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/rhashtable.h>
  52#include <linux/socket.h>	/* linux/in.h needs this!!    */
  53#include <linux/in.h>		/* We get struct sockaddr_in. */
  54#include <linux/in6.h>		/* We get struct in6_addr     */
  55#include <linux/ipv6.h>
  56#include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
  57#include <linux/atomic.h>		/* This gets us atomic counters.  */
  58#include <linux/skbuff.h>	/* We need sk_buff_head. */
  59#include <linux/workqueue.h>	/* We need tq_struct.	 */
  60#include <linux/sctp.h>		/* We need sctp* header structs.  */
  61#include <net/sctp/auth.h>	/* We need auth specific structs */
  62#include <net/ip.h>		/* For inet_skb_parm */
  63
  64/* A convenience structure for handling sockaddr structures.
  65 * We should wean ourselves off this.
  66 */
  67union sctp_addr {
  68	struct sockaddr_in v4;
  69	struct sockaddr_in6 v6;
  70	struct sockaddr sa;
  71};
  72
  73/* Forward declarations for data structures. */
  74struct sctp_globals;
  75struct sctp_endpoint;
  76struct sctp_association;
  77struct sctp_transport;
  78struct sctp_packet;
  79struct sctp_chunk;
  80struct sctp_inq;
  81struct sctp_outq;
  82struct sctp_bind_addr;
  83struct sctp_ulpq;
  84struct sctp_ep_common;
  85struct crypto_shash;
  86struct sctp_stream;
  87
  88
  89#include <net/sctp/tsnmap.h>
  90#include <net/sctp/ulpevent.h>
  91#include <net/sctp/ulpqueue.h>
  92#include <net/sctp/stream_interleave.h>
  93
  94/* Structures useful for managing bind/connect. */
  95
  96struct sctp_bind_bucket {
  97	unsigned short	port;
  98	unsigned short	fastreuse;
  99	struct hlist_node	node;
 100	struct hlist_head	owner;
 101	struct net	*net;
 102};
 103
 104struct sctp_bind_hashbucket {
 105	spinlock_t	lock;
 106	struct hlist_head	chain;
 107};
 108
 109/* Used for hashing all associations.  */
 110struct sctp_hashbucket {
 111	rwlock_t	lock;
 112	struct hlist_head	chain;
 113} __attribute__((__aligned__(8)));
 114
 115
 116/* The SCTP globals structure. */
 117extern struct sctp_globals {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 118	/* This is a list of groups of functions for each address
 119	 * family that we support.
 120	 */
 121	struct list_head address_families;
 122
 123	/* This is the hash of all endpoints. */
 
 124	struct sctp_hashbucket *ep_hashtable;
 
 
 
 
 
 125	/* This is the sctp port control hash.	*/
 
 126	struct sctp_bind_hashbucket *port_hashtable;
 127	/* This is the hash of all transports. */
 128	struct rhltable transport_hashtable;
 129
 130	/* Sizes of above hashtables. */
 131	int ep_hashsize;
 132	int port_hashsize;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 133
 134	/* Default initialization values to be applied to new associations. */
 135	__u16 max_instreams;
 136	__u16 max_outstreams;
 
 
 
 
 
 
 
 
 
 
 
 137
 138	/* Flag to indicate whether computing and verifying checksum
 139	 * is disabled. */
 140        bool checksum_disable;
 
 
 
 
 
 141} sctp_globals;
 142
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 143#define sctp_max_instreams		(sctp_globals.max_instreams)
 144#define sctp_max_outstreams		(sctp_globals.max_outstreams)
 145#define sctp_address_families		(sctp_globals.address_families)
 146#define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
 147#define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
 
 
 148#define sctp_port_hashsize		(sctp_globals.port_hashsize)
 149#define sctp_port_hashtable		(sctp_globals.port_hashtable)
 150#define sctp_transport_hashtable	(sctp_globals.transport_hashtable)
 
 
 
 
 
 
 
 
 
 
 
 151#define sctp_checksum_disable		(sctp_globals.checksum_disable)
 
 152
 153/* SCTP Socket type: UDP or TCP style. */
 154enum sctp_socket_type {
 155	SCTP_SOCKET_UDP = 0,
 156	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
 157	SCTP_SOCKET_TCP
 158};
 159
 160/* Per socket SCTP information. */
 161struct sctp_sock {
 162	/* inet_sock has to be the first member of sctp_sock */
 163	struct inet_sock inet;
 164	/* What kind of a socket is this? */
 165	enum sctp_socket_type type;
 166
 167	/* PF_ family specific functions.  */
 168	struct sctp_pf *pf;
 169
 170	/* Access to HMAC transform. */
 171	struct crypto_shash *hmac;
 172	char *sctp_hmac_alg;
 173
 174	/* What is our base endpointer? */
 175	struct sctp_endpoint *ep;
 176
 177	struct sctp_bind_bucket *bind_hash;
 178	/* Various Socket Options.  */
 179	__u16 default_stream;
 180	__u32 default_ppid;
 181	__u16 default_flags;
 182	__u32 default_context;
 183	__u32 default_timetolive;
 184	__u32 default_rcv_context;
 185	int max_burst;
 186
 187	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 188	 * the destination address every heartbeat interval. This value
 189	 * will be inherited by all new associations.
 190	 */
 191	__u32 hbinterval;
 192
 193	/* This is the max_retrans value for new associations. */
 194	__u16 pathmaxrxt;
 195
 196	/* The initial Path MTU to use for new associations. */
 197	__u32 pathmtu;
 198
 199	/* The default SACK delay timeout for new associations. */
 200	__u32 sackdelay;
 201	__u32 sackfreq;
 202
 203	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 204	__u32 param_flags;
 205
 
 206	struct sctp_rtoinfo rtoinfo;
 207	struct sctp_paddrparams paddrparam;
 208	struct sctp_assocparams assocparams;
 209
 210	/*
 211	 * These two structures must be grouped together for the usercopy
 212	 * whitelist region.
 213	 */
 214	struct sctp_event_subscribe subscribe;
 215	struct sctp_initmsg initmsg;
 216
 217	int user_frag;
 218
 219	__u32 autoclose;
 
 
 
