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, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    La Monte H.P. Yarroll <piggy@acm.org>
  33  *    Xingang Guo           <xingang.guo@intel.com>
  34  *    Jon Grimm             <jgrimm@us.ibm.com>
  35  *    Daisy Chang           <daisyc@us.ibm.com>
  36  *    Sridhar Samudrala     <sri@us.ibm.com>
  37  *    Ardelle Fan           <ardelle.fan@intel.com>
  38  *    Ryan Layer            <rmlayer@us.ibm.com>
  39  *    Kevin Gao             <kevin.gao@intel.com>
  40  */
  41
  42 #ifndef __net_sctp_h__
  43 #define __net_sctp_h__
  44
  45 /* Header Strategy.
  46  *    Start getting some control over the header file depencies:
  47  *       includes
  48  *       constants
  49  *       structs
  50  *       prototypes
  51  *       macros, externs, and inlines
  52  *
  53  *   Move test_frame specific items out of the kernel headers
  54  *   and into the test frame headers.   This is not perfect in any sense
  55  *   and will continue to evolve.
  56  */
  57
  58 #include <linux/types.h>
  59 #include <linux/slab.h>
  60 #include <linux/in.h>
  61 #include <linux/tty.h>
  62 #include <linux/proc_fs.h>
  63 #include <linux/spinlock.h>
  64 #include <linux/jiffies.h>
  65 #include <linux/idr.h>
  66
  67 #if IS_ENABLED(CONFIG_IPV6)
  68 #include <net/ipv6.h>
  69 #include <net/ip6_route.h>
  70 #endif
  71
  72 #include <asm/uaccess.h>
  73 #include <asm/page.h>
  74 #include <net/sock.h>
  75 #include <net/snmp.h>
  76 #include <net/sctp/structs.h>
  77 #include <net/sctp/constants.h>
  78
  79 #ifdef CONFIG_IP_SCTP_MODULE
  80 #define SCTP_PROTOSW_FLAG 0
  81 #else /* static! */
  82 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
  83 #endif
  84
  85 /*
  86  * Function declarations.
  87  */
  88
  89 /*
  90  * sctp/protocol.c
  91  */
  92 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
  93                               sctp_scope_t, gfp_t gfp, int flags);
  94 struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
  95 int sctp_register_pf(struct sctp_pf *, sa_family_t);
  96 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
  97
  98 /*
  99  * sctp/socket.c
 100  */
 101 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 102 int sctp_inet_listen(struct socket *sock, int backlog);
 103 void sctp_write_space(struct sock *sk);
 104 void sctp_data_ready(struct sock *sk, int len);
 105 unsigned int sctp_poll(struct file *file, struct socket *sock,
 106                 poll_table *wait);
 107 void sctp_sock_rfree(struct sk_buff *skb);
 108 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 109                     struct sctp_association *asoc);
 110 extern struct percpu_counter sctp_sockets_allocated;
 111 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 112
 113 /*
 114  * sctp/primitive.c
 115  */
 116 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 117 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 118 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 119 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 120 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 121 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 122
 123 /*
 124  * sctp/input.c
 125  */
 126 int sctp_rcv(struct sk_buff *skb);
 127 void sctp_v4_err(struct sk_buff *skb, u32 info);
 128 void sctp_hash_established(struct sctp_association *);
 129 void sctp_unhash_established(struct sctp_association *);
 130 void sctp_hash_endpoint(struct sctp_endpoint *);
 131 void sctp_unhash_endpoint(struct sctp_endpoint *);
 132 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 133                              struct sctphdr *, struct sctp_association **,
 134                              struct sctp_transport **);
 135 void sctp_err_finish(struct sock *, struct sctp_association *);
 136 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 137                            struct sctp_transport *t, __u32 pmtu);
 138 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 139                         struct sk_buff *);
 140 void sctp_icmp_proto_unreachable(struct sock *sk,
 141                                  struct sctp_association *asoc,
 142                                  struct sctp_transport *t);
 143 void sctp_backlog_migrate(struct sctp_association *assoc,
 144                           struct sock *oldsk, struct sock *newsk);
 145
 146 /*
 147  * sctp/proc.c
 148  */
 149 int sctp_snmp_proc_init(struct net *net);
 150 void sctp_snmp_proc_exit(struct net *net);
 151 int sctp_eps_proc_init(struct net *net);
 152 void sctp_eps_proc_exit(struct net *net);
 153 int sctp_assocs_proc_init(struct net *net);
 154 void sctp_assocs_proc_exit(struct net *net);
 155 int sctp_remaddr_proc_init(struct net *net);
 156 void sctp_remaddr_proc_exit(struct net *net);
 157
 158
 159 /*
 160  * Module global variables
 161  */
 162
 163  /*
 164   * sctp/protocol.c
 165   */
 166 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 167 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 168
 169 /*
