include/net/sctp/structs.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 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * This SCTP implementation is free software;
  10  * you can redistribute it and/or modify it under the terms of
  11  * the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2, or (at your option)
  13  * any later version.
  14  *
  15  * This SCTP implementation is distributed in the hope that it
  16  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  17  *                 ************************
  18  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  19  * See the GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with GNU CC; see the file COPYING.  If not, see
  23  * <http://www.gnu.org/licenses/>.
  24  *
  25  * Please send any bug reports or fixes you make to the
  26  * email addresses:
  27  *    lksctp developers <linux-sctp@vger.kernel.org>
  28  *
  29  * Written or modified by:
  30  *    Randall Stewart       <randall@sctp.chicago.il.us>
  31  *    Ken Morneau           <kmorneau@cisco.com>
  32  *    Qiaobing Xie          <qxie1@email.mot.com>
  33  *    La Monte H.P. Yarroll <piggy@acm.org>
  34  *    Karl Knutson          <karl@athena.chicago.il.us>
  35  *    Jon Grimm             <jgrimm@us.ibm.com>
  36  *    Xingang Guo           <xingang.guo@intel.com>
  37  *    Hui Huang             <hui.huang@nokia.com>
  38  *    Sridhar Samudrala     <sri@us.ibm.com>
  39  *    Daisy Chang           <daisyc@us.ibm.com>
  40  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *    Ryan Layer            <rmlayer@us.ibm.com>
  43  *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
  44  *    Kevin Gao             <kevin.gao@intel.com>
  45  */
  46
  47 #ifndef __sctp_structs_h__
  48 #define __sctp_structs_h__
  49
  50 #include <linux/ktime.h>
  51 #include <linux/socket.h>       /* linux/in.h needs this!!    */
  52 #include <linux/in.h>           /* We get struct sockaddr_in. */
  53 #include <linux/in6.h>          /* We get struct in6_addr     */
  54 #include <linux/ipv6.h>
  55 #include <asm/param.h>          /* We get MAXHOSTNAMELEN.     */
  56 #include <linux/atomic.h>               /* This gets us atomic counters.  */
  57 #include <linux/skbuff.h>       /* We need sk_buff_head. */
  58 #include <linux/workqueue.h>    /* We need tq_struct.    */
  59 #include <linux/sctp.h>         /* We need sctp* header structs.  */
  60 #include <net/sctp/auth.h>      /* We need auth specific structs */
  61
  62 /* A convenience structure for handling sockaddr structures.
  63  * We should wean ourselves off this.
  64  */
  65 union sctp_addr {
  66         struct sockaddr_in v4;
  67         struct sockaddr_in6 v6;
  68         struct sockaddr sa;
  69 };
  70
  71 /* Forward declarations for data structures. */
  72 struct sctp_globals;
  73 struct sctp_endpoint;
  74 struct sctp_association;
  75 struct sctp_transport;
  76 struct sctp_packet;
  77 struct sctp_chunk;
  78 struct sctp_inq;
  79 struct sctp_outq;
  80 struct sctp_bind_addr;
  81 struct sctp_ulpq;
  82 struct sctp_ep_common;
  83 struct sctp_ssnmap;
  84 struct crypto_hash;
  85
  86
  87 #include <net/sctp/tsnmap.h>
  88 #include <net/sctp/ulpevent.h>
  89 #include <net/sctp/ulpqueue.h>
  90
  91 /* Structures useful for managing bind/connect. */
  92
  93 struct sctp_bind_bucket {
  94         unsigned short  port;
  95         unsigned short  fastreuse;
  96         struct hlist_node       node;
  97         struct hlist_head       owner;
  98         struct net      *net;
  99 };
 100
 101 struct sctp_bind_hashbucket {
 102         spinlock_t      lock;
 103         struct hlist_head       chain;
 104 };
 105
 106 /* Used for hashing all associations.  */
 107 struct sctp_hashbucket {
 108         rwlock_t        lock;
 109         struct hlist_head       chain;
 110 } __attribute__((__aligned__(8)));
 111
 112
 113 /* The SCTP globals structure. */
 114 extern struct sctp_globals {
 115         /* This is a list of groups of functions for each address
 116          * family that we support.
 117          */
 118         struct list_head address_families;
 119
 120         /* This is the hash of all endpoints. */
 121         struct sctp_hashbucket *ep_hashtable;
 122         /* This is the hash of all associations. */
 123         struct sctp_hashbucket *assoc_hashtable;
 124         /* This is the sctp port control hash.  */
 125         struct sctp_bind_hashbucket *port_hashtable;
 126
 127         /* Sizes of above hashtables. */
 128         int ep_hashsize;
 129         int assoc_hashsize;
 130         int port_hashsize;
 131
 132         /* Default initialization values to be applied to new associations. */
 133         __u16 max_instreams;
 134         __u16 max_outstreams;
 135
 136         /* Flag to indicate whether computing and verifying checksum
 137          * is disabled. */
 138         bool checksum_disable;
 139 } sctp_globals;
 140
 141 #define sctp_max_instreams              (sctp_globals.max_instreams)
 142 #define sctp_max_outstreams             (sctp_globals.max_outstreams)
 143 #define sctp_address_families           (sctp_globals.address_families)
 144 #define sctp_ep_hashsize                (sctp_globals.ep_hashsize)
 145 #define sctp_ep_hashtable               (sctp_globals.ep_hashtable)
 146 #define sctp_assoc_hashsize             (sctp_globals.assoc_hashsize)
 147 #define sctp_assoc_hashtable            (sctp_globals.assoc_hashtable)
 148 #define sctp_port_hashsize              (sctp_globals.port_hashsize)
 149 #define sctp_port_hashtable             (sctp_globals.port_hashtable)
 150 #define sctp_checksum_disable           (sctp_globals.checksum_disable)
 151
 152 /* SCTP Socket type: UDP or TCP style. */
 153 typedef enum {
 154         SCTP_SOCKET_UDP = 0,
 155         SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
 156         SCTP_SOCKET_TCP
 157 } sctp_socket_type_t;
 158
 159 /* Per socket SCTP information. */
 160 struct sctp_sock {
 161         /* inet_sock has to be the first member of sctp_sock */
 162         struct inet_sock inet;
 163         /* What kind of a socket is this? */
 164         sctp_socket_type_t type;
 165
 166         /* PF_ family specific functions.  */
 167         struct sctp_pf *pf;
 168
 169         /* Access to HMAC transform. */
 170         struct crypto_hash *hmac;
 171         char *sctp_hmac_alg;
 172
 173         /* What is our base endpointer? */
 174         struct sctp_endpoint *ep;
 175
 176         struct sctp_bind_bucket *bind_hash;
 177         /* Various Socket Options.  */
 178         __u16 default_stream;
 179         __u32 default_ppid;
 180         __u16 default_flags;
 181         __u32 default_context;
 182         __u32 default_timetolive;
 183         __u32 default_rcv_context;
 184         int max_burst;
 185
 186         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 187          * the destination address every heartbeat interval. This value
 188          * will be inherited by all new associations.
 189          */
 190         __u32 hbinterval;
 191
 192         /* This is the max_retrans value for new associations. */
 193         __u16 pathmaxrxt;
 194
 195         /* The initial Path MTU to use for new associations. */
 196         __u32 pathmtu;
 197
 198         /* The default SACK delay timeout for new associations. */
 199         __u32 sackdelay;
 200         __u32 sackfreq;
 201
 202         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 203         __u32 param_flags;
 204
 205         struct sctp_initmsg initmsg;
 206         struct sctp_rtoinfo rtoinfo;
 207         struct sctp_paddrparams paddrparam;
 208         struct sctp_event_subscribe subscribe;
 209         struct sctp_assocparams assocparams;
 210
 211         int user_frag;
 212
 213         __u32 autoclose;
 214         __u8 nodelay;
 215         __u8 disable_fragments;
 216         __u8 v4mapped;
 217         __u8 frag_interleave;
 218         __u32 adaptation_ind;
 219         __u32 pd_point;
 220         __u8 recvrcvinfo;
 221         __u8 recvnxtinfo;
 222
 223         atomic_t pd_mode;
 224         /* Receive to here while partial delivery is in effect. */
 225         struct sk_buff_head pd_lobby;
 226         struct list_head auto_asconf_list;
 227         int do_auto_asconf;
 228 };
 229
 230 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
 231 {
 232        return (struct sctp_sock *)sk;
 233 }
 234
 235 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
 236 {
 237        return (struct sock *)sp;
 238 }
 239
 240 #if IS_ENABLED(CONFIG_IPV6)
 241 struct sctp6_sock {
 242        struct sctp_sock  sctp;
 243        struct ipv6_pinfo inet6;
 244 };
 245 #endif /* CONFIG_IPV6 */
 246
 247
 248 /* This is our APPLICATION-SPECIFIC state cookie.
