blob: d49dc2ed30adb97a809eb37902b9956c366a2862 [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
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)) {
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
Neil Horman8465a5f2014-04-17 15:26:51 -0400208 if (!sctp_ulpevent_is_notification(event))
209 sk_mark_napi_id(sk, skb);
210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 /* Check if the user wishes to receive this event. */
212 if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe))
213 goto out_free;
214
215 /* If we are in partial delivery mode, post to the lobby until
216 * partial delivery is cleared, unless, of course _this_ is
217 * the association the cause of the partial delivery.
218 */
219
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700220 if (atomic_read(&sctp_sk(sk)->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 queue = &sk->sk_receive_queue;
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700222 } else {
223 if (ulpq->pd_mode) {
224 /* If the association is in partial delivery, we
225 * need to finish delivering the partially processed
226 * packet before passing any other data. This is
227 * because we don't truly support stream interleaving.
228 */
229 if ((event->msg_flags & MSG_NOTIFICATION) ||
230 (SCTP_DATA_NOT_FRAG ==
231 (event->msg_flags & SCTP_DATA_FRAG_MASK)))
232 queue = &sctp_sk(sk)->pd_lobby;
233 else {
234 clear_pd = event->msg_flags & MSG_EOR;
235 queue = &sk->sk_receive_queue;
236 }
237 } else {
238 /*
239 * If fragment interleave is enabled, we
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300240 * can queue this to the receive queue instead
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700241 * of the lobby.
242 */
243 if (sctp_sk(sk)->frag_interleave)
244 queue = &sk->sk_receive_queue;
245 else
246 queue = &sctp_sk(sk)->pd_lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 }
Vlad Yasevichb6e13312007-04-20 12:23:15 -0700248 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250 /* If we are harvesting multiple skbs they will be
251 * collected on a list.
252 */
David S. Miller8728b832005-08-09 19:25:21 -0700253 if (skb_list)
254 sctp_skb_list_tail(skb_list, queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 else
David S. Miller8728b832005-08-09 19:25:21 -0700256 __skb_queue_tail(queue, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 /* Did we just complete partial delivery and need to get
259 * rolling again? Move pending data to the receive
260 * queue.
261 */
262 if (clear_pd)
263 sctp_ulpq_clear_pd(ulpq);
264
265 if (queue == &sk->sk_receive_queue)
David S. Miller676d2362014-04-11 16:15:36 -0400266 sk->sk_data_ready(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 return 1;
268
269out_free:
David S. Miller8728b832005-08-09 19:25:21 -0700270 if (skb_list)
271 sctp_queue_purge_ulpevents(skb_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 else
273 sctp_ulpevent_free(event);
David S. Miller8728b832005-08-09 19:25:21 -0700274
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 return 0;
276}
277
278/* 2nd Level Abstractions */
279
280/* Helper function to store chunks that need to be reassembled. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500281static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 struct sctp_ulpevent *event)
283{
284 struct sk_buff *pos;
285 struct sctp_ulpevent *cevent;
286 __u32 tsn, ctsn;
287
288 tsn = event->tsn;
289
290 /* See if it belongs at the end. */
291 pos = skb_peek_tail(&ulpq->reasm);
292 if (!pos) {
293 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
294 return;
295 }
296
297 /* Short circuit just dropping it at the end. */
298 cevent = sctp_skb2event(pos);
299 ctsn = cevent->tsn;
300 if (TSN_lt(ctsn, tsn)) {
301 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
302 return;
303 }
304
305 /* Find the right place in this list. We store them by TSN. */
306 skb_queue_walk(&ulpq->reasm, pos) {
307 cevent = sctp_skb2event(pos);
308 ctsn = cevent->tsn;
309
310 if (TSN_lt(tsn, ctsn))
311 break;
312 }
313
314 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700315 __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317}
318
319/* Helper function to return an event corresponding to the reassembled
320 * datagram.
321 * This routine creates a re-assembled skb given the first and last skb's
322 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
323 * payload was fragmented on the way and ip had to reassemble them.
324 * We add the rest of skb's to the first skb's fraglist.
