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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, | |
8728b834 | 53 | struct sctp_ulpevent *); |
1da177e4 | 54 | static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *, |
8728b834 | 55 | struct sctp_ulpevent *); |
1da177e4 LT |
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, | |
dd0fc66f | 103 | gfp_t 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 | ||
8728b834 DM |
128 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
129 | * very first SKB on the 'temp' list. | |
130 | */ | |
1da177e4 LT |
131 | if (event) |
132 | sctp_ulpq_tail_event(ulpq, event); | |
133 | ||
134 | return 0; | |
135 | } | |
136 | ||
137 | /* Add a new event for propagation to the ULP. */ | |
138 | /* Clear the partial delivery mode for this socket. Note: This | |
139 | * assumes that no association is currently in partial delivery mode. | |
140 | */ | |
141 | int sctp_clear_pd(struct sock *sk) | |
142 | { | |
143 | struct sctp_sock *sp = sctp_sk(sk); | |
144 | ||
145 | sp->pd_mode = 0; | |
146 | if (!skb_queue_empty(&sp->pd_lobby)) { | |
147 | struct list_head *list; | |
148 | sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue); | |
149 | list = (struct list_head *)&sctp_sk(sk)->pd_lobby; | |
150 | INIT_LIST_HEAD(list); | |
151 | return 1; | |
152 | } | |
153 | return 0; | |
154 | } | |
155 | ||
156 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ | |
157 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) | |
158 | { | |
159 | ulpq->pd_mode = 0; | |
160 | return sctp_clear_pd(ulpq->asoc->base.sk); | |
161 | } | |
162 | ||
8728b834 DM |
163 | /* If the SKB of 'event' is on a list, it is the first such member |
164 | * of that list. | |
165 | */ | |
1da177e4 LT |
166 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) |
167 | { | |
168 | struct sock *sk = ulpq->asoc->base.sk; | |
8728b834 DM |
169 | struct sk_buff_head *queue, *skb_list; |
170 | struct sk_buff *skb = sctp_event2skb(event); | |
1da177e4 LT |
171 | int clear_pd = 0; |
172 | ||
8728b834 DM |
173 | skb_list = (struct sk_buff_head *) skb->prev; |
174 | ||
1da177e4 LT |
175 | /* If the socket is just going to throw this away, do not |
176 | * even try to deliver it. | |
177 | */ | |
178 | if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
179 | goto out_free; | |
180 | ||
181 | /* Check if the user wishes to receive this event. */ | |
182 | if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) | |
183 | goto out_free; | |
184 | ||
185 | /* If we are in partial delivery mode, post to the lobby until | |
186 | * partial delivery is cleared, unless, of course _this_ is | |
187 | * the association the cause of the partial delivery. | |
188 | */ | |
189 | ||
190 | if (!sctp_sk(sk)->pd_mode) { | |
191 | queue = &sk->sk_receive_queue; | |
192 | } else if (ulpq->pd_mode) { | |
193 | if (event->msg_flags & MSG_NOTIFICATION) | |
194 | queue = &sctp_sk(sk)->pd_lobby; | |
195 | else { | |
196 | clear_pd = event->msg_flags & MSG_EOR; | |
197 | queue = &sk->sk_receive_queue; | |
198 | } | |
199 | } else | |
200 | queue = &sctp_sk(sk)->pd_lobby; | |
201 | ||
202 | ||
203 | /* If we are harvesting multiple skbs they will be | |
204 | * collected on a list. | |
205 | */ | |
8728b834 DM |
206 | if (skb_list) |
207 | sctp_skb_list_tail(skb_list, queue); | |
1da177e4 | 208 | else |
8728b834 | 209 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
210 | |
211 | /* Did we just complete partial delivery and need to get | |
212 | * rolling again? Move pending data to the receive | |
213 | * queue. | |
