nfsd: simplify fh_verify access checks
[safe/jmp/linux-2.6] / net / sctp / associola.c
index eaad5c5..7eed77a 100644 (file)
@@ -1,21 +1,21 @@
-/* SCTP kernel reference Implementation
+/* SCTP kernel 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 La Monte H.P. Yarroll
  *
- * This file is part of the SCTP kernel reference Implementation
+ * This file is part of the SCTP kernel implementation
  *
  * This module provides the abstraction for an SCTP association.
  *
- * The SCTP reference implementation is free software;
+ * This SCTP 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
+ * This SCTP 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.
@@ -61,6 +61,7 @@
 
 /* Forward declarations for internal functions. */
 static void sctp_assoc_bh_rcv(struct work_struct *work);
+static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
 
 
 /* 1st Level Abstractions. */
@@ -111,6 +112,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
        asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
                                        * 1000;
        asoc->frag_point = 0;
+       asoc->user_frag = sp->user_frag;
 
        /* Set the association max_retrans and RTO values from the
         * socket values.
@@ -135,6 +137,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 
        /* Set association default SACK delay */
        asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
+       asoc->sackfreq = sp->sackfreq;
 
        /* Set the association default flags controlling
         * Heartbeat, SACK delay, and Path MTU Discovery.
@@ -167,11 +170,9 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
                sp->autoclose * HZ;
 
        /* Initilizes the timers */
-       for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
-               init_timer(&asoc->timers[i]);
-               asoc->timers[i].function = sctp_timer_events[i];
-               asoc->timers[i].data = (unsigned long) asoc;
-       }
+       for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
+               setup_timer(&asoc->timers[i], sctp_timer_events[i],
+                               (unsigned long)asoc);
 
        /* Pull default initialization values from the sock options.
         * Note: This assumes that the values have already been
@@ -202,6 +203,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
        asoc->a_rwnd = asoc->rwnd;
 
        asoc->rwnd_over = 0;
+       asoc->rwnd_press = 0;
 
        /* Use my own max window until I learn something better.  */
        asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
@@ -244,6 +246,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
        asoc->addip_serial = asoc->c.initial_tsn;
 
        INIT_LIST_HEAD(&asoc->addip_chunk_list);
+       INIT_LIST_HEAD(&asoc->asconf_ack_list);
 
        /* Make an empty list of remote transport addresses.  */
        INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
@@ -261,11 +264,16 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
         * already received one packet.]
         */
        asoc->peer.sack_needed = 1;
+       asoc->peer.sack_cnt = 0;
 
-       /* Assume that the peer recongizes ASCONF until reported otherwise
-        * via an ERROR chunk.
+       /* Assume that the peer will tell us if he recognizes ASCONF
+        * as part of INIT exchange.
+        * The sctp_addip_noauth option is there for backward compatibilty
+        * and will revert old behavior.
         */
        asoc->peer.asconf_capable = 0;
+       if (sctp_addip_noauth)
+               asoc->peer.asconf_capable = 1;
 
        /* Create an input queue.  */
        sctp_inq_init(&asoc->base.inqueue);
@@ -277,8 +285,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
        if (!sctp_ulpq_init(&asoc->ulpq, asoc))
                goto fail_init;
 
-       /* Set up the tsn tracking. */
-       sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
+       memset(&asoc->peer.tsn_map, 0, sizeof(struct sctp_tsnmap));
 
        asoc->need_ecne = 0;
 
@@ -288,7 +295,8 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
         * told otherwise.
         */
        asoc->peer.ipv4_address = 1;
-       asoc->peer.ipv6_address = 1;
+       if (asoc->base.sk->sk_family == PF_INET6)
+               asoc->peer.ipv6_address = 1;
        INIT_LIST_HEAD(&asoc->asocs);
 
        asoc->autoclose = sp->autoclose;
@@ -396,6 +404,8 @@ void sctp_association_free(struct sctp_association *asoc)
        /* Dispose of any pending chunks on the inqueue. */
        sctp_inq_free(&asoc->base.inqueue);
 
