Commit | Line | Data |
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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; | |
0970f5b3 | 197 | struct sctp_sock *sp = sctp_sk(sk); |
8728b834 DM |
198 | struct sk_buff_head *queue, *skb_list; |
199 | struct sk_buff *skb = sctp_event2skb(event); | |
1da177e4 LT |
200 | int clear_pd = 0; |
201 | ||
8728b834 DM |
202 | skb_list = (struct sk_buff_head *) skb->prev; |
203 | ||
1da177e4 LT |
204 | /* If the socket is just going to throw this away, do not |
205 | * even try to deliver it. | |
206 | */ | |
a0fc6843 XL |
207 | if (sk->sk_shutdown & RCV_SHUTDOWN && |
208 | (sk->sk_shutdown & SEND_SHUTDOWN || | |
209 | !sctp_ulpevent_is_notification(event))) | |
1da177e4 LT |
210 | goto out_free; |
211 | ||
2c8c56e1 | 212 | if (!sctp_ulpevent_is_notification(event)) { |
8465a5fc | 213 | sk_mark_napi_id(sk, skb); |
2c8c56e1 ED |
214 | sk_incoming_cpu_update(sk); |
215 | } | |
1da177e4 | 216 | /* Check if the user wishes to receive this event. */ |
0970f5b3 | 217 | if (!sctp_ulpevent_is_enabled(event, &sp->subscribe)) |
1da177e4 LT |
218 | goto out_free; |
219 | ||
220 | /* If we are in partial delivery mode, post to the lobby until | |
221 | * partial delivery is cleared, unless, of course _this_ is | |
222 | * the association the cause of the partial delivery. | |
223 | */ | |
224 | ||
0970f5b3 | 225 | if (atomic_read(&sp->pd_mode) == 0) { |
1da177e4 | 226 | queue = &sk->sk_receive_queue; |
b6e1331f VY |
227 | } else { |
228 | if (ulpq->pd_mode) { | |
229 | /* If the association is in partial delivery, we | |
230 | * need to finish delivering the partially processed | |
231 | * packet before passing any other data. This is | |
232 | * because we don't truly support stream interleaving. | |
233 | */ | |
234 | if ((event->msg_flags & MSG_NOTIFICATION) || | |
235 | (SCTP_DATA_NOT_FRAG == | |
236 | (event->msg_flags & SCTP_DATA_FRAG_MASK))) | |
0970f5b3 | 237 | queue = &sp->pd_lobby; |
b6e1331f VY |
238 | else { |
239 | clear_pd = event->msg_flags & MSG_EOR; | |
240 | queue = &sk->sk_receive_queue; | |
241 | } | |
242 | } else { | |
243 | /* | |
244 | * If fragment interleave is enabled, we | |
25985edc | 245 | * can queue this to the receive queue instead |
b6e1331f VY |
246 | * of the lobby. |
247 | */ | |
0970f5b3 | 248 | if (sp->frag_interleave) |
b6e1331f VY |
249 | queue = &sk->sk_receive_queue; |
250 | else | |
0970f5b3 | 251 | queue = &sp->pd_lobby; |
1da177e4 | 252 | } |
b6e1331f | 253 | } |
1da177e4 LT |
254 | |
255 | /* If we are harvesting multiple skbs they will be | |
256 | * collected on a list. | |
257 | */ | |
8728b834 | 258 | if (skb_list) |
311b2177 | 259 | skb_queue_splice_tail_init(skb_list, queue); |
1da177e4 | 260 | else |
8728b834 | 261 | __skb_queue_tail(queue, skb); |
1da177e4 LT |
262 | |
263 | /* Did we just complete partial delivery and need to get | |
264 | * rolling again? Move pending data to the receive | |
265 | * queue. | |
266 | */ | |
267 | if (clear_pd) | |
268 | sctp_ulpq_clear_pd(ulpq); | |
269 | ||
0970f5b3 MRL |
270 | if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) { |
271 | sp->data_ready_signalled = 1; | |
272 | sk->sk_data_ready(sk); | |
273 | } | |
1da177e4 LT |
274 | return 1; |
275 | ||
276 | out_free: | |
8728b834 DM |
277 | if (skb_list) |
278 | sctp_queue_purge_ulpevents(skb_list); | |
1da177e4 LT |
279 | else |
280 | sctp_ulpevent_free(event); | |
8728b834 | 281 | |
1da177e4 LT |
282 | return 0; |
283 | } | |
284 | ||
285 | /* 2nd Level Abstractions */ | |
286 | ||
287 | /* Helper function to store chunks that need to be reassembled. */ | |
01f2d384 | 288 | static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, |
1da177e4 LT |
289 | struct sctp_ulpevent *event) |
290 | { | |
291 | struct sk_buff *pos; | |
292 | struct sctp_ulpevent *cevent; | |
293 | __u32 tsn, ctsn; | |
294 | ||
295 | tsn = event->tsn; | |
296 | ||
297 | /* See if it belongs at the end. */ | |
298 | pos = skb_peek_tail(&ulpq->reasm); | |
299 | if (!pos) { | |
300 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
301 | return; | |
302 | } | |
303 | ||
304 | /* Short circuit just dropping it at the end. */ | |
305 | cevent = sctp_skb2event(pos); | |
306 | ctsn = cevent->tsn; | |
307 | if (TSN_lt(ctsn, tsn)) { | |
