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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * Copyright (c) 1999-2000 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2001-2002 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 *
9 * This file is part of the SCTP kernel reference Implementation
10 *
11 * This abstraction represents an SCTP endpoint.
12 *
13 * This file is part of the implementation of the add-IP extension,
14 * based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
15 * for the SCTP kernel reference Implementation.
16 *
17 * The SCTP reference implementation is free software;
18 * you can redistribute it and/or modify it under the terms of
19 * the GNU General Public License as published by
20 * the Free Software Foundation; either version 2, or (at your option)
21 * any later version.
22 *
23 * The SCTP reference implementation is distributed in the hope that it
24 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
25 * ************************
26 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
27 * See the GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with GNU CC; see the file COPYING. If not, write to
31 * the Free Software Foundation, 59 Temple Place - Suite 330,
32 * Boston, MA 02111-1307, USA.
33 *
34 * Please send any bug reports or fixes you make to the
35 * email address(es):
36 * lksctp developers <lksctp-developers@lists.sourceforge.net>
37 *
38 * Or submit a bug report through the following website:
39 * http://www.sf.net/projects/lksctp
40 *
41 * Written or modified by:
42 * La Monte H.P. Yarroll <piggy@acm.org>
43 * Karl Knutson <karl@athena.chicago.il.us>
44 * Jon Grimm <jgrimm@austin.ibm.com>
45 * Daisy Chang <daisyc@us.ibm.com>
46 * Dajiang Zhang <dajiang.zhang@nokia.com>
47 *
48 * Any bugs reported given to us we will try to fix... any fixes shared will
49 * be incorporated into the next SCTP release.
50 */
51
52#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070053#include <linux/slab.h>
54#include <linux/in.h>
55#include <linux/random.h> /* get_random_bytes() */
56#include <linux/crypto.h>
57#include <net/sock.h>
58#include <net/ipv6.h>
59#include <net/sctp/sctp.h>
60#include <net/sctp/sm.h>
61
62/* Forward declarations for internal helpers. */
David Howellsc4028952006-11-22 14:57:56 +000063static void sctp_endpoint_bh_rcv(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65/*
66 * Initialize the base fields of the endpoint structure.
67 */
68static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -070069 struct sock *sk,
Al Virodd0fc662005-10-07 07:46:04 +010070 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 memset(ep, 0, sizeof(struct sctp_endpoint));
73
Vlad Yasevichb68dbca2006-11-09 16:29:57 -080074 ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
75 if (!ep->digest)
76 return NULL;
77
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 /* Initialize the base structure. */
79 /* What type of endpoint are we? */
80 ep->base.type = SCTP_EP_TYPE_SOCKET;
81
82 /* Initialize the basic object fields. */
83 atomic_set(&ep->base.refcnt, 1);
84 ep->base.dead = 0;
85 ep->base.malloced = 1;
86
87 /* Create an input queue. */
88 sctp_inq_init(&ep->base.inqueue);
89
90 /* Set its top-half handler */
David Howellsc4028952006-11-22 14:57:56 +000091 sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 /* Initialize the bind addr area */
94 sctp_bind_addr_init(&ep->base.bind_addr, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 /* Remember who we are attached to. */
97 ep->base.sk = sk;
98 sock_hold(ep->base.sk);
99
100 /* Create the lists of associations. */
101 INIT_LIST_HEAD(&ep->asocs);
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 /* Use SCTP specific send buffer space queues. */
Neil Horman4eb701d2005-04-28 12:02:04 -0700104 ep->sndbuf_policy = sctp_sndbuf_policy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 sk->sk_write_space = sctp_write_space;
106 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
107
Neil Horman049b3ff2005-11-11 16:08:24 -0800108 /* Get the receive buffer policy for this endpoint */
109 ep->rcvbuf_policy = sctp_rcvbuf_policy;
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 /* Initialize the secret key used with cookie. */
112 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
113 ep->last_key = ep->current_key = 0;
114 ep->key_changed_at = jiffies;
115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 return ep;
117}
118
119/* Create a sctp_endpoint with all that boring stuff initialized.
120 * Returns NULL if there isn't enough memory.
121 */
Al Virodd0fc662005-10-07 07:46:04 +0100122struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123{
124 struct sctp_endpoint *ep;
125
126 /* Build a local endpoint. */
127 ep = t_new(struct sctp_endpoint, gfp);
128 if (!ep)
129 goto fail;
130 if (!sctp_endpoint_init(ep, sk, gfp))
131 goto fail_init;
132 ep->base.malloced = 1;
133 SCTP_DBG_OBJCNT_INC(ep);
134 return ep;
135
136fail_init:
137 kfree(ep);
138fail:
139 return NULL;
140}
141
142/* Add an association to an endpoint. */
143void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
144 struct sctp_association *asoc)
145{
146 struct sock *sk = ep->base.sk;
147
Vlad Yasevichde76e692006-10-30 18:55:11 -0800148 /* If this is a temporary association, don't bother
149 * since we'll be removing it shortly and don't
150 * want anyone to find it anyway.
151 */
152 if (asoc->temp)
153 return;
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 /* Now just add it to our list of asocs */
156 list_add_tail(&asoc->asocs, &ep->asocs);
157
158 /* Increment the backlog value for a TCP-style listening socket. */
159 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
160 sk->sk_ack_backlog++;
161}
162
163/* Free the endpoint structure. Delay cleanup until
164 * all users have released their reference count on this structure.
