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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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
8 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05009 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * These functions handle all input from the IP layer into SCTP.
12 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050013 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 * 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)
17 * any later version.
18 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050019 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 * 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.
24 *
25 * You should have received a copy of the GNU General Public License
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080026 * along with GNU CC; see the file COPYING. If not, see
27 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020031 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 * 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 */
43
44#include <linux/types.h>
45#include <linux/list.h> /* For struct list_head */
46#include <linux/socket.h>
47#include <linux/ip.h>
48#include <linux/time.h> /* For struct timeval */
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090049#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <net/ip.h>
51#include <net/icmp.h>
52#include <net/snmp.h>
53#include <net/sock.h>
54#include <net/xfrm.h>
55#include <net/sctp/sctp.h>
56#include <net/sctp/sm.h>
Vlad Yasevich9ad09772007-12-16 14:06:41 -080057#include <net/sctp/checksum.h>
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -070058#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60/* Forward declarations for internal helpers. */
61static int sctp_rcv_ootb(struct sk_buff *);
Eric W. Biederman4110cc22012-08-06 08:41:13 +000062static struct sctp_association *__sctp_rcv_lookup(struct net *net,
63 struct sk_buff *skb,
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 const union sctp_addr *paddr,
Nicolas Dichtel57565992012-10-03 05:43:21 +000065 const union sctp_addr *laddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 struct sctp_transport **transportp);
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +000067static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
68 const union sctp_addr *laddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static struct sctp_association *__sctp_lookup_association(
Eric W. Biederman4110cc22012-08-06 08:41:13 +000070 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 const union sctp_addr *local,
72 const union sctp_addr *peer,
73 struct sctp_transport **pt);
74
Zhu Yi50b1a782010-03-04 18:01:44 +000075static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -070076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78/* Calculate the SCTP checksum of an SCTP packet. */
Eric W. Biedermanb01a2402012-08-06 08:47:55 +000079static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
Arnaldo Carvalho de Melo2c0fd382007-03-13 13:59:32 -030081 struct sctphdr *sh = sctp_hdr(skb);
Vlad Yasevich4458f042009-02-13 08:33:42 +000082 __le32 cmp = sh->checksum;
Joe Stringer024ec3d2013-07-25 10:52:05 +090083 __le32 val = sctp_compute_cksum(skb, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85 if (val != cmp) {
86 /* CRC failure, dump it. */
Eric Dumazet08e3bae2016-04-27 16:44:34 -070087 __SCTP_INC_STATS(net, SCTP_MIB_CHECKSUMERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return -1;
89 }
90 return 0;
91}
92
Linus Torvalds1da177e2005-04-16 15:20:36 -070093/*
94 * This is the routine which IP calls when receiving an SCTP packet.
95 */
96int sctp_rcv(struct sk_buff *skb)
97{
98 struct sock *sk;
99 struct sctp_association *asoc;
100 struct sctp_endpoint *ep = NULL;
101 struct sctp_ep_common *rcvr;
102 struct sctp_transport *transport = NULL;
103 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 union sctp_addr src;
105 union sctp_addr dest;
106 int family;
107 struct sctp_af *af;
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000108 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
wangweidongcb3f8372013-12-23 12:16:50 +0800110 if (skb->pkt_type != PACKET_HOST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 goto discard_it;
112
Eric Dumazet08e3bae2016-04-27 16:44:34 -0700113 __SCTP_INC_STATS(net, SCTP_MIB_INSCTPPACKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300115 /* If packet is too small to contain a single chunk, let's not
116 * waste time on it anymore.
117 */
118 if (skb->len < sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) +
119 skb_transport_offset(skb))
Herbert Xu28cd7752006-10-29 23:46:42 -0800120 goto discard_it;
121
Marcelo Ricardo Leitner4c2f2452016-08-18 14:58:35 -0300122 /* If the packet is fragmented and we need to do crc checking,
123 * it's better to just linearize it otherwise crc computing
124 * takes longer.
125 */
126 if ((!(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) &&
127 skb_linearize(skb)) ||
128 !pskb_may_pull(skb, sizeof(struct sctphdr)))
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300129 goto discard_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300131 /* Pull up the IP header. */
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700132 __skb_pull(skb, skb_transport_offset(skb));
Tom Herbert202863f2014-08-27 21:27:06 -0700133
134 skb->csum_valid = 0; /* Previous value not applicable */
135 if (skb_csum_unnecessary(skb))
136 __skb_decr_checksum_unnecessary(skb);
Marcelo Ricardo Leitner90017ac2016-06-02 15:05:43 -0300137 else if (!sctp_checksum_disable &&
138 !(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) &&
139 sctp_rcv_checksum(net, skb) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 goto discard_it;
Tom Herbert202863f2014-08-27 21:27:06 -0700141 skb->csum_valid = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300143 __skb_pull(skb, sizeof(struct sctphdr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700145 family = ipver2af(ip_hdr(skb)->version);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 af = sctp_get_af_specific(family);
147 if (unlikely(!af))
148 goto discard_it;
Marcelo Ricardo Leitnere7487c82016-07-13 15:08:58 -0300149 SCTP_INPUT_CB(skb)->af = af;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
151 /* Initialize local addresses for lookups. */
152 af->from_skb(&src, skb, 1);
153 af->from_skb(&dest, skb, 0);
154
155 /* If the packet is to or from a non-unicast address,
156 * silently discard the packet.
157 *
158 * This is not clearly defined in the RFC except in section
159 * 8.4 - OOTB handling. However, based on the book "Stream Control
160 * Transmission Protocol" 2.1, "It is important to note that the
161 * IP address of an SCTP transport address must be a routable
162 * unicast address. In other words, IP multicast addresses and
163 * IP broadcast addresses cannot be used in an SCTP transport
164 * address."
