blob: 1c1484ed605d490686c8daa87e0a7e595b9fba3c [file] [log] [blame]
Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050011 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * 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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050017 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, write to
25 * the Free Software Foundation, 59 Temple Place - Suite 330,
26 * Boston, MA 02111-1307, USA.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020030 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * Written or modified by:
33 * Jon Grimm <jgrimm@us.ibm.com>
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Sridhar Samudrala <sri@us.ibm.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 */
37
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090038#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/types.h>
40#include <linux/skbuff.h>
41#include <net/sock.h>
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. */
47static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
David S. Miller8728b832005-08-09 19:25:21 -070048 struct sctp_ulpevent *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *,
David S. Miller8728b832005-08-09 19:25:21 -070050 struct sctp_ulpevent *);
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -080051static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53/* 1st Level Abstractions */
54
55/* Initialize a ULP queue from a block of memory. */
56struct 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 return ulpq;
67}
68
69
70/* Flush the reassembly and ordering queues. */
Vlad Yasevich0b58a812007-03-19 17:01:17 -070071void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
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. */
89void sctp_ulpq_free(struct sctp_ulpq *ulpq)
90{
91 sctp_ulpq_flush(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092}
93
94/* Process an incoming DATA chunk. */
95int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
Al Virodd0fc662005-10-07 07:46:04 +010096 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
98 struct sk_buff_head temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 struct sctp_ulpevent *event;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000100 int event_eor = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 /* 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. */
111 if ((event) && (event->msg_flags & MSG_EOR)){
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
David S. Miller8728b832005-08-09 19:25:21 -0700119 /* Send event to the ULP. 'event' is the sctp_ulpevent for
120 * very first SKB on the 'temp' list.
121 */
Lee A. Robertsd003b412013-02-28 04:37:30 +0000122 if (event) {
123 event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 sctp_ulpq_tail_event(ulpq, event);
Lee A. Robertsd003b412013-02-28 04:37:30 +0000125 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Lee A. Robertsd003b412013-02-28 04:37:30 +0000127 return event_eor;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128}
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 */
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700134int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135{
136 struct sctp_sock *sp = sctp_sk(sk);
137
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700138 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;
144 sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue);
145 list = (struct list_head *)&sctp_sk(sk)->pd_lobby;
146 INIT_LIST_HEAD(list);
147 return 1;
148 }
149 } else {
150 /* There are other associations in PD, so we only need to
151 * pull stuff out of the lobby that belongs to the
152 * associations that is exiting PD (all of its notifications
153 * are posted here).
154 */
155 if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
156 struct sk_buff *skb, *tmp;
157 struct sctp_ulpevent *event;
158
159 sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
160 event = sctp_skb2event(skb);
161 if (event->asoc == asoc) {
162 __skb_unlink(skb, &sp->pd_lobby);
163 __skb_queue_tail(&sk->sk_receive_queue,
164 skb);
165 }
166 }
167 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 }
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 return 0;
171}
172
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700173/* Set the pd_mode on the socket and ulpq */
174static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
175{
176 struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
177
178 atomic_inc(&sp->pd_mode);
179 ulpq->pd_mode = 1;
180}
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182/* Clear the pd_mode and restart any pending messages waiting for delivery. */
183static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
184{
185 ulpq->pd_mode = 0;
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800186 sctp_ulpq_reasm_drain(ulpq);
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700187 return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188}
189
David S. Miller8728b832005-08-09 19:25:21 -0700190/* If the SKB of 'event' is on a list, it is the first such member
191 * of that list.
192 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
194{
195 struct sock *sk = ulpq->asoc->base.sk;
David S. Miller8728b832005-08-09 19:25:21 -0700196 struct sk_buff_head *queue, *skb_list;
197 struct sk_buff *skb = sctp_event2skb(event);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 int clear_pd = 0;
199
David S. Miller8728b832005-08-09 19:25:21 -0700200 skb_list = (struct sk_buff_head *) skb->prev;
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 /* If the socket is just going to throw this away, do not
203 * even try to deliver it.
