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 */ 92int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *, 93 sctp_scope_t, gfp_t gfp, int flags); 94struct sctp_pf *sctp_get_pf_specific(sa_family_t family); 95int sctp_register_pf(struct sctp_pf *, sa_family_t); 96void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int); 97 98/* 99 * sctp/socket.c 100 */ 101int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); 102int sctp_inet_listen(struct socket *sock, int backlog); 103void sctp_write_space(struct sock *sk); 104void sctp_data_ready(struct sock *sk); 105unsigned int sctp_poll(struct file *file, struct socket *sock, 106 poll_table *wait); 107void sctp_sock_rfree(struct sk_buff *skb); 108void sctp_copy_sock(struct sock *newsk, struct sock *sk, 109 struct sctp_association *asoc); 110extern struct percpu_counter sctp_sockets_allocated; 111int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *); 112struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *); 113 114/* 115 * sctp/primitive.c 116 */ 117int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg); 118int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg); 119int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg); 120int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg); 121int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg); 122int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg); 123 124/* 125 * sctp/input.c 126 */ 127int sctp_rcv(struct sk_buff *skb); 128void sctp_v4_err(struct sk_buff *skb, u32 info); 129void sctp_hash_established(struct sctp_association *); 130void sctp_unhash_established(struct sctp_association *); 131void sctp_hash_endpoint(struct sctp_endpoint *); 132void sctp_unhash_endpoint(struct sctp_endpoint *); 133struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *, 134 struct sctphdr *, struct sctp_association **, 135 struct sctp_transport **); 136void sctp_err_finish(struct sock *, struct sctp_association *); 137void sctp_icmp_frag_needed(struct sock *, struct sctp_association *, 138 struct sctp_transport *t, __u32 pmtu); 139void sctp_icmp_redirect(struct sock *, struct sctp_transport *, 140 struct sk_buff *); 141void sctp_icmp_proto_unreachable(struct sock *sk, 142 struct sctp_association *asoc, 143 struct sctp_transport *t); 144void sctp_backlog_migrate(struct sctp_association *assoc, 145 struct sock *oldsk, struct sock *newsk); 146 147/* 148 * sctp/proc.c 149 */ 150int sctp_snmp_proc_init(struct net *net); 151void sctp_snmp_proc_exit(struct net *net); 152int sctp_eps_proc_init(struct net *net); 153void sctp_eps_proc_exit(struct net *net); 154int sctp_assocs_proc_init(struct net *net); 155void sctp_assocs_proc_exit(struct net *net); 156int sctp_remaddr_proc_init(struct net *net); 157void sctp_remaddr_proc_exit(struct net *net); 158 159 160/* 161 * Module global variables 162 */ 163 164 /* 165 * sctp/protocol.c 166 */ 167extern struct kmem_cache *sctp_chunk_cachep __read_mostly; 168extern struct kmem_cache *sctp_bucket_cachep __read_mostly; 169extern long sysctl_sctp_mem[3]; 170extern int sysctl_sctp_rmem[3]; 171extern int sysctl_sctp_wmem[3]; 172 173/* 174 * Section: Macros, externs, and inlines 175 */ 176 177/* SCTP SNMP MIB stats handlers */ 178#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field) 179#define SCTP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field) 180#define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field) 181#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field) 182 183/* sctp mib definitions */ 184enum { 185 SCTP_MIB_NUM = 0, 186 SCTP_MIB_CURRESTAB, /* CurrEstab */ 187 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */ 188 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */ 189 SCTP_MIB_ABORTEDS, /* Aborteds */ 190 SCTP_MIB_SHUTDOWNS, /* Shutdowns */ 191 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */ 192 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */ 193 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */ 194 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */ 195 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */ 196 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */ 197 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */ 198 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */ 199 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */ 200 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */ 201 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */ 202 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */ 203 SCTP_MIB_T1_INIT_EXPIREDS, 204 SCTP_MIB_T1_COOKIE_EXPIREDS, 205 SCTP_MIB_T2_SHUTDOWN_EXPIREDS, 206 SCTP_MIB_T3_RTX_EXPIREDS, 207 SCTP_MIB_T4_RTO_EXPIREDS, 208 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS, 209 SCTP_MIB_DELAY_SACK_EXPIREDS, 210 SCTP_MIB_AUTOCLOSE_EXPIREDS, 211 SCTP_MIB_T1_RETRANSMITS, 212 SCTP_MIB_T3_RETRANSMITS, 213 SCTP_MIB_PMTUD_RETRANSMITS, 214 SCTP_MIB_FAST_RETRANSMITS, 215 SCTP_MIB_IN_PKT_SOFTIRQ, 216 SCTP_MIB_IN_PKT_BACKLOG, 217 SCTP_MIB_IN_PKT_DISCARDS, 218 SCTP_MIB_IN_DATA_CHUNK_DISCARDS, 219 __SCTP_MIB_MAX 220}; 221 222#define SCTP_MIB_MAX __SCTP_MIB_MAX 223struct sctp_mib { 224 unsigned long mibs[SCTP_MIB_MAX]; 225}; 226 227/* helper function to track stats about max rto and related transport */ 228static inline void sctp_max_rto(struct sctp_association *asoc, 229 struct sctp_transport *trans) 230{ 231 if (asoc->stats.max_obs_rto < (__u64)trans->rto) { 232 asoc->stats.max_obs_rto = trans->rto; 233 memset(&asoc->stats.obs_rto_ipaddr, 0, 234 sizeof(struct sockaddr_storage)); 235 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr, 236 trans->af_specific->sockaddr_len); 237 } 238} 239 240/* 241 * Macros for keeping a global reference of object allocations. 242 */ 243#ifdef CONFIG_SCTP_DBG_OBJCNT 244 245extern atomic_t sctp_dbg_objcnt_sock; 246extern atomic_t sctp_dbg_objcnt_ep; 247extern atomic_t sctp_dbg_objcnt_assoc; 248extern atomic_t sctp_dbg_objcnt_transport; 249extern atomic_t sctp_dbg_objcnt_chunk; 250extern atomic_t sctp_dbg_objcnt_bind_addr; 251extern atomic_t sctp_dbg_objcnt_bind_bucket; 252extern atomic_t sctp_dbg_objcnt_addr; 253extern atomic_t sctp_dbg_objcnt_ssnmap; 254extern atomic_t sctp_dbg_objcnt_datamsg; 255extern atomic_t sctp_dbg_objcnt_keys; 256 257/* Macros to atomically increment/decrement objcnt counters. */ 258#define SCTP_DBG_OBJCNT_INC(name) \ 259atomic_inc(&sctp_dbg_objcnt_## name) 260#define SCTP_DBG_OBJCNT_DEC(name) \ 261atomic_dec(&sctp_dbg_objcnt_## name) 262#define SCTP_DBG_OBJCNT(name) \ 263atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0) 264 265/* Macro to help create new entries in in the global array of 266 * objcnt counters. 267 */ 268#define SCTP_DBG_OBJCNT_ENTRY(name) \ 269{.label= #name, .counter= &sctp_dbg_objcnt_## name} 270 271void sctp_dbg_objcnt_init(struct net *); 272void sctp_dbg_objcnt_exit(struct net *); 273 274#else 275 276#define SCTP_DBG_OBJCNT_INC(name) 277#define SCTP_DBG_OBJCNT_DEC(name) 278 279static inline void sctp_dbg_objcnt_init(struct net *net) { return; } 280static inline void sctp_dbg_objcnt_exit(struct net *net) { return; } 281 282#endif /* CONFIG_SCTP_DBG_OBJCOUNT */ 283 284#if defined CONFIG_SYSCTL 285void sctp_sysctl_register(void); 286void sctp_sysctl_unregister(void); 287int sctp_sysctl_net_register(struct net *net); 288void sctp_sysctl_net_unregister(struct net *net); 289#else 290static inline void sctp_sysctl_register(void) { return; } 291static inline void sctp_sysctl_unregister(void) { return; } 292static inline int sctp_sysctl_net_register(struct net *net) { return 0; } 293static inline void sctp_sysctl_net_unregister(struct net *net) { return; } 294#endif 295 296/* Size of Supported Address Parameter for 'x' address types. */ 297#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16)) 298 299#if IS_ENABLED(CONFIG_IPV6) 300 301void sctp_v6_pf_init(void); 302void sctp_v6_pf_exit(void); 303int sctp_v6_protosw_init(void); 304void sctp_v6_protosw_exit(void); 305int sctp_v6_add_protocol(void); 306void sctp_v6_del_protocol(void); 307 308#else /* #ifdef defined(CONFIG_IPV6) */ 309 310static inline void sctp_v6_pf_init(void) { return; } 311static inline void sctp_v6_pf_exit(void) { return; } 312static inline int sctp_v6_protosw_init(void) { return 0; } 313static inline void sctp_v6_protosw_exit(void) { return; } 314static inline int sctp_v6_add_protocol(void) { return 0; } 315static inline void sctp_v6_del_protocol(void) { return; } 316 317#endif /* #if defined(CONFIG_IPV6) */ 318 319 320/* Map an association to an assoc_id. */ 321static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc) 322{ 323 return asoc ? asoc->assoc_id : 0; 324} 325 326static inline enum sctp_sstat_state 327sctp_assoc_to_state(const struct sctp_association *asoc) 328{ 329 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we 330 * got rid of it in kernel space. Therefore SCTP_CLOSED et al 331 * start at =1 in user space, but actually as =0 in kernel space. 