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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; | |
672e7cca | 282 | struct sk_buff *new = NULL; |
1da177e4 LT |
283 | struct sctp_ulpevent *event; |
284 | struct sk_buff *pnext, *last; | |
285 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
286 | ||
287 | /* Store the pointer to the 2nd skb */ | |
288 | if (f_frag == l_frag) | |
289 | pos = NULL; | |
290 | else | |
291 | pos = f_frag->next; | |
292 | ||
293 | /* Get the last skb in the f_frag's frag_list if present. */ | |
294 | for (last = list; list; last = list, list = list->next); | |
295 | ||
296 | /* Add the list of remaining fragments to the first fragments | |
297 | * frag_list. | |
298 | */ | |
299 | if (last) | |
300 | last->next = pos; | |
672e7cca VY |
301 | else { |
302 | if (skb_cloned(f_frag)) { | |
303 | /* This is a cloned skb, we can't just modify | |
304 | * the frag_list. We need a new skb to do that. | |
305 | * Instead of calling skb_unshare(), we'll do it | |
306 | * ourselves since we need to delay the free. | |
307 | */ | |
308 | new = skb_copy(f_frag, GFP_ATOMIC); | |
309 | if (!new) | |
310 | return NULL; /* try again later */ | |
311 | ||
312 | new->sk = f_frag->sk; | |
313 | ||
314 | skb_shinfo(new)->frag_list = pos; | |
315 | } else | |
316 | skb_shinfo(f_frag)->frag_list = pos; | |
317 | } | |
1da177e4 LT |
318 | |
319 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 320 | __skb_unlink(f_frag, queue); |
672e7cca VY |
321 | |
322 | /* if we did unshare, then free the old skb and re-assign */ | |
323 | if (new) { | |
324 | kfree_skb(f_frag); | |
325 | f_frag = new; | |
326 | } | |
327 | ||
1da177e4 LT |
328 | while (pos) { |
329 | ||
330 | pnext = pos->next; | |
331 | ||
332 | /* Update the len and data_len fields of the first fragment. */ | |
333 | f_frag->len += pos->len; | |
334 | f_frag->data_len += pos->len; | |
335 | ||
336 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 337 | __skb_unlink(pos, queue); |
1da177e4 LT |
338 | |
339 | /* Break if we have reached the last fragment. */ | |
340 | if (pos == l_frag) | |
341 | break; | |
342 | pos->next = pnext; | |
343 | pos = pnext; | |
344 | }; | |
345 | ||
346 | event = sctp_skb2event(f_frag); | |
347 | SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS); | |
348 | ||
349 | return event; | |
350 | } | |
351 | ||
352 | ||
353 | /* Helper function to check if an incoming chunk has filled up the last | |
354 | * missing fragment in a SCTP datagram and return the corresponding event. | |
355 | */ | |
356 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) | |
357 | { | |
358 | struct sk_buff *pos; | |
359 | struct sctp_ulpevent *cevent; | |
360 | struct sk_buff *first_frag = NULL; | |
361 | __u32 ctsn, next_tsn; | |
362 | struct sctp_ulpevent *retval = NULL; | |
363 | ||
364 | /* Initialized to 0 just to avoid compiler warning message. Will | |
365 | * never be used with this value. It is referenced only after it | |
366 | * is set when we find the first fragment of a message. | |
367 | */ | |
368 | next_tsn = 0; | |
369 | ||
370 | /* The chunks are held in the reasm queue sorted by TSN. | |
371 | * Walk through the queue sequentially and look for a sequence of | |
372 | * fragmented chunks that complete a datagram. | |
373 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
374 | * is the first fragment of a datagram. Once these 2 fields are set | |
375 | * we expect to find the remaining middle fragments and the last | |
376 | * fragment in order. If not, first_frag is reset to NULL and we | |
377 | * start the next pass when we find another first fragment. | |
378 | */ | |
379 | skb_queue_walk(&ulpq->reasm, pos) { | |
380 | cevent = sctp_skb2event(pos); | |
381 | ctsn = cevent->tsn; | |
382 | ||
383 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
384 | case SCTP_DATA_FIRST_FRAG: | |
385 | first_frag = pos; | |
386 | next_tsn = ctsn + 1; | |
387 | break; | |
388 | ||
389 | case SCTP_DATA_MIDDLE_FRAG: | |
390 | if ((first_frag) && (ctsn == next_tsn)) | |
