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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
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 | * | |
60c778b2 | 11 | * This SCTP implementation is free software; |
1da177e4 LT |
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 | * | |
60c778b2 | 17 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
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 | |
4b2f13a2 JK |
24 | * along with GNU CC; see the file COPYING. If not, see |
25 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
26 | * |
27 | * Please send any bug reports or fixes you make to the | |
28 | * email address(es): | |
91705c61 | 29 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 30 | * |
1da177e4 LT |
31 | * Written or modified by: |
32 | * Jon Grimm <jgrimm@us.ibm.com> | |
33 | * La Monte H.P. Yarroll <piggy@acm.org> | |
34 | * Sridhar Samudrala <sri@us.ibm.com> | |
1da177e4 LT |
35 | */ |
36 | ||
5a0e3ad6 | 37 | #include <linux/slab.h> |
1da177e4 LT |
38 | #include <linux/types.h> |
39 | #include <linux/skbuff.h> | |
40 | #include <net/sock.h> | |
41 | #include <net/sctp/structs.h> | |
42 | #include <net/sctp/sctp.h> | |
43 | #include <net/sctp/sm.h> | |
44 | ||
45 | /* Forward declarations for internal helpers. */ | |
46 | static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
8728b834 | 47 | struct sctp_ulpevent *); |
1da177e4 | 48 | static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *, |
8728b834 | 49 | struct sctp_ulpevent *); |
ef5d4cf2 | 50 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq); |
1da177e4 LT |
51 | |
52 | /* 1st Level Abstractions */ | |
53 | ||
54 | /* Initialize a ULP queue from a block of memory. */ | |
55 | struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, | |
56 | struct sctp_association *asoc) | |
57 | { | |
58 | memset(ulpq, 0, sizeof(struct sctp_ulpq)); | |
59 | ||
60 | ulpq->asoc = asoc; | |
61 | skb_queue_head_init(&ulpq->reasm); | |
62 | skb_queue_head_init(&ulpq->lobby); | |
63 | ulpq->pd_mode = 0; | |
1da177e4 LT |
64 | |
65 | return ulpq; | |
66 | } | |
67 | ||
68 | ||
69 | /* Flush the reassembly and ordering queues. */ | |
0b58a811 | 70 | void sctp_ulpq_flush(struct sctp_ulpq *ulpq) |
1da177e4 LT |
71 | { |
72 | struct sk_buff *skb; | |
73 | struct sctp_ulpevent *event; | |
74 | ||
75 | while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { | |
76 | event = sctp_skb2event(skb); | |
77 | sctp_ulpevent_free(event); | |
78 | } | |
79 | ||
80 | while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { | |
81 | event = sctp_skb2event(skb); | |
82 | sctp_ulpevent_free(event); | |
83 | } | |
84 | ||
85 | } | |
86 | ||
87 | /* Dispose of a ulpqueue. */ | |
88 | void sctp_ulpq_free(struct sctp_ulpq *ulpq) | |
89 | { | |
90 | sctp_ulpq_flush(ulpq); | |
1da177e4 LT |
91 | } |
92 | ||
93 | /* Process an incoming DATA chunk. */ | |
94 | int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 95 | gfp_t gfp) |
1da177e4 LT |
96 | { |
97 | struct sk_buff_head temp; | |
1da177e4 | 98 | struct sctp_ulpevent *event; |
d003b41b | 99 | int event_eor = 0; |
1da177e4 | 100 | |
1da177e4 LT |
101 | /* Create an event from the incoming chunk. */ |
102 | event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); | |
103 | if (!event) | |
104 | return -ENOMEM; | |
105 | ||
106 | /* Do reassembly if needed. */ | |
107 | event = sctp_ulpq_reasm(ulpq, event); | |
108 | ||
109 | /* Do ordering if needed. */ | |
110 | if ((event) && (event->msg_flags & MSG_EOR)){ | |
111 | /* Create a temporary list to collect chunks on. */ | |
112 | skb_queue_head_init(&temp); | |
113 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
114 | ||
115 | event = sctp_ulpq_order(ulpq, event); | |
116 | } | |
117 | ||
8728b834 DM |
118 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
119 | * very first SKB on the 'temp' list. | |
120 | */ | |
d003b41b LR |
121 | if (event) { |
122 | event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0; | |
1da177e4 | 123 | sctp_ulpq_tail_event(ulpq, event); |
d003b41b | 124 | } |
1da177e4 | 125 | |
d003b41b | 126 | return event_eor; |
1da177e4 LT |
127 | } |
128 | ||
129 | /* Add a new event for propagation to the ULP. */ | |
130 | /* Clear the partial delivery mode for this socket. Note: This | |
131 | * assumes that no association is currently in partial delivery mode. | |
132 | */ | |
b6e1331f | 133 | int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc) |
1da177e4 LT |
134 | { |
135 | struct sctp_sock *sp = sctp_sk(sk); | |
136 | ||
b6e1331f VY |
137 | if (atomic_dec_and_test(&sp->pd_mode)) { |
138 | /* This means there are no other associations in PD, so | |
139 | * we can go ahead and clear out the lobby in one shot | |
140 | */ | |
141 | if (!skb_queue_empty(&sp->pd_lobby)) { | |
142 | struct list_head *list; | |
143 | sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue); | |
144 | list = (struct list_head *)&sctp_sk(sk)->pd_lobby; | |
145 | INIT_LIST_HEAD(list); | |