165 */
Vlad Yasevich5636bef2006-06-17 22:55:35 -0700166 if (!af->addr_valid(&src, NULL, skb) ||
167 !af->addr_valid(&dest, NULL, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 goto discard_it;
169
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000170 asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);
Al Viro1c7d1fc2006-11-20 17:08:09 -0800171
Neil Horman0fd9a652005-06-13 15:11:24 -0700172 if (!asoc)
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000173 ep = __sctp_rcv_lookup_endpoint(net, &dest);
Neil Horman0fd9a652005-06-13 15:11:24 -0700174
175 /* Retrieve the common input handling substructure. */
176 rcvr = asoc ? &asoc->base : &ep->base;
177 sk = rcvr->sk;
178
179 /*
180 * If a frame arrives on an interface and the receiving socket is
181 * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
182 */
wangweidong8d726512013-12-23 12:16:53 +0800183 if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) {
Xin Longdae399d2016-10-31 20:32:33 +0800184 if (transport) {
185 sctp_transport_put(transport);
Neil Horman0fd9a652005-06-13 15:11:24 -0700186 asoc = NULL;
Xin Longdae399d2016-10-31 20:32:33 +0800187 transport = NULL;
Neil Horman0fd9a652005-06-13 15:11:24 -0700188 } else {
189 sctp_endpoint_put(ep);
190 ep = NULL;
191 }
Eric W. Biederman2ce95502012-08-06 08:43:06 +0000192 sk = net->sctp.ctl_sock;
Neil Horman0fd9a652005-06-13 15:11:24 -0700193 ep = sctp_sk(sk)->ep;
194 sctp_endpoint_hold(ep);
Neil Horman0fd9a652005-06-13 15:11:24 -0700195 rcvr = &ep->base;
196 }
197
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 /*
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
204 * packet belongs.
205 */
206 if (!asoc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 if (sctp_rcv_ootb(skb)) {
Eric Dumazet08e3bae2016-04-27 16:44:34 -0700208 __SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 goto discard_release;
210 }
211 }
212
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
214 goto discard_release;
Patrick McHardyb59c2702006-01-06 23:06:10 -0800215 nf_reset(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
Dmitry Mishinfda9ef52006-08-31 15:28:39 -0700217 if (sk_filter(sk, skb))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900218 goto discard_release;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 /* Create an SCTP packet structure. */
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -0300221 chunk = sctp_chunkify(skb, asoc, sk, GFP_ATOMIC);
Herbert Xu2babf9d2006-03-25 01:25:29 -0800222 if (!chunk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 goto discard_release;
David S. Miller79af02c2005-07-08 21:47:49 -0700224 SCTP_INPUT_CB(skb)->chunk = chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 /* Remember what endpoint is to handle this packet. */
227 chunk->rcvr = rcvr;
228
229 /* Remember the SCTP header. */
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300230 chunk->sctp_hdr = sctp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232 /* Set the source and destination addresses of the incoming chunk. */
Al Virod55c41b2006-11-20 17:09:40 -0800233 sctp_init_addrs(chunk, &src, &dest);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
235 /* Remember where we came from. */
236 chunk->transport = transport;
237
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.
241 */
wangweidong5bc1d1b2014-01-21 15:44:12 +0800242 bh_lock_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
Vlad Yasevichae53b5b2009-01-22 14:53:23 -0800244 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
250 * of the current sk.
251 */
wangweidong5bc1d1b2014-01-21 15:44:12 +0800252 bh_unlock_sock(sk);
Vlad Yasevichae53b5b2009-01-22 14:53:23 -0800253 sk = rcvr->sk;
wangweidong5bc1d1b2014-01-21 15:44:12 +0800254 bh_lock_sock(sk);
Vlad Yasevichae53b5b2009-01-22 14:53:23 -0800255 }
256
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700257 if (sock_owned_by_user(sk)) {
Zhu Yi50b1a782010-03-04 18:01:44 +0000258 if (sctp_add_backlog(sk, skb)) {
wangweidong5bc1d1b2014-01-21 15:44:12 +0800259 bh_unlock_sock(sk);
Zhu Yi50b1a782010-03-04 18:01:44 +0000260 sctp_chunk_free(chunk);
261 skb = NULL; /* sctp_chunk_free already freed the skb */
262 goto discard_release;
263 }
Eric Dumazet08e3bae2016-04-27 16:44:34 -0700264 __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_BACKLOG);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700265 } else {
Eric Dumazet08e3bae2016-04-27 16:44:34 -0700266 __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_SOFTIRQ);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700267 sctp_inq_push(&chunk->rcvr->inqueue, chunk);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700268 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
wangweidong5bc1d1b2014-01-21 15:44:12 +0800270 bh_unlock_sock(sk);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700271
272 /* Release the asoc/ep ref we took in the lookup calls. */
Xin Longdae399d2016-10-31 20:32:33 +0800273 if (transport)
274 sctp_transport_put(transport);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700275 else
276 sctp_endpoint_put(ep);
Sridhar Samudrala7a48f922006-01-17 11:51:28 -0800277
Herbert Xu2babf9d2006-03-25 01:25:29 -0800278 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280discard_it:
Eric Dumazet08e3bae2016-04-27 16:44:34 -0700281 __SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 kfree_skb(skb);
Herbert Xu2babf9d2006-03-25 01:25:29 -0800283 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285discard_release:
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700286 /* Release the asoc/ep ref we took in the lookup calls. */
Xin Longdae399d2016-10-31 20:32:33 +0800287 if (transport)
288 sctp_transport_put(transport);
Neil Horman0fd9a652005-06-13 15:11:24 -0700289 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 sctp_endpoint_put(ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 goto discard_it;
293}
294
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700295/* 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 */
300int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
301{
David S. Miller79af02c2005-07-08 21:47:49 -0700302 struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900303 struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
Xin Longdae399d2016-10-31 20:32:33 +0800304 struct sctp_transport *t = chunk->transport;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900305 struct sctp_ep_common *rcvr = NULL;
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700306 int backloged = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900308 rcvr = chunk->rcvr;
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800309
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700310 /* If the rcvr is dead then the association or endpoint
311 * has been deleted and we can safely drop the chunk
312 * and refs that we are holding.
313 */
314 if (rcvr->dead) {
315 sctp_chunk_free(chunk);
316 goto done;
317 }
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800318
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700319 if (unlikely(rcvr->sk != sk)) {
320 /* In this case, the association moved from one socket to
321 * another. We are currently sitting on the backlog of the
322 * old socket, so we need to move.
323 * However, since we are here in the process context we
324 * need to take make sure that the user doesn't own
325 * the new socket when we process the packet.
326 * If the new socket is user-owned, queue the chunk to the
327 * backlog of the new socket without dropping any refs.
328 * Otherwise, we can safely push the chunk on the inqueue.
