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 *net, struct sctp_bind_addr *addr,
  98                               enum sctp_scope, 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                             int (*cb_done)(struct sctp_transport *, void *),
 131                             struct net *net, int *pos, void *p);
 132 int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
 133 int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
 134                        struct sctp_info *info);
 135
 136 /*
 137  * sctp/primitive.c
 138  */
 139 int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 140 int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 141 int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 142 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 143 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 144 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 145 int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
 146                           void *arg);
 147
 148 /*
 149  * sctp/input.c
 150  */
 151 int sctp_rcv(struct sk_buff *skb);
 152 void sctp_v4_err(struct sk_buff *skb, u32 info);
 153 void sctp_hash_endpoint(struct sctp_endpoint *);
 154 void sctp_unhash_endpoint(struct sctp_endpoint *);
 155 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 156                              struct sctphdr *, struct sctp_association **,
 157                              struct sctp_transport **);
 158 void sctp_err_finish(struct sock *, struct sctp_transport *);
 159 void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 160                            struct sctp_transport *t, __u32 pmtu);
 161 void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 162                         struct sk_buff *);
 163 void sctp_icmp_proto_unreachable(struct sock *sk,
 164                                  struct sctp_association *asoc,
 165                                  struct sctp_transport *t);
 166 void sctp_backlog_migrate(struct sctp_association *assoc,
 167                           struct sock *oldsk, struct sock *newsk);
 168 int sctp_transport_hashtable_init(void);
 169 void sctp_transport_hashtable_destroy(void);
 170 int sctp_hash_transport(struct sctp_transport *t);
 171 void sctp_unhash_transport(struct sctp_transport *t);
 172 struct sctp_transport *sctp_addrs_lookup_transport(
 173                                 struct net *net,
 174                                 const union sctp_addr *laddr,
 175                                 const union sctp_addr *paddr);
 176 struct sctp_transport *sctp_epaddr_lookup_transport(
 177                                 const struct sctp_endpoint *ep,
 178                                 const union sctp_addr *paddr);
 179
 180 /*
 181  * sctp/proc.c
 182  */
 183 int sctp_snmp_proc_init(struct net *net);
 184 void sctp_snmp_proc_exit(struct net *net);
 185 int sctp_eps_proc_init(struct net *net);
 186 void sctp_eps_proc_exit(struct net *net);
 187 int sctp_assocs_proc_init(struct net *net);
 188 void sctp_assocs_proc_exit(struct net *net);
 189 int sctp_remaddr_proc_init(struct net *net);
 190 void sctp_remaddr_proc_exit(struct net *net);
 191
 192 /*
 193  * sctp/offload.c
 194  */
 195 int sctp_offload_init(void);
 196
 197 /*
 198  * sctp/stream_sched.c
 199  */
 200 void sctp_sched_ops_init(void);
 201
 202 /*
 203  * sctp/stream.c
 204  */
 205 int sctp_send_reset_streams(struct sctp_association *asoc,
 206                             struct sctp_reset_streams *params);
 207 int sctp_send_reset_assoc(struct sctp_association *asoc);
 208 int sctp_send_add_streams(struct sctp_association *asoc,
 209                           struct sctp_add_streams *params);
 210
 211 /*
 212  * Module global variables
 213  */
 214
 215  /*
 216   * sctp/protocol.c
 217   */
 218 extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 219 extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 220 extern long sysctl_sctp_mem[3];
 221 extern int sysctl_sctp_rmem[3];
 222 extern int sysctl_sctp_wmem[3];
 223
 224 /*
 225  *  Section:  Macros, externs, and inlines
 226  */
 227
 228 /* SCTP SNMP MIB stats handlers */
 229 #define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 230 #define __SCTP_INC_STATS(net, field)    __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 231 #define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 232
 233 /* sctp mib definitions */
 234 enum {
 235         SCTP_MIB_NUM = 0,
 236         SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 237         SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 238         SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 239         SCTP_MIB_ABORTEDS,                      /* Aborteds */
 240         SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 241         SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 242         SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 243         SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 244         SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 245         SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 246         SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 247         SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 248         SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 249         SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 250         SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 251         SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 252         SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 253         SCTP_MIB_T1_INIT_EXPIREDS,