146 | return 1; | |
147 | } | |
148 | } else { | |
149 | /* There are other associations in PD, so we only need to | |
150 | * pull stuff out of the lobby that belongs to the | |
151 | * associations that is exiting PD (all of its notifications | |
152 | * are posted here). | |
153 | */ | |
154 | if (!skb_queue_empty(&sp->pd_lobby) && asoc) { | |
155 | struct sk_buff *skb, *tmp; | |
156 | struct sctp_ulpevent *event; | |
157 | ||
158 | sctp_skb_for_each(skb, &sp->pd_lobby, tmp) { | |
159 | event = sctp_skb2event(skb); | |
160 | if (event->asoc == asoc) { | |
161 | __skb_unlink(skb, &sp->pd_lobby); | |
162 | __skb_queue_tail(&sk->sk_receive_queue, | |
163 | skb); | |
164 | } | |
165 | } | |
166 | } | |
1da177e4 | 167 | } |
b6e1331f | 168 | |
1da177e4 LT |
169 | return 0; |
170 | } | |
171 | ||
d49d91d7 VY |
172 | /* Set the pd_mode on the socket and ulpq */ |
173 | static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq) | |
174 | { | |
175 | struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk); | |
176 | ||
177 | atomic_inc(&sp->pd_mode); | |
178 | ulpq->pd_mode = 1; | |
179 | } | |
180 | ||
1da177e4 LT |
181 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ |
182 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) | |
183 | { | |
184 | ulpq->pd_mode = 0; | |
ef5d4cf2 | 185 | sctp_ulpq_reasm_drain(ulpq); |
b6e1331f | 186 | return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc); |
1da177e4 LT |
187 | } |
188 | ||
8728b834 DM |
189 | /* If the SKB of 'event' is on a list, it is the first such member |
190 | * of that list. | |
191 | */ | |
1da177e4 LT |
192 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) |
193 | { | |
194 | struct sock *sk = ulpq->asoc->base.sk; | |
8728b834 DM |
195 | struct sk_buff_head *queue, *skb_list; |
196 | struct sk_buff *skb = sctp_event2skb(event); | |
1da177e4 LT |
197 | int clear_pd = 0; |
198 | ||
8728b834 DM |
199 | skb_list = (struct sk_buff_head *) skb->prev; |
200 | ||
1da177e4 LT |
201 | /* If the socket is just going to throw this away, do not |
202 | * even try to deliver it. | |
203 | */ | |
204 | if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
205 | goto out_free; | |
206 | ||
207 | /* Check if the user wishes to receive this event. */ | |
208 | if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) | |
209 | goto out_free; | |
210 | ||
211 | /* If we are in partial delivery mode, post to the lobby until | |
212 | * partial delivery is cleared, unless, of course _this_ is | |
213 | * the association the cause of the partial delivery. | |
214 | */ | |
215 | ||
b6e1331f | 216 | if (atomic_read(&sctp_sk(sk)->pd_mode) == 0) { |
1da177e4 | 217 | queue = &sk->sk_receive_queue; |
b6e1331f VY |
218 | } else { |
219 | if (ulpq->pd_mode) { | |
220 | /* If the association is in partial delivery, we | |
221 | * need to finish delivering the partially processed | |
222 | * packet before passing any other data. This is | |
223 | * because we don't truly support stream interleaving. | |
224 | */ | |
225 | if ((event->msg_flags & MSG_NOTIFICATION) || | |
226 | (SCTP_DATA_NOT_FRAG == | |
227 | (event->msg_flags & SCTP_DATA_FRAG_MASK))) | |
228 | queue = &sctp_sk(sk)->pd_lobby; | |
229 | else { | |
230 | clear_pd = event->msg_flags & MSG_EOR; | |
231 | queue = &sk->sk_receive_queue; | |
232 | } | |
233 | } else { | |
234 | /* | |
235 | * If fragment interleave is enabled, we | |
25985edc | 236 | * can queue this to the receive queue instead |
b6e1331f VY |
237 | * of the lobby. |
238 | */ | |
239 | if (sctp_sk(sk)->frag_interleave) | |
240 | queue = &sk->sk_receive_queue; | |
241 | else | |
242 | queue = &sctp_sk(sk)->pd_lobby; | |
1da177e4 | 243 | } |
b6e1331f | 244 | } |
1da177e4 LT |
245 | |
246 | /* If we are harvesting multiple skbs they will be | |
247 | * collected on a list. | |
248 | */ | |
8728b834 DM |
249 | if (skb_list) |
250 | sctp_skb_list_tail(skb_list, queue); | |
1da177e4 | 251 | else |
8728b834 | 252 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
253 | |
254 | /* Did we just complete partial delivery and need to get | |
255 | * rolling again? Move pending data to the receive | |
256 | * queue. | |
257 | */ | |
258 | if (clear_pd) | |
259 | sctp_ulpq_clear_pd(ulpq); | |
260 | ||
261 | if (queue == &sk->sk_receive_queue) | |
262 | sk->sk_data_ready(sk, 0); | |
263 | return 1; | |
264 | ||
265 | out_free: | |
8728b834 DM |
266 | if (skb_list) |
267 | sctp_queue_purge_ulpevents(skb_list); | |
1da177e4 LT |
268 | else |
269 | sctp_ulpevent_free(event); | |
8728b834 | 270 | |
1da177e4 LT |
271 | return 0; |
272 | } | |
273 | ||
274 | /* 2nd Level Abstractions */ | |
275 | ||
276 | /* Helper function to store chunks that need to be reassembled. */ | |
01f2d384 | 277 | static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, |
1da177e4 LT |
278 | struct sctp_ulpevent *event) |
279 | { | |
280 | struct sk_buff *pos; | |
281 | struct sctp_ulpevent *cevent; | |
282 | __u32 tsn, ctsn; | |
283 | ||
