments and the last | |
346 | * fragment in order. If not, first_frag is reset to NULL and we | |
347 | * start the next pass when we find another first fragment. | |
348 | */ | |
349 | skb_queue_walk(&ulpq->reasm, pos) { | |
350 | cevent = sctp_skb2event(pos); | |
351 | ctsn = cevent->tsn; | |
352 | ||
353 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
354 | case SCTP_DATA_FIRST_FRAG: | |
355 | first_frag = pos; | |
356 | next_tsn = ctsn + 1; | |
357 | break; | |
358 | ||
359 | case SCTP_DATA_MIDDLE_FRAG: | |
360 | if ((first_frag) && (ctsn == next_tsn)) | |
361 | next_tsn++; | |
362 | else | |
363 | first_frag = NULL; | |
364 | break; | |
365 | ||
366 | case SCTP_DATA_LAST_FRAG: | |
367 | if (first_frag && (ctsn == next_tsn)) | |
368 | goto found; | |
369 | else | |
370 | first_frag = NULL; | |
371 | break; | |
372 | }; | |
373 | ||
374 | } | |
375 | done: | |
376 | return retval; | |
377 | found: | |
378 | retval = sctp_make_reassembled_event(first_frag, pos); | |
379 | if (retval) | |
380 | retval->msg_flags |= MSG_EOR; | |
381 | goto done; | |
382 | } | |
383 | ||
384 | /* Retrieve the next set of fragments of a partial message. */ | |
385 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) | |
386 | { | |
387 | struct sk_buff *pos, *last_frag, *first_frag; | |
388 | struct sctp_ulpevent *cevent; | |
389 | __u32 ctsn, next_tsn; | |
390 | int is_last; | |
391 | struct sctp_ulpevent *retval; | |
392 | ||
393 | /* The chunks are held in the reasm queue sorted by TSN. | |
394 | * Walk through the queue sequentially and look for the first | |
395 | * sequence of fragmented chunks. | |
396 | */ | |
397 | ||
398 | if (skb_queue_empty(&ulpq->reasm)) | |
399 | return NULL; | |
400 | ||
401 | last_frag = first_frag = NULL; | |
402 | retval = NULL; | |
403 | next_tsn = 0; | |
404 | is_last = 0; | |
405 | ||
406 | skb_queue_walk(&ulpq->reasm, pos) { | |
407 | cevent = sctp_skb2event(pos); | |
408 | ctsn = cevent->tsn; | |
409 | ||
410 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
411 | case SCTP_DATA_MIDDLE_FRAG: | |
412 | if (!first_frag) { | |
413 | first_frag = pos; | |
414 | next_tsn = ctsn + 1; | |
415 | last_frag = pos; | |
416 | } else if (next_tsn == ctsn) | |
417 | next_tsn++; | |
418 | else | |
419 | goto done; | |
420 | break; | |
421 | case SCTP_DATA_LAST_FRAG: | |
422 | if (!first_frag) | |
423 | first_frag = pos; | |
424 | else if (ctsn != next_tsn) | |
425 | goto done; | |
426 | last_frag = pos; | |
427 | is_last = 1; | |
428 | goto done; | |
429 | default: | |
430 | return NULL; | |
431 | }; | |
432 | } | |
433 | ||
434 | /* We have the reassembled event. There is no need to look | |
435 | * further. | |
436 | */ | |
437 | done: | |
438 | retval = sctp_make_reassembled_event(first_frag, last_frag); | |
439 | if (retval && is_last) | |
440 | retval->msg_flags |= MSG_EOR; | |
441 | ||
442 | return retval; | |
443 | } | |
444 | ||
445 | ||
446 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
447 | * need reassembling. | |
448 | */ | |
449 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
450 | struct sctp_ulpevent *event) | |
451 | { | |
452 | struct sctp_ulpevent *retval = NULL; | |
453 | ||
454 | /* Check if this is part of a fragmented message. */ | |
455 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
456 | event->msg_flags |= MSG_EOR; | |
457 | return event; | |
458 | } | |
459 | ||
460 | sctp_ulpq_store_reasm(ulpq, event); | |
461 | if (!ulpq->pd_mode) | |
462 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
463 | else { | |
464 | __u32 ctsn, ctsnap; | |
465 | ||
466 | /* Do not even bother unless this is the next tsn to | |
467 | * be delivered. | |
468 | */ | |
469 | ctsn = event->tsn; | |
470 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
471 | if (TSN_lte(ctsn, ctsnap)) | |
472 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
473 | } | |
474 | ||
475 | return retval; | |
476 | } | |
477 | ||
478 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
479 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) | |
480 | { | |
