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, write to
  23 * the Free Software Foundation, 59 Temple Place - Suite 330,
  24 * Boston, MA 02111-1307, USA.
  25 *
  26 * Please send any bug reports or fixes you make to the
  27 * email addresses:
  28 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  29 *
  30 * Or submit a bug report through the following website:
  31 *    http://www.sf.net/projects/lksctp
  32 *
  33 * Written or modified by:
  34 *    Randall Stewart	    <randall@sctp.chicago.il.us>
  35 *    Ken Morneau	    <kmorneau@cisco.com>
  36 *    Qiaobing Xie	    <qxie1@email.mot.com>
  37 *    La Monte H.P. Yarroll <piggy@acm.org>
  38 *    Karl Knutson	    <karl@athena.chicago.il.us>
  39 *    Jon Grimm		    <jgrimm@us.ibm.com>
  40 *    Xingang Guo	    <xingang.guo@intel.com>
  41 *    Hui Huang		    <hui.huang@nokia.com>
  42 *    Sridhar Samudrala	    <sri@us.ibm.com>
  43 *    Daisy Chang	    <daisyc@us.ibm.com>
  44 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
  45 *    Ardelle Fan	    <ardelle.fan@intel.com>
  46 *    Ryan Layer	    <rmlayer@us.ibm.com>
  47 *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
  48 *    Kevin Gao             <kevin.gao@intel.com>
  49 *
  50 * Any bugs reported given to us we will try to fix... any fixes shared will
  51 * be incorporated into the next SCTP release.
  52 */
  53
  54#ifndef __sctp_structs_h__
  55#define __sctp_structs_h__
  56
  57#include <linux/time.h>		/* We get struct timespec.    */
  58#include <linux/socket.h>	/* linux/in.h needs this!!    */
  59#include <linux/in.h>		/* We get struct sockaddr_in. */
  60#include <linux/in6.h>		/* We get struct in6_addr     */
  61#include <linux/ipv6.h>
  62#include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
  63#include <linux/atomic.h>		/* This gets us atomic counters.  */
  64#include <linux/skbuff.h>	/* We need sk_buff_head. */
  65#include <linux/workqueue.h>	/* We need tq_struct.	 */
  66#include <linux/sctp.h>		/* We need sctp* header structs.  */
  67#include <net/sctp/auth.h>	/* We need auth specific structs */
  68
  69/* A convenience structure for handling sockaddr structures.
  70 * We should wean ourselves off this.
  71 */
  72union sctp_addr {
  73	struct sockaddr_in v4;
  74	struct sockaddr_in6 v6;
  75	struct sockaddr sa;
  76};
  77
  78/* Forward declarations for data structures. */
  79struct sctp_globals;
  80struct sctp_endpoint;
  81struct sctp_association;
  82struct sctp_transport;
  83struct sctp_packet;
  84struct sctp_chunk;
  85struct sctp_inq;
  86struct sctp_outq;
  87struct sctp_bind_addr;
  88struct sctp_ulpq;
  89struct sctp_ep_common;
  90struct sctp_ssnmap;
  91struct crypto_hash;
  92
  93
  94#include <net/sctp/tsnmap.h>
  95#include <net/sctp/ulpevent.h>
  96#include <net/sctp/ulpqueue.h>
  97
  98/* Structures useful for managing bind/connect. */
  99
 100struct sctp_bind_bucket {
 101	unsigned short	port;
 102	unsigned short	fastreuse;
 103	struct hlist_node	node;
 104	struct hlist_head	owner;
 105};
 106
 107struct sctp_bind_hashbucket {
 108	spinlock_t	lock;
 109	struct hlist_head	chain;
 110};
 111
 112/* Used for hashing all associations.  */
 113struct sctp_hashbucket {
 114	rwlock_t	lock;
 115	struct hlist_head	chain;
 116} __attribute__((__aligned__(8)));
 117
 118
 119/* The SCTP globals structure. */
 120extern struct sctp_globals {
 121	/* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values
 122	 *
 123	 * The following protocol parameters are RECOMMENDED:
 124	 *
 125	 * RTO.Initial		    - 3	 seconds
 126	 * RTO.Min		    - 1	 second
 127	 * RTO.Max		   -  60 seconds
 128	 * RTO.Alpha		    - 1/8  (3 when converted to right shifts.)
 129	 * RTO.Beta		    - 1/4  (2 when converted to right shifts.)
 130	 */
 131	unsigned int rto_initial;
 132	unsigned int rto_min;
 133	unsigned int rto_max;
 134
 135	/* Note: rto_alpha and rto_beta are really defined as inverse
 136	 * powers of two to facilitate integer operations.
 137	 */
 138	int rto_alpha;
 139	int rto_beta;
 140
 141	/* Max.Burst		    - 4 */
 142	int max_burst;
 143
 144	/* Whether Cookie Preservative is enabled(1) or not(0) */
 145	int cookie_preserve_enable;
 146
 147	/* Valid.Cookie.Life	    - 60  seconds  */
 148	unsigned int valid_cookie_life;
 149
 150	/* Delayed SACK timeout  200ms default*/
 151	unsigned int sack_timeout;
 152
 153	/* HB.interval		    - 30 seconds  */
 154	unsigned int hb_interval;
 155
 156	/* Association.Max.Retrans  - 10 attempts
 157	 * Path.Max.Retrans	    - 5	 attempts (per destination address)
 158	 * Max.Init.Retransmits	    - 8	 attempts
 159	 */
 160	int max_retrans_association;
 161	int max_retrans_path;
 162	int max_retrans_init;
 163
 164	/*
 165	 * Policy for preforming sctp/socket accounting
 166	 * 0   - do socket level accounting, all assocs share sk_sndbuf
 167	 * 1   - do sctp accounting, each asoc may use sk_sndbuf bytes
 168	 */
 169	int sndbuf_policy;
 170
 171	/*
 172	 * Policy for preforming sctp/socket accounting
 173	 * 0   - do socket level accounting, all assocs share sk_rcvbuf
 174	 * 1   - do sctp accounting, each asoc may use sk_rcvbuf bytes
 175	 */
 176	int rcvbuf_policy;
 177
 178	/* The following variables are implementation specific.	 */
 179
 180	/* Default initialization values to be applied to new associations. */
 181	__u16 max_instreams;
 182	__u16 max_outstreams;
 183
 184	/* This is a list of groups of functions for each address
 185	 * family that we support.
 186	 */
 187	struct list_head address_families;
 188
 189	/* This is the hash of all endpoints. */
 190	int ep_hashsize;
 191	struct sctp_hashbucket *ep_hashtable;
 192
 193	/* This is the hash of all associations. */
 194	int assoc_hashsize;
 195	struct sctp_hashbucket *assoc_hashtable;
 196
 197	/* This is the sctp port control hash.	*/
 198	int port_hashsize;
 199	struct sctp_bind_hashbucket *port_hashtable;
 200
 201	/* This is the global local address list.
 202	 * We actively maintain this complete list of addresses on
 203	 * the system by catching address add/delete events.
 204	 *
 205	 * It is a list of sctp_sockaddr_entry.
 206	 */
 207	struct list_head local_addr_list;
 208	int default_auto_asconf;
 209	struct list_head addr_waitq;
 210	struct timer_list addr_wq_timer;
 211	struct list_head auto_asconf_splist;
 212	spinlock_t addr_wq_lock;
 213
 214	/* Lock that protects the local_addr_list writers */
 215	spinlock_t addr_list_lock;
 216	
 217	/* Flag to indicate if addip is enabled. */
 218	int addip_enable;
 219	int addip_noauth_enable;
 220
 221	/* Flag to indicate if PR-SCTP is enabled. */
 222	int prsctp_enable;
 223
 224	/* Flag to idicate if SCTP-AUTH is enabled */
 225	int auth_enable;
 226
 227	/*
 228	 * Policy to control SCTP IPv4 address scoping
 229	 * 0   - Disable IPv4 address scoping
 230	 * 1   - Enable IPv4 address scoping
 231	 * 2   - Selectively allow only IPv4 private addresses
 232	 * 3   - Selectively allow only IPv4 link local address
 233	 */
 234	int ipv4_scope_policy;
 235
 236	/* Flag to indicate whether computing and verifying checksum
 237	 * is disabled. */
 238        int checksum_disable;
 239
 240	/* Threshold for rwnd update SACKS.  Receive buffer shifted this many
 241	 * bits is an indicator of when to send and window update SACK.