308 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
309 | return; | |
310 | } | |
311 | ||
312 | /* Find the right place in this list. We store them by TSN. */ | |
313 | skb_queue_walk(&ulpq->reasm, pos) { | |
314 | cevent = sctp_skb2event(pos); | |
315 | ctsn = cevent->tsn; | |
316 | ||
317 | if (TSN_lt(tsn, ctsn)) | |
318 | break; | |
319 | } | |
320 | ||
321 | /* Insert before pos. */ | |
43f59c89 | 322 | __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event)); |
1da177e4 LT |
323 | |
324 | } | |
325 | ||
326 | /* Helper function to return an event corresponding to the reassembled | |
327 | * datagram. | |
328 | * This routine creates a re-assembled skb given the first and last skb's | |
329 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
330 | * payload was fragmented on the way and ip had to reassemble them. | |
331 | * We add the rest of skb's to the first skb's fraglist. | |
332 | */ | |
b01a2407 EB |
333 | static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net, |
334 | struct sk_buff_head *queue, struct sk_buff *f_frag, | |
335 | struct sk_buff *l_frag) | |
1da177e4 LT |
336 | { |
337 | struct sk_buff *pos; | |
672e7cca | 338 | struct sk_buff *new = NULL; |
1da177e4 LT |
339 | struct sctp_ulpevent *event; |
340 | struct sk_buff *pnext, *last; | |
341 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
342 | ||
343 | /* Store the pointer to the 2nd skb */ | |
344 | if (f_frag == l_frag) | |
345 | pos = NULL; | |
346 | else | |
347 | pos = f_frag->next; | |
348 | ||
349 | /* Get the last skb in the f_frag's frag_list if present. */ | |
8d72651d | 350 | for (last = list; list; last = list, list = list->next) |
351 | ; | |
1da177e4 LT |
352 | |
353 | /* Add the list of remaining fragments to the first fragments | |
354 | * frag_list. | |
355 | */ | |
356 | if (last) | |
357 | last->next = pos; | |
d808ad9a YH |
358 | else { |
359 | if (skb_cloned(f_frag)) { | |
360 | /* This is a cloned skb, we can't just modify | |
361 | * the frag_list. We need a new skb to do that. | |
362 | * Instead of calling skb_unshare(), we'll do it | |
363 | * ourselves since we need to delay the free. | |
364 | */ | |
365 | new = skb_copy(f_frag, GFP_ATOMIC); | |
366 | if (!new) | |
367 | return NULL; /* try again later */ | |
368 | ||
369 | sctp_skb_set_owner_r(new, f_frag->sk); | |
370 | ||
371 | skb_shinfo(new)->frag_list = pos; | |
372 | } else | |
373 | skb_shinfo(f_frag)->frag_list = pos; | |
374 | } | |
1da177e4 LT |
375 | |
376 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 377 | __skb_unlink(f_frag, queue); |
672e7cca | 378 | |
d808ad9a YH |
379 | /* if we did unshare, then free the old skb and re-assign */ |
380 | if (new) { | |
381 | kfree_skb(f_frag); | |
382 | f_frag = new; | |
383 | } | |
672e7cca | 384 | |
1da177e4 LT |
385 | while (pos) { |
386 | ||
387 | pnext = pos->next; | |
388 | ||
389 | /* Update the len and data_len fields of the first fragment. */ | |
390 | f_frag->len += pos->len; | |
391 | f_frag->data_len += pos->len; | |
392 | ||
393 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 394 | __skb_unlink(pos, queue); |
d808ad9a | 395 | |
1da177e4 LT |
396 | /* Break if we have reached the last fragment. */ |
397 | if (pos == l_frag) | |
398 | break; | |
399 | pos->next = pnext; | |
400 | pos = pnext; | |
3ff50b79 | 401 | } |
1da177e4 LT |
402 | |
403 | event = sctp_skb2event(f_frag); | |
b01a2407 | 404 | SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS); |
1da177e4 LT |
405 | |
406 | return event; | |
407 | } | |
408 | ||
409 | ||
410 | /* Helper function to check if an incoming chunk has filled up the last | |
411 | * missing fragment in a SCTP datagram and return the corresponding event. | |
412 | */ | |
01f2d384 | 413 | static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) |
1da177e4 LT |
414 | { |
415 | struct sk_buff *pos; | |
416 | struct sctp_ulpevent *cevent; | |
417 | struct sk_buff *first_frag = NULL; | |
418 | __u32 ctsn, next_tsn; | |
419 | struct sctp_ulpevent *retval = NULL; | |
d49d91d7 VY |
420 | struct sk_buff *pd_first = NULL; |
421 | struct sk_buff *pd_last = NULL; | |
422 | size_t pd_len = 0; | |
423 | struct sctp_association *asoc; | |
424 | u32 pd_point; | |
1da177e4 LT |
425 | |
