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47505b8b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
60c778b2 | 2 | /* SCTP kernel implementation |
1da177e4 LT |
3 | * (C) Copyright IBM Corp. 2001, 2004 |
4 | * Copyright (c) 1999-2000 Cisco, Inc. | |
5 | * Copyright (c) 1999-2001 Motorola, Inc. | |
6 | * Copyright (c) 2001 Intel Corp. | |
7 | * Copyright (c) 2001 Nokia, Inc. | |
8 | * Copyright (c) 2001 La Monte H.P. Yarroll | |
9 | * | |
10 | * This abstraction carries sctp events to the ULP (sockets). | |
11 | * | |
1da177e4 LT |
12 | * Please send any bug reports or fixes you make to the |
13 | * email address(es): | |
91705c61 | 14 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 15 | * |
1da177e4 LT |
16 | * Written or modified by: |
17 | * Jon Grimm <jgrimm@us.ibm.com> | |
18 | * La Monte H.P. Yarroll <piggy@acm.org> | |
19 | * Sridhar Samudrala <sri@us.ibm.com> | |
1da177e4 LT |
20 | */ |
21 | ||
5a0e3ad6 | 22 | #include <linux/slab.h> |
1da177e4 LT |
23 | #include <linux/types.h> |
24 | #include <linux/skbuff.h> | |
25 | #include <net/sock.h> | |
8465a5fc | 26 | #include <net/busy_poll.h> |
1da177e4 LT |
27 | #include <net/sctp/structs.h> |
28 | #include <net/sctp/sctp.h> | |
29 | #include <net/sctp/sm.h> | |
30 | ||
31 | /* Forward declarations for internal helpers. */ | |
26ac8e5f | 32 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, |
8728b834 | 33 | struct sctp_ulpevent *); |
26ac8e5f | 34 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *, |
8728b834 | 35 | struct sctp_ulpevent *); |
ef5d4cf2 | 36 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq); |
1da177e4 LT |
37 | |
38 | /* 1st Level Abstractions */ | |
39 | ||
40 | /* Initialize a ULP queue from a block of memory. */ | |
41 | struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq, | |
42 | struct sctp_association *asoc) | |
43 | { | |
44 | memset(ulpq, 0, sizeof(struct sctp_ulpq)); | |
45 | ||
46 | ulpq->asoc = asoc; | |
47 | skb_queue_head_init(&ulpq->reasm); | |
13228238 | 48 | skb_queue_head_init(&ulpq->reasm_uo); |
1da177e4 LT |
49 | skb_queue_head_init(&ulpq->lobby); |
50 | ulpq->pd_mode = 0; | |
1da177e4 LT |
51 | |
52 | return ulpq; | |
53 | } | |
54 | ||
55 | ||
56 | /* Flush the reassembly and ordering queues. */ | |
0b58a811 | 57 | void sctp_ulpq_flush(struct sctp_ulpq *ulpq) |
1da177e4 LT |
58 | { |
59 | struct sk_buff *skb; | |
60 | struct sctp_ulpevent *event; | |
61 | ||
62 | while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { | |
63 | event = sctp_skb2event(skb); | |
64 | sctp_ulpevent_free(event); | |
65 | } | |
66 | ||
67 | while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { | |
68 | event = sctp_skb2event(skb); | |
69 | sctp_ulpevent_free(event); | |
70 | } | |
71 | ||
13228238 XL |
72 | while ((skb = __skb_dequeue(&ulpq->reasm_uo)) != NULL) { |
73 | event = sctp_skb2event(skb); | |
74 | sctp_ulpevent_free(event); | |
75 | } | |
1da177e4 LT |
76 | } |
77 | ||
78 | /* Dispose of a ulpqueue. */ | |
79 | void sctp_ulpq_free(struct sctp_ulpq *ulpq) | |
80 | { | |
81 | sctp_ulpq_flush(ulpq); | |
1da177e4 LT |
82 | } |
83 | ||
84 | /* Process an incoming DATA chunk. */ | |
85 | int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 86 | gfp_t gfp) |
1da177e4 LT |
87 | { |
88 | struct sk_buff_head temp; | |
1da177e4 | 89 | struct sctp_ulpevent *event; |
d003b41b | 90 | int event_eor = 0; |
1da177e4 | 91 | |
1da177e4 LT |
92 | /* Create an event from the incoming chunk. */ |
93 | event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); | |
94 | if (!event) | |
95 | return -ENOMEM; | |
96 | ||
bd4d627d XL |
97 | event->ssn = ntohs(chunk->subh.data_hdr->ssn); |
98 | event->ppid = chunk->subh.data_hdr->ppid; | |
99 | ||
1da177e4 LT |
100 | /* Do reassembly if needed. */ |
101 | event = sctp_ulpq_reasm(ulpq, event); | |
102 | ||
103 | /* Do ordering if needed. */ | |
178ca044 | 104 | if (event) { |
1da177e4 LT |
105 | /* Create a temporary list to collect chunks on. */ |
106 | skb_queue_head_init(&temp); | |
107 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
108 | ||
178ca044 DM |
109 | if (event->msg_flags & MSG_EOR) |
110 | event = sctp_ulpq_order(ulpq, event); | |
1da177e4 LT |
111 | } |
112 | ||
8728b834 DM |
113 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
114 | * very first SKB on the 'temp' list. | |
115 | */ | |
d003b41b LR |
116 | if (event) { |
117 | event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0; | |
013b96ec | 118 | sctp_ulpq_tail_event(ulpq, &temp); |
d003b41b | 119 | } |
1da177e4 | 120 | |
d003b41b | 121 | return event_eor; |
1da177e4 LT |
122 | } |
123 | ||
124 | /* Add a new event for propagation to the ULP. */ | |
125 | /* Clear the partial delivery mode for this socket. Note: This | |
126 | * assumes that no association is currently in partial delivery mode. | |
127 | */ | |
b6e1331f | 128 | int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc) |
1da177e4 LT |
129 | { |
130 | struct sctp_sock *sp = sctp_sk(sk); | |
131 | ||
b6e1331f VY |
132 | if (atomic_dec_and_test(&sp->pd_mode)) { |
133 | /* This means there are no other associations in PD, so | |
134 | * we can go ahead and clear out the lobby in one shot | |
135 | */ | |
