include/net/sctp/sctp.h

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999-2000 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  * Copyright (c) 2001-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * The base lksctp header.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, 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_SCTP_DBG_OBJCNT
  69 #undef CONFIG_SYSCTL
  70 #endif /* TEST_FRAME */
  71
  72 #include <linux/types.h>
  73 #include <linux/slab.h>
  74 #include <linux/in.h>
  75 #include <linux/tty.h>
  76 #include <linux/proc_fs.h>
  77 #include <linux/spinlock.h>
  78 #include <linux/jiffies.h>
  79 #include <linux/idr.h>
  80
  81 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  82 #include <net/ipv6.h>
  83 #include <net/ip6_route.h>
  84 #endif
  85
  86 #include <asm/uaccess.h>
  87 #include <asm/page.h>
  88 #include <net/sock.h>
  89 #include <net/snmp.h>
  90 #include <net/sctp/structs.h>
  91 #include <net/sctp/constants.h>
  92
  93
  94 /* Set SCTP_DEBUG flag via config if not already set. */
  95 #ifndef SCTP_DEBUG
  96 #ifdef CONFIG_SCTP_DBG_MSG
  97 #define SCTP_DEBUG      1
  98 #else
  99 #define SCTP_DEBUG      0
 100 #endif /* CONFIG_SCTP_DBG */
 101 #endif /* SCTP_DEBUG */
 102
 103 #ifdef CONFIG_IP_SCTP_MODULE
 104 #define SCTP_PROTOSW_FLAG 0
 105 #else /* static! */
 106 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
 107 #endif
 108
 109
 110 /* Certain internal static functions need to be exported when
 111  * compiled into the test frame.
 112  */
 113 #ifndef SCTP_STATIC
 114 #define SCTP_STATIC static
 115 #endif
 116
 117 /*
 118  * Function declarations.
 119  */
 120
 121 /*
 122  * sctp/protocol.c
 123  */
 124 extern struct sock *sctp_get_ctl_sock(void);
 125 extern void sctp_local_addr_free(struct rcu_head *head);
 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/input.c
 154  */
 155 int sctp_rcv(struct sk_buff *skb);
 156 void sctp_v4_err(struct sk_buff *skb, u32 info);
 157 void sctp_hash_established(struct sctp_association *);
 158 void sctp_unhash_established(struct sctp_association *);
 159 void sctp_hash_endpoint(struct sctp_endpoint *);
 160 void sctp_unhash_endpoint(struct sctp_endpoint *);
 161 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 162                              struct sctphdr *, struct sctp_association **,
 163                              struct sctp_transport **);
 164 void sctp_err_finish(struct sock *, struct sctp_association *);
 165 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 166                            struct sctp_transport *t, __u32 pmtu);
 167 void sctp_icmp_proto_unreachable(struct sock *sk,
 168                                  struct sctp_association *asoc,
 169                                  struct sctp_transport *t);
 170 void sctp_backlog_migrate(struct sctp_association *assoc,
 171                           struct sock *oldsk, struct sock *newsk);
 172
 173 /*
 174  * sctp/proc.c
 175  */
 176 int sctp_snmp_proc_init(void);
 177 void sctp_snmp_proc_exit(void);
 178 int sctp_eps_proc_init(void);
 179 void sctp_eps_proc_exit(void);
 180 int sctp_assocs_proc_init(void);
 181 void sctp_assocs_proc_exit(void);
 182
 183
 184 /*
 185  * Module global variables
 186  */
 187
 188  /*
 189   * sctp/protocol.c
 190   */
 191 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 192 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 193
 194 /*
 195  *  Section:  Macros, externs, and inlines
 196  */
 197
 198
 199 #ifdef TEST_FRAME
 200 #include <test_frame.h>
 201 #else
 202
 203 /* spin lock wrappers. */
 204 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 205 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 206        spin_unlock_irqrestore(lock, flags)
 207 #define sctp_local_bh_disable() local_bh_disable()
 208 #define sctp_local_bh_enable()  local_bh_enable()
 209 #define sctp_spin_lock(lock)    spin_lock(lock)
 210 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 211 #define sctp_write_lock(lock)   write_lock(lock)
 212 #define sctp_write_unlock(lock) write_unlock(lock)
 213 #define sctp_read_lock(lock)    read_lock(lock)
 214 #define sctp_read_unlock(lock)  read_unlock(lock)
 215
 216 /* sock lock wrappers. */
 217 #define sctp_lock_sock(sk)       lock_sock(sk)
 218 #define sctp_release_sock(sk)    release_sock(sk)
