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 #include <linux/config.h>
  67
  68 #ifdef TEST_FRAME
  69 #undef CONFIG_PROC_FS
  70 #undef CONFIG_SCTP_DBG_OBJCNT
  71 #undef CONFIG_SYSCTL
  72 #endif /* TEST_FRAME */
  73
  74 #include <linux/types.h>
  75 #include <linux/slab.h>
  76 #include <linux/in.h>
  77 #include <linux/tty.h>
  78 #include <linux/proc_fs.h>
  79 #include <linux/spinlock.h>
  80 #include <linux/jiffies.h>
  81 #include <linux/idr.h>
  82
  83 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  84 #include <net/ipv6.h>
  85 #include <net/ip6_route.h>
  86 #endif
  87
  88 #include <asm/uaccess.h>
  89 #include <asm/page.h>
  90 #include <net/sock.h>
  91 #include <net/snmp.h>
  92 #include <net/sctp/structs.h>
  93 #include <net/sctp/constants.h>
  94
  95
  96 /* Set SCTP_DEBUG flag via config if not already set. */
  97 #ifndef SCTP_DEBUG
  98 #ifdef CONFIG_SCTP_DBG_MSG
  99 #define SCTP_DEBUG      1
 100 #else
 101 #define SCTP_DEBUG      0
 102 #endif /* CONFIG_SCTP_DBG */
 103 #endif /* SCTP_DEBUG */
 104
 105 #ifdef CONFIG_IP_SCTP_MODULE
 106 #define SCTP_PROTOSW_FLAG 0
 107 #else /* static! */
 108 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
 109 #endif
 110
 111
 112 /* Certain internal static functions need to be exported when
 113  * compiled into the test frame.
 114  */
 115 #ifndef SCTP_STATIC
 116 #define SCTP_STATIC static
 117 #endif
 118
 119 /*
 120  * Function declarations.
 121  */
 122
 123 /*
 124  * sctp/protocol.c
 125  */
 126 extern struct sock *sctp_get_ctl_sock(void);
 127 extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
 128                                      sctp_scope_t, gfp_t gfp,
 129                                      int flags);
 130 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 131 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
 132
 133 /*
 134  * sctp/socket.c
 135  */
 136 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 137 int sctp_inet_listen(struct socket *sock, int backlog);
 138 void sctp_write_space(struct sock *sk);
 139 unsigned int sctp_poll(struct file *file, struct socket *sock,
 140                 poll_table *wait);
 141
 142 /*
 143  * sctp/primitive.c
 144  */
 145 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
 146 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
 147 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
 148 int sctp_primitive_SEND(struct sctp_association *, void *arg);
 149 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
 150 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
 151
 152 /*
 153  * sctp/crc32c.c
 154  */
 155 __u32 sctp_start_cksum(__u8 *ptr, __u16 count);
 156 __u32 sctp_update_cksum(__u8 *ptr, __u16 count, __u32 cksum);
 157 __u32 sctp_end_cksum(__u32 cksum);
 158 __u32 sctp_update_copy_cksum(__u8 *, __u8 *, __u16 count, __u32 cksum);
 159
 160 /*
 161  * sctp/input.c
 162  */
 163 int sctp_rcv(struct sk_buff *skb);
 164 void sctp_v4_err(struct sk_buff *skb, u32 info);
 165 void sctp_hash_established(struct sctp_association *);
 166 void sctp_unhash_established(struct sctp_association *);
 167 void sctp_hash_endpoint(struct sctp_endpoint *);
 168 void sctp_unhash_endpoint(struct sctp_endpoint *);
 169 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 170                              struct sctphdr *, struct sctp_association **,
 171                              struct sctp_transport **);
 172 void sctp_err_finish(struct sock *, struct sctp_association *);
 173 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 174                            struct sctp_transport *t, __u32 pmtu);
 175 void sctp_icmp_proto_unreachable(struct sock *sk,
 176                                  struct sctp_association *asoc,
 177                                  struct sctp_transport *t);
 178 void sctp_backlog_migrate(struct sctp_association *assoc,
 179                           struct sock *oldsk, struct sock *newsk);
 180
 181 /*
 182  *  Section:  Macros, externs, and inlines
 183  */
 184
 185
 186 #ifdef TEST_FRAME
 187 #include <test_frame.h>
 188 #else
 189
 190 /* spin lock wrappers. */
 191 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 192 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 193        spin_unlock_irqrestore(lock, flags)
 194 #define sctp_local_bh_disable() local_bh_disable()
 195 #define sctp_local_bh_enable()  local_bh_enable()
 196 #define sctp_spin_lock(lock)    spin_lock(lock)
 197 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 198 #define sctp_write_lock(lock)   write_lock(lock)
 199 #define sctp_write_unlock(lock) write_unlock(lock)
 200 #define sctp_read_lock(lock)    read_lock(lock)
 201 #define sctp_read_unlock(lock)  read_unlock(lock)
 202
 203 /* sock lock wrappers. */
 204 #define sctp_lock_sock(sk)       lock_sock(sk)
 205 #define sctp_release_sock(sk)    release_sock(sk)
 206 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 207 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 208 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
