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1da177e4 LT |
1 | /* 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. */ | |
64 | static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep); | |
65 | ||
66 | /* | |
67 | * Initialize the base fields of the endpoint structure. | |
68 | */ | |
69 | static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep, | |
70 | struct sock *sk, int gfp) | |
71 | { | |
72 | struct sctp_sock *sp = sctp_sk(sk); | |
73 | 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 | ||
102 | /* Set up the base timeout information. */ | |
103 | ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0; | |
104 | ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = | |
105 | SCTP_DEFAULT_TIMEOUT_T1_COOKIE; | |
106 | ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = | |
107 | SCTP_DEFAULT_TIMEOUT_T1_INIT; | |
108 | ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = | |
109 | msecs_to_jiffies(sp->rtoinfo.srto_initial); | |
110 | ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0; | |
111 | ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0; | |
112 | ||
113 | /* sctpimpguide-05 Section 2.12.2 | |
114 | * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the | |
115 | * recommended value of 5 times 'RTO.Max'. | |
116 | */ | |
117 | ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] | |
118 | = 5 * msecs_to_jiffies(sp->rtoinfo.srto_max); | |
119 | ||
120 | ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = | |
121 | SCTP_DEFAULT_TIMEOUT_HEARTBEAT; | |
122 | ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] = | |
123 | SCTP_DEFAULT_TIMEOUT_SACK; | |
124 | ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = | |
125 | sp->autoclose * HZ; | |
126 | ||
127 | /* Use SCTP specific send buffer space queues. */ | |
4eb701df | 128 | ep->sndbuf_policy = sctp_sndbuf_policy; |
1da177e4 LT |
129 | sk->sk_write_space = sctp_write_space; |
130 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
131 | ||
132 | /* Initialize the secret key used with cookie. */ | |
133 | get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE); | |
134 | ep->last_key = ep->current_key = 0; | |
135 | ep->key_changed_at = jiffies; | |
136 | ||
1da177e4 LT |
137 | return ep; |
138 | } | |
139 | ||
140 | /* Create a sctp_endpoint with all that boring stuff initialized. | |
141 | * Returns NULL if there isn't enough memory. | |
142 | */ | |
143 | struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, int gfp) | |
144 | { | |
145 | struct sctp_endpoint *ep; | |
146 | ||
147 | /* Build a local endpoint. */ | |
148 | ep = t_new(struct sctp_endpoint, gfp); | |
149 | if (!ep) | |
150 | goto fail; | |
151 | if (!sctp_endpoint_init(ep, sk, gfp)) | |
152 | goto fail_init; | |
153 | ep->base.malloced = 1; | |
154 | SCTP_DBG_OBJCNT_INC(ep); | |
155 | return ep; | |
156 | ||
157 | fail_init: | |
158 | kfree(ep); | |
159 | fail: | |
160 | return NULL; | |
161 | } | |
162 | ||
163 | /* Add an association to an endpoint. */ | |
164 | void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, | |
165 | struct sctp_association *asoc) | |
166 | { | |
167 | struct sock *sk = ep->base.sk; | |
168 | ||
169 | /* Now just add it to our list of asocs */ | |
170 | list_add_tail(&asoc->asocs, &ep->asocs); | |
171 | ||
172 | /* Increment the backlog value for a TCP-style listening socket. */ | |
173 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
174 | sk->sk_ack_backlog++; | |
175 | } | |
176 | ||
177 | /* Free the endpoint structure. Delay cleanup until | |
178 | * all users have released their reference count on this structure. | |
179 | */ | |
180 | void sctp_endpoint_free(struct sctp_endpoint *ep) | |
181 | { | |
182 | ep->base.dead = 1; | |
183 | sctp_endpoint_put(ep); | |
184 | } | |
185 | ||
186 | /* Final destructor for endpoint. */ | |
187 | static void sctp_endpoint_destroy(struct sctp_endpoint *ep) | |
188 | { | |
189 | SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); | |
190 | ||
191 | ep->base.sk->sk_state = SCTP_SS_CLOSED; | |
192 | ||
193 | /* Unlink this endpoint, so we can't find it again! */ | |
194 | sctp_unhash_endpoint(ep); | |
195 | ||
196 | /* Free up the HMAC transform. */ | |
197 | if (sctp_sk(ep->base.sk)->hmac) | |
198 | sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac); | |
199 | ||
200 | /* Cleanup. */ | |
201 | sctp_inq_free(&ep->base.inqueue); | |
202 | sctp_bind_addr_free(&ep->base.bind_addr); | |
203 | ||
204 | /* Remove and free the port */ | |
205 | if (sctp_sk(ep->base.sk)->bind_hash) | |
206 | sctp_put_port(ep->base.sk); | |
207 | ||
208 | /* Give up our hold on the sock. */ | |
209 | if (ep->base.sk) | |
210 | sock_put(ep->base.sk); | |
211 | ||
212 | /* Finally, free up our memory. */ | |
213 | if (ep->base.malloced) { | |
214 | kfree(ep); | |
215 | SCTP_DBG_OBJCNT_DEC(ep); | |
216 | } | |
217 | } | |
218 | ||
219 | /* Hold a reference to an endpoint. */ | |
220 | void sctp_endpoint_hold(struct sctp_endpoint *ep) | |
221 | { | |
222 | atomic_inc(&ep->base.refcnt); | |
223 | } | |
224 | ||
225 | /* Release a reference to an endpoint and clean up if there are | |
226 | * no more references. | |
227 | */ | |
228 | void sctp_endpoint_put(struct sctp_endpoint *ep) | |
229 | { | |
230 | if (atomic_dec_and_test(&ep->base.refcnt)) | |
231 | sctp_endpoint_destroy(ep); | |
232 | } | |
233 | ||
234 | /* Is this the endpoint we are looking for? */ | |
235 | struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, | |
236 | const union sctp_addr *laddr) | |
237 | { | |
238 | struct sctp_endpoint *retval; | |
239 | ||
240 | sctp_read_lock(&ep->base.addr_lock); | |
241 | if (ep->base.bind_addr.port == laddr->v4.sin_port) { | |
242 | if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, | |
243 | sctp_sk(ep->base.sk))) { | |
244 | retval = ep; | |
245 | goto out; | |
246 | } | |
247 | } | |
248 | ||
249 | retval = NULL; | |
250 | ||
251 | out: | |
252 | sctp_read_unlock(&ep->base.addr_lock); | |
253 | return retval; | |
254 | } | |
255 | ||
256 | /* Find the association that goes with this chunk. | |
257 | * We do a linear search of the associations for this endpoint. | |
258 | * We return the matching transport address too. | |
259 | */ | |
260 | static struct sctp_association *__sctp_endpoint_lookup_assoc( | |
261 | const struct sctp_endpoint *ep, | |
262 | const union sctp_addr *paddr, | |
263 | struct sctp_transport **transport) | |
264 | { | |
265 | int rport; | |
266 | struct sctp_association *asoc; | |
267 | struct list_head *pos; | |
268 | ||
269 | rport = paddr->v4.sin_port; | |
270 | ||
271 | list_for_each(pos, &ep->asocs) { | |
272 | asoc = list_entry(pos, struct sctp_association, asocs); | |
273 | if (rport == asoc->peer.port) { | |
274 | sctp_read_lock(&asoc->base.addr_lock); | |
275 | *transport = sctp_assoc_lookup_paddr(asoc, paddr); | |
276 | sctp_read_unlock(&asoc->base.addr_lock); | |
277 | ||
278 | if (*transport) | |
279 | return asoc; | |
280 | } | |
281 | } | |
282 | ||
283 | *transport = NULL; | |