 219 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 220 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 221 #define SCTP_SOCK_SLEEP_PRE(sk)  SOCK_SLEEP_PRE(sk)
 222 #define SCTP_SOCK_SLEEP_POST(sk) SOCK_SLEEP_POST(sk)
 223
 224 /* SCTP SNMP MIB stats handlers */
 225 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 226 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 227 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 228 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 229 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 230
 231 #endif /* !TEST_FRAME */
 232
 233 /* sctp mib definitions */
 234 enum
 235 {
 236         SCTP_MIB_NUM = 0,
 237         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 238         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 239         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 240         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 241         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 242         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 243         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 244         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 245         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 246         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 247         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 248         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 249         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 250         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 251         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 252         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 253         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 254         SCTP_MIB_T1_INIT_EXPIREDS,
 255         SCTP_MIB_T1_COOKIE_EXPIREDS,
 256         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 257         SCTP_MIB_T3_RTX_EXPIREDS,
 258         SCTP_MIB_T4_RTO_EXPIREDS,
 259         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 260         SCTP_MIB_DELAY_SACK_EXPIREDS,
 261         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 262         SCTP_MIB_T1_RETRANSMITS,
 263         SCTP_MIB_T3_RETRANSMITS,
 264         SCTP_MIB_PMTUD_RETRANSMITS,
 265         SCTP_MIB_FAST_RETRANSMITS,
 266         SCTP_MIB_IN_PKT_SOFTIRQ,
 267         SCTP_MIB_IN_PKT_BACKLOG,
 268         SCTP_MIB_IN_PKT_DISCARDS,
 269         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 270         __SCTP_MIB_MAX
 271 };
 272
 273 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 274 struct sctp_mib {
 275         unsigned long   mibs[SCTP_MIB_MAX];
 276 } __SNMP_MIB_ALIGN__;
 277
 278
 279 /* Print debugging messages.  */
 280 #if SCTP_DEBUG
 281 extern int sctp_debug_flag;
 282 #define SCTP_DEBUG_PRINTK(whatever...) \
 283         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 284 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 285         if (sctp_debug_flag) { \
 286                 if (saddr->sa.sa_family == AF_INET6) { \
 287                         printk(KERN_DEBUG \
 288                                lead NIP6_FMT trail, \
 289                                leadparm, \
 290                                NIP6(saddr->v6.sin6_addr), \
 291                                otherparms); \
 292                 } else { \
 293                         printk(KERN_DEBUG \
 294                                lead NIPQUAD_FMT trail, \
 295                                leadparm, \
 296                                NIPQUAD(saddr->v4.sin_addr.s_addr), \
 297                                otherparms); \
 298                 } \
 299         }
 300 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 301 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 302
 303 #define SCTP_ASSERT(expr, str, func) \
 304         if (!(expr)) { \
 305                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 306                         str, (#expr), __FILE__, __FUNCTION__, __LINE__); \
 307                 func; \
 308         }
 309
 310 #else   /* SCTP_DEBUG */
 311
 312 #define SCTP_DEBUG_PRINTK(whatever...)
 313 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 314 #define SCTP_ENABLE_DEBUG
 315 #define SCTP_DISABLE_DEBUG
 316 #define SCTP_ASSERT(expr, str, func)
 317
 318 #endif /* SCTP_DEBUG */
 319
 320
 321 /*
 322  * Macros for keeping a global reference of object allocations.