481 | struct sk_buff *pos, *last_frag, *first_frag; | |
482 | struct sctp_ulpevent *cevent; | |
483 | __u32 ctsn, next_tsn; | |
484 | struct sctp_ulpevent *retval; | |
485 | ||
486 | /* The chunks are held in the reasm queue sorted by TSN. | |
487 | * Walk through the queue sequentially and look for a sequence of | |
488 | * fragmented chunks that start a datagram. | |
489 | */ | |
490 | ||
491 | if (skb_queue_empty(&ulpq->reasm)) | |
492 | return NULL; | |
493 | ||
494 | last_frag = first_frag = NULL; | |
495 | retval = NULL; | |
496 | next_tsn = 0; | |
497 | ||
498 | skb_queue_walk(&ulpq->reasm, pos) { | |
499 | cevent = sctp_skb2event(pos); | |
500 | ctsn = cevent->tsn; | |
501 | ||
502 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
503 | case SCTP_DATA_FIRST_FRAG: | |
504 | if (!first_frag) { | |
505 | first_frag = pos; | |
506 | next_tsn = ctsn + 1; | |
507 | last_frag = pos; | |
508 | } else | |
509 | goto done; | |
510 | break; | |
511 | ||
512 | case SCTP_DATA_MIDDLE_FRAG: | |
513 | if (!first_frag) | |
514 | return NULL; | |
515 | if (ctsn == next_tsn) { | |
516 | next_tsn++; | |
517 | last_frag = pos; | |
518 | } else | |
519 | goto done; | |
520 | break; | |
521 | default: | |
522 | return NULL; | |
523 | }; | |
524 | } | |
525 | ||
526 | /* We have the reassembled event. There is no need to look | |
527 | * further. | |
528 | */ | |
529 | done: | |
530 | retval = sctp_make_reassembled_event(first_frag, last_frag); | |
531 | return retval; | |
532 | } | |
533 | ||
534 | /* Helper function to gather skbs that have possibly become | |
535 | * ordered by an an incoming chunk. | |
536 | */ | |
537 | static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, | |
538 | struct sctp_ulpevent *event) | |
539 | { | |
540 | struct sk_buff *pos, *tmp; | |
541 | struct sctp_ulpevent *cevent; | |
542 | struct sctp_stream *in; | |
543 | __u16 sid, csid; | |
544 | __u16 ssn, cssn; | |
545 | ||
546 | sid = event->stream; | |
547 | ssn = event->ssn; | |
548 | in = &ulpq->asoc->ssnmap->in; | |
549 | ||
550 | /* We are holding the chunks by stream, by SSN. */ | |
551 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
552 | cevent = (struct sctp_ulpevent *) pos->cb; | |
553 | csid = cevent->stream; | |
554 | cssn = cevent->ssn; | |
555 | ||
556 | /* Have we gone too far? */ | |
557 | if (csid > sid) | |
558 | break; | |
559 | ||
560 | /* Have we not gone far enough? */ | |
561 | if (csid < sid) | |
562 | continue; | |
563 | ||
564 | if (cssn != sctp_ssn_peek(in, sid)) | |
565 | break; | |
566 | ||
567 | /* Found it, so mark in the ssnmap. */ | |
568 | sctp_ssn_next(in, sid); | |
569 | ||
570 | __skb_unlink(pos, pos->list); | |
571 | ||
572 | /* Attach all gathered skbs to the event. */ | |
573 | __skb_queue_tail(sctp_event2skb(event)->list, pos); | |
574 | } | |
575 | } | |
576 | ||
577 | /* Helper function to store chunks needing ordering. */ | |
578 | static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, | |
579 | struct sctp_ulpevent *event) | |
580 | { | |
581 | struct sk_buff *pos; | |
582 | struct sctp_ulpevent *cevent; | |
583 | __u16 sid, csid; | |
584 | __u16 ssn, cssn; | |
585 | ||
586 | pos = skb_peek_tail(&ulpq->lobby); | |
587 | if (!pos) { | |
588 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
589 | return; | |
590 | } | |
591 | ||
592 | sid = event->stream; | |
593 | ssn = event->ssn; | |
594 | ||
595 | cevent = (struct sctp_ulpevent *) pos->cb; | |
596 | csid = cevent->stream; | |
597 | cssn = cevent->ssn; | |
598 | if (sid > csid) { | |
599 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
600 | return; | |
601 | } | |
602 | ||
603 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
604 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
605 | return; | |
606 | } | |
607 | ||
608 | /* Find the right place in this list. We store them by | |
609 | * stream ID and then by SSN. | |
610 | */ | |
611 | skb_queue_walk(&ulpq->lobby, pos) { | |
612 | cevent = (struct sctp_ulpevent *) pos->cb; | |
613 | csid = cevent->stream; | |
614 | cssn = cevent->ssn; | |
615 | ||
616 | if (csid > sid) | |
