Linux-2.6.12-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, 913 insertions, 0 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
new file mode 100644
index 00000000000..b719a77d66b
--- /dev/null
+++ b/net/sctp/input.c
@@ -0,0 +1,913 @@
+/* SCTP kernel reference Implementation
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2003 International Business Machines, Corp.
+ * Copyright (c) 2001 Intel Corp.
+ * Copyright (c) 2001 Nokia, Inc.
+ * Copyright (c) 2001 La Monte H.P. Yarroll
+ *
+ * This file is part of the SCTP kernel reference Implementation
+ *
+ * These functions handle all input from the IP layer into SCTP.
+ *
+ * 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:
+ *    La Monte H.P. Yarroll <piggy@acm.org>
+ *    Karl Knutson <karl@athena.chicago.il.us>
+ *    Xingang Guo <xingang.guo@intel.com>
+ *    Jon Grimm <jgrimm@us.ibm.com>
+ *    Hui Huang <hui.huang@nokia.com>
+ *    Daisy Chang <daisyc@us.ibm.com>
+ *    Sridhar Samudrala <sri@us.ibm.com>
+ *    Ardelle Fan <ardelle.fan@intel.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/list.h> /* For struct list_head */
+#include <linux/socket.h>
+#include <linux/ip.h>
+#include <linux/time.h> /* For struct timeval */
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/snmp.h>
+#include <net/sock.h>
+#include <net/xfrm.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/* Forward declarations for internal helpers. */
+static int sctp_rcv_ootb(struct sk_buff *);
+static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
+                                      const union sctp_addr *laddr,
+                                      const union sctp_addr *paddr,
+                                      struct sctp_transport **transportp);
+static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr);
+static struct sctp_association *__sctp_lookup_association(
+                                        const union sctp_addr *local,
+                                        const union sctp_addr *peer,
+                                        struct sctp_transport **pt);
+
+
+/* Calculate the SCTP checksum of an SCTP packet.  */
+static inline int sctp_rcv_checksum(struct sk_buff *skb)
+{
+        struct sctphdr *sh;
+        __u32 cmp, val;
+        struct sk_buff *list = skb_shinfo(skb)->frag_list;
+
+        sh = (struct sctphdr *) skb->h.raw;
+        cmp = ntohl(sh->checksum);
+
+        val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
+
+        for (; list; list = list->next)
+                val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
+                                        val);
+
+        val = sctp_end_cksum(val);
+
+        if (val != cmp) {
+                /* CRC failure, dump it. */
+                SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS);
+                return -1;
+        }
+        return 0;
+}
+
+/* The free routine for skbuffs that sctp receives */
+static void sctp_rfree(struct sk_buff *skb)
+{
+        atomic_sub(sizeof(struct sctp_chunk),&skb->sk->sk_rmem_alloc);
+        sock_rfree(skb);
+}
+
+/* The ownership wrapper routine to do receive buffer accounting */
+static void sctp_rcv_set_owner_r(struct sk_buff *skb, struct sock *sk)
+{
+        skb_set_owner_r(skb,sk);
+        skb->destructor = sctp_rfree;
+        atomic_add(sizeof(struct sctp_chunk),&sk->sk_rmem_alloc);
+}
+
+/*
+ * This is the routine which IP calls when receiving an SCTP packet.