 249  * THIS IS NOT DICTATED BY THE SPECIFICATION.
 250  */
 251 /* These are the parts of an association which we send in the cookie.
 252  * Most of these are straight out of:
 253  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
 254  *
 255  */
 256
 257 struct sctp_cookie {
 258
 259         /* My          : Tag expected in every inbound packet and sent
 260          * Verification: in the INIT or INIT ACK chunk.
 261          * Tag         :
 262          */
 263         __u32 my_vtag;
 264
 265         /* Peer's      : Tag expected in every outbound packet except
 266          * Verification: in the INIT chunk.
 267          * Tag         :
 268          */
 269         __u32 peer_vtag;
 270
 271         /* The rest of these are not from the spec, but really need to
 272          * be in the cookie.
 273          */
 274
 275         /* My Tie Tag  : Assist in discovering a restarting association. */
 276         __u32 my_ttag;
 277
 278         /* Peer's Tie Tag: Assist in discovering a restarting association. */
 279         __u32 peer_ttag;
 280
 281         /* When does this cookie expire? */
 282         ktime_t expiration;
 283
 284         /* Number of inbound/outbound streams which are set
 285          * and negotiated during the INIT process.
 286          */
 287         __u16 sinit_num_ostreams;
 288         __u16 sinit_max_instreams;
 289
 290         /* This is the first sequence number I used.  */
 291         __u32 initial_tsn;
 292
 293         /* This holds the originating address of the INIT packet.  */
 294         union sctp_addr peer_addr;
 295
 296         /* IG Section 2.35.3
 297          * Include the source port of the INIT-ACK
 298          */
 299         __u16           my_port;
 300
 301         __u8 prsctp_capable;
 302
 303         /* Padding for future use */
 304         __u8 padding;
 305
 306         __u32 adaptation_ind;
 307
 308         __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
 309         __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
 310         __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
 311
 312         /* This is a shim for my peer's INIT packet, followed by
 313          * a copy of the raw address list of the association.
 314          * The length of the raw address list is saved in the
 315          * raw_addr_list_len field, which will be used at the time when
 316          * the association TCB is re-constructed from the cookie.
 317          */
 318         __u32 raw_addr_list_len;
 319         struct sctp_init_chunk peer_init[0];
 320 };
 321
 322
 323 /* The format of our cookie that we send to our peer. */
 324 struct sctp_signed_cookie {
 325         __u8 signature[SCTP_SECRET_SIZE];
 326         __u32 __pad;            /* force sctp_cookie alignment to 64 bits */
 327         struct sctp_cookie c;
 328 } __packed;
 329
 330 /* This is another convenience type to allocate memory for address
 331  * params for the maximum size and pass such structures around
 332  * internally.
 333  */
 334 union sctp_addr_param {
 335         struct sctp_paramhdr p;
 336         struct sctp_ipv4addr_param v4;
 337         struct sctp_ipv6addr_param v6;
 338 };
 339
 340 /* A convenience type to allow walking through the various
 341  * parameters and avoid casting all over the place.
 342  */
 343 union sctp_params {
 344         void *v;
 345         struct sctp_paramhdr *p;
 346         struct sctp_cookie_preserve_param *life;
 347         struct sctp_hostname_param *dns;
 348         struct sctp_cookie_param *cookie;
 349         struct sctp_supported_addrs_param *sat;
 350         struct sctp_ipv4addr_param *v4;
 351         struct sctp_ipv6addr_param *v6;
 352         union sctp_addr_param *addr;
 353         struct sctp_adaptation_ind_param *aind;
 354         struct sctp_supported_ext_param *ext;
 355         struct sctp_random_param *random;
 356         struct sctp_chunks_param *chunks;
 357         struct sctp_hmac_algo_param *hmac_algo;
 358         struct sctp_addip_param *addip;
 359 };
 360
 361 /* RFC 2960.  Section 3.3.5 Heartbeat.
 362  *    Heartbeat Information: variable length
 363  *    The Sender-specific Heartbeat Info field should normally include
 364  *    information about the sender's current time when this HEARTBEAT
 365  *    chunk is sent and the destination transport address to which this
 366  *    HEARTBEAT is sent (see Section 8.3).
 367  */
 368 typedef struct sctp_sender_hb_info {
 369         struct sctp_paramhdr param_hdr;
 370         union sctp_addr daddr;
 371         unsigned long sent_at;
 372         __u64 hb_nonce;
 373 } __packed sctp_sender_hb_info_t;
 374
 375 /*
 376  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
 377  *
 378  *  The term "stream" is used in SCTP to refer to a sequence of user
 379  *  messages that are to be delivered to the upper-layer protocol in
 380  *  order with respect to other messages within the same stream.  This is
 381  *  in contrast to its usage in TCP, where it refers to a sequence of
 382  *  bytes (in this document a byte is assumed to be eight bits).
 383  *  ...
 384  *
 385  *  This is the structure we use to track both our outbound and inbound
 386  *  SSN, or Stream Sequence Numbers.
 387  */
 388
 389 struct sctp_stream {
 390         __u16 *ssn;
 391         unsigned int len;
 392 };
 393
 394 struct sctp_ssnmap {
 395         struct sctp_stream in;
 396         struct sctp_stream out;
 397 };
 398
 399 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
 400                                     gfp_t gfp);
 401 void sctp_ssnmap_free(struct sctp_ssnmap *map);
 402 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
 403
 404 /* What is the current SSN number for this stream? */
 405 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
 406 {
 407         return stream->ssn[id];
 408 }
 409
 410 /* Return the next SSN number for this stream.  */
 411 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
 412 {
 413         return stream->ssn[id]++;
 414 }
 415
 416 /* Skip over this ssn and all below. */
 417 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
 418                                  __u16 ssn)
 419 {
 420         stream->ssn[id] = ssn+1;
 421 }
 422
 423 /*
 424  * Pointers to address related SCTP functions.
 425  * (i.e. things that depend on the address family.)
 426  */
 427 struct sctp_af {
 428         int             (*sctp_xmit)    (struct sk_buff *skb,
 429                                          struct sctp_transport *);
 430         int             (*setsockopt)   (struct sock *sk,
 431                                          int level,
 432                                          int optname,
 433                                          char __user *optval,
 434                                          unsigned int optlen);
 435         int             (*getsockopt)   (struct sock *sk,
 436                                          int level,
 437                                          int optname,
 438                                          char __user *optval,
 439                                          int __user *optlen);
 440         int             (*compat_setsockopt)    (struct sock *sk,
 441                                          int level,
 442                                          int optname,
 443                                          char __user *optval,
 444                                          unsigned int optlen);
 445         int             (*compat_getsockopt)    (struct sock *sk,
 446                                          int level,
 447                                          int optname,
 448                                          char __user *optval,
 449                                          int __user *optlen);
 450         void            (*get_dst)      (struct sctp_transport *t,
 451                                          union sctp_addr *saddr,
 452                                          struct flowi *fl,
 453                                          struct sock *sk);
 454         void            (*get_saddr)    (struct sctp_sock *sk,
 455                                          struct sctp_transport *t,
 456                                          struct flowi *fl);
 457         void            (*copy_addrlist) (struct list_head *,
 458                                           struct net_device *);
 459         int             (*cmp_addr)     (const union sctp_addr *addr1,
 460                                          const union sctp_addr *addr2);
 461         void            (*addr_copy)    (union sctp_addr *dst,
 462                                          union sctp_addr *src);
 463         void            (*from_skb)     (union sctp_addr *,
 464                                          struct sk_buff *skb,
 465                                          int saddr);
 466         void            (*from_sk)      (union sctp_addr *,
 467                                          struct sock *sk);
 468         void            (*from_addr_param) (union sctp_addr *,
 469                                             union sctp_addr_param *,
 470                                             __be16 port, int iif);
 471         int             (*to_addr_param) (const union sctp_addr *,
 472                                           union sctp_addr_param *);
 473         int             (*addr_valid)   (union sctp_addr *,
 474                                          struct sctp_sock *,
 475                                          const struct sk_buff *);
 476         sctp_scope_t    (*scope) (union sctp_addr *);
 477         void            (*inaddr_any)   (union sctp_addr *, __be16);
 478         int             (*is_any)       (const union sctp_addr *);
 479         int             (*available)    (union sctp_addr *,
 480                                          struct sctp_sock *);
 481         int             (*skb_iif)      (const struct sk_buff *sk);
 482         int             (*is_ce)        (const struct sk_buff *sk);
 483         void            (*seq_dump_addr)(struct seq_file *seq,
 484                                          union sctp_addr *addr);
 485         void            (*ecn_capable)(struct sock *sk);
 486         __u16           net_header_len;
 487         int             sockaddr_len;
 488         sa_family_t     sa_family;
 489         struct list_head list;
 490 };
 491
 492 struct sctp_af *sctp_get_af_specific(sa_family_t);
 493 int sctp_register_af(struct sctp_af *);
 494
 495 /* Protocol family functions. */
 496 struct sctp_pf {
 497         void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
 498         void (*skb_msgname)  (struct sk_buff *, char *, int *);
 499         int  (*af_supported) (sa_family_t, struct sctp_sock *);
 500         int  (*cmp_addr) (const union sctp_addr *,
 501                           const union sctp_addr *,
 502                           struct sctp_sock *);
 503         int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
 504         int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
 505         int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
 506         struct sock *(*create_accept_sk) (struct sock *sk,
 507                                           struct sctp_association *asoc);
 508         int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
 509         void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
 510         void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
 511         struct sctp_af *af;
 512 };
 513
 514
 515 /* Structure to track chunk fragments that have been acked, but peer
 516  * fragments of the same message have not.