204 */
205 if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN))
206 goto out_free;
207
208 /* Check if the user wishes to receive this event. */
209 if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe))
210 goto out_free;
211
212 /* If we are in partial delivery mode, post to the lobby until
213 * partial delivery is cleared, unless, of course _this_ is
214 * the association the cause of the partial delivery.
215 */
216
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700217 if (atomic_read(&sctp_sk(sk)->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 queue = &sk->sk_receive_queue;
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700219 } else {
220 if (ulpq->pd_mode) {
221 /* If the association is in partial delivery, we
222 * need to finish delivering the partially processed
223 * packet before passing any other data. This is
224 * because we don't truly support stream interleaving.
225 */
226 if ((event->msg_flags & MSG_NOTIFICATION) ||
227 (SCTP_DATA_NOT_FRAG ==
228 (event->msg_flags & SCTP_DATA_FRAG_MASK)))
229 queue = &sctp_sk(sk)->pd_lobby;
230 else {
231 clear_pd = event->msg_flags & MSG_EOR;
232 queue = &sk->sk_receive_queue;
233 }
234 } else {
235 /*
236 * If fragment interleave is enabled, we
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300237 * can queue this to the receive queue instead
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700238 * of the lobby.
239 */
240 if (sctp_sk(sk)->frag_interleave)
241 queue = &sk->sk_receive_queue;
242 else
243 queue = &sctp_sk(sk)->pd_lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 }
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700245 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 /* If we are harvesting multiple skbs they will be
248 * collected on a list.
249 */
David S. Miller8728b832005-08-09 19:25:21 -0700250 if (skb_list)
251 sctp_skb_list_tail(skb_list, queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 else
David S. Miller8728b832005-08-09 19:25:21 -0700253 __skb_queue_tail(queue, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255 /* Did we just complete partial delivery and need to get
256 * rolling again? Move pending data to the receive
257 * queue.
258 */
259 if (clear_pd)
260 sctp_ulpq_clear_pd(ulpq);
261
262 if (queue == &sk->sk_receive_queue)
263 sk->sk_data_ready(sk, 0);
264 return 1;
265
266out_free:
David S. Miller8728b832005-08-09 19:25:21 -0700267 if (skb_list)
268 sctp_queue_purge_ulpevents(skb_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 else
270 sctp_ulpevent_free(event);
David S. Miller8728b832005-08-09 19:25:21 -0700271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 return 0;
273}
274
275/* 2nd Level Abstractions */
276
277/* Helper function to store chunks that need to be reassembled. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500278static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 struct sctp_ulpevent *event)
280{
281 struct sk_buff *pos;
282 struct sctp_ulpevent *cevent;
283 __u32 tsn, ctsn;
284
285 tsn = event->tsn;
286
287 /* See if it belongs at the end. */
288 pos = skb_peek_tail(&ulpq->reasm);
289 if (!pos) {
290 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
291 return;
292 }
293
294 /* Short circuit just dropping it at the end. */
295 cevent = sctp_skb2event(pos);
296 ctsn = cevent->tsn;
297 if (TSN_lt(ctsn, tsn)) {
298 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
299 return;
300 }
301
302 /* Find the right place in this list. We store them by TSN. */
303 skb_queue_walk(&ulpq->reasm, pos) {
304 cevent = sctp_skb2event(pos);
305 ctsn = cevent->tsn;
306
307 if (TSN_lt(tsn, ctsn))
308 break;
309 }
310
311 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700312 __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
314}
315
316/* Helper function to return an event corresponding to the reassembled
317 * datagram.
318 * This routine creates a re-assembled skb given the first and last skb's
319 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
320 * payload was fragmented on the way and ip had to reassemble them.
321 * We add the rest of skb's to the first skb's fraglist.
322 */
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000323static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
324 struct sk_buff_head *queue, struct sk_buff *f_frag,
325 struct sk_buff *l_frag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326{
327 struct sk_buff *pos;
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700328 struct sk_buff *new = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 struct sctp_ulpevent *event;
330 struct sk_buff *pnext, *last;
331 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
332
333 /* Store the pointer to the 2nd skb */
334 if (f_frag == l_frag)
335 pos = NULL;
336 else
337 pos = f_frag->next;
338
339 /* Get the last skb in the f_frag's frag_list if present. */
340 for (last = list; list; last = list, list = list->next);
341
342 /* Add the list of remaining fragments to the first fragments
343 * frag_list.
