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 void sctp_local_addr_free(struct rcu_head *head);
 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 void sctp_sock_rfree(struct sk_buff *skb);
 142
 143 /*
 144  * sctp/primitive.c
 145  */
 146 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
 147 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
 148 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
 149 int sctp_primitive_SEND(struct sctp_association *, void *arg);
 150 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
 151 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
 152
 153 /*
 154  * sctp/crc32c.c
 155  */
 156 __u32 sctp_start_cksum(__u8 *ptr, __u16 count);
 157 __u32 sctp_update_cksum(__u8 *ptr, __u16 count, __u32 cksum);
 158 __u32 sctp_end_cksum(__u32 cksum);
 159 __u32 sctp_update_copy_cksum(__u8 *, __u8 *, __u16 count, __u32 cksum);
 160
 161 /*
 162  * sctp/input.c
 163  */
 164 int sctp_rcv(struct sk_buff *skb);
 165 void sctp_v4_err(struct sk_buff *skb, u32 info);
 166 void sctp_hash_established(struct sctp_association *);
 167 void sctp_unhash_established(struct sctp_association *);
 168 void sctp_hash_endpoint(struct sctp_endpoint *);
 169 void sctp_unhash_endpoint(struct sctp_endpoint *);
 170 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 171                              struct sctphdr *, struct sctp_association **,
 172                              struct sctp_transport **);
 173 void sctp_err_finish(struct sock *, struct sctp_association *);
 174 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 175                            struct sctp_transport *t, __u32 pmtu);
 176 void sctp_icmp_proto_unreachable(struct sock *sk,
 177                                  struct sctp_association *asoc,
 178                                  struct sctp_transport *t);
 179 void sctp_backlog_migrate(struct sctp_association *assoc,
 180                           struct sock *oldsk, struct sock *newsk);
 181
 182 /*
 183  * sctp/proc.c
 184  */
 185 int sctp_snmp_proc_init(void);
 186 void sctp_snmp_proc_exit(void);
 187 int sctp_eps_proc_init(void);
 188 void sctp_eps_proc_exit(void);
 189 int sctp_assocs_proc_init(void);
 190 void sctp_assocs_proc_exit(void);
 191
 192
 193 /*
 194  * Module global variables
 195  */
 196
 197  /*
 198   * sctp/protocol.c
 199   */
 200 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 201 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 202
 203 /*
 204  *  Section:  Macros, externs, and inlines
 205  */
 206
 207
 208 #ifdef TEST_FRAME
 209 #include <test_frame.h>
 210 #else
 211
 212 /* spin lock wrappers. */
 213 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 214 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 215        spin_unlock_irqrestore(lock, flags)
 216 #define sctp_local_bh_disable() local_bh_disable()
 217 #define sctp_local_bh_enable()  local_bh_enable()
 218 #define sctp_spin_lock(lock)    spin_lock(lock)
 219 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 220 #define sctp_write_lock(lock)   write_lock(lock)
 221 #define sctp_write_unlock(lock) write_unlock(lock)
 222 #define sctp_read_lock(lock)    read_lock(lock)
 223 #define sctp_read_unlock(lock)  read_unlock(lock)
 224
 225 /* sock lock wrappers. */
 226 #define sctp_lock_sock(sk)       lock_sock(sk)
 227 #define sctp_release_sock(sk)    release_sock(sk)
 228 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 229 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 230 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
 231 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
 232
 233 /* SCTP SNMP MIB stats handlers */
 234 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 235 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 236 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 237 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 238 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 239
 240 #endif /* !TEST_FRAME */
 241
 242 /* sctp mib definitions */
 243 enum
 244 {
 245         SCTP_MIB_NUM = 0,
