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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) 2001-2002 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 *
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 * This abstraction represents an SCTP endpoint.
12 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050013 * The 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 * The 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
26 * along with GNU CC; see the file COPYING. If not, write to
27 * the Free Software Foundation, 59 Temple Place - Suite 330,
28 * Boston, MA 02111-1307, USA.
29 *
30 * Please send any bug reports or fixes you make to the
31 * email address(es):
32 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 *
34 * Or submit a bug report through the following website:
35 * http://www.sf.net/projects/lksctp
36 *
37 * Written or modified by:
38 * La Monte H.P. Yarroll <piggy@acm.org>
39 * Karl Knutson <karl@athena.chicago.il.us>
40 * Jon Grimm <jgrimm@austin.ibm.com>
41 * Daisy Chang <daisyc@us.ibm.com>
42 * Dajiang Zhang <dajiang.zhang@nokia.com>
43 *
44 * Any bugs reported given to us we will try to fix... any fixes shared will
45 * be incorporated into the next SCTP release.
46 */
47
48#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/slab.h>
50#include <linux/in.h>
51#include <linux/random.h> /* get_random_bytes() */
52#include <linux/crypto.h>
53#include <net/sock.h>
54#include <net/ipv6.h>
55#include <net/sctp/sctp.h>
56#include <net/sctp/sm.h>
57
58/* Forward declarations for internal helpers. */
David Howellsc4028952006-11-22 14:57:56 +000059static void sctp_endpoint_bh_rcv(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61/*
62 * Initialize the base fields of the endpoint structure.
63 */
64static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -070065 struct sock *sk,
Al Virodd0fc662005-10-07 07:46:04 +010066 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070068 struct sctp_hmac_algo_param *auth_hmacs = NULL;
69 struct sctp_chunks_param *auth_chunks = NULL;
70 struct sctp_shared_key *null_key;
71 int err;
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 memset(ep, 0, sizeof(struct sctp_endpoint));
74
Vlad Yasevichb68dbca2006-11-09 16:29:57 -080075 ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
76 if (!ep->digest)
77 return NULL;
78
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070079 if (sctp_auth_enable) {
80 /* Allocate space for HMACS and CHUNKS authentication
81 * variables. There are arrays that we encode directly
82 * into parameters to make the rest of the operations easier.
83 */
84 auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
85 sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
86 if (!auth_hmacs)
87 goto nomem;
88
89 auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
90 SCTP_NUM_CHUNK_TYPES, gfp);
91 if (!auth_chunks)
92 goto nomem;
93
94 /* Initialize the HMACS parameter.
95 * SCTP-AUTH: Section 3.3
96 * Every endpoint supporting SCTP chunk authentication MUST
97 * support the HMAC based on the SHA-1 algorithm.
98 */
99 auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
100 auth_hmacs->param_hdr.length =
101 htons(sizeof(sctp_paramhdr_t) + 2);
102 auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
103
104 /* Initialize the CHUNKS parameter */
105 auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
106
107 /* If the Add-IP functionality is enabled, we must
108 * authenticate, ASCONF and ASCONF-ACK chunks
109 */
110 if (sctp_addip_enable) {
111 auth_chunks->chunks[0] = SCTP_CID_ASCONF;
112 auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
113 auth_chunks->param_hdr.length =
114 htons(sizeof(sctp_paramhdr_t) + 2);
115 }
116 }
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 /* Initialize the base structure. */
119 /* What type of endpoint are we? */
120 ep->base.type = SCTP_EP_TYPE_SOCKET;