 
 220	__u32 adaptation_ind;
 221	__u32 pd_point;
 222	__u16	nodelay:1,
 223		disable_fragments:1,
 224		v4mapped:1,
 225		frag_interleave:1,
 226		strm_interleave:1,
 227		recvrcvinfo:1,
 228		recvnxtinfo:1,
 229		data_ready_signalled:1;
 230
 231	atomic_t pd_mode;
 232	/* Receive to here while partial delivery is in effect. */
 233	struct sk_buff_head pd_lobby;
 234
 235	/* These must be the last fields, as they will skipped on copies,
 236	 * like on accept and peeloff operations
 237	 */
 238	struct list_head auto_asconf_list;
 239	int do_auto_asconf;
 240};
 241
 242static inline struct sctp_sock *sctp_sk(const struct sock *sk)
 243{
 244       return (struct sctp_sock *)sk;
 245}
 246
 247static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
 248{
 249       return (struct sock *)sp;
 250}
 251
 252#if IS_ENABLED(CONFIG_IPV6)
 253struct sctp6_sock {
 254       struct sctp_sock  sctp;
 255       struct ipv6_pinfo inet6;
 256};
 257#endif /* CONFIG_IPV6 */
 258
 259
 260/* This is our APPLICATION-SPECIFIC state cookie.
 261 * THIS IS NOT DICTATED BY THE SPECIFICATION.
 262 */
 263/* These are the parts of an association which we send in the cookie.
 264 * Most of these are straight out of:
 265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
 266 *
 267 */
 268
 269struct sctp_cookie {
 270
 271	/* My	       : Tag expected in every inbound packet and sent
 272	 * Verification: in the INIT or INIT ACK chunk.
 273	 * Tag	       :
 274	 */
 275	__u32 my_vtag;
 276
 277	/* Peer's      : Tag expected in every outbound packet except
 278	 * Verification: in the INIT chunk.
 279	 * Tag	       :
 280	 */
 281	__u32 peer_vtag;
 282
 283	/* The rest of these are not from the spec, but really need to
 284	 * be in the cookie.
 285	 */
 286
 287	/* My Tie Tag  : Assist in discovering a restarting association. */
 288	__u32 my_ttag;
 289
 290	/* Peer's Tie Tag: Assist in discovering a restarting association. */
 291	__u32 peer_ttag;
 292
 293	/* When does this cookie expire? */
 294	ktime_t expiration;
 295
 296	/* Number of inbound/outbound streams which are set
 297	 * and negotiated during the INIT process.
 298	 */
 299	__u16 sinit_num_ostreams;
 300	__u16 sinit_max_instreams;
 301
 302	/* This is the first sequence number I used.  */
 303	__u32 initial_tsn;
 304
 305	/* This holds the originating address of the INIT packet.  */
 306	union sctp_addr peer_addr;
 307
 308	/* IG Section 2.35.3 
 309	 * Include the source port of the INIT-ACK
 310	 */
 311	__u16		my_port;
 312
 313	__u8 prsctp_capable;
 314
 315	/* Padding for future use */
 316	__u8 padding;  		
 317
 318	__u32 adaptation_ind;
 319
 320	__u8 auth_random[sizeof(struct sctp_paramhdr) +
 321			 SCTP_AUTH_RANDOM_LENGTH];
 322	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
 323	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
 324
 325	/* This is a shim for my peer's INIT packet, followed by
 326	 * a copy of the raw address list of the association.
 327	 * The length of the raw address list is saved in the
 328	 * raw_addr_list_len field, which will be used at the time when
 329	 * the association TCB is re-constructed from the cookie.
 330	 */
 331	__u32 raw_addr_list_len;
 332	struct sctp_init_chunk peer_init[0];
 333};
 334
 335
 336/* The format of our cookie that we send to our peer. */
 337struct sctp_signed_cookie {
 338	__u8 signature[SCTP_SECRET_SIZE];
 339	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
 340	struct sctp_cookie c;
 341} __packed;
 342
 343/* This is another convenience type to allocate memory for address
 344 * params for the maximum size and pass such structures around
 345 * internally.
 346 */
 347union sctp_addr_param {
 348	struct sctp_paramhdr p;
 349	struct sctp_ipv4addr_param v4;
 350	struct sctp_ipv6addr_param v6;
 351};
 352
 353/* A convenience type to allow walking through the various
 354 * parameters and avoid casting all over the place.
 355 */
 356union sctp_params {
 357	void *v;
 358	struct sctp_paramhdr *p;
 359	struct sctp_cookie_preserve_param *life;
 360	struct sctp_hostname_param *dns;
 361	struct sctp_cookie_param *cookie;
 362	struct sctp_supported_addrs_param *sat;
 363	struct sctp_ipv4addr_param *v4;
 364	struct sctp_ipv6addr_param *v6;
 365	union sctp_addr_param *addr;
 366	struct sctp_adaptation_ind_param *aind;
 367	struct sctp_supported_ext_param *ext;
 368	struct sctp_random_param *random;
 369	struct sctp_chunks_param *chunks;
 370	struct sctp_hmac_algo_param *hmac_algo;
 371	struct sctp_addip_param *addip;
 372};
 373
 374/* RFC 2960.  Section 3.3.5 Heartbeat.
 375 *    Heartbeat Information: variable length
 376 *    The Sender-specific Heartbeat Info field should normally include
 377 *    information about the sender's current time when this HEARTBEAT
 378 *    chunk is sent and the destination transport address to which this
 379 *    HEARTBEAT is sent (see Section 8.3).
 380 */
 381struct sctp_sender_hb_info {
 382	struct sctp_paramhdr param_hdr;
 383	union sctp_addr daddr;
 384	unsigned long sent_at;
 385	__u64 hb_nonce;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 386};
 387
 388int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 389		     gfp_t gfp);
 390int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
 391void sctp_stream_free(struct sctp_stream *stream);
 392void sctp_stream_clear(struct sctp_stream *stream);
 393void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
 394
 395/* What is the current SSN number for this stream? */
 396#define sctp_ssn_peek(stream, type, sid) \
 397	((stream)->type[sid].ssn)
 
 
 398
 399/* Return the next SSN number for this stream.	*/
 400#define sctp_ssn_next(stream, type, sid) \
 401	((stream)->type[sid].ssn++)
 