 517  */
 518 struct sctp_datamsg {
 519         /* Chunks waiting to be submitted to lower layer. */
 520         struct list_head chunks;
 521         /* Reference counting. */
 522         atomic_t refcnt;
 523         /* When is this message no longer interesting to the peer? */
 524         unsigned long expires_at;
 525         /* Did the messenge fail to send? */
 526         int send_error;
 527         u8 send_failed:1,
 528            can_abandon:1,   /* can chunks from this message can be abandoned. */
 529            can_delay;       /* should this message be Nagle delayed */
 530 };
 531
 532 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 533                                             struct sctp_sndrcvinfo *,
 534                                             struct msghdr *, int len);
 535 void sctp_datamsg_free(struct sctp_datamsg *);
 536 void sctp_datamsg_put(struct sctp_datamsg *);
 537 void sctp_chunk_fail(struct sctp_chunk *, int error);
 538 int sctp_chunk_abandoned(struct sctp_chunk *);
 539
 540 /* RFC2960 1.4 Key Terms
 541  *
 542  * o Chunk: A unit of information within an SCTP packet, consisting of
 543  * a chunk header and chunk-specific content.
 544  *
 545  * As a matter of convenience, we remember the SCTP common header for
 546  * each chunk as well as a few other header pointers...
 547  */
 548 struct sctp_chunk {
 549         struct list_head list;
 550
 551         atomic_t refcnt;
 552
 553         /* This is our link to the per-transport transmitted list.  */
 554         struct list_head transmitted_list;
 555
 556         /* This field is used by chunks that hold fragmented data.
 557          * For the first fragment this is the list that holds the rest of
 558          * fragments. For the remaining fragments, this is the link to the
 559          * frag_list maintained in the first fragment.
 560          */
 561         struct list_head frag_list;
 562
 563         /* This points to the sk_buff containing the actual data.  */
 564         struct sk_buff *skb;
 565
 566         /* These are the SCTP headers by reverse order in a packet.
 567          * Note that some of these may happen more than once.  In that
 568          * case, we point at the "current" one, whatever that means
 569          * for that level of header.
 570          */
 571
 572         /* We point this at the FIRST TLV parameter to chunk_hdr.  */
 573         union sctp_params param_hdr;
 574         union {
 575                 __u8 *v;
 576                 struct sctp_datahdr *data_hdr;
 577                 struct sctp_inithdr *init_hdr;
 578                 struct sctp_sackhdr *sack_hdr;
 579                 struct sctp_heartbeathdr *hb_hdr;
 580                 struct sctp_sender_hb_info *hbs_hdr;
 581                 struct sctp_shutdownhdr *shutdown_hdr;
 582                 struct sctp_signed_cookie *cookie_hdr;
 583                 struct sctp_ecnehdr *ecne_hdr;
 584                 struct sctp_cwrhdr *ecn_cwr_hdr;
 585                 struct sctp_errhdr *err_hdr;
 586                 struct sctp_addiphdr *addip_hdr;
 587                 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
 588                 struct sctp_authhdr *auth_hdr;
 589         } subh;
 590
 591         __u8 *chunk_end;
 592
 593         struct sctp_chunkhdr *chunk_hdr;
 594         struct sctphdr *sctp_hdr;
 595
 596         /* This needs to be recoverable for SCTP_SEND_FAILED events. */
 597         struct sctp_sndrcvinfo sinfo;
 598
 599         /* Which association does this belong to?  */
 600         struct sctp_association *asoc;
 601
 602         /* What endpoint received this chunk? */
 603         struct sctp_ep_common *rcvr;
 604
 605         /* We fill this in if we are calculating RTT. */
 606         unsigned long sent_at;
 607
 608         /* What is the origin IP address for this chunk?  */
 609         union sctp_addr source;
 610         /* Destination address for this chunk. */
 611         union sctp_addr dest;
 612
 613         /* For outbound message, track all fragments for SEND_FAILED. */
 614         struct sctp_datamsg *msg;
 615
 616         /* For an inbound chunk, this tells us where it came from.
 617          * For an outbound chunk, it tells us where we'd like it to
 618          * go.  It is NULL if we have no preference.
 619          */
 620         struct sctp_transport *transport;
 621
 622         /* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
 623          * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
 624          * spec violates the principle premis that all chunks are processed
 625          * in order.
 626          */
 627         struct sk_buff *auth_chunk;
 628
 629 #define SCTP_CAN_FRTX 0x0
 630 #define SCTP_NEED_FRTX 0x1
 631 #define SCTP_DONT_FRTX 0x2
 632         __u16   rtt_in_progress:1,      /* This chunk used for RTT calc? */
 633                 resent:1,               /* Has this chunk ever been resent. */
 634                 has_tsn:1,              /* Does this chunk have a TSN yet? */
 635                 has_ssn:1,              /* Does this chunk have a SSN yet? */
 636                 singleton:1,            /* Only chunk in the packet? */
 637                 end_of_packet:1,        /* Last chunk in the packet? */
 638                 ecn_ce_done:1,          /* Have we processed the ECN CE bit? */
 639                 pdiscard:1,             /* Discard the whole packet now? */
 640                 tsn_gap_acked:1,        /* Is this chunk acked by a GAP ACK? */
 641                 data_accepted:1,        /* At least 1 chunk accepted */
 642                 auth:1,                 /* IN: was auth'ed | OUT: needs auth */
 643                 has_asconf:1,           /* IN: have seen an asconf before */
 644                 tsn_missing_report:2,   /* Data chunk missing counter. */
 645                 fast_retransmit:2;      /* Is this chunk fast retransmitted? */
 646 };
 647
 648 void sctp_chunk_hold(struct sctp_chunk *);
 649 void sctp_chunk_put(struct sctp_chunk *);
 650 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
 651                           struct iovec *data);
 652 void sctp_chunk_free(struct sctp_chunk *);
 653 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
 654 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
 655                                  const struct sctp_association *,
 656                                  struct sock *);
 657 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 658                      union sctp_addr *);
 659 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 660
 661 enum {
 662         SCTP_ADDR_NEW,          /* new address added to assoc/ep */
 663         SCTP_ADDR_SRC,          /* address can be used as source */
 664         SCTP_ADDR_DEL,          /* address about to be deleted */
 665 };
 666
 667 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
 668 struct sctp_sockaddr_entry {
 669         struct list_head list;
 670         struct rcu_head rcu;
 671         union sctp_addr a;
 672         __u8 state;
 673         __u8 valid;
 674 };
 675
 676 #define SCTP_ADDRESS_TICK_DELAY 500
 677
 678 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
 679
 680 /* This structure holds lists of chunks as we are assembling for
 681  * transmission.
 682  */
 683 struct sctp_packet {
 684         /* These are the SCTP header values (host order) for the packet. */
 685         __u16 source_port;
 686         __u16 destination_port;
 687         __u32 vtag;
 688
 689         /* This contains the payload chunks.  */
 690         struct list_head chunk_list;
 691
 692         /* This is the overhead of the sctp and ip headers. */
 693         size_t overhead;
 694         /* This is the total size of all chunks INCLUDING padding.  */
 695         size_t size;
 696
 697         /* The packet is destined for this transport address.
 698          * The function we finally use to pass down to the next lower
 699          * layer lives in the transport structure.