325 */
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000326static struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
327 struct sk_buff_head *queue, struct sk_buff *f_frag,
328 struct sk_buff *l_frag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329{
330 struct sk_buff *pos;
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700331 struct sk_buff *new = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 struct sctp_ulpevent *event;
333 struct sk_buff *pnext, *last;
334 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
335
336 /* Store the pointer to the 2nd skb */
337 if (f_frag == l_frag)
338 pos = NULL;
339 else
340 pos = f_frag->next;
341
342 /* Get the last skb in the f_frag's frag_list if present. */
wangweidong8d726512013-12-23 12:16:53 +0800343 for (last = list; list; last = list, list = list->next)
344 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /* Add the list of remaining fragments to the first fragments
347 * frag_list.
348 */
349 if (last)
350 last->next = pos;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900351 else {
352 if (skb_cloned(f_frag)) {
353 /* This is a cloned skb, we can't just modify
354 * the frag_list. We need a new skb to do that.
355 * Instead of calling skb_unshare(), we'll do it
356 * ourselves since we need to delay the free.
357 */
358 new = skb_copy(f_frag, GFP_ATOMIC);
359 if (!new)
360 return NULL; /* try again later */
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700361
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900362 sctp_skb_set_owner_r(new, f_frag->sk);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700363
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900364 skb_shinfo(new)->frag_list = pos;
365 } else
366 skb_shinfo(f_frag)->frag_list = pos;
367 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
369 /* Remove the first fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700370 __skb_unlink(f_frag, queue);
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700371
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900372 /* if we did unshare, then free the old skb and re-assign */
373 if (new) {
374 kfree_skb(f_frag);
375 f_frag = new;
376 }
Vladislav Yasevich672e7cc2006-05-05 17:03:49 -0700377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 while (pos) {
379
380 pnext = pos->next;
381
382 /* Update the len and data_len fields of the first fragment. */
383 f_frag->len += pos->len;
384 f_frag->data_len += pos->len;
385
386 /* Remove the fragment from the reassembly queue. */
David S. Miller8728b832005-08-09 19:25:21 -0700387 __skb_unlink(pos, queue);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 /* Break if we have reached the last fragment. */
390 if (pos == l_frag)
391 break;
392 pos->next = pnext;
393 pos = pnext;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700394 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396 event = sctp_skb2event(f_frag);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000397 SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
399 return event;
400}
401
402
403/* Helper function to check if an incoming chunk has filled up the last
404 * missing fragment in a SCTP datagram and return the corresponding event.
405 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500406static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407{
408 struct sk_buff *pos;
409 struct sctp_ulpevent *cevent;
410 struct sk_buff *first_frag = NULL;
411 __u32 ctsn, next_tsn;
412 struct sctp_ulpevent *retval = NULL;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700413 struct sk_buff *pd_first = NULL;
414 struct sk_buff *pd_last = NULL;
415 size_t pd_len = 0;
416 struct sctp_association *asoc;
417 u32 pd_point;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
419 /* Initialized to 0 just to avoid compiler warning message. Will
420 * never be used with this value. It is referenced only after it
421 * is set when we find the first fragment of a message.
422 */
423 next_tsn = 0;
424
425 /* The chunks are held in the reasm queue sorted by TSN.
426 * Walk through the queue sequentially and look for a sequence of
427 * fragmented chunks that complete a datagram.
428 * 'first_frag' and next_tsn are reset when we find a chunk which
429 * is the first fragment of a datagram. Once these 2 fields are set
430 * we expect to find the remaining middle fragments and the last
431 * fragment in order. If not, first_frag is reset to NULL and we
432 * start the next pass when we find another first fragment.
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700433 *
434 * There is a potential to do partial delivery if user sets
435 * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
436 * to see if can do PD.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 */
438 skb_queue_walk(&ulpq->reasm, pos) {
439 cevent = sctp_skb2event(pos);
440 ctsn = cevent->tsn;
441
442 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
443 case SCTP_DATA_FIRST_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700444 /* If this "FIRST_FRAG" is the first
445 * element in the queue, then count it towards
446 * possible PD.
447 */
448 if (pos == ulpq->reasm.next) {
449 pd_first = pos;
450 pd_last = pos;
451 pd_len = pos->len;
452 } else {
453 pd_first = NULL;
454 pd_last = NULL;
455 pd_len = 0;
456 }
457
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 first_frag = pos;
459 next_tsn = ctsn + 1;
460 break;
461
462 case SCTP_DATA_MIDDLE_FRAG:
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700463 if ((first_frag) && (ctsn == next_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 next_tsn++;
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700465 if (pd_first) {
466 pd_last = pos;
467 pd_len += pos->len;
468 }
469 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 first_frag = NULL;
471 break;
472
473 case SCTP_DATA_LAST_FRAG:
474 if (first_frag && (ctsn == next_tsn))
475 goto found;
476 else
477 first_frag = NULL;
478 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700479 }
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700480 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700482 asoc = ulpq->asoc;
483 if (pd_first) {
484 /* Make sure we can enter partial deliver.
