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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> | |
8465a5fc | 41 | #include <net/busy_poll.h> |
1da177e4 LT |
42 | #include <net/sctp/structs.h> |
43 | #include <net/sctp/sctp.h> | |
44 | #include <net/sctp/sm.h> | |
45 | ||
46 | /* Forward declarations for internal helpers. */ | |
26ac8e5f | 47 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, |
8728b834 | 48 | struct sctp_ulpevent *); |
26ac8e5f | 49 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *, |
8728b834 | 50 | struct sctp_ulpevent *); |
ef5d4cf2 | 51 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq); |
1da177e4 LT |
52 | |
53 | /* 1st Level Abstractions */ | |
54 | ||
55 | /* Initialize a ULP queue from a block of memory. */ | |
56 | struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, | |
57 | struct sctp_association *asoc) | |
58 | { | |
59 | memset(ulpq, 0, sizeof(struct sctp_ulpq)); | |
60 | ||
61 | ulpq->asoc = asoc; | |
62 | skb_queue_head_init(&ulpq->reasm); | |
63 | skb_queue_head_init(&ulpq->lobby); | |
64 | ulpq->pd_mode = 0; | |
1da177e4 LT |
65 | |
66 | return ulpq; | |
67 | } | |
68 | ||
69 | ||
70 | /* Flush the reassembly and ordering queues. */ | |
0b58a811 | 71 | void sctp_ulpq_flush(struct sctp_ulpq *ulpq) |
1da177e4 LT |
72 | { |
73 | struct sk_buff *skb; | |
74 | struct sctp_ulpevent *event; | |
75 | ||
76 | while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { | |
77 | event = sctp_skb2event(skb); | |
78 | sctp_ulpevent_free(event); | |
79 | } | |
80 | ||
81 | while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { | |
82 | event = sctp_skb2event(skb); | |
83 | sctp_ulpevent_free(event); | |
84 | } | |
85 | ||
86 | } | |
87 | ||
88 | /* Dispose of a ulpqueue. */ | |
89 | void sctp_ulpq_free(struct sctp_ulpq *ulpq) | |
90 | { | |
91 | sctp_ulpq_flush(ulpq); | |
1da177e4 LT |
92 | } |
93 | ||
94 | /* Process an incoming DATA chunk. */ | |
95 | int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 96 | gfp_t gfp) |
1da177e4 LT |
97 | { |
98 | struct sk_buff_head temp; | |
1da177e4 | 99 | struct sctp_ulpevent *event; |
d003b41b | 100 | int event_eor = 0; |
1da177e4 | 101 | |
1da177e4 LT |
102 | /* Create an event from the incoming chunk. */ |
103 | event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); | |
104 | if (!event) | |
105 | return -ENOMEM; | |
106 | ||
107 | /* Do reassembly if needed. */ | |
108 | event = sctp_ulpq_reasm(ulpq, event); | |
109 | ||
110 | /* Do ordering if needed. */ | |
cb3f837b | 111 | if ((event) && (event->msg_flags & MSG_EOR)) { |
1da177e4 LT |
112 | /* Create a temporary list to collect chunks on. */ |
113 | skb_queue_head_init(&temp); | |
114 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
115 | ||
116 | event = sctp_ulpq_order(ulpq, event); | |
117 | } | |
118 | ||
8728b834 DM |
119 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
120 | * very first SKB on the 'temp' list. | |
121 | */ | |
d003b41b LR |
122 | if (event) { |
123 | event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0; | |
1da177e4 | 124 | sctp_ulpq_tail_event(ulpq, event); |
d003b41b | 125 | } |
1da177e4 | 126 | |
d003b41b | 127 | return event_eor; |
1da177e4 LT |
128 | } |
129 | ||
130 | /* Add a new event for propagation to the ULP. */ | |
131 | /* Clear the partial delivery mode for this socket. Note: This | |
132 | * assumes that no association is currently in partial delivery mode. | |
133 | */ | |
b6e1331f | 134 | int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc) |
1da177e4 LT |
135 | { |
136 | struct sctp_sock *sp = sctp_sk(sk); | |
137 | ||
b6e1331f VY |
138 | if (atomic_dec_and_test(&sp->pd_mode)) { |
139 | /* This means there are no other associations in PD, so | |
140 | * we can go ahead and clear out the lobby in one shot | |
141 | */ | |
142 | if (!skb_queue_empty(&sp->pd_lobby)) { | |
143 | struct list_head *list; | |
311b2177 MRL |
144 | skb_queue_splice_tail_init(&sp->pd_lobby, |
145 | &sk->sk_receive_queue); | |
b6e1331f VY |
146 | list = (struct list_head *)&sctp_sk(sk)->pd_lobby; |
147 | INIT_LIST_HEAD(list); | |
148 | return 1; | |
149 | } | |
150 | } else { | |
151 | /* There are other associations in PD, so we only need to | |
152 | * pull stuff out of the lobby that belongs to the | |
153 | * associations that is exiting PD (all of its notifications | |
154 | * are posted here). | |
155 | */ | |
156 | if (!skb_queue_empty(&sp->pd_lobby) && asoc) { | |
157 | struct sk_buff *skb, *tmp; | |
158 | struct sctp_ulpevent *event; | |
159 | ||
160 | sctp_skb_for_each(skb, &sp->pd_lobby, tmp) { | |
161 | event = sctp_skb2event(skb); | |
162 | if (event->asoc == asoc) { | |
163 | __skb_unlink(skb, &sp->pd_lobby); | |
164 | __skb_queue_tail(&sk->sk_receive_queue, | |
165 | skb); | |
166 | } | |
167 | } | |
168 | } | |
1da177e4 | 169 | } |
b6e1331f | 170 | |
1da177e4 LT |
171 | return 0; |
172 | } | |
173 | ||
