1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 Nokia, Inc.
7 * Copyright (c) 2001 La Monte H.P. Yarroll
9 * This abstraction carries sctp events to the ULP (sockets).
11 * This SCTP implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
17 * This SCTP implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
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.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 * Or submit a bug report through the following website:
33 * http://www.sf.net/projects/lksctp
35 * Written or modified by:
36 * Jon Grimm <jgrimm@us.ibm.com>
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Sridhar Samudrala <sri@us.ibm.com>
40 * Any bugs reported given to us we will try to fix... any fixes shared will
41 * be incorporated into the next SCTP release.
44 #include <linux/types.h>
45 #include <linux/skbuff.h>
47 #include <net/sctp/structs.h>
48 #include <net/sctp/sctp.h>
49 #include <net/sctp/sm.h>
51 /* Forward declarations for internal helpers. */
52 static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
53 struct sctp_ulpevent *);
54 static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *,
55 struct sctp_ulpevent *);
56 static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq);
58 /* 1st Level Abstractions */
60 /* Initialize a ULP queue from a block of memory. */
61 struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
62 struct sctp_association *asoc)
64 memset(ulpq, 0, sizeof(struct sctp_ulpq));
67 skb_queue_head_init(&ulpq->reasm);
68 skb_queue_head_init(&ulpq->lobby);
76 /* Flush the reassembly and ordering queues. */
77 void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
80 struct sctp_ulpevent *event;
82 while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
83 event = sctp_skb2event(skb);
84 sctp_ulpevent_free(event);
87 while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
88 event = sctp_skb2event(skb);
89 sctp_ulpevent_free(event);
94 /* Dispose of a ulpqueue. */
95 void sctp_ulpq_free(struct sctp_ulpq *ulpq)
97 sctp_ulpq_flush(ulpq);
102 /* Process an incoming DATA chunk. */
103 int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
106 struct sk_buff_head temp;
107 sctp_data_chunk_t *hdr;
108 struct sctp_ulpevent *event;
110 hdr = (sctp_data_chunk_t *) chunk->chunk_hdr;
112 /* Create an event from the incoming chunk. */
113 event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
117 /* Do reassembly if needed. */
118 event = sctp_ulpq_reasm(ulpq, event);
120 /* Do ordering if needed. */
121 if ((event) && (event->msg_flags & MSG_EOR)){
122 /* Create a temporary list to collect chunks on. */
123 skb_queue_head_init(&temp);
124 __skb_queue_tail(&temp, sctp_event2skb(event));
126 event = sctp_ulpq_order(ulpq, event);
129 /* Send event to the ULP. 'event' is the sctp_ulpevent for
130 * very first SKB on the 'temp' list.
133 sctp_ulpq_tail_event(ulpq, event);
138 /* Add a new event for propagation to the ULP. */
139 /* Clear the partial delivery mode for this socket. Note: This
140 * assumes that no association is currently in partial delivery mode.
142 int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc)
144 struct sctp_sock *sp = sctp_sk(sk);
146 if (atomic_dec_and_test(&sp->pd_mode)) {
147 /* This means there are no other associations in PD, so
148 * we can go ahead and clear out the lobby in one shot
150 if (!skb_queue_empty(&sp->pd_lobby)) {
151 struct list_head *list;
152 sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue);
153 list = (struct list_head *)&sctp_sk(sk)->pd_lobby;
154 INIT_LIST_HEAD(list);
158 /* There are other associations in PD, so we only need to
159 * pull stuff out of the lobby that belongs to the
160 * associations that is exiting PD (all of its notifications
163 if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
164 struct sk_buff *skb, *tmp;
165 struct sctp_ulpevent *event;
167 sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
168 event = sctp_skb2event(skb);
169 if (event->asoc == asoc) {
170 __skb_unlink(skb, &sp->pd_lobby);
171 __skb_queue_tail(&sk->sk_receive_queue,
181 /* Set the pd_mode on the socket and ulpq */
182 static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
184 struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
186 atomic_inc(&sp->pd_mode);
190 /* Clear the pd_mode and restart any pending messages waiting for delivery. */
191 static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
194 sctp_ulpq_reasm_drain(ulpq);
195 return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
198 /* If the SKB of 'event' is on a list, it is the first such member
201 int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
203 struct sock *sk = ulpq->asoc->base.sk;
204 struct sk_buff_head *queue, *skb_list;
205 struct sk_buff *skb = sctp_event2skb(event);
208 skb_list = (struct sk_buff_head *) skb->prev;
210 /* If the socket is just going to throw this away, do not
211 * even try to deliver it.
