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