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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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080024 * along with GNU CC; see the file COPYING. If not, see
25 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020029 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 */
36
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090037#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/types.h>
39#include <linux/skbuff.h>
40#include <net/sock.h>
Neil Horman8465a5f2014-04-17 15:26:51 -040041#include <net/busy_poll.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <net/sctp/structs.h>
43#include <net/sctp/sctp.h>
44#include <net/sctp/sm.h>
45
46/* Forward declarations for internal helpers. */
wangweidong26ac8e52013-12-23 12:16:51 +080047static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
David S. Miller8728b832005-08-09 19:25:21 -070048 struct sctp_ulpevent *);
wangweidong26ac8e52013-12-23 12:16:51 +080049static 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. */
wangweidongcb3f8372013-12-23 12:16:50 +0800111 if ((event) && (event->msg_flags & MSG_EOR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 /* 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)) {
Marcelo Ricardo Leitner311b2172016-04-13 19:12:29 -0300143 skb_queue_splice_tail_init(&sp->pd_lobby,
144 &sk->sk_receive_queue);
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700145 return 1;
146 }
147 } else {
148 /* There are other associations in PD, so we only need to
149 * pull stuff out of the lobby that belongs to the
150 * associations that is exiting PD (all of its notifications
151 * are posted here).
152 */
153 if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
154 struct sk_buff *skb, *tmp;
155 struct sctp_ulpevent *event;
156
157 sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
158 event = sctp_skb2event(skb);
159 if (event->asoc == asoc) {
160 __skb_unlink(skb, &sp->pd_lobby);
161 __skb_queue_tail(&sk->sk_receive_queue,
162 skb);
163 }
164 }
165 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 }
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 return 0;
169}
170
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700171/* Set the pd_mode on the socket and ulpq */
172static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
173{
174 struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
175
176 atomic_inc(&sp->pd_mode);
177 ulpq->pd_mode = 1;
178}
179
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180/* Clear the pd_mode and restart any pending messages waiting for delivery. */
181static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
182{
183 ulpq->pd_mode = 0;
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800184 sctp_ulpq_reasm_drain(ulpq);
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700185 return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
David S. Miller8728b832005-08-09 19:25:21 -0700188/* If the SKB of 'event' is on a list, it is the first such member
189 * of that list.
190 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
192{
193 struct sock *sk = ulpq->asoc->base.sk;
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300194 struct sctp_sock *sp = sctp_sk(sk);
David S. Miller8728b832005-08-09 19:25:21 -0700195 struct sk_buff_head *queue, *skb_list;
196 struct sk_buff *skb = sctp_event2skb(event);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 int clear_pd = 0;
198
David S. Miller8728b832005-08-09 19:25:21 -0700199 skb_list = (struct sk_buff_head *) skb->prev;
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 /* If the socket is just going to throw this away, do not
202 * even try to deliver it.
203 */
Xin Longa0fc6842016-07-30 14:09:09 +0800204 if (sk->sk_shutdown & RCV_SHUTDOWN &&
205 (sk->sk_shutdown & SEND_SHUTDOWN ||
206 !sctp_ulpevent_is_notification(event)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 goto out_free;
208
Eric Dumazet2c8c56e2014-11-11 05:54:28 -0800209 if (!sctp_ulpevent_is_notification(event)) {
Neil Horman8465a5f2014-04-17 15:26:51 -0400210 sk_mark_napi_id(sk, skb);
Eric Dumazet2c8c56e2014-11-11 05:54:28 -0800211 sk_incoming_cpu_update(sk);
212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 /* Check if the user wishes to receive this event. */
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300214 if (!sctp_ulpevent_is_enabled(event, &sp->subscribe))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 goto out_free;
216
217 /* If we are in partial delivery mode, post to the lobby until
218 * partial delivery is cleared, unless, of course _this_ is
219 * the association the cause of the partial delivery.
220 */
221
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300222 if (atomic_read(&sp->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 queue = &sk->sk_receive_queue;
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700224 } else {
225 if (ulpq->pd_mode) {
226 /* If the association is in partial delivery, we
227 * need to finish delivering the partially processed
228 * packet before passing any other data. This is
229 * because we don't truly support stream interleaving.
