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, see
25 * <http://www.gnu.org/licenses/>.
27 * Please send any bug reports or fixes you make to the
29 * lksctp developers <linux-sctp@vger.kernel.org>
31 * 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>
37 #include <linux/slab.h>
38 #include <linux/types.h>
39 #include <linux/skbuff.h>
41 #include <net/busy_poll.h>
42 #include <net/sctp/structs.h>
43 #include <net/sctp/sctp.h>
44 #include <net/sctp/sm.h>
46 /* Forward declarations for internal helpers. */
47 static struct sctp_ulpevent
*sctp_ulpq_reasm(struct sctp_ulpq
*ulpq
,
48 struct sctp_ulpevent
*);
49 static struct sctp_ulpevent
*sctp_ulpq_order(struct sctp_ulpq
*,
50 struct sctp_ulpevent
*);
51 static void sctp_ulpq_reasm_drain(struct sctp_ulpq
*ulpq
);
53 /* 1st Level Abstractions */
55 /* Initialize a ULP queue from a block of memory. */
56 struct sctp_ulpq
*sctp_ulpq_init(struct sctp_ulpq
*ulpq
,
57 struct sctp_association
*asoc
)
59 memset(ulpq
, 0, sizeof(struct sctp_ulpq
));
62 skb_queue_head_init(&ulpq
->reasm
);
63 skb_queue_head_init(&ulpq
->lobby
);
70 /* Flush the reassembly and ordering queues. */
71 void sctp_ulpq_flush(struct sctp_ulpq
*ulpq
)
74 struct sctp_ulpevent
*event
;
76 while ((skb
= __skb_dequeue(&ulpq
->lobby
)) != NULL
) {
77 event
= sctp_skb2event(skb
);
78 sctp_ulpevent_free(event
);
81 while ((skb
= __skb_dequeue(&ulpq
->reasm
)) != NULL
) {
82 event
= sctp_skb2event(skb
);
83 sctp_ulpevent_free(event
);
88 /* Dispose of a ulpqueue. */
89 void sctp_ulpq_free(struct sctp_ulpq
*ulpq
)
91 sctp_ulpq_flush(ulpq
);
94 /* Process an incoming DATA chunk. */
95 int sctp_ulpq_tail_data(struct sctp_ulpq
*ulpq
, struct sctp_chunk
*chunk
,
98 struct sk_buff_head temp
;
99 struct sctp_ulpevent
*event
;
102 /* Create an event from the incoming chunk. */
103 event
= sctp_ulpevent_make_rcvmsg(chunk
->asoc
, chunk
, gfp
);
107 /* Do reassembly if needed. */
108 event
= sctp_ulpq_reasm(ulpq
, event
);
110 /* Do ordering if needed. */
111 if ((event
) && (event
->msg_flags
& MSG_EOR
)) {
112 /* Create a temporary list to collect chunks on. */
113 skb_queue_head_init(&temp
);
114 __skb_queue_tail(&temp
, sctp_event2skb(event
));
116 event
= sctp_ulpq_order(ulpq
, event
);
119 /* Send event to the ULP. 'event' is the sctp_ulpevent for
120 * very first SKB on the 'temp' list.
123 event_eor
= (event
->msg_flags
& MSG_EOR
) ? 1 : 0;
124 sctp_ulpq_tail_event(ulpq
, event
);
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.