391 | next_tsn++; | |
392 | else | |
393 | first_frag = NULL; | |
394 | break; | |
395 | ||
396 | case SCTP_DATA_LAST_FRAG: | |
397 | if (first_frag && (ctsn == next_tsn)) | |
398 | goto found; | |
399 | else | |
400 | first_frag = NULL; | |
401 | break; | |
402 | }; | |
403 | ||
404 | } | |
405 | done: | |
406 | return retval; | |
407 | found: | |
8728b834 | 408 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, pos); |
1da177e4 LT |
409 | if (retval) |
410 | retval->msg_flags |= MSG_EOR; | |
411 | goto done; | |
412 | } | |
413 | ||
414 | /* Retrieve the next set of fragments of a partial message. */ | |
415 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) | |
416 | { | |
417 | struct sk_buff *pos, *last_frag, *first_frag; | |
418 | struct sctp_ulpevent *cevent; | |
419 | __u32 ctsn, next_tsn; | |
420 | int is_last; | |
421 | struct sctp_ulpevent *retval; | |
422 | ||
423 | /* The chunks are held in the reasm queue sorted by TSN. | |
424 | * Walk through the queue sequentially and look for the first | |
425 | * sequence of fragmented chunks. | |
426 | */ | |
427 | ||
428 | if (skb_queue_empty(&ulpq->reasm)) | |
429 | return NULL; | |
430 | ||
431 | last_frag = first_frag = NULL; | |
432 | retval = NULL; | |
433 | next_tsn = 0; | |
434 | is_last = 0; | |
435 | ||
436 | skb_queue_walk(&ulpq->reasm, pos) { | |
437 | cevent = sctp_skb2event(pos); | |
438 | ctsn = cevent->tsn; | |
439 | ||
440 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
441 | case SCTP_DATA_MIDDLE_FRAG: | |
442 | if (!first_frag) { | |
443 | first_frag = pos; | |
444 | next_tsn = ctsn + 1; | |
445 | last_frag = pos; | |
446 | } else if (next_tsn == ctsn) | |
447 | next_tsn++; | |
448 | else | |
449 | goto done; | |
450 | break; | |
451 | case SCTP_DATA_LAST_FRAG: | |
452 | if (!first_frag) | |
453 | first_frag = pos; | |
454 | else if (ctsn != next_tsn) | |
455 | goto done; | |
456 | last_frag = pos; | |
457 | is_last = 1; | |
458 | goto done; | |
459 | default: | |
460 | return NULL; | |
461 | }; | |
462 | } | |
463 | ||
464 | /* We have the reassembled event. There is no need to look | |
465 | * further. | |
466 | */ | |
467 | done: | |
8728b834 | 468 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag); |
1da177e4 LT |
469 | if (retval && is_last) |
470 | retval->msg_flags |= MSG_EOR; | |
471 | ||
472 | return retval; | |
473 | } | |
474 | ||
475 | ||
476 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
477 | * need reassembling. | |
478 | */ | |
479 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
480 | struct sctp_ulpevent *event) | |
481 | { | |
482 | struct sctp_ulpevent *retval = NULL; | |
483 | ||
484 | /* Check if this is part of a fragmented message. */ | |
485 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
486 | event->msg_flags |= MSG_EOR; | |
487 | return event; | |
488 | } | |
489 | ||
490 | sctp_ulpq_store_reasm(ulpq, event); | |
491 | if (!ulpq->pd_mode) | |
492 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
493 | else { | |
494 | __u32 ctsn, ctsnap; | |
495 | ||
496 | /* Do not even bother unless this is the next tsn to | |
497 | * be delivered. | |
498 | */ | |
499 | ctsn = event->tsn; | |
500 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
501 | if (TSN_lte(ctsn, ctsnap)) | |
502 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
503 | } | |
504 | ||
505 | return retval; | |
506 | } | |
507 | ||
508 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
509 | static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) | |
510 | { | |
511 | struct sk_buff *pos, *last_frag, *first_frag; | |
512 | struct sctp_ulpevent *cevent; | |
513 | __u32 ctsn, next_tsn; | |
514 | struct sctp_ulpevent *retval; | |
515 | ||
516 | /* The chunks are held in the reasm queue sorted by TSN. | |
517 | * Walk through the queue sequentially and look for a sequence of | |
518 | * fragmented chunks that start a datagram. | |
519 | */ | |
520 | ||
521 | if (skb_queue_empty(&ulpq->reasm)) | |
522 | return NULL; | |
523 | ||