284 | return NULL; | |
285 | } | |
286 | ||
287 | /* Lookup association on an endpoint based on a peer address. BH-safe. */ | |
288 | struct sctp_association *sctp_endpoint_lookup_assoc( | |
289 | const struct sctp_endpoint *ep, | |
290 | const union sctp_addr *paddr, | |
291 | struct sctp_transport **transport) | |
292 | { | |
293 | struct sctp_association *asoc; | |
294 | ||
295 | sctp_local_bh_disable(); | |
296 | asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport); | |
297 | sctp_local_bh_enable(); | |
298 | ||
299 | return asoc; | |
300 | } | |
301 | ||
302 | /* Look for any peeled off association from the endpoint that matches the | |
303 | * given peer address. | |
304 | */ | |
305 | int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, | |
306 | const union sctp_addr *paddr) | |
307 | { | |
308 | struct list_head *pos; | |
309 | struct sctp_sockaddr_entry *addr; | |
310 | struct sctp_bind_addr *bp; | |
311 | ||
312 | sctp_read_lock(&ep->base.addr_lock); | |
313 | bp = &ep->base.bind_addr; | |
314 | list_for_each(pos, &bp->address_list) { | |
315 | addr = list_entry(pos, struct sctp_sockaddr_entry, list); | |
316 | if (sctp_has_association(&addr->a, paddr)) { | |
317 | sctp_read_unlock(&ep->base.addr_lock); | |
318 | return 1; | |
319 | } | |
320 | } | |
321 | sctp_read_unlock(&ep->base.addr_lock); | |
322 | ||
323 | return 0; | |
324 | } | |
325 | ||
326 | /* Do delayed input processing. This is scheduled by sctp_rcv(). | |
327 | * This may be called on BH or task time. | |
328 | */ | |
329 | static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep) | |
330 | { | |
331 | struct sctp_association *asoc; | |
332 | struct sock *sk; | |
333 | struct sctp_transport *transport; | |
334 | struct sctp_chunk *chunk; | |
335 | struct sctp_inq *inqueue; | |
336 | sctp_subtype_t subtype; | |
337 | sctp_state_t state; | |
338 | int error = 0; | |
339 | ||
340 | if (ep->base.dead) | |
341 | return; | |
342 | ||
343 | asoc = NULL; | |
344 | inqueue = &ep->base.inqueue; | |
345 | sk = ep->base.sk; | |
346 | ||
347 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
348 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
349 | ||
350 | /* We might have grown an association since last we | |
351 | * looked, so try again. | |
352 | * | |
353 | * This happens when we've just processed our | |
354 | * COOKIE-ECHO chunk. | |
355 | */ | |
356 | if (NULL == chunk->asoc) { | |
357 | asoc = sctp_endpoint_lookup_assoc(ep, | |
358 | sctp_source(chunk), | |
359 | &transport); | |
360 | chunk->asoc = asoc; | |
361 | chunk->transport = transport; | |
362 | } | |
363 | ||
364 | state = asoc ? asoc->state : SCTP_STATE_CLOSED; | |
365 | ||
366 | /* Remember where the last DATA chunk came from so we | |
367 | * know where to send the SACK. | |
368 | */ | |
369 | if (asoc && sctp_chunk_is_data(chunk)) | |
370 | asoc->peer.last_data_from = chunk->transport; | |
371 | else | |
372 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); | |
373 | ||
374 | if (chunk->transport) | |
375 | chunk->transport->last_time_heard = jiffies; | |
376 | ||
377 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state, | |
378 | ep, asoc, chunk, GFP_ATOMIC); | |
379 | ||
380 | if (error && chunk) | |
381 | chunk->pdiscard = 1; | |
382 | ||
383 | /* Check to see if the endpoint is freed in response to | |
384 | * the incoming chunk. If so, get out of the while loop. | |
385 | */ | |
386 | if (!sctp_sk(sk)->ep) | |
387 | break; | |
388 | } | |
389 | } |