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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sctp/ulpqueue.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/sctp/ulpqueue.c')
-rw-r--r--net/sctp/ulpqueue.c864
1 files changed, 864 insertions, 0 deletions
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
new file mode 100644
index 00000000000..d5dd2cf7ac4
--- /dev/null
+++ b/net/sctp/ulpqueue.c
@@ -0,0 +1,864 @@
+/* SCTP kernel reference Implementation
+ * (C) Copyright IBM Corp. 2001, 2004
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001 Intel Corp.
+ * Copyright (c) 2001 Nokia, Inc.
+ * Copyright (c) 2001 La Monte H.P. Yarroll
+ *
+ * This abstraction carries sctp events to the ULP (sockets).
+ *
+ * The SCTP reference implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * The SCTP reference implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING. If not, write to
+ * the Free Software Foundation, 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ * lksctp developers <lksctp-developers@lists.sourceforge.net>
+ *
+ * Or submit a bug report through the following website:
+ * http://www.sf.net/projects/lksctp
+ *
+ * Written or modified by:
+ * Jon Grimm <jgrimm@us.ibm.com>
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Sridhar Samudrala <sri@us.ibm.com>
+ *
+ * Any bugs reported given to us we will try to fix... any fixes shared will
+ * be incorporated into the next SCTP release.
+ */
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/sctp/structs.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/* Forward declarations for internal helpers. */
+static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *);
+static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *,
+ struct sctp_ulpevent *);
+
+/* 1st Level Abstractions */
+
+/* Initialize a ULP queue from a block of memory. */
+struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
+ struct sctp_association *asoc)
+{
+ memset(ulpq, 0, sizeof(struct sctp_ulpq));
+
+ ulpq->asoc = asoc;
+ skb_queue_head_init(&ulpq->reasm);
+ skb_queue_head_init(&ulpq->lobby);
+ ulpq->pd_mode = 0;
+ ulpq->malloced = 0;
+
+ return ulpq;
+}
+
+
+/* Flush the reassembly and ordering queues. */
+static void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *skb;
+ struct sctp_ulpevent *event;
+
+ while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
+ event = sctp_skb2event(skb);
+ sctp_ulpevent_free(event);
+ }
+
+ while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
+ event = sctp_skb2event(skb);
+ sctp_ulpevent_free(event);
+ }
+
+}
+
+/* Dispose of a ulpqueue. */
+void sctp_ulpq_free(struct sctp_ulpq *ulpq)
+{
+ sctp_ulpq_flush(ulpq);
+ if (ulpq->malloced)
+ kfree(ulpq);
+}
+
+/* Process an incoming DATA chunk. */
+int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
+ int gfp)
+{
+ struct sk_buff_head temp;
+ sctp_data_chunk_t *hdr;
+ struct sctp_ulpevent *event;
+
+ hdr = (sctp_data_chunk_t *) chunk->chunk_hdr;
+
+ /* Create an event from the incoming chunk. */
+ event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
+ if (!event)
+ return -ENOMEM;
+
+ /* Do reassembly if needed. */
+ event = sctp_ulpq_reasm(ulpq, event);
+
+ /* Do ordering if needed. */
+ if ((event) && (event->msg_flags & MSG_EOR)){
+ /* Create a temporary list to collect chunks on. */
+ skb_queue_head_init(&temp);
+ __skb_queue_tail(&temp, sctp_event2skb(event));
+
+ event = sctp_ulpq_order(ulpq, event);
+ }
+
+ /* Send event to the ULP. */
+ if (event)
+ sctp_ulpq_tail_event(ulpq, event);
+
+ return 0;
+}
+
+/* Add a new event for propagation to the ULP. */
+/* Clear the partial delivery mode for this socket. Note: This
+ * assumes that no association is currently in partial delivery mode.