 209 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
 210
 211 /* SCTP SNMP MIB stats handlers */
 212 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 213 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 214 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 215 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 216 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 217
 218 #endif /* !TEST_FRAME */
 219
 220
 221 /* Print debugging messages.  */
 222 #if SCTP_DEBUG
 223 extern int sctp_debug_flag;
 224 #define SCTP_DEBUG_PRINTK(whatever...) \
 225         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 226 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 227         if (sctp_debug_flag) { \
 228                 if (saddr->sa.sa_family == AF_INET6) { \
 229                         printk(KERN_DEBUG \
 230                                lead NIP6_FMT trail, \
 231                                leadparm, \
 232                                NIP6(saddr->v6.sin6_addr), \
 233                                otherparms); \
 234                 } else { \
 235                         printk(KERN_DEBUG \
 236                                lead NIPQUAD_FMT trail, \
 237                                leadparm, \
 238                                NIPQUAD(saddr->v4.sin_addr.s_addr), \
 239                                otherparms); \
 240                 } \
 241         }
 242 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 243 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 244
 245 #define SCTP_ASSERT(expr, str, func) \
 246         if (!(expr)) { \
 247                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 248                         str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
 249                 func; \
 250         }
 251
 252 #else   /* SCTP_DEBUG */
 253
 254 #define SCTP_DEBUG_PRINTK(whatever...)
 255 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 256 #define SCTP_ENABLE_DEBUG
 257 #define SCTP_DISABLE_DEBUG
 258 #define SCTP_ASSERT(expr, str, func) BUG_ON(!(expr))
 259
 260 #endif /* SCTP_DEBUG */
 261
 262
 263 /*
 264  * Macros for keeping a global reference of object allocations.
 265  */
 266 #ifdef CONFIG_SCTP_DBG_OBJCNT
 267
 268 extern atomic_t sctp_dbg_objcnt_sock;
 269 extern atomic_t sctp_dbg_objcnt_ep;
 270 extern atomic_t sctp_dbg_objcnt_assoc;
 271 extern atomic_t sctp_dbg_objcnt_transport;
 272 extern atomic_t sctp_dbg_objcnt_chunk;
 273 extern atomic_t sctp_dbg_objcnt_bind_addr;
 274 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 275 extern atomic_t sctp_dbg_objcnt_addr;
 276 extern atomic_t sctp_dbg_objcnt_ssnmap;
 277 extern atomic_t sctp_dbg_objcnt_datamsg;
 278
 279 /* Macros to atomically increment/decrement objcnt counters.  */
 280 #define SCTP_DBG_OBJCNT_INC(name) \
 281 atomic_inc(&sctp_dbg_objcnt_## name)
 282 #define SCTP_DBG_OBJCNT_DEC(name) \
 283 atomic_dec(&sctp_dbg_objcnt_## name)
 284 #define SCTP_DBG_OBJCNT(name) \
 285 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 286
 287 /* Macro to help create new entries in in the global array of
 288  * objcnt counters.
 289  */
 290 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 291 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 292
 293 void sctp_dbg_objcnt_init(void);
 294 void sctp_dbg_objcnt_exit(void);
 295
 296 #else
 297
 298 #define SCTP_DBG_OBJCNT_INC(name)
 299 #define SCTP_DBG_OBJCNT_DEC(name)
 300
 301 static inline void sctp_dbg_objcnt_init(void) { return; }
 302 static inline void sctp_dbg_objcnt_exit(void) { return; }
 303
 304 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 305
 306 #if defined CONFIG_SYSCTL
 307 void sctp_sysctl_register(void);
 308 void sctp_sysctl_unregister(void);
 309 #else
 310 static inline void sctp_sysctl_register(void) { return; }
 311 static inline void sctp_sysctl_unregister(void) { return; }
 312 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
 313                 void __user *oldval, size_t __user *oldlenp,
 314                 void __user *newval, size_t newlen, void **context) {
 315         return -ENOSYS;
 316 }
 317 #endif
 318
 319 /* Size of Supported Address Parameter for 'x' address types. */
 320 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 321
 322 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 323
 324 int sctp_v6_init(void);
 325 void sctp_v6_exit(void);
 326
 327 #else /* #ifdef defined(CONFIG_IPV6) */
 328
 329 static inline int sctp_v6_init(void) { return 0; }
 330 static inline void sctp_v6_exit(void) { return; }
 331
 332 #endif /* #if defined(CONFIG_IPV6) */
 333
 334 /* Some wrappers, in case crypto not available. */
 335 #if defined (CONFIG_CRYPTO_HMAC)
 336 #define sctp_crypto_alloc_tfm crypto_alloc_tfm
 337 #define sctp_crypto_free_tfm crypto_free_tfm
 338 #define sctp_crypto_hmac crypto_hmac
 339 #else
 340 #define sctp_crypto_alloc_tfm(x...) NULL
 341 #define sctp_crypto_free_tfm(x...)
