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 #include <linux/types.h>
  66 #include <linux/slab.h>
  67 #include <linux/in.h>
  68 #include <linux/tty.h>
  69 #include <linux/proc_fs.h>
  70 #include <linux/spinlock.h>
  71 #include <linux/jiffies.h>
  72 #include <linux/idr.h>
  73
  74 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  75 #include <net/ipv6.h>
  76 #include <net/ip6_route.h>
  77 #endif
  78
  79 #include <asm/uaccess.h>
  80 #include <asm/page.h>
  81 #include <net/sock.h>
  82 #include <net/snmp.h>
  83 #include <net/sctp/structs.h>
  84 #include <net/sctp/constants.h>
  85
  86
  87 /* Set SCTP_DEBUG flag via config if not already set. */
  88 #ifndef SCTP_DEBUG
  89 #ifdef CONFIG_SCTP_DBG_MSG
  90 #define SCTP_DEBUG      1
  91 #else
  92 #define SCTP_DEBUG      0
  93 #endif /* CONFIG_SCTP_DBG */
  94 #endif /* SCTP_DEBUG */
  95
  96 #ifdef CONFIG_IP_SCTP_MODULE
  97 #define SCTP_PROTOSW_FLAG 0
  98 #else /* static! */
  99 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
 100 #endif
 101
 102
 103 /* Certain internal static functions need to be exported when
 104  * compiled into the test frame.
 105  */
 106 #ifndef SCTP_STATIC
 107 #define SCTP_STATIC static
 108 #endif
 109
 110 /*
 111  * Function declarations.
 112  */
 113
 114 /*
 115  * sctp/protocol.c
 116  */
 117 extern struct sock *sctp_get_ctl_sock(void);
 118 extern void sctp_local_addr_free(struct rcu_head *head);
 119 extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
 120                                      sctp_scope_t, gfp_t gfp,
 121                                      int flags);
 122 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 123 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
 124
 125 /*
 126  * sctp/socket.c
 127  */
 128 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 129 int sctp_inet_listen(struct socket *sock, int backlog);
 130 void sctp_write_space(struct sock *sk);
 131 unsigned int sctp_poll(struct file *file, struct socket *sock,
 132                 poll_table *wait);
 133 void sctp_sock_rfree(struct sk_buff *skb);
 134 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 135                     struct sctp_association *asoc);
 136 extern struct percpu_counter sctp_sockets_allocated;
 137
 138 /*
 139  * sctp/primitive.c
 140  */
 141 int sctp_primitive_ASSOCIATE(struct sctp_association *, void *arg);
 142 int sctp_primitive_SHUTDOWN(struct sctp_association *, void *arg);
 143 int sctp_primitive_ABORT(struct sctp_association *, void *arg);
 144 int sctp_primitive_SEND(struct sctp_association *, void *arg);
 145 int sctp_primitive_REQUESTHEARTBEAT(struct sctp_association *, void *arg);
 146 int sctp_primitive_ASCONF(struct sctp_association *, void *arg);
 147
 148 /*
 149  * sctp/input.c
 150  */
 151 int sctp_rcv(struct sk_buff *skb);
 152 void sctp_v4_err(struct sk_buff *skb, u32 info);
 153 void sctp_hash_established(struct sctp_association *);
 154 void sctp_unhash_established(struct sctp_association *);
 155 void sctp_hash_endpoint(struct sctp_endpoint *);
 156 void sctp_unhash_endpoint(struct sctp_endpoint *);
 157 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 158                              struct sctphdr *, struct sctp_association **,
 159                              struct sctp_transport **);
 160 void sctp_err_finish(struct sock *, struct sctp_association *);
 161 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 162                            struct sctp_transport *t, __u32 pmtu);
 163 void sctp_icmp_proto_unreachable(struct sock *sk,
 164                                  struct sctp_association *asoc,
 165                                  struct sctp_transport *t);
 166 void sctp_backlog_migrate(struct sctp_association *assoc,
 167                           struct sock *oldsk, struct sock *newsk);
 168
 169 /*
 170  * sctp/proc.c
 171  */
 172 int sctp_snmp_proc_init(void);
 173 void sctp_snmp_proc_exit(void);
 174 int sctp_eps_proc_init(void);
 175 void sctp_eps_proc_exit(void);
 176 int sctp_assocs_proc_init(void);
 177 void sctp_assocs_proc_exit(void);
 178 int sctp_remaddr_proc_init(void);
 179 void sctp_remaddr_proc_exit(void);
 180
 181
 182 /*
 183  * Module global variables
 184  */
 185
 186  /*
 187   * sctp/protocol.c
 188   */
 189 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 190 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 191
 192 /*
 193  *  Section:  Macros, externs, and inlines
 194  */
 195
 196
 197 #ifdef TEST_FRAME
 198 #include <test_frame.h>
 199 #else
 200
 201 /* spin lock wrappers. */
 202 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 203 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 204        spin_unlock_irqrestore(lock, flags)
