1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 * Copyright (c) 2001 Nokia, Inc.
8 * Copyright (c) 2001 La Monte H.P. Yarroll
10 * This abstraction carries sctp events to the ULP (sockets).
12 * Please send any bug reports or fixes you make to the
14 * lksctp developers <linux-sctp@vger.kernel.org>
16 * Written or modified by:
17 * Jon Grimm <jgrimm@us.ibm.com>
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Sridhar Samudrala <sri@us.ibm.com>
22 #include <linux/slab.h>
23 #include <linux/types.h>
24 #include <linux/skbuff.h>
26 #include <net/busy_poll.h>
27 #include <net/sctp/structs.h>
28 #include <net/sctp/sctp.h>
29 #include <net/sctp/sm.h>
31 /* Forward declarations for internal helpers. */
32 static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
33 struct sctp_ulpevent *);
34 static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *,
35 struct sctp_ulpevent *);
36 static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq);
38 /* 1st Level Abstractions */
40 /* Initialize a ULP queue from a block of memory. */
41 struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
42 struct sctp_association *asoc)
44 memset(ulpq, 0, sizeof(struct sctp_ulpq));
47 skb_queue_head_init(&ulpq->reasm);
48 skb_queue_head_init(&ulpq->reasm_uo);
49 skb_queue_head_init(&ulpq->lobby);
56 /* Flush the reassembly and ordering queues. */
57 void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
60 struct sctp_ulpevent *event;
62 while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
63 event = sctp_skb2event(skb);
64 sctp_ulpevent_free(event);
67 while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
68 event = sctp_skb2event(skb);
69 sctp_ulpevent_free(event);
72 while ((skb = __skb_dequeue(&ulpq->reasm_uo)) != NULL) {
73 event = sctp_skb2event(skb);
74 sctp_ulpevent_free(event);
78 /* Dispose of a ulpqueue. */
79 void sctp_ulpq_free(struct sctp_ulpq *ulpq)
81 sctp_ulpq_flush(ulpq);
84 /* Process an incoming DATA chunk. */
85 int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
88 struct sk_buff_head temp;
89 struct sctp_ulpevent *event;
92 /* Create an event from the incoming chunk. */
93 event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
97 event->ssn = ntohs(chunk->subh.data_hdr->ssn);
98 event->ppid = chunk->subh.data_hdr->ppid;
100 /* Do reassembly if needed. */
101 event = sctp_ulpq_reasm(ulpq, event);
103 /* Do ordering if needed. */
105 /* Create a temporary list to collect chunks on. */
106 skb_queue_head_init(&temp);
107 __skb_queue_tail(&temp, sctp_event2skb(event));
109 if (event->msg_flags & MSG_EOR)
110 event = sctp_ulpq_order(ulpq, event);
113 /* Send event to the ULP. 'event' is the sctp_ulpevent for
114 * very first SKB on the 'temp' list.
117 event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
118 sctp_ulpq_tail_event(ulpq, &temp);
124 /* Add a new event for propagation to the ULP. */
125 /* Clear the partial delivery mode for this socket. Note: This
126 * assumes that no association is currently in partial delivery mode.
128 int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc)
130 struct sctp_sock *sp = sctp_sk(sk);
132 if (atomic_dec_and_test(&sp->pd_mode)) {
133 /* This means there are no other associations in PD, so
134 * we can go ahead and clear out the lobby in one shot
136 if (!skb_queue_empty(&sp->pd_lobby)) {
137 skb_queue_splice_tail_init(&sp->pd_lobby,
138 &sk->sk_receive_queue);
142 /* There are other associations in PD, so we only need to
143 * pull stuff out of the lobby that belongs to the
144 * associations that is exiting PD (all of its notifications
147 if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
148 struct sk_buff *skb, *tmp;
149 struct sctp_ulpevent *event;
151 sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
152 event = sctp_skb2event(skb);
153 if (event->asoc == asoc) {
154 __skb_unlink(skb, &sp->pd_lobby);
155 __skb_queue_tail(&sk->sk_receive_queue,
165 /* Set the pd_mode on the socket and ulpq */
166 static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
168 struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
170 atomic_inc(&sp->pd_mode);
174 /* Clear the pd_mode and restart any pending messages waiting for delivery. */
175 static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
178 sctp_ulpq_reasm_drain(ulpq);
179 return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
182 int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sk_buff_head *skb_list)
184 struct sock *sk = ulpq->asoc->base.sk;
185 struct sctp_sock *sp = sctp_sk(sk);
186 struct sctp_ulpevent *event;
187 struct sk_buff_head *queue;
191 skb = __skb_peek(skb_list);
192 event = sctp_skb2event(skb);
194 /* If the socket is just going to throw this away, do not
195 * even try to deliver it.
