linux/include/net/sctp/sctp.h
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   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 */
  97int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
  98                              enum sctp_scope, gfp_t gfp, int flags);
  99struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
 100int sctp_register_pf(struct sctp_pf *, sa_family_t);
 101void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
 102
 103/*
 104 * sctp/socket.c
 105 */
 106int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 107int sctp_inet_listen(struct socket *sock, int backlog);
 108void sctp_write_space(struct sock *sk);
 109void sctp_data_ready(struct sock *sk);
 110unsigned int sctp_poll(struct file *file, struct socket *sock,
 111                poll_table *wait);
 112void sctp_sock_rfree(struct sk_buff *skb);
 113void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 114                    struct sctp_association *asoc);
 115extern struct percpu_counter sctp_sockets_allocated;
 116int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
 117struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
 118
 119int sctp_transport_walk_start(struct rhashtable_iter *iter);
 120void sctp_transport_walk_stop(struct rhashtable_iter *iter);
 121struct sctp_transport *sctp_transport_get_next(struct net *net,
 122                        struct rhashtable_iter *iter);
 123struct sctp_transport *sctp_transport_get_idx(struct net *net,
 124                        struct rhashtable_iter *iter, int pos);
 125int 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);
 129int 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);
 132int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
 133int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
 134                       struct sctp_info *info);
 135
 136/*
 137 * sctp/primitive.c
 138 */
 139int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
 140int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
 141int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 142int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 143int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 144int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
 145int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
 146                          void *arg);
 147
 148/*
 149 * sctp/input.c
 150 */
 151int sctp_rcv(struct sk_buff *skb);
 152void sctp_v4_err(struct sk_buff *skb, u32 info);
 153void sctp_hash_endpoint(struct sctp_endpoint *);
 154void sctp_unhash_endpoint(struct sctp_endpoint *);
 155struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 156                             struct sctphdr *, struct sctp_association **,
 157                             struct sctp_transport **);
 158void sctp_err_finish(struct sock *, struct sctp_transport *);
 159void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
 160                           struct sctp_transport *t, __u32 pmtu);
 161void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
 162                        struct sk_buff *);
 163void sctp_icmp_proto_unreachable(struct sock *sk,
 164                                 struct sctp_association *asoc,
 165                                 struct sctp_transport *t);
 166void sctp_backlog_migrate(struct sctp_association *assoc,
 167                          struct sock *oldsk, struct sock *newsk);
 168int sctp_transport_hashtable_init(void);
 169void sctp_transport_hashtable_destroy(void);
 170int sctp_hash_transport(struct sctp_transport *t);
 171void sctp_unhash_transport(struct sctp_transport *t);
 172struct sctp_transport *sctp_addrs_lookup_transport(
 173                                struct net *net,
 174                                const union sctp_addr *laddr,
 175                                const union sctp_addr *paddr);
 176struct 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 */
 183int sctp_snmp_proc_init(struct net *net);
 184void sctp_snmp_proc_exit(struct net *net);
 185int sctp_eps_proc_init(struct net *net);
 186void sctp_eps_proc_exit(struct net *net);
 187int sctp_assocs_proc_init(struct net *net);
 188void sctp_assocs_proc_exit(struct net *net);
 189int sctp_remaddr_proc_init(struct net *net);
 190void sctp_remaddr_proc_exit(struct net *net);
 191
 192/*
 193 * sctp/offload.c
 194 */
 195int sctp_offload_init(void);
 196
 197/*
 198 * sctp/stream.c
 199 */
 200int sctp_send_reset_streams(struct sctp_association *asoc,
 201                            struct sctp_reset_streams *params);
 202int sctp_send_reset_assoc(struct sctp_association *asoc);