426 | /* Initialized to 0 just to avoid compiler warning message. Will | |
427 | * never be used with this value. It is referenced only after it | |
428 | * is set when we find the first fragment of a message. | |
429 | */ | |
430 | next_tsn = 0; | |
431 | ||
432 | /* The chunks are held in the reasm queue sorted by TSN. | |
433 | * Walk through the queue sequentially and look for a sequence of | |
434 | * fragmented chunks that complete a datagram. | |
435 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
436 | * is the first fragment of a datagram. Once these 2 fields are set | |
437 | * we expect to find the remaining middle fragments and the last | |
438 | * fragment in order. If not, first_frag is reset to NULL and we | |
439 | * start the next pass when we find another first fragment. | |
d49d91d7 VY |
440 | * |
441 | * There is a potential to do partial delivery if user sets | |
442 | * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here | |
443 | * to see if can do PD. | |
1da177e4 LT |
444 | */ |
445 | skb_queue_walk(&ulpq->reasm, pos) { | |
446 | cevent = sctp_skb2event(pos); | |
447 | ctsn = cevent->tsn; | |
448 | ||
449 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
450 | case SCTP_DATA_FIRST_FRAG: | |
d49d91d7 VY |
451 | /* If this "FIRST_FRAG" is the first |
452 | * element in the queue, then count it towards | |
453 | * possible PD. | |
454 | */ | |
455 | if (pos == ulpq->reasm.next) { | |
456 | pd_first = pos; | |
457 | pd_last = pos; | |
458 | pd_len = pos->len; | |
459 | } else { | |
460 | pd_first = NULL; | |
461 | pd_last = NULL; | |
462 | pd_len = 0; | |
463 | } | |
464 | ||
1da177e4 LT |
465 | first_frag = pos; |
466 | next_tsn = ctsn + 1; | |
467 | break; | |
468 | ||
469 | case SCTP_DATA_MIDDLE_FRAG: | |
d49d91d7 | 470 | if ((first_frag) && (ctsn == next_tsn)) { |
1da177e4 | 471 | next_tsn++; |
d49d91d7 VY |
472 | if (pd_first) { |
473 | pd_last = pos; | |
474 | pd_len += pos->len; | |
475 | } | |
476 | } else | |
1da177e4 LT |
477 | first_frag = NULL; |
478 | break; | |
479 | ||
480 | case SCTP_DATA_LAST_FRAG: | |
481 | if (first_frag && (ctsn == next_tsn)) | |
482 | goto found; | |
483 | else | |
484 | first_frag = NULL; | |
485 | break; | |
3ff50b79 | 486 | } |
d49d91d7 VY |
487 | } |
488 | ||
489 | asoc = ulpq->asoc; | |
490 | if (pd_first) { | |
491 | /* Make sure we can enter partial deliver. | |
492 | * We can trigger partial delivery only if framgent | |
493 | * interleave is set, or the socket is not already | |
494 | * in partial delivery. | |
495 | */ | |
496 | if (!sctp_sk(asoc->base.sk)->frag_interleave && | |
497 | atomic_read(&sctp_sk(asoc->base.sk)->pd_mode)) | |
498 | goto done; | |
1da177e4 | 499 | |
d49d91d7 VY |
500 | cevent = sctp_skb2event(pd_first); |
501 | pd_point = sctp_sk(asoc->base.sk)->pd_point; | |
502 | if (pd_point && pd_point <= pd_len) { | |
b01a2407 EB |
503 | retval = sctp_make_reassembled_event(sock_net(asoc->base.sk), |
504 | &ulpq->reasm, | |
d49d91d7 VY |
505 | pd_first, |
506 | pd_last); | |
507 | if (retval) | |
508 | sctp_ulpq_set_pd(ulpq); | |
509 | } | |
1da177e4 LT |
510 | } |
511 | done: | |
512 | return retval; | |
513 | found: | |
b01a2407 EB |
514 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
515 | &ulpq->reasm, first_frag, pos); | |
1da177e4 LT |
516 | if (retval) |
517 | retval->msg_flags |= MSG_EOR; | |
518 | goto done; | |
519 | } | |
520 | ||
521 | /* Retrieve the next set of fragments of a partial message. */ | |
01f2d384 | 522 | static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) |
1da177e4 LT |
523 | { |
524 | struct sk_buff *pos, *last_frag, *first_frag; | |
525 | struct sctp_ulpevent *cevent; | |
526 | __u32 ctsn, next_tsn; | |
527 | int is_last; | |
528 | struct sctp_ulpevent *retval; | |
529 | ||
530 | /* The chunks are held in the reasm queue sorted by TSN. | |
531 | * Walk through the queue sequentially and look for the first | |
532 | * sequence of fragmented chunks. | |
533 | */ | |
534 | ||
535 | if (skb_queue_empty(&ulpq->reasm)) | |
536 | return NULL; | |
537 | ||
538 | last_frag = first_frag = NULL; | |
539 | retval = NULL; | |
540 | next_tsn = 0; | |
541 | is_last = 0; | |
542 | ||
543 | skb_queue_walk(&ulpq->reasm, pos) { | |
544 | cevent = sctp_skb2event(pos); | |