213 if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN))
216 /* Check if the user wishes to receive this event. */
217 if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe))
220 /* If we are in partial delivery mode, post to the lobby until
221 * partial delivery is cleared, unless, of course _this_ is
222 * the association the cause of the partial delivery.
225 if (atomic_read(&sctp_sk(sk)->pd_mode) == 0) {
226 queue = &sk->sk_receive_queue;
229 /* If the association is in partial delivery, we
230 * need to finish delivering the partially processed
231 * packet before passing any other data. This is
232 * because we don't truly support stream interleaving.
234 if ((event->msg_flags & MSG_NOTIFICATION) ||
235 (SCTP_DATA_NOT_FRAG ==
236 (event->msg_flags & SCTP_DATA_FRAG_MASK)))
237 queue = &sctp_sk(sk)->pd_lobby;
239 clear_pd = event->msg_flags & MSG_EOR;
240 queue = &sk->sk_receive_queue;
244 * If fragment interleave is enabled, we
245 * can queue this to the recieve queue instead
248 if (sctp_sk(sk)->frag_interleave)
249 queue = &sk->sk_receive_queue;
251 queue = &sctp_sk(sk)->pd_lobby;
255 /* If we are harvesting multiple skbs they will be
256 * collected on a list.
259 sctp_skb_list_tail(skb_list, queue);
261 __skb_queue_tail(queue, skb);
263 /* Did we just complete partial delivery and need to get
264 * rolling again? Move pending data to the receive
268 sctp_ulpq_clear_pd(ulpq);
270 if (queue == &sk->sk_receive_queue)
271 sk->sk_data_ready(sk, 0);
276 sctp_queue_purge_ulpevents(skb_list);
278 sctp_ulpevent_free(event);
283 /* 2nd Level Abstractions */
285 /* Helper function to store chunks that need to be reassembled. */
286 static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
287 struct sctp_ulpevent *event)
290 struct sctp_ulpevent *cevent;
295 /* See if it belongs at the end. */
296 pos = skb_peek_tail(&ulpq->reasm);
298 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
302 /* Short circuit just dropping it at the end. */
303 cevent = sctp_skb2event(pos);
305 if (TSN_lt(ctsn, tsn)) {
306 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
310 /* Find the right place in this list. We store them by TSN. */
311 skb_queue_walk(&ulpq->reasm, pos) {
312 cevent = sctp_skb2event(pos);
315 if (TSN_lt(tsn, ctsn))
319 /* Insert before pos. */
320 __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
324 /* Helper function to return an event corresponding to the reassembled
326 * This routine creates a re-assembled skb given the first and last skb's
327 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
328 * payload was fragmented on the way and ip had to reassemble them.
329 * We add the rest of skb's to the first skb's fraglist.
331 static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff_head *queue, struct sk_buff *f_frag, struct sk_buff *l_frag)
334 struct sk_buff *new = NULL;
335 struct sctp_ulpevent *event;
336 struct sk_buff *pnext, *last;
337 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
339 /* Store the pointer to the 2nd skb */
340 if (f_frag == l_frag)
345 /* Get the last skb in the f_frag's frag_list if present. */
346 for (last = list; list; last = list, list = list->next);
348 /* Add the list of remaining fragments to the first fragments
354 if (skb_cloned(f_frag)) {
355 /* This is a cloned skb, we can't just modify
356 * the frag_list. We need a new skb to do that.