329 */
Sridhar Samudrala7a48f922006-01-17 11:51:28 -0800330
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700331 sk = rcvr->sk;
Marcelo Ricardo Leitnereefc1b12016-07-23 00:32:48 -0300332 local_bh_disable();
wangweidong5bc1d1b2014-01-21 15:44:12 +0800333 bh_lock_sock(sk);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700334
335 if (sock_owned_by_user(sk)) {
Eric Dumazetf545a382012-04-22 23:34:26 +0000336 if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
Zhu Yi50b1a782010-03-04 18:01:44 +0000337 sctp_chunk_free(chunk);
338 else
339 backloged = 1;
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700340 } else
341 sctp_inq_push(inqueue, chunk);
342
wangweidong5bc1d1b2014-01-21 15:44:12 +0800343 bh_unlock_sock(sk);
Marcelo Ricardo Leitnereefc1b12016-07-23 00:32:48 -0300344 local_bh_enable();
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700345
346 /* If the chunk was backloged again, don't drop refs */
347 if (backloged)
348 return 0;
349 } else {
350 sctp_inq_push(inqueue, chunk);
351 }
352
353done:
354 /* Release the refs we took in sctp_add_backlog */
355 if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
Xin Longdae399d2016-10-31 20:32:33 +0800356 sctp_transport_put(t);
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700357 else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
358 sctp_endpoint_put(sctp_ep(rcvr));
359 else
360 BUG();
361
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900362 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363}
364
Zhu Yi50b1a782010-03-04 18:01:44 +0000365static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800366{
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700367 struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
Xin Longdae399d2016-10-31 20:32:33 +0800368 struct sctp_transport *t = chunk->transport;
Vladislav Yasevich61c9fed2006-05-19 11:01:18 -0700369 struct sctp_ep_common *rcvr = chunk->rcvr;
Zhu Yi50b1a782010-03-04 18:01:44 +0000370 int ret;
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800371
Eric Dumazetf545a382012-04-22 23:34:26 +0000372 ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf);
Zhu Yi50b1a782010-03-04 18:01:44 +0000373 if (!ret) {
374 /* Hold the assoc/ep while hanging on the backlog queue.
375 * This way, we know structures we need will not disappear
376 * from us
377 */
378 if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
Xin Longdae399d2016-10-31 20:32:33 +0800379 sctp_transport_hold(t);
Zhu Yi50b1a782010-03-04 18:01:44 +0000380 else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
381 sctp_endpoint_hold(sctp_ep(rcvr));
382 else
383 BUG();
384 }
385 return ret;
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800386
Sridhar Samudralac4d24442006-01-17 11:56:26 -0800387}
388
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389/* Handle icmp frag needed error. */
390void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
391 struct sctp_transport *t, __u32 pmtu)
392{
Wei Yongjun91bd6b12008-10-23 00:59:52 -0700393 if (!t || (t->pathmtu <= pmtu))
Frank Filz52ccb8e2005-12-22 11:36:46 -0800394 return;
395
Vlad Yasevich8a479492007-06-07 14:21:05 -0400396 if (sock_owned_by_user(sk)) {
397 asoc->pmtu_pending = 1;
398 t->pmtu_pending = 1;
399 return;
400 }
401
Frank Filz52ccb8e2005-12-22 11:36:46 -0800402 if (t->param_flags & SPP_PMTUD_ENABLE) {
Vlad Yasevichc910b472007-06-07 13:47:03 -0400403 /* Update transports view of the MTU */
David S. Miller02f3d4c2012-07-16 03:57:14 -0700404 sctp_transport_update_pmtu(sk, t, pmtu);
Frank Filz52ccb8e2005-12-22 11:36:46 -0800405
406 /* Update association pmtu. */
David S. Miller02f3d4c2012-07-16 03:57:14 -0700407 sctp_assoc_sync_pmtu(sk, asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 }
409
Frank Filz52ccb8e2005-12-22 11:36:46 -0800410 /* Retransmit with the new pmtu setting.
411 * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
412 * Needed will never be sent, but if a message was sent before
413 * PMTU discovery was disabled that was larger than the PMTU, it
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900414 * would not be fragmented, so it must be re-transmitted fragmented.
Frank Filz52ccb8e2005-12-22 11:36:46 -0800415 */
416 sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417}
418
David S. Millerec18d9a2012-07-12 00:25:15 -0700419void sctp_icmp_redirect(struct sock *sk, struct sctp_transport *t,
420 struct sk_buff *skb)
David S. Miller55be7a92012-07-11 21:27:49 -0700421{
422 struct dst_entry *dst;
423
Xin Longbcb9ced2017-10-18 21:37:49 +0800424 if (sock_owned_by_user(sk) || !t)
David S. Miller55be7a92012-07-11 21:27:49 -0700425 return;
426 dst = sctp_transport_dst_check(t);
David S. Miller1ed5c482012-07-12 00:41:25 -0700427 if (dst)
David S. Miller6700c272012-07-17 03:29:28 -0700428 dst->ops->redirect(dst, sk, skb);
David S. Miller55be7a92012-07-11 21:27:49 -0700429}
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431/*
432 * SCTP Implementer's Guide, 2.37 ICMP handling procedures
433 *
434 * ICMP8) If the ICMP code is a "Unrecognized next header type encountered"
435 * or a "Protocol Unreachable" treat this message as an abort
436 * with the T bit set.
437 *
438 * This function sends an event to the state machine, which will abort the
439 * association.
440 *
441 */
442void sctp_icmp_proto_unreachable(struct sock *sk,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900443 struct sctp_association *asoc,
444 struct sctp_transport *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445{
Vlad Yasevich50b5d6a2010-05-06 00:56:07 -0700446 if (sock_owned_by_user(sk)) {
447 if (timer_pending(&t->proto_unreach_timer))
448 return;
449 else {
450 if (!mod_timer(&t->proto_unreach_timer,
451 jiffies + (HZ/20)))
452 sctp_association_hold(asoc);
453 }
Vlad Yasevich50b5d6a2010-05-06 00:56:07 -0700454 } else {
Eric W. Biederman55e26eb2012-08-07 07:25:24 +0000455 struct net *net = sock_net(sk);
456
Daniel Borkmannbb333812013-06-28 19:49:40 +0200457 pr_debug("%s: unrecognized next header type "
458 "encountered!\n", __func__);
459
Ying Xue25cc4ae2013-02-03 20:32:57 +0000460 if (del_timer(&t->proto_unreach_timer))
Vlad Yasevich50b5d6a2010-05-06 00:56:07 -0700461 sctp_association_put(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
Eric W. Biederman55e26eb2012-08-07 07:25:24 +0000463 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
Vlad Yasevich50b5d6a2010-05-06 00:56:07 -0700464 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
465 asoc->state, asoc->ep, asoc, t,
466 GFP_ATOMIC);
467 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468}
469
470/* Common lookup code for icmp/icmpv6 error handler. */
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000471struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 struct sctphdr *sctphdr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 struct sctp_association **app,
474 struct sctp_transport **tpp)
475{
Davide Caratti1de51502017-05-25 19:14:56 +0200476 struct sctp_init_chunk *chunkhdr, _chunkhdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 union sctp_addr saddr;
478 union sctp_addr daddr;
479 struct sctp_af *af;
480 struct sock *sk = NULL;
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700481 struct sctp_association *asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 struct sctp_transport *transport = NULL;
Wei Yongjun7115e632008-06-19 16:07:48 -0700483 __u32 vtag = ntohl(sctphdr->vtag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Sridhar Samudralad1ad1ff2005-07-18 13:44:10 -0700485 *app = NULL; *tpp = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
487 af = sctp_get_af_specific(family);
488 if (unlikely(!af)) {
489 return NULL;
490 }
491
492 /* Initialize local addresses for lookups. */
493 af->from_skb(&saddr, skb, 1);
494 af->from_skb(&daddr, skb, 0);
495
496 /* Look for an association that matches the incoming ICMP error
497 * packet.