+       sctp_tsnmap_free(&asoc->peer.tsn_map);
+
        /* Free ssnmap storage. */
        sctp_ssnmap_free(asoc->ssnmap);
 
@@ -429,8 +439,7 @@ void sctp_association_free(struct sctp_association *asoc)
        asoc->peer.transport_count = 0;
 
        /* Free any cached ASCONF_ACK chunk. */
-       if (asoc->addip_last_asconf_ack)
-               sctp_chunk_free(asoc->addip_last_asconf_ack);
+       sctp_assoc_free_asconf_acks(asoc);
 
        /* Free any cached ASCONF chunk. */
        if (asoc->addip_last_asconf)
@@ -459,7 +468,7 @@ static void sctp_association_destroy(struct sctp_association *asoc)
                spin_unlock_bh(&sctp_assocs_id_lock);
        }
 
-       BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
+       WARN_ON(atomic_read(&asoc->rmem_alloc));
 
        if (asoc->base.malloced) {
                kfree(asoc);
@@ -471,6 +480,15 @@ static void sctp_association_destroy(struct sctp_association *asoc)
 void sctp_assoc_set_primary(struct sctp_association *asoc,
                            struct sctp_transport *transport)
 {
+       int changeover = 0;
+
+       /* it's a changeover only if we already have a primary path
+        * that we are changing
+        */
+       if (asoc->peer.primary_path != NULL &&
+           asoc->peer.primary_path != transport)
+               changeover = 1 ;
+
        asoc->peer.primary_path = transport;
 
        /* Set a default msg_name for events. */
@@ -496,12 +514,12 @@ void sctp_assoc_set_primary(struct sctp_association *asoc,
         * double switch to the same destination address.
         */
        if (transport->cacc.changeover_active)
-               transport->cacc.cycling_changeover = 1;
+               transport->cacc.cycling_changeover = changeover;
 
        /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
         * a changeover has occurred.
         */
-       transport->cacc.changeover_active = 1;
+       transport->cacc.changeover_active = changeover;
 
        /* 3) The sender MUST store the next TSN to be sent in
         * next_tsn_at_change.
@@ -551,6 +569,48 @@ void sctp_assoc_rm_peer(struct sctp_association *asoc,
        if (asoc->init_last_sent_to == peer)
                asoc->init_last_sent_to = NULL;
 
+       /* If we remove the transport an SHUTDOWN was last sent to, set it
+        * to NULL. Combined with the update of the retran path above, this
+        * will cause the next SHUTDOWN to be sent to the next available
+        * transport, maintaining the cycle.
+        */
+       if (asoc->shutdown_last_sent_to == peer)
+               asoc->shutdown_last_sent_to = NULL;
+
+       /* If we remove the transport an ASCONF was last sent to, set it to
+        * NULL.
+        */
+       if (asoc->addip_last_asconf &&
+           asoc->addip_last_asconf->transport == peer)
+               asoc->addip_last_asconf->transport = NULL;
+
+       /* If we have something on the transmitted list, we have to
+        * save it off.  The best place is the active path.
+        */
+       if (!list_empty(&peer->transmitted)) {
+               struct sctp_transport *active = asoc->peer.active_path;
+               struct sctp_chunk *ch;
+
+               /* Reset the transport of each chunk on this list */
+               list_for_each_entry(ch, &peer->transmitted,
+                                       transmitted_list) {
+                       ch->transport = NULL;
+                       ch->rtt_in_progress = 0;
+               }
+
+               list_splice_tail_init(&peer->transmitted,
+                                       &active->transmitted);
+
+               /* Start a T3 timer here in case it wasn't running so
+                * that these migrated packets have a chance to get
+                * retrnasmitted.
+                */
+               if (!timer_pending(&active->T3_rtx_timer))
+                       if (!mod_timer(&active->T3_rtx_timer,
+                                       jiffies + active->rto))
+                               sctp_transport_hold(active);
+       }
+
        asoc->peer.transport_count--;
 
