1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/* SCTP kernel implementation
   3 * (C) Copyright IBM Corp. 2001, 2004
   4 * Copyright (c) 1999-2000 Cisco, Inc.
   5 * Copyright (c) 1999-2001 Motorola, Inc.
   6 * Copyright (c) 2001 Intel Corp.
   7 *
   8 * This file is part of the SCTP kernel implementation
   9 *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  10 * Please send any bug reports or fixes you make to the
  11 * email addresses:
  12 *    lksctp developers <linux-sctp@vger.kernel.org>
  13 *
  14 * Written or modified by:
  15 *    Randall Stewart	    <randall@sctp.chicago.il.us>
  16 *    Ken Morneau	    <kmorneau@cisco.com>
  17 *    Qiaobing Xie	    <qxie1@email.mot.com>
  18 *    La Monte H.P. Yarroll <piggy@acm.org>
  19 *    Karl Knutson	    <karl@athena.chicago.il.us>
  20 *    Jon Grimm		    <jgrimm@us.ibm.com>
  21 *    Xingang Guo	    <xingang.guo@intel.com>
  22 *    Hui Huang		    <hui.huang@nokia.com>
  23 *    Sridhar Samudrala	    <sri@us.ibm.com>
  24 *    Daisy Chang	    <daisyc@us.ibm.com>
  25 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
  26 *    Ardelle Fan	    <ardelle.fan@intel.com>
  27 *    Ryan Layer	    <rmlayer@us.ibm.com>
  28 *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
  29 *    Kevin Gao             <kevin.gao@intel.com>
  30 */
  31
  32#ifndef __sctp_structs_h__
  33#define __sctp_structs_h__
  34
  35#include <linux/ktime.h>
  36#include <linux/generic-radix-tree.h>
  37#include <linux/rhashtable-types.h>
  38#include <linux/socket.h>	/* linux/in.h needs this!!    */
  39#include <linux/in.h>		/* We get struct sockaddr_in. */
  40#include <linux/in6.h>		/* We get struct in6_addr     */
  41#include <linux/ipv6.h>
  42#include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
  43#include <linux/atomic.h>		/* This gets us atomic counters.  */
  44#include <linux/skbuff.h>	/* We need sk_buff_head. */
  45#include <linux/workqueue.h>	/* We need tq_struct.	 */
  46#include <linux/sctp.h>		/* We need sctp* header structs.  */
  47#include <net/sctp/auth.h>	/* We need auth specific structs */
  48#include <net/ip.h>		/* For inet_skb_parm */
  49
  50/* A convenience structure for handling sockaddr structures.
  51 * We should wean ourselves off this.
  52 */
  53union sctp_addr {
  54	struct sockaddr_in v4;
  55	struct sockaddr_in6 v6;
  56	struct sockaddr sa;
  57};
  58
  59/* Forward declarations for data structures. */
  60struct sctp_globals;
  61struct sctp_endpoint;
  62struct sctp_association;
  63struct sctp_transport;
  64struct sctp_packet;
  65struct sctp_chunk;
  66struct sctp_inq;
  67struct sctp_outq;
  68struct sctp_bind_addr;
  69struct sctp_ulpq;
  70struct sctp_ep_common;
 
  71struct crypto_shash;
  72struct sctp_stream;
  73
  74
  75#include <net/sctp/tsnmap.h>
  76#include <net/sctp/ulpevent.h>
  77#include <net/sctp/ulpqueue.h>
  78#include <net/sctp/stream_interleave.h>
  79
  80/* Structures useful for managing bind/connect. */
  81
  82struct sctp_bind_bucket {
  83	unsigned short	port;
  84	signed char	fastreuse;
  85	signed char	fastreuseport;
  86	kuid_t		fastuid;
  87	struct hlist_node	node;
  88	struct hlist_head	owner;
  89	struct net	*net;
  90};
  91
  92struct sctp_bind_hashbucket {
  93	spinlock_t	lock;
  94	struct hlist_head	chain;
  95};
  96
  97/* Used for hashing all associations.  */
  98struct sctp_hashbucket {
  99	rwlock_t	lock;
 100	struct hlist_head	chain;
 101} __attribute__((__aligned__(8)));
 102
 103
 104/* The SCTP globals structure. */
 105extern struct sctp_globals {
 106	/* This is a list of groups of functions for each address
 107	 * family that we support.
 108	 */
 109	struct list_head address_families;
 110
 111	/* This is the hash of all endpoints. */
 112	struct sctp_hashbucket *ep_hashtable;
 113	/* This is the sctp port control hash.	*/
 114	struct sctp_bind_hashbucket *port_hashtable;
 115	/* This is the hash of all transports. */
 116	struct rhltable transport_hashtable;
 117
 118	/* Sizes of above hashtables. */
 119	int ep_hashsize;
 120	int port_hashsize;
 121
 122	/* Default initialization values to be applied to new associations. */
 123	__u16 max_instreams;
 124	__u16 max_outstreams;
 125
 126	/* Flag to indicate whether computing and verifying checksum
 127	 * is disabled. */
 128        bool checksum_disable;
 129} sctp_globals;
 130
 131#define sctp_max_instreams		(sctp_globals.max_instreams)
 132#define sctp_max_outstreams		(sctp_globals.max_outstreams)
 133#define sctp_address_families		(sctp_globals.address_families)
 134#define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
 135#define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
 136#define sctp_port_hashsize		(sctp_globals.port_hashsize)
 137#define sctp_port_hashtable		(sctp_globals.port_hashtable)
 138#define sctp_transport_hashtable	(sctp_globals.transport_hashtable)
 139#define sctp_checksum_disable		(sctp_globals.checksum_disable)
 140
 141/* SCTP Socket type: UDP or TCP style. */
 142enum sctp_socket_type {
 143	SCTP_SOCKET_UDP = 0,
 144	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
 145	SCTP_SOCKET_TCP
 146};
 147
 148/* Per socket SCTP information. */
 149struct sctp_sock {
 150	/* inet_sock has to be the first member of sctp_sock */
 151	struct inet_sock inet;
 152	/* What kind of a socket is this? */
 153	enum sctp_socket_type type;
 154
 155	/* PF_ family specific functions.  */
 156	struct sctp_pf *pf;
 157
 158	/* Access to HMAC transform. */
 159	struct crypto_shash *hmac;
 160	char *sctp_hmac_alg;
 161
 162	/* What is our base endpointer? */
 163	struct sctp_endpoint *ep;
 164
 165	struct sctp_bind_bucket *bind_hash;
 166	/* Various Socket Options.  */
 167	__u16 default_stream;
 168	__u32 default_ppid;
 169	__u16 default_flags;
 170	__u32 default_context;
 171	__u32 default_timetolive;
 172	__u32 default_rcv_context;
 173	int max_burst;
 174
 175	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 176	 * the destination address every heartbeat interval. This value
 177	 * will be inherited by all new associations.
 178	 */
 179	__u32 hbinterval;
 180
 181	/* This is the max_retrans value for new associations. */
 182	__u16 pathmaxrxt;
 183
 184	__u32 flowlabel;
 185	__u8  dscp;
 186
 187	int pf_retrans;
 188
 189	/* The initial Path MTU to use for new associations. */
 190	__u32 pathmtu;
 191
 192	/* The default SACK delay timeout for new associations. */
 193	__u32 sackdelay;
 194	__u32 sackfreq;
 195
 196	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 197	__u32 param_flags;
 198
 199	__u32 default_ss;
 200
 201	struct sctp_rtoinfo rtoinfo;
 202	struct sctp_paddrparams paddrparam;
 
 203	struct sctp_assocparams assocparams;
 204
 205	/*
 206	 * These two structures must be grouped together for the usercopy
 207	 * whitelist region.
 208	 */
 209	__u16 subscribe;
 210	struct sctp_initmsg initmsg;
 211
 212	int user_frag;
 213
 214	__u32 autoclose;
 215	__u32 adaptation_ind;
 216	__u32 pd_point;
 217	__u16	nodelay:1,
 218		reuse:1,
 219		disable_fragments:1,
 220		v4mapped:1,
 221		frag_interleave:1,
 222		recvrcvinfo:1,
 223		recvnxtinfo:1,
 224		data_ready_signalled:1;
 225
 226	atomic_t pd_mode;
 227	/* Receive to here while partial delivery is in effect. */
 228	struct sk_buff_head pd_lobby;
 229
 230	/* These must be the last fields, as they will skipped on copies,
 231	 * like on accept and peeloff operations
 232	 */
 233	struct list_head auto_asconf_list;
 234	int do_auto_asconf;
 235};
 236
 237static inline struct sctp_sock *sctp_sk(const struct sock *sk)
 238{
 239       return (struct sctp_sock *)sk;
 240}
 241
 242static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
 243{
 244       return (struct sock *)sp;
 245}
 246
 247#if IS_ENABLED(CONFIG_IPV6)
 248struct sctp6_sock {
 249       struct sctp_sock  sctp;
 250       struct ipv6_pinfo inet6;
 251};
 252#endif /* CONFIG_IPV6 */
 253
 254
 255/* This is our APPLICATION-SPECIFIC state cookie.
 256 * THIS IS NOT DICTATED BY THE SPECIFICATION.
 257 */
 258/* These are the parts of an association which we send in the cookie.