 242	 */
 243	int rwnd_update_shift;
 
 
 
 244} sctp_globals;
 245
 246#define sctp_rto_initial		(sctp_globals.rto_initial)
 247#define sctp_rto_min			(sctp_globals.rto_min)
 248#define sctp_rto_max			(sctp_globals.rto_max)
 249#define sctp_rto_alpha			(sctp_globals.rto_alpha)
 250#define sctp_rto_beta			(sctp_globals.rto_beta)
 251#define sctp_max_burst			(sctp_globals.max_burst)
 252#define sctp_valid_cookie_life		(sctp_globals.valid_cookie_life)
 253#define sctp_cookie_preserve_enable	(sctp_globals.cookie_preserve_enable)
 254#define sctp_max_retrans_association	(sctp_globals.max_retrans_association)
 255#define sctp_sndbuf_policy	 	(sctp_globals.sndbuf_policy)
 256#define sctp_rcvbuf_policy	 	(sctp_globals.rcvbuf_policy)
 257#define sctp_max_retrans_path		(sctp_globals.max_retrans_path)
 258#define sctp_max_retrans_init		(sctp_globals.max_retrans_init)
 259#define sctp_sack_timeout		(sctp_globals.sack_timeout)
 260#define sctp_hb_interval		(sctp_globals.hb_interval)
 261#define sctp_max_instreams		(sctp_globals.max_instreams)
 262#define sctp_max_outstreams		(sctp_globals.max_outstreams)
 263#define sctp_address_families		(sctp_globals.address_families)
 264#define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
 265#define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
 266#define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
 267#define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
 268#define sctp_port_hashsize		(sctp_globals.port_hashsize)
 269#define sctp_port_hashtable		(sctp_globals.port_hashtable)
 270#define sctp_local_addr_list		(sctp_globals.local_addr_list)
 271#define sctp_local_addr_lock		(sctp_globals.addr_list_lock)
 272#define sctp_auto_asconf_splist		(sctp_globals.auto_asconf_splist)
 273#define sctp_addr_waitq			(sctp_globals.addr_waitq)
 274#define sctp_addr_wq_timer		(sctp_globals.addr_wq_timer)
 275#define sctp_addr_wq_lock		(sctp_globals.addr_wq_lock)
 276#define sctp_default_auto_asconf	(sctp_globals.default_auto_asconf)
 277#define sctp_scope_policy		(sctp_globals.ipv4_scope_policy)
 278#define sctp_addip_enable		(sctp_globals.addip_enable)
 279#define sctp_addip_noauth		(sctp_globals.addip_noauth_enable)
 280#define sctp_prsctp_enable		(sctp_globals.prsctp_enable)
 281#define sctp_auth_enable		(sctp_globals.auth_enable)
 282#define sctp_checksum_disable		(sctp_globals.checksum_disable)
 283#define sctp_rwnd_upd_shift		(sctp_globals.rwnd_update_shift)
 
 284
 285/* SCTP Socket type: UDP or TCP style. */
 286typedef enum {
 287	SCTP_SOCKET_UDP = 0,
 288	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
 289	SCTP_SOCKET_TCP
 290} sctp_socket_type_t;
 291
 292/* Per socket SCTP information. */
 293struct sctp_sock {
 294	/* inet_sock has to be the first member of sctp_sock */
 295	struct inet_sock inet;
 296	/* What kind of a socket is this? */
 297	sctp_socket_type_t type;
 298
 299	/* PF_ family specific functions.  */
 300	struct sctp_pf *pf;
 301
 302	/* Access to HMAC transform. */
 303	struct crypto_hash *hmac;
 304
 305	/* What is our base endpointer? */
 306	struct sctp_endpoint *ep;
 307
 308	struct sctp_bind_bucket *bind_hash;
 309	/* Various Socket Options.  */
 310	__u16 default_stream;
 311	__u32 default_ppid;
 312	__u16 default_flags;
 313	__u32 default_context;
 314	__u32 default_timetolive;
 315	__u32 default_rcv_context;
 316	int max_burst;
 317
 318	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 319	 * the destination address every heartbeat interval. This value
 320	 * will be inherited by all new associations.
 321	 */
 322	__u32 hbinterval;
 323
 324	/* This is the max_retrans value for new associations. */
 325	__u16 pathmaxrxt;
 326
 327	/* The initial Path MTU to use for new associations. */
 328	__u32 pathmtu;
 329
 330	/* The default SACK delay timeout for new associations. */
 331	__u32 sackdelay;
 332	__u32 sackfreq;
 333
 334	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 335	__u32 param_flags;
 336
 337	struct sctp_initmsg initmsg;
 338	struct sctp_rtoinfo rtoinfo;
 339	struct sctp_paddrparams paddrparam;
 340	struct sctp_event_subscribe subscribe;
 341	struct sctp_assocparams assocparams;
 342	int user_frag;
 343	__u32 autoclose;
 344	__u8 nodelay;
 345	__u8 disable_fragments;
 346	__u8 v4mapped;
 347	__u8 frag_interleave;
 348	__u32 adaptation_ind;
 349	__u32 pd_point;
 350
 351	atomic_t pd_mode;
 352	/* Receive to here while partial delivery is in effect. */
 353	struct sk_buff_head pd_lobby;
 354	struct list_head auto_asconf_list;
 355	int do_auto_asconf;
 356};
 357
 358static inline struct sctp_sock *sctp_sk(const struct sock *sk)
 359{
 360       return (struct sctp_sock *)sk;
 361}
 362
 363static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
 364{
 365       return (struct sock *)sp;
 366}
 367
 368#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 369struct sctp6_sock {
 370       struct sctp_sock  sctp;
 371       struct ipv6_pinfo inet6;
 372};
 373#endif /* CONFIG_IPV6 */
 374
 375
 376/* This is our APPLICATION-SPECIFIC state cookie.
 377 * THIS IS NOT DICTATED BY THE SPECIFICATION.
 378 */
 379/* These are the parts of an association which we send in the cookie.
 380 * Most of these are straight out of:
 381 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
 382 *
 383 */
 384
 385struct sctp_cookie {
 386
 387	/* My	       : Tag expected in every inbound packet and sent
 388	 * Verification: in the INIT or INIT ACK chunk.
 389	 * Tag	       :
 390	 */
 391	__u32 my_vtag;
 392
 393	/* Peer's      : Tag expected in every outbound packet except
 394	 * Verification: in the INIT chunk.
 395	 * Tag	       :
 396	 */
 397	__u32 peer_vtag;
 398
 399	/* The rest of these are not from the spec, but really need to
 400	 * be in the cookie.
 401	 */
 402
 403	/* My Tie Tag  : Assist in discovering a restarting association. */
 404	__u32 my_ttag;
 405
 406	/* Peer's Tie Tag: Assist in discovering a restarting association. */
 407	__u32 peer_ttag;
 408
 409	/* When does this cookie expire? */
 410	struct timeval expiration;
 411
 412	/* Number of inbound/outbound streams which are set
 413	 * and negotiated during the INIT process.
 414	 */
 415	__u16 sinit_num_ostreams;
 416	__u16 sinit_max_instreams;
 417
 418	/* This is the first sequence number I used.  */
 419	__u32 initial_tsn;
 420
 421	/* This holds the originating address of the INIT packet.  */
 422	union sctp_addr peer_addr;
 423
 424	/* IG Section 2.35.3 
 425	 * Include the source port of the INIT-ACK
 426	 */
 427	__u16		my_port;
 428
 429	__u8 prsctp_capable;
 430
 431	/* Padding for future use */
 432	__u8 padding;  		
 433
 434	__u32 adaptation_ind;
 435
 436	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
 437	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
 438	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
 439
 440	/* This is a shim for my peer's INIT packet, followed by
 441	 * a copy of the raw address list of the association.
 442	 * The length of the raw address list is saved in the
 443	 * raw_addr_list_len field, which will be used at the time when
 444	 * the association TCB is re-constructed from the cookie.
 445	 */
 446	__u32 raw_addr_list_len;
 447	struct sctp_init_chunk peer_init[0];
 448};
 449
 450
 451/* The format of our cookie that we send to our peer. */
 452struct sctp_signed_cookie {
 453	__u8 signature[SCTP_SECRET_SIZE];
 454	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
 455	struct sctp_cookie c;
 456} __packed;
 457
 458/* This is another convenience type to allocate memory for address
 459 * params for the maximum size and pass such structures around
 460 * internally.
 461 */
 462union sctp_addr_param {
 463	struct sctp_paramhdr p;
 464	struct sctp_ipv4addr_param v4;
 465	struct sctp_ipv6addr_param v6;
 466};
 467
 468/* A convenience type to allow walking through the various
 469 * parameters and avoid casting all over the place.
 470 */
 471union sctp_params {
 472	void *v;
 473	struct sctp_paramhdr *p;
 474	struct sctp_cookie_preserve_param *life;
 475	struct sctp_hostname_param *dns;
 476	struct sctp_cookie_param *cookie;
 477	struct sctp_supported_addrs_param *sat;
 478	struct sctp_ipv4addr_param *v4;
 479	struct sctp_ipv6addr_param *v6;
 480	union sctp_addr_param *addr;
 481	struct sctp_adaptation_ind_param *aind;
 482	struct sctp_supported_ext_param *ext;
 483	struct sctp_random_param *random;
 484	struct sctp_chunks_param *chunks;
 485	struct sctp_hmac_algo_param *hmac_algo;
 486	struct sctp_addip_param *addip;
 487};
 488
 489/* RFC 2960.  Section 3.3.5 Heartbeat.