 700          */
 701         struct sctp_transport *transport;
 702
 703         /* pointer to the auth chunk for this packet */
 704         struct sctp_chunk *auth;
 705
 706         u8  has_cookie_echo:1,  /* This packet contains a COOKIE-ECHO chunk. */
 707             has_sack:1,         /* This packet contains a SACK chunk. */
 708             has_auth:1,         /* This packet contains an AUTH chunk */
 709             has_data:1,         /* This packet contains at least 1 DATA chunk */
 710             ipfragok:1;         /* So let ip fragment this packet */
 711 };
 712
 713 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
 714                                      struct sctp_transport *,
 715                                      __u16 sport, __u16 dport);
 716 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
 717 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
 718                                        struct sctp_chunk *, int);
 719 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
 720                                      struct sctp_chunk *);
 721 int sctp_packet_transmit(struct sctp_packet *);
 722 void sctp_packet_free(struct sctp_packet *);
 723
 724 static inline int sctp_packet_empty(struct sctp_packet *packet)
 725 {
 726         return packet->size == packet->overhead;
 727 }
 728
 729 /* This represents a remote transport address.
 730  * For local transport addresses, we just use union sctp_addr.
 731  *
 732  * RFC2960 Section 1.4 Key Terms
 733  *
 734  *   o  Transport address:  A Transport Address is traditionally defined
 735  *      by Network Layer address, Transport Layer protocol and Transport
 736  *      Layer port number.  In the case of SCTP running over IP, a
 737  *      transport address is defined by the combination of an IP address
 738  *      and an SCTP port number (where SCTP is the Transport protocol).
 739  *
 740  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
 741  *
 742  *   o  The sender keeps a separate congestion control parameter set for
 743  *      each of the destination addresses it can send to (not each
 744  *      source-destination pair but for each destination).  The parameters
 745  *      should decay if the address is not used for a long enough time
 746  *      period.
 747  *
 748  */
 749 struct sctp_transport {
 750         /* A list of transports. */
 751         struct list_head transports;
 752
 753         /* Reference counting. */
 754         atomic_t refcnt;
 755         __u32    dead:1,
 756                 /* RTO-Pending : A flag used to track if one of the DATA
 757                  *              chunks sent to this address is currently being
 758                  *              used to compute a RTT. If this flag is 0,
 759                  *              the next DATA chunk sent to this destination
 760                  *              should be used to compute a RTT and this flag
 761                  *              should be set. Every time the RTT
 762                  *              calculation completes (i.e. the DATA chunk
 763                  *              is SACK'd) clear this flag.
 764                  */
 765                  rto_pending:1,
 766
 767                 /*
 768                  * hb_sent : a flag that signals that we have a pending
 769                  * heartbeat.
 770                  */
 771                 hb_sent:1,
 772
 773                 /* Is the Path MTU update pending on this tranport */
 774                 pmtu_pending:1;
 775
 776         /* Has this transport moved the ctsn since we last sacked */
 777         __u32 sack_generation;
 778         u32 dst_cookie;
 779
 780         struct flowi fl;
 781
 782         /* This is the peer's IP address and port. */
 783         union sctp_addr ipaddr;
 784
 785         /* These are the functions we call to handle LLP stuff.  */
 786         struct sctp_af *af_specific;
 787
 788         /* Which association do we belong to?  */
 789         struct sctp_association *asoc;
 790
 791         /* RFC2960
 792          *
 793          * 12.3 Per Transport Address Data
 794          *
 795          * For each destination transport address in the peer's
 796          * address list derived from the INIT or INIT ACK chunk, a
 797          * number of data elements needs to be maintained including:
 798          */
 799         /* RTO         : The current retransmission timeout value.  */
 800         unsigned long rto;
 801
 802         __u32 rtt;              /* This is the most recent RTT.  */
 803
 804         /* RTTVAR      : The current RTT variation.  */
 805         __u32 rttvar;
 806
 807         /* SRTT        : The current smoothed round trip time.  */
 808         __u32 srtt;
 809
 810         /*
 811          * These are the congestion stats.
 812          */
 813         /* cwnd        : The current congestion window.  */
 814         __u32 cwnd;               /* This is the actual cwnd.  */
 815
 816         /* ssthresh    : The current slow start threshold value.  */
 817         __u32 ssthresh;
 818
 819         /* partial     : The tracking method for increase of cwnd when in
 820          * bytes acked : congestion avoidance mode (see Section 6.2.2)
 821          */
 822         __u32 partial_bytes_acked;
 823
 824         /* Data that has been sent, but not acknowledged. */
 825         __u32 flight_size;
 826
 827         __u32 burst_limited;    /* Holds old cwnd when max.burst is applied */
 828
 829         /* Destination */
 830         struct dst_entry *dst;
 831         /* Source address. */
 832         union sctp_addr saddr;
 833
 834         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 835          * the destination address every heartbeat interval.
 836          */
 837         unsigned long hbinterval;
 838
 839         /* SACK delay timeout */
 840         unsigned long sackdelay;
 841         __u32 sackfreq;
 842
 843         /* When was the last time that we heard from this transport? We use
 844          * this to pick new active and retran paths.
 845          */
 846         ktime_t last_time_heard;
 847
 848         /* Last time(in jiffies) when cwnd is reduced due to the congestion
 849          * indication based on ECNE chunk.
 850          */
 851         unsigned long last_time_ecne_reduced;
 852
 853         /* This is the max_retrans value for the transport and will
 854          * be initialized from the assocs value.  This can be changed
 855          * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
 856          */
 857         __u16 pathmaxrxt;
 858
 859         /* This is the partially failed retrans value for the transport
 860          * and will be initialized from the assocs value.  This can be changed
 861          * using the SCTP_PEER_ADDR_THLDS socket option
 862          */
 863         int pf_retrans;
 864         /* PMTU       : The current known path MTU.  */
 865         __u32 pathmtu;
 866
 867         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 868         __u32 param_flags;
 869
 870         /* The number of times INIT has been sent on this transport. */
 871         int init_sent_count;
 872
 873         /* state       : The current state of this destination,
 874          *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
 875          */
 876         int state;
 877
 878         /* These are the error stats for this destination.  */
 879
 880         /* Error count : The current error count for this destination.  */
 881         unsigned short error_count;
 882
 883         /* Per         : A timer used by each destination.
 884          * Destination :
 885          * Timer       :
 886          *
 887          * [Everywhere else in the text this is called T3-rtx. -ed]
 888          */
 889         struct timer_list T3_rtx_timer;
 890
 891         /* Heartbeat timer is per destination. */
 892         struct timer_list hb_timer;
 893
 894         /* Timer to handle ICMP proto unreachable envets */
 895         struct timer_list proto_unreach_timer;
 896
 897         /* Since we're using per-destination retransmission timers
 898          * (see above), we're also using per-destination "transmitted"
 899          * queues.  This probably ought to be a private struct
 900          * accessible only within the outqueue, but it's not, yet.
 901          */
 902         struct list_head transmitted;
 903
 904         /* We build bundle-able packets for this transport here.  */
 905         struct sctp_packet packet;
 906
 907         /* This is the list of transports that have chunks to send.  */
 908         struct list_head send_ready;
 909
 910         /* State information saved for SFR_CACC algorithm. The key
 911          * idea in SFR_CACC is to maintain state at the sender on a
 912          * per-destination basis when a changeover happens.
 913          *      char changeover_active;
 914          *      char cycling_changeover;
 915          *      __u32 next_tsn_at_change;
 916          *      char cacc_saw_newack;
 917          */
 918         struct {
 919                 /* An unsigned integer, which stores the next TSN to be
 920                  * used by the sender, at the moment of changeover.
 921                  */
 922                 __u32 next_tsn_at_change;
 923
 924                 /* A flag which indicates the occurrence of a changeover */
 925                 char changeover_active;
 926
 927                 /* A flag which indicates whether the change of primary is
 928                  * the first switch to this destination address during an
 929                  * active switch.
 930                  */
 931                 char cycling_changeover;
 932
 933                 /* A temporary flag, which is used during the processing of
 934                  * a SACK to estimate the causative TSN(s)'s group.