 246         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 247         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 248         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 249         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 250         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 251         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 252         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 253         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 254         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 255         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 256         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 257         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 258         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 259         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 260         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 261         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 262         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 263         SCTP_MIB_T1_INIT_EXPIREDS,
 264         SCTP_MIB_T1_COOKIE_EXPIREDS,
 265         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 266         SCTP_MIB_T3_RTX_EXPIREDS,
 267         SCTP_MIB_T4_RTO_EXPIREDS,
 268         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 269         SCTP_MIB_DELAY_SACK_EXPIREDS,
 270         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 271         SCTP_MIB_T3_RETRANSMITS,
 272         SCTP_MIB_PMTUD_RETRANSMITS,
 273         SCTP_MIB_FAST_RETRANSMITS,
 274         SCTP_MIB_IN_PKT_SOFTIRQ,
 275         SCTP_MIB_IN_PKT_BACKLOG,
 276         SCTP_MIB_IN_PKT_DISCARDS,
 277         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 278         __SCTP_MIB_MAX
 279 };
 280
 281 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 282 struct sctp_mib {
 283         unsigned long   mibs[SCTP_MIB_MAX];
 284 } __SNMP_MIB_ALIGN__;
 285
 286
 287 /* Print debugging messages.  */
 288 #if SCTP_DEBUG
 289 extern int sctp_debug_flag;
 290 #define SCTP_DEBUG_PRINTK(whatever...) \
 291         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 292 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 293         if (sctp_debug_flag) { \
 294                 if (saddr->sa.sa_family == AF_INET6) { \
 295                         printk(KERN_DEBUG \
 296                                lead NIP6_FMT trail, \
 297                                leadparm, \
 298                                NIP6(saddr->v6.sin6_addr), \
 299                                otherparms); \
 300                 } else { \
 301                         printk(KERN_DEBUG \
 302                                lead NIPQUAD_FMT trail, \
 303                                leadparm, \
 304                                NIPQUAD(saddr->v4.sin_addr.s_addr), \
 305                                otherparms); \
 306                 } \
 307         }
 308 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 309 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 310
 311 #define SCTP_ASSERT(expr, str, func) \
 312         if (!(expr)) { \
 313                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 314                         str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
 315                 func; \
 316         }
 317
 318 #else   /* SCTP_DEBUG */
 319
 320 #define SCTP_DEBUG_PRINTK(whatever...)
 321 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 322 #define SCTP_ENABLE_DEBUG
 323 #define SCTP_DISABLE_DEBUG
 324 #define SCTP_ASSERT(expr, str, func)
 325
 326 #endif /* SCTP_DEBUG */
 327
 328
 329 /*
 330  * Macros for keeping a global reference of object allocations.
 331  */
 332 #ifdef CONFIG_SCTP_DBG_OBJCNT
 333
 334 extern atomic_t sctp_dbg_objcnt_sock;
 335 extern atomic_t sctp_dbg_objcnt_ep;
 336 extern atomic_t sctp_dbg_objcnt_assoc;
 337 extern atomic_t sctp_dbg_objcnt_transport;
 338 extern atomic_t sctp_dbg_objcnt_chunk;
 339 extern atomic_t sctp_dbg_objcnt_bind_addr;
 340 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 341 extern atomic_t sctp_dbg_objcnt_addr;
 342 extern atomic_t sctp_dbg_objcnt_ssnmap;
 343 extern atomic_t sctp_dbg_objcnt_datamsg;
 344 extern atomic_t sctp_dbg_objcnt_keys;
 345
 346 /* Macros to atomically increment/decrement objcnt counters.  */
 347 #define SCTP_DBG_OBJCNT_INC(name) \
 348 atomic_inc(&sctp_dbg_objcnt_## name)
 349 #define SCTP_DBG_OBJCNT_DEC(name) \
 350 atomic_dec(&sctp_dbg_objcnt_## name)
 351 #define SCTP_DBG_OBJCNT(name) \
 352 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 353
 354 /* Macro to help create new entries in in the global array of
 355  * objcnt counters.
