1 /* SCTP kernel 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 implementation
11 * These functions handle all input from the IP layer into SCTP.
13 * This SCTP 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 * This SCTP 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, see
27 * <http://www.gnu.org/licenses/>.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <linux-sctp@vger.kernel.org>
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
44 #include <linux/types.h>
45 #include <linux/list.h> /* For struct list_head */
46 #include <linux/socket.h>
48 #include <linux/time.h> /* For struct timeval */
49 #include <linux/slab.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
57 #include <net/sctp/checksum.h>
58 #include <net/net_namespace.h>
60 /* Forward declarations for internal helpers. */
61 static int sctp_rcv_ootb(struct sk_buff
*);
62 static struct sctp_association
*__sctp_rcv_lookup(struct net
*net
,
64 const union sctp_addr
*paddr
,
65 const union sctp_addr
*laddr
,
66 struct sctp_transport
**transportp
);
67 static struct sctp_endpoint
*__sctp_rcv_lookup_endpoint(struct net
*net
,
68 const union sctp_addr
*laddr
);
69 static struct sctp_association
*__sctp_lookup_association(
71 const union sctp_addr
*local
,
72 const union sctp_addr
*peer
,
73 struct sctp_transport
**pt
);
75 static int sctp_add_backlog(struct sock
*sk
, struct sk_buff
*skb
);
78 /* Calculate the SCTP checksum of an SCTP packet. */
79 static inline int sctp_rcv_checksum(struct net
*net
, struct sk_buff
*skb
)
81 struct sctphdr
*sh
= sctp_hdr(skb
);
82 __le32 cmp
= sh
->checksum
;
83 __le32 val
= sctp_compute_cksum(skb
, 0);
86 /* CRC failure, dump it. */
87 __SCTP_INC_STATS(net
, SCTP_MIB_CHECKSUMERRORS
);
93 struct sctp_input_cb
{
95 struct inet_skb_parm h4
;
96 #if IS_ENABLED(CONFIG_IPV6)
97 struct inet6_skb_parm h6
;
100 struct sctp_chunk
*chunk
;
102 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
105 * This is the routine which IP calls when receiving an SCTP packet.
107 int sctp_rcv(struct sk_buff
*skb
)
110 struct sctp_association
*asoc
;
111 struct sctp_endpoint
*ep
= NULL
;
112 struct sctp_ep_common
*rcvr
;
113 struct sctp_transport
*transport
= NULL
;
114 struct sctp_chunk
*chunk
;
116 union sctp_addr dest
;
119 struct net
*net
= dev_net(skb
->dev
);
121 if (skb
->pkt_type
!= PACKET_HOST
)
124 __SCTP_INC_STATS(net
, SCTP_MIB_INSCTPPACKS
);
126 if (skb_linearize(skb
))
129 /* Pull up the IP and SCTP headers. */
130 __skb_pull(skb
, skb_transport_offset(skb
));
131 if (skb
->len
< sizeof(struct sctphdr
))
134 skb
->csum_valid
= 0; /* Previous value not applicable */
135 if (skb_csum_unnecessary(skb
))
136 __skb_decr_checksum_unnecessary(skb
);
137 else if (!sctp_checksum_disable
&& sctp_rcv_checksum(net
, skb
) < 0)
141 skb_pull(skb
, sizeof(struct sctphdr
));
143 /* Make sure we at least have chunk headers worth of data left. */
144 if (skb
->len
< sizeof(struct sctp_chunkhdr
))
147 family
= ipver2af(ip_hdr(skb
)->version
);
148 af
= sctp_get_af_specific(family
);
152 /* Initialize local addresses for lookups. */
153 af
->from_skb(&src
, skb
, 1);
154 af
->from_skb(&dest
, skb
, 0);
156 /* If the packet is to or from a non-unicast address,
157 * silently discard the packet.