 259 * Most of these are straight out of:
 260 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
 261 *
 262 */
 263
 264struct sctp_cookie {
 265
 266	/* My	       : Tag expected in every inbound packet and sent
 267	 * Verification: in the INIT or INIT ACK chunk.
 268	 * Tag	       :
 269	 */
 270	__u32 my_vtag;
 271
 272	/* Peer's      : Tag expected in every outbound packet except
 273	 * Verification: in the INIT chunk.
 274	 * Tag	       :
 275	 */
 276	__u32 peer_vtag;
 277
 278	/* The rest of these are not from the spec, but really need to
 279	 * be in the cookie.
 280	 */
 281
 282	/* My Tie Tag  : Assist in discovering a restarting association. */
 283	__u32 my_ttag;
 284
 285	/* Peer's Tie Tag: Assist in discovering a restarting association. */
 286	__u32 peer_ttag;
 287
 288	/* When does this cookie expire? */
 289	ktime_t expiration;
 290
 291	/* Number of inbound/outbound streams which are set
 292	 * and negotiated during the INIT process.
 293	 */
 294	__u16 sinit_num_ostreams;
 295	__u16 sinit_max_instreams;
 296
 297	/* This is the first sequence number I used.  */
 298	__u32 initial_tsn;
 299
 300	/* This holds the originating address of the INIT packet.  */
 301	union sctp_addr peer_addr;
 302
 303	/* IG Section 2.35.3 
 304	 * Include the source port of the INIT-ACK
 305	 */
 306	__u16		my_port;
 307
 308	__u8 prsctp_capable;
 309
 310	/* Padding for future use */
 311	__u8 padding;  		
 312
 313	__u32 adaptation_ind;
 314
 315	__u8 auth_random[sizeof(struct sctp_paramhdr) +
 316			 SCTP_AUTH_RANDOM_LENGTH];
 317	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
 318	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
 319
 320	/* This is a shim for my peer's INIT packet, followed by
 321	 * a copy of the raw address list of the association.
 322	 * The length of the raw address list is saved in the
 323	 * raw_addr_list_len field, which will be used at the time when
 324	 * the association TCB is re-constructed from the cookie.
 325	 */
 326	__u32 raw_addr_list_len;
 327	struct sctp_init_chunk peer_init[0];
 328};
 329
 330
 331/* The format of our cookie that we send to our peer. */
 332struct sctp_signed_cookie {
 333	__u8 signature[SCTP_SECRET_SIZE];
 334	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
 335	struct sctp_cookie c;
 336} __packed;
 337
 338/* This is another convenience type to allocate memory for address
 339 * params for the maximum size and pass such structures around
 340 * internally.
 341 */
 342union sctp_addr_param {
 343	struct sctp_paramhdr p;
 344	struct sctp_ipv4addr_param v4;
 345	struct sctp_ipv6addr_param v6;
 346};
 347
 348/* A convenience type to allow walking through the various
 349 * parameters and avoid casting all over the place.
 350 */
 351union sctp_params {
 352	void *v;
 353	struct sctp_paramhdr *p;
 354	struct sctp_cookie_preserve_param *life;
 355	struct sctp_hostname_param *dns;
 356	struct sctp_cookie_param *cookie;
 357	struct sctp_supported_addrs_param *sat;
 358	struct sctp_ipv4addr_param *v4;
 359	struct sctp_ipv6addr_param *v6;
 360	union sctp_addr_param *addr;
 361	struct sctp_adaptation_ind_param *aind;
 362	struct sctp_supported_ext_param *ext;
 363	struct sctp_random_param *random;
 364	struct sctp_chunks_param *chunks;
 365	struct sctp_hmac_algo_param *hmac_algo;
 366	struct sctp_addip_param *addip;
 367};
 368
 369/* RFC 2960.  Section 3.3.5 Heartbeat.
 370 *    Heartbeat Information: variable length
 371 *    The Sender-specific Heartbeat Info field should normally include
 372 *    information about the sender's current time when this HEARTBEAT
 373 *    chunk is sent and the destination transport address to which this
 374 *    HEARTBEAT is sent (see Section 8.3).
 375 */
 376struct sctp_sender_hb_info {
 377	struct sctp_paramhdr param_hdr;
 378	union sctp_addr daddr;
 379	unsigned long sent_at;
 380	__u64 hb_nonce;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 381};
 382
 383int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 384		     gfp_t gfp);
 385int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
 386void sctp_stream_free(struct sctp_stream *stream);
 387void sctp_stream_clear(struct sctp_stream *stream);
 388void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
 
 
 
 389
 390/* What is the current SSN number for this stream? */
 391#define sctp_ssn_peek(stream, type, sid) \
 392	(sctp_stream_##type((stream), (sid))->ssn)
 
 
 393
 394/* Return the next SSN number for this stream.	*/
 395#define sctp_ssn_next(stream, type, sid) \
 396	(sctp_stream_##type((stream), (sid))->ssn++)
 
 
 397
 398/* Skip over this ssn and all below. */
 399#define sctp_ssn_skip(stream, type, sid, ssn) \
 400	(sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
 401
 402/* What is the current MID number for this stream? */
 403#define sctp_mid_peek(stream, type, sid) \
 404	(sctp_stream_##type((stream), (sid))->mid)
 405
 406/* Return the next MID number for this stream.  */
 407#define sctp_mid_next(stream, type, sid) \
 408	(sctp_stream_##type((stream), (sid))->mid++)
 409
 410/* Skip over this mid and all below. */
 411#define sctp_mid_skip(stream, type, sid, mid) \
 412	(sctp_stream_##type((stream), (sid))->mid = mid + 1)
 413
 414/* What is the current MID_uo number for this stream? */
 415#define sctp_mid_uo_peek(stream, type, sid) \
 416	(sctp_stream_##type((stream), (sid))->mid_uo)
 417
 418/* Return the next MID_uo number for this stream.  */
 419#define sctp_mid_uo_next(stream, type, sid) \
 420	(sctp_stream_##type((stream), (sid))->mid_uo++)
 421
 422/*
 423 * Pointers to address related SCTP functions.
 424 * (i.e. things that depend on the address family.)
 425 */
 426struct sctp_af {
 427	int		(*sctp_xmit)	(struct sk_buff *skb,
 428					 struct sctp_transport *);
 429	int		(*setsockopt)	(struct sock *sk,
 430					 int level,
 431					 int optname,
 432					 char __user *optval,
 433					 unsigned int optlen);
 434	int		(*getsockopt)	(struct sock *sk,
 435					 int level,
 436					 int optname,
 437					 char __user *optval,
 438					 int __user *optlen);
 439	int		(*compat_setsockopt)	(struct sock *sk,
 440					 int level,
 441					 int optname,
 442					 char __user *optval,
 443					 unsigned int optlen);
 444	int		(*compat_getsockopt)	(struct sock *sk,
 445					 int level,
 446					 int optname,
 447					 char __user *optval,
 448					 int __user *optlen);
 449	void		(*get_dst)	(struct sctp_transport *t,
 450					 union sctp_addr *saddr,
 451					 struct flowi *fl,
 452					 struct sock *sk);
 453	void		(*get_saddr)	(struct sctp_sock *sk,
 454					 struct sctp_transport *t,
 455					 struct flowi *fl);
 456	void		(*copy_addrlist) (struct list_head *,
 457					  struct net_device *);
 458	int		(*cmp_addr)	(const union sctp_addr *addr1,
 459					 const union sctp_addr *addr2);
 460	void		(*addr_copy)	(union sctp_addr *dst,
 461					 union sctp_addr *src);
 462	void		(*from_skb)	(union sctp_addr *,
 463					 struct sk_buff *skb,
 464					 int saddr);
 465	void		(*from_sk)	(union sctp_addr *,
 466					 struct sock *sk);
 467	void		(*from_addr_param) (union sctp_addr *,
 468					    union sctp_addr_param *,
 469					    __be16 port, int iif);
 470	int		(*to_addr_param) (const union sctp_addr *,
 471					  union sctp_addr_param *); 
 472	int		(*addr_valid)	(union sctp_addr *,
 473					 struct sctp_sock *,
 474					 const struct sk_buff *);
 475	enum sctp_scope	(*scope)(union sctp_addr *);
 476	void		(*inaddr_any)	(union sctp_addr *, __be16);
 477	int		(*is_any)	(const union sctp_addr *);
 478	int		(*available)	(union sctp_addr *,
 479					 struct sctp_sock *);
 480	int		(*skb_iif)	(const struct sk_buff *sk);
 481	int		(*is_ce)	(const struct sk_buff *sk);
 482	void		(*seq_dump_addr)(struct seq_file *seq,
 483					 union sctp_addr *addr);
 484	void		(*ecn_capable)(struct sock *sk);
 485	__u16		net_header_len;
 486	int		sockaddr_len;
 487	int		(*ip_options_len)(struct sock *sk);
 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					  bool kern);
 509	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
 510	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
 511	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
 512	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
 513	struct sctp_af *af;
 514};
 515
 516
 517/* Structure to track chunk fragments that have been acked, but peer
 518 * fragments of the same message have not.
