include/net/sctp/sctp.h

   1 /* SCTP kernel reference 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 reference Implementation
   8  *
   9  * The base lksctp header.
  10  *
  11  * The SCTP reference 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  * The SCTP reference 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, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    La Monte H.P. Yarroll <piggy@acm.org>
  37  *    Xingang Guo           <xingang.guo@intel.com>
  38  *    Jon Grimm             <jgrimm@us.ibm.com>
  39  *    Daisy Chang           <daisyc@us.ibm.com>
  40  *    Sridhar Samudrala     <sri@us.ibm.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *    Ryan Layer            <rmlayer@us.ibm.com>
  43  *    Kevin Gao             <kevin.gao@intel.com>
  44  *
  45  * Any bugs reported given to us we will try to fix... any fixes shared will
  46  * be incorporated into the next SCTP release.
  47  */
  48
  49 #ifndef __net_sctp_h__
  50 #define __net_sctp_h__
  51
  52 /* Header Strategy.
  53  *    Start getting some control over the header file depencies:
  54  *       includes
  55  *       constants
  56  *       structs
  57  *       prototypes
  58  *       macros, externs, and inlines
  59  *
  60  *   Move test_frame specific items out of the kernel headers
  61  *   and into the test frame headers.   This is not perfect in any sense
  62  *   and will continue to evolve.
  63  */
  64
  65
  66
  67 #ifdef TEST_FRAME
  68 #undef CONFIG_PROC_FS
  69 #undef CONFIG_SCTP_DBG_OBJCNT
  70 #undef CONFIG_SYSCTL
  71 #endif /* TEST_FRAME */
  72
  73 #include <linux/types.h>
  74 #include <linux/slab.h>
  75 #include <linux/in.h>
  76 #include <linux/tty.h>
  77 #include <linux/proc_fs.h>
  78 #include <linux/spinlock.h>
  79 #include <linux/jiffies.h>
  80 #include <linux/idr.h>
  81
  82 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  83 #include <net/ipv6.h>
  84 #include <net/ip6_route.h>
  85 #endif
  86
  87 #include <asm/uaccess.h>
  88 #include <asm/page.h>
  89 #include <net/sock.h>
  90 #include <net/snmp.h>
  91 #include <net/sctp/structs.h>
  92 #include <net/sctp/constants.h>
  93
  94
  95 /* Set SCTP_DEBUG flag via config if not already set. */
  96 #ifndef SCTP_DEBUG
  97 #ifdef CONFIG_SCTP_DBG_MSG
  98 #define SCTP_DEBUG      1
  99 #else
 100 #define SCTP_DEBUG      0
 101 #endif /* CONFIG_SCTP_DBG */
 102 #endif /* SCTP_DEBUG */
 103
 104 #ifdef CONFIG_IP_SCTP_MODULE
 105 #define SCTP_PROTOSW_FLAG 0
 106 #else /* static! */
 107 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
 108 #endif
 109
 110
 111 /* Certain internal static functions need to be exported when
 112  * compiled into the test frame.
 113  */
 114 #ifndef SCTP_STATIC
 115 #define SCTP_STATIC static
 116 #endif
 117
 118 /*
 119  * Function declarations.
 120  */
 121
 122 /*
 123  * sctp/protocol.c
 124  */
 125 extern struct sock *sctp_get_ctl_sock(void);
 126 extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
 127                                      sctp_scope_t, gfp_t gfp,
 128                                      int flags);
 129 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 130 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
 131
 132 /*
 133  * sctp/socket.c
 134  */
 135 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 136 int sctp_inet_listen(struct socket *sock, int backlog);
 137 void sctp_write_space(struct sock *sk);
 138 unsigned int sctp_poll(struct file *file, struct socket *sock,
 139                 poll_table *wait);
 140
 141 /*
 142  * sctp/primitive.c
 143  */
 144 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
 145 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
 146 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
 147 int sctp_primitive_SEND(struct sctp_association *, void *arg);
 148 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
 149 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
 150
 151 /*
 152  * sctp/crc32c.c
 153  */
 154 __u32 sctp_start_cksum(__u8 *ptr, __u16 count);
 155 __u32 sctp_update_cksum(__u8 *ptr, __u16 count, __u32 cksum);
 156 __u32 sctp_end_cksum(__u32 cksum);
 157 __u32 sctp_update_copy_cksum(__u8 *, __u8 *, __u16 count, __u32 cksum);
 158
 159 /*
 160  * sctp/input.c
 161  */
 162 int sctp_rcv(struct sk_buff *skb);
 163 void sctp_v4_err(struct sk_buff *skb, u32 info);
 164 void sctp_hash_established(struct sctp_association *);
 165 void sctp_unhash_established(struct sctp_association *);
 166 void sctp_hash_endpoint(struct sctp_endpoint *);
 167 void sctp_unhash_endpoint(struct sctp_endpoint *);
 168 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 169                              struct sctphdr *, struct sctp_association **,
 170                              struct sctp_transport **);