159 * This is not clearly defined in the RFC except in section
160 * 8.4 - OOTB handling. However, based on the book "Stream Control
161 * Transmission Protocol" 2.1, "It is important to note that the
162 * IP address of an SCTP transport address must be a routable
163 * unicast address. In other words, IP multicast addresses and
164 * IP broadcast addresses cannot be used in an SCTP transport
167 if (!af
->addr_valid(&src
, NULL
, skb
) ||
168 !af
->addr_valid(&dest
, NULL
, skb
))
171 asoc
= __sctp_rcv_lookup(net
, skb
, &src
, &dest
, &transport
);
174 ep
= __sctp_rcv_lookup_endpoint(net
, &dest
);
176 /* Retrieve the common input handling substructure. */
177 rcvr
= asoc
? &asoc
->base
: &ep
->base
;
181 * If a frame arrives on an interface and the receiving socket is
182 * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
184 if (sk
->sk_bound_dev_if
&& (sk
->sk_bound_dev_if
!= af
->skb_iif(skb
))) {
186 sctp_association_put(asoc
);
189 sctp_endpoint_put(ep
);
192 sk
= net
->sctp
.ctl_sock
;
193 ep
= sctp_sk(sk
)->ep
;
194 sctp_endpoint_hold(ep
);
199 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
200 * An SCTP packet is called an "out of the blue" (OOTB)
201 * packet if it is correctly formed, i.e., passed the
202 * receiver's checksum check, but the receiver is not
203 * able to identify the association to which this
207 if (sctp_rcv_ootb(skb
)) {
208 __SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
209 goto discard_release
;
213 if (!xfrm_policy_check(sk
, XFRM_POLICY_IN
, skb
, family
))
214 goto discard_release
;
217 if (sk_filter(sk
, skb
))
218 goto discard_release
;
220 /* Create an SCTP packet structure. */
221 chunk
= sctp_chunkify(skb
, asoc
, sk
, GFP_ATOMIC
);
223 goto discard_release
;
224 SCTP_INPUT_CB(skb
)->chunk
= chunk
;
226 /* Remember what endpoint is to handle this packet. */
229 /* Remember the SCTP header. */
230 chunk
->sctp_hdr
= sctp_hdr(skb
);
232 /* Set the source and destination addresses of the incoming chunk. */
233 sctp_init_addrs(chunk
, &src
, &dest
);
235 /* Remember where we came from. */
236 chunk
->transport
= transport
;
238 /* Acquire access to the sock lock. Note: We are safe from other
239 * bottom halves on this lock, but a user may be in the lock too,
240 * so check if it is busy.
244 if (sk
!= rcvr
->sk
) {
245 /* Our cached sk is different from the rcvr->sk. This is
246 * because migrate()/accept() may have moved the association
247 * to a new socket and released all the sockets. So now we
248 * are holding a lock on the old socket while the user may
249 * be doing something with the new socket. Switch our veiw
257 if (sock_owned_by_user(sk
)) {
258 if (sctp_add_backlog(sk
, skb
)) {
260 sctp_chunk_free(chunk
);
261 skb
= NULL
; /* sctp_chunk_free already freed the skb */
262 goto discard_release
;
264 __SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_BACKLOG
);
266 __SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_SOFTIRQ
);
267 sctp_inq_push(&chunk
->rcvr
->inqueue
, chunk
);
272 /* Release the asoc/ep ref we took in the lookup calls. */
274 sctp_association_put(asoc
);
276 sctp_endpoint_put(ep
);
281 __SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_DISCARDS
);
286 /* Release the asoc/ep ref we took in the lookup calls. */
288 sctp_association_put(asoc
);
290 sctp_endpoint_put(ep
);
295 /* Process the backlog queue of the socket. Every skb on
296 * the backlog holds a ref on an association or endpoint.
297 * We hold this ref throughout the state machine to make
298 * sure that the structure we need is still around.
300 int sctp_backlog_rcv(struct sock
*sk
, struct sk_buff
*skb
)
302 struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
303 struct sctp_inq
*inqueue
= &chunk
->rcvr
->inqueue
;
304 struct sctp_ep_common
*rcvr
= NULL
;
309 /* If the rcvr is dead then the association or endpoint
310 * has been deleted and we can safely drop the chunk
311 * and refs that we are holding.
314 sctp_chunk_free(chunk
);
318 if (unlikely(rcvr
->sk
!= sk
)) {
319 /* In this case, the association moved from one socket to
320 * another. We are currently sitting on the backlog of the
321 * old socket, so we need to move.
322 * However, since we are here in the process context we
323 * need to take make sure that the user doesn't own
324 * the new socket when we process the packet.
325 * If the new socket is user-owned, queue the chunk to the
326 * backlog of the new socket without dropping any refs.
327 * Otherwise, we can safely push the chunk on the inqueue.