 519 */
 520struct sctp_datamsg {
 521	/* Chunks waiting to be submitted to lower layer. */
 522	struct list_head chunks;
 523	/* Reference counting. */
 524	refcount_t refcnt;
 525	/* When is this message no longer interesting to the peer? */
 526	unsigned long expires_at;
 527	/* Did the messenge fail to send? */
 528	int send_error;
 529	u8 send_failed:1,
 530	   can_delay:1,	/* should this message be Nagle delayed */
 531	   abandoned:1;	/* should this message be abandoned */
 532};
 533
 534struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 535					    struct sctp_sndrcvinfo *,
 536					    struct iov_iter *);
 537void sctp_datamsg_free(struct sctp_datamsg *);
 538void sctp_datamsg_put(struct sctp_datamsg *);
 539void sctp_chunk_fail(struct sctp_chunk *, int error);
 540int sctp_chunk_abandoned(struct sctp_chunk *);
 541
 542/* RFC2960 1.4 Key Terms
 543 *
 544 * o Chunk: A unit of information within an SCTP packet, consisting of
 545 * a chunk header and chunk-specific content.
 546 *
 547 * As a matter of convenience, we remember the SCTP common header for
 548 * each chunk as well as a few other header pointers...
 549 */
 550struct sctp_chunk {
 551	struct list_head list;
 552
 553	refcount_t refcnt;
 554
 555	/* How many times this chunk have been sent, for prsctp RTX policy */
 556	int sent_count;
 557
 558	union {
 559		/* This is our link to the per-transport transmitted list.  */
 560		struct list_head transmitted_list;
 561		/* List in specific stream outq */
 562		struct list_head stream_list;
 563	};
 564
 565	/* This field is used by chunks that hold fragmented data.
 566	 * For the first fragment this is the list that holds the rest of
 567	 * fragments. For the remaining fragments, this is the link to the
 568	 * frag_list maintained in the first fragment.
 569	 */
 570	struct list_head frag_list;
 571
 572	/* This points to the sk_buff containing the actual data.  */
 573	struct sk_buff *skb;
 574
 575	union {
 576		/* In case of GSO packets, this will store the head one */
 577		struct sk_buff *head_skb;
 578		/* In case of auth enabled, this will point to the shkey */
 579		struct sctp_shared_key *shkey;
 580	};
 581
 582	/* These are the SCTP headers by reverse order in a packet.
 583	 * Note that some of these may happen more than once.  In that
 584	 * case, we point at the "current" one, whatever that means
 585	 * for that level of header.
 586	 */
 587
 588	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
 589	union sctp_params param_hdr;
 590	union {
 591		__u8 *v;
 592		struct sctp_datahdr *data_hdr;
 593		struct sctp_inithdr *init_hdr;
 594		struct sctp_sackhdr *sack_hdr;
 595		struct sctp_heartbeathdr *hb_hdr;
 596		struct sctp_sender_hb_info *hbs_hdr;
 597		struct sctp_shutdownhdr *shutdown_hdr;
 598		struct sctp_signed_cookie *cookie_hdr;
 599		struct sctp_ecnehdr *ecne_hdr;
 600		struct sctp_cwrhdr *ecn_cwr_hdr;
 601		struct sctp_errhdr *err_hdr;
 602		struct sctp_addiphdr *addip_hdr;
 603		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
 604		struct sctp_authhdr *auth_hdr;
 605		struct sctp_idatahdr *idata_hdr;
 606		struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
 607	} subh;
 608
 609	__u8 *chunk_end;
 610
 611	struct sctp_chunkhdr *chunk_hdr;
 612	struct sctphdr *sctp_hdr;
 613
 614	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
 615	struct sctp_sndrcvinfo sinfo;
 616
 617	/* Which association does this belong to?  */
 618	struct sctp_association *asoc;
 619
 620	/* What endpoint received this chunk? */
 621	struct sctp_ep_common *rcvr;
 622
 623	/* We fill this in if we are calculating RTT. */
 624	unsigned long sent_at;
 625
 626	/* What is the origin IP address for this chunk?  */
 627	union sctp_addr source;
 628	/* Destination address for this chunk. */
 629	union sctp_addr dest;
 630
 631	/* For outbound message, track all fragments for SEND_FAILED. */
 632	struct sctp_datamsg *msg;
 633
 634	/* For an inbound chunk, this tells us where it came from.
 635	 * For an outbound chunk, it tells us where we'd like it to
 636	 * go.	It is NULL if we have no preference.
 637	 */
 638	struct sctp_transport *transport;
 639
 640	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
 641	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
 642	 * spec violates the principle premis that all chunks are processed
 643	 * in order.
 644	 */
 645	struct sk_buff *auth_chunk;
 646
 647#define SCTP_CAN_FRTX 0x0
 648#define SCTP_NEED_FRTX 0x1
 649#define SCTP_DONT_FRTX 0x2
 650	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
 651		has_tsn:1,		/* Does this chunk have a TSN yet? */
 652		has_ssn:1,		/* Does this chunk have a SSN yet? */
 653#define has_mid has_ssn
 654		singleton:1,		/* Only chunk in the packet? */
 655		end_of_packet:1,	/* Last chunk in the packet? */
 656		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
 657		pdiscard:1,		/* Discard the whole packet now? */
 658		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
 659		data_accepted:1,	/* At least 1 chunk accepted */
 660		auth:1,			/* IN: was auth'ed | OUT: needs auth */
 661		has_asconf:1,		/* IN: have seen an asconf before */
 662		tsn_missing_report:2,	/* Data chunk missing counter. */
 663		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
 664};
 665
 666#define sctp_chunk_retransmitted(chunk)	(chunk->sent_count > 1)
 667void sctp_chunk_hold(struct sctp_chunk *);
 668void sctp_chunk_put(struct sctp_chunk *);
 669int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
 670			  struct iov_iter *from);
 671void sctp_chunk_free(struct sctp_chunk *);
 672void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
 673struct sctp_chunk *sctp_chunkify(struct sk_buff *,
 674				 const struct sctp_association *,
 675				 struct sock *, gfp_t gfp);
 676void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 677		     union sctp_addr *);
 678const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 679
 680static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
 681{
 682	return ntohs(ch->subh.data_hdr->stream);
 683}
 684
 685enum {
 686	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
 687	SCTP_ADDR_SRC,		/* address can be used as source */
 688	SCTP_ADDR_DEL,		/* address about to be deleted */
 689};
 690
 691/* This is a structure for holding either an IPv6 or an IPv4 address.  */
 692struct sctp_sockaddr_entry {
 693	struct list_head list;
 694	struct rcu_head	rcu;
 695	union sctp_addr a;
 696	__u8 state;
 697	__u8 valid;
 698};
 699
 700#define SCTP_ADDRESS_TICK_DELAY	500
 701
 
 
 702/* This structure holds lists of chunks as we are assembling for
 703 * transmission.
 704 */
 705struct sctp_packet {
 706	/* These are the SCTP header values (host order) for the packet. */
 707	__u16 source_port;
 708	__u16 destination_port;
 709	__u32 vtag;
 710
 711	/* This contains the payload chunks.  */
 712	struct list_head chunk_list;
 713
 714	/* This is the overhead of the sctp and ip headers. */
 715	size_t overhead;
 716	/* This is the total size of all chunks INCLUDING padding.  */
 717	size_t size;
 718	/* This is the maximum size this packet may have */
 719	size_t max_size;
 720
 721	/* The packet is destined for this transport address.
 722	 * The function we finally use to pass down to the next lower
 723	 * layer lives in the transport structure.
 724	 */
 725	struct sctp_transport *transport;
 726
 727	/* pointer to the auth chunk for this packet */
 728	struct sctp_chunk *auth;
 729
 730	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
 731	    has_sack:1,		/* This packet contains a SACK chunk. */
 732	    has_auth:1,		/* This packet contains an AUTH chunk */
 733	    has_data:1,		/* This packet contains at least 1 DATA chunk */
 734	    ipfragok:1;		/* So let ip fragment this packet */
 735};
 736
 737void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
 738		      __u16 sport, __u16 dport);
 739void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
 740enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
 741					  struct sctp_chunk *chunk,
 742					  int one_packet, gfp_t gfp);
 743enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
 744					struct sctp_chunk *chunk);
 745int sctp_packet_transmit(struct sctp_packet *, gfp_t);
 746void sctp_packet_free(struct sctp_packet *);
 747
 748static inline int sctp_packet_empty(struct sctp_packet *packet)
 749{
 750	return packet->size == packet->overhead;
 751}
 752
 753/* This represents a remote transport address.
 754 * For local transport addresses, we just use union sctp_addr.
 755 *
 756 * RFC2960 Section 1.4 Key Terms
 757 *
 758 *   o	Transport address:  A Transport Address is traditionally defined
 759 *	by Network Layer address, Transport Layer protocol and Transport
 760 *	Layer port number.  In the case of SCTP running over IP, a
 761 *	transport address is defined by the combination of an IP address
 762 *	and an SCTP port number (where SCTP is the Transport protocol).
 763 *
 764 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
 765 *
 766 *   o	The sender keeps a separate congestion control parameter set for
 767 *	each of the destination addresses it can send to (not each
 768 *	source-destination pair but for each destination).  The parameters
 769 *	should decay if the address is not used for a long enough time
 770 *	period.
 771 *
 772 */
 773struct sctp_transport {
 774	/* A list of transports. */
 775	struct list_head transports;
 776	struct rhlist_head node;
 777
 778	/* Reference counting. */
 779	refcount_t refcnt;
 780		/* RTO-Pending : A flag used to track if one of the DATA
 781		 *		chunks sent to this address is currently being
 782		 *		used to compute a RTT. If this flag is 0,
 783		 *		the next DATA chunk sent to this destination
 784		 *		should be used to compute a RTT and this flag
 785		 *		should be set. Every time the RTT
 786		 *		calculation completes (i.e. the DATA chunk
 787		 *		is SACK'd) clear this flag.