498 */
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000499 asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport);
Sridhar Samudralad1ad1ff2005-07-18 13:44:10 -0700500 if (!asoc)
501 return NULL;
502
503 sk = asoc->base.sk;
504
Wei Yongjun7115e632008-06-19 16:07:48 -0700505 /* RFC 4960, Appendix C. ICMP Handling
506 *
507 * ICMP6) An implementation MUST validate that the Verification Tag
508 * contained in the ICMP message matches the Verification Tag of
509 * the peer. If the Verification Tag is not 0 and does NOT
510 * match, discard the ICMP message. If it is 0 and the ICMP
511 * message contains enough bytes to verify that the chunk type is
512 * an INIT chunk and that the Initiate Tag matches the tag of the
513 * peer, continue with ICMP7. If the ICMP message is too short
514 * or the chunk type or the Initiate Tag does not match, silently
515 * discard the packet.
516 */
517 if (vtag == 0) {
Davide Caratti1de51502017-05-25 19:14:56 +0200518 /* chunk header + first 4 octects of init header */
519 chunkhdr = skb_header_pointer(skb, skb_transport_offset(skb) +
520 sizeof(struct sctphdr),
521 sizeof(struct sctp_chunkhdr) +
522 sizeof(__be32), &_chunkhdr);
523 if (!chunkhdr ||
Wei Yongjun7115e632008-06-19 16:07:48 -0700524 chunkhdr->chunk_hdr.type != SCTP_CID_INIT ||
Davide Caratti1de51502017-05-25 19:14:56 +0200525 ntohl(chunkhdr->init_hdr.init_tag) != asoc->c.my_vtag)
Wei Yongjun7115e632008-06-19 16:07:48 -0700526 goto out;
Davide Caratti1de51502017-05-25 19:14:56 +0200527
Wei Yongjun7115e632008-06-19 16:07:48 -0700528 } else if (vtag != asoc->c.peer_vtag) {
Sridhar Samudralad1ad1ff2005-07-18 13:44:10 -0700529 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 }
531
wangweidong5bc1d1b2014-01-21 15:44:12 +0800532 bh_lock_sock(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
534 /* If too many ICMPs get dropped on busy
535 * servers this needs to be solved differently.
536 */
537 if (sock_owned_by_user(sk))
Eric Dumazet02a1d6e2016-04-27 16:44:39 -0700538 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 *app = asoc;
541 *tpp = transport;
542 return sk;
543
544out:
Xin Longdae399d2016-10-31 20:32:33 +0800545 sctp_transport_put(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 return NULL;
547}
548
549/* Common cleanup code for icmp/icmpv6 error handler. */
Xin Longdae399d2016-10-31 20:32:33 +0800550void sctp_err_finish(struct sock *sk, struct sctp_transport *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551{
wangweidong5bc1d1b2014-01-21 15:44:12 +0800552 bh_unlock_sock(sk);
Xin Longdae399d2016-10-31 20:32:33 +0800553 sctp_transport_put(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554}
555
556/*
557 * This routine is called by the ICMP module when it gets some
558 * sort of error condition. If err < 0 then the socket should
559 * be closed and the error returned to the user. If err > 0
560 * it's just the icmp type << 8 | icmp code. After adjustment
561 * header points to the first 8 bytes of the sctp header. We need
562 * to find the appropriate port.
563 *
564 * The locking strategy used here is very "optimistic". When
565 * someone else accesses the socket the ICMP is just dropped
566 * and for some paths there is no check at all.
567 * A more general error queue to queue errors for later handling
568 * is probably better.
569 *
570 */
571void sctp_v4_err(struct sk_buff *skb, __u32 info)
572{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000573 const struct iphdr *iph = (const struct iphdr *)skb->data;
Arnaldo Carvalho de Meloa27ef742007-03-13 17:17:10 -0300574 const int ihlen = iph->ihl * 4;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300575 const int type = icmp_hdr(skb)->type;
576 const int code = icmp_hdr(skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 struct sock *sk;
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700578 struct sctp_association *asoc = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 struct sctp_transport *transport;
580 struct inet_sock *inet;
Simon Hormanaef6de52013-05-30 20:36:11 +0000581 __u16 saveip, savesctp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 int err;
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000583 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 /* Fix up skb to look at the embedded net header. */
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700586 saveip = skb->network_header;
587 savesctp = skb->transport_header;
Arnaldo Carvalho de Melo31c77112007-03-10 19:04:55 -0300588 skb_reset_network_header(skb);
Arnaldo Carvalho de Meloa27ef742007-03-13 17:17:10 -0300589 skb_set_transport_header(skb, ihlen);
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000590 sk = sctp_err_lookup(net, AF_INET, skb, sctp_hdr(skb), &asoc, &transport);
Arnaldo Carvalho de Melo2e07fa92007-04-10 21:22:35 -0700591 /* Put back, the original values. */
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700592 skb->network_header = saveip;
593 skb->transport_header = savesctp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 if (!sk) {
Eric Dumazet5d3848b2016-04-27 16:44:29 -0700595 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 return;
597 }
598 /* Warning: The sock lock is held. Remember to call
599 * sctp_err_finish!
600 */
601
602 switch (type) {
603 case ICMP_PARAMETERPROB:
604 err = EPROTO;
605 break;
606 case ICMP_DEST_UNREACH:
607 if (code > NR_ICMP_UNREACH)
608 goto out_unlock;
609
610 /* PMTU discovery (RFC1191) */
611 if (ICMP_FRAG_NEEDED == code) {
Marcelo Ricardo Leitner3822a5f2016-03-19 12:17:20 -0300612 sctp_icmp_frag_needed(sk, asoc, transport,
Marcelo Ricardo Leitnere2f036a2016-09-21 08:45:55 -0300613 SCTP_TRUNC4(info));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 goto out_unlock;
wangweidong8d726512013-12-23 12:16:53 +0800615 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 if (ICMP_PROT_UNREACH == code) {
Sridhar Samudralad1ad1ff2005-07-18 13:44:10 -0700617 sctp_icmp_proto_unreachable(sk, asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 transport);
619 goto out_unlock;
620 }
621 }
622 err = icmp_err_convert[code].errno;
623 break;
624 case ICMP_TIME_EXCEEDED:
625 /* Ignore any time exceeded errors due to fragment reassembly
626 * timeouts.