+ */
+int sctp_rcv(struct sk_buff *skb)
+{
+        struct sock *sk;
+        struct sctp_association *asoc;
+        struct sctp_endpoint *ep = NULL;
+        struct sctp_ep_common *rcvr;
+        struct sctp_transport *transport = NULL;
+        struct sctp_chunk *chunk;
+        struct sctphdr *sh;
+        union sctp_addr src;
+        union sctp_addr dest;
+        int family;
+        struct sctp_af *af;
+        int ret = 0;
+
+        if (skb->pkt_type!=PACKET_HOST)
+                goto discard_it;
+
+        SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
+
+        sh = (struct sctphdr *) skb->h.raw;
+
+        /* Pull up the IP and SCTP headers. */
+        __skb_pull(skb, skb->h.raw - skb->data);
+        if (skb->len < sizeof(struct sctphdr))
+                goto discard_it;
+        if (sctp_rcv_checksum(skb) < 0)
+                goto discard_it;
+
+        skb_pull(skb, sizeof(struct sctphdr));
+
+        /* Make sure we at least have chunk headers worth of data left. */
+        if (skb->len < sizeof(struct sctp_chunkhdr))
+                goto discard_it;
+
+        family = ipver2af(skb->nh.iph->version);
+        af = sctp_get_af_specific(family);
+        if (unlikely(!af))
+                goto discard_it;
+
+        /* Initialize local addresses for lookups. */
+        af->from_skb(&src, skb, 1);
+        af->from_skb(&dest, skb, 0);
+
+        /* If the packet is to or from a non-unicast address,
+         * silently discard the packet.
+         *
+         * This is not clearly defined in the RFC except in section
+         * 8.4 - OOTB handling.  However, based on the book "Stream Control
+         * Transmission Protocol" 2.1, "It is important to note that the
+         * IP address of an SCTP transport address must be a routable
+         * unicast address.  In other words, IP multicast addresses and
+         * IP broadcast addresses cannot be used in an SCTP transport
+         * address."
+         */
+        if (!af->addr_valid(&src, NULL) || !af->addr_valid(&dest, NULL))
+                goto discard_it;
+
+        asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport);
+
+        /*
+         * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
+         * An SCTP packet is called an "out of the blue" (OOTB)
+         * packet if it is correctly formed, i.e., passed the
+         * receiver's checksum check, but the receiver is not
+         * able to identify the association to which this
+         * packet belongs.
+         */
+        if (!asoc) {
+                ep = __sctp_rcv_lookup_endpoint(&dest);
+                if (sctp_rcv_ootb(skb)) {
+                        SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES);
+                        goto discard_release;
+                }
+        }
+
+        /* Retrieve the common input handling substructure. */
+        rcvr = asoc ? &asoc->base : &ep->base;
+        sk = rcvr->sk;
+
+        if ((sk) && (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)) {
+                goto discard_release;
+        }
+
+
+        /* SCTP seems to always need a timestamp right now (FIXME) */
+        if (skb->stamp.tv_sec == 0) {
+                do_gettimeofday(&skb->stamp);
+                sock_enable_timestamp(sk); 
+        }
+
+        if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
+                goto discard_release;
+
+        ret = sk_filter(sk, skb, 1);
+        if (ret)
+                goto discard_release;
+
+        /* Create an SCTP packet structure. */
+        chunk = sctp_chunkify(skb, asoc, sk);
+        if (!chunk) {
+                ret = -ENOMEM;
+                goto discard_release;
+        }
+
+        sctp_rcv_set_owner_r(skb,sk);
+
+        /* Remember what endpoint is to handle this packet. */
+        chunk->rcvr = rcvr;
+
+        /* Remember the SCTP header. */
+        chunk->sctp_hdr = sh;
+
+        /* Set the source and destination addresses of the incoming chunk.  */
+        sctp_init_addrs(chunk, &src, &dest);
+
+        /* Remember where we came from.  */
+        chunk->transport = transport;
+
+        /* Acquire access to the sock lock. Note: We are safe from other
+         * bottom halves on this lock, but a user may be in the lock too,
+         * so check if it is busy.
+         */
+        sctp_bh_lock_sock(sk);
+
+        if (sock_owned_by_user(sk))
+                sk_add_backlog(sk, (struct sk_buff *) chunk);
+        else
+                sctp_backlog_rcv(sk, (struct sk_buff *) chunk);
+
+        /* Release the sock and any reference counts we took in the
+         * lookup calls.