+ */
+int sctp_clear_pd(struct sock *sk)
+{
+ struct sctp_sock *sp = sctp_sk(sk);
+
+ sp->pd_mode = 0;
+ if (!skb_queue_empty(&sp->pd_lobby)) {
+ struct list_head *list;
+ sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue);
+ list = (struct list_head *)&sctp_sk(sk)->pd_lobby;
+ INIT_LIST_HEAD(list);
+ return 1;
+ }
+ return 0;
+}
+
+/* Clear the pd_mode and restart any pending messages waiting for delivery. */
+static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
+{
+ ulpq->pd_mode = 0;
+ return sctp_clear_pd(ulpq->asoc->base.sk);
+}
+
+
+
+int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
+{
+ struct sock *sk = ulpq->asoc->base.sk;
+ struct sk_buff_head *queue;
+ int clear_pd = 0;
+
+ /* If the socket is just going to throw this away, do not
+ * even try to deliver it.
+ */
+ if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN))
+ goto out_free;
+
+ /* Check if the user wishes to receive this event. */
+ if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe))
+ goto out_free;
+
+ /* If we are in partial delivery mode, post to the lobby until
+ * partial delivery is cleared, unless, of course _this_ is
+ * the association the cause of the partial delivery.
+ */
+
+ if (!sctp_sk(sk)->pd_mode) {
+ queue = &sk->sk_receive_queue;
+ } else if (ulpq->pd_mode) {
+ if (event->msg_flags & MSG_NOTIFICATION)
+ queue = &sctp_sk(sk)->pd_lobby;
+ else {
+ clear_pd = event->msg_flags & MSG_EOR;
+ queue = &sk->sk_receive_queue;
+ }
+ } else
+ queue = &sctp_sk(sk)->pd_lobby;
+
+
+ /* If we are harvesting multiple skbs they will be
+ * collected on a list.
+ */
+ if (sctp_event2skb(event)->list)
+ sctp_skb_list_tail(sctp_event2skb(event)->list, queue);
+ else
+ __skb_queue_tail(queue, sctp_event2skb(event));
+
+ /* Did we just complete partial delivery and need to get
+ * rolling again? Move pending data to the receive
+ * queue.
+ */
+ if (clear_pd)
+ sctp_ulpq_clear_pd(ulpq);
+
+ if (queue == &sk->sk_receive_queue)
+ sk->sk_data_ready(sk, 0);
+ return 1;
+
+out_free:
+ if (sctp_event2skb(event)->list)
+ sctp_queue_purge_ulpevents(sctp_event2skb(event)->list);
+ else
+ sctp_ulpevent_free(event);
+ return 0;
+}
+
+/* 2nd Level Abstractions */
+
+/* Helper function to store chunks that need to be reassembled. */
+static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *cevent;
+ __u32 tsn, ctsn;
+
+ tsn = event->tsn;
+
+ /* See if it belongs at the end. */
+ pos = skb_peek_tail(&ulpq->reasm);
+ if (!pos) {
+ __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
+ return;
+ }
+
+ /* Short circuit just dropping it at the end. */
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+ if (TSN_lt(ctsn, tsn)) {
+ __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
+ return;
+ }
+
+ /* Find the right place in this list. We store them by TSN. */
+ skb_queue_walk(&ulpq->reasm, pos) {
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+
+ if (TSN_lt(tsn, ctsn))
+ break;
+ }
+
+ /* Insert before pos. */
+ __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm);
+
+}
+
+/* Helper function to return an event corresponding to the reassembled
+ * datagram.
+ * This routine creates a re-assembled skb given the first and last skb's
+ * as stored in the reassembly queue. The skb's may be non-linear if the sctp
+ * payload was fragmented on the way and ip had to reassemble them.
+ * We add the rest of skb's to the first skb's fraglist.
+ */
+static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff *f_frag, struct sk_buff *l_frag)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *event;
+ struct sk_buff *pnext, *last;
+ struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
+
+ /* Store the pointer to the 2nd skb */
+ if (f_frag == l_frag)
+ pos = NULL;
+ else
+ pos = f_frag->next;
+
+ /* Get the last skb in the f_frag's frag_list if present. */
+ for (last = list; list; last = list, list = list->next);
+
+ /* Add the list of remaining fragments to the first fragments
+ * frag_list.
