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 void sctp_sock_rfree(struct sk_buff *skb);
 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  * sctp/proc.c
 183  */
 184 int sctp_snmp_proc_init(void);
 185 void sctp_snmp_proc_exit(void);
 186 int sctp_eps_proc_init(void);
 187 void sctp_eps_proc_exit(void);
 188 int sctp_assocs_proc_init(void);
 189 void sctp_assocs_proc_exit(void);
 190
 191
 192 /*
 193  * Module global variables
 194  */
 195
 196  /*
 197   * sctp/protocol.c
 198   */
 199 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 200 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 201
 202 /*
 203  *  Section:  Macros, externs, and inlines
 204  */
 205
 206
 207 #ifdef TEST_FRAME
 208 #include <test_frame.h>
 209 #else
 210
 211 /* spin lock wrappers. */
 212 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 213 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 214        spin_unlock_irqrestore(lock, flags)
 215 #define sctp_local_bh_disable() local_bh_disable()
 216 #define sctp_local_bh_enable()  local_bh_enable()
 217 #define sctp_spin_lock(lock)    spin_lock(lock)
 218 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 219 #define sctp_write_lock(lock)   write_lock(lock)
 220 #define sctp_write_unlock(lock) write_unlock(lock)
 221 #define sctp_read_lock(lock)    read_lock(lock)
 222 #define sctp_read_unlock(lock)  read_unlock(lock)
 223
 224 /* sock lock wrappers. */
 225 #define sctp_lock_sock(sk)       lock_sock(sk)
 226 #define sctp_release_sock(sk)    release_sock(sk)
 227 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 228 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 229 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
 230 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
 231
 232 /* SCTP SNMP MIB stats handlers */
 233 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 234 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 235 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 236 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 237 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 238
 239 #endif /* !TEST_FRAME */
 240
 241 /* sctp mib definitions */
 242 enum
 243 {
 244         SCTP_MIB_NUM = 0,
 245         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 246         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 247         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 248         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 249         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 250         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 251         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 252         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 253         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 254         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 255         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 256         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 257         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 258         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 259         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 260         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 261         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 262         SCTP_MIB_T1_INIT_EXPIREDS,
 263         SCTP_MIB_T1_COOKIE_EXPIREDS,
 264         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 265         SCTP_MIB_T3_RTX_EXPIREDS,
 266         SCTP_MIB_T4_RTO_EXPIREDS,
 267         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 268         SCTP_MIB_DELAY_SACK_EXPIREDS,
 269         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 270         SCTP_MIB_T3_RETRANSMITS,
 271         SCTP_MIB_PMTUD_RETRANSMITS,
 272         SCTP_MIB_FAST_RETRANSMITS,
 273         SCTP_MIB_IN_PKT_SOFTIRQ,
 274         SCTP_MIB_IN_PKT_BACKLOG,
 275         SCTP_MIB_IN_PKT_DISCARDS,
 276         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 277         __SCTP_MIB_MAX
 278 };
 279
 280 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 281 struct sctp_mib {
 282         unsigned long   mibs[SCTP_MIB_MAX];
 283 } __SNMP_MIB_ALIGN__;
 284
 285
 286 /* Print debugging messages.  */
 287 #if SCTP_DEBUG
 288 extern int sctp_debug_flag;
 289 #define SCTP_DEBUG_PRINTK(whatever...) \
 290         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 291 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 292         if (sctp_debug_flag) { \
 293                 if (saddr->sa.sa_family == AF_INET6) { \
 294                         printk(KERN_DEBUG \
 295                                lead NIP6_FMT trail, \
 296                                leadparm, \
 297                                NIP6(saddr->v6.sin6_addr), \
 298                                otherparms); \
 299                 } else { \
 300                         printk(KERN_DEBUG \
 301                                lead NIPQUAD_FMT trail, \
 302                                leadparm, \
 303                                NIPQUAD(saddr->v4.sin_addr.s_addr), \
 304                                otherparms); \
 305                 } \
 306         }
 307 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 308 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 309
 310 #define SCTP_ASSERT(expr, str, func) \
 311         if (!(expr)) { \
 312                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 313                         str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
 314                 func; \
 315         }
 316
 317 #else   /* SCTP_DEBUG */
 318
 319 #define SCTP_DEBUG_PRINTK(whatever...)
