1 /* SCTP kernel reference Implementation
2 * Copyright (c) 1999-2000 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2001-2003 International Business Machines, Corp.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 Nokia, Inc.
7 * Copyright (c) 2001 La Monte H.P. Yarroll
9 * This file is part of the SCTP kernel reference Implementation
11 * These functions handle all input from the IP layer into SCTP.
13 * The SCTP reference implementation is free software;
14 * you can redistribute it and/or modify it under the terms of
15 * the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
19 * The SCTP reference implementation is distributed in the hope that it
20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21 * ************************
22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 * See the GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, write to
27 * the Free Software Foundation, 59 Temple Place - Suite 330,
28 * Boston, MA 02111-1307, USA.
30 * Please send any bug reports or fixes you make to the
32 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 * Or submit a bug report through the following website:
35 * http://www.sf.net/projects/lksctp
37 * Written or modified by:
38 * La Monte H.P. Yarroll <piggy@acm.org>
39 * Karl Knutson <karl@athena.chicago.il.us>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Daisy Chang <daisyc@us.ibm.com>
44 * Sridhar Samudrala <sri@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
47 * Any bugs reported given to us we will try to fix... any fixes shared will
48 * be incorporated into the next SCTP release.
51 #include <linux/types.h>
52 #include <linux/list.h> /* For struct list_head */
53 #include <linux/socket.h>
55 #include <linux/time.h> /* For struct timeval */
61 #include <net/sctp/sctp.h>
62 #include <net/sctp/sm.h>
64 /* Forward declarations for internal helpers. */
65 static int sctp_rcv_ootb(struct sk_buff
*);
66 static struct sctp_association
*__sctp_rcv_lookup(struct sk_buff
*skb
,
67 const union sctp_addr
*laddr
,
68 const union sctp_addr
*paddr
,
69 struct sctp_transport
**transportp
);
70 static struct sctp_endpoint
*__sctp_rcv_lookup_endpoint(const union sctp_addr
*laddr
);
71 static struct sctp_association
*__sctp_lookup_association(
72 const union sctp_addr
*local
,
73 const union sctp_addr
*peer
,
74 struct sctp_transport
**pt
);
77 /* Calculate the SCTP checksum of an SCTP packet. */
78 static inline int sctp_rcv_checksum(struct sk_buff
*skb
)
82 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
84 sh
= (struct sctphdr
*) skb
->h
.raw
;
85 cmp
= ntohl(sh
->checksum
);
87 val
= sctp_start_cksum((__u8
*)sh
, skb_headlen(skb
));
89 for (; list
; list
= list
->next
)
90 val
= sctp_update_cksum((__u8
*)list
->data
, skb_headlen(list
),
93 val
= sctp_end_cksum(val
);
96 /* CRC failure, dump it. */
97 SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS
);
103 struct sctp_input_cb
{
105 struct inet_skb_parm h4
;
106 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
107 struct inet6_skb_parm h6
;
110 struct sctp_chunk
*chunk
;
112 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
115 * This is the routine which IP calls when receiving an SCTP packet.
117 int sctp_rcv(struct sk_buff
*skb
)
120 struct sctp_association
*asoc
;
121 struct sctp_endpoint
*ep
= NULL
;
122 struct sctp_ep_common
*rcvr
;
123 struct sctp_transport
*transport
= NULL
;
124 struct sctp_chunk
*chunk
;
127 union sctp_addr dest
;
132 if (skb
->pkt_type
!=PACKET_HOST
)
135 SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS
);
137 if (skb_linearize(skb
, GFP_ATOMIC
))
140 sh
= (struct sctphdr
*) skb
->h
.raw
;
142 /* Pull up the IP and SCTP headers. */
143 __skb_pull(skb
, skb
->h
.raw
- skb
->data
);
144 if (skb
->len
< sizeof(struct sctphdr
))
146 if (sctp_rcv_checksum(skb
) < 0)
149 skb_pull(skb
, sizeof(struct sctphdr
));
151 /* Make sure we at least have chunk headers worth of data left. */
152 if (skb
->len
< sizeof(struct sctp_chunkhdr
))
155 family
= ipver2af(skb
->nh
.iph
->version
);
156 af
= sctp_get_af_specific(family
);
160 /* Initialize local addresses for lookups. */
161 af
->from_skb(&src
, skb
, 1);
162 af
->from_skb(&dest
, skb
, 0);
164 /* If the packet is to or from a non-unicast address,
165 * silently discard the packet.
