-/* SCTP kernel reference Implementation
+/* SCTP kernel implementation
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2003 International Business Machines, Corp.
* Copyright (c) 2001 Nokia, Inc.
* 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
*
* These functions handle all input from the IP layer into SCTP.
*
- * 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.
#include <linux/socket.h>
#include <linux/ip.h>
#include <linux/time.h> /* For struct timeval */
+#include <linux/slab.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/snmp.h>
#include <net/xfrm.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
+#include <net/sctp/checksum.h>
+#include <net/net_namespace.h>
/* Forward declarations for internal helpers. */
static int sctp_rcv_ootb(struct sk_buff *);
const union sctp_addr *peer,
struct sctp_transport **pt);
+static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
+
/* 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);
+ struct sctphdr *sh = sctp_hdr(skb);
+ __le32 cmp = sh->checksum;
+ struct sk_buff *list;
+ __le32 val;
+ __u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
- val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
+ skb_walk_frags(skb, list)
+ tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
+ tmp);
- for (; list; list = list->next)
- val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
- val);
-
- val = sctp_end_cksum(val);
+ val = sctp_end_cksum(tmp);
if (val != cmp) {
/* CRC failure, dump it. */
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;
+ if (skb_linearize(skb))
+ goto discard_it;
+
+ sh = sctp_hdr(skb);
/* Pull up the IP and SCTP headers. */
- __skb_pull(skb, skb->h.raw - skb->data);
+ __skb_pull(skb, skb_transport_offset(skb));
if (skb->len < sizeof(struct sctphdr))
goto discard_it;
- if (sctp_rcv_checksum(skb) < 0)
+ if (!sctp_checksum_disable && !skb_csum_unnecessary(skb) &&
+ sctp_rcv_checksum(skb) < 0)
goto discard_it;
skb_pull(skb, sizeof(struct sctphdr));
if (skb->len < sizeof(struct sctp_chunkhdr))
goto discard_it;
- family = ipver2af(skb->nh.iph->version);
+ family = ipver2af(ip_hdr(skb)->version);
af = sctp_get_af_specific(family);
if (unlikely(!af))
goto discard_it;
* IP broadcast addresses cannot be used in an SCTP transport
* address."
*/
- if (!af->addr_valid(&src, NULL) || !af->addr_valid(&dest, NULL))
+ if (!af->addr_valid(&src, NULL, skb) ||
+ !af->addr_valid(&dest, NULL, skb))
goto discard_it;
asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport);
*/
if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb)))
{
- sock_put(sk);
if (asoc) {
sctp_association_put(asoc);
asoc = NULL;
sk = sctp_get_ctl_sock();
ep = sctp_sk(sk)->ep;
sctp_endpoint_hold(ep);
- sock_hold(sk);
rcvr = &ep->base;
}
}
}
- /* SCTP seems to always need a timestamp right now (FIXME) */
- if (skb->tstamp.off_sec == 0) {
- __net_timestamp(skb);
- sock_enable_timestamp(sk);
- }
-
if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
goto discard_release;
+ nf_reset(skb);
- ret = sk_filter(sk, skb, 1);
- if (ret)
- goto discard_release;
+ if (sk_filter(sk, skb))
+ goto discard_release;
/* Create an SCTP packet structure. */
chunk = sctp_chunkify(skb, asoc, sk);
- if (!chunk) {
- ret = -ENOMEM;
+ if (!chunk)
goto discard_release;
- }
SCTP_INPUT_CB(skb)->chunk = chunk;
/* Remember what endpoint is to handle this packet. */
*/
sctp_bh_lock_sock(sk);
- if (sock_owned_by_user(sk))
- sk_add_backlog(sk, skb);
- else
- sctp_backlog_rcv(sk, skb);
+ if (sk != rcvr->sk) {
+ /* Our cached sk is different from the rcvr->sk. This is
+ * because migrate()/accept() may have moved the association
+ * to a new socket and released all the sockets. So now we
+ * are holding a lock on the old socket while the user may
+ * be doing something with the new socket. Switch our veiw
+ * of the current sk.