 490 *    Heartbeat Information: variable length
 491 *    The Sender-specific Heartbeat Info field should normally include
 492 *    information about the sender's current time when this HEARTBEAT
 493 *    chunk is sent and the destination transport address to which this
 494 *    HEARTBEAT is sent (see Section 8.3).
 495 */
 496typedef struct sctp_sender_hb_info {
 497	struct sctp_paramhdr param_hdr;
 498	union sctp_addr daddr;
 499	unsigned long sent_at;
 500	__u64 hb_nonce;
 501} __packed sctp_sender_hb_info_t;
 502
 503/*
 504 *  RFC 2960 1.3.2 Sequenced Delivery within Streams
 505 *
 506 *  The term "stream" is used in SCTP to refer to a sequence of user
 507 *  messages that are to be delivered to the upper-layer protocol in
 508 *  order with respect to other messages within the same stream.  This is
 509 *  in contrast to its usage in TCP, where it refers to a sequence of
 510 *  bytes (in this document a byte is assumed to be eight bits).
 511 *  ...
 512 *
 513 *  This is the structure we use to track both our outbound and inbound
 514 *  SSN, or Stream Sequence Numbers.
 515 */
 516
 517struct sctp_stream {
 518	__u16 *ssn;
 519	unsigned int len;
 520};
 521
 522struct sctp_ssnmap {
 523	struct sctp_stream in;
 524	struct sctp_stream out;
 525	int malloced;
 526};
 527
 528struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
 529				    gfp_t gfp);
 530void sctp_ssnmap_free(struct sctp_ssnmap *map);
 531void sctp_ssnmap_clear(struct sctp_ssnmap *map);
 532
 533/* What is the current SSN number for this stream? */
 534static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
 535{
 536	return stream->ssn[id];
 537}
 538
 539/* Return the next SSN number for this stream.	*/
 540static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
 541{
 542	return stream->ssn[id]++;
 543}
 544
 545/* Skip over this ssn and all below. */
 546static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 
 547				 __u16 ssn)
 548{
 549	stream->ssn[id] = ssn+1;
 550}
 551              
 552/*
 553 * Pointers to address related SCTP functions.
 554 * (i.e. things that depend on the address family.)
 555 */
 556struct sctp_af {
 557	int		(*sctp_xmit)	(struct sk_buff *skb,
 558					 struct sctp_transport *);
 559	int		(*setsockopt)	(struct sock *sk,
 560					 int level,
 561					 int optname,
 562					 char __user *optval,
 563					 unsigned int optlen);
 564	int		(*getsockopt)	(struct sock *sk,
 565					 int level,
 566					 int optname,
 567					 char __user *optval,
 568					 int __user *optlen);
 569	int		(*compat_setsockopt)	(struct sock *sk,
 570					 int level,
 571					 int optname,
 572					 char __user *optval,
 573					 unsigned int optlen);
 574	int		(*compat_getsockopt)	(struct sock *sk,
 575					 int level,
 576					 int optname,
 577					 char __user *optval,
 578					 int __user *optlen);
 579	void		(*get_dst)	(struct sctp_transport *t,
 580					 union sctp_addr *saddr,
 581					 struct flowi *fl,
 582					 struct sock *sk);
 583	void		(*get_saddr)	(struct sctp_sock *sk,
 584					 struct sctp_transport *t,
 585					 struct flowi *fl);
 586	void		(*copy_addrlist) (struct list_head *,
 587					  struct net_device *);
 588	int		(*cmp_addr)	(const union sctp_addr *addr1,
 589					 const union sctp_addr *addr2);
 590	void		(*addr_copy)	(union sctp_addr *dst,
 591					 union sctp_addr *src);
 592	void		(*from_skb)	(union sctp_addr *,
 593					 struct sk_buff *skb,
 594					 int saddr);
 595	void		(*from_sk)	(union sctp_addr *,
 596					 struct sock *sk);
 597	void		(*to_sk_saddr)	(union sctp_addr *,
 598					 struct sock *sk);
 599	void		(*to_sk_daddr)	(union sctp_addr *,
 600					 struct sock *sk);
 601	void		(*from_addr_param) (union sctp_addr *,
 602					    union sctp_addr_param *,
 603					    __be16 port, int iif);
 604	int		(*to_addr_param) (const union sctp_addr *,
 605					  union sctp_addr_param *); 
 606	int		(*addr_valid)	(union sctp_addr *,
 607					 struct sctp_sock *,
 608					 const struct sk_buff *);
 609	sctp_scope_t	(*scope) (union sctp_addr *);
 610	void		(*inaddr_any)	(union sctp_addr *, __be16);
 611	int		(*is_any)	(const union sctp_addr *);
 612	int		(*available)	(union sctp_addr *,
 613					 struct sctp_sock *);
 614	int		(*skb_iif)	(const struct sk_buff *sk);
 615	int		(*is_ce)	(const struct sk_buff *sk);
 616	void		(*seq_dump_addr)(struct seq_file *seq,
 617					 union sctp_addr *addr);
 618	void		(*ecn_capable)(struct sock *sk);
 619	__u16		net_header_len;
 620	int		sockaddr_len;
 621	sa_family_t	sa_family;
 622	struct list_head list;
 623};
 624
 625struct sctp_af *sctp_get_af_specific(sa_family_t);
 626int sctp_register_af(struct sctp_af *);
 627
 628/* Protocol family functions. */
 629struct sctp_pf {
 630	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
 631	void (*skb_msgname)  (struct sk_buff *, char *, int *);
 632	int  (*af_supported) (sa_family_t, struct sctp_sock *);
 633	int  (*cmp_addr) (const union sctp_addr *,
 634			  const union sctp_addr *,
 635			  struct sctp_sock *);
 636	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
 637	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
 638	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
 639	struct sock *(*create_accept_sk) (struct sock *sk,
 640					  struct sctp_association *asoc);
 641	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
 642	struct sctp_af *af;
 643};
 644
 645
 646/* Structure to track chunk fragments that have been acked, but peer
 647 * fragments of the same message have not.
 648 */
 649struct sctp_datamsg {
 650	/* Chunks waiting to be submitted to lower layer. */
 651	struct list_head chunks;
 652	/* Reference counting. */
 653	atomic_t refcnt;
 654	/* When is this message no longer interesting to the peer? */
 655	unsigned long expires_at;
 656	/* Did the messenge fail to send? */
 657	int send_error;
 658	u8 send_failed:1,
 659	   can_abandon:1,   /* can chunks from this message can be abandoned. */
 660	   can_delay;	    /* should this message be Nagle delayed */
 661};
 662
 663struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 664					    struct sctp_sndrcvinfo *,
 665					    struct msghdr *, int len);
 666void sctp_datamsg_free(struct sctp_datamsg *);
 667void sctp_datamsg_put(struct sctp_datamsg *);
 668void sctp_chunk_fail(struct sctp_chunk *, int error);
 669int sctp_chunk_abandoned(struct sctp_chunk *);
 670
 671/* RFC2960 1.4 Key Terms
 672 *
 673 * o Chunk: A unit of information within an SCTP packet, consisting of
 674 * a chunk header and chunk-specific content.
 675 *
 676 * As a matter of convenience, we remember the SCTP common header for
 677 * each chunk as well as a few other header pointers...
 678 */
 679struct sctp_chunk {
 680	struct list_head list;
 681
 682	atomic_t refcnt;
 683
 684	/* This is our link to the per-transport transmitted list.  */
 685	struct list_head transmitted_list;
 686
 687	/* This field is used by chunks that hold fragmented data.
 688	 * For the first fragment this is the list that holds the rest of
 689	 * fragments. For the remaining fragments, this is the link to the
 690	 * frag_list maintained in the first fragment.
 691	 */
 692	struct list_head frag_list;
 693
 694	/* This points to the sk_buff containing the actual data.  */
 695	struct sk_buff *skb;
 696
 697	/* These are the SCTP headers by reverse order in a packet.
 698	 * Note that some of these may happen more than once.  In that
 699	 * case, we point at the "current" one, whatever that means
 700	 * for that level of header.
 701	 */
 702
 703	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
 704	union sctp_params param_hdr;
 705	union {
 706		__u8 *v;
 707		struct sctp_datahdr *data_hdr;
 708		struct sctp_inithdr *init_hdr;
 709		struct sctp_sackhdr *sack_hdr;
 710		struct sctp_heartbeathdr *hb_hdr;
 711		struct sctp_sender_hb_info *hbs_hdr;
 712		struct sctp_shutdownhdr *shutdown_hdr;
 713		struct sctp_signed_cookie *cookie_hdr;
 714		struct sctp_ecnehdr *ecne_hdr;
 715		struct sctp_cwrhdr *ecn_cwr_hdr;
 716		struct sctp_errhdr *err_hdr;
 717		struct sctp_addiphdr *addip_hdr;
 718		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
 719		struct sctp_authhdr *auth_hdr;
 720	} subh;
 721
 722	__u8 *chunk_end;
 723
 724	struct sctp_chunkhdr *chunk_hdr;
 725	struct sctphdr *sctp_hdr;
 726
 727	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
 728	struct sctp_sndrcvinfo sinfo;
 729
 730	/* Which association does this belong to?  */
 731	struct sctp_association *asoc;
 732
 733	/* What endpoint received this chunk? */
 734	struct sctp_ep_common *rcvr;
 735
 736	/* We fill this in if we are calculating RTT. */
 737	unsigned long sent_at;
 738
 739	/* What is the origin IP address for this chunk?  */
 740	union sctp_addr source;
 741	/* Destination address for this chunk. */
 742	union sctp_addr dest;
 743
 744	/* For outbound message, track all fragments for SEND_FAILED. */
 745	struct sctp_datamsg *msg;
 746
 747	/* For an inbound chunk, this tells us where it came from.