 
 402
 403/* Skip over this ssn and all below. */
 404#define sctp_ssn_skip(stream, type, sid, ssn) \
 405	((stream)->type[sid].ssn = ssn + 1)
 406
 407/* What is the current MID number for this stream? */
 408#define sctp_mid_peek(stream, type, sid) \
 409	((stream)->type[sid].mid)
 410
 411/* Return the next MID number for this stream.  */
 412#define sctp_mid_next(stream, type, sid) \
 413	((stream)->type[sid].mid++)
 414
 415/* Skip over this mid and all below. */
 416#define sctp_mid_skip(stream, type, sid, mid) \
 417	((stream)->type[sid].mid = mid + 1)
 418
 419#define sctp_stream_in(asoc, sid) (&(asoc)->stream.in[sid])
 420
 421/* What is the current MID_uo number for this stream? */
 422#define sctp_mid_uo_peek(stream, type, sid) \
 423	((stream)->type[sid].mid_uo)
 424
 425/* Return the next MID_uo number for this stream.  */
 426#define sctp_mid_uo_next(stream, type, sid) \
 427	((stream)->type[sid].mid_uo++)
 428
 429/*
 430 * Pointers to address related SCTP functions.
 431 * (i.e. things that depend on the address family.)
 432 */
 433struct sctp_af {
 434	int		(*sctp_xmit)	(struct sk_buff *skb,
 435					 struct sctp_transport *);
 436	int		(*setsockopt)	(struct sock *sk,
 437					 int level,
 438					 int optname,
 439					 char __user *optval,
 440					 unsigned int optlen);
 441	int		(*getsockopt)	(struct sock *sk,
 442					 int level,
 443					 int optname,
 444					 char __user *optval,
 445					 int __user *optlen);
 446	int		(*compat_setsockopt)	(struct sock *sk,
 447					 int level,
 448					 int optname,
 449					 char __user *optval,
 450					 unsigned int optlen);
 451	int		(*compat_getsockopt)	(struct sock *sk,
 452					 int level,
 453					 int optname,
 454					 char __user *optval,
 455					 int __user *optlen);
 456	void		(*get_dst)	(struct sctp_transport *t,
 457					 union sctp_addr *saddr,
 458					 struct flowi *fl,
 459					 struct sock *sk);
 460	void		(*get_saddr)	(struct sctp_sock *sk,
 461					 struct sctp_transport *t,
 462					 struct flowi *fl);
 463	void		(*copy_addrlist) (struct list_head *,
 464					  struct net_device *);
 465	int		(*cmp_addr)	(const union sctp_addr *addr1,
 466					 const union sctp_addr *addr2);
 467	void		(*addr_copy)	(union sctp_addr *dst,
 468					 union sctp_addr *src);
 469	void		(*from_skb)	(union sctp_addr *,
 470					 struct sk_buff *skb,
 471					 int saddr);
 472	void		(*from_sk)	(union sctp_addr *,
 473					 struct sock *sk);
 
 
 
 
 474	void		(*from_addr_param) (union sctp_addr *,
 475					    union sctp_addr_param *,
 476					    __be16 port, int iif);
 477	int		(*to_addr_param) (const union sctp_addr *,
 478					  union sctp_addr_param *); 
 479	int		(*addr_valid)	(union sctp_addr *,
 480					 struct sctp_sock *,
 481					 const struct sk_buff *);
 482	enum sctp_scope	(*scope)(union sctp_addr *);
 483	void		(*inaddr_any)	(union sctp_addr *, __be16);
 484	int		(*is_any)	(const union sctp_addr *);
 485	int		(*available)	(union sctp_addr *,
 486					 struct sctp_sock *);
 487	int		(*skb_iif)	(const struct sk_buff *sk);
 488	int		(*is_ce)	(const struct sk_buff *sk);
 489	void		(*seq_dump_addr)(struct seq_file *seq,
 490					 union sctp_addr *addr);
 491	void		(*ecn_capable)(struct sock *sk);
 492	__u16		net_header_len;
 493	int		sockaddr_len;
 494	int		(*ip_options_len)(struct sock *sk);
 495	sa_family_t	sa_family;
 496	struct list_head list;
 497};
 498
 499struct sctp_af *sctp_get_af_specific(sa_family_t);
 500int sctp_register_af(struct sctp_af *);
 501
 502/* Protocol family functions. */
 503struct sctp_pf {
 504	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
 505	void (*skb_msgname)  (struct sk_buff *, char *, int *);
 506	int  (*af_supported) (sa_family_t, struct sctp_sock *);
 507	int  (*cmp_addr) (const union sctp_addr *,
 508			  const union sctp_addr *,
 509			  struct sctp_sock *);
 510	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
 511	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
 512	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
 513	struct sock *(*create_accept_sk) (struct sock *sk,
 514					  struct sctp_association *asoc,
 515					  bool kern);
 516	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
 517	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
 518	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
 519	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
 520	struct sctp_af *af;
 521};
 522
 523
 524/* Structure to track chunk fragments that have been acked, but peer
 525 * fragments of the same message have not.
 526 */
 527struct sctp_datamsg {
 528	/* Chunks waiting to be submitted to lower layer. */
 529	struct list_head chunks;
 530	/* Reference counting. */
 531	refcount_t refcnt;
 532	/* When is this message no longer interesting to the peer? */
 533	unsigned long expires_at;
 534	/* Did the messenge fail to send? */
 535	int send_error;
 536	u8 send_failed:1,
 537	   can_delay:1,	/* should this message be Nagle delayed */
 538	   abandoned:1;	/* should this message be abandoned */
 539};
 540
 541struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 542					    struct sctp_sndrcvinfo *,
 543					    struct iov_iter *);
 544void sctp_datamsg_free(struct sctp_datamsg *);
 545void sctp_datamsg_put(struct sctp_datamsg *);
 546void sctp_chunk_fail(struct sctp_chunk *, int error);
 547int sctp_chunk_abandoned(struct sctp_chunk *);
 548
 549/* RFC2960 1.4 Key Terms
 550 *
 551 * o Chunk: A unit of information within an SCTP packet, consisting of
 552 * a chunk header and chunk-specific content.
 553 *
 554 * As a matter of convenience, we remember the SCTP common header for
 555 * each chunk as well as a few other header pointers...
 556 */
 557struct sctp_chunk {
 558	struct list_head list;
 559
 560	refcount_t refcnt;
 561
 562	/* How many times this chunk have been sent, for prsctp RTX policy */
 563	int sent_count;
 564
 565	union {
 566		/* This is our link to the per-transport transmitted list.  */
 567		struct list_head transmitted_list;
 568		/* List in specific stream outq */
 569		struct list_head stream_list;
 570	};
 571
 572	/* This field is used by chunks that hold fragmented data.
 573	 * For the first fragment this is the list that holds the rest of
 574	 * fragments. For the remaining fragments, this is the link to the
 575	 * frag_list maintained in the first fragment.
 576	 */
 577	struct list_head frag_list;
 578
 579	/* This points to the sk_buff containing the actual data.  */
 580	struct sk_buff *skb;
 581
 582	union {
 583		/* In case of GSO packets, this will store the head one */
 584		struct sk_buff *head_skb;
 585		/* In case of auth enabled, this will point to the shkey */
 586		struct sctp_shared_key *shkey;
 587	};
 588
 589	/* These are the SCTP headers by reverse order in a packet.
 590	 * Note that some of these may happen more than once.  In that
 591	 * case, we point at the "current" one, whatever that means
 592	 * for that level of header.
 593	 */
 594
 595	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
 596	union sctp_params param_hdr;
 597	union {
 598		__u8 *v;
 599		struct sctp_datahdr *data_hdr;
 600		struct sctp_inithdr *init_hdr;
 601		struct sctp_sackhdr *sack_hdr;
 602		struct sctp_heartbeathdr *hb_hdr;
 603		struct sctp_sender_hb_info *hbs_hdr;
 604		struct sctp_shutdownhdr *shutdown_hdr;
 605		struct sctp_signed_cookie *cookie_hdr;
 606		struct sctp_ecnehdr *ecne_hdr;
 607		struct sctp_cwrhdr *ecn_cwr_hdr;
 608		struct sctp_errhdr *err_hdr;
 609		struct sctp_addiphdr *addip_hdr;
 610		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
 611		struct sctp_authhdr *auth_hdr;
 612		struct sctp_idatahdr *idata_hdr;
 613		struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
 614	} subh;
 615
 616	__u8 *chunk_end;
 617
 618	struct sctp_chunkhdr *chunk_hdr;
 619	struct sctphdr *sctp_hdr;
 620
 621	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
 622	struct sctp_sndrcvinfo sinfo;
 623
 624	/* Which association does this belong to?  */
 625	struct sctp_association *asoc;
 626
 627	/* What endpoint received this chunk? */
 628	struct sctp_ep_common *rcvr;
 629
 630	/* We fill this in if we are calculating RTT. */
 631	unsigned long sent_at;
 632
 633	/* What is the origin IP address for this chunk?  */
 634	union sctp_addr source;
 635	/* Destination address for this chunk. */
 636	union sctp_addr dest;
 637
 638	/* For outbound message, track all fragments for SEND_FAILED. */
 639	struct sctp_datamsg *msg;
 640
 641	/* For an inbound chunk, this tells us where it came from.
 642	 * For an outbound chunk, it tells us where we'd like it to
 643	 * go.	It is NULL if we have no preference.
 644	 */
 645	struct sctp_transport *transport;
 646
 647	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
 648	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
 649	 * spec violates the principle premis that all chunks are processed
 650	 * in order.
 651	 */
 652	struct sk_buff *auth_chunk;
 653
 654#define SCTP_CAN_FRTX 0x0
 655#define SCTP_NEED_FRTX 0x1
 656#define SCTP_DONT_FRTX 0x2
 657	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
 658		has_tsn:1,		/* Does this chunk have a TSN yet? */
 659		has_ssn:1,		/* Does this chunk have a SSN yet? */
 660#define has_mid has_ssn
 661		singleton:1,		/* Only chunk in the packet? */
 662		end_of_packet:1,	/* Last chunk in the packet? */
 663		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
 664		pdiscard:1,		/* Discard the whole packet now? */
 665		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
 666		data_accepted:1,	/* At least 1 chunk accepted */
 667		auth:1,			/* IN: was auth'ed | OUT: needs auth */
 668		has_asconf:1,		/* IN: have seen an asconf before */
 669		tsn_missing_report:2,	/* Data chunk missing counter. */
 670		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
 671};
 672
 673#define sctp_chunk_retransmitted(chunk)	(chunk->sent_count > 1)
 674void sctp_chunk_hold(struct sctp_chunk *);
 675void sctp_chunk_put(struct sctp_chunk *);
 676int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
 677			  struct iov_iter *from);
 678void sctp_chunk_free(struct sctp_chunk *);
 679void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
 