485 * We can trigger partial delivery only if framgent
486 * interleave is set, or the socket is not already
487 * in partial delivery.
488 */
489 if (!sctp_sk(asoc->base.sk)->frag_interleave &&
490 atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
491 goto done;
492
493 cevent = sctp_skb2event(pd_first);
494 pd_point = sctp_sk(asoc->base.sk)->pd_point;
495 if (pd_point && pd_point <= pd_len) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000496 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
497 &ulpq->reasm,
Vlad Yasevichd49d91d2007-03-23 11:32:00 -0700498 pd_first,
499 pd_last);
500 if (retval)
501 sctp_ulpq_set_pd(ulpq);
502 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 }
504done:
505 return retval;
506found:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000507 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
508 &ulpq->reasm, first_frag, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 if (retval)
510 retval->msg_flags |= MSG_EOR;
511 goto done;
512}
513
514/* Retrieve the next set of fragments of a partial message. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500515static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516{
517 struct sk_buff *pos, *last_frag, *first_frag;
518 struct sctp_ulpevent *cevent;
519 __u32 ctsn, next_tsn;
520 int is_last;
521 struct sctp_ulpevent *retval;
522
523 /* The chunks are held in the reasm queue sorted by TSN.
524 * Walk through the queue sequentially and look for the first
525 * sequence of fragmented chunks.
526 */
527
528 if (skb_queue_empty(&ulpq->reasm))
529 return NULL;
530
531 last_frag = first_frag = NULL;
532 retval = NULL;
533 next_tsn = 0;
534 is_last = 0;
535
536 skb_queue_walk(&ulpq->reasm, pos) {
537 cevent = sctp_skb2event(pos);
538 ctsn = cevent->tsn;
539
540 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
Lee A. Robertsd003b412013-02-28 04:37:30 +0000541 case SCTP_DATA_FIRST_FRAG:
542 if (!first_frag)
543 return NULL;
544 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 case SCTP_DATA_MIDDLE_FRAG:
546 if (!first_frag) {
547 first_frag = pos;
548 next_tsn = ctsn + 1;
549 last_frag = pos;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000550 } else if (next_tsn == ctsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 next_tsn++;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000552 last_frag = pos;
553 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 goto done;
555 break;
556 case SCTP_DATA_LAST_FRAG:
557 if (!first_frag)
558 first_frag = pos;
559 else if (ctsn != next_tsn)
560 goto done;
561 last_frag = pos;
562 is_last = 1;
563 goto done;
564 default:
565 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700566 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 }
568
569 /* We have the reassembled event. There is no need to look
570 * further.
571 */
572done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000573 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
574 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 if (retval && is_last)
576 retval->msg_flags |= MSG_EOR;
577
578 return retval;
579}
580
581
582/* Helper function to reassemble chunks. Hold chunks on the reasm queue that
583 * need reassembling.
584 */
585static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
586 struct sctp_ulpevent *event)
587{
588 struct sctp_ulpevent *retval = NULL;
589
590 /* Check if this is part of a fragmented message. */
591 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
592 event->msg_flags |= MSG_EOR;
593 return event;
594 }
595
596 sctp_ulpq_store_reasm(ulpq, event);
597 if (!ulpq->pd_mode)
598 retval = sctp_ulpq_retrieve_reassembled(ulpq);
599 else {
600 __u32 ctsn, ctsnap;
601
602 /* Do not even bother unless this is the next tsn to
603 * be delivered.
604 */
605 ctsn = event->tsn;
606 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
607 if (TSN_lte(ctsn, ctsnap))
608 retval = sctp_ulpq_retrieve_partial(ulpq);
609 }
610
611 return retval;
612}
613
614/* Retrieve the first part (sequential fragments) for partial delivery. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500615static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616{
617 struct sk_buff *pos, *last_frag, *first_frag;
618 struct sctp_ulpevent *cevent;
619 __u32 ctsn, next_tsn;
620 struct sctp_ulpevent *retval;
621
622 /* The chunks are held in the reasm queue sorted by TSN.