524 | last_frag = first_frag = NULL; | |
525 | retval = NULL; | |
526 | next_tsn = 0; | |
527 | ||
528 | skb_queue_walk(&ulpq->reasm, pos) { | |
529 | cevent = sctp_skb2event(pos); | |
530 | ctsn = cevent->tsn; | |
531 | ||
532 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
533 | case SCTP_DATA_FIRST_FRAG: | |
534 | if (!first_frag) { | |
535 | first_frag = pos; | |
536 | next_tsn = ctsn + 1; | |
537 | last_frag = pos; | |
538 | } else | |
539 | goto done; | |
540 | break; | |
541 | ||
542 | case SCTP_DATA_MIDDLE_FRAG: | |
543 | if (!first_frag) | |
544 | return NULL; | |
545 | if (ctsn == next_tsn) { | |
546 | next_tsn++; | |
547 | last_frag = pos; | |
548 | } else | |
549 | goto done; | |
550 | break; | |
551 | default: | |
552 | return NULL; | |
553 | }; | |
554 | } | |
555 | ||
556 | /* We have the reassembled event. There is no need to look | |
557 | * further. | |
558 | */ | |
559 | done: | |
8728b834 | 560 | retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag); |
1da177e4 LT |
561 | return retval; |
562 | } | |
563 | ||
564 | /* Helper function to gather skbs that have possibly become | |
565 | * ordered by an an incoming chunk. | |
566 | */ | |
567 | static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, | |
568 | struct sctp_ulpevent *event) | |
569 | { | |
8728b834 | 570 | struct sk_buff_head *event_list; |
1da177e4 LT |
571 | struct sk_buff *pos, *tmp; |
572 | struct sctp_ulpevent *cevent; | |
573 | struct sctp_stream *in; | |
574 | __u16 sid, csid; | |
575 | __u16 ssn, cssn; | |
576 | ||
577 | sid = event->stream; | |
578 | ssn = event->ssn; | |
579 | in = &ulpq->asoc->ssnmap->in; | |
580 | ||
8728b834 DM |
581 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
582 | ||
1da177e4 LT |
583 | /* We are holding the chunks by stream, by SSN. */ |
584 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
585 | cevent = (struct sctp_ulpevent *) pos->cb; | |
586 | csid = cevent->stream; | |
587 | cssn = cevent->ssn; | |
588 | ||
589 | /* Have we gone too far? */ | |
590 | if (csid > sid) | |
591 | break; | |
592 | ||
593 | /* Have we not gone far enough? */ | |
594 | if (csid < sid) | |
595 | continue; | |
596 | ||
597 | if (cssn != sctp_ssn_peek(in, sid)) | |
598 | break; | |
599 | ||
600 | /* Found it, so mark in the ssnmap. */ | |
601 | sctp_ssn_next(in, sid); | |
602 | ||
8728b834 | 603 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
604 | |
605 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 606 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
607 | } |
608 | } | |
609 | ||
610 | /* Helper function to store chunks needing ordering. */ | |
611 | static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, | |
612 | struct sctp_ulpevent *event) | |
613 | { | |
614 | struct sk_buff *pos; | |
615 | struct sctp_ulpevent *cevent; | |
616 | __u16 sid, csid; | |
617 | __u16 ssn, cssn; | |
618 | ||
619 | pos = skb_peek_tail(&ulpq->lobby); | |
620 | if (!pos) { | |
621 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
622 | return; | |
623 | } | |
624 | ||
625 | sid = event->stream; | |
626 | ssn = event->ssn; | |
627 | ||
628 | cevent = (struct sctp_ulpevent *) pos->cb; | |
629 | csid = cevent->stream; | |
630 | cssn = cevent->ssn; | |
631 | if (sid > csid) { | |
632 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
633 | return; | |
634 | } | |
635 | ||
636 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
637 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
638 | return; | |
639 | } | |
640 | ||
641 | /* Find the right place in this list. We store them by | |
642 | * stream ID and then by SSN. | |
643 | */ | |
644 | skb_queue_walk(&ulpq->lobby, pos) { | |
645 | cevent = (struct sctp_ulpevent *) pos->cb; | |
646 | csid = cevent->stream; | |
647 | cssn = cevent->ssn; | |
648 | ||
649 | if (csid > sid) | |
650 | break; | |
651 | if (csid == sid && SSN_lt(ssn, cssn)) | |
652 | break; | |
653 | } | |
654 | ||
655 | ||
656 | /* Insert before pos. */ | |
657 | __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby); | |