627 */
628 if (ICMP_EXC_FRAGTIME == code)
629 goto out_unlock;
630
631 err = EHOSTUNREACH;
632 break;
David S. Miller55be7a92012-07-11 21:27:49 -0700633 case ICMP_REDIRECT:
634 sctp_icmp_redirect(sk, transport, skb);
Daniel Borkmann3f96a532013-09-16 12:36:02 +0200635 /* Fall through to out_unlock. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 default:
637 goto out_unlock;
638 }
639
640 inet = inet_sk(sk);
641 if (!sock_owned_by_user(sk) && inet->recverr) {
642 sk->sk_err = err;
643 sk->sk_error_report(sk);
644 } else { /* Only an error on timeout */
645 sk->sk_err_soft = err;
646 }
647
648out_unlock:
Xin Longdae399d2016-10-31 20:32:33 +0800649 sctp_err_finish(sk, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650}
651
652/*
653 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
654 *
655 * This function scans all the chunks in the OOTB packet to determine if
656 * the packet should be discarded right away. If a response might be needed
657 * for this packet, or, if further processing is possible, the packet will
658 * be queued to a proper inqueue for the next phase of handling.
659 *
660 * Output:
661 * Return 0 - If further processing is needed.
662 * Return 1 - If the packet can be discarded right away.
663 */
sebastian@breakpoint.cc04675212007-07-26 23:21:31 +0200664static int sctp_rcv_ootb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665{
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300666 sctp_chunkhdr_t *ch, _ch;
667 int ch_end, offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
669 /* Scan through all the chunks in the packet. */
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -0800670 do {
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300671 /* Make sure we have at least the header there */
672 if (offset + sizeof(sctp_chunkhdr_t) > skb->len)
673 break;
674
675 ch = skb_header_pointer(skb, offset, sizeof(*ch), &_ch);
676
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -0800677 /* Break out if chunk length is less then minimal. */
678 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
679 break;
680
Marcelo Ricardo Leitnere2f036a2016-09-21 08:45:55 -0300681 ch_end = offset + SCTP_PAD4(ntohs(ch->length));
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300682 if (ch_end > skb->len)
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -0800683 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 /* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
686 * receiver MUST silently discard the OOTB packet and take no
687 * further action.
688 */
689 if (SCTP_CID_ABORT == ch->type)
690 goto discard;
691
692 /* RFC 8.4, 6) If the packet contains a SHUTDOWN COMPLETE
693 * chunk, the receiver should silently discard the packet
694 * and take no further action.
695 */
696 if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
697 goto discard;
698
Vlad Yasevich3c77f962007-09-17 15:14:28 -0400699 /* RFC 4460, 2.11.2
700 * This will discard packets with INIT chunk bundled as
701 * subsequent chunks in the packet. When INIT is first,
702 * the normal INIT processing will discard the chunk.
703 */
704 if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
705 goto discard;
706
Marcelo Ricardo Leitner3acb50c2016-06-02 15:05:42 -0300707 offset = ch_end;
708 } while (ch_end < skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
710 return 0;
711
712discard:
713 return 1;
714}
715
716/* Insert endpoint into the hash table. */
717static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
718{
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000719 struct net *net = sock_net(ep->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 struct sctp_ep_common *epb;
721 struct sctp_hashbucket *head;
722
723 epb = &ep->base;
724
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000725 epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 head = &sctp_ep_hashtable[epb->hashent];
727
wangweidong387602d2014-01-21 15:44:09 +0800728 write_lock(&head->lock);
Vlad Yasevichd970dbf2007-11-09 11:43:40 -0500729 hlist_add_head(&epb->node, &head->chain);
wangweidong387602d2014-01-21 15:44:09 +0800730 write_unlock(&head->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731}
732
733/* Add an endpoint to the hash. Local BH-safe. */
734void sctp_hash_endpoint(struct sctp_endpoint *ep)
735{
wangweidong79b91132014-01-21 15:44:07 +0800736 local_bh_disable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 __sctp_hash_endpoint(ep);
wangweidong79b91132014-01-21 15:44:07 +0800738 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739}
740
741/* Remove endpoint from the hash table. */
742static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
743{
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000744 struct net *net = sock_net(ep->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 struct sctp_hashbucket *head;
746 struct sctp_ep_common *epb;
747
748 epb = &ep->base;
749
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000750 epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751
752 head = &sctp_ep_hashtable[epb->hashent];
753
wangweidong387602d2014-01-21 15:44:09 +0800754 write_lock(&head->lock);
Neil Horman2eebc1e2012-07-16 09:13:51 +0000755 hlist_del_init(&epb->node);
wangweidong387602d2014-01-21 15:44:09 +0800756 write_unlock(&head->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757}
758
759/* Remove endpoint from the hash. Local BH-safe. */
760void sctp_unhash_endpoint(struct sctp_endpoint *ep)
761{
wangweidong79b91132014-01-21 15:44:07 +0800762 local_bh_disable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 __sctp_unhash_endpoint(ep);
wangweidong79b91132014-01-21 15:44:07 +0800764 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765}
766
767/* Look up an endpoint. */
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000768static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
769 const union sctp_addr *laddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770{
771 struct sctp_hashbucket *head;
772 struct sctp_ep_common *epb;
773 struct sctp_endpoint *ep;
774 int hash;
775
