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 <linux-sctp@vger.kernel.org>
  31  *
  32  * Written or modified by:
  33  *    La Monte H.P. Yarroll <piggy@acm.org>
  34  *    Xingang Guo           <xingang.guo@intel.com>
  35  *    Jon Grimm             <jgrimm@us.ibm.com>
  36  *    Daisy Chang           <daisyc@us.ibm.com>
  37  *    Sridhar Samudrala     <sri@us.ibm.com>
  38  *    Ardelle Fan           <ardelle.fan@intel.com>
  39  *    Ryan Layer            <rmlayer@us.ibm.com>
  40  *    Kevin Gao             <kevin.gao@intel.com>
  41  */
  42
  43 #ifndef __net_sctp_h__
  44 #define __net_sctp_h__
  45
  46 /* Header Strategy.
  47  *    Start getting some control over the header file depencies:
  48  *       includes
  49  *       constants
  50  *       structs
  51  *       prototypes
  52  *       macros, externs, and inlines
  53  *
  54  *   Move test_frame specific items out of the kernel headers
  55  *   and into the test frame headers.   This is not perfect in any sense
  56  *   and will continue to evolve.
  57  */
  58
  59 #include <linux/types.h>
  60 #include <linux/slab.h>
  61 #include <linux/in.h>
  62 #include <linux/tty.h>
  63 #include <linux/proc_fs.h>
  64 #include <linux/spinlock.h>
  65 #include <linux/jiffies.h>
  66 #include <linux/idr.h>
  67
  68 #if IS_ENABLED(CONFIG_IPV6)
  69 #include <net/ipv6.h>
  70 #include <net/ip6_route.h>
  71 #endif
  72
  73 #include <asm/uaccess.h>
  74 #include <asm/page.h>
  75 #include <net/sock.h>
  76 #include <net/snmp.h>
  77 #include <net/sctp/structs.h>
  78 #include <net/sctp/constants.h>
  79
  80 #ifdef CONFIG_IP_SCTP_MODULE
  81 #define SCTP_PROTOSW_FLAG 0
  82 #else /* static! */
  83 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
  84 #endif
  85
  86 /*
  87  * Function declarations.
  88  */
  89
  90 /*
  91  * sctp/protocol.c
  92  */
  93 extern int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
  94                                      sctp_scope_t, gfp_t gfp,
  95                                      int flags);
  96 extern struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
  97 extern int sctp_register_pf(struct sctp_pf *, sa_family_t);
  98 extern void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
  99
 100 /*
 101  * sctp/socket.c
 102  */
 103 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 104 int sctp_inet_listen(struct socket *sock, int backlog);
 105 void sctp_write_space(struct sock *sk);
 106 void sctp_data_ready(struct sock *sk, int len);
 107 unsigned int sctp_poll(struct file *file, struct socket *sock,
 108                 poll_table *wait);
 109 void sctp_sock_rfree(struct sk_buff *skb);
 110 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 111                     struct sctp_association *asoc);
 112 extern struct percpu_counter sctp_sockets_allocated;
 113 extern int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 114
 115 /*
 116  * sctp/primitive.c
 117  */
 118 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 119 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 120 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 121 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 122 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 123 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 124
 125 /*
 126  * sctp/input.c
 127  */
 128 int sctp_rcv(struct sk_buff *skb);
 129 void sctp_v4_err(struct sk_buff *skb, u32 info);
 130 void sctp_hash_established(struct sctp_association *);
 131 void sctp_unhash_established(struct sctp_association *);
 132 void sctp_hash_endpoint(struct sctp_endpoint *);
 133 void sctp_unhash_endpoint(struct sctp_endpoint *);
 134 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 135                              struct sctphdr *, struct sctp_association **,
 136                              struct sctp_transport **);
 137 void sctp_err_finish(struct sock *, struct sctp_association *);
 138 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 139                            struct sctp_transport *t, __u32 pmtu);
 140 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 141                         struct sk_buff *);
 142 void sctp_icmp_proto_unreachable(struct sock *sk,
 143                                  struct sctp_association *asoc,
 144                                  struct sctp_transport *t);
 145 void sctp_backlog_migrate(struct sctp_association *assoc,
 146                           struct sock *oldsk, struct sock *newsk);
 147
 148 /*
 149  * sctp/proc.c
 150  */
 151 int sctp_snmp_proc_init(struct net *net);
 152 void sctp_snmp_proc_exit(struct net *net);
