1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2003 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * The base lksctp header. 10 * 11 * This SCTP implementation is free software; 12 * you can redistribute it and/or modify it under the terms of 13 * the GNU General Public License as published by 14 * the Free Software Foundation; either version 2, or (at your option) 15 * any later version. 16 * 17 * This SCTP implementation is distributed in the hope that it 18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 19 * ************************ 20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 21 * See the GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with GNU CC; see the file COPYING. If not, see 25 * <http://www.gnu.org/licenses/>. 26 * 27 * Please send any bug reports or fixes you make to the 28 * email address(es): 29 * lksctp developers <linux-sctp@vger.kernel.org> 30 * 31 * Written or modified by: 32 * La Monte H.P. Yarroll <piggy@acm.org> 33 * Xingang Guo <xingang.guo@intel.com> 34 * Jon Grimm <jgrimm@us.ibm.com> 35 * Daisy Chang <daisyc@us.ibm.com> 36 * Sridhar Samudrala <sri@us.ibm.com> 37 * Ardelle Fan <ardelle.fan@intel.com> 38 * Ryan Layer <rmlayer@us.ibm.com> 39 * Kevin Gao <kevin.gao@intel.com> 40 */ 41 42 #ifndef __net_sctp_h__ 43 #define __net_sctp_h__ 44 45 /* Header Strategy. 46 * Start getting some control over the header file depencies: 47 * includes 48 * constants 49 * structs 50 * prototypes 51 * macros, externs, and inlines 52 * 53 * Move test_frame specific items out of the kernel headers 54 * and into the test frame headers. This is not perfect in any sense 55 * and will continue to evolve. 56 */ 57 58 #include <linux/types.h> 59 #include <linux/slab.h> 60 #include <linux/in.h> 61 #include <linux/tty.h> 62 #include <linux/proc_fs.h> 63 #include <linux/spinlock.h> 64 #include <linux/jiffies.h> 65 #include <linux/idr.h> 66 67 #if IS_ENABLED(CONFIG_IPV6) 68 #include <net/ipv6.h> 69 #include <net/ip6_route.h> 70 #endif 71 72 #include <asm/uaccess.h> 73 #include <asm/page.h> 74 #include <net/sock.h> 75 #include <net/snmp.h> 76 #include <net/sctp/structs.h> 77 #include <net/sctp/constants.h> 78 79 #ifdef CONFIG_IP_SCTP_MODULE 80 #define SCTP_PROTOSW_FLAG 0 81 #else /* static! */ 82 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT 83 #endif 84 85 /* 86 * Function declarations. 87 */ 88 89 /* 90 * sctp/protocol.c 91 */ 92 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *, 93 sctp_scope_t, gfp_t gfp, int flags); 94 struct sctp_pf *sctp_get_pf_specific(sa_family_t family); 95 int sctp_register_pf(struct sctp_pf *, sa_family_t); 96 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); 97 98 /* 99 * sctp/socket.c 100 */ 101 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); 102 int sctp_inet_listen(struct socket *sock, int backlog); 103 void sctp_write_space(struct sock *sk); 104 void sctp_data_ready(struct sock *sk, int len); 105 unsigned int sctp_poll(struct file *file, struct socket *sock, 106 poll_table *wait); 107 void sctp_sock_rfree(struct sk_buff *skb); 108 void sctp_copy_sock(struct sock *newsk, struct sock *sk, 109 struct sctp_association *asoc); 110 extern struct percpu_counter sctp_sockets_allocated; 111 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); 112 113 /* 114 * sctp/primitive.c 115 */ 116 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg); 117 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg); 118 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg); 119 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg); 120 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg); 121 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg); 122 123 /* 124 * sctp/input.c 125 */ 126 int sctp_rcv(struct sk_buff *skb); 127 void sctp_v4_err(struct sk_buff *skb, u32 info); 128 void sctp_hash_established(struct sctp_association *); 129 void sctp_unhash_established(struct sctp_association *); 130 void sctp_hash_endpoint(struct sctp_endpoint *); 131 void sctp_unhash_endpoint(struct sctp_endpoint *); 132 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *, 133 struct sctphdr *, struct sctp_association **, 134 struct sctp_transport **); 135 void sctp_err_finish(struct sock *, struct sctp_association *); 136 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 137 struct sctp_transport *t, __u32 pmtu); 138 void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 139 struct sk_buff *); 140 void sctp_icmp_proto_unreachable(struct sock *sk, 141 struct sctp_association *asoc, 142 struct sctp_transport *t); 143 void sctp_backlog_migrate(struct sctp_association *assoc, 144 struct sock *oldsk, struct sock *newsk); 145 146 /* 147 * sctp/proc.c 148 */ 149 int sctp_snmp_proc_init(struct net *net); 150 void sctp_snmp_proc_exit(struct net *net); 151 int sctp_eps_proc_init(struct net *net); 152 void sctp_eps_proc_exit(struct net *net); 153 int sctp_assocs_proc_init(struct net *net); 154 void sctp_assocs_proc_exit(struct net *net); 155 int sctp_remaddr_proc_init(struct net *net); 156 void sctp_remaddr_proc_exit(struct net *net); 157 158 159 /* 160 * Module global variables 161 */ 162 163 /* 164 * sctp/protocol.c 165 */ 166 extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 167 extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 168 169 /* 170 * Section: Macros, externs, and inlines 171 */ 172 173 /* SCTP SNMP MIB stats handlers */ 174 #define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 175 #define SCTP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field) 176 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field) 177 #define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field) 178 179 /* sctp mib definitions */ 180 enum { 181 SCTP_MIB_NUM = 0, 182 SCTP_MIB_CURRESTAB, /* CurrEstab */ 183 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */ 184 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */ 185 SCTP_MIB_ABORTEDS, /* Aborteds */ 186 SCTP_MIB_SHUTDOWNS, /* Shutdowns */ 187 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */ 188 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */ 189 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */ 190 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */ 191 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */ 192 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */ 193 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */ 194 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */ 195 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */ 196 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */ 197 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */ 198 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */ 199 SCTP_MIB_T1_INIT_EXPIREDS, 200 SCTP_MIB_T1_COOKIE_EXPIREDS, 201 SCTP_MIB_T2_SHUTDOWN_EXPIREDS, 202 SCTP_MIB_T3_RTX_EXPIREDS, 203 SCTP_MIB_T4_RTO_EXPIREDS, 204 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS, 205 SCTP_MIB_DELAY_SACK_EXPIREDS, 206 SCTP_MIB_AUTOCLOSE_EXPIREDS, 207 SCTP_MIB_T1_RETRANSMITS, 208 SCTP_MIB_T3_RETRANSMITS, 209 SCTP_MIB_PMTUD_RETRANSMITS, 210 SCTP_MIB_FAST_RETRANSMITS, 211 SCTP_MIB_IN_PKT_SOFTIRQ, 212 SCTP_MIB_IN_PKT_BACKLOG, 213 SCTP_MIB_IN_PKT_DISCARDS, 214 SCTP_MIB_IN_DATA_CHUNK_DISCARDS, 215 __SCTP_MIB_MAX 216 }; 217 218 #define SCTP_MIB_MAX __SCTP_MIB_MAX 219 struct sctp_mib { 220 unsigned long mibs[SCTP_MIB_MAX]; 221 }; 222 223 /* helper function to track stats about max rto and related transport */ 224 static inline void sctp_max_rto(struct sctp_association *asoc, 225 struct sctp_transport *trans) 226 { 227 if (asoc->stats.max_obs_rto < (__u64)trans->rto) { 228 asoc->stats.max_obs_rto = trans->rto; 229 memset(&asoc->stats.obs_rto_ipaddr, 0, 230 sizeof(struct sockaddr_storage)); 231 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr, 232 trans->af_specific->sockaddr_len); 233 } 234 } 235 236 /* 237 * Macros for keeping a global reference of object allocations. 238 */ 239 #ifdef CONFIG_SCTP_DBG_OBJCNT 240 241 extern atomic_t sctp_dbg_objcnt_sock; 242 extern atomic_t sctp_dbg_objcnt_ep; 243 extern atomic_t sctp_dbg_objcnt_assoc; 244 extern atomic_t sctp_dbg_objcnt_transport; 245 extern atomic_t sctp_dbg_objcnt_chunk; 246 extern atomic_t sctp_dbg_objcnt_bind_addr; 247 extern atomic_t sctp_dbg_objcnt_bind_bucket; 248 extern atomic_t sctp_dbg_objcnt_addr; 249 extern atomic_t sctp_dbg_objcnt_ssnmap; 250 extern atomic_t sctp_dbg_objcnt_datamsg; 251 extern atomic_t sctp_dbg_objcnt_keys; 252 253 /* Macros to atomically increment/decrement objcnt counters. */ 254 #define SCTP_DBG_OBJCNT_INC(name) \ 255 atomic_inc(&sctp_dbg_objcnt_## name) 256 #define SCTP_DBG_OBJCNT_DEC(name) \ 257 atomic_dec(&sctp_dbg_objcnt_## name) 258 #define SCTP_DBG_OBJCNT(name) \ 259 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0) 260 261 /* Macro to help create new entries in in the global array of 262 * objcnt counters. 263 */ 264 #define SCTP_DBG_OBJCNT_ENTRY(name) \ 265 {.label= #name, .counter= &sctp_dbg_objcnt_## name} 266 267 void sctp_dbg_objcnt_init(struct net *); 268 void sctp_dbg_objcnt_exit(struct net *); 269 270 #else 271 272 #define SCTP_DBG_OBJCNT_INC(name) 273 #define SCTP_DBG_OBJCNT_DEC(name) 274 275 static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 276 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; } 277 278 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 279 280 #if defined CONFIG_SYSCTL 281 void sctp_sysctl_register(void); 282 void sctp_sysctl_unregister(void); 283 int sctp_sysctl_net_register(struct net *net); 284 void sctp_sysctl_net_unregister(struct net *net); 285 #else 286 static inline void sctp_sysctl_register(void) { return; } 287 static inline void sctp_sysctl_unregister(void) { return; } 288 static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 289 static inline void sctp_sysctl_net_unregister(struct net *net) { return; } 290 #endif 291 292 /* Size of Supported Address Parameter for 'x' address types. */ 293 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16)) 294 295 #if IS_ENABLED(CONFIG_IPV6) 296 297 void sctp_v6_pf_init(void); 298 void sctp_v6_pf_exit(void); 299 int sctp_v6_protosw_init(void); 300 void sctp_v6_protosw_exit(void); 301 int sctp_v6_add_protocol(void); 302 void sctp_v6_del_protocol(void); 303 304 #else /* #ifdef defined(CONFIG_IPV6) */ 305 306 static inline void sctp_v6_pf_init(void) { return; } 307 static inline void sctp_v6_pf_exit(void) { return; } 308 static inline int sctp_v6_protosw_init(void) { return 0; } 309 static inline void sctp_v6_protosw_exit(void) { return; } 310 static inline int sctp_v6_add_protocol(void) { return 0; } 311 static inline void sctp_v6_del_protocol(void) { return; } 312 313 #endif /* #if defined(CONFIG_IPV6) */ 314 315 316 /* Map an association to an assoc_id. */ 317 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 318 { 319 return asoc ? asoc->assoc_id : 0; 320 } 321 322 /* Look up the association by its id. */ 323 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 324 325 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp); 326 327 /* A macro to walk a list of skbs. */ 328 #define sctp_skb_for_each(pos, head, tmp) \ 329 skb_queue_walk_safe(head, pos, tmp) 330 331 /* A helper to append an entire skb list (list) to another (head). */ 332 static inline void sctp_skb_list_tail(struct sk_buff_head *list, 333 struct sk_buff_head *head) 334 { 335 unsigned long flags; 336 337 spin_lock_irqsave(&head->lock, flags); 338 spin_lock(&list->lock); 339 340 skb_queue_splice_tail_init(list, head); 341 342 spin_unlock(&list->lock); 343 spin_unlock_irqrestore(&head->lock, flags); 344 } 345 346 /** 347 * sctp_list_dequeue - remove from the head of the queue 348 * @list: list to dequeue from 349 * 350 * Remove the head of the list. The head item is 351 * returned or %NULL if the list is empty. 