+ */
+ sctp_bh_unlock_sock(sk);
+ sk = rcvr->sk;
+ sctp_bh_lock_sock(sk);
+ }
+
+ if (sock_owned_by_user(sk)) {
+ if (sctp_add_backlog(sk, skb)) {
+ sctp_bh_unlock_sock(sk);
+ sctp_chunk_free(chunk);
+ skb = NULL; /* sctp_chunk_free already freed the skb */
+ goto discard_release;
+ }
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG);
+ } else {
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ);
+ sctp_inq_push(&chunk->rcvr->inqueue, chunk);
+ }
- /* Release the sock and any reference counts we took in the
- * lookup calls.
- */
sctp_bh_unlock_sock(sk);
+
+ /* Release the asoc/ep ref we took in the lookup calls. */
if (asoc)
sctp_association_put(asoc);
else
sctp_endpoint_put(ep);
- sock_put(sk);
- return ret;
+
+ return 0;
discard_it:
+ SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS);
kfree_skb(skb);
- return ret;
+ return 0;
discard_release:
- /* Release any structures we may be holding. */
- sock_put(sk);
+ /* Release the asoc/ep ref we took in the lookup calls. */
if (asoc)
sctp_association_put(asoc);
else
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.
+/* Process the backlog queue of the socket. Every skb on
+ * the backlog holds a ref on an association or endpoint.
+ * We hold this ref throughout the state machine to make
+ * sure that the structure we need is still around.
*/
int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
+ struct sctp_ep_common *rcvr = NULL;
+ int backloged = 0;
+
+ rcvr = chunk->rcvr;
+
+ /* If the rcvr is dead then the association or endpoint
+ * has been deleted and we can safely drop the chunk
+ * and refs that we are holding.
+ */
+ if (rcvr->dead) {
+ sctp_chunk_free(chunk);
+ goto done;
+ }
+
+ if (unlikely(rcvr->sk != sk)) {
+ /* In this case, the association moved from one socket to
+ * another. We are currently sitting on the backlog of the
+ * old socket, so we need to move.
+ * However, since we are here in the process context we
+ * need to take make sure that the user doesn't own
+ * the new socket when we process the packet.
+ * If the new socket is user-owned, queue the chunk to the
+ * backlog of the new socket without dropping any refs.
+ * Otherwise, we can safely push the chunk on the inqueue.
+ */
+
+ sk = rcvr->sk;
+ sctp_bh_lock_sock(sk);
+
+ if (sock_owned_by_user(sk)) {
+ if (sk_add_backlog(sk, skb))
+ sctp_chunk_free(chunk);
+ else
+ backloged = 1;
+ } else
+ sctp_inq_push(inqueue, chunk);
+
+ sctp_bh_unlock_sock(sk);
+
+ /* If the chunk was backloged again, don't drop refs */
+ if (backloged)
+ return 0;
+ } else {
+ sctp_inq_push(inqueue, chunk);
+ }
+
+done:
+ /* Release the refs we took in sctp_add_backlog */
+ if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
+ sctp_association_put(sctp_assoc(rcvr));
+ else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
+ sctp_endpoint_put(sctp_ep(rcvr));
+ else
+ BUG();
+
+ return 0;
+}
+
+static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
+{
+ struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
+ struct sctp_ep_common *rcvr = chunk->rcvr;
+ int ret;
+
+ ret = sk_add_backlog(sk, skb);
+ if (!ret) {
+ /* Hold the assoc/ep while hanging on the backlog queue.
+ * This way, we know structures we need will not disappear
+ * from us
+ */
+ if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
+ sctp_association_hold(sctp_assoc(rcvr));
+ else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
+ sctp_endpoint_hold(sctp_ep(rcvr));
+ else
+ BUG();
+ }
+ return ret;
- 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 (!t || (t->pathmtu <= pmtu))
+ return;
+
+ if (sock_owned_by_user(sk)) {
+ asoc->pmtu_pending = 1;
+ t->pmtu_pending = 1;
+ return;
}
- if (!sock_owned_by_user(sk) && t && (t->pmtu != pmtu)) {
- t->pmtu = pmtu;
+ if (t->param_flags & SPP_PMTUD_ENABLE) {
+ /* Update transports view of the MTU */
+ sctp_transport_update_pmtu(t, pmtu);
+
+ /* Update association pmtu. */
sctp_assoc_sync_pmtu(asoc);
- sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
}
+
+ /* Retransmit with the new pmtu setting.
+ * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
+ * Needed will never be sent, but if a message was sent before
+ * PMTU discovery was disabled that was larger than the PMTU, it
+ * would not be fragmented, so it must be re-transmitted fragmented.