 320 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 321 #define SCTP_ENABLE_DEBUG
 322 #define SCTP_DISABLE_DEBUG
 323 #define SCTP_ASSERT(expr, str, func)
 324
 325 #endif /* SCTP_DEBUG */
 326
 327
 328 /*
 329  * Macros for keeping a global reference of object allocations.
 330  */
 331 #ifdef CONFIG_SCTP_DBG_OBJCNT
 332
 333 extern atomic_t sctp_dbg_objcnt_sock;
 334 extern atomic_t sctp_dbg_objcnt_ep;
 335 extern atomic_t sctp_dbg_objcnt_assoc;
 336 extern atomic_t sctp_dbg_objcnt_transport;
 337 extern atomic_t sctp_dbg_objcnt_chunk;
 338 extern atomic_t sctp_dbg_objcnt_bind_addr;
 339 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 340 extern atomic_t sctp_dbg_objcnt_addr;
 341 extern atomic_t sctp_dbg_objcnt_ssnmap;
 342 extern atomic_t sctp_dbg_objcnt_datamsg;
 343
 344 /* Macros to atomically increment/decrement objcnt counters.  */
 345 #define SCTP_DBG_OBJCNT_INC(name) \
 346 atomic_inc(&sctp_dbg_objcnt_## name)
 347 #define SCTP_DBG_OBJCNT_DEC(name) \
 348 atomic_dec(&sctp_dbg_objcnt_## name)
 349 #define SCTP_DBG_OBJCNT(name) \
 350 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 351
 352 /* Macro to help create new entries in in the global array of
 353  * objcnt counters.
 354  */
 355 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 356 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 357
 358 void sctp_dbg_objcnt_init(void);
 359 void sctp_dbg_objcnt_exit(void);
 360
 361 #else
 362
 363 #define SCTP_DBG_OBJCNT_INC(name)
 364 #define SCTP_DBG_OBJCNT_DEC(name)
 365
 366 static inline void sctp_dbg_objcnt_init(void) { return; }
 367 static inline void sctp_dbg_objcnt_exit(void) { return; }
 368
 369 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 370
 371 #if defined CONFIG_SYSCTL
 372 void sctp_sysctl_register(void);
 373 void sctp_sysctl_unregister(void);
 374 #else
 375 static inline void sctp_sysctl_register(void) { return; }
 376 static inline void sctp_sysctl_unregister(void) { return; }
 377 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
 378                 void __user *oldval, size_t __user *oldlenp,
 379                 void __user *newval, size_t newlen) {
 380         return -ENOSYS;
 381 }
 382 #endif
 383
 384 /* Size of Supported Address Parameter for 'x' address types. */
 385 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 386
 387 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 388
 389 int sctp_v6_init(void);
 390 void sctp_v6_exit(void);
 391 int sctp_v6_add_protocol(void);
 392 void sctp_v6_del_protocol(void);
 393
 394 #else /* #ifdef defined(CONFIG_IPV6) */
 395
 396 static inline int sctp_v6_init(void) { return 0; }
 397 static inline void sctp_v6_exit(void) { return; }
 398 static inline int sctp_v6_add_protocol(void) { return 0; }
 399 static inline void sctp_v6_del_protocol(void) { return; }
 400
 401 #endif /* #if defined(CONFIG_IPV6) */
 402
 403
 404 /* Map an association to an assoc_id. */
 405 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 406 {
 407         return (asoc?asoc->assoc_id:0);
 408 }
 409
 410 /* Look up the association by its id.  */
 411 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 412
 413
 414 /* A macro to walk a list of skbs.  */
 415 #define sctp_skb_for_each(pos, head, tmp) \
 416 for (pos = (head)->next;\
 417      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
 418      pos = tmp)
 419
 420
 421 /* A helper to append an entire skb list (list) to another (head). */
 422 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 423                                       struct sk_buff_head *head)
 424 {
 425         unsigned long flags;
 426
 427         sctp_spin_lock_irqsave(&head->lock, flags);
 428         sctp_spin_lock(&list->lock);
 429
 430         list_splice((struct list_head *)list, (struct list_head *)head->prev);
 431
 432         head->qlen += list->qlen;
 433         list->qlen = 0;
 434
 435         sctp_spin_unlock(&list->lock);
 436         sctp_spin_unlock_irqrestore(&head->lock, flags);
 437 }
 438
 439 /**
 440  *      sctp_list_dequeue - remove from the head of the queue
 441  *      @list: list to dequeue from
 442  *
 443  *      Remove the head of the list. The head item is
 444  *      returned or %NULL if the list is empty.