 788		 */
 789	__u32	rto_pending:1,
 790
 791		/*
 792		 * hb_sent : a flag that signals that we have a pending
 793		 * heartbeat.
 794		 */
 795		hb_sent:1,
 796
 797		/* Is the Path MTU update pending on this tranport */
 798		pmtu_pending:1,
 799
 800		dst_pending_confirm:1,	/* need to confirm neighbour */
 801
 802		/* Has this transport moved the ctsn since we last sacked */
 803		sack_generation:1;
 804	u32 dst_cookie;
 805
 806	struct flowi fl;
 807
 808	/* This is the peer's IP address and port. */
 809	union sctp_addr ipaddr;
 810
 811	/* These are the functions we call to handle LLP stuff.	 */
 812	struct sctp_af *af_specific;
 813
 814	/* Which association do we belong to?  */
 815	struct sctp_association *asoc;
 816
 817	/* RFC2960
 818	 *
 819	 * 12.3 Per Transport Address Data
 820	 *
 821	 * For each destination transport address in the peer's
 822	 * address list derived from the INIT or INIT ACK chunk, a
 823	 * number of data elements needs to be maintained including:
 824	 */
 825	/* RTO	       : The current retransmission timeout value.  */
 826	unsigned long rto;
 827
 828	__u32 rtt;		/* This is the most recent RTT.	 */
 829
 830	/* RTTVAR      : The current RTT variation.  */
 831	__u32 rttvar;
 832
 833	/* SRTT	       : The current smoothed round trip time.	*/
 834	__u32 srtt;
 835
 836	/*
 837	 * These are the congestion stats.
 838	 */
 839	/* cwnd	       : The current congestion window.	 */
 840	__u32 cwnd;		  /* This is the actual cwnd.  */
 841
 842	/* ssthresh    : The current slow start threshold value.  */
 843	__u32 ssthresh;
 844
 845	/* partial     : The tracking method for increase of cwnd when in
 846	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
 847	 */
 848	__u32 partial_bytes_acked;
 849
 850	/* Data that has been sent, but not acknowledged. */
 851	__u32 flight_size;
 852
 853	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
 854
 855	/* Destination */
 856	struct dst_entry *dst;
 857	/* Source address. */
 858	union sctp_addr saddr;
 859
 860	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 861	 * the destination address every heartbeat interval.
 862	 */
 863	unsigned long hbinterval;
 864
 865	/* SACK delay timeout */
 866	unsigned long sackdelay;
 867	__u32 sackfreq;
 868
 869	atomic_t mtu_info;
 870
 871	/* When was the last time that we heard from this transport? We use
 872	 * this to pick new active and retran paths.
 873	 */
 874	ktime_t last_time_heard;
 875
 876	/* When was the last time that we sent a chunk using this
 877	 * transport? We use this to check for idle transports
 878	 */
 879	unsigned long last_time_sent;
 880
 881	/* Last time(in jiffies) when cwnd is reduced due to the congestion
 882	 * indication based on ECNE chunk.
 883	 */
 884	unsigned long last_time_ecne_reduced;
 885
 886	/* This is the max_retrans value for the transport and will
 887	 * be initialized from the assocs value.  This can be changed
 888	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
 889	 */
 890	__u16 pathmaxrxt;
 891
 892	__u32 flowlabel;
 893	__u8  dscp;
 894
 895	/* This is the partially failed retrans value for the transport
 896	 * and will be initialized from the assocs value.  This can be changed
 897	 * using the SCTP_PEER_ADDR_THLDS socket option
 898	 */
 899	int pf_retrans;
 900	/* PMTU	      : The current known path MTU.  */
 901	__u32 pathmtu;
 902
 903	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 904	__u32 param_flags;
 905
 906	/* The number of times INIT has been sent on this transport. */
 907	int init_sent_count;
 908
 909	/* state       : The current state of this destination,
 910	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
 911	 */
 912	int state;
 913
 914	/* These are the error stats for this destination.  */
 915
 916	/* Error count : The current error count for this destination.	*/
 917	unsigned short error_count;
 918
 919	/* Per	       : A timer used by each destination.
 920	 * Destination :
 921	 * Timer       :
 922	 *
 923	 * [Everywhere else in the text this is called T3-rtx. -ed]
 924	 */
 925	struct timer_list T3_rtx_timer;
 926
 927	/* Heartbeat timer is per destination. */
 928	struct timer_list hb_timer;
 929
 930	/* Timer to handle ICMP proto unreachable envets */
 931	struct timer_list proto_unreach_timer;
 932
 933	/* Timer to handler reconf chunk rtx */
 934	struct timer_list reconf_timer;
 935
 936	/* Since we're using per-destination retransmission timers
 937	 * (see above), we're also using per-destination "transmitted"
 938	 * queues.  This probably ought to be a private struct
 939	 * accessible only within the outqueue, but it's not, yet.
 940	 */
 941	struct list_head transmitted;
 942
 943	/* We build bundle-able packets for this transport here.  */
 944	struct sctp_packet packet;
 945
 946	/* This is the list of transports that have chunks to send.  */
 947	struct list_head send_ready;
 948
 949	/* State information saved for SFR_CACC algorithm. The key
 950	 * idea in SFR_CACC is to maintain state at the sender on a
 951	 * per-destination basis when a changeover happens.
 952	 *	char changeover_active;
 953	 *	char cycling_changeover;
 954	 *	__u32 next_tsn_at_change;
 955	 *	char cacc_saw_newack;
 956	 */
 957	struct {
 958		/* An unsigned integer, which stores the next TSN to be
 959		 * used by the sender, at the moment of changeover.
 960		 */
 961		__u32 next_tsn_at_change;
 962
 963		/* A flag which indicates the occurrence of a changeover */
 964		char changeover_active;
 965
 966		/* A flag which indicates whether the change of primary is
 967		 * the first switch to this destination address during an
 968		 * active switch.
 969		 */
 970		char cycling_changeover;
 971
 972		/* A temporary flag, which is used during the processing of
 973		 * a SACK to estimate the causative TSN(s)'s group.
 974		 */
 975		char cacc_saw_newack;
 976	} cacc;
 977
 978	/* 64-bit random number sent with heartbeat. */
 979	__u64 hb_nonce;
 980
 981	struct rcu_head rcu;
 982};
 983
 984struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
 985					  gfp_t);
 986void sctp_transport_set_owner(struct sctp_transport *,
 987			      struct sctp_association *);
 988void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
 989			  struct sctp_sock *);
 990void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
 991void sctp_transport_free(struct sctp_transport *);
 992void sctp_transport_reset_t3_rtx(struct sctp_transport *);
 993void sctp_transport_reset_hb_timer(struct sctp_transport *);
 994void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
 995int sctp_transport_hold(struct sctp_transport *);
 996void sctp_transport_put(struct sctp_transport *);
 997void sctp_transport_update_rto(struct sctp_transport *, __u32);
 998void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
 999void sctp_transport_lower_cwnd(struct sctp_transport *t,
1000			       enum sctp_lower_cwnd reason);
1001void sctp_transport_burst_limited(struct sctp_transport *);
1002void sctp_transport_burst_reset(struct sctp_transport *);
1003unsigned long sctp_transport_timeout(struct sctp_transport *);
1004void sctp_transport_reset(struct sctp_transport *t);
1005bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1006void sctp_transport_immediate_rtx(struct sctp_transport *);
1007void sctp_transport_dst_release(struct sctp_transport *t);
1008void sctp_transport_dst_confirm(struct sctp_transport *t);
1009
1010
1011/* This is the structure we use to queue packets as they come into
1012 * SCTP.  We write packets to it and read chunks from it.
1013 */
1014struct sctp_inq {
1015	/* This is actually a queue of sctp_chunk each
1016	 * containing a partially decoded packet.
1017	 */
1018	struct list_head in_chunk_list;
1019	/* This is the packet which is currently off the in queue and is
1020	 * being worked on through the inbound chunk processing.
1021	 */
1022	struct sctp_chunk *in_progress;
1023
1024	/* This is the delayed task to finish delivering inbound
1025	 * messages.
1026	 */
1027	struct work_struct immediate;
1028};
1029
1030void sctp_inq_init(struct sctp_inq *);
1031void sctp_inq_free(struct sctp_inq *);
1032void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1033struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1034struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1035void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1036
1037/* This is the structure we use to hold outbound chunks.  You push
1038 * chunks in and they automatically pop out the other end as bundled
1039 * packets (it calls (*output_handler)()).
1040 *
1041 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1042 * and 8.2 of the v13 draft.
1043 *
1044 * It handles retransmissions.	The connection to the timeout portion
1045 * of the state machine is through sctp_..._timeout() and timeout_handler.
1046 *
1047 * If you feed it SACKs, it will eat them.
1048 *
1049 * If you give it big chunks, it will fragment them.
1050 *
1051 * It assigns TSN's to data chunks.  This happens at the last possible
1052 * instant before transmission.
1053 *
1054 * When free()'d, it empties itself out via output_handler().