d49d91d7 VY |
174 | /* Set the pd_mode on the socket and ulpq */ |
175 | static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq) | |
176 | { | |
177 | struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk); | |
178 | ||
179 | atomic_inc(&sp->pd_mode); | |
180 | ulpq->pd_mode = 1; | |
181 | } | |
182 | ||
1da177e4 LT |
183 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ |
184 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) | |
185 | { | |
186 | ulpq->pd_mode = 0; | |
ef5d4cf2 | 187 | sctp_ulpq_reasm_drain(ulpq); |
b6e1331f | 188 | return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc); |
1da177e4 LT |
189 | } |
190 | ||
8728b834 DM |
191 | /* If the SKB of 'event' is on a list, it is the first such member |
192 | * of that list. | |
193 | */ | |
1da177e4 LT |
194 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) |
195 | { | |
196 | struct sock *sk = ulpq->asoc->base.sk; | |
8728b834 DM |
197 | struct sk_buff_head *queue, *skb_list; |
198 | struct sk_buff *skb = sctp_event2skb(event); | |
1da177e4 LT |
199 | int clear_pd = 0; |
200 | ||
8728b834 DM |
201 | skb_list = (struct sk_buff_head *) skb->prev; |
202 | ||
1da177e4 LT |
203 | /* If the socket is just going to throw this away, do not |
204 | * even try to deliver it. | |
205 | */ | |
206 | if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN)) | |
207 | goto out_free; | |
208 | ||
2c8c56e1 | 209 | if (!sctp_ulpevent_is_notification(event)) { |
8465a5fc | 210 | sk_mark_napi_id(sk, skb); |
2c8c56e1 ED |
211 | sk_incoming_cpu_update(sk); |
212 | } | |
1da177e4 LT |
213 | /* Check if the user wishes to receive this event. */ |
214 | if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe)) | |
215 | goto out_free; | |
216 | ||
217 | /* If we are in partial delivery mode, post to the lobby until | |
218 | * partial delivery is cleared, unless, of course _this_ is | |
219 | * the association the cause of the partial delivery. | |
220 | */ | |
221 | ||
b6e1331f | 222 | if (atomic_read(&sctp_sk(sk)->pd_mode) == 0) { |
1da177e4 | 223 | queue = &sk->sk_receive_queue; |
b6e1331f VY |
224 | } else { |
225 | if (ulpq->pd_mode) { | |
226 | /* If the association is in partial delivery, we | |
227 | * need to finish delivering the partially processed | |
228 | * packet before passing any other data. This is | |
229 | * because we don't truly support stream interleaving. | |
230 | */ | |
231 | if ((event->msg_flags & MSG_NOTIFICATION) || | |
232 | (SCTP_DATA_NOT_FRAG == | |
233 | (event->msg_flags & SCTP_DATA_FRAG_MASK))) | |
234 | queue = &sctp_sk(sk)->pd_lobby; | |
235 | else { | |
236 | clear_pd = event->msg_flags & MSG_EOR; | |
237 | queue = &sk->sk_receive_queue; | |
238 | } | |
239 | } else { | |
240 | /* | |
241 | * If fragment interleave is enabled, we | |
25985edc | 242 | * can queue this to the receive queue instead |
b6e1331f VY |
243 | * of the lobby. |
244 | */ | |
245 | if (sctp_sk(sk)->frag_interleave) | |
246 | queue = &sk->sk_receive_queue; | |
247 | else | |
248 | queue = &sctp_sk(sk)->pd_lobby; | |
1da177e4 | 249 | } |
b6e1331f | 250 | } |
1da177e4 LT |
251 | |
252 | /* If we are harvesting multiple skbs they will be | |
253 | * collected on a list. | |
254 | */ | |
8728b834 | 255 | if (skb_list) |
311b2177 | 256 | skb_queue_splice_tail_init(skb_list, queue); |
1da177e4 | 257 | else |
8728b834 | 258 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
259 | |
260 | /* Did we just complete partial delivery and need to get | |
261 | * rolling again? Move pending data to the receive | |
262 | * queue. | |
263 | */ | |
264 | if (clear_pd) | |
265 | sctp_ulpq_clear_pd(ulpq); | |
266 | ||
267 | if (queue == &sk->sk_receive_queue) | |
fb586f25 | 268 | sctp_sk(sk)->pending_data_ready = 1; |
1da177e4 LT |
269 | return 1; |
270 | ||
271 | out_free: | |
8728b834 DM |
272 | if (skb_list) |
273 | sctp_queue_purge_ulpevents(skb_list); | |
1da177e4 LT |
274 | else |
275 | sctp_ulpevent_free(event); | |
8728b834 | 276 | |
1da177e4 LT |
277 | return 0; |
278 | } | |
279 | ||
280 | /* 2nd Level Abstractions */ | |
281 | ||
282 | /* Helper function to store chunks that need to be reassembled. */ | |
01f2d384 | 283 | static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, |
1da177e4 LT |
284 | struct sctp_ulpevent *event) |
285 | { | |
286 | struct sk_buff *pos; | |
287 | struct sctp_ulpevent *cevent; | |
288 | __u32 tsn, ctsn; | |
289 | ||
290 | tsn = event->tsn; | |
291 | ||
292 | /* See if it belongs at the end. */ | |
293 | pos = skb_peek_tail(&ulpq->reasm); | |
294 | if (!pos) { | |
295 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
296 | return; | |
297 | } | |
298 | ||
299 | /* Short circuit just dropping it at the end. */ | |
300 | cevent = sctp_skb2event(pos); | |
301 | ctsn = cevent->tsn; | |
302 | if (TSN_lt(ctsn, tsn)) { | |
303 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
304 | return; | |
305 | } | |
306 | ||