617 | break; | |
618 | if (csid == sid && SSN_lt(ssn, cssn)) | |
619 | break; | |
620 | } | |
621 | ||
622 | ||
623 | /* Insert before pos. */ | |
624 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby); | |
625 | ||
626 | } | |
627 | ||
628 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
629 | struct sctp_ulpevent *event) | |
630 | { | |
631 | __u16 sid, ssn; | |
632 | struct sctp_stream *in; | |
633 | ||
634 | /* Check if this message needs ordering. */ | |
635 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
636 | return event; | |
637 | ||
638 | /* Note: The stream ID must be verified before this routine. */ | |
639 | sid = event->stream; | |
640 | ssn = event->ssn; | |
641 | in = &ulpq->asoc->ssnmap->in; | |
642 | ||
643 | /* Is this the expected SSN for this stream ID? */ | |
644 | if (ssn != sctp_ssn_peek(in, sid)) { | |
645 | /* We've received something out of order, so find where it | |
646 | * needs to be placed. We order by stream and then by SSN. | |
647 | */ | |
648 | sctp_ulpq_store_ordered(ulpq, event); | |
649 | return NULL; | |
650 | } | |
651 | ||
652 | /* Mark that the next chunk has been found. */ | |
653 | sctp_ssn_next(in, sid); | |
654 | ||
655 | /* Go find any other chunks that were waiting for | |
656 | * ordering. | |
657 | */ | |
658 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
659 | ||
660 | return event; | |
661 | } | |
662 | ||
663 | /* Helper function to gather skbs that have possibly become | |
664 | * ordered by forward tsn skipping their dependencies. | |
665 | */ | |
666 | static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) | |
667 | { | |
668 | struct sk_buff *pos, *tmp; | |
669 | struct sctp_ulpevent *cevent; | |
670 | struct sctp_ulpevent *event = NULL; | |
671 | struct sctp_stream *in; | |
672 | struct sk_buff_head temp; | |
673 | __u16 csid, cssn; | |
674 | ||
675 | in = &ulpq->asoc->ssnmap->in; | |
676 | ||
677 | /* We are holding the chunks by stream, by SSN. */ | |
678 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
679 | cevent = (struct sctp_ulpevent *) pos->cb; | |
680 | csid = cevent->stream; | |
681 | cssn = cevent->ssn; | |
682 | ||
683 | if (cssn != sctp_ssn_peek(in, csid)) | |
684 | break; | |
685 | ||
686 | /* Found it, so mark in the ssnmap. */ | |
687 | sctp_ssn_next(in, csid); | |
688 | ||
689 | __skb_unlink(pos, pos->list); | |
690 | if (!event) { | |
691 | /* Create a temporary list to collect chunks on. */ | |
692 | event = sctp_skb2event(pos); | |
693 | skb_queue_head_init(&temp); | |
694 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
695 | } else { | |
696 | /* Attach all gathered skbs to the event. */ | |
697 | __skb_queue_tail(sctp_event2skb(event)->list, pos); | |
698 | } | |
699 | } | |
700 | ||
701 | /* Send event to the ULP. */ | |
702 | if (event) | |
703 | sctp_ulpq_tail_event(ulpq, event); | |
704 | } | |
705 | ||
706 | /* Skip over an SSN. */ | |
707 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) | |
708 | { | |
709 | struct sctp_stream *in; | |
710 | ||
711 | /* Note: The stream ID must be verified before this routine. */ | |
712 | in = &ulpq->asoc->ssnmap->in; | |
713 | ||
714 | /* Is this an old SSN? If so ignore. */ | |
715 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
716 | return; | |
717 | ||
718 | /* Mark that we are no longer expecting this SSN or lower. */ | |
719 | sctp_ssn_skip(in, sid, ssn); | |
720 | ||
721 | /* Go find any other chunks that were waiting for | |
722 | * ordering and deliver them if needed. | |
723 | */ | |
724 | sctp_ulpq_reap_ordered(ulpq); | |
725 | return; | |
726 | } | |
727 | ||
728 | /* Renege 'needed' bytes from the ordering queue. */ | |
729 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
730 | { | |
731 | __u16 freed = 0; | |
732 | __u32 tsn; | |
733 | struct sk_buff *skb; | |
734 | struct sctp_ulpevent *event; | |
735 | struct sctp_tsnmap *tsnmap; | |
736 | ||
737 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
738 | ||
739 | while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) { | |
740 | freed += skb_headlen(skb); | |