1055 */
1056struct sctp_outq {
1057	struct sctp_association *asoc;
1058
1059	/* Data pending that has never been transmitted.  */
1060	struct list_head out_chunk_list;
1061
1062	/* Stream scheduler being used */
1063	struct sctp_sched_ops *sched;
1064
1065	unsigned int out_qlen;	/* Total length of queued data chunks. */
1066
1067	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1068	unsigned int error;
1069
1070	/* These are control chunks we want to send.  */
1071	struct list_head control_chunk_list;
1072
1073	/* These are chunks that have been sacked but are above the
1074	 * CTSN, or cumulative tsn ack point.
1075	 */
1076	struct list_head sacked;
1077
1078	/* Put chunks on this list to schedule them for
1079	 * retransmission.
1080	 */
1081	struct list_head retransmit;
1082
1083	/* Put chunks on this list to save them for FWD TSN processing as
1084	 * they were abandoned.
1085	 */
1086	struct list_head abandoned;
1087
1088	/* How many unackd bytes do we have in-flight?	*/
1089	__u32 outstanding_bytes;
1090
1091	/* Are we doing fast-rtx on this queue */
1092	char fast_rtx;
1093
1094	/* Corked? */
1095	char cork;
1096};
1097
1098void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1099void sctp_outq_teardown(struct sctp_outq *);
1100void sctp_outq_free(struct sctp_outq*);
1101void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1102int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1103int sctp_outq_is_empty(const struct sctp_outq *);
1104void sctp_outq_restart(struct sctp_outq *);
1105
1106void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1107		     enum sctp_retransmit_reason reason);
1108void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1109void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1110void sctp_prsctp_prune(struct sctp_association *asoc,
1111		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1112void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1113/* Uncork and flush an outqueue.  */
1114static inline void sctp_outq_cork(struct sctp_outq *q)
1115{
1116	q->cork = 1;
1117}
1118
1119/* SCTP skb control block.
1120 * sctp_input_cb is currently used on rx and sock rx queue
1121 */
1122struct sctp_input_cb {
1123	union {
1124		struct inet_skb_parm	h4;
1125#if IS_ENABLED(CONFIG_IPV6)
1126		struct inet6_skb_parm	h6;
1127#endif
1128	} header;
1129	struct sctp_chunk *chunk;
1130	struct sctp_af *af;
1131};
1132#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1133
1134struct sctp_output_cb {
1135	struct sk_buff *last;
1136};
1137#define SCTP_OUTPUT_CB(__skb)	((struct sctp_output_cb *)&((__skb)->cb[0]))
1138
1139static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1140{
1141	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1142
1143	return chunk->head_skb ? : skb;
1144}
1145
1146/* These bind address data fields common between endpoints and associations */
1147struct sctp_bind_addr {
1148
1149	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1150	 *
1151	 * SCTP Port:	The local SCTP port number the endpoint is
1152	 *		bound to.
1153	 */
1154	__u16 port;
1155
1156	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1157	 *
1158	 * Address List: The list of IP addresses that this instance
1159	 *	has bound.  This information is passed to one's
1160	 *	peer(s) in INIT and INIT ACK chunks.
1161	 */
1162	struct list_head address_list;
1163};
1164
1165void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1166void sctp_bind_addr_free(struct sctp_bind_addr *);
1167int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1168			const struct sctp_bind_addr *src,
1169			enum sctp_scope scope, gfp_t gfp,
1170			int flags);
1171int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1172			const struct sctp_bind_addr *src,
1173			gfp_t gfp);
1174int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1175		       int new_size, __u8 addr_state, gfp_t gfp);
1176int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1177int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1178			 struct sctp_sock *);
1179int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1180			 struct sctp_sock *, struct sctp_sock *);
1181int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1182			 const union sctp_addr *addr);
1183int sctp_bind_addrs_check(struct sctp_sock *sp,
1184			  struct sctp_sock *sp2, int cnt2);
1185union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1186					const union sctp_addr	*addrs,
1187					int			addrcnt,
1188					struct sctp_sock	*opt);
1189union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1190					 int *addrs_len,
1191					 gfp_t gfp);
1192int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1193			   __u16 port, gfp_t gfp);
1194
1195enum sctp_scope sctp_scope(const union sctp_addr *addr);
1196int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1197		  const enum sctp_scope scope);
1198int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1199int sctp_is_ep_boundall(struct sock *sk);
1200
1201
1202/* What type of endpoint?  */
1203enum sctp_endpoint_type {
1204	SCTP_EP_TYPE_SOCKET,
1205	SCTP_EP_TYPE_ASSOCIATION,
1206};
1207
1208/*
1209 * A common base class to bridge the implmentation view of a
1210 * socket (usually listening) endpoint versus an association's
1211 * local endpoint.
1212 * This common structure is useful for several purposes:
1213 *   1) Common interface for lookup routines.
1214 *	a) Subfunctions work for either endpoint or association
1215 *	b) Single interface to lookup allows hiding the lookup lock rather
1216 *	   than acquiring it externally.
1217 *   2) Common interface for the inbound chunk handling/state machine.
1218 *   3) Common object handling routines for reference counting, etc.
1219 *   4) Disentangle association lookup from endpoint lookup, where we
1220 *	do not have to find our endpoint to find our association.
1221 *
1222 */
1223
1224struct sctp_ep_common {
1225	/* Fields to help us manage our entries in the hash tables. */
1226	struct hlist_node node;
1227	int hashent;
1228
1229	/* Runtime type information.  What kind of endpoint is this? */
1230	enum sctp_endpoint_type type;
1231
1232	/* Some fields to help us manage this object.
1233	 *   refcnt   - Reference count access to this object.
1234	 *   dead     - Do not attempt to use this object.
1235	 */
1236	refcount_t    refcnt;
1237	bool	    dead;
1238
1239	/* What socket does this endpoint belong to?  */
1240	struct sock *sk;
1241
1242	/* This is where we receive inbound chunks.  */
1243	struct sctp_inq	  inqueue;
1244
1245	/* This substructure includes the defining parameters of the
1246	 * endpoint:
1247	 * bind_addr.port is our shared port number.
1248	 * bind_addr.address_list is our set of local IP addresses.
1249	 */
1250	struct sctp_bind_addr bind_addr;
1251};
1252
1253
1254/* RFC Section 1.4 Key Terms
1255 *
1256 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1257 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1258 *   combination of a set of eligible destination transport addresses to
1259 *   which SCTP packets can be sent and a set of eligible source
1260 *   transport addresses from which SCTP packets can be received.
1261 *   All transport addresses used by an SCTP endpoint must use the
1262 *   same port number, but can use multiple IP addresses. A transport
1263 *   address used by an SCTP endpoint must not be used by another
1264 *   SCTP endpoint. In other words, a transport address is unique
1265 *   to an SCTP endpoint.
1266 *
1267 * From an implementation perspective, each socket has one of these.
1268 * A TCP-style socket will have exactly one association on one of
1269 * these.  An UDP-style socket will have multiple associations hanging
1270 * off one of these.
1271 */
1272
1273struct sctp_endpoint {
1274	/* Common substructure for endpoint and association. */
1275	struct sctp_ep_common base;
1276
1277	/* Associations: A list of current associations and mappings
1278	 *	      to the data consumers for each association. This
1279	 *	      may be in the form of a hash table or other
1280	 *	      implementation dependent structure. The data
1281	 *	      consumers may be process identification
1282	 *	      information such as file descriptors, named pipe
1283	 *	      pointer, or table pointers dependent on how SCTP
1284	 *	      is implemented.
1285	 */
1286	/* This is really a list of struct sctp_association entries. */
1287	struct list_head asocs;
1288
1289	/* Secret Key: A secret key used by this endpoint to compute
1290	 *	      the MAC.	This SHOULD be a cryptographic quality
1291	 *	      random number with a sufficient length.
1292	 *	      Discussion in [RFC1750] can be helpful in
1293	 *	      selection of the key.
1294	 */
1295	__u8 secret_key[SCTP_SECRET_SIZE];
1296
1297 	/* digest:  This is a digest of the sctp cookie.  This field is
1298 	 * 	    only used on the receive path when we try to validate
1299 	 * 	    that the cookie has not been tampered with.  We put
1300 	 * 	    this here so we pre-allocate this once and can re-use
1301 	 * 	    on every receive.
1302 	 */
1303 	__u8 *digest;
1304 
1305	/* sendbuf acct. policy.	*/
1306	__u32 sndbuf_policy;
1307
1308	/* rcvbuf acct. policy.	*/
1309	__u32 rcvbuf_policy;
1310
1311	/* SCTP AUTH: array of the HMACs that will be allocated
1312	 * we need this per association so that we don't serialize
1313	 */
1314	struct crypto_shash **auth_hmacs;
1315
1316	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1317	 struct sctp_hmac_algo_param *auth_hmacs_list;
1318
1319	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1320	struct sctp_chunks_param *auth_chunk_list;
1321
1322	/* SCTP-AUTH: endpoint shared keys */
1323	struct list_head endpoint_shared_keys;
1324	__u16 active_key_id;
1325	__u8  ecn_enable:1,
1326	      auth_enable:1,
1327	      intl_enable:1,
1328	      prsctp_enable:1,
1329	      asconf_enable:1,
1330	      reconf_enable:1;
1331
1332	__u8  strreset_enable;
1333
1334	/* Security identifiers from incoming (INIT). These are set by
1335	 * security_sctp_assoc_request(). These will only be used by
1336	 * SCTP TCP type sockets and peeled off connections as they
1337	 * cause a new socket to be generated. security_sctp_sk_clone()
1338	 * will then plug these into the new socket.