 254         SCTP_MIB_T1_COOKIE_EXPIREDS,
 255         SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 256         SCTP_MIB_T3_RTX_EXPIREDS,
 257         SCTP_MIB_T4_RTO_EXPIREDS,
 258         SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 259         SCTP_MIB_DELAY_SACK_EXPIREDS,
 260         SCTP_MIB_AUTOCLOSE_EXPIREDS,
 261         SCTP_MIB_T1_RETRANSMITS,
 262         SCTP_MIB_T3_RETRANSMITS,
 263         SCTP_MIB_PMTUD_RETRANSMITS,
 264         SCTP_MIB_FAST_RETRANSMITS,
 265         SCTP_MIB_IN_PKT_SOFTIRQ,
 266         SCTP_MIB_IN_PKT_BACKLOG,
 267         SCTP_MIB_IN_PKT_DISCARDS,
 268         SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 269         __SCTP_MIB_MAX
 270 };
 271
 272 #define SCTP_MIB_MAX    __SCTP_MIB_MAX
 273 struct sctp_mib {
 274         unsigned long   mibs[SCTP_MIB_MAX];
 275 };
 276
 277 /* helper function to track stats about max rto and related transport */
 278 static inline void sctp_max_rto(struct sctp_association *asoc,
 279                                 struct sctp_transport *trans)
 280 {
 281         if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 282                 asoc->stats.max_obs_rto = trans->rto;
 283                 memset(&asoc->stats.obs_rto_ipaddr, 0,
 284                         sizeof(struct sockaddr_storage));
 285                 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 286                         trans->af_specific->sockaddr_len);
 287         }
 288 }
 289
 290 /*
 291  * Macros for keeping a global reference of object allocations.
 292  */
 293 #ifdef CONFIG_SCTP_DBG_OBJCNT
 294
 295 extern atomic_t sctp_dbg_objcnt_sock;
 296 extern atomic_t sctp_dbg_objcnt_ep;
 297 extern atomic_t sctp_dbg_objcnt_assoc;
 298 extern atomic_t sctp_dbg_objcnt_transport;
 299 extern atomic_t sctp_dbg_objcnt_chunk;
 300 extern atomic_t sctp_dbg_objcnt_bind_addr;
 301 extern atomic_t sctp_dbg_objcnt_bind_bucket;
 302 extern atomic_t sctp_dbg_objcnt_addr;
 303 extern atomic_t sctp_dbg_objcnt_datamsg;
 304 extern atomic_t sctp_dbg_objcnt_keys;
 305
 306 /* Macros to atomically increment/decrement objcnt counters.  */
 307 #define SCTP_DBG_OBJCNT_INC(name) \
 308 atomic_inc(&sctp_dbg_objcnt_## name)
 309 #define SCTP_DBG_OBJCNT_DEC(name) \
 310 atomic_dec(&sctp_dbg_objcnt_## name)
 311 #define SCTP_DBG_OBJCNT(name) \
 312 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 313
 314 /* Macro to help create new entries in in the global array of
 315  * objcnt counters.
 316  */
 317 #define SCTP_DBG_OBJCNT_ENTRY(name) \
 318 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
 319
 320 void sctp_dbg_objcnt_init(struct net *);
 321 void sctp_dbg_objcnt_exit(struct net *);
 322
 323 #else
 324
 325 #define SCTP_DBG_OBJCNT_INC(name)
 326 #define SCTP_DBG_OBJCNT_DEC(name)
 327
 328 static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 329 static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 330
 331 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 332
 333 #if defined CONFIG_SYSCTL
 334 void sctp_sysctl_register(void);
 335 void sctp_sysctl_unregister(void);
 336 int sctp_sysctl_net_register(struct net *net);
 337 void sctp_sysctl_net_unregister(struct net *net);
 338 #else
 339 static inline void sctp_sysctl_register(void) { return; }
 340 static inline void sctp_sysctl_unregister(void) { return; }
 341 static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 342 static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 343 #endif
 344
 345 /* Size of Supported Address Parameter for 'x' address types. */
 346 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 347
 348 #if IS_ENABLED(CONFIG_IPV6)
 349
 350 void sctp_v6_pf_init(void);
 351 void sctp_v6_pf_exit(void);
 352 int sctp_v6_protosw_init(void);
 353 void sctp_v6_protosw_exit(void);
 354 int sctp_v6_add_protocol(void);
 355 void sctp_v6_del_protocol(void);
 356
 357 #else /* #ifdef defined(CONFIG_IPV6) */
 358
 359 static inline void sctp_v6_pf_init(void) { return; }
 360 static inline void sctp_v6_pf_exit(void) { return; }
 361 static inline int sctp_v6_protosw_init(void) { return 0; }
 362 static inline void sctp_v6_protosw_exit(void) { return; }
 363 static inline int sctp_v6_add_protocol(void) { return 0; }
 364 static inline void sctp_v6_del_protocol(void) { return; }
 365
 366 #endif /* #if defined(CONFIG_IPV6) */
 367
 368
 369 /* Map an association to an assoc_id. */
 370 static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 371 {
 372         return asoc ? asoc->assoc_id : 0;
 373 }
 374
 375 static inline enum sctp_sstat_state
 376 sctp_assoc_to_state(const struct sctp_association *asoc)
 377 {
 378         /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
 379          * got rid of it in kernel space. Therefore SCTP_CLOSED et al
 380          * start at =1 in user space, but actually as =0 in kernel space.