344 */
345 if (last)
346 last->next = pos;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900347 else {
348 if (skb_cloned(f_frag)) {
349 /* This is a cloned skb, we can't just modify
350 * the frag_list. We need a new skb to do that.
351 * Instead of calling skb_unshare(), we'll do it
352 * ourselves since we need to delay the free.
353 */
354 new = skb_copy(f_frag, GFP_ATOMIC);
355 if (!new)
356 return NULL; /* try again later */
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700357
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900358 sctp_skb_set_owner_r(new, f_frag->sk);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700359
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900360 skb_shinfo(new)->frag_list = pos;
361 } else
362 skb_shinfo(f_frag)->frag_list = pos;
363 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
365 /* Remove the first fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700366 __skb_unlink(f_frag, queue);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700367
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900368 /* if we did unshare, then free the old skb and re-assign */
369 if (new) {
370 kfree_skb(f_frag);
371 f_frag = new;
372 }
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700373
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 while (pos) {
375
376 pnext = pos->next;
377
378 /* Update the len and data_len fields of the first fragment. */
379 f_frag->len += pos->len;
380 f_frag->data_len += pos->len;
381
382 /* Remove the fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700383 __skb_unlink(pos, queue);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 /* Break if we have reached the last fragment. */
386 if (pos == l_frag)
387 break;
388 pos->next = pnext;
389 pos = pnext;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700390 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 event = sctp_skb2event(f_frag);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000393 SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 return event;
396}
397
398
399/* Helper function to check if an incoming chunk has filled up the last
400 * missing fragment in a SCTP datagram and return the corresponding event.
401 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500402static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403{
404 struct sk_buff *pos;
405 struct sctp_ulpevent *cevent;
406 struct sk_buff *first_frag = NULL;
407 __u32 ctsn, next_tsn;
408 struct sctp_ulpevent *retval = NULL;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700409 struct sk_buff *pd_first = NULL;
410 struct sk_buff *pd_last = NULL;
411 size_t pd_len = 0;
412 struct sctp_association *asoc;
413 u32 pd_point;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
415 /* Initialized to 0 just to avoid compiler warning message. Will
416 * never be used with this value. It is referenced only after it
417 * is set when we find the first fragment of a message.
418 */
419 next_tsn = 0;
420
421 /* The chunks are held in the reasm queue sorted by TSN.
422 * Walk through the queue sequentially and look for a sequence of
423 * fragmented chunks that complete a datagram.
424 * 'first_frag' and next_tsn are reset when we find a chunk which
425 * is the first fragment of a datagram. Once these 2 fields are set
426 * we expect to find the remaining middle fragments and the last
427 * fragment in order. If not, first_frag is reset to NULL and we
428 * start the next pass when we find another first fragment.
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700429 *
430 * There is a potential to do partial delivery if user sets
431 * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
432 * to see if can do PD.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 */
434 skb_queue_walk(&ulpq->reasm, pos) {
435 cevent = sctp_skb2event(pos);
436 ctsn = cevent->tsn;
437
438 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
439 case SCTP_DATA_FIRST_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700440 /* If this "FIRST_FRAG" is the first
441 * element in the queue, then count it towards
442 * possible PD.
443 */
444 if (pos == ulpq->reasm.next) {
445 pd_first = pos;
446 pd_last = pos;
447 pd_len = pos->len;
448 } else {
449 pd_first = NULL;
450 pd_last = NULL;
451 pd_len = 0;
452 }
453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 first_frag = pos;
455 next_tsn = ctsn + 1;
456 break;
457
458 case SCTP_DATA_MIDDLE_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700459 if ((first_frag) && (ctsn == next_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 next_tsn++;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700461 if (pd_first) {
462 pd_last = pos;
463 pd_len += pos->len;
464 }
465 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 first_frag = NULL;
467 break;
468
469 case SCTP_DATA_LAST_FRAG:
470 if (first_frag && (ctsn == next_tsn))
471 goto found;
472 else
473 first_frag = NULL;
474 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700475 }
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700476 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700478 asoc = ulpq->asoc;
479 if (pd_first) {
480 /* Make sure we can enter partial deliver.