 153 int sctp_eps_proc_init(struct net *net);
 154 void sctp_eps_proc_exit(struct net *net);
 155 int sctp_assocs_proc_init(struct net *net);
 156 void sctp_assocs_proc_exit(struct net *net);
 157 int sctp_remaddr_proc_init(struct net *net);
 158 void sctp_remaddr_proc_exit(struct net *net);
 159
 160
 161 /*
 162  * Module global variables
 163  */
 164
 165  /*
 166   * sctp/protocol.c
 167   */
 168 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 169 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 170
 171 /*
 172  *  Section:  Macros, externs, and inlines
 173  */
 174
 175 /* spin lock wrappers. */
 176 #define sctp_spin_lock_irqsave(lock, flags) spin_lock_irqsave(lock, flags)
 177 #define sctp_spin_unlock_irqrestore(lock, flags)  \
 178        spin_unlock_irqrestore(lock, flags)
 179 #define sctp_local_bh_disable() local_bh_disable()
 180 #define sctp_local_bh_enable()  local_bh_enable()
 181 #define sctp_spin_lock(lock)    spin_lock(lock)
 182 #define sctp_spin_unlock(lock)  spin_unlock(lock)
 183 #define sctp_write_lock(lock)   write_lock(lock)
 184 #define sctp_write_unlock(lock) write_unlock(lock)
 185 #define sctp_read_lock(lock)    read_lock(lock)
 186 #define sctp_read_unlock(lock)  read_unlock(lock)
 187
 188 /* sock lock wrappers. */
 189 #define sctp_lock_sock(sk)       lock_sock(sk)
 190 #define sctp_release_sock(sk)    release_sock(sk)
 191 #define sctp_bh_lock_sock(sk)    bh_lock_sock(sk)
 192 #define sctp_bh_unlock_sock(sk)  bh_unlock_sock(sk)
 193
 194 /* SCTP SNMP MIB stats handlers */
 195 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 196 #define SCTP_INC_STATS_BH(net, field)   SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
 197 #define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
 198 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 199
 200 /* sctp mib definitions */
 201 enum {
 202         SCTP_MIB_NUM = 0,
 203         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 204         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 205         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 206         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 207         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 208         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 209         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 210         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 211         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 212         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 213         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 214         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 215         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 216         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 217         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 218         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 219         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 220         SCTP_MIB_T1_INIT_EXPIREDS,
 221         SCTP_MIB_T1_COOKIE_EXPIREDS,
 222         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 223         SCTP_MIB_T3_RTX_EXPIREDS,
 224         SCTP_MIB_T4_RTO_EXPIREDS,
 225         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 226         SCTP_MIB_DELAY_SACK_EXPIREDS,
 227         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 228         SCTP_MIB_T1_RETRANSMITS,
 229         SCTP_MIB_T3_RETRANSMITS,
 230         SCTP_MIB_PMTUD_RETRANSMITS,
 231         SCTP_MIB_FAST_RETRANSMITS,
 232         SCTP_MIB_IN_PKT_SOFTIRQ,
 233         SCTP_MIB_IN_PKT_BACKLOG,
 234         SCTP_MIB_IN_PKT_DISCARDS,
 235         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 236         __SCTP_MIB_MAX
 237 };
 238
 239 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 240 struct sctp_mib {
 241         unsigned long   mibs[SCTP_MIB_MAX];
 242 };
 243
 244 /* helper function to track stats about max rto and related transport */
 245 static inline void sctp_max_rto(struct sctp_association *asoc,
 246                                 struct sctp_transport *trans)
 247 {
 248         if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 249                 asoc->stats.max_obs_rto = trans->rto;
 250                 memset(&asoc->stats.obs_rto_ipaddr, 0,
 251                         sizeof(struct sockaddr_storage));
 252                 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 253                         trans->af_specific->sockaddr_len);
 254         }
 255 }
 256
 257 /*
 258  * Macros for keeping a global reference of object allocations.
