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 /* Round an int up to the next multiple of 4.  */
  86 #define WORD_ROUND(s) (((s)+3)&~3)
  87 /* Truncate to the previous multiple of 4.  */
  88 #define WORD_TRUNC(s) ((s)&~3)
  89
  90 /*
  91  * Function declarations.
  92  */
  93
  94 /*
  95  * sctp/protocol.c
  96  */
  97 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
  98                               sctp_scope_t, gfp_t gfp, int flags);
  99 struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 100 int sctp_register_pf(struct sctp_pf *, sa_family_t);
 101 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
 102
 103 /*
 104  * sctp/socket.c
 105  */
 106 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 107 int sctp_inet_listen(struct socket *sock, int backlog);
 108 void sctp_write_space(struct sock *sk);
 109 void sctp_data_ready(struct sock *sk);
 110 unsigned int sctp_poll(struct file *file, struct socket *sock,
 111                 poll_table *wait);
 112 void sctp_sock_rfree(struct sk_buff *skb);
 113 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 114                     struct sctp_association *asoc);
 115 extern struct percpu_counter sctp_sockets_allocated;
 116 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 117 struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
 118
 119 /*
 120  * sctp/primitive.c
 121  */
 122 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 123 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 124 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 125 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 126 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 127 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 128
 129 /*
 130  * sctp/input.c
 131  */
 132 int sctp_rcv(struct sk_buff *skb);
 133 void sctp_v4_err(struct sk_buff *skb, u32 info);
 134 void sctp_hash_endpoint(struct sctp_endpoint *);
 135 void sctp_unhash_endpoint(struct sctp_endpoint *);
 136 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 137                              struct sctphdr *, struct sctp_association **,
 138                              struct sctp_transport **);
 139 void sctp_err_finish(struct sock *, struct sctp_association *);
 140 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 141                            struct sctp_transport *t, __u32 pmtu);
 142 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 143                         struct sk_buff *);
 144 void sctp_icmp_proto_unreachable(struct sock *sk,
 145                                  struct sctp_association *asoc,
 146                                  struct sctp_transport *t);
 147 void sctp_backlog_migrate(struct sctp_association *assoc,
 148                           struct sock *oldsk, struct sock *newsk);
 149 int sctp_transport_hashtable_init(void);
 150 void sctp_transport_hashtable_destroy(void);
 151 void sctp_hash_transport(struct sctp_transport *t);
 152 void sctp_unhash_transport(struct sctp_transport *t);
 153 struct sctp_transport *sctp_addrs_lookup_transport(
 154                                 struct net *net,
 155                                 const union sctp_addr *laddr,
 156                                 const union sctp_addr *paddr);
 157 struct sctp_transport *sctp_epaddr_lookup_transport(
 158                                 const struct sctp_endpoint *ep,
 159                                 const union sctp_addr *paddr);
 160
 161 /*
 162  * sctp/proc.c
 163  */
 164 int sctp_snmp_proc_init(struct net *net);
 165 void sctp_snmp_proc_exit(struct net *net);
 166 int sctp_eps_proc_init(struct net *net);
 167 void sctp_eps_proc_exit(struct net *net);
 168 int sctp_assocs_proc_init(struct net *net);
 169 void sctp_assocs_proc_exit(struct net *net);
 170 int sctp_remaddr_proc_init(struct net *net);
 171 void sctp_remaddr_proc_exit(struct net *net);
 172
 173
 174 /*
 175  * Module global variables
 176  */
 177
 178  /*
 179   * sctp/protocol.c
 180   */
 181 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 182 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 183 extern long sysctl_sctp_mem[3];
 184 extern int sysctl_sctp_rmem[3];
 185 extern int sysctl_sctp_wmem[3];