333 if (sock_owned_by_user(sk
)) {
334 if (sk_add_backlog(sk
, skb
, sk
->sk_rcvbuf
))
335 sctp_chunk_free(chunk
);
339 sctp_inq_push(inqueue
, chunk
);
343 /* If the chunk was backloged again, don't drop refs */
347 sctp_inq_push(inqueue
, chunk
);
351 /* Release the refs we took in sctp_add_backlog */
352 if (SCTP_EP_TYPE_ASSOCIATION
== rcvr
->type
)
353 sctp_association_put(sctp_assoc(rcvr
));
354 else if (SCTP_EP_TYPE_SOCKET
== rcvr
->type
)
355 sctp_endpoint_put(sctp_ep(rcvr
));
362 static int sctp_add_backlog(struct sock
*sk
, struct sk_buff
*skb
)
364 struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
365 struct sctp_ep_common
*rcvr
= chunk
->rcvr
;
368 ret
= sk_add_backlog(sk
, skb
, sk
->sk_rcvbuf
);
370 /* Hold the assoc/ep while hanging on the backlog queue.
371 * This way, we know structures we need will not disappear
374 if (SCTP_EP_TYPE_ASSOCIATION
== rcvr
->type
)
375 sctp_association_hold(sctp_assoc(rcvr
));
376 else if (SCTP_EP_TYPE_SOCKET
== rcvr
->type
)
377 sctp_endpoint_hold(sctp_ep(rcvr
));
385 /* Handle icmp frag needed error. */
386 void sctp_icmp_frag_needed(struct sock
*sk
, struct sctp_association
*asoc
,
387 struct sctp_transport
*t
, __u32 pmtu
)
389 if (!t
|| (t
->pathmtu
<= pmtu
))
392 if (sock_owned_by_user(sk
)) {
393 asoc
->pmtu_pending
= 1;
398 if (t
->param_flags
& SPP_PMTUD_ENABLE
) {
399 /* Update transports view of the MTU */
400 sctp_transport_update_pmtu(sk
, t
, pmtu
);
402 /* Update association pmtu. */
403 sctp_assoc_sync_pmtu(sk
, asoc
);
406 /* Retransmit with the new pmtu setting.
407 * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
408 * Needed will never be sent, but if a message was sent before
409 * PMTU discovery was disabled that was larger than the PMTU, it
410 * would not be fragmented, so it must be re-transmitted fragmented.
412 sctp_retransmit(&asoc
->outqueue
, t
, SCTP_RTXR_PMTUD
);
415 void sctp_icmp_redirect(struct sock
*sk
, struct sctp_transport
*t
,
418 struct dst_entry
*dst
;
422 dst
= sctp_transport_dst_check(t
);
424 dst
->ops
->redirect(dst
, sk
, skb
);
428 * SCTP Implementer's Guide, 2.37 ICMP handling procedures
430 * ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
431 * or a "Protocol Unreachable" treat this message as an abort
432 * with the T bit set.
434 * This function sends an event to the state machine, which will abort the
438 void sctp_icmp_proto_unreachable(struct sock
*sk
,
439 struct sctp_association
*asoc
,
440 struct sctp_transport
*t
)
442 if (sock_owned_by_user(sk
)) {
443 if (timer_pending(&t
->proto_unreach_timer
))
446 if (!mod_timer(&t
->proto_unreach_timer
,
448 sctp_association_hold(asoc
);
451 struct net
*net
= sock_net(sk
);
453 pr_debug("%s: unrecognized next header type "
454 "encountered!\n", __func__
);
456 if (del_timer(&t
->proto_unreach_timer
))
457 sctp_association_put(asoc
);
459 sctp_do_sm(net
, SCTP_EVENT_T_OTHER
,
460 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH
),
461 asoc
->state
, asoc
->ep
, asoc
, t
,
466 /* Common lookup code for icmp/icmpv6 error handler. */
467 struct sock
*sctp_err_lookup(struct net
*net
, int family
, struct sk_buff
*skb
,
468 struct sctphdr
*sctphdr
,
469 struct sctp_association
**app
,
470 struct sctp_transport
**tpp
)
472 union sctp_addr saddr
;
473 union sctp_addr daddr
;
475 struct sock
*sk
= NULL
;
476 struct sctp_association
*asoc
;
477 struct sctp_transport
*transport
= NULL
;
478 struct sctp_init_chunk
*chunkhdr
;
479 __u32 vtag
= ntohl(sctphdr
->vtag
);
480 int len
= skb
->len
- ((void *)sctphdr
- (void *)skb
->data
);
482 *app
= NULL
; *tpp
= NULL
;
484 af
= sctp_get_af_specific(family
);
489 /* Initialize local addresses for lookups. */
490 af
->from_skb(&saddr
, skb
, 1);
491 af
->from_skb(&daddr
, skb
, 0);
493 /* Look for an association that matches the incoming ICMP error
496 asoc
= __sctp_lookup_association(net
, &saddr
, &daddr
, &transport
);
502 /* RFC 4960, Appendix C. ICMP Handling
504 * ICMP6) An implementation MUST validate that the Verification Tag
505 * contained in the ICMP message matches the Verification Tag of
506 * the peer. If the Verification Tag is not 0 and does NOT
507 * match, discard the ICMP message. If it is 0 and the ICMP
508 * message contains enough bytes to verify that the chunk type is
509 * an INIT chunk and that the Initiate Tag matches the tag of the
510 * peer, continue with ICMP7. If the ICMP message is too short
511 * or the chunk type or the Initiate Tag does not match, silently
512 * discard the packet.