+         */
+        sctp_bh_unlock_sock(sk);
+        if (asoc)
+                sctp_association_put(asoc);
+        else
+                sctp_endpoint_put(ep);
+        sock_put(sk);
+        return ret;
+
+discard_it:
+        kfree_skb(skb);
+        return ret;
+
+discard_release:
+        /* Release any structures we may be holding. */
+        if (asoc) {
+                sock_put(asoc->base.sk);
+                sctp_association_put(asoc);
+        } else {
+                sock_put(ep->base.sk);
+                sctp_endpoint_put(ep);
+        }
+
+        goto discard_it;
+}
+
+/* Handle second half of inbound skb processing.  If the sock was busy,
+ * we may have need to delay processing until later when the sock is
+ * released (on the backlog).   If not busy, we call this routine
+ * directly from the bottom half.
+ */
+int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
+{
+        struct sctp_chunk *chunk;
+        struct sctp_inq *inqueue;
+
+        /* One day chunk will live inside the skb, but for
+         * now this works.
+         */
+        chunk = (struct sctp_chunk *) skb;
+        inqueue = &chunk->rcvr->inqueue;
+
+        sctp_inq_push(inqueue, chunk);
+        return 0;
+}
+
+/* Handle icmp frag needed error. */
+void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
+                           struct sctp_transport *t, __u32 pmtu)
+{
+        if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
+                printk(KERN_WARNING "%s: Reported pmtu %d too low, "
+                       "using default minimum of %d\n", __FUNCTION__, pmtu,
+                       SCTP_DEFAULT_MINSEGMENT);
+                pmtu = SCTP_DEFAULT_MINSEGMENT;
+        }
+
+        if (!sock_owned_by_user(sk) && t && (t->pmtu != pmtu)) {
+                t->pmtu = pmtu;
+                sctp_assoc_sync_pmtu(asoc);
+                sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
+        }
+}
+
+/*
+ * SCTP Implementer's Guide, 2.37 ICMP handling procedures
+ *
+ * ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
+ *        or a "Protocol Unreachable" treat this message as an abort
+ *        with the T bit set.
+ *
+ * This function sends an event to the state machine, which will abort the
+ * association.
+ *
+ */
+void sctp_icmp_proto_unreachable(struct sock *sk,
+                           struct sctp_endpoint *ep,
+                           struct sctp_association *asoc,
+                           struct sctp_transport *t)
+{
+        SCTP_DEBUG_PRINTK("%s\n",  __FUNCTION__);
+
+        sctp_do_sm(SCTP_EVENT_T_OTHER,
+                   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
+                   asoc->state, asoc->ep, asoc, NULL,
+                   GFP_ATOMIC);
+
+}
+
+/* Common lookup code for icmp/icmpv6 error handler. */
+struct sock *sctp_err_lookup(int family, struct sk_buff *skb,
+                             struct sctphdr *sctphdr,
+                             struct sctp_endpoint **epp,
+                             struct sctp_association **app,
+                             struct sctp_transport **tpp)
+{
+        union sctp_addr saddr;
+        union sctp_addr daddr;
+        struct sctp_af *af;
+        struct sock *sk = NULL;
+        struct sctp_endpoint *ep = NULL;
+        struct sctp_association *asoc = NULL;
+        struct sctp_transport *transport = NULL;
+
+        *app = NULL; *epp = NULL; *tpp = NULL;
+
+        af = sctp_get_af_specific(family);
+        if (unlikely(!af)) {
+                return NULL;
+        }
+
+        /* Initialize local addresses for lookups. */
+        af->from_skb(&saddr, skb, 1);
+        af->from_skb(&daddr, skb, 0);
+
+        /* Look for an association that matches the incoming ICMP error
+         * packet.
+         */
+        asoc = __sctp_lookup_association(&saddr, &daddr, &transport);
+        if (!asoc) {
+                /* If there is no matching association, see if it matches any
+                 * endpoint. This may happen for an ICMP error generated in
+                 * response to an INIT_ACK.
+                 */
+                ep = __sctp_rcv_lookup_endpoint(&daddr);
+                if (!ep) {
+                        return NULL;
+                }
+        }
+
+        if (asoc) {
+                sk = asoc->base.sk;
+
+                if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) {
+                        ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+                        goto out;
+                }
+        } else
+                sk = ep->base.sk;
+
+        sctp_bh_lock_sock(sk);
+
+        /* If too many ICMPs get dropped on busy
+         * servers this needs to be solved differently.
