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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
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 | * | |
60c778b2 | 9 | * This file is part of the SCTP kernel implementation |
1da177e4 LT |
10 | * |
11 | * This abstraction represents an SCTP endpoint. | |
12 | * | |
60c778b2 | 13 | * The SCTP implementation is free software; |
1da177e4 LT |
14 | * 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 | * | |
60c778b2 | 19 | * The SCTP implementation is distributed in the hope that it |
1da177e4 LT |
20 | * 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 | |
4b2f13a2 JK |
26 | * along with GNU CC; see the file COPYING. If not, see |
27 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
28 | * |
29 | * Please send any bug reports or fixes you make to the | |
30 | * email address(es): | |
91705c61 | 31 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 32 | * |
1da177e4 LT |
33 | * Written or modified by: |
34 | * La Monte H.P. Yarroll <piggy@acm.org> | |
35 | * Karl Knutson <karl@athena.chicago.il.us> | |
36 | * Jon Grimm <jgrimm@austin.ibm.com> | |
37 | * Daisy Chang <daisyc@us.ibm.com> | |
38 | * Dajiang Zhang <dajiang.zhang@nokia.com> | |
1da177e4 LT |
39 | */ |
40 | ||
41 | #include <linux/types.h> | |
1da177e4 LT |
42 | #include <linux/slab.h> |
43 | #include <linux/in.h> | |
44 | #include <linux/random.h> /* get_random_bytes() */ | |
1da177e4 LT |
45 | #include <net/sock.h> |
46 | #include <net/ipv6.h> | |
47 | #include <net/sctp/sctp.h> | |
48 | #include <net/sctp/sm.h> | |
49 | ||
50 | /* Forward declarations for internal helpers. */ | |
c4028958 | 51 | static void sctp_endpoint_bh_rcv(struct work_struct *work); |
1da177e4 LT |
52 | |
53 | /* | |
54 | * Initialize the base fields of the endpoint structure. | |
55 | */ | |
56 | static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep, | |
3182cd84 | 57 | struct sock *sk, |
dd0fc66f | 58 | gfp_t gfp) |
1da177e4 | 59 | { |
e1fc3b14 | 60 | struct net *net = sock_net(sk); |
a29a5bd4 VY |
61 | struct sctp_hmac_algo_param *auth_hmacs = NULL; |
62 | struct sctp_chunks_param *auth_chunks = NULL; | |
63 | struct sctp_shared_key *null_key; | |
64 | int err; | |
65 | ||
b68dbcab VY |
66 | ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp); |
67 | if (!ep->digest) | |
68 | return NULL; | |
69 | ||
b14878cc VY |
70 | ep->auth_enable = net->sctp.auth_enable; |
71 | if (ep->auth_enable) { | |
a29a5bd4 VY |
72 | /* Allocate space for HMACS and CHUNKS authentication |
73 | * variables. There are arrays that we encode directly | |
74 | * into parameters to make the rest of the operations easier. | |
75 | */ | |
76 | auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) + | |
77 | sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp); | |
78 | if (!auth_hmacs) | |
79 | goto nomem; | |
80 | ||
81 | auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) + | |
82 | SCTP_NUM_CHUNK_TYPES, gfp); | |
83 | if (!auth_chunks) | |
84 | goto nomem; | |
85 | ||
86 | /* Initialize the HMACS parameter. | |
87 | * SCTP-AUTH: Section 3.3 | |
88 | * Every endpoint supporting SCTP chunk authentication MUST | |
89 | * support the HMAC based on the SHA-1 algorithm. | |
90 | */ | |
91 | auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO; | |
92 | auth_hmacs->param_hdr.length = | |
93 | htons(sizeof(sctp_paramhdr_t) + 2); | |
94 | auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1); | |