 170  *  Section:  Macros, externs, and inlines
 171  */
 172
 173 /* spin lock wrappers. */
 174 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 175 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 176        spin_unlock_irqrestore(lock, flags)
 177 #define sctp_local_bh_disable() local_bh_disable()
 178 #define sctp_local_bh_enable()  local_bh_enable()
 179 #define sctp_spin_lock(lock)    spin_lock(lock)
 180 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 181 #define sctp_write_lock(lock)   write_lock(lock)
 182 #define sctp_write_unlock(lock) write_unlock(lock)
 183 #define sctp_read_lock(lock)    read_lock(lock)
 184 #define sctp_read_unlock(lock)  read_unlock(lock)
 185
 186 /* sock lock wrappers. */
 187 #define sctp_lock_sock(sk)       lock_sock(sk)
 188 #define sctp_release_sock(sk)    release_sock(sk)
 189 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 190 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 191
 192 /* SCTP SNMP MIB stats handlers */
 193 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 194 #define SCTP_INC_STATS_BH(net, field)   SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
 195 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
 196 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 197
 198 /* sctp mib definitions */
 199 enum {
 200         SCTP_MIB_NUM = 0,
 201         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 202         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 203         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 204         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 205         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 206         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 207         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 208         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 209         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 210         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 211         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 212         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 213         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 214         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 215         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 216         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 217         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 218         SCTP_MIB_T1_INIT_EXPIREDS,
 219         SCTP_MIB_T1_COOKIE_EXPIREDS,
 220         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 221         SCTP_MIB_T3_RTX_EXPIREDS,
 222         SCTP_MIB_T4_RTO_EXPIREDS,
 223         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 224         SCTP_MIB_DELAY_SACK_EXPIREDS,
 225         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 226         SCTP_MIB_T1_RETRANSMITS,
 227         SCTP_MIB_T3_RETRANSMITS,
 228         SCTP_MIB_PMTUD_RETRANSMITS,
 229         SCTP_MIB_FAST_RETRANSMITS,
 230         SCTP_MIB_IN_PKT_SOFTIRQ,
 231         SCTP_MIB_IN_PKT_BACKLOG,
 232         SCTP_MIB_IN_PKT_DISCARDS,
 233         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 234         __SCTP_MIB_MAX
 235 };
 236
 237 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 238 struct sctp_mib {
 239         unsigned long   mibs[SCTP_MIB_MAX];
 240 };
 241
 242 /* helper function to track stats about max rto and related transport */
 243 static inline void sctp_max_rto(struct sctp_association *asoc,
 244                                 struct sctp_transport *trans)
 245 {
 246         if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 247                 asoc->stats.max_obs_rto = trans->rto;
 248                 memset(&asoc->stats.obs_rto_ipaddr, 0,
 249                         sizeof(struct sockaddr_storage));
 250                 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 251                         trans->af_specific->sockaddr_len);
 252         }
 253 }
 254
 255 /*
 256  * Macros for keeping a global reference of object allocations.
 257  */
 258 #ifdef CONFIG_SCTP_DBG_OBJCNT
 259
 260 extern atomic_t sctp_dbg_objcnt_sock;
 261 extern atomic_t sctp_dbg_objcnt_ep;
 262 extern atomic_t sctp_dbg_objcnt_assoc;
 263 extern atomic_t sctp_dbg_objcnt_transport;
 264 extern atomic_t sctp_dbg_objcnt_chunk;
 265 extern atomic_t sctp_dbg_objcnt_bind_addr;
 266 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 267 extern atomic_t sctp_dbg_objcnt_addr;
 268 extern atomic_t sctp_dbg_objcnt_ssnmap;
 269 extern atomic_t sctp_dbg_objcnt_datamsg;
 270 extern atomic_t sctp_dbg_objcnt_keys;
 271
 272 /* Macros to atomically increment/decrement objcnt counters.  */
 273 #define SCTP_DBG_OBJCNT_INC(name) \
 274 atomic_inc(&sctp_dbg_objcnt_## name)
 275 #define SCTP_DBG_OBJCNT_DEC(name) \
 276 atomic_dec(&sctp_dbg_objcnt_## name)
 277 #define SCTP_DBG_OBJCNT(name) \
 278 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 279
 280 /* Macro to help create new entries in in the global array of
 281  * objcnt counters.