307 | /* Find the right place in this list. We store them by TSN. */ | |
308 | skb_queue_walk(&ulpq->reasm, pos) { | |
309 | cevent = sctp_skb2event(pos); | |
310 | ctsn = cevent->tsn; | |
311 | ||
312 | if (TSN_lt(tsn, ctsn)) | |
313 | break; | |
314 | } | |
315 | ||
316 | /* Insert before pos. */ | |
43f59c89 | 317 | __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event)); |
1da177e4 LT |
318 | |
319 | } | |
320 | ||
321 | /* Helper function to return an event corresponding to the reassembled | |
322 | * datagram. | |
323 | * This routine creates a re-assembled skb given the first and last skb's | |
324 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
325 | * payload was fragmented on the way and ip had to reassemble them. | |
326 | * We add the rest of skb's to the first skb's fraglist. | |
327 | */ | |
b01a2407 EB |
328 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net, |
329 | struct sk_buff_head *queue, struct sk_buff *f_frag, | |
330 | struct sk_buff *l_frag) | |
1da177e4 LT |
331 | { |
332 | struct sk_buff *pos; | |
672e7cca | 333 | struct sk_buff *new = NULL; |
1da177e4 LT |
334 | struct sctp_ulpevent *event; |
335 | struct sk_buff *pnext, *last; | |
336 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
337 | ||
338 | /* Store the pointer to the 2nd skb */ | |
339 | if (f_frag == l_frag) | |
340 | pos = NULL; | |
341 | else | |
342 | pos = f_frag->next; | |
343 | ||
344 | /* Get the last skb in the f_frag's frag_list if present. */ | |
8d72651d | 345 | for (last = list; list; last = list, list = list->next) |
346 | ; | |
1da177e4 LT |
347 | |
348 | /* Add the list of remaining fragments to the first fragments | |
349 | * frag_list. | |
350 | */ | |
351 | if (last) | |
352 | last->next = pos; | |
d808ad9a YH |
353 | else { |
354 | if (skb_cloned(f_frag)) { | |
355 | /* This is a cloned skb, we can't just modify | |
356 | * the frag_list. We need a new skb to do that. | |
357 | * Instead of calling skb_unshare(), we'll do it | |
358 | * ourselves since we need to delay the free. | |
359 | */ | |
360 | new = skb_copy(f_frag, GFP_ATOMIC); | |
361 | if (!new) | |
362 | return NULL; /* try again later */ | |
363 | ||
364 | sctp_skb_set_owner_r(new, f_frag->sk); | |
365 | ||
366 | skb_shinfo(new)->frag_list = pos; | |
367 | } else | |
368 | skb_shinfo(f_frag)->frag_list = pos; | |
369 | } | |
1da177e4 LT |
370 | |
371 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 372 | __skb_unlink(f_frag, queue); |
672e7cca | 373 | |
d808ad9a YH |
374 | /* if we did unshare, then free the old skb and re-assign */ |
375 | if (new) { | |
376 | kfree_skb(f_frag); | |
377 | f_frag = new; | |
378 | } | |
672e7cca | 379 | |
1da177e4 LT |
380 | while (pos) { |
381 | ||
382 | pnext = pos->next; | |
383 | ||
384 | /* Update the len and data_len fields of the first fragment. */ | |
385 | f_frag->len += pos->len; | |
386 | f_frag->data_len += pos->len; | |
387 | ||
388 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 389 | __skb_unlink(pos, queue); |
d808ad9a | 390 | |
1da177e4 LT |
391 | /* Break if we have reached the last fragment. */ |
392 | if (pos == l_frag) | |
393 | break; | |
394 | pos->next = pnext; | |
395 | pos = pnext; | |
3ff50b79 | 396 | } |
1da177e4 LT |
397 | |
398 | event = sctp_skb2event(f_frag); | |
b01a2407 | 399 | SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS); |
1da177e4 LT |
400 | |
401 | return event; | |
402 | } | |
403 | ||
404 | ||
405 | /* Helper function to check if an incoming chunk has filled up the last | |
406 | * missing fragment in a SCTP datagram and return the corresponding event. | |
407 | */ | |
01f2d384 | 408 | static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) |
1da177e4 LT |
409 | { |
410 | struct sk_buff *pos; | |
411 | struct sctp_ulpevent *cevent; | |
412 | struct sk_buff *first_frag = NULL; | |
413 | __u32 ctsn, next_tsn; | |
414 | struct sctp_ulpevent *retval = NULL; | |
d49d91d7 VY |
415 | struct sk_buff *pd_first = NULL; |
416 | struct sk_buff *pd_last = NULL; | |
417 | size_t pd_len = 0; | |
418 | struct sctp_association *asoc; | |
419 | u32 pd_point; | |
1da177e4 LT |
420 | |
421 | /* Initialized to 0 just to avoid compiler warning message. Will | |
422 | * never be used with this value. It is referenced only after it | |
423 | * is set when we find the first fragment of a message. | |
424 | */ | |
425 | next_tsn = 0; | |
426 | ||
427 | /* The chunks are held in the reasm queue sorted by TSN. | |
428 | * Walk through the queue sequentially and look for a sequence of | |
429 | * fragmented chunks that complete a datagram. | |
430 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
431 | * is the first fragment of a datagram. Once these 2 fields are set | |
432 | * we expect to find the remaining middle fragments and the last | |
433 | * fragment in order. If not, first_frag is reset to NULL and we | |
434 | * start the next pass when we find another first fragment. | |