284 | tsn = event->tsn; | |
285 | ||
286 | /* See if it belongs at the end. */ | |
287 | pos = skb_peek_tail(&ulpq->reasm); | |
288 | if (!pos) { | |
289 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
290 | return; | |
291 | } | |
292 | ||
293 | /* Short circuit just dropping it at the end. */ | |
294 | cevent = sctp_skb2event(pos); | |
295 | ctsn = cevent->tsn; | |
296 | if (TSN_lt(ctsn, tsn)) { | |
297 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
298 | return; | |
299 | } | |
300 | ||
301 | /* Find the right place in this list. We store them by TSN. */ | |
302 | skb_queue_walk(&ulpq->reasm, pos) { | |
303 | cevent = sctp_skb2event(pos); | |
304 | ctsn = cevent->tsn; | |
305 | ||
306 | if (TSN_lt(tsn, ctsn)) | |
307 | break; | |
308 | } | |
309 | ||
310 | /* Insert before pos. */ | |
43f59c89 | 311 | __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event)); |
1da177e4 LT |
312 | |
313 | } | |
314 | ||
315 | /* Helper function to return an event corresponding to the reassembled | |
316 | * datagram. | |
317 | * This routine creates a re-assembled skb given the first and last skb's | |
318 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
319 | * payload was fragmented on the way and ip had to reassemble them. | |
320 | * We add the rest of skb's to the first skb's fraglist. | |
321 | */ | |
b01a2407 EB |
322 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net, |
323 | struct sk_buff_head *queue, struct sk_buff *f_frag, | |
324 | struct sk_buff *l_frag) | |
1da177e4 LT |
325 | { |
326 | struct sk_buff *pos; | |
672e7cca | 327 | struct sk_buff *new = NULL; |
1da177e4 LT |
328 | struct sctp_ulpevent *event; |
329 | struct sk_buff *pnext, *last; | |
330 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
331 | ||
332 | /* Store the pointer to the 2nd skb */ | |
333 | if (f_frag == l_frag) | |
334 | pos = NULL; | |
335 | else | |
336 | pos = f_frag->next; | |
337 | ||
338 | /* Get the last skb in the f_frag's frag_list if present. */ | |
339 | for (last = list; list; last = list, list = list->next); | |
340 | ||
341 | /* Add the list of remaining fragments to the first fragments | |
342 | * frag_list. | |
343 | */ | |
344 | if (last) | |
345 | last->next = pos; | |
d808ad9a YH |
346 | else { |
347 | if (skb_cloned(f_frag)) { | |
348 | /* This is a cloned skb, we can't just modify | |
349 | * the frag_list. We need a new skb to do that. | |
350 | * Instead of calling skb_unshare(), we'll do it | |
351 | * ourselves since we need to delay the free. | |
352 | */ | |
353 | new = skb_copy(f_frag, GFP_ATOMIC); | |
354 | if (!new) | |
355 | return NULL; /* try again later */ | |
356 | ||
357 | sctp_skb_set_owner_r(new, f_frag->sk); | |
358 | ||
359 | skb_shinfo(new)->frag_list = pos; | |
360 | } else | |
361 | skb_shinfo(f_frag)->frag_list = pos; | |
362 | } | |
1da177e4 LT |
363 | |
364 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 365 | __skb_unlink(f_frag, queue); |
672e7cca | 366 | |
d808ad9a YH |
367 | /* if we did unshare, then free the old skb and re-assign */ |
368 | if (new) { | |
369 | kfree_skb(f_frag); | |
370 | f_frag = new; | |
371 | } | |
672e7cca | 372 | |
1da177e4 LT |
373 | while (pos) { |
374 | ||
375 | pnext = pos->next; | |
376 | ||
377 | /* Update the len and data_len fields of the first fragment. */ | |
378 | f_frag->len += pos->len; | |
379 | f_frag->data_len += pos->len; | |
380 | ||
381 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 382 | __skb_unlink(pos, queue); |
d808ad9a | 383 | |
1da177e4 LT |
384 | /* Break if we have reached the last fragment. */ |
385 | if (pos == l_frag) | |
386 | break; | |
387 | pos->next = pnext; | |
388 | pos = pnext; | |
3ff50b79 | 389 | } |
1da177e4 LT |
390 | |
391 | event = sctp_skb2event(f_frag); | |
b01a2407 | 392 | SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS); |
1da177e4 LT |
393 | |
394 | return event; | |
395 | } | |
396 | ||
397 | ||
398 | /* Helper function to check if an incoming chunk has filled up the last | |
399 | * missing fragment in a SCTP datagram and return the corresponding event. | |
400 | */ | |
01f2d384 | 401 | static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) |
1da177e4 LT |
402 | { |
403 | struct sk_buff *pos; | |
404 | struct sctp_ulpevent *cevent; | |
405 | struct sk_buff *first_frag = NULL; | |
406 | __u32 ctsn, next_tsn; | |
407 | struct sctp_ulpevent *retval = NULL; | |
d49d91d7 VY |
408 | struct sk_buff *pd_first = NULL; |
409 | struct sk_buff *pd_last = NULL; | |
410 | size_t pd_len = 0; | |
411 | struct sctp_association *asoc; | |
412 | u32 pd_point; | |
1da177e4 LT |
413 | |
414 | /* Initialized to 0 just to avoid compiler warning message. Will | |
415 | * never be used with this value. It is referenced only after it | |
416 | * is set when we find the first fragment of a message. | |
417 | */ | |
418 | next_tsn = 0; | |
419 | ||
420 | /* The chunks are held in the reasm queue sorted by TSN. | |
421 | * Walk through the queue sequentially and look for a sequence of | |