230 */
231 if ((event->msg_flags & MSG_NOTIFICATION) ||
232 (SCTP_DATA_NOT_FRAG ==
233 (event->msg_flags & SCTP_DATA_FRAG_MASK)))
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300234 queue = &sp->pd_lobby;
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700235 else {
236 clear_pd = event->msg_flags & MSG_EOR;
237 queue = &sk->sk_receive_queue;
238 }
239 } else {
240 /*
241 * If fragment interleave is enabled, we
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300242 * can queue this to the receive queue instead
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700243 * of the lobby.
244 */
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300245 if (sp->frag_interleave)
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700246 queue = &sk->sk_receive_queue;
247 else
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300248 queue = &sp->pd_lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 }
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 /* If we are harvesting multiple skbs they will be
253 * collected on a list.
254 */
David S. Miller8728b832005-08-09 19:25:21 -0700255 if (skb_list)
Marcelo Ricardo Leitner311b2172016-04-13 19:12:29 -0300256 skb_queue_splice_tail_init(skb_list, queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 else
David S. Miller8728b832005-08-09 19:25:21 -0700258 __skb_queue_tail(queue, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
260 /* Did we just complete partial delivery and need to get
261 * rolling again? Move pending data to the receive
262 * queue.
263 */
264 if (clear_pd)
265 sctp_ulpq_clear_pd(ulpq);
266
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -0300267 if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) {
268 sp->data_ready_signalled = 1;
269 sk->sk_data_ready(sk);
270 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 return 1;
272
273out_free:
David S. Miller8728b832005-08-09 19:25:21 -0700274 if (skb_list)
275 sctp_queue_purge_ulpevents(skb_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 else
277 sctp_ulpevent_free(event);
David S. Miller8728b832005-08-09 19:25:21 -0700278
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return 0;
280}
281
282/* 2nd Level Abstractions */
283
284/* Helper function to store chunks that need to be reassembled. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500285static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 struct sctp_ulpevent *event)
287{
288 struct sk_buff *pos;
289 struct sctp_ulpevent *cevent;
290 __u32 tsn, ctsn;
291
292 tsn = event->tsn;
293
294 /* See if it belongs at the end. */
295 pos = skb_peek_tail(&ulpq->reasm);
296 if (!pos) {
297 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
298 return;
299 }
300
301 /* Short circuit just dropping it at the end. */
302 cevent = sctp_skb2event(pos);
303 ctsn = cevent->tsn;
304 if (TSN_lt(ctsn, tsn)) {
305 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
306 return;
307 }
308
309 /* Find the right place in this list. We store them by TSN. */
310 skb_queue_walk(&ulpq->reasm, pos) {
311 cevent = sctp_skb2event(pos);
312 ctsn = cevent->tsn;
313
314 if (TSN_lt(tsn, ctsn))
315 break;
316 }
317
318 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700319 __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
321}
322
323/* Helper function to return an event corresponding to the reassembled
324 * datagram.
325 * This routine creates a re-assembled skb given the first and last skb's
326 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
327 * payload was fragmented on the way and ip had to reassemble them.
328 * We add the rest of skb's to the first skb's fraglist.
329 */
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000330static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
331 struct sk_buff_head *queue, struct sk_buff *f_frag,
332 struct sk_buff *l_frag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333{
334 struct sk_buff *pos;
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700335 struct sk_buff *new = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 struct sctp_ulpevent *event;
337 struct sk_buff *pnext, *last;
338 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
339
340 /* Store the pointer to the 2nd skb */
341 if (f_frag == l_frag)
342 pos = NULL;
343 else
344 pos = f_frag->next;
345
346 /* Get the last skb in the f_frag's frag_list if present. */
wangweidong8d726512013-12-23 12:16:53 +0800347 for (last = list; list; last = list, list = list->next)
348 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
350 /* Add the list of remaining fragments to the first fragments
351 * frag_list.
352 */
353 if (last)
354 last->next = pos;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900355 else {
356 if (skb_cloned(f_frag)) {
357 /* This is a cloned skb, we can't just modify
358 * the frag_list. We need a new skb to do that.