 381          * Now that we can not break user space and SCTP_EMPTY is exposed
 382          * there, we need to fix it up with an ugly offset not to break
 383          * applications. :(
 384          */
 385         return asoc->state + 1;
 386 }
 387
 388 /* Look up the association by its id.  */
 389 struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 390
 391 int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 392
 393 /* A macro to walk a list of skbs.  */
 394 #define sctp_skb_for_each(pos, head, tmp) \
 395         skb_queue_walk_safe(head, pos, tmp)
 396
 397 /**
 398  *      sctp_list_dequeue - remove from the head of the queue
 399  *      @list: list to dequeue from
 400  *
 401  *      Remove the head of the list. The head item is
 402  *      returned or %NULL if the list is empty.
 403  */
 404
 405 static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 406 {
 407         struct list_head *result = NULL;
 408
 409         if (!list_empty(list)) {
 410                 result = list->next;
 411                 list_del_init(result);
 412         }
 413         return result;
 414 }
 415
 416 /* SCTP version of skb_set_owner_r.  We need this one because
 417  * of the way we have to do receive buffer accounting on bundled
 418  * chunks.
 419  */
 420 static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 421 {
 422         struct sctp_ulpevent *event = sctp_skb2event(skb);
 423
 424         skb_orphan(skb);
 425         skb->sk = sk;
 426         skb->destructor = sctp_sock_rfree;
 427         atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 428         /*
 429          * This mimics the behavior of skb_set_owner_r
 430          */
 431         sk->sk_forward_alloc -= event->rmem_len;
 432 }
 433
 434 /* Tests if the list has one and only one entry. */
 435 static inline int sctp_list_single_entry(struct list_head *head)
 436 {
 437         return (head->next != head) && (head->next == head->prev);
 438 }
 439
 440 /* Break down data chunks at this point.  */
 441 static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 442 {
 443         struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 444         int frag = pmtu;
 445
 446         frag -= sp->pf->af->net_header_len;
 447         frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 448
 449         if (asoc->user_frag)
 450                 frag = min_t(int, frag, asoc->user_frag);
 451
 452         frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN -
 453                                             sizeof(struct sctp_data_chunk)));
 454
 455         return frag;
 456 }
 457
 458 static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 459 {
 460         sctp_assoc_sync_pmtu(asoc);
 461         asoc->pmtu_pending = 0;
 462 }
 463
 464 static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
 465 {
 466         return !list_empty(&chunk->list);
 467 }
 468
 469 /* Walk through a list of TLV parameters.  Don't trust the
 470  * individual parameter lengths and instead depend on
 471  * the chunk length to indicate when to stop.  Make sure
 472  * there is room for a param header too.