545 | ctsn = cevent->tsn; | |
546 | ||
547 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
d003b41b LR |
548 | case SCTP_DATA_FIRST_FRAG: |
549 | if (!first_frag) | |
550 | return NULL; | |
551 | goto done; | |
1da177e4 LT |
552 | case SCTP_DATA_MIDDLE_FRAG: |
553 | if (!first_frag) { | |
554 | first_frag = pos; | |
555 | next_tsn = ctsn + 1; | |
556 | last_frag = pos; | |
d003b41b | 557 | } else if (next_tsn == ctsn) { |
1da177e4 | 558 | next_tsn++; |
d003b41b LR |
559 | last_frag = pos; |
560 | } else | |
1da177e4 LT |
561 | goto done; |
562 | break; | |
563 | case SCTP_DATA_LAST_FRAG: | |
564 | if (!first_frag) | |
565 | first_frag = pos; | |
566 | else if (ctsn != next_tsn) | |
567 | goto done; | |
568 | last_frag = pos; | |
569 | is_last = 1; | |
570 | goto done; | |
571 | default: | |
572 | return NULL; | |
3ff50b79 | 573 | } |
1da177e4 LT |
574 | } |
575 | ||
576 | /* We have the reassembled event. There is no need to look | |
577 | * further. | |
578 | */ | |
579 | done: | |
b01a2407 EB |
580 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
581 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
582 | if (retval && is_last) |
583 | retval->msg_flags |= MSG_EOR; | |
584 | ||
585 | return retval; | |
586 | } | |
587 | ||
588 | ||
589 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
590 | * need reassembling. | |
591 | */ | |
592 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
593 | struct sctp_ulpevent *event) | |
594 | { | |
595 | struct sctp_ulpevent *retval = NULL; | |
596 | ||
597 | /* Check if this is part of a fragmented message. */ | |
598 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
599 | event->msg_flags |= MSG_EOR; | |
600 | return event; | |
601 | } | |
602 | ||
603 | sctp_ulpq_store_reasm(ulpq, event); | |
604 | if (!ulpq->pd_mode) | |
605 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
606 | else { | |
607 | __u32 ctsn, ctsnap; | |
608 | ||
609 | /* Do not even bother unless this is the next tsn to | |
610 | * be delivered. | |
611 | */ | |
612 | ctsn = event->tsn; | |
613 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
614 | if (TSN_lte(ctsn, ctsnap)) | |
615 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
616 | } | |
617 | ||
618 | return retval; | |
619 | } | |
620 | ||
621 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
01f2d384 | 622 | static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) |
1da177e4 LT |
623 | { |
624 | struct sk_buff *pos, *last_frag, *first_frag; | |
625 | struct sctp_ulpevent *cevent; | |
626 | __u32 ctsn, next_tsn; | |
627 | struct sctp_ulpevent *retval; | |
628 | ||
629 | /* The chunks are held in the reasm queue sorted by TSN. | |
630 | * Walk through the queue sequentially and look for a sequence of | |
631 | * fragmented chunks that start a datagram. | |
632 | */ | |
633 | ||
634 | if (skb_queue_empty(&ulpq->reasm)) | |
635 | return NULL; | |
636 | ||
637 | last_frag = first_frag = NULL; | |
638 | retval = NULL; | |
639 | next_tsn = 0; | |
640 | ||
641 | skb_queue_walk(&ulpq->reasm, pos) { | |
642 | cevent = sctp_skb2event(pos); | |
643 | ctsn = cevent->tsn; | |
644 | ||
645 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
646 | case SCTP_DATA_FIRST_FRAG: | |
647 | if (!first_frag) { | |
648 | first_frag = pos; | |
649 | next_tsn = ctsn + 1; | |
650 | last_frag = pos; | |
651 | } else | |
652 | goto done; | |
653 | break; | |
654 | ||
655 | case SCTP_DATA_MIDDLE_FRAG: | |
656 | if (!first_frag) | |
657 | return NULL; | |
658 | if (ctsn == next_tsn) { | |
659 | next_tsn++; | |
660 | last_frag = pos; | |
661 | } else | |
662 | goto done; | |
663 | break; | |
d003b41b LR |
664 | |
665 | case SCTP_DATA_LAST_FRAG: | |
666 | if (!first_frag) | |
667 | return NULL; | |
668 | else | |
669 | goto done; | |
670 | break; | |
671 | ||
1da177e4 LT |
672 | default: |
673 | return NULL; | |
3ff50b79 | 674 | } |
1da177e4 LT |
675 | } |
676 | ||
677 | /* We have the reassembled event. There is no need to look | |
678 | * further. | |
679 | */ | |
680 | done: | |
b01a2407 EB |
681 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
682 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
683 | return retval; |
684 | } | |
685 | ||
ea2dfb37 VY |
686 | /* |