 935                  */
 936                 char cacc_saw_newack;
 937         } cacc;
 938
 939         /* 64-bit random number sent with heartbeat. */
 940         __u64 hb_nonce;
 941
 942         struct rcu_head rcu;
 943 };
 944
 945 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
 946                                           gfp_t);
 947 void sctp_transport_set_owner(struct sctp_transport *,
 948                               struct sctp_association *);
 949 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
 950                           struct sctp_sock *);
 951 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
 952 void sctp_transport_free(struct sctp_transport *);
 953 void sctp_transport_reset_timers(struct sctp_transport *);
 954 void sctp_transport_hold(struct sctp_transport *);
 955 void sctp_transport_put(struct sctp_transport *);
 956 void sctp_transport_update_rto(struct sctp_transport *, __u32);
 957 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
 958 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
 959 void sctp_transport_burst_limited(struct sctp_transport *);
 960 void sctp_transport_burst_reset(struct sctp_transport *);
 961 unsigned long sctp_transport_timeout(struct sctp_transport *);
 962 void sctp_transport_reset(struct sctp_transport *);
 963 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
 964 void sctp_transport_immediate_rtx(struct sctp_transport *);
 965
 966
 967 /* This is the structure we use to queue packets as they come into
 968  * SCTP.  We write packets to it and read chunks from it.
 969  */
 970 struct sctp_inq {
 971         /* This is actually a queue of sctp_chunk each
 972          * containing a partially decoded packet.
 973          */
 974         struct list_head in_chunk_list;
 975         /* This is the packet which is currently off the in queue and is
 976          * being worked on through the inbound chunk processing.
 977          */
 978         struct sctp_chunk *in_progress;
 979
 980         /* This is the delayed task to finish delivering inbound
 981          * messages.
 982          */
 983         struct work_struct immediate;
 984 };
 985
 986 void sctp_inq_init(struct sctp_inq *);
 987 void sctp_inq_free(struct sctp_inq *);
 988 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
 989 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
 990 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
 991 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
 992
 993 /* This is the structure we use to hold outbound chunks.  You push
 994  * chunks in and they automatically pop out the other end as bundled
 995  * packets (it calls (*output_handler)()).
 996  *
 997  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
 998  * and 8.2 of the v13 draft.
 999  *
1000  * It handles retransmissions.  The connection to the timeout portion
1001  * of the state machine is through sctp_..._timeout() and timeout_handler.
1002  *
1003  * If you feed it SACKs, it will eat them.
1004  *
1005  * If you give it big chunks, it will fragment them.
1006  *
1007  * It assigns TSN's to data chunks.  This happens at the last possible
1008  * instant before transmission.
1009  *
1010  * When free()'d, it empties itself out via output_handler().
1011  */
1012 struct sctp_outq {
1013         struct sctp_association *asoc;
1014
1015         /* Data pending that has never been transmitted.  */
1016         struct list_head out_chunk_list;
1017
1018         unsigned int out_qlen;  /* Total length of queued data chunks. */
1019
1020         /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1021         unsigned int error;
1022
1023         /* These are control chunks we want to send.  */
1024         struct list_head control_chunk_list;
1025
1026         /* These are chunks that have been sacked but are above the
1027          * CTSN, or cumulative tsn ack point.
1028          */
1029         struct list_head sacked;
1030
1031         /* Put chunks on this list to schedule them for
1032          * retransmission.
1033          */
1034         struct list_head retransmit;
1035
1036         /* Put chunks on this list to save them for FWD TSN processing as
1037          * they were abandoned.
1038          */
1039         struct list_head abandoned;
1040
1041         /* How many unackd bytes do we have in-flight?  */
1042         __u32 outstanding_bytes;
1043
1044         /* Are we doing fast-rtx on this queue */
1045         char fast_rtx;
1046
1047         /* Corked? */
1048         char cork;
1049 };
1050
1051 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1052 void sctp_outq_teardown(struct sctp_outq *);
1053 void sctp_outq_free(struct sctp_outq*);
1054 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1055 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1056 int sctp_outq_is_empty(const struct sctp_outq *);
1057 void sctp_outq_restart(struct sctp_outq *);
1058
1059 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1060                      sctp_retransmit_reason_t);
1061 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1062 int sctp_outq_uncork(struct sctp_outq *);
1063 /* Uncork and flush an outqueue.  */
1064 static inline void sctp_outq_cork(struct sctp_outq *q)
1065 {
1066         q->cork = 1;
1067 }
1068
1069 /* These bind address data fields common between endpoints and associations */
1070 struct sctp_bind_addr {
1071
1072         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1073          *
1074          * SCTP Port:   The local SCTP port number the endpoint is
1075          *              bound to.
1076          */
1077         __u16 port;
1078
1079         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1080          *
1081          * Address List: The list of IP addresses that this instance
1082          *      has bound.  This information is passed to one's
1083          *      peer(s) in INIT and INIT ACK chunks.
1084          */
1085         struct list_head address_list;
1086 };
1087
1088 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1089 void sctp_bind_addr_free(struct sctp_bind_addr *);
1090 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1091                         const struct sctp_bind_addr *src,
1092                         sctp_scope_t scope, gfp_t gfp,
1093                         int flags);
1094 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1095                         const struct sctp_bind_addr *src,
1096                         gfp_t gfp);
1097 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1098                        __u8 addr_state, gfp_t gfp);
1099 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1100 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1101                          struct sctp_sock *);
1102 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1103                          struct sctp_sock *, struct sctp_sock *);
1104 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1105                          const union sctp_addr *addr);
1106 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
1107                                         const union sctp_addr   *addrs,
1108                                         int                     addrcnt,
1109                                         struct sctp_sock        *opt);
1110 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1111                                          int *addrs_len,
1112                                          gfp_t gfp);
1113 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1114                            __u16 port, gfp_t gfp);
1115
1116 sctp_scope_t sctp_scope(const union sctp_addr *);
1117 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1118 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1119 int sctp_addr_is_valid(const union sctp_addr *addr);
1120 int sctp_is_ep_boundall(struct sock *sk);
1121
1122
1123 /* What type of endpoint?  */
1124 typedef enum {
1125         SCTP_EP_TYPE_SOCKET,
1126         SCTP_EP_TYPE_ASSOCIATION,
1127 } sctp_endpoint_type_t;
1128
1129 /*
1130  * A common base class to bridge the implmentation view of a
1131  * socket (usually listening) endpoint versus an association's
1132  * local endpoint.
1133  * This common structure is useful for several purposes:
1134  *   1) Common interface for lookup routines.
1135  *      a) Subfunctions work for either endpoint or association
1136  *      b) Single interface to lookup allows hiding the lookup lock rather
1137  *         than acquiring it externally.
1138  *   2) Common interface for the inbound chunk handling/state machine.
1139  *   3) Common object handling routines for reference counting, etc.
1140  *   4) Disentangle association lookup from endpoint lookup, where we
1141  *      do not have to find our endpoint to find our association.
1142  *
1143  */
1144
1145 struct sctp_ep_common {
1146         /* Fields to help us manage our entries in the hash tables. */
1147         struct hlist_node node;
1148         int hashent;
1149
1150         /* Runtime type information.  What kind of endpoint is this? */
1151         sctp_endpoint_type_t type;
1152
1153         /* Some fields to help us manage this object.
1154          *   refcnt   - Reference count access to this object.
1155          *   dead     - Do not attempt to use this object.
1156          */
1157         atomic_t    refcnt;
1158         bool        dead;
1159
1160         /* What socket does this endpoint belong to?  */
1161         struct sock *sk;
1162
1163         /* This is where we receive inbound chunks.  */
1164         struct sctp_inq   inqueue;
1165
1166         /* This substructure includes the defining parameters of the
1167          * endpoint:
1168          * bind_addr.port is our shared port number.
1169          * bind_addr.address_list is our set of local IP addresses.
1170          */
1171         struct sctp_bind_addr bind_addr;
1172 };
1173
1174
1175 /* RFC Section 1.4 Key Terms
1176  *
1177  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1178  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1179  *   combination of a set of eligible destination transport addresses to
1180  *   which SCTP packets can be sent and a set of eligible source
1181  *   transport addresses from which SCTP packets can be received.
1182  *   All transport addresses used by an SCTP endpoint must use the
1183  *   same port number, but can use multiple IP addresses. A transport
1184  *   address used by an SCTP endpoint must not be used by another
1185  *   SCTP endpoint. In other words, a transport address is unique
1186  *   to an SCTP endpoint.
1187  *
1188  * From an implementation perspective, each socket has one of these.
1189  * A TCP-style socket will have exactly one association on one of
1190  * these.  An UDP-style socket will have multiple associations hanging
1191  * off one of these.
1192  */
1193
1194 struct sctp_endpoint {
1195         /* Common substructure for endpoint and association. */
1196         struct sctp_ep_common base;
1197
1198         /* Associations: A list of current associations and mappings
1199          *            to the data consumers for each association. This
1200          *            may be in the form of a hash table or other
1201          *            implementation dependent structure. The data
1202          *            consumers may be process identification
1203          *            information such as file descriptors, named pipe
1204          *            pointer, or table pointers dependent on how SCTP
1205          *            is implemented.