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000776 hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 head = &sctp_ep_hashtable[hash];
778 read_lock(&head->lock);
Sasha Levinb67bfe02013-02-27 17:06:00 -0800779 sctp_for_each_hentry(epb, &head->chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 ep = sctp_ep(epb);
Eric W. Biederman4cdadcb2012-08-06 08:40:21 +0000781 if (sctp_endpoint_is_match(ep, net, laddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 goto hit;
783 }
784
Eric W. Biederman2ce95502012-08-06 08:43:06 +0000785 ep = sctp_sk(net->sctp.ctl_sock)->ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
787hit:
788 sctp_endpoint_hold(ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 read_unlock(&head->lock);
790 return ep;
791}
792
Xin Longd6c02562015-12-30 23:50:46 +0800793/* rhashtable for transport */
794struct sctp_hash_cmp_arg {
Xin Long65a51242016-01-14 13:49:34 +0800795 const struct sctp_endpoint *ep;
Xin Longd6c02562015-12-30 23:50:46 +0800796 const union sctp_addr *laddr;
797 const union sctp_addr *paddr;
798 const struct net *net;
799};
800
801static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg,
802 const void *ptr)
803{
Xin Long715f5552016-09-10 23:11:23 +0800804 struct sctp_transport *t = (struct sctp_transport *)ptr;
Xin Longd6c02562015-12-30 23:50:46 +0800805 const struct sctp_hash_cmp_arg *x = arg->key;
Xin Long715f5552016-09-10 23:11:23 +0800806 struct sctp_association *asoc;
807 int err = 1;
Xin Longd6c02562015-12-30 23:50:46 +0800808
Xin Longd6c02562015-12-30 23:50:46 +0800809 if (!sctp_cmp_addr_exact(&t->ipaddr, x->paddr))
Xin Long715f5552016-09-10 23:11:23 +0800810 return err;
811 if (!sctp_transport_hold(t))
812 return err;
813
814 asoc = t->asoc;
815 if (!net_eq(sock_net(asoc->base.sk), x->net))
816 goto out;
Xin Long65a51242016-01-14 13:49:34 +0800817 if (x->ep) {
818 if (x->ep != asoc->ep)
Xin Long715f5552016-09-10 23:11:23 +0800819 goto out;
Xin Long65a51242016-01-14 13:49:34 +0800820 } else {
821 if (x->laddr->v4.sin_port != htons(asoc->base.bind_addr.port))
Xin Long715f5552016-09-10 23:11:23 +0800822 goto out;
Xin Long65a51242016-01-14 13:49:34 +0800823 if (!sctp_bind_addr_match(&asoc->base.bind_addr,
824 x->laddr, sctp_sk(asoc->base.sk)))
Xin Long715f5552016-09-10 23:11:23 +0800825 goto out;
Xin Long65a51242016-01-14 13:49:34 +0800826 }
Xin Longd6c02562015-12-30 23:50:46 +0800827
Xin Long715f5552016-09-10 23:11:23 +0800828 err = 0;
829out:
830 sctp_transport_put(t);
831 return err;
Xin Longd6c02562015-12-30 23:50:46 +0800832}
833
834static inline u32 sctp_hash_obj(const void *data, u32 len, u32 seed)
835{
836 const struct sctp_transport *t = data;
837 const union sctp_addr *paddr = &t->ipaddr;
838 const struct net *net = sock_net(t->asoc->base.sk);
839 u16 lport = htons(t->asoc->base.bind_addr.port);
840 u32 addr;
841
842 if (paddr->sa.sa_family == AF_INET6)
843 addr = jhash(&paddr->v6.sin6_addr, 16, seed);
844 else
845 addr = paddr->v4.sin_addr.s_addr;
846
847 return jhash_3words(addr, ((__u32)paddr->v4.sin_port) << 16 |
848 (__force __u32)lport, net_hash_mix(net), seed);
849}
850
851static inline u32 sctp_hash_key(const void *data, u32 len, u32 seed)
852{
853 const struct sctp_hash_cmp_arg *x = data;
854 const union sctp_addr *paddr = x->paddr;
855 const struct net *net = x->net;
Xin Long65a51242016-01-14 13:49:34 +0800856 u16 lport;
Xin Longd6c02562015-12-30 23:50:46 +0800857 u32 addr;
858
Xin Long65a51242016-01-14 13:49:34 +0800859 lport = x->ep ? htons(x->ep->base.bind_addr.port) :
860 x->laddr->v4.sin_port;
Xin Longd6c02562015-12-30 23:50:46 +0800861 if (paddr->sa.sa_family == AF_INET6)
862 addr = jhash(&paddr->v6.sin6_addr, 16, seed);
863 else
864 addr = paddr->v4.sin_addr.s_addr;
865
866 return jhash_3words(addr, ((__u32)paddr->v4.sin_port) << 16 |
867 (__force __u32)lport, net_hash_mix(net), seed);
868}
869
870static const struct rhashtable_params sctp_hash_params = {
871 .head_offset = offsetof(struct sctp_transport, node),
872 .hashfn = sctp_hash_key,
873 .obj_hashfn = sctp_hash_obj,
874 .obj_cmpfn = sctp_hash_cmp,
875 .automatic_shrinking = true,
876};
877
878int sctp_transport_hashtable_init(void)
879{
880 return rhashtable_init(&sctp_transport_hashtable, &sctp_hash_params);
881}
882
883void sctp_transport_hashtable_destroy(void)
884{
885 rhashtable_destroy(&sctp_transport_hashtable);
886}
887
888void sctp_hash_transport(struct sctp_transport *t)
889{
Xin Longd6c02562015-12-30 23:50:46 +0800890 struct sctp_hash_cmp_arg arg;
891
Xin Longdd7445a2016-01-16 20:17:17 +0800892 if (t->asoc->temp)
893 return;
894
Xin Long65a51242016-01-14 13:49:34 +0800895 arg.ep = t->asoc->ep;
Xin Longd6c02562015-12-30 23:50:46 +0800896 arg.paddr = &t->ipaddr;
897 arg.net = sock_net(t->asoc->base.sk);
898
899reinsert:
900 if (rhashtable_lookup_insert_key(&sctp_transport_hashtable, &arg,
901 &t->node, sctp_hash_params) == -EBUSY)
902 goto reinsert;
903}
904
905void sctp_unhash_transport(struct sctp_transport *t)
906{
Xin Longdd7445a2016-01-16 20:17:17 +0800907 if (t->asoc->temp)
908 return;
909
Xin Longd6c02562015-12-30 23:50:46 +0800910 rhashtable_remove_fast(&sctp_transport_hashtable, &t->node,
911 sctp_hash_params);
912}
913
914struct sctp_transport *sctp_addrs_lookup_transport(
915 struct net *net,
916 const union sctp_addr *laddr,
917 const union sctp_addr *paddr)
918{
919 struct sctp_hash_cmp_arg arg = {
Xin Long65a51242016-01-14 13:49:34 +0800920 .ep = NULL,
Xin Longd6c02562015-12-30 23:50:46 +0800921 .laddr = laddr,
922 .paddr = paddr,
923 .net = net,
924 };
925
926 return rhashtable_lookup_fast(&sctp_transport_hashtable, &arg,
927 sctp_hash_params);
928}
929
930struct sctp_transport *sctp_epaddr_lookup_transport(
931 const struct sctp_endpoint *ep,
932 const union sctp_addr *paddr)
933{
Xin Longd6c02562015-12-30 23:50:46 +0800934 struct net *net = sock_net(ep->base.sk);
Xin Long65a51242016-01-14 13:49:34 +0800935 struct sctp_hash_cmp_arg arg = {
936 .ep = ep,
937 .paddr = paddr,
938 .net = net,
939 };
Xin Longd6c02562015-12-30 23:50:46 +0800940
Xin Long65a51242016-01-14 13:49:34 +0800941 return rhashtable_lookup_fast(&sctp_transport_hashtable, &arg,
942 sctp_hash_params);