+ */
+ sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
}
/*
*
*/
void sctp_icmp_proto_unreachable(struct sock *sk,
- struct sctp_association *asoc,
- struct sctp_transport *t)
+ struct sctp_association *asoc,
+ struct sctp_transport *t)
{
- SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__);
+ SCTP_DEBUG_PRINTK("%s\n", __func__);
- sctp_do_sm(SCTP_EVENT_T_OTHER,
- SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
- asoc->state, asoc->ep, asoc, t,
- GFP_ATOMIC);
+ if (sock_owned_by_user(sk)) {
+ if (timer_pending(&t->proto_unreach_timer))
+ return;
+ else {
+ if (!mod_timer(&t->proto_unreach_timer,
+ jiffies + (HZ/20)))
+ sctp_association_hold(asoc);
+ }
+
+ } else {
+ if (timer_pending(&t->proto_unreach_timer) &&
+ del_timer(&t->proto_unreach_timer))
+ sctp_association_put(asoc);
+ sctp_do_sm(SCTP_EVENT_T_OTHER,
+ SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
+ asoc->state, asoc->ep, asoc, t,
+ GFP_ATOMIC);
+ }
}
/* Common lookup code for icmp/icmpv6 error handler. */
union sctp_addr daddr;
struct sctp_af *af;
struct sock *sk = NULL;
- struct sctp_association *asoc = NULL;
+ struct sctp_association *asoc;
struct sctp_transport *transport = NULL;
+ struct sctp_init_chunk *chunkhdr;
+ __u32 vtag = ntohl(sctphdr->vtag);
+ int len = skb->len - ((void *)sctphdr - (void *)skb->data);
*app = NULL; *tpp = NULL;
sk = asoc->base.sk;
- if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ /* RFC 4960, Appendix C. ICMP Handling
+ *
+ * ICMP6) An implementation MUST validate that the Verification Tag
+ * contained in the ICMP message matches the Verification Tag of
+ * the peer. If the Verification Tag is not 0 and does NOT
+ * match, discard the ICMP message. If it is 0 and the ICMP
+ * message contains enough bytes to verify that the chunk type is
+ * an INIT chunk and that the Initiate Tag matches the tag of the
+ * peer, continue with ICMP7. If the ICMP message is too short
+ * or the chunk type or the Initiate Tag does not match, silently
+ * discard the packet.
+ */
+ if (vtag == 0) {
+ chunkhdr = (struct sctp_init_chunk *)((void *)sctphdr
+ + sizeof(struct sctphdr));
+ if (len < sizeof(struct sctphdr) + sizeof(sctp_chunkhdr_t)
+ + sizeof(__be32) ||
+ chunkhdr->chunk_hdr.type != SCTP_CID_INIT ||
+ ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag) {
+ goto out;
+ }
+ } else if (vtag != asoc->c.peer_vtag) {
goto out;
}
* servers this needs to be solved differently.
*/
if (sock_owned_by_user(sk))
- NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
+ NET_INC_STATS_BH(&init_net, LINUX_MIB_LOCKDROPPEDICMPS);
*app = asoc;
*tpp = transport;
return sk;
out:
- sock_put(sk);
if (asoc)
sctp_association_put(asoc);
return NULL;
void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
{
sctp_bh_unlock_sock(sk);
- sock_put(sk);
if (asoc)
sctp_association_put(asoc);
}
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;
+ const int ihlen = iph->ihl * 4;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
struct sock *sk;
- struct sctp_association *asoc;
+ struct sctp_association *asoc = NULL;
struct sctp_transport *transport;
struct inet_sock *inet;
- char *saveip, *savesctp;
+ sk_buff_data_t saveip, savesctp;
int err;
- if (skb->len < ((iph->ihl << 2) + 8)) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ if (skb->len < ihlen + 8) {
+ ICMP_INC_STATS_BH(&init_net, 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, &asoc, &transport);
- /* Put back, the original pointers. */
- skb->nh.raw = saveip;
- skb->h.raw = savesctp;
+ saveip = skb->network_header;
+ savesctp = skb->transport_header;
+ skb_reset_network_header(skb);
+ skb_set_transport_header(skb, ihlen);
+ sk = sctp_err_lookup(AF_INET, skb, sctp_hdr(skb), &asoc, &transport);
+ /* Put back, the original values. */
+ skb->network_header = saveip;
+ skb->transport_header = savesctp;
if (!sk) {
- ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+ ICMP_INC_STATS_BH(&init_net, ICMP_MIB_INERRORS);
return;
}
/* Warning: The sock lock is held. Remember to call
* 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)
+static 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) {
+ do {
+ /* Break out if chunk length is less then minimal. */
+ if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
+ break;
+
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ break;
/* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
* receiver MUST silently discard the OOTB packet and take no
if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
goto discard;
+ /* RFC 4460, 2.11.2
+ * This will discard packets with INIT chunk bundled as
+ * subsequent chunks in the packet. When INIT is first,
+ * the normal INIT processing will discard the chunk.