 203int sctp_send_add_streams(struct sctp_association *asoc,
 204                          struct sctp_add_streams *params);
 205
 206/*
 207 * Module global variables
 208 */
 209
 210 /*
 211  * sctp/protocol.c
 212  */
 213extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
 214extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
 215extern long sysctl_sctp_mem[3];
 216extern int sysctl_sctp_rmem[3];
 217extern int sysctl_sctp_wmem[3];
 218
 219/*
 220 *  Section:  Macros, externs, and inlines
 221 */
 222
 223/* SCTP SNMP MIB stats handlers */
 224#define SCTP_INC_STATS(net, field)      SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 225#define __SCTP_INC_STATS(net, field)    __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
 226#define SCTP_DEC_STATS(net, field)      SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
 227
 228/* sctp mib definitions */
 229enum {
 230        SCTP_MIB_NUM = 0,
 231        SCTP_MIB_CURRESTAB,                     /* CurrEstab */
 232        SCTP_MIB_ACTIVEESTABS,                  /* ActiveEstabs */
 233        SCTP_MIB_PASSIVEESTABS,                 /* PassiveEstabs */
 234        SCTP_MIB_ABORTEDS,                      /* Aborteds */
 235        SCTP_MIB_SHUTDOWNS,                     /* Shutdowns */
 236        SCTP_MIB_OUTOFBLUES,                    /* OutOfBlues */
 237        SCTP_MIB_CHECKSUMERRORS,                /* ChecksumErrors */
 238        SCTP_MIB_OUTCTRLCHUNKS,                 /* OutCtrlChunks */
 239        SCTP_MIB_OUTORDERCHUNKS,                /* OutOrderChunks */
 240        SCTP_MIB_OUTUNORDERCHUNKS,              /* OutUnorderChunks */
 241        SCTP_MIB_INCTRLCHUNKS,                  /* InCtrlChunks */
 242        SCTP_MIB_INORDERCHUNKS,                 /* InOrderChunks */
 243        SCTP_MIB_INUNORDERCHUNKS,               /* InUnorderChunks */
 244        SCTP_MIB_FRAGUSRMSGS,                   /* FragUsrMsgs */
 245        SCTP_MIB_REASMUSRMSGS,                  /* ReasmUsrMsgs */
 246        SCTP_MIB_OUTSCTPPACKS,                  /* OutSCTPPacks */
 247        SCTP_MIB_INSCTPPACKS,                   /* InSCTPPacks */
 248        SCTP_MIB_T1_INIT_EXPIREDS,
 249        SCTP_MIB_T1_COOKIE_EXPIREDS,
 250        SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
 251        SCTP_MIB_T3_RTX_EXPIREDS,
 252        SCTP_MIB_T4_RTO_EXPIREDS,
 253        SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
 254        SCTP_MIB_DELAY_SACK_EXPIREDS,
 255        SCTP_MIB_AUTOCLOSE_EXPIREDS,
 256        SCTP_MIB_T1_RETRANSMITS,
 257        SCTP_MIB_T3_RETRANSMITS,
 258        SCTP_MIB_PMTUD_RETRANSMITS,
 259        SCTP_MIB_FAST_RETRANSMITS,
 260        SCTP_MIB_IN_PKT_SOFTIRQ,
 261        SCTP_MIB_IN_PKT_BACKLOG,
 262        SCTP_MIB_IN_PKT_DISCARDS,
 263        SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
 264        __SCTP_MIB_MAX
 265};
 266
 267#define SCTP_MIB_MAX    __SCTP_MIB_MAX
 268struct sctp_mib {
 269        unsigned long   mibs[SCTP_MIB_MAX];
 270};
 271
 272/* helper function to track stats about max rto and related transport */
 273static inline void sctp_max_rto(struct sctp_association *asoc,
 274                                struct sctp_transport *trans)
 275{
 276        if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
 277                asoc->stats.max_obs_rto = trans->rto;
 278                memset(&asoc->stats.obs_rto_ipaddr, 0,
 279                        sizeof(struct sockaddr_storage));
 280                memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
 281                        trans->af_specific->sockaddr_len);
 282        }
 283}
 284
 285/*
 286 * Macros for keeping a global reference of object allocations.
 287 */
 288#ifdef CONFIG_SCTP_DBG_OBJCNT
 289
 290extern atomic_t sctp_dbg_objcnt_sock;
 291extern atomic_t sctp_dbg_objcnt_ep;
 292extern atomic_t sctp_dbg_objcnt_assoc;
 293extern atomic_t sctp_dbg_objcnt_transport;
 294extern atomic_t sctp_dbg_objcnt_chunk;
 295extern atomic_t sctp_dbg_objcnt_bind_addr;
 296extern atomic_t sctp_dbg_objcnt_bind_bucket;
 297extern atomic_t sctp_dbg_objcnt_addr;
 298extern atomic_t sctp_dbg_objcnt_datamsg;
 299extern atomic_t sctp_dbg_objcnt_keys;
 300
 301/* Macros to atomically increment/decrement objcnt counters.  */
 302#define SCTP_DBG_OBJCNT_INC(name) \
 303atomic_inc(&sctp_dbg_objcnt_## name)
 304#define SCTP_DBG_OBJCNT_DEC(name) \
 305atomic_dec(&sctp_dbg_objcnt_## name)
 306#define SCTP_DBG_OBJCNT(name) \
 307atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
 308
 309/* Macro to help create new entries in in the global array of
 310 * objcnt counters.