 186
 187 /*
 188  *  Section:  Macros, externs, and inlines
 189  */
 190
 191 /* SCTP SNMP MIB stats handlers */
 192 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 193 #define SCTP_INC_STATS_BH(net, field)   SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
 194 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
 195 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 196
 197 /* sctp mib definitions */
 198 enum {
 199         SCTP_MIB_NUM = 0,
 200         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 201         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 202         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 203         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 204         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 205         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 206         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 207         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 208         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 209         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 210         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 211         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 212         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 213         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 214         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 215         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 216         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 217         SCTP_MIB_T1_INIT_EXPIREDS,
 218         SCTP_MIB_T1_COOKIE_EXPIREDS,
 219         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 220         SCTP_MIB_T3_RTX_EXPIREDS,
 221         SCTP_MIB_T4_RTO_EXPIREDS,
 222         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 223         SCTP_MIB_DELAY_SACK_EXPIREDS,
 224         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 225         SCTP_MIB_T1_RETRANSMITS,
 226         SCTP_MIB_T3_RETRANSMITS,
 227         SCTP_MIB_PMTUD_RETRANSMITS,
 228         SCTP_MIB_FAST_RETRANSMITS,
 229         SCTP_MIB_IN_PKT_SOFTIRQ,
 230         SCTP_MIB_IN_PKT_BACKLOG,
 231         SCTP_MIB_IN_PKT_DISCARDS,
 232         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 233         __SCTP_MIB_MAX
 234 };
 235
 236 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 237 struct sctp_mib {
 238         unsigned long   mibs[SCTP_MIB_MAX];
 239 };
 240
 241 /* helper function to track stats about max rto and related transport */
 242 static inline void sctp_max_rto(struct sctp_association *asoc,
 243                                 struct sctp_transport *trans)
 244 {
 245         if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 246                 asoc->stats.max_obs_rto = trans->rto;
 247                 memset(&asoc->stats.obs_rto_ipaddr, 0,
 248                         sizeof(struct sockaddr_storage));
 249                 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 250                         trans->af_specific->sockaddr_len);
 251         }
 252 }
 253
 254 /*
 255  * Macros for keeping a global reference of object allocations.
 256  */
 257 #ifdef CONFIG_SCTP_DBG_OBJCNT
 258
 259 extern atomic_t sctp_dbg_objcnt_sock;
 260 extern atomic_t sctp_dbg_objcnt_ep;
 261 extern atomic_t sctp_dbg_objcnt_assoc;
 262 extern atomic_t sctp_dbg_objcnt_transport;
 263 extern atomic_t sctp_dbg_objcnt_chunk;
 264 extern atomic_t sctp_dbg_objcnt_bind_addr;
 265 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 266 extern atomic_t sctp_dbg_objcnt_addr;
 267 extern atomic_t sctp_dbg_objcnt_ssnmap;
 268 extern atomic_t sctp_dbg_objcnt_datamsg;
 269 extern atomic_t sctp_dbg_objcnt_keys;
 270
 271 /* Macros to atomically increment/decrement objcnt counters.  */
 272 #define SCTP_DBG_OBJCNT_INC(name) \
 273 atomic_inc(&sctp_dbg_objcnt_## name)
 274 #define SCTP_DBG_OBJCNT_DEC(name) \
 275 atomic_dec(&sctp_dbg_objcnt_## name)
 276 #define SCTP_DBG_OBJCNT(name) \
 277 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 278
 279 /* Macro to help create new entries in in the global array of
 280  * objcnt counters.