+ */
+ if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
+ 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.
}
ch = (sctp_chunkhdr_t *) ch_end;
- ch_end = ((__u8 *) ch) + WORD_ROUND(ntohs(ch->length));
- }
+ } while (ch_end < skb_tail_pointer(skb));
return 0;
/* 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;
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;
+ hlist_add_head(&epb->node, &head->chain);
sctp_write_unlock(&head->lock);
}
epb = &ep->base;
+ if (hlist_unhashed(&epb->node))
+ return;
+
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;
- }
-
+ __hlist_del(&epb->node);
sctp_write_unlock(&head->lock);
}
struct sctp_hashbucket *head;
struct sctp_ep_common *epb;
struct sctp_endpoint *ep;
+ struct hlist_node *node;
int hash;
- hash = sctp_ep_hashfn(laddr->v4.sin_port);
+ hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port));
head = &sctp_ep_hashtable[hash];
read_lock(&head->lock);
- for (epb = head->chain; epb; epb = epb->next) {
+ sctp_for_each_hentry(epb, node, &head->chain) {
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;
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;
+ hlist_add_head(&epb->node, &head->chain);
sctp_write_unlock(&head->lock);
}
/* Add an association to the hash. Local BH-safe. */
void sctp_hash_established(struct sctp_association *asoc)
{
+ if (asoc->temp)
+ return;
+
sctp_local_bh_disable();
__sctp_hash_established(asoc);
sctp_local_bh_enable();
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;
- }
-
+ __hlist_del(&epb->node);
sctp_write_unlock(&head->lock);
}
/* Remove association from the hash table. Local BH-safe. */
void sctp_unhash_established(struct sctp_association *asoc)
{
+ if (asoc->temp)
+ return;
+
sctp_local_bh_disable();
__sctp_unhash_established(asoc);
sctp_local_bh_enable();
struct sctp_ep_common *epb;
struct sctp_association *asoc;
struct sctp_transport *transport;
+ struct hlist_node *node;
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);
+ hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port));
head = &sctp_assoc_hashtable[hash];
read_lock(&head->lock);
- for (epb = head->chain; epb; epb = epb->next) {
+ sctp_for_each_hentry(epb, node, &head->chain) {
asoc = sctp_assoc(epb);
transport = sctp_assoc_is_match(asoc, local, peer);
if (transport)
hit:
*pt = transport;
sctp_association_hold(asoc);
- sock_hold(epb->sk);
read_unlock(&head->lock);
return asoc;
}
struct sctp_transport *transport;
if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) {
- sock_put(asoc->base.sk);
sctp_association_put(asoc);
return 1;
}
struct sctp_association *asoc;
union sctp_addr addr;
union sctp_addr *paddr = &addr;
- struct sctphdr *sh = (struct sctphdr *) skb->h.raw;
+ struct sctphdr *sh = sctp_hdr(skb);
sctp_chunkhdr_t *ch;
union sctp_params params;
sctp_init_chunk_t *init;
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.
if (!af)
continue;
- af->from_addr_param(paddr, params.addr, ntohs(sh->source), 0);
+ af->from_addr_param(paddr, params.addr, sh->source, 0);
asoc = __sctp_lookup_association(laddr, paddr, &transport);
if (asoc)
return NULL;
}
+/* ADD-IP, Section 5.2
+ * When an endpoint receives an ASCONF Chunk from the remote peer
+ * special procedures may be needed to identify the association the
+ * ASCONF Chunk is associated with. To properly find the association
+ * the following procedures SHOULD be followed:
+ *
+ * D2) If the association is not found, use the address found in the
+ * Address Parameter TLV combined with the port number found in the
+ * SCTP common header. If found proceed to rule D4.