422 | * fragmented chunks that complete a datagram. | |
423 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
424 | * is the first fragment of a datagram. Once these 2 fields are set | |
425 | * we expect to find the remaining middle fragments and the last | |
426 | * fragment in order. If not, first_frag is reset to NULL and we | |
427 | * start the next pass when we find another first fragment. | |
d49d91d7 VY |
428 | * |
429 | * There is a potential to do partial delivery if user sets | |
430 | * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here | |
431 | * to see if can do PD. | |
1da177e4 LT |
432 | */ |
433 | skb_queue_walk(&ulpq->reasm, pos) { | |
434 | cevent = sctp_skb2event(pos); | |
435 | ctsn = cevent->tsn; | |
436 | ||
437 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
438 | case SCTP_DATA_FIRST_FRAG: | |
d49d91d7 VY |
439 | /* If this "FIRST_FRAG" is the first |
440 | * element in the queue, then count it towards | |
441 | * possible PD. | |
442 | */ | |
443 | if (pos == ulpq->reasm.next) { | |
444 | pd_first = pos; | |
445 | pd_last = pos; | |
446 | pd_len = pos->len; | |
447 | } else { | |
448 | pd_first = NULL; | |
449 | pd_last = NULL; | |
450 | pd_len = 0; | |
451 | } | |
452 | ||
1da177e4 LT |
453 | first_frag = pos; |
454 | next_tsn = ctsn + 1; | |
455 | break; | |
456 | ||
457 | case SCTP_DATA_MIDDLE_FRAG: | |
d49d91d7 | 458 | if ((first_frag) && (ctsn == next_tsn)) { |
1da177e4 | 459 | next_tsn++; |
d49d91d7 VY |
460 | if (pd_first) { |
461 | pd_last = pos; | |
462 | pd_len += pos->len; | |
463 | } | |
464 | } else | |
1da177e4 LT |
465 | first_frag = NULL; |
466 | break; | |
467 | ||
468 | case SCTP_DATA_LAST_FRAG: | |
469 | if (first_frag && (ctsn == next_tsn)) | |
470 | goto found; | |
471 | else | |
472 | first_frag = NULL; | |
473 | break; | |
3ff50b79 | 474 | } |
d49d91d7 VY |
475 | } |
476 | ||
477 | asoc = ulpq->asoc; | |
478 | if (pd_first) { | |
479 | /* Make sure we can enter partial deliver. | |
480 | * We can trigger partial delivery only if framgent | |
481 | * interleave is set, or the socket is not already | |
482 | * in partial delivery. | |
483 | */ | |
484 | if (!sctp_sk(asoc->base.sk)->frag_interleave && | |
485 | atomic_read(&sctp_sk(asoc->base.sk)->pd_mode)) | |
486 | goto done; | |
1da177e4 | 487 | |
d49d91d7 VY |
488 | cevent = sctp_skb2event(pd_first); |
489 | pd_point = sctp_sk(asoc->base.sk)->pd_point; | |
490 | if (pd_point && pd_point <= pd_len) { | |
b01a2407 EB |
491 | retval = sctp_make_reassembled_event(sock_net(asoc->base.sk), |
492 | &ulpq->reasm, | |
d49d91d7 VY |
493 | pd_first, |
494 | pd_last); | |
495 | if (retval) | |
496 | sctp_ulpq_set_pd(ulpq); | |
497 | } | |
1da177e4 LT |
498 | } |
499 | done: | |
500 | return retval; | |
501 | found: | |
b01a2407 EB |
502 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
503 | &ulpq->reasm, first_frag, pos); | |
1da177e4 LT |
504 | if (retval) |
505 | retval->msg_flags |= MSG_EOR; | |
506 | goto done; | |
507 | } | |
508 | ||
509 | /* Retrieve the next set of fragments of a partial message. */ | |
01f2d384 | 510 | static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) |
1da177e4 LT |
511 | { |
512 | struct sk_buff *pos, *last_frag, *first_frag; | |
513 | struct sctp_ulpevent *cevent; | |
514 | __u32 ctsn, next_tsn; | |
515 | int is_last; | |
516 | struct sctp_ulpevent *retval; | |
517 | ||
518 | /* The chunks are held in the reasm queue sorted by TSN. | |
519 | * Walk through the queue sequentially and look for the first | |
520 | * sequence of fragmented chunks. | |
521 | */ | |
522 | ||
523 | if (skb_queue_empty(&ulpq->reasm)) | |
524 | return NULL; | |
525 | ||
526 | last_frag = first_frag = NULL; | |
527 | retval = NULL; | |
528 | next_tsn = 0; | |
529 | is_last = 0; | |
530 | ||
531 | skb_queue_walk(&ulpq->reasm, pos) { | |
532 | cevent = sctp_skb2event(pos); | |
533 | ctsn = cevent->tsn; | |
534 | ||
535 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
d003b41b LR |
536 | case SCTP_DATA_FIRST_FRAG: |
537 | if (!first_frag) | |
538 | return NULL; | |
539 | goto done; | |
1da177e4 LT |
540 | case SCTP_DATA_MIDDLE_FRAG: |
541 | if (!first_frag) { | |
542 | first_frag = pos; | |
543 | next_tsn = ctsn + 1; | |
544 | last_frag = pos; | |
d003b41b | 545 | } else if (next_tsn == ctsn) { |
1da177e4 | 546 | next_tsn++; |
d003b41b LR |
547 | last_frag = pos; |
548 | } else | |
1da177e4 LT |
549 | goto done; |
550 | break; | |
551 | case SCTP_DATA_LAST_FRAG: | |
552 | if (!first_frag) | |
553 | first_frag = pos; | |
554 | else if (ctsn != next_tsn) | |
555 | goto done; | |
556 | last_frag = pos; | |
557 | is_last = 1; | |
558 | goto done; | |
559 | default: | |
560 | return NULL; | |
3ff50b79 | 561 | } |
1da177e4 LT |
562 | } |
563 | ||
564 | /* We have the reassembled event. There is no need to look | |
565 | * further. | |
566 | */ | |
567 | done: | |
b01a2407 EB |
568 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