481 * We can trigger partial delivery only if framgent
482 * interleave is set, or the socket is not already
483 * in partial delivery.
484 */
485 if (!sctp_sk(asoc->base.sk)->frag_interleave &&
486 atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
487 goto done;
488
489 cevent = sctp_skb2event(pd_first);
490 pd_point = sctp_sk(asoc->base.sk)->pd_point;
491 if (pd_point && pd_point <= pd_len) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000492 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
493 &ulpq->reasm,
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700494 pd_first,
495 pd_last);
496 if (retval)
497 sctp_ulpq_set_pd(ulpq);
498 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 }
500done:
501 return retval;
502found:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000503 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
504 &ulpq->reasm, first_frag, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (retval)
506 retval->msg_flags |= MSG_EOR;
507 goto done;
508}
509
510/* Retrieve the next set of fragments of a partial message. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500511static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512{
513 struct sk_buff *pos, *last_frag, *first_frag;
514 struct sctp_ulpevent *cevent;
515 __u32 ctsn, next_tsn;
516 int is_last;
517 struct sctp_ulpevent *retval;
518
519 /* The chunks are held in the reasm queue sorted by TSN.
520 * Walk through the queue sequentially and look for the first
521 * sequence of fragmented chunks.
522 */
523
524 if (skb_queue_empty(&ulpq->reasm))
525 return NULL;
526
527 last_frag = first_frag = NULL;
528 retval = NULL;
529 next_tsn = 0;
530 is_last = 0;
531
532 skb_queue_walk(&ulpq->reasm, pos) {
533 cevent = sctp_skb2event(pos);
534 ctsn = cevent->tsn;
535
536 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
Lee A. Robertsd003b412013-02-28 04:37:30 +0000537 case SCTP_DATA_FIRST_FRAG:
538 if (!first_frag)
539 return NULL;
540 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 case SCTP_DATA_MIDDLE_FRAG:
542 if (!first_frag) {
543 first_frag = pos;
544 next_tsn = ctsn + 1;
545 last_frag = pos;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000546 } else if (next_tsn == ctsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 next_tsn++;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000548 last_frag = pos;
549 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 goto done;
551 break;
552 case SCTP_DATA_LAST_FRAG:
553 if (!first_frag)
554 first_frag = pos;
555 else if (ctsn != next_tsn)
556 goto done;
557 last_frag = pos;
558 is_last = 1;
559 goto done;
560 default:
561 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700562 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
564
565 /* We have the reassembled event. There is no need to look
566 * further.
567 */
568done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000569 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
570 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 if (retval && is_last)
572 retval->msg_flags |= MSG_EOR;
573
574 return retval;
575}
576
577
578/* Helper function to reassemble chunks. Hold chunks on the reasm queue that
579 * need reassembling.
580 */
581static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
582 struct sctp_ulpevent *event)
583{
584 struct sctp_ulpevent *retval = NULL;
585
586 /* Check if this is part of a fragmented message. */
587 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
588 event->msg_flags |= MSG_EOR;
589 return event;
590 }
591
592 sctp_ulpq_store_reasm(ulpq, event);
593 if (!ulpq->pd_mode)
594 retval = sctp_ulpq_retrieve_reassembled(ulpq);
595 else {
596 __u32 ctsn, ctsnap;
597
598 /* Do not even bother unless this is the next tsn to
599 * be delivered.
600 */
601 ctsn = event->tsn;
602 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
603 if (TSN_lte(ctsn, ctsnap))
604 retval = sctp_ulpq_retrieve_partial(ulpq);
605 }
606
607 return retval;
608}
609
610/* Retrieve the first part (sequential fragments) for partial delivery. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500611static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612{
613 struct sk_buff *pos, *last_frag, *first_frag;
614 struct sctp_ulpevent *cevent;
615 __u32 ctsn, next_tsn;
616 struct sctp_ulpevent *retval;
617
618 /* The chunks are held in the reasm queue sorted by TSN.