134 int sctp_clear_pd(struct sock
*sk
, struct sctp_association
*asoc
)
136 struct sctp_sock
*sp
= sctp_sk(sk
);
138 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
142 if (!skb_queue_empty(&sp
->pd_lobby
)) {
143 struct list_head
*list
;
144 skb_queue_splice_tail_init(&sp
->pd_lobby
,
145 &sk
->sk_receive_queue
);
146 list
= (struct list_head
*)&sctp_sk(sk
)->pd_lobby
;
147 INIT_LIST_HEAD(list
);
151 /* There are other associations in PD, so we only need to
152 * pull stuff out of the lobby that belongs to the
153 * associations that is exiting PD (all of its notifications
156 if (!skb_queue_empty(&sp
->pd_lobby
) && asoc
) {
157 struct sk_buff
*skb
, *tmp
;
158 struct sctp_ulpevent
*event
;
160 sctp_skb_for_each(skb
, &sp
->pd_lobby
, tmp
) {
161 event
= sctp_skb2event(skb
);
162 if (event
->asoc
== asoc
) {
163 __skb_unlink(skb
, &sp
->pd_lobby
);
164 __skb_queue_tail(&sk
->sk_receive_queue
,
174 /* Set the pd_mode on the socket and ulpq */
175 static void sctp_ulpq_set_pd(struct sctp_ulpq
*ulpq
)
177 struct sctp_sock
*sp
= sctp_sk(ulpq
->asoc
->base
.sk
);
179 atomic_inc(&sp
->pd_mode
);
183 /* Clear the pd_mode and restart any pending messages waiting for delivery. */
184 static int sctp_ulpq_clear_pd(struct sctp_ulpq
*ulpq
)
187 sctp_ulpq_reasm_drain(ulpq
);
188 return sctp_clear_pd(ulpq
->asoc
->base
.sk
, ulpq
->asoc
);
191 /* If the SKB of 'event' is on a list, it is the first such member
194 int sctp_ulpq_tail_event(struct sctp_ulpq
*ulpq
, struct sctp_ulpevent
*event
)
196 struct sock
*sk
= ulpq
->asoc
->base
.sk
;
197 struct sk_buff_head
*queue
, *skb_list
;
198 struct sk_buff
*skb
= sctp_event2skb(event
);
201 skb_list
= (struct sk_buff_head
*) skb
->prev
;
203 /* If the socket is just going to throw this away, do not
204 * even try to deliver it.
206 if (sock_flag(sk
, SOCK_DEAD
) || (sk
->sk_shutdown
& RCV_SHUTDOWN
))
209 if (!sctp_ulpevent_is_notification(event
)) {
210 sk_mark_napi_id(sk
, skb
);
211 sk_incoming_cpu_update(sk
);
213 /* Check if the user wishes to receive this event. */
214 if (!sctp_ulpevent_is_enabled(event
, &sctp_sk(sk
)->subscribe
))
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.
222 if (atomic_read(&sctp_sk(sk
)->pd_mode
) == 0) {
223 queue
= &sk
->sk_receive_queue
;
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.
231 if ((event
->msg_flags
& MSG_NOTIFICATION
) ||
232 (SCTP_DATA_NOT_FRAG
==
233 (event
->msg_flags
& SCTP_DATA_FRAG_MASK
)))
234 queue
= &sctp_sk(sk
)->pd_lobby
;
236 clear_pd
= event
->msg_flags
& MSG_EOR
;
237 queue
= &sk
->sk_receive_queue
;
241 * If fragment interleave is enabled, we
242 * can queue this to the receive queue instead
245 if (sctp_sk(sk
)->frag_interleave
)
246 queue
= &sk
->sk_receive_queue
;
248 queue
= &sctp_sk(sk
)->pd_lobby
;
252 /* If we are harvesting multiple skbs they will be
253 * collected on a list.
256 skb_queue_splice_tail_init(skb_list
, queue
);
258 __skb_queue_tail(queue
, skb
);
260 /* Did we just complete partial delivery and need to get
261 * rolling again? Move pending data to the receive
265 sctp_ulpq_clear_pd(ulpq
);
267 if (queue
== &sk
->sk_receive_queue
)
268 sctp_sk(sk
)->pending_data_ready
= 1;
273 sctp_queue_purge_ulpevents(skb_list
);
275 sctp_ulpevent_free(event
);
280 /* 2nd Level Abstractions */
282 /* Helper function to store chunks that need to be reassembled. */
283 static void sctp_ulpq_store_reasm(struct sctp_ulpq
*ulpq
,
284 struct sctp_ulpevent
*event
)
287 struct sctp_ulpevent
*cevent
;
292 /* See if it belongs at the end. */
293 pos
= skb_peek_tail(&ulpq
->reasm
);
295 __skb_queue_tail(&ulpq
->reasm
, sctp_event2skb(event
));
299 /* Short circuit just dropping it at the end. */
300 cevent
= sctp_skb2event(pos
);
302 if (TSN_lt(ctsn
, tsn
)) {
303 __skb_queue_tail(&ulpq
->reasm
, sctp_event2skb(event
));
307 /* Find the right place in this list. We store them by TSN. */
308 skb_queue_walk(&ulpq
->reasm
, pos
) {
309 cevent
= sctp_skb2event(pos
);
312 if (TSN_lt(tsn
, ctsn
))
316 /* Insert before pos. */
317 __skb_queue_before(&ulpq
->reasm
, pos
, sctp_event2skb(event
));
321 /* Helper function to return an event corresponding to the reassembled
323 * This routine creates a re-assembled skb given the first and last skb's
324 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
325 * payload was fragmented on the way and ip had to reassemble them.