332 * Now that we can not break user space and SCTP_EMPTY is exposed 333 * there, we need to fix it up with an ugly offset not to break 334 * applications. :( 335 */ 336 return asoc->state + 1; 337} 338 339/* Look up the association by its id. */ 340struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id); 341 342int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp); 343 344/* A macro to walk a list of skbs. */ 345#define sctp_skb_for_each(pos, head, tmp) \ 346 skb_queue_walk_safe(head, pos, tmp) 347 348/* A helper to append an entire skb list (list) to another (head). */ 349static inline void sctp_skb_list_tail(struct sk_buff_head *list, 350 struct sk_buff_head *head) 351{ 352 unsigned long flags; 353 354 spin_lock_irqsave(&head->lock, flags); 355 spin_lock(&list->lock); 356 357 skb_queue_splice_tail_init(list, head); 358 359 spin_unlock(&list->lock); 360 spin_unlock_irqrestore(&head->lock, flags); 361} 362 363/** 364 * sctp_list_dequeue - remove from the head of the queue 365 * @list: list to dequeue from 366 * 367 * Remove the head of the list. The head item is 368 * returned or %NULL if the list is empty. 369 */ 370 371static inline struct list_head *sctp_list_dequeue(struct list_head *list) 372{ 373 struct list_head *result = NULL; 374 375 if (list->next != list) { 376 result = list->next; 377 list->next = result->next; 378 list->next->prev = list; 379 INIT_LIST_HEAD(result); 380 } 381 return result; 382} 383 384/* SCTP version of skb_set_owner_r. We need this one because 385 * of the way we have to do receive buffer accounting on bundled 386 * chunks. 387 */ 388static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) 389{ 390 struct sctp_ulpevent *event = sctp_skb2event(skb); 391 392 skb_orphan(skb); 393 skb->sk = sk; 394 skb->destructor = sctp_sock_rfree; 395 atomic_add(event->rmem_len, &sk->sk_rmem_alloc); 396 /* 397 * This mimics the behavior of skb_set_owner_r 398 */ 399 sk->sk_forward_alloc -= event->rmem_len; 400} 401 402/* Tests if the list has one and only one entry. */ 403static inline int sctp_list_single_entry(struct list_head *head) 404{ 405 return (head->next != head) && (head->next == head->prev); 406} 407 408/* Break down data chunks at this point. */ 409static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu) 410{ 411 struct sctp_sock *sp = sctp_sk(asoc->base.sk); 412 int frag = pmtu; 413 414 frag -= sp->pf->af->net_header_len; 415 frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); 416 417 if (asoc->user_frag) 418 frag = min_t(int, frag, asoc->user_frag); 419 420 frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN); 421 422 return frag; 423} 424 425static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc) 426{ 427 428 sctp_assoc_sync_pmtu(sk, asoc); 429 asoc->pmtu_pending = 0; 430} 431 432static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk) 433{ 434 return !list_empty(&chunk->list); 435} 436 437/* Walk through a list of TLV parameters. Don't trust the 438 * individual parameter lengths and instead depend on 439 * the chunk length to indicate when to stop. Make sure 440 * there is room for a param header too. 441 */ 442#define sctp_walk_params(pos, chunk, member)\ 443_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member) 444 445#define _sctp_walk_params(pos, chunk, end, member)\ 446for (pos.v = chunk->member;\ 447 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\ 448 ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\ 449 pos.v += WORD_ROUND(ntohs(pos.p->length))) 450 451#define sctp_walk_errors(err, chunk_hdr)\ 452_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length)) 453 454#define _sctp_walk_errors(err, chunk_hdr, end)\ 455for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \ 456 sizeof(sctp_chunkhdr_t));\ 457 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\ 458 