1339	 */
1340
1341	u32 secid;
1342	u32 peer_secid;
1343};
1344
1345/* Recover the outter endpoint structure. */
1346static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1347{
1348	struct sctp_endpoint *ep;
1349
1350	ep = container_of(base, struct sctp_endpoint, base);
1351	return ep;
1352}
1353
1354/* These are function signatures for manipulating endpoints.  */
1355struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1356void sctp_endpoint_free(struct sctp_endpoint *);
1357void sctp_endpoint_put(struct sctp_endpoint *);
1358void sctp_endpoint_hold(struct sctp_endpoint *);
1359void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1360struct sctp_association *sctp_endpoint_lookup_assoc(
1361	const struct sctp_endpoint *ep,
1362	const union sctp_addr *paddr,
1363	struct sctp_transport **);
1364bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1365				 const union sctp_addr *paddr);
1366struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1367					struct net *, const union sctp_addr *);
1368bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1369			  const union sctp_addr *paddr);
1370
1371int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1372		     const struct sctp_association *asoc,
1373		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1374		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1375int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1376		      const union sctp_addr *peer,
1377		      struct sctp_init_chunk *init, gfp_t gfp);
1378__u32 sctp_generate_tag(const struct sctp_endpoint *);
1379__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1380
1381struct sctp_inithdr_host {
1382	__u32 init_tag;
1383	__u32 a_rwnd;
1384	__u16 num_outbound_streams;
1385	__u16 num_inbound_streams;
1386	__u32 initial_tsn;
1387};
1388
1389struct sctp_stream_priorities {
1390	/* List of priorities scheduled */
1391	struct list_head prio_sched;
1392	/* List of streams scheduled */
1393	struct list_head active;
1394	/* The next stream stream in line */
1395	struct sctp_stream_out_ext *next;
1396	__u16 prio;
1397};
1398
1399struct sctp_stream_out_ext {
1400	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1401	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1402	struct list_head outq; /* chunks enqueued by this stream */
1403	union {
1404		struct {
1405			/* Scheduled streams list */
1406			struct list_head prio_list;
1407			struct sctp_stream_priorities *prio_head;
1408		};
1409		/* Fields used by RR scheduler */
1410		struct {
1411			struct list_head rr_list;
1412		};
1413	};
1414};
1415
1416struct sctp_stream_out {
1417	union {
1418		__u32 mid;
1419		__u16 ssn;
1420	};
1421	__u32 mid_uo;
1422	struct sctp_stream_out_ext *ext;
1423	__u8 state;
1424};
1425
1426struct sctp_stream_in {
1427	union {
1428		__u32 mid;
1429		__u16 ssn;
1430	};
1431	__u32 mid_uo;
1432	__u32 fsn;
1433	__u32 fsn_uo;
1434	char pd_mode;
1435	char pd_mode_uo;
1436};
1437
1438struct sctp_stream {
1439	GENRADIX(struct sctp_stream_out) out;
1440	GENRADIX(struct sctp_stream_in)	in;
1441
1442	__u16 outcnt;
1443	__u16 incnt;
1444	/* Current stream being sent, if any */
1445	struct sctp_stream_out *out_curr;
1446	union {
1447		/* Fields used by priority scheduler */
1448		struct {
1449			/* List of priorities scheduled */
1450			struct list_head prio_list;
1451		};
1452		/* Fields used by RR scheduler */
1453		struct {
1454			/* List of streams scheduled */
1455			struct list_head rr_list;
1456			/* The next stream stream in line */
1457			struct sctp_stream_out_ext *rr_next;
1458		};
1459	};
1460	struct sctp_stream_interleave *si;
1461};
1462
1463static inline struct sctp_stream_out *sctp_stream_out(
1464	struct sctp_stream *stream,
1465	__u16 sid)
1466{
1467	return genradix_ptr(&stream->out, sid);
1468}
1469
1470static inline struct sctp_stream_in *sctp_stream_in(
1471	struct sctp_stream *stream,
1472	__u16 sid)
1473{
1474	return genradix_ptr(&stream->in, sid);
1475}
1476
1477#define SCTP_SO(s, i) sctp_stream_out((s), (i))
1478#define SCTP_SI(s, i) sctp_stream_in((s), (i))
1479
1480#define SCTP_STREAM_CLOSED		0x00
1481#define SCTP_STREAM_OPEN		0x01
1482
1483static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1484{
1485	return stream->si->data_chunk_len;
1486}
1487
1488static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1489{
1490	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1491}
1492
1493static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1494{
1495	return stream->si->ftsn_chunk_len;
1496}
1497
1498static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1499{
1500	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1501}
1502
1503/* SCTP_GET_ASSOC_STATS counters */
1504struct sctp_priv_assoc_stats {
1505	/* Maximum observed rto in the association during subsequent
1506	 * observations. Value is set to 0 if no RTO measurement took place
1507	 * The transport where the max_rto was observed is returned in
1508	 * obs_rto_ipaddr
1509	 */
1510	struct sockaddr_storage obs_rto_ipaddr;
1511	__u64 max_obs_rto;
1512	/* Total In and Out SACKs received and sent */
1513	__u64 isacks;
1514	__u64 osacks;
1515	/* Total In and Out packets received and sent */
1516	__u64 opackets;
1517	__u64 ipackets;
1518	/* Total retransmitted chunks */
1519	__u64 rtxchunks;
1520	/* TSN received > next expected */
1521	__u64 outofseqtsns;
1522	/* Duplicate Chunks received */
1523	__u64 idupchunks;
1524	/* Gap Ack Blocks received */
1525	__u64 gapcnt;
1526	/* Unordered data chunks sent and received */
1527	__u64 ouodchunks;
1528	__u64 iuodchunks;
1529	/* Ordered data chunks sent and received */
1530	__u64 oodchunks;
1531	__u64 iodchunks;
1532	/* Control chunks sent and received */
1533	__u64 octrlchunks;
1534	__u64 ictrlchunks;
1535};
1536
1537/* RFC2960
1538 *
1539 * 12. Recommended Transmission Control Block (TCB) Parameters
1540 *
1541 * This section details a recommended set of parameters that should
1542 * be contained within the TCB for an implementation. This section is
1543 * for illustrative purposes and should not be deemed as requirements
1544 * on an implementation or as an exhaustive list of all parameters
1545 * inside an SCTP TCB. Each implementation may need its own additional
1546 * parameters for optimization.
1547 */
1548
1549
1550/* Here we have information about each individual association. */
1551struct sctp_association {
1552
1553	/* A base structure common to endpoint and association.
1554	 * In this context, it represents the associations's view
1555	 * of the local endpoint of the association.
1556	 */
1557	struct sctp_ep_common base;
1558
1559	/* Associations on the same socket. */
1560	struct list_head asocs;
1561
1562	/* association id. */
1563	sctp_assoc_t assoc_id;
1564
1565	/* This is our parent endpoint.	 */
1566	struct sctp_endpoint *ep;
1567
1568	/* These are those association elements needed in the cookie.  */
1569	struct sctp_cookie c;
1570
1571	/* This is all information about our peer.  */
1572	struct {
1573		/* transport_addr_list
1574		 *
1575		 * Peer	       : A list of SCTP transport addresses that the
1576		 * Transport   : peer is bound to. This information is derived
1577		 * Address     : from the INIT or INIT ACK and is used to
1578		 * List	       : associate an inbound packet with a given
1579		 *	       : association. Normally this information is
1580		 *	       : hashed or keyed for quick lookup and access
1581		 *	       : of the TCB.
1582		 *	       : The list is also initialized with the list
1583		 *	       : of addresses passed with the sctp_connectx()
1584		 *	       : call.
1585		 *
1586		 * It is a list of SCTP_transport's.
1587		 */
1588		struct list_head transport_addr_list;
1589
1590		/* rwnd
1591		 *
1592		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1593		 */
1594		__u32 rwnd;
1595
1596		/* transport_count
1597		 *
1598		 * Peer        : A count of the number of peer addresses
1599		 * Transport   : in the Peer Transport Address List.
1600		 * Address     :
1601		 * Count       :
1602		 */
1603		__u16 transport_count;
1604
1605		/* port
1606		 *   The transport layer port number.
1607		 */
1608		__u16 port;
1609
1610		/* primary_path
1611		 *
1612		 * Primary     : This is the current primary destination
1613		 * Path	       : transport address of the peer endpoint.  It
1614		 *	       : may also specify a source transport address
1615		 *	       : on this endpoint.
1616		 *
1617		 * All of these paths live on transport_addr_list.
1618		 *
1619		 * At the bakeoffs, we discovered that the intent of
1620		 * primaryPath is that it only changes when the ULP
1621		 * asks to have it changed.  We add the activePath to
1622		 * designate the connection we are currently using to
1623		 * transmit new data and most control chunks.
1624		 */
1625		struct sctp_transport *primary_path;
1626
1627		/* Cache the primary path address here, when we
1628		 * need a an address for msg_name.
1629		 */
1630		union sctp_addr primary_addr;
1631
1632		/* active_path
1633		 *   The path that we are currently using to
1634		 *   transmit new data and most control chunks.