+ */
+ if (last)
+ last->next = pos;
+ else
+ skb_shinfo(f_frag)->frag_list = pos;
+
+ /* Remove the first fragment from the reassembly queue. */
+ __skb_unlink(f_frag, f_frag->list);
+ while (pos) {
+
+ pnext = pos->next;
+
+ /* Update the len and data_len fields of the first fragment. */
+ f_frag->len += pos->len;
+ f_frag->data_len += pos->len;
+
+ /* Remove the fragment from the reassembly queue. */
+ __skb_unlink(pos, pos->list);
+
+ /* Break if we have reached the last fragment. */
+ if (pos == l_frag)
+ break;
+ pos->next = pnext;
+ pos = pnext;
+ };
+
+ event = sctp_skb2event(f_frag);
+ SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS);
+
+ return event;
+}
+
+
+/* Helper function to check if an incoming chunk has filled up the last
+ * missing fragment in a SCTP datagram and return the corresponding event.
+ */
+static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *cevent;
+ struct sk_buff *first_frag = NULL;
+ __u32 ctsn, next_tsn;
+ struct sctp_ulpevent *retval = NULL;
+
+ /* Initialized to 0 just to avoid compiler warning message. Will
+ * never be used with this value. It is referenced only after it
+ * is set when we find the first fragment of a message.
+ */
+ next_tsn = 0;
+
+ /* The chunks are held in the reasm queue sorted by TSN.
+ * Walk through the queue sequentially and look for a sequence of
+ * fragmented chunks that complete a datagram.
+ * 'first_frag' and next_tsn are reset when we find a chunk which
+ * is the first fragment of a datagram. Once these 2 fields are set
+ * we expect to find the remaining middle fragments and the last
+ * fragment in order. If not, first_frag is reset to NULL and we
+ * start the next pass when we find another first fragment.
+ */
+ skb_queue_walk(&ulpq->reasm, pos) {
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+
+ switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
+ case SCTP_DATA_FIRST_FRAG:
+ first_frag = pos;
+ next_tsn = ctsn + 1;
+ break;
+
+ case SCTP_DATA_MIDDLE_FRAG:
+ if ((first_frag) && (ctsn == next_tsn))
+ next_tsn++;
+ else
+ first_frag = NULL;
+ break;
+
+ case SCTP_DATA_LAST_FRAG:
+ if (first_frag && (ctsn == next_tsn))
+ goto found;
+ else
+ first_frag = NULL;
+ break;
+ };
+
+ }
+done:
+ return retval;
+found:
+ retval = sctp_make_reassembled_event(first_frag, pos);
+ if (retval)
+ retval->msg_flags |= MSG_EOR;
+ goto done;
+}
+
+/* Retrieve the next set of fragments of a partial message. */
+static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *pos, *last_frag, *first_frag;
+ struct sctp_ulpevent *cevent;
+ __u32 ctsn, next_tsn;
+ int is_last;
+ struct sctp_ulpevent *retval;
+
+ /* The chunks are held in the reasm queue sorted by TSN.
+ * Walk through the queue sequentially and look for the first
+ * sequence of fragmented chunks.
+ */
+
+ if (skb_queue_empty(&ulpq->reasm))
+ return NULL;
+
+ last_frag = first_frag = NULL;
+ retval = NULL;
+ next_tsn = 0;
+ is_last = 0;
+
+ skb_queue_walk(&ulpq->reasm, pos) {
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+
+ switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
+ case SCTP_DATA_MIDDLE_FRAG:
+ if (!first_frag) {
+ first_frag = pos;
+ next_tsn = ctsn + 1;
+ last_frag = pos;
+ } else if (next_tsn == ctsn)
+ next_tsn++;
+ else
+ goto done;
+ break;
+ case SCTP_DATA_LAST_FRAG:
+ if (!first_frag)
+ first_frag = pos;
+ else if (ctsn != next_tsn)
+ goto done;
+ last_frag = pos;
+ is_last = 1;
+ goto done;
+ default:
+ return NULL;
+ };
+ }
+
+ /* We have the reassembled event. There is no need to look
+ * further.