+         */
+        if (sock_owned_by_user(sk))
+                NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
+
+        *epp = ep;
+        *app = asoc;
+        *tpp = transport;
+        return sk;
+
+out:
+        sock_put(sk);
+        if (asoc)
+                sctp_association_put(asoc);
+        if (ep)
+                sctp_endpoint_put(ep);
+        return NULL;
+}
+
+/* Common cleanup code for icmp/icmpv6 error handler. */
+void sctp_err_finish(struct sock *sk, struct sctp_endpoint *ep,
+                     struct sctp_association *asoc)
+{
+        sctp_bh_unlock_sock(sk);
+        sock_put(sk);
+        if (asoc)
+                sctp_association_put(asoc);
+        if (ep)
+                sctp_endpoint_put(ep);
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.  After adjustment
+ * header points to the first 8 bytes of the sctp header.  We need
+ * to find the appropriate port.
+ *
+ * The locking strategy used here is very "optimistic". When
+ * someone else accesses the socket the ICMP is just dropped
+ * and for some paths there is no check at all.
+ * A more general error queue to queue errors for later handling
+ * is probably better.
+ *
+ */
+void sctp_v4_err(struct sk_buff *skb, __u32 info)
+{
+        struct iphdr *iph = (struct iphdr *)skb->data;
+        struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2));
+        int type = skb->h.icmph->type;
+        int code = skb->h.icmph->code;
+        struct sock *sk;
+        struct sctp_endpoint *ep;
+        struct sctp_association *asoc;
+        struct sctp_transport *transport;
+        struct inet_sock *inet;
+        char *saveip, *savesctp;
+        int err;
+
+        if (skb->len < ((iph->ihl << 2) + 8)) {
+                ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+                return;
+        }
+
+        /* Fix up skb to look at the embedded net header. */
+        saveip = skb->nh.raw;
+        savesctp  = skb->h.raw;
+        skb->nh.iph = iph;
+        skb->h.raw = (char *)sh;
+        sk = sctp_err_lookup(AF_INET, skb, sh, &ep, &asoc, &transport);
+        /* Put back, the original pointers. */
+        skb->nh.raw = saveip;
+        skb->h.raw = savesctp;
+        if (!sk) {
+                ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+                return;
+        }
+        /* Warning:  The sock lock is held.  Remember to call
+         * sctp_err_finish!
+         */
+
+        switch (type) {
+        case ICMP_PARAMETERPROB:
+                err = EPROTO;
+                break;
+        case ICMP_DEST_UNREACH:
+                if (code > NR_ICMP_UNREACH)
+                        goto out_unlock;
+
+                /* PMTU discovery (RFC1191) */
+                if (ICMP_FRAG_NEEDED == code) {
+                        sctp_icmp_frag_needed(sk, asoc, transport, info);
+                        goto out_unlock;
+                }
+                else {
+                        if (ICMP_PROT_UNREACH == code) {
+                                sctp_icmp_proto_unreachable(sk, ep, asoc,
+                                                            transport);
+                                goto out_unlock;
+                        }
+                }
+                err = icmp_err_convert[code].errno;
+                break;
+        case ICMP_TIME_EXCEEDED:
+                /* Ignore any time exceeded errors due to fragment reassembly
+                 * timeouts.
+                 */
+                if (ICMP_EXC_FRAGTIME == code)
+                        goto out_unlock;
+
+                err = EHOSTUNREACH;
+                break;
+        default:
+                goto out_unlock;
+        }
+
+        inet = inet_sk(sk);
+        if (!sock_owned_by_user(sk) && inet->recverr) {
+                sk->sk_err = err;
+                sk->sk_error_report(sk);
+        } else {  /* Only an error on timeout */
+                sk->sk_err_soft = err;
+        }
+
+out_unlock:
+        sctp_err_finish(sk, ep, asoc);
+}
+
+/*
+ * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
+ *
+ * This function scans all the chunks in the OOTB packet to determine if
+ * the packet should be discarded right away.  If a response might be needed
+ * for this packet, or, if further processing is possible, the packet will
+ * be queued to a proper inqueue for the next phase of handling.