515 chunkhdr
= (void *)sctphdr
+ sizeof(struct sctphdr
);
516 if (len
< sizeof(struct sctphdr
) + sizeof(sctp_chunkhdr_t
)
518 chunkhdr
->chunk_hdr
.type
!= SCTP_CID_INIT
||
519 ntohl(chunkhdr
->init_hdr
.init_tag
) != asoc
->c
.my_vtag
) {
522 } else if (vtag
!= asoc
->c
.peer_vtag
) {
528 /* If too many ICMPs get dropped on busy
529 * servers this needs to be solved differently.
531 if (sock_owned_by_user(sk
))
532 __NET_INC_STATS(net
, LINUX_MIB_LOCKDROPPEDICMPS
);
539 sctp_association_put(asoc
);
543 /* Common cleanup code for icmp/icmpv6 error handler. */
544 void sctp_err_finish(struct sock
*sk
, struct sctp_association
*asoc
)
547 sctp_association_put(asoc
);
551 * This routine is called by the ICMP module when it gets some
552 * sort of error condition. If err < 0 then the socket should
553 * be closed and the error returned to the user. If err > 0
554 * it's just the icmp type << 8 | icmp code. After adjustment
555 * header points to the first 8 bytes of the sctp header. We need
556 * to find the appropriate port.
558 * The locking strategy used here is very "optimistic". When
559 * someone else accesses the socket the ICMP is just dropped
560 * and for some paths there is no check at all.
561 * A more general error queue to queue errors for later handling
562 * is probably better.
565 void sctp_v4_err(struct sk_buff
*skb
, __u32 info
)
567 const struct iphdr
*iph
= (const struct iphdr
*)skb
->data
;
568 const int ihlen
= iph
->ihl
* 4;
569 const int type
= icmp_hdr(skb
)->type
;
570 const int code
= icmp_hdr(skb
)->code
;
572 struct sctp_association
*asoc
= NULL
;
573 struct sctp_transport
*transport
;
574 struct inet_sock
*inet
;
575 __u16 saveip
, savesctp
;
577 struct net
*net
= dev_net(skb
->dev
);
579 /* Fix up skb to look at the embedded net header. */
580 saveip
= skb
->network_header
;
581 savesctp
= skb
->transport_header
;
582 skb_reset_network_header(skb
);
583 skb_set_transport_header(skb
, ihlen
);
584 sk
= sctp_err_lookup(net
, AF_INET
, skb
, sctp_hdr(skb
), &asoc
, &transport
);
585 /* Put back, the original values. */
586 skb
->network_header
= saveip
;
587 skb
->transport_header
= savesctp
;
589 __ICMP_INC_STATS(net
, ICMP_MIB_INERRORS
);
592 /* Warning: The sock lock is held. Remember to call
597 case ICMP_PARAMETERPROB
:
600 case ICMP_DEST_UNREACH
:
601 if (code
> NR_ICMP_UNREACH
)
604 /* PMTU discovery (RFC1191) */
605 if (ICMP_FRAG_NEEDED
== code
) {
606 sctp_icmp_frag_needed(sk
, asoc
, transport
,
610 if (ICMP_PROT_UNREACH
== code
) {
611 sctp_icmp_proto_unreachable(sk
, asoc
,
616 err
= icmp_err_convert
[code
].errno
;
618 case ICMP_TIME_EXCEEDED
:
619 /* Ignore any time exceeded errors due to fragment reassembly
622 if (ICMP_EXC_FRAGTIME
== code
)
628 sctp_icmp_redirect(sk
, transport
, skb
);
629 /* Fall through to out_unlock. */
635 if (!sock_owned_by_user(sk
) && inet
->recverr
) {
637 sk
->sk_error_report(sk
);
638 } else { /* Only an error on timeout */
639 sk
->sk_err_soft
= err
;
643 sctp_err_finish(sk
, asoc
);
647 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
649 * This function scans all the chunks in the OOTB packet to determine if
650 * the packet should be discarded right away. If a response might be needed
651 * for this packet, or, if further processing is possible, the packet will
652 * be queued to a proper inqueue for the next phase of handling.