 356  */
 357 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 358 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 359
 360 void sctp_dbg_objcnt_init(void);
 361 void sctp_dbg_objcnt_exit(void);
 362
 363 #else
 364
 365 #define SCTP_DBG_OBJCNT_INC(name)
 366 #define SCTP_DBG_OBJCNT_DEC(name)
 367
 368 static inline void sctp_dbg_objcnt_init(void) { return; }
 369 static inline void sctp_dbg_objcnt_exit(void) { return; }
 370
 371 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 372
 373 #if defined CONFIG_SYSCTL
 374 void sctp_sysctl_register(void);
 375 void sctp_sysctl_unregister(void);
 376 #else
 377 static inline void sctp_sysctl_register(void) { return; }
 378 static inline void sctp_sysctl_unregister(void) { return; }
 379 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
 380                 void __user *oldval, size_t __user *oldlenp,
 381                 void __user *newval, size_t newlen) {
 382         return -ENOSYS;
 383 }
 384 #endif
 385
 386 /* Size of Supported Address Parameter for 'x' address types. */
 387 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 388
 389 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 390
 391 int sctp_v6_init(void);
 392 void sctp_v6_exit(void);
 393 int sctp_v6_add_protocol(void);
 394 void sctp_v6_del_protocol(void);
 395
 396 #else /* #ifdef defined(CONFIG_IPV6) */
 397
 398 static inline int sctp_v6_init(void) { return 0; }
 399 static inline void sctp_v6_exit(void) { return; }
 400 static inline int sctp_v6_add_protocol(void) { return 0; }
 401 static inline void sctp_v6_del_protocol(void) { return; }
 402
 403 #endif /* #if defined(CONFIG_IPV6) */
 404
 405
 406 /* Map an association to an assoc_id. */
 407 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 408 {
 409         return (asoc?asoc->assoc_id:0);
 410 }
 411
 412 /* Look up the association by its id.  */
 413 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 414
 415
 416 /* A macro to walk a list of skbs.  */
 417 #define sctp_skb_for_each(pos, head, tmp) \
 418 for (pos = (head)->next;\
 419      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
 420      pos = tmp)
 421
 422
 423 /* A helper to append an entire skb list (list) to another (head). */
 424 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 425                                       struct sk_buff_head *head)
 426 {
 427         unsigned long flags;
 428
 429         sctp_spin_lock_irqsave(&head->lock, flags);
 430         sctp_spin_lock(&list->lock);
 431
 432         list_splice((struct list_head *)list, (struct list_head *)head->prev);
 433
 434         head->qlen += list->qlen;
 435         list->qlen = 0;
 436
 437         sctp_spin_unlock(&list->lock);
 438         sctp_spin_unlock_irqrestore(&head->lock, flags);
 439 }
 440
 441 /**
 442  *      sctp_list_dequeue - remove from the head of the queue
 443  *      @list: list to dequeue from
 444  *
 445  *      Remove the head of the list. The head item is
 446  *      returned or %NULL if the list is empty.
 447  */
 448
 449 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 450 {
 451         struct list_head *result = NULL;
 452
 453         if (list->next != list) {
 454                 result = list->next;
 455                 list->next = result->next;
 456                 list->next->prev = list;
 457                 INIT_LIST_HEAD(result);
 458         }
 459         return result;
 460 }
 461
 462 /* SCTP version of skb_set_owner_r.  We need this one because
 463  * of the way we have to do receive buffer accounting on bundled
 464  * chunks.
 465  */
 466 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 467 {
 468         struct sctp_ulpevent *event = sctp_skb2event(skb);
 469
 470         skb->sk = sk;
 471         skb->destructor = sctp_sock_rfree;
 472         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 473         /*
 474          * This mimics the behavior of
 475          * sk_stream_set_owner_r
 476          */
 477         sk->sk_forward_alloc -= event->rmem_len;
 478 }
 479
 480 /* Tests if the list has one and only one entry. */
 481 static inline int sctp_list_single_entry(struct list_head *head)
 482 {
 483         return ((head->next != head) && (head->next == head->prev));
 484 }
 485
 486 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 487 static inline __s32 sctp_jitter(__u32 rto)
 488 {
 489         static __u32 sctp_rand;
 490         __s32 ret;
 491
 492         /* Avoid divide by zero. */
 493         if (!rto)
 494                 rto = 1;
 495
 496         sctp_rand += jiffies;
 497         sctp_rand ^= (sctp_rand << 12);
 498         sctp_rand ^= (sctp_rand >> 20);
 499
 500         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 501          * of rto.
 502          */
 503         ret = sctp_rand % rto - (rto >> 1);
 504         return ret;
 505 }
 506
 507 /* Break down data chunks at this point.  */
 508 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 509 {
 510         int frag = pmtu;
 511
 512         frag -= sp->pf->af->net_header_len;
 513         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 514
 515         if (sp->user_frag)
 516                 frag = min_t(int, frag, sp->user_frag);
 517
 518         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 519
 520         return frag;
 521 }
 522
 523 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 524 {
 525
 526         sctp_assoc_sync_pmtu(asoc);
 527         asoc->pmtu_pending = 0;
 528 }
 529
 530 /* Walk through a list of TLV parameters.  Don't trust the
 531  * individual parameter lengths and instead depend on
 532  * the chunk length to indicate when to stop.  Make sure
 533  * there is room for a param header too.