 748	 * For an outbound chunk, it tells us where we'd like it to
 749	 * go.	It is NULL if we have no preference.
 750	 */
 751	struct sctp_transport *transport;
 752
 753	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
 754	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
 755	 * spec violates the principle premis that all chunks are processed
 756	 * in order.
 757	 */
 758	struct sk_buff *auth_chunk;
 759
 760#define SCTP_CAN_FRTX 0x0
 761#define SCTP_NEED_FRTX 0x1
 762#define SCTP_DONT_FRTX 0x2
 763	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
 764		has_tsn:1,		/* Does this chunk have a TSN yet? */
 765		has_ssn:1,		/* Does this chunk have a SSN yet? */
 766		singleton:1,		/* Only chunk in the packet? */
 767		end_of_packet:1,	/* Last chunk in the packet? */
 768		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
 769		pdiscard:1,		/* Discard the whole packet now? */
 770		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
 771		data_accepted:1,	/* At least 1 chunk accepted */
 772		auth:1,			/* IN: was auth'ed | OUT: needs auth */
 773		has_asconf:1,		/* IN: have seen an asconf before */
 774		tsn_missing_report:2,	/* Data chunk missing counter. */
 775		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
 776};
 777
 778void sctp_chunk_hold(struct sctp_chunk *);
 779void sctp_chunk_put(struct sctp_chunk *);
 780int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
 781			  struct iovec *data);
 782void sctp_chunk_free(struct sctp_chunk *);
 783void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
 784void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
 785struct sctp_chunk *sctp_chunkify(struct sk_buff *,
 786				 const struct sctp_association *,
 787				 struct sock *);
 788void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 789		     union sctp_addr *);
 790const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 791
 792enum {
 793	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
 794	SCTP_ADDR_SRC,		/* address can be used as source */
 795	SCTP_ADDR_DEL,		/* address about to be deleted */
 796};
 797
 798/* This is a structure for holding either an IPv6 or an IPv4 address.  */
 799struct sctp_sockaddr_entry {
 800	struct list_head list;
 801	struct rcu_head	rcu;
 802	union sctp_addr a;
 803	__u8 state;
 804	__u8 valid;
 805};
 806
 807#define SCTP_ADDRESS_TICK_DELAY	500
 808
 809typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
 810
 811/* This structure holds lists of chunks as we are assembling for
 812 * transmission.
 813 */
 814struct sctp_packet {
 815	/* These are the SCTP header values (host order) for the packet. */
 816	__u16 source_port;
 817	__u16 destination_port;
 818	__u32 vtag;
 819
 820	/* This contains the payload chunks.  */
 821	struct list_head chunk_list;
 822
 823	/* This is the overhead of the sctp and ip headers. */
 824	size_t overhead;
 825	/* This is the total size of all chunks INCLUDING padding.  */
 826	size_t size;
 827
 828	/* The packet is destined for this transport address.
 829	 * The function we finally use to pass down to the next lower
 830	 * layer lives in the transport structure.
 831	 */
 832	struct sctp_transport *transport;
 833
 834	/* pointer to the auth chunk for this packet */
 835	struct sctp_chunk *auth;
 836
 837	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
 838	    has_sack:1,		/* This packet contains a SACK chunk. */
 839	    has_auth:1,		/* This packet contains an AUTH chunk */
 840	    has_data:1,		/* This packet contains at least 1 DATA chunk */
 841	    ipfragok:1,		/* So let ip fragment this packet */
 842	    malloced:1;		/* Is it malloced? */
 843};
 844
 845struct sctp_packet *sctp_packet_init(struct sctp_packet *,
 846				     struct sctp_transport *,
 847				     __u16 sport, __u16 dport);
 848struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
 849sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
 850                                       struct sctp_chunk *, int);
 851sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
 852                                     struct sctp_chunk *);
 853int sctp_packet_transmit(struct sctp_packet *);
 854void sctp_packet_free(struct sctp_packet *);
 855
 856static inline int sctp_packet_empty(struct sctp_packet *packet)
 857{
 858	return packet->size == packet->overhead;
 859}
 860
 861/* This represents a remote transport address.
 862 * For local transport addresses, we just use union sctp_addr.
 863 *
 864 * RFC2960 Section 1.4 Key Terms
 865 *
 866 *   o	Transport address:  A Transport Address is traditionally defined
 867 *	by Network Layer address, Transport Layer protocol and Transport
 868 *	Layer port number.  In the case of SCTP running over IP, a
 869 *	transport address is defined by the combination of an IP address
 870 *	and an SCTP port number (where SCTP is the Transport protocol).
 871 *
 872 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
 873 *
 874 *   o	The sender keeps a separate congestion control parameter set for
 875 *	each of the destination addresses it can send to (not each
 876 *	source-destination pair but for each destination).  The parameters
 877 *	should decay if the address is not used for a long enough time
 878 *	period.
 879 *
 880 */
 881struct sctp_transport {
 882	/* A list of transports. */
 883	struct list_head transports;
 884
 885	/* Reference counting. */
 886	atomic_t refcnt;
 887	__u32	 dead:1,
 888		/* RTO-Pending : A flag used to track if one of the DATA
 889		 *		chunks sent to this address is currently being
 890		 *		used to compute a RTT. If this flag is 0,
 891		 *		the next DATA chunk sent to this destination
 892		 *		should be used to compute a RTT and this flag
 893		 *		should be set. Every time the RTT
 894		 *		calculation completes (i.e. the DATA chunk
 895		 *		is SACK'd) clear this flag.
 896		 */
 897		 rto_pending:1,
 898
 899		/*
 900		 * hb_sent : a flag that signals that we have a pending
 901		 * heartbeat.
 902		 */
 903		hb_sent:1,
 904
 905		/* Is the Path MTU update pending on this tranport */
 906		pmtu_pending:1,
 907
 908		/* Is this structure kfree()able? */
 909		malloced:1;
 910
 
 
 
 911	struct flowi fl;
 912
 913	/* This is the peer's IP address and port. */
 914	union sctp_addr ipaddr;
 915
 916	/* These are the functions we call to handle LLP stuff.	 */
 917	struct sctp_af *af_specific;
 918
 919	/* Which association do we belong to?  */
 920	struct sctp_association *asoc;
 921
 922	/* RFC2960
 923	 *
 924	 * 12.3 Per Transport Address Data
 925	 *
 926	 * For each destination transport address in the peer's
 927	 * address list derived from the INIT or INIT ACK chunk, a
 928	 * number of data elements needs to be maintained including:
 929	 */
 930	/* RTO	       : The current retransmission timeout value.  */
 931	unsigned long rto;
 932
 933	__u32 rtt;		/* This is the most recent RTT.	 */
 934
 935	/* RTTVAR      : The current RTT variation.  */
 936	__u32 rttvar;
 937
 938	/* SRTT	       : The current smoothed round trip time.	*/
 939	__u32 srtt;
 940
 941	/*
 942	 * These are the congestion stats.
 943	 */
 944	/* cwnd	       : The current congestion window.	 */
 945	__u32 cwnd;		  /* This is the actual cwnd.  */
 946
 947	/* ssthresh    : The current slow start threshold value.  */
 948	__u32 ssthresh;
 949
 950	/* partial     : The tracking method for increase of cwnd when in
 951	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
 952	 */
 953	__u32 partial_bytes_acked;
 954
 955	/* Data that has been sent, but not acknowledged. */
 956	__u32 flight_size;
 957
 958	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
 959
 960	/* Destination */
 961	struct dst_entry *dst;
 962	/* Source address. */
 963	union sctp_addr saddr;
 964
 965	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 966	 * the destination address every heartbeat interval.
 967	 */
 968	unsigned long hbinterval;
 969
 970	/* SACK delay timeout */
 971	unsigned long sackdelay;
 972	__u32 sackfreq;
 973
 974	/* When was the last time (in jiffies) that we heard from this
 975	 * transport?  We use this to pick new active and retran paths.
 976	 */
 977	unsigned long last_time_heard;
 978
 979	/* Last time(in jiffies) when cwnd is reduced due to the congestion
 980	 * indication based on ECNE chunk.
