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 extern struct percpu_counter sctp_sockets_allocated;
 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/input.c
 155  */
 156 int sctp_rcv(struct sk_buff *skb);
 157 void sctp_v4_err(struct sk_buff *skb, u32 info);
 158 void sctp_hash_established(struct sctp_association *);
 159 void sctp_unhash_established(struct sctp_association *);
 160 void sctp_hash_endpoint(struct sctp_endpoint *);
 161 void sctp_unhash_endpoint(struct sctp_endpoint *);
 162 struct sock *sctp_err_lookup(int family, struct sk_buff *,
 163                              struct sctphdr *, struct sctp_association **,
 164                              struct sctp_transport **);
 165 void sctp_err_finish(struct sock *, struct sctp_association *);
 166 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 167                            struct sctp_transport *t, __u32 pmtu);
 168 void sctp_icmp_proto_unreachable(struct sock *sk,
 169                                  struct sctp_association *asoc,
 170                                  struct sctp_transport *t);
 171 void sctp_backlog_migrate(struct sctp_association *assoc,
 172                           struct sock *oldsk, struct sock *newsk);
 173
 174 /*
 175  * sctp/proc.c
 176  */
 177 int sctp_snmp_proc_init(void);
 178 void sctp_snmp_proc_exit(void);
 179 int sctp_eps_proc_init(void);
 180 void sctp_eps_proc_exit(void);
 181 int sctp_assocs_proc_init(void);
 182 void sctp_assocs_proc_exit(void);
 183 int sctp_remaddr_proc_init(void);
 184 void sctp_remaddr_proc_exit(void);
 185
 186
 187 /*
 188  * Module global variables
 189  */
 190
 191  /*
 192   * sctp/protocol.c
 193   */
 194 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 195 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 196
 197 /*
 198  *  Section:  Macros, externs, and inlines
 199  */
 200
 201
 202 #ifdef TEST_FRAME
 203 #include <test_frame.h>
 204 #else
 205
 206 /* spin lock wrappers. */
 207 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 208 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 209        spin_unlock_irqrestore(lock, flags)
 210 #define sctp_local_bh_disable() local_bh_disable()
 211 #define sctp_local_bh_enable()  local_bh_enable()
 212 #define sctp_spin_lock(lock)    spin_lock(lock)
 213 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 214 #define sctp_write_lock(lock)   write_lock(lock)
 215 #define sctp_write_unlock(lock) write_unlock(lock)
 216 #define sctp_read_lock(lock)    read_lock(lock)
 217 #define sctp_read_unlock(lock)  read_unlock(lock)
 218
 219 /* sock lock wrappers. */
 220 #define sctp_lock_sock(sk)       lock_sock(sk)
 221 #define sctp_release_sock(sk)    release_sock(sk)
 222 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 223 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 224
 225 /* SCTP SNMP MIB stats handlers */
 226 DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 227 #define SCTP_INC_STATS(field)      SNMP_INC_STATS(sctp_statistics, field)
 228 #define SCTP_INC_STATS_BH(field)   SNMP_INC_STATS_BH(sctp_statistics, field)
 229 #define SCTP_INC_STATS_USER(field) SNMP_INC_STATS_USER(sctp_statistics, field)
 230 #define SCTP_DEC_STATS(field)      SNMP_DEC_STATS(sctp_statistics, field)
 231
 232 #endif /* !TEST_FRAME */
 233
 234 /* sctp mib definitions */
 235 enum
 236 {
 237         SCTP_MIB_NUM = 0,
 238         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 239         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 240         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 241         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 242         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 243         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 244         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 245         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 246         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 247         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 248         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 249         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 250         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 251         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 252         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 253         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 254         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 255         SCTP_MIB_T1_INIT_EXPIREDS,
 256         SCTP_MIB_T1_COOKIE_EXPIREDS,