 534  */
 535 #define sctp_walk_params(pos, chunk, member)\
 536 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 537
 538 #define _sctp_walk_params(pos, chunk, end, member)\
 539 for (pos.v = chunk->member;\
 540      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 541      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 542      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 543      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 544
 545 #define sctp_walk_errors(err, chunk_hdr)\
 546 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 547
 548 #define _sctp_walk_errors(err, chunk_hdr, end)\
 549 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 550             sizeof(sctp_chunkhdr_t));\
 551      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 552      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 553      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 554      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 555
 556 #define sctp_walk_fwdtsn(pos, chunk)\
 557 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 558
 559 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 560 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 561      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 562      pos++)
 563
 564 /* Round an int up to the next multiple of 4.  */
 565 #define WORD_ROUND(s) (((s)+3)&~3)
 566
 567 /* Make a new instance of type.  */
 568 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 569
 570 /* Compare two timevals.  */
 571 #define tv_lt(s, t) \
 572    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 573
 574 /* Add tv1 to tv2. */
 575 #define TIMEVAL_ADD(tv1, tv2) \
 576 ({ \
 577         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 578         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 579 \
 580         if (usecs >= 1000000) { \
 581                 usecs -= 1000000; \
 582                 secs++; \
 583         } \
 584         (tv2).tv_sec = secs; \
 585         (tv2).tv_usec = usecs; \
 586 })
 587
 588 /* External references. */
 589
 590 extern struct proto sctp_prot;
 591 extern struct proto sctpv6_prot;
 592 extern struct proc_dir_entry *proc_net_sctp;
 593 void sctp_put_port(struct sock *sk);
 594
 595 extern struct idr sctp_assocs_id;
 596 extern spinlock_t sctp_assocs_id_lock;
 597
 598 /* Static inline functions. */
 599
 600 /* Convert from an IP version number to an Address Family symbol.  */
 601 static inline int ipver2af(__u8 ipver)
 602 {
 603         switch (ipver) {
 604         case 4:
 605                 return  AF_INET;
 606         case 6:
 607                 return AF_INET6;
 608         default:
 609                 return 0;
 610         };
 611 }
 612
 613 /* Convert from an address parameter type to an address family.  */
 614 static inline int param_type2af(__be16 type)
 615 {
 616         switch (type) {
 617         case SCTP_PARAM_IPV4_ADDRESS:
 618                 return  AF_INET;
 619         case SCTP_PARAM_IPV6_ADDRESS:
 620                 return AF_INET6;
 621         default:
 622                 return 0;
 623         };
 624 }
 625
 626 /* Perform some sanity checks. */
 627 static inline int sctp_sanity_check(void)
 628 {
 629         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 630                     sizeof(((struct sk_buff *)0)->cb),
 631                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 632
 633         return 1;
 634 }
 635
 636 /* Warning: The following hash functions assume a power of two 'size'. */
 637 /* This is the hash function for the SCTP port hash table. */
 638 static inline int sctp_phashfn(__u16 lport)
 639 {
 640         return (lport & (sctp_port_hashsize - 1));
 641 }
 642
 643 /* This is the hash function for the endpoint hash table. */
 644 static inline int sctp_ep_hashfn(__u16 lport)
 645 {
 646         return (lport & (sctp_ep_hashsize - 1));
 647 }
 648
 649 /* This is the hash function for the association hash table. */
 650 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 651 {
 652         int h = (lport << 16) + rport;
 653         h ^= h>>8;
 654         return (h & (sctp_assoc_hashsize - 1));
 655 }
 656
 657 /* This is the hash function for the association hash table.  This is
 658  * not used yet, but could be used as a better hash function when
 659  * we have a vtag.
 660  */
 661 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 662 {
 663         int h = (lport << 16) + rport;
 664         h ^= vtag;
 665         return (h & (sctp_assoc_hashsize-1));
 666 }
 667
 668 /* Is a socket of this style? */
 669 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 670 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 671 {
 672         return sctp_sk(sk)->type == style;
 673 }
 674
 675 /* Is the association in this state? */
 676 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 677 static inline int __sctp_state(const struct sctp_association *asoc,
 678                                sctp_state_t state)
 679 {
 680         return asoc->state == state;
 681 }
 682
 683 /* Is the socket in this state? */
 684 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 685 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 686 {
 687         return sk->sk_state == state;
 688 }
 689
 690 /* Map v4-mapped v6 address back to v4 address */
 691 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 692 {
 693         addr->v4.sin_family = AF_INET;
 694         addr->v4.sin_port = addr->v6.sin6_port;
 695         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 696 }
 697
 698 /* Map v4 address to v4-mapped v6 address */
 699 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 700 {
 701         addr->v6.sin6_family = AF_INET6;
 702         addr->v6.sin6_port = addr->v4.sin_port;
 703         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 704         addr->v6.sin6_addr.s6_addr32[0] = 0;
 705         addr->v6.sin6_addr.s6_addr32[1] = 0;
 706         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 707 }
 708
 709 #endif /* __net_sctp_h__ */