136 | if (!skb_queue_empty(&sp->pd_lobby)) { | |
311b2177 MRL |
137 | skb_queue_splice_tail_init(&sp->pd_lobby, |
138 | &sk->sk_receive_queue); | |
b6e1331f VY |
139 | return 1; |
140 | } | |
141 | } else { | |
142 | /* There are other associations in PD, so we only need to | |
143 | * pull stuff out of the lobby that belongs to the | |
144 | * associations that is exiting PD (all of its notifications | |
145 | * are posted here). | |
146 | */ | |
147 | if (!skb_queue_empty(&sp->pd_lobby) && asoc) { | |
148 | struct sk_buff *skb, *tmp; | |
149 | struct sctp_ulpevent *event; | |
150 | ||
151 | sctp_skb_for_each(skb, &sp->pd_lobby, tmp) { | |
152 | event = sctp_skb2event(skb); | |
153 | if (event->asoc == asoc) { | |
154 | __skb_unlink(skb, &sp->pd_lobby); | |
155 | __skb_queue_tail(&sk->sk_receive_queue, | |
156 | skb); | |
157 | } | |
158 | } | |
159 | } | |
1da177e4 | 160 | } |
b6e1331f | 161 | |
1da177e4 LT |
162 | return 0; |
163 | } | |
164 | ||
d49d91d7 VY |
165 | /* Set the pd_mode on the socket and ulpq */ |
166 | static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq) | |
167 | { | |
168 | struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk); | |
169 | ||
170 | atomic_inc(&sp->pd_mode); | |
171 | ulpq->pd_mode = 1; | |
172 | } | |
173 | ||
1da177e4 LT |
174 | /* Clear the pd_mode and restart any pending messages waiting for delivery. */ |
175 | static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) | |
176 | { | |
177 | ulpq->pd_mode = 0; | |
ef5d4cf2 | 178 | sctp_ulpq_reasm_drain(ulpq); |
b6e1331f | 179 | return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc); |
1da177e4 LT |
180 | } |
181 | ||
013b96ec | 182 | int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sk_buff_head *skb_list) |
1da177e4 LT |
183 | { |
184 | struct sock *sk = ulpq->asoc->base.sk; | |
0970f5b3 | 185 | struct sctp_sock *sp = sctp_sk(sk); |
013b96ec DM |
186 | struct sctp_ulpevent *event; |
187 | struct sk_buff_head *queue; | |
188 | struct sk_buff *skb; | |
1da177e4 LT |
189 | int clear_pd = 0; |
190 | ||
013b96ec DM |
191 | skb = __skb_peek(skb_list); |
192 | event = sctp_skb2event(skb); | |
8728b834 | 193 | |
1da177e4 LT |
194 | /* If the socket is just going to throw this away, do not |
195 | * even try to deliver it. | |
196 | */ | |
a0fc6843 XL |
197 | if (sk->sk_shutdown & RCV_SHUTDOWN && |
198 | (sk->sk_shutdown & SEND_SHUTDOWN || | |
199 | !sctp_ulpevent_is_notification(event))) | |
1da177e4 LT |
200 | goto out_free; |
201 | ||
2c8c56e1 | 202 | if (!sctp_ulpevent_is_notification(event)) { |
8465a5fc | 203 | sk_mark_napi_id(sk, skb); |
2c8c56e1 ED |
204 | sk_incoming_cpu_update(sk); |
205 | } | |
1da177e4 | 206 | /* Check if the user wishes to receive this event. */ |
a1e3a059 | 207 | if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe)) |
1da177e4 LT |
208 | goto out_free; |
209 | ||
210 | /* If we are in partial delivery mode, post to the lobby until | |
211 | * partial delivery is cleared, unless, of course _this_ is | |
212 | * the association the cause of the partial delivery. | |
213 | */ | |
214 | ||
0970f5b3 | 215 | if (atomic_read(&sp->pd_mode) == 0) { |
1da177e4 | 216 | queue = &sk->sk_receive_queue; |
b6e1331f VY |
217 | } else { |
218 | if (ulpq->pd_mode) { | |
219 | /* If the association is in partial delivery, we | |
220 | * need to finish delivering the partially processed | |
221 | * packet before passing any other data. This is | |
222 | * because we don't truly support stream interleaving. | |
223 | */ | |
224 | if ((event->msg_flags & MSG_NOTIFICATION) || | |
225 | (SCTP_DATA_NOT_FRAG == | |
226 | (event->msg_flags & SCTP_DATA_FRAG_MASK))) | |
0970f5b3 | 227 | queue = &sp->pd_lobby; |
b6e1331f VY |
228 | else { |
229 | clear_pd = event->msg_flags & MSG_EOR; | |
230 | queue = &sk->sk_receive_queue; | |
231 | } | |
232 | } else { | |
233 | /* | |
234 | * If fragment interleave is enabled, we | |
25985edc | 235 | * can queue this to the receive queue instead |
b6e1331f VY |
236 | * of the lobby. |
237 | */ | |
0970f5b3 | 238 | if (sp->frag_interleave) |
b6e1331f VY |
239 | queue = &sk->sk_receive_queue; |
240 | else | |
0970f5b3 | 241 | queue = &sp->pd_lobby; |
1da177e4 | 242 | } |
b6e1331f | 243 | } |
1da177e4 | 244 | |
013b96ec | 245 | skb_queue_splice_tail_init(skb_list, queue); |
1da177e4 LT |
246 | |
247 | /* Did we just complete partial delivery and need to get | |
248 | * rolling again? Move pending data to the receive | |
249 | * queue. | |
250 | */ | |
251 | if (clear_pd) | |
252 | sctp_ulpq_clear_pd(ulpq); | |
253 | ||
0970f5b3 | 254 | if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) { |
7906b00f MRL |
255 | if (!sock_owned_by_user(sk)) |
256 | sp->data_ready_signalled = 1; | |
0970f5b3 MRL |
257 | sk->sk_data_ready(sk); |
258 | } | |
1da177e4 LT |
259 | return 1; |
260 | ||
261 | out_free: | |
8728b834 DM |
262 | if (skb_list) |
263 | sctp_queue_purge_ulpevents(skb_list); | |
1da177e4 LT |
264 | else |
265 | sctp_ulpevent_free(event); | |
8728b834 | 266 | |
1da177e4 LT |
267 | return 0; |
268 | } | |
269 | ||
270 | /* 2nd Level Abstractions */ | |
271 | ||
272 | /* Helper function to store chunks that need to be reassembled. */ | |
01f2d384 | 273 | static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, |
1da177e4 LT |
274 | struct sctp_ulpevent *event) |
275 | { | |
276 | struct sk_buff *pos; | |
277 | struct sctp_ulpevent *cevent; | |
278 | __u32 tsn, ctsn; | |
279 | ||
280 | tsn = event->tsn; | |
281 | ||
282 | /* See if it belongs at the end. */ | |
283 | pos = skb_peek_tail(&ulpq->reasm); | |
284 | if (!pos) { | |
285 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
286 | return; | |
287 | } | |
288 | ||
289 | /* Short circuit just dropping it at the end. */ | |
290 | cevent = sctp_skb2event(pos); | |
291 | ctsn = cevent->tsn; | |
292 | if (TSN_lt(ctsn, tsn)) { | |
293 | __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); | |
294 | return; | |
295 | } | |
296 | ||
297 | /* Find the right place in this list. We store them by TSN. */ | |
298 | skb_queue_walk(&ulpq->reasm, pos) { | |
299 | cevent = sctp_skb2event(pos); | |
300 | ctsn = cevent->tsn; | |
301 | ||
302 | if (TSN_lt(tsn, ctsn)) | |
303 | break; | |
304 | } | |
305 | ||
306 | /* Insert before pos. */ | |
43f59c89 | 307 | __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event)); |
1da177e4 LT |
308 | |
309 | } | |
310 | ||
311 | /* Helper function to return an event corresponding to the reassembled | |
312 | * datagram. | |
313 | * This routine creates a re-assembled skb given the first and last skb's | |
314 | * as stored in the reassembly queue. The skb's may be non-linear if the sctp | |
315 | * payload was fragmented on the way and ip had to reassemble them. | |
316 | * We add the rest of skb's to the first skb's fraglist. | |
317 | */ | |
bd4d627d XL |
318 | struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net, |
319 | struct sk_buff_head *queue, | |
320 | struct sk_buff *f_frag, | |
321 | struct sk_buff *l_frag) | |
1da177e4 LT |
322 | { |
323 | struct sk_buff *pos; | |
672e7cca | 324 | struct sk_buff *new = NULL; |
1da177e4 LT |
325 | struct sctp_ulpevent *event; |
326 | struct sk_buff *pnext, *last; | |
327 | struct sk_buff *list = skb_shinfo(f_frag)->frag_list; | |
328 | ||
329 | /* Store the pointer to the 2nd skb */ | |
330 | if (f_frag == l_frag) | |
331 | pos = NULL; | |
332 | else | |
333 | pos = f_frag->next; | |
334 | ||
335 | /* Get the last skb in the f_frag's frag_list if present. */ | |
8d72651d | 336 | for (last = list; list; last = list, list = list->next) |
337 | ; | |
1da177e4 LT |
338 | |
339 | /* Add the list of remaining fragments to the first fragments | |
340 | * frag_list. | |
341 | */ | |
342 | if (last) | |
343 | last->next = pos; | |
d808ad9a YH |
344 | else { |
345 | if (skb_cloned(f_frag)) { | |
346 | /* This is a cloned skb, we can't just modify | |
347 | * the frag_list. We need a new skb to do that. | |
348 | * Instead of calling skb_unshare(), we'll do it | |
349 | * ourselves since we need to delay the free. | |
350 | */ | |
351 | new = skb_copy(f_frag, GFP_ATOMIC); | |
352 | if (!new) | |
353 | return NULL; /* try again later */ | |
354 | ||
355 | sctp_skb_set_owner_r(new, f_frag->sk); | |
356 | ||
357 | skb_shinfo(new)->frag_list = pos; | |
358 | } else | |
359 | skb_shinfo(f_frag)->frag_list = pos; | |
360 | } | |
1da177e4 LT |
361 | |
362 | /* Remove the first fragment from the reassembly queue. */ | |
8728b834 | 363 | __skb_unlink(f_frag, queue); |
672e7cca | 364 | |
d808ad9a YH |
365 | /* if we did unshare, then free the old skb and re-assign */ |
366 | if (new) { | |
367 | kfree_skb(f_frag); | |
368 | f_frag = new; | |
369 | } | |
672e7cca | 370 | |
1da177e4 LT |
371 | while (pos) { |
372 | ||
373 | pnext = pos->next; | |
374 | ||
375 | /* Update the len and data_len fields of the first fragment. */ | |
376 | f_frag->len += pos->len; | |
377 | f_frag->data_len += pos->len; | |
378 | ||
379 | /* Remove the fragment from the reassembly queue. */ | |
8728b834 | 380 | __skb_unlink(pos, queue); |
d808ad9a | 381 | |
1da177e4 LT |
382 | /* Break if we have reached the last fragment. */ |
383 | if (pos == l_frag) | |
384 | break; | |
385 | pos->next = pnext; | |
386 | pos = pnext; | |
3ff50b79 | 387 | } |
1da177e4 LT |
388 | |
389 | event = sctp_skb2event(f_frag); | |
b01a2407 | 390 | SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS); |
1da177e4 LT |
391 | |
392 | return event; | |
393 | } | |
394 | ||
395 | ||
396 | /* Helper function to check if an incoming chunk has filled up the last | |
397 | * missing fragment in a SCTP datagram and return the corresponding event. | |
398 | */ | |
01f2d384 | 399 | static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) |
1da177e4 LT |
400 | { |
401 | struct sk_buff *pos; | |
402 | struct sctp_ulpevent *cevent; | |
403 | struct sk_buff *first_frag = NULL; | |
404 | __u32 ctsn, next_tsn; | |
405 | struct sctp_ulpevent *retval = NULL; | |
d49d91d7 VY |
406 | struct sk_buff *pd_first = NULL; |
407 | struct sk_buff *pd_last = NULL; | |
408 | size_t pd_len = 0; | |
409 | struct sctp_association *asoc; | |
410 | u32 pd_point; | |
1da177e4 LT |
411 | |
412 | /* Initialized to 0 just to avoid compiler warning message. Will | |
413 | * never be used with this value. It is referenced only after it | |
414 | * is set when we find the first fragment of a message. | |
415 | */ | |
416 | next_tsn = 0; | |
417 | ||
418 | /* The chunks are held in the reasm queue sorted by TSN. | |