167 * This is not clearly defined in the RFC except in section
168 * 8.4 - OOTB handling. However, based on the book "Stream Control
169 * Transmission Protocol" 2.1, "It is important to note that the
170 * IP address of an SCTP transport address must be a routable
171 * unicast address. In other words, IP multicast addresses and
172 * IP broadcast addresses cannot be used in an SCTP transport
175 if (!af
->addr_valid(&src
, NULL
, skb
) ||
176 !af
->addr_valid(&dest
, NULL
, skb
))
179 asoc
= __sctp_rcv_lookup(skb
, &src
, &dest
, &transport
);
182 ep
= __sctp_rcv_lookup_endpoint(&dest
);
184 /* Retrieve the common input handling substructure. */
185 rcvr
= asoc
? &asoc
->base
: &ep
->base
;
189 * If a frame arrives on an interface and the receiving socket is
190 * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
192 if (sk
->sk_bound_dev_if
&& (sk
->sk_bound_dev_if
!= af
->skb_iif(skb
)))
196 sctp_association_put(asoc
);
199 sctp_endpoint_put(ep
);
202 sk
= sctp_get_ctl_sock();
203 ep
= sctp_sk(sk
)->ep
;
204 sctp_endpoint_hold(ep
);
210 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
211 * An SCTP packet is called an "out of the blue" (OOTB)
212 * packet if it is correctly formed, i.e., passed the
213 * receiver's checksum check, but the receiver is not
214 * able to identify the association to which this
218 if (sctp_rcv_ootb(skb
)) {
219 SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES
);
220 goto discard_release
;
224 /* SCTP seems to always need a timestamp right now (FIXME) */
225 if (skb
->tstamp
.off_sec
== 0) {
226 __net_timestamp(skb
);
227 sock_enable_timestamp(sk
);
230 if (!xfrm_policy_check(sk
, XFRM_POLICY_IN
, skb
, family
))
231 goto discard_release
;
234 ret
= sk_filter(sk
, skb
, 1);
236 goto discard_release
;
238 /* Create an SCTP packet structure. */
239 chunk
= sctp_chunkify(skb
, asoc
, sk
);
242 goto discard_release
;
244 SCTP_INPUT_CB(skb
)->chunk
= chunk
;
246 /* Remember what endpoint is to handle this packet. */
249 /* Remember the SCTP header. */
250 chunk
->sctp_hdr
= sh
;
252 /* Set the source and destination addresses of the incoming chunk. */
253 sctp_init_addrs(chunk
, &src
, &dest
);
255 /* Remember where we came from. */
256 chunk
->transport
= transport
;
258 /* Acquire access to the sock lock. Note: We are safe from other
259 * bottom halves on this lock, but a user may be in the lock too,
260 * so check if it is busy.
262 sctp_bh_lock_sock(sk
);
264 /* It is possible that the association could have moved to a different
265 * socket if it is peeled off. If so, update the sk.
267 if (sk
!= rcvr
->sk
) {
268 sctp_bh_lock_sock(rcvr
->sk
);
269 sctp_bh_unlock_sock(sk
);
273 if (sock_owned_by_user(sk
))
274 sk_add_backlog(sk
, skb
);
276 sctp_backlog_rcv(sk
, skb
);
278 /* Release the sock and the sock ref we took in the lookup calls.
279 * The asoc/ep ref will be released in sctp_backlog_rcv.
281 sctp_bh_unlock_sock(sk
);
291 /* Release any structures we may be holding. */
294 sctp_association_put(asoc
);
296 sctp_endpoint_put(ep
);
301 /* Handle second half of inbound skb processing. If the sock was busy,
302 * we may have need to delay processing until later when the sock is
303 * released (on the backlog). If not busy, we call this routine
304 * directly from the bottom half.