95 | ||
96 | /* Initialize the CHUNKS parameter */ | |
97 | auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS; | |
5e739d17 | 98 | auth_chunks->param_hdr.length = htons(sizeof(sctp_paramhdr_t)); |
a29a5bd4 VY |
99 | |
100 | /* If the Add-IP functionality is enabled, we must | |
101 | * authenticate, ASCONF and ASCONF-ACK chunks | |
102 | */ | |
e1fc3b14 | 103 | if (net->sctp.addip_enable) { |
a29a5bd4 VY |
104 | auth_chunks->chunks[0] = SCTP_CID_ASCONF; |
105 | auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK; | |
cb0dc77d AV |
106 | auth_chunks->param_hdr.length = |
107 | htons(sizeof(sctp_paramhdr_t) + 2); | |
a29a5bd4 VY |
108 | } |
109 | } | |
110 | ||
1da177e4 LT |
111 | /* Initialize the base structure. */ |
112 | /* What type of endpoint are we? */ | |
113 | ep->base.type = SCTP_EP_TYPE_SOCKET; | |
114 | ||
115 | /* Initialize the basic object fields. */ | |
116 | atomic_set(&ep->base.refcnt, 1); | |
0022d2dd | 117 | ep->base.dead = false; |
1da177e4 LT |
118 | |
119 | /* Create an input queue. */ | |
120 | sctp_inq_init(&ep->base.inqueue); | |
121 | ||
122 | /* Set its top-half handler */ | |
c4028958 | 123 | sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv); |
1da177e4 LT |
124 | |
125 | /* Initialize the bind addr area */ | |
126 | sctp_bind_addr_init(&ep->base.bind_addr, 0); | |
1da177e4 LT |
127 | |
128 | /* Remember who we are attached to. */ | |
129 | ep->base.sk = sk; | |
130 | sock_hold(ep->base.sk); | |
131 | ||
132 | /* Create the lists of associations. */ | |
133 | INIT_LIST_HEAD(&ep->asocs); | |
134 | ||
1da177e4 | 135 | /* Use SCTP specific send buffer space queues. */ |
e1fc3b14 | 136 | ep->sndbuf_policy = net->sctp.sndbuf_policy; |
4d93df0a | 137 | |
561b1733 | 138 | sk->sk_data_ready = sctp_data_ready; |
1da177e4 LT |
139 | sk->sk_write_space = sctp_write_space; |
140 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
141 | ||
049b3ff5 | 142 | /* Get the receive buffer policy for this endpoint */ |
e1fc3b14 | 143 | ep->rcvbuf_policy = net->sctp.rcvbuf_policy; |
049b3ff5 | 144 | |
1da177e4 | 145 | /* Initialize the secret key used with cookie. */ |
570617e7 | 146 | get_random_bytes(ep->secret_key, sizeof(ep->secret_key)); |
1da177e4 | 147 | |
a29a5bd4 VY |
148 | /* SCTP-AUTH extensions*/ |
149 | INIT_LIST_HEAD(&ep->endpoint_shared_keys); | |
81ce0dbc | 150 | null_key = sctp_auth_shkey_create(0, gfp); |
a29a5bd4 VY |
151 | if (!null_key) |
152 | goto nomem; | |
153 | ||
154 | list_add(&null_key->key_list, &ep->endpoint_shared_keys); | |
155 | ||
02582e9b | 156 | /* Allocate and initialize transorms arrays for supported HMACs. */ |
a29a5bd4 VY |
157 | err = sctp_auth_init_hmacs(ep, gfp); |
158 | if (err) | |
159 | goto nomem_hmacs; | |
160 | ||
161 | /* Add the null key to the endpoint shared keys list and | |
162 | * set the hmcas and chunks pointers. | |
163 | */ | |
164 | ep->auth_hmacs_list = auth_hmacs; | |
165 | ep->auth_chunk_list = auth_chunks; | |
28aa4c26 | 166 | ep->prsctp_enable = net->sctp.prsctp_enable; |
a29a5bd4 | 167 | |
1da177e4 | 168 | return ep; |
a29a5bd4 VY |
169 | |
170 | nomem_hmacs: | |
171 | sctp_auth_destroy_keys(&ep->endpoint_shared_keys); | |
172 | nomem: | |
173 | /* Free all allocations */ | |
174 | kfree(auth_hmacs); | |
175 | kfree(auth_chunks); | |
176 | kfree(ep->digest); | |
177 | return NULL; | |
178 | ||
1da177e4 LT |
179 | } |
180 | ||
181 | /* Create a sctp_endpoint with all that boring stuff initialized. | |