326 * We add the rest of skb's to the first skb's fraglist.
328 static struct sctp_ulpevent
*sctp_make_reassembled_event(struct net
*net
,
329 struct sk_buff_head
*queue
, struct sk_buff
*f_frag
,
330 struct sk_buff
*l_frag
)
333 struct sk_buff
*new = NULL
;
334 struct sctp_ulpevent
*event
;
335 struct sk_buff
*pnext
, *last
;
336 struct sk_buff
*list
= skb_shinfo(f_frag
)->frag_list
;
338 /* Store the pointer to the 2nd skb */
339 if (f_frag
== l_frag
)
344 /* Get the last skb in the f_frag's frag_list if present. */
345 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(net
, 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(sock_net(asoc
->base
.sk
),
503 sctp_ulpq_set_pd(ulpq
);
509 retval
= sctp_make_reassembled_event(sock_net(ulpq
->asoc
->base
.sk
),
510 &ulpq
->reasm
, first_frag
, pos
);
512 retval
->msg_flags
|= MSG_EOR
;
516 /* Retrieve the next set of fragments of a partial message. */
517 static struct sctp_ulpevent
*sctp_ulpq_retrieve_partial(struct sctp_ulpq
*ulpq
)
519 struct sk_buff
*pos
, *last_frag
, *first_frag
;
520 struct sctp_ulpevent
*cevent
;
521 __u32 ctsn
, next_tsn
;
523 struct sctp_ulpevent
*retval
;
525 /* The chunks are held in the reasm queue sorted by TSN.
526 * Walk through the queue sequentially and look for the first
527 * sequence of fragmented chunks.
530 if (skb_queue_empty(&ulpq
->reasm
))
533 last_frag
= first_frag
= NULL
;
538 skb_queue_walk(&ulpq
->reasm
, pos
) {
539 cevent
= sctp_skb2event(pos
);
542 switch (cevent
->msg_flags
& SCTP_DATA_FRAG_MASK
) {
543 case SCTP_DATA_FIRST_FRAG
:
547 case SCTP_DATA_MIDDLE_FRAG
:
552 } else if (next_tsn
== ctsn
) {
558 case SCTP_DATA_LAST_FRAG
:
561 else if (ctsn
!= next_tsn
)
571 /* We have the reassembled event. There is no need to look
575 retval
= sctp_make_reassembled_event(sock_net(ulpq
->asoc
->base
.sk
),
576 &ulpq
->reasm
, first_frag
, last_frag
);
577 if (retval
&& is_last
)
578 retval
->msg_flags
|= MSG_EOR
;
584 /* Helper function to reassemble chunks. Hold chunks on the reasm queue that
587 static struct sctp_ulpevent
*sctp_ulpq_reasm(struct sctp_ulpq
*ulpq
,
588 struct sctp_ulpevent
*event
)
590 struct sctp_ulpevent
*retval
= NULL
;
592 /* Check if this is part of a fragmented message. */
593 if (SCTP_DATA_NOT_FRAG
== (event
->msg_flags
& SCTP_DATA_FRAG_MASK
)) {
594 event
->msg_flags
|= MSG_EOR
;
598 sctp_ulpq_store_reasm(ulpq
, event
);
600 retval
= sctp_ulpq_retrieve_reassembled(ulpq
);
604 /* Do not even bother unless this is the next tsn to
608 ctsnap
= sctp_tsnmap_get_ctsn(&ulpq
->asoc
->peer
.tsn_map
);
609 if (TSN_lte(ctsn
, ctsnap
))
610 retval
= sctp_ulpq_retrieve_partial(ulpq
);
616 /* Retrieve the first part (sequential fragments) for partial delivery. */
617 static struct sctp_ulpevent
*sctp_ulpq_retrieve_first(struct sctp_ulpq
*ulpq
)
619 struct sk_buff
*pos
, *last_frag
, *first_frag
;
620 struct sctp_ulpevent
*cevent
;
621 __u32 ctsn
, next_tsn
;
622 struct sctp_ulpevent
*retval
;
624 /* The chunks are held in the reasm queue sorted by TSN.