687 | * Flush out stale fragments from the reassembly queue when processing | |
688 | * a Forward TSN. | |
689 | * | |
690 | * RFC 3758, Section 3.6 | |
691 | * | |
692 | * After receiving and processing a FORWARD TSN, the data receiver MUST | |
693 | * take cautions in updating its re-assembly queue. The receiver MUST | |
694 | * remove any partially reassembled message, which is still missing one | |
695 | * or more TSNs earlier than or equal to the new cumulative TSN point. | |
696 | * In the event that the receiver has invoked the partial delivery API, | |
697 | * a notification SHOULD also be generated to inform the upper layer API | |
698 | * that the message being partially delivered will NOT be completed. | |
699 | */ | |
700 | void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn) | |
701 | { | |
702 | struct sk_buff *pos, *tmp; | |
703 | struct sctp_ulpevent *event; | |
704 | __u32 tsn; | |
705 | ||
706 | if (skb_queue_empty(&ulpq->reasm)) | |
707 | return; | |
708 | ||
709 | skb_queue_walk_safe(&ulpq->reasm, pos, tmp) { | |
710 | event = sctp_skb2event(pos); | |
711 | tsn = event->tsn; | |
712 | ||
713 | /* Since the entire message must be abandoned by the | |
714 | * sender (item A3 in Section 3.5, RFC 3758), we can | |
715 | * free all fragments on the list that are less then | |
716 | * or equal to ctsn_point | |
717 | */ | |
718 | if (TSN_lte(tsn, fwd_tsn)) { | |
719 | __skb_unlink(pos, &ulpq->reasm); | |
720 | sctp_ulpevent_free(event); | |
721 | } else | |
722 | break; | |
723 | } | |
724 | } | |
725 | ||
ef5d4cf2 VY |
726 | /* |
727 | * Drain the reassembly queue. If we just cleared parted delivery, it | |
728 | * is possible that the reassembly queue will contain already reassembled | |
729 | * messages. Retrieve any such messages and give them to the user. | |
730 | */ | |
731 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq) | |
732 | { | |
733 | struct sctp_ulpevent *event = NULL; | |
734 | struct sk_buff_head temp; | |
735 | ||
736 | if (skb_queue_empty(&ulpq->reasm)) | |
737 | return; | |
738 | ||
739 | while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) { | |
740 | /* Do ordering if needed. */ | |
cb3f837b | 741 | if ((event) && (event->msg_flags & MSG_EOR)) { |
ef5d4cf2 VY |
742 | skb_queue_head_init(&temp); |
743 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
744 | ||
745 | event = sctp_ulpq_order(ulpq, event); | |
746 | } | |
747 | ||
748 | /* Send event to the ULP. 'event' is the | |
749 | * sctp_ulpevent for very first SKB on the temp' list. | |
750 | */ | |
751 | if (event) | |
752 | sctp_ulpq_tail_event(ulpq, event); | |
753 | } | |
754 | } | |
755 | ||
756 | ||
1da177e4 LT |
757 | /* Helper function to gather skbs that have possibly become |
758 | * ordered by an an incoming chunk. | |
759 | */ | |
01f2d384 | 760 | static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
761 | struct sctp_ulpevent *event) |
762 | { | |
8728b834 | 763 | struct sk_buff_head *event_list; |
1da177e4 LT |
764 | struct sk_buff *pos, *tmp; |
765 | struct sctp_ulpevent *cevent; | |
766 | struct sctp_stream *in; | |
efea2c6b | 767 | __u16 sid, csid, cssn; |
1da177e4 LT |
768 | |
769 | sid = event->stream; | |
1da177e4 LT |
770 | in = &ulpq->asoc->ssnmap->in; |
771 | ||
8728b834 DM |
772 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
773 | ||
1da177e4 LT |
774 | /* We are holding the chunks by stream, by SSN. */ |
775 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
776 | cevent = (struct sctp_ulpevent *) pos->cb; | |
777 | csid = cevent->stream; | |
778 | cssn = cevent->ssn; | |
779 | ||
780 | /* Have we gone too far? */ | |
781 | if (csid > sid) | |
782 | break; | |
783 | ||
784 | /* Have we not gone far enough? */ | |
785 | if (csid < sid) | |
786 | continue; | |
787 | ||
788 | if (cssn != sctp_ssn_peek(in, sid)) | |
789 | break; | |
790 | ||
791 | /* Found it, so mark in the ssnmap. */ | |
792 | sctp_ssn_next(in, sid); | |
793 | ||
8728b834 | 794 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
795 | |
796 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 797 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
798 | } |
799 | } | |
800 | ||
801 | /* Helper function to store chunks needing ordering. */ | |