357 * Instead of calling skb_unshare(), we'll do it
358 * ourselves since we need to delay the free.
360 new = skb_copy(f_frag, GFP_ATOMIC);
362 return NULL; /* try again later */
364 sctp_skb_set_owner_r(new, f_frag->sk);
366 skb_shinfo(new)->frag_list = pos;
368 skb_shinfo(f_frag)->frag_list = pos;
371 /* Remove the first fragment from the reassembly queue. */
372 __skb_unlink(f_frag, queue);
374 /* if we did unshare, then free the old skb and re-assign */
384 /* Update the len and data_len fields of the first fragment. */
385 f_frag->len += pos->len;
386 f_frag->data_len += pos->len;
388 /* Remove the fragment from the reassembly queue. */
389 __skb_unlink(pos, queue);
391 /* Break if we have reached the last fragment. */
398 event = sctp_skb2event(f_frag);
399 SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS);
405 /* Helper function to check if an incoming chunk has filled up the last
406 * missing fragment in a SCTP datagram and return the corresponding event.
408 static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
411 struct sctp_ulpevent *cevent;
412 struct sk_buff *first_frag = NULL;
413 __u32 ctsn, next_tsn;
414 struct sctp_ulpevent *retval = NULL;
415 struct sk_buff *pd_first = NULL;
416 struct sk_buff *pd_last = NULL;
418 struct sctp_association *asoc;
421 /* Initialized to 0 just to avoid compiler warning message. Will
422 * never be used with this value. It is referenced only after it
423 * is set when we find the first fragment of a message.
427 /* The chunks are held in the reasm queue sorted by TSN.
428 * Walk through the queue sequentially and look for a sequence of
429 * fragmented chunks that complete a datagram.
430 * 'first_frag' and next_tsn are reset when we find a chunk which
431 * is the first fragment of a datagram. Once these 2 fields are set
432 * we expect to find the remaining middle fragments and the last
433 * fragment in order. If not, first_frag is reset to NULL and we
434 * start the next pass when we find another first fragment.
436 * There is a potential to do partial delivery if user sets
437 * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
438 * to see if can do PD.
440 skb_queue_walk(&ulpq->reasm, pos) {
441 cevent = sctp_skb2event(pos);
444 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
445 case SCTP_DATA_FIRST_FRAG:
446 /* If this "FIRST_FRAG" is the first
447 * element in the queue, then count it towards
450 if (pos == ulpq->reasm.next) {
464 case SCTP_DATA_MIDDLE_FRAG:
465 if ((first_frag) && (ctsn == next_tsn)) {
475 case SCTP_DATA_LAST_FRAG:
476 if (first_frag && (ctsn == next_tsn))
486 /* Make sure we can enter partial deliver.
487 * We can trigger partial delivery only if framgent
488 * interleave is set, or the socket is not already
489 * in partial delivery.
491 if (!sctp_sk(asoc->base.sk)->frag_interleave &&
492 atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
495 cevent = sctp_skb2event(pd_first);
496 pd_point = sctp_sk(asoc->base.sk)->pd_point;
497 if (pd_point && pd_point <= pd_len) {
498 retval = sctp_make_reassembled_event(&ulpq->reasm,
502 sctp_ulpq_set_pd(ulpq);
508 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, pos);
510 retval->msg_flags |= MSG_EOR;
514 /* Retrieve the next set of fragments of a partial message. */
515 static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
517 struct sk_buff *pos, *last_frag, *first_frag;
518 struct sctp_ulpevent *cevent;
519 __u32 ctsn, next_tsn;
521 struct sctp_ulpevent *retval;
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.
