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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>
53#include <linux/sched.h>
54#include <linux/slab.h>
55#include <linux/in.h>
56#include <linux/random.h> /* get_random_bytes() */
57#include <linux/crypto.h>
58#include <net/sock.h>
59#include <net/ipv6.h>
60#include <net/sctp/sctp.h>
61#include <net/sctp/sm.h>
62
63/* Forward declarations for internal helpers. */
64static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep);
65
66/*
67 * Initialize the base fields of the endpoint structure.
68 */
69static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -070070 struct sock *sk,
Al Virodd0fc662005-10-07 07:46:04 +010071 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072{
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 memset(ep, 0, sizeof(struct sctp_endpoint));
74
75 /* Initialize the base structure. */
76 /* What type of endpoint are we? */
77 ep->base.type = SCTP_EP_TYPE_SOCKET;
78
79 /* Initialize the basic object fields. */
80 atomic_set(&ep->base.refcnt, 1);
81 ep->base.dead = 0;
82 ep->base.malloced = 1;
83
84 /* Create an input queue. */
85 sctp_inq_init(&ep->base.inqueue);
86
87 /* Set its top-half handler */
88 sctp_inq_set_th_handler(&ep->base.inqueue,
89 (void (*)(void *))sctp_endpoint_bh_rcv, ep);
90
91 /* Initialize the bind addr area */
92 sctp_bind_addr_init(&ep->base.bind_addr, 0);
93 rwlock_init(&ep->base.addr_lock);
94
95 /* Remember who we are attached to. */
96 ep->base.sk = sk;
97 sock_hold(ep->base.sk);
98
99 /* Create the lists of associations. */
100 INIT_LIST_HEAD(&ep->asocs);
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 /* Use SCTP specific send buffer space queues. */
Neil Horman4eb701d2005-04-28 12:02:04 -0700103 ep->sndbuf_policy = sctp_sndbuf_policy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 sk->sk_write_space = sctp_write_space;
105 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
106
Neil Horman049b3ff2005-11-11 16:08:24 -0800107 /* Get the receive buffer policy for this endpoint */
108 ep->rcvbuf_policy = sctp_rcvbuf_policy;
109
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 /* Initialize the secret key used with cookie. */
111 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
112 ep->last_key = ep->current_key = 0;
113 ep->key_changed_at = jiffies;
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 return ep;
116}
117
118/* Create a sctp_endpoint with all that boring stuff initialized.
119 * Returns NULL if there isn't enough memory.
120 */
Al Virodd0fc662005-10-07 07:46:04 +0100121struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122{
123 struct sctp_endpoint *ep;
124
125 /* Build a local endpoint. */
126 ep = t_new(struct sctp_endpoint, gfp);
127 if (!ep)
128 goto fail;
129 if (!sctp_endpoint_init(ep, sk, gfp))
130 goto fail_init;
131 ep->base.malloced = 1;
132 SCTP_DBG_OBJCNT_INC(ep);
133 return ep;
134
135fail_init:
136 kfree(ep);
137fail:
138 return NULL;
139}
140
141/* Add an association to an endpoint. */
142void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
143 struct sctp_association *asoc)
144{
145 struct sock *sk = ep->base.sk;
146
147 /* Now just add it to our list of asocs */
148 list_add_tail(&asoc->asocs, &ep->asocs);
149
150 /* Increment the backlog value for a TCP-style listening socket. */
151 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
152 sk->sk_ack_backlog++;
153}
154
155/* Free the endpoint structure. Delay cleanup until
156 * all users have released their reference count on this structure.
157 */
158void sctp_endpoint_free(struct sctp_endpoint *ep)
159{
160 ep->base.dead = 1;
161 sctp_endpoint_put(ep);
162}
163
164/* Final destructor for endpoint. */
165static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
166{
167 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
168
169 ep->base.sk->sk_state = SCTP_SS_CLOSED;
170
171 /* Unlink this endpoint, so we can't find it again! */
172 sctp_unhash_endpoint(ep);
173
174 /* Free up the HMAC transform. */
Jesper Juhl573dbd92005-09-01 17:44:29 -0700175 sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
177 /* Cleanup. */
178 sctp_inq_free(&ep->base.inqueue);
179 sctp_bind_addr_free(&ep->base.bind_addr);
180
181 /* Remove and free the port */
182 if (sctp_sk(ep->base.sk)->bind_hash)
183 sctp_put_port(ep->base.sk);
184
185 /* Give up our hold on the sock. */
186 if (ep->base.sk)
187 sock_put(ep->base.sk);
188
189 /* Finally, free up our memory. */
190 if (ep->base.malloced) {
191 kfree(ep);
192 SCTP_DBG_OBJCNT_DEC(ep);
193 }
194}
195
196/* Hold a reference to an endpoint. */
197void sctp_endpoint_hold(struct sctp_endpoint *ep)
198{
199 atomic_inc(&ep->base.refcnt);
200}
201
202/* Release a reference to an endpoint and clean up if there are
203 * no more references.