 171 void sctp_err_finish(struct sock *, struct sctp_association *);
 172 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 173                            struct sctp_transport *t, __u32 pmtu);
 174 void sctp_icmp_proto_unreachable(struct sock *sk,
 175                                  struct sctp_association *asoc,
 176                                  struct sctp_transport *t);
 177 void sctp_backlog_migrate(struct sctp_association *assoc,
 178                           struct sock *oldsk, struct sock *newsk);
 179
 180 /*
 181  *  Section:  Macros, externs, and inlines
 182  */
 183
 184
 185 #ifdef TEST_FRAME
 186 #include <test_frame.h>
 187 #else
 188
 189 /* spin lock wrappers. */
 190 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 191 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 192        spin_unlock_irqrestore(lock, flags)
 193 #define sctp_local_bh_disable() local_bh_disable()
 194 #define sctp_local_bh_enable()  local_bh_enable()
 195 #define sctp_spin_lock(lock)    spin_lock(lock)
 196 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 197 #define sctp_write_lock(lock)   write_lock(lock)
 198 #define sctp_write_unlock(lock) write_unlock(lock)
 199 #define sctp_read_lock(lock)    read_lock(lock)
 200 #define sctp_read_unlock(lock)  read_unlock(lock)
 201
 202 /* sock lock wrappers. */
 203 #define sctp_lock_sock(sk)       lock_sock(sk)
 204 #define sctp_release_sock(sk)    release_sock(sk)
 205 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 206 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 207 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
 208 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
 209
 210 /* SCTP SNMP MIB stats handlers */
 211 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 212 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 213 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 214 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 215 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 216
 217 #endif /* !TEST_FRAME */
 218
 219
 220 /* Print debugging messages.  */
 221 #if SCTP_DEBUG
 222 extern int sctp_debug_flag;
 223 #define SCTP_DEBUG_PRINTK(whatever...) \
 224         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 225 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 226         if (sctp_debug_flag) { \
 227                 if (saddr->sa.sa_family == AF_INET6) { \
 228                         printk(KERN_DEBUG \
 229                                lead NIP6_FMT trail, \
 230                                leadparm, \
 231                                NIP6(saddr->v6.sin6_addr), \
 232                                otherparms); \
 233                 } else { \
 234                         printk(KERN_DEBUG \
 235                                lead NIPQUAD_FMT trail, \
 236                                leadparm, \
 237                                NIPQUAD(saddr->v4.sin_addr.s_addr), \
 238                                otherparms); \
 239                 } \
 240         }
 241 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 242 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 243
 244 #define SCTP_ASSERT(expr, str, func) \
 245         if (!(expr)) { \
 246                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 247                         str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
 248                 func; \
 249         }
 250
 251 #else   /* SCTP_DEBUG */
 252
 253 #define SCTP_DEBUG_PRINTK(whatever...)
 254 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 255 #define SCTP_ENABLE_DEBUG
 256 #define SCTP_DISABLE_DEBUG
 257 #define SCTP_ASSERT(expr, str, func)
 258
 259 #endif /* SCTP_DEBUG */
 260
 261
 262 /*
 263  * Macros for keeping a global reference of object allocations.
 264  */
 265 #ifdef CONFIG_SCTP_DBG_OBJCNT
 266
 267 extern atomic_t sctp_dbg_objcnt_sock;
 268 extern atomic_t sctp_dbg_objcnt_ep;
 269 extern atomic_t sctp_dbg_objcnt_assoc;
 270 extern atomic_t sctp_dbg_objcnt_transport;
 271 extern atomic_t sctp_dbg_objcnt_chunk;
 272 extern atomic_t sctp_dbg_objcnt_bind_addr;
 273 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 274 extern atomic_t sctp_dbg_objcnt_addr;
 275 extern atomic_t sctp_dbg_objcnt_ssnmap;
 276 extern atomic_t sctp_dbg_objcnt_datamsg;
 277
 278 /* Macros to atomically increment/decrement objcnt counters.  */
 279 #define SCTP_DBG_OBJCNT_INC(name) \
 280 atomic_inc(&sctp_dbg_objcnt_## name)
 281 #define SCTP_DBG_OBJCNT_DEC(name) \
 282 atomic_dec(&sctp_dbg_objcnt_## name)
 283 #define SCTP_DBG_OBJCNT(name) \
 284 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 285
 286 /* Macro to help create new entries in in the global array of
 287  * objcnt counters.