419 | * Walk through the queue sequentially and look for a sequence of | |
420 | * fragmented chunks that complete a datagram. | |
421 | * 'first_frag' and next_tsn are reset when we find a chunk which | |
422 | * is the first fragment of a datagram. Once these 2 fields are set | |
423 | * we expect to find the remaining middle fragments and the last | |
424 | * fragment in order. If not, first_frag is reset to NULL and we | |
425 | * start the next pass when we find another first fragment. | |
d49d91d7 VY |
426 | * |
427 | * There is a potential to do partial delivery if user sets | |
428 | * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here | |
429 | * to see if can do PD. | |
1da177e4 LT |
430 | */ |
431 | skb_queue_walk(&ulpq->reasm, pos) { | |
432 | cevent = sctp_skb2event(pos); | |
433 | ctsn = cevent->tsn; | |
434 | ||
435 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
436 | case SCTP_DATA_FIRST_FRAG: | |
d49d91d7 VY |
437 | /* If this "FIRST_FRAG" is the first |
438 | * element in the queue, then count it towards | |
439 | * possible PD. | |
440 | */ | |
1181d629 | 441 | if (skb_queue_is_first(&ulpq->reasm, pos)) { |
d49d91d7 VY |
442 | pd_first = pos; |
443 | pd_last = pos; | |
444 | pd_len = pos->len; | |
445 | } else { | |
446 | pd_first = NULL; | |
447 | pd_last = NULL; | |
448 | pd_len = 0; | |
449 | } | |
450 | ||
1da177e4 LT |
451 | first_frag = pos; |
452 | next_tsn = ctsn + 1; | |
453 | break; | |
454 | ||
455 | case SCTP_DATA_MIDDLE_FRAG: | |
d49d91d7 | 456 | if ((first_frag) && (ctsn == next_tsn)) { |
1da177e4 | 457 | next_tsn++; |
d49d91d7 VY |
458 | if (pd_first) { |
459 | pd_last = pos; | |
460 | pd_len += pos->len; | |
461 | } | |
462 | } else | |
1da177e4 LT |
463 | first_frag = NULL; |
464 | break; | |
465 | ||
466 | case SCTP_DATA_LAST_FRAG: | |
467 | if (first_frag && (ctsn == next_tsn)) | |
468 | goto found; | |
469 | else | |
470 | first_frag = NULL; | |
471 | break; | |
3ff50b79 | 472 | } |
d49d91d7 VY |
473 | } |
474 | ||
475 | asoc = ulpq->asoc; | |
476 | if (pd_first) { | |
477 | /* Make sure we can enter partial deliver. | |
478 | * We can trigger partial delivery only if framgent | |
479 | * interleave is set, or the socket is not already | |
480 | * in partial delivery. | |
481 | */ | |
482 | if (!sctp_sk(asoc->base.sk)->frag_interleave && | |
483 | atomic_read(&sctp_sk(asoc->base.sk)->pd_mode)) | |
484 | goto done; | |
1da177e4 | 485 | |
d49d91d7 VY |
486 | cevent = sctp_skb2event(pd_first); |
487 | pd_point = sctp_sk(asoc->base.sk)->pd_point; | |
488 | if (pd_point && pd_point <= pd_len) { | |
b01a2407 EB |
489 | retval = sctp_make_reassembled_event(sock_net(asoc->base.sk), |
490 | &ulpq->reasm, | |
d49d91d7 VY |
491 | pd_first, |
492 | pd_last); | |
493 | if (retval) | |
494 | sctp_ulpq_set_pd(ulpq); | |
495 | } | |
1da177e4 LT |
496 | } |
497 | done: | |
498 | return retval; | |
499 | found: | |
b01a2407 EB |
500 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
501 | &ulpq->reasm, first_frag, pos); | |
1da177e4 LT |
502 | if (retval) |
503 | retval->msg_flags |= MSG_EOR; | |
504 | goto done; | |
505 | } | |
506 | ||
507 | /* Retrieve the next set of fragments of a partial message. */ | |
01f2d384 | 508 | static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) |
1da177e4 LT |
509 | { |
510 | struct sk_buff *pos, *last_frag, *first_frag; | |
511 | struct sctp_ulpevent *cevent; | |
512 | __u32 ctsn, next_tsn; | |
513 | int is_last; | |
514 | struct sctp_ulpevent *retval; | |
515 | ||
516 | /* The chunks are held in the reasm queue sorted by TSN. | |
517 | * Walk through the queue sequentially and look for the first | |
518 | * sequence of fragmented chunks. | |
519 | */ | |
520 | ||
521 | if (skb_queue_empty(&ulpq->reasm)) | |
522 | return NULL; | |
523 | ||
524 | last_frag = first_frag = NULL; | |
525 | retval = NULL; | |
526 | next_tsn = 0; | |
527 | is_last = 0; | |
528 | ||
529 | skb_queue_walk(&ulpq->reasm, pos) { | |
530 | cevent = sctp_skb2event(pos); | |
531 | ctsn = cevent->tsn; | |
532 | ||
533 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
d003b41b LR |
534 | case SCTP_DATA_FIRST_FRAG: |
535 | if (!first_frag) | |
536 | return NULL; | |
537 | goto done; | |
1da177e4 LT |
538 | case SCTP_DATA_MIDDLE_FRAG: |
539 | if (!first_frag) { | |
540 | first_frag = pos; | |
541 | next_tsn = ctsn + 1; | |
542 | last_frag = pos; | |
d003b41b | 543 | } else if (next_tsn == ctsn) { |
1da177e4 | 544 | next_tsn++; |
d003b41b LR |
545 | last_frag = pos; |
546 | } else | |
1da177e4 LT |
547 | goto done; |
548 | break; | |
549 | case SCTP_DATA_LAST_FRAG: | |
550 | if (!first_frag) | |
551 | first_frag = pos; | |
552 | else if (ctsn != next_tsn) | |
553 | goto done; | |
554 | last_frag = pos; | |
555 | is_last = 1; | |
556 | goto done; | |
557 | default: | |
558 | return NULL; | |
3ff50b79 | 559 | } |
1da177e4 LT |
560 | } |
561 | ||
562 | /* We have the reassembled event. There is no need to look | |
563 | * further. | |
564 | */ | |
565 | done: | |
b01a2407 EB |
566 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
567 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
568 | if (retval && is_last) |
569 | retval->msg_flags |= MSG_EOR; | |
570 | ||