569 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
570 | if (retval && is_last) |
571 | retval->msg_flags |= MSG_EOR; | |
572 | ||
573 | return retval; | |
574 | } | |
575 | ||
576 | ||
577 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
578 | * need reassembling. | |
579 | */ | |
580 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
581 | struct sctp_ulpevent *event) | |
582 | { | |
583 | struct sctp_ulpevent *retval = NULL; | |
584 | ||
585 | /* Check if this is part of a fragmented message. */ | |
586 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
587 | event->msg_flags |= MSG_EOR; | |
588 | return event; | |
589 | } | |
590 | ||
591 | sctp_ulpq_store_reasm(ulpq, event); | |
592 | if (!ulpq->pd_mode) | |
593 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
594 | else { | |
595 | __u32 ctsn, ctsnap; | |
596 | ||
597 | /* Do not even bother unless this is the next tsn to | |
598 | * be delivered. | |
599 | */ | |
600 | ctsn = event->tsn; | |
601 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
602 | if (TSN_lte(ctsn, ctsnap)) | |
603 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
604 | } | |
605 | ||
606 | return retval; | |
607 | } | |
608 | ||
609 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
01f2d384 | 610 | static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) |
1da177e4 LT |
611 | { |
612 | struct sk_buff *pos, *last_frag, *first_frag; | |
613 | struct sctp_ulpevent *cevent; | |
614 | __u32 ctsn, next_tsn; | |
615 | struct sctp_ulpevent *retval; | |
616 | ||
617 | /* The chunks are held in the reasm queue sorted by TSN. | |
618 | * Walk through the queue sequentially and look for a sequence of | |
619 | * fragmented chunks that start a datagram. | |
620 | */ | |
621 | ||
622 | if (skb_queue_empty(&ulpq->reasm)) | |
623 | return NULL; | |
624 | ||
625 | last_frag = first_frag = NULL; | |
626 | retval = NULL; | |
627 | next_tsn = 0; | |
628 | ||
629 | skb_queue_walk(&ulpq->reasm, pos) { | |
630 | cevent = sctp_skb2event(pos); | |
631 | ctsn = cevent->tsn; | |
632 | ||
633 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
634 | case SCTP_DATA_FIRST_FRAG: | |
635 | if (!first_frag) { | |
636 | first_frag = pos; | |
637 | next_tsn = ctsn + 1; | |
638 | last_frag = pos; | |
639 | } else | |
640 | goto done; | |
641 | break; | |
642 | ||
643 | case SCTP_DATA_MIDDLE_FRAG: | |
644 | if (!first_frag) | |
645 | return NULL; | |
646 | if (ctsn == next_tsn) { | |
647 | next_tsn++; | |
648 | last_frag = pos; | |
649 | } else | |
650 | goto done; | |
651 | break; | |
d003b41b LR |
652 | |
653 | case SCTP_DATA_LAST_FRAG: | |
654 | if (!first_frag) | |
655 | return NULL; | |
656 | else | |
657 | goto done; | |
658 | break; | |
659 | ||
1da177e4 LT |
660 | default: |
661 | return NULL; | |
3ff50b79 | 662 | } |
1da177e4 LT |
663 | } |
664 | ||
665 | /* We have the reassembled event. There is no need to look | |
666 | * further. | |
667 | */ | |
668 | done: | |
b01a2407 EB |
669 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
670 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
671 | return retval; |
672 | } | |
673 | ||
ea2dfb37 VY |
674 | /* |
675 | * Flush out stale fragments from the reassembly queue when processing | |
676 | * a Forward TSN. | |
677 | * | |
678 | * RFC 3758, Section 3.6 | |
679 | * | |
680 | * After receiving and processing a FORWARD TSN, the data receiver MUST | |
681 | * take cautions in updating its re-assembly queue. The receiver MUST | |
682 | * remove any partially reassembled message, which is still missing one | |
683 | * or more TSNs earlier than or equal to the new cumulative TSN point. | |
684 | * In the event that the receiver has invoked the partial delivery API, | |
685 | * a notification SHOULD also be generated to inform the upper layer API | |
686 | * that the message being partially delivered will NOT be completed. | |
687 | */ | |
688 | void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn) | |
689 | { | |
690 | struct sk_buff *pos, *tmp; | |
691 | struct sctp_ulpevent *event; | |
692 | __u32 tsn; | |
693 | ||
694 | if (skb_queue_empty(&ulpq->reasm)) | |
695 | return; | |
696 | ||
697 | skb_queue_walk_safe(&ulpq->reasm, pos, tmp) { | |
698 | event = sctp_skb2event(pos); | |
699 | tsn = event->tsn; | |
700 | ||
701 | /* Since the entire message must be abandoned by the | |
702 | * sender (item A3 in Section 3.5, RFC 3758), we can | |
703 | * free all fragments on the list that are less then | |
704 | * or equal to ctsn_point | |
705 | */ | |
706 | if (TSN_lte(tsn, fwd_tsn)) { | |
707 | __skb_unlink(pos, &ulpq->reasm); | |
708 | sctp_ulpevent_free(event); | |
709 | } else | |
710 | break; | |
711 | } | |
712 | } | |
713 | ||
ef5d4cf2 VY |
714 | /* |
715 | * Drain the reassembly queue. If we just cleared parted delivery, it | |
716 | * is possible that the reassembly queue will contain already reassembled | |
717 | * messages. Retrieve any such messages and give them to the user. | |
718 | */ | |