655 * Return 0 - If further processing is needed.
656 * Return 1 - If the packet can be discarded right away.
658 static int sctp_rcv_ootb(struct sk_buff
*skb
)
663 ch
= (sctp_chunkhdr_t
*) skb
->data
;
665 /* Scan through all the chunks in the packet. */
667 /* Break out if chunk length is less then minimal. */
668 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
671 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
672 if (ch_end
> skb_tail_pointer(skb
))
675 /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
676 * receiver MUST silently discard the OOTB packet and take no
679 if (SCTP_CID_ABORT
== ch
->type
)
682 /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE
683 * chunk, the receiver should silently discard the packet
684 * and take no further action.
686 if (SCTP_CID_SHUTDOWN_COMPLETE
== ch
->type
)
690 * This will discard packets with INIT chunk bundled as
691 * subsequent chunks in the packet. When INIT is first,
692 * the normal INIT processing will discard the chunk.
694 if (SCTP_CID_INIT
== ch
->type
&& (void *)ch
!= skb
->data
)
697 ch
= (sctp_chunkhdr_t
*) ch_end
;
698 } while (ch_end
< skb_tail_pointer(skb
));
706 /* Insert endpoint into the hash table. */
707 static void __sctp_hash_endpoint(struct sctp_endpoint
*ep
)
709 struct net
*net
= sock_net(ep
->base
.sk
);
710 struct sctp_ep_common
*epb
;
711 struct sctp_hashbucket
*head
;
715 epb
->hashent
= sctp_ep_hashfn(net
, epb
->bind_addr
.port
);
716 head
= &sctp_ep_hashtable
[epb
->hashent
];
718 write_lock(&head
->lock
);
719 hlist_add_head(&epb
->node
, &head
->chain
);
720 write_unlock(&head
->lock
);
723 /* Add an endpoint to the hash. Local BH-safe. */
724 void sctp_hash_endpoint(struct sctp_endpoint
*ep
)
727 __sctp_hash_endpoint(ep
);
731 /* Remove endpoint from the hash table. */
732 static void __sctp_unhash_endpoint(struct sctp_endpoint
*ep
)
734 struct net
*net
= sock_net(ep
->base
.sk
);
735 struct sctp_hashbucket
*head
;
736 struct sctp_ep_common
*epb
;
740 epb
->hashent
= sctp_ep_hashfn(net
, epb
->bind_addr
.port
);
742 head
= &sctp_ep_hashtable
[epb
->hashent
];
744 write_lock(&head
->lock
);
745 hlist_del_init(&epb
->node
);
746 write_unlock(&head
->lock
);
749 /* Remove endpoint from the hash. Local BH-safe. */
750 void sctp_unhash_endpoint(struct sctp_endpoint
*ep
)
753 __sctp_unhash_endpoint(ep
);
757 /* Look up an endpoint. */
758 static struct sctp_endpoint
*__sctp_rcv_lookup_endpoint(struct net
*net
,
759 const union sctp_addr
*laddr
)
761 struct sctp_hashbucket
*head
;
762 struct sctp_ep_common
*epb
;
763 struct sctp_endpoint
*ep
;
766 hash
= sctp_ep_hashfn(net
, ntohs(laddr
->v4
.sin_port
));
767 head
= &sctp_ep_hashtable
[hash
];
768 read_lock(&head
->lock
);
769 sctp_for_each_hentry(epb
, &head
->chain
) {
771 if (sctp_endpoint_is_match(ep
, net
, laddr
))
775 ep
= sctp_sk(net
->sctp
.ctl_sock
)->ep
;
778 sctp_endpoint_hold(ep
);
779 read_unlock(&head
->lock
);
783 /* rhashtable for transport */
784 struct sctp_hash_cmp_arg
{
785 const struct sctp_endpoint
*ep
;
786 const union sctp_addr
*laddr
;
787 const union sctp_addr
*paddr
;
788 const struct net
*net
;
791 static inline int sctp_hash_cmp(struct rhashtable_compare_arg
*arg
,
794 const struct sctp_hash_cmp_arg
*x
= arg
->key
;
795 const struct sctp_transport
*t
= ptr
;
796 struct sctp_association
*asoc
= t
->asoc
;
797 const struct net
*net
= x
->net
;