 445  */
 446
 447 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 448 {
 449         struct list_head *result = NULL;
 450
 451         if (list->next != list) {
 452                 result = list->next;
 453                 list->next = result->next;
 454                 list->next->prev = list;
 455                 INIT_LIST_HEAD(result);
 456         }
 457         return result;
 458 }
 459
 460 /* SCTP version of skb_set_owner_r.  We need this one because
 461  * of the way we have to do receive buffer accounting on bundled
 462  * chunks.
 463  */
 464 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 465 {
 466         struct sctp_ulpevent *event = sctp_skb2event(skb);
 467
 468         skb->sk = sk;
 469         skb->destructor = sctp_sock_rfree;
 470         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 471 }
 472
 473 /* Tests if the list has one and only one entry. */
 474 static inline int sctp_list_single_entry(struct list_head *head)
 475 {
 476         return ((head->next != head) && (head->next == head->prev));
 477 }
 478
 479 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 480 static inline __s32 sctp_jitter(__u32 rto)
 481 {
 482         static __u32 sctp_rand;
 483         __s32 ret;
 484
 485         /* Avoid divide by zero. */
 486         if (!rto)
 487                 rto = 1;
 488
 489         sctp_rand += jiffies;
 490         sctp_rand ^= (sctp_rand << 12);
 491         sctp_rand ^= (sctp_rand >> 20);
 492
 493         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 494          * of rto.
 495          */
 496         ret = sctp_rand % rto - (rto >> 1);
 497         return ret;
 498 }
 499
 500 /* Break down data chunks at this point.  */
 501 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 502 {
 503         int frag = pmtu;
 504
 505         frag -= sp->pf->af->net_header_len;
 506         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 507
 508         if (sp->user_frag)
 509                 frag = min_t(int, frag, sp->user_frag);
 510
 511         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 512
 513         return frag;
 514 }
 515
 516 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 517 {
 518
 519         sctp_assoc_sync_pmtu(asoc);
 520         asoc->pmtu_pending = 0;
 521 }
 522
 523 /* Walk through a list of TLV parameters.  Don't trust the
 524  * individual parameter lengths and instead depend on
 525  * the chunk length to indicate when to stop.  Make sure
 526  * there is room for a param header too.