 981	 */
 982	unsigned long last_time_ecne_reduced;
 983
 984	/* This is the max_retrans value for the transport and will
 985	 * be initialized from the assocs value.  This can be changed
 986	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
 987	 */
 988	__u16 pathmaxrxt;
 989
 990	/* PMTU	      : The current known path MTU.  */
 991	__u32 pathmtu;
 992
 993	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 994	__u32 param_flags;
 995
 996	/* The number of times INIT has been sent on this transport. */
 997	int init_sent_count;
 998
 999	/* state       : The current state of this destination,
1000	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
1001	 */
1002	int state;
1003
1004	/* These are the error stats for this destination.  */
1005
1006	/* Error count : The current error count for this destination.	*/
1007	unsigned short error_count;
1008
1009	/* Per	       : A timer used by each destination.
1010	 * Destination :
1011	 * Timer       :
1012	 *
1013	 * [Everywhere else in the text this is called T3-rtx. -ed]
1014	 */
1015	struct timer_list T3_rtx_timer;
1016
1017	/* Heartbeat timer is per destination. */
1018	struct timer_list hb_timer;
1019
1020	/* Timer to handle ICMP proto unreachable envets */
1021	struct timer_list proto_unreach_timer;
1022
1023	/* Since we're using per-destination retransmission timers
1024	 * (see above), we're also using per-destination "transmitted"
1025	 * queues.  This probably ought to be a private struct
1026	 * accessible only within the outqueue, but it's not, yet.
1027	 */
1028	struct list_head transmitted;
1029
1030	/* We build bundle-able packets for this transport here.  */
1031	struct sctp_packet packet;
1032
1033	/* This is the list of transports that have chunks to send.  */
1034	struct list_head send_ready;
1035
1036	/* State information saved for SFR_CACC algorithm. The key
1037	 * idea in SFR_CACC is to maintain state at the sender on a
1038	 * per-destination basis when a changeover happens.
1039	 *	char changeover_active;
1040	 *	char cycling_changeover;
1041	 *	__u32 next_tsn_at_change;
1042	 *	char cacc_saw_newack;
1043	 */
1044	struct {
1045		/* An unsigned integer, which stores the next TSN to be
1046		 * used by the sender, at the moment of changeover.
1047		 */
1048		__u32 next_tsn_at_change;
1049
1050		/* A flag which indicates the occurrence of a changeover */
1051		char changeover_active;
1052
1053		/* A flag which indicates whether the change of primary is
1054		 * the first switch to this destination address during an
1055		 * active switch.
1056		 */
1057		char cycling_changeover;
1058
1059		/* A temporary flag, which is used during the processing of
1060		 * a SACK to estimate the causative TSN(s)'s group.
1061		 */
1062		char cacc_saw_newack;
1063	} cacc;
1064
1065	/* 64-bit random number sent with heartbeat. */
1066	__u64 hb_nonce;
1067};
1068
1069struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1070					  gfp_t);
1071void sctp_transport_set_owner(struct sctp_transport *,
1072			      struct sctp_association *);
1073void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1074			  struct sctp_sock *);
1075void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1076void sctp_transport_free(struct sctp_transport *);
1077void sctp_transport_reset_timers(struct sctp_transport *);
1078void sctp_transport_hold(struct sctp_transport *);
1079void sctp_transport_put(struct sctp_transport *);
1080void sctp_transport_update_rto(struct sctp_transport *, __u32);
1081void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1082void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1083void sctp_transport_burst_limited(struct sctp_transport *);
1084void sctp_transport_burst_reset(struct sctp_transport *);
1085unsigned long sctp_transport_timeout(struct sctp_transport *);
1086void sctp_transport_reset(struct sctp_transport *);
1087void sctp_transport_update_pmtu(struct sctp_transport *, u32);
 
1088
1089
1090/* This is the structure we use to queue packets as they come into
1091 * SCTP.  We write packets to it and read chunks from it.
1092 */
1093struct sctp_inq {
1094	/* This is actually a queue of sctp_chunk each
1095	 * containing a partially decoded packet.
1096	 */
1097	struct list_head in_chunk_list;
1098	/* This is the packet which is currently off the in queue and is
1099	 * being worked on through the inbound chunk processing.
1100	 */
1101	struct sctp_chunk *in_progress;
1102
1103	/* This is the delayed task to finish delivering inbound
1104	 * messages.
1105	 */
1106	struct work_struct immediate;
1107
1108	int malloced;	     /* Is this structure kfree()able?	*/
1109};
1110
1111void sctp_inq_init(struct sctp_inq *);
1112void sctp_inq_free(struct sctp_inq *);
1113void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1114struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1115struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1116void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1117
1118/* This is the structure we use to hold outbound chunks.  You push
1119 * chunks in and they automatically pop out the other end as bundled
1120 * packets (it calls (*output_handler)()).
1121 *
1122 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1123 * and 8.2 of the v13 draft.
1124 *
1125 * It handles retransmissions.	The connection to the timeout portion
1126 * of the state machine is through sctp_..._timeout() and timeout_handler.
1127 *
1128 * If you feed it SACKs, it will eat them.
1129 *
1130 * If you give it big chunks, it will fragment them.
1131 *
1132 * It assigns TSN's to data chunks.  This happens at the last possible
1133 * instant before transmission.
1134 *
1135 * When free()'d, it empties itself out via output_handler().
1136 */
1137struct sctp_outq {
1138	struct sctp_association *asoc;
1139
1140	/* Data pending that has never been transmitted.  */
1141	struct list_head out_chunk_list;
1142
1143	unsigned out_qlen;	/* Total length of queued data chunks. */
1144
1145	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1146	unsigned error;
1147
1148	/* These are control chunks we want to send.  */
1149	struct list_head control_chunk_list;
1150
1151	/* These are chunks that have been sacked but are above the
1152	 * CTSN, or cumulative tsn ack point.
1153	 */
1154	struct list_head sacked;
1155
1156	/* Put chunks on this list to schedule them for
1157	 * retransmission.
1158	 */
1159	struct list_head retransmit;
1160
1161	/* Put chunks on this list to save them for FWD TSN processing as
1162	 * they were abandoned.
1163	 */
1164	struct list_head abandoned;
1165
1166	/* How many unackd bytes do we have in-flight?	*/
1167	__u32 outstanding_bytes;
1168
1169	/* Are we doing fast-rtx on this queue */
1170	char fast_rtx;
1171
1172	/* Corked? */
1173	char cork;
1174
1175	/* Is this structure empty?  */
1176	char empty;
1177
1178	/* Are we kfree()able? */
1179	char malloced;
1180};
1181
1182void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1183void sctp_outq_teardown(struct sctp_outq *);
1184void sctp_outq_free(struct sctp_outq*);
1185int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1186int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1187int sctp_outq_is_empty(const struct sctp_outq *);
1188void sctp_outq_restart(struct sctp_outq *);
1189
1190void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1191		     sctp_retransmit_reason_t);
1192void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1193int sctp_outq_uncork(struct sctp_outq *);
1194/* Uncork and flush an outqueue.  */
1195static inline void sctp_outq_cork(struct sctp_outq *q)
1196{
1197	q->cork = 1;
1198}
1199
1200/* These bind address data fields common between endpoints and associations */
1201struct sctp_bind_addr {
1202
1203	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1204	 *
1205	 * SCTP Port:	The local SCTP port number the endpoint is
1206	 *		bound to.
1207	 */
1208	__u16 port;
1209
1210	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1211	 *
1212	 * Address List: The list of IP addresses that this instance
1213	 *	has bound.  This information is passed to one's
1214	 *	peer(s) in INIT and INIT ACK chunks.
1215	 */
1216	struct list_head address_list;
1217
1218	int malloced;	     /* Are we kfree()able?  */
1219};
1220
1221void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1222void sctp_bind_addr_free(struct sctp_bind_addr *);
1223int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1224			const struct sctp_bind_addr *src,
1225			sctp_scope_t scope, gfp_t gfp,
1226			int flags);
1227int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1228			const struct sctp_bind_addr *src,
1229			gfp_t gfp);
1230int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1231		       __u8 addr_state, gfp_t gfp);
1232int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1233int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1234			 struct sctp_sock *);
1235int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1236			 struct sctp_sock *, struct sctp_sock *);
1237int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1238			 const union sctp_addr *addr);
1239union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1240					const union sctp_addr	*addrs,
1241					int			addrcnt,
1242					struct sctp_sock	*opt);
1243union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1244					 int *addrs_len,
1245					 gfp_t gfp);
1246int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1247			   __u16 port, gfp_t gfp);
1248
1249sctp_scope_t sctp_scope(const union sctp_addr *);
1250int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1251int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1252int sctp_addr_is_valid(const union sctp_addr *addr);
1253int sctp_is_ep_boundall(struct sock *sk);
1254
1255
1256/* What type of endpoint?  */
1257typedef enum {
1258	SCTP_EP_TYPE_SOCKET,
1259	SCTP_EP_TYPE_ASSOCIATION,
1260} sctp_endpoint_type_t;
1261
1262/*
1263 * A common base class to bridge the implmentation view of a
1264 * socket (usually listening) endpoint versus an association's
1265 * local endpoint.