625 * Walk through the queue sequentially and look for a sequence of
626 * fragmented chunks that start a datagram.
629 if (skb_queue_empty(&ulpq
->reasm
))
632 last_frag
= first_frag
= NULL
;
636 skb_queue_walk(&ulpq
->reasm
, pos
) {
637 cevent
= sctp_skb2event(pos
);
640 switch (cevent
->msg_flags
& SCTP_DATA_FRAG_MASK
) {
641 case SCTP_DATA_FIRST_FRAG
:
650 case SCTP_DATA_MIDDLE_FRAG
:
653 if (ctsn
== next_tsn
) {
660 case SCTP_DATA_LAST_FRAG
:
672 /* We have the reassembled event. There is no need to look
676 retval
= sctp_make_reassembled_event(sock_net(ulpq
->asoc
->base
.sk
),
677 &ulpq
->reasm
, first_frag
, last_frag
);
682 * Flush out stale fragments from the reassembly queue when processing
685 * RFC 3758, Section 3.6
687 * After receiving and processing a FORWARD TSN, the data receiver MUST
688 * take cautions in updating its re-assembly queue. The receiver MUST
689 * remove any partially reassembled message, which is still missing one
690 * or more TSNs earlier than or equal to the new cumulative TSN point.
691 * In the event that the receiver has invoked the partial delivery API,
692 * a notification SHOULD also be generated to inform the upper layer API
693 * that the message being partially delivered will NOT be completed.
695 void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq
*ulpq
, __u32 fwd_tsn
)
697 struct sk_buff
*pos
, *tmp
;
698 struct sctp_ulpevent
*event
;
701 if (skb_queue_empty(&ulpq
->reasm
))
704 skb_queue_walk_safe(&ulpq
->reasm
, pos
, tmp
) {
705 event
= sctp_skb2event(pos
);
708 /* Since the entire message must be abandoned by the
709 * sender (item A3 in Section 3.5, RFC 3758), we can
710 * free all fragments on the list that are less then
711 * or equal to ctsn_point
713 if (TSN_lte(tsn
, fwd_tsn
)) {
714 __skb_unlink(pos
, &ulpq
->reasm
);
715 sctp_ulpevent_free(event
);
722 * Drain the reassembly queue. If we just cleared parted delivery, it
723 * is possible that the reassembly queue will contain already reassembled
724 * messages. Retrieve any such messages and give them to the user.
726 static void sctp_ulpq_reasm_drain(struct sctp_ulpq
*ulpq
)
728 struct sctp_ulpevent
*event
= NULL
;
729 struct sk_buff_head temp
;
731 if (skb_queue_empty(&ulpq
->reasm
))
734 while ((event
= sctp_ulpq_retrieve_reassembled(ulpq
)) != NULL
) {
735 /* Do ordering if needed. */
736 if ((event
) && (event
->msg_flags
& MSG_EOR
)) {
737 skb_queue_head_init(&temp
);
738 __skb_queue_tail(&temp
, sctp_event2skb(event
));
740 event
= sctp_ulpq_order(ulpq
, event
);
743 /* Send event to the ULP. 'event' is the
744 * sctp_ulpevent for very first SKB on the temp' list.
747 sctp_ulpq_tail_event(ulpq
, event
);
752 /* Helper function to gather skbs that have possibly become
753 * ordered by an an incoming chunk.