d49d91d7 VY |
435 | * |
436 | * There is a potential to do partial delivery if user sets | |
437 | * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here | |
438 | * to see if can do PD. | |
1da177e4 LT |
439 | */ |
440 | skb_queue_walk(&ulpq->reasm, pos) { | |
441 | cevent = sctp_skb2event(pos); | |
442 | ctsn = cevent->tsn; | |
443 | ||
444 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
445 | case SCTP_DATA_FIRST_FRAG: | |
d49d91d7 VY |
446 | /* If this "FIRST_FRAG" is the first |
447 | * element in the queue, then count it towards | |
448 | * possible PD. | |
449 | */ | |
450 | if (pos == ulpq->reasm.next) { | |
451 | pd_first = pos; | |
452 | pd_last = pos; | |
453 | pd_len = pos->len; | |
454 | } else { | |
455 | pd_first = NULL; | |
456 | pd_last = NULL; | |
457 | pd_len = 0; | |
458 | } | |
459 | ||
1da177e4 LT |
460 | first_frag = pos; |
461 | next_tsn = ctsn + 1; | |
462 | break; | |
463 | ||
464 | case SCTP_DATA_MIDDLE_FRAG: | |
d49d91d7 | 465 | if ((first_frag) && (ctsn == next_tsn)) { |
1da177e4 | 466 | next_tsn++; |
d49d91d7 VY |
467 | if (pd_first) { |
468 | pd_last = pos; | |
469 | pd_len += pos->len; | |
470 | } | |
471 | } else | |
1da177e4 LT |
472 | first_frag = NULL; |
473 | break; | |
474 | ||
475 | case SCTP_DATA_LAST_FRAG: | |
476 | if (first_frag && (ctsn == next_tsn)) | |
477 | goto found; | |
478 | else | |
479 | first_frag = NULL; | |
480 | break; | |
3ff50b79 | 481 | } |
d49d91d7 VY |
482 | } |
483 | ||
484 | asoc = ulpq->asoc; | |
485 | if (pd_first) { | |
486 | /* Make sure we can enter partial deliver. | |
487 | * We can trigger partial delivery only if framgent | |
488 | * interleave is set, or the socket is not already | |
489 | * in partial delivery. | |
490 | */ | |
491 | if (!sctp_sk(asoc->base.sk)->frag_interleave && | |
492 | atomic_read(&sctp_sk(asoc->base.sk)->pd_mode)) | |
493 | goto done; | |
1da177e4 | 494 | |
d49d91d7 VY |
495 | cevent = sctp_skb2event(pd_first); |
496 | pd_point = sctp_sk(asoc->base.sk)->pd_point; | |
497 | if (pd_point && pd_point <= pd_len) { | |
b01a2407 EB |
498 | retval = sctp_make_reassembled_event(sock_net(asoc->base.sk), |
499 | &ulpq->reasm, | |
d49d91d7 VY |
500 | pd_first, |
501 | pd_last); | |
502 | if (retval) | |
503 | sctp_ulpq_set_pd(ulpq); | |
504 | } | |
1da177e4 LT |
505 | } |
506 | done: | |
507 | return retval; | |
508 | found: | |
b01a2407 EB |
509 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
510 | &ulpq->reasm, first_frag, pos); | |
1da177e4 LT |
511 | if (retval) |
512 | retval->msg_flags |= MSG_EOR; | |
513 | goto done; | |
514 | } | |
515 | ||
516 | /* Retrieve the next set of fragments of a partial message. */ | |
01f2d384 | 517 | static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) |
1da177e4 LT |
518 | { |
519 | struct sk_buff *pos, *last_frag, *first_frag; | |
520 | struct sctp_ulpevent *cevent; | |
521 | __u32 ctsn, next_tsn; | |
522 | int is_last; | |
523 | struct sctp_ulpevent *retval; | |
524 | ||
525 | /* The chunks are held in the reasm queue sorted by TSN. | |
526 | * Walk through the queue sequentially and look for the first | |
527 | * sequence of fragmented chunks. | |
528 | */ | |
529 | ||
530 | if (skb_queue_empty(&ulpq->reasm)) | |
531 | return NULL; | |
532 | ||
533 | last_frag = first_frag = NULL; | |
534 | retval = NULL; | |
535 | next_tsn = 0; | |
536 | is_last = 0; | |
537 | ||
538 | skb_queue_walk(&ulpq->reasm, pos) { | |
539 | cevent = sctp_skb2event(pos); | |
540 | ctsn = cevent->tsn; | |
541 | ||
542 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
d003b41b LR |
543 | case SCTP_DATA_FIRST_FRAG: |
544 | if (!first_frag) | |
545 | return NULL; | |
546 | goto done; | |
1da177e4 LT |
547 | case SCTP_DATA_MIDDLE_FRAG: |
548 | if (!first_frag) { | |
549 | first_frag = pos; | |
550 | next_tsn = ctsn + 1; | |
551 | last_frag = pos; | |
d003b41b | 552 | } else if (next_tsn == ctsn) { |
1da177e4 | 553 | next_tsn++; |
d003b41b LR |
554 | last_frag = pos; |
555 | } else | |
1da177e4 LT |
556 | goto done; |
557 | break; | |
558 | case SCTP_DATA_LAST_FRAG: | |
559 | if (!first_frag) | |
560 | first_frag = pos; | |
561 | else if (ctsn != next_tsn) | |
562 | goto done; | |
563 | last_frag = pos; | |
564 | is_last = 1; | |
565 | goto done; | |
566 | default: | |
567 | return NULL; | |
3ff50b79 | 568 | } |
1da177e4 LT |
569 | } |
570 | ||
571 | /* We have the reassembled event. There is no need to look | |
572 | * further. | |
573 | */ | |
574 | done: | |
b01a2407 EB |
575 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
576 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
577 | if (retval && is_last) |
578 | retval->msg_flags |= MSG_EOR; | |
579 | ||
580 | return retval; | |
581 | } | |
582 | ||
583 | ||
584 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
585 | * need reassembling. | |
586 | */ | |
587 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