719 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq) | |
720 | { | |
721 | struct sctp_ulpevent *event = NULL; | |
722 | struct sk_buff_head temp; | |
723 | ||
724 | if (skb_queue_empty(&ulpq->reasm)) | |
725 | return; | |
726 | ||
727 | while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) { | |
728 | /* Do ordering if needed. */ | |
729 | if ((event) && (event->msg_flags & MSG_EOR)){ | |
730 | skb_queue_head_init(&temp); | |
731 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
732 | ||
733 | event = sctp_ulpq_order(ulpq, event); | |
734 | } | |
735 | ||
736 | /* Send event to the ULP. 'event' is the | |
737 | * sctp_ulpevent for very first SKB on the temp' list. | |
738 | */ | |
739 | if (event) | |
740 | sctp_ulpq_tail_event(ulpq, event); | |
741 | } | |
742 | } | |
743 | ||
744 | ||
1da177e4 LT |
745 | /* Helper function to gather skbs that have possibly become |
746 | * ordered by an an incoming chunk. | |
747 | */ | |
01f2d384 | 748 | static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
749 | struct sctp_ulpevent *event) |
750 | { | |
8728b834 | 751 | struct sk_buff_head *event_list; |
1da177e4 LT |
752 | struct sk_buff *pos, *tmp; |
753 | struct sctp_ulpevent *cevent; | |
754 | struct sctp_stream *in; | |
efea2c6b | 755 | __u16 sid, csid, cssn; |
1da177e4 LT |
756 | |
757 | sid = event->stream; | |
1da177e4 LT |
758 | in = &ulpq->asoc->ssnmap->in; |
759 | ||
8728b834 DM |
760 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
761 | ||
1da177e4 LT |
762 | /* We are holding the chunks by stream, by SSN. */ |
763 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
764 | cevent = (struct sctp_ulpevent *) pos->cb; | |
765 | csid = cevent->stream; | |
766 | cssn = cevent->ssn; | |
767 | ||
768 | /* Have we gone too far? */ | |
769 | if (csid > sid) | |
770 | break; | |
771 | ||
772 | /* Have we not gone far enough? */ | |
773 | if (csid < sid) | |
774 | continue; | |
775 | ||
776 | if (cssn != sctp_ssn_peek(in, sid)) | |
777 | break; | |
778 | ||
779 | /* Found it, so mark in the ssnmap. */ | |
780 | sctp_ssn_next(in, sid); | |
781 | ||
8728b834 | 782 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
783 | |
784 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 785 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
786 | } |
787 | } | |
788 | ||
789 | /* Helper function to store chunks needing ordering. */ | |
01f2d384 | 790 | static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
791 | struct sctp_ulpevent *event) |
792 | { | |
793 | struct sk_buff *pos; | |
794 | struct sctp_ulpevent *cevent; | |
795 | __u16 sid, csid; | |
796 | __u16 ssn, cssn; | |
797 | ||
798 | pos = skb_peek_tail(&ulpq->lobby); | |
799 | if (!pos) { | |
800 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
801 | return; | |
802 | } | |
803 | ||
804 | sid = event->stream; | |
805 | ssn = event->ssn; | |
d808ad9a | 806 | |
1da177e4 LT |
807 | cevent = (struct sctp_ulpevent *) pos->cb; |
808 | csid = cevent->stream; | |
809 | cssn = cevent->ssn; | |
810 | if (sid > csid) { | |
811 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
812 | return; | |
813 | } | |
814 | ||
815 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
816 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
817 | return; | |
818 | } | |
819 | ||
820 | /* Find the right place in this list. We store them by | |
821 | * stream ID and then by SSN. | |
822 | */ | |
823 | skb_queue_walk(&ulpq->lobby, pos) { | |
824 | cevent = (struct sctp_ulpevent *) pos->cb; | |
825 | csid = cevent->stream; | |
826 | cssn = cevent->ssn; | |
827 | ||
828 | if (csid > sid) | |
829 | break; | |
830 | if (csid == sid && SSN_lt(ssn, cssn)) | |
831 | break; | |
832 | } | |
833 | ||
834 | ||
835 | /* Insert before pos. */ | |
43f59c89 | 836 | __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event)); |
1da177e4 LT |
837 | } |
838 | ||
839 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 840 | struct sctp_ulpevent *event) |
1da177e4 LT |
841 | { |
842 | __u16 sid, ssn; | |
843 | struct sctp_stream *in; | |
844 | ||
845 | /* Check if this message needs ordering. */ | |
846 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
847 | return event; | |
848 | ||
849 | /* Note: The stream ID must be verified before this routine. */ | |
850 | sid = event->stream; | |
851 | ssn = event->ssn; | |
852 | in = &ulpq->asoc->ssnmap->in; | |
853 | ||
854 | /* Is this the expected SSN for this stream ID? */ | |
855 | if (ssn != sctp_ssn_peek(in, sid)) { | |
856 | /* We've received something out of order, so find where it | |
857 | * needs to be placed. We order by stream and then by SSN. | |
858 | */ | |
859 | sctp_ulpq_store_ordered(ulpq, event); | |
860 | return NULL; | |
861 | } | |
862 | ||
863 | /* Mark that the next chunk has been found. */ | |
864 | sctp_ssn_next(in, sid); | |
865 | ||
866 | /* Go find any other chunks that were waiting for | |
867 | * ordering. | |
868 | */ | |
869 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