214 | */ | |
215 | if (clear_pd) | |
216 | sctp_ulpq_clear_pd(ulpq); | |
217 | ||
218 | if (queue == &sk->sk_receive_queue) | |
219 | sk->sk_data_ready(sk, 0); | |
220 | return 1; | |
221 | ||
222 | out_free: | |
8728b834 DM |
223 | if (skb_list) |
224 | sctp_queue_purge_ulpevents(skb_list); | |
1da177e4 LT |
225 | else |
226 | sctp_ulpevent_free(event); | |
8728b834 | 227 | |
1da177e4 LT |
228 | return 0; |
229 | } | |
230 | ||
231 | /* 2nd Level Abstractions */ | |
232 | ||
233 | /* Helper function to store chunks that need to be reassembled. */ | |
234 | static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, | |
235 | struct sctp_ulpevent *event) | |
236 | { | |
237 | struct sk_buff *pos; | |
238 | struct sctp_ulpevent *cevent; | |
239 | __u32 tsn, ctsn; | |
240 | ||
241 | tsn = event->tsn; | |
242 | ||
243 | /* See if it belongs at the end. */ | |
244 | pos = skb_peek_tail(&ulpq->reasm); | |
245 | if (!pos) { | |
246 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
247 | return; | |
248 | } | |
249 | ||
250 | /* Short circuit just dropping it at the end. */ | |
251 | cevent = sctp_skb2event(pos); | |
252 | ctsn = cevent->tsn; | |
253 | if (TSN_lt(ctsn, tsn)) { | |
254 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
255 | return; | |
256 | } | |
257 | ||
258 | /* Find the right place in this list. We store them by TSN. */ | |
259 | skb_queue_walk(&ulpq->reasm, pos) { | |
260 | cevent = sctp_skb2event(pos); | |
261 | ctsn = cevent->tsn; | |
262 | ||
263 | if (TSN_lt(tsn, ctsn)) | |
264 | break; | |
265 | } | |
266 | ||
267 | /* Insert before pos. */ | |
268 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm); | |
269 | ||
270 | } | |
271 | ||
272 | /* Helper function to return an event corresponding to the reassembled | |
273 | * datagram. | |
274 | * This routine creates a re-assembled skb given the first and last skb's | |
275 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
276 | * payload was fragmented on the way and ip had to reassemble them. | |
277 | * We add the rest of skb's to the first skb's fraglist. | |
278 | */ | |
8728b834 | 279 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff_head *queue, struct sk_buff *f_frag, struct sk_buff *l_frag) |
1da177e4 LT |
280 | { |
281 | struct sk_buff *pos; | |
282 | struct sctp_ulpevent *event; | |
283 | struct sk_buff *pnext, *last; | |
284 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
285 | ||
286 | /* Store the pointer to the 2nd skb */ | |
287 | if (f_frag == l_frag) | |
288 | pos = NULL; | |
289 | else | |
290 | pos = f_frag->next; | |
291 | ||
292 | /* Get the last skb in the f_frag's frag_list if present. */ | |
293 | for (last = list; list; last = list, list = list->next); | |
294 | ||
295 | /* Add the list of remaining fragments to the first fragments | |
296 | * frag_list. | |
297 | */ | |
298 | if (last) | |
299 | last->next = pos; | |
300 | else | |
301 | skb_shinfo(f_frag)->frag_list = pos; | |
302 | ||
303 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 304 | __skb_unlink(f_frag, queue); |
1da177e4 LT |
305 | while (pos) { |
306 | ||
307 | pnext = pos->next; | |
308 | ||
309 | /* Update the len and data_len fields of the first fragment. */ | |
310 | f_frag->len += pos->len; | |
311 | f_frag->data_len += pos->len; | |
312 | ||
313 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 314 | __skb_unlink(pos, queue); |
1da177e4 LT |
315 | |
316 | /* Break if we have reached the last fragment. */ | |
317 | if (pos == l_frag) | |
318 | break; | |
319 | pos->next = pnext; | |
320 | pos = pnext; | |
321 | }; | |
322 | ||