623 * Walk through the queue sequentially and look for a sequence of
624 * fragmented chunks that start a datagram.
625 */
626
627 if (skb_queue_empty(&ulpq->reasm))
628 return NULL;
629
630 last_frag = first_frag = NULL;
631 retval = NULL;
632 next_tsn = 0;
633
634 skb_queue_walk(&ulpq->reasm, pos) {
635 cevent = sctp_skb2event(pos);
636 ctsn = cevent->tsn;
637
638 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
639 case SCTP_DATA_FIRST_FRAG:
640 if (!first_frag) {
641 first_frag = pos;
642 next_tsn = ctsn + 1;
643 last_frag = pos;
644 } else
645 goto done;
646 break;
647
648 case SCTP_DATA_MIDDLE_FRAG:
649 if (!first_frag)
650 return NULL;
651 if (ctsn == next_tsn) {
652 next_tsn++;
653 last_frag = pos;
654 } else
655 goto done;
656 break;
Lee A. Robertsd003b412013-02-28 04:37:30 +0000657
658 case SCTP_DATA_LAST_FRAG:
659 if (!first_frag)
660 return NULL;
661 else
662 goto done;
663 break;
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 default:
666 return NULL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700667 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 }
669
670 /* We have the reassembled event. There is no need to look
671 * further.
672 */
673done:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000674 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
675 &ulpq->reasm, first_frag, last_frag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 return retval;
677}
678
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400679/*
680 * Flush out stale fragments from the reassembly queue when processing
681 * a Forward TSN.
682 *
683 * RFC 3758, Section 3.6
684 *
685 * After receiving and processing a FORWARD TSN, the data receiver MUST
686 * take cautions in updating its re-assembly queue. The receiver MUST
687 * remove any partially reassembled message, which is still missing one
688 * or more TSNs earlier than or equal to the new cumulative TSN point.
689 * In the event that the receiver has invoked the partial delivery API,
690 * a notification SHOULD also be generated to inform the upper layer API
691 * that the message being partially delivered will NOT be completed.
692 */
693void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
694{
695 struct sk_buff *pos, *tmp;
696 struct sctp_ulpevent *event;
697 __u32 tsn;
698
699 if (skb_queue_empty(&ulpq->reasm))
700 return;
701
702 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
703 event = sctp_skb2event(pos);
704 tsn = event->tsn;
705
706 /* Since the entire message must be abandoned by the
707 * sender (item A3 in Section 3.5, RFC 3758), we can
708 * free all fragments on the list that are less then
709 * or equal to ctsn_point
710 */
711 if (TSN_lte(tsn, fwd_tsn)) {
712 __skb_unlink(pos, &ulpq->reasm);
713 sctp_ulpevent_free(event);
714 } else
715 break;
716 }
717}
718
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800719/*
720 * Drain the reassembly queue. If we just cleared parted delivery, it
721 * is possible that the reassembly queue will contain already reassembled
722 * messages. Retrieve any such messages and give them to the user.
723 */
724static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
725{
726 struct sctp_ulpevent *event = NULL;
727 struct sk_buff_head temp;
728
729 if (skb_queue_empty(&ulpq->reasm))
730 return;
731
732 while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
733 /* Do ordering if needed. */
wangweidongcb3f8372013-12-23 12:16:50 +0800734 if ((event) && (event->msg_flags & MSG_EOR)) {
Vlad Yasevichef5d4cf22007-12-16 14:05:45 -0800735 skb_queue_head_init(&temp);
736 __skb_queue_tail(&temp, sctp_event2skb(event));
737
738 event = sctp_ulpq_order(ulpq, event);
739 }
740
741 /* Send event to the ULP. 'event' is the
742 * sctp_ulpevent for very first SKB on the temp' list.
743 */
744 if (event)
745 sctp_ulpq_tail_event(ulpq, event);
746 }
747}
748
749
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750/* Helper function to gather skbs that have possibly become
751 * ordered by an an incoming chunk.