165 */
166void sctp_endpoint_free(struct sctp_endpoint *ep)
167{
168 ep->base.dead = 1;
Vlad Yasevichcfdeef32006-07-21 14:48:26 -0700169
170 ep->base.sk->sk_state = SCTP_SS_CLOSED;
171
172 /* Unlink this endpoint, so we can't find it again! */
173 sctp_unhash_endpoint(ep);
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 sctp_endpoint_put(ep);
176}
177
178/* Final destructor for endpoint. */
179static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
180{
181 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 /* Free up the HMAC transform. */
Herbert Xu1b489e12006-08-20 15:07:14 +1000184 crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Vlad Yasevichb68dbca2006-11-09 16:29:57 -0800186 /* Free the digest buffer */
187 kfree(ep->digest);
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 /* Cleanup. */
190 sctp_inq_free(&ep->base.inqueue);
191 sctp_bind_addr_free(&ep->base.bind_addr);
192
193 /* Remove and free the port */
194 if (sctp_sk(ep->base.sk)->bind_hash)
195 sctp_put_port(ep->base.sk);
196
197 /* Give up our hold on the sock. */
198 if (ep->base.sk)
199 sock_put(ep->base.sk);
200
201 /* Finally, free up our memory. */
202 if (ep->base.malloced) {
203 kfree(ep);
204 SCTP_DBG_OBJCNT_DEC(ep);
205 }
206}
207
208/* Hold a reference to an endpoint. */
209void sctp_endpoint_hold(struct sctp_endpoint *ep)
210{
211 atomic_inc(&ep->base.refcnt);
212}
213
214/* Release a reference to an endpoint and clean up if there are
215 * no more references.
216 */
217void sctp_endpoint_put(struct sctp_endpoint *ep)
218{
219 if (atomic_dec_and_test(&ep->base.refcnt))
220 sctp_endpoint_destroy(ep);
221}
222
223/* Is this the endpoint we are looking for? */
224struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
225 const union sctp_addr *laddr)
226{
Vlad Yasevich559cf712007-09-16 16:03:28 -0700227 struct sctp_endpoint *retval = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Al Viro1c7d1fc2006-11-20 17:08:09 -0800229 if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -0700231 sctp_sk(ep->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 retval = ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 }
234
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 return retval;
236}
237
238/* Find the association that goes with this chunk.
239 * We do a linear search of the associations for this endpoint.
240 * We return the matching transport address too.
241 */
242static struct sctp_association *__sctp_endpoint_lookup_assoc(
243 const struct sctp_endpoint *ep,
244 const union sctp_addr *paddr,
245 struct sctp_transport **transport)
246{
247 int rport;
248 struct sctp_association *asoc;
249 struct list_head *pos;
250
Al Virocd4ff032006-11-20 17:11:33 -0800251 rport = ntohs(paddr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 list_for_each(pos, &ep->asocs) {
254 asoc = list_entry(pos, struct sctp_association, asocs);
255 if (rport == asoc->peer.port) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 *transport = sctp_assoc_lookup_paddr(asoc, paddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 if (*transport)
259 return asoc;
260 }
261 }
262
263 *transport = NULL;
264 return NULL;
265}
266
267/* Lookup association on an endpoint based on a peer address. BH-safe. */
268struct sctp_association *sctp_endpoint_lookup_assoc(
269 const struct sctp_endpoint *ep,
270 const union sctp_addr *paddr,
271 struct sctp_transport **transport)
272{
273 struct sctp_association *asoc;
274
275 sctp_local_bh_disable();
276 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
277 sctp_local_bh_enable();
278
279 return asoc;
280}
281
282/* Look for any peeled off association from the endpoint that matches the
283 * given peer address.
284 */
285int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
286 const union sctp_addr *paddr)
287{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 struct sctp_sockaddr_entry *addr;
289 struct sctp_bind_addr *bp;
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 bp = &ep->base.bind_addr;
Vlad Yasevich559cf712007-09-16 16:03:28 -0700292 /* This function is called with the socket lock held,
293 * so the address_list can not change.
294 */
295 list_for_each_entry(addr, &bp->address_list, list) {
296 if (sctp_has_association(&addr->a, paddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
300 return 0;
301}
302
303/* Do delayed input processing. This is scheduled by sctp_rcv().
304 * This may be called on BH or task time.
305 */
David Howellsc4028952006-11-22 14:57:56 +0000306static void sctp_endpoint_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
David Howellsc4028952006-11-22 14:57:56 +0000308 struct sctp_endpoint *ep =
309 container_of(work, struct sctp_endpoint,
310 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 struct sctp_association *asoc;
312 struct sock *sk;
313 struct sctp_transport *transport;
314 struct sctp_chunk *chunk;
315 struct sctp_inq *inqueue;
316 sctp_subtype_t subtype;
317 sctp_state_t state;
318 int error = 0;
319
320 if (ep->base.dead)
321 return;
322
323 asoc = NULL;
324 inqueue = &ep->base.inqueue;
325 sk = ep->base.sk;
326
327 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
328 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
329
330 /* We might have grown an association since last we
331 * looked, so try again.
332 *
333 * This happens when we've just processed our
334 * COOKIE-ECHO chunk.
335 */
336 if (NULL == chunk->asoc) {
337 asoc = sctp_endpoint_lookup_assoc(ep,
338 sctp_source(chunk),
339 &transport);
340 chunk->asoc = asoc;
341 chunk->transport = transport;
342 }
343
344 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
345
346 /* Remember where the last DATA chunk came from so we
347 * know where to send the SACK.
348 */
349 if (asoc && sctp_chunk_is_data(chunk))
350 asoc->peer.last_data_from = chunk->transport;
351 else
352 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
353
354 if (chunk->transport)
355 chunk->transport->last_time_heard = jiffies;
356
357 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900358 ep, asoc, chunk, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
360 if (error && chunk)
361 chunk->pdiscard = 1;
362
363 /* Check to see if the endpoint is freed in response to
364 * the incoming chunk. If so, get out of the while loop.
365 */
366 if (!sctp_sk(sk)->ep)
367 break;
368 }
369}