323 | event = sctp_skb2event(f_frag); | |
324 | SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS); | |
325 | ||
326 | return event; | |
327 | } | |
328 | ||
329 | ||
330 | /* Helper function to check if an incoming chunk has filled up the last | |
331 | * missing fragment in a SCTP datagram and return the corresponding event. | |
332 | */ | |
333 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) | |
334 | { | |
335 | struct sk_buff *pos; | |
336 | struct sctp_ulpevent *cevent; | |
337 | struct sk_buff *first_frag = NULL; | |
338 | __u32 ctsn, next_tsn; | |
339 | struct sctp_ulpevent *retval = NULL; | |
340 | ||
341 | /* Initialized to 0 just to avoid compiler warning message. Will | |
342 | * never be used with this value. It is referenced only after it | |
343 | * is set when we find the first fragment of a message. | |
344 | */ | |
345 | next_tsn = 0; | |
346 | ||
347 | /* The chunks are held in the reasm queue sorted by TSN. | |
348 | * Walk through the queue sequentially and look for a sequence of | |
349 | * fragmented chunks that complete a datagram. | |
350 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
351 | * is the first fragment of a datagram. Once these 2 fields are set | |
352 | * we expect to find the remaining middle fragments and the last | |
353 | * fragment in order. If not, first_frag is reset to NULL and we | |
354 | * start the next pass when we find another first fragment. | |
355 | */ | |
356 | skb_queue_walk(&ulpq->reasm, pos) { | |
357 | cevent = sctp_skb2event(pos); | |
358 | ctsn = cevent->tsn; | |
359 | ||
360 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
361 | case SCTP_DATA_FIRST_FRAG: | |
362 | first_frag = pos; | |
363 | next_tsn = ctsn + 1; | |
364 | break; | |
365 | ||
366 | case SCTP_DATA_MIDDLE_FRAG: | |
367 | if ((first_frag) && (ctsn == next_tsn)) | |
368 | next_tsn++; | |
369 | else | |
370 | first_frag = NULL; | |
371 | break; | |
372 | ||
373 | case SCTP_DATA_LAST_FRAG: | |
374 | if (first_frag && (ctsn == next_tsn)) | |
375 | goto found; | |
376 | else | |
377 | first_frag = NULL; | |
378 | break; | |
379 | }; | |
380 | ||
381 | } | |
382 | done: | |
383 | return retval; | |
384 | found: | |
8728b834 | 385 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, pos); |
1da177e4 LT |
386 | if (retval) |
387 | retval->msg_flags |= MSG_EOR; | |
388 | goto done; | |
389 | } | |
390 | ||
391 | /* Retrieve the next set of fragments of a partial message. */ | |
392 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) | |
393 | { | |
394 | struct sk_buff *pos, *last_frag, *first_frag; | |
395 | struct sctp_ulpevent *cevent; | |
396 | __u32 ctsn, next_tsn; | |
397 | int is_last; | |
398 | struct sctp_ulpevent *retval; | |
399 | ||
400 | /* The chunks are held in the reasm queue sorted by TSN. | |
401 | * Walk through the queue sequentially and look for the first | |
402 | * sequence of fragmented chunks. | |
403 | */ | |
404 | ||
405 | if (skb_queue_empty(&ulpq->reasm)) | |
406 | return NULL; | |
407 | ||
408 | last_frag = first_frag = NULL; | |
409 | retval = NULL; | |
410 | next_tsn = 0; | |
411 | is_last = 0; | |
412 | ||
413 | skb_queue_walk(&ulpq->reasm, pos) { | |
414 | cevent = sctp_skb2event(pos); | |
415 | ctsn = cevent->tsn; | |
416 | ||
417 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
418 | case SCTP_DATA_MIDDLE_FRAG: | |
419 | if (!first_frag) { | |
420 | first_frag = pos; | |
421 | next_tsn = ctsn + 1; | |
422 | last_frag = pos; | |
423 | } else if (next_tsn == ctsn) | |
424 | next_tsn++; | |
425 | else | |
426 | goto done; | |
427 | break; | |