 680struct sctp_chunk *sctp_chunkify(struct sk_buff *,
 681				 const struct sctp_association *,
 682				 struct sock *, gfp_t gfp);
 683void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
 684		     union sctp_addr *);
 685const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
 686
 687static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
 688{
 689	return ntohs(ch->subh.data_hdr->stream);
 690}
 691
 692enum {
 693	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
 694	SCTP_ADDR_SRC,		/* address can be used as source */
 695	SCTP_ADDR_DEL,		/* address about to be deleted */
 696};
 697
 698/* This is a structure for holding either an IPv6 or an IPv4 address.  */
 699struct sctp_sockaddr_entry {
 700	struct list_head list;
 701	struct rcu_head	rcu;
 702	union sctp_addr a;
 703	__u8 state;
 704	__u8 valid;
 705};
 706
 707#define SCTP_ADDRESS_TICK_DELAY	500
 708
 
 
 709/* This structure holds lists of chunks as we are assembling for
 710 * transmission.
 711 */
 712struct sctp_packet {
 713	/* These are the SCTP header values (host order) for the packet. */
 714	__u16 source_port;
 715	__u16 destination_port;
 716	__u32 vtag;
 717
 718	/* This contains the payload chunks.  */
 719	struct list_head chunk_list;
 720
 721	/* This is the overhead of the sctp and ip headers. */
 722	size_t overhead;
 723	/* This is the total size of all chunks INCLUDING padding.  */
 724	size_t size;
 725	/* This is the maximum size this packet may have */
 726	size_t max_size;
 727
 728	/* The packet is destined for this transport address.
 729	 * The function we finally use to pass down to the next lower
 730	 * layer lives in the transport structure.
 731	 */
 732	struct sctp_transport *transport;
 733
 734	/* pointer to the auth chunk for this packet */
 735	struct sctp_chunk *auth;
 736
 737	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
 738	    has_sack:1,		/* This packet contains a SACK chunk. */
 739	    has_auth:1,		/* This packet contains an AUTH chunk */
 740	    has_data:1,		/* This packet contains at least 1 DATA chunk */
 741	    ipfragok:1;		/* So let ip fragment this packet */
 
 742};
 743
 744void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
 745		      __u16 sport, __u16 dport);
 746void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
 747enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
 748					  struct sctp_chunk *chunk,
 749					  int one_packet, gfp_t gfp);
 750enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
 751					struct sctp_chunk *chunk);
 752int sctp_packet_transmit(struct sctp_packet *, gfp_t);
 753void sctp_packet_free(struct sctp_packet *);
 754
 755static inline int sctp_packet_empty(struct sctp_packet *packet)
 756{
 757	return packet->size == packet->overhead;
 758}
 759
 760/* This represents a remote transport address.
 761 * For local transport addresses, we just use union sctp_addr.
 762 *
 763 * RFC2960 Section 1.4 Key Terms
 764 *
 765 *   o	Transport address:  A Transport Address is traditionally defined
 766 *	by Network Layer address, Transport Layer protocol and Transport
 767 *	Layer port number.  In the case of SCTP running over IP, a
 768 *	transport address is defined by the combination of an IP address
 769 *	and an SCTP port number (where SCTP is the Transport protocol).
 770 *
 771 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
 772 *
 773 *   o	The sender keeps a separate congestion control parameter set for
 774 *	each of the destination addresses it can send to (not each
 775 *	source-destination pair but for each destination).  The parameters
 776 *	should decay if the address is not used for a long enough time
 777 *	period.
 778 *
 779 */
 780struct sctp_transport {
 781	/* A list of transports. */
 782	struct list_head transports;
 783	struct rhlist_head node;
 784
 785	/* Reference counting. */
 786	refcount_t refcnt;
 