528 if (skb_queue_empty(&ulpq->reasm))
531 last_frag = first_frag = NULL;
536 skb_queue_walk(&ulpq->reasm, pos) {
537 cevent = sctp_skb2event(pos);
540 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
541 case SCTP_DATA_MIDDLE_FRAG:
546 } else if (next_tsn == ctsn)
551 case SCTP_DATA_LAST_FRAG:
554 else if (ctsn != next_tsn)
564 /* We have the reassembled event. There is no need to look
568 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag);
569 if (retval && is_last)
570 retval->msg_flags |= MSG_EOR;
576 /* Helper function to reassemble chunks. Hold chunks on the reasm queue that
579 static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
580 struct sctp_ulpevent *event)
582 struct sctp_ulpevent *retval = NULL;
584 /* Check if this is part of a fragmented message. */
585 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
586 event->msg_flags |= MSG_EOR;
590 sctp_ulpq_store_reasm(ulpq, event);
592 retval = sctp_ulpq_retrieve_reassembled(ulpq);
596 /* Do not even bother unless this is the next tsn to
600 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
601 if (TSN_lte(ctsn, ctsnap))
602 retval = sctp_ulpq_retrieve_partial(ulpq);
608 /* Retrieve the first part (sequential fragments) for partial delivery. */
609 static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
611 struct sk_buff *pos, *last_frag, *first_frag;
612 struct sctp_ulpevent *cevent;
613 __u32 ctsn, next_tsn;
614 struct sctp_ulpevent *retval;
616 /* The chunks are held in the reasm queue sorted by TSN.
617 * Walk through the queue sequentially and look for a sequence of
618 * fragmented chunks that start a datagram.
621 if (skb_queue_empty(&ulpq->reasm))
624 last_frag = first_frag = NULL;
628 skb_queue_walk(&ulpq->reasm, pos) {
629 cevent = sctp_skb2event(pos);
632 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
633 case SCTP_DATA_FIRST_FRAG:
642 case SCTP_DATA_MIDDLE_FRAG:
645 if (ctsn == next_tsn) {
656 /* We have the reassembled event. There is no need to look
660 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag);
665 * Flush out stale fragments from the reassembly queue when processing
668 * RFC 3758, Section 3.6
670 * After receiving and processing a FORWARD TSN, the data receiver MUST
671 * take cautions in updating its re-assembly queue. The receiver MUST
672 * remove any partially reassembled message, which is still missing one
673 * or more TSNs earlier than or equal to the new cumulative TSN point.
674 * In the event that the receiver has invoked the partial delivery API,
675 * a notification SHOULD also be generated to inform the upper layer API
676 * that the message being partially delivered will NOT be completed.
678 void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
680 struct sk_buff *pos, *tmp;
681 struct sctp_ulpevent *event;
684 if (skb_queue_empty(&ulpq->reasm))
687 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
688 event = sctp_skb2event(pos);
691 /* Since the entire message must be abandoned by the
692 * sender (item A3 in Section 3.5, RFC 3758), we can
693 * free all fragments on the list that are less then
694 * or equal to ctsn_point
696 if (TSN_lte(tsn, fwd_tsn)) {
697 __skb_unlink(pos, &ulpq->reasm);
698 sctp_ulpevent_free(event);
705 * Drain the reassembly queue. If we just cleared parted delivery, it
706 * is possible that the reassembly queue will contain already reassembled
707 * messages. Retrieve any such messages and give them to the user.
709 static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
711 struct sctp_ulpevent *event = NULL;
712 struct sk_buff_head temp;
714 if (skb_queue_empty(&ulpq->reasm))
717 while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
718 /* Do ordering if needed. */
719 if ((event) && (event->msg_flags & MSG_EOR)){
720 skb_queue_head_init(&temp);
721 __skb_queue_tail(&temp, sctp_event2skb(event));
723 event = sctp_ulpq_order(ulpq, event);
726 /* Send event to the ULP. 'event' is the
727 * sctp_ulpevent for very first SKB on the temp' list.
730 sctp_ulpq_tail_event(ulpq, event);
735 /* Helper function to gather skbs that have possibly become
736 * ordered by an an incoming chunk.