428 | case SCTP_DATA_LAST_FRAG: | |
429 | if (!first_frag) | |
430 | first_frag = pos; | |
431 | else if (ctsn != next_tsn) | |
432 | goto done; | |
433 | last_frag = pos; | |
434 | is_last = 1; | |
435 | goto done; | |
436 | default: | |
437 | return NULL; | |
438 | }; | |
439 | } | |
440 | ||
441 | /* We have the reassembled event. There is no need to look | |
442 | * further. | |
443 | */ | |
444 | done: | |
8728b834 | 445 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag); |
1da177e4 LT |
446 | if (retval && is_last) |
447 | retval->msg_flags |= MSG_EOR; | |
448 | ||
449 | return retval; | |
450 | } | |
451 | ||
452 | ||
453 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
454 | * need reassembling. | |
455 | */ | |
456 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
457 | struct sctp_ulpevent *event) | |
458 | { | |
459 | struct sctp_ulpevent *retval = NULL; | |
460 | ||
461 | /* Check if this is part of a fragmented message. */ | |
462 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
463 | event->msg_flags |= MSG_EOR; | |
464 | return event; | |
465 | } | |
466 | ||
467 | sctp_ulpq_store_reasm(ulpq, event); | |
468 | if (!ulpq->pd_mode) | |
469 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
470 | else { | |
471 | __u32 ctsn, ctsnap; | |
472 | ||
473 | /* Do not even bother unless this is the next tsn to | |
474 | * be delivered. | |
475 | */ | |
476 | ctsn = event->tsn; | |
477 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
478 | if (TSN_lte(ctsn, ctsnap)) | |
479 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
480 | } | |
481 | ||
482 | return retval; | |
483 | } | |
484 | ||
485 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
486 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) | |
487 | { | |
488 | struct sk_buff *pos, *last_frag, *first_frag; | |
489 | struct sctp_ulpevent *cevent; | |
490 | __u32 ctsn, next_tsn; | |
491 | struct sctp_ulpevent *retval; | |
492 | ||
493 | /* The chunks are held in the reasm queue sorted by TSN. | |
494 | * Walk through the queue sequentially and look for a sequence of | |
495 | * fragmented chunks that start a datagram. | |
496 | */ | |
497 | ||
498 | if (skb_queue_empty(&ulpq->reasm)) | |
499 | return NULL; | |
500 | ||
501 | last_frag = first_frag = NULL; | |
502 | retval = NULL; | |
503 | next_tsn = 0; | |
504 | ||
505 | skb_queue_walk(&ulpq->reasm, pos) { | |
506 | cevent = sctp_skb2event(pos); | |
507 | ctsn = cevent->tsn; | |
508 | ||
509 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
510 | case SCTP_DATA_FIRST_FRAG: | |
511 | if (!first_frag) { | |
512 | first_frag = pos; | |
513 | next_tsn = ctsn + 1; | |
514 | last_frag = pos; | |
515 | } else | |
516 | goto done; | |
517 | break; | |
518 | ||
519 | case SCTP_DATA_MIDDLE_FRAG: | |
520 | if (!first_frag) | |
521 | return NULL; | |
522 | if (ctsn == next_tsn) { | |
523 | next_tsn++; | |
524 | last_frag = pos; | |
525 | } else | |
526 | goto done; | |
527 | break; | |
528 | default: | |
529 | return NULL; | |
530 | }; | |
531 | } | |
532 | ||
533 | /* We have the reassembled event. There is no need to look | |
534 | * further. | |
535 | */ | |
536 | done: | |
8728b834 | 537 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag); |
1da177e4 LT |
538 | return retval; |
539 | } | |
540 | ||
541 | /* Helper function to gather skbs that have possibly become | |
542 | * ordered by an an incoming chunk. | |
543 | */ | |
544 | static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, | |
545 | struct sctp_ulpevent *event) | |
546 | { | |
8728b834 | 547 | struct sk_buff_head *event_list; |