752 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500753static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 struct sctp_ulpevent *event)
755{
David S. Miller8728b832005-08-09 19:25:21 -0700756 struct sk_buff_head *event_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 struct sk_buff *pos, *tmp;
758 struct sctp_ulpevent *cevent;
759 struct sctp_stream *in;
Hagen Paul Pfeiferefea2c62011-03-04 11:45:05 +0000760 __u16 sid, csid, cssn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
762 sid = event->stream;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 in = &ulpq->asoc->ssnmap->in;
764
David S. Miller8728b832005-08-09 19:25:21 -0700765 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
766
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 /* We are holding the chunks by stream, by SSN. */
768 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
769 cevent = (struct sctp_ulpevent *) pos->cb;
770 csid = cevent->stream;
771 cssn = cevent->ssn;
772
773 /* Have we gone too far? */
774 if (csid > sid)
775 break;
776
777 /* Have we not gone far enough? */
778 if (csid < sid)
779 continue;
780
781 if (cssn != sctp_ssn_peek(in, sid))
782 break;
783
784 /* Found it, so mark in the ssnmap. */
785 sctp_ssn_next(in, sid);
786
David S. Miller8728b832005-08-09 19:25:21 -0700787 __skb_unlink(pos, &ulpq->lobby);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788
789 /* Attach all gathered skbs to the event. */
David S. Miller8728b832005-08-09 19:25:21 -0700790 __skb_queue_tail(event_list, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 }
792}
793
794/* Helper function to store chunks needing ordering. */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500795static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 struct sctp_ulpevent *event)
797{
798 struct sk_buff *pos;
799 struct sctp_ulpevent *cevent;
800 __u16 sid, csid;
801 __u16 ssn, cssn;
802
803 pos = skb_peek_tail(&ulpq->lobby);
804 if (!pos) {
805 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
806 return;
807 }
808
809 sid = event->stream;
810 ssn = event->ssn;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900811
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 cevent = (struct sctp_ulpevent *) pos->cb;
813 csid = cevent->stream;
814 cssn = cevent->ssn;
815 if (sid > csid) {
816 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
817 return;
818 }
819
820 if ((sid == csid) && SSN_lt(cssn, ssn)) {
821 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
822 return;
823 }
824
825 /* Find the right place in this list. We store them by
826 * stream ID and then by SSN.
827 */
828 skb_queue_walk(&ulpq->lobby, pos) {
829 cevent = (struct sctp_ulpevent *) pos->cb;
830 csid = cevent->stream;
831 cssn = cevent->ssn;
832
833 if (csid > sid)
834 break;
835 if (csid == sid && SSN_lt(ssn, cssn))
836 break;
837 }
838
839
840 /* Insert before pos. */
David S. Miller43f59c82008-09-21 21:28:51 -0700841 __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842}
843
844static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
David S. Miller8728b832005-08-09 19:25:21 -0700845 struct sctp_ulpevent *event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846{
847 __u16 sid, ssn;
848 struct sctp_stream *in;
849
850 /* Check if this message needs ordering. */
851 if (SCTP_DATA_UNORDERED & event->msg_flags)
852 return event;
853
854 /* Note: The stream ID must be verified before this routine. */
855 sid = event->stream;
856 ssn = event->ssn;
857 in = &ulpq->asoc->ssnmap->in;
858
859 /* Is this the expected SSN for this stream ID? */
860 if (ssn != sctp_ssn_peek(in, sid)) {
861 /* We've received something out of order, so find where it
862 * needs to be placed. We order by stream and then by SSN.
863 */
864 sctp_ulpq_store_ordered(ulpq, event);
865 return NULL;
866 }
867
868 /* Mark that the next chunk has been found. */
869 sctp_ssn_next(in, sid);
870
871 /* Go find any other chunks that were waiting for
872 * ordering.
873 */
874 sctp_ulpq_retrieve_ordered(ulpq, event);
875
876 return event;
877}
878
879/* Helper function to gather skbs that have possibly become
880 * ordered by forward tsn skipping their dependencies.