738 static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
739 struct sctp_ulpevent *event)
741 struct sk_buff_head *event_list;
742 struct sk_buff *pos, *tmp;
743 struct sctp_ulpevent *cevent;
744 struct sctp_stream *in;
750 in = &ulpq->asoc->ssnmap->in;
752 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
754 /* We are holding the chunks by stream, by SSN. */
755 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
756 cevent = (struct sctp_ulpevent *) pos->cb;
757 csid = cevent->stream;
760 /* Have we gone too far? */
764 /* Have we not gone far enough? */
768 if (cssn != sctp_ssn_peek(in, sid))
771 /* Found it, so mark in the ssnmap. */
772 sctp_ssn_next(in, sid);
774 __skb_unlink(pos, &ulpq->lobby);
776 /* Attach all gathered skbs to the event. */
777 __skb_queue_tail(event_list, pos);
781 /* Helper function to store chunks needing ordering. */
782 static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
783 struct sctp_ulpevent *event)
786 struct sctp_ulpevent *cevent;
790 pos = skb_peek_tail(&ulpq->lobby);
792 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
799 cevent = (struct sctp_ulpevent *) pos->cb;
800 csid = cevent->stream;
803 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
807 if ((sid == csid) && SSN_lt(cssn, ssn)) {
808 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
812 /* Find the right place in this list. We store them by
813 * stream ID and then by SSN.
815 skb_queue_walk(&ulpq->lobby, pos) {
816 cevent = (struct sctp_ulpevent *) pos->cb;
817 csid = cevent->stream;
822 if (csid == sid && SSN_lt(ssn, cssn))
827 /* Insert before pos. */
828 __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
831 static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
832 struct sctp_ulpevent *event)
835 struct sctp_stream *in;
837 /* Check if this message needs ordering. */
838 if (SCTP_DATA_UNORDERED & event->msg_flags)
841 /* Note: The stream ID must be verified before this routine. */
844 in = &ulpq->asoc->ssnmap->in;
846 /* Is this the expected SSN for this stream ID? */
847 if (ssn != sctp_ssn_peek(in, sid)) {
848 /* We've received something out of order, so find where it
849 * needs to be placed. We order by stream and then by SSN.
851 sctp_ulpq_store_ordered(ulpq, event);
855 /* Mark that the next chunk has been found. */
856 sctp_ssn_next(in, sid);
858 /* Go find any other chunks that were waiting for
861 sctp_ulpq_retrieve_ordered(ulpq, event);
866 /* Helper function to gather skbs that have possibly become
867 * ordered by forward tsn skipping their dependencies.
869 static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
871 struct sk_buff *pos, *tmp;
872 struct sctp_ulpevent *cevent;
873 struct sctp_ulpevent *event;
874 struct sctp_stream *in;
875 struct sk_buff_head temp;
876 struct sk_buff_head *lobby = &ulpq->lobby;
879 in = &ulpq->asoc->ssnmap->in;
881 /* We are holding the chunks by stream, by SSN. */
882 skb_queue_head_init(&temp);
884 sctp_skb_for_each(pos, lobby, tmp) {
885 cevent = (struct sctp_ulpevent *) pos->cb;
886 csid = cevent->stream;
889 /* Have we gone too far? */
893 /* Have we not gone far enough? */
897 /* see if this ssn has been marked by skipping */
898 if (!SSN_lt(cssn, sctp_ssn_peek(in, csid)))
901 __skb_unlink(pos, lobby);
903 /* Create a temporary list to collect chunks on. */
904 event = sctp_skb2event(pos);
906 /* Attach all gathered skbs to the event. */
907 __skb_queue_tail(&temp, pos);
910 /* If we didn't reap any data, see if the next expected SSN
911 * is next on the queue and if so, use that.
913 if (event == NULL && pos != (struct sk_buff *)lobby) {
914 cevent = (struct sctp_ulpevent *) pos->cb;
915 csid = cevent->stream;
918 if (csid == sid && cssn == sctp_ssn_peek(in, csid)) {
919 sctp_ssn_next(in, csid);
920 __skb_unlink(pos, lobby);
921 __skb_queue_tail(&temp, pos);
922 event = sctp_skb2event(pos);
926 /* Send event to the ULP. 'event' is the sctp_ulpevent for
927 * very first SKB on the 'temp' list.