121
122 /* Initialize the basic object fields. */
123 atomic_set(&ep->base.refcnt, 1);
124 ep->base.dead = 0;
125 ep->base.malloced = 1;
126
127 /* Create an input queue. */
128 sctp_inq_init(&ep->base.inqueue);
129
130 /* Set its top-half handler */
David Howellsc4028952006-11-22 14:57:56 +0000131 sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133 /* Initialize the bind addr area */
134 sctp_bind_addr_init(&ep->base.bind_addr, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
136 /* Remember who we are attached to. */
137 ep->base.sk = sk;
138 sock_hold(ep->base.sk);
139
140 /* Create the lists of associations. */
141 INIT_LIST_HEAD(&ep->asocs);
142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 /* Use SCTP specific send buffer space queues. */
Neil Horman4eb701d2005-04-28 12:02:04 -0700144 ep->sndbuf_policy = sctp_sndbuf_policy;
Neil Horman4d93df02007-08-15 16:07:44 -0700145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 sk->sk_write_space = sctp_write_space;
147 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
148
Neil Horman049b3ff2005-11-11 16:08:24 -0800149 /* Get the receive buffer policy for this endpoint */
150 ep->rcvbuf_policy = sctp_rcvbuf_policy;
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 /* Initialize the secret key used with cookie. */
153 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
154 ep->last_key = ep->current_key = 0;
155 ep->key_changed_at = jiffies;
156
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700157 /* SCTP-AUTH extensions*/
158 INIT_LIST_HEAD(&ep->endpoint_shared_keys);
159 null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
160 if (!null_key)
161 goto nomem;
162
163 list_add(&null_key->key_list, &ep->endpoint_shared_keys);
164
165 /* Allocate and initialize transorms arrays for suported HMACs. */
166 err = sctp_auth_init_hmacs(ep, gfp);
167 if (err)
168 goto nomem_hmacs;
169
170 /* Add the null key to the endpoint shared keys list and
171 * set the hmcas and chunks pointers.
172 */
173 ep->auth_hmacs_list = auth_hmacs;
174 ep->auth_chunk_list = auth_chunks;
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 return ep;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700177
178nomem_hmacs:
179 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
180nomem:
181 /* Free all allocations */
182 kfree(auth_hmacs);
183 kfree(auth_chunks);
184 kfree(ep->digest);
185 return NULL;
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187}
188
189/* Create a sctp_endpoint with all that boring stuff initialized.
190 * Returns NULL if there isn't enough memory.
191 */
Al Virodd0fc662005-10-07 07:46:04 +0100192struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
194 struct sctp_endpoint *ep;
195
196 /* Build a local endpoint. */
197 ep = t_new(struct sctp_endpoint, gfp);
198 if (!ep)
199 goto fail;
200 if (!sctp_endpoint_init(ep, sk, gfp))
201 goto fail_init;
202 ep->base.malloced = 1;
203 SCTP_DBG_OBJCNT_INC(ep);
204 return ep;
205
206fail_init:
207 kfree(ep);
208fail:
209 return NULL;
210}
211
212/* Add an association to an endpoint. */
213void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
214 struct sctp_association *asoc)
215{
216 struct sock *sk = ep->base.sk;
217
Vlad Yasevichde76e692006-10-30 18:55:11 -0800218 /* If this is a temporary association, don't bother
219 * since we'll be removing it shortly and don't
220 * want anyone to find it anyway.
221 */
222 if (asoc->temp)
223 return;
224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 /* Now just add it to our list of asocs */
226 list_add_tail(&asoc->asocs, &ep->asocs);
227
228 /* Increment the backlog value for a TCP-style listening socket. */
229 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
230 sk->sk_ack_backlog++;
231}
232
233/* Free the endpoint structure. Delay cleanup until
234 * all users have released their reference count on this structure.