881 */
Vlad Yasevich01f2d382008-01-11 11:17:27 -0500882static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883{
884 struct sk_buff *pos, *tmp;
885 struct sctp_ulpevent *cevent;
David S. Miller8728b832005-08-09 19:25:21 -0700886 struct sctp_ulpevent *event;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 struct sctp_stream *in;
888 struct sk_buff_head temp;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500889 struct sk_buff_head *lobby = &ulpq->lobby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 __u16 csid, cssn;
891
892 in = &ulpq->asoc->ssnmap->in;
893
894 /* We are holding the chunks by stream, by SSN. */
David S. Miller8728b832005-08-09 19:25:21 -0700895 skb_queue_head_init(&temp);
896 event = NULL;
Vlad Yasevichc068be52008-01-15 11:41:56 -0500897 sctp_skb_for_each(pos, lobby, tmp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 cevent = (struct sctp_ulpevent *) pos->cb;
899 csid = cevent->stream;
900 cssn = cevent->ssn;
901
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400902 /* Have we gone too far? */
903 if (csid > sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 break;
905
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400906 /* Have we not gone far enough? */
907 if (csid < sid)
908 continue;
909
910 /* see if this ssn has been marked by skipping */
Vlad Yasevichc068be52008-01-15 11:41:56 -0500911 if (!SSN_lt(cssn, sctp_ssn_peek(in, csid)))
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400912 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913
Vlad Yasevichc068be52008-01-15 11:41:56 -0500914 __skb_unlink(pos, lobby);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400915 if (!event)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 /* Create a temporary list to collect chunks on. */
917 event = sctp_skb2event(pos);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400918
919 /* Attach all gathered skbs to the event. */
920 __skb_queue_tail(&temp, pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 }
922
Vlad Yasevichc068be52008-01-15 11:41:56 -0500923 /* If we didn't reap any data, see if the next expected SSN
924 * is next on the queue and if so, use that.
925 */
926 if (event == NULL && pos != (struct sk_buff *)lobby) {
927 cevent = (struct sctp_ulpevent *) pos->cb;
928 csid = cevent->stream;
929 cssn = cevent->ssn;
930
931 if (csid == sid && cssn == sctp_ssn_peek(in, csid)) {
932 sctp_ssn_next(in, csid);
933 __skb_unlink(pos, lobby);
934 __skb_queue_tail(&temp, pos);
935 event = sctp_skb2event(pos);
936 }
937 }
938
David S. Miller8728b832005-08-09 19:25:21 -0700939 /* Send event to the ULP. 'event' is the sctp_ulpevent for
940 * very first SKB on the 'temp' list.
941 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400942 if (event) {
943 /* see if we have more ordered that we can deliver */
944 sctp_ulpq_retrieve_ordered(ulpq, event);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400946 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947}
948
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400949/* Skip over an SSN. This is used during the processing of
950 * Forwared TSN chunk to skip over the abandoned ordered data
951 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
953{
954 struct sctp_stream *in;
955
956 /* Note: The stream ID must be verified before this routine. */
957 in = &ulpq->asoc->ssnmap->in;
958
959 /* Is this an old SSN? If so ignore. */
960 if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
961 return;
962
963 /* Mark that we are no longer expecting this SSN or lower. */
964 sctp_ssn_skip(in, sid, ssn);
965
966 /* Go find any other chunks that were waiting for
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900967 * ordering and deliver them if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 */
Vlad Yasevichea2dfb32007-07-13 17:01:19 -0400969 sctp_ulpq_reap_ordered(ulpq, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970}
971
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -0700972static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq,
973 struct sk_buff_head *list, __u16 needed)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974{
975 __u16 freed = 0;
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000976 __u32 tsn, last_tsn;
977 struct sk_buff *skb, *flist, *last;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 struct sctp_ulpevent *event;
979 struct sctp_tsnmap *tsnmap;
980
981 tsnmap = &ulpq->asoc->peer.tsn_map;
982
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000983 while ((skb = skb_peek_tail(list)) != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 event = sctp_skb2event(skb);
985 tsn = event->tsn;
986
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000987 /* Don't renege below the Cumulative TSN ACK Point. */
988 if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap)))
989 break;
990
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000991 /* Events in ordering queue may have multiple fragments
992 * corresponding to additional TSNs. Sum the total
993 * freed space; find the last TSN.