 257         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 258         SCTP_MIB_T3_RTX_EXPIREDS,
 259         SCTP_MIB_T4_RTO_EXPIREDS,
 260         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 261         SCTP_MIB_DELAY_SACK_EXPIREDS,
 262         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 263         SCTP_MIB_T1_RETRANSMITS,
 264         SCTP_MIB_T3_RETRANSMITS,
 265         SCTP_MIB_PMTUD_RETRANSMITS,
 266         SCTP_MIB_FAST_RETRANSMITS,
 267         SCTP_MIB_IN_PKT_SOFTIRQ,
 268         SCTP_MIB_IN_PKT_BACKLOG,
 269         SCTP_MIB_IN_PKT_DISCARDS,
 270         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 271         __SCTP_MIB_MAX
 272 };
 273
 274 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 275 struct sctp_mib {
 276         unsigned long   mibs[SCTP_MIB_MAX];
 277 } __SNMP_MIB_ALIGN__;
 278
 279
 280 /* Print debugging messages.  */
 281 #if SCTP_DEBUG
 282 extern int sctp_debug_flag;
 283 #define SCTP_DEBUG_PRINTK(whatever...) \
 284         ((void) (sctp_debug_flag && printk(KERN_DEBUG whatever)))
 285 #define SCTP_DEBUG_PRINTK_IPADDR(lead, trail, leadparm, saddr, otherparms...) \
 286         if (sctp_debug_flag) { \
 287                 if (saddr->sa.sa_family == AF_INET6) { \
 288                         printk(KERN_DEBUG \
 289                                lead "%pI6" trail, \
 290                                leadparm, \
 291                                &saddr->v6.sin6_addr, \
 292                                otherparms); \
 293                 } else { \
 294                         printk(KERN_DEBUG \
 295                                lead "%pI4" trail, \
 296                                leadparm, \
 297                                &saddr->v4.sin_addr.s_addr, \
 298                                otherparms); \
 299                 } \
 300         }
 301 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 302 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 303
 304 #define SCTP_ASSERT(expr, str, func) \
 305         if (!(expr)) { \
 306                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 307                         str, (#expr), __FILE__, __func__, __LINE__); \
 308                 func; \
 309         }
 310
 311 #else   /* SCTP_DEBUG */
 312
 313 #define SCTP_DEBUG_PRINTK(whatever...)
 314 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 315 #define SCTP_ENABLE_DEBUG
 316 #define SCTP_DISABLE_DEBUG
 317 #define SCTP_ASSERT(expr, str, func)
 318
 319 #endif /* SCTP_DEBUG */
 320
 321
 322 /*
 323  * Macros for keeping a global reference of object allocations.
 324  */
 325 #ifdef CONFIG_SCTP_DBG_OBJCNT
 326
 327 extern atomic_t sctp_dbg_objcnt_sock;
 328 extern atomic_t sctp_dbg_objcnt_ep;
 329 extern atomic_t sctp_dbg_objcnt_assoc;
 330 extern atomic_t sctp_dbg_objcnt_transport;
 331 extern atomic_t sctp_dbg_objcnt_chunk;
 332 extern atomic_t sctp_dbg_objcnt_bind_addr;
 333 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 334 extern atomic_t sctp_dbg_objcnt_addr;
 335 extern atomic_t sctp_dbg_objcnt_ssnmap;
 336 extern atomic_t sctp_dbg_objcnt_datamsg;
 337 extern atomic_t sctp_dbg_objcnt_keys;
 338
 339 /* Macros to atomically increment/decrement objcnt counters.  */
 340 #define SCTP_DBG_OBJCNT_INC(name) \
 341 atomic_inc(&sctp_dbg_objcnt_## name)
 342 #define SCTP_DBG_OBJCNT_DEC(name) \
 343 atomic_dec(&sctp_dbg_objcnt_## name)
 344 #define SCTP_DBG_OBJCNT(name) \
 345 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 346
 347 /* Macro to help create new entries in in the global array of
 348  * objcnt counters.
 349  */
 350 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 351 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 352
 353 void sctp_dbg_objcnt_init(void);
 354 void sctp_dbg_objcnt_exit(void);
 355
 356 #else
 357
 358 #define SCTP_DBG_OBJCNT_INC(name)
 359 #define SCTP_DBG_OBJCNT_DEC(name)
 360
 361 static inline void sctp_dbg_objcnt_init(void) { return; }
 362 static inline void sctp_dbg_objcnt_exit(void) { return; }
 363
 364 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 365
 366 #if defined CONFIG_SYSCTL
 367 void sctp_sysctl_register(void);
 368 void sctp_sysctl_unregister(void);
 369 #else
 370 static inline void sctp_sysctl_register(void) { return; }
 371 static inline void sctp_sysctl_unregister(void) { return; }
 372 #endif
 373
 374 /* Size of Supported Address Parameter for 'x' address types. */
 375 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 376
 377 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 378