619 * Walk through the queue sequentially and look for a sequence of
620 * fragmented chunks that start a datagram.
621 */
622
623 if (skb_queue_empty(&ulpq->reasm))
624 return NULL;
625
626 last_frag = first_frag = NULL;
627 retval = NULL;
628 next_tsn = 0;
629
630 skb_queue_walk(&ulpq->reasm, pos) {
631 cevent = sctp_skb2event(pos);
632 ctsn = cevent->tsn;
633
634 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
635 case SCTP_DATA_FIRST_FRAG:
636 if (!first_frag) {
637 first_frag = pos;
638 next_tsn = ctsn + 1;
639 last_frag = pos;
640 } else
641 goto done;
642 break;
643
644 case SCTP_DATA_MIDDLE_FRAG:
645 if (!first_frag)
646 return NULL;
647 if (ctsn == next_tsn) {
648 next_tsn++;
649 last_frag = pos;
650 } else
651 goto done;
652 break;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000653
654 case SCTP_DATA_LAST_FRAG:
655 if (!first_frag)
656 return NULL;
657 else
658 goto done;
659 break;
660
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 default:
662 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700663 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 }
665
666 /* We have the reassembled event. There is no need to look
667 * further.
668 */
669done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000670 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
671 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 return retval;
673}
674
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400675/*
676 * Flush out stale fragments from the reassembly queue when processing
677 * a Forward TSN.
678 *
679 * RFC 3758, Section 3.6
680 *
681 * After receiving and processing a FORWARD TSN, the data receiver MUST
682 * take cautions in updating its re-assembly queue. The receiver MUST
683 * remove any partially reassembled message, which is still missing one
684 * or more TSNs earlier than or equal to the new cumulative TSN point.
685 * In the event that the receiver has invoked the partial delivery API,
686 * a notification SHOULD also be generated to inform the upper layer API
687 * that the message being partially delivered will NOT be completed.
688 */
689void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
690{
691 struct sk_buff *pos, *tmp;
692 struct sctp_ulpevent *event;
693 __u32 tsn;
694
695 if (skb_queue_empty(&ulpq->reasm))
696 return;
697
698 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
699 event = sctp_skb2event(pos);
700 tsn = event->tsn;
701
702 /* Since the entire message must be abandoned by the
703 * sender (item A3 in Section 3.5, RFC 3758), we can
704 * free all fragments on the list that are less then
705 * or equal to ctsn_point
706 */
707 if (TSN_lte(tsn, fwd_tsn)) {
708 __skb_unlink(pos, &ulpq->reasm);
709 sctp_ulpevent_free(event);
710 } else
711 break;
712 }
713}
714
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800715/*
716 * Drain the reassembly queue. If we just cleared parted delivery, it
717 * is possible that the reassembly queue will contain already reassembled
718 * messages. Retrieve any such messages and give them to the user.
719 */
720static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
721{
722 struct sctp_ulpevent *event = NULL;
723 struct sk_buff_head temp;
724
725 if (skb_queue_empty(&ulpq->reasm))
726 return;
727
728 while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
729 /* Do ordering if needed. */
730 if ((event) && (event->msg_flags & MSG_EOR)){
731 skb_queue_head_init(&temp);
732 __skb_queue_tail(&temp, sctp_event2skb(event));
733
734 event = sctp_ulpq_order(ulpq, event);
735 }
736
737 /* Send event to the ULP. 'event' is the
738 * sctp_ulpevent for very first SKB on the temp' list.
739 */
740 if (event)
741 sctp_ulpq_tail_event(ulpq, event);
742 }
743}
744
745
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746/* Helper function to gather skbs that have possibly become
747 * ordered by an an incoming chunk.
