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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);
95 rwlock_init(&ep->base.addr_lock);
96
97 /* Remember who we are attached to. */
98 ep->base.sk = sk;
99 sock_hold(ep->base.sk);
100
101 /* Create the lists of associations. */
102 INIT_LIST_HEAD(&ep->asocs);
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 /* Use SCTP specific send buffer space queues. */
Neil Horman4eb701d2005-04-28 12:02:04 -0700105 ep->sndbuf_policy = sctp_sndbuf_policy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 sk->sk_write_space = sctp_write_space;
107 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
108
Neil Horman049b3ff2005-11-11 16:08:24 -0800109 /* Get the receive buffer policy for this endpoint */
110 ep->rcvbuf_policy = sctp_rcvbuf_policy;
111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 /* Initialize the secret key used with cookie. */
113 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
114 ep->last_key = ep->current_key = 0;
115 ep->key_changed_at = jiffies;
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 return ep;
118}
119
120/* Create a sctp_endpoint with all that boring stuff initialized.
121 * Returns NULL if there isn't enough memory.
122 */
Al Virodd0fc662005-10-07 07:46:04 +0100123struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124{
125 struct sctp_endpoint *ep;
126
127 /* Build a local endpoint. */
128 ep = t_new(struct sctp_endpoint, gfp);
129 if (!ep)
130 goto fail;
131 if (!sctp_endpoint_init(ep, sk, gfp))
132 goto fail_init;
133 ep->base.malloced = 1;
134 SCTP_DBG_OBJCNT_INC(ep);
135 return ep;
136
137fail_init:
138 kfree(ep);
139fail:
140 return NULL;
141}
142
143/* Add an association to an endpoint. */
144void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
145 struct sctp_association *asoc)
146{
147 struct sock *sk = ep->base.sk;
148
Vlad Yasevichde76e692006-10-30 18:55:11 -0800149 /* If this is a temporary association, don't bother
150 * since we'll be removing it shortly and don't
151 * want anyone to find it anyway.
152 */
153 if (asoc->temp)
154 return;
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 /* Now just add it to our list of asocs */
157 list_add_tail(&asoc->asocs, &ep->asocs);
158
159 /* Increment the backlog value for a TCP-style listening socket. */
160 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
161 sk->sk_ack_backlog++;
162}
163
164/* Free the endpoint structure. Delay cleanup until
165 * all users have released their reference count on this structure.
166 */
167void sctp_endpoint_free(struct sctp_endpoint *ep)
168{
169 ep->base.dead = 1;
Vlad Yasevichcfdeef32006-07-21 14:48:26 -0700170
171 ep->base.sk->sk_state = SCTP_SS_CLOSED;
172
173 /* Unlink this endpoint, so we can't find it again! */
174 sctp_unhash_endpoint(ep);
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 sctp_endpoint_put(ep);
177}
178
179/* Final destructor for endpoint. */
180static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
181{
182 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 /* Free up the HMAC transform. */
Herbert Xu1b489e12006-08-20 15:07:14 +1000185 crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
Vlad Yasevichb68dbca2006-11-09 16:29:57 -0800187 /* Free the digest buffer */
188 kfree(ep->digest);
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 /* Cleanup. */
191 sctp_inq_free(&ep->base.inqueue);
192 sctp_bind_addr_free(&ep->base.bind_addr);
193
194 /* Remove and free the port */
195 if (sctp_sk(ep->base.sk)->bind_hash)
196 sctp_put_port(ep->base.sk);
197
198 /* Give up our hold on the sock. */
199 if (ep->base.sk)
200 sock_put(ep->base.sk);
201
202 /* Finally, free up our memory. */
203 if (ep->base.malloced) {
204 kfree(ep);
205 SCTP_DBG_OBJCNT_DEC(ep);
206 }
207}
208
209/* Hold a reference to an endpoint. */
210void sctp_endpoint_hold(struct sctp_endpoint *ep)
211{
212 atomic_inc(&ep->base.refcnt);
213}
214
215/* Release a reference to an endpoint and clean up if there are
216 * no more references.
217 */
218void sctp_endpoint_put(struct sctp_endpoint *ep)
219{
220 if (atomic_dec_and_test(&ep->base.refcnt))
221 sctp_endpoint_destroy(ep);
222}
223
224/* Is this the endpoint we are looking for? */
225struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
226 const union sctp_addr *laddr)
227{
228 struct sctp_endpoint *retval;
229
230 sctp_read_lock(&ep->base.addr_lock);
Al Viro1c7d1fc2006-11-20 17:08:09 -0800231 if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
233 sctp_sk(ep->base.sk))) {
234 retval = ep;
235 goto out;
236 }
237 }
238
239 retval = NULL;
240
241out:
242 sctp_read_unlock(&ep->base.addr_lock);
243 return retval;
244}
245
246/* Find the association that goes with this chunk.