+ *
+ * D2-ext) If more than one ASCONF Chunks are packed together, use the
+ * address found in the ASCONF Address Parameter TLV of each of the
+ * subsequent ASCONF Chunks. If found, proceed to rule D4.
+ */
+static struct sctp_association *__sctp_rcv_asconf_lookup(
+ sctp_chunkhdr_t *ch,
+ const union sctp_addr *laddr,
+ __be16 peer_port,
+ struct sctp_transport **transportp)
+{
+ sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch;
+ struct sctp_af *af;
+ union sctp_addr_param *param;
+ union sctp_addr paddr;
+
+ /* Skip over the ADDIP header and find the Address parameter */
+ param = (union sctp_addr_param *)(asconf + 1);
+
+ af = sctp_get_af_specific(param_type2af(param->v4.param_hdr.type));
+ if (unlikely(!af))
+ return NULL;
+
+ af->from_addr_param(&paddr, param, peer_port, 0);
+
+ return __sctp_lookup_association(laddr, &paddr, transportp);
+}
+
+
+/* SCTP-AUTH, Section 6.3:
+* If the receiver does not find a STCB for a packet containing an AUTH
+* chunk as the first chunk and not a COOKIE-ECHO chunk as the second
+* chunk, it MUST use the chunks after the AUTH chunk to look up an existing
+* association.
+*
+* This means that any chunks that can help us identify the association need
+* to be looked at to find this assocation.
+*/
+static struct sctp_association *__sctp_rcv_walk_lookup(struct sk_buff *skb,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ struct sctp_association *asoc = NULL;
+ sctp_chunkhdr_t *ch;
+ int have_auth = 0;
+ unsigned int chunk_num = 1;
+ __u8 *ch_end;
+
+ /* Walk through the chunks looking for AUTH or ASCONF chunks
+ * to help us find the association.
+ */
+ ch = (sctp_chunkhdr_t *) skb->data;
+ do {
+ /* Break out if chunk length is less then minimal. */
+ if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
+ break;
+
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ break;
+
+ switch(ch->type) {
+ case SCTP_CID_AUTH:
+ have_auth = chunk_num;
+ break;
+
+ case SCTP_CID_COOKIE_ECHO:
+ /* If a packet arrives containing an AUTH chunk as
+ * a first chunk, a COOKIE-ECHO chunk as the second
+ * chunk, and possibly more chunks after them, and
+ * the receiver does not have an STCB for that
+ * packet, then authentication is based on
+ * the contents of the COOKIE- ECHO chunk.
+ */
+ if (have_auth == 1 && chunk_num == 2)
+ return NULL;
+ break;
+
+ case SCTP_CID_ASCONF:
+ if (have_auth || sctp_addip_noauth)
+ asoc = __sctp_rcv_asconf_lookup(ch, laddr,
+ sctp_hdr(skb)->source,
+ transportp);
+ default:
+ break;
+ }
+
+ if (asoc)
+ break;
+
+ ch = (sctp_chunkhdr_t *) ch_end;
+ chunk_num++;
+ } while (ch_end < skb_tail_pointer(skb));
+
+ return asoc;
+}
+
+/*
+ * There are circumstances when we need to look inside the SCTP packet
+ * for information to help us find the association. Examples
+ * include looking inside of INIT/INIT-ACK chunks or after the AUTH
+ * chunks.
+ */
+static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
+ const union sctp_addr *laddr,
+ struct sctp_transport **transportp)
+{
+ sctp_chunkhdr_t *ch;
+
+ ch = (sctp_chunkhdr_t *) skb->data;
+
+ /* 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;
+
+ /* If this is INIT/INIT-ACK look inside the chunk too. */
+ switch (ch->type) {
+ case SCTP_CID_INIT:
+ case SCTP_CID_INIT_ACK:
+ return __sctp_rcv_init_lookup(skb, laddr, transportp);
+ break;
+
+ default:
+ return __sctp_rcv_walk_lookup(skb, laddr, transportp);
+ break;
+ }
+
+
+ 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,
* parameters within the INIT or INIT-ACK.
*/
if (!asoc)
- asoc = __sctp_rcv_init_lookup(skb, laddr, transportp);
+ asoc = __sctp_rcv_lookup_harder(skb, laddr, transportp);
return asoc;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff