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, 71 unsigned int __nocast gfp) 72 { 73 struct sctp_sock *sp = sctp_sk(sk); 74 memset(ep, 0, sizeof(struct sctp_endpoint)); 75 76 /* Initialize the base structure. */ 77 /* What type of endpoint are we? */ 78 ep->base.type = SCTP_EP_TYPE_SOCKET; 79 80 /* Initialize the basic object fields. */ 81 atomic_set(&ep->base.refcnt, 1); 82 ep->base.dead = 0; 83 ep->base.malloced = 1; 84 85 /* Create an input queue. */ 86 sctp_inq_init(&ep->base.inqueue); 87 88 /* Set its top-half handler */ 89 sctp_inq_set_th_handler(&ep->base.inqueue, 90 (void (*)(void *))sctp_endpoint_bh_rcv, ep); 91 92 /* Initialize the bind addr area */ 93 sctp_bind_addr_init(&ep->base.bind_addr, 0); 94 rwlock_init(&ep->base.addr_lock); 95 96 /* Remember who we are attached to. */ 97 ep->base.sk = sk; 98 sock_hold(ep->base.sk); 99 100 /* Create the lists of associations. */ 101 INIT_LIST_HEAD(&ep->asocs); 102 103 /* Set up the base timeout information. */ 104 ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0; 105 ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = 106 msecs_to_jiffies(sp->rtoinfo.srto_initial); 107 ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = 108 msecs_to_jiffies(sp->rtoinfo.srto_initial); 109 ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = 110 msecs_to_jiffies(sp->rtoinfo.srto_initial); 111 ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0; 112 ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0; 113 114 /* sctpimpguide-05 Section 2.12.2 115 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the 116 * recommended value of 5 times 'RTO.Max'. 117 */ 118 ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] 119 = 5 * msecs_to_jiffies(sp->rtoinfo.srto_max); 120 121 ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0; 122 ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] = sctp_sack_timeout; 123 ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ; 124 125 /* Use SCTP specific send buffer space queues. */ 126 ep->sndbuf_policy = sctp_sndbuf_policy; 127 sk->sk_write_space = sctp_write_space; 128 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); 129 130 /* Initialize the secret key used with cookie. */ 131 get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE); 132 ep->last_key = ep->current_key = 0; 133 ep->key_changed_at = jiffies; 134 135 return ep; 136 } 137 138 /* Create a sctp_endpoint with all that boring stuff initialized. 139 * Returns NULL if there isn't enough memory. 140 */ 141 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, 142 unsigned int __nocast gfp) 143 { 144 struct sctp_endpoint *ep; 145 146 /* Build a local endpoint. */ 147 ep = t_new(struct sctp_endpoint, gfp); 148 if (!ep) 149 goto fail; 150 if (!sctp_endpoint_init(ep, sk, gfp)) 151 goto fail_init; 152 ep->base.malloced = 1; 153 SCTP_DBG_OBJCNT_INC(ep); 154 return ep; 155 156 fail_init: 157 kfree(ep); 158 fail: 159 return NULL; 160 } 161 162 /* Add an association to an endpoint. */ 163 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, 164 struct sctp_association *asoc) 165 { 166 struct sock *sk = ep->base.sk; 167 168 /* Now just add it to our list of asocs */ 169 list_add_tail(&asoc->asocs, &ep->asocs); 170 171 /* Increment the backlog value for a TCP-style listening socket. */ 172 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) 173 sk->sk_ack_backlog++; 174 } 175 176 /* Free the endpoint structure. Delay cleanup until 177 * all users have released their reference count on this structure. 178 */ 179 void sctp_endpoint_free(struct sctp_endpoint *ep) 180 { 181 ep->base.dead = 1; 182 sctp_endpoint_put(ep); 183 } 184 185 /* Final destructor for endpoint. */ 186 static void sctp_endpoint_destroy(struct sctp_endpoint *ep) 187 { 188 SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); 189 190 ep->base.sk->sk_state = SCTP_SS_CLOSED; 191 192 /* Unlink this endpoint, so we can't find it again! */ 193 sctp_unhash_endpoint(ep); 194 195 /* Free up the HMAC transform. */ 196 sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac); 197 198 /* Cleanup. */ 199 sctp_inq_free(&ep->base.inqueue); 200 sctp_bind_addr_free(&ep->base.bind_addr); 201 202 /* Remove and free the port */ 203 if (sctp_sk(ep->base.sk)->bind_hash) 204 sctp_put_port(ep->base.sk); 205 206 /* Give up our hold on the sock. */ 207 if (ep->base.sk) 208 sock_put(ep->base.sk); 209 210 /* Finally, free up our memory. */ 211 if (ep->base.malloced) { 212 kfree(ep); 213 SCTP_DBG_OBJCNT_DEC(ep); 214 } 215 } 216 217 /* Hold a reference to an endpoint. */ 218 void sctp_endpoint_hold(struct sctp_endpoint *ep) 219 { 220 atomic_inc(&ep->base.refcnt); 221 } 222 223 /* Release a reference to an endpoint and clean up if there are 224 * no more references. 