 311 */
 312#define SCTP_DBG_OBJCNT_ENTRY(name) \
 313{.label= #name, .counter= &sctp_dbg_objcnt_## name}
 314
 315void sctp_dbg_objcnt_init(struct net *);
 316void sctp_dbg_objcnt_exit(struct net *);
 317
 318#else
 319
 320#define SCTP_DBG_OBJCNT_INC(name)
 321#define SCTP_DBG_OBJCNT_DEC(name)
 322
 323static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
 324static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
 325
 326#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
 327
 328#if defined CONFIG_SYSCTL
 329void sctp_sysctl_register(void);
 330void sctp_sysctl_unregister(void);
 331int sctp_sysctl_net_register(struct net *net);
 332void sctp_sysctl_net_unregister(struct net *net);
 333#else
 334static inline void sctp_sysctl_register(void) { return; }
 335static inline void sctp_sysctl_unregister(void) { return; }
 336static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
 337static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
 338#endif
 339
 340/* Size of Supported Address Parameter for 'x' address types. */
 341#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
 342
 343#if IS_ENABLED(CONFIG_IPV6)
 344
 345void sctp_v6_pf_init(void);
 346void sctp_v6_pf_exit(void);
 347int sctp_v6_protosw_init(void);
 348void sctp_v6_protosw_exit(void);
 349int sctp_v6_add_protocol(void);
 350void sctp_v6_del_protocol(void);
 351
 352#else /* #ifdef defined(CONFIG_IPV6) */
 353
 354static inline void sctp_v6_pf_init(void) { return; }
 355static inline void sctp_v6_pf_exit(void) { return; }
 356static inline int sctp_v6_protosw_init(void) { return 0; }
 357static inline void sctp_v6_protosw_exit(void) { return; }
 358static inline int sctp_v6_add_protocol(void) { return 0; }
 359static inline void sctp_v6_del_protocol(void) { return; }
 360
 361#endif /* #if defined(CONFIG_IPV6) */
 362
 363
 364/* Map an association to an assoc_id. */
 365static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
 366{
 367        return asoc ? asoc->assoc_id : 0;
 368}
 369
 370static inline enum sctp_sstat_state
 371sctp_assoc_to_state(const struct sctp_association *asoc)
 372{
 373        /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
 374         * got rid of it in kernel space. Therefore SCTP_CLOSED et al
 375         * start at =1 in user space, but actually as =0 in kernel space.
 376         * Now that we can not break user space and SCTP_EMPTY is exposed
 377         * there, we need to fix it up with an ugly offset not to break
 378         * applications. :(
 379         */
 380        return asoc->state + 1;
 381}
 382
 383/* Look up the association by its id.  */
 384struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
 385
 386int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
 387
 388/* A macro to walk a list of skbs.  */
 389#define sctp_skb_for_each(pos, head, tmp) \
 390        skb_queue_walk_safe(head, pos, tmp)
 391
 392/**
 393 *      sctp_list_dequeue - remove from the head of the queue
 394 *      @list: list to dequeue from
 395 *
 396 *      Remove the head of the list. The head item is
 397 *      returned or %NULL if the list is empty.
 398 */
 399
 400static inline struct list_head *sctp_list_dequeue(struct list_head *list)
 401{
 402        struct list_head *result = NULL;
 403
 404        if (!list_empty(list)) {
 405                result = list->next;
 406                list_del_init(result);
 407        }
 408        return result;
 409}
 410
 411/* SCTP version of skb_set_owner_r.  We need this one because
 412 * of the way we have to do receive buffer accounting on bundled
 413 * chunks.
 414 */
 415static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 416{
 417        struct sctp_ulpevent *event = sctp_skb2event(skb);
 418
 419        skb_orphan(skb);
 420        skb->sk = sk;
 421        skb->destructor = sctp_sock_rfree;
 422        atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
 423        /*
 424         * This mimics the behavior of skb_set_owner_r
 425         */
 426        sk->sk_forward_alloc -= event->rmem_len;
 427}
 428
 429/* Tests if the list has one and only one entry. */
 430static inline int sctp_list_single_entry(struct list_head *head)
 431{
 432        return (head->next != head) && (head->next == head->prev);
 433}
 434
 435/* Break down data chunks at this point.  */
 436static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
 437{
 438        struct sctp_sock *sp = sctp_sk(asoc->base.sk);
 439        int frag = pmtu;
 440
 441        frag -= sp->pf->af->net_header_len;
 442        frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
 443
 444        if (asoc->user_frag)
 445                frag = min_t(int, frag, asoc->user_frag);
 446
 447        frag = SCTP_TRUNC4(min_t(int, frag, SCTP_MAX_CHUNK_LEN));
 448
 449        return frag;
 450}
 451
 452static inline void sctp_assoc_pending_pmtu(struct sctp_association *asoc)
 453{
 454        sctp_assoc_sync_pmtu(asoc);
 455        asoc->pmtu_pending = 0;
 456}
 457
 458static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
 459{
 460        return !list_empty(&chunk->list);
 461}
 462
 463/* Walk through a list of TLV parameters.  Don't trust the
 464 * individual parameter lengths and instead depend on
 465 * the chunk length to indicate when to stop.  Make sure
 466 * there is room for a param header too.
 467 */
 468#define sctp_walk_params(pos, chunk, member)\
 469_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 470
 471#define _sctp_walk_params(pos, chunk, end, member)\
 472for (pos.v = chunk->member;\
 473     (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
 474      (void *)chunk + end) &&\
 475     pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
 476     ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
 477     pos.v += SCTP_PAD4(ntohs(pos.p->length)))
 478
 479#define sctp_walk_errors(err, chunk_hdr)\
 480_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 481
 482#define _sctp_walk_errors(err, chunk_hdr, end)\
 483for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
 484            sizeof(struct sctp_chunkhdr));\
 485     ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
 486      (void *)chunk_hdr + end) &&\
 487     (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
 488     ntohs(err->length) >= sizeof(struct sctp_errhdr); \
 489     err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
 490
 491#define sctp_walk_fwdtsn(pos, chunk)\
 492_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
 493
 494#define _sctp_walk_fwdtsn(pos, chunk, end)\
 495for (pos = chunk->subh.fwdtsn_hdr->skip;\
 496     (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
 497     pos++)
 498
 499/* External references. */
 500
 501extern struct proto sctp_prot;
 502extern struct proto sctpv6_prot;
 503void sctp_put_port(struct sock *sk);
 504
 505extern struct idr sctp_assocs_id;
 506extern spinlock_t sctp_assocs_id_lock;
 507
 508/* Static inline functions. */
 509
 510/* Convert from an IP version number to an Address Family symbol.  */
 511static inline int ipver2af(__u8 ipver)
 512{
 513        switch (ipver) {
 514        case 4:
 515                return  AF_INET;
 516        case 6:
 517                return AF_INET6;
 518        default:
 519                return 0;
 520        }
 521}
 522
 523/* Convert from an address parameter type to an address family.  */
 524static inline int param_type2af(__be16 type)
 525{
 526        switch (type) {
 527        case SCTP_PARAM_IPV4_ADDRESS:
 528                return  AF_INET;
 529        case SCTP_PARAM_IPV6_ADDRESS:
 530                return AF_INET6;
 531        default:
 532                return 0;
 533        }
 534}
 535
 536/* Warning: The following hash functions assume a power of two 'size'. */
 537/* This is the hash function for the SCTP port hash table. */
 538static inline int sctp_phashfn(struct net *net, __u16 lport)
 539{
 540        return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
 541}
 542
 543/* This is the hash function for the endpoint hash table. */
 544static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
 545{
 546        return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
 547}
 548
 549#define sctp_for_each_hentry(epb, head) \
 550        hlist_for_each_entry(epb, head, node)
 551
 552/* Is a socket of this style? */
 553#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
 554static inline int __sctp_style(const struct sock *sk,
 555                               enum sctp_socket_type style)
 556{
 557        return sctp_sk(sk)->type == style;
 558}
 559
 560/* Is the association in this state? */
 561#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
 562static inline int __sctp_state(const struct sctp_association *asoc,
 563                               enum sctp_state state)
 564{
 565        return asoc->state == state;
 566}
 567
 568/* Is the socket in this state? */
 569#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
 570static inline int __sctp_sstate(const struct sock *sk,
 571                                enum sctp_sock_state state)
 572{
 573        return sk->sk_state == state;
 574}
 575
 576/* Map v4-mapped v6 address back to v4 address */
 577static inline void sctp_v6_map_v4(union sctp_addr *addr)
 578{
 579        addr->v4.sin_family = AF_INET;
 580        addr->v4.sin_port = addr->v6.sin6_port;
 581        addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
 582}
 583
 584/* Map v4 address to v4-mapped v6 address */
 585static inline void sctp_v4_map_v6(union sctp_addr *addr)
 586{
 587        __be16 port;
 588
 589        port = addr->v4.sin_port;
 590        addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 591        addr->v6.sin6_port = port;
 592        addr->v6.sin6_family = AF_INET6;
 593        addr->v6.sin6_flowinfo = 0;
 594        addr->v6.sin6_scope_id = 0;
 595        addr->v6.sin6_addr.s6_addr32[0] = 0;
 596        addr->v6.sin6_addr.s6_addr32[1] = 0;
 597        addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
 598}
 599
 600/* The cookie is always 0 since this is how it's used in the
 601 * pmtu code.
 602 */
 603static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
 604{
 605        if (t->dst && !dst_check(t->dst, t->dst_cookie))
 606                sctp_transport_dst_release(t);
 607
 608        return t->dst;
 609}
 610
 611static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
 612{
 613        __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
 614                           SCTP_DEFAULT_MINSEGMENT);
 615
 616        if (t->pathmtu == pmtu)
 617                return true;
 618
 619        t->pathmtu = pmtu;
 620
 621        return false;
 622}
 623
 624#endif /* __net_sctp_h__ */
 625