Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/net/sctp/endpointola.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 10820 byte(s)
Tag kernel26-2.6.12-alx-r9
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. */ |
128 | ep->sndbuf_policy = sctp_sndbuf_policy; |
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 | |
137 | ep->debug_name = "unnamedEndpoint"; |
138 | return ep; |
139 | } |
140 | |
141 | /* Create a sctp_endpoint with all that boring stuff initialized. |
142 | * Returns NULL if there isn't enough memory. |
143 | */ |
144 | struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, int gfp) |
145 | { |
146 | struct sctp_endpoint *ep; |
147 | |
148 | /* Build a local endpoint. */ |
149 | ep = t_new(struct sctp_endpoint, gfp); |
150 | if (!ep) |
151 | goto fail; |
152 | if (!sctp_endpoint_init(ep, sk, gfp)) |
153 | goto fail_init; |
154 | ep->base.malloced = 1; |
155 | SCTP_DBG_OBJCNT_INC(ep); |
156 | return ep; |
157 | |
158 | fail_init: |
159 | kfree(ep); |
160 | fail: |
161 | return NULL; |
162 | } |
163 | |
164 | /* Add an association to an endpoint. */ |
165 | void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, |
166 | struct sctp_association *asoc) |
167 | { |
168 | struct sock *sk = ep->base.sk; |
169 | |
170 | /* Now just add it to our list of asocs */ |
171 | list_add_tail(&asoc->asocs, &ep->asocs); |
172 | |
173 | /* Increment the backlog value for a TCP-style listening socket. */ |
174 | if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) |
175 | sk->sk_ack_backlog++; |
176 | } |
177 | |
178 | /* Free the endpoint structure. Delay cleanup until |
179 | * all users have released their reference count on this structure. |
180 | */ |
181 | void sctp_endpoint_free(struct sctp_endpoint *ep) |
182 | { |
183 | ep->base.dead = 1; |
184 | sctp_endpoint_put(ep); |
185 | } |
186 | |
187 | /* Final destructor for endpoint. */ |
188 | static void sctp_endpoint_destroy(struct sctp_endpoint *ep) |
189 | { |
190 | SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); |
191 | |
192 | ep->base.sk->sk_state = SCTP_SS_CLOSED; |
193 | |
194 | /* Unlink this endpoint, so we can't find it again! */ |
195 | sctp_unhash_endpoint(ep); |
196 | |
197 | /* Free up the HMAC transform. */ |
198 | if (sctp_sk(ep->base.sk)->hmac) |
199 | sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac); |
200 | |
201 | /* Cleanup. */ |
202 | sctp_inq_free(&ep->base.inqueue); |
203 | sctp_bind_addr_free(&ep->base.bind_addr); |
204 | |
205 | /* Remove and free the port */ |
206 | if (sctp_sk(ep->base.sk)->bind_hash) |
207 | sctp_put_port(ep->base.sk); |
208 | |
209 | /* Give up our hold on the sock. */ |
210 | if (ep->base.sk) |
211 | sock_put(ep->base.sk); |
212 | |
213 | /* Finally, free up our memory. */ |
214 | if (ep->base.malloced) { |
215 | kfree(ep); |
216 | SCTP_DBG_OBJCNT_DEC(ep); |
217 | } |
218 | } |
219 | |
220 | /* Hold a reference to an endpoint. */ |
221 | void sctp_endpoint_hold(struct sctp_endpoint *ep) |
222 | { |
223 | atomic_inc(&ep->base.refcnt); |
224 | } |
225 | |
226 | /* Release a reference to an endpoint and clean up if there are |
227 | * no more references. |
228 | */ |
229 | void sctp_endpoint_put(struct sctp_endpoint *ep) |
230 | { |
231 | if (atomic_dec_and_test(&ep->base.refcnt)) |
232 | sctp_endpoint_destroy(ep); |
233 | } |
234 | |
235 | /* Is this the endpoint we are looking for? */ |
236 | struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, |
237 | const union sctp_addr *laddr) |
238 | { |
239 | struct sctp_endpoint *retval; |
240 | |
241 | sctp_read_lock(&ep->base.addr_lock); |
242 | if (ep->base.bind_addr.port == laddr->v4.sin_port) { |
243 | if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, |
244 | sctp_sk(ep->base.sk))) { |
245 | retval = ep; |
246 | goto out; |
247 | } |
248 | } |
249 | |
250 | retval = NULL; |
251 | |
252 | out: |
253 | sctp_read_unlock(&ep->base.addr_lock); |
254 | return retval; |
255 | } |
256 | |
257 | /* Find the association that goes with this chunk. |
258 | * We do a linear search of the associations for this endpoint. |