        sctp_transport_free(peer);
@@ -585,11 +645,12 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
        /* Check to see if this is a duplicate. */
        peer = sctp_assoc_lookup_paddr(asoc, addr);
        if (peer) {
+               /* An UNKNOWN state is only set on transports added by
+                * user in sctp_connectx() call.  Such transports should be
+                * considered CONFIRMED per RFC 4960, Section 5.4.
+                */
                if (peer->state == SCTP_UNKNOWN) {
-                       if (peer_state == SCTP_ACTIVE)
-                               peer->state = SCTP_ACTIVE;
-                       if (peer_state == SCTP_UNCONFIRMED)
-                               peer->state = SCTP_UNCONFIRMED;
+                       peer->state = SCTP_ACTIVE;
                }
                return peer;
        }
@@ -612,19 +673,22 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
         * association configured value.
         */
        peer->sackdelay = asoc->sackdelay;
+       peer->sackfreq = asoc->sackfreq;
 
        /* Enable/disable heartbeat, SACK delay, and path MTU discovery
         * based on association setting.
         */
        peer->param_flags = asoc->param_flags;
 
+       sctp_transport_route(peer, NULL, sp);
+
        /* Initialize the pmtu of the transport. */
-       if (peer->param_flags & SPP_PMTUD_ENABLE)
-               sctp_transport_pmtu(peer);
-       else if (asoc->pathmtu)
-               peer->pathmtu = asoc->pathmtu;
-       else
-               peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
+       if (peer->param_flags & SPP_PMTUD_DISABLE) {
+               if (asoc->pathmtu)
+                       peer->pathmtu = asoc->pathmtu;
+               else
+                       peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
+       }
 
        /* If this is the first transport addr on this association,
         * initialize the association PMTU to the peer's PMTU.
@@ -638,8 +702,9 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 
        SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
                          "%d\n", asoc, asoc->pathmtu);
+       peer->pmtu_pending = 0;
 
-       asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
+       asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
 
        /* The asoc->peer.port might not be meaningful yet, but
         * initialize the packet structure anyway.
@@ -715,12 +780,11 @@ struct sctp_transport *sctp_assoc_lookup_paddr(
                                        const union sctp_addr *address)
 {
        struct sctp_transport *t;
-       struct list_head *pos;
 
        /* Cycle through all transports searching for a peer address. */
 
-       list_for_each(pos, &asoc->peer.transport_addr_list) {
-               t = list_entry(pos, struct sctp_transport, transports);
+       list_for_each_entry(t, &asoc->peer.transport_addr_list,
+                       transports) {
                if (sctp_cmp_addr_exact(address, &t->ipaddr))
                        return t;
        }
@@ -728,6 +792,23 @@ struct sctp_transport *sctp_assoc_lookup_paddr(
        return NULL;
 }
 
+/* Remove all transports except a give one */
+void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
+                                    struct sctp_transport *primary)
+{
+       struct sctp_transport   *temp;
+       struct sctp_transport   *t;
+
+       list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
+                                transports) {
+               /* if the current transport is not the primary one, delete it */
+               if (t != primary)
+                       sctp_assoc_rm_peer(asoc, t);
+       }
+
+       return;
+}
+
 /* Engage in transport control operations.
  * Mark the transport up or down and send a notification to the user.
  * Select and update the new active and retran paths.
@@ -742,7 +823,6 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
        struct sctp_transport *second;
        struct sctp_ulpevent *event;
        struct sockaddr_storage addr;
-       struct list_head *pos;
        int spc_state = 0;
 
        /* Record the transition on the transport.  */
@@ -761,11 +841,16 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
                break;
 
        case SCTP_TRANSPORT_DOWN:
-               /* if the transort was never confirmed, do not transition it
-                * to inactive state.
+               /* If the transport was never confirmed, do not transition it
+                * to inactive state.  Also, release the cached route since
+                * there may be a better route next time.
                 */
                if (transport->state != SCTP_UNCONFIRMED)
                        transport->state = SCTP_INACTIVE;
+               else {
+                       dst_release(transport->dst);
+                       transport->dst = NULL;
+               }
 
                spc_state = SCTP_ADDR_UNREACHABLE;
                break;
@@ -794,8 +879,8 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
         */
        first = NULL; second = NULL;
 