 205 #define sctp_local_bh_disable() local_bh_disable()
 206 #define sctp_local_bh_enable()  local_bh_enable()
 207 #define sctp_spin_lock(lock)    spin_lock(lock)
 208 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 209 #define sctp_write_lock(lock)   write_lock(lock)
 210 #define sctp_write_unlock(lock) write_unlock(lock)
 211 #define sctp_read_lock(lock)    read_lock(lock)
 212 #define sctp_read_unlock(lock)  read_unlock(lock)
 213
 214 /* sock lock wrappers. */
 215 #define sctp_lock_sock(sk)       lock_sock(sk)
 216 #define sctp_release_sock(sk)    release_sock(sk)
 217 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 218 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 219
 220 /* SCTP SNMP MIB stats handlers */
 221 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 222 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 223 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 224 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 225 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 226
 227 #endif /* !TEST_FRAME */
 228
 229 /* sctp mib definitions */
 230 enum
 231 {
 232         SCTP_MIB_NUM = 0,
 233         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 234         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 235         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 236         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 237         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 238         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 239         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 240         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 241         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 242         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 243         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 244         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 245         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 246         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 247         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 248         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 249         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 250         SCTP_MIB_T1_INIT_EXPIREDS,
 251         SCTP_MIB_T1_COOKIE_EXPIREDS,
 252         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 253         SCTP_MIB_T3_RTX_EXPIREDS,
 254         SCTP_MIB_T4_RTO_EXPIREDS,
 255         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 256         SCTP_MIB_DELAY_SACK_EXPIREDS,
 257         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 258         SCTP_MIB_T1_RETRANSMITS,
 259         SCTP_MIB_T3_RETRANSMITS,
 260         SCTP_MIB_PMTUD_RETRANSMITS,
 261         SCTP_MIB_FAST_RETRANSMITS,
 262         SCTP_MIB_IN_PKT_SOFTIRQ,
 263         SCTP_MIB_IN_PKT_BACKLOG,
 264         SCTP_MIB_IN_PKT_DISCARDS,
 265         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 266         __SCTP_MIB_MAX
 267 };
 268
 269 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 270 struct sctp_mib {
 271         unsigned long   mibs[SCTP_MIB_MAX];
 272 } __SNMP_MIB_ALIGN__;
 273
 274
 275 /* Print debugging messages.  */
 276 #if SCTP_DEBUG
 277 extern int sctp_debug_flag;
 278 #define SCTP_DEBUG_PRINTK(whatever...) \
 279         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 280 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 281         if (sctp_debug_flag) { \
 282                 if (saddr->sa.sa_family == AF_INET6) { \
 283                         printk(KERN_DEBUG \
 284                                lead "%pI6" trail, \
 285                                leadparm, \
 286                                &saddr->v6.sin6_addr, \
 287                                otherparms); \
 288                 } else { \
 289                         printk(KERN_DEBUG \
 290                                lead "%pI4" trail, \
 291                                leadparm, \
 292                                &saddr->v4.sin_addr.s_addr, \
 293                                otherparms); \
 294                 } \
 295         }
 296 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 297 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 298
 299 #define SCTP_ASSERT(expr, str, func) \
 300         if (!(expr)) { \
 301                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 302                         str, (#expr), __FILE__, __func__, __LINE__); \
 303                 func; \
 304         }
 305
 306 #else   /* SCTP_DEBUG */
 307
 308 #define SCTP_DEBUG_PRINTK(whatever...)