 259  */
 260 #ifdef CONFIG_SCTP_DBG_OBJCNT
 261
 262 extern atomic_t sctp_dbg_objcnt_sock;
 263 extern atomic_t sctp_dbg_objcnt_ep;
 264 extern atomic_t sctp_dbg_objcnt_assoc;
 265 extern atomic_t sctp_dbg_objcnt_transport;
 266 extern atomic_t sctp_dbg_objcnt_chunk;
 267 extern atomic_t sctp_dbg_objcnt_bind_addr;
 268 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 269 extern atomic_t sctp_dbg_objcnt_addr;
 270 extern atomic_t sctp_dbg_objcnt_ssnmap;
 271 extern atomic_t sctp_dbg_objcnt_datamsg;
 272 extern atomic_t sctp_dbg_objcnt_keys;
 273
 274 /* Macros to atomically increment/decrement objcnt counters.  */
 275 #define SCTP_DBG_OBJCNT_INC(name) \
 276 atomic_inc(&sctp_dbg_objcnt_## name)
 277 #define SCTP_DBG_OBJCNT_DEC(name) \
 278 atomic_dec(&sctp_dbg_objcnt_## name)
 279 #define SCTP_DBG_OBJCNT(name) \
 280 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 281
 282 /* Macro to help create new entries in in the global array of
 283  * objcnt counters.
 284  */
 285 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 286 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 287
 288 void sctp_dbg_objcnt_init(struct net *);
 289 void sctp_dbg_objcnt_exit(struct net *);
 290
 291 #else
 292
 293 #define SCTP_DBG_OBJCNT_INC(name)
 294 #define SCTP_DBG_OBJCNT_DEC(name)
 295
 296 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 297 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 298
 299 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 300
 301 #if defined CONFIG_SYSCTL
 302 void sctp_sysctl_register(void);
 303 void sctp_sysctl_unregister(void);
 304 int sctp_sysctl_net_register(struct net *net);
 305 void sctp_sysctl_net_unregister(struct net *net);
 306 #else
 307 static inline void sctp_sysctl_register(void) { return; }
 308 static inline void sctp_sysctl_unregister(void) { return; }
 309 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 310 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 311 #endif
 312
 313 /* Size of Supported Address Parameter for 'x' address types. */
 314 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 315
 316 #if IS_ENABLED(CONFIG_IPV6)
 317
 318 void sctp_v6_pf_init(void);
 319 void sctp_v6_pf_exit(void);
 320 int sctp_v6_protosw_init(void);
 321 void sctp_v6_protosw_exit(void);
 322 int sctp_v6_add_protocol(void);
 323 void sctp_v6_del_protocol(void);
 324
 325 #else /* #ifdef defined(CONFIG_IPV6) */
 326
 327 static inline void sctp_v6_pf_init(void) { return; }
 328 static inline void sctp_v6_pf_exit(void) { return; }
 329 static inline int sctp_v6_protosw_init(void) { return 0; }
 330 static inline void sctp_v6_protosw_exit(void) { return; }
 331 static inline int sctp_v6_add_protocol(void) { return 0; }
 332 static inline void sctp_v6_del_protocol(void) { return; }
 333
 334 #endif /* #if defined(CONFIG_IPV6) */
 335
 336
 337 /* Map an association to an assoc_id. */
 338 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 339 {
 340         return asoc ? asoc->assoc_id : 0;
 341 }
 342
 343 /* Look up the association by its id.  */
 344 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 345
 346 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 347
 348 /* A macro to walk a list of skbs.  */
 349 #define sctp_skb_for_each(pos, head, tmp) \
 350         skb_queue_walk_safe(head, pos, tmp)
 351
 352 /* A helper to append an entire skb list (list) to another (head). */
 353 static inline void sctp_skb_list_tail(struct sk_buff_head *list,
 354                                       struct sk_buff_head *head)
 355 {
 356         unsigned long flags;
 357
 358         sctp_spin_lock_irqsave(&head->lock, flags);
 359         sctp_spin_lock(&list->lock);
 360
 361         skb_queue_splice_tail_init(list, head);
 362
 363         sctp_spin_unlock(&list->lock);
 364         sctp_spin_unlock_irqrestore(&head->lock, flags);
 365 }
 366
 367 /**
 368  *      sctp_list_dequeue - remove from the head of the queue
 369  *      @list: list to dequeue from
 370  *
 371  *      Remove the head of the list. The head item is
 372  *      returned or %NULL if the list is empty.