359 * Instead of calling skb_unshare(), we'll do it
360 * ourselves since we need to delay the free.
361 */
362 new = skb_copy(f_frag, GFP_ATOMIC);
363 if (!new)
364 return NULL; /* try again later */
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700365
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900366 sctp_skb_set_owner_r(new, f_frag->sk);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700367
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900368 skb_shinfo(new)->frag_list = pos;
369 } else
370 skb_shinfo(f_frag)->frag_list = pos;
371 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373 /* Remove the first fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700374 __skb_unlink(f_frag, queue);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700375
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900376 /* if we did unshare, then free the old skb and re-assign */
377 if (new) {
378 kfree_skb(f_frag);
379 f_frag = new;
380 }
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700381
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 while (pos) {
383
384 pnext = pos->next;
385
386 /* Update the len and data_len fields of the first fragment. */
387 f_frag->len += pos->len;
388 f_frag->data_len += pos->len;
389
390 /* Remove the fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700391 __skb_unlink(pos, queue);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 /* Break if we have reached the last fragment. */
394 if (pos == l_frag)
395 break;
396 pos->next = pnext;
397 pos = pnext;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700398 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 event = sctp_skb2event(f_frag);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000401 SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402
403 return event;
404}
405
406
407/* Helper function to check if an incoming chunk has filled up the last
408 * missing fragment in a SCTP datagram and return the corresponding event.
409 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500410static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411{
412 struct sk_buff *pos;
413 struct sctp_ulpevent *cevent;
414 struct sk_buff *first_frag = NULL;
415 __u32 ctsn, next_tsn;
416 struct sctp_ulpevent *retval = NULL;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700417 struct sk_buff *pd_first = NULL;
418 struct sk_buff *pd_last = NULL;
419 size_t pd_len = 0;
420 struct sctp_association *asoc;
421 u32 pd_point;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
423 /* Initialized to 0 just to avoid compiler warning message. Will
424 * never be used with this value. It is referenced only after it
425 * is set when we find the first fragment of a message.
426 */
427 next_tsn = 0;
428
429 /* The chunks are held in the reasm queue sorted by TSN.
430 * Walk through the queue sequentially and look for a sequence of
431 * fragmented chunks that complete a datagram.
432 * 'first_frag' and next_tsn are reset when we find a chunk which
433 * is the first fragment of a datagram. Once these 2 fields are set
434 * we expect to find the remaining middle fragments and the last
435 * fragment in order. If not, first_frag is reset to NULL and we
436 * start the next pass when we find another first fragment.
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700437 *
438 * There is a potential to do partial delivery if user sets
439 * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
440 * to see if can do PD.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 */
442 skb_queue_walk(&ulpq->reasm, pos) {
443 cevent = sctp_skb2event(pos);
444 ctsn = cevent->tsn;
445
446 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
447 case SCTP_DATA_FIRST_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700448 /* If this "FIRST_FRAG" is the first
449 * element in the queue, then count it towards
450 * possible PD.
451 */
452 if (pos == ulpq->reasm.next) {
453 pd_first = pos;
454 pd_last = pos;
455 pd_len = pos->len;
456 } else {
457 pd_first = NULL;
458 pd_last = NULL;
459 pd_len = 0;
460 }
461
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 first_frag = pos;
463 next_tsn = ctsn + 1;
464 break;
465
466 case SCTP_DATA_MIDDLE_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700467 if ((first_frag) && (ctsn == next_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 next_tsn++;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700469 if (pd_first) {
470 pd_last = pos;
471 pd_len += pos->len;
472 }
473 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 first_frag = NULL;
475 break;
476
477 case SCTP_DATA_LAST_FRAG:
478 if (first_frag && (ctsn == next_tsn))
479 goto found;
480 else
481 first_frag = NULL;
482 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700483 }
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700484 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700486 asoc = ulpq->asoc;
487 if (pd_first) {
488 /* Make sure we can enter partial deliver.
489 * We can trigger partial delivery only if framgent
490 * interleave is set, or the socket is not already
491 * in partial delivery.