 473  */
 474 #define sctp_walk_params(pos, chunk, member)\
 475 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 476
 477 #define _sctp_walk_params(pos, chunk, end, member)\
 478 for (pos.v = chunk->member;\
 479      (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
 480       (void *)chunk + end) &&\
 481      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 482      ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
 483      pos.v += SCTP_PAD4(ntohs(pos.p->length)))
 484
 485 #define sctp_walk_errors(err, chunk_hdr)\
 486 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 487
 488 #define _sctp_walk_errors(err, chunk_hdr, end)\
 489 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
 490             sizeof(struct sctp_chunkhdr));\
 491      ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
 492       (void *)chunk_hdr + end) &&\
 493      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 494      ntohs(err->length) >= sizeof(struct sctp_errhdr); \
 495      err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
 496
 497 #define sctp_walk_fwdtsn(pos, chunk)\
 498 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 499
 500 #define _sctp_walk_fwdtsn(pos, chunk, end)\
 501 for (pos = chunk->subh.fwdtsn_hdr->skip;\
 502      (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 503      pos++)
 504
 505 /* External references. */
 506
 507 extern struct proto sctp_prot;
 508 extern struct proto sctpv6_prot;
 509 void sctp_put_port(struct sock *sk);
 510
 511 extern struct idr sctp_assocs_id;
 512 extern spinlock_t sctp_assocs_id_lock;
 513
 514 /* Static inline functions. */
 515
 516 /* Convert from an IP version number to an Address Family symbol.  */
 517 static inline int ipver2af(__u8 ipver)
 518 {
 519         switch (ipver) {
 520         case 4:
 521                 return  AF_INET;
 522         case 6:
 523                 return AF_INET6;
 524         default:
 525                 return 0;
 526         }
 527 }
 528
 529 /* Convert from an address parameter type to an address family.  */
 530 static inline int param_type2af(__be16 type)
 531 {
 532         switch (type) {
 533         case SCTP_PARAM_IPV4_ADDRESS:
 534                 return  AF_INET;
 535         case SCTP_PARAM_IPV6_ADDRESS:
 536                 return AF_INET6;
 537         default:
 538                 return 0;
 539         }
 540 }
 541
 542 /* Warning: The following hash functions assume a power of two 'size'. */
 543 /* This is the hash function for the SCTP port hash table. */
 544 static inline int sctp_phashfn(struct net *net, __u16 lport)
 545 {
 546         return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 547 }
 548
 549 /* This is the hash function for the endpoint hash table. */
 550 static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 551 {
 552         return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 553 }
 554
 555 #define sctp_for_each_hentry(epb, head) \
 556         hlist_for_each_entry(epb, head, node)
 557
 558 /* Is a socket of this style? */
 559 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 560 static inline int __sctp_style(const struct sock *sk,
 561                                enum sctp_socket_type style)
 562 {
 563         return sctp_sk(sk)->type == style;
 564 }
 565
 566 /* Is the association in this state? */
 567 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 568 static inline int __sctp_state(const struct sctp_association *asoc,
 569                                enum sctp_state state)
 570 {
 571         return asoc->state == state;
 572 }
 573
 574 /* Is the socket in this state? */
 575 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 576 static inline int __sctp_sstate(const struct sock *sk,
 577                                 enum sctp_sock_state state)
 578 {
 579         return sk->sk_state == state;
 580 }
 581
 582 /* Map v4-mapped v6 address back to v4 address */
 583 static inline void sctp_v6_map_v4(union sctp_addr *addr)
 584 {
 585         addr->v4.sin_family = AF_INET;
 586         addr->v4.sin_port = addr->v6.sin6_port;
 587         addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 588 }
 589
 590 /* Map v4 address to v4-mapped v6 address */
 591 static inline void sctp_v4_map_v6(union sctp_addr *addr)
 592 {
 593         __be16 port;
 594
 595         port = addr->v4.sin_port;
 596         addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 597         addr->v6.sin6_port = port;
 598         addr->v6.sin6_family = AF_INET6;
 599         addr->v6.sin6_flowinfo = 0;
 600         addr->v6.sin6_scope_id = 0;
 601         addr->v6.sin6_addr.s6_addr32[0] = 0;
 602         addr->v6.sin6_addr.s6_addr32[1] = 0;
 603         addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 604 }
 605
 606 /* The cookie is always 0 since this is how it's used in the
 607  * pmtu code.
 608  */
 609 static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 610 {
 611         if (t->dst && !dst_check(t->dst, t->dst_cookie))
 612                 sctp_transport_dst_release(t);
 613
 614         return t->dst;
 615 }
 616
 617 static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
 618 {
 619         __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
 620                            SCTP_DEFAULT_MINSEGMENT);
 621
 622         if (t->pathmtu == pmtu)
 623                 return true;
 624
 625         t->pathmtu = pmtu;
 626
 627         return false;
 628 }
 629
 630 #endif /* __net_sctp_h__ */