306 int sctp_backlog_rcv(struct sock
*sk
, struct sk_buff
*skb
)
308 struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
309 struct sctp_inq
*inqueue
= NULL
;
310 struct sctp_ep_common
*rcvr
= NULL
;
314 BUG_TRAP(rcvr
->sk
== sk
);
317 sctp_chunk_free(chunk
);
319 inqueue
= &chunk
->rcvr
->inqueue
;
320 sctp_inq_push(inqueue
, chunk
);
323 /* Release the asoc/ep ref we took in the lookup calls in sctp_rcv. */
324 if (SCTP_EP_TYPE_ASSOCIATION
== rcvr
->type
)
325 sctp_association_put(sctp_assoc(rcvr
));
327 sctp_endpoint_put(sctp_ep(rcvr
));
332 void sctp_backlog_migrate(struct sctp_association
*assoc
,
333 struct sock
*oldsk
, struct sock
*newsk
)
336 struct sctp_chunk
*chunk
;
338 skb
= oldsk
->sk_backlog
.head
;
339 oldsk
->sk_backlog
.head
= oldsk
->sk_backlog
.tail
= NULL
;
340 while (skb
!= NULL
) {
341 struct sk_buff
*next
= skb
->next
;
343 chunk
= SCTP_INPUT_CB(skb
)->chunk
;
345 if (&assoc
->base
== chunk
->rcvr
)
346 sk_add_backlog(newsk
, skb
);
348 sk_add_backlog(oldsk
, skb
);
353 /* Handle icmp frag needed error. */
354 void sctp_icmp_frag_needed(struct sock
*sk
, struct sctp_association
*asoc
,
355 struct sctp_transport
*t
, __u32 pmtu
)
357 if (sock_owned_by_user(sk
) || !t
|| (t
->pathmtu
== pmtu
))
360 if (t
->param_flags
& SPP_PMTUD_ENABLE
) {
361 if (unlikely(pmtu
< SCTP_DEFAULT_MINSEGMENT
)) {
362 printk(KERN_WARNING
"%s: Reported pmtu %d too low, "
363 "using default minimum of %d\n",
365 SCTP_DEFAULT_MINSEGMENT
);
366 /* Use default minimum segment size and disable
367 * pmtu discovery on this transport.
369 t
->pathmtu
= SCTP_DEFAULT_MINSEGMENT
;
370 t
->param_flags
= (t
->param_flags
& ~SPP_HB
) |
376 /* Update association pmtu. */
377 sctp_assoc_sync_pmtu(asoc
);
380 /* Retransmit with the new pmtu setting.
381 * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
382 * Needed will never be sent, but if a message was sent before
383 * PMTU discovery was disabled that was larger than the PMTU, it
384 * would not be fragmented, so it must be re-transmitted fragmented.
386 sctp_retransmit(&asoc
->outqueue
, t
, SCTP_RTXR_PMTUD
);
390 * SCTP Implementer's Guide, 2.37 ICMP handling procedures
392 * ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
393 * or a "Protocol Unreachable" treat this message as an abort
394 * with the T bit set.
396 * This function sends an event to the state machine, which will abort the
400 void sctp_icmp_proto_unreachable(struct sock
*sk
,
401 struct sctp_association
*asoc
,
402 struct sctp_transport
*t
)
404 SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__
);
406 sctp_do_sm(SCTP_EVENT_T_OTHER
,
407 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH
),
408 asoc
->state
, asoc
->ep
, asoc
, t
,
413 /* Common lookup code for icmp/icmpv6 error handler. */
414 struct sock
*sctp_err_lookup(int family
, struct sk_buff
*skb
,
415 struct sctphdr
*sctphdr
,
416 struct sctp_association
**app
,
417 struct sctp_transport
**tpp
)
419 union sctp_addr saddr
;
420 union sctp_addr daddr
;
422 struct sock
*sk
= NULL
;
423 struct sctp_association
*asoc
= NULL
;
424 struct sctp_transport
*transport
= NULL
;
426 *app
= NULL
; *tpp
= NULL
;
428 af
= sctp_get_af_specific(family
);
433 /* Initialize local addresses for lookups. */
434 af
->from_skb(&saddr
, skb
, 1);
435 af
->from_skb(&daddr
, skb
, 0);
437 /* Look for an association that matches the incoming ICMP error
440 asoc
= __sctp_lookup_association(&saddr
, &daddr
, &transport
);
446 if (ntohl(sctphdr
->vtag
) != asoc
->c
.peer_vtag
) {
447 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS
);
451 sctp_bh_lock_sock(sk
);
453 /* If too many ICMPs get dropped on busy
454 * servers this needs to be solved differently.
456 if (sock_owned_by_user(sk
))
457 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS
);
466 sctp_association_put(asoc
);
470 /* Common cleanup code for icmp/icmpv6 error handler. */
471 void sctp_err_finish(struct sock
*sk
, struct sctp_association
*asoc
)
473 sctp_bh_unlock_sock(sk
);
476 sctp_association_put(asoc
);
480 * This routine is called by the ICMP module when it gets some
481 * sort of error condition. If err < 0 then the socket should
482 * be closed and the error returned to the user. If err > 0
483 * it's just the icmp type << 8 | icmp code. After adjustment
484 * header points to the first 8 bytes of the sctp header. We need
485 * to find the appropriate port.