 309 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 310 #define SCTP_ENABLE_DEBUG
 311 #define SCTP_DISABLE_DEBUG
 312 #define SCTP_ASSERT(expr, str, func)
 313
 314 #endif /* SCTP_DEBUG */
 315
 316
 317 /*
 318  * Macros for keeping a global reference of object allocations.
 319  */
 320 #ifdef CONFIG_SCTP_DBG_OBJCNT
 321
 322 extern atomic_t sctp_dbg_objcnt_sock;
 323 extern atomic_t sctp_dbg_objcnt_ep;
 324 extern atomic_t sctp_dbg_objcnt_assoc;
 325 extern atomic_t sctp_dbg_objcnt_transport;
 326 extern atomic_t sctp_dbg_objcnt_chunk;
 327 extern atomic_t sctp_dbg_objcnt_bind_addr;
 328 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 329 extern atomic_t sctp_dbg_objcnt_addr;
 330 extern atomic_t sctp_dbg_objcnt_ssnmap;
 331 extern atomic_t sctp_dbg_objcnt_datamsg;
 332 extern atomic_t sctp_dbg_objcnt_keys;
 333
 334 /* Macros to atomically increment/decrement objcnt counters.  */
 335 #define SCTP_DBG_OBJCNT_INC(name) \
 336 atomic_inc(&sctp_dbg_objcnt_## name)
 337 #define SCTP_DBG_OBJCNT_DEC(name) \
 338 atomic_dec(&sctp_dbg_objcnt_## name)
 339 #define SCTP_DBG_OBJCNT(name) \
 340 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 341
 342 /* Macro to help create new entries in in the global array of
 343  * objcnt counters.
 344  */
 345 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 346 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 347
 348 void sctp_dbg_objcnt_init(void);
 349 void sctp_dbg_objcnt_exit(void);
 350
 351 #else
 352
 353 #define SCTP_DBG_OBJCNT_INC(name)
 354 #define SCTP_DBG_OBJCNT_DEC(name)
 355
 356 static inline void sctp_dbg_objcnt_init(void) { return; }
 357 static inline void sctp_dbg_objcnt_exit(void) { return; }
 358
 359 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 360
 361 #if defined CONFIG_SYSCTL
 362 void sctp_sysctl_register(void);
 363 void sctp_sysctl_unregister(void);
 364 #else
 365 static inline void sctp_sysctl_register(void) { return; }
 366 static inline void sctp_sysctl_unregister(void) { return; }
 367 #endif
 368
 369 /* Size of Supported Address Parameter for 'x' address types. */
 370 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 371
 372 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 373
 374 void sctp_v6_pf_init(void);
 375 void sctp_v6_pf_exit(void);
 376 int sctp_v6_protosw_init(void);
 377 void sctp_v6_protosw_exit(void);
 378 int sctp_v6_add_protocol(void);
 379 void sctp_v6_del_protocol(void);
 380
 381 #else /* #ifdef defined(CONFIG_IPV6) */
 382
 383 static inline void sctp_v6_pf_init(void) { return; }
 384 static inline void sctp_v6_pf_exit(void) { return; }
 385 static inline int sctp_v6_protosw_init(void) { return 0; }
 386 static inline void sctp_v6_protosw_exit(void) { return; }
 387 static inline int sctp_v6_add_protocol(void) { return 0; }
 388 static inline void sctp_v6_del_protocol(void) { return; }
 389
 390 #endif /* #if defined(CONFIG_IPV6) */
 391
 392
 393 /* Map an association to an assoc_id. */
 394 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 395 {
 396         return (asoc?asoc->assoc_id:0);
 397 }
 398
 399 /* Look up the association by its id.  */
 400 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 401
 402
 403 /* A macro to walk a list of skbs.  */
 404 #define sctp_skb_for_each(pos, head, tmp) \
 405         skb_queue_walk_safe(head, pos, tmp)
 406
 407 /* A helper to append an entire skb list (list) to another (head). */
 408 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 409                                       struct sk_buff_head *head)
 410 {
 411         unsigned long flags;
 412
 413         sctp_spin_lock_irqsave(&head->lock, flags);
 414         sctp_spin_lock(&list->lock);
 415
 416         skb_queue_splice_tail_init(list, head);
 417
 418         sctp_spin_unlock(&list->lock);
 419         sctp_spin_unlock_irqrestore(&head->lock, flags);
 420 }
 421
 422 /**
 423  *      sctp_list_dequeue - remove from the head of the queue
 424  *      @list: list to dequeue from
 425  *
 426  *      Remove the head of the list. The head item is
 427  *      returned or %NULL if the list is empty.