1da177e4 LT |
548 | struct sk_buff *pos, *tmp; |
549 | struct sctp_ulpevent *cevent; | |
550 | struct sctp_stream *in; | |
551 | __u16 sid, csid; | |
552 | __u16 ssn, cssn; | |
553 | ||
554 | sid = event->stream; | |
555 | ssn = event->ssn; | |
556 | in = &ulpq->asoc->ssnmap->in; | |
557 | ||
8728b834 DM |
558 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
559 | ||
1da177e4 LT |
560 | /* We are holding the chunks by stream, by SSN. */ |
561 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
562 | cevent = (struct sctp_ulpevent *) pos->cb; | |
563 | csid = cevent->stream; | |
564 | cssn = cevent->ssn; | |
565 | ||
566 | /* Have we gone too far? */ | |
567 | if (csid > sid) | |
568 | break; | |
569 | ||
570 | /* Have we not gone far enough? */ | |
571 | if (csid < sid) | |
572 | continue; | |
573 | ||
574 | if (cssn != sctp_ssn_peek(in, sid)) | |
575 | break; | |
576 | ||
577 | /* Found it, so mark in the ssnmap. */ | |
578 | sctp_ssn_next(in, sid); | |
579 | ||
8728b834 | 580 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
581 | |
582 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 583 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
584 | } |
585 | } | |
586 | ||
587 | /* Helper function to store chunks needing ordering. */ | |
588 | static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, | |
589 | struct sctp_ulpevent *event) | |
590 | { | |
591 | struct sk_buff *pos; | |
592 | struct sctp_ulpevent *cevent; | |
593 | __u16 sid, csid; | |
594 | __u16 ssn, cssn; | |
595 | ||
596 | pos = skb_peek_tail(&ulpq->lobby); | |
597 | if (!pos) { | |
598 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
599 | return; | |
600 | } | |
601 | ||
602 | sid = event->stream; | |
603 | ssn = event->ssn; | |
604 | ||
605 | cevent = (struct sctp_ulpevent *) pos->cb; | |
606 | csid = cevent->stream; | |
607 | cssn = cevent->ssn; | |
608 | if (sid > csid) { | |
609 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
610 | return; | |
611 | } | |
612 | ||
613 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
614 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
615 | return; | |
616 | } | |
617 | ||
618 | /* Find the right place in this list. We store them by | |
619 | * stream ID and then by SSN. | |
620 | */ | |
621 | skb_queue_walk(&ulpq->lobby, pos) { | |
622 | cevent = (struct sctp_ulpevent *) pos->cb; | |
623 | csid = cevent->stream; | |
624 | cssn = cevent->ssn; | |
625 | ||
626 | if (csid > sid) | |
627 | break; | |
628 | if (csid == sid && SSN_lt(ssn, cssn)) | |
629 | break; | |
630 | } | |
631 | ||
632 | ||
633 | /* Insert before pos. */ | |
634 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby); | |
635 | ||
636 | } | |
637 | ||
638 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 639 | struct sctp_ulpevent *event) |
1da177e4 LT |
640 | { |
641 | __u16 sid, ssn; | |
642 | struct sctp_stream *in; | |
643 | ||
644 | /* Check if this message needs ordering. */ | |
645 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
646 | return event; | |
647 | ||
648 | /* Note: The stream ID must be verified before this routine. */ | |
649 | sid = event->stream; | |
650 | ssn = event->ssn; | |
651 | in = &ulpq->asoc->ssnmap->in; | |
652 | ||
653 | /* Is this the expected SSN for this stream ID? */ | |
654 | if (ssn != sctp_ssn_peek(in, sid)) { | |
655 | /* We've received something out of order, so find where it | |
656 | * needs to be placed. We order by stream and then by SSN. | |
657 | */ | |
658 | sctp_ulpq_store_ordered(ulpq, event); | |
659 | return NULL; | |
660 | } | |
