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 IS_ENABLED(CONFIG_IPV6)
  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 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
 118                                      sctp_scope_t, gfp_t gfp,
 119                                      int flags);
 120 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 121 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
 122 extern void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
 123
 124 /*
 125  * sctp/socket.c
 126  */
 127 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 128 int sctp_inet_listen(struct socket *sock, int backlog);
 129 void sctp_write_space(struct sock *sk);
 130 void sctp_data_ready(struct sock *sk, int len);
 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 extern int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 138
 139 /*
 140  * sctp/primitive.c
 141  */
 142 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 143 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 144 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 145 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 146 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 147 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 148
 149 /*
 150  * sctp/input.c
 151  */
 152 int sctp_rcv(struct sk_buff *skb);
 153 void sctp_v4_err(struct sk_buff *skb, u32 info);
 154 void sctp_hash_established(struct sctp_association *);
 155 void sctp_unhash_established(struct sctp_association *);
 156 void sctp_hash_endpoint(struct sctp_endpoint *);
 157 void sctp_unhash_endpoint(struct sctp_endpoint *);
 158 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 159                              struct sctphdr *, struct sctp_association **,
 160                              struct sctp_transport **);
 161 void sctp_err_finish(struct sock *, struct sctp_association *);
 162 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 163                            struct sctp_transport *t, __u32 pmtu);
 164 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 165                         struct sk_buff *);
 166 void sctp_icmp_proto_unreachable(struct sock *sk,
 167                                  struct sctp_association *asoc,
 168                                  struct sctp_transport *t);
 169 void sctp_backlog_migrate(struct sctp_association *assoc,
 170                           struct sock *oldsk, struct sock *newsk);
 171
 172 /*
 173  * sctp/proc.c
 174  */
 175 int sctp_snmp_proc_init(struct net *net);
 176 void sctp_snmp_proc_exit(struct net *net);
 177 int sctp_eps_proc_init(struct net *net);
 178 void sctp_eps_proc_exit(struct net *net);
 179 int sctp_assocs_proc_init(struct net *net);
 180 void sctp_assocs_proc_exit(struct net *net);
 181 int sctp_remaddr_proc_init(struct net *net);
 182 void sctp_remaddr_proc_exit(struct net *net);
 183
 184
 185 /*
 186  * Module global variables
 187  */
 188
 189  /*
 190   * sctp/protocol.c
 191   */
 192 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 193 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 194
 195 /*
 196  *  Section:  Macros, externs, and inlines
 197  */
 198
 199
 200 #ifdef TEST_FRAME
 201 #include <test_frame.h>
 202 #else
 203
 204 /* spin lock wrappers. */
 205 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 206 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 207        spin_unlock_irqrestore(lock, flags)
 208 #define sctp_local_bh_disable() local_bh_disable()
 209 #define sctp_local_bh_enable()  local_bh_enable()
 210 #define sctp_spin_lock(lock)    spin_lock(lock)
 211 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 212 #define sctp_write_lock(lock)   write_lock(lock)
 213 #define sctp_write_unlock(lock) write_unlock(lock)
 214 #define sctp_read_lock(lock)    read_lock(lock)
 215 #define sctp_read_unlock(lock)  read_unlock(lock)
 216
 217 /* sock lock wrappers. */
 218 #define sctp_lock_sock(sk)       lock_sock(sk)
 219 #define sctp_release_sock(sk)    release_sock(sk)
 220 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 221 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 222
 223 /* SCTP SNMP MIB stats handlers */
 224 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 225 #define SCTP_INC_STATS_BH(net, field)   SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
 226 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
 227 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 228
 229 #endif /* !TEST_FRAME */
 230
 231 /* sctp mib definitions */
 232 enum {
 233         SCTP_MIB_NUM = 0,
 234         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 235         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 236         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 237         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 238         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 239         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 240         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 241         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 242         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 243         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 244         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 245         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 246         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 247         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 248         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 249         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 250         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 251         SCTP_MIB_T1_INIT_EXPIREDS,