 428  */
 429
 430 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 431 {
 432         struct list_head *result = NULL;
 433
 434         if (list->next != list) {
 435                 result = list->next;
 436                 list->next = result->next;
 437                 list->next->prev = list;
 438                 INIT_LIST_HEAD(result);
 439         }
 440         return result;
 441 }
 442
 443 /* SCTP version of skb_set_owner_r.  We need this one because
 444  * of the way we have to do receive buffer accounting on bundled
 445  * chunks.
 446  */
 447 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 448 {
 449         struct sctp_ulpevent *event = sctp_skb2event(skb);
 450
 451         skb_orphan(skb);
 452         skb->sk = sk;
 453         skb->destructor = sctp_sock_rfree;
 454         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 455         /*
 456          * This mimics the behavior of skb_set_owner_r
 457          */
 458         sk->sk_forward_alloc -= event->rmem_len;
 459 }
 460
 461 /* Tests if the list has one and only one entry. */
 462 static inline int sctp_list_single_entry(struct list_head *head)
 463 {
 464         return ((head->next != head) && (head->next == head->prev));
 465 }
 466
 467 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 468 static inline __s32 sctp_jitter(__u32 rto)
 469 {
 470         static __u32 sctp_rand;
 471         __s32 ret;
 472
 473         /* Avoid divide by zero. */
 474         if (!rto)
 475                 rto = 1;
 476
 477         sctp_rand += jiffies;
 478         sctp_rand ^= (sctp_rand << 12);
 479         sctp_rand ^= (sctp_rand >> 20);
 480
 481         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 482          * of rto.
 483          */
 484         ret = sctp_rand % rto - (rto >> 1);
 485         return ret;
 486 }
 487
 488 /* Break down data chunks at this point.  */
 489 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 490 {
 491         int frag = pmtu;
 492
 493         frag -= sp->pf->af->net_header_len;
 494         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 495
 496         if (sp->user_frag)
 497                 frag = min_t(int, frag, sp->user_frag);
 498
 499         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 500
 501         return frag;
 502 }
 503
 504 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 505 {
 506
 507         sctp_assoc_sync_pmtu(asoc);
 508         asoc->pmtu_pending = 0;
 509 }
 510
 511 /* Walk through a list of TLV parameters.  Don't trust the
 512  * individual parameter lengths and instead depend on
 513  * the chunk length to indicate when to stop.  Make sure
 514  * there is room for a param header too.