 373  */
 374
 375 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 376 {
 377         struct list_head *result = NULL;
 378
 379         if (list->next != list) {
 380                 result = list->next;
 381                 list->next = result->next;
 382                 list->next->prev = list;
 383                 INIT_LIST_HEAD(result);
 384         }
 385         return result;
 386 }
 387
 388 /* SCTP version of skb_set_owner_r.  We need this one because
 389  * of the way we have to do receive buffer accounting on bundled
 390  * chunks.
 391  */
 392 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 393 {
 394         struct sctp_ulpevent *event = sctp_skb2event(skb);
 395
 396         skb_orphan(skb);
 397         skb->sk = sk;
 398         skb->destructor = sctp_sock_rfree;
 399         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 400         /*
 401          * This mimics the behavior of skb_set_owner_r
 402          */
 403         sk->sk_forward_alloc -= event->rmem_len;
 404 }
 405
 406 /* Tests if the list has one and only one entry. */
 407 static inline int sctp_list_single_entry(struct list_head *head)
 408 {
 409         return (head->next != head) && (head->next == head->prev);
 410 }
 411
 412 /* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
 413 static inline __s32 sctp_jitter(__u32 rto)
 414 {
 415         static __u32 sctp_rand;
 416         __s32 ret;
 417
 418         /* Avoid divide by zero. */
 419         if (!rto)
 420                 rto = 1;
 421
 422         sctp_rand += jiffies;
 423         sctp_rand ^= (sctp_rand << 12);
 424         sctp_rand ^= (sctp_rand >> 20);
 425
 426         /* Choose random number from 0 to rto, then move to -50% ~ +50%
 427          * of rto.
 428          */
 429         ret = sctp_rand % rto - (rto >> 1);
 430         return ret;
 431 }
 432
 433 /* Break down data chunks at this point.  */
 434 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 435 {
 436         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 437         int frag = pmtu;
 438
 439         frag -= sp->pf->af->net_header_len;
 440         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 441
 442         if (asoc->user_frag)
 443                 frag = min_t(int, frag, asoc->user_frag);
 444
 445         frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
 446
 447         return frag;
 448 }
 449
 450 static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
 451 {
 452
 453         sctp_assoc_sync_pmtu(sk, asoc);
 454         asoc->pmtu_pending = 0;
 455 }
 456
 457 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
 458 {
 459         return !list_empty(&chunk->list);
 460 }
 461
 462 /* Walk through a list of TLV parameters.  Don't trust the
 463  * individual parameter lengths and instead depend on
 464  * the chunk length to indicate when to stop.  Make sure
 465  * there is room for a param header too.