Xin Longd6c02562015-12-30 23:50:46 +0800943}
944
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945/* Look up an association. */
946static struct sctp_association *__sctp_lookup_association(
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000947 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 const union sctp_addr *local,
949 const union sctp_addr *peer,
950 struct sctp_transport **pt)
951{
Xin Long4f008782015-12-30 23:50:47 +0800952 struct sctp_transport *t;
Xin Long1eed6772016-01-22 01:49:07 +0800953 struct sctp_association *asoc = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
Xin Long4f008782015-12-30 23:50:47 +0800955 t = sctp_addrs_lookup_transport(net, local, peer);
Xin Long1eed6772016-01-22 01:49:07 +0800956 if (!t || !sctp_transport_hold(t))
957 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
Xin Long1eed6772016-01-22 01:49:07 +0800959 asoc = t->asoc;
Xin Long4f008782015-12-30 23:50:47 +0800960 *pt = t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
Xin Long1eed6772016-01-22 01:49:07 +0800962out:
Xin Long1eed6772016-01-22 01:49:07 +0800963 return asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964}
965
Xin Long4f008782015-12-30 23:50:47 +0800966/* Look up an association. protected by RCU read lock */
Daniel Borkmanndda91922013-06-17 11:40:05 +0200967static
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000968struct sctp_association *sctp_lookup_association(struct net *net,
969 const union sctp_addr *laddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 const union sctp_addr *paddr,
Daniel Borkmanndda91922013-06-17 11:40:05 +0200971 struct sctp_transport **transportp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972{
973 struct sctp_association *asoc;
974
Xin Longf46c7012016-02-15 14:28:03 +0800975 rcu_read_lock();
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000976 asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
Xin Longf46c7012016-02-15 14:28:03 +0800977 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 return asoc;
980}
981
982/* Is there an association matching the given local and peer addresses? */
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000983int sctp_has_association(struct net *net,
984 const union sctp_addr *laddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 const union sctp_addr *paddr)
986{
987 struct sctp_association *asoc;
988 struct sctp_transport *transport;
989
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000990 if ((asoc = sctp_lookup_association(net, laddr, paddr, &transport))) {
Xin Longdae399d2016-10-31 20:32:33 +0800991 sctp_transport_put(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 return 1;
993 }
994
995 return 0;
996}
997
998/*
999 * SCTP Implementors Guide, 2.18 Handling of address
1000 * parameters within the INIT or INIT-ACK.
1001 *
1002 * D) When searching for a matching TCB upon reception of an INIT
1003 * or INIT-ACK chunk the receiver SHOULD use not only the
1004 * source address of the packet (containing the INIT or
1005 * INIT-ACK) but the receiver SHOULD also use all valid
1006 * address parameters contained within the chunk.
1007 *
1008 * 2.18.3 Solution description
1009 *
1010 * This new text clearly specifies to an implementor the need
1011 * to look within the INIT or INIT-ACK. Any implementation that
1012 * does not do this, may not be able to establish associations
1013 * in certain circumstances.
1014 *
1015 */
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001016static struct sctp_association *__sctp_rcv_init_lookup(struct net *net,
1017 struct sk_buff *skb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 const union sctp_addr *laddr, struct sctp_transport **transportp)
1019{
1020 struct sctp_association *asoc;
1021 union sctp_addr addr;
1022 union sctp_addr *paddr = &addr;
Arnaldo Carvalho de Melo2c0fd382007-03-13 13:59:32 -03001023 struct sctphdr *sh = sctp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 union sctp_params params;
1025 sctp_init_chunk_t *init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 struct sctp_af *af;
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 /*
1029 * This code will NOT touch anything inside the chunk--it is
1030 * strictly READ-ONLY.
1031 *
1032 * RFC 2960 3 SCTP packet Format
1033 *
1034 * Multiple chunks can be bundled into one SCTP packet up to
1035 * the MTU size, except for the INIT, INIT ACK, and SHUTDOWN
1036 * COMPLETE chunks. These chunks MUST NOT be bundled with any
1037 * other chunk in a packet. See Section 6.10 for more details
1038 * on chunk bundling.
1039 */
1040
1041 /* Find the start of the TLVs and the end of the chunk. This is
1042 * the region we search for address parameters.
1043 */
1044 init = (sctp_init_chunk_t *)skb->data;
1045
1046 /* Walk the parameters looking for embedded addresses. */
1047 sctp_walk_params(params, init, init_hdr.params) {
1048
1049 /* Note: Ignoring hostname addresses. */
1050 af = sctp_get_af_specific(param_type2af(params.p->type));
1051 if (!af)
1052 continue;
1053
Al Virodd86d132006-11-20 17:11:13 -08001054 af->from_addr_param(paddr, params.addr, sh->source, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055
Xin Long7c17fcc2016-10-31 20:32:32 +08001056 asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 if (asoc)
1058 return asoc;
1059 }
1060
1061 return NULL;
1062}
1063
Vlad Yasevichdf218572007-12-20 14:10:38 -08001064/* ADD-IP, Section 5.2
1065 * When an endpoint receives an ASCONF Chunk from the remote peer
1066 * special procedures may be needed to identify the association the
1067 * ASCONF Chunk is associated with. To properly find the association
1068 * the following procedures SHOULD be followed:
1069 *
1070 * D2) If the association is not found, use the address found in the
1071 * Address Parameter TLV combined with the port number found in the
1072 * SCTP common header. If found proceed to rule D4.
1073 *
1074 * D2-ext) If more than one ASCONF Chunks are packed together, use the
1075 * address found in the ASCONF Address Parameter TLV of each of the
1076 * subsequent ASCONF Chunks. If found, proceed to rule D4.