197 if (sk->sk_shutdown & RCV_SHUTDOWN &&
198 (sk->sk_shutdown & SEND_SHUTDOWN ||
199 !sctp_ulpevent_is_notification(event)))
202 if (!sctp_ulpevent_is_notification(event)) {
203 sk_mark_napi_id(sk, skb);
204 sk_incoming_cpu_update(sk);
206 /* Check if the user wishes to receive this event. */
207 if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe))
210 /* If we are in partial delivery mode, post to the lobby until
211 * partial delivery is cleared, unless, of course _this_ is
212 * the association the cause of the partial delivery.
215 if (atomic_read(&sp->pd_mode) == 0) {
216 queue = &sk->sk_receive_queue;
219 /* If the association is in partial delivery, we
220 * need to finish delivering the partially processed
221 * packet before passing any other data. This is
222 * because we don't truly support stream interleaving.
224 if ((event->msg_flags & MSG_NOTIFICATION) ||
225 (SCTP_DATA_NOT_FRAG ==
226 (event->msg_flags & SCTP_DATA_FRAG_MASK)))
227 queue = &sp->pd_lobby;
229 clear_pd = event->msg_flags & MSG_EOR;
230 queue = &sk->sk_receive_queue;
234 * If fragment interleave is enabled, we
235 * can queue this to the receive queue instead
238 if (sp->frag_interleave)
239 queue = &sk->sk_receive_queue;
241 queue = &sp->pd_lobby;
245 skb_queue_splice_tail_init(skb_list, queue);
247 /* Did we just complete partial delivery and need to get
248 * rolling again? Move pending data to the receive
252 sctp_ulpq_clear_pd(ulpq);
254 if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) {
255 if (!sock_owned_by_user(sk))
256 sp->data_ready_signalled = 1;
257 sk->sk_data_ready(sk);
263 sctp_queue_purge_ulpevents(skb_list);
265 sctp_ulpevent_free(event);
270 /* 2nd Level Abstractions */
272 /* Helper function to store chunks that need to be reassembled. */
273 static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
274 struct sctp_ulpevent *event)
277 struct sctp_ulpevent *cevent;
282 /* See if it belongs at the end. */
283 pos = skb_peek_tail(&ulpq->reasm);
285 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
289 /* Short circuit just dropping it at the end. */
290 cevent = sctp_skb2event(pos);
292 if (TSN_lt(ctsn, tsn)) {
293 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
297 /* Find the right place in this list. We store them by TSN. */
298 skb_queue_walk(&ulpq->reasm, pos) {
299 cevent = sctp_skb2event(pos);
302 if (TSN_lt(tsn, ctsn))
306 /* Insert before pos. */
307 __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
311 /* Helper function to return an event corresponding to the reassembled
313 * This routine creates a re-assembled skb given the first and last skb's
314 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
315 * payload was fragmented on the way and ip had to reassemble them.
316 * We add the rest of skb's to the first skb's fraglist.
318 struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
319 struct sk_buff_head *queue,
320 struct sk_buff *f_frag,
321 struct sk_buff *l_frag)
324 struct sk_buff *new = NULL;
325 struct sctp_ulpevent *event;
326 struct sk_buff *pnext, *last;
327 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
329 /* Store the pointer to the 2nd skb */
330 if (f_frag == l_frag)
335 /* Get the last skb in the f_frag's frag_list if present. */
336 for (last = list; list; last = list, list = list->next)
339 /* Add the list of remaining fragments to the first fragments
345 if (skb_cloned(f_frag)) {
346 /* This is a cloned skb, we can't just modify
347 * the frag_list. We need a new skb to do that.
348 * Instead of calling skb_unshare(), we'll do it
349 * ourselves since we need to delay the free.