661 | ||
662 | /* Mark that the next chunk has been found. */ | |
663 | sctp_ssn_next(in, sid); | |
664 | ||
665 | /* Go find any other chunks that were waiting for | |
666 | * ordering. | |
667 | */ | |
668 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
669 | ||
670 | return event; | |
671 | } | |
672 | ||
673 | /* Helper function to gather skbs that have possibly become | |
674 | * ordered by forward tsn skipping their dependencies. | |
675 | */ | |
676 | static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) | |
677 | { | |
678 | struct sk_buff *pos, *tmp; | |
679 | struct sctp_ulpevent *cevent; | |
8728b834 | 680 | struct sctp_ulpevent *event; |
1da177e4 LT |
681 | struct sctp_stream *in; |
682 | struct sk_buff_head temp; | |
683 | __u16 csid, cssn; | |
684 | ||
685 | in = &ulpq->asoc->ssnmap->in; | |
686 | ||
687 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
688 | skb_queue_head_init(&temp); |
689 | event = NULL; | |
1da177e4 LT |
690 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { |
691 | cevent = (struct sctp_ulpevent *) pos->cb; | |
692 | csid = cevent->stream; | |
693 | cssn = cevent->ssn; | |
694 | ||
695 | if (cssn != sctp_ssn_peek(in, csid)) | |
696 | break; | |
697 | ||
698 | /* Found it, so mark in the ssnmap. */ | |
699 | sctp_ssn_next(in, csid); | |
700 | ||
8728b834 | 701 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
702 | if (!event) { |
703 | /* Create a temporary list to collect chunks on. */ | |
704 | event = sctp_skb2event(pos); | |
1da177e4 LT |
705 | __skb_queue_tail(&temp, sctp_event2skb(event)); |
706 | } else { | |
707 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 708 | __skb_queue_tail(&temp, pos); |
1da177e4 LT |
709 | } |
710 | } | |
711 | ||
8728b834 DM |
712 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
713 | * very first SKB on the 'temp' list. | |
714 | */ | |
1da177e4 LT |
715 | if (event) |
716 | sctp_ulpq_tail_event(ulpq, event); | |
717 | } | |
718 | ||
719 | /* Skip over an SSN. */ | |
720 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) | |
721 | { | |
722 | struct sctp_stream *in; | |
723 | ||
724 | /* Note: The stream ID must be verified before this routine. */ | |
725 | in = &ulpq->asoc->ssnmap->in; | |
726 | ||
727 | /* Is this an old SSN? If so ignore. */ | |
728 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
729 | return; | |
730 | ||
731 | /* Mark that we are no longer expecting this SSN or lower. */ | |
732 | sctp_ssn_skip(in, sid, ssn); | |
733 | ||
734 | /* Go find any other chunks that were waiting for | |
735 | * ordering and deliver them if needed. | |
736 | */ | |
737 | sctp_ulpq_reap_ordered(ulpq); | |
738 | return; | |
739 | } | |
740 | ||
741 | /* Renege 'needed' bytes from the ordering queue. */ | |
742 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
743 | { | |
744 | __u16 freed = 0; | |
745 | __u32 tsn; | |
746 | struct sk_buff *skb; | |
747 | struct sctp_ulpevent *event; | |
748 | struct sctp_tsnmap *tsnmap; | |
749 | ||
750 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
751 | ||
752 | while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) { | |
753 | freed += skb_headlen(skb); | |
754 | event = sctp_skb2event(skb); | |
755 | tsn = event->tsn; | |
756 | ||
757 | sctp_ulpevent_free(event); | |
758 | sctp_tsnmap_renege(tsnmap, tsn); | |
759 | if (freed >= needed) | |
760 | return freed; | |
761 | } | |
762 | ||
763 | return freed; | |
764 | } | |
765 | ||
766 | /* Renege 'needed' bytes from the reassembly queue. */ | |
767 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