492 */
493 if (!sctp_sk(asoc->base.sk)->frag_interleave &&
494 atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
495 goto done;
496
497 cevent = sctp_skb2event(pd_first);
498 pd_point = sctp_sk(asoc->base.sk)->pd_point;
499 if (pd_point && pd_point <= pd_len) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000500 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
501 &ulpq->reasm,
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700502 pd_first,
503 pd_last);
504 if (retval)
505 sctp_ulpq_set_pd(ulpq);
506 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 }
508done:
509 return retval;
510found:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000511 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
512 &ulpq->reasm, first_frag, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 if (retval)
514 retval->msg_flags |= MSG_EOR;
515 goto done;
516}
517
518/* Retrieve the next set of fragments of a partial message. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500519static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520{
521 struct sk_buff *pos, *last_frag, *first_frag;
522 struct sctp_ulpevent *cevent;
523 __u32 ctsn, next_tsn;
524 int is_last;
525 struct sctp_ulpevent *retval;
526
527 /* The chunks are held in the reasm queue sorted by TSN.
528 * Walk through the queue sequentially and look for the first
529 * sequence of fragmented chunks.
530 */
531
532 if (skb_queue_empty(&ulpq->reasm))
533 return NULL;
534
535 last_frag = first_frag = NULL;
536 retval = NULL;
537 next_tsn = 0;
538 is_last = 0;
539
540 skb_queue_walk(&ulpq->reasm, pos) {
541 cevent = sctp_skb2event(pos);
542 ctsn = cevent->tsn;
543
544 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
Lee A. Robertsd003b412013-02-28 04:37:30 +0000545 case SCTP_DATA_FIRST_FRAG:
546 if (!first_frag)
547 return NULL;
548 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 case SCTP_DATA_MIDDLE_FRAG:
550 if (!first_frag) {
551 first_frag = pos;
552 next_tsn = ctsn + 1;
553 last_frag = pos;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000554 } else if (next_tsn == ctsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 next_tsn++;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000556 last_frag = pos;
557 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 goto done;
559 break;
560 case SCTP_DATA_LAST_FRAG:
561 if (!first_frag)
562 first_frag = pos;
563 else if (ctsn != next_tsn)
564 goto done;
565 last_frag = pos;
566 is_last = 1;
567 goto done;
568 default:
569 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700570 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 }
572
573 /* We have the reassembled event. There is no need to look
574 * further.
575 */
576done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000577 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
578 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 if (retval && is_last)
580 retval->msg_flags |= MSG_EOR;
581
582 return retval;
583}
584
585
586/* Helper function to reassemble chunks. Hold chunks on the reasm queue that
587 * need reassembling.
588 */
589static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
590 struct sctp_ulpevent *event)
591{
592 struct sctp_ulpevent *retval = NULL;
593
594 /* Check if this is part of a fragmented message. */
595 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
596 event->msg_flags |= MSG_EOR;
597 return event;
598 }
599
600 sctp_ulpq_store_reasm(ulpq, event);
601 if (!ulpq->pd_mode)
602 retval = sctp_ulpq_retrieve_reassembled(ulpq);
603 else {
604 __u32 ctsn, ctsnap;
605
606 /* Do not even bother unless this is the next tsn to
607 * be delivered.
608 */
609 ctsn = event->tsn;
610 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
611 if (TSN_lte(ctsn, ctsnap))
612 retval = sctp_ulpq_retrieve_partial(ulpq);
613 }
614
615 return retval;
616}
617
618/* Retrieve the first part (sequential fragments) for partial delivery. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500619static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620{
621 struct sk_buff *pos, *last_frag, *first_frag;
622 struct sctp_ulpevent *cevent;
623 __u32 ctsn, next_tsn;
624 struct sctp_ulpevent *retval;
625
626 /* The chunks are held in the reasm queue sorted by TSN.
627 * Walk through the queue sequentially and look for a sequence of
628 * fragmented chunks that start a datagram.