351 new = skb_copy(f_frag, GFP_ATOMIC);
353 return NULL; /* try again later */
355 sctp_skb_set_owner_r(new, f_frag->sk);
357 skb_shinfo(new)->frag_list = pos;
359 skb_shinfo(f_frag)->frag_list = pos;
362 /* Remove the first fragment from the reassembly queue. */
363 __skb_unlink(f_frag, queue);
365 /* if we did unshare, then free the old skb and re-assign */
375 /* Update the len and data_len fields of the first fragment. */
376 f_frag->len += pos->len;
377 f_frag->data_len += pos->len;
379 /* Remove the fragment from the reassembly queue. */
380 __skb_unlink(pos, queue);
382 /* Break if we have reached the last fragment. */
389 event = sctp_skb2event(f_frag);
390 SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
396 /* Helper function to check if an incoming chunk has filled up the last
397 * missing fragment in a SCTP datagram and return the corresponding event.
399 static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
402 struct sctp_ulpevent *cevent;
403 struct sk_buff *first_frag = NULL;
404 __u32 ctsn, next_tsn;
405 struct sctp_ulpevent *retval = NULL;
406 struct sk_buff *pd_first = NULL;
407 struct sk_buff *pd_last = NULL;
409 struct sctp_association *asoc;
412 /* Initialized to 0 just to avoid compiler warning message. Will
413 * never be used with this value. It is referenced only after it
414 * is set when we find the first fragment of a message.
418 /* The chunks are held in the reasm queue sorted by TSN.
419 * Walk through the queue sequentially and look for a sequence of
420 * fragmented chunks that complete a datagram.
421 * 'first_frag' and next_tsn are reset when we find a chunk which
422 * is the first fragment of a datagram. Once these 2 fields are set
423 * we expect to find the remaining middle fragments and the last
424 * fragment in order. If not, first_frag is reset to NULL and we
425 * start the next pass when we find another first fragment.
427 * There is a potential to do partial delivery if user sets
428 * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
429 * to see if can do PD.
431 skb_queue_walk(&ulpq->reasm, pos) {
432 cevent = sctp_skb2event(pos);
435 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
436 case SCTP_DATA_FIRST_FRAG:
437 /* If this "FIRST_FRAG" is the first
438 * element in the queue, then count it towards
441 if (skb_queue_is_first(&ulpq->reasm, pos)) {
455 case SCTP_DATA_MIDDLE_FRAG:
456 if ((first_frag) && (ctsn == next_tsn)) {
466 case SCTP_DATA_LAST_FRAG:
467 if (first_frag && (ctsn == next_tsn))
477 /* Make sure we can enter partial deliver.
478 * We can trigger partial delivery only if framgent
479 * interleave is set, or the socket is not already
480 * in partial delivery.
482 if (!sctp_sk(asoc->base.sk)->frag_interleave &&
483 atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
486 cevent = sctp_skb2event(pd_first);
487 pd_point = sctp_sk(asoc->base.sk)->pd_point;
488 if (pd_point && pd_point <= pd_len) {
489 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
494 sctp_ulpq_set_pd(ulpq);
500 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
501 &ulpq->reasm, first_frag, pos);
503 retval->msg_flags |= MSG_EOR;
507 /* Retrieve the next set of fragments of a partial message. */
508 static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
510 struct sk_buff *pos, *last_frag, *first_frag;
511 struct sctp_ulpevent *cevent;
512 __u32 ctsn, next_tsn;
514 struct sctp_ulpevent *retval;
516 /* The chunks are held in the reasm queue sorted by TSN.
517 * Walk through the queue sequentially and look for the first
518 * sequence of fragmented chunks.
521 if (skb_queue_empty(&ulpq->reasm))
524 last_frag = first_frag = NULL;
529 skb_queue_walk(&ulpq->reasm, pos) {
530 cevent = sctp_skb2event(pos);
533 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
534 case SCTP_DATA_FIRST_FRAG:
538 case SCTP_DATA_MIDDLE_FRAG:
543 } else if (next_tsn == ctsn) {
549 case SCTP_DATA_LAST_FRAG:
552 else if (ctsn != next_tsn)
562 /* We have the reassembled event. There is no need to look
566 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
567 &ulpq->reasm, first_frag, last_frag);
568 if (retval && is_last)
569 retval->msg_flags |= MSG_EOR;
575 /* Helper function to reassemble chunks. Hold chunks on the reasm queue that
578 static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
579 struct sctp_ulpevent *event)
581 struct sctp_ulpevent *retval = NULL;
583 /* Check if this is part of a fragmented message. */
584 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
585 event->msg_flags |= MSG_EOR;
589 sctp_ulpq_store_reasm(ulpq, event);
591 retval = sctp_ulpq_retrieve_reassembled(ulpq);
595 /* Do not even bother unless this is the next tsn to
599 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
600 if (TSN_lte(ctsn, ctsnap))
601 retval = sctp_ulpq_retrieve_partial(ulpq);
607 /* Retrieve the first part (sequential fragments) for partial delivery. */
608 static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
610 struct sk_buff *pos, *last_frag, *first_frag;
611 struct sctp_ulpevent *cevent;
612 __u32 ctsn, next_tsn;
613 struct sctp_ulpevent *retval;
615 /* The chunks are held in the reasm queue sorted by TSN.