741 | event = sctp_skb2event(skb); | |
742 | tsn = event->tsn; | |
743 | ||
744 | sctp_ulpevent_free(event); | |
745 | sctp_tsnmap_renege(tsnmap, tsn); | |
746 | if (freed >= needed) | |
747 | return freed; | |
748 | } | |
749 | ||
750 | return freed; | |
751 | } | |
752 | ||
753 | /* Renege 'needed' bytes from the reassembly queue. */ | |
754 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
755 | { | |
756 | __u16 freed = 0; | |
757 | __u32 tsn; | |
758 | struct sk_buff *skb; | |
759 | struct sctp_ulpevent *event; | |
760 | struct sctp_tsnmap *tsnmap; | |
761 | ||
762 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
763 | ||
764 | /* Walk backwards through the list, reneges the newest tsns. */ | |
765 | while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) { | |
766 | freed += skb_headlen(skb); | |
767 | event = sctp_skb2event(skb); | |
768 | tsn = event->tsn; | |
769 | ||
770 | sctp_ulpevent_free(event); | |
771 | sctp_tsnmap_renege(tsnmap, tsn); | |
772 | if (freed >= needed) | |
773 | return freed; | |
774 | } | |
775 | ||
776 | return freed; | |
777 | } | |
778 | ||
779 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
780 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
3182cd84 AD |
781 | struct sctp_chunk *chunk, |
782 | unsigned int __nocast gfp) | |
1da177e4 LT |
783 | { |
784 | struct sctp_ulpevent *event; | |
785 | struct sctp_association *asoc; | |
786 | ||
787 | asoc = ulpq->asoc; | |
788 | ||
789 | /* Are we already in partial delivery mode? */ | |
790 | if (!sctp_sk(asoc->base.sk)->pd_mode) { | |
791 | ||
792 | /* Is partial delivery possible? */ | |
793 | event = sctp_ulpq_retrieve_first(ulpq); | |
794 | /* Send event to the ULP. */ | |
795 | if (event) { | |
796 | sctp_ulpq_tail_event(ulpq, event); | |
797 | sctp_sk(asoc->base.sk)->pd_mode = 1; | |
798 | ulpq->pd_mode = 1; | |
799 | return; | |
800 | } | |
801 | } | |
802 | } | |
803 | ||
804 | /* Renege some packets to make room for an incoming chunk. */ | |
805 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
3182cd84 | 806 | unsigned int __nocast gfp) |
1da177e4 LT |
807 | { |
808 | struct sctp_association *asoc; | |
809 | __u16 needed, freed; | |
810 | ||
811 | asoc = ulpq->asoc; | |
812 | ||
813 | if (chunk) { | |
814 | needed = ntohs(chunk->chunk_hdr->length); | |
815 | needed -= sizeof(sctp_data_chunk_t); | |
816 | } else | |
817 | needed = SCTP_DEFAULT_MAXWINDOW; | |
818 | ||
819 | freed = 0; | |
820 | ||
821 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
822 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
823 | if (freed < needed) { | |
824 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
825 | } | |
826 | } | |
827 | /* If able to free enough room, accept this chunk. */ | |
828 | if (chunk && (freed >= needed)) { | |
829 | __u32 tsn; | |
830 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
831 | sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn); | |
832 | sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
833 | ||
834 | sctp_ulpq_partial_delivery(ulpq, chunk, gfp); | |
835 | } | |
836 | ||
837 | return; | |
838 | } | |
839 | ||
840 | ||
841 | ||
842 | /* Notify the application if an association is aborted and in | |
843 | * partial delivery mode. Send up any pending received messages. | |
844 | */ | |
3182cd84 | 845 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, unsigned int __nocast gfp) |
1da177e4 LT |
846 | { |
847 | struct sctp_ulpevent *ev = NULL; | |
848 | struct sock *sk; | |
849 | ||
850 | if (!ulpq->pd_mode) | |
851 | return; | |
852 | ||
853 | sk = ulpq->asoc->base.sk; | |
854 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, | |
855 | &sctp_sk(sk)->subscribe)) | |
856 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
857 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
858 | gfp); | |
859 | if (ev) | |
860 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
861 | ||
862 | /* If there is data waiting, send it up the socket now. */ | |
863 | if (sctp_ulpq_clear_pd(ulpq) || ev) | |
864 | sk->sk_data_ready(sk, 0); | |
865 | } |