352 */ 353 354 static inline struct list_head *sctp_list_dequeue(struct list_head *list) 355 { 356 struct list_head *result = NULL; 357 358 if (list->next != list) { 359 result = list->next; 360 list->next = result->next; 361 list->next->prev = list; 362 INIT_LIST_HEAD(result); 363 } 364 return result; 365 } 366 367 /* SCTP version of skb_set_owner_r. We need this one because 368 * of the way we have to do receive buffer accounting on bundled 369 * chunks. 370 */ 371 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 372 { 373 struct sctp_ulpevent *event = sctp_skb2event(skb); 374 375 skb_orphan(skb); 376 skb->sk = sk; 377 skb->destructor = sctp_sock_rfree; 378 atomic_add(event->rmem_len, &sk->sk_rmem_alloc); 379 /* 380 * This mimics the behavior of skb_set_owner_r 381 */ 382 sk->sk_forward_alloc -= event->rmem_len; 383 } 384 385 /* Tests if the list has one and only one entry. */ 386 static inline int sctp_list_single_entry(struct list_head *head) 387 { 388 return (head->next != head) && (head->next == head->prev); 389 } 390 391 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */ 392 static inline __s32 sctp_jitter(__u32 rto) 393 { 394 static __u32 sctp_rand; 395 __s32 ret; 396 397 /* Avoid divide by zero. */ 398 if (!rto) 399 rto = 1; 400 401 sctp_rand += jiffies; 402 sctp_rand ^= (sctp_rand << 12); 403 sctp_rand ^= (sctp_rand >> 20); 404 405 /* Choose random number from 0 to rto, then move to -50% ~ +50% 406 * of rto. 407 */ 408 ret = sctp_rand % rto - (rto >> 1); 409 return ret; 410 } 411 412 /* Break down data chunks at this point. */ 413 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu) 414 { 415 struct sctp_sock *sp = sctp_sk(asoc->base.sk); 416 int frag = pmtu; 417 418 frag -= sp->pf->af->net_header_len; 419 frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); 420 421 if (asoc->user_frag) 422 frag = min_t(int, frag, asoc->user_frag); 423 424 frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN); 425 426 return frag; 427 } 428 429 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc) 430 { 431 432 sctp_assoc_sync_pmtu(sk, asoc); 433 asoc->pmtu_pending = 0; 434 } 435 436 /* Walk through a list of TLV parameters. Don't trust the 437 * individual parameter lengths and instead depend on 438 * the chunk length to indicate when to stop. Make sure 439 * there is room for a param header too. 440 */ 441 #define sctp_walk_params(pos, chunk, member)\ 442 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member) 443 444 #define _sctp_walk_params(pos, chunk, end, member)\ 445 for (pos.v = chunk->member;\ 446 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 447 ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\ 448 pos.v += WORD_ROUND(ntohs(pos.p->length))) 449 450 #define sctp_walk_errors(err, chunk_hdr)\ 451 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 452 453 #define _sctp_walk_errors(err, chunk_hdr, end)\ 454 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \ 455 sizeof(sctp_chunkhdr_t));\ 456 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 457 ntohs(err->length) >= sizeof(sctp_errhdr_t); \ 458 err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length)))) 459 460 #define sctp_walk_fwdtsn(pos, chunk)\ 461 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 462 463 #define _sctp_walk_fwdtsn(pos, chunk, end)\ 464 for (pos = chunk->subh.fwdtsn_hdr->skip;\ 465 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\ 