 515  */
 516 #define sctp_walk_params(pos, chunk, member)\
 517 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 518
 519 #define _sctp_walk_params(pos, chunk, end, member)\
 520 for (pos.v = chunk->member;\
 521      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 522      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 523      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 524      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 525
 526 #define sctp_walk_errors(err, chunk_hdr)\
 527 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 528
 529 #define _sctp_walk_errors(err, chunk_hdr, end)\
 530 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 531             sizeof(sctp_chunkhdr_t));\
 532      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 533      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 534      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 535      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 536
 537 #define sctp_walk_fwdtsn(pos, chunk)\
 538 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 539
 540 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 541 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 542      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 543      pos++)
 544
 545 /* Round an int up to the next multiple of 4.  */
 546 #define WORD_ROUND(s) (((s)+3)&~3)
 547
 548 /* Make a new instance of type.  */
 549 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 550
 551 /* Compare two timevals.  */
 552 #define tv_lt(s, t) \
 553    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 554
 555 /* Add tv1 to tv2. */
 556 #define TIMEVAL_ADD(tv1, tv2) \
 557 ({ \
 558         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 559         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 560 \
 561         if (usecs >= 1000000) { \
 562                 usecs -= 1000000; \
 563                 secs++; \
 564         } \
 565         (tv2).tv_sec = secs; \
 566         (tv2).tv_usec = usecs; \
 567 })
 568
 569 /* External references. */
 570
 571 extern struct proto sctp_prot;
 572 extern struct proto sctpv6_prot;
 573 extern struct proc_dir_entry *proc_net_sctp;
 574 void sctp_put_port(struct sock *sk);
 575
 576 extern struct idr sctp_assocs_id;
 577 extern spinlock_t sctp_assocs_id_lock;
 578
 579 /* Static inline functions. */
 580
 581 /* Convert from an IP version number to an Address Family symbol.  */
 582 static inline int ipver2af(__u8 ipver)
 583 {
 584         switch (ipver) {
 585         case 4:
 586                 return  AF_INET;
 587         case 6:
 588                 return AF_INET6;
 589         default:
 590                 return 0;
 591         };
 592 }
 593
 594 /* Convert from an address parameter type to an address family.  */
 595 static inline int param_type2af(__be16 type)
 596 {
 597         switch (type) {
 598         case SCTP_PARAM_IPV4_ADDRESS:
 599                 return  AF_INET;
 600         case SCTP_PARAM_IPV6_ADDRESS:
 601                 return AF_INET6;
 602         default:
 603                 return 0;
 604         };
 605 }
 606
 607 /* Perform some sanity checks. */
 608 static inline int sctp_sanity_check(void)
 609 {
 610         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 611                     sizeof(((struct sk_buff *)0)->cb),
 612                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 613
 614         return 1;
 615 }
 616
 617 /* Warning: The following hash functions assume a power of two 'size'. */
 618 /* This is the hash function for the SCTP port hash table. */
 619 static inline int sctp_phashfn(__u16 lport)
 620 {
 621         return (lport & (sctp_port_hashsize - 1));
 622 }
 623
 624 /* This is the hash function for the endpoint hash table. */
 625 static inline int sctp_ep_hashfn(__u16 lport)
 626 {
 627         return (lport & (sctp_ep_hashsize - 1));
 628 }
 629
 630 /* This is the hash function for the association hash table. */
 631 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 632 {
 633         int h = (lport << 16) + rport;
 634         h ^= h>>8;
 635         return (h & (sctp_assoc_hashsize - 1));
 636 }
 637
 638 /* This is the hash function for the association hash table.  This is
 639  * not used yet, but could be used as a better hash function when
 640  * we have a vtag.
 641  */
 642 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 643 {
 644         int h = (lport << 16) + rport;
 645         h ^= vtag;
 646         return (h & (sctp_assoc_hashsize-1));
 647 }
 648
 649 #define sctp_for_each_hentry(epb, node, head) \
 650         hlist_for_each_entry(epb, node, head, node)
 651
 652 /* Is a socket of this style? */
 653 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 654 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 655 {
 656         return sctp_sk(sk)->type == style;
 657 }
 658
 659 /* Is the association in this state? */
 660 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 661 static inline int __sctp_state(const struct sctp_association *asoc,
 662                                sctp_state_t state)
 663 {
 664         return asoc->state == state;
 665 }
 666
 667 /* Is the socket in this state? */
 668 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 669 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 670 {
 671         return sk->sk_state == state;
 672 }
 673
 674 /* Map v4-mapped v6 address back to v4 address */
 675 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 676 {
 677         addr->v4.sin_family = AF_INET;
 678         addr->v4.sin_port = addr->v6.sin6_port;
 679         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 680 }
 681
 682 /* Map v4 address to v4-mapped v6 address */
 683 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 684 {
 685         addr->v6.sin6_family = AF_INET6;
 686         addr->v6.sin6_port = addr->v4.sin_port;
 687         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 688         addr->v6.sin6_addr.s6_addr32[0] = 0;
 689         addr->v6.sin6_addr.s6_addr32[1] = 0;
 690         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 691 }
 692
 693 #endif /* __net_sctp_h__ */