 282  */
 283 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 284 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 285
 286 void sctp_dbg_objcnt_init(struct net *);
 287 void sctp_dbg_objcnt_exit(struct net *);
 288
 289 #else
 290
 291 #define SCTP_DBG_OBJCNT_INC(name)
 292 #define SCTP_DBG_OBJCNT_DEC(name)
 293
 294 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 295 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 296
 297 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 298
 299 #if defined CONFIG_SYSCTL
 300 void sctp_sysctl_register(void);
 301 void sctp_sysctl_unregister(void);
 302 int sctp_sysctl_net_register(struct net *net);
 303 void sctp_sysctl_net_unregister(struct net *net);
 304 #else
 305 static inline void sctp_sysctl_register(void) { return; }
 306 static inline void sctp_sysctl_unregister(void) { return; }
 307 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 308 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 309 #endif
 310
 311 /* Size of Supported Address Parameter for 'x' address types. */
 312 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 313
 314 #if IS_ENABLED(CONFIG_IPV6)
 315
 316 void sctp_v6_pf_init(void);
 317 void sctp_v6_pf_exit(void);
 318 int sctp_v6_protosw_init(void);
 319 void sctp_v6_protosw_exit(void);
 320 int sctp_v6_add_protocol(void);
 321 void sctp_v6_del_protocol(void);
 322
 323 #else /* #ifdef defined(CONFIG_IPV6) */
 324
 325 static inline void sctp_v6_pf_init(void) { return; }
 326 static inline void sctp_v6_pf_exit(void) { return; }
 327 static inline int sctp_v6_protosw_init(void) { return 0; }
 328 static inline void sctp_v6_protosw_exit(void) { return; }
 329 static inline int sctp_v6_add_protocol(void) { return 0; }
 330 static inline void sctp_v6_del_protocol(void) { return; }
 331
 332 #endif /* #if defined(CONFIG_IPV6) */
 333
 334
 335 /* Map an association to an assoc_id. */
 336 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 337 {
 338         return asoc ? asoc->assoc_id : 0;
 339 }
 340
 341 /* Look up the association by its id.  */
 342 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 343
 344 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 345
 346 /* A macro to walk a list of skbs.  */
 347 #define sctp_skb_for_each(pos, head, tmp) \
 348         skb_queue_walk_safe(head, pos, tmp)
 349
 350 /* A helper to append an entire skb list (list) to another (head). */
 351 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 352                                       struct sk_buff_head *head)
 353 {
 354         unsigned long flags;
 355
 356         sctp_spin_lock_irqsave(&head->lock, flags);
 357         sctp_spin_lock(&list->lock);
 358
 359         skb_queue_splice_tail_init(list, head);
 360
 361         sctp_spin_unlock(&list->lock);
 362         sctp_spin_unlock_irqrestore(&head->lock, flags);
 363 }
 364
 365 /**
 366  *      sctp_list_dequeue - remove from the head of the queue
 367  *      @list: list to dequeue from
 368  *
 369  *      Remove the head of the list. The head item is
 370  *      returned or %NULL if the list is empty.
 371  */
 372
 373 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 374 {
 375         struct list_head *result = NULL;
 376
 377         if (list->next != list) {
 378                 result = list->next;
 379                 list->next = result->next;
 380                 list->next->prev = list;
 381                 INIT_LIST_HEAD(result);
 382         }
 383         return result;
 384 }
 385
 386 /* SCTP version of skb_set_owner_r.  We need this one because
 387  * of the way we have to do receive buffer accounting on bundled
 388  * chunks.
 389  */
 390 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 391 {
 392         struct sctp_ulpevent *event = sctp_skb2event(skb);
 393
 394         skb_orphan(skb);
 395         skb->sk = sk;
 396         skb->destructor = sctp_sock_rfree;
 397         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 398         /*
 399          * This mimics the behavior of skb_set_owner_r
 400          */
 401         sk->sk_forward_alloc -= event->rmem_len;
 402 }
 403
 404 /* Tests if the list has one and only one entry. */
 405 static inline int sctp_list_single_entry(struct list_head *head)
 406 {
 407         return (head->next != head) && (head->next == head->prev);
 408 }
 409
 410 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 411 static inline __s32 sctp_jitter(__u32 rto)
 412 {
 413         static __u32 sctp_rand;
 414         __s32 ret;
 415
 416         /* Avoid divide by zero. */
 417         if (!rto)
 418                 rto = 1;
 419
 420         sctp_rand += jiffies;
 421         sctp_rand ^= (sctp_rand << 12);
 422         sctp_rand ^= (sctp_rand >> 20);
 423
 424         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 425          * of rto.
 426          */
 427         ret = sctp_rand % rto - (rto >> 1);
 428         return ret;
 429 }
 430
 431 /* Break down data chunks at this point.  */
 432 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 433 {
 434         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 435         int frag = pmtu;
 436
 437         frag -= sp->pf->af->net_header_len;
 438         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 439
 440         if (asoc->user_frag)
 441                 frag = min_t(int, frag, asoc->user_frag);
 442
 443         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 444
 445         return frag;
 446 }
 447
 448 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
 449 {
 450
 451         sctp_assoc_sync_pmtu(sk, asoc);
 452         asoc->pmtu_pending = 0;
 453 }
 454
 455 /* Walk through a list of TLV parameters.  Don't trust the
 456  * individual parameter lengths and instead depend on
 457  * the chunk length to indicate when to stop.  Make sure
 458  * there is room for a param header too.