1266 * This common structure is useful for several purposes:
1267 *   1) Common interface for lookup routines.
1268 *	a) Subfunctions work for either endpoint or association
1269 *	b) Single interface to lookup allows hiding the lookup lock rather
1270 *	   than acquiring it externally.
1271 *   2) Common interface for the inbound chunk handling/state machine.
1272 *   3) Common object handling routines for reference counting, etc.
1273 *   4) Disentangle association lookup from endpoint lookup, where we
1274 *	do not have to find our endpoint to find our association.
1275 *
1276 */
1277
1278struct sctp_ep_common {
1279	/* Fields to help us manage our entries in the hash tables. */
1280	struct hlist_node node;
1281	int hashent;
1282
1283	/* Runtime type information.  What kind of endpoint is this? */
1284	sctp_endpoint_type_t type;
1285
1286	/* Some fields to help us manage this object.
1287	 *   refcnt   - Reference count access to this object.
1288	 *   dead     - Do not attempt to use this object.
1289	 *   malloced - Do we need to kfree this object?
1290	 */
1291	atomic_t    refcnt;
1292	char	    dead;
1293	char	    malloced;
1294
1295	/* What socket does this endpoint belong to?  */
1296	struct sock *sk;
1297
1298	/* This is where we receive inbound chunks.  */
1299	struct sctp_inq	  inqueue;
1300
1301	/* This substructure includes the defining parameters of the
1302	 * endpoint:
1303	 * bind_addr.port is our shared port number.
1304	 * bind_addr.address_list is our set of local IP addresses.
1305	 */
1306	struct sctp_bind_addr bind_addr;
1307};
1308
1309
1310/* RFC Section 1.4 Key Terms
1311 *
1312 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1313 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1314 *   combination of a set of eligible destination transport addresses to
1315 *   which SCTP packets can be sent and a set of eligible source
1316 *   transport addresses from which SCTP packets can be received.
1317 *   All transport addresses used by an SCTP endpoint must use the
1318 *   same port number, but can use multiple IP addresses. A transport
1319 *   address used by an SCTP endpoint must not be used by another
1320 *   SCTP endpoint. In other words, a transport address is unique
1321 *   to an SCTP endpoint.
1322 *
1323 * From an implementation perspective, each socket has one of these.
1324 * A TCP-style socket will have exactly one association on one of
1325 * these.  An UDP-style socket will have multiple associations hanging
1326 * off one of these.
1327 */
1328
1329struct sctp_endpoint {
1330	/* Common substructure for endpoint and association. */
1331	struct sctp_ep_common base;
1332
1333	/* Associations: A list of current associations and mappings
1334	 *	      to the data consumers for each association. This
1335	 *	      may be in the form of a hash table or other
1336	 *	      implementation dependent structure. The data
1337	 *	      consumers may be process identification
1338	 *	      information such as file descriptors, named pipe
1339	 *	      pointer, or table pointers dependent on how SCTP
1340	 *	      is implemented.
1341	 */
1342	/* This is really a list of struct sctp_association entries. */
1343	struct list_head asocs;
1344
1345	/* Secret Key: A secret key used by this endpoint to compute
1346	 *	      the MAC.	This SHOULD be a cryptographic quality
1347	 *	      random number with a sufficient length.
1348	 *	      Discussion in [RFC1750] can be helpful in
1349	 *	      selection of the key.
1350	 */
1351	__u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1352	int current_key;
1353	int last_key;
1354	int key_changed_at;
1355
1356 	/* digest:  This is a digest of the sctp cookie.  This field is
1357 	 * 	    only used on the receive path when we try to validate
1358 	 * 	    that the cookie has not been tampered with.  We put
1359 	 * 	    this here so we pre-allocate this once and can re-use
1360 	 * 	    on every receive.
1361 	 */
1362 	__u8 *digest;
1363 
1364	/* sendbuf acct. policy.	*/
1365	__u32 sndbuf_policy;
1366
1367	/* rcvbuf acct. policy.	*/
1368	__u32 rcvbuf_policy;
1369
1370	/* SCTP AUTH: array of the HMACs that will be allocated
1371	 * we need this per association so that we don't serialize
1372	 */
1373	struct crypto_hash **auth_hmacs;
1374
1375	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1376	 struct sctp_hmac_algo_param *auth_hmacs_list;
1377
1378	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1379	struct sctp_chunks_param *auth_chunk_list;
1380
1381	/* SCTP-AUTH: endpoint shared keys */
1382	struct list_head endpoint_shared_keys;
1383	__u16 active_key_id;
1384};
1385
1386/* Recover the outter endpoint structure. */
1387static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1388{
1389	struct sctp_endpoint *ep;
1390
1391	ep = container_of(base, struct sctp_endpoint, base);
1392	return ep;
1393}
1394
1395/* These are function signatures for manipulating endpoints.  */
1396struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1397void sctp_endpoint_free(struct sctp_endpoint *);
1398void sctp_endpoint_put(struct sctp_endpoint *);
1399void sctp_endpoint_hold(struct sctp_endpoint *);
1400void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1401struct sctp_association *sctp_endpoint_lookup_assoc(
1402	const struct sctp_endpoint *ep,
1403	const union sctp_addr *paddr,
1404	struct sctp_transport **);
1405int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1406				const union sctp_addr *);
1407struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1408					const union sctp_addr *);
1409int sctp_has_association(const union sctp_addr *laddr,
1410			 const union sctp_addr *paddr);
1411
1412int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1413		     sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1414		     struct sctp_chunk **err_chunk);
1415int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1416		      const union sctp_addr *peer,
1417		      sctp_init_chunk_t *init, gfp_t gfp);
1418__u32 sctp_generate_tag(const struct sctp_endpoint *);
1419__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1420
1421struct sctp_inithdr_host {
1422	__u32 init_tag;
1423	__u32 a_rwnd;
1424	__u16 num_outbound_streams;
1425	__u16 num_inbound_streams;
1426	__u32 initial_tsn;
1427};
1428
1429/* RFC2960
1430 *
1431 * 12. Recommended Transmission Control Block (TCB) Parameters
1432 *
1433 * This section details a recommended set of parameters that should
1434 * be contained within the TCB for an implementation. This section is
1435 * for illustrative purposes and should not be deemed as requirements
1436 * on an implementation or as an exhaustive list of all parameters
1437 * inside an SCTP TCB. Each implementation may need its own additional
1438 * parameters for optimization.
1439 */
1440
1441
1442/* Here we have information about each individual association. */
1443struct sctp_association {
1444
1445	/* A base structure common to endpoint and association.
1446	 * In this context, it represents the associations's view
1447	 * of the local endpoint of the association.
1448	 */
1449	struct sctp_ep_common base;
1450
1451	/* Associations on the same socket. */
1452	struct list_head asocs;
1453
1454	/* association id. */
1455	sctp_assoc_t assoc_id;
1456
1457	/* This is our parent endpoint.	 */
1458	struct sctp_endpoint *ep;
1459
1460	/* These are those association elements needed in the cookie.  */
1461	struct sctp_cookie c;
1462
1463	/* This is all information about our peer.  */
1464	struct {
1465		/* rwnd
1466		 *
1467		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1468		 */
1469		__u32 rwnd;
1470
1471		/* transport_addr_list
1472		 *
1473		 * Peer	       : A list of SCTP transport addresses that the
1474		 * Transport   : peer is bound to. This information is derived
1475		 * Address     : from the INIT or INIT ACK and is used to
1476		 * List	       : associate an inbound packet with a given
1477		 *	       : association. Normally this information is
1478		 *	       : hashed or keyed for quick lookup and access
1479		 *	       : of the TCB.
1480		 *	       : The list is also initialized with the list
1481		 *	       : of addresses passed with the sctp_connectx()
1482		 *	       : call.
1483		 *
1484		 * It is a list of SCTP_transport's.
1485		 */
1486		struct list_head transport_addr_list;
1487
1488		/* transport_count
1489		 *
1490		 * Peer        : A count of the number of peer addresses
1491		 * Transport   : in the Peer Transport Address List.
1492		 * Address     :
1493		 * Count       :
1494		 */
1495		__u16 transport_count;
1496
1497		/* port
1498		 *   The transport layer port number.
1499		 */
1500		__u16 port;
1501
1502		/* primary_path
1503		 *
1504		 * Primary     : This is the current primary destination
1505		 * Path	       : transport address of the peer endpoint.  It
1506		 *	       : may also specify a source transport address
1507		 *	       : on this endpoint.
1508		 *
1509		 * All of these paths live on transport_addr_list.
1510		 *
1511		 * At the bakeoffs, we discovered that the intent of
1512		 * primaryPath is that it only changes when the ULP
1513		 * asks to have it changed.  We add the activePath to
1514		 * designate the connection we are currently using to
1515		 * transmit new data and most control chunks.
1516		 */
1517		struct sctp_transport *primary_path;
1518
1519		/* Cache the primary path address here, when we
1520		 * need a an address for msg_name.