 252         SCTP_MIB_T1_COOKIE_EXPIREDS,
 253         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 254         SCTP_MIB_T3_RTX_EXPIREDS,
 255         SCTP_MIB_T4_RTO_EXPIREDS,
 256         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 257         SCTP_MIB_DELAY_SACK_EXPIREDS,
 258         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 259         SCTP_MIB_T1_RETRANSMITS,
 260         SCTP_MIB_T3_RETRANSMITS,
 261         SCTP_MIB_PMTUD_RETRANSMITS,
 262         SCTP_MIB_FAST_RETRANSMITS,
 263         SCTP_MIB_IN_PKT_SOFTIRQ,
 264         SCTP_MIB_IN_PKT_BACKLOG,
 265         SCTP_MIB_IN_PKT_DISCARDS,
 266         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 267         __SCTP_MIB_MAX
 268 };
 269
 270 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 271 struct sctp_mib {
 272         unsigned long   mibs[SCTP_MIB_MAX];
 273 };
 274
 275
 276 /* Print debugging messages.  */
 277 #if SCTP_DEBUG
 278 extern int sctp_debug_flag;
 279 #define SCTP_DEBUG_PRINTK(fmt, args...)                 \
 280 do {                                                    \
 281         if (sctp_debug_flag)                            \
 282                 printk(KERN_DEBUG pr_fmt(fmt), ##args); \
 283 } while (0)
 284 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)            \
 285 do {                                                    \
 286         if (sctp_debug_flag)                            \
 287                 pr_cont(fmt, ##args);                   \
 288 } while (0)
 289 #define SCTP_DEBUG_PRINTK_IPADDR(fmt_lead, fmt_trail,                   \
 290                                  args_lead, addr, args_trail...)        \
 291 do {                                                                    \
 292         const union sctp_addr *_addr = (addr);                          \
 293         if (sctp_debug_flag) {                                          \
 294                 if (_addr->sa.sa_family == AF_INET6) {                  \
 295                         printk(KERN_DEBUG                               \
 296                                pr_fmt(fmt_lead "%pI6" fmt_trail),       \
 297                                args_lead,                               \
 298                                &_addr->v6.sin6_addr,                    \
 299                                args_trail);                             \
 300                 } else {                                                \
 301                         printk(KERN_DEBUG                               \
 302                                pr_fmt(fmt_lead "%pI4" fmt_trail),       \
 303                                args_lead,                               \
 304                                &_addr->v4.sin_addr.s_addr,              \
 305                                args_trail);                             \
 306                 }                                                       \
 307         }                                                               \
 308 } while (0)
 309 #define SCTP_ENABLE_DEBUG { sctp_debug_flag = 1; }
 310 #define SCTP_DISABLE_DEBUG { sctp_debug_flag = 0; }
 311
 312 #define SCTP_ASSERT(expr, str, func) \
 313         if (!(expr)) { \
 314                 SCTP_DEBUG_PRINTK("Assertion Failed: %s(%s) at %s:%s:%d\n", \
 315                         str, (#expr), __FILE__, __func__, __LINE__); \
 316                 func; \
 317         }
 318
 319 #else   /* SCTP_DEBUG */
 320
 321 #define SCTP_DEBUG_PRINTK(whatever...)
 322 #define SCTP_DEBUG_PRINTK_CONT(fmt, args...)
 323 #define SCTP_DEBUG_PRINTK_IPADDR(whatever...)
 324 #define SCTP_ENABLE_DEBUG
 325 #define SCTP_DISABLE_DEBUG
 326 #define SCTP_ASSERT(expr, str, func)
 327
 328 #endif /* SCTP_DEBUG */
 329
 330
 331 /*
 332  * Macros for keeping a global reference of object allocations.
 333  */
 334 #ifdef CONFIG_SCTP_DBG_OBJCNT
 335
 336 extern atomic_t sctp_dbg_objcnt_sock;
 337 extern atomic_t sctp_dbg_objcnt_ep;
 338 extern atomic_t sctp_dbg_objcnt_assoc;
 339 extern atomic_t sctp_dbg_objcnt_transport;
 340 extern atomic_t sctp_dbg_objcnt_chunk;
 341 extern atomic_t sctp_dbg_objcnt_bind_addr;
 342 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 343 extern atomic_t sctp_dbg_objcnt_addr;
 344 extern atomic_t sctp_dbg_objcnt_ssnmap;
 345 extern atomic_t sctp_dbg_objcnt_datamsg;
 346 extern atomic_t sctp_dbg_objcnt_keys;
 347
 348 /* Macros to atomically increment/decrement objcnt counters.  */
 349 #define SCTP_DBG_OBJCNT_INC(name) \
 350 atomic_inc(&sctp_dbg_objcnt_## name)
 351 #define SCTP_DBG_OBJCNT_DEC(name) \
 352 atomic_dec(&sctp_dbg_objcnt_## name)
 353 #define SCTP_DBG_OBJCNT(name) \
 354 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 355
 356 /* Macro to help create new entries in in the global array of
 357  * objcnt counters.