 281  */
 282 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 283 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 284
 285 void sctp_dbg_objcnt_init(struct net *);
 286 void sctp_dbg_objcnt_exit(struct net *);
 287
 288 #else
 289
 290 #define SCTP_DBG_OBJCNT_INC(name)
 291 #define SCTP_DBG_OBJCNT_DEC(name)
 292
 293 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 294 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 295
 296 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 297
 298 #if defined CONFIG_SYSCTL
 299 void sctp_sysctl_register(void);
 300 void sctp_sysctl_unregister(void);
 301 int sctp_sysctl_net_register(struct net *net);
 302 void sctp_sysctl_net_unregister(struct net *net);
 303 #else
 304 static inline void sctp_sysctl_register(void) { return; }
 305 static inline void sctp_sysctl_unregister(void) { return; }
 306 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 307 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 308 #endif
 309
 310 /* Size of Supported Address Parameter for 'x' address types. */
 311 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 312
 313 #if IS_ENABLED(CONFIG_IPV6)
 314
 315 void sctp_v6_pf_init(void);
 316 void sctp_v6_pf_exit(void);
 317 int sctp_v6_protosw_init(void);
 318 void sctp_v6_protosw_exit(void);
 319 int sctp_v6_add_protocol(void);
 320 void sctp_v6_del_protocol(void);
 321
 322 #else /* #ifdef defined(CONFIG_IPV6) */
 323
 324 static inline void sctp_v6_pf_init(void) { return; }
 325 static inline void sctp_v6_pf_exit(void) { return; }
 326 static inline int sctp_v6_protosw_init(void) { return 0; }
 327 static inline void sctp_v6_protosw_exit(void) { return; }
 328 static inline int sctp_v6_add_protocol(void) { return 0; }
 329 static inline void sctp_v6_del_protocol(void) { return; }
 330
 331 #endif /* #if defined(CONFIG_IPV6) */
 332
 333
 334 /* Map an association to an assoc_id. */
 335 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 336 {
 337         return asoc ? asoc->assoc_id : 0;
 338 }
 339
 340 static inline enum sctp_sstat_state
 341 sctp_assoc_to_state(const struct sctp_association *asoc)
 342 {
 343         /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
 344          * got rid of it in kernel space. Therefore SCTP_CLOSED et al
 345          * start at =1 in user space, but actually as =0 in kernel space.
 346          * Now that we can not break user space and SCTP_EMPTY is exposed
 347          * there, we need to fix it up with an ugly offset not to break
 348          * applications. :(
 349          */
 350         return asoc->state + 1;
 351 }
 352
 353 /* Look up the association by its id.  */
 354 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 355
 356 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 357
 358 /* A macro to walk a list of skbs.  */
 359 #define sctp_skb_for_each(pos, head, tmp) \
 360         skb_queue_walk_safe(head, pos, tmp)
 361
 362 /* A helper to append an entire skb list (list) to another (head). */
 363 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 364                                       struct sk_buff_head *head)
 365 {
 366         unsigned long flags;
 367
 368         spin_lock_irqsave(&head->lock, flags);
 369         spin_lock(&list->lock);
 370
 371         skb_queue_splice_tail_init(list, head);
 372
 373         spin_unlock(&list->lock);
 374         spin_unlock_irqrestore(&head->lock, flags);
 375 }
 376
 377 /**
 378  *      sctp_list_dequeue - remove from the head of the queue
 379  *      @list: list to dequeue from
 380  *
 381  *      Remove the head of the list. The head item is
 382  *      returned or %NULL if the list is empty.
 383  */
 384
 385 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 386 {
 387         struct list_head *result = NULL;
 388
 389         if (list->next != list) {
 390                 result = list->next;
 391                 list->next = result->next;
 392                 list->next->prev = list;
 393                 INIT_LIST_HEAD(result);
 394         }
 395         return result;
 396 }
 397
 398 /* SCTP version of skb_set_owner_r.  We need this one because
 399  * of the way we have to do receive buffer accounting on bundled
 400  * chunks.
 401  */
 402 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 403 {
 404         struct sctp_ulpevent *event = sctp_skb2event(skb);
 405
 406         skb_orphan(skb);
 407         skb->sk = sk;
 408         skb->destructor = sctp_sock_rfree;
 409         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 410         /*
 411          * This mimics the behavior of skb_set_owner_r
 412          */
 413         sk->sk_forward_alloc -= event->rmem_len;
 414 }
 415
 416 /* Tests if the list has one and only one entry. */
 417 static inline int sctp_list_single_entry(struct list_head *head)
 418 {
 419         return (head->next != head) && (head->next == head->prev);
 420 }
 421
 422 /* Break down data chunks at this point.  */
 423 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 424 {
 425         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 426         int frag = pmtu;
 427
 428         frag -= sp->pf->af->net_header_len;
 429         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 430
 431         if (asoc->user_frag)
 432                 frag = min_t(int, frag, asoc->user_frag);
 433
 434         frag = WORD_TRUNC(min_t(int, frag, SCTP_MAX_CHUNK_LEN));
 435
 436         return frag;
 437 }
 438
 439 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
 440 {
 441
 442         sctp_assoc_sync_pmtu(sk, asoc);
 443         asoc->pmtu_pending = 0;
 444 }
 445
 446 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
 447 {
 448         return !list_empty(&chunk->list);
 449 }
 450
 451 /* Walk through a list of TLV parameters.  Don't trust the
 452  * individual parameter lengths and instead depend on
 453  * the chunk length to indicate when to stop.  Make sure
 454  * there is room for a param header too.