 787		/* RTO-Pending : A flag used to track if one of the DATA
 788		 *		chunks sent to this address is currently being
 789		 *		used to compute a RTT. If this flag is 0,
 790		 *		the next DATA chunk sent to this destination
 791		 *		should be used to compute a RTT and this flag
 792		 *		should be set. Every time the RTT
 793		 *		calculation completes (i.e. the DATA chunk
 794		 *		is SACK'd) clear this flag.
 795		 */
 796	__u32	rto_pending:1,
 797
 798		/*
 799		 * hb_sent : a flag that signals that we have a pending
 800		 * heartbeat.
 801		 */
 802		hb_sent:1,
 803
 804		/* Is the Path MTU update pending on this tranport */
 805		pmtu_pending:1,
 806
 807		dst_pending_confirm:1,	/* need to confirm neighbour */
 808
 809		/* Has this transport moved the ctsn since we last sacked */
 810		sack_generation:1;
 811	u32 dst_cookie;
 812
 813	struct flowi fl;
 814
 815	/* This is the peer's IP address and port. */
 816	union sctp_addr ipaddr;
 817
 818	/* These are the functions we call to handle LLP stuff.	 */
 819	struct sctp_af *af_specific;
 820
 821	/* Which association do we belong to?  */
 822	struct sctp_association *asoc;
 823
 824	/* RFC2960
 825	 *
 826	 * 12.3 Per Transport Address Data
 827	 *
 828	 * For each destination transport address in the peer's
 829	 * address list derived from the INIT or INIT ACK chunk, a
 830	 * number of data elements needs to be maintained including:
 831	 */
 832	/* RTO	       : The current retransmission timeout value.  */
 833	unsigned long rto;
 834
 835	__u32 rtt;		/* This is the most recent RTT.	 */
 836
 837	/* RTTVAR      : The current RTT variation.  */
 838	__u32 rttvar;
 839
 840	/* SRTT	       : The current smoothed round trip time.	*/
 841	__u32 srtt;
 842
 843	/*
 844	 * These are the congestion stats.
 845	 */
 846	/* cwnd	       : The current congestion window.	 */
 847	__u32 cwnd;		  /* This is the actual cwnd.  */
 848
 849	/* ssthresh    : The current slow start threshold value.  */
 850	__u32 ssthresh;
 851
 852	/* partial     : The tracking method for increase of cwnd when in
 853	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
 854	 */
 855	__u32 partial_bytes_acked;
 856
 857	/* Data that has been sent, but not acknowledged. */
 858	__u32 flight_size;
 859
 860	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
 861
 862	/* Destination */
 863	struct dst_entry *dst;
 864	/* Source address. */
 865	union sctp_addr saddr;
 866
 867	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
 868	 * the destination address every heartbeat interval.
 869	 */
 870	unsigned long hbinterval;
 871
 872	/* SACK delay timeout */
 873	unsigned long sackdelay;
 874	__u32 sackfreq;
 875
 876	/* When was the last time that we heard from this transport? We use
 877	 * this to pick new active and retran paths.
 878	 */
 879	ktime_t last_time_heard;
 880
 881	/* When was the last time that we sent a chunk using this
 882	 * transport? We use this to check for idle transports
 883	 */
 884	unsigned long last_time_sent;
 885
 886	/* Last time(in jiffies) when cwnd is reduced due to the congestion
 887	 * indication based on ECNE chunk.
 888	 */
 889	unsigned long last_time_ecne_reduced;
 890
 891	/* This is the max_retrans value for the transport and will
 892	 * be initialized from the assocs value.  This can be changed
 893	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
 894	 */
 895	__u16 pathmaxrxt;
 896
 897	/* This is the partially failed retrans value for the transport
 898	 * and will be initialized from the assocs value.  This can be changed
 899	 * using the SCTP_PEER_ADDR_THLDS socket option
 900	 */
 901	int pf_retrans;
 902	/* PMTU	      : The current known path MTU.  */
 903	__u32 pathmtu;
 904
 905	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 906	__u32 param_flags;
 907
 908	/* The number of times INIT has been sent on this transport. */
 909	int init_sent_count;
 910
 911	/* state       : The current state of this destination,
 912	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
 913	 */
 914	int state;
 915
 916	/* These are the error stats for this destination.  */
 917
 918	/* Error count : The current error count for this destination.	*/
 919	unsigned short error_count;
 920
 921	/* Per	       : A timer used by each destination.
 922	 * Destination :
 923	 * Timer       :
 924	 *
 925	 * [Everywhere else in the text this is called T3-rtx. -ed]
 926	 */
 927	struct timer_list T3_rtx_timer;
 928
 929	/* Heartbeat timer is per destination. */
 930	struct timer_list hb_timer;
 931
 932	/* Timer to handle ICMP proto unreachable envets */
 933	struct timer_list proto_unreach_timer;
 934
 935	/* Timer to handler reconf chunk rtx */
 936	struct timer_list reconf_timer;
 937
 938	/* Since we're using per-destination retransmission timers
 939	 * (see above), we're also using per-destination "transmitted"
 940	 * queues.  This probably ought to be a private struct
 941	 * accessible only within the outqueue, but it's not, yet.
 942	 */
 943	struct list_head transmitted;
 944
 945	/* We build bundle-able packets for this transport here.  */
 946	struct sctp_packet packet;
 947
 948	/* This is the list of transports that have chunks to send.  */
 949	struct list_head send_ready;
 950
 951	/* State information saved for SFR_CACC algorithm. The key
 952	 * idea in SFR_CACC is to maintain state at the sender on a
 953	 * per-destination basis when a changeover happens.
 954	 *	char changeover_active;
 955	 *	char cycling_changeover;
 956	 *	__u32 next_tsn_at_change;
 957	 *	char cacc_saw_newack;
 958	 */
 959	struct {
 960		/* An unsigned integer, which stores the next TSN to be
 961		 * used by the sender, at the moment of changeover.
 962		 */
 963		__u32 next_tsn_at_change;
 964
 965		/* A flag which indicates the occurrence of a changeover */
 966		char changeover_active;
 967
 968		/* A flag which indicates whether the change of primary is
 969		 * the first switch to this destination address during an
 970		 * active switch.
 971		 */
 972		char cycling_changeover;
 973
 974		/* A temporary flag, which is used during the processing of
 975		 * a SACK to estimate the causative TSN(s)'s group.
 976		 */
 977		char cacc_saw_newack;
 978	} cacc;
 979
 980	/* 64-bit random number sent with heartbeat. */
 981	__u64 hb_nonce;
 982
 983	struct rcu_head rcu;
 984};
 985
 986struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
 987					  gfp_t);
 988void sctp_transport_set_owner(struct sctp_transport *,
 989			      struct sctp_association *);
 990void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
 991			  struct sctp_sock *);
 992void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
 993void sctp_transport_free(struct sctp_transport *);
 994void sctp_transport_reset_t3_rtx(struct sctp_transport *);
 995void sctp_transport_reset_hb_timer(struct sctp_transport *);
 996void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
 997int sctp_transport_hold(struct sctp_transport *);
 998void sctp_transport_put(struct sctp_transport *);
 999void sctp_transport_update_rto(struct sctp_transport *, __u32);
1000void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1001void sctp_transport_lower_cwnd(struct sctp_transport *t,
1002			       enum sctp_lower_cwnd reason);
1003void sctp_transport_burst_limited(struct sctp_transport *);
1004void sctp_transport_burst_reset(struct sctp_transport *);
1005unsigned long sctp_transport_timeout(struct sctp_transport *);
1006void sctp_transport_reset(struct sctp_transport *t);
1007bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1008void sctp_transport_immediate_rtx(struct sctp_transport *);
1009void sctp_transport_dst_release(struct sctp_transport *t);
1010void sctp_transport_dst_confirm(struct sctp_transport *t);
1011
1012
1013/* This is the structure we use to queue packets as they come into
1014 * SCTP.  We write packets to it and read chunks from it.
1015 */
1016struct sctp_inq {
1017	/* This is actually a queue of sctp_chunk each
1018	 * containing a partially decoded packet.
1019	 */
1020	struct list_head in_chunk_list;
1021	/* This is the packet which is currently off the in queue and is
1022	 * being worked on through the inbound chunk processing.
1023	 */
1024	struct sctp_chunk *in_progress;
1025
1026	/* This is the delayed task to finish delivering inbound
1027	 * messages.
1028	 */
1029	struct work_struct immediate;
 