658 | ||
659 | } | |
660 | ||
661 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 662 | struct sctp_ulpevent *event) |
1da177e4 LT |
663 | { |
664 | __u16 sid, ssn; | |
665 | struct sctp_stream *in; | |
666 | ||
667 | /* Check if this message needs ordering. */ | |
668 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
669 | return event; | |
670 | ||
671 | /* Note: The stream ID must be verified before this routine. */ | |
672 | sid = event->stream; | |
673 | ssn = event->ssn; | |
674 | in = &ulpq->asoc->ssnmap->in; | |
675 | ||
676 | /* Is this the expected SSN for this stream ID? */ | |
677 | if (ssn != sctp_ssn_peek(in, sid)) { | |
678 | /* We've received something out of order, so find where it | |
679 | * needs to be placed. We order by stream and then by SSN. | |
680 | */ | |
681 | sctp_ulpq_store_ordered(ulpq, event); | |
682 | return NULL; | |
683 | } | |
684 | ||
685 | /* Mark that the next chunk has been found. */ | |
686 | sctp_ssn_next(in, sid); | |
687 | ||
688 | /* Go find any other chunks that were waiting for | |
689 | * ordering. | |
690 | */ | |
691 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
692 | ||
693 | return event; | |
694 | } | |
695 | ||
696 | /* Helper function to gather skbs that have possibly become | |
697 | * ordered by forward tsn skipping their dependencies. | |
698 | */ | |
699 | static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq) | |
700 | { | |
701 | struct sk_buff *pos, *tmp; | |
702 | struct sctp_ulpevent *cevent; | |
8728b834 | 703 | struct sctp_ulpevent *event; |
1da177e4 LT |
704 | struct sctp_stream *in; |
705 | struct sk_buff_head temp; | |
706 | __u16 csid, cssn; | |
707 | ||
708 | in = &ulpq->asoc->ssnmap->in; | |
709 | ||
710 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
711 | skb_queue_head_init(&temp); |
712 | event = NULL; | |
1da177e4 LT |
713 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { |
714 | cevent = (struct sctp_ulpevent *) pos->cb; | |
715 | csid = cevent->stream; | |
716 | cssn = cevent->ssn; | |
717 | ||
718 | if (cssn != sctp_ssn_peek(in, csid)) | |
719 | break; | |
720 | ||
721 | /* Found it, so mark in the ssnmap. */ | |
722 | sctp_ssn_next(in, csid); | |
723 | ||
8728b834 | 724 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
725 | if (!event) { |
726 | /* Create a temporary list to collect chunks on. */ | |
727 | event = sctp_skb2event(pos); | |
1da177e4 LT |
728 | __skb_queue_tail(&temp, sctp_event2skb(event)); |
729 | } else { | |
730 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 731 | __skb_queue_tail(&temp, pos); |
1da177e4 LT |
732 | } |
733 | } | |
734 | ||
8728b834 DM |
735 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
736 | * very first SKB on the 'temp' list. | |
737 | */ | |
1da177e4 LT |
738 | if (event) |
739 | sctp_ulpq_tail_event(ulpq, event); | |
740 | } | |
741 | ||
742 | /* Skip over an SSN. */ | |
743 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) | |
744 | { | |
745 | struct sctp_stream *in; | |
746 | ||
747 | /* Note: The stream ID must be verified before this routine. */ | |
748 | in = &ulpq->asoc->ssnmap->in; | |
749 | ||
750 | /* Is this an old SSN? If so ignore. */ | |
751 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
752 | return; | |
753 | ||
754 | /* Mark that we are no longer expecting this SSN or lower. */ | |
755 | sctp_ssn_skip(in, sid, ssn); | |
756 | ||
757 | /* Go find any other chunks that were waiting for | |
758 | * ordering and deliver them if needed. | |
759 | */ | |
760 | sctp_ulpq_reap_ordered(ulpq); | |
761 | return; | |
762 | } | |
763 | ||
764 | /* Renege 'needed' bytes from the ordering queue. */ | |
765 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
766 | { | |
767 | __u16 freed = 0; | |
768 | __u32 tsn; | |
769 | struct sk_buff *skb; | |
770 | struct sctp_ulpevent *event; | |
771 | struct sctp_tsnmap *tsnmap; | |
772 | ||
773 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
774 | ||
775 | while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) { | |