-       list_for_each(pos, &asoc->peer.transport_addr_list) {
-               t = list_entry(pos, struct sctp_transport, transports);
+       list_for_each_entry(t, &asoc->peer.transport_addr_list,
+                       transports) {
 
                if ((t->state == SCTP_INACTIVE) ||
                    (t->state == SCTP_UNCONFIRMED))
@@ -912,7 +997,6 @@ struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
 {
        struct sctp_transport *active;
        struct sctp_transport *match;
-       struct list_head *entry, *pos;
        struct sctp_transport *transport;
        struct sctp_chunk *chunk;
        __be32 key = htonl(tsn);
@@ -936,8 +1020,8 @@ struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
 
        active = asoc->peer.active_path;
 
-       list_for_each(entry, &active->transmitted) {
-               chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
+       list_for_each_entry(chunk, &active->transmitted,
+                       transmitted_list) {
 
                if (key == chunk->subh.data_hdr->tsn) {
                        match = active;
@@ -946,14 +1030,13 @@ struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
        }
 
        /* If not found, go search all the other transports. */
-       list_for_each(pos, &asoc->peer.transport_addr_list) {
-               transport = list_entry(pos, struct sctp_transport, transports);
+       list_for_each_entry(transport, &asoc->peer.transport_addr_list,
+                       transports) {
 
                if (transport == active)
                        break;
-               list_for_each(entry, &transport->transmitted) {
-                       chunk = list_entry(entry, struct sctp_chunk,
-                                          transmitted_list);
+               list_for_each_entry(chunk, &transport->transmitted,
+                               transmitted_list) {
                        if (key == chunk->subh.data_hdr->tsn) {
                                match = transport;
                                goto out;
@@ -1092,8 +1175,8 @@ void sctp_assoc_update(struct sctp_association *asoc,
        asoc->peer.rwnd = new->peer.rwnd;
        asoc->peer.sack_needed = new->peer.sack_needed;
        asoc->peer.i = new->peer.i;
-       sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
-                        asoc->peer.i.initial_tsn);
+       sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
+                        asoc->peer.i.initial_tsn, GFP_ATOMIC);
 
        /* Remove any peer addresses not present in the new association. */
        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
@@ -1134,9 +1217,8 @@ void sctp_assoc_update(struct sctp_association *asoc,
 
        } else {
                /* Add any peer addresses from the new association. */
-               list_for_each(pos, &new->peer.transport_addr_list) {
-                       trans = list_entry(pos, struct sctp_transport,
-                                          transports);
+               list_for_each_entry(trans, &new->peer.transport_addr_list,
+                               transports) {
                        if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
                                sctp_assoc_add_peer(asoc, &trans->ipaddr,
                                                    GFP_ATOMIC, trans->state);
@@ -1188,6 +1270,9 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
        struct list_head *head = &asoc->peer.transport_addr_list;
        struct list_head *pos;
 
+       if (asoc->peer.transport_count == 1)
+               return;
+
        /* Find the next transport in a round-robin fashion. */
        t = asoc->peer.retran_path;
        pos = &t->transports;
@@ -1202,6 +1287,15 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 
                t = list_entry(pos, struct sctp_transport, transports);
 
+               /* We have exhausted the list, but didn't find any
+                * other active transports.  If so, use the next
+                * transport.
+                */
+               if (t == asoc->peer.retran_path) {
+                       t = next;
+                       break;
+               }
+
                /* Try to find an active transport. */
 
                if ((t->state == SCTP_ACTIVE) ||
@@ -1214,15 +1308,6 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
                        if (!next)
                                next = t;
                }
-
-               /* We have exhausted the list, but didn't find any
-                * other active transports.  If so, use the next
-                * transport.
-                */
-               if (t == asoc->peer.retran_path) {
-                       t = next;
-                       break;
-               }
        }
 
        asoc->peer.retran_path = t;
@@ -1235,49 +1320,21 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
                                 ntohs(t->ipaddr.v4.sin_port));
 }
 