01f2d384 | 802 | static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
803 | struct sctp_ulpevent *event) |
804 | { | |
805 | struct sk_buff *pos; | |
806 | struct sctp_ulpevent *cevent; | |
807 | __u16 sid, csid; | |
808 | __u16 ssn, cssn; | |
809 | ||
810 | pos = skb_peek_tail(&ulpq->lobby); | |
811 | if (!pos) { | |
812 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
813 | return; | |
814 | } | |
815 | ||
816 | sid = event->stream; | |
817 | ssn = event->ssn; | |
d808ad9a | 818 | |
1da177e4 LT |
819 | cevent = (struct sctp_ulpevent *) pos->cb; |
820 | csid = cevent->stream; | |
821 | cssn = cevent->ssn; | |
822 | if (sid > csid) { | |
823 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
824 | return; | |
825 | } | |
826 | ||
827 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
828 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
829 | return; | |
830 | } | |
831 | ||
832 | /* Find the right place in this list. We store them by | |
833 | * stream ID and then by SSN. | |
834 | */ | |
835 | skb_queue_walk(&ulpq->lobby, pos) { | |
836 | cevent = (struct sctp_ulpevent *) pos->cb; | |
837 | csid = cevent->stream; | |
838 | cssn = cevent->ssn; | |
839 | ||
840 | if (csid > sid) | |
841 | break; | |
842 | if (csid == sid && SSN_lt(ssn, cssn)) | |
843 | break; | |
844 | } | |
845 | ||
846 | ||
847 | /* Insert before pos. */ | |
43f59c89 | 848 | __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event)); |
1da177e4 LT |
849 | } |
850 | ||
851 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 852 | struct sctp_ulpevent *event) |
1da177e4 LT |
853 | { |
854 | __u16 sid, ssn; | |
855 | struct sctp_stream *in; | |
856 | ||
857 | /* Check if this message needs ordering. */ | |
858 | if (SCTP_DATA_UNORDERED & event->msg_flags) | |
859 | return event; | |
860 | ||
861 | /* Note: The stream ID must be verified before this routine. */ | |
862 | sid = event->stream; | |
863 | ssn = event->ssn; | |
864 | in = &ulpq->asoc->ssnmap->in; | |
865 | ||
866 | /* Is this the expected SSN for this stream ID? */ | |
867 | if (ssn != sctp_ssn_peek(in, sid)) { | |
868 | /* We've received something out of order, so find where it | |
869 | * needs to be placed. We order by stream and then by SSN. | |
870 | */ | |
871 | sctp_ulpq_store_ordered(ulpq, event); | |
872 | return NULL; | |
873 | } | |
874 | ||
875 | /* Mark that the next chunk has been found. */ | |
876 | sctp_ssn_next(in, sid); | |
877 | ||
878 | /* Go find any other chunks that were waiting for | |
879 | * ordering. | |
880 | */ | |
881 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
882 | ||
883 | return event; | |
884 | } | |
885 | ||
886 | /* Helper function to gather skbs that have possibly become | |
887 | * ordered by forward tsn skipping their dependencies. | |
888 | */ | |
01f2d384 | 889 | static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid) |
1da177e4 LT |
890 | { |
891 | struct sk_buff *pos, *tmp; | |
892 | struct sctp_ulpevent *cevent; | |
8728b834 | 893 | struct sctp_ulpevent *event; |
1da177e4 LT |
894 | struct sctp_stream *in; |
895 | struct sk_buff_head temp; | |
c068be54 | 896 | struct sk_buff_head *lobby = &ulpq->lobby; |
1da177e4 LT |
897 | __u16 csid, cssn; |
898 | ||
899 | in = &ulpq->asoc->ssnmap->in; | |
900 | ||
901 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
902 | skb_queue_head_init(&temp); |
903 | event = NULL; | |
c068be54 | 904 | sctp_skb_for_each(pos, lobby, tmp) { |
1da177e4 LT |
905 | cevent = (struct sctp_ulpevent *) pos->cb; |
906 | csid = cevent->stream; | |
907 | cssn = cevent->ssn; | |
908 | ||
ea2dfb37 VY |
909 | /* Have we gone too far? */ |
910 | if (csid > sid) | |
1da177e4 LT |
911 | break; |
912 | ||
ea2dfb37 VY |
913 | /* Have we not gone far enough? */ |
914 | if (csid < sid) | |
915 | continue; | |
916 | ||
917 | /* see if this ssn has been marked by skipping */ | |
c068be54 | 918 | if (!SSN_lt(cssn, sctp_ssn_peek(in, csid))) |
ea2dfb37 | 919 | break; |
1da177e4 | 920 | |
c068be54 | 921 | __skb_unlink(pos, lobby); |
ea2dfb37 | 922 | if (!event) |
1da177e4 LT |
923 | /* Create a temporary list to collect chunks on. */ |
924 | event = sctp_skb2event(pos); | |
ea2dfb37 VY |
925 | |
926 | /* Attach all gathered skbs to the event. */ | |
927 | __skb_queue_tail(&temp, pos); | |