930 /* see if we have more ordered that we can deliver */
931 sctp_ulpq_retrieve_ordered(ulpq, event);
932 sctp_ulpq_tail_event(ulpq, event);
936 /* Skip over an SSN. This is used during the processing of
937 * Forwared TSN chunk to skip over the abandoned ordered data
939 void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
941 struct sctp_stream *in;
943 /* Note: The stream ID must be verified before this routine. */
944 in = &ulpq->asoc->ssnmap->in;
946 /* Is this an old SSN? If so ignore. */
947 if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
950 /* Mark that we are no longer expecting this SSN or lower. */
951 sctp_ssn_skip(in, sid, ssn);
953 /* Go find any other chunks that were waiting for
954 * ordering and deliver them if needed.
956 sctp_ulpq_reap_ordered(ulpq, sid);
960 static __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq,
961 struct sk_buff_head *list, __u16 needed)
966 struct sctp_ulpevent *event;
967 struct sctp_tsnmap *tsnmap;
969 tsnmap = &ulpq->asoc->peer.tsn_map;
971 while ((skb = __skb_dequeue_tail(list)) != NULL) {
972 freed += skb_headlen(skb);
973 event = sctp_skb2event(skb);
976 sctp_ulpevent_free(event);
977 sctp_tsnmap_renege(tsnmap, tsn);
985 /* Renege 'needed' bytes from the ordering queue. */
986 static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
988 return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
991 /* Renege 'needed' bytes from the reassembly queue. */
992 static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
994 return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
997 /* Partial deliver the first message as there is pressure on rwnd. */
998 void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
999 struct sctp_chunk *chunk,
1002 struct sctp_ulpevent *event;
1003 struct sctp_association *asoc;
1004 struct sctp_sock *sp;
1007 sp = sctp_sk(asoc->base.sk);
1009 /* If the association is already in Partial Delivery mode
1010 * we have noting to do.
1015 /* If the user enabled fragment interleave socket option,
1016 * multiple associations can enter partial delivery.
1017 * Otherwise, we can only enter partial delivery if the
1018 * socket is not in partial deliver mode.
1020 if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
1021 /* Is partial delivery possible? */
1022 event = sctp_ulpq_retrieve_first(ulpq);
1023 /* Send event to the ULP. */
1025 sctp_ulpq_tail_event(ulpq, event);
1026 sctp_ulpq_set_pd(ulpq);
1032 /* Renege some packets to make room for an incoming chunk. */
1033 void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
1036 struct sctp_association *asoc;
1037 __u16 needed, freed;
1042 needed = ntohs(chunk->chunk_hdr->length);
1043 needed -= sizeof(sctp_data_chunk_t);
1045 needed = SCTP_DEFAULT_MAXWINDOW;
1049 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
1050 freed = sctp_ulpq_renege_order(ulpq, needed);
1051 if (freed < needed) {
1052 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
1055 /* If able to free enough room, accept this chunk. */
1056 if (chunk && (freed >= needed)) {
1058 tsn = ntohl(chunk->subh.data_hdr->tsn);
1059 sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn);
1060 sctp_ulpq_tail_data(ulpq, chunk, gfp);
1062 sctp_ulpq_partial_delivery(ulpq, chunk, gfp);
1065 sk_mem_reclaim(asoc->base.sk);
1071 /* Notify the application if an association is aborted and in
1072 * partial delivery mode. Send up any pending received messages.
1074 void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
1076 struct sctp_ulpevent *ev = NULL;
1082 sk = ulpq->asoc->base.sk;
1083 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
1084 &sctp_sk(sk)->subscribe))
1085 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
1086 SCTP_PARTIAL_DELIVERY_ABORTED,
1089 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1091 /* If there is data waiting, send it up the socket now. */
1092 if (sctp_ulpq_clear_pd(ulpq) || ev)
1093 sk->sk_data_ready(sk, 0);