+ *
+ * Output:
+ * Return 0 - If further processing is needed.
+ * Return 1 - If the packet can be discarded right away.
+ */
+int sctp_rcv_ootb(struct sk_buff *skb)
+{
+        sctp_chunkhdr_t *ch;
+        __u8 *ch_end;
+        sctp_errhdr_t *err;
+
+        ch = (sctp_chunkhdr_t *) skb->data;
+        ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length));
+
+        /* Scan through all the chunks in the packet.  */
+        while (ch_end > (__u8 *)ch && ch_end < skb->tail) {
+
+                /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
+                 * receiver MUST silently discard the OOTB packet and take no
+                 * further action.
+                 */
+                if (SCTP_CID_ABORT == ch->type)
+                        goto discard;
+
+                /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE
+                 * chunk, the receiver should silently discard the packet
+                 * and take no further action.
+                 */
+                if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
+                        goto discard;
+
+                /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
+                 * or a COOKIE ACK the SCTP Packet should be silently
+                 * discarded.
+                 */
+                if (SCTP_CID_COOKIE_ACK == ch->type)
+                        goto discard;
+
+                if (SCTP_CID_ERROR == ch->type) {
+                        sctp_walk_errors(err, ch) {
+                                if (SCTP_ERROR_STALE_COOKIE == err->cause)
+                                        goto discard;
+                        }
+                }
+
+                ch = (sctp_chunkhdr_t *) ch_end;
+                ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length));
+        }
+
+        return 0;
+
+discard:
+        return 1;
+}
+
+/* Insert endpoint into the hash table.  */
+static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
+{
+        struct sctp_ep_common **epp;
+        struct sctp_ep_common *epb;
+        struct sctp_hashbucket *head;
+
+        epb = &ep->base;
+
+        epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
+        head = &sctp_ep_hashtable[epb->hashent];
+
+        sctp_write_lock(&head->lock);
+        epp = &head->chain;
+        epb->next = *epp;
+        if (epb->next)
+                (*epp)->pprev = &epb->next;
+        *epp = epb;
+        epb->pprev = epp;
+        sctp_write_unlock(&head->lock);
+}
+
+/* Add an endpoint to the hash. Local BH-safe. */
+void sctp_hash_endpoint(struct sctp_endpoint *ep)
+{
+        sctp_local_bh_disable();
+        __sctp_hash_endpoint(ep);
+        sctp_local_bh_enable();
+}
+
+/* Remove endpoint from the hash table.  */
+static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
+{
+        struct sctp_hashbucket *head;
+        struct sctp_ep_common *epb;
+
+        epb = &ep->base;
+
+        epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
+
+        head = &sctp_ep_hashtable[epb->hashent];
+
+        sctp_write_lock(&head->lock);
+
+        if (epb->pprev) {
+                if (epb->next)
+                        epb->next->pprev = epb->pprev;
+                *epb->pprev = epb->next;
+                epb->pprev = NULL;
+        }
+
+        sctp_write_unlock(&head->lock);
+}
+
+/* Remove endpoint from the hash.  Local BH-safe. */
+void sctp_unhash_endpoint(struct sctp_endpoint *ep)
+{
+        sctp_local_bh_disable();
+        __sctp_unhash_endpoint(ep);
+        sctp_local_bh_enable();
+}
+
+/* Look up an endpoint. */
+static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr)
+{
+        struct sctp_hashbucket *head;
+        struct sctp_ep_common *epb;
+        struct sctp_endpoint *ep;
+        int hash;
+
+        hash = sctp_ep_hashfn(laddr->v4.sin_port);
+        head = &sctp_ep_hashtable[hash];
+        read_lock(&head->lock);
+        for (epb = head->chain; epb; epb = epb->next) {
+                ep = sctp_ep(epb);
+                if (sctp_endpoint_is_match(ep, laddr))
+                        goto hit;
+        }
+
+        ep = sctp_sk((sctp_get_ctl_sock()))->ep;
+        epb = &ep->base;
+
+hit:
+        sctp_endpoint_hold(ep);
+        sock_hold(epb->sk);