629 */
630
631 if (skb_queue_empty(&ulpq->reasm))
632 return NULL;
633
634 last_frag = first_frag = NULL;
635 retval = NULL;
636 next_tsn = 0;
637
638 skb_queue_walk(&ulpq->reasm, pos) {
639 cevent = sctp_skb2event(pos);
640 ctsn = cevent->tsn;
641
642 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
643 case SCTP_DATA_FIRST_FRAG:
644 if (!first_frag) {
645 first_frag = pos;
646 next_tsn = ctsn + 1;
647 last_frag = pos;
648 } else
649 goto done;
650 break;
651
652 case SCTP_DATA_MIDDLE_FRAG:
653 if (!first_frag)
654 return NULL;
655 if (ctsn == next_tsn) {
656 next_tsn++;
657 last_frag = pos;
658 } else
659 goto done;
660 break;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000661
662 case SCTP_DATA_LAST_FRAG:
663 if (!first_frag)
664 return NULL;
665 else
666 goto done;
667 break;
668
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 default:
670 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700671 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 }
673
674 /* We have the reassembled event. There is no need to look
675 * further.
676 */
677done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000678 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
679 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 return retval;
681}
682
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400683/*
684 * Flush out stale fragments from the reassembly queue when processing
685 * a Forward TSN.
686 *
687 * RFC 3758, Section 3.6
688 *
689 * After receiving and processing a FORWARD TSN, the data receiver MUST
690 * take cautions in updating its re-assembly queue. The receiver MUST
691 * remove any partially reassembled message, which is still missing one
692 * or more TSNs earlier than or equal to the new cumulative TSN point.
693 * In the event that the receiver has invoked the partial delivery API,
694 * a notification SHOULD also be generated to inform the upper layer API
695 * that the message being partially delivered will NOT be completed.
696 */
697void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
698{
699 struct sk_buff *pos, *tmp;
700 struct sctp_ulpevent *event;
701 __u32 tsn;
702
703 if (skb_queue_empty(&ulpq->reasm))
704 return;
705
706 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
707 event = sctp_skb2event(pos);
708 tsn = event->tsn;
709
710 /* Since the entire message must be abandoned by the
711 * sender (item A3 in Section 3.5, RFC 3758), we can
712 * free all fragments on the list that are less then
713 * or equal to ctsn_point
714 */
715 if (TSN_lte(tsn, fwd_tsn)) {
716 __skb_unlink(pos, &ulpq->reasm);
717 sctp_ulpevent_free(event);
718 } else
719 break;
720 }
721}
722
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800723/*
724 * Drain the reassembly queue. If we just cleared parted delivery, it
725 * is possible that the reassembly queue will contain already reassembled
726 * messages. Retrieve any such messages and give them to the user.
727 */
728static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
729{
730 struct sctp_ulpevent *event = NULL;
731 struct sk_buff_head temp;
732
733 if (skb_queue_empty(&ulpq->reasm))
734 return;
735
736 while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
737 /* Do ordering if needed. */
wangweidongcb3f8372013-12-23 12:16:50 +0800738 if ((event) && (event->msg_flags & MSG_EOR)) {
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800739 skb_queue_head_init(&temp);
740 __skb_queue_tail(&temp, sctp_event2skb(event));
741
742 event = sctp_ulpq_order(ulpq, event);
743 }
744
745 /* Send event to the ULP. 'event' is the
746 * sctp_ulpevent for very first SKB on the temp' list.
747 */
748 if (event)
749 sctp_ulpq_tail_event(ulpq, event);
750 }
751}
752
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754/* Helper function to gather skbs that have possibly become
755 * ordered by an an incoming chunk.