487 * The locking strategy used here is very "optimistic". When
488 * someone else accesses the socket the ICMP is just dropped
489 * and for some paths there is no check at all.
490 * A more general error queue to queue errors for later handling
491 * is probably better.
494 void sctp_v4_err(struct sk_buff
*skb
, __u32 info
)
496 struct iphdr
*iph
= (struct iphdr
*)skb
->data
;
497 struct sctphdr
*sh
= (struct sctphdr
*)(skb
->data
+ (iph
->ihl
<<2));
498 int type
= skb
->h
.icmph
->type
;
499 int code
= skb
->h
.icmph
->code
;
501 struct sctp_association
*asoc
;
502 struct sctp_transport
*transport
;
503 struct inet_sock
*inet
;
504 char *saveip
, *savesctp
;
507 if (skb
->len
< ((iph
->ihl
<< 2) + 8)) {
508 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS
);
512 /* Fix up skb to look at the embedded net header. */
513 saveip
= skb
->nh
.raw
;
514 savesctp
= skb
->h
.raw
;
516 skb
->h
.raw
= (char *)sh
;
517 sk
= sctp_err_lookup(AF_INET
, skb
, sh
, &asoc
, &transport
);
518 /* Put back, the original pointers. */
519 skb
->nh
.raw
= saveip
;
520 skb
->h
.raw
= savesctp
;
522 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS
);
525 /* Warning: The sock lock is held. Remember to call
530 case ICMP_PARAMETERPROB
:
533 case ICMP_DEST_UNREACH
:
534 if (code
> NR_ICMP_UNREACH
)
537 /* PMTU discovery (RFC1191) */
538 if (ICMP_FRAG_NEEDED
== code
) {
539 sctp_icmp_frag_needed(sk
, asoc
, transport
, info
);
543 if (ICMP_PROT_UNREACH
== code
) {
544 sctp_icmp_proto_unreachable(sk
, asoc
,
549 err
= icmp_err_convert
[code
].errno
;
551 case ICMP_TIME_EXCEEDED
:
552 /* Ignore any time exceeded errors due to fragment reassembly
555 if (ICMP_EXC_FRAGTIME
== code
)
565 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
567 sk
->sk_error_report(sk
);
568 } else { /* Only an error on timeout */
569 sk
->sk_err_soft
= err
;
573 sctp_err_finish(sk
, asoc
);
577 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
579 * This function scans all the chunks in the OOTB packet to determine if
580 * the packet should be discarded right away. If a response might be needed
581 * for this packet, or, if further processing is possible, the packet will
582 * be queued to a proper inqueue for the next phase of handling.
585 * Return 0 - If further processing is needed.
586 * Return 1 - If the packet can be discarded right away.
588 int sctp_rcv_ootb(struct sk_buff
*skb
)
594 ch
= (sctp_chunkhdr_t
*) skb
->data
;
596 /* Scan through all the chunks in the packet. */
598 /* Break out if chunk length is less then minimal. */
599 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
602 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
603 if (ch_end
> skb
->tail
)
606 /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
607 * receiver MUST silently discard the OOTB packet and take no
610 if (SCTP_CID_ABORT
== ch
->type
)
613 /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE
614 * chunk, the receiver should silently discard the packet
615 * and take no further action.