+        read_unlock(&head->lock);
+        return ep;
+}
+
+/* Insert association into the hash table.  */
+static void __sctp_hash_established(struct sctp_association *asoc)
+{
+        struct sctp_ep_common **epp;
+        struct sctp_ep_common *epb;
+        struct sctp_hashbucket *head;
+
+        epb = &asoc->base;
+
+        /* Calculate which chain this entry will belong to. */
+        epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port);
+
+        head = &sctp_assoc_hashtable[epb->hashent];
+
+        sctp_write_lock(&head->lock);
+        epp = &head->chain;
+        epb->next = *epp;
+        if (epb->next)
+                (*epp)->pprev = &epb->next;
+        *epp = epb;
+        epb->pprev = epp;
+        sctp_write_unlock(&head->lock);
+}
+
+/* Add an association to the hash. Local BH-safe. */
+void sctp_hash_established(struct sctp_association *asoc)
+{
+        sctp_local_bh_disable();
+        __sctp_hash_established(asoc);
+        sctp_local_bh_enable();
+}
+
+/* Remove association from the hash table.  */
+static void __sctp_unhash_established(struct sctp_association *asoc)
+{
+        struct sctp_hashbucket *head;
+        struct sctp_ep_common *epb;
+
+        epb = &asoc->base;
+
+        epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port,
+                                         asoc->peer.port);
+
+        head = &sctp_assoc_hashtable[epb->hashent];
+
+        sctp_write_lock(&head->lock);
+
+        if (epb->pprev) {
+                if (epb->next)
+                        epb->next->pprev = epb->pprev;
+                *epb->pprev = epb->next;
+                epb->pprev = NULL;
+        }
+
+        sctp_write_unlock(&head->lock);
+}
+
+/* Remove association from the hash table.  Local BH-safe. */
+void sctp_unhash_established(struct sctp_association *asoc)
+{
+        sctp_local_bh_disable();
+        __sctp_unhash_established(asoc);
+        sctp_local_bh_enable();
+}
+
+/* Look up an association. */
+static struct sctp_association *__sctp_lookup_association(
+                                        const union sctp_addr *local,
+                                        const union sctp_addr *peer,
+                                        struct sctp_transport **pt)
+{
+        struct sctp_hashbucket *head;
+        struct sctp_ep_common *epb;
+        struct sctp_association *asoc;
+        struct sctp_transport *transport;
+        int hash;
+
+        /* Optimize here for direct hit, only listening connections can
+         * have wildcards anyways.
+         */
+        hash = sctp_assoc_hashfn(local->v4.sin_port, peer->v4.sin_port);
+        head = &sctp_assoc_hashtable[hash];
+        read_lock(&head->lock);
+        for (epb = head->chain; epb; epb = epb->next) {
+                asoc = sctp_assoc(epb);
+                transport = sctp_assoc_is_match(asoc, local, peer);
+                if (transport)
+                        goto hit;
+        }
+
+        read_unlock(&head->lock);
+
+        return NULL;
+
+hit:
+        *pt = transport;
+        sctp_association_hold(asoc);
+        sock_hold(epb->sk);
+        read_unlock(&head->lock);
+        return asoc;
+}
+
+/* Look up an association. BH-safe. */
+SCTP_STATIC
+struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr,
+                                                 const union sctp_addr *paddr,
+                                            struct sctp_transport **transportp)
+{
+        struct sctp_association *asoc;
+
+        sctp_local_bh_disable();
+        asoc = __sctp_lookup_association(laddr, paddr, transportp);
+        sctp_local_bh_enable();
+
+        return asoc;
+}
+
+/* Is there an association matching the given local and peer addresses? */
+int sctp_has_association(const union sctp_addr *laddr,
+                         const union sctp_addr *paddr)
+{
+        struct sctp_association *asoc;
+        struct sctp_transport *transport;
+
+        if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) {
+                sock_put(asoc->base.sk);
+                sctp_association_put(asoc);
+                return 1;
+        }
+
+        return 0;
+}
+
+/*
+ * SCTP Implementors Guide, 2.18 Handling of address
+ * parameters within the INIT or INIT-ACK.