 342 #define sctp_crypto_hmac(x...)
 343 #endif
 344
 345
 346 /* Map an association to an assoc_id. */
 347 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 348 {
 349         return (asoc?asoc->assoc_id:0);
 350 }
 351
 352 /* Look up the association by its id.  */
 353 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 354
 355
 356 /* A macro to walk a list of skbs.  */
 357 #define sctp_skb_for_each(pos, head, tmp) \
 358 for (pos = (head)->next;\
 359      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
 360      pos = tmp)
 361
 362
 363 /* A helper to append an entire skb list (list) to another (head). */
 364 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 365                                       struct sk_buff_head *head)
 366 {
 367         unsigned long flags;
 368
 369         sctp_spin_lock_irqsave(&head->lock, flags);
 370         sctp_spin_lock(&list->lock);
 371
 372         list_splice((struct list_head *)list, (struct list_head *)head->prev);
 373
 374         head->qlen += list->qlen;
 375         list->qlen = 0;
 376
 377         sctp_spin_unlock(&list->lock);
 378         sctp_spin_unlock_irqrestore(&head->lock, flags);
 379 }
 380
 381 /**
 382  *      sctp_list_dequeue - remove from the head of the queue
 383  *      @list: list to dequeue from
 384  *
 385  *      Remove the head of the list. The head item is
 386  *      returned or %NULL if the list is empty.
 387  */
 388
 389 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 390 {
 391         struct list_head *result = NULL;
 392
 393         if (list->next != list) {
 394                 result = list->next;
 395                 list->next = result->next;
 396                 list->next->prev = list;
 397                 INIT_LIST_HEAD(result);
 398         }
 399         return result;
 400 }
 401
 402 /* Tests if the list has one and only one entry. */
 403 static inline int sctp_list_single_entry(struct list_head *head)
 404 {
 405         return ((head->next != head) && (head->next == head->prev));
 406 }
 407
 408 /* Calculate the size (in bytes) occupied by the data of an iovec.  */
 409 static inline size_t get_user_iov_size(struct iovec *iov, int iovlen)
 410 {
 411         size_t retval = 0;
 412
 413         for (; iovlen > 0; --iovlen) {
 414                 retval += iov->iov_len;
 415                 iov++;
 416         }
 417
 418         return retval;
 419 }
 420
 421 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 422 static inline __s32 sctp_jitter(__u32 rto)
 423 {
 424         static __u32 sctp_rand;
 425         __s32 ret;
 426
 427         /* Avoid divide by zero. */
 428         if (!rto)
 429                 rto = 1;
 430
 431         sctp_rand += jiffies;
 432         sctp_rand ^= (sctp_rand << 12);
 433         sctp_rand ^= (sctp_rand >> 20);
 434
 435         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 436          * of rto.
 437          */
 438         ret = sctp_rand % rto - (rto >> 1);
 439         return ret;
 440 }
 441
 442 /* Break down data chunks at this point.  */
 443 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 444 {
 445         int frag = pmtu;
 446
 447         frag -= sp->pf->af->net_header_len;
 448         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 449
 450         if (sp->user_frag)
 451                 frag = min_t(int, frag, sp->user_frag);
 452
 453         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 454
 455         return frag;
 456 }
 457
 458 /* Walk through a list of TLV parameters.  Don't trust the
 459  * individual parameter lengths and instead depend on
 460  * the chunk length to indicate when to stop.  Make sure
 461  * there is room for a param header too.