1635		 */
1636		struct sctp_transport *active_path;
1637
1638		/* retran_path
1639		 *
1640		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1641		 * ...
1642		 * Furthermore, when its peer is multi-homed, an
1643		 * endpoint SHOULD try to retransmit a chunk to an
1644		 * active destination transport address that is
1645		 * different from the last destination address to
1646		 * which the DATA chunk was sent.
1647		 */
1648		struct sctp_transport *retran_path;
1649
1650		/* Pointer to last transport I have sent on.  */
1651		struct sctp_transport *last_sent_to;
1652
1653		/* This is the last transport I have received DATA on.	*/
1654		struct sctp_transport *last_data_from;
1655
1656		/*
1657		 * Mapping  An array of bits or bytes indicating which out of
1658		 * Array    order TSN's have been received (relative to the
1659		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1660		 *	    order packets have been received, this array
1661		 *	    will be set to all zero. This structure may be
1662		 *	    in the form of a circular buffer or bit array.
1663		 *
1664		 * Last Rcvd   : This is the last TSN received in
1665		 * TSN	       : sequence. This value is set initially by
1666		 *	       : taking the peer's Initial TSN, received in
1667		 *	       : the INIT or INIT ACK chunk, and subtracting
1668		 *	       : one from it.
1669		 *
1670		 * Throughout most of the specification this is called the
1671		 * "Cumulative TSN ACK Point".	In this case, we
1672		 * ignore the advice in 12.2 in favour of the term
1673		 * used in the bulk of the text.  This value is hidden
1674		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1675		 */
1676		struct sctp_tsnmap tsn_map;
1677
1678		/* This mask is used to disable sending the ASCONF chunk
1679		 * with specified parameter to peer.
1680		 */
1681		__be16 addip_disabled_mask;
1682
1683		/* These are capabilities which our peer advertised.  */
1684		__u16	ecn_capable:1,      /* Can peer do ECN? */
1685			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1686			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1687			hostname_address:1, /* Peer understands DNS addresses? */
1688			asconf_capable:1,   /* Does peer support ADDIP? */
1689			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1690			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1691			intl_capable:1,     /* Can peer do INTERLEAVE */
1692			auth_capable:1,     /* Is peer doing SCTP-AUTH? */
1693			/* sack_needed:
1694			 *   This flag indicates if the next received
1695			 *   packet is to be responded to with a
1696			 *   SACK. This is initialized to 0.  When a packet
1697			 *   is received sack_cnt is incremented. If this value
1698			 *   reaches 2 or more, a SACK is sent and the
1699			 *   value is reset to 0. Note: This is used only
1700			 *   when no DATA chunks are received out of
1701			 *   order.  When DATA chunks are out of order,
1702			 *   SACK's are not delayed (see Section 6).
1703			 */
1704			sack_needed:1,     /* Do we need to sack the peer? */
1705			sack_generation:1,
1706			zero_window_announced:1;
1707
1708		__u32	sack_cnt;
1709
1710		__u32   adaptation_ind;	 /* Adaptation Code point. */
1711
1712		struct sctp_inithdr_host i;
1713		void *cookie;
1714		int cookie_len;
1715
1716		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1717		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1718		 * Initial TSN Value minus 1
1719		 */
1720		__u32 addip_serial;
1721
1722		/* SCTP-AUTH: We need to know pears random number, hmac list
1723		 * and authenticated chunk list.  All that is part of the
1724		 * cookie and these are just pointers to those locations
1725		 */
1726		struct sctp_random_param *peer_random;
1727		struct sctp_chunks_param *peer_chunks;
1728		struct sctp_hmac_algo_param *peer_hmacs;
1729	} peer;
1730
1731	/* State       : A state variable indicating what state the
1732	 *	       : association is in, i.e. COOKIE-WAIT,
1733	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1734	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1735	 *
1736	 *		Note: No "CLOSED" state is illustrated since if a
1737	 *		association is "CLOSED" its TCB SHOULD be removed.
1738	 *
1739	 *		In this implementation we DO have a CLOSED
1740	 *		state which is used during initiation and shutdown.
1741	 *
1742	 *		State takes values from SCTP_STATE_*.
1743	 */
1744	enum sctp_state state;
1745
1746	/* Overall     : The overall association error count.
1747	 * Error Count : [Clear this any time I get something.]
1748	 */
1749	int overall_error_count;
1750
1751	/* The cookie life I award for any cookie.  */
1752	ktime_t cookie_life;
1753
1754	/* These are the association's initial, max, and min RTO values.
1755	 * These values will be initialized by system defaults, but can
1756	 * be modified via the SCTP_RTOINFO socket option.
1757	 */
1758	unsigned long rto_initial;
1759	unsigned long rto_max;
1760	unsigned long rto_min;
1761
1762	/* Maximum number of new data packets that can be sent in a burst.  */
1763	int max_burst;
1764
1765	/* This is the max_retrans value for the association.  This value will
1766	 * be initialized initialized from system defaults, but can be
1767	 * modified by the SCTP_ASSOCINFO socket option.
1768	 */
1769	int max_retrans;
1770
1771	/* This is the partially failed retrans value for the transport
1772	 * and will be initialized from the assocs value.  This can be
1773	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1774	 */
1775	int pf_retrans;
1776
1777	/* Maximum number of times the endpoint will retransmit INIT  */
1778	__u16 max_init_attempts;
1779
1780	/* How many times have we resent an INIT? */
1781	__u16 init_retries;
1782
1783	/* The largest timeout or RTO value to use in attempting an INIT */
1784	unsigned long max_init_timeo;
1785
1786	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1787	 * the destination address every heartbeat interval. This value
1788	 * will be inherited by all new transports.
1789	 */
1790	unsigned long hbinterval;
1791
1792	/* This is the max_retrans value for new transports in the
1793	 * association.
1794	 */
1795	__u16 pathmaxrxt;
1796
1797	__u32 flowlabel;
1798	__u8  dscp;
1799
1800	/* Flag that path mtu update is pending */
1801	__u8   pmtu_pending;
1802
1803	/* Association : The smallest PMTU discovered for all of the
1804	 * PMTU	       : peer's transport addresses.
1805	 */
1806	__u32 pathmtu;
1807
1808	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1809	__u32 param_flags;
1810
1811	__u32 sackfreq;
1812	/* SACK delay timeout */
1813	unsigned long sackdelay;
1814
1815	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1816	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1817
1818	/* Transport to which SHUTDOWN chunk was last sent.  */
1819	struct sctp_transport *shutdown_last_sent_to;
1820
1821	/* Transport to which INIT chunk was last sent.  */
1822	struct sctp_transport *init_last_sent_to;
1823
1824	/* How many times have we resent a SHUTDOWN */
1825	int shutdown_retries;
1826
1827	/* Next TSN    : The next TSN number to be assigned to a new
1828	 *	       : DATA chunk.  This is sent in the INIT or INIT
1829	 *	       : ACK chunk to the peer and incremented each
1830	 *	       : time a DATA chunk is assigned a TSN
1831	 *	       : (normally just prior to transmit or during
1832	 *	       : fragmentation).
1833	 */
1834	__u32 next_tsn;
1835
1836	/*
1837	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1838	 * TSN	       : is set initially by taking the peer's Initial TSN,
1839	 *	       : received in the INIT or INIT ACK chunk, and
1840	 *	       : subtracting one from it.
1841	 *
1842	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1843	 */
1844
1845	__u32 ctsn_ack_point;
1846
1847	/* PR-SCTP Advanced.Peer.Ack.Point */
1848	__u32 adv_peer_ack_point;
1849
1850	/* Highest TSN that is acknowledged by incoming SACKs. */
1851	__u32 highest_sacked;
1852
1853	/* TSN marking the fast recovery exit point */
1854	__u32 fast_recovery_exit;
1855
1856	/* Flag to track the current fast recovery state */
1857	__u8 fast_recovery;
1858
1859	/* The number of unacknowledged data chunks.  Reported through
1860	 * the SCTP_STATUS sockopt.
1861	 */
1862	__u16 unack_data;
1863
1864	/* The total number of data chunks that we've had to retransmit
1865	 * as the result of a T3 timer expiration
1866	 */
1867	__u32 rtx_data_chunks;
1868
1869	/* This is the association's receive buffer space.  This value is used
1870	 * to set a_rwnd field in an INIT or a SACK chunk.
1871	 */
1872	__u32 rwnd;
1873
1874	/* This is the last advertised value of rwnd over a SACK chunk. */
1875	__u32 a_rwnd;
1876
1877	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1878	 * to slop over a maximum of the association's frag_point.
1879	 */
1880	__u32 rwnd_over;
1881
1882	/* Keeps treack of rwnd pressure.  This happens when we have
1883	 * a window, but not recevie buffer (i.e small packets).  This one
1884	 * is releases slowly (1 PMTU at a time ).
1885	 */
1886	__u32 rwnd_press;
1887
1888	/* This is the sndbuf size in use for the association.
1889	 * This corresponds to the sndbuf size for the association,
1890	 * as specified in the sk->sndbuf.
1891	 */
1892	int sndbuf_used;
1893
1894	/* This is the amount of memory that this association has allocated
1895	 * in the receive path at any given time.
1896	 */
1897	atomic_t rmem_alloc;
1898
1899	/* This is the wait queue head for send requests waiting on
1900	 * the association sndbuf space.