616 * Walk through the queue sequentially and look for a sequence of
617 * fragmented chunks that start a datagram.
620 if (skb_queue_empty(&ulpq->reasm))
623 last_frag = first_frag = NULL;
627 skb_queue_walk(&ulpq->reasm, pos) {
628 cevent = sctp_skb2event(pos);
631 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
632 case SCTP_DATA_FIRST_FRAG:
641 case SCTP_DATA_MIDDLE_FRAG:
644 if (ctsn == next_tsn) {
651 case SCTP_DATA_LAST_FRAG:
663 /* We have the reassembled event. There is no need to look
667 retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
668 &ulpq->reasm, first_frag, last_frag);
673 * Flush out stale fragments from the reassembly queue when processing
676 * RFC 3758, Section 3.6
678 * After receiving and processing a FORWARD TSN, the data receiver MUST
679 * take cautions in updating its re-assembly queue. The receiver MUST
680 * remove any partially reassembled message, which is still missing one
681 * or more TSNs earlier than or equal to the new cumulative TSN point.
682 * In the event that the receiver has invoked the partial delivery API,
683 * a notification SHOULD also be generated to inform the upper layer API
684 * that the message being partially delivered will NOT be completed.
686 void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
688 struct sk_buff *pos, *tmp;
689 struct sctp_ulpevent *event;
692 if (skb_queue_empty(&ulpq->reasm))
695 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
696 event = sctp_skb2event(pos);
699 /* Since the entire message must be abandoned by the
700 * sender (item A3 in Section 3.5, RFC 3758), we can
701 * free all fragments on the list that are less then
702 * or equal to ctsn_point
704 if (TSN_lte(tsn, fwd_tsn)) {
705 __skb_unlink(pos, &ulpq->reasm);
706 sctp_ulpevent_free(event);
713 * Drain the reassembly queue. If we just cleared parted delivery, it
714 * is possible that the reassembly queue will contain already reassembled
715 * messages. Retrieve any such messages and give them to the user.
717 static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
719 struct sctp_ulpevent *event = NULL;
721 if (skb_queue_empty(&ulpq->reasm))
724 while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
725 struct sk_buff_head temp;
727 skb_queue_head_init(&temp);
728 __skb_queue_tail(&temp, sctp_event2skb(event));
730 /* Do ordering if needed. */
731 if (event->msg_flags & MSG_EOR)
732 event = sctp_ulpq_order(ulpq, event);
734 /* Send event to the ULP. 'event' is the
735 * sctp_ulpevent for very first SKB on the temp' list.
738 sctp_ulpq_tail_event(ulpq, &temp);
743 /* Helper function to gather skbs that have possibly become
744 * ordered by an an incoming chunk.
746 static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
747 struct sctp_ulpevent *event)
749 struct sk_buff_head *event_list;
750 struct sk_buff *pos, *tmp;
751 struct sctp_ulpevent *cevent;
752 struct sctp_stream *stream;
753 __u16 sid, csid, cssn;
756 stream = &ulpq->asoc->stream;
758 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
760 /* We are holding the chunks by stream, by SSN. */
761 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
762 cevent = (struct sctp_ulpevent *) pos->cb;
763 csid = cevent->stream;
766 /* Have we gone too far? */
770 /* Have we not gone far enough? */
774 if (cssn != sctp_ssn_peek(stream, in, sid))
777 /* Found it, so mark in the stream. */
778 sctp_ssn_next(stream, in, sid);
780 __skb_unlink(pos, &ulpq->lobby);
782 /* Attach all gathered skbs to the event. */
783 __skb_queue_tail(event_list, pos);
787 /* Helper function to store chunks needing ordering. */
788 static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
789 struct sctp_ulpevent *event)
792 struct sctp_ulpevent *cevent;
796 pos = skb_peek_tail(&ulpq->lobby);
798 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
805 cevent = (struct sctp_ulpevent *) pos->cb;
806 csid = cevent->stream;
809 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
813 if ((sid == csid) && SSN_lt(cssn, ssn)) {
814 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
818 /* Find the right place in this list. We store them by
819 * stream ID and then by SSN.