 455  */
 456 #define sctp_walk_params(pos, chunk, member)\
 457 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 458
 459 #define _sctp_walk_params(pos, chunk, end, member)\
 460 for (pos.v = chunk->member;\
 461      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 462      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 463      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 464
 465 #define sctp_walk_errors(err, chunk_hdr)\
 466 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 467
 468 #define _sctp_walk_errors(err, chunk_hdr, end)\
 469 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 470             sizeof(sctp_chunkhdr_t));\
 471      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 472      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 473      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 474
 475 #define sctp_walk_fwdtsn(pos, chunk)\
 476 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 477
 478 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 479 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 480      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 481      pos++)
 482
 483 /* External references. */
 484
 485 extern struct proto sctp_prot;
 486 extern struct proto sctpv6_prot;
 487 void sctp_put_port(struct sock *sk);
 488
 489 extern struct idr sctp_assocs_id;
 490 extern spinlock_t sctp_assocs_id_lock;
 491
 492 /* Static inline functions. */
 493
 494 /* Convert from an IP version number to an Address Family symbol.  */
 495 static inline int ipver2af(__u8 ipver)
 496 {
 497         switch (ipver) {
 498         case 4:
 499                 return  AF_INET;
 500         case 6:
 501                 return AF_INET6;
 502         default:
 503                 return 0;
 504         }
 505 }
 506
 507 /* Convert from an address parameter type to an address family.  */
 508 static inline int param_type2af(__be16 type)
 509 {
 510         switch (type) {
 511         case SCTP_PARAM_IPV4_ADDRESS:
 512                 return  AF_INET;
 513         case SCTP_PARAM_IPV6_ADDRESS:
 514                 return AF_INET6;
 515         default:
 516                 return 0;
 517         }
 518 }
 519
 520 /* Warning: The following hash functions assume a power of two 'size'. */
 521 /* This is the hash function for the SCTP port hash table. */
 522 static inline int sctp_phashfn(struct net *net, __u16 lport)
 523 {
 524         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 525 }
 526
 527 /* This is the hash function for the endpoint hash table. */
 528 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 529 {
 530         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 531 }
 532
 533 #define sctp_for_each_hentry(epb, head) \
 534         hlist_for_each_entry(epb, head, node)
 535
 536 /* Is a socket of this style? */
 537 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 538 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 539 {
 540         return sctp_sk(sk)->type == style;
 541 }
 542
 543 /* Is the association in this state? */
 544 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 545 static inline int __sctp_state(const struct sctp_association *asoc,
 546                                sctp_state_t state)
 547 {
 548         return asoc->state == state;
 549 }
 550
 551 /* Is the socket in this state? */
 552 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 553 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 554 {
 555         return sk->sk_state == state;
 556 }
 557
 558 /* Map v4-mapped v6 address back to v4 address */
 559 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 560 {
 561         addr->v4.sin_family = AF_INET;
 562         addr->v4.sin_port = addr->v6.sin6_port;
 563         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 564 }
 565
 566 /* Map v4 address to v4-mapped v6 address */
 567 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 568 {
 569         __be16 port;
 570
 571         port = addr->v4.sin_port;
 572         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 573         addr->v6.sin6_port = port;
 574         addr->v6.sin6_family = AF_INET6;
 575         addr->v6.sin6_flowinfo = 0;
 576         addr->v6.sin6_scope_id = 0;
 577         addr->v6.sin6_addr.s6_addr32[0] = 0;
 578         addr->v6.sin6_addr.s6_addr32[1] = 0;
 579         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 580 }
 581
 582 /* The cookie is always 0 since this is how it's used in the
 583  * pmtu code.
 584  */
 585 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 586 {
 587         if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
 588                 dst_release(t->dst);
 589                 t->dst = NULL;
 590         }
 591
 592         return t->dst;
 593 }
 594
 595 #endif /* __net_sctp_h__ */