588 | struct sctp_ulpevent *event) | |
589 | { | |
590 | struct sctp_ulpevent *retval = NULL; | |
591 | ||
592 | /* Check if this is part of a fragmented message. */ | |
593 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
594 | event->msg_flags |= MSG_EOR; | |
595 | return event; | |
596 | } | |
597 | ||
598 | sctp_ulpq_store_reasm(ulpq, event); | |
599 | if (!ulpq->pd_mode) | |
600 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
601 | else { | |
602 | __u32 ctsn, ctsnap; | |
603 | ||
604 | /* Do not even bother unless this is the next tsn to | |
605 | * be delivered. | |
606 | */ | |
607 | ctsn = event->tsn; | |
608 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
609 | if (TSN_lte(ctsn, ctsnap)) | |
610 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
611 | } | |
612 | ||
613 | return retval; | |
614 | } | |
615 | ||
616 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
01f2d384 | 617 | static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) |
1da177e4 LT |
618 | { |
619 | struct sk_buff *pos, *last_frag, *first_frag; | |
620 | struct sctp_ulpevent *cevent; | |
621 | __u32 ctsn, next_tsn; | |
622 | struct sctp_ulpevent *retval; | |
623 | ||
624 | /* The chunks are held in the reasm queue sorted by TSN. | |
625 | * Walk through the queue sequentially and look for a sequence of | |
626 | * fragmented chunks that start a datagram. | |
627 | */ | |
628 | ||
629 | if (skb_queue_empty(&ulpq->reasm)) | |
630 | return NULL; | |
631 | ||
632 | last_frag = first_frag = NULL; | |
633 | retval = NULL; | |
634 | next_tsn = 0; | |
635 | ||
636 | skb_queue_walk(&ulpq->reasm, pos) { | |
637 | cevent = sctp_skb2event(pos); | |
638 | ctsn = cevent->tsn; | |
639 | ||
640 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
641 | case SCTP_DATA_FIRST_FRAG: | |
642 | if (!first_frag) { | |
643 | first_frag = pos; | |
644 | next_tsn = ctsn + 1; | |
645 | last_frag = pos; | |
646 | } else | |
647 | goto done; | |
648 | break; | |
649 | ||
650 | case SCTP_DATA_MIDDLE_FRAG: | |
651 | if (!first_frag) | |
652 | return NULL; | |
653 | if (ctsn == next_tsn) { | |
654 | next_tsn++; | |
655 | last_frag = pos; | |
656 | } else | |
657 | goto done; | |
658 | break; | |
d003b41b LR |
659 | |
660 | case SCTP_DATA_LAST_FRAG: | |
661 | if (!first_frag) | |
662 | return NULL; | |
663 | else | |
664 | goto done; | |
665 | break; | |
666 | ||
1da177e4 LT |
667 | default: |
668 | return NULL; | |
3ff50b79 | 669 | } |
1da177e4 LT |
670 | } |
671 | ||
672 | /* We have the reassembled event. There is no need to look | |
673 | * further. | |
674 | */ | |
675 | done: | |
b01a2407 EB |
676 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
677 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
678 | return retval; |
679 | } | |
680 | ||
ea2dfb37 VY |
681 | /* |
682 | * Flush out stale fragments from the reassembly queue when processing | |
683 | * a Forward TSN. | |
684 | * | |
685 | * RFC 3758, Section 3.6 | |
686 | * | |
687 | * After receiving and processing a FORWARD TSN, the data receiver MUST | |
688 | * take cautions in updating its re-assembly queue. The receiver MUST | |
689 | * remove any partially reassembled message, which is still missing one | |
690 | * or more TSNs earlier than or equal to the new cumulative TSN point. | |
691 | * In the event that the receiver has invoked the partial delivery API, | |
692 | * a notification SHOULD also be generated to inform the upper layer API | |
693 | * that the message being partially delivered will NOT be completed. | |
694 | */ | |
695 | void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn) | |
696 | { | |
697 | struct sk_buff *pos, *tmp; | |
698 | struct sctp_ulpevent *event; | |
699 | __u32 tsn; | |
700 | ||
701 | if (skb_queue_empty(&ulpq->reasm)) | |
702 | return; | |
703 | ||
704 | skb_queue_walk_safe(&ulpq->reasm, pos, tmp) { | |
705 | event = sctp_skb2event(pos); | |
706 | tsn = event->tsn; | |
707 | ||
708 | /* Since the entire message must be abandoned by the | |
709 | * sender (item A3 in Section 3.5, RFC 3758), we can | |
710 | * free all fragments on the list that are less then | |
711 | * or equal to ctsn_point | |
712 | */ | |
713 | if (TSN_lte(tsn, fwd_tsn)) { | |
714 | __skb_unlink(pos, &ulpq->reasm); | |
715 | sctp_ulpevent_free(event); | |
716 | } else | |
717 | break; | |
718 | } | |
719 | } | |
720 | ||
ef5d4cf2 VY |
721 | /* |
722 | * Drain the reassembly queue. If we just cleared parted delivery, it | |
723 | * is possible that the reassembly queue will contain already reassembled | |
724 | * messages. Retrieve any such messages and give them to the user. | |
725 | */ | |
726 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq) | |
727 | { | |
728 | struct sctp_ulpevent *event = NULL; | |
729 | struct sk_buff_head temp; | |
730 | ||
731 | if (skb_queue_empty(&ulpq->reasm)) | |
732 | return; | |
733 | ||
734 | while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) { | |