1da177e4 LT |
928 | } |
929 | ||
c068be54 VY |
930 | /* If we didn't reap any data, see if the next expected SSN |
931 | * is next on the queue and if so, use that. | |
932 | */ | |
933 | if (event == NULL && pos != (struct sk_buff *)lobby) { | |
934 | cevent = (struct sctp_ulpevent *) pos->cb; | |
935 | csid = cevent->stream; | |
936 | cssn = cevent->ssn; | |
937 | ||
938 | if (csid == sid && cssn == sctp_ssn_peek(in, csid)) { | |
939 | sctp_ssn_next(in, csid); | |
940 | __skb_unlink(pos, lobby); | |
941 | __skb_queue_tail(&temp, pos); | |
942 | event = sctp_skb2event(pos); | |
943 | } | |
944 | } | |
945 | ||
8728b834 DM |
946 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
947 | * very first SKB on the 'temp' list. | |
948 | */ | |
ea2dfb37 VY |
949 | if (event) { |
950 | /* see if we have more ordered that we can deliver */ | |
951 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
1da177e4 | 952 | sctp_ulpq_tail_event(ulpq, event); |
ea2dfb37 | 953 | } |
1da177e4 LT |
954 | } |
955 | ||
ea2dfb37 VY |
956 | /* Skip over an SSN. This is used during the processing of |
957 | * Forwared TSN chunk to skip over the abandoned ordered data | |
958 | */ | |
1da177e4 LT |
959 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) |
960 | { | |
961 | struct sctp_stream *in; | |
962 | ||
963 | /* Note: The stream ID must be verified before this routine. */ | |
964 | in = &ulpq->asoc->ssnmap->in; | |
965 | ||
966 | /* Is this an old SSN? If so ignore. */ | |
967 | if (SSN_lt(ssn, sctp_ssn_peek(in, sid))) | |
968 | return; | |
969 | ||
970 | /* Mark that we are no longer expecting this SSN or lower. */ | |
971 | sctp_ssn_skip(in, sid, ssn); | |
972 | ||
973 | /* Go find any other chunks that were waiting for | |
d808ad9a | 974 | * ordering and deliver them if needed. |
1da177e4 | 975 | */ |
ea2dfb37 | 976 | sctp_ulpq_reap_ordered(ulpq, sid); |
1da177e4 LT |
977 | } |
978 | ||
16d14ef9 PE |
979 | static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, |
980 | struct sk_buff_head *list, __u16 needed) | |
1da177e4 LT |
981 | { |
982 | __u16 freed = 0; | |
95ac7b85 LR |
983 | __u32 tsn, last_tsn; |
984 | struct sk_buff *skb, *flist, *last; | |
1da177e4 LT |
985 | struct sctp_ulpevent *event; |
986 | struct sctp_tsnmap *tsnmap; | |
987 | ||
988 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
989 | ||
e67f85ec | 990 | while ((skb = skb_peek_tail(list)) != NULL) { |
1da177e4 LT |
991 | event = sctp_skb2event(skb); |
992 | tsn = event->tsn; | |
993 | ||
e67f85ec LR |
994 | /* Don't renege below the Cumulative TSN ACK Point. */ |
995 | if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) | |
996 | break; | |
997 | ||
95ac7b85 LR |
998 | /* Events in ordering queue may have multiple fragments |
999 | * corresponding to additional TSNs. Sum the total | |
1000 | * freed space; find the last TSN. | |
1001 | */ | |
e67f85ec | 1002 | freed += skb_headlen(skb); |
95ac7b85 LR |
1003 | flist = skb_shinfo(skb)->frag_list; |
1004 | for (last = flist; flist; flist = flist->next) { | |
1005 | last = flist; | |
1006 | freed += skb_headlen(last); | |
1007 | } | |
1008 | if (last) | |
1009 | last_tsn = sctp_skb2event(last)->tsn; | |
1010 | else | |
1011 | last_tsn = tsn; | |
1012 | ||
1013 | /* Unlink the event, then renege all applicable TSNs. */ | |
1014 | __skb_unlink(skb, list); | |
1da177e4 | 1015 | sctp_ulpevent_free(event); |
95ac7b85 LR |
1016 | while (TSN_lte(tsn, last_tsn)) { |
1017 | sctp_tsnmap_renege(tsnmap, tsn); | |
1018 | tsn++; | |
1019 | } | |
1da177e4 LT |
1020 | if (freed >= needed) |
1021 | return freed; | |
1022 | } | |
1023 | ||
1024 | return freed; | |
1025 | } | |
1026 | ||
16d14ef9 PE |
1027 | /* Renege 'needed' bytes from the ordering queue. */ |
1028 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
1029 | { | |
1030 | return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed); | |
1031 | } | |
1032 | ||
1da177e4 LT |
1033 | /* Renege 'needed' bytes from the reassembly queue. */ |
1034 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
1035 | { | |
16d14ef9 | 1036 | return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed); |
1da177e4 LT |
1037 | } |
1038 | ||
1039 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