1521		 */
1522		union sctp_addr primary_addr;
1523
1524		/* active_path
1525		 *   The path that we are currently using to
1526		 *   transmit new data and most control chunks.
1527		 */
1528		struct sctp_transport *active_path;
1529
1530		/* retran_path
1531		 *
1532		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1533		 * ...
1534		 * Furthermore, when its peer is multi-homed, an
1535		 * endpoint SHOULD try to retransmit a chunk to an
1536		 * active destination transport address that is
1537		 * different from the last destination address to
1538		 * which the DATA chunk was sent.
1539		 */
1540		struct sctp_transport *retran_path;
1541
1542		/* Pointer to last transport I have sent on.  */
1543		struct sctp_transport *last_sent_to;
1544
1545		/* This is the last transport I have received DATA on.	*/
1546		struct sctp_transport *last_data_from;
1547
1548		/*
1549		 * Mapping  An array of bits or bytes indicating which out of
1550		 * Array    order TSN's have been received (relative to the
1551		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1552		 *	    order packets have been received, this array
1553		 *	    will be set to all zero. This structure may be
1554		 *	    in the form of a circular buffer or bit array.
1555		 *
1556		 * Last Rcvd   : This is the last TSN received in
1557		 * TSN	       : sequence. This value is set initially by
1558		 *	       : taking the peer's Initial TSN, received in
1559		 *	       : the INIT or INIT ACK chunk, and subtracting
1560		 *	       : one from it.
1561		 *
1562		 * Throughout most of the specification this is called the
1563		 * "Cumulative TSN ACK Point".	In this case, we
1564		 * ignore the advice in 12.2 in favour of the term
1565		 * used in the bulk of the text.  This value is hidden
1566		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1567		 */
1568		struct sctp_tsnmap tsn_map;
1569
1570		/* Ack State   : This flag indicates if the next received
1571		 *             : packet is to be responded to with a
1572		 *             : SACK. This is initializedto 0.  When a packet
1573		 *             : is received it is incremented. If this value
1574		 *             : reaches 2 or more, a SACK is sent and the
1575		 *             : value is reset to 0. Note: This is used only
1576		 *             : when no DATA chunks are received out of
1577		 *             : order.  When DATA chunks are out of order,
1578		 *             : SACK's are not delayed (see Section 6).
1579		 */
1580		__u8    sack_needed;     /* Do we need to sack the peer? */
1581		__u32	sack_cnt;
 
1582
1583		/* These are capabilities which our peer advertised.  */
1584		__u8	ecn_capable:1,	    /* Can peer do ECN? */
1585			ipv4_address:1,	    /* Peer understands IPv4 addresses? */
1586			ipv6_address:1,	    /* Peer understands IPv6 addresses? */
1587			hostname_address:1, /* Peer understands DNS addresses? */
1588			asconf_capable:1,   /* Does peer support ADDIP? */
1589			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1590			auth_capable:1;	    /* Is peer doing SCTP-AUTH? */
1591
1592		__u32   adaptation_ind;	 /* Adaptation Code point. */
1593
1594		/* This mask is used to disable sending the ASCONF chunk
1595		 * with specified parameter to peer.
1596		 */
1597		__be16 addip_disabled_mask;
1598
1599		struct sctp_inithdr_host i;
1600		int cookie_len;
1601		void *cookie;
1602
1603		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1604		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1605		 * Initial TSN Value minus 1
1606		 */
1607		__u32 addip_serial;
1608
1609		/* SCTP-AUTH: We need to know pears random number, hmac list
1610		 * and authenticated chunk list.  All that is part of the
1611		 * cookie and these are just pointers to those locations
1612		 */
1613		sctp_random_param_t *peer_random;
1614		sctp_chunks_param_t *peer_chunks;
1615		sctp_hmac_algo_param_t *peer_hmacs;
1616	} peer;
1617
1618	/* State       : A state variable indicating what state the
1619	 *	       : association is in, i.e. COOKIE-WAIT,
1620	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1621	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1622	 *
1623	 *		Note: No "CLOSED" state is illustrated since if a
1624	 *		association is "CLOSED" its TCB SHOULD be removed.
1625	 *
1626	 *		In this implementation we DO have a CLOSED
1627	 *		state which is used during initiation and shutdown.
1628	 *
1629	 *		State takes values from SCTP_STATE_*.
1630	 */
1631	sctp_state_t state;
1632
1633	/* The cookie life I award for any cookie.  */
1634	struct timeval cookie_life;
1635
1636	/* Overall     : The overall association error count.
1637	 * Error Count : [Clear this any time I get something.]
1638	 */
1639	int overall_error_count;
1640
1641	/* These are the association's initial, max, and min RTO values.
1642	 * These values will be initialized by system defaults, but can
1643	 * be modified via the SCTP_RTOINFO socket option.
1644	 */
1645	unsigned long rto_initial;
1646	unsigned long rto_max;
1647	unsigned long rto_min;
1648
1649	/* Maximum number of new data packets that can be sent in a burst.  */
1650	int max_burst;
1651
1652	/* This is the max_retrans value for the association.  This value will
1653	 * be initialized initialized from system defaults, but can be
1654	 * modified by the SCTP_ASSOCINFO socket option.
1655	 */
1656	int max_retrans;
1657
1658	/* Maximum number of times the endpoint will retransmit INIT  */
1659	__u16 max_init_attempts;
1660
1661	/* How many times have we resent an INIT? */
1662	__u16 init_retries;
1663
1664	/* The largest timeout or RTO value to use in attempting an INIT */
1665	unsigned long max_init_timeo;
1666
1667	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1668	 * the destination address every heartbeat interval. This value
1669	 * will be inherited by all new transports.
1670	 */
1671	unsigned long hbinterval;
1672
1673	/* This is the max_retrans value for new transports in the
1674	 * association.
1675	 */
1676	__u16 pathmaxrxt;
1677
1678	/* Flag that path mtu update is pending */
1679	__u8   pmtu_pending;
1680
1681	/* Association : The smallest PMTU discovered for all of the
1682	 * PMTU	       : peer's transport addresses.
1683	 */
1684	__u32 pathmtu;
1685
1686	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1687	__u32 param_flags;
1688
1689	/* SACK delay timeout */
1690	unsigned long sackdelay;
1691	__u32 sackfreq;
1692
1693
1694	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1695	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1696
1697	/* Transport to which SHUTDOWN chunk was last sent.  */
1698	struct sctp_transport *shutdown_last_sent_to;
1699
1700	/* How many times have we resent a SHUTDOWN */
1701	int shutdown_retries;
1702
1703	/* Transport to which INIT chunk was last sent.  */
1704	struct sctp_transport *init_last_sent_to;
1705
1706	/* Next TSN    : The next TSN number to be assigned to a new
1707	 *	       : DATA chunk.  This is sent in the INIT or INIT
1708	 *	       : ACK chunk to the peer and incremented each
1709	 *	       : time a DATA chunk is assigned a TSN
1710	 *	       : (normally just prior to transmit or during
1711	 *	       : fragmentation).
1712	 */
1713	__u32 next_tsn;
1714
1715	/*
1716	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1717	 * TSN	       : is set initially by taking the peer's Initial TSN,
1718	 *	       : received in the INIT or INIT ACK chunk, and
1719	 *	       : subtracting one from it.
1720	 *
1721	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1722	 */
1723
1724	__u32 ctsn_ack_point;
1725
1726	/* PR-SCTP Advanced.Peer.Ack.Point */
1727	__u32 adv_peer_ack_point;
1728
1729	/* Highest TSN that is acknowledged by incoming SACKs. */
1730	__u32 highest_sacked;
1731
1732	/* TSN marking the fast recovery exit point */
1733	__u32 fast_recovery_exit;
1734
1735	/* Flag to track the current fast recovery state */
1736	__u8 fast_recovery;
1737
1738	/* The number of unacknowledged data chunks.  Reported through
1739	 * the SCTP_STATUS sockopt.
1740	 */
1741	__u16 unack_data;
1742
1743	/* The total number of data chunks that we've had to retransmit
1744	 * as the result of a T3 timer expiration
1745	 */
1746	__u32 rtx_data_chunks;
1747
1748	/* This is the association's receive buffer space.  This value is used
1749	 * to set a_rwnd field in an INIT or a SACK chunk.
1750	 */
1751	__u32 rwnd;
1752
1753	/* This is the last advertised value of rwnd over a SACK chunk. */
1754	__u32 a_rwnd;
1755
1756	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1757	 * to slop over a maximum of the association's frag_point.
1758	 */
1759	__u32 rwnd_over;
1760
1761	/* Keeps treack of rwnd pressure.  This happens when we have
1762	 * a window, but not recevie buffer (i.e small packets).  This one
1763	 * is releases slowly (1 PMTU at a time ).
1764	 */
1765	__u32 rwnd_press;
1766
1767	/* This is the sndbuf size in use for the association.
1768	 * This corresponds to the sndbuf size for the association,
1769	 * as specified in the sk->sndbuf.