799 if (!sctp_cmp_addr_exact(&t
->ipaddr
, x
->paddr
))
801 if (!net_eq(sock_net(asoc
->base
.sk
), net
))
804 if (x
->ep
!= asoc
->ep
)
807 if (x
->laddr
->v4
.sin_port
!= htons(asoc
->base
.bind_addr
.port
))
809 if (!sctp_bind_addr_match(&asoc
->base
.bind_addr
,
810 x
->laddr
, sctp_sk(asoc
->base
.sk
)))
817 static inline u32
sctp_hash_obj(const void *data
, u32 len
, u32 seed
)
819 const struct sctp_transport
*t
= data
;
820 const union sctp_addr
*paddr
= &t
->ipaddr
;
821 const struct net
*net
= sock_net(t
->asoc
->base
.sk
);
822 u16 lport
= htons(t
->asoc
->base
.bind_addr
.port
);
825 if (paddr
->sa
.sa_family
== AF_INET6
)
826 addr
= jhash(&paddr
->v6
.sin6_addr
, 16, seed
);
828 addr
= paddr
->v4
.sin_addr
.s_addr
;
830 return jhash_3words(addr
, ((__u32
)paddr
->v4
.sin_port
) << 16 |
831 (__force __u32
)lport
, net_hash_mix(net
), seed
);
834 static inline u32
sctp_hash_key(const void *data
, u32 len
, u32 seed
)
836 const struct sctp_hash_cmp_arg
*x
= data
;
837 const union sctp_addr
*paddr
= x
->paddr
;
838 const struct net
*net
= x
->net
;
842 lport
= x
->ep
? htons(x
->ep
->base
.bind_addr
.port
) :
843 x
->laddr
->v4
.sin_port
;
844 if (paddr
->sa
.sa_family
== AF_INET6
)
845 addr
= jhash(&paddr
->v6
.sin6_addr
, 16, seed
);
847 addr
= paddr
->v4
.sin_addr
.s_addr
;
849 return jhash_3words(addr
, ((__u32
)paddr
->v4
.sin_port
) << 16 |
850 (__force __u32
)lport
, net_hash_mix(net
), seed
);
853 static const struct rhashtable_params sctp_hash_params
= {
854 .head_offset
= offsetof(struct sctp_transport
, node
),
855 .hashfn
= sctp_hash_key
,
856 .obj_hashfn
= sctp_hash_obj
,
857 .obj_cmpfn
= sctp_hash_cmp
,
858 .automatic_shrinking
= true,
861 int sctp_transport_hashtable_init(void)
863 return rhashtable_init(&sctp_transport_hashtable
, &sctp_hash_params
);
866 void sctp_transport_hashtable_destroy(void)
868 rhashtable_destroy(&sctp_transport_hashtable
);
871 void sctp_hash_transport(struct sctp_transport
*t
)
873 struct sctp_hash_cmp_arg arg
;
878 arg
.ep
= t
->asoc
->ep
;
879 arg
.paddr
= &t
->ipaddr
;
880 arg
.net
= sock_net(t
->asoc
->base
.sk
);
883 if (rhashtable_lookup_insert_key(&sctp_transport_hashtable
, &arg
,
884 &t
->node
, sctp_hash_params
) == -EBUSY
)
888 void sctp_unhash_transport(struct sctp_transport
*t
)
893 rhashtable_remove_fast(&sctp_transport_hashtable
, &t
->node
,
897 struct sctp_transport
*sctp_addrs_lookup_transport(
899 const union sctp_addr
*laddr
,
900 const union sctp_addr
*paddr
)
902 struct sctp_hash_cmp_arg arg
= {
909 return rhashtable_lookup_fast(&sctp_transport_hashtable
, &arg
,
913 struct sctp_transport
*sctp_epaddr_lookup_transport(
914 const struct sctp_endpoint
*ep
,
915 const union sctp_addr
*paddr
)
917 struct net
*net
= sock_net(ep
->base
.sk
);
918 struct sctp_hash_cmp_arg arg
= {
924 return rhashtable_lookup_fast(&sctp_transport_hashtable
, &arg
,
928 /* Look up an association. */
929 static struct sctp_association
*__sctp_lookup_association(
931 const union sctp_addr
*local
,
932 const union sctp_addr
*peer
,
933 struct sctp_transport
**pt
)
935 struct sctp_transport
*t
;
936 struct sctp_association
*asoc
= NULL
;
938 t
= sctp_addrs_lookup_transport(net
, local
, peer
);
939 if (!t
|| !sctp_transport_hold(t
))
943 sctp_association_hold(asoc
);
946 sctp_transport_put(t
);
952 /* Look up an association. protected by RCU read lock */
954 struct sctp_association