768 | { | |
769 | __u16 freed = 0; | |
770 | __u32 tsn; | |
771 | struct sk_buff *skb; | |
772 | struct sctp_ulpevent *event; | |
773 | struct sctp_tsnmap *tsnmap; | |
774 | ||
775 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
776 | ||
777 | /* Walk backwards through the list, reneges the newest tsns. */ | |
778 | while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) { | |
779 | freed += skb_headlen(skb); | |
780 | event = sctp_skb2event(skb); | |
781 | tsn = event->tsn; | |
782 | ||
783 | sctp_ulpevent_free(event); | |
784 | sctp_tsnmap_renege(tsnmap, tsn); | |
785 | if (freed >= needed) | |
786 | return freed; | |
787 | } | |
788 | ||
789 | return freed; | |
790 | } | |
791 | ||
792 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
793 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
3182cd84 | 794 | struct sctp_chunk *chunk, |
dd0fc66f | 795 | gfp_t gfp) |
1da177e4 LT |
796 | { |
797 | struct sctp_ulpevent *event; | |
798 | struct sctp_association *asoc; | |
799 | ||
800 | asoc = ulpq->asoc; | |
801 | ||
802 | /* Are we already in partial delivery mode? */ | |
803 | if (!sctp_sk(asoc->base.sk)->pd_mode) { | |
804 | ||
805 | /* Is partial delivery possible? */ | |
806 | event = sctp_ulpq_retrieve_first(ulpq); | |
807 | /* Send event to the ULP. */ | |
808 | if (event) { | |
809 | sctp_ulpq_tail_event(ulpq, event); | |
810 | sctp_sk(asoc->base.sk)->pd_mode = 1; | |
811 | ulpq->pd_mode = 1; | |
812 | return; | |
813 | } | |
814 | } | |
815 | } | |
816 | ||
817 | /* Renege some packets to make room for an incoming chunk. */ | |
818 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 819 | gfp_t gfp) |
1da177e4 LT |
820 | { |
821 | struct sctp_association *asoc; | |
822 | __u16 needed, freed; | |
823 | ||
824 | asoc = ulpq->asoc; | |
825 | ||
826 | if (chunk) { | |
827 | needed = ntohs(chunk->chunk_hdr->length); | |
828 | needed -= sizeof(sctp_data_chunk_t); | |
829 | } else | |
830 | needed = SCTP_DEFAULT_MAXWINDOW; | |
831 | ||
832 | freed = 0; | |
833 | ||
834 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
835 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
836 | if (freed < needed) { | |
837 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
838 | } | |
839 | } | |
840 | /* If able to free enough room, accept this chunk. */ | |
841 | if (chunk && (freed >= needed)) { | |
842 | __u32 tsn; | |
843 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
844 | sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn); | |
845 | sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
846 | ||
847 | sctp_ulpq_partial_delivery(ulpq, chunk, gfp); | |
848 | } | |
849 | ||
850 | return; | |
851 | } | |
852 | ||
853 | ||
854 | ||
855 | /* Notify the application if an association is aborted and in | |
856 | * partial delivery mode. Send up any pending received messages. | |
857 | */ | |
dd0fc66f | 858 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
859 | { |
860 | struct sctp_ulpevent *ev = NULL; | |
861 | struct sock *sk; | |
862 | ||
863 | if (!ulpq->pd_mode) | |
864 | return; | |
865 | ||
866 | sk = ulpq->asoc->base.sk; | |
867 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, | |
868 | &sctp_sk(sk)->subscribe)) | |
869 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
870 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
871 | gfp); | |
872 | if (ev) | |
873 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
874 | ||
875 | /* If there is data waiting, send it up the socket now. */ | |
876 | if (sctp_ulpq_clear_pd(ulpq) || ev) | |
877 | sk->sk_data_ready(sk, 0); | |
878 | } |