 323  */
 324 #ifdef CONFIG_SCTP_DBG_OBJCNT
 325
 326 extern atomic_t sctp_dbg_objcnt_sock;
 327 extern atomic_t sctp_dbg_objcnt_ep;
 328 extern atomic_t sctp_dbg_objcnt_assoc;
 329 extern atomic_t sctp_dbg_objcnt_transport;
 330 extern atomic_t sctp_dbg_objcnt_chunk;
 331 extern atomic_t sctp_dbg_objcnt_bind_addr;
 332 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 333 extern atomic_t sctp_dbg_objcnt_addr;
 334 extern atomic_t sctp_dbg_objcnt_ssnmap;
 335 extern atomic_t sctp_dbg_objcnt_datamsg;
 336 extern atomic_t sctp_dbg_objcnt_keys;
 337
 338 /* Macros to atomically increment/decrement objcnt counters.  */
 339 #define SCTP_DBG_OBJCNT_INC(name) \
 340 atomic_inc(&sctp_dbg_objcnt_## name)
 341 #define SCTP_DBG_OBJCNT_DEC(name) \
 342 atomic_dec(&sctp_dbg_objcnt_## name)
 343 #define SCTP_DBG_OBJCNT(name) \
 344 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 345
 346 /* Macro to help create new entries in in the global array of
 347  * objcnt counters.
 348  */
 349 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 350 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 351
 352 void sctp_dbg_objcnt_init(void);
 353 void sctp_dbg_objcnt_exit(void);
 354
 355 #else
 356
 357 #define SCTP_DBG_OBJCNT_INC(name)
 358 #define SCTP_DBG_OBJCNT_DEC(name)
 359
 360 static inline void sctp_dbg_objcnt_init(void) { return; }
 361 static inline void sctp_dbg_objcnt_exit(void) { return; }
 362
 363 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 364
 365 #if defined CONFIG_SYSCTL
 366 void sctp_sysctl_register(void);
 367 void sctp_sysctl_unregister(void);
 368 #else
 369 static inline void sctp_sysctl_register(void) { return; }
 370 static inline void sctp_sysctl_unregister(void) { return; }
 371 static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int nlen,
 372                 void __user *oldval, size_t __user *oldlenp,
 373                 void __user *newval, size_t newlen) {
 374         return -ENOSYS;
 375 }
 376 #endif
 377
 378 /* Size of Supported Address Parameter for 'x' address types. */
 379 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 380
 381 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 382
 383 void sctp_v6_pf_init(void);
 384 void sctp_v6_pf_exit(void);
 385 int sctp_v6_protosw_init(void);
 386 void sctp_v6_protosw_exit(void);
 387 int sctp_v6_add_protocol(void);
 388 void sctp_v6_del_protocol(void);
 389
 390 #else /* #ifdef defined(CONFIG_IPV6) */
 391
 392 static inline void sctp_v6_pf_init(void) { return; }
 393 static inline void sctp_v6_pf_exit(void) { return; }
 394 static inline int sctp_v6_protosw_init(void) { return 0; }
 395 static inline void sctp_v6_protosw_exit(void) { return; }
 396 static inline int sctp_v6_add_protocol(void) { return 0; }
 397 static inline void sctp_v6_del_protocol(void) { return; }
 398
 399 #endif /* #if defined(CONFIG_IPV6) */
 400
 401
 402 /* Map an association to an assoc_id. */
 403 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 404 {
 405         return (asoc?asoc->assoc_id:0);
 406 }
 407
 408 /* Look up the association by its id.  */
 409 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 410
 411
 412 /* A macro to walk a list of skbs.  */
 413 #define sctp_skb_for_each(pos, head, tmp) \
 414 for (pos = (head)->next;\
 415      tmp = (pos)->next, pos != ((struct sk_buff *)(head));\
 416      pos = tmp)
 417
 418
 419 /* A helper to append an entire skb list (list) to another (head). */
 420 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 421                                       struct sk_buff_head *head)
 422 {
 423         unsigned long flags;
 424
 425         sctp_spin_lock_irqsave(&head->lock, flags);
 426         sctp_spin_lock(&list->lock);
 427
 428         list_splice((struct list_head *)list, (struct list_head *)head->prev);
 429
 430         head->qlen += list->qlen;
 431         list->qlen = 0;
 432
 433         sctp_spin_unlock(&list->lock);
 434         sctp_spin_unlock_irqrestore(&head->lock, flags);
 435 }
 436
 437 /**
 438  *      sctp_list_dequeue - remove from the head of the queue
 439  *      @list: list to dequeue from
 440  *
 441  *      Remove the head of the list. The head item is
 442  *      returned or %NULL if the list is empty.