755 static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq
*ulpq
,
756 struct sctp_ulpevent
*event
)
758 struct sk_buff_head
*event_list
;
759 struct sk_buff
*pos
, *tmp
;
760 struct sctp_ulpevent
*cevent
;
761 struct sctp_stream
*in
;
762 __u16 sid
, csid
, cssn
;
765 in
= &ulpq
->asoc
->ssnmap
->in
;
767 event_list
= (struct sk_buff_head
*) sctp_event2skb(event
)->prev
;
769 /* We are holding the chunks by stream, by SSN. */
770 sctp_skb_for_each(pos
, &ulpq
->lobby
, tmp
) {
771 cevent
= (struct sctp_ulpevent
*) pos
->cb
;
772 csid
= cevent
->stream
;
775 /* Have we gone too far? */
779 /* Have we not gone far enough? */
783 if (cssn
!= sctp_ssn_peek(in
, sid
))
786 /* Found it, so mark in the ssnmap. */
787 sctp_ssn_next(in
, sid
);
789 __skb_unlink(pos
, &ulpq
->lobby
);
791 /* Attach all gathered skbs to the event. */
792 __skb_queue_tail(event_list
, pos
);
796 /* Helper function to store chunks needing ordering. */
797 static void sctp_ulpq_store_ordered(struct sctp_ulpq
*ulpq
,
798 struct sctp_ulpevent
*event
)
801 struct sctp_ulpevent
*cevent
;
805 pos
= skb_peek_tail(&ulpq
->lobby
);
807 __skb_queue_tail(&ulpq
->lobby
, sctp_event2skb(event
));
814 cevent
= (struct sctp_ulpevent
*) pos
->cb
;
815 csid
= cevent
->stream
;
818 __skb_queue_tail(&ulpq
->lobby
, sctp_event2skb(event
));
822 if ((sid
== csid
) && SSN_lt(cssn
, ssn
)) {
823 __skb_queue_tail(&ulpq
->lobby
, sctp_event2skb(event
));
827 /* Find the right place in this list. We store them by
828 * stream ID and then by SSN.
830 skb_queue_walk(&ulpq
->lobby
, pos
) {
831 cevent
= (struct sctp_ulpevent
*) pos
->cb
;
832 csid
= cevent
->stream
;
837 if (csid
== sid
&& SSN_lt(ssn
, cssn
))
842 /* Insert before pos. */
843 __skb_queue_before(&ulpq
->lobby
, pos
, sctp_event2skb(event
));
846 static struct sctp_ulpevent
*sctp_ulpq_order(struct sctp_ulpq
*ulpq
,
847 struct sctp_ulpevent
*event
)
850 struct sctp_stream
*in
;
852 /* Check if this message needs ordering. */
853 if (SCTP_DATA_UNORDERED
& event
->msg_flags
)
856 /* Note: The stream ID must be verified before this routine. */
859 in
= &ulpq
->asoc
->ssnmap
->in
;
861 /* Is this the expected SSN for this stream ID? */
862 if (ssn
!= sctp_ssn_peek(in
, sid
)) {
863 /* We've received something out of order, so find where it
864 * needs to be placed. We order by stream and then by SSN.
866 sctp_ulpq_store_ordered(ulpq
, event
);
870 /* Mark that the next chunk has been found. */
871 sctp_ssn_next(in
, sid
);
873 /* Go find any other chunks that were waiting for
876 sctp_ulpq_retrieve_ordered(ulpq
, event
);
881 /* Helper function to gather skbs that have possibly become
882 * ordered by forward tsn skipping their dependencies.