 527  */
 528 #define sctp_walk_params(pos, chunk, member)\
 529 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 530
 531 #define _sctp_walk_params(pos, chunk, end, member)\
 532 for (pos.v = chunk->member;\
 533      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 534      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 535      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 536      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 537
 538 #define sctp_walk_errors(err, chunk_hdr)\
 539 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 540
 541 #define _sctp_walk_errors(err, chunk_hdr, end)\
 542 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 543             sizeof(sctp_chunkhdr_t));\
 544      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 545      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 546      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 547      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 548
 549 #define sctp_walk_fwdtsn(pos, chunk)\
 550 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 551
 552 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 553 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 554      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 555      pos++)
 556
 557 /* Round an int up to the next multiple of 4.  */
 558 #define WORD_ROUND(s) (((s)+3)&~3)
 559
 560 /* Make a new instance of type.  */
 561 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 562
 563 /* Compare two timevals.  */
 564 #define tv_lt(s, t) \
 565    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 566
 567 /* Add tv1 to tv2. */
 568 #define TIMEVAL_ADD(tv1, tv2) \
 569 ({ \
 570         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 571         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 572 \
 573         if (usecs >= 1000000) { \
 574                 usecs -= 1000000; \
 575                 secs++; \
 576         } \
 577         (tv2).tv_sec = secs; \
 578         (tv2).tv_usec = usecs; \
 579 })
 580
 581 /* External references. */
 582
 583 extern struct proto sctp_prot;
 584 extern struct proto sctpv6_prot;
 585 extern struct proc_dir_entry *proc_net_sctp;
 586 void sctp_put_port(struct sock *sk);
 587
 588 extern struct idr sctp_assocs_id;
 589 extern spinlock_t sctp_assocs_id_lock;
 590
 591 /* Static inline functions. */
 592
 593 /* Convert from an IP version number to an Address Family symbol.  */
 594 static inline int ipver2af(__u8 ipver)
 595 {
 596         switch (ipver) {
 597         case 4:
 598                 return  AF_INET;
 599         case 6:
 600                 return AF_INET6;
 601         default:
 602                 return 0;
 603         };
 604 }
 605
 606 /* Convert from an address parameter type to an address family.  */
 607 static inline int param_type2af(__be16 type)
 608 {
 609         switch (type) {
 610         case SCTP_PARAM_IPV4_ADDRESS:
 611                 return  AF_INET;
 612         case SCTP_PARAM_IPV6_ADDRESS:
 613                 return AF_INET6;
 614         default:
 615                 return 0;
 616         };
 617 }
 618
 619 /* Perform some sanity checks. */
 620 static inline int sctp_sanity_check(void)
 621 {
 622         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 623                     sizeof(((struct sk_buff *)0)->cb),
 624                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 625
 626         return 1;
 627 }
 628
 629 /* Warning: The following hash functions assume a power of two 'size'. */
 630 /* This is the hash function for the SCTP port hash table. */
 631 static inline int sctp_phashfn(__u16 lport)
 632 {
 633         return (lport & (sctp_port_hashsize - 1));
 634 }
 635
 636 /* This is the hash function for the endpoint hash table. */
 637 static inline int sctp_ep_hashfn(__u16 lport)
 638 {
 639         return (lport & (sctp_ep_hashsize - 1));
 640 }
 641
 642 /* This is the hash function for the association hash table. */
 643 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 644 {
 645         int h = (lport << 16) + rport;
 646         h ^= h>>8;
 647         return (h & (sctp_assoc_hashsize - 1));
 648 }
 649
 650 /* This is the hash function for the association hash table.  This is
 651  * not used yet, but could be used as a better hash function when
 652  * we have a vtag.
 653  */
 654 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 655 {
 656         int h = (lport << 16) + rport;
 657         h ^= vtag;
 658         return (h & (sctp_assoc_hashsize-1));
 659 }
 660
 661 /* Is a socket of this style? */
 662 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 663 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 664 {
 665         return sctp_sk(sk)->type == style;
 666 }
 667
 668 /* Is the association in this state? */
 669 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 670 static inline int __sctp_state(const struct sctp_association *asoc,
 671                                sctp_state_t state)
 672 {
 673         return asoc->state == state;
 674 }
 675
 676 /* Is the socket in this state? */
 677 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 678 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 679 {
 680         return sk->sk_state == state;
 681 }
 682
 683 /* Map v4-mapped v6 address back to v4 address */
 684 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 685 {
 686         addr->v4.sin_family = AF_INET;
 687         addr->v4.sin_port = addr->v6.sin6_port;
 688         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 689 }
 690
 691 /* Map v4 address to v4-mapped v6 address */
 692 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 693 {
 694         addr->v6.sin6_family = AF_INET6;
 695         addr->v6.sin6_port = addr->v4.sin_port;
 696         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 697         addr->v6.sin6_addr.s6_addr32[0] = 0;
 698         addr->v6.sin6_addr.s6_addr32[1] = 0;
 699         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 700 }
 701
 702 #endif /* __net_sctp_h__ */