235 */
236void sctp_endpoint_free(struct sctp_endpoint *ep)
237{
238 ep->base.dead = 1;
Vlad Yasevichcfdeef32006-07-21 14:48:26 -0700239
240 ep->base.sk->sk_state = SCTP_SS_CLOSED;
241
242 /* Unlink this endpoint, so we can't find it again! */
243 sctp_unhash_endpoint(ep);
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 sctp_endpoint_put(ep);
246}
247
248/* Final destructor for endpoint. */
249static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
250{
251 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 /* Free up the HMAC transform. */
Herbert Xu1b489e12006-08-20 15:07:14 +1000254 crypto_free_hash(sctp_sk(ep->base.sk)->hmac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
Vlad Yasevichb68dbca2006-11-09 16:29:57 -0800256 /* Free the digest buffer */
257 kfree(ep->digest);
258
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700259 /* SCTP-AUTH: Free up AUTH releated data such as shared keys
260 * chunks and hmacs arrays that were allocated
261 */
262 sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
263 kfree(ep->auth_hmacs_list);
264 kfree(ep->auth_chunk_list);
265
266 /* AUTH - Free any allocated HMAC transform containers */
267 sctp_auth_destroy_hmacs(ep->auth_hmacs);
268
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 /* Cleanup. */
270 sctp_inq_free(&ep->base.inqueue);
271 sctp_bind_addr_free(&ep->base.bind_addr);
272
273 /* Remove and free the port */
274 if (sctp_sk(ep->base.sk)->bind_hash)
275 sctp_put_port(ep->base.sk);
276
277 /* Give up our hold on the sock. */
278 if (ep->base.sk)
279 sock_put(ep->base.sk);
280
281 /* Finally, free up our memory. */
282 if (ep->base.malloced) {
283 kfree(ep);
284 SCTP_DBG_OBJCNT_DEC(ep);
285 }
286}
287
288/* Hold a reference to an endpoint. */
289void sctp_endpoint_hold(struct sctp_endpoint *ep)
290{
291 atomic_inc(&ep->base.refcnt);
292}
293
294/* Release a reference to an endpoint and clean up if there are
295 * no more references.
296 */
297void sctp_endpoint_put(struct sctp_endpoint *ep)
298{
299 if (atomic_dec_and_test(&ep->base.refcnt))
300 sctp_endpoint_destroy(ep);
301}
302
303/* Is this the endpoint we are looking for? */
304struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
305 const union sctp_addr *laddr)
306{
Vlad Yasevich559cf712007-09-16 16:03:28 -0700307 struct sctp_endpoint *retval = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
Al Viro1c7d1fc2006-11-20 17:08:09 -0800309 if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -0700311 sctp_sk(ep->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 retval = ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 }
314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 return retval;
316}
317
318/* Find the association that goes with this chunk.
319 * We do a linear search of the associations for this endpoint.
320 * We return the matching transport address too.
321 */
322static struct sctp_association *__sctp_endpoint_lookup_assoc(
323 const struct sctp_endpoint *ep,
324 const union sctp_addr *paddr,
325 struct sctp_transport **transport)
326{
Vlad Yasevich123ed972007-11-09 11:41:36 -0500327 struct sctp_association *asoc = NULL;
328 struct sctp_transport *t = NULL;
329 struct sctp_hashbucket *head;
330 struct sctp_ep_common *epb;
Vlad Yasevichd970dbf2007-11-09 11:43:40 -0500331 struct hlist_node *node;
Vlad Yasevich123ed972007-11-09 11:41:36 -0500332 int hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 int rport;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335 *transport = NULL;
Vlad Yasevich123ed972007-11-09 11:41:36 -0500336 rport = ntohs(paddr->v4.sin_port);
337
338 hash = sctp_assoc_hashfn(ep->base.bind_addr.port, rport);
339 head = &sctp_assoc_hashtable[hash];
340 read_lock(&head->lock);
Vlad Yasevichd970dbf2007-11-09 11:43:40 -0500341 sctp_for_each_hentry(epb, node, &head->chain) {
Vlad Yasevich123ed972007-11-09 11:41:36 -0500342 asoc = sctp_assoc(epb);
343 if (asoc->ep != ep || rport != asoc->peer.port)
344 goto next;
345
346 t = sctp_assoc_lookup_paddr(asoc, paddr);
347 if (t) {
348 *transport = t;
349 break;
350 }
351next:
352 asoc = NULL;
353 }
354 read_unlock(&head->lock);
355 return asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356}
357
358/* Lookup association on an endpoint based on a peer address. BH-safe. */
359struct sctp_association *sctp_endpoint_lookup_assoc(
360 const struct sctp_endpoint *ep,
361 const union sctp_addr *paddr,
362 struct sctp_transport **transport)
363{
364 struct sctp_association *asoc;
365
366 sctp_local_bh_disable();
367 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
368 sctp_local_bh_enable();
369
370 return asoc;
371}
372
373/* Look for any peeled off association from the endpoint that matches the
374 * given peer address.