735 | /* Do ordering if needed. */ | |
cb3f837b | 736 | if ((event) && (event->msg_flags & MSG_EOR)) { |
ef5d4cf2 VY |
737 | skb_queue_head_init(&temp); |
738 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
739 | ||
740 | event = sctp_ulpq_order(ulpq, event); | |
741 | } | |
742 | ||
743 | /* Send event to the ULP. 'event' is the | |
744 | * sctp_ulpevent for very first SKB on the temp' list. | |
745 | */ | |
746 | if (event) | |
747 | sctp_ulpq_tail_event(ulpq, event); | |
748 | } | |
749 | } | |
750 | ||
751 | ||
1da177e4 LT |
752 | /* Helper function to gather skbs that have possibly become |
753 | * ordered by an an incoming chunk. | |
754 | */ | |
01f2d384 | 755 | static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
756 | struct sctp_ulpevent *event) |
757 | { | |
8728b834 | 758 | struct sk_buff_head *event_list; |
1da177e4 LT |
759 | struct sk_buff *pos, *tmp; |
760 | struct sctp_ulpevent *cevent; | |
761 | struct sctp_stream *in; | |
efea2c6b | 762 | __u16 sid, csid, cssn; |
1da177e4 LT |
763 | |
764 | sid = event->stream; | |
1da177e4 LT |
765 | in = &ulpq->asoc->ssnmap->in; |
766 | ||
8728b834 DM |
767 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
768 | ||
1da177e4 LT |
769 | /* We are holding the chunks by stream, by SSN. */ |
770 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
771 | cevent = (struct sctp_ulpevent *) pos->cb; | |
772 | csid = cevent->stream; | |
773 | cssn = cevent->ssn; | |
774 | ||
775 | /* Have we gone too far? */ | |
776 | if (csid > sid) | |
777 | break; | |
778 | ||
779 | /* Have we not gone far enough? */ | |
780 | if (csid < sid) | |
781 | continue; | |
782 | ||
783 | if (cssn != sctp_ssn_peek(in, sid)) | |
784 | break; | |
785 | ||
786 | /* Found it, so mark in the ssnmap. */ | |
787 | sctp_ssn_next(in, sid); | |
788 | ||
8728b834 | 789 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
790 | |
791 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 792 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
793 | } |
794 | } | |
795 | ||
796 | /* Helper function to store chunks needing ordering. */ | |
01f2d384 | 797 | static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
798 | struct sctp_ulpevent *event) |
799 | { | |
800 | struct sk_buff *pos; | |
801 | struct sctp_ulpevent *cevent; | |
802 | __u16 sid, csid; | |
803 | __u16 ssn, cssn; | |
804 | ||
805 | pos = skb_peek_tail(&ulpq->lobby); | |
806 | if (!pos) { | |
807 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
808 | return; | |
809 | } | |
810 | ||
811 | sid = event->stream; | |
812 | ssn = event->ssn; | |
d808ad9a | 813 | |
1da177e4 LT |
814 | cevent = (struct sctp_ulpevent *) pos->cb; |
815 | csid = cevent->stream; | |
816 | cssn = cevent->ssn; | |
817 | if (sid > csid) { | |
818 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
819 | return; | |
820 | } | |
821 | ||
822 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
823 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
824 | return; | |
825 | } | |
826 | ||
827 | /* Find the right place in this list. We store them by | |
828 | * stream ID and then by SSN. | |
829 | */ | |
830 | skb_queue_walk(&ulpq->lobby, pos) { | |
831 | cevent = (struct sctp_ulpevent *) pos->cb; | |
832 | csid = cevent->stream; | |
833 | cssn = cevent->ssn; | |
834 | ||
835 | if (csid > sid) | |
836 | break; | |
837 | if (csid == sid && SSN_lt(ssn, cssn)) | |
838 | break; | |
839 | } | |
840 | ||
841 | ||
842 | /* Insert before pos. */ | |
43f59c89 | 843 | __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event)); |
1da177e4 LT |
844 | } |
845 | ||
846 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 847 | struct sctp_ulpevent *event) |
1da177e4 LT |
848 | { |
849 | __u16 sid, ssn; | |
850 | struct sctp_stream *in; | |
851 | ||
852 | /* Check if this message needs ordering. */ | |
853 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
854 | return event; | |
855 | ||
856 | /* Note: The stream ID must be verified before this routine. */ | |
857 | sid = event->stream; | |
858 | ssn = event->ssn; | |
859 | in = &ulpq->asoc->ssnmap->in; | |
860 | ||
861 | /* Is this the expected SSN for this stream ID? */ | |
862 | if (ssn != sctp_ssn_peek(in, sid)) { | |
863 | /* We've received something out of order, so find where it | |
864 | * needs to be placed. We order by stream and then by SSN. | |
865 | */ | |
866 | sctp_ulpq_store_ordered(ulpq, event); | |
867 | return NULL; | |
868 | } | |
869 | ||
870 | /* Mark that the next chunk has been found. */ | |
871 | sctp_ssn_next(in, sid); | |
872 | ||
873 | /* Go find any other chunks that were waiting for | |
874 | * ordering. | |
875 | */ | |
876 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
877 | ||
878 | return event; | |
879 | } | |
880 | ||
881 | /* Helper function to gather skbs that have possibly become | |
882 | * ordered by forward tsn skipping their dependencies. | |