1206          */
1207         /* This is really a list of struct sctp_association entries. */
1208         struct list_head asocs;
1209
1210         /* Secret Key: A secret key used by this endpoint to compute
1211          *            the MAC.  This SHOULD be a cryptographic quality
1212          *            random number with a sufficient length.
1213          *            Discussion in [RFC1750] can be helpful in
1214          *            selection of the key.
1215          */
1216         __u8 secret_key[SCTP_SECRET_SIZE];
1217
1218         /* digest:  This is a digest of the sctp cookie.  This field is
1219          *          only used on the receive path when we try to validate
1220          *          that the cookie has not been tampered with.  We put
1221          *          this here so we pre-allocate this once and can re-use
1222          *          on every receive.
1223          */
1224         __u8 *digest;
1225
1226         /* sendbuf acct. policy.        */
1227         __u32 sndbuf_policy;
1228
1229         /* rcvbuf acct. policy. */
1230         __u32 rcvbuf_policy;
1231
1232         /* SCTP AUTH: array of the HMACs that will be allocated
1233          * we need this per association so that we don't serialize
1234          */
1235         struct crypto_hash **auth_hmacs;
1236
1237         /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1238          struct sctp_hmac_algo_param *auth_hmacs_list;
1239
1240         /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1241         struct sctp_chunks_param *auth_chunk_list;
1242
1243         /* SCTP-AUTH: endpoint shared keys */
1244         struct list_head endpoint_shared_keys;
1245         __u16 active_key_id;
1246         __u8  auth_enable;
1247 };
1248
1249 /* Recover the outter endpoint structure. */
1250 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1251 {
1252         struct sctp_endpoint *ep;
1253
1254         ep = container_of(base, struct sctp_endpoint, base);
1255         return ep;
1256 }
1257
1258 /* These are function signatures for manipulating endpoints.  */
1259 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1260 void sctp_endpoint_free(struct sctp_endpoint *);
1261 void sctp_endpoint_put(struct sctp_endpoint *);
1262 void sctp_endpoint_hold(struct sctp_endpoint *);
1263 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1264 struct sctp_association *sctp_endpoint_lookup_assoc(
1265         const struct sctp_endpoint *ep,
1266         const union sctp_addr *paddr,
1267         struct sctp_transport **);
1268 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1269                                 const union sctp_addr *);
1270 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1271                                         struct net *, const union sctp_addr *);
1272 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1273                          const union sctp_addr *paddr);
1274
1275 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1276                      const struct sctp_association *asoc,
1277                      sctp_cid_t, sctp_init_chunk_t *peer_init,
1278                      struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1279 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1280                       const union sctp_addr *peer,
1281                       sctp_init_chunk_t *init, gfp_t gfp);
1282 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1283 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1284
1285 struct sctp_inithdr_host {
1286         __u32 init_tag;
1287         __u32 a_rwnd;
1288         __u16 num_outbound_streams;
1289         __u16 num_inbound_streams;
1290         __u32 initial_tsn;
1291 };
1292
1293 /* SCTP_GET_ASSOC_STATS counters */
1294 struct sctp_priv_assoc_stats {
1295         /* Maximum observed rto in the association during subsequent
1296          * observations. Value is set to 0 if no RTO measurement took place
1297          * The transport where the max_rto was observed is returned in
1298          * obs_rto_ipaddr
1299          */
1300         struct sockaddr_storage obs_rto_ipaddr;
1301         __u64 max_obs_rto;
1302         /* Total In and Out SACKs received and sent */
1303         __u64 isacks;
1304         __u64 osacks;
1305         /* Total In and Out packets received and sent */
1306         __u64 opackets;
1307         __u64 ipackets;
1308         /* Total retransmitted chunks */
1309         __u64 rtxchunks;
1310         /* TSN received > next expected */
1311         __u64 outofseqtsns;
1312         /* Duplicate Chunks received */
1313         __u64 idupchunks;
1314         /* Gap Ack Blocks received */
1315         __u64 gapcnt;
1316         /* Unordered data chunks sent and received */
1317         __u64 ouodchunks;
1318         __u64 iuodchunks;
1319         /* Ordered data chunks sent and received */
1320         __u64 oodchunks;
1321         __u64 iodchunks;
1322         /* Control chunks sent and received */
1323         __u64 octrlchunks;
1324         __u64 ictrlchunks;
1325 };
1326
1327 /* RFC2960
1328  *
1329  * 12. Recommended Transmission Control Block (TCB) Parameters
1330  *
1331  * This section details a recommended set of parameters that should
1332  * be contained within the TCB for an implementation. This section is
1333  * for illustrative purposes and should not be deemed as requirements
1334  * on an implementation or as an exhaustive list of all parameters
1335  * inside an SCTP TCB. Each implementation may need its own additional
1336  * parameters for optimization.
1337  */
1338
1339
1340 /* Here we have information about each individual association. */
1341 struct sctp_association {
1342
1343         /* A base structure common to endpoint and association.
1344          * In this context, it represents the associations's view
1345          * of the local endpoint of the association.
1346          */
1347         struct sctp_ep_common base;
1348
1349         /* Associations on the same socket. */
1350         struct list_head asocs;
1351
1352         /* association id. */
1353         sctp_assoc_t assoc_id;
1354
1355         /* This is our parent endpoint.  */
1356         struct sctp_endpoint *ep;
1357
1358         /* These are those association elements needed in the cookie.  */
1359         struct sctp_cookie c;
1360
1361         /* This is all information about our peer.  */
1362         struct {
1363                 /* transport_addr_list
1364                  *
1365                  * Peer        : A list of SCTP transport addresses that the
1366                  * Transport   : peer is bound to. This information is derived
1367                  * Address     : from the INIT or INIT ACK and is used to
1368                  * List        : associate an inbound packet with a given
1369                  *             : association. Normally this information is
1370                  *             : hashed or keyed for quick lookup and access
1371                  *             : of the TCB.
1372                  *             : The list is also initialized with the list
1373                  *             : of addresses passed with the sctp_connectx()
1374                  *             : call.
1375                  *
1376                  * It is a list of SCTP_transport's.
1377                  */
1378                 struct list_head transport_addr_list;
1379
1380                 /* rwnd
1381                  *
1382                  * Peer Rwnd   : Current calculated value of the peer's rwnd.
1383                  */
1384                 __u32 rwnd;
1385
1386                 /* transport_count
1387                  *
1388                  * Peer        : A count of the number of peer addresses
1389                  * Transport   : in the Peer Transport Address List.
1390                  * Address     :
1391                  * Count       :
1392                  */
1393                 __u16 transport_count;
1394
1395                 /* port
1396                  *   The transport layer port number.
1397                  */
1398                 __u16 port;
1399
1400                 /* primary_path
1401                  *
1402                  * Primary     : This is the current primary destination
1403                  * Path        : transport address of the peer endpoint.  It
1404                  *             : may also specify a source transport address
1405                  *             : on this endpoint.
1406                  *
1407                  * All of these paths live on transport_addr_list.
1408                  *
1409                  * At the bakeoffs, we discovered that the intent of
1410                  * primaryPath is that it only changes when the ULP
1411                  * asks to have it changed.  We add the activePath to
1412                  * designate the connection we are currently using to
1413                  * transmit new data and most control chunks.
1414                  */
1415                 struct sctp_transport *primary_path;
1416
1417                 /* Cache the primary path address here, when we
1418                  * need a an address for msg_name.
1419                  */
1420                 union sctp_addr primary_addr;
1421
1422                 /* active_path
1423                  *   The path that we are currently using to
1424                  *   transmit new data and most control chunks.
1425                  */
1426                 struct sctp_transport *active_path;
1427
1428                 /* retran_path
1429                  *
1430                  * RFC2960 6.4 Multi-homed SCTP Endpoints
1431                  * ...
1432                  * Furthermore, when its peer is multi-homed, an
1433                  * endpoint SHOULD try to retransmit a chunk to an
1434                  * active destination transport address that is
1435                  * different from the last destination address to
1436                  * which the DATA chunk was sent.
1437                  */
1438                 struct sctp_transport *retran_path;
1439
1440                 /* Pointer to last transport I have sent on.  */
1441                 struct sctp_transport *last_sent_to;
1442
1443                 /* This is the last transport I have received DATA on.  */
1444                 struct sctp_transport *last_data_from;
1445
1446                 /*
1447                  * Mapping  An array of bits or bytes indicating which out of
1448                  * Array    order TSN's have been received (relative to the
1449                  *          Last Rcvd TSN). If no gaps exist, i.e. no out of
1450                  *          order packets have been received, this array
1451                  *          will be set to all zero. This structure may be
1452                  *          in the form of a circular buffer or bit array.