 379 void sctp_v6_pf_init(void);
 380 void sctp_v6_pf_exit(void);
 381 int sctp_v6_protosw_init(void);
 382 void sctp_v6_protosw_exit(void);
 383 int sctp_v6_add_protocol(void);
 384 void sctp_v6_del_protocol(void);
 385
 386 #else /* #ifdef defined(CONFIG_IPV6) */
 387
 388 static inline void sctp_v6_pf_init(void) { return; }
 389 static inline void sctp_v6_pf_exit(void) { return; }
 390 static inline int sctp_v6_protosw_init(void) { return 0; }
 391 static inline void sctp_v6_protosw_exit(void) { return; }
 392 static inline int sctp_v6_add_protocol(void) { return 0; }
 393 static inline void sctp_v6_del_protocol(void) { return; }
 394
 395 #endif /* #if defined(CONFIG_IPV6) */
 396
 397
 398 /* Map an association to an assoc_id. */
 399 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 400 {
 401         return (asoc?asoc->assoc_id:0);
 402 }
 403
 404 /* Look up the association by its id.  */
 405 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 406
 407
 408 /* A macro to walk a list of skbs.  */
 409 #define sctp_skb_for_each(pos, head, tmp) \
 410         skb_queue_walk_safe(head, pos, tmp)
 411
 412 /* A helper to append an entire skb list (list) to another (head). */
 413 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 414                                       struct sk_buff_head *head)
 415 {
 416         unsigned long flags;
 417
 418         sctp_spin_lock_irqsave(&head->lock, flags);
 419         sctp_spin_lock(&list->lock);
 420
 421         skb_queue_splice_tail_init(list, head);
 422
 423         sctp_spin_unlock(&list->lock);
 424         sctp_spin_unlock_irqrestore(&head->lock, flags);
 425 }
 426
 427 /**
 428  *      sctp_list_dequeue - remove from the head of the queue
 429  *      @list: list to dequeue from
 430  *
 431  *      Remove the head of the list. The head item is
 432  *      returned or %NULL if the list is empty.
 433  */
 434
 435 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 436 {
 437         struct list_head *result = NULL;
 438
 439         if (list->next != list) {
 440                 result = list->next;
 441                 list->next = result->next;
 442                 list->next->prev = list;
 443                 INIT_LIST_HEAD(result);
 444         }
 445         return result;
 446 }
 447
 448 /* SCTP version of skb_set_owner_r.  We need this one because
 449  * of the way we have to do receive buffer accounting on bundled
 450  * chunks.
 451  */
 452 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 453 {
 454         struct sctp_ulpevent *event = sctp_skb2event(skb);
 455
 456         skb->sk = sk;
 457         skb->destructor = sctp_sock_rfree;
 458         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 459         /*
 460          * This mimics the behavior of skb_set_owner_r
 461          */
 462         sk->sk_forward_alloc -= event->rmem_len;
 463 }
 464
 465 /* Tests if the list has one and only one entry. */
 466 static inline int sctp_list_single_entry(struct list_head *head)
 467 {
 468         return ((head->next != head) && (head->next == head->prev));
 469 }
 470
 471 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 472 static inline __s32 sctp_jitter(__u32 rto)
 473 {
 474         static __u32 sctp_rand;
 475         __s32 ret;
 476
 477         /* Avoid divide by zero. */
 478         if (!rto)
 479                 rto = 1;
 480
 481         sctp_rand += jiffies;
 482         sctp_rand ^= (sctp_rand << 12);
 483         sctp_rand ^= (sctp_rand >> 20);
 484
 485         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 486          * of rto.
 487          */
 488         ret = sctp_rand % rto - (rto >> 1);
 489         return ret;
 490 }
 491
 492 /* Break down data chunks at this point.  */
 493 static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
 494 {
 495         int frag = pmtu;
 496
 497         frag -= sp->pf->af->net_header_len;
 498         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 499
 500         if (sp->user_frag)
 501                 frag = min_t(int, frag, sp->user_frag);
 502
 503         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 504
 505         return frag;
 506 }
 507
 508 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 509 {
 510
 511         sctp_assoc_sync_pmtu(asoc);
 512         asoc->pmtu_pending = 0;
 513 }
 514
 515 /* Walk through a list of TLV parameters.  Don't trust the
 516  * individual parameter lengths and instead depend on
 517  * the chunk length to indicate when to stop.  Make sure
 518  * there is room for a param header too.
