include/net/sctp/sctp.h

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