756 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500757static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 struct sctp_ulpevent *event)
759{
David S. Miller8728b832005-08-09 19:25:21 -0700760 struct sk_buff_head *event_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 struct sk_buff *pos, *tmp;
762 struct sctp_ulpevent *cevent;
763 struct sctp_stream *in;
Hagen Paul Pfeiferefea2c62011-03-04 11:45:05 +0000764 __u16 sid, csid, cssn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
766 sid = event->stream;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 in = &ulpq->asoc->ssnmap->in;
768
David S. Miller8728b832005-08-09 19:25:21 -0700769 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
770
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 /* We are holding the chunks by stream, by SSN. */
772 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
773 cevent = (struct sctp_ulpevent *) pos->cb;
774 csid = cevent->stream;
775 cssn = cevent->ssn;
776
777 /* Have we gone too far? */
778 if (csid > sid)
779 break;
780
781 /* Have we not gone far enough? */
782 if (csid < sid)
783 continue;
784
785 if (cssn != sctp_ssn_peek(in, sid))
786 break;
787
788 /* Found it, so mark in the ssnmap. */
789 sctp_ssn_next(in, sid);
790
David S. Miller8728b832005-08-09 19:25:21 -0700791 __skb_unlink(pos, &ulpq->lobby);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 /* Attach all gathered skbs to the event. */
David S. Miller8728b832005-08-09 19:25:21 -0700794 __skb_queue_tail(event_list, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 }
796}
797
798/* Helper function to store chunks needing ordering. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500799static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 struct sctp_ulpevent *event)
801{
802 struct sk_buff *pos;
803 struct sctp_ulpevent *cevent;
804 __u16 sid, csid;
805 __u16 ssn, cssn;
806
807 pos = skb_peek_tail(&ulpq->lobby);
808 if (!pos) {
809 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
810 return;
811 }
812
813 sid = event->stream;
814 ssn = event->ssn;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 cevent = (struct sctp_ulpevent *) pos->cb;
817 csid = cevent->stream;
818 cssn = cevent->ssn;
819 if (sid > csid) {
820 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
821 return;
822 }
823
824 if ((sid == csid) && SSN_lt(cssn, ssn)) {
825 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
826 return;
827 }
828
829 /* Find the right place in this list. We store them by
830 * stream ID and then by SSN.
831 */
832 skb_queue_walk(&ulpq->lobby, pos) {
833 cevent = (struct sctp_ulpevent *) pos->cb;
834 csid = cevent->stream;
835 cssn = cevent->ssn;
836
837 if (csid > sid)
838 break;
839 if (csid == sid && SSN_lt(ssn, cssn))
840 break;
841 }
842
843
844 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700845 __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846}
847
848static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
David S. Miller8728b832005-08-09 19:25:21 -0700849 struct sctp_ulpevent *event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850{
851 __u16 sid, ssn;
852 struct sctp_stream *in;
853
854 /* Check if this message needs ordering. */
855 if (SCTP_DATA_UNORDERED & event->msg_flags)
856 return event;
857
858 /* Note: The stream ID must be verified before this routine. */
859 sid = event->stream;
860 ssn = event->ssn;
861 in = &ulpq->asoc->ssnmap->in;
862
863 /* Is this the expected SSN for this stream ID? */
864 if (ssn != sctp_ssn_peek(in, sid)) {
865 /* We've received something out of order, so find where it
866 * needs to be placed. We order by stream and then by SSN.
867 */
868 sctp_ulpq_store_ordered(ulpq, event);
869 return NULL;
870 }
871
872 /* Mark that the next chunk has been found. */
873 sctp_ssn_next(in, sid);
874
875 /* Go find any other chunks that were waiting for
876 * ordering.
877 */
878 sctp_ulpq_retrieve_ordered(ulpq, event);
879
880 return event;
881}
882
883/* Helper function to gather skbs that have possibly become
884 * ordered by forward tsn skipping their dependencies.
885 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500886static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887{
888 struct sk_buff *pos, *tmp;
889 struct sctp_ulpevent *cevent;
David S. Miller8728b832005-08-09 19:25:21 -0700890 struct sctp_ulpevent *event;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 struct sctp_stream *in;
892 struct sk_buff_head temp;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500893 struct sk_buff_head *lobby = &ulpq->lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 __u16 csid, cssn;
895
896 in = &ulpq->asoc->ssnmap->in;
897
898 /* We are holding the chunks by stream, by SSN. */
David S. Miller8728b832005-08-09 19:25:21 -0700899 skb_queue_head_init(&temp);
900 event = NULL;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500901 sctp_skb_for_each(pos, lobby, tmp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 cevent = (struct sctp_ulpevent *) pos->cb;
903 csid = cevent->stream;
904 cssn = cevent->ssn;
905
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400906 /* Have we gone too far? */
907 if (csid > sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 break;
909
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400910 /* Have we not gone far enough? */
911 if (csid < sid)
912 continue;
913
914 /* see if this ssn has been marked by skipping */
Vlad Yasevichc068be52008-01-15 11:41:56 -0500915 if (!SSN_lt(cssn, sctp_ssn_peek(in, csid)))
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400916 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917
Vlad Yasevichc068be52008-01-15 11:41:56 -0500918 __skb_unlink(pos, lobby);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400919 if (!event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 /* Create a temporary list to collect chunks on. */
921 event = sctp_skb2event(pos);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400922
923 /* Attach all gathered skbs to the event. */
924 __skb_queue_tail(&temp, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 }
926
Vlad Yasevichc068be52008-01-15 11:41:56 -0500927 /* If we didn't reap any data, see if the next expected SSN
928 * is next on the queue and if so, use that.