+ */
+done:
+ retval = sctp_make_reassembled_event(first_frag, last_frag);
+ if (retval && is_last)
+ retval->msg_flags |= MSG_EOR;
+
+ return retval;
+}
+
+
+/* Helper function to reassemble chunks. Hold chunks on the reasm queue that
+ * need reassembling.
+ */
+static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ struct sctp_ulpevent *retval = NULL;
+
+ /* Check if this is part of a fragmented message. */
+ if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
+ event->msg_flags |= MSG_EOR;
+ return event;
+ }
+
+ sctp_ulpq_store_reasm(ulpq, event);
+ if (!ulpq->pd_mode)
+ retval = sctp_ulpq_retrieve_reassembled(ulpq);
+ else {
+ __u32 ctsn, ctsnap;
+
+ /* Do not even bother unless this is the next tsn to
+ * be delivered.
+ */
+ ctsn = event->tsn;
+ ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
+ if (TSN_lte(ctsn, ctsnap))
+ retval = sctp_ulpq_retrieve_partial(ulpq);
+ }
+
+ return retval;
+}
+
+/* Retrieve the first part (sequential fragments) for partial delivery. */
+static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *pos, *last_frag, *first_frag;
+ struct sctp_ulpevent *cevent;
+ __u32 ctsn, next_tsn;
+ struct sctp_ulpevent *retval;
+
+ /* The chunks are held in the reasm queue sorted by TSN.
+ * Walk through the queue sequentially and look for a sequence of
+ * fragmented chunks that start a datagram.
+ */
+
+ if (skb_queue_empty(&ulpq->reasm))
+ return NULL;
+
+ last_frag = first_frag = NULL;
+ retval = NULL;
+ next_tsn = 0;
+
+ skb_queue_walk(&ulpq->reasm, pos) {
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+
+ switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
+ case SCTP_DATA_FIRST_FRAG:
+ if (!first_frag) {
+ first_frag = pos;
+ next_tsn = ctsn + 1;
+ last_frag = pos;
+ } else
+ goto done;
+ break;
+
+ case SCTP_DATA_MIDDLE_FRAG:
+ if (!first_frag)
+ return NULL;
+ if (ctsn == next_tsn) {
+ next_tsn++;
+ last_frag = pos;
+ } else
+ goto done;
+ break;
+ default:
+ return NULL;
+ };
+ }
+
+ /* We have the reassembled event. There is no need to look
+ * further.
+ */
+done:
+ retval = sctp_make_reassembled_event(first_frag, last_frag);
+ return retval;
+}
+
+/* Helper function to gather skbs that have possibly become
+ * ordered by an an incoming chunk.
+ */
+static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ struct sk_buff *pos, *tmp;
+ struct sctp_ulpevent *cevent;
+ struct sctp_stream *in;
+ __u16 sid, csid;
+ __u16 ssn, cssn;
+
+ sid = event->stream;
+ ssn = event->ssn;
+ in = &ulpq->asoc->ssnmap->in;
+
+ /* We are holding the chunks by stream, by SSN. */
+ sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
+ cevent = (struct sctp_ulpevent *) pos->cb;
+ csid = cevent->stream;
+ cssn = cevent->ssn;
+
+ /* Have we gone too far? */
+ if (csid > sid)
+ break;
+
+ /* Have we not gone far enough? */
+ if (csid < sid)
+ continue;
+
+ if (cssn != sctp_ssn_peek(in, sid))
+ break;
+
+ /* Found it, so mark in the ssnmap. */
+ sctp_ssn_next(in, sid);
+
+ __skb_unlink(pos, pos->list);
+
+ /* Attach all gathered skbs to the event. */
+ __skb_queue_tail(sctp_event2skb(event)->list, pos);
+ }
+}
+
+/* Helper function to store chunks needing ordering. */
+static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *cevent;
+ __u16 sid, csid;
+ __u16 ssn, cssn;
+
+ pos = skb_peek_tail(&ulpq->lobby);
+ if (!pos) {
+ __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
+ return;
+ }
+
+ sid = event->stream;
+ ssn = event->ssn;
+
+ cevent = (struct sctp_ulpevent *) pos->cb;
+ csid = cevent->stream;
+ cssn = cevent->ssn;
+ if (sid > csid) {
+ __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
+ return;
+ }
+
+ if ((sid == csid) && SSN_lt(cssn, ssn)) {
+ __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
+ return;
+ }
+
+ /* Find the right place in this list. We store them by
+ * stream ID and then by SSN.