 443  */
 444
 445 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 446 {
 447         struct list_head *result = NULL;
 448
 449         if (list->next != list) {
 450                 result = list->next;
 451                 list->next = result->next;
 452                 list->next->prev = list;
 453                 INIT_LIST_HEAD(result);
 454         }
 455         return result;
 456 }
 457
 458 /* SCTP version of skb_set_owner_r.  We need this one because
 459  * of the way we have to do receive buffer accounting on bundled
 460  * chunks.
 461  */
 462 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 463 {
 464         struct sctp_ulpevent *event = sctp_skb2event(skb);
 465
 466         skb->sk = sk;
 467         skb->destructor = sctp_sock_rfree;
 468         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 469         /*
 470          * This mimics the behavior of skb_set_owner_r
 471          */
 472         sk->sk_forward_alloc -= event->rmem_len;
 473 }
 474
 475 /* Tests if the list has one and only one entry. */
 476 static inline int sctp_list_single_entry(struct list_head *head)
 477 {
 478         return ((head->next != head) && (head->next == head->prev));
 479 }
 480
 481 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 482 static inline __s32 sctp_jitter(__u32 rto)
 483 {
 484         static __u32 sctp_rand;
 485         __s32 ret;
 486
 487         /* Avoid divide by zero. */
 488         if (!rto)
 489                 rto = 1;
 490
 491         sctp_rand += jiffies;
 492         sctp_rand ^= (sctp_rand << 12);
 493         sctp_rand ^= (sctp_rand >> 20);
 494
 495         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 496          * of rto.
 497          */
 498         ret = sctp_rand % rto - (rto >> 1);
 499         return ret;
 500 }
 501
 502 /* Break down data chunks at this point.  */
 503 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 504 {
 505         int frag = pmtu;
 506
 507         frag -= sp->pf->af->net_header_len;
 508         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 509
 510         if (sp->user_frag)
 511                 frag = min_t(int, frag, sp->user_frag);
 512
 513         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 514
 515         return frag;
 516 }
 517
 518 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 519 {
 520
 521         sctp_assoc_sync_pmtu(asoc);
 522         asoc->pmtu_pending = 0;
 523 }
 524
 525 /* Walk through a list of TLV parameters.  Don't trust the
 526  * individual parameter lengths and instead depend on
 527  * the chunk length to indicate when to stop.  Make sure
 528  * there is room for a param header too.