 466  */
 467 #define sctp_walk_params(pos, chunk, member)\
 468 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 469
 470 #define _sctp_walk_params(pos, chunk, end, member)\
 471 for (pos.v = chunk->member;\
 472      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 473      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
 474      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 475
 476 #define sctp_walk_errors(err, chunk_hdr)\
 477 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 478
 479 #define _sctp_walk_errors(err, chunk_hdr, end)\
 480 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 481             sizeof(sctp_chunkhdr_t));\
 482      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 483      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 484      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
 485
 486 #define sctp_walk_fwdtsn(pos, chunk)\
 487 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 488
 489 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 490 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 491      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 492      pos++)
 493
 494 /* Round an int up to the next multiple of 4.  */
 495 #define WORD_ROUND(s) (((s)+3)&~3)
 496
 497 /* External references. */
 498
 499 extern struct proto sctp_prot;
 500 extern struct proto sctpv6_prot;
 501 void sctp_put_port(struct sock *sk);
 502
 503 extern struct idr sctp_assocs_id;
 504 extern spinlock_t sctp_assocs_id_lock;
 505
 506 /* Static inline functions. */
 507
 508 /* Convert from an IP version number to an Address Family symbol.  */
 509 static inline int ipver2af(__u8 ipver)
 510 {
 511         switch (ipver) {
 512         case 4:
 513                 return  AF_INET;
 514         case 6:
 515                 return AF_INET6;
 516         default:
 517                 return 0;
 518         }
 519 }
 520
 521 /* Convert from an address parameter type to an address family.  */
 522 static inline int param_type2af(__be16 type)
 523 {
 524         switch (type) {
 525         case SCTP_PARAM_IPV4_ADDRESS:
 526                 return  AF_INET;
 527         case SCTP_PARAM_IPV6_ADDRESS:
 528                 return AF_INET6;
 529         default:
 530                 return 0;
 531         }
 532 }
 533
 534 /* Warning: The following hash functions assume a power of two 'size'. */
 535 /* This is the hash function for the SCTP port hash table. */
 536 static inline int sctp_phashfn(struct net *net, __u16 lport)
 537 {
 538         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 539 }
 540
 541 /* This is the hash function for the endpoint hash table. */
 542 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 543 {
 544         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 545 }
 546
 547 /* This is the hash function for the association hash table. */
 548 static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
 549 {
 550         int h = (lport << 16) + rport + net_hash_mix(net);
 551         h ^= h>>8;
 552         return h & (sctp_assoc_hashsize - 1);
 553 }
 554
 555 /* This is the hash function for the association hash table.  This is
 556  * not used yet, but could be used as a better hash function when
 557  * we have a vtag.
 558  */
 559 static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
 560 {
 561         int h = (lport << 16) + rport;
 562         h ^= vtag;
 563         return h & (sctp_assoc_hashsize - 1);
 564 }
 565
 566 #define sctp_for_each_hentry(epb, head) \
 567         hlist_for_each_entry(epb, head, node)
 568
 569 /* Is a socket of this style? */
 570 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 571 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 572 {
 573         return sctp_sk(sk)->type == style;
 574 }
 575
 576 /* Is the association in this state? */
 577 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 578 static inline int __sctp_state(const struct sctp_association *asoc,
 579                                sctp_state_t state)
 580 {
 581         return asoc->state == state;
 582 }
 583
 584 /* Is the socket in this state? */
 585 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 586 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 587 {
 588         return sk->sk_state == state;
 589 }
 590
 591 /* Map v4-mapped v6 address back to v4 address */
 592 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 593 {
 594         addr->v4.sin_family = AF_INET;
 595         addr->v4.sin_port = addr->v6.sin6_port;
 596         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 597 }
 598
 599 /* Map v4 address to v4-mapped v6 address */
 600 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 601 {
 602         addr->v6.sin6_family = AF_INET6;
 603         addr->v6.sin6_port = addr->v4.sin_port;
 604         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 605         addr->v6.sin6_addr.s6_addr32[0] = 0;
 606         addr->v6.sin6_addr.s6_addr32[1] = 0;
 607         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 608 }
 609
 610 /* The cookie is always 0 since this is how it's used in the
 611  * pmtu code.
 612  */
 613 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 614 {
 615         if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
 616                 dst_release(t->dst);
 617                 t->dst = NULL;
 618         }
 619
 620         return t->dst;
 621 }
 622
 623 #endif /* __net_sctp_h__ */