1770	 */
1771	int sndbuf_used;
1772
1773	/* This is the amount of memory that this association has allocated
1774	 * in the receive path at any given time.
1775	 */
1776	atomic_t rmem_alloc;
1777
1778	/* This is the wait queue head for send requests waiting on
1779	 * the association sndbuf space.
1780	 */
1781	wait_queue_head_t	wait;
1782
1783	/* The message size at which SCTP fragmentation will occur. */
1784	__u32 frag_point;
1785	__u32 user_frag;
1786
1787	/* Counter used to count INIT errors. */
1788	int init_err_counter;
1789
1790	/* Count the number of INIT cycles (for doubling timeout). */
1791	int init_cycle;
1792
1793	/* Default send parameters. */
1794	__u16 default_stream;
1795	__u16 default_flags;
1796	__u32 default_ppid;
1797	__u32 default_context;
1798	__u32 default_timetolive;
1799
1800	/* Default receive parameters */
1801	__u32 default_rcv_context;
1802
1803	/* This tracks outbound ssn for a given stream.	 */
1804	struct sctp_ssnmap *ssnmap;
1805
1806	/* All outbound chunks go through this structure.  */
1807	struct sctp_outq outqueue;
1808
1809	/* A smart pipe that will handle reordering and fragmentation,
1810	 * as well as handle passing events up to the ULP.
1811	 */
1812	struct sctp_ulpq ulpq;
1813
1814	/* Last TSN that caused an ECNE Chunk to be sent.  */
1815	__u32 last_ecne_tsn;
1816
1817	/* Last TSN that caused a CWR Chunk to be sent.	 */
1818	__u32 last_cwr_tsn;
1819
1820	/* How many duplicated TSNs have we seen?  */
1821	int numduptsns;
1822
1823	/* Number of seconds of idle time before an association is closed.
1824	 * In the association context, this is really used as a boolean
1825	 * since the real timeout is stored in the timeouts array
1826	 */
1827	__u32 autoclose;
1828
1829	/* These are to support
1830	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1831	 *  and Enforcement of Flow and Message Limits"
1832	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1833	 * or "ADDIP" for short.
1834	 */
1835
1836
1837
1838	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1839	 *
1840	 * R1) One and only one ASCONF Chunk MAY be in transit and
1841	 * unacknowledged at any one time.  If a sender, after sending
1842	 * an ASCONF chunk, decides it needs to transfer another
1843	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1844	 * returns from the previous ASCONF Chunk before sending a
1845	 * subsequent ASCONF. Note this restriction binds each side,
1846	 * so at any time two ASCONF may be in-transit on any given
1847	 * association (one sent from each endpoint).
1848	 *
1849	 * [This is our one-and-only-one ASCONF in flight.  If we do
1850	 * not have an ASCONF in flight, this is NULL.]
1851	 */
1852	struct sctp_chunk *addip_last_asconf;
1853
1854	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1855	 *
1856	 * This is needed to implement itmes E1 - E4 of the updated
1857	 * spec.  Here is the justification:
1858	 *
1859	 * Since the peer may bundle multiple ASCONF chunks toward us,
1860	 * we now need the ability to cache multiple ACKs.  The section
1861	 * describes in detail how they are cached and cleaned up.
1862	 */
1863	struct list_head asconf_ack_list;
1864
1865	/* These ASCONF chunks are waiting to be sent.
1866	 *
1867	 * These chunaks can't be pushed to outqueue until receiving
1868	 * ASCONF_ACK for the previous ASCONF indicated by
1869	 * addip_last_asconf, so as to guarantee that only one ASCONF
1870	 * is in flight at any time.
1871	 *
1872	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1873	 *
1874	 * In defining the ASCONF Chunk transfer procedures, it is
1875	 * essential that these transfers MUST NOT cause congestion
1876	 * within the network.	To achieve this, we place these
1877	 * restrictions on the transfer of ASCONF Chunks:
1878	 *
1879	 * R1) One and only one ASCONF Chunk MAY be in transit and
1880	 * unacknowledged at any one time.  If a sender, after sending
1881	 * an ASCONF chunk, decides it needs to transfer another
1882	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1883	 * returns from the previous ASCONF Chunk before sending a
1884	 * subsequent ASCONF. Note this restriction binds each side,
1885	 * so at any time two ASCONF may be in-transit on any given
1886	 * association (one sent from each endpoint).
1887	 *
1888	 *
1889	 * [I really think this is EXACTLY the sort of intelligence
1890	 *  which already resides in sctp_outq.	 Please move this
1891	 *  queue and its supporting logic down there.	--piggy]
1892	 */
1893	struct list_head addip_chunk_list;
1894
1895	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1896	 *
1897	 * A2) A serial number should be assigned to the Chunk. The
1898	 * serial number SHOULD be a monotonically increasing
1899	 * number. The serial number SHOULD be initialized at
1900	 * the start of the association to the same value as the
1901	 * Initial TSN and every time a new ASCONF chunk is created
1902	 * it is incremented by one after assigning the serial number
1903	 * to the newly created chunk.
1904	 *
1905	 * ADDIP
1906	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1907	 *
1908	 * Serial Number : 32 bits (unsigned integer)
1909	 *
1910	 * This value represents a Serial Number for the ASCONF
1911	 * Chunk. The valid range of Serial Number is from 0 to
1912	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1913	 * after reaching 4294967295.
1914	 */
1915	__u32 addip_serial;
1916	union sctp_addr *asconf_addr_del_pending;
1917	int src_out_of_asoc_ok;
 
1918
1919	/* SCTP AUTH: list of the endpoint shared keys.  These
1920	 * keys are provided out of band by the user applicaton
1921	 * and can't change during the lifetime of the association
1922	 */
1923	struct list_head endpoint_shared_keys;
1924
1925	/* SCTP AUTH:
1926	 * The current generated assocaition shared key (secret)
1927	 */
1928	struct sctp_auth_bytes *asoc_shared_key;
1929
1930	/* SCTP AUTH: hmac id of the first peer requested algorithm
1931	 * that we support.
1932	 */
1933	__u16 default_hmac_id;
1934
1935	__u16 active_key_id;
1936
1937	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1938	     temp:1;		/* Is it a temporary association? */
1939};
1940
1941
1942/* An eyecatcher for determining if we are really looking at an
1943 * association data structure.
1944 */
1945enum {
1946	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1947};
1948
1949/* Recover the outter association structure. */
1950static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1951{
1952	struct sctp_association *asoc;
1953
1954	asoc = container_of(base, struct sctp_association, base);
1955	return asoc;
1956}
1957
1958/* These are function signatures for manipulating associations.	 */
1959
1960
1961struct sctp_association *
1962sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1963		     sctp_scope_t scope, gfp_t gfp);
1964void sctp_association_free(struct sctp_association *);
1965void sctp_association_put(struct sctp_association *);
1966void sctp_association_hold(struct sctp_association *);
1967
1968struct sctp_transport *sctp_assoc_choose_alter_transport(
1969	struct sctp_association *, struct sctp_transport *);
1970void sctp_assoc_update_retran_path(struct sctp_association *);
1971struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1972					  const union sctp_addr *);
1973int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1974			    const union sctp_addr *laddr);
1975struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1976				     const union sctp_addr *address,
1977				     const gfp_t gfp,
1978				     const int peer_state);
1979void sctp_assoc_del_peer(struct sctp_association *asoc,
1980			 const union sctp_addr *addr);
1981void sctp_assoc_rm_peer(struct sctp_association *asoc,
1982			 struct sctp_transport *peer);
1983void sctp_assoc_control_transport(struct sctp_association *,
1984				  struct sctp_transport *,
1985				  sctp_transport_cmd_t, sctp_sn_error_t);
1986struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1987struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1988					   const union sctp_addr *,
1989					   const union sctp_addr *);
1990void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1991void sctp_assoc_update(struct sctp_association *old,
1992		       struct sctp_association *new);
1993
1994__u32 sctp_association_get_next_tsn(struct sctp_association *);
1995
1996void sctp_assoc_sync_pmtu(struct sctp_association *);
1997void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1998void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1999void sctp_assoc_set_primary(struct sctp_association *,
2000			    struct sctp_transport *);
2001void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2002				    struct sctp_transport *);
2003int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
2004				     sctp_scope_t, gfp_t);
2005int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2006					 struct sctp_cookie*,
2007					 gfp_t gfp);
2008int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2009void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2010struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2011					const struct sctp_association *asoc,
2012					__be32 serial);
2013void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2014
2015int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2016			const union sctp_addr *ss2);
2017struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2018
2019/* A convenience structure to parse out SCTP specific CMSGs. */
2020typedef struct sctp_cmsgs {
2021	struct sctp_initmsg *init;
2022	struct sctp_sndrcvinfo *info;
2023} sctp_cmsgs_t;
2024
2025/* Structure for tracking memory objects */
2026typedef struct {
2027	char *label;
2028	atomic_t *counter;
2029} sctp_dbg_objcnt_entry_t;
2030
2031#endif /* __sctp_structs_h__ */