821 skb_queue_walk(&ulpq->lobby, pos) {
822 cevent = (struct sctp_ulpevent *) pos->cb;
823 csid = cevent->stream;
828 if (csid == sid && SSN_lt(ssn, cssn))
833 /* Insert before pos. */
834 __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
837 static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
838 struct sctp_ulpevent *event)
841 struct sctp_stream *stream;
843 /* Check if this message needs ordering. */
844 if (event->msg_flags & SCTP_DATA_UNORDERED)
847 /* Note: The stream ID must be verified before this routine. */
850 stream = &ulpq->asoc->stream;
852 /* Is this the expected SSN for this stream ID? */
853 if (ssn != sctp_ssn_peek(stream, in, sid)) {
854 /* We've received something out of order, so find where it
855 * needs to be placed. We order by stream and then by SSN.
857 sctp_ulpq_store_ordered(ulpq, event);
861 /* Mark that the next chunk has been found. */
862 sctp_ssn_next(stream, in, sid);
864 /* Go find any other chunks that were waiting for
867 sctp_ulpq_retrieve_ordered(ulpq, event);
872 /* Helper function to gather skbs that have possibly become
873 * ordered by forward tsn skipping their dependencies.
875 static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
877 struct sk_buff *pos, *tmp;
878 struct sctp_ulpevent *cevent;
879 struct sctp_ulpevent *event;
880 struct sctp_stream *stream;
881 struct sk_buff_head temp;
882 struct sk_buff_head *lobby = &ulpq->lobby;
885 stream = &ulpq->asoc->stream;
887 /* We are holding the chunks by stream, by SSN. */
888 skb_queue_head_init(&temp);
890 sctp_skb_for_each(pos, lobby, tmp) {
891 cevent = (struct sctp_ulpevent *) pos->cb;
892 csid = cevent->stream;
895 /* Have we gone too far? */
899 /* Have we not gone far enough? */
903 /* see if this ssn has been marked by skipping */
904 if (!SSN_lt(cssn, sctp_ssn_peek(stream, in, csid)))
907 __skb_unlink(pos, lobby);
909 /* Create a temporary list to collect chunks on. */
910 event = sctp_skb2event(pos);
912 /* Attach all gathered skbs to the event. */
913 __skb_queue_tail(&temp, pos);
916 /* If we didn't reap any data, see if the next expected SSN
917 * is next on the queue and if so, use that.
919 if (event == NULL && pos != (struct sk_buff *)lobby) {
920 cevent = (struct sctp_ulpevent *) pos->cb;
921 csid = cevent->stream;
924 if (csid == sid && cssn == sctp_ssn_peek(stream, in, csid)) {
925 sctp_ssn_next(stream, in, csid);
926 __skb_unlink(pos, lobby);
927 __skb_queue_tail(&temp, pos);
928 event = sctp_skb2event(pos);
932 /* Send event to the ULP. 'event' is the sctp_ulpevent for
933 * very first SKB on the 'temp' list.
936 /* see if we have more ordered that we can deliver */
937 sctp_ulpq_retrieve_ordered(ulpq, event);
938 sctp_ulpq_tail_event(ulpq, &temp);
942 /* Skip over an SSN. This is used during the processing of
943 * Forwared TSN chunk to skip over the abandoned ordered data
945 void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
947 struct sctp_stream *stream;
949 /* Note: The stream ID must be verified before this routine. */
950 stream = &ulpq->asoc->stream;
952 /* Is this an old SSN? If so ignore. */
953 if (SSN_lt(ssn, sctp_ssn_peek(stream, in, sid)))
956 /* Mark that we are no longer expecting this SSN or lower. */
957 sctp_ssn_skip(stream, in, sid, ssn);
959 /* Go find any other chunks that were waiting for
960 * ordering and deliver them if needed.