 
1030};
1031
1032void sctp_inq_init(struct sctp_inq *);
1033void sctp_inq_free(struct sctp_inq *);
1034void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1035struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1036struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1037void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1038
1039/* This is the structure we use to hold outbound chunks.  You push
1040 * chunks in and they automatically pop out the other end as bundled
1041 * packets (it calls (*output_handler)()).
1042 *
1043 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1044 * and 8.2 of the v13 draft.
1045 *
1046 * It handles retransmissions.	The connection to the timeout portion
1047 * of the state machine is through sctp_..._timeout() and timeout_handler.
1048 *
1049 * If you feed it SACKs, it will eat them.
1050 *
1051 * If you give it big chunks, it will fragment them.
1052 *
1053 * It assigns TSN's to data chunks.  This happens at the last possible
1054 * instant before transmission.
1055 *
1056 * When free()'d, it empties itself out via output_handler().
1057 */
1058struct sctp_outq {
1059	struct sctp_association *asoc;
1060
1061	/* Data pending that has never been transmitted.  */
1062	struct list_head out_chunk_list;
1063
1064	/* Stream scheduler being used */
1065	struct sctp_sched_ops *sched;
1066
1067	unsigned int out_qlen;	/* Total length of queued data chunks. */
1068
1069	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1070	unsigned int error;
1071
1072	/* These are control chunks we want to send.  */
1073	struct list_head control_chunk_list;
1074
1075	/* These are chunks that have been sacked but are above the
1076	 * CTSN, or cumulative tsn ack point.
1077	 */
1078	struct list_head sacked;
1079
1080	/* Put chunks on this list to schedule them for
1081	 * retransmission.
1082	 */
1083	struct list_head retransmit;
1084
1085	/* Put chunks on this list to save them for FWD TSN processing as
1086	 * they were abandoned.
1087	 */
1088	struct list_head abandoned;
1089
1090	/* How many unackd bytes do we have in-flight?	*/
1091	__u32 outstanding_bytes;
1092
1093	/* Are we doing fast-rtx on this queue */
1094	char fast_rtx;
1095
1096	/* Corked? */
1097	char cork;
 
 
 
 
 
 
1098};
1099
1100void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1101void sctp_outq_teardown(struct sctp_outq *);
1102void sctp_outq_free(struct sctp_outq*);
1103void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1104int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1105int sctp_outq_is_empty(const struct sctp_outq *);
1106void sctp_outq_restart(struct sctp_outq *);
1107
1108void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1109		     enum sctp_retransmit_reason reason);
1110void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1111void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1112void sctp_prsctp_prune(struct sctp_association *asoc,
1113		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1114void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1115/* Uncork and flush an outqueue.  */
1116static inline void sctp_outq_cork(struct sctp_outq *q)
1117{
1118	q->cork = 1;
1119}
1120
1121/* SCTP skb control block.
1122 * sctp_input_cb is currently used on rx and sock rx queue
1123 */
1124struct sctp_input_cb {
1125	union {
1126		struct inet_skb_parm	h4;
1127#if IS_ENABLED(CONFIG_IPV6)
1128		struct inet6_skb_parm	h6;
1129#endif
1130	} header;
1131	struct sctp_chunk *chunk;
1132	struct sctp_af *af;
1133};
1134#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1135
1136static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1137{
1138	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1139
1140	return chunk->head_skb ? : skb;
1141}
1142
1143/* These bind address data fields common between endpoints and associations */
1144struct sctp_bind_addr {
1145
1146	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1147	 *
1148	 * SCTP Port:	The local SCTP port number the endpoint is
1149	 *		bound to.
1150	 */
1151	__u16 port;
1152
1153	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1154	 *
1155	 * Address List: The list of IP addresses that this instance
1156	 *	has bound.  This information is passed to one's
1157	 *	peer(s) in INIT and INIT ACK chunks.
1158	 */
1159	struct list_head address_list;
 
 
1160};
1161
1162void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1163void sctp_bind_addr_free(struct sctp_bind_addr *);
1164int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1165			const struct sctp_bind_addr *src,
1166			enum sctp_scope scope, gfp_t gfp,
1167			int flags);
1168int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1169			const struct sctp_bind_addr *src,
1170			gfp_t gfp);
1171int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1172		       int new_size, __u8 addr_state, gfp_t gfp);
1173int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1174int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1175			 struct sctp_sock *);
1176int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1177			 struct sctp_sock *, struct sctp_sock *);
1178int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1179			 const union sctp_addr *addr);
1180union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1181					const union sctp_addr	*addrs,
1182					int			addrcnt,
1183					struct sctp_sock	*opt);
1184union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1185					 int *addrs_len,
1186					 gfp_t gfp);
1187int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1188			   __u16 port, gfp_t gfp);
1189
1190enum sctp_scope sctp_scope(const union sctp_addr *addr);
1191int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1192		  const enum sctp_scope scope);
1193int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
 