929 */
930 if (event == NULL && pos != (struct sk_buff *)lobby) {
931 cevent = (struct sctp_ulpevent *) pos->cb;
932 csid = cevent->stream;
933 cssn = cevent->ssn;
934
935 if (csid == sid && cssn == sctp_ssn_peek(in, csid)) {
936 sctp_ssn_next(in, csid);
937 __skb_unlink(pos, lobby);
938 __skb_queue_tail(&temp, pos);
939 event = sctp_skb2event(pos);
940 }
941 }
942
David S. Miller8728b832005-08-09 19:25:21 -0700943 /* Send event to the ULP. 'event' is the sctp_ulpevent for
944 * very first SKB on the 'temp' list.
945 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400946 if (event) {
947 /* see if we have more ordered that we can deliver */
948 sctp_ulpq_retrieve_ordered(ulpq, event);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400950 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951}
952
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400953/* Skip over an SSN. This is used during the processing of
954 * Forwared TSN chunk to skip over the abandoned ordered data
955 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
957{
958 struct sctp_stream *in;
959
960 /* Note: The stream ID must be verified before this routine. */
961 in = &ulpq->asoc->ssnmap->in;
962
963 /* Is this an old SSN? If so ignore. */
964 if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
965 return;
966
967 /* Mark that we are no longer expecting this SSN or lower. */
968 sctp_ssn_skip(in, sid, ssn);
969
970 /* Go find any other chunks that were waiting for
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900971 * ordering and deliver them if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400973 sctp_ulpq_reap_ordered(ulpq, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974}
975
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -0700976static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq,
977 struct sk_buff_head *list, __u16 needed)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978{
979 __u16 freed = 0;
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000980 __u32 tsn, last_tsn;
981 struct sk_buff *skb, *flist, *last;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 struct sctp_ulpevent *event;
983 struct sctp_tsnmap *tsnmap;
984
985 tsnmap = &ulpq->asoc->peer.tsn_map;
986
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000987 while ((skb = skb_peek_tail(list)) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 event = sctp_skb2event(skb);
989 tsn = event->tsn;
990
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000991 /* Don't renege below the Cumulative TSN ACK Point. */
992 if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap)))
993 break;
994
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000995 /* Events in ordering queue may have multiple fragments
996 * corresponding to additional TSNs. Sum the total
997 * freed space; find the last TSN.
998 */
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000999 freed += skb_headlen(skb);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +00001000 flist = skb_shinfo(skb)->frag_list;
1001 for (last = flist; flist; flist = flist->next) {
1002 last = flist;
1003 freed += skb_headlen(last);
1004 }
1005 if (last)
1006 last_tsn = sctp_skb2event(last)->tsn;
1007 else
1008 last_tsn = tsn;
1009
1010 /* Unlink the event, then renege all applicable TSNs. */
1011 __skb_unlink(skb, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 sctp_ulpevent_free(event);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +00001013 while (TSN_lte(tsn, last_tsn)) {
1014 sctp_tsnmap_renege(tsnmap, tsn);
1015 tsn++;
1016 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 if (freed >= needed)
1018 return freed;
1019 }
1020
1021 return freed;
1022}
1023
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001024/* Renege 'needed' bytes from the ordering queue. */
1025static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
1026{
1027 return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
1028}
1029
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030/* Renege 'needed' bytes from the reassembly queue. */
1031static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
1032{
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001033 return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034}
1035
1036/* Partial deliver the first message as there is pressure on rwnd. */
1037void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
Al Virodd0fc662005-10-07 07:46:04 +01001038 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039{
1040 struct sctp_ulpevent *event;
1041 struct sctp_association *asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001042 struct sctp_sock *sp;
Lee A. Robertsd003b412013-02-28 04:37:30 +00001043 __u32 ctsn;
1044 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
1046 asoc = ulpq->asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001047 sp = sctp_sk(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001049 /* If the association is already in Partial Delivery mode
Lee A. Robertsd003b412013-02-28 04:37:30 +00001050 * we have nothing to do.