375 */
376int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
377 const union sctp_addr *paddr)
378{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 struct sctp_sockaddr_entry *addr;
380 struct sctp_bind_addr *bp;
381
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 bp = &ep->base.bind_addr;
Vlad Yasevich559cf712007-09-16 16:03:28 -0700383 /* This function is called with the socket lock held,
384 * so the address_list can not change.
385 */
386 list_for_each_entry(addr, &bp->address_list, list) {
387 if (sctp_has_association(&addr->a, paddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
391 return 0;
392}
393
394/* Do delayed input processing. This is scheduled by sctp_rcv().
395 * This may be called on BH or task time.
396 */
David Howellsc4028952006-11-22 14:57:56 +0000397static void sctp_endpoint_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398{
David Howellsc4028952006-11-22 14:57:56 +0000399 struct sctp_endpoint *ep =
400 container_of(work, struct sctp_endpoint,
401 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 struct sctp_association *asoc;
403 struct sock *sk;
404 struct sctp_transport *transport;
405 struct sctp_chunk *chunk;
406 struct sctp_inq *inqueue;
407 sctp_subtype_t subtype;
408 sctp_state_t state;
409 int error = 0;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700410 int first_time = 1; /* is this the first time through the looop */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
412 if (ep->base.dead)
413 return;
414
415 asoc = NULL;
416 inqueue = &ep->base.inqueue;
417 sk = ep->base.sk;
418
419 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
420 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
421
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700422 /* If the first chunk in the packet is AUTH, do special
423 * processing specified in Section 6.3 of SCTP-AUTH spec
424 */
425 if (first_time && (subtype.chunk == SCTP_CID_AUTH)) {
426 struct sctp_chunkhdr *next_hdr;
427
428 next_hdr = sctp_inq_peek(inqueue);
429 if (!next_hdr)
430 goto normal;
431
432 /* If the next chunk is COOKIE-ECHO, skip the AUTH
433 * chunk while saving a pointer to it so we can do
434 * Authentication later (during cookie-echo
435 * processing).
436 */
437 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
438 chunk->auth_chunk = skb_clone(chunk->skb,
439 GFP_ATOMIC);
440 chunk->auth = 1;
441 continue;
442 }
443 }
444normal:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 /* We might have grown an association since last we
446 * looked, so try again.
447 *
448 * This happens when we've just processed our
449 * COOKIE-ECHO chunk.
450 */
451 if (NULL == chunk->asoc) {
452 asoc = sctp_endpoint_lookup_assoc(ep,
453 sctp_source(chunk),
454 &transport);
455 chunk->asoc = asoc;
456 chunk->transport = transport;
457 }
458
459 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700460 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
461 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
463 /* Remember where the last DATA chunk came from so we
464 * know where to send the SACK.
465 */
466 if (asoc && sctp_chunk_is_data(chunk))
467 asoc->peer.last_data_from = chunk->transport;
468 else
469 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
470
471 if (chunk->transport)
472 chunk->transport->last_time_heard = jiffies;
473
474 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900475 ep, asoc, chunk, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477 if (error && chunk)
478 chunk->pdiscard = 1;
479
480 /* Check to see if the endpoint is freed in response to
481 * the incoming chunk. If so, get out of the while loop.
482 */
483 if (!sctp_sk(sk)->ep)
484 break;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700485
486 if (first_time)
487 first_time = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 }
489}