 529  */
 530 #define sctp_walk_params(pos, chunk, member)\
 531 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 532
 533 #define _sctp_walk_params(pos, chunk, end, member)\
 534 for (pos.v = chunk->member;\
 535      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 536      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 537      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 538      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 539
 540 #define sctp_walk_errors(err, chunk_hdr)\
 541 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 542
 543 #define _sctp_walk_errors(err, chunk_hdr, end)\
 544 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 545             sizeof(sctp_chunkhdr_t));\
 546      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 547      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 548      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 549      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 550
 551 #define sctp_walk_fwdtsn(pos, chunk)\
 552 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 553
 554 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 555 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 556      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 557      pos++)
 558
 559 /* Round an int up to the next multiple of 4.  */
 560 #define WORD_ROUND(s) (((s)+3)&~3)
 561
 562 /* Make a new instance of type.  */
 563 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 564
 565 /* Compare two timevals.  */
 566 #define tv_lt(s, t) \
 567    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 568
 569 /* Add tv1 to tv2. */
 570 #define TIMEVAL_ADD(tv1, tv2) \
 571 ({ \
 572         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 573         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 574 \
 575         if (usecs >= 1000000) { \
 576                 usecs -= 1000000; \
 577                 secs++; \
 578         } \
 579         (tv2).tv_sec = secs; \
 580         (tv2).tv_usec = usecs; \
 581 })
 582
 583 /* External references. */
 584
 585 extern struct proto sctp_prot;
 586 extern struct proto sctpv6_prot;
 587 extern struct proc_dir_entry *proc_net_sctp;
 588 void sctp_put_port(struct sock *sk);
 589
 590 extern struct idr sctp_assocs_id;
 591 extern spinlock_t sctp_assocs_id_lock;
 592
 593 /* Static inline functions. */
 594
 595 /* Convert from an IP version number to an Address Family symbol.  */
 596 static inline int ipver2af(__u8 ipver)
 597 {
 598         switch (ipver) {
 599         case 4:
 600                 return  AF_INET;
 601         case 6:
 602                 return AF_INET6;
 603         default:
 604                 return 0;
 605         };
 606 }
 607
 608 /* Convert from an address parameter type to an address family.  */
 609 static inline int param_type2af(__be16 type)
 610 {
 611         switch (type) {
 612         case SCTP_PARAM_IPV4_ADDRESS:
 613                 return  AF_INET;
 614         case SCTP_PARAM_IPV6_ADDRESS:
 615                 return AF_INET6;
 616         default:
 617                 return 0;
 618         };
 619 }
 620
 621 /* Perform some sanity checks. */
 622 static inline int sctp_sanity_check(void)
 623 {
 624         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 625                     sizeof(((struct sk_buff *)0)->cb),
 626                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 627
 628         return 1;
 629 }
 630
 631 /* Warning: The following hash functions assume a power of two 'size'. */
 632 /* This is the hash function for the SCTP port hash table. */
 633 static inline int sctp_phashfn(__u16 lport)
 634 {
 635         return (lport & (sctp_port_hashsize - 1));
 636 }
 637
 638 /* This is the hash function for the endpoint hash table. */
 639 static inline int sctp_ep_hashfn(__u16 lport)
 640 {
 641         return (lport & (sctp_ep_hashsize - 1));
 642 }
 643
 644 /* This is the hash function for the association hash table. */
 645 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 646 {
 647         int h = (lport << 16) + rport;
 648         h ^= h>>8;
 649         return (h & (sctp_assoc_hashsize - 1));
 650 }
 651
 652 /* This is the hash function for the association hash table.  This is
 653  * not used yet, but could be used as a better hash function when
 654  * we have a vtag.
 655  */
 656 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 657 {
 658         int h = (lport << 16) + rport;
 659         h ^= vtag;
 660         return (h & (sctp_assoc_hashsize-1));
 661 }
 662
 663 #define sctp_for_each_hentry(epb, node, head) \
 664         hlist_for_each_entry(epb, node, head, node)
 665
 666 /* Is a socket of this style? */
 667 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 668 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 669 {
 670         return sctp_sk(sk)->type == style;
 671 }
 672
 673 /* Is the association in this state? */
 674 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 675 static inline int __sctp_state(const struct sctp_association *asoc,
 676                                sctp_state_t state)
 677 {
 678         return asoc->state == state;
 679 }
 680
 681 /* Is the socket in this state? */
 682 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 683 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 684 {
 685         return sk->sk_state == state;
 686 }
 687
 688 /* Map v4-mapped v6 address back to v4 address */
 689 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 690 {
 691         addr->v4.sin_family = AF_INET;
 692         addr->v4.sin_port = addr->v6.sin6_port;
 693         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 694 }
 695
 696 /* Map v4 address to v4-mapped v6 address */
 697 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 698 {
 699         addr->v6.sin6_family = AF_INET6;
 700         addr->v6.sin6_port = addr->v4.sin_port;
 701         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 702         addr->v6.sin6_addr.s6_addr32[0] = 0;
 703         addr->v6.sin6_addr.s6_addr32[1] = 0;
 704         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 705 }
 706
 707 #endif /* __net_sctp_h__ */