748 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500749static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 struct sctp_ulpevent *event)
751{
David S. Miller8728b832005-08-09 19:25:21 -0700752 struct sk_buff_head *event_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 struct sk_buff *pos, *tmp;
754 struct sctp_ulpevent *cevent;
755 struct sctp_stream *in;
Hagen Paul Pfeiferefea2c62011-03-04 11:45:05 +0000756 __u16 sid, csid, cssn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757
758 sid = event->stream;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 in = &ulpq->asoc->ssnmap->in;
760
David S. Miller8728b832005-08-09 19:25:21 -0700761 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
762
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 /* We are holding the chunks by stream, by SSN. */
764 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
765 cevent = (struct sctp_ulpevent *) pos->cb;
766 csid = cevent->stream;
767 cssn = cevent->ssn;
768
769 /* Have we gone too far? */
770 if (csid > sid)
771 break;
772
773 /* Have we not gone far enough? */
774 if (csid < sid)
775 continue;
776
777 if (cssn != sctp_ssn_peek(in, sid))
778 break;
779
780 /* Found it, so mark in the ssnmap. */
781 sctp_ssn_next(in, sid);
782
David S. Miller8728b832005-08-09 19:25:21 -0700783 __skb_unlink(pos, &ulpq->lobby);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784
785 /* Attach all gathered skbs to the event. */
David S. Miller8728b832005-08-09 19:25:21 -0700786 __skb_queue_tail(event_list, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 }
788}
789
790/* Helper function to store chunks needing ordering. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500791static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 struct sctp_ulpevent *event)
793{
794 struct sk_buff *pos;
795 struct sctp_ulpevent *cevent;
796 __u16 sid, csid;
797 __u16 ssn, cssn;
798
799 pos = skb_peek_tail(&ulpq->lobby);
800 if (!pos) {
801 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
802 return;
803 }
804
805 sid = event->stream;
806 ssn = event->ssn;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900807
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 cevent = (struct sctp_ulpevent *) pos->cb;
809 csid = cevent->stream;
810 cssn = cevent->ssn;
811 if (sid > csid) {
812 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
813 return;
814 }
815
816 if ((sid == csid) && SSN_lt(cssn, ssn)) {
817 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
818 return;
819 }
820
821 /* Find the right place in this list. We store them by
822 * stream ID and then by SSN.
823 */
824 skb_queue_walk(&ulpq->lobby, pos) {
825 cevent = (struct sctp_ulpevent *) pos->cb;
826 csid = cevent->stream;
827 cssn = cevent->ssn;
828
829 if (csid > sid)
830 break;
831 if (csid == sid && SSN_lt(ssn, cssn))
832 break;
833 }
834
835
836 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700837 __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838}
839
840static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
David S. Miller8728b832005-08-09 19:25:21 -0700841 struct sctp_ulpevent *event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842{
843 __u16 sid, ssn;
844 struct sctp_stream *in;
845
846 /* Check if this message needs ordering. */
847 if (SCTP_DATA_UNORDERED & event->msg_flags)
848 return event;
849
850 /* Note: The stream ID must be verified before this routine. */
851 sid = event->stream;
852 ssn = event->ssn;
853 in = &ulpq->asoc->ssnmap->in;
854
855 /* Is this the expected SSN for this stream ID? */
856 if (ssn != sctp_ssn_peek(in, sid)) {
857 /* We've received something out of order, so find where it
858 * needs to be placed. We order by stream and then by SSN.
859 */
860 sctp_ulpq_store_ordered(ulpq, event);
861 return NULL;
862 }
863
864 /* Mark that the next chunk has been found. */
865 sctp_ssn_next(in, sid);
866
867 /* Go find any other chunks that were waiting for
868 * ordering.
869 */
870 sctp_ulpq_retrieve_ordered(ulpq, event);
871
872 return event;
873}
874
875/* Helper function to gather skbs that have possibly become
876 * ordered by forward tsn skipping their dependencies.