+ */
+ skb_queue_walk(&ulpq->lobby, pos) {
+ cevent = (struct sctp_ulpevent *) pos->cb;
+ csid = cevent->stream;
+ cssn = cevent->ssn;
+
+ if (csid > sid)
+ break;
+ if (csid == sid && SSN_lt(ssn, cssn))
+ break;
+ }
+
+
+ /* Insert before pos. */
+ __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby);
+
+}
+
+static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ __u16 sid, ssn;
+ struct sctp_stream *in;
+
+ /* Check if this message needs ordering. */
+ if (SCTP_DATA_UNORDERED & event->msg_flags)
+ return event;
+
+ /* Note: The stream ID must be verified before this routine. */
+ sid = event->stream;
+ ssn = event->ssn;
+ in = &ulpq->asoc->ssnmap->in;
+
+ /* Is this the expected SSN for this stream ID? */
+ if (ssn != sctp_ssn_peek(in, sid)) {
+ /* We've received something out of order, so find where it
+ * needs to be placed. We order by stream and then by SSN.
+ */
+ sctp_ulpq_store_ordered(ulpq, event);
+ return NULL;
+ }
+
+ /* Mark that the next chunk has been found. */
+ sctp_ssn_next(in, sid);
+
+ /* Go find any other chunks that were waiting for
+ * ordering.
+ */
+ sctp_ulpq_retrieve_ordered(ulpq, event);
+
+ return event;
+}
+
+/* Helper function to gather skbs that have possibly become
+ * ordered by forward tsn skipping their dependencies.
+ */
+static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *pos, *tmp;
+ struct sctp_ulpevent *cevent;
+ struct sctp_ulpevent *event = NULL;
+ struct sctp_stream *in;
+ struct sk_buff_head temp;
+ __u16 csid, cssn;
+
+ in = &ulpq->asoc->ssnmap->in;
+
+ /* We are holding the chunks by stream, by SSN. */
+ sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
+ cevent = (struct sctp_ulpevent *) pos->cb;
+ csid = cevent->stream;
+ cssn = cevent->ssn;
+
+ if (cssn != sctp_ssn_peek(in, csid))
+ break;
+
+ /* Found it, so mark in the ssnmap. */
+ sctp_ssn_next(in, csid);
+
+ __skb_unlink(pos, pos->list);
+ if (!event) {
+ /* Create a temporary list to collect chunks on. */
+ event = sctp_skb2event(pos);
+ skb_queue_head_init(&temp);
+ __skb_queue_tail(&temp, sctp_event2skb(event));
+ } else {
+ /* Attach all gathered skbs to the event. */
+ __skb_queue_tail(sctp_event2skb(event)->list, pos);
+ }
+ }
+
+ /* Send event to the ULP. */
+ if (event)
+ sctp_ulpq_tail_event(ulpq, event);
+}
+
+/* Skip over an SSN. */
+void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
+{
+ struct sctp_stream *in;
+
+ /* Note: The stream ID must be verified before this routine. */
+ in = &ulpq->asoc->ssnmap->in;
+
+ /* Is this an old SSN? If so ignore. */
+ if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
+ return;
+
+ /* Mark that we are no longer expecting this SSN or lower. */
+ sctp_ssn_skip(in, sid, ssn);
+
+ /* Go find any other chunks that were waiting for
+ * ordering and deliver them if needed.