*sctp_lookup_association(struct net
*net
,
955 const union sctp_addr
*laddr
,
956 const union sctp_addr
*paddr
,
957 struct sctp_transport
**transportp
)
959 struct sctp_association
*asoc
;
962 asoc
= __sctp_lookup_association(net
, laddr
, paddr
, transportp
);
968 /* Is there an association matching the given local and peer addresses? */
969 int sctp_has_association(struct net
*net
,
970 const union sctp_addr
*laddr
,
971 const union sctp_addr
*paddr
)
973 struct sctp_association
*asoc
;
974 struct sctp_transport
*transport
;
976 if ((asoc
= sctp_lookup_association(net
, laddr
, paddr
, &transport
))) {
977 sctp_association_put(asoc
);
985 * SCTP Implementors Guide, 2.18 Handling of address
986 * parameters within the INIT or INIT-ACK.
988 * D) When searching for a matching TCB upon reception of an INIT
989 * or INIT-ACK chunk the receiver SHOULD use not only the
990 * source address of the packet (containing the INIT or
991 * INIT-ACK) but the receiver SHOULD also use all valid
992 * address parameters contained within the chunk.
994 * 2.18.3 Solution description
996 * This new text clearly specifies to an implementor the need
997 * to look within the INIT or INIT-ACK. Any implementation that
998 * does not do this, may not be able to establish associations
999 * in certain circumstances.
1002 static struct sctp_association
*__sctp_rcv_init_lookup(struct net
*net
,
1003 struct sk_buff
*skb
,
1004 const union sctp_addr
*laddr
, struct sctp_transport
**transportp
)
1006 struct sctp_association
*asoc
;
1007 union sctp_addr addr
;
1008 union sctp_addr
*paddr
= &addr
;
1009 struct sctphdr
*sh
= sctp_hdr(skb
);
1010 union sctp_params params
;
1011 sctp_init_chunk_t
*init
;
1012 struct sctp_transport
*transport
;
1016 * This code will NOT touch anything inside the chunk--it is
1017 * strictly READ-ONLY.
1019 * RFC 2960 3 SCTP packet Format
1021 * Multiple chunks can be bundled into one SCTP packet up to
1022 * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN
1023 * COMPLETE chunks. These chunks MUST NOT be bundled with any
1024 * other chunk in a packet. See Section 6.10 for more details
1025 * on chunk bundling.
1028 /* Find the start of the TLVs and the end of the chunk. This is
1029 * the region we search for address parameters.
1031 init
= (sctp_init_chunk_t
*)skb
->data
;
1033 /* Walk the parameters looking for embedded addresses. */
1034 sctp_walk_params(params
, init
, init_hdr
.params
) {
1036 /* Note: Ignoring hostname addresses. */
1037 af
= sctp_get_af_specific(param_type2af(params
.p
->type
));
1041 af
->from_addr_param(paddr
, params
.addr
, sh
->source
, 0);
1043 asoc
= __sctp_lookup_association(net
, laddr
, paddr
, &transport
);
1051 /* ADD-IP, Section 5.2
1052 * When an endpoint receives an ASCONF Chunk from the remote peer
1053 * special procedures may be needed to identify the association the
1054 * ASCONF Chunk is associated with. To properly find the association
1055 * the following procedures SHOULD be followed:
1057 * D2) If the association is not found, use the address found in the
1058 * Address Parameter TLV combined with the port number found in the
1059 * SCTP common header. If found proceed to rule D4.
1061 * D2-ext) If more than one ASCONF Chunks are packed together, use the
1062 * address found in the ASCONF Address Parameter TLV of each of the
1063 * subsequent ASCONF Chunks. If found, proceed to rule D4.