 358  */
 359 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 360 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 361
 362 void sctp_dbg_objcnt_init(struct net *);
 363 void sctp_dbg_objcnt_exit(struct net *);
 364
 365 #else
 366
 367 #define SCTP_DBG_OBJCNT_INC(name)
 368 #define SCTP_DBG_OBJCNT_DEC(name)
 369
 370 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 371 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 372
 373 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 374
 375 #if defined CONFIG_SYSCTL
 376 void sctp_sysctl_register(void);
 377 void sctp_sysctl_unregister(void);
 378 int sctp_sysctl_net_register(struct net *net);
 379 void sctp_sysctl_net_unregister(struct net *net);
 380 #else
 381 static inline void sctp_sysctl_register(void) { return; }
 382 static inline void sctp_sysctl_unregister(void) { return; }
 383 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 384 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 385 #endif
 386
 387 /* Size of Supported Address Parameter for 'x' address types. */
 388 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 389
 390 #if IS_ENABLED(CONFIG_IPV6)
 391
 392 void sctp_v6_pf_init(void);
 393 void sctp_v6_pf_exit(void);
 394 int sctp_v6_protosw_init(void);
 395 void sctp_v6_protosw_exit(void);
 396 int sctp_v6_add_protocol(void);
 397 void sctp_v6_del_protocol(void);
 398
 399 #else /* #ifdef defined(CONFIG_IPV6) */
 400
 401 static inline void sctp_v6_pf_init(void) { return; }
 402 static inline void sctp_v6_pf_exit(void) { return; }
 403 static inline int sctp_v6_protosw_init(void) { return 0; }
 404 static inline void sctp_v6_protosw_exit(void) { return; }
 405 static inline int sctp_v6_add_protocol(void) { return 0; }
 406 static inline void sctp_v6_del_protocol(void) { return; }
 407
 408 #endif /* #if defined(CONFIG_IPV6) */
 409
 410
 411 /* Map an association to an assoc_id. */
 412 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 413 {
 414         return asoc ? asoc->assoc_id : 0;
 415 }
 416
 417 /* Look up the association by its id.  */
 418 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 419
 420 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 421
 422 /* A macro to walk a list of skbs.  */
 423 #define sctp_skb_for_each(pos, head, tmp) \
 424         skb_queue_walk_safe(head, pos, tmp)
 425
 426 /* A helper to append an entire skb list (list) to another (head). */
 427 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 428                                       struct sk_buff_head *head)
 429 {
 430         unsigned long flags;
 431
 432         sctp_spin_lock_irqsave(&head->lock, flags);
 433         sctp_spin_lock(&list->lock);
 434
 435         skb_queue_splice_tail_init(list, head);
 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_orphan(skb);
 471         skb->sk = sk;
 472         skb->destructor = sctp_sock_rfree;
 473         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 474         /*
 475          * This mimics the behavior of skb_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_association *asoc, int pmtu)
 509 {
 510         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 511         int frag = pmtu;
 512
 513         frag -= sp->pf->af->net_header_len;
 514         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 515
 516         if (asoc->user_frag)
 517                 frag = min_t(int, frag, asoc->user_frag);
 518
 519         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 520
 521         return frag;
 522 }
 523
 524 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
 525 {
 526
 527         sctp_assoc_sync_pmtu(sk, asoc);
 528         asoc->pmtu_pending = 0;
 529 }
 530
 531 /* Walk through a list of TLV parameters.  Don't trust the
 532  * individual parameter lengths and instead depend on
 533  * the chunk length to indicate when to stop.  Make sure
 534  * there is room for a param header too.