182 | * Returns NULL if there isn't enough memory. | |
183 | */ | |
dd0fc66f | 184 | struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp) |
1da177e4 LT |
185 | { |
186 | struct sctp_endpoint *ep; | |
187 | ||
188 | /* Build a local endpoint. */ | |
939cfa75 | 189 | ep = kzalloc(sizeof(*ep), gfp); |
1da177e4 LT |
190 | if (!ep) |
191 | goto fail; | |
939cfa75 | 192 | |
1da177e4 LT |
193 | if (!sctp_endpoint_init(ep, sk, gfp)) |
194 | goto fail_init; | |
ff2266cd | 195 | |
1da177e4 LT |
196 | SCTP_DBG_OBJCNT_INC(ep); |
197 | return ep; | |
198 | ||
199 | fail_init: | |
200 | kfree(ep); | |
201 | fail: | |
202 | return NULL; | |
203 | } | |
204 | ||
205 | /* Add an association to an endpoint. */ | |
206 | void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, | |
207 | struct sctp_association *asoc) | |
208 | { | |
209 | struct sock *sk = ep->base.sk; | |
210 | ||
de76e695 VY |
211 | /* If this is a temporary association, don't bother |
212 | * since we'll be removing it shortly and don't | |
213 | * want anyone to find it anyway. | |
214 | */ | |
215 | if (asoc->temp) | |
216 | return; | |
217 | ||
1da177e4 LT |
218 | /* Now just add it to our list of asocs */ |
219 | list_add_tail(&asoc->asocs, &ep->asocs); | |
220 | ||
221 | /* Increment the backlog value for a TCP-style listening socket. */ | |
222 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
223 | sk->sk_ack_backlog++; | |
224 | } | |
225 | ||
226 | /* Free the endpoint structure. Delay cleanup until | |
227 | * all users have released their reference count on this structure. | |
228 | */ | |
229 | void sctp_endpoint_free(struct sctp_endpoint *ep) | |
230 | { | |
0022d2dd | 231 | ep->base.dead = true; |
cfdeef32 VY |
232 | |
233 | ep->base.sk->sk_state = SCTP_SS_CLOSED; | |
234 | ||
235 | /* Unlink this endpoint, so we can't find it again! */ | |
236 | sctp_unhash_endpoint(ep); | |
237 | ||
1da177e4 LT |
238 | sctp_endpoint_put(ep); |
239 | } | |
240 | ||
241 | /* Final destructor for endpoint. */ | |
242 | static void sctp_endpoint_destroy(struct sctp_endpoint *ep) | |
243 | { | |
0a2fbac1 | 244 | struct sock *sk; |
1da177e4 | 245 | |
bb33381d DB |
246 | if (unlikely(!ep->base.dead)) { |
247 | WARN(1, "Attempt to destroy undead endpoint %p!\n", ep); | |
248 | return; | |
249 | } | |
1da177e4 | 250 | |
b68dbcab VY |
251 | /* Free the digest buffer */ |
252 | kfree(ep->digest); | |
253 | ||
a29a5bd4 VY |
254 | /* SCTP-AUTH: Free up AUTH releated data such as shared keys |
255 | * chunks and hmacs arrays that were allocated | |
256 | */ | |
257 | sctp_auth_destroy_keys(&ep->endpoint_shared_keys); | |
258 | kfree(ep->auth_hmacs_list); | |
259 | kfree(ep->auth_chunk_list); | |
260 | ||
261 | /* AUTH - Free any allocated HMAC transform containers */ | |
262 | sctp_auth_destroy_hmacs(ep->auth_hmacs); | |
263 | ||
1da177e4 LT |
264 | /* Cleanup. */ |
265 | sctp_inq_free(&ep->base.inqueue); | |
266 | sctp_bind_addr_free(&ep->base.bind_addr); | |
267 | ||
570617e7 | 268 | memset(ep->secret_key, 0, sizeof(ep->secret_key)); |
b5c37fe6 | 269 | |
1da177e4 | 270 | /* Give up our hold on the sock. */ |
0a2fbac1 DB |
271 | sk = ep->base.sk; |
272 | if (sk != NULL) { | |
273 | /* Remove and free the port */ | |
274 | if (sctp_sk(sk)->bind_hash) | |
275 | sctp_put_port(sk); | |
276 | ||
277 | sock_put(sk); | |
278 | } | |
1da177e4 | 279 | |
ff2266cd DB |
280 | kfree(ep); |
281 | SCTP_DBG_OBJCNT_DEC(ep); | |
1da177e4 LT |
282 | } |
283 | ||
284 | /* Hold a reference to an endpoint. */ | |
285 | void sctp_endpoint_hold(struct sctp_endpoint *ep) | |
286 | { | |
287 | atomic_inc(&ep->base.refcnt); | |
288 | } | |
289 | ||
290 | /* Release a reference to an endpoint and clean up if there are | |
291 | * no more references. | |
292 | */ | |
293 | void sctp_endpoint_put(struct sctp_endpoint *ep) | |
294 | { | |
295 | if (atomic_dec_and_test(&ep->base.refcnt)) | |
296 | sctp_endpoint_destroy(ep); | |
297 | } | |
298 | ||
299 | /* Is this the endpoint we are looking for? */ | |
300 | struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, | |
4cdadcbc | 301 | struct net *net, |
1da177e4 LT |
302 | const union sctp_addr *laddr) |
303 | { | |
559cf710 | 304 | struct sctp_endpoint *retval = NULL; |
1da177e4 | 305 | |
4cdadcbc EB |
306 | if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) && |
307 | net_eq(sock_net(ep->base.sk), net)) { | |
1da177e4 | 308 | if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, |
559cf710 | 309 | sctp_sk(ep->base.sk))) |
1da177e4 | 310 | retval = ep; |
1da177e4 LT |
311 | } |
312 | ||
1da177e4 LT |
313 | return retval; |
314 | } | |
315 | ||
316 | /* Find the association that goes with this chunk. | |
4f008781 XL |
317 | * We lookup the transport from hashtable at first, then get association |
318 | * through t->assoc. | |
1da177e4 | 319 | */ |
c79c0666 | 320 | struct sctp_association *sctp_endpoint_lookup_assoc( |
1da177e4 LT |
321 | const struct sctp_endpoint *ep, |
322 | const union sctp_addr *paddr, | |
323 | struct sctp_transport **transport) | |
324 | { | |
123ed979 | 325 | struct sctp_association *asoc = NULL; |
4f008781 | 326 | struct sctp_transport *t; |
1da177e4 | 327 | |
123ed979 | 328 | *transport = NULL; |
deb85a6e VY |
329 | |
330 | /* If the local port is not set, there can't be any associations | |
331 | * on this endpoint. | |
332 | */ | |
333 | if (!ep->base.bind_addr.port) | |
5cb2cd68 XL |
334 | return NULL; |
335 | ||
336 | rcu_read_lock(); | |
4f008781 | 337 | t = sctp_epaddr_lookup_transport(ep, paddr); |
dd7445ad | 338 | if (!t) |
4f008781 | 339 | goto out; |
deb85a6e | 340 | |
4f008781 XL |
341 | *transport = t; |
342 | asoc = t->asoc; | |
deb85a6e | 343 | out: |
5cb2cd68 | 344 | rcu_read_unlock(); |
123ed979 | 345 | return asoc; |
1da177e4 LT |
346 | } |
347 | ||
1da177e4 LT |
348 | /* Look for any peeled off association from the endpoint that matches the |
349 | * given peer address. | |
350 | */ | |
351 | int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, | |
352 | const union sctp_addr *paddr) | |
353 | { | |
1da177e4 LT |
354 | struct sctp_sockaddr_entry *addr; |
355 | struct sctp_bind_addr *bp; | |
4110cc25 | 356 | struct net *net = sock_net(ep->base.sk); |
1da177e4 | 357 | |
1da177e4 | 358 | bp = &ep->base.bind_addr; |
559cf710 VY |
359 | /* This function is called with the socket lock held, |
360 | * so the address_list can not change. | |
361 | */ | |
362 | list_for_each_entry(addr, &bp->address_list, list) { | |
4110cc25 | 363 | if (sctp_has_association(net, &addr->a, paddr)) |
1da177e4 | 364 | return 1; |
1da177e4 | 365 | } |
1da177e4 LT |
366 | |
367 | return 0; | |
368 | } | |
369 | ||
370 | /* Do delayed input processing. This is scheduled by sctp_rcv(). | |
371 | * This may be called on BH or task time. | |
372 | */ | |
c4028958 | 373 | static void sctp_endpoint_bh_rcv(struct work_struct *work) |
1da177e4 | 374 | { |
c4028958 DH |
375 | struct sctp_endpoint *ep = |
376 | container_of(work, struct sctp_endpoint, | |
377 | base.inqueue.immediate); | |
1da177e4 LT |
378 | struct sctp_association *asoc; |
379 | struct sock *sk; | |
55e26eb9 | 380 | struct net *net; |
1da177e4 LT |
381 | struct sctp_transport *transport; |
382 | struct sctp_chunk *chunk; | |
383 | struct sctp_inq *inqueue; | |
384 | sctp_subtype_t subtype; | |
385 | sctp_state_t state; | |
386 | int error = 0; | |
42b2aa86 | 387 | int first_time = 1; /* is this the first time through the loop */ |
1da177e4 LT |
388 | |
389 | if (ep->base.dead) | |
390 | return; | |
391 | ||
392 | asoc = NULL; | |
393 | inqueue = &ep->base.inqueue; | |
394 | sk = ep->base.sk; | |
55e26eb9 | 395 | net = sock_net(sk); |
1da177e4 LT |
396 | |
397 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
398 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
399 | ||
bbd0d598 VY |
400 | /* If the first chunk in the packet is AUTH, do special |
401 | * processing specified in Section 6.3 of SCTP-AUTH spec | |
402 | */ | |
403 | if (first_time && (subtype.chunk == SCTP_CID_AUTH)) { | |
404 | struct sctp_chunkhdr *next_hdr; | |
405 | ||
406 | next_hdr = sctp_inq_peek(inqueue); | |
407 | if (!next_hdr) | |
408 | goto normal; | |
409 | ||
410 | /* If the next chunk is COOKIE-ECHO, skip the AUTH | |
411 | * chunk while saving a pointer to it so we can do | |
412 | * Authentication later (during cookie-echo | |
413 | * processing). | |
414 | */ | |
415 | if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { | |
416 | chunk->auth_chunk = skb_clone(chunk->skb, | |
417 | GFP_ATOMIC); | |
418 | chunk->auth = 1; | |
419 | continue; | |
420 | } | |
421 | } | |
422 | normal: | |
1da177e4 LT |
423 | /* We might have grown an association since last we |
424 | * looked, so try again. | |
425 | * | |
426 | * This happens when we've just processed our | |
427 | * COOKIE-ECHO chunk. | |
428 | */ | |
429 | if (NULL == chunk->asoc) { | |
430 | asoc = sctp_endpoint_lookup_assoc(ep, | |
431 | sctp_source(chunk), | |
432 | &transport); | |
433 | chunk->asoc = asoc; | |
434 | chunk->transport = transport; | |
435 | } | |
436 | ||
437 | state = asoc ? asoc->state : SCTP_STATE_CLOSED; | |
bbd0d598 VY |
438 | if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) |
439 | continue; | |
1da177e4 LT |
440 | |
441 | /* Remember where the last DATA chunk came from so we | |
442 | * know where to send the SACK. | |
443 | */ | |
444 | if (asoc && sctp_chunk_is_data(chunk)) | |
445 | asoc->peer.last_data_from = chunk->transport; | |
196d6759 | 446 | else { |
b01a2407 | 447 | SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS); |
196d6759 MB |
448 | if (asoc) |
449 | asoc->stats.ictrlchunks++; | |
450 | } | |
1da177e4 LT |
451 | |
452 | if (chunk->transport) | |
e575235f | 453 | chunk->transport->last_time_heard = ktime_get(); |
1da177e4 | 454 | |
55e26eb9 | 455 | error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state, |
d808ad9a | 456 | ep, asoc, chunk, GFP_ATOMIC); |
1da177e4 LT |
457 | |
458 | if (error && chunk) | |
459 | chunk->pdiscard = 1; | |
460 | ||
461 | /* Check to see if the endpoint is freed in response to | |
462 | * the incoming chunk. If so, get out of the while loop. | |
463 | */ | |
464 | if (!sctp_sk(sk)->ep) | |
465 | break; | |
bbd0d598 VY |
466 | |
467 | if (first_time) | |
468 | first_time = 0; | |
1da177e4 LT |
469 | } |
470 | } |