1453                  *
1454                  * Last Rcvd   : This is the last TSN received in
1455                  * TSN         : sequence. This value is set initially by
1456                  *             : taking the peer's Initial TSN, received in
1457                  *             : the INIT or INIT ACK chunk, and subtracting
1458                  *             : one from it.
1459                  *
1460                  * Throughout most of the specification this is called the
1461                  * "Cumulative TSN ACK Point".  In this case, we
1462                  * ignore the advice in 12.2 in favour of the term
1463                  * used in the bulk of the text.  This value is hidden
1464                  * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1465                  */
1466                 struct sctp_tsnmap tsn_map;
1467
1468                 /* This mask is used to disable sending the ASCONF chunk
1469                  * with specified parameter to peer.
1470                  */
1471                 __be16 addip_disabled_mask;
1472
1473                 /* These are capabilities which our peer advertised.  */
1474                 __u8    ecn_capable:1,      /* Can peer do ECN? */
1475                         ipv4_address:1,     /* Peer understands IPv4 addresses? */
1476                         ipv6_address:1,     /* Peer understands IPv6 addresses? */
1477                         hostname_address:1, /* Peer understands DNS addresses? */
1478                         asconf_capable:1,   /* Does peer support ADDIP? */
1479                         prsctp_capable:1,   /* Can peer do PR-SCTP? */
1480                         auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1481
1482                 /* Ack State   : This flag indicates if the next received
1483                  *             : packet is to be responded to with a
1484                  *             : SACK. This is initializedto 0.  When a packet
1485                  *             : is received it is incremented. If this value
1486                  *             : reaches 2 or more, a SACK is sent and the
1487                  *             : value is reset to 0. Note: This is used only
1488                  *             : when no DATA chunks are received out of
1489                  *             : order.  When DATA chunks are out of order,
1490                  *             : SACK's are not delayed (see Section 6).
1491                  */
1492                 __u8    sack_needed;     /* Do we need to sack the peer? */
1493                 __u32   sack_cnt;
1494                 __u32   sack_generation;
1495
1496                 __u32   adaptation_ind;  /* Adaptation Code point. */
1497
1498                 struct sctp_inithdr_host i;
1499                 void *cookie;
1500                 int cookie_len;
1501
1502                 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1503                  * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1504                  * Initial TSN Value minus 1
1505                  */
1506                 __u32 addip_serial;
1507
1508                 /* SCTP-AUTH: We need to know pears random number, hmac list
1509                  * and authenticated chunk list.  All that is part of the
1510                  * cookie and these are just pointers to those locations
1511                  */
1512                 sctp_random_param_t *peer_random;
1513                 sctp_chunks_param_t *peer_chunks;
1514                 sctp_hmac_algo_param_t *peer_hmacs;
1515         } peer;
1516
1517         /* State       : A state variable indicating what state the
1518          *             : association is in, i.e. COOKIE-WAIT,
1519          *             : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1520          *             : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1521          *
1522          *              Note: No "CLOSED" state is illustrated since if a
1523          *              association is "CLOSED" its TCB SHOULD be removed.
1524          *
1525          *              In this implementation we DO have a CLOSED
1526          *              state which is used during initiation and shutdown.
1527          *
1528          *              State takes values from SCTP_STATE_*.
1529          */
1530         sctp_state_t state;
1531
1532         /* Overall     : The overall association error count.
1533          * Error Count : [Clear this any time I get something.]
1534          */
1535         int overall_error_count;
1536
1537         /* The cookie life I award for any cookie.  */
1538         ktime_t cookie_life;
1539
1540         /* These are the association's initial, max, and min RTO values.
1541          * These values will be initialized by system defaults, but can
1542          * be modified via the SCTP_RTOINFO socket option.
1543          */
1544         unsigned long rto_initial;
1545         unsigned long rto_max;
1546         unsigned long rto_min;
1547
1548         /* Maximum number of new data packets that can be sent in a burst.  */
1549         int max_burst;
1550
1551         /* This is the max_retrans value for the association.  This value will
1552          * be initialized initialized from system defaults, but can be
1553          * modified by the SCTP_ASSOCINFO socket option.
1554          */
1555         int max_retrans;
1556
1557         /* This is the partially failed retrans value for the transport
1558          * and will be initialized from the assocs value.  This can be
1559          * changed using the SCTP_PEER_ADDR_THLDS socket option
1560          */
1561         int pf_retrans;
1562
1563         /* Maximum number of times the endpoint will retransmit INIT  */
1564         __u16 max_init_attempts;
1565
1566         /* How many times have we resent an INIT? */
1567         __u16 init_retries;
1568
1569         /* The largest timeout or RTO value to use in attempting an INIT */
1570         unsigned long max_init_timeo;
1571
1572         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1573          * the destination address every heartbeat interval. This value
1574          * will be inherited by all new transports.
1575          */
1576         unsigned long hbinterval;
1577
1578         /* This is the max_retrans value for new transports in the
1579          * association.
1580          */
1581         __u16 pathmaxrxt;
1582
1583         /* Flag that path mtu update is pending */
1584         __u8   pmtu_pending;
1585
1586         /* Association : The smallest PMTU discovered for all of the
1587          * PMTU        : peer's transport addresses.
1588          */
1589         __u32 pathmtu;
1590
1591         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1592         __u32 param_flags;
1593
1594         __u32 sackfreq;
1595         /* SACK delay timeout */
1596         unsigned long sackdelay;
1597
1598         unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1599         struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1600
1601         /* Transport to which SHUTDOWN chunk was last sent.  */
1602         struct sctp_transport *shutdown_last_sent_to;
1603
1604         /* Transport to which INIT chunk was last sent.  */
1605         struct sctp_transport *init_last_sent_to;
1606
1607         /* How many times have we resent a SHUTDOWN */
1608         int shutdown_retries;
1609
1610         /* Next TSN    : The next TSN number to be assigned to a new
1611          *             : DATA chunk.  This is sent in the INIT or INIT
1612          *             : ACK chunk to the peer and incremented each
1613          *             : time a DATA chunk is assigned a TSN
1614          *             : (normally just prior to transmit or during
1615          *             : fragmentation).
1616          */
1617         __u32 next_tsn;
1618
1619         /*
1620          * Last Rcvd   : This is the last TSN received in sequence.  This value
1621          * TSN         : is set initially by taking the peer's Initial TSN,
1622          *             : received in the INIT or INIT ACK chunk, and
1623          *             : subtracting one from it.
1624          *
1625          * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1626          */
1627
1628         __u32 ctsn_ack_point;
1629
1630         /* PR-SCTP Advanced.Peer.Ack.Point */
1631         __u32 adv_peer_ack_point;
1632
1633         /* Highest TSN that is acknowledged by incoming SACKs. */
1634         __u32 highest_sacked;
1635
1636         /* TSN marking the fast recovery exit point */
1637         __u32 fast_recovery_exit;
1638
1639         /* Flag to track the current fast recovery state */
1640         __u8 fast_recovery;
1641
1642         /* The number of unacknowledged data chunks.  Reported through
1643          * the SCTP_STATUS sockopt.
1644          */
1645         __u16 unack_data;
1646
1647         /* The total number of data chunks that we've had to retransmit
1648          * as the result of a T3 timer expiration
1649          */
1650         __u32 rtx_data_chunks;
1651
1652         /* This is the association's receive buffer space.  This value is used
1653          * to set a_rwnd field in an INIT or a SACK chunk.
1654          */
1655         __u32 rwnd;
1656
1657         /* This is the last advertised value of rwnd over a SACK chunk. */
1658         __u32 a_rwnd;
1659
1660         /* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1661          * to slop over a maximum of the association's frag_point.
1662          */
1663         __u32 rwnd_over;
1664
1665         /* Keeps treack of rwnd pressure.  This happens when we have
1666          * a window, but not recevie buffer (i.e small packets).  This one
1667          * is releases slowly (1 PMTU at a time ).
1668          */
1669         __u32 rwnd_press;
1670
1671         /* This is the sndbuf size in use for the association.
1672          * This corresponds to the sndbuf size for the association,
1673          * as specified in the sk->sndbuf.
1674          */
1675         int sndbuf_used;
1676
1677         /* This is the amount of memory that this association has allocated
1678          * in the receive path at any given time.
1679          */
1680         atomic_t rmem_alloc;
1681
1682         /* This is the wait queue head for send requests waiting on
1683          * the association sndbuf space.
