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!

1 files changed, 864 insertions, 0 deletions

diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
new file mode 100644
index 000000000000..d5dd2cf7ac4a
--- /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);
+}