571 | return retval; | |
572 | } | |
573 | ||
574 | ||
575 | /* Helper function to reassemble chunks. Hold chunks on the reasm queue that | |
576 | * need reassembling. | |
577 | */ | |
578 | static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, | |
579 | struct sctp_ulpevent *event) | |
580 | { | |
581 | struct sctp_ulpevent *retval = NULL; | |
582 | ||
583 | /* Check if this is part of a fragmented message. */ | |
584 | if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { | |
585 | event->msg_flags |= MSG_EOR; | |
586 | return event; | |
587 | } | |
588 | ||
589 | sctp_ulpq_store_reasm(ulpq, event); | |
590 | if (!ulpq->pd_mode) | |
591 | retval = sctp_ulpq_retrieve_reassembled(ulpq); | |
592 | else { | |
593 | __u32 ctsn, ctsnap; | |
594 | ||
595 | /* Do not even bother unless this is the next tsn to | |
596 | * be delivered. | |
597 | */ | |
598 | ctsn = event->tsn; | |
599 | ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); | |
600 | if (TSN_lte(ctsn, ctsnap)) | |
601 | retval = sctp_ulpq_retrieve_partial(ulpq); | |
602 | } | |
603 | ||
604 | return retval; | |
605 | } | |
606 | ||
607 | /* Retrieve the first part (sequential fragments) for partial delivery. */ | |
01f2d384 | 608 | static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) |
1da177e4 LT |
609 | { |
610 | struct sk_buff *pos, *last_frag, *first_frag; | |
611 | struct sctp_ulpevent *cevent; | |
612 | __u32 ctsn, next_tsn; | |
613 | struct sctp_ulpevent *retval; | |
614 | ||
615 | /* The chunks are held in the reasm queue sorted by TSN. | |
616 | * Walk through the queue sequentially and look for a sequence of | |
617 | * fragmented chunks that start a datagram. | |
618 | */ | |
619 | ||
620 | if (skb_queue_empty(&ulpq->reasm)) | |
621 | return NULL; | |
622 | ||
623 | last_frag = first_frag = NULL; | |
624 | retval = NULL; | |
625 | next_tsn = 0; | |
626 | ||
627 | skb_queue_walk(&ulpq->reasm, pos) { | |
628 | cevent = sctp_skb2event(pos); | |
629 | ctsn = cevent->tsn; | |
630 | ||
631 | switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { | |
632 | case SCTP_DATA_FIRST_FRAG: | |
633 | if (!first_frag) { | |
634 | first_frag = pos; | |
635 | next_tsn = ctsn + 1; | |
636 | last_frag = pos; | |
637 | } else | |
638 | goto done; | |
639 | break; | |
640 | ||
641 | case SCTP_DATA_MIDDLE_FRAG: | |
642 | if (!first_frag) | |
643 | return NULL; | |
644 | if (ctsn == next_tsn) { | |
645 | next_tsn++; | |
646 | last_frag = pos; | |
647 | } else | |
648 | goto done; | |
649 | break; | |
d003b41b LR |
650 | |
651 | case SCTP_DATA_LAST_FRAG: | |
652 | if (!first_frag) | |
653 | return NULL; | |
654 | else | |
655 | goto done; | |
656 | break; | |
657 | ||
1da177e4 LT |
658 | default: |
659 | return NULL; | |
3ff50b79 | 660 | } |
1da177e4 LT |
661 | } |
662 | ||
663 | /* We have the reassembled event. There is no need to look | |
664 | * further. | |
665 | */ | |
666 | done: | |
b01a2407 EB |
667 | retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk), |
668 | &ulpq->reasm, first_frag, last_frag); | |
1da177e4 LT |
669 | return retval; |
670 | } | |
671 | ||
ea2dfb37 VY |
672 | /* |
673 | * Flush out stale fragments from the reassembly queue when processing | |
674 | * a Forward TSN. | |
675 | * | |
676 | * RFC 3758, Section 3.6 | |
677 | * | |
678 | * After receiving and processing a FORWARD TSN, the data receiver MUST | |
679 | * take cautions in updating its re-assembly queue. The receiver MUST | |
680 | * remove any partially reassembled message, which is still missing one | |
681 | * or more TSNs earlier than or equal to the new cumulative TSN point. | |
682 | * In the event that the receiver has invoked the partial delivery API, | |
683 | * a notification SHOULD also be generated to inform the upper layer API | |
684 | * that the message being partially delivered will NOT be completed. | |
685 | */ | |
686 | void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn) | |
687 | { | |
688 | struct sk_buff *pos, *tmp; | |
689 | struct sctp_ulpevent *event; | |
690 | __u32 tsn; | |
691 | ||
692 | if (skb_queue_empty(&ulpq->reasm)) | |
693 | return; | |
694 | ||
695 | skb_queue_walk_safe(&ulpq->reasm, pos, tmp) { | |
696 | event = sctp_skb2event(pos); | |
697 | tsn = event->tsn; | |
698 | ||
699 | /* Since the entire message must be abandoned by the | |
700 | * sender (item A3 in Section 3.5, RFC 3758), we can | |
701 | * free all fragments on the list that are less then | |
702 | * or equal to ctsn_point | |
703 | */ | |
704 | if (TSN_lte(tsn, fwd_tsn)) { | |
705 | __skb_unlink(pos, &ulpq->reasm); | |
706 | sctp_ulpevent_free(event); | |
707 | } else | |
708 | break; | |
709 | } | |
710 | } | |
711 | ||
ef5d4cf2 VY |
712 | /* |
713 | * Drain the reassembly queue. If we just cleared parted delivery, it | |
714 | * is possible that the reassembly queue will contain already reassembled | |
715 | * messages. Retrieve any such messages and give them to the user. | |
716 | */ | |
717 | static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq) | |
718 | { | |
719 | struct sctp_ulpevent *event = NULL; | |
ef5d4cf2 VY |
720 | |
721 | if (skb_queue_empty(&ulpq->reasm)) | |
722 | return; | |
723 | ||
724 | while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) { | |