466 pos++) 467 468 /* Round an int up to the next multiple of 4. */ 469 #define WORD_ROUND(s) (((s)+3)&~3) 470 471 /* External references. */ 472 473 extern struct proto sctp_prot; 474 extern struct proto sctpv6_prot; 475 void sctp_put_port(struct sock *sk); 476 477 extern struct idr sctp_assocs_id; 478 extern spinlock_t sctp_assocs_id_lock; 479 480 /* Static inline functions. */ 481 482 /* Convert from an IP version number to an Address Family symbol. */ 483 static inline int ipver2af(__u8 ipver) 484 { 485 switch (ipver) { 486 case 4: 487 return AF_INET; 488 case 6: 489 return AF_INET6; 490 default: 491 return 0; 492 } 493 } 494 495 /* Convert from an address parameter type to an address family. */ 496 static inline int param_type2af(__be16 type) 497 { 498 switch (type) { 499 case SCTP_PARAM_IPV4_ADDRESS: 500 return AF_INET; 501 case SCTP_PARAM_IPV6_ADDRESS: 502 return AF_INET6; 503 default: 504 return 0; 505 } 506 } 507 508 /* Warning: The following hash functions assume a power of two 'size'. */ 509 /* This is the hash function for the SCTP port hash table. */ 510 static inline int sctp_phashfn(struct net *net, __u16 lport) 511 { 512 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 513 } 514 515 /* This is the hash function for the endpoint hash table. */ 516 static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 517 { 518 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 519 } 520 521 /* This is the hash function for the association hash table. */ 522 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport) 523 { 524 int h = (lport << 16) + rport + net_hash_mix(net); 525 h ^= h>>8; 526 return h & (sctp_assoc_hashsize - 1); 527 } 528 529 /* This is the hash function for the association hash table. This is 530 * not used yet, but could be used as a better hash function when 531 * we have a vtag. 532 */ 533 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag) 534 { 535 int h = (lport << 16) + rport; 536 h ^= vtag; 537 return h & (sctp_assoc_hashsize - 1); 538 } 539 540 #define sctp_for_each_hentry(epb, head) \ 541 hlist_for_each_entry(epb, head, node) 542 543 /* Is a socket of this style? */ 544 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 545 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style) 546 { 547 return sctp_sk(sk)->type == style; 548 } 549 550 /* Is the association in this state? */ 551 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 552 static inline int __sctp_state(const struct sctp_association *asoc, 553 sctp_state_t state) 554 { 555 return asoc->state == state; 556 } 557 558 /* Is the socket in this state? */ 559 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 560 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state) 561 { 562 return sk->sk_state == state; 563 } 564 565 /* Map v4-mapped v6 address back to v4 address */ 566 static inline void sctp_v6_map_v4(union sctp_addr *addr) 567 { 568 addr->v4.sin_family = AF_INET; 569 addr->v4.sin_port = addr->v6.sin6_port; 570 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 571 } 572 573 /* Map v4 address to v4-mapped v6 address */ 574 static inline void sctp_v4_map_v6(union sctp_addr *addr) 575 { 576 addr->v6.sin6_family = AF_INET6; 577 addr->v6.sin6_port = addr->v4.sin_port; 578 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 579 addr->v6.sin6_addr.s6_addr32[0] = 0; 580 addr->v6.sin6_addr.s6_addr32[1] = 0; 581 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 582 } 583 584 /* The cookie is always 0 since this is how it's used in the 585 * pmtu code. 586 */ 587 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 588 { 589 if (t->dst && !dst_check(t->dst, t->dst_cookie)) { 590 dst_release(t->dst); 591 t->dst = NULL; 592 } 593 594 return t->dst; 595 } 596 597 #endif /* __net_sctp_h__ */ 598