883 | */ | |
01f2d384 | 884 | static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid) |
1da177e4 LT |
885 | { |
886 | struct sk_buff *pos, *tmp; | |
887 | struct sctp_ulpevent *cevent; | |
8728b834 | 888 | struct sctp_ulpevent *event; |
1da177e4 LT |
889 | struct sctp_stream *in; |
890 | struct sk_buff_head temp; | |
c068be54 | 891 | struct sk_buff_head *lobby = &ulpq->lobby; |
1da177e4 LT |
892 | __u16 csid, cssn; |
893 | ||
894 | in = &ulpq->asoc->ssnmap->in; | |
895 | ||
896 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
897 | skb_queue_head_init(&temp); |
898 | event = NULL; | |
c068be54 | 899 | sctp_skb_for_each(pos, lobby, tmp) { |
1da177e4 LT |
900 | cevent = (struct sctp_ulpevent *) pos->cb; |
901 | csid = cevent->stream; | |
902 | cssn = cevent->ssn; | |
903 | ||
ea2dfb37 VY |
904 | /* Have we gone too far? */ |
905 | if (csid > sid) | |
1da177e4 LT |
906 | break; |
907 | ||
ea2dfb37 VY |
908 | /* Have we not gone far enough? */ |
909 | if (csid < sid) | |
910 | continue; | |
911 | ||
912 | /* see if this ssn has been marked by skipping */ | |
c068be54 | 913 | if (!SSN_lt(cssn, sctp_ssn_peek(in, csid))) |
ea2dfb37 | 914 | break; |
1da177e4 | 915 | |
c068be54 | 916 | __skb_unlink(pos, lobby); |
ea2dfb37 | 917 | if (!event) |
1da177e4 LT |
918 | /* Create a temporary list to collect chunks on. */ |
919 | event = sctp_skb2event(pos); | |
ea2dfb37 VY |
920 | |
921 | /* Attach all gathered skbs to the event. */ | |
922 | __skb_queue_tail(&temp, pos); | |
1da177e4 LT |
923 | } |
924 | ||
c068be54 VY |
925 | /* If we didn't reap any data, see if the next expected SSN |
926 | * is next on the queue and if so, use that. | |
927 | */ | |
928 | if (event == NULL && pos != (struct sk_buff *)lobby) { | |
929 | cevent = (struct sctp_ulpevent *) pos->cb; | |
930 | csid = cevent->stream; | |
931 | cssn = cevent->ssn; | |
932 | ||
933 | if (csid == sid && cssn == sctp_ssn_peek(in, csid)) { | |
934 | sctp_ssn_next(in, csid); | |
935 | __skb_unlink(pos, lobby); | |
936 | __skb_queue_tail(&temp, pos); | |
937 | event = sctp_skb2event(pos); | |
938 | } | |
939 | } | |
940 | ||
8728b834 DM |
941 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
942 | * very first SKB on the 'temp' list. | |
943 | */ | |
ea2dfb37 VY |
944 | if (event) { |
945 | /* see if we have more ordered that we can deliver */ | |
946 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
1da177e4 | 947 | sctp_ulpq_tail_event(ulpq, event); |
ea2dfb37 | 948 | } |
1da177e4 LT |
949 | } |
950 | ||
ea2dfb37 VY |
951 | /* Skip over an SSN. This is used during the processing of |
952 | * Forwared TSN chunk to skip over the abandoned ordered data | |
953 | */ | |
1da177e4 LT |
954 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) |
955 | { | |
956 | struct sctp_stream *in; | |
957 | ||
958 | /* Note: The stream ID must be verified before this routine. */ | |
959 | in = &ulpq->asoc->ssnmap->in; | |
960 | ||
961 | /* Is this an old SSN? If so ignore. */ | |
962 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
963 | return; | |
964 | ||
965 | /* Mark that we are no longer expecting this SSN or lower. */ | |
966 | sctp_ssn_skip(in, sid, ssn); | |
967 | ||
968 | /* Go find any other chunks that were waiting for | |
d808ad9a | 969 | * ordering and deliver them if needed. |
1da177e4 | 970 | */ |
ea2dfb37 | 971 | sctp_ulpq_reap_ordered(ulpq, sid); |
1da177e4 LT |
972 | } |
973 | ||
16d14ef9 PE |
974 | static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, |
975 | struct sk_buff_head *list, __u16 needed) | |
1da177e4 LT |
976 | { |
977 | __u16 freed = 0; | |
95ac7b85 LR |
978 | __u32 tsn, last_tsn; |
979 | struct sk_buff *skb, *flist, *last; | |
1da177e4 LT |
980 | struct sctp_ulpevent *event; |
981 | struct sctp_tsnmap *tsnmap; | |
982 | ||
983 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
984 | ||
e67f85ec | 985 | while ((skb = skb_peek_tail(list)) != NULL) { |
1da177e4 LT |
986 | event = sctp_skb2event(skb); |
987 | tsn = event->tsn; | |
988 | ||
e67f85ec LR |
989 | /* Don't renege below the Cumulative TSN ACK Point. */ |
990 | if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) | |
991 | break; | |
992 | ||
95ac7b85 LR |
993 | /* Events in ordering queue may have multiple fragments |
994 | * corresponding to additional TSNs. Sum the total | |
995 | * freed space; find the last TSN. | |
996 | */ | |
e67f85ec | 997 | freed += skb_headlen(skb); |
95ac7b85 LR |
998 | flist = skb_shinfo(skb)->frag_list; |
999 | for (last = flist; flist; flist = flist->next) { | |
1000 | last = flist; | |
1001 | freed += skb_headlen(last); | |
1002 | } | |
1003 | if (last) | |
1004 | last_tsn = sctp_skb2event(last)->tsn; | |
1005 | else | |
1006 | last_tsn = tsn; | |
1007 | ||
1008 | /* Unlink the event, then renege all applicable TSNs. */ | |
1009 | __skb_unlink(skb, list); | |
1da177e4 | 1010 | sctp_ulpevent_free(event); |
95ac7b85 LR |