1065 static struct sctp_association
*__sctp_rcv_asconf_lookup(
1067 sctp_chunkhdr_t
*ch
,
1068 const union sctp_addr
*laddr
,
1070 struct sctp_transport
**transportp
)
1072 sctp_addip_chunk_t
*asconf
= (struct sctp_addip_chunk
*)ch
;
1074 union sctp_addr_param
*param
;
1075 union sctp_addr paddr
;
1077 /* Skip over the ADDIP header and find the Address parameter */
1078 param
= (union sctp_addr_param
*)(asconf
+ 1);
1080 af
= sctp_get_af_specific(param_type2af(param
->p
.type
));
1084 af
->from_addr_param(&paddr
, param
, peer_port
, 0);
1086 return __sctp_lookup_association(net
, laddr
, &paddr
, transportp
);
1090 /* SCTP-AUTH, Section 6.3:
1091 * If the receiver does not find a STCB for a packet containing an AUTH
1092 * chunk as the first chunk and not a COOKIE-ECHO chunk as the second
1093 * chunk, it MUST use the chunks after the AUTH chunk to look up an existing
1096 * This means that any chunks that can help us identify the association need
1097 * to be looked at to find this association.
1099 static struct sctp_association
*__sctp_rcv_walk_lookup(struct net
*net
,
1100 struct sk_buff
*skb
,
1101 const union sctp_addr
*laddr
,
1102 struct sctp_transport
**transportp
)
1104 struct sctp_association
*asoc
= NULL
;
1105 sctp_chunkhdr_t
*ch
;
1107 unsigned int chunk_num
= 1;
1110 /* Walk through the chunks looking for AUTH or ASCONF chunks
1111 * to help us find the association.
1113 ch
= (sctp_chunkhdr_t
*) skb
->data
;
1115 /* Break out if chunk length is less then minimal. */
1116 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
1119 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
1120 if (ch_end
> skb_tail_pointer(skb
))
1125 have_auth
= chunk_num
;
1128 case SCTP_CID_COOKIE_ECHO
:
1129 /* If a packet arrives containing an AUTH chunk as
1130 * a first chunk, a COOKIE-ECHO chunk as the second
1131 * chunk, and possibly more chunks after them, and
1132 * the receiver does not have an STCB for that
1133 * packet, then authentication is based on
1134 * the contents of the COOKIE- ECHO chunk.
1136 if (have_auth
== 1 && chunk_num
== 2)
1140 case SCTP_CID_ASCONF
:
1141 if (have_auth
|| net
->sctp
.addip_noauth
)
1142 asoc
= __sctp_rcv_asconf_lookup(
1144 sctp_hdr(skb
)->source
,
1153 ch
= (sctp_chunkhdr_t
*) ch_end
;
1155 } while (ch_end
< skb_tail_pointer(skb
));
1161 * There are circumstances when we need to look inside the SCTP packet
1162 * for information to help us find the association. Examples
1163 * include looking inside of INIT/INIT-ACK chunks or after the AUTH
1166 static struct sctp_association
*__sctp_rcv_lookup_harder(struct net
*net
,
1167 struct sk_buff
*skb
,
1168 const union sctp_addr
*laddr
,
1169 struct sctp_transport
**transportp
)
1171 sctp_chunkhdr_t
*ch
;
1173 ch
= (sctp_chunkhdr_t
*) skb
->data
;
1175 /* The code below will attempt to walk the chunk and extract
1176 * parameter information. Before we do that, we need to verify
1177 * that the chunk length doesn't cause overflow. Otherwise, we'll
1180 if (WORD_ROUND(ntohs(ch
->length
)) > skb
->len
)
1183 /* If this is INIT/INIT-ACK look inside the chunk too. */
1184 if (ch
->type
== SCTP_CID_INIT
|| ch
->type
== SCTP_CID_INIT_ACK
)
1185 return __sctp_rcv_init_lookup(net
, skb
, laddr
, transportp
);
1187 return __sctp_rcv_walk_lookup(net
, skb
, laddr
, transportp
);
1190 /* Lookup an association for an inbound skb. */
1191 static struct sctp_association
*__sctp_rcv_lookup(struct net
*net
,
1192 struct sk_buff
*skb
,
1193 const union sctp_addr
*paddr
,
1194 const union sctp_addr
*laddr
,
1195 struct sctp_transport
**transportp
)
1197 struct sctp_association
*asoc
;
1199 asoc
= __sctp_lookup_association(net
, laddr
, paddr
, transportp
);
1201 /* Further lookup for INIT/INIT-ACK packets.
1202 * SCTP Implementors Guide, 2.18 Handling of address
1203 * parameters within the INIT or INIT-ACK.
1206 asoc
= __sctp_rcv_lookup_harder(net
, skb
, laddr
, transportp
);