877 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500878static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879{
880 struct sk_buff *pos, *tmp;
881 struct sctp_ulpevent *cevent;
David S. Miller8728b832005-08-09 19:25:21 -0700882 struct sctp_ulpevent *event;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 struct sctp_stream *in;
884 struct sk_buff_head temp;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500885 struct sk_buff_head *lobby = &ulpq->lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 __u16 csid, cssn;
887
888 in = &ulpq->asoc->ssnmap->in;
889
890 /* We are holding the chunks by stream, by SSN. */
David S. Miller8728b832005-08-09 19:25:21 -0700891 skb_queue_head_init(&temp);
892 event = NULL;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500893 sctp_skb_for_each(pos, lobby, tmp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 cevent = (struct sctp_ulpevent *) pos->cb;
895 csid = cevent->stream;
896 cssn = cevent->ssn;
897
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400898 /* Have we gone too far? */
899 if (csid > sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 break;
901
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400902 /* Have we not gone far enough? */
903 if (csid < sid)
904 continue;
905
906 /* see if this ssn has been marked by skipping */
Vlad Yasevichc068be52008-01-15 11:41:56 -0500907 if (!SSN_lt(cssn, sctp_ssn_peek(in, csid)))
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400908 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
Vlad Yasevichc068be52008-01-15 11:41:56 -0500910 __skb_unlink(pos, lobby);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400911 if (!event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 /* Create a temporary list to collect chunks on. */
913 event = sctp_skb2event(pos);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400914
915 /* Attach all gathered skbs to the event. */
916 __skb_queue_tail(&temp, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 }
918
Vlad Yasevichc068be52008-01-15 11:41:56 -0500919 /* If we didn't reap any data, see if the next expected SSN
920 * is next on the queue and if so, use that.
921 */
922 if (event == NULL && pos != (struct sk_buff *)lobby) {
923 cevent = (struct sctp_ulpevent *) pos->cb;
924 csid = cevent->stream;
925 cssn = cevent->ssn;
926
927 if (csid == sid && cssn == sctp_ssn_peek(in, csid)) {
928 sctp_ssn_next(in, csid);
929 __skb_unlink(pos, lobby);
930 __skb_queue_tail(&temp, pos);
931 event = sctp_skb2event(pos);
932 }
933 }
934
David S. Miller8728b832005-08-09 19:25:21 -0700935 /* Send event to the ULP. 'event' is the sctp_ulpevent for
936 * very first SKB on the 'temp' list.
937 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400938 if (event) {
939 /* see if we have more ordered that we can deliver */
940 sctp_ulpq_retrieve_ordered(ulpq, event);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400942 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943}
944
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400945/* Skip over an SSN. This is used during the processing of
946 * Forwared TSN chunk to skip over the abandoned ordered data
947 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
949{
950 struct sctp_stream *in;
951
952 /* Note: The stream ID must be verified before this routine. */
953 in = &ulpq->asoc->ssnmap->in;
954
955 /* Is this an old SSN? If so ignore. */
956 if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
957 return;
958
959 /* Mark that we are no longer expecting this SSN or lower. */
960 sctp_ssn_skip(in, sid, ssn);
961
962 /* Go find any other chunks that were waiting for
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900963 * ordering and deliver them if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400965 sctp_ulpq_reap_ordered(ulpq, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966}
967
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -0700968static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq,
969 struct sk_buff_head *list, __u16 needed)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970{
971 __u16 freed = 0;
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000972 __u32 tsn, last_tsn;
973 struct sk_buff *skb, *flist, *last;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 struct sctp_ulpevent *event;
975 struct sctp_tsnmap *tsnmap;
976
977 tsnmap = &ulpq->asoc->peer.tsn_map;
978
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000979 while ((skb = skb_peek_tail(list)) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 event = sctp_skb2event(skb);
981 tsn = event->tsn;
982
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000983 /* Don't renege below the Cumulative TSN ACK Point. */
984 if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap)))
985 break;
986
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000987 /* Events in ordering queue may have multiple fragments
988 * corresponding to additional TSNs. Sum the total
989 * freed space; find the last TSN.