1011 | while (TSN_lte(tsn, last_tsn)) { |
1012 | sctp_tsnmap_renege(tsnmap, tsn); | |
1013 | tsn++; | |
1014 | } | |
1da177e4 LT |
1015 | if (freed >= needed) |
1016 | return freed; | |
1017 | } | |
1018 | ||
1019 | return freed; | |
1020 | } | |
1021 | ||
16d14ef9 PE |
1022 | /* Renege 'needed' bytes from the ordering queue. */ |
1023 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
1024 | { | |
1025 | return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed); | |
1026 | } | |
1027 | ||
1da177e4 LT |
1028 | /* Renege 'needed' bytes from the reassembly queue. */ |
1029 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
1030 | { | |
16d14ef9 | 1031 | return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed); |
1da177e4 LT |
1032 | } |
1033 | ||
1034 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
1035 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
dd0fc66f | 1036 | gfp_t gfp) |
1da177e4 LT |
1037 | { |
1038 | struct sctp_ulpevent *event; | |
1039 | struct sctp_association *asoc; | |
b6e1331f | 1040 | struct sctp_sock *sp; |
d003b41b LR |
1041 | __u32 ctsn; |
1042 | struct sk_buff *skb; | |
1da177e4 LT |
1043 | |
1044 | asoc = ulpq->asoc; | |
b6e1331f | 1045 | sp = sctp_sk(asoc->base.sk); |
1da177e4 | 1046 | |
b6e1331f | 1047 | /* If the association is already in Partial Delivery mode |
d003b41b | 1048 | * we have nothing to do. |
b6e1331f VY |
1049 | */ |
1050 | if (ulpq->pd_mode) | |
1051 | return; | |
1da177e4 | 1052 | |
d003b41b LR |
1053 | /* Data must be at or below the Cumulative TSN ACK Point to |
1054 | * start partial delivery. | |
1055 | */ | |
1056 | skb = skb_peek(&asoc->ulpq.reasm); | |
1057 | if (skb != NULL) { | |
1058 | ctsn = sctp_skb2event(skb)->tsn; | |
1059 | if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map))) | |
1060 | return; | |
1061 | } | |
1062 | ||
b6e1331f VY |
1063 | /* If the user enabled fragment interleave socket option, |
1064 | * multiple associations can enter partial delivery. | |
1065 | * Otherwise, we can only enter partial delivery if the | |
1066 | * socket is not in partial deliver mode. | |
1067 | */ | |
1068 | if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) { | |
1da177e4 LT |
1069 | /* Is partial delivery possible? */ |
1070 | event = sctp_ulpq_retrieve_first(ulpq); | |
1071 | /* Send event to the ULP. */ | |
1072 | if (event) { | |
1073 | sctp_ulpq_tail_event(ulpq, event); | |
d49d91d7 | 1074 | sctp_ulpq_set_pd(ulpq); |
1da177e4 LT |
1075 | return; |
1076 | } | |
1077 | } | |
1078 | } | |
1079 | ||
1080 | /* Renege some packets to make room for an incoming chunk. */ | |
1081 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 1082 | gfp_t gfp) |
1da177e4 LT |
1083 | { |
1084 | struct sctp_association *asoc; | |
1085 | __u16 needed, freed; | |
1086 | ||
1087 | asoc = ulpq->asoc; | |
1088 | ||
1089 | if (chunk) { | |
1090 | needed = ntohs(chunk->chunk_hdr->length); | |
1091 | needed -= sizeof(sctp_data_chunk_t); | |
d808ad9a | 1092 | } else |
1da177e4 LT |
1093 | needed = SCTP_DEFAULT_MAXWINDOW; |
1094 | ||
1095 | freed = 0; | |
1096 | ||
1097 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
1098 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
1099 | if (freed < needed) { | |
1100 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
1101 | } | |
1102 | } | |
1103 | /* If able to free enough room, accept this chunk. */ | |
1104 | if (chunk && (freed >= needed)) { | |
d003b41b LR |
1105 | int retval; |
1106 | retval = sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
1107 | /* | |
1108 | * Enter partial delivery if chunk has not been | |
1109 | * delivered; otherwise, drain the reassembly queue. | |
1110 | */ | |
1111 | if (retval <= 0) | |
1112 | sctp_ulpq_partial_delivery(ulpq, gfp); | |
1113 | else if (retval == 1) | |
1114 | sctp_ulpq_reasm_drain(ulpq); | |
1da177e4 LT |
1115 | } |
1116 | ||
3ab224be | 1117 | sk_mem_reclaim(asoc->base.sk); |
1da177e4 LT |
1118 | } |
1119 | ||
1120 | ||
1121 | ||
1122 | /* Notify the application if an association is aborted and in | |
1123 | * partial delivery mode. Send up any pending received messages. | |
1124 | */ | |
dd0fc66f | 1125 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
1126 | { |
1127 | struct sctp_ulpevent *ev = NULL; | |
1128 | struct sock *sk; | |
1129 | ||
1130 | if (!ulpq->pd_mode) | |
1131 | return; | |
1132 | ||
1133 | sk = ulpq->asoc->base.sk; | |
1134 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, | |
1135 | &sctp_sk(sk)->subscribe)) | |
1136 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
1137 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
1138 | gfp); | |
1139 | if (ev) | |
1140 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
1141 | ||
1142 | /* If there is data waiting, send it up the socket now. */ | |
1143 | if (sctp_ulpq_clear_pd(ulpq) || ev) | |
fb586f25 | 1144 | sctp_sk(sk)->pending_data_ready = 1; |
1da177e4 | 1145 | } |