247 * We do a linear search of the associations for this endpoint.
248 * We return the matching transport address too.
249 */
250static struct sctp_association *__sctp_endpoint_lookup_assoc(
251 const struct sctp_endpoint *ep,
252 const union sctp_addr *paddr,
253 struct sctp_transport **transport)
254{
255 int rport;
256 struct sctp_association *asoc;
257 struct list_head *pos;
258
Al Virocd4ff032006-11-20 17:11:33 -0800259 rport = ntohs(paddr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
261 list_for_each(pos, &ep->asocs) {
262 asoc = list_entry(pos, struct sctp_association, asocs);
263 if (rport == asoc->peer.port) {
264 sctp_read_lock(&asoc->base.addr_lock);
265 *transport = sctp_assoc_lookup_paddr(asoc, paddr);
266 sctp_read_unlock(&asoc->base.addr_lock);
267
268 if (*transport)
269 return asoc;
270 }
271 }
272
273 *transport = NULL;
274 return NULL;
275}
276
277/* Lookup association on an endpoint based on a peer address. BH-safe. */
278struct sctp_association *sctp_endpoint_lookup_assoc(
279 const struct sctp_endpoint *ep,
280 const union sctp_addr *paddr,
281 struct sctp_transport **transport)
282{
283 struct sctp_association *asoc;
284
285 sctp_local_bh_disable();
286 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
287 sctp_local_bh_enable();
288
289 return asoc;
290}
291
292/* Look for any peeled off association from the endpoint that matches the
293 * given peer address.
294 */
295int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
296 const union sctp_addr *paddr)
297{
298 struct list_head *pos;
299 struct sctp_sockaddr_entry *addr;
300 struct sctp_bind_addr *bp;
301
302 sctp_read_lock(&ep->base.addr_lock);
303 bp = &ep->base.bind_addr;
304 list_for_each(pos, &bp->address_list) {
305 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
306 if (sctp_has_association(&addr->a, paddr)) {
307 sctp_read_unlock(&ep->base.addr_lock);
308 return 1;
309 }
310 }
311 sctp_read_unlock(&ep->base.addr_lock);
312
313 return 0;
314}
315
316/* Do delayed input processing. This is scheduled by sctp_rcv().
317 * This may be called on BH or task time.
318 */
David Howellsc4028952006-11-22 14:57:56 +0000319static void sctp_endpoint_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
David Howellsc4028952006-11-22 14:57:56 +0000321 struct sctp_endpoint *ep =
322 container_of(work, struct sctp_endpoint,
323 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 struct sctp_association *asoc;
325 struct sock *sk;
326 struct sctp_transport *transport;
327 struct sctp_chunk *chunk;
328 struct sctp_inq *inqueue;
329 sctp_subtype_t subtype;
330 sctp_state_t state;
331 int error = 0;
332
333 if (ep->base.dead)
334 return;
335
336 asoc = NULL;
337 inqueue = &ep->base.inqueue;
338 sk = ep->base.sk;
339
340 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
341 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
342
343 /* We might have grown an association since last we
344 * looked, so try again.
345 *
346 * This happens when we've just processed our
347 * COOKIE-ECHO chunk.
348 */
349 if (NULL == chunk->asoc) {
350 asoc = sctp_endpoint_lookup_assoc(ep,
351 sctp_source(chunk),
352 &transport);
353 chunk->asoc = asoc;
354 chunk->transport = transport;
355 }
356
357 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
358
359 /* Remember where the last DATA chunk came from so we
360 * know where to send the SACK.
361 */
362 if (asoc && sctp_chunk_is_data(chunk))
363 asoc->peer.last_data_from = chunk->transport;
364 else
365 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
366
367 if (chunk->transport)
368 chunk->transport->last_time_heard = jiffies;
369
370 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900371 ep, asoc, chunk, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373 if (error && chunk)
374 chunk->pdiscard = 1;
375
376 /* Check to see if the endpoint is freed in response to
377 * the incoming chunk. If so, get out of the while loop.
378 */
379 if (!sctp_sk(sk)->ep)
380 break;
381 }
382}