925b9374 DM |
725 | struct sk_buff_head temp; |
726 | ||
727 | skb_queue_head_init(&temp); | |
728 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
ef5d4cf2 | 729 | |
925b9374 DM |
730 | /* Do ordering if needed. */ |
731 | if (event->msg_flags & MSG_EOR) | |
ef5d4cf2 | 732 | event = sctp_ulpq_order(ulpq, event); |
ef5d4cf2 VY |
733 | |
734 | /* Send event to the ULP. 'event' is the | |
735 | * sctp_ulpevent for very first SKB on the temp' list. | |
736 | */ | |
737 | if (event) | |
013b96ec | 738 | sctp_ulpq_tail_event(ulpq, &temp); |
ef5d4cf2 VY |
739 | } |
740 | } | |
741 | ||
742 | ||
1da177e4 LT |
743 | /* Helper function to gather skbs that have possibly become |
744 | * ordered by an an incoming chunk. | |
745 | */ | |
01f2d384 | 746 | static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
747 | struct sctp_ulpevent *event) |
748 | { | |
8728b834 | 749 | struct sk_buff_head *event_list; |
1da177e4 LT |
750 | struct sk_buff *pos, *tmp; |
751 | struct sctp_ulpevent *cevent; | |
a8386317 | 752 | struct sctp_stream *stream; |
efea2c6b | 753 | __u16 sid, csid, cssn; |
1da177e4 LT |
754 | |
755 | sid = event->stream; | |
cee360ab | 756 | stream = &ulpq->asoc->stream; |
1da177e4 | 757 | |
8728b834 DM |
758 | event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; |
759 | ||
1da177e4 LT |
760 | /* We are holding the chunks by stream, by SSN. */ |
761 | sctp_skb_for_each(pos, &ulpq->lobby, tmp) { | |
762 | cevent = (struct sctp_ulpevent *) pos->cb; | |
763 | csid = cevent->stream; | |
764 | cssn = cevent->ssn; | |
765 | ||
766 | /* Have we gone too far? */ | |
767 | if (csid > sid) | |
768 | break; | |
769 | ||
770 | /* Have we not gone far enough? */ | |
771 | if (csid < sid) | |
772 | continue; | |
773 | ||
a8386317 | 774 | if (cssn != sctp_ssn_peek(stream, in, sid)) |
1da177e4 LT |
775 | break; |
776 | ||
a8386317 XL |
777 | /* Found it, so mark in the stream. */ |
778 | sctp_ssn_next(stream, in, sid); | |
1da177e4 | 779 | |
8728b834 | 780 | __skb_unlink(pos, &ulpq->lobby); |
1da177e4 LT |
781 | |
782 | /* Attach all gathered skbs to the event. */ | |
8728b834 | 783 | __skb_queue_tail(event_list, pos); |
1da177e4 LT |
784 | } |
785 | } | |
786 | ||
787 | /* Helper function to store chunks needing ordering. */ | |
01f2d384 | 788 | static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, |
1da177e4 LT |
789 | struct sctp_ulpevent *event) |
790 | { | |
791 | struct sk_buff *pos; | |
792 | struct sctp_ulpevent *cevent; | |
793 | __u16 sid, csid; | |
794 | __u16 ssn, cssn; | |
795 | ||
796 | pos = skb_peek_tail(&ulpq->lobby); | |
797 | if (!pos) { | |
798 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
799 | return; | |
800 | } | |
801 | ||
802 | sid = event->stream; | |
803 | ssn = event->ssn; | |
d808ad9a | 804 | |
1da177e4 LT |
805 | cevent = (struct sctp_ulpevent *) pos->cb; |
806 | csid = cevent->stream; | |
807 | cssn = cevent->ssn; | |
808 | if (sid > csid) { | |
809 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
810 | return; | |
811 | } | |
812 | ||
813 | if ((sid == csid) && SSN_lt(cssn, ssn)) { | |
814 | __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); | |
815 | return; | |
816 | } | |
817 | ||
818 | /* Find the right place in this list. We store them by | |
819 | * stream ID and then by SSN. | |
820 | */ | |
821 | skb_queue_walk(&ulpq->lobby, pos) { | |
822 | cevent = (struct sctp_ulpevent *) pos->cb; | |
823 | csid = cevent->stream; | |
824 | cssn = cevent->ssn; | |
825 | ||
826 | if (csid > sid) | |
827 | break; | |
828 | if (csid == sid && SSN_lt(ssn, cssn)) | |
829 | break; | |
830 | } | |
831 | ||
832 | ||
833 | /* Insert before pos. */ | |
43f59c89 | 834 | __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event)); |
1da177e4 LT |
835 | } |
836 | ||
837 | static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, | |
8728b834 | 838 | struct sctp_ulpevent *event) |
1da177e4 LT |
839 | { |
840 | __u16 sid, ssn; | |
a8386317 | 841 | struct sctp_stream *stream; |
1da177e4 LT |
842 | |
843 | /* Check if this message needs ordering. */ | |
bd4d627d | 844 | if (event->msg_flags & SCTP_DATA_UNORDERED) |
1da177e4 LT |
845 | return event; |
846 | ||
847 | /* Note: The stream ID must be verified before this routine. */ | |
848 | sid = event->stream; | |
849 | ssn = event->ssn; | |
cee360ab | 850 | stream = &ulpq->asoc->stream; |
1da177e4 LT |
851 | |
852 | /* Is this the expected SSN for this stream ID? */ | |
a8386317 | 853 | if (ssn != sctp_ssn_peek(stream, in, sid)) { |
1da177e4 LT |
854 | /* We've received something out of order, so find where it |
855 | * needs to be placed. We order by stream and then by SSN. | |
856 | */ | |
857 | sctp_ulpq_store_ordered(ulpq, event); | |
858 | return NULL; | |
859 | } | |
860 | ||
861 | /* Mark that the next chunk has been found. */ | |
a8386317 | 862 | sctp_ssn_next(stream, in, sid); |
1da177e4 LT |
863 | |
864 | /* Go find any other chunks that were waiting for | |
865 | * ordering. | |
866 | */ | |
867 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
868 | ||
869 | return event; | |
870 | } | |
871 | ||
872 | /* Helper function to gather skbs that have possibly become | |
873 | * ordered by forward tsn skipping their dependencies. | |