1040 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
dd0fc66f | 1041 | gfp_t gfp) |
1da177e4 LT |
1042 | { |
1043 | struct sctp_ulpevent *event; | |
1044 | struct sctp_association *asoc; | |
b6e1331f | 1045 | struct sctp_sock *sp; |
d003b41b LR |
1046 | __u32 ctsn; |
1047 | struct sk_buff *skb; | |
1da177e4 LT |
1048 | |
1049 | asoc = ulpq->asoc; | |
b6e1331f | 1050 | sp = sctp_sk(asoc->base.sk); |
1da177e4 | 1051 | |
b6e1331f | 1052 | /* If the association is already in Partial Delivery mode |
d003b41b | 1053 | * we have nothing to do. |
b6e1331f VY |
1054 | */ |
1055 | if (ulpq->pd_mode) | |
1056 | return; | |
1da177e4 | 1057 | |
d003b41b LR |
1058 | /* Data must be at or below the Cumulative TSN ACK Point to |
1059 | * start partial delivery. | |
1060 | */ | |
1061 | skb = skb_peek(&asoc->ulpq.reasm); | |
1062 | if (skb != NULL) { | |
1063 | ctsn = sctp_skb2event(skb)->tsn; | |
1064 | if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map))) | |
1065 | return; | |
1066 | } | |
1067 | ||
b6e1331f VY |
1068 | /* If the user enabled fragment interleave socket option, |
1069 | * multiple associations can enter partial delivery. | |
1070 | * Otherwise, we can only enter partial delivery if the | |
1071 | * socket is not in partial deliver mode. | |
1072 | */ | |
1073 | if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) { | |
1da177e4 LT |
1074 | /* Is partial delivery possible? */ |
1075 | event = sctp_ulpq_retrieve_first(ulpq); | |
1076 | /* Send event to the ULP. */ | |
1077 | if (event) { | |
1078 | sctp_ulpq_tail_event(ulpq, event); | |
d49d91d7 | 1079 | sctp_ulpq_set_pd(ulpq); |
1da177e4 LT |
1080 | return; |
1081 | } | |
1082 | } | |
1083 | } | |
1084 | ||
1085 | /* Renege some packets to make room for an incoming chunk. */ | |
1086 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 1087 | gfp_t gfp) |
1da177e4 LT |
1088 | { |
1089 | struct sctp_association *asoc; | |
1090 | __u16 needed, freed; | |
1091 | ||
1092 | asoc = ulpq->asoc; | |
1093 | ||
1094 | if (chunk) { | |
1095 | needed = ntohs(chunk->chunk_hdr->length); | |
1096 | needed -= sizeof(sctp_data_chunk_t); | |
d808ad9a | 1097 | } else |
1da177e4 LT |
1098 | needed = SCTP_DEFAULT_MAXWINDOW; |
1099 | ||
1100 | freed = 0; | |
1101 | ||
1102 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
1103 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
1104 | if (freed < needed) { | |
1105 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); | |
1106 | } | |
1107 | } | |
1108 | /* If able to free enough room, accept this chunk. */ | |
1109 | if (chunk && (freed >= needed)) { | |
d003b41b LR |
1110 | int retval; |
1111 | retval = sctp_ulpq_tail_data(ulpq, chunk, gfp); | |
1112 | /* | |
1113 | * Enter partial delivery if chunk has not been | |
1114 | * delivered; otherwise, drain the reassembly queue. | |
1115 | */ | |
1116 | if (retval <= 0) | |
1117 | sctp_ulpq_partial_delivery(ulpq, gfp); | |
1118 | else if (retval == 1) | |
1119 | sctp_ulpq_reasm_drain(ulpq); | |
1da177e4 LT |
1120 | } |
1121 | ||
3ab224be | 1122 | sk_mem_reclaim(asoc->base.sk); |
1da177e4 LT |
1123 | } |
1124 | ||
1125 | ||
1126 | ||
1127 | /* Notify the application if an association is aborted and in | |
1128 | * partial delivery mode. Send up any pending received messages. | |
1129 | */ | |
dd0fc66f | 1130 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
1131 | { |
1132 | struct sctp_ulpevent *ev = NULL; | |
1133 | struct sock *sk; | |
0970f5b3 | 1134 | struct sctp_sock *sp; |
1da177e4 LT |
1135 | |
1136 | if (!ulpq->pd_mode) | |
1137 | return; | |
1138 | ||
1139 | sk = ulpq->asoc->base.sk; | |
0970f5b3 | 1140 | sp = sctp_sk(sk); |
1da177e4 LT |
1141 | if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT, |
1142 | &sctp_sk(sk)->subscribe)) | |
1143 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, | |
1144 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
1145 | gfp); | |
1146 | if (ev) | |
1147 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
1148 | ||
1149 | /* If there is data waiting, send it up the socket now. */ | |
0970f5b3 MRL |
1150 | if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) { |
1151 | sp->data_ready_signalled = 1; | |
1152 | sk->sk_data_ready(sk); | |
1153 | } | |
1da177e4 | 1154 | } |