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 } 391