617 if (SCTP_CID_SHUTDOWN_COMPLETE
== ch
->type
)
620 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
621 * or a COOKIE ACK the SCTP Packet should be silently
624 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
627 if (SCTP_CID_ERROR
== ch
->type
) {
628 sctp_walk_errors(err
, ch
) {
629 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
634 ch
= (sctp_chunkhdr_t
*) ch_end
;
635 } while (ch_end
< skb
->tail
);
643 /* Insert endpoint into the hash table. */
644 static void __sctp_hash_endpoint(struct sctp_endpoint
*ep
)
646 struct sctp_ep_common
**epp
;
647 struct sctp_ep_common
*epb
;
648 struct sctp_hashbucket
*head
;
652 epb
->hashent
= sctp_ep_hashfn(epb
->bind_addr
.port
);
653 head
= &sctp_ep_hashtable
[epb
->hashent
];
655 sctp_write_lock(&head
->lock
);
659 (*epp
)->pprev
= &epb
->next
;
662 sctp_write_unlock(&head
->lock
);
665 /* Add an endpoint to the hash. Local BH-safe. */
666 void sctp_hash_endpoint(struct sctp_endpoint
*ep
)
668 sctp_local_bh_disable();
669 __sctp_hash_endpoint(ep
);
670 sctp_local_bh_enable();
673 /* Remove endpoint from the hash table. */
674 static void __sctp_unhash_endpoint(struct sctp_endpoint
*ep
)
676 struct sctp_hashbucket
*head
;
677 struct sctp_ep_common
*epb
;
681 epb
->hashent
= sctp_ep_hashfn(epb
->bind_addr
.port
);
683 head
= &sctp_ep_hashtable
[epb
->hashent
];
685 sctp_write_lock(&head
->lock
);
689 epb
->next
->pprev
= epb
->pprev
;
690 *epb
->pprev
= epb
->next
;
694 sctp_write_unlock(&head
->lock
);
697 /* Remove endpoint from the hash. Local BH-safe. */
698 void sctp_unhash_endpoint(struct sctp_endpoint
*ep
)
700 sctp_local_bh_disable();
701 __sctp_unhash_endpoint(ep
);
702 sctp_local_bh_enable();
705 /* Look up an endpoint. */
706 static struct sctp_endpoint
*__sctp_rcv_lookup_endpoint(const union sctp_addr
*laddr
)
708 struct sctp_hashbucket
*head
;
709 struct sctp_ep_common
*epb
;
710 struct sctp_endpoint
*ep
;
713 hash
= sctp_ep_hashfn(laddr
->v4
.sin_port
);
714 head
= &sctp_ep_hashtable
[hash
];
715 read_lock(&head
->lock
);
716 for (epb
= head
->chain
; epb
; epb
= epb
->next
) {
718 if (sctp_endpoint_is_match(ep
, laddr
))
722 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
726 sctp_endpoint_hold(ep
);
728 read_unlock(&head
->lock
);
732 /* Insert association into the hash table. */
733 static void __sctp_hash_established(struct sctp_association
*asoc
)
735 struct sctp_ep_common
**epp
;
736 struct sctp_ep_common
*epb
;
737 struct sctp_hashbucket
*head
;
741 /* Calculate which chain this entry will belong to. */
742 epb
->hashent
= sctp_assoc_hashfn(epb
->bind_addr
.port
, asoc
->peer
.port
);
744 head
= &sctp_assoc_hashtable
[epb
->hashent
];
746 sctp_write_lock(&head
->lock
);
750 (*epp
)->pprev
= &epb
->next
;
753 sctp_write_unlock(&head
->lock
);
756 /* Add an association to the hash. Local BH-safe. */
757 void sctp_hash_established(struct sctp_association
*asoc
)
759 sctp_local_bh_disable();
760 __sctp_hash_established(asoc
);
761 sctp_local_bh_enable();
764 /* Remove association from the hash table. */
765 static void __sctp_unhash_established(struct sctp_association
*asoc
)
767 struct sctp_hashbucket
*head
;
768 struct sctp_ep_common
*epb
;
772 epb
->hashent
= sctp_assoc_hashfn(epb
->bind_addr
.port
,
775 head
= &sctp_assoc_hashtable
[epb
->hashent
];
777 sctp_write_lock(&head
->lock
);
781 epb
->next
->pprev
= epb
->pprev
;
782 *epb
->pprev
= epb
->next
;
786 sctp_write_unlock(&head
->lock
);
789 /* Remove association from the hash table. Local BH-safe. */
790 void sctp_unhash_established(struct sctp_association
*asoc
)
792 sctp_local_bh_disable();
793 __sctp_unhash_established(asoc
);
794 sctp_local_bh_enable();
797 /* Look up an association. */
798 static struct sctp_association
*__sctp_lookup_association(
799 const union sctp_addr
*local
,
800 const union sctp_addr
*peer
,
801 struct sctp_transport
**pt
)
803 struct sctp_hashbucket
*head
;
804 struct sctp_ep_common
*epb
;
805 struct sctp_association
*asoc
;
806 struct sctp_transport
*transport
;
809 /* Optimize here for direct hit, only listening connections can
810 * have wildcards anyways.
