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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, | |
3182cd84 | 70 | struct sock *sk, |
dd0fc66f | 71 | gfp_t gfp) |
1da177e4 | 72 | { |
1da177e4 LT |
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 | ||
1da177e4 | 102 | /* Use SCTP specific send buffer space queues. */ |
4eb701df | 103 | ep->sndbuf_policy = sctp_sndbuf_policy; |
1da177e4 LT |
104 | sk->sk_write_space = sctp_write_space; |
105 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
106 | ||
049b3ff5 NH |
107 | /* Get the receive buffer policy for this endpoint */ |
108 | ep->rcvbuf_policy = sctp_rcvbuf_policy; | |
109 | ||
1da177e4 LT |
110 | /* 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 | ||
1da177e4 LT |
115 | 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 | */ | |
dd0fc66f | 121 | struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp) |
1da177e4 LT |
122 | { |
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 | ||
135 | fail_init: | |
136 | kfree(ep); | |
137 | fail: | |
138 | return NULL; | |
139 | } | |
140 | ||
141 | /* Add an association to an endpoint. */ | |
142 | void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, | |
143 | struct sctp_association *asoc) | |
144 | { | |
145 | struct sock *sk = ep->base.sk; | |
146 | ||
de76e695 VY |
147 | /* If this is a temporary association, don't bother |
148 | * since we'll be removing it shortly and don't | |
149 | * want anyone to find it anyway. | |
150 | */ | |
151 | if (asoc->temp) | |
152 | return; | |
153 | ||
1da177e4 LT |
154 | /* Now just add it to our list of asocs */ |
155 | list_add_tail(&asoc->asocs, &ep->asocs); | |
156 | ||
157 | /* Increment the backlog value for a TCP-style listening socket. */ | |
158 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) | |
159 | sk->sk_ack_backlog++; | |
160 | } | |
161 | ||
162 | /* Free the endpoint structure. Delay cleanup until | |
163 | * all users have released their reference count on this structure. | |
164 | */ | |
165 | void sctp_endpoint_free(struct sctp_endpoint *ep) | |
166 | { | |
167 | ep->base.dead = 1; | |
cfdeef32 VY |
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 | ||
1da177e4 LT |
174 | sctp_endpoint_put(ep); |
175 | } | |
176 | ||
177 | /* Final destructor for endpoint. */ | |
178 | static void sctp_endpoint_destroy(struct sctp_endpoint *ep) | |
179 | { | |
180 | SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); | |
181 | ||
1da177e4 | 182 | /* Free up the HMAC transform. */ |
1b489e11 | 183 | crypto_free_hash(sctp_sk(ep->base.sk)->hmac); |
1da177e4 LT |
184 | |
185 | /* Cleanup. */ | |
186 | sctp_inq_free(&ep->base.inqueue); | |
187 | sctp_bind_addr_free(&ep->base.bind_addr); | |
188 | ||
189 | /* Remove and free the port */ | |
190 | if (sctp_sk(ep->base.sk)->bind_hash) | |
191 | sctp_put_port(ep->base.sk); | |
192 | ||
193 | /* Give up our hold on the sock. */ | |
194 | if (ep->base.sk) | |
195 | sock_put(ep->base.sk); | |
196 | ||
197 | /* Finally, free up our memory. */ | |
198 | if (ep->base.malloced) { | |
199 | kfree(ep); | |
200 | SCTP_DBG_OBJCNT_DEC(ep); | |
201 | } | |
202 | } | |
203 | ||
204 | /* Hold a reference to an endpoint. */ | |
205 | void sctp_endpoint_hold(struct sctp_endpoint *ep) | |
206 | { | |
207 | atomic_inc(&ep->base.refcnt); | |
208 | } | |
209 | ||
210 | /* Release a reference to an endpoint and clean up if there are | |
211 | * no more references. | |
212 | */ | |
213 | void sctp_endpoint_put(struct sctp_endpoint *ep) | |
214 | { | |
215 | if (atomic_dec_and_test(&ep->base.refcnt)) | |
216 | sctp_endpoint_destroy(ep); | |
217 | } | |
218 | ||
219 | /* Is this the endpoint we are looking for? */ | |
220 | struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, | |
221 | const union sctp_addr *laddr) | |
222 | { | |
223 | struct sctp_endpoint *retval; | |
224 | ||
225 | sctp_read_lock(&ep->base.addr_lock); | |
226 | if (ep->base.bind_addr.port == laddr->v4.sin_port) { | |
227 | if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, | |
228 | sctp_sk(ep->base.sk))) { | |
229 | retval = ep; | |
230 | goto out; | |
231 | } | |
232 | } | |
233 | ||
234 | retval = NULL; | |
235 | ||
236 | out: | |
237 | sctp_read_unlock(&ep->base.addr_lock); | |
238 | return retval; | |
239 | } | |
240 | ||
241 | /* Find the association that goes with this chunk. | |
242 | * We do a linear search of the associations for this endpoint. | |