 459  */
 460 #define sctp_walk_params(pos, chunk, member)\
 461 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 462
 463 #define _sctp_walk_params(pos, chunk, end, member)\
 464 for (pos.v = chunk->member;\
 465      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 466      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 467      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 468
 469 #define sctp_walk_errors(err, chunk_hdr)\
 470 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 471
 472 #define _sctp_walk_errors(err, chunk_hdr, end)\
 473 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 474             sizeof(sctp_chunkhdr_t));\
 475      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 476      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 477      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 478
 479 #define sctp_walk_fwdtsn(pos, chunk)\
 480 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 481
 482 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 483 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 484      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 485      pos++)
 486
 487 /* Round an int up to the next multiple of 4.  */
 488 #define WORD_ROUND(s) (((s)+3)&~3)
 489
 490 /* External references. */
 491
 492 extern struct proto sctp_prot;
 493 extern struct proto sctpv6_prot;
 494 void sctp_put_port(struct sock *sk);
 495
 496 extern struct idr sctp_assocs_id;
 497 extern spinlock_t sctp_assocs_id_lock;
 498
 499 /* Static inline functions. */
 500
 501 /* Convert from an IP version number to an Address Family symbol.  */
 502 static inline int ipver2af(__u8 ipver)
 503 {
 504         switch (ipver) {
 505         case 4:
 506                 return  AF_INET;
 507         case 6:
 508                 return AF_INET6;
 509         default:
 510                 return 0;
 511         }
 512 }
 513
 514 /* Convert from an address parameter type to an address family.  */
 515 static inline int param_type2af(__be16 type)
 516 {
 517         switch (type) {
 518         case SCTP_PARAM_IPV4_ADDRESS:
 519                 return  AF_INET;
 520         case SCTP_PARAM_IPV6_ADDRESS:
 521                 return AF_INET6;
 522         default:
 523                 return 0;
 524         }
 525 }
 526
 527 /* Warning: The following hash functions assume a power of two 'size'. */
 528 /* This is the hash function for the SCTP port hash table. */
 529 static inline int sctp_phashfn(struct net *net, __u16 lport)
 530 {
 531         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 532 }
 533
 534 /* This is the hash function for the endpoint hash table. */
 535 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 536 {
 537         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 538 }
 539
 540 /* This is the hash function for the association hash table. */
 541 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
 542 {
 543         int h = (lport << 16) + rport + net_hash_mix(net);
 544         h ^= h>>8;
 545         return h & (sctp_assoc_hashsize - 1);
 546 }
 547
 548 /* This is the hash function for the association hash table.  This is
 549  * not used yet, but could be used as a better hash function when
 550  * we have a vtag.
 551  */
 552 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 553 {
 554         int h = (lport << 16) + rport;
 555         h ^= vtag;
 556         return h & (sctp_assoc_hashsize - 1);
 557 }
 558
 559 #define sctp_for_each_hentry(epb, head) \
 560         hlist_for_each_entry(epb, head, node)
 561
 562 /* Is a socket of this style? */
 563 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 564 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 565 {
 566         return sctp_sk(sk)->type == style;
 567 }
 568
 569 /* Is the association in this state? */
 570 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 571 static inline int __sctp_state(const struct sctp_association *asoc,
 572                                sctp_state_t state)
 573 {
 574         return asoc->state == state;
 575 }
 576
 577 /* Is the socket in this state? */
 578 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 579 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 580 {
 581         return sk->sk_state == state;
 582 }
 583
 584 /* Map v4-mapped v6 address back to v4 address */
 585 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 586 {
 587         addr->v4.sin_family = AF_INET;
 588         addr->v4.sin_port = addr->v6.sin6_port;
 589         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 590 }
 591
 592 /* Map v4 address to v4-mapped v6 address */
 593 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 594 {
 595         addr->v6.sin6_family = AF_INET6;
 596         addr->v6.sin6_port = addr->v4.sin_port;
 597         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 598         addr->v6.sin6_addr.s6_addr32[0] = 0;
 599         addr->v6.sin6_addr.s6_addr32[1] = 0;
 600         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 601 }
 602
 603 /* The cookie is always 0 since this is how it's used in the
 604  * pmtu code.
 605  */
 606 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 607 {
 608         if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
 609                 dst_release(t->dst);
 610                 t->dst = NULL;
 611         }
 612
 613         return t->dst;
 614 }
 615
 616 #endif /* __net_sctp_h__ */