ntohs(err->length) >= sizeof(sctp_errhdr_t); \ 459 err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length)))) 460 461#define sctp_walk_fwdtsn(pos, chunk)\ 462_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk)) 463 464#define _sctp_walk_fwdtsn(pos, chunk, end)\ 465for (pos = chunk->subh.fwdtsn_hdr->skip;\ 466 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\ 467 pos++) 468 469/* Round an int up to the next multiple of 4. */ 470#define WORD_ROUND(s) (((s)+3)&~3) 471 472/* External references. */ 473 474extern struct proto sctp_prot; 475extern struct proto sctpv6_prot; 476void sctp_put_port(struct sock *sk); 477 478extern struct idr sctp_assocs_id; 479extern spinlock_t sctp_assocs_id_lock; 480 481/* Static inline functions. */ 482 483/* Convert from an IP version number to an Address Family symbol. */ 484static inline int ipver2af(__u8 ipver) 485{ 486 switch (ipver) { 487 case 4: 488 return AF_INET; 489 case 6: 490 return AF_INET6; 491 default: 492 return 0; 493 } 494} 495 496/* Convert from an address parameter type to an address family. */ 497static inline int param_type2af(__be16 type) 498{ 499 switch (type) { 500 case SCTP_PARAM_IPV4_ADDRESS: 501 return AF_INET; 502 case SCTP_PARAM_IPV6_ADDRESS: 503 return AF_INET6; 504 default: 505 return 0; 506 } 507} 508 509/* Warning: The following hash functions assume a power of two 'size'. */ 510/* This is the hash function for the SCTP port hash table. */ 511static inline int sctp_phashfn(struct net *net, __u16 lport) 512{ 513 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1); 514} 515 516/* This is the hash function for the endpoint hash table. */ 517static inline int sctp_ep_hashfn(struct net *net, __u16 lport) 518{ 519 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1); 520} 521 522/* This is the hash function for the association hash table. */ 523static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport) 524{ 525 int h = (lport << 16) + rport + net_hash_mix(net); 526 h ^= h>>8; 527 return h & (sctp_assoc_hashsize - 1); 528} 529 530/* This is the hash function for the association hash table. This is 531 * not used yet, but could be used as a better hash function when 532 * we have a vtag. 533 */ 534static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag) 535{ 536 int h = (lport << 16) + rport; 537 h ^= vtag; 538 return h & (sctp_assoc_hashsize - 1); 539} 540 541#define sctp_for_each_hentry(epb, head) \ 542 hlist_for_each_entry(epb, head, node) 543 544/* Is a socket of this style? */ 545#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style)) 546static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style) 547{ 548 return sctp_sk(sk)->type == style; 549} 550 551/* Is the association in this state? */ 552#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state)) 553static inline int __sctp_state(const struct sctp_association *asoc, 554 sctp_state_t state) 555{ 556 return asoc->state == state; 557} 558 559/* Is the socket in this state? */ 560#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state)) 561static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state) 562{ 563 return sk->sk_state == state; 564} 565 566/* Map v4-mapped v6 address back to v4 address */ 567static inline void sctp_v6_map_v4(union sctp_addr *addr) 568{ 569 addr->v4.sin_family = AF_INET; 570 addr->v4.sin_port = addr->v6.sin6_port; 571 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3]; 572} 573 574/* Map v4 address to v4-mapped v6 address */ 575static inline void sctp_v4_map_v6(union sctp_addr *addr) 576{ 577 __be16 port; 578 579 port = addr->v4.sin_port; 580 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 581 addr->v6.sin6_port = port; 582 addr->v6.sin6_family = AF_INET6; 583 addr->v6.sin6_flowinfo = 0; 584 addr->v6.sin6_scope_id = 0; 585 addr->v6.sin6_addr.s6_addr32[0] = 0; 586 addr->v6.sin6_addr.s6_addr32[1] = 0; 587 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); 588} 589 590/* The cookie is always 0 since this is how it's used in the 591 * pmtu code. 592 */ 593static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) 594{ 595 if (t->dst && !dst_check(t->dst, t->dst_cookie)) { 596 dst_release(t->dst); 597 t->dst = NULL; 598 } 599 600 return t->dst; 601} 602 603#endif /* __net_sctp_h__ */ 604