874 | */ | |
01f2d384 | 875 | static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid) |
1da177e4 LT |
876 | { |
877 | struct sk_buff *pos, *tmp; | |
878 | struct sctp_ulpevent *cevent; | |
8728b834 | 879 | struct sctp_ulpevent *event; |
a8386317 | 880 | struct sctp_stream *stream; |
1da177e4 | 881 | struct sk_buff_head temp; |
c068be54 | 882 | struct sk_buff_head *lobby = &ulpq->lobby; |
1da177e4 LT |
883 | __u16 csid, cssn; |
884 | ||
cee360ab | 885 | stream = &ulpq->asoc->stream; |
1da177e4 LT |
886 | |
887 | /* We are holding the chunks by stream, by SSN. */ | |
8728b834 DM |
888 | skb_queue_head_init(&temp); |
889 | event = NULL; | |
c068be54 | 890 | sctp_skb_for_each(pos, lobby, tmp) { |
1da177e4 LT |
891 | cevent = (struct sctp_ulpevent *) pos->cb; |
892 | csid = cevent->stream; | |
893 | cssn = cevent->ssn; | |
894 | ||
ea2dfb37 VY |
895 | /* Have we gone too far? */ |
896 | if (csid > sid) | |
1da177e4 LT |
897 | break; |
898 | ||
ea2dfb37 VY |
899 | /* Have we not gone far enough? */ |
900 | if (csid < sid) | |
901 | continue; | |
902 | ||
903 | /* see if this ssn has been marked by skipping */ | |
a8386317 | 904 | if (!SSN_lt(cssn, sctp_ssn_peek(stream, in, csid))) |
ea2dfb37 | 905 | break; |
1da177e4 | 906 | |
c068be54 | 907 | __skb_unlink(pos, lobby); |
ea2dfb37 | 908 | if (!event) |
1da177e4 LT |
909 | /* Create a temporary list to collect chunks on. */ |
910 | event = sctp_skb2event(pos); | |
ea2dfb37 VY |
911 | |
912 | /* Attach all gathered skbs to the event. */ | |
913 | __skb_queue_tail(&temp, pos); | |
1da177e4 LT |
914 | } |
915 | ||
c068be54 VY |
916 | /* If we didn't reap any data, see if the next expected SSN |
917 | * is next on the queue and if so, use that. | |
918 | */ | |
919 | if (event == NULL && pos != (struct sk_buff *)lobby) { | |
920 | cevent = (struct sctp_ulpevent *) pos->cb; | |
921 | csid = cevent->stream; | |
922 | cssn = cevent->ssn; | |
923 | ||
a8386317 XL |
924 | if (csid == sid && cssn == sctp_ssn_peek(stream, in, csid)) { |
925 | sctp_ssn_next(stream, in, csid); | |
c068be54 VY |
926 | __skb_unlink(pos, lobby); |
927 | __skb_queue_tail(&temp, pos); | |
928 | event = sctp_skb2event(pos); | |
929 | } | |
930 | } | |
931 | ||
8728b834 DM |
932 | /* Send event to the ULP. 'event' is the sctp_ulpevent for |
933 | * very first SKB on the 'temp' list. | |
934 | */ | |
ea2dfb37 VY |
935 | if (event) { |
936 | /* see if we have more ordered that we can deliver */ | |
937 | sctp_ulpq_retrieve_ordered(ulpq, event); | |
013b96ec | 938 | sctp_ulpq_tail_event(ulpq, &temp); |
ea2dfb37 | 939 | } |
1da177e4 LT |
940 | } |
941 | ||
ea2dfb37 VY |
942 | /* Skip over an SSN. This is used during the processing of |
943 | * Forwared TSN chunk to skip over the abandoned ordered data | |
944 | */ | |
1da177e4 LT |
945 | void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) |
946 | { | |
a8386317 | 947 | struct sctp_stream *stream; |
1da177e4 LT |
948 | |
949 | /* Note: The stream ID must be verified before this routine. */ | |
cee360ab | 950 | stream = &ulpq->asoc->stream; |
1da177e4 LT |
951 | |
952 | /* Is this an old SSN? If so ignore. */ | |
a8386317 | 953 | if (SSN_lt(ssn, sctp_ssn_peek(stream, in, sid))) |
1da177e4 LT |
954 | return; |
955 | ||
956 | /* Mark that we are no longer expecting this SSN or lower. */ | |
a8386317 | 957 | sctp_ssn_skip(stream, in, sid, ssn); |
1da177e4 LT |
958 | |
959 | /* Go find any other chunks that were waiting for | |
d808ad9a | 960 | * ordering and deliver them if needed. |
1da177e4 | 961 | */ |
ea2dfb37 | 962 | sctp_ulpq_reap_ordered(ulpq, sid); |
1da177e4 LT |
963 | } |
964 | ||
94014e8d XL |
965 | __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list, |
966 | __u16 needed) | |
1da177e4 LT |
967 | { |
968 | __u16 freed = 0; | |
95ac7b85 LR |
969 | __u32 tsn, last_tsn; |
970 | struct sk_buff *skb, *flist, *last; | |
1da177e4 LT |
971 | struct sctp_ulpevent *event; |
972 | struct sctp_tsnmap *tsnmap; | |
973 | ||
974 | tsnmap = &ulpq->asoc->peer.tsn_map; | |
975 | ||
e67f85ec | 976 | while ((skb = skb_peek_tail(list)) != NULL) { |
1da177e4 LT |
977 | event = sctp_skb2event(skb); |
978 | tsn = event->tsn; | |
979 | ||
e67f85ec LR |
980 | /* Don't renege below the Cumulative TSN ACK Point. */ |
981 | if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) | |
982 | break; | |
983 | ||
95ac7b85 LR |
984 | /* Events in ordering queue may have multiple fragments |
985 | * corresponding to additional TSNs. Sum the total | |
986 | * freed space; find the last TSN. | |
987 | */ | |
e67f85ec | 988 | freed += skb_headlen(skb); |
95ac7b85 LR |
989 | flist = skb_shinfo(skb)->frag_list; |
990 | for (last = flist; flist; flist = flist->next) { | |
991 | last = flist; | |
992 | freed += skb_headlen(last); | |
993 | } | |
994 | if (last) | |
995 | last_tsn = sctp_skb2event(last)->tsn; | |
996 | else | |
997 | last_tsn = tsn; | |
998 | ||
999 | /* Unlink the event, then renege all applicable TSNs. */ | |
1000 | __skb_unlink(skb, list); | |
1da177e4 | 1001 | sctp_ulpevent_free(event); |
95ac7b85 LR |
1002 | while (TSN_lte(tsn, last_tsn)) { |
1003 | sctp_tsnmap_renege(tsnmap, tsn); | |
1004 | tsn++; | |
1005 | } | |
1da177e4 LT |
1006 | if (freed >= needed) |