870 | ||
871 | return event; | |
872 | } | |
873 | ||
874 | /* Helper function to gather skbs that have possibly become | |
875 | * ordered by forward tsn skipping their dependencies. | |
876 | */ | |
01f2d384 | 877 | static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid) |
1da177e4 LT |
878 | { |
879 | struct sk_buff *pos, *tmp; | |
880 | struct sctp_ulpevent *cevent; | |
8728b834 | 881 | struct sctp_ulpevent *event; |
1da177e4 LT |
882 | struct sctp_stream *in; |
883 | struct sk_buff_head temp; | |
c068be54 | 884 | struct sk_buff_head *lobby = &ulpq->lobby; |
1da177e4 LT |
885 | __u16 csid, cssn; |
886 | ||
887 | in = &ulpq->asoc->ssnmap->in; | |
888 | ||
889 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
890 | skb_queue_head_init(&temp); |
891 | event = NULL; | |
c068be54 | 892 | sctp_skb_for_each(pos, lobby, tmp) { |
1da177e4 LT |
893 | cevent = (struct sctp_ulpevent *) pos->cb; |
894 | csid = cevent->stream; | |
895 | cssn = cevent->ssn; | |
896 | ||
ea2dfb37 VY |
897 | /* Have we gone too far? */ |
898 | if (csid > sid) | |
1da177e4 LT |
899 | break; |
900 | ||
ea2dfb37 VY |
901 | /* Have we not gone far enough? */ |
902 | if (csid < sid) | |
903 | continue; | |
904 | ||
905 | /* see if this ssn has been marked by skipping */ | |
c068be54 | 906 | if (!SSN_lt(cssn, sctp_ssn_peek(in, csid))) |
ea2dfb37 | 907 | break; |
1da177e4 | 908 | |
c068be54 | 909 | __skb_unlink(pos, lobby); |
ea2dfb37 | 910 | if (!event) |
1da177e4 LT |
911 | /* Create a temporary list to collect chunks on. */ |
912 | event = sctp_skb2event(pos); | |
ea2dfb37 VY |
913 | |
914 | /* Attach all gathered skbs to the event. */ | |
915 | __skb_queue_tail(&temp, pos); | |
1da177e4 LT |
916 | } |
917 | ||
c068be54 VY |
918 | /* If we didn't reap any data, see if the next expected SSN |
919 | * is next on the queue and if so, use that. | |
920 | */ | |
921 | if (event == NULL && pos != (struct sk_buff *)lobby) { | |
922 | cevent = (struct sctp_ulpevent *) pos->cb; | |
923 | csid = cevent->stream; | |
924 | cssn = cevent->ssn; | |
925 | ||
926 | if (csid == sid && cssn == sctp_ssn_peek(in, csid)) { | |
927 | sctp_ssn_next(in, csid); | |
928 | __skb_unlink(pos, lobby); | |
929 | __skb_queue_tail(&temp, pos); | |
930 | event = sctp_skb2event(pos); | |
931 | } | |
932 | } | |
933 | ||
8728b834 DM |
934 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
935 | * very first SKB on the 'temp' list. | |
936 | */ | |
ea2dfb37 VY |
937 | if (event) { |
938 | /* see if we have more ordered that we can deliver */ | |
939 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
1da177e4 | 940 | sctp_ulpq_tail_event(ulpq, event); |
ea2dfb37 | 941 | } |
1da177e4 LT |
942 | } |
943 | ||
ea2dfb37 VY |
944 | /* Skip over an SSN. This is used during the processing of |
945 | * Forwared TSN chunk to skip over the abandoned ordered data | |
946 | */ | |
1da177e4 LT |
947 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) |
948 | { | |
949 | struct sctp_stream *in; | |
950 | ||
951 | /* Note: The stream ID must be verified before this routine. */ | |
952 | in = &ulpq->asoc->ssnmap->in; | |
953 | ||
954 | /* Is this an old SSN? If so ignore. */ | |
955 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
956 | return; | |
957 | ||
958 | /* Mark that we are no longer expecting this SSN or lower. */ | |
959 | sctp_ssn_skip(in, sid, ssn); | |
960 | ||
961 | /* Go find any other chunks that were waiting for | |
d808ad9a | 962 | * ordering and deliver them if needed. |
1da177e4 | 963 | */ |
ea2dfb37 | 964 | sctp_ulpq_reap_ordered(ulpq, sid); |
1da177e4 LT |
965 | } |
966 | ||
16d14ef9 PE |
967 | static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, |
968 | struct sk_buff_head *list, __u16 needed) | |
1da177e4 LT |
969 | { |
970 | __u16 freed = 0; | |
95ac7b85 LR |
971 | __u32 tsn, last_tsn; |
972 | struct sk_buff *skb, *flist, *last; | |
1da177e4 LT |
973 | struct sctp_ulpevent *event; |
974 | struct sctp_tsnmap *tsnmap; | |
975 | ||
976 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
977 | ||
e67f85ec | 978 | while ((skb = skb_peek_tail(list)) != NULL) { |
1da177e4 LT |
979 | event = sctp_skb2event(skb); |
980 | tsn = event->tsn; | |
981 | ||
e67f85ec LR |
982 | /* Don't renege below the Cumulative TSN ACK Point. */ |
983 | if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) | |
984 | break; | |
985 | ||
95ac7b85 LR |
986 | /* Events in ordering queue may have multiple fragments |
987 | * corresponding to additional TSNs. Sum the total | |
988 | * freed space; find the last TSN. | |
989 | */ | |
e67f85ec | 990 | freed += skb_headlen(skb); |
95ac7b85 LR |
991 | flist = skb_shinfo(skb)->frag_list; |
992 | for (last = flist; flist; flist = flist->next) { | |
993 | last = flist; | |
994 | freed += skb_headlen(last); | |
995 | } | |
996 | if (last) | |
997 | last_tsn = sctp_skb2event(last)->tsn; | |
998 | else | |
999 | last_tsn = tsn; | |
1000 | ||
1001 | /* Unlink the event, then renege all applicable TSNs. */ | |