884 static void sctp_ulpq_reap_ordered(struct sctp_ulpq
*ulpq
, __u16 sid
)
886 struct sk_buff
*pos
, *tmp
;
887 struct sctp_ulpevent
*cevent
;
888 struct sctp_ulpevent
*event
;
889 struct sctp_stream
*in
;
890 struct sk_buff_head temp
;
891 struct sk_buff_head
*lobby
= &ulpq
->lobby
;
894 in
= &ulpq
->asoc
->ssnmap
->in
;
896 /* We are holding the chunks by stream, by SSN. */
897 skb_queue_head_init(&temp
);
899 sctp_skb_for_each(pos
, lobby
, tmp
) {
900 cevent
= (struct sctp_ulpevent
*) pos
->cb
;
901 csid
= cevent
->stream
;
904 /* Have we gone too far? */
908 /* Have we not gone far enough? */
912 /* see if this ssn has been marked by skipping */
913 if (!SSN_lt(cssn
, sctp_ssn_peek(in
, csid
)))
916 __skb_unlink(pos
, lobby
);
918 /* Create a temporary list to collect chunks on. */
919 event
= sctp_skb2event(pos
);
921 /* Attach all gathered skbs to the event. */
922 __skb_queue_tail(&temp
, pos
);
925 /* If we didn't reap any data, see if the next expected SSN
926 * is next on the queue and if so, use that.
928 if (event
== NULL
&& pos
!= (struct sk_buff
*)lobby
) {
929 cevent
= (struct sctp_ulpevent
*) pos
->cb
;
930 csid
= cevent
->stream
;
933 if (csid
== sid
&& cssn
== sctp_ssn_peek(in
, csid
)) {
934 sctp_ssn_next(in
, csid
);
935 __skb_unlink(pos
, lobby
);
936 __skb_queue_tail(&temp
, pos
);
937 event
= sctp_skb2event(pos
);
941 /* Send event to the ULP. 'event' is the sctp_ulpevent for
942 * very first SKB on the 'temp' list.
945 /* see if we have more ordered that we can deliver */
946 sctp_ulpq_retrieve_ordered(ulpq
, event
);
947 sctp_ulpq_tail_event(ulpq
, event
);
951 /* Skip over an SSN. This is used during the processing of
952 * Forwared TSN chunk to skip over the abandoned ordered data
954 void sctp_ulpq_skip(struct sctp_ulpq
*ulpq
, __u16 sid
, __u16 ssn
)
956 struct sctp_stream
*in
;
958 /* Note: The stream ID must be verified before this routine. */
959 in
= &ulpq
->asoc
->ssnmap
->in
;
961 /* Is this an old SSN? If so ignore. */
962 if (SSN_lt(ssn
, sctp_ssn_peek(in
, sid
)))
965 /* Mark that we are no longer expecting this SSN or lower. */
966 sctp_ssn_skip(in
, sid
, ssn
);
968 /* Go find any other chunks that were waiting for
969 * ordering and deliver them if needed.
971 sctp_ulpq_reap_ordered(ulpq
, sid
);
974 static __u16
sctp_ulpq_renege_list(struct sctp_ulpq
*ulpq
,
975 struct sk_buff_head
*list
, __u16 needed
)
979 struct sk_buff
*skb
, *flist
, *last
;
980 struct sctp_ulpevent
*event
;
981 struct sctp_tsnmap
*tsnmap
;
983 tsnmap
= &ulpq
->asoc
->peer
.tsn_map
;
985 while ((skb
= skb_peek_tail(list
)) != NULL
) {
986 event
= sctp_skb2event(skb
);
989 /* Don't renege below the Cumulative TSN ACK Point. */
990 if (TSN_lte(tsn
, sctp_tsnmap_get_ctsn(tsnmap
)))
993 /* Events in ordering queue may have multiple fragments
994 * corresponding to additional TSNs. Sum the total
995 * freed space; find the last TSN.
997 freed
+= skb_headlen(skb
);
998 flist
= skb_shinfo(skb
)->frag_list
;
999 for (last
= flist
; flist
; flist
= flist
->next
) {
1001 freed
+= skb_headlen(last
);
1004 last_tsn
= sctp_skb2event(last
)->tsn
;
1008 /* Unlink the event, then renege all applicable TSNs. */
1009 __skb_unlink(skb
, list
);
1010 sctp_ulpevent_free(event
);
1011 while (TSN_lte(tsn
, last_tsn
)) {
1012 sctp_tsnmap_renege(tsnmap
, tsn
);
1015 if (freed
>= needed
)
1022 /* Renege 'needed' bytes from the ordering queue. */
1023 static __u16
sctp_ulpq_renege_order(struct sctp_ulpq
*ulpq
, __u16 needed
)
1025 return sctp_ulpq_renege_list(ulpq
, &ulpq
->lobby
, needed
);
1028 /* Renege 'needed' bytes from the reassembly queue. */
1029 static __u16
sctp_ulpq_renege_frags(struct sctp_ulpq
*ulpq
, __u16 needed
)
1031 return sctp_ulpq_renege_list(ulpq
, &ulpq
->reasm
, needed
);
1034 /* Partial deliver the first message as there is pressure on rwnd. */
1035 void sctp_ulpq_partial_delivery(struct sctp_ulpq
*ulpq
,
1038 struct sctp_ulpevent
*event
;
1039 struct sctp_association
*asoc
;
1040 struct sctp_sock
*sp
;
1042 struct sk_buff
*skb
;
1045 sp
= sctp_sk(asoc
->base
.sk
);
1047 /* If the association is already in Partial Delivery mode
1048 * we have nothing to do.