1077 */
1078static struct sctp_association *__sctp_rcv_asconf_lookup(
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001079 struct net *net,
Vlad Yasevichdf218572007-12-20 14:10:38 -08001080 sctp_chunkhdr_t *ch,
1081 const union sctp_addr *laddr,
Al Virobc92dd12008-03-17 22:47:32 -07001082 __be16 peer_port,
Vlad Yasevichdf218572007-12-20 14:10:38 -08001083 struct sctp_transport **transportp)
1084{
1085 sctp_addip_chunk_t *asconf = (struct sctp_addip_chunk *)ch;
1086 struct sctp_af *af;
1087 union sctp_addr_param *param;
1088 union sctp_addr paddr;
1089
1090 /* Skip over the ADDIP header and find the Address parameter */
1091 param = (union sctp_addr_param *)(asconf + 1);
1092
Shan Wei6a435732011-04-18 19:11:47 +00001093 af = sctp_get_af_specific(param_type2af(param->p.type));
Vlad Yasevichdf218572007-12-20 14:10:38 -08001094 if (unlikely(!af))
1095 return NULL;
1096
1097 af->from_addr_param(&paddr, param, peer_port, 0);
1098
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001099 return __sctp_lookup_association(net, laddr, &paddr, transportp);
Vlad Yasevichdf218572007-12-20 14:10:38 -08001100}
1101
1102
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001103/* SCTP-AUTH, Section 6.3:
1104* If the receiver does not find a STCB for a packet containing an AUTH
1105* chunk as the first chunk and not a COOKIE-ECHO chunk as the second
1106* chunk, it MUST use the chunks after the AUTH chunk to look up an existing
1107* association.
1108*
1109* This means that any chunks that can help us identify the association need
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001110* to be looked at to find this association.
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001111*/
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001112static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
1113 struct sk_buff *skb,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001114 const union sctp_addr *laddr,
1115 struct sctp_transport **transportp)
1116{
Vlad Yasevichdf218572007-12-20 14:10:38 -08001117 struct sctp_association *asoc = NULL;
1118 sctp_chunkhdr_t *ch;
1119 int have_auth = 0;
1120 unsigned int chunk_num = 1;
1121 __u8 *ch_end;
1122
1123 /* Walk through the chunks looking for AUTH or ASCONF chunks
1124 * to help us find the association.
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001125 */
Vlad Yasevichdf218572007-12-20 14:10:38 -08001126 ch = (sctp_chunkhdr_t *) skb->data;
1127 do {
1128 /* Break out if chunk length is less then minimal. */
1129 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
1130 break;
1131
Marcelo Ricardo Leitnere2f036a2016-09-21 08:45:55 -03001132 ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
Vlad Yasevichdf218572007-12-20 14:10:38 -08001133 if (ch_end > skb_tail_pointer(skb))
1134 break;
1135
wangweidongcb3f8372013-12-23 12:16:50 +08001136 switch (ch->type) {
wangweidongf7010e62013-12-23 12:16:52 +08001137 case SCTP_CID_AUTH:
1138 have_auth = chunk_num;
1139 break;
Vlad Yasevichdf218572007-12-20 14:10:38 -08001140
wangweidongf7010e62013-12-23 12:16:52 +08001141 case SCTP_CID_COOKIE_ECHO:
1142 /* If a packet arrives containing an AUTH chunk as
1143 * a first chunk, a COOKIE-ECHO chunk as the second
1144 * chunk, and possibly more chunks after them, and
1145 * the receiver does not have an STCB for that
1146 * packet, then authentication is based on
1147 * the contents of the COOKIE- ECHO chunk.
1148 */
1149 if (have_auth == 1 && chunk_num == 2)
1150 return NULL;
1151 break;
Vlad Yasevichdf218572007-12-20 14:10:38 -08001152
wangweidongf7010e62013-12-23 12:16:52 +08001153 case SCTP_CID_ASCONF:
1154 if (have_auth || net->sctp.addip_noauth)
1155 asoc = __sctp_rcv_asconf_lookup(
1156 net, ch, laddr,
1157 sctp_hdr(skb)->source,
1158 transportp);
1159 default:
1160 break;
Vlad Yasevichdf218572007-12-20 14:10:38 -08001161 }
1162
1163 if (asoc)
1164 break;
1165
1166 ch = (sctp_chunkhdr_t *) ch_end;
1167 chunk_num++;
1168 } while (ch_end < skb_tail_pointer(skb));
1169
1170 return asoc;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001171}
1172
1173/*
1174 * There are circumstances when we need to look inside the SCTP packet
1175 * for information to help us find the association. Examples
1176 * include looking inside of INIT/INIT-ACK chunks or after the AUTH
1177 * chunks.
1178 */
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001179static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net,
1180 struct sk_buff *skb,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001181 const union sctp_addr *laddr,
1182 struct sctp_transport **transportp)
1183{
1184 sctp_chunkhdr_t *ch;
1185
Marcelo Ricardo Leitner90017ac2016-06-02 15:05:43 -03001186 /* We do not allow GSO frames here as we need to linearize and
1187 * then cannot guarantee frame boundaries. This shouldn't be an
1188 * issue as packets hitting this are mostly INIT or INIT-ACK and
1189 * those cannot be on GSO-style anyway.
1190 */
1191 if ((skb_shinfo(skb)->gso_type & SKB_GSO_SCTP) == SKB_GSO_SCTP)
1192 return NULL;
1193
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001194 ch = (sctp_chunkhdr_t *) skb->data;
1195
Vlad Yasevichdf218572007-12-20 14:10:38 -08001196 /* The code below will attempt to walk the chunk and extract
1197 * parameter information. Before we do that, we need to verify
1198 * that the chunk length doesn't cause overflow. Otherwise, we'll
1199 * walk off the end.
1200 */
Marcelo Ricardo Leitnere2f036a2016-09-21 08:45:55 -03001201 if (SCTP_PAD4(ntohs(ch->length)) > skb->len)
Vlad Yasevichdf218572007-12-20 14:10:38 -08001202 return NULL;
1203
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001204 /* If this is INIT/INIT-ACK look inside the chunk too. */
wangweidongf482f2f2013-12-19 10:02:42 +08001205 if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK)
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001206 return __sctp_rcv_init_lookup(net, skb, laddr, transportp);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001207
wangweidongf482f2f2013-12-19 10:02:42 +08001208 return __sctp_rcv_walk_lookup(net, skb, laddr, transportp);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001209}
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211/* Lookup an association for an inbound skb. */
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001212static struct sctp_association *__sctp_rcv_lookup(struct net *net,
1213 struct sk_buff *skb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 const union sctp_addr *paddr,
1215 const union sctp_addr *laddr,
1216 struct sctp_transport **transportp)
1217{
1218 struct sctp_association *asoc;
1219
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001220 asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221
1222 /* Further lookup for INIT/INIT-ACK packets.
1223 * SCTP Implementors Guide, 2.18 Handling of address
1224 * parameters within the INIT or INIT-ACK.
1225 */
1226 if (!asoc)
Eric W. Biederman4110cc22012-08-06 08:41:13 +00001227 asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228
1229 return asoc;
1230}