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 <linux/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 /* Round an int up to the next multiple of 4.  */
  86 #define SCTP_PAD4(s) (((s)+3)&~3)
  87 /* Truncate to the previous multiple of 4.  */
  88 #define SCTP_TRUNC4(s) ((s)&~3)
  89
  90 /*
  91  * Function declarations.
  92  */
  93
  94 /*
  95  * sctp/protocol.c
  96  */
  97 int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
  98                               sctp_scope_t, gfp_t gfp, int flags);
  99 struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 100 int sctp_register_pf(struct sctp_pf *, sa_family_t);
 101 void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
 102
 103 /*
 104  * sctp/socket.c
 105  */
 106 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 107 int sctp_inet_listen(struct socket *sock, int backlog);
 108 void sctp_write_space(struct sock *sk);
 109 void sctp_data_ready(struct sock *sk);
 110 unsigned int sctp_poll(struct file *file, struct socket *sock,
 111                 poll_table *wait);
 112 void sctp_sock_rfree(struct sk_buff *skb);
 113 void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 114                     struct sctp_association *asoc);
 115 extern struct percpu_counter sctp_sockets_allocated;
 116 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 117 struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
 118
 119 int sctp_transport_walk_start(struct rhashtable_iter *iter);
 120 void sctp_transport_walk_stop(struct rhashtable_iter *iter);
 121 struct sctp_transport *sctp_transport_get_next(struct net *net,
 122                         struct rhashtable_iter *iter);
 123 struct sctp_transport *sctp_transport_get_idx(struct net *net,
 124                         struct rhashtable_iter *iter, int pos);
 125 int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
 126                                   struct net *net,
 127                                   const union sctp_addr *laddr,
 128                                   const union sctp_addr *paddr, void *p);
 129 int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
 130                             struct net *net, int pos, void *p);
 131 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
 132 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
 133                        struct sctp_info *info);
 134
 135 /*
 136  * sctp/primitive.c
 137  */
 138 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 139 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 140 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 141 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 142 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 143 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 144 int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
 145                           void *arg);
 146
 147 /*
 148  * sctp/input.c
 149  */
 150 int sctp_rcv(struct sk_buff *skb);
 151 void sctp_v4_err(struct sk_buff *skb, u32 info);
 152 void sctp_hash_endpoint(struct sctp_endpoint *);
 153 void sctp_unhash_endpoint(struct sctp_endpoint *);
 154 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 155                              struct sctphdr *, struct sctp_association **,
 156                              struct sctp_transport **);
 157 void sctp_err_finish(struct sock *, struct sctp_transport *);
 158 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 159                            struct sctp_transport *t, __u32 pmtu);
 160 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 161                         struct sk_buff *);
 162 void sctp_icmp_proto_unreachable(struct sock *sk,
 163                                  struct sctp_association *asoc,
 164                                  struct sctp_transport *t);
 165 void sctp_backlog_migrate(struct sctp_association *assoc,
 166                           struct sock *oldsk, struct sock *newsk);
 167 int sctp_transport_hashtable_init(void);
 168 void sctp_transport_hashtable_destroy(void);
 169 int sctp_hash_transport(struct sctp_transport *t);
 170 void sctp_unhash_transport(struct sctp_transport *t);
 171 struct sctp_transport *sctp_addrs_lookup_transport(
 172                                 struct net *net,
 173                                 const union sctp_addr *laddr,
 174                                 const union sctp_addr *paddr);
 175 struct sctp_transport *sctp_epaddr_lookup_transport(
 176                                 const struct sctp_endpoint *ep,
 177                                 const union sctp_addr *paddr);
 178
 179 /*
 180  * sctp/proc.c
 181  */
 182 int sctp_snmp_proc_init(struct net *net);
 183 void sctp_snmp_proc_exit(struct net *net);
 184 int sctp_eps_proc_init(struct net *net);
 185 void sctp_eps_proc_exit(struct net *net);
 186 int sctp_assocs_proc_init(struct net *net);
 187 void sctp_assocs_proc_exit(struct net *net);
 188 int sctp_remaddr_proc_init(struct net *net);
 189 void sctp_remaddr_proc_exit(struct net *net);
 190
 191 /*
 192  * sctp/offload.c
 193  */
 194 int sctp_offload_init(void);
 195
 196 /*
 197  * sctp/stream.c
 198  */
 199 int sctp_send_reset_streams(struct sctp_association *asoc,
 200                             struct sctp_reset_streams *params);
 201 int sctp_send_reset_assoc(struct sctp_association *asoc);
 202 int sctp_send_add_streams(struct sctp_association *asoc,
 203                           struct sctp_add_streams *params);
 204
 205 /*
 206  * Module global variables
 207  */
 208
 209  /*
 210   * sctp/protocol.c
 211   */
 212 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 213 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 214 extern long sysctl_sctp_mem[3];
 215 extern int sysctl_sctp_rmem[3];
 216 extern int sysctl_sctp_wmem[3];
 217
 218 /*
 219  *  Section:  Macros, externs, and inlines
 220  */
 221
 222 /* SCTP SNMP MIB stats handlers */
 223 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 224 #define __SCTP_INC_STATS(net, field)    __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 225 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 226
 227 /* sctp mib definitions */
 228 enum {
 229         SCTP_MIB_NUM = 0,
 230         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 231         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 232         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 233         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 234         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 235         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 236         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 237         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 238         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 239         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 240         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 241         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 242         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 243         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 244         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 245         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 246         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 247         SCTP_MIB_T1_INIT_EXPIREDS,
 248         SCTP_MIB_T1_COOKIE_EXPIREDS,
 249         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 250         SCTP_MIB_T3_RTX_EXPIREDS,
 251         SCTP_MIB_T4_RTO_EXPIREDS,
 252         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 253         SCTP_MIB_DELAY_SACK_EXPIREDS,
 254         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 255         SCTP_MIB_T1_RETRANSMITS,
 256         SCTP_MIB_T3_RETRANSMITS,
 257         SCTP_MIB_PMTUD_RETRANSMITS,
 258         SCTP_MIB_FAST_RETRANSMITS,
 259         SCTP_MIB_IN_PKT_SOFTIRQ,
 260         SCTP_MIB_IN_PKT_BACKLOG,
 261         SCTP_MIB_IN_PKT_DISCARDS,
 262         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 263         __SCTP_MIB_MAX
 264 };
 265
 266 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 267 struct sctp_mib {
 268         unsigned long   mibs[SCTP_MIB_MAX];
 269 };
 270
 271 /* helper function to track stats about max rto and related transport */
 272 static inline void sctp_max_rto(struct sctp_association *asoc,
 273                                 struct sctp_transport *trans)
 274 {
 275         if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 276                 asoc->stats.max_obs_rto = trans->rto;
 277                 memset(&asoc->stats.obs_rto_ipaddr, 0,
 278                         sizeof(struct sockaddr_storage));
 279                 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 280                         trans->af_specific->sockaddr_len);
 281         }
 282 }
 283
 284 /*
 285  * Macros for keeping a global reference of object allocations.
 286  */
 287 #ifdef CONFIG_SCTP_DBG_OBJCNT
 288
 289 extern atomic_t sctp_dbg_objcnt_sock;
 290 extern atomic_t sctp_dbg_objcnt_ep;
 291 extern atomic_t sctp_dbg_objcnt_assoc;
 292 extern atomic_t sctp_dbg_objcnt_transport;
 293 extern atomic_t sctp_dbg_objcnt_chunk;
 294 extern atomic_t sctp_dbg_objcnt_bind_addr;
 295 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 296 extern atomic_t sctp_dbg_objcnt_addr;
 297 extern atomic_t sctp_dbg_objcnt_datamsg;
 298 extern atomic_t sctp_dbg_objcnt_keys;
 299
 300 /* Macros to atomically increment/decrement objcnt counters.  */
 301 #define SCTP_DBG_OBJCNT_INC(name) \
 302 atomic_inc(&sctp_dbg_objcnt_## name)
 303 #define SCTP_DBG_OBJCNT_DEC(name) \
 304 atomic_dec(&sctp_dbg_objcnt_## name)
 305 #define SCTP_DBG_OBJCNT(name) \
 306 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 307
 308 /* Macro to help create new entries in in the global array of
 309  * objcnt counters.
 310  */
 311 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 312 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 313
 314 void sctp_dbg_objcnt_init(struct net *);
 315 void sctp_dbg_objcnt_exit(struct net *);
 316
 317 #else
 318
 319 #define SCTP_DBG_OBJCNT_INC(name)
 320 #define SCTP_DBG_OBJCNT_DEC(name)
 321
 322 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 323 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 324
 325 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 326
 327 #if defined CONFIG_SYSCTL
 328 void sctp_sysctl_register(void);
 329 void sctp_sysctl_unregister(void);
 330 int sctp_sysctl_net_register(struct net *net);
 331 void sctp_sysctl_net_unregister(struct net *net);
 332 #else
 333 static inline void sctp_sysctl_register(void) { return; }
 334 static inline void sctp_sysctl_unregister(void) { return; }
 335 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 336 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 337 #endif
 338
 339 /* Size of Supported Address Parameter for 'x' address types. */
 340 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 341
 342 #if IS_ENABLED(CONFIG_IPV6)
 343
 344 void sctp_v6_pf_init(void);
 345 void sctp_v6_pf_exit(void);
 346 int sctp_v6_protosw_init(void);
 347 void sctp_v6_protosw_exit(void);
 348 int sctp_v6_add_protocol(void);
 349 void sctp_v6_del_protocol(void);
 350
 351 #else /* #ifdef defined(CONFIG_IPV6) */
 352
 353 static inline void sctp_v6_pf_init(void) { return; }
 354 static inline void sctp_v6_pf_exit(void) { return; }
 355 static inline int sctp_v6_protosw_init(void) { return 0; }
 356 static inline void sctp_v6_protosw_exit(void) { return; }
 357 static inline int sctp_v6_add_protocol(void) { return 0; }
 358 static inline void sctp_v6_del_protocol(void) { return; }
 359
 360 #endif /* #if defined(CONFIG_IPV6) */
 361
 362
 363 /* Map an association to an assoc_id. */
 364 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 365 {
 366         return asoc ? asoc->assoc_id : 0;
 367 }
 368
 369 static inline enum sctp_sstat_state
 370 sctp_assoc_to_state(const struct sctp_association *asoc)
 371 {
 372         /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
 373          * got rid of it in kernel space. Therefore SCTP_CLOSED et al
 374          * start at =1 in user space, but actually as =0 in kernel space.
 375          * Now that we can not break user space and SCTP_EMPTY is exposed
 376          * there, we need to fix it up with an ugly offset not to break
 377          * applications. :(
 378          */
 379         return asoc->state + 1;
 380 }
 381
 382 /* Look up the association by its id.  */
 383 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 384
 385 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 386
 387 /* A macro to walk a list of skbs.  */
 388 #define sctp_skb_for_each(pos, head, tmp) \
 389         skb_queue_walk_safe(head, pos, tmp)
 390
 391 /**
 392  *      sctp_list_dequeue - remove from the head of the queue
 393  *      @list: list to dequeue from
 394  *
 395  *      Remove the head of the list. The head item is
 396  *      returned or %NULL if the list is empty.
 397  */
 398
 399 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 400 {
 401         struct list_head *result = NULL;
 402
 403         if (!list_empty(list)) {
 404                 result = list->next;
 405                 list_del_init(result);
 406         }
 407         return result;
 408 }
 409
 410 /* SCTP version of skb_set_owner_r.  We need this one because
 411  * of the way we have to do receive buffer accounting on bundled
 412  * chunks.