1053 /* Data must be at or below the Cumulative TSN ACK Point to
1054 * start partial delivery.
1056 skb
= skb_peek(&asoc
->ulpq
.reasm
);
1058 ctsn
= sctp_skb2event(skb
)->tsn
;
1059 if (!TSN_lte(ctsn
, sctp_tsnmap_get_ctsn(&asoc
->peer
.tsn_map
)))
1063 /* If the user enabled fragment interleave socket option,
1064 * multiple associations can enter partial delivery.
1065 * Otherwise, we can only enter partial delivery if the
1066 * socket is not in partial deliver mode.
1068 if (sp
->frag_interleave
|| atomic_read(&sp
->pd_mode
) == 0) {
1069 /* Is partial delivery possible? */
1070 event
= sctp_ulpq_retrieve_first(ulpq
);
1071 /* Send event to the ULP. */
1073 sctp_ulpq_tail_event(ulpq
, event
);
1074 sctp_ulpq_set_pd(ulpq
);
1080 /* Renege some packets to make room for an incoming chunk. */
1081 void sctp_ulpq_renege(struct sctp_ulpq
*ulpq
, struct sctp_chunk
*chunk
,
1084 struct sctp_association
*asoc
;
1085 __u16 needed
, freed
;
1090 needed
= ntohs(chunk
->chunk_hdr
->length
);
1091 needed
-= sizeof(sctp_data_chunk_t
);
1093 needed
= SCTP_DEFAULT_MAXWINDOW
;
1097 if (skb_queue_empty(&asoc
->base
.sk
->sk_receive_queue
)) {
1098 freed
= sctp_ulpq_renege_order(ulpq
, needed
);
1099 if (freed
< needed
) {
1100 freed
+= sctp_ulpq_renege_frags(ulpq
, needed
- freed
);
1103 /* If able to free enough room, accept this chunk. */
1104 if (chunk
&& (freed
>= needed
)) {
1106 retval
= sctp_ulpq_tail_data(ulpq
, chunk
, gfp
);
1108 * Enter partial delivery if chunk has not been
1109 * delivered; otherwise, drain the reassembly queue.
1112 sctp_ulpq_partial_delivery(ulpq
, gfp
);
1113 else if (retval
== 1)
1114 sctp_ulpq_reasm_drain(ulpq
);
1117 sk_mem_reclaim(asoc
->base
.sk
);
1122 /* Notify the application if an association is aborted and in
1123 * partial delivery mode. Send up any pending received messages.
1125 void sctp_ulpq_abort_pd(struct sctp_ulpq
*ulpq
, gfp_t gfp
)
1127 struct sctp_ulpevent
*ev
= NULL
;
1133 sk
= ulpq
->asoc
->base
.sk
;
1134 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT
,
1135 &sctp_sk(sk
)->subscribe
))
1136 ev
= sctp_ulpevent_make_pdapi(ulpq
->asoc
,
1137 SCTP_PARTIAL_DELIVERY_ABORTED
,
1140 __skb_queue_tail(&sk
->sk_receive_queue
, sctp_event2skb(ev
));
1142 /* If there is data waiting, send it up the socket now. */
1143 if (sctp_ulpq_clear_pd(ulpq
) || ev
)
1144 sctp_sk(sk
)->pending_data_ready
= 1;