1007 | return freed; | |
1008 | } | |
1009 | ||
1010 | return freed; | |
1011 | } | |
1012 | ||
16d14ef9 PE |
1013 | /* Renege 'needed' bytes from the ordering queue. */ |
1014 | static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) | |
1015 | { | |
1016 | return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed); | |
1017 | } | |
1018 | ||
1da177e4 LT |
1019 | /* Renege 'needed' bytes from the reassembly queue. */ |
1020 | static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) | |
1021 | { | |
16d14ef9 | 1022 | return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed); |
1da177e4 LT |
1023 | } |
1024 | ||
1025 | /* Partial deliver the first message as there is pressure on rwnd. */ | |
1026 | void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, | |
dd0fc66f | 1027 | gfp_t gfp) |
1da177e4 LT |
1028 | { |
1029 | struct sctp_ulpevent *event; | |
1030 | struct sctp_association *asoc; | |
b6e1331f | 1031 | struct sctp_sock *sp; |
d003b41b LR |
1032 | __u32 ctsn; |
1033 | struct sk_buff *skb; | |
1da177e4 LT |
1034 | |
1035 | asoc = ulpq->asoc; | |
b6e1331f | 1036 | sp = sctp_sk(asoc->base.sk); |
1da177e4 | 1037 | |
b6e1331f | 1038 | /* If the association is already in Partial Delivery mode |
d003b41b | 1039 | * we have nothing to do. |
b6e1331f VY |
1040 | */ |
1041 | if (ulpq->pd_mode) | |
1042 | return; | |
1da177e4 | 1043 | |
d003b41b LR |
1044 | /* Data must be at or below the Cumulative TSN ACK Point to |
1045 | * start partial delivery. | |
1046 | */ | |
1047 | skb = skb_peek(&asoc->ulpq.reasm); | |
1048 | if (skb != NULL) { | |
1049 | ctsn = sctp_skb2event(skb)->tsn; | |
1050 | if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map))) | |
1051 | return; | |
1052 | } | |
1053 | ||
b6e1331f VY |
1054 | /* If the user enabled fragment interleave socket option, |
1055 | * multiple associations can enter partial delivery. | |
1056 | * Otherwise, we can only enter partial delivery if the | |
1057 | * socket is not in partial deliver mode. | |
1058 | */ | |
1059 | if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) { | |
1da177e4 LT |
1060 | /* Is partial delivery possible? */ |
1061 | event = sctp_ulpq_retrieve_first(ulpq); | |
1062 | /* Send event to the ULP. */ | |
1063 | if (event) { | |
925b9374 DM |
1064 | struct sk_buff_head temp; |
1065 | ||
1066 | skb_queue_head_init(&temp); | |
1067 | __skb_queue_tail(&temp, sctp_event2skb(event)); | |
013b96ec | 1068 | sctp_ulpq_tail_event(ulpq, &temp); |
d49d91d7 | 1069 | sctp_ulpq_set_pd(ulpq); |
1da177e4 LT |
1070 | return; |
1071 | } | |
1072 | } | |
1073 | } | |
1074 | ||
1075 | /* Renege some packets to make room for an incoming chunk. */ | |
1076 | void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, | |
dd0fc66f | 1077 | gfp_t gfp) |
1da177e4 | 1078 | { |
5c468674 XL |
1079 | struct sctp_association *asoc = ulpq->asoc; |
1080 | __u32 freed = 0; | |
1081 | __u16 needed; | |
1da177e4 | 1082 | |
5c468674 XL |
1083 | needed = ntohs(chunk->chunk_hdr->length) - |
1084 | sizeof(struct sctp_data_chunk); | |
1da177e4 LT |
1085 | |
1086 | if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { | |
1087 | freed = sctp_ulpq_renege_order(ulpq, needed); | |
5c468674 | 1088 | if (freed < needed) |
1da177e4 | 1089 | freed += sctp_ulpq_renege_frags(ulpq, needed - freed); |
1da177e4 LT |
1090 | } |
1091 | /* If able to free enough room, accept this chunk. */ | |
9dde27de XL |
1092 | if (sk_rmem_schedule(asoc->base.sk, chunk->skb, needed) && |
1093 | freed >= needed) { | |
5c468674 | 1094 | int retval = sctp_ulpq_tail_data(ulpq, chunk, gfp); |
d003b41b LR |
1095 | /* |
1096 | * Enter partial delivery if chunk has not been | |
1097 | * delivered; otherwise, drain the reassembly queue. | |
1098 | */ | |
1099 | if (retval <= 0) | |
1100 | sctp_ulpq_partial_delivery(ulpq, gfp); | |
1101 | else if (retval == 1) | |
1102 | sctp_ulpq_reasm_drain(ulpq); | |
1da177e4 LT |
1103 | } |
1104 | ||
3ab224be | 1105 | sk_mem_reclaim(asoc->base.sk); |
1da177e4 LT |
1106 | } |
1107 | ||
1108 | ||
1109 | ||
1110 | /* Notify the application if an association is aborted and in | |
1111 | * partial delivery mode. Send up any pending received messages. | |
1112 | */ | |
dd0fc66f | 1113 | void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) |
1da177e4 LT |
1114 | { |
1115 | struct sctp_ulpevent *ev = NULL; | |
0970f5b3 | 1116 | struct sctp_sock *sp; |
2cc0eeb6 | 1117 | struct sock *sk; |
1da177e4 LT |
1118 | |
1119 | if (!ulpq->pd_mode) | |
1120 | return; | |
1121 | ||
1122 | sk = ulpq->asoc->base.sk; | |
0970f5b3 | 1123 | sp = sctp_sk(sk); |
a1e3a059 | 1124 | if (sctp_ulpevent_type_enabled(ulpq->asoc->subscribe, |
2cc0eeb6 | 1125 | SCTP_PARTIAL_DELIVERY_EVENT)) |
1da177e4 LT |
1126 | ev = sctp_ulpevent_make_pdapi(ulpq->asoc, |
1127 | SCTP_PARTIAL_DELIVERY_ABORTED, | |
65f5e357 | 1128 | 0, 0, 0, gfp); |
1da177e4 LT |
1129 | if (ev) |
1130 | __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); | |
1131 | ||
1132 | /* If there is data waiting, send it up the socket now. */ | |
0970f5b3 MRL |
1133 | if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) { |
1134 | sp->data_ready_signalled = 1; | |
1135 | sk->sk_data_ready(sk); | |
1136 | } | |
1da177e4 | 1137 | } |