776 | freed += skb_headlen(skb); | |
777 | event = sctp_skb2event(skb); | |
778 | tsn = event->tsn; | |
779 | ||
780 | sctp_ulpevent_free(event); | |
781 | sctp_tsnmap_renege(tsnmap, tsn); | |
782 | if (freed >= needed) | |
783 | return freed; | |
784 | } | |
785 | ||
786 | return freed; | |
787 | } | |
788 | ||
789 | /* Renege 'needed' bytes from the reassembly queue. */ | |
790 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
791 | { | |
792 | __u16 freed = 0; | |
793 | __u32 tsn; | |
794 | struct sk_buff *skb; | |
795 | struct sctp_ulpevent *event; | |
796 | struct sctp_tsnmap *tsnmap; | |
797 | ||
798 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
799 | ||
800 | /* Walk backwards through the list, reneges the newest tsns. */ | |
801 | while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) { | |
802 | freed += skb_headlen(skb); | |
803 | event = sctp_skb2event(skb); | |
804 | tsn = event->tsn; | |
805 | ||
806 | sctp_ulpevent_free(event); | |
807 | sctp_tsnmap_renege(tsnmap, tsn); | |
808 | if (freed >= needed) | |
809 | return freed; | |
810 | } | |
811 | ||
812 | return freed; | |
813 | } | |
814 | ||
815 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
816 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
3182cd84 | 817 | struct sctp_chunk *chunk, |
dd0fc66f | 818 | gfp_t gfp) |
1da177e4 LT |
819 | { |
820 | struct sctp_ulpevent *event; | |
821 | struct sctp_association *asoc; | |
822 | ||
823 | asoc = ulpq->asoc; | |
824 | ||
825 | /* Are we already in partial delivery mode? */ | |
826 | if (!sctp_sk(asoc->base.sk)->pd_mode) { | |
827 | ||
828 | /* Is partial delivery possible? */ | |
829 | event = sctp_ulpq_retrieve_first(ulpq); | |
830 | /* Send event to the ULP. */ | |
831 | if (event) { | |
832 | sctp_ulpq_tail_event(ulpq, event); | |
833 | sctp_sk(asoc->base.sk)->pd_mode = 1; | |
834 | ulpq->pd_mode = 1; | |
835 | return; | |
836 | } | |
837 | } | |
838 | } | |
839 | ||
840 | /* Renege some packets to make room for an incoming chunk. */ | |
841 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 842 | gfp_t gfp) |
1da177e4 LT |
843 | { |
844 | struct sctp_association *asoc; | |
845 | __u16 needed, freed; | |
846 | ||
847 | asoc = ulpq->asoc; | |
848 | ||
849 | if (chunk) { | |
850 | needed = ntohs(chunk->chunk_hdr->length); | |
851 | needed -= sizeof(sctp_data_chunk_t); | |
852 | } else | |
853 | needed = SCTP_DEFAULT_MAXWINDOW; | |
854 | ||
855 | freed = 0; | |
856 | ||
857 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
858 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
859 | if (freed < needed) { | |
860 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
861 | } | |
862 | } | |
863 | /* If able to free enough room, accept this chunk. */ | |
864 | if (chunk && (freed >= needed)) { | |
865 | __u32 tsn; | |
866 | tsn = ntohl(chunk->subh.data_hdr->tsn); | |
867 | sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn); | |
868 | sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
869 | ||
870 | sctp_ulpq_partial_delivery(ulpq, chunk, gfp); | |
871 | } | |
872 | ||
873 | return; | |
874 | } | |
875 | ||
876 | ||
877 | ||
878 | /* Notify the application if an association is aborted and in | |
879 | * partial delivery mode. Send up any pending received messages. | |
880 | */ | |
dd0fc66f | 881 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
882 | { |
883 | struct sctp_ulpevent *ev = NULL; | |
884 | struct sock *sk; | |
885 | ||
886 | if (!ulpq->pd_mode) | |
887 | return; | |
888 | ||
889 | sk = ulpq->asoc->base.sk; | |
890 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, | |
891 | &sctp_sk(sk)->subscribe)) | |
892 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
893 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
894 | gfp); | |
895 | if (ev) | |
896 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
897 | ||
898 | /* If there is data waiting, send it up the socket now. */ | |
899 | if (sctp_ulpq_clear_pd(ulpq) || ev) | |
900 | sk->sk_data_ready(sk, 0); | |
901 | } |