994 */
Lee A. Robertse67f85e2013-02-28 04:37:28 +0000995 freed += skb_headlen(skb);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +0000996 flist = skb_shinfo(skb)->frag_list;
997 for (last = flist; flist; flist = flist->next) {
998 last = flist;
999 freed += skb_headlen(last);
1000 }
1001 if (last)
1002 last_tsn = sctp_skb2event(last)->tsn;
1003 else
1004 last_tsn = tsn;
1005
1006 /* Unlink the event, then renege all applicable TSNs. */
1007 __skb_unlink(skb, list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 sctp_ulpevent_free(event);
Lee A. Roberts95ac7b82013-02-28 04:37:29 +00001009 while (TSN_lte(tsn, last_tsn)) {
1010 sctp_tsnmap_renege(tsnmap, tsn);
1011 tsn++;
1012 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 if (freed >= needed)
1014 return freed;
1015 }
1016
1017 return freed;
1018}
1019
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001020/* Renege 'needed' bytes from the ordering queue. */
1021static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
1022{
1023 return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
1024}
1025
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026/* Renege 'needed' bytes from the reassembly queue. */
1027static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
1028{
Pavel Emelyanov16d14ef2007-10-23 20:30:25 -07001029 return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030}
1031
1032/* Partial deliver the first message as there is pressure on rwnd. */
1033void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
Al Virodd0fc662005-10-07 07:46:04 +01001034 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035{
1036 struct sctp_ulpevent *event;
1037 struct sctp_association *asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001038 struct sctp_sock *sp;
Lee A. Robertsd003b412013-02-28 04:37:30 +00001039 __u32 ctsn;
1040 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
1042 asoc = ulpq->asoc;
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001043 sp = sctp_sk(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001045 /* If the association is already in Partial Delivery mode
Lee A. Robertsd003b412013-02-28 04:37:30 +00001046 * we have nothing to do.
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001047 */
1048 if (ulpq->pd_mode)
1049 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050
Lee A. Robertsd003b412013-02-28 04:37:30 +00001051 /* Data must be at or below the Cumulative TSN ACK Point to
1052 * start partial delivery.
1053 */
1054 skb = skb_peek(&asoc->ulpq.reasm);
1055 if (skb != NULL) {
1056 ctsn = sctp_skb2event(skb)->tsn;
1057 if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)))
1058 return;
1059 }
1060
Vlad Yasevichb6e13312007-04-20 12:23:15 -07001061 /* If the user enabled fragment interleave socket option,
1062 * multiple associations can enter partial delivery.
1063 * Otherwise, we can only enter partial delivery if the
1064 * socket is not in partial deliver mode.
1065 */
1066 if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 /* Is partial delivery possible? */
1068 event = sctp_ulpq_retrieve_first(ulpq);
1069 /* Send event to the ULP. */
1070 if (event) {
1071 sctp_ulpq_tail_event(ulpq, event);
Vlad Yasevichd49d91d2007-03-23 11:32:00 -07001072 sctp_ulpq_set_pd(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073 return;
1074 }
1075 }
1076}
1077
1078/* Renege some packets to make room for an incoming chunk. */
1079void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
Al Virodd0fc662005-10-07 07:46:04 +01001080 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081{
1082 struct sctp_association *asoc;
1083 __u16 needed, freed;
1084
1085 asoc = ulpq->asoc;
1086
1087 if (chunk) {
1088 needed = ntohs(chunk->chunk_hdr->length);
1089 needed -= sizeof(sctp_data_chunk_t);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001090 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 needed = SCTP_DEFAULT_MAXWINDOW;
1092
1093 freed = 0;
1094
1095 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
1096 freed = sctp_ulpq_renege_order(ulpq, needed);
1097 if (freed < needed) {
1098 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
1099 }
1100 }
1101 /* If able to free enough room, accept this chunk. */
1102 if (chunk && (freed >= needed)) {
Lee A. Robertsd003b412013-02-28 04:37:30 +00001103 int retval;
1104 retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
1105 /*
1106 * Enter partial delivery if chunk has not been
1107 * delivered; otherwise, drain the reassembly queue.
1108 */
1109 if (retval <= 0)
1110 sctp_ulpq_partial_delivery(ulpq, gfp);
1111 else if (retval == 1)
1112 sctp_ulpq_reasm_drain(ulpq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 }
1114
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001115 sk_mem_reclaim(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116}
1117
1118
1119
1120/* Notify the application if an association is aborted and in
1121 * partial delivery mode. Send up any pending received messages.
1122 */
Al Virodd0fc662005-10-07 07:46:04 +01001123void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124{
1125 struct sctp_ulpevent *ev = NULL;
1126 struct sock *sk;
1127
1128 if (!ulpq->pd_mode)
1129 return;
1130
1131 sk = ulpq->asoc->base.sk;
1132 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
1133 &sctp_sk(sk)->subscribe))
1134 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
1135 SCTP_PARTIAL_DELIVERY_ABORTED,
1136 gfp);
1137 if (ev)
1138 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1139
1140 /* If there is data waiting, send it up the socket now. */
1141 if (sctp_ulpq_clear_pd(ulpq) || ev)
David S. Miller676d2362014-04-11 16:15:36 -04001142 sk->sk_data_ready(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143}