1901	 */
1902	wait_queue_head_t	wait;
1903
1904	/* The message size at which SCTP fragmentation will occur. */
1905	__u32 frag_point;
1906	__u32 user_frag;
1907
1908	/* Counter used to count INIT errors. */
1909	int init_err_counter;
1910
1911	/* Count the number of INIT cycles (for doubling timeout). */
1912	int init_cycle;
1913
1914	/* Default send parameters. */
1915	__u16 default_stream;
1916	__u16 default_flags;
1917	__u32 default_ppid;
1918	__u32 default_context;
1919	__u32 default_timetolive;
1920
1921	/* Default receive parameters */
1922	__u32 default_rcv_context;
1923
1924	/* Stream arrays */
1925	struct sctp_stream stream;
1926
1927	/* All outbound chunks go through this structure.  */
1928	struct sctp_outq outqueue;
1929
1930	/* A smart pipe that will handle reordering and fragmentation,
1931	 * as well as handle passing events up to the ULP.
1932	 */
1933	struct sctp_ulpq ulpq;
1934
1935	/* Last TSN that caused an ECNE Chunk to be sent.  */
1936	__u32 last_ecne_tsn;
1937
1938	/* Last TSN that caused a CWR Chunk to be sent.	 */
1939	__u32 last_cwr_tsn;
1940
1941	/* How many duplicated TSNs have we seen?  */
1942	int numduptsns;
1943
1944	/* These are to support
1945	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1946	 *  and Enforcement of Flow and Message Limits"
1947	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1948	 * or "ADDIP" for short.
1949	 */
1950
1951
1952
1953	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1954	 *
1955	 * R1) One and only one ASCONF Chunk MAY be in transit and
1956	 * unacknowledged at any one time.  If a sender, after sending
1957	 * an ASCONF chunk, decides it needs to transfer another
1958	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1959	 * returns from the previous ASCONF Chunk before sending a
1960	 * subsequent ASCONF. Note this restriction binds each side,
1961	 * so at any time two ASCONF may be in-transit on any given
1962	 * association (one sent from each endpoint).
1963	 *
1964	 * [This is our one-and-only-one ASCONF in flight.  If we do
1965	 * not have an ASCONF in flight, this is NULL.]
1966	 */
1967	struct sctp_chunk *addip_last_asconf;
1968
1969	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1970	 *
1971	 * This is needed to implement itmes E1 - E4 of the updated
1972	 * spec.  Here is the justification:
1973	 *
1974	 * Since the peer may bundle multiple ASCONF chunks toward us,
1975	 * we now need the ability to cache multiple ACKs.  The section
1976	 * describes in detail how they are cached and cleaned up.
1977	 */
1978	struct list_head asconf_ack_list;
1979
1980	/* These ASCONF chunks are waiting to be sent.
1981	 *
1982	 * These chunaks can't be pushed to outqueue until receiving
1983	 * ASCONF_ACK for the previous ASCONF indicated by
1984	 * addip_last_asconf, so as to guarantee that only one ASCONF
1985	 * is in flight at any time.
1986	 *
1987	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1988	 *
1989	 * In defining the ASCONF Chunk transfer procedures, it is
1990	 * essential that these transfers MUST NOT cause congestion
1991	 * within the network.	To achieve this, we place these
1992	 * restrictions on the transfer of ASCONF Chunks:
1993	 *
1994	 * R1) One and only one ASCONF Chunk MAY be in transit and
1995	 * unacknowledged at any one time.  If a sender, after sending
1996	 * an ASCONF chunk, decides it needs to transfer another
1997	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1998	 * returns from the previous ASCONF Chunk before sending a
1999	 * subsequent ASCONF. Note this restriction binds each side,
2000	 * so at any time two ASCONF may be in-transit on any given
2001	 * association (one sent from each endpoint).
2002	 *
2003	 *
2004	 * [I really think this is EXACTLY the sort of intelligence
2005	 *  which already resides in sctp_outq.	 Please move this
2006	 *  queue and its supporting logic down there.	--piggy]
2007	 */
2008	struct list_head addip_chunk_list;
2009
2010	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2011	 *
2012	 * A2) A serial number should be assigned to the Chunk. The
2013	 * serial number SHOULD be a monotonically increasing
2014	 * number. The serial number SHOULD be initialized at
2015	 * the start of the association to the same value as the
2016	 * Initial TSN and every time a new ASCONF chunk is created
2017	 * it is incremented by one after assigning the serial number
2018	 * to the newly created chunk.
2019	 *
2020	 * ADDIP
2021	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2022	 *
2023	 * Serial Number : 32 bits (unsigned integer)
2024	 *
2025	 * This value represents a Serial Number for the ASCONF
2026	 * Chunk. The valid range of Serial Number is from 0 to
2027	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2028	 * after reaching 4294967295.
2029	 */
2030	__u32 addip_serial;
2031	int src_out_of_asoc_ok;
2032	union sctp_addr *asconf_addr_del_pending;
2033	struct sctp_transport *new_transport;
2034
2035	/* SCTP AUTH: list of the endpoint shared keys.  These
2036	 * keys are provided out of band by the user applicaton
2037	 * and can't change during the lifetime of the association
2038	 */
2039	struct list_head endpoint_shared_keys;
2040
2041	/* SCTP AUTH:
2042	 * The current generated assocaition shared key (secret)
2043	 */
2044	struct sctp_auth_bytes *asoc_shared_key;
2045	struct sctp_shared_key *shkey;
2046
2047	/* SCTP AUTH: hmac id of the first peer requested algorithm
2048	 * that we support.
2049	 */
2050	__u16 default_hmac_id;
2051
2052	__u16 active_key_id;
2053
2054	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2055	     temp:1,		/* Is it a temporary association? */
2056	     force_delay:1;
2057
2058	__u8 strreset_enable;
2059	__u8 strreset_outstanding; /* request param count on the fly */
2060
2061	__u32 strreset_outseq; /* Update after receiving response */
2062	__u32 strreset_inseq; /* Update after receiving request */
2063	__u32 strreset_result[2]; /* save the results of last 2 responses */
2064
2065	struct sctp_chunk *strreset_chunk; /* save request chunk */
2066
2067	struct sctp_priv_assoc_stats stats;
2068
2069	int sent_cnt_removable;
2070
2071	__u16 subscribe;
2072
2073	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2074	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2075
2076	struct rcu_head rcu;
2077};
2078
2079
2080/* An eyecatcher for determining if we are really looking at an
2081 * association data structure.
2082 */
2083enum {
2084	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2085};
2086
2087/* Recover the outter association structure. */
2088static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2089{
2090	struct sctp_association *asoc;
2091
2092	asoc = container_of(base, struct sctp_association, base);
2093	return asoc;
2094}
2095
2096/* These are function signatures for manipulating associations.	 */
2097
2098
2099struct sctp_association *
2100sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2101		     enum sctp_scope scope, gfp_t gfp);
2102void sctp_association_free(struct sctp_association *);
2103void sctp_association_put(struct sctp_association *);
2104void sctp_association_hold(struct sctp_association *);
2105
2106struct sctp_transport *sctp_assoc_choose_alter_transport(
2107	struct sctp_association *, struct sctp_transport *);
2108void sctp_assoc_update_retran_path(struct sctp_association *);
2109struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2110					  const union sctp_addr *);
2111int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2112			    const union sctp_addr *laddr);
2113struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2114				     const union sctp_addr *address,
2115				     const gfp_t gfp,
2116				     const int peer_state);
2117void sctp_assoc_del_peer(struct sctp_association *asoc,
2118			 const union sctp_addr *addr);
2119void sctp_assoc_rm_peer(struct sctp_association *asoc,
2120			 struct sctp_transport *peer);
2121void sctp_assoc_control_transport(struct sctp_association *asoc,
2122				  struct sctp_transport *transport,
2123				  enum sctp_transport_cmd command,
2124				  sctp_sn_error_t error);
2125struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
 
 
 
 
2126void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2127int sctp_assoc_update(struct sctp_association *old,
2128		      struct sctp_association *new);
2129
2130__u32 sctp_association_get_next_tsn(struct sctp_association *);
2131
2132void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2133void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2134void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2135void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2136void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2137void sctp_assoc_set_primary(struct sctp_association *,
2138			    struct sctp_transport *);
2139void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2140				    struct sctp_transport *);
2141int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2142				     enum sctp_scope scope, gfp_t gfp);
2143int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2144					 struct sctp_cookie*,
2145					 gfp_t gfp);
2146int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2147void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2148struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2149					const struct sctp_association *asoc,
2150					__be32 serial);
2151void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2152
2153int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2154			const union sctp_addr *ss2);
2155struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2156
2157/* A convenience structure to parse out SCTP specific CMSGs. */
2158struct sctp_cmsgs {
2159	struct sctp_initmsg *init;
2160	struct sctp_sndrcvinfo *srinfo;
2161	struct sctp_sndinfo *sinfo;
2162	struct sctp_prinfo *prinfo;
2163	struct sctp_authinfo *authinfo;
2164	struct msghdr *addrs_msg;
2165};
2166
2167/* Structure for tracking memory objects */
2168struct sctp_dbg_objcnt_entry {
2169	char *label;
2170	atomic_t *counter;
2171};
2172
2173#endif /* __sctp_structs_h__ */