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