-/* Choose the transport for sending a INIT packet.  */
-struct sctp_transport *sctp_assoc_choose_init_transport(
-       struct sctp_association *asoc)
-{
-       struct sctp_transport *t;
-
-       /* Use the retran path. If the last INIT was sent over the
-        * retran path, update the retran path and use it.
-        */
-       if (!asoc->init_last_sent_to) {
-               t = asoc->peer.active_path;
-       } else {
-               if (asoc->init_last_sent_to == asoc->peer.retran_path)
-                       sctp_assoc_update_retran_path(asoc);
-               t = asoc->peer.retran_path;
-       }
-
-       SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
-                                " %p addr: ",
-                                " port: %d\n",
-                                asoc,
-                                (&t->ipaddr),
-                                ntohs(t->ipaddr.v4.sin_port));
-
-       return t;
-}
-
-/* Choose the transport for sending a SHUTDOWN packet.  */
-struct sctp_transport *sctp_assoc_choose_shutdown_transport(
-       struct sctp_association *asoc)
+/* Choose the transport for sending retransmit packet.  */
+struct sctp_transport *sctp_assoc_choose_alter_transport(
+       struct sctp_association *asoc, struct sctp_transport *last_sent_to)
 {
-       /* If this is the first time SHUTDOWN is sent, use the active path,
-        * else use the retran path. If the last SHUTDOWN was sent over the
+       /* If this is the first time packet is sent, use the active path,
+        * else use the retran path. If the last packet was sent over the
         * retran path, update the retran path and use it.
         */
-       if (!asoc->shutdown_last_sent_to)
+       if (!last_sent_to)
                return asoc->peer.active_path;
        else {
-               if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
+               if (last_sent_to == asoc->peer.retran_path)
                        sctp_assoc_update_retran_path(asoc);
                return asoc->peer.retran_path;
        }
-
 }
 
 /* Update the association's pmtu and frag_point by going through all the
@@ -1286,15 +1343,14 @@ struct sctp_transport *sctp_assoc_choose_shutdown_transport(
 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
 {
        struct sctp_transport *t;
-       struct list_head *pos;
        __u32 pmtu = 0;
 
        if (!asoc)
                return;
 
        /* Get the lowest pmtu of all the transports. */
-       list_for_each(pos, &asoc->peer.transport_addr_list) {
-               t = list_entry(pos, struct sctp_transport, transports);
+       list_for_each_entry(t, &asoc->peer.transport_addr_list,
+                               transports) {
                if (t->pmtu_pending && t->dst) {
                        sctp_transport_update_pmtu(t, dst_mtu(t->dst));
                        t->pmtu_pending = 0;
@@ -1304,13 +1360,12 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
        }
 
        if (pmtu) {
-               struct sctp_sock *sp = sctp_sk(asoc->base.sk);
                asoc->pathmtu = pmtu;
-               asoc->frag_point = sctp_frag_point(sp, pmtu);
+               asoc->frag_point = sctp_frag_point(asoc, pmtu);
        }
 
        SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
-                         __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
+                         __func__, asoc, asoc->pathmtu, asoc->frag_point);
 }
 
 /* Should we send a SACK to update our peer? */
@@ -1349,8 +1404,19 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
                asoc->rwnd += len;
        }
 
+       /* If we had window pressure, start recovering it
+        * once our rwnd had reached the accumulated pressure
+        * threshold.  The idea is to recover slowly, but up
+        * to the initial advertised window.
+        */
+       if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) {
+               int change = min(asoc->pathmtu, asoc->rwnd_press);
+               asoc->rwnd += change;
+               asoc->rwnd_press -= change;
+       }
+
        SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
-                         "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
+                         "- %u\n", __func__, asoc, len, asoc->rwnd,
                          asoc->rwnd_over, asoc->a_rwnd);
 
        /* Send a window update SACK if the rwnd has increased by at least the
@@ -1361,7 +1427,7 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
        if (sctp_peer_needs_update(asoc)) {
                asoc->a_rwnd = asoc->rwnd;
                SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
-                                 "rwnd: %u a_rwnd: %u\n", __FUNCTION__,
+                                 "rwnd: %u a_rwnd: %u\n", __func__,
                                  asoc, asoc->rwnd, asoc->a_rwnd);
                sack = sctp_make_sack(asoc);
                if (!sack)
@@ -1381,32 +1447,51 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
 /* Decrease asoc's rwnd by len. */
 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
 {
+       int rx_count;
+       int over = 0;
+
        SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
        SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
+
+       if (asoc->ep->rcvbuf_policy)
+               rx_count = atomic_read(&asoc->rmem_alloc);
+       else
+               rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
+
+       /* If we've reached or overflowed our receive buffer, announce
+        * a 0 rwnd if rwnd would still be positive.  Store the
+        * the pottential pressure overflow so that the window can be restored
+        * back to original value.
+        */
+       if (rx_count >= asoc->base.sk->sk_rcvbuf)
+               over = 1;
+
        if (asoc->rwnd >= len) {
                asoc->rwnd -= len;
+               if (over) {
+                       asoc->rwnd_press = asoc->rwnd;
+                       asoc->rwnd = 0;
+               }
        } else {
                asoc->rwnd_over = len - asoc->rwnd;
                asoc->rwnd = 0;
        }
-       SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
-                         __FUNCTION__, asoc, len, asoc->rwnd,
-                         asoc->rwnd_over);
+       SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
+                         __func__, asoc, len, asoc->rwnd,
+                         asoc->rwnd_over, asoc->rwnd_press);
 }
 
 /* Build the bind address list for the association based on info from the
  * local endpoint and the remote peer.
  */
 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
-                                    gfp_t gfp)
+                                    sctp_scope_t scope, gfp_t gfp)
 {
-       sctp_scope_t scope;
        int flags;
 
        /* Use scoping rules to determine the subset of addresses from
         * the endpoint.
         */
-       scope = sctp_scope(&asoc->peer.active_path->ipaddr);
        flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
        if (asoc->peer.ipv4_address)
                flags |= SCTP_ADDR4_PEERSUPP;
@@ -1450,6 +1535,10 @@ int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
 {
        int assoc_id;
        int error = 0;
+
+       /* If the id is already assigned, keep it. */
+       if (asoc->assoc_id)
+               return error;
 retry:
        if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
                return -ENOMEM;
@@ -1466,3 +1555,56 @@ retry:
        asoc->assoc_id = (sctp_assoc_t) assoc_id;
        return error;
 }
+
+/* Free asconf_ack cache */
+static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
+{
+       struct sctp_chunk *ack;
+       struct sctp_chunk *tmp;
+
+       list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
+                               transmitted_list) {
+               list_del_init(&ack->transmitted_list);
+               sctp_chunk_free(ack);
+       }
+}
+
+/* Clean up the ASCONF_ACK queue */
+void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
+{
+       struct sctp_chunk *ack;
+       struct sctp_chunk *tmp;
+
+       /* We can remove all the entries from the queue upto
+        * the "Peer-Sequence-Number".
+        */
+       list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
+                               transmitted_list) {
+               if (ack->subh.addip_hdr->serial ==
+                               htonl(asoc->peer.addip_serial))
+                       break;
+
+               list_del_init(&ack->transmitted_list);
+               sctp_chunk_free(ack);
+       }
+}
+
+/* Find the ASCONF_ACK whose serial number matches ASCONF */
+struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
+                                       const struct sctp_association *asoc,
+                                       __be32 serial)
+{
+       struct sctp_chunk *ack;
+
+       /* Walk through the list of cached ASCONF-ACKs and find the
+        * ack chunk whose serial number matches that of the request.
+        */
+       list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
+               if (ack->subh.addip_hdr->serial == serial) {
+                       sctp_chunk_hold(ack);
+                       return ack;
+               }
+       }
+
+       return NULL;
+}