204 */
205void sctp_endpoint_put(struct sctp_endpoint *ep)
206{
207 if (atomic_dec_and_test(&ep->base.refcnt))
208 sctp_endpoint_destroy(ep);
209}
210
211/* Is this the endpoint we are looking for? */
212struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
213 const union sctp_addr *laddr)
214{
215 struct sctp_endpoint *retval;
216
217 sctp_read_lock(&ep->base.addr_lock);
218 if (ep->base.bind_addr.port == laddr->v4.sin_port) {
219 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
220 sctp_sk(ep->base.sk))) {
221 retval = ep;
222 goto out;
223 }
224 }
225
226 retval = NULL;
227
228out:
229 sctp_read_unlock(&ep->base.addr_lock);
230 return retval;
231}
232
233/* Find the association that goes with this chunk.
234 * We do a linear search of the associations for this endpoint.
235 * We return the matching transport address too.
236 */
237static struct sctp_association *__sctp_endpoint_lookup_assoc(
238 const struct sctp_endpoint *ep,
239 const union sctp_addr *paddr,
240 struct sctp_transport **transport)
241{
242 int rport;
243 struct sctp_association *asoc;
244 struct list_head *pos;
245
246 rport = paddr->v4.sin_port;
247
248 list_for_each(pos, &ep->asocs) {
249 asoc = list_entry(pos, struct sctp_association, asocs);
250 if (rport == asoc->peer.port) {
251 sctp_read_lock(&asoc->base.addr_lock);
252 *transport = sctp_assoc_lookup_paddr(asoc, paddr);
253 sctp_read_unlock(&asoc->base.addr_lock);
254
255 if (*transport)
256 return asoc;
257 }
258 }
259
260 *transport = NULL;
261 return NULL;
262}
263
264/* Lookup association on an endpoint based on a peer address. BH-safe. */
265struct sctp_association *sctp_endpoint_lookup_assoc(
266 const struct sctp_endpoint *ep,
267 const union sctp_addr *paddr,
268 struct sctp_transport **transport)
269{
270 struct sctp_association *asoc;
271
272 sctp_local_bh_disable();
273 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
274 sctp_local_bh_enable();
275
276 return asoc;
277}
278
279/* Look for any peeled off association from the endpoint that matches the
280 * given peer address.
281 */
282int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
283 const union sctp_addr *paddr)
284{
285 struct list_head *pos;
286 struct sctp_sockaddr_entry *addr;
287 struct sctp_bind_addr *bp;
288
289 sctp_read_lock(&ep->base.addr_lock);
290 bp = &ep->base.bind_addr;
291 list_for_each(pos, &bp->address_list) {
292 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
293 if (sctp_has_association(&addr->a, paddr)) {
294 sctp_read_unlock(&ep->base.addr_lock);
295 return 1;
296 }
297 }
298 sctp_read_unlock(&ep->base.addr_lock);
299
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 */
306static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
307{
308 struct sctp_association *asoc;
309 struct sock *sk;
310 struct sctp_transport *transport;
311 struct sctp_chunk *chunk;
312 struct sctp_inq *inqueue;
313 sctp_subtype_t subtype;
314 sctp_state_t state;
315 int error = 0;
316
317 if (ep->base.dead)
318 return;
319
320 asoc = NULL;
321 inqueue = &ep->base.inqueue;
322 sk = ep->base.sk;
323
324 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
325 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
326
327 /* We might have grown an association since last we
328 * looked, so try again.
329 *
330 * This happens when we've just processed our
331 * COOKIE-ECHO chunk.
332 */
333 if (NULL == chunk->asoc) {
334 asoc = sctp_endpoint_lookup_assoc(ep,
335 sctp_source(chunk),
336 &transport);
337 chunk->asoc = asoc;
338 chunk->transport = transport;
339 }
340
341 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
342
343 /* Remember where the last DATA chunk came from so we
344 * know where to send the SACK.
345 */
346 if (asoc && sctp_chunk_is_data(chunk))
347 asoc->peer.last_data_from = chunk->transport;
348 else
349 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
350
351 if (chunk->transport)
352 chunk->transport->last_time_heard = jiffies;
353
354 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
355 ep, asoc, chunk, GFP_ATOMIC);
356
357 if (error && chunk)
358 chunk->pdiscard = 1;
359
360 /* Check to see if the endpoint is freed in response to
361 * the incoming chunk. If so, get out of the while loop.
362 */
363 if (!sctp_sk(sk)->ep)
364 break;
365 }
366}