225 */ 226 void sctp_endpoint_put(struct sctp_endpoint *ep) 227 { 228 if (atomic_dec_and_test(&ep->base.refcnt)) 229 sctp_endpoint_destroy(ep); 230 } 231 232 /* Is this the endpoint we are looking for? */ 233 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, 234 const union sctp_addr *laddr) 235 { 236 struct sctp_endpoint *retval; 237 238 sctp_read_lock(&ep->base.addr_lock); 239 if (ep->base.bind_addr.port == laddr->v4.sin_port) { 240 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, 241 sctp_sk(ep->base.sk))) { 242 retval = ep; 243 goto out; 244 } 245 } 246 247 retval = NULL; 248 249 out: 250 sctp_read_unlock(&ep->base.addr_lock); 251 return retval; 252 } 253 254 /* Find the association that goes with this chunk. 255 * We do a linear search of the associations for this endpoint. 256 * We return the matching transport address too. 257 */ 258 static struct sctp_association *__sctp_endpoint_lookup_assoc( 259 const struct sctp_endpoint *ep, 260 const union sctp_addr *paddr, 261 struct sctp_transport **transport) 262 { 263 int rport; 264 struct sctp_association *asoc; 265 struct list_head *pos; 266 267 rport = paddr->v4.sin_port; 268 269 list_for_each(pos, &ep->asocs) { 270 asoc = list_entry(pos, struct sctp_association, asocs); 271 if (rport == asoc->peer.port) { 272 sctp_read_lock(&asoc->base.addr_lock); 273 *transport = sctp_assoc_lookup_paddr(asoc, paddr); 274 sctp_read_unlock(&asoc->base.addr_lock); 275 276 if (*transport) 277 return asoc; 278 } 279 } 280 281 *transport = NULL; 282 return NULL; 283 } 284 285 /* Lookup association on an endpoint based on a peer address. BH-safe. */ 286 struct sctp_association *sctp_endpoint_lookup_assoc( 287 const struct sctp_endpoint *ep, 288 const union sctp_addr *paddr, 289 struct sctp_transport **transport) 290 { 291 struct sctp_association *asoc; 292 293 sctp_local_bh_disable(); 294 asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport); 295 sctp_local_bh_enable(); 296 297 return asoc; 298 } 299 300 /* Look for any peeled off association from the endpoint that matches the 301 * given peer address. 302 */ 303 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, 304 const union sctp_addr *paddr) 305 { 306 struct list_head *pos; 307 struct sctp_sockaddr_entry *addr; 308 struct sctp_bind_addr *bp; 309 310 sctp_read_lock(&ep->base.addr_lock); 311 bp = &ep->base.bind_addr; 312 list_for_each(pos, &bp->address_list) { 313 addr = list_entry(pos, struct sctp_sockaddr_entry, list); 314 if (sctp_has_association(&addr->a, paddr)) { 315 sctp_read_unlock(&ep->base.addr_lock); 316 return 1; 317 } 318 } 319 sctp_read_unlock(&ep->base.addr_lock); 320 321 return 0; 322 } 323 324 /* Do delayed input processing. This is scheduled by sctp_rcv(). 325 * This may be called on BH or task time. 326 */ 327 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep) 328 { 329 struct sctp_association *asoc; 330 struct sock *sk; 331 struct sctp_transport *transport; 332 struct sctp_chunk *chunk; 333 struct sctp_inq *inqueue; 334 sctp_subtype_t subtype; 335 sctp_state_t state; 336 int error = 0; 337 338 if (ep->base.dead) 339 return; 340 341 asoc = NULL; 342 inqueue = &ep->base.inqueue; 343 sk = ep->base.sk; 344 345 while (NULL != (chunk = sctp_inq_pop(inqueue))) { 346 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); 347 348 /* We might have grown an association since last we 349 * looked, so try again. 350 * 351 * This happens when we've just processed our 352 * COOKIE-ECHO chunk. 353 */ 354 if (NULL == chunk->asoc) { 355 asoc = sctp_endpoint_lookup_assoc(ep, 356 sctp_source(chunk), 357 &transport); 358 chunk->asoc = asoc; 359 chunk->transport = transport; 360 } 361 362 state = asoc ? asoc->state : SCTP_STATE_CLOSED; 363 364 /* Remember where the last DATA chunk came from so we 365 * know where to send the SACK. 366 */ 367 if (asoc && sctp_chunk_is_data(chunk)) 368 asoc->peer.last_data_from = chunk->transport; 369 else 370 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS); 371 372 if (chunk->transport) 373 chunk->transport->last_time_heard = jiffies; 374 375 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state, 376 ep, asoc, chunk, GFP_ATOMIC); 377 378 if (error && chunk) 379 chunk->pdiscard = 1; 380 381 /* Check to see if the endpoint is freed in response to 382 * the incoming chunk. If so, get out of the while loop. 383 */ 384 if (!sctp_sk(sk)->ep) 385 break; 386 } 387 } 388