 288  */
 289 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 290 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 291
 292 void sctp_dbg_objcnt_init(void);
 293 void sctp_dbg_objcnt_exit(void);
 294
 295 #else
 296
 297 #define SCTP_DBG_OBJCNT_INC(name)
 298 #define SCTP_DBG_OBJCNT_DEC(name)
 299
 300 static inline void sctp_dbg_objcnt_init(void) { return; }
 301 static inline void sctp_dbg_objcnt_exit(void) { return; }
 302
 303 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 304
 305 #if defined CONFIG_SYSCTL
 306 void sctp_sysctl_register(void);
 307 void sctp_sysctl_unregister(void);
 308 #else
 309 static inline void sctp_sysctl_register(void) { return; }
 310 static inline void sctp_sysctl_unregister(void) { return; }
 311 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
 312                 void __user *oldval, size_t __user *oldlenp,
 313                 void __user *newval, size_t newlen, void **context) {
 314         return -ENOSYS;
 315 }
 316 #endif
 317
 318 /* Size of Supported Address Parameter for 'x' address types. */
 319 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 320
 321 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 322
 323 int sctp_v6_init(void);
 324 void sctp_v6_exit(void);
 325
 326 #else /* #ifdef defined(CONFIG_IPV6) */
 327
 328 static inline int sctp_v6_init(void) { return 0; }
 329 static inline void sctp_v6_exit(void) { return; }
 330
 331 #endif /* #if defined(CONFIG_IPV6) */
 332
 333 /* Some wrappers, in case crypto not available. */
 334 #if defined (CONFIG_CRYPTO_HMAC)
 335 #define sctp_crypto_alloc_tfm crypto_alloc_tfm
 336 #define sctp_crypto_free_tfm crypto_free_tfm
 337 #define sctp_crypto_hmac crypto_hmac
 338 #else
 339 #define sctp_crypto_alloc_tfm(x...) NULL
 340 #define sctp_crypto_free_tfm(x...)
 341 #define sctp_crypto_hmac(x...)
 342 #endif
 343
 344
 345 /* Map an association to an assoc_id. */
 346 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 347 {
 348         return (asoc?asoc->assoc_id:0);
 349 }
 350
 351 /* Look up the association by its id.  */
 352 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 353
 354
 355 /* A macro to walk a list of skbs.  */
 356 #define sctp_skb_for_each(pos, head, tmp) \
 357 for (pos = (head)->next;\
 358      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
 359      pos = tmp)
 360
 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         sctp_spin_lock_irqsave(&head->lock, flags);
 369         sctp_spin_lock(&list->lock);
 370
 371         list_splice((struct list_head *)list, (struct list_head *)head->prev);
 372
 373         head->qlen += list->qlen;
 374         list->qlen = 0;
 375
 376         sctp_spin_unlock(&list->lock);
 377         sctp_spin_unlock_irqrestore(&head->lock, flags);
 378 }
 379
 380 /**
 381  *      sctp_list_dequeue - remove from the head of the queue
 382  *      @list: list to dequeue from
 383  *
 384  *      Remove the head of the list. The head item is
 385  *      returned or %NULL if the list is empty.
 386  */
 387
 388 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 389 {
 390         struct list_head *result = NULL;
 391
 392         if (list->next != list) {
 393                 result = list->next;
 394                 list->next = result->next;
 395                 list->next->prev = list;
 396                 INIT_LIST_HEAD(result);
 397         }
 398         return result;
 399 }
 400
 401 /* Tests if the list has one and only one entry. */
 402 static inline int sctp_list_single_entry(struct list_head *head)
 403 {
 404         return ((head->next != head) && (head->next == head->prev));
 405 }
 406
 407 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 408 static inline __s32 sctp_jitter(__u32 rto)
 409 {
 410         static __u32 sctp_rand;
 411         __s32 ret;
 412
 413         /* Avoid divide by zero. */
 414         if (!rto)
 415                 rto = 1;
 416
 417         sctp_rand += jiffies;
 418         sctp_rand ^= (sctp_rand << 12);
 419         sctp_rand ^= (sctp_rand >> 20);
 420
 421         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 422          * of rto.
 423          */
 424         ret = sctp_rand % rto - (rto >> 1);
 425         return ret;
 426 }
 427
 428 /* Break down data chunks at this point.  */
 429 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 430 {
 431         int frag = pmtu;
 432
 433         frag -= sp->pf->af->net_header_len;
 434         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 435
 436         if (sp->user_frag)
 437                 frag = min_t(int, frag, sp->user_frag);
 438
 439         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 440
 441         return frag;
 442 }
 443
 444 /* Walk through a list of TLV parameters.  Don't trust the
 445  * individual parameter lengths and instead depend on
 446  * the chunk length to indicate when to stop.  Make sure
 447  * there is room for a param header too.