 462  */
 463 #define sctp_walk_params(pos, chunk, member)\
 464 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 465
 466 #define _sctp_walk_params(pos, chunk, end, member)\
 467 for (pos.v = chunk->member;\
 468      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 469      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 470      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 471      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 472
 473 #define sctp_walk_errors(err, chunk_hdr)\
 474 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 475
 476 #define _sctp_walk_errors(err, chunk_hdr, end)\
 477 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 478             sizeof(sctp_chunkhdr_t));\
 479      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 480      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 481      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 482      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 483
 484 #define sctp_walk_fwdtsn(pos, chunk)\
 485 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 486
 487 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 488 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 489      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 490      pos++)
 491
 492 /* Round an int up to the next multiple of 4.  */
 493 #define WORD_ROUND(s) (((s)+3)&~3)
 494
 495 /* Make a new instance of type.  */
 496 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 497
 498 /* Compare two timevals.  */
 499 #define tv_lt(s, t) \
 500    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 501
 502 /* Add tv1 to tv2. */
 503 #define TIMEVAL_ADD(tv1, tv2) \
 504 ({ \
 505         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 506         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 507 \
 508         if (usecs >= 1000000) { \
 509                 usecs -= 1000000; \
 510                 secs++; \
 511         } \
 512         (tv2).tv_sec = secs; \
 513         (tv2).tv_usec = usecs; \
 514 })
 515
 516 /* External references. */
 517
 518 extern struct proto sctp_prot;
 519 extern struct proto sctpv6_prot;
 520 extern struct proc_dir_entry *proc_net_sctp;
 521 void sctp_put_port(struct sock *sk);
 522
 523 extern struct idr sctp_assocs_id;
 524 extern spinlock_t sctp_assocs_id_lock;
 525
 526 /* Static inline functions. */
 527
 528 /* Convert from an IP version number to an Address Family symbol.  */
 529 static inline int ipver2af(__u8 ipver)
 530 {
 531         switch (ipver) {
 532         case 4:
 533                 return  AF_INET;
 534         case 6:
 535                 return AF_INET6;
 536         default:
 537                 return 0;
 538         };
 539 }
 540
 541 /* Convert from an address parameter type to an address family.  */
 542 static inline int param_type2af(__u16 type)
 543 {
 544         switch (type) {
 545         case SCTP_PARAM_IPV4_ADDRESS:
 546                 return  AF_INET;
 547         case SCTP_PARAM_IPV6_ADDRESS:
 548                 return AF_INET6;
 549         default:
 550                 return 0;
 551         };
 552 }
 553
 554 /* Perform some sanity checks. */
 555 static inline int sctp_sanity_check(void)
 556 {
 557         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 558                     sizeof(((struct sk_buff *)0)->cb),
 559                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 560
 561         return 1;
 562 }
 563
 564 /* Warning: The following hash functions assume a power of two 'size'. */
 565 /* This is the hash function for the SCTP port hash table. */
 566 static inline int sctp_phashfn(__u16 lport)
 567 {
 568         return (lport & (sctp_port_hashsize - 1));
 569 }
 570
 571 /* This is the hash function for the endpoint hash table. */
 572 static inline int sctp_ep_hashfn(__u16 lport)
 573 {
 574         return (lport & (sctp_ep_hashsize - 1));
 575 }
 576
 577 /* This is the hash function for the association hash table. */
 578 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 579 {
 580         int h = (lport << 16) + rport;
 581         h ^= h>>8;
 582         return (h & (sctp_assoc_hashsize - 1));
 583 }
 584
 585 /* This is the hash function for the association hash table.  This is
 586  * not used yet, but could be used as a better hash function when
 587  * we have a vtag.
 588  */
 589 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 590 {
 591         int h = (lport << 16) + rport;
 592         h ^= vtag;
 593         return (h & (sctp_assoc_hashsize-1));
 594 }
 595
 596 /* Is a socket of this style? */
 597 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 598 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 599 {
 600         return sctp_sk(sk)->type == style;
 601 }
 602
 603 /* Is the association in this state? */
 604 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 605 static inline int __sctp_state(const struct sctp_association *asoc,
 606                                sctp_state_t state)
 607 {
 608         return asoc->state == state;
 609 }
 610
 611 /* Is the socket in this state? */
 612 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 613 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 614 {
 615         return sk->sk_state == state;
 616 }
 617
 618 /* Map v4-mapped v6 address back to v4 address */
 619 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 620 {
 621         addr->v4.sin_family = AF_INET;
 622         addr->v4.sin_port = addr->v6.sin6_port;
 623         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 624 }
 625
 626 /* Map v4 address to v4-mapped v6 address */
 627 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 628 {
 629         addr->v6.sin6_family = AF_INET6;
 630         addr->v6.sin6_port = addr->v4.sin_port;
 631         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 632         addr->v6.sin6_addr.s6_addr32[0] = 0;
 633         addr->v6.sin6_addr.s6_addr32[1] = 0;
 634         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 635 }
 636
 637 #endif /* __net_sctp_h__ */