 413  */
 414 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 415 {
 416         struct sctp_ulpevent *event = sctp_skb2event(skb);
 417
 418         skb_orphan(skb);
 419         skb->sk = sk;
 420         skb->destructor = sctp_sock_rfree;
 421         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 422         /*
 423          * This mimics the behavior of skb_set_owner_r
 424          */
 425         sk->sk_forward_alloc -= event->rmem_len;
 426 }
 427
 428 /* Tests if the list has one and only one entry. */
 429 static inline int sctp_list_single_entry(struct list_head *head)
 430 {
 431         return (head->next != head) && (head->next == head->prev);
 432 }
 433
 434 /* Break down data chunks at this point.  */
 435 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 436 {
 437         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 438         int frag = pmtu;
 439
 440         frag -= sp->pf->af->net_header_len;
 441         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 442
 443         if (asoc->user_frag)
 444                 frag = min_t(int, frag, asoc->user_frag);
 445
 446         frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN));
 447
 448         return frag;
 449 }
 450
 451 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 452 {
 453         sctp_assoc_sync_pmtu(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 + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
 473       (void *)chunk + end) &&\
 474      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 475      ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
 476      pos.v += SCTP_PAD4(ntohs(pos.p->length)))
 477
 478 #define sctp_walk_errors(err, chunk_hdr)\
 479 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 480
 481 #define _sctp_walk_errors(err, chunk_hdr, end)\
 482 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 483             sizeof(struct sctp_chunkhdr));\
 484      ((void *)err + offsetof(sctp_errhdr_t, length) + sizeof(err->length) <=\
 485       (void *)chunk_hdr + end) &&\
 486      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 487      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
 488      err = (sctp_errhdr_t *)((void *)err + SCTP_PAD4(ntohs(err->length))))
 489
 490 #define sctp_walk_fwdtsn(pos, chunk)\
 491 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 492
 493 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 494 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 495      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 496      pos++)
 497
 498 /* External references. */
 499
 500 extern struct proto sctp_prot;
 501 extern struct proto sctpv6_prot;
 502 void sctp_put_port(struct sock *sk);
 503
 504 extern struct idr sctp_assocs_id;
 505 extern spinlock_t sctp_assocs_id_lock;
 506
 507 /* Static inline functions. */
 508
 509 /* Convert from an IP version number to an Address Family symbol.  */
 510 static inline int ipver2af(__u8 ipver)
 511 {
 512         switch (ipver) {
 513         case 4:
 514                 return  AF_INET;
 515         case 6:
 516                 return AF_INET6;
 517         default:
 518                 return 0;
 519         }
 520 }
 521
 522 /* Convert from an address parameter type to an address family.  */
 523 static inline int param_type2af(__be16 type)
 524 {
 525         switch (type) {
 526         case SCTP_PARAM_IPV4_ADDRESS:
 527                 return  AF_INET;
 528         case SCTP_PARAM_IPV6_ADDRESS:
 529                 return AF_INET6;
 530         default:
 531                 return 0;
 532         }
 533 }
 534
 535 /* Warning: The following hash functions assume a power of two 'size'. */
 536 /* This is the hash function for the SCTP port hash table. */
 537 static inline int sctp_phashfn(struct net *net, __u16 lport)
 538 {
 539         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 540 }
 541
 542 /* This is the hash function for the endpoint hash table. */
 543 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 544 {
 545         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 546 }
 547
 548 #define sctp_for_each_hentry(epb, head) \
 549         hlist_for_each_entry(epb, head, node)
 550
 551 /* Is a socket of this style? */
 552 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 553 static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
 554 {
 555         return sctp_sk(sk)->type == style;
 556 }
 557
 558 /* Is the association in this state? */
 559 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 560 static inline int __sctp_state(const struct sctp_association *asoc,
 561                                sctp_state_t state)
 562 {
 563         return asoc->state == state;
 564 }
 565
 566 /* Is the socket in this state? */
 567 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 568 static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
 569 {
 570         return sk->sk_state == state;
 571 }
 572
 573 /* Map v4-mapped v6 address back to v4 address */
 574 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 575 {
 576         addr->v4.sin_family = AF_INET;
 577         addr->v4.sin_port = addr->v6.sin6_port;
 578         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 579 }
 580
 581 /* Map v4 address to v4-mapped v6 address */
 582 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 583 {
 584         __be16 port;
 585
 586         port = addr->v4.sin_port;
 587         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 588         addr->v6.sin6_port = port;
 589         addr->v6.sin6_family = AF_INET6;
 590         addr->v6.sin6_flowinfo = 0;
 591         addr->v6.sin6_scope_id = 0;
 592         addr->v6.sin6_addr.s6_addr32[0] = 0;
 593         addr->v6.sin6_addr.s6_addr32[1] = 0;
 594         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 595 }
 596
 597 /* The cookie is always 0 since this is how it's used in the
 598  * pmtu code.
 599  */
 600 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 601 {
 602         if (t->dst && !dst_check(t->dst, t->dst_cookie))
 603                 sctp_transport_dst_release(t);
 604
 605         return t->dst;
 606 }
 607
 608 static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
 609 {
 610         __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
 611                            SCTP_DEFAULT_MINSEGMENT);
 612
 613         if (t->pathmtu == pmtu)
 614                 return true;
 615
 616         t->pathmtu = pmtu;
 617
 618         return false;
 619 }
 620
 621 #endif /* __net_sctp_h__ */