259 | * We return the matching transport address too. |
260 | */ |
261 | static struct sctp_association *__sctp_endpoint_lookup_assoc( |
262 | const struct sctp_endpoint *ep, |
263 | const union sctp_addr *paddr, |
264 | struct sctp_transport **transport) |
265 | { |
266 | int rport; |
267 | struct sctp_association *asoc; |
268 | struct list_head *pos; |
269 | |
270 | rport = paddr->v4.sin_port; |
271 | |
272 | list_for_each(pos, &ep->asocs) { |
273 | asoc = list_entry(pos, struct sctp_association, asocs); |
274 | if (rport == asoc->peer.port) { |
275 | sctp_read_lock(&asoc->base.addr_lock); |
276 | *transport = sctp_assoc_lookup_paddr(asoc, paddr); |
277 | sctp_read_unlock(&asoc->base.addr_lock); |
278 | |
279 | if (*transport) |
280 | return asoc; |
281 | } |
282 | } |
283 | |
284 | *transport = NULL; |
285 | return NULL; |
286 | } |
287 | |
288 | /* Lookup association on an endpoint based on a peer address. BH-safe. */ |
289 | struct sctp_association *sctp_endpoint_lookup_assoc( |
290 | const struct sctp_endpoint *ep, |
291 | const union sctp_addr *paddr, |
292 | struct sctp_transport **transport) |
293 | { |
294 | struct sctp_association *asoc; |
295 | |
296 | sctp_local_bh_disable(); |
297 | asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport); |
298 | sctp_local_bh_enable(); |
299 | |
300 | return asoc; |
301 | } |
302 | |
303 | /* Look for any peeled off association from the endpoint that matches the |
304 | * given peer address. |
305 | */ |
306 | int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, |
307 | const union sctp_addr *paddr) |
308 | { |
309 | struct list_head *pos; |
310 | struct sctp_sockaddr_entry *addr; |
311 | struct sctp_bind_addr *bp; |
312 | |
313 | sctp_read_lock(&ep->base.addr_lock); |
314 | bp = &ep->base.bind_addr; |
315 | list_for_each(pos, &bp->address_list) { |
316 | addr = list_entry(pos, struct sctp_sockaddr_entry, list); |
317 | if (sctp_has_association(&addr->a, paddr)) { |
318 | sctp_read_unlock(&ep->base.addr_lock); |
319 | return 1; |
320 | } |
321 | } |
322 | sctp_read_unlock(&ep->base.addr_lock); |
323 | |
324 | return 0; |
325 | } |
326 | |
327 | /* Do delayed input processing. This is scheduled by sctp_rcv(). |
328 | * This may be called on BH or task time. |
329 | */ |
330 | static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep) |
331 | { |
332 | struct sctp_association *asoc; |
333 | struct sock *sk; |
334 | struct sctp_transport *transport; |
335 | struct sctp_chunk *chunk; |
336 | struct sctp_inq *inqueue; |
337 | sctp_subtype_t subtype; |
338 | sctp_state_t state; |
339 | int error = 0; |
340 | |
341 | if (ep->base.dead) |
342 | return; |
343 | |
344 | asoc = NULL; |
345 | inqueue = &ep->base.inqueue; |
346 | sk = ep->base.sk; |
347 | |
348 | while (NULL != (chunk = sctp_inq_pop(inqueue))) { |
349 | subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); |
350 | |
351 | /* We might have grown an association since last we |
352 | * looked, so try again. |
353 | * |
354 | * This happens when we've just processed our |
355 | * COOKIE-ECHO chunk. |
356 | */ |
357 | if (NULL == chunk->asoc) { |
358 | asoc = sctp_endpoint_lookup_assoc(ep, |
359 | sctp_source(chunk), |
360 | &transport); |
361 | chunk->asoc = asoc; |
362 | chunk->transport = transport; |
363 | } |
364 | |
365 | state = asoc ? asoc->state : SCTP_STATE_CLOSED; |
366 | |
367 | /* Remember where the last DATA chunk came from so we |
368 | * know where to send the SACK. |
369 | */ |
370 | if (asoc && sctp_chunk_is_data(chunk)) |
371 | asoc->peer.last_data_from = chunk->transport; |
372 | else |
373 | SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); |
374 | |
375 | if (chunk->transport) |
376 | chunk->transport->last_time_heard = jiffies; |
377 | |
378 | error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state, |
379 | ep, asoc, chunk, GFP_ATOMIC); |
380 | |
381 | if (error && chunk) |
382 | chunk->pdiscard = 1; |
383 | |
384 | /* Check to see if the endpoint is freed in response to |
385 | * the incoming chunk. If so, get out of the while loop. |
386 | */ |
387 | if (!sctp_sk(sk)->ep) |
388 | break; |
389 | } |
390 | } |