243 | * We return the matching transport address too. | |
244 | */ | |
245 | static struct sctp_association *__sctp_endpoint_lookup_assoc( | |
246 | const struct sctp_endpoint *ep, | |
247 | const union sctp_addr *paddr, | |
248 | struct sctp_transport **transport) | |
249 | { | |
250 | int rport; | |
251 | struct sctp_association *asoc; | |
252 | struct list_head *pos; | |
253 | ||
254 | rport = paddr->v4.sin_port; | |
255 | ||
256 | list_for_each(pos, &ep->asocs) { | |
257 | asoc = list_entry(pos, struct sctp_association, asocs); | |
258 | if (rport == asoc->peer.port) { | |
259 | sctp_read_lock(&asoc->base.addr_lock); | |
260 | *transport = sctp_assoc_lookup_paddr(asoc, paddr); | |
261 | sctp_read_unlock(&asoc->base.addr_lock); | |
262 | ||
263 | if (*transport) | |
264 | return asoc; | |
265 | } | |
266 | } | |
267 | ||
268 | *transport = NULL; | |
269 | return NULL; | |
270 | } | |
271 | ||
272 | /* Lookup association on an endpoint based on a peer address. BH-safe. */ | |
273 | struct sctp_association *sctp_endpoint_lookup_assoc( | |
274 | const struct sctp_endpoint *ep, | |
275 | const union sctp_addr *paddr, | |
276 | struct sctp_transport **transport) | |
277 | { | |
278 | struct sctp_association *asoc; | |
279 | ||
280 | sctp_local_bh_disable(); | |
281 | asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport); | |
282 | sctp_local_bh_enable(); | |
283 | ||
284 | return asoc; | |
285 | } | |
286 | ||
287 | /* Look for any peeled off association from the endpoint that matches the | |
288 | * given peer address. | |
289 | */ | |
290 | int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, | |
291 | const union sctp_addr *paddr) | |
292 | { | |
293 | struct list_head *pos; | |
294 | struct sctp_sockaddr_entry *addr; | |
295 | struct sctp_bind_addr *bp; | |
296 | ||
297 | sctp_read_lock(&ep->base.addr_lock); | |
298 | bp = &ep->base.bind_addr; | |
299 | list_for_each(pos, &bp->address_list) { | |
300 | addr = list_entry(pos, struct sctp_sockaddr_entry, list); | |
301 | if (sctp_has_association(&addr->a, paddr)) { | |
302 | sctp_read_unlock(&ep->base.addr_lock); | |
303 | return 1; | |
304 | } | |
305 | } | |
306 | sctp_read_unlock(&ep->base.addr_lock); | |
307 | ||
308 | return 0; | |
309 | } | |
310 | ||
311 | /* Do delayed input processing. This is scheduled by sctp_rcv(). | |
312 | * This may be called on BH or task time. | |
313 | */ | |
314 | static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep) | |
315 | { | |
316 | struct sctp_association *asoc; | |
317 | struct sock *sk; | |
318 | struct sctp_transport *transport; | |
319 | struct sctp_chunk *chunk; | |
320 | struct sctp_inq *inqueue; | |
321 | sctp_subtype_t subtype; | |
322 | sctp_state_t state; | |
323 | int error = 0; | |
324 | ||
325 | if (ep->base.dead) | |
326 | return; | |
327 | ||
328 | asoc = NULL; | |
329 | inqueue = &ep->base.inqueue; | |
330 | sk = ep->base.sk; | |
331 | ||
332 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { | |
333 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); | |
334 | ||
335 | /* We might have grown an association since last we | |
336 | * looked, so try again. | |
337 | * | |
338 | * This happens when we've just processed our | |
339 | * COOKIE-ECHO chunk. | |
340 | */ | |
341 | if (NULL == chunk->asoc) { | |
342 | asoc = sctp_endpoint_lookup_assoc(ep, | |
343 | sctp_source(chunk), | |
344 | &transport); | |
345 | chunk->asoc = asoc; | |
346 | chunk->transport = transport; | |
347 | } | |
348 | ||
349 | state = asoc ? asoc->state : SCTP_STATE_CLOSED; | |
350 | ||
351 | /* Remember where the last DATA chunk came from so we | |
352 | * know where to send the SACK. | |
353 | */ | |
354 | if (asoc && sctp_chunk_is_data(chunk)) | |
355 | asoc->peer.last_data_from = chunk->transport; | |
356 | else | |
357 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); | |
358 | ||
359 | if (chunk->transport) | |
360 | chunk->transport->last_time_heard = jiffies; | |
361 | ||
362 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state, | |
363 | ep, asoc, chunk, GFP_ATOMIC); | |
364 | ||
365 | if (error && chunk) | |
366 | chunk->pdiscard = 1; | |
367 | ||
368 | /* Check to see if the endpoint is freed in response to | |
369 | * the incoming chunk. If so, get out of the while loop. | |
370 | */ | |
371 | if (!sctp_sk(sk)->ep) | |
372 | break; | |
373 | } | |
374 | } |