+ */
+ sctp_ulpq_reap_ordered(ulpq);
+ return;
+}
+
+/* Renege 'needed' bytes from the ordering queue. */
+static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
+{
+ __u16 freed = 0;
+ __u32 tsn;
+ struct sk_buff *skb;
+ struct sctp_ulpevent *event;
+ struct sctp_tsnmap *tsnmap;
+
+ tsnmap = &ulpq->asoc->peer.tsn_map;
+
+ while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) {
+ freed += skb_headlen(skb);
+ event = sctp_skb2event(skb);
+ tsn = event->tsn;
+
+ sctp_ulpevent_free(event);
+ sctp_tsnmap_renege(tsnmap, tsn);
+ if (freed >= needed)
+ return freed;
+ }
+
+ return freed;
+}
+
+/* Renege 'needed' bytes from the reassembly queue. */
+static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
+{
+ __u16 freed = 0;
+ __u32 tsn;
+ struct sk_buff *skb;
+ struct sctp_ulpevent *event;
+ struct sctp_tsnmap *tsnmap;
+
+ tsnmap = &ulpq->asoc->peer.tsn_map;
+
+ /* Walk backwards through the list, reneges the newest tsns. */
+ while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) {
+ freed += skb_headlen(skb);
+ event = sctp_skb2event(skb);
+ tsn = event->tsn;
+
+ sctp_ulpevent_free(event);
+ sctp_tsnmap_renege(tsnmap, tsn);
+ if (freed >= needed)
+ return freed;
+ }
+
+ return freed;
+}
+
+/* Partial deliver the first message as there is pressure on rwnd. */
+void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
+ struct sctp_chunk *chunk, int gfp)
+{
+ struct sctp_ulpevent *event;
+ struct sctp_association *asoc;
+
+ asoc = ulpq->asoc;
+
+ /* Are we already in partial delivery mode? */
+ if (!sctp_sk(asoc->base.sk)->pd_mode) {
+
+ /* Is partial delivery possible? */
+ event = sctp_ulpq_retrieve_first(ulpq);
+ /* Send event to the ULP. */
+ if (event) {
+ sctp_ulpq_tail_event(ulpq, event);
+ sctp_sk(asoc->base.sk)->pd_mode = 1;
+ ulpq->pd_mode = 1;
+ return;
+ }
+ }
+}
+
+/* Renege some packets to make room for an incoming chunk. */
+void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
+ int gfp)
+{
+ struct sctp_association *asoc;
+ __u16 needed, freed;
+
+ asoc = ulpq->asoc;
+
+ if (chunk) {
+ needed = ntohs(chunk->chunk_hdr->length);
+ needed -= sizeof(sctp_data_chunk_t);
+ } else
+ needed = SCTP_DEFAULT_MAXWINDOW;
+
+ freed = 0;
+
+ if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
+ freed = sctp_ulpq_renege_order(ulpq, needed);
+ if (freed < needed) {
+ freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
+ }
+ }
+ /* If able to free enough room, accept this chunk. */
+ if (chunk && (freed >= needed)) {
+ __u32 tsn;
+ tsn = ntohl(chunk->subh.data_hdr->tsn);
+ sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn);
+ sctp_ulpq_tail_data(ulpq, chunk, gfp);
+
+ sctp_ulpq_partial_delivery(ulpq, chunk, gfp);
+ }
+
+ return;
+}
+
+
+
+/* Notify the application if an association is aborted and in
+ * partial delivery mode. Send up any pending received messages.
+ */
+void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, int gfp)
+{
+ struct sctp_ulpevent *ev = NULL;
+ struct sock *sk;
+
+ if (!ulpq->pd_mode)
+ return;
+
+ sk = ulpq->asoc->base.sk;
+ if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
+ &sctp_sk(sk)->subscribe))
+ ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
+ SCTP_PARTIAL_DELIVERY_ABORTED,
+ gfp);
+ if (ev)
+ __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
+
+ /* If there is data waiting, send it up the socket now. */
+ if (sctp_ulpq_clear_pd(ulpq) || ev)
+ sk->sk_data_ready(sk, 0);
+}