 519  */
 520 #define sctp_walk_params(pos, chunk, member)\
 521 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 522
 523 #define _sctp_walk_params(pos, chunk, end, member)\
 524 for (pos.v = chunk->member;\
 525      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
 526      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 527      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 528      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 529
 530 #define sctp_walk_errors(err, chunk_hdr)\
 531 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 532
 533 #define _sctp_walk_errors(err, chunk_hdr, end)\
 534 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 535             sizeof(sctp_chunkhdr_t));\
 536      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
 537      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 538      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 539      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 540
 541 #define sctp_walk_fwdtsn(pos, chunk)\
 542 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 543
 544 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 545 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 546      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 547      pos++)
 548
 549 /* Round an int up to the next multiple of 4.  */
 550 #define WORD_ROUND(s) (((s)+3)&~3)
 551
 552 /* Make a new instance of type.  */
 553 #define t_new(type, flags)      (type *)kmalloc(sizeof(type), flags)
 554
 555 /* Compare two timevals.  */
 556 #define tv_lt(s, t) \
 557    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 558
 559 /* Add tv1 to tv2. */
 560 #define TIMEVAL_ADD(tv1, tv2) \
 561 ({ \
 562         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 563         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 564 \
 565         if (usecs >= 1000000) { \
 566                 usecs -= 1000000; \
 567                 secs++; \
 568         } \
 569         (tv2).tv_sec = secs; \
 570         (tv2).tv_usec = usecs; \
 571 })
 572
 573 /* External references. */
 574
 575 extern struct proto sctp_prot;
 576 extern struct proto sctpv6_prot;
 577 extern struct proc_dir_entry *proc_net_sctp;
 578 void sctp_put_port(struct sock *sk);
 579
 580 extern struct idr sctp_assocs_id;
 581 extern spinlock_t sctp_assocs_id_lock;
 582
 583 /* Static inline functions. */
 584
 585 /* Convert from an IP version number to an Address Family symbol.  */
 586 static inline int ipver2af(__u8 ipver)
 587 {
 588         switch (ipver) {
 589         case 4:
 590                 return  AF_INET;
 591         case 6:
 592                 return AF_INET6;
 593         default:
 594                 return 0;
 595         };
 596 }
 597
 598 /* Convert from an address parameter type to an address family.  */
 599 static inline int param_type2af(__be16 type)
 600 {
 601         switch (type) {
 602         case SCTP_PARAM_IPV4_ADDRESS:
 603                 return  AF_INET;
 604         case SCTP_PARAM_IPV6_ADDRESS:
 605                 return AF_INET6;
 606         default:
 607                 return 0;
 608         };
 609 }
 610
 611 /* Perform some sanity checks. */
 612 static inline int sctp_sanity_check(void)
 613 {
 614         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 615                     sizeof(((struct sk_buff *)0)->cb),
 616                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 617
 618         return 1;
 619 }
 620
 621 /* Warning: The following hash functions assume a power of two 'size'. */
 622 /* This is the hash function for the SCTP port hash table. */
 623 static inline int sctp_phashfn(__u16 lport)
 624 {
 625         return (lport & (sctp_port_hashsize - 1));
 626 }
 627
 628 /* This is the hash function for the endpoint hash table. */
 629 static inline int sctp_ep_hashfn(__u16 lport)
 630 {
 631         return (lport & (sctp_ep_hashsize - 1));
 632 }
 633
 634 /* This is the hash function for the association hash table. */
 635 static inline int sctp_assoc_hashfn(__u16 lport, __u16 rport)
 636 {
 637         int h = (lport << 16) + rport;
 638         h ^= h>>8;
 639         return (h & (sctp_assoc_hashsize - 1));
 640 }
 641
 642 /* This is the hash function for the association hash table.  This is
 643  * not used yet, but could be used as a better hash function when
 644  * we have a vtag.
 645  */
 646 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 647 {
 648         int h = (lport << 16) + rport;
 649         h ^= vtag;
 650         return (h & (sctp_assoc_hashsize-1));
 651 }
 652
 653 #define sctp_for_each_hentry(epb, node, head) \
 654         hlist_for_each_entry(epb, node, head, node)
 655
 656 /* Is a socket of this style? */
 657 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 658 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 659 {
 660         return sctp_sk(sk)->type == style;
 661 }
 662
 663 /* Is the association in this state? */
 664 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 665 static inline int __sctp_state(const struct sctp_association *asoc,
 666                                sctp_state_t state)
 667 {
 668         return asoc->state == state;
 669 }
 670
 671 /* Is the socket in this state? */
 672 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 673 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 674 {
 675         return sk->sk_state == state;
 676 }
 677
 678 /* Map v4-mapped v6 address back to v4 address */
 679 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 680 {
 681         addr->v4.sin_family = AF_INET;
 682         addr->v4.sin_port = addr->v6.sin6_port;
 683         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 684 }
 685
 686 /* Map v4 address to v4-mapped v6 address */
 687 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 688 {
 689         addr->v6.sin6_family = AF_INET6;
 690         addr->v6.sin6_port = addr->v4.sin_port;
 691         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 692         addr->v6.sin6_addr.s6_addr32[0] = 0;
 693         addr->v6.sin6_addr.s6_addr32[1] = 0;
 694         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 695 }
 696
 697 #endif /* __net_sctp_h__ */