+ *
+ * D) When searching for a matching TCB upon reception of an INIT
+ *    or INIT-ACK chunk the receiver SHOULD use not only the
+ *    source address of the packet (containing the INIT or
+ *    INIT-ACK) but the receiver SHOULD also use all valid
+ *    address parameters contained within the chunk.
+ *
+ * 2.18.3 Solution description
+ *
+ * This new text clearly specifies to an implementor the need
+ * to look within the INIT or INIT-ACK. Any implementation that
+ * does not do this, may not be able to establish associations
+ * in certain circumstances.
+ *
+ */
+static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
+        const union sctp_addr *laddr, struct sctp_transport **transportp)
+{
+        struct sctp_association *asoc;
+        union sctp_addr addr;
+        union sctp_addr *paddr = &addr;
+        struct sctphdr *sh = (struct sctphdr *) skb->h.raw;
+        sctp_chunkhdr_t *ch;
+        union sctp_params params;
+        sctp_init_chunk_t *init;
+        struct sctp_transport *transport;
+        struct sctp_af *af;
+
+        ch = (sctp_chunkhdr_t *) skb->data;
+
+        /* If this is INIT/INIT-ACK look inside the chunk too. */
+        switch (ch->type) {
+        case SCTP_CID_INIT:
+        case SCTP_CID_INIT_ACK:
+                break;
+        default:
+                return NULL;
+        }
+
+        /* The code below will attempt to walk the chunk and extract
+         * parameter information.  Before we do that, we need to verify
+         * that the chunk length doesn't cause overflow.  Otherwise, we'll
+         * walk off the end.
+         */
+        if (WORD_ROUND(ntohs(ch->length)) > skb->len)
+                return NULL;
+
+        /*
+         * This code will NOT touch anything inside the chunk--it is
+         * strictly READ-ONLY.
+         *
+         * RFC 2960 3  SCTP packet Format
+         *
+         * Multiple chunks can be bundled into one SCTP packet up to
+         * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN
+         * COMPLETE chunks.  These chunks MUST NOT be bundled with any
+         * other chunk in a packet.  See Section 6.10 for more details
+         * on chunk bundling.
+         */
+
+        /* Find the start of the TLVs and the end of the chunk.  This is
+         * the region we search for address parameters.
+         */
+        init = (sctp_init_chunk_t *)skb->data;
+
+        /* Walk the parameters looking for embedded addresses. */
+        sctp_walk_params(params, init, init_hdr.params) {
+
+                /* Note: Ignoring hostname addresses. */
+                af = sctp_get_af_specific(param_type2af(params.p->type));
+                if (!af)
+                        continue;
+
+                af->from_addr_param(paddr, params.addr, ntohs(sh->source), 0);
+
+                asoc = __sctp_lookup_association(laddr, paddr, &transport);
+                if (asoc)
+                        return asoc;
+        }
+
+        return NULL;
+}
+
+/* Lookup an association for an inbound skb. */
+static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
+                                      const union sctp_addr *paddr,
+                                      const union sctp_addr *laddr,
+                                      struct sctp_transport **transportp)
+{
+        struct sctp_association *asoc;
+
+        asoc = __sctp_lookup_association(laddr, paddr, transportp);
+
+        /* Further lookup for INIT/INIT-ACK packets.
+         * SCTP Implementors Guide, 2.18 Handling of address
+         * parameters within the INIT or INIT-ACK.
+         */
+        if (!asoc)
+                asoc = __sctp_rcv_init_lookup(skb, laddr, transportp);
+
+        return asoc;
+}