 535  */
 536 #define sctp_walk_params(pos, chunk, member)\
 537 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 538
 539 #define _sctp_walk_params(pos, chunk, end, member)\
 540 for (pos.v = chunk->member;\
 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 - ntohs(err->length) &&\
 552      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 553      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 554
 555 #define sctp_walk_fwdtsn(pos, chunk)\
 556 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 557
 558 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 559 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 560      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 561      pos++)
 562
 563 /* Round an int up to the next multiple of 4.  */
 564 #define WORD_ROUND(s) (((s)+3)&~3)
 565
 566 /* Make a new instance of type.  */
 567 #define t_new(type, flags)      (type *)kzalloc(sizeof(type), flags)
 568
 569 /* Compare two timevals.  */
 570 #define tv_lt(s, t) \
 571    (s.tv_sec < t.tv_sec || (s.tv_sec == t.tv_sec && s.tv_usec < t.tv_usec))
 572
 573 /* Add tv1 to tv2. */
 574 #define TIMEVAL_ADD(tv1, tv2) \
 575 ({ \
 576         suseconds_t usecs = (tv2).tv_usec + (tv1).tv_usec; \
 577         time_t secs = (tv2).tv_sec + (tv1).tv_sec; \
 578 \
 579         if (usecs >= 1000000) { \
 580                 usecs -= 1000000; \
 581                 secs++; \
 582         } \
 583         (tv2).tv_sec = secs; \
 584         (tv2).tv_usec = usecs; \
 585 })
 586
 587 /* External references. */
 588
 589 extern struct proto sctp_prot;
 590 extern struct proto sctpv6_prot;
 591 void sctp_put_port(struct sock *sk);
 592
 593 extern struct idr sctp_assocs_id;
 594 extern spinlock_t sctp_assocs_id_lock;
 595
 596 /* Static inline functions. */
 597
 598 /* Convert from an IP version number to an Address Family symbol.  */
 599 static inline int ipver2af(__u8 ipver)
 600 {
 601         switch (ipver) {
 602         case 4:
 603                 return  AF_INET;
 604         case 6:
 605                 return AF_INET6;
 606         default:
 607                 return 0;
 608         }
 609 }
 610
 611 /* Convert from an address parameter type to an address family.  */
 612 static inline int param_type2af(__be16 type)
 613 {
 614         switch (type) {
 615         case SCTP_PARAM_IPV4_ADDRESS:
 616                 return  AF_INET;
 617         case SCTP_PARAM_IPV6_ADDRESS:
 618                 return AF_INET6;
 619         default:
 620                 return 0;
 621         }
 622 }
 623
 624 /* Perform some sanity checks. */
 625 static inline int sctp_sanity_check(void)
 626 {
 627         SCTP_ASSERT(sizeof(struct sctp_ulpevent) <=
 628                     sizeof(((struct sk_buff *)0)->cb),
 629                     "SCTP: ulpevent does not fit in skb!\n", return 0);
 630
 631         return 1;
 632 }
 633
 634 /* Warning: The following hash functions assume a power of two 'size'. */
 635 /* This is the hash function for the SCTP port hash table. */
 636 static inline int sctp_phashfn(struct net *net, __u16 lport)
 637 {
 638         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 639 }
 640
 641 /* This is the hash function for the endpoint hash table. */
 642 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 643 {
 644         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 645 }
 646
 647 /* This is the hash function for the association hash table. */
 648 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
 649 {
 650         int h = (lport << 16) + rport + net_hash_mix(net);
 651         h ^= h>>8;
 652         return h & (sctp_assoc_hashsize - 1);
 653 }
 654
 655 /* This is the hash function for the association hash table.  This is
 656  * not used yet, but could be used as a better hash function when
 657  * we have a vtag.
 658  */
 659 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 660 {
 661         int h = (lport << 16) + rport;
 662         h ^= vtag;
 663         return h & (sctp_assoc_hashsize - 1);
 664 }
 665
 666 #define sctp_for_each_hentry(epb, node, head) \
 667         hlist_for_each_entry(epb, node, head, node)
 668
 669 /* Is a socket of this style? */
 670 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 671 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 672 {
 673         return sctp_sk(sk)->type == style;
 674 }
 675
 676 /* Is the association in this state? */
 677 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 678 static inline int __sctp_state(const struct sctp_association *asoc,
 679                                sctp_state_t state)
 680 {
 681         return asoc->state == state;
 682 }
 683
 684 /* Is the socket in this state? */
 685 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 686 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 687 {
 688         return sk->sk_state == state;
 689 }
 690
 691 /* Map v4-mapped v6 address back to v4 address */
 692 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 693 {
 694         addr->v4.sin_family = AF_INET;
 695         addr->v4.sin_port = addr->v6.sin6_port;
 696         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 697 }
 698
 699 /* Map v4 address to v4-mapped v6 address */
 700 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 701 {
 702         addr->v6.sin6_family = AF_INET6;
 703         addr->v6.sin6_port = addr->v4.sin_port;
 704         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 705         addr->v6.sin6_addr.s6_addr32[0] = 0;
 706         addr->v6.sin6_addr.s6_addr32[1] = 0;
 707         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 708 }
 709
 710 /* The cookie is always 0 since this is how it's used in the
 711  * pmtu code.
 712  */
 713 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 714 {
 715         if (t->dst && !dst_check(t->dst, 0)) {
 716                 dst_release(t->dst);
 717                 t->dst = NULL;
 718         }
 719
 720         return t->dst;
 721 }
 722
 723 #endif /* __net_sctp_h__ */