962 sctp_ulpq_reap_ordered(ulpq, sid);
965 __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list,
970 struct sk_buff *skb, *flist, *last;
971 struct sctp_ulpevent *event;
972 struct sctp_tsnmap *tsnmap;
974 tsnmap = &ulpq->asoc->peer.tsn_map;
976 while ((skb = skb_peek_tail(list)) != NULL) {
977 event = sctp_skb2event(skb);
980 /* Don't renege below the Cumulative TSN ACK Point. */
981 if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap)))
984 /* Events in ordering queue may have multiple fragments
985 * corresponding to additional TSNs. Sum the total
986 * freed space; find the last TSN.
988 freed += skb_headlen(skb);
989 flist = skb_shinfo(skb)->frag_list;
990 for (last = flist; flist; flist = flist->next) {
992 freed += skb_headlen(last);
995 last_tsn = sctp_skb2event(last)->tsn;
999 /* Unlink the event, then renege all applicable TSNs. */
1000 __skb_unlink(skb, list);
1001 sctp_ulpevent_free(event);
1002 while (TSN_lte(tsn, last_tsn)) {
1003 sctp_tsnmap_renege(tsnmap, tsn);
1006 if (freed >= needed)
1013 /* Renege 'needed' bytes from the ordering queue. */
1014 static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
1016 return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
1019 /* Renege 'needed' bytes from the reassembly queue. */
1020 static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
1022 return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
1025 /* Partial deliver the first message as there is pressure on rwnd. */
1026 void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
1029 struct sctp_ulpevent *event;
1030 struct sctp_association *asoc;
1031 struct sctp_sock *sp;
1033 struct sk_buff *skb;
1036 sp = sctp_sk(asoc->base.sk);
1038 /* If the association is already in Partial Delivery mode
1039 * we have nothing to do.
1044 /* Data must be at or below the Cumulative TSN ACK Point to
1045 * start partial delivery.
1047 skb = skb_peek(&asoc->ulpq.reasm);
1049 ctsn = sctp_skb2event(skb)->tsn;
1050 if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)))
1054 /* If the user enabled fragment interleave socket option,
1055 * multiple associations can enter partial delivery.
1056 * Otherwise, we can only enter partial delivery if the
1057 * socket is not in partial deliver mode.
1059 if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
1060 /* Is partial delivery possible? */
1061 event = sctp_ulpq_retrieve_first(ulpq);
1062 /* Send event to the ULP. */
1064 struct sk_buff_head temp;
1066 skb_queue_head_init(&temp);
1067 __skb_queue_tail(&temp, sctp_event2skb(event));
1068 sctp_ulpq_tail_event(ulpq, &temp);
1069 sctp_ulpq_set_pd(ulpq);
1075 /* Renege some packets to make room for an incoming chunk. */
1076 void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
1079 struct sctp_association *asoc = ulpq->asoc;
1083 needed = ntohs(chunk->chunk_hdr->length) -
1084 sizeof(struct sctp_data_chunk);
1086 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
1087 freed = sctp_ulpq_renege_order(ulpq, needed);
1089 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
1091 /* If able to free enough room, accept this chunk. */
1092 if (sk_rmem_schedule(asoc->base.sk, chunk->skb, needed) &&
1094 int retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
1096 * Enter partial delivery if chunk has not been
1097 * delivered; otherwise, drain the reassembly queue.
1100 sctp_ulpq_partial_delivery(ulpq, gfp);
1101 else if (retval == 1)
1102 sctp_ulpq_reasm_drain(ulpq);
1105 sk_mem_reclaim(asoc->base.sk);
1110 /* Notify the application if an association is aborted and in
1111 * partial delivery mode. Send up any pending received messages.
1113 void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
1115 struct sctp_ulpevent *ev = NULL;
1116 struct sctp_sock *sp;
1122 sk = ulpq->asoc->base.sk;
1124 if (sctp_ulpevent_type_enabled(ulpq->asoc->subscribe,
1125 SCTP_PARTIAL_DELIVERY_EVENT))
1126 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
1127 SCTP_PARTIAL_DELIVERY_ABORTED,
1130 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1132 /* If there is data waiting, send it up the socket now. */
1133 if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) {
1134 sp->data_ready_signalled = 1;
1135 sk->sk_data_ready(sk);