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001051 */
1052 if (ulpq->pd_mode)
1053 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054
Lee A. Robertsd003b412013-02-28 04:37:30 +00001055 /* Data must be at or below the Cumulative TSN ACK Point to
1056 * start partial delivery.
1057 */
1058 skb = skb_peek(&asoc->ulpq.reasm);
1059 if (skb != NULL) {
1060 ctsn = sctp_skb2event(skb)->tsn;
1061 if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)))
1062 return;
1063 }
1064
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001065 /* If the user enabled fragment interleave socket option,
1066 * multiple associations can enter partial delivery.
1067 * Otherwise, we can only enter partial delivery if the
1068 * socket is not in partial deliver mode.
1069 */
1070 if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 /* Is partial delivery possible? */
1072 event = sctp_ulpq_retrieve_first(ulpq);
1073 /* Send event to the ULP. */
1074 if (event) {
1075 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichd49d91d2007-03-23 11:32:00 -07001076 sctp_ulpq_set_pd(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 return;
1078 }
1079 }
1080}
1081
1082/* Renege some packets to make room for an incoming chunk. */
1083void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
Al Virodd0fc662005-10-07 07:46:04 +01001084 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085{
1086 struct sctp_association *asoc;
1087 __u16 needed, freed;
1088
1089 asoc = ulpq->asoc;
1090
1091 if (chunk) {
1092 needed = ntohs(chunk->chunk_hdr->length);
1093 needed -= sizeof(sctp_data_chunk_t);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001094 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 needed = SCTP_DEFAULT_MAXWINDOW;
1096
1097 freed = 0;
1098
1099 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
1100 freed = sctp_ulpq_renege_order(ulpq, needed);
1101 if (freed < needed) {
1102 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
1103 }
1104 }
1105 /* If able to free enough room, accept this chunk. */
1106 if (chunk && (freed >= needed)) {
Lee A. Robertsd003b412013-02-28 04:37:30 +00001107 int retval;
1108 retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
1109 /*
1110 * Enter partial delivery if chunk has not been
1111 * delivered; otherwise, drain the reassembly queue.
1112 */
1113 if (retval <= 0)
1114 sctp_ulpq_partial_delivery(ulpq, gfp);
1115 else if (retval == 1)
1116 sctp_ulpq_reasm_drain(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 }
1118
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001119 sk_mem_reclaim(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120}
1121
1122
1123
1124/* Notify the application if an association is aborted and in
1125 * partial delivery mode. Send up any pending received messages.
1126 */
Al Virodd0fc662005-10-07 07:46:04 +01001127void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128{
1129 struct sctp_ulpevent *ev = NULL;
1130 struct sock *sk;
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -03001131 struct sctp_sock *sp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132
1133 if (!ulpq->pd_mode)
1134 return;
1135
1136 sk = ulpq->asoc->base.sk;
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -03001137 sp = sctp_sk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
1139 &sctp_sk(sk)->subscribe))
1140 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
1141 SCTP_PARTIAL_DELIVERY_ABORTED,
1142 gfp);
1143 if (ev)
1144 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1145
1146 /* If there is data waiting, send it up the socket now. */
Marcelo Ricardo Leitner0970f5b2016-04-29 14:17:08 -03001147 if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) {
1148 sp->data_ready_signalled = 1;
1149 sk->sk_data_ready(sk);
1150 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151}