1194int sctp_is_ep_boundall(struct sock *sk);
1195
1196
1197/* What type of endpoint?  */
1198enum sctp_endpoint_type {
1199	SCTP_EP_TYPE_SOCKET,
1200	SCTP_EP_TYPE_ASSOCIATION,
1201};
1202
1203/*
1204 * A common base class to bridge the implmentation view of a
1205 * socket (usually listening) endpoint versus an association's
1206 * local endpoint.
1207 * This common structure is useful for several purposes:
1208 *   1) Common interface for lookup routines.
1209 *	a) Subfunctions work for either endpoint or association
1210 *	b) Single interface to lookup allows hiding the lookup lock rather
1211 *	   than acquiring it externally.
1212 *   2) Common interface for the inbound chunk handling/state machine.
1213 *   3) Common object handling routines for reference counting, etc.
1214 *   4) Disentangle association lookup from endpoint lookup, where we
1215 *	do not have to find our endpoint to find our association.
1216 *
1217 */
1218
1219struct sctp_ep_common {
1220	/* Fields to help us manage our entries in the hash tables. */
1221	struct hlist_node node;
1222	int hashent;
1223
1224	/* Runtime type information.  What kind of endpoint is this? */
1225	enum sctp_endpoint_type type;
1226
1227	/* Some fields to help us manage this object.
1228	 *   refcnt   - Reference count access to this object.
1229	 *   dead     - Do not attempt to use this object.
 
1230	 */
1231	refcount_t    refcnt;
1232	bool	    dead;
 
1233
1234	/* What socket does this endpoint belong to?  */
1235	struct sock *sk;
1236
1237	/* This is where we receive inbound chunks.  */
1238	struct sctp_inq	  inqueue;
1239
1240	/* This substructure includes the defining parameters of the
1241	 * endpoint:
1242	 * bind_addr.port is our shared port number.
1243	 * bind_addr.address_list is our set of local IP addresses.
1244	 */
1245	struct sctp_bind_addr bind_addr;
1246};
1247
1248
1249/* RFC Section 1.4 Key Terms
1250 *
1251 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1252 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1253 *   combination of a set of eligible destination transport addresses to
1254 *   which SCTP packets can be sent and a set of eligible source
1255 *   transport addresses from which SCTP packets can be received.
1256 *   All transport addresses used by an SCTP endpoint must use the
1257 *   same port number, but can use multiple IP addresses. A transport
1258 *   address used by an SCTP endpoint must not be used by another
1259 *   SCTP endpoint. In other words, a transport address is unique
1260 *   to an SCTP endpoint.
1261 *
1262 * From an implementation perspective, each socket has one of these.
1263 * A TCP-style socket will have exactly one association on one of
1264 * these.  An UDP-style socket will have multiple associations hanging
1265 * off one of these.
1266 */
1267
1268struct sctp_endpoint {
1269	/* Common substructure for endpoint and association. */
1270	struct sctp_ep_common base;
1271
1272	/* Associations: A list of current associations and mappings
1273	 *	      to the data consumers for each association. This
1274	 *	      may be in the form of a hash table or other
1275	 *	      implementation dependent structure. The data
1276	 *	      consumers may be process identification
1277	 *	      information such as file descriptors, named pipe
1278	 *	      pointer, or table pointers dependent on how SCTP
1279	 *	      is implemented.
1280	 */
1281	/* This is really a list of struct sctp_association entries. */
1282	struct list_head asocs;
1283
1284	/* Secret Key: A secret key used by this endpoint to compute
1285	 *	      the MAC.	This SHOULD be a cryptographic quality
1286	 *	      random number with a sufficient length.
1287	 *	      Discussion in [RFC1750] can be helpful in
1288	 *	      selection of the key.
1289	 */
1290	__u8 secret_key[SCTP_SECRET_SIZE];
 
 
 