812 hash
= sctp_assoc_hashfn(local
->v4
.sin_port
, peer
->v4
.sin_port
);
813 head
= &sctp_assoc_hashtable
[hash
];
814 read_lock(&head
->lock
);
815 for (epb
= head
->chain
; epb
; epb
= epb
->next
) {
816 asoc
= sctp_assoc(epb
);
817 transport
= sctp_assoc_is_match(asoc
, local
, peer
);
822 read_unlock(&head
->lock
);
828 sctp_association_hold(asoc
);
830 read_unlock(&head
->lock
);
834 /* Look up an association. BH-safe. */
836 struct sctp_association
*sctp_lookup_association(const union sctp_addr
*laddr
,
837 const union sctp_addr
*paddr
,
838 struct sctp_transport
**transportp
)
840 struct sctp_association
*asoc
;
842 sctp_local_bh_disable();
843 asoc
= __sctp_lookup_association(laddr
, paddr
, transportp
);
844 sctp_local_bh_enable();
849 /* Is there an association matching the given local and peer addresses? */
850 int sctp_has_association(const union sctp_addr
*laddr
,
851 const union sctp_addr
*paddr
)
853 struct sctp_association
*asoc
;
854 struct sctp_transport
*transport
;
856 if ((asoc
= sctp_lookup_association(laddr
, paddr
, &transport
))) {
857 sock_put(asoc
->base
.sk
);
858 sctp_association_put(asoc
);
866 * SCTP Implementors Guide, 2.18 Handling of address
867 * parameters within the INIT or INIT-ACK.
869 * D) When searching for a matching TCB upon reception of an INIT
870 * or INIT-ACK chunk the receiver SHOULD use not only the
871 * source address of the packet (containing the INIT or
872 * INIT-ACK) but the receiver SHOULD also use all valid
873 * address parameters contained within the chunk.
875 * 2.18.3 Solution description
877 * This new text clearly specifies to an implementor the need
878 * to look within the INIT or INIT-ACK. Any implementation that
879 * does not do this, may not be able to establish associations
880 * in certain circumstances.
883 static struct sctp_association
*__sctp_rcv_init_lookup(struct sk_buff
*skb
,
884 const union sctp_addr
*laddr
, struct sctp_transport
**transportp
)
886 struct sctp_association
*asoc
;
887 union sctp_addr addr
;
888 union sctp_addr
*paddr
= &addr
;
889 struct sctphdr
*sh
= (struct sctphdr
*) skb
->h
.raw
;
891 union sctp_params params
;
892 sctp_init_chunk_t
*init
;
893 struct sctp_transport
*transport
;
896 ch
= (sctp_chunkhdr_t
*) skb
->data
;
898 /* If this is INIT/INIT-ACK look inside the chunk too. */
901 case SCTP_CID_INIT_ACK
:
907 /* The code below will attempt to walk the chunk and extract
908 * parameter information. Before we do that, we need to verify
909 * that the chunk length doesn't cause overflow. Otherwise, we'll
912 if (WORD_ROUND(ntohs(ch
->length
)) > skb
->len
)
916 * This code will NOT touch anything inside the chunk--it is
917 * strictly READ-ONLY.
919 * RFC 2960 3 SCTP packet Format
921 * Multiple chunks can be bundled into one SCTP packet up to
922 * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN
923 * COMPLETE chunks. These chunks MUST NOT be bundled with any
924 * other chunk in a packet. See Section 6.10 for more details
928 /* Find the start of the TLVs and the end of the chunk. This is
929 * the region we search for address parameters.
931 init
= (sctp_init_chunk_t
*)skb
->data
;
933 /* Walk the parameters looking for embedded addresses. */
934 sctp_walk_params(params
, init
, init_hdr
.params
) {
936 /* Note: Ignoring hostname addresses. */
937 af
= sctp_get_af_specific(param_type2af(params
.p
->type
));
941 af
->from_addr_param(paddr
, params
.addr
, ntohs(sh
->source
), 0);
943 asoc
= __sctp_lookup_association(laddr
, paddr
, &transport
);
951 /* Lookup an association for an inbound skb. */
952 static struct sctp_association
*__sctp_rcv_lookup(struct sk_buff
*skb
,
953 const union sctp_addr
*paddr
,
954 const union sctp_addr
*laddr
,
955 struct sctp_transport
**transportp
)
957 struct sctp_association
*asoc
;
959 asoc
= __sctp_lookup_association(laddr
, paddr
, transportp
);
961 /* Further lookup for INIT/INIT-ACK packets.
962 * SCTP Implementors Guide, 2.18 Handling of address
963 * parameters within the INIT or INIT-ACK.
966 asoc
= __sctp_rcv_init_lookup(skb
, laddr
, transportp
);