1002 | __skb_unlink(skb, list); | |
1da177e4 | 1003 | sctp_ulpevent_free(event); |
95ac7b85 LR |
1004 | while (TSN_lte(tsn, last_tsn)) { |
1005 | sctp_tsnmap_renege(tsnmap, tsn); | |
1006 | tsn++; | |
1007 | } | |
1da177e4 LT |
1008 | if (freed >= needed) |
1009 | return freed; | |
1010 | } | |
1011 | ||
1012 | return freed; | |
1013 | } | |
1014 | ||
16d14ef9 PE |
1015 | /* Renege 'needed' bytes from the ordering queue. */ |
1016 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
1017 | { | |
1018 | return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed); | |
1019 | } | |
1020 | ||
1da177e4 LT |
1021 | /* Renege 'needed' bytes from the reassembly queue. */ |
1022 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
1023 | { | |
16d14ef9 | 1024 | return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed); |
1da177e4 LT |
1025 | } |
1026 | ||
1027 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
1028 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
dd0fc66f | 1029 | gfp_t gfp) |
1da177e4 LT |
1030 | { |
1031 | struct sctp_ulpevent *event; | |
1032 | struct sctp_association *asoc; | |
b6e1331f | 1033 | struct sctp_sock *sp; |
d003b41b LR |
1034 | __u32 ctsn; |
1035 | struct sk_buff *skb; | |
1da177e4 LT |
1036 | |
1037 | asoc = ulpq->asoc; | |
b6e1331f | 1038 | sp = sctp_sk(asoc->base.sk); |
1da177e4 | 1039 | |
b6e1331f | 1040 | /* If the association is already in Partial Delivery mode |
d003b41b | 1041 | * we have nothing to do. |
b6e1331f VY |
1042 | */ |
1043 | if (ulpq->pd_mode) | |
1044 | return; | |
1da177e4 | 1045 | |
d003b41b LR |
1046 | /* Data must be at or below the Cumulative TSN ACK Point to |
1047 | * start partial delivery. | |
1048 | */ | |
1049 | skb = skb_peek(&asoc->ulpq.reasm); | |
1050 | if (skb != NULL) { | |
1051 | ctsn = sctp_skb2event(skb)->tsn; | |
1052 | if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map))) | |
1053 | return; | |
1054 | } | |
1055 | ||
b6e1331f VY |
1056 | /* If the user enabled fragment interleave socket option, |
1057 | * multiple associations can enter partial delivery. | |
1058 | * Otherwise, we can only enter partial delivery if the | |
1059 | * socket is not in partial deliver mode. | |
1060 | */ | |
1061 | if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) { | |
1da177e4 LT |
1062 | /* Is partial delivery possible? */ |
1063 | event = sctp_ulpq_retrieve_first(ulpq); | |
1064 | /* Send event to the ULP. */ | |
1065 | if (event) { | |
1066 | sctp_ulpq_tail_event(ulpq, event); | |
d49d91d7 | 1067 | sctp_ulpq_set_pd(ulpq); |
1da177e4 LT |
1068 | return; |
1069 | } | |
1070 | } | |
1071 | } | |
1072 | ||
1073 | /* Renege some packets to make room for an incoming chunk. */ | |
1074 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 1075 | gfp_t gfp) |
1da177e4 LT |
1076 | { |
1077 | struct sctp_association *asoc; | |
1078 | __u16 needed, freed; | |
1079 | ||
1080 | asoc = ulpq->asoc; | |
1081 | ||
1082 | if (chunk) { | |
1083 | needed = ntohs(chunk->chunk_hdr->length); | |
1084 | needed -= sizeof(sctp_data_chunk_t); | |
d808ad9a | 1085 | } else |
1da177e4 LT |
1086 | needed = SCTP_DEFAULT_MAXWINDOW; |
1087 | ||
1088 | freed = 0; | |
1089 | ||
1090 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
1091 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
1092 | if (freed < needed) { | |
1093 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
1094 | } | |
1095 | } | |
1096 | /* If able to free enough room, accept this chunk. */ | |
1097 | if (chunk && (freed >= needed)) { | |
d003b41b LR |
1098 | int retval; |
1099 | retval = sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
1100 | /* | |
1101 | * Enter partial delivery if chunk has not been | |
1102 | * delivered; otherwise, drain the reassembly queue. | |
1103 | */ | |
1104 | if (retval <= 0) | |
1105 | sctp_ulpq_partial_delivery(ulpq, gfp); | |
1106 | else if (retval == 1) | |
1107 | sctp_ulpq_reasm_drain(ulpq); | |
1da177e4 LT |
1108 | } |
1109 | ||
3ab224be | 1110 | sk_mem_reclaim(asoc->base.sk); |
1da177e4 LT |
1111 | } |
1112 | ||
1113 | ||
1114 | ||
1115 | /* Notify the application if an association is aborted and in | |
1116 | * partial delivery mode. Send up any pending received messages. | |
1117 | */ | |
dd0fc66f | 1118 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
1119 | { |
1120 | struct sctp_ulpevent *ev = NULL; | |
1121 | struct sock *sk; | |
1122 | ||
1123 | if (!ulpq->pd_mode) | |
1124 | return; | |
1125 | ||
1126 | sk = ulpq->asoc->base.sk; | |
1127 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, | |
1128 | &sctp_sk(sk)->subscribe)) | |
1129 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
1130 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
1131 | gfp); | |
1132 | if (ev) | |
1133 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
1134 | ||
1135 | /* If there is data waiting, send it up the socket now. */ | |
1136 | if (sctp_ulpq_clear_pd(ulpq) || ev) | |
1137 | sk->sk_data_ready(sk, 0); | |
1138 | } |