1291
1292 	/* digest:  This is a digest of the sctp cookie.  This field is
1293 	 * 	    only used on the receive path when we try to validate
1294 	 * 	    that the cookie has not been tampered with.  We put
1295 	 * 	    this here so we pre-allocate this once and can re-use
1296 	 * 	    on every receive.
1297 	 */
1298 	__u8 *digest;
1299 
1300	/* sendbuf acct. policy.	*/
1301	__u32 sndbuf_policy;
1302
1303	/* rcvbuf acct. policy.	*/
1304	__u32 rcvbuf_policy;
1305
1306	/* SCTP AUTH: array of the HMACs that will be allocated
1307	 * we need this per association so that we don't serialize
1308	 */
1309	struct crypto_shash **auth_hmacs;
1310
1311	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1312	 struct sctp_hmac_algo_param *auth_hmacs_list;
1313
1314	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1315	struct sctp_chunks_param *auth_chunk_list;
1316
1317	/* SCTP-AUTH: endpoint shared keys */
1318	struct list_head endpoint_shared_keys;
1319	__u16 active_key_id;
1320	__u8  auth_enable:1,
1321	      prsctp_enable:1,
1322	      reconf_enable:1;
1323
1324	__u8  strreset_enable;
1325
1326	/* Security identifiers from incoming (INIT). These are set by
1327	 * security_sctp_assoc_request(). These will only be used by
1328	 * SCTP TCP type sockets and peeled off connections as they
1329	 * cause a new socket to be generated. security_sctp_sk_clone()
1330	 * will then plug these into the new socket.
1331	 */
1332
1333	u32 secid;
1334	u32 peer_secid;
1335};
1336
1337/* Recover the outter endpoint structure. */
1338static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1339{
1340	struct sctp_endpoint *ep;
1341
1342	ep = container_of(base, struct sctp_endpoint, base);
1343	return ep;
1344}
1345
1346/* These are function signatures for manipulating endpoints.  */
1347struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1348void sctp_endpoint_free(struct sctp_endpoint *);
1349void sctp_endpoint_put(struct sctp_endpoint *);
1350void sctp_endpoint_hold(struct sctp_endpoint *);
1351void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1352struct sctp_association *sctp_endpoint_lookup_assoc(
1353	const struct sctp_endpoint *ep,
1354	const union sctp_addr *paddr,
1355	struct sctp_transport **);
1356bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1357				 const union sctp_addr *paddr);
1358struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1359					struct net *, const union sctp_addr *);
1360bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1361			  const union sctp_addr *paddr);
1362
1363int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1364		     const struct sctp_association *asoc,
1365		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1366		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1367int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1368		      const union sctp_addr *peer,
1369		      struct sctp_init_chunk *init, gfp_t gfp);
1370__u32 sctp_generate_tag(const struct sctp_endpoint *);
1371__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1372
1373struct sctp_inithdr_host {
1374	__u32 init_tag;
1375	__u32 a_rwnd;
1376	__u16 num_outbound_streams;
1377	__u16 num_inbound_streams;
1378	__u32 initial_tsn;
1379};
1380
1381struct sctp_stream_priorities {
1382	/* List of priorities scheduled */
1383	struct list_head prio_sched;
1384	/* List of streams scheduled */
1385	struct list_head active;
1386	/* The next stream stream in line */
1387	struct sctp_stream_out_ext *next;
1388	__u16 prio;
1389};
1390
1391struct sctp_stream_out_ext {
1392	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1393	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1394	struct list_head outq; /* chunks enqueued by this stream */
1395	union {
1396		struct {
1397			/* Scheduled streams list */
1398			struct list_head prio_list;
1399			struct sctp_stream_priorities *prio_head;
1400		};
1401		/* Fields used by RR scheduler */
1402		struct {
1403			struct list_head rr_list;
1404		};
1405	};
1406};
1407
1408struct sctp_stream_out {
1409	union {
1410		__u32 mid;
1411		__u16 ssn;
1412	};
1413	__u32 mid_uo;
1414	struct sctp_stream_out_ext *ext;
1415	__u8 state;
1416};
1417
1418struct sctp_stream_in {
1419	union {
1420		__u32 mid;
1421		__u16 ssn;
1422	};
1423	__u32 mid_uo;
1424	__u32 fsn;
1425	__u32 fsn_uo;
1426	char pd_mode;
1427	char pd_mode_uo;
1428};
1429
1430struct sctp_stream {
1431	struct sctp_stream_out *out;
1432	struct sctp_stream_in *in;
1433	__u16 outcnt;
1434	__u16 incnt;
1435	/* Current stream being sent, if any */
1436	struct sctp_stream_out *out_curr;
1437	union {
1438		/* Fields used by priority scheduler */
1439		struct {
1440			/* List of priorities scheduled */
1441			struct list_head prio_list;
1442		};
1443		/* Fields used by RR scheduler */
1444		struct {
1445			/* List of streams scheduled */
1446			struct list_head rr_list;
1447			/* The next stream stream in line */
1448			struct sctp_stream_out_ext *rr_next;
1449		};
1450	};
1451	struct sctp_stream_interleave *si;
1452};
1453
1454#define SCTP_STREAM_CLOSED		0x00
1455#define SCTP_STREAM_OPEN		0x01
1456
1457static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1458{
1459	return stream->si->data_chunk_len;
1460}
1461
1462static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1463{
1464	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1465}
1466
1467static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1468{
1469	return stream->si->ftsn_chunk_len;
1470}
1471
1472static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1473{
1474	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1475}
1476
1477/* SCTP_GET_ASSOC_STATS counters */
1478struct sctp_priv_assoc_stats {
1479	/* Maximum observed rto in the association during subsequent
1480	 * observations. Value is set to 0 if no RTO measurement took place
1481	 * The transport where the max_rto was observed is returned in
1482	 * obs_rto_ipaddr
1483	 */
1484	struct sockaddr_storage obs_rto_ipaddr;
1485	__u64 max_obs_rto;
1486	/* Total In and Out SACKs received and sent */
1487	__u64 isacks;
1488	__u64 osacks;
1489	/* Total In and Out packets received and sent */
1490	__u64 opackets;
1491	__u64 ipackets;
1492	/* Total retransmitted chunks */
1493	__u64 rtxchunks;
1494	/* TSN received > next expected */
1495	__u64 outofseqtsns;
1496	/* Duplicate Chunks received */
1497	__u64 idupchunks;
1498	/* Gap Ack Blocks received */
1499	__u64 gapcnt;
1500	/* Unordered data chunks sent and received */
1501	__u64 ouodchunks;
1502	__u64 iuodchunks;
1503	/* Ordered data chunks sent and received */
1504	__u64 oodchunks;
1505	__u64 iodchunks;
1506	/* Control chunks sent and received */
1507	__u64 octrlchunks;
1508	__u64 ictrlchunks;
1509};
1510
1511/* RFC2960
1512 *
1513 * 12. Recommended Transmission Control Block (TCB) Parameters
1514 *
1515 * This section details a recommended set of parameters that should
1516 * be contained within the TCB for an implementation. This section is
1517 * for illustrative purposes and should not be deemed as requirements
1518 * on an implementation or as an exhaustive list of all parameters
1519 * inside an SCTP TCB. Each implementation may need its own additional
1520 * parameters for optimization.
1521 */
1522
1523
1524/* Here we have information about each individual association. */
1525struct sctp_association {
1526
1527	/* A base structure common to endpoint and association.
1528	 * In this context, it represents the associations's view
1529	 * of the local endpoint of the association.
1530	 */
1531	struct sctp_ep_common base;
1532
1533	/* Associations on the same socket. */
1534	struct list_head asocs;
1535
1536	/* association id. */
1537	sctp_assoc_t assoc_id;
1538
1539	/* This is our parent endpoint.	 */
1540	struct sctp_endpoint *ep;
1541
1542	/* These are those association elements needed in the cookie.  */
1543	struct sctp_cookie c;
1544
1545	/* This is all information about our peer.  */
1546	struct {
 
 
 
 
 
 
1547		/* transport_addr_list
1548		 *
1549		 * Peer	       : A list of SCTP transport addresses that the
1550		 * Transport   : peer is bound to. This information is derived
1551		 * Address     : from the INIT or INIT ACK and is used to
1552		 * List	       : associate an inbound packet with a given
1553		 *	       : association. Normally this information is
1554		 *	       : hashed or keyed for quick lookup and access
1555		 *	       : of the TCB.
1556		 *	       : The list is also initialized with the list
1557		 *	       : of addresses passed with the sctp_connectx()
1558		 *	       : call.
1559		 *
1560		 * It is a list of SCTP_transport's.
1561		 */
1562		struct list_head transport_addr_list;
1563
1564		/* rwnd
1565		 *
1566		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1567		 */
1568		__u32 rwnd;
1569
1570		/* transport_count
1571		 *
1572		 * Peer        : A count of the number of peer addresses
1573		 * Transport   : in the Peer Transport Address List.
1574		 * Address     :
1575		 * Count       :
1576		 */
1577		__u16 transport_count;
1578
1579		/* port
1580		 *   The transport layer port number.
1581		 */
1582		__u16 port;
1583
1584		/* primary_path
1585		 *
1586		 * Primary     : This is the current primary destination
1587		 * Path	       : transport address of the peer endpoint.  It
1588		 *	       : may also specify a source transport address
1589		 *	       : on this endpoint.
1590		 *
1591		 * All of these paths live on transport_addr_list.
1592		 *
1593		 * At the bakeoffs, we discovered that the intent of
1594		 * primaryPath is that it only changes when the ULP
1595		 * asks to have it changed.  We add the activePath to
1596		 * designate the connection we are currently using to
1597		 * transmit new data and most control chunks.
1598		 */
1599		struct sctp_transport *primary_path;
1600
1601		/* Cache the primary path address here, when we
1602		 * need a an address for msg_name.
1603		 */
1604		union sctp_addr primary_addr;
1