990 */
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000991 freed += skb_headlen(skb);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000992 flist = skb_shinfo(skb)->frag_list;
993 for (last = flist; flist; flist = flist->next) {
994 last = flist;
995 freed += skb_headlen(last);
996 }
997 if (last)
998 last_tsn = sctp_skb2event(last)->tsn;
999 else
1000 last_tsn = tsn;
1001
1002 /* Unlink the event, then renege all applicable TSNs. */
1003 __skb_unlink(skb, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 sctp_ulpevent_free(event);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +00001005 while (TSN_lte(tsn, last_tsn)) {
1006 sctp_tsnmap_renege(tsnmap, tsn);
1007 tsn++;
1008 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 if (freed >= needed)
1010 return freed;
1011 }
1012
1013 return freed;
1014}
1015
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001016/* Renege 'needed' bytes from the ordering queue. */
1017static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
1018{
1019 return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
1020}
1021
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022/* Renege 'needed' bytes from the reassembly queue. */
1023static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
1024{
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001025 return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026}
1027
1028/* Partial deliver the first message as there is pressure on rwnd. */
1029void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
Al Virodd0fc662005-10-07 07:46:04 +01001030 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031{
1032 struct sctp_ulpevent *event;
1033 struct sctp_association *asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001034 struct sctp_sock *sp;
Lee A. Robertsd003b412013-02-28 04:37:30 +00001035 __u32 ctsn;
1036 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037
1038 asoc = ulpq->asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001039 sp = sctp_sk(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001041 /* If the association is already in Partial Delivery mode
Lee A. Robertsd003b412013-02-28 04:37:30 +00001042 * we have nothing to do.
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001043 */
1044 if (ulpq->pd_mode)
1045 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046
Lee A. Robertsd003b412013-02-28 04:37:30 +00001047 /* Data must be at or below the Cumulative TSN ACK Point to
1048 * start partial delivery.
1049 */
1050 skb = skb_peek(&asoc->ulpq.reasm);
1051 if (skb != NULL) {
1052 ctsn = sctp_skb2event(skb)->tsn;
1053 if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)))
1054 return;
1055 }
1056
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001057 /* If the user enabled fragment interleave socket option,
1058 * multiple associations can enter partial delivery.
1059 * Otherwise, we can only enter partial delivery if the
1060 * socket is not in partial deliver mode.
1061 */
1062 if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 /* Is partial delivery possible? */
1064 event = sctp_ulpq_retrieve_first(ulpq);
1065 /* Send event to the ULP. */
1066 if (event) {
1067 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichd49d91d2007-03-23 11:32:00 -07001068 sctp_ulpq_set_pd(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 return;
1070 }
1071 }
1072}
1073
1074/* Renege some packets to make room for an incoming chunk. */
1075void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
Al Virodd0fc662005-10-07 07:46:04 +01001076 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077{
1078 struct sctp_association *asoc;
1079 __u16 needed, freed;
1080
1081 asoc = ulpq->asoc;
1082
1083 if (chunk) {
1084 needed = ntohs(chunk->chunk_hdr->length);
1085 needed -= sizeof(sctp_data_chunk_t);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001086 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 needed = SCTP_DEFAULT_MAXWINDOW;
1088
1089 freed = 0;
1090
1091 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
1092 freed = sctp_ulpq_renege_order(ulpq, needed);
1093 if (freed < needed) {
1094 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
1095 }
1096 }
1097 /* If able to free enough room, accept this chunk. */
1098 if (chunk && (freed >= needed)) {
Lee A. Robertsd003b412013-02-28 04:37:30 +00001099 int retval;
1100 retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
1101 /*
1102 * Enter partial delivery if chunk has not been
1103 * delivered; otherwise, drain the reassembly queue.
1104 */
1105 if (retval <= 0)
1106 sctp_ulpq_partial_delivery(ulpq, gfp);
1107 else if (retval == 1)
1108 sctp_ulpq_reasm_drain(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 }
1110
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001111 sk_mem_reclaim(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112}
1113
1114
1115
1116/* Notify the application if an association is aborted and in
1117 * partial delivery mode. Send up any pending received messages.
1118 */
Al Virodd0fc662005-10-07 07:46:04 +01001119void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120{
1121 struct sctp_ulpevent *ev = NULL;
1122 struct sock *sk;
1123
1124 if (!ulpq->pd_mode)
1125 return;
1126
1127 sk = ulpq->asoc->base.sk;
1128 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
1129 &sctp_sk(sk)->subscribe))
1130 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
1131 SCTP_PARTIAL_DELIVERY_ABORTED,
1132 gfp);
1133 if (ev)
1134 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1135
1136 /* If there is data waiting, send it up the socket now. */
1137 if (sctp_ulpq_clear_pd(ulpq) || ev)
1138 sk->sk_data_ready(sk, 0);
1139}