1684          */
1685         wait_queue_head_t       wait;
1686
1687         /* The message size at which SCTP fragmentation will occur. */
1688         __u32 frag_point;
1689         __u32 user_frag;
1690
1691         /* Counter used to count INIT errors. */
1692         int init_err_counter;
1693
1694         /* Count the number of INIT cycles (for doubling timeout). */
1695         int init_cycle;
1696
1697         /* Default send parameters. */
1698         __u16 default_stream;
1699         __u16 default_flags;
1700         __u32 default_ppid;
1701         __u32 default_context;
1702         __u32 default_timetolive;
1703
1704         /* Default receive parameters */
1705         __u32 default_rcv_context;
1706
1707         /* This tracks outbound ssn for a given stream.  */
1708         struct sctp_ssnmap *ssnmap;
1709
1710         /* All outbound chunks go through this structure.  */
1711         struct sctp_outq outqueue;
1712
1713         /* A smart pipe that will handle reordering and fragmentation,
1714          * as well as handle passing events up to the ULP.
1715          */
1716         struct sctp_ulpq ulpq;
1717
1718         /* Last TSN that caused an ECNE Chunk to be sent.  */
1719         __u32 last_ecne_tsn;
1720
1721         /* Last TSN that caused a CWR Chunk to be sent.  */
1722         __u32 last_cwr_tsn;
1723
1724         /* How many duplicated TSNs have we seen?  */
1725         int numduptsns;
1726
1727         /* These are to support
1728          * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1729          *  and Enforcement of Flow and Message Limits"
1730          * <draft-ietf-tsvwg-addip-sctp-02.txt>
1731          * or "ADDIP" for short.
1732          */
1733
1734
1735
1736         /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1737          *
1738          * R1) One and only one ASCONF Chunk MAY be in transit and
1739          * unacknowledged at any one time.  If a sender, after sending
1740          * an ASCONF chunk, decides it needs to transfer another
1741          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1742          * returns from the previous ASCONF Chunk before sending a
1743          * subsequent ASCONF. Note this restriction binds each side,
1744          * so at any time two ASCONF may be in-transit on any given
1745          * association (one sent from each endpoint).
1746          *
1747          * [This is our one-and-only-one ASCONF in flight.  If we do
1748          * not have an ASCONF in flight, this is NULL.]
1749          */
1750         struct sctp_chunk *addip_last_asconf;
1751
1752         /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1753          *
1754          * This is needed to implement itmes E1 - E4 of the updated
1755          * spec.  Here is the justification:
1756          *
1757          * Since the peer may bundle multiple ASCONF chunks toward us,
1758          * we now need the ability to cache multiple ACKs.  The section
1759          * describes in detail how they are cached and cleaned up.
1760          */
1761         struct list_head asconf_ack_list;
1762
1763         /* These ASCONF chunks are waiting to be sent.
1764          *
1765          * These chunaks can't be pushed to outqueue until receiving
1766          * ASCONF_ACK for the previous ASCONF indicated by
1767          * addip_last_asconf, so as to guarantee that only one ASCONF
1768          * is in flight at any time.
1769          *
1770          * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1771          *
1772          * In defining the ASCONF Chunk transfer procedures, it is
1773          * essential that these transfers MUST NOT cause congestion
1774          * within the network.  To achieve this, we place these
1775          * restrictions on the transfer of ASCONF Chunks:
1776          *
1777          * R1) One and only one ASCONF Chunk MAY be in transit and
1778          * unacknowledged at any one time.  If a sender, after sending
1779          * an ASCONF chunk, decides it needs to transfer another
1780          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1781          * returns from the previous ASCONF Chunk before sending a
1782          * subsequent ASCONF. Note this restriction binds each side,
1783          * so at any time two ASCONF may be in-transit on any given
1784          * association (one sent from each endpoint).
1785          *
1786          *
1787          * [I really think this is EXACTLY the sort of intelligence
1788          *  which already resides in sctp_outq.  Please move this
1789          *  queue and its supporting logic down there.  --piggy]
1790          */
1791         struct list_head addip_chunk_list;
1792
1793         /* ADDIP Section 4.1 ASCONF Chunk Procedures
1794          *
1795          * A2) A serial number should be assigned to the Chunk. The
1796          * serial number SHOULD be a monotonically increasing
1797          * number. The serial number SHOULD be initialized at
1798          * the start of the association to the same value as the
1799          * Initial TSN and every time a new ASCONF chunk is created
1800          * it is incremented by one after assigning the serial number
1801          * to the newly created chunk.
1802          *
1803          * ADDIP
1804          * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1805          *
1806          * Serial Number : 32 bits (unsigned integer)
1807          *
1808          * This value represents a Serial Number for the ASCONF
1809          * Chunk. The valid range of Serial Number is from 0 to
1810          * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1811          * after reaching 4294967295.
1812          */
1813         __u32 addip_serial;
1814         int src_out_of_asoc_ok;
1815         union sctp_addr *asconf_addr_del_pending;
1816         struct sctp_transport *new_transport;
1817
1818         /* SCTP AUTH: list of the endpoint shared keys.  These
1819          * keys are provided out of band by the user applicaton
1820          * and can't change during the lifetime of the association
1821          */
1822         struct list_head endpoint_shared_keys;
1823
1824         /* SCTP AUTH:
1825          * The current generated assocaition shared key (secret)
1826          */
1827         struct sctp_auth_bytes *asoc_shared_key;
1828
1829         /* SCTP AUTH: hmac id of the first peer requested algorithm
1830          * that we support.
1831          */
1832         __u16 default_hmac_id;
1833
1834         __u16 active_key_id;
1835
1836         __u8 need_ecne:1,       /* Need to send an ECNE Chunk? */
1837              temp:1;            /* Is it a temporary association? */
1838
1839         struct sctp_priv_assoc_stats stats;
1840 };
1841
1842
1843 /* An eyecatcher for determining if we are really looking at an
1844  * association data structure.
1845  */
1846 enum {
1847         SCTP_ASSOC_EYECATCHER = 0xa550c123,
1848 };
1849
1850 /* Recover the outter association structure. */
1851 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1852 {
1853         struct sctp_association *asoc;
1854
1855         asoc = container_of(base, struct sctp_association, base);
1856         return asoc;
1857 }
1858
1859 /* These are function signatures for manipulating associations.  */
1860
1861
1862 struct sctp_association *
1863 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1864                      sctp_scope_t scope, gfp_t gfp);
1865 void sctp_association_free(struct sctp_association *);
1866 void sctp_association_put(struct sctp_association *);
1867 void sctp_association_hold(struct sctp_association *);
1868
1869 struct sctp_transport *sctp_assoc_choose_alter_transport(
1870         struct sctp_association *, struct sctp_transport *);
1871 void sctp_assoc_update_retran_path(struct sctp_association *);
1872 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1873                                           const union sctp_addr *);
1874 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1875                             const union sctp_addr *laddr);
1876 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1877                                      const union sctp_addr *address,
1878                                      const gfp_t gfp,
1879                                      const int peer_state);
1880 void sctp_assoc_del_peer(struct sctp_association *asoc,
1881                          const union sctp_addr *addr);
1882 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1883                          struct sctp_transport *peer);
1884 void sctp_assoc_control_transport(struct sctp_association *,
1885                                   struct sctp_transport *,
1886                                   sctp_transport_cmd_t, sctp_sn_error_t);
1887 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1888 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1889                                            struct net *,
1890                                            const union sctp_addr *,
1891                                            const union sctp_addr *);
1892 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1893 void sctp_assoc_update(struct sctp_association *old,
1894                        struct sctp_association *new);
1895
1896 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1897
1898 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1899 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1900 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1901 void sctp_assoc_set_primary(struct sctp_association *,
1902                             struct sctp_transport *);
1903 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1904                                     struct sctp_transport *);
1905 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1906                                      sctp_scope_t, gfp_t);
1907 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1908                                          struct sctp_cookie*,
1909                                          gfp_t gfp);
1910 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1911 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1912 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1913                                         const struct sctp_association *asoc,
1914                                         __be32 serial);
1915 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1916
1917 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1918                         const union sctp_addr *ss2);
1919 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1920
1921 /* A convenience structure to parse out SCTP specific CMSGs. */
1922 typedef struct sctp_cmsgs {
1923         struct sctp_initmsg *init;
1924         struct sctp_sndrcvinfo *srinfo;
1925         struct sctp_sndinfo *sinfo;
1926 } sctp_cmsgs_t;
1927
1928 /* Structure for tracking memory objects */
1929 typedef struct {
1930         char *label;
1931         atomic_t *counter;
1932 } sctp_dbg_objcnt_entry_t;
1933
1934 #endif /* __sctp_structs_h__ */