 448  */
 449 #define sctp_walk_params(pos, chunk, member)\
 450 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 451
 452 #define _sctp_walk_params(pos, chunk, end, member)\
 453 for (pos.v = chunk->member;\
 454      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 455      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 456      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 457      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 458
 459 #define sctp_walk_errors(err, chunk_hdr)\
 460 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 461
 462 #define _sctp_walk_errors(err, chunk_hdr, end)\
 463 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 464             sizeof(sctp_chunkhdr_t));\
 465      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 466      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 467      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 468      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 469
 470 #define sctp_walk_fwdtsn(pos, chunk)\
 471 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 472
 473 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 474 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 475      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 476      pos++)
 477
 478 /* Round an int up to the next multiple of 4.  */
 479 #define WORD_ROUND(s) (((s)+3)&~3)
 480
 481 /* Make a new instance of type.  */
 482 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 483
 484 /* Compare two timevals.  */
 485 #define tv_lt(s, t) \
 486    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 487
 488 /* Add tv1 to tv2. */
 489 #define TIMEVAL_ADD(tv1, tv2) \
 490 ({ \
 491         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 492         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 493 \
 494         if (usecs >= 1000000) { \
 495                 usecs -= 1000000; \
 496                 secs++; \
 497         } \
 498         (tv2).tv_sec = secs; \
 499         (tv2).tv_usec = usecs; \
 500 })
 501
 502 /* External references. */
 503
 504 extern struct proto sctp_prot;
 505 extern struct proto sctpv6_prot;
 506 extern struct proc_dir_entry *proc_net_sctp;
 507 void sctp_put_port(struct sock *sk);
 508
 509 extern struct idr sctp_assocs_id;
 510 extern spinlock_t sctp_assocs_id_lock;
 511
 512 /* Static inline functions. */
 513
 514 /* Convert from an IP version number to an Address Family symbol.  */
 515 static inline int ipver2af(__u8 ipver)
 516 {
 517         switch (ipver) {
 518         case 4:
 519                 return  AF_INET;
 520         case 6:
 521                 return AF_INET6;
 522         default:
 523                 return 0;
 524         };
 525 }
 526
 527 /* Convert from an address parameter type to an address family.  */
 528 static inline int param_type2af(__u16 type)
 529 {
 530         switch (type) {
 531         case SCTP_PARAM_IPV4_ADDRESS:
 532                 return  AF_INET;
 533         case SCTP_PARAM_IPV6_ADDRESS:
 534                 return AF_INET6;
 535         default:
 536                 return 0;
 537         };
 538 }
 539
 540 /* Perform some sanity checks. */
 541 static inline int sctp_sanity_check(void)
 542 {
 543         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 544                     sizeof(((struct sk_buff *)0)->cb),
 545                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 546
 547         return 1;
 548 }
 549
 550 /* Warning: The following hash functions assume a power of two 'size'. */
 551 /* This is the hash function for the SCTP port hash table. */
 552 static inline int sctp_phashfn(__u16 lport)
 553 {
 554         return (lport & (sctp_port_hashsize - 1));
 555 }
 556
 557 /* This is the hash function for the endpoint hash table. */
 558 static inline int sctp_ep_hashfn(__u16 lport)
 559 {
 560         return (lport & (sctp_ep_hashsize - 1));
 561 }
 562
 563 /* This is the hash function for the association hash table. */
 564 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 565 {
 566         int h = (lport << 16) + rport;
 567         h ^= h>>8;
 568         return (h & (sctp_assoc_hashsize - 1));
 569 }
 570
 571 /* This is the hash function for the association hash table.  This is
 572  * not used yet, but could be used as a better hash function when
 573  * we have a vtag.
 574  */
 575 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 576 {
 577         int h = (lport << 16) + rport;
 578         h ^= vtag;
 579         return (h & (sctp_assoc_hashsize-1));
 580 }
 581
 582 /* Is a socket of this style? */
 583 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 584 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 585 {
 586         return sctp_sk(sk)->type == style;
 587 }
 588
 589 /* Is the association in this state? */
 590 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 591 static inline int __sctp_state(const struct sctp_association *asoc,
 592                                sctp_state_t state)
 593 {
 594         return asoc->state == state;
 595 }
 596
 597 /* Is the socket in this state? */
 598 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 599 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 600 {
 601         return sk->sk_state == state;
 602 }
 603
 604 /* Map v4-mapped v6 address back to v4 address */
 605 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 606 {
 607         addr->v4.sin_family = AF_INET;
 608         addr->v4.sin_port = addr->v6.sin6_port;
 609         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 610 }
 611
 612 /* Map v4 address to v4-mapped v6 address */
 613 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 614 {
 615         addr->v6.sin6_family = AF_INET6;
 616         addr->v6.sin6_port = addr->v4.sin_port;
 617         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 618         addr->v6.sin6_addr.s6_addr32[0] = 0;
 619         addr->v6.sin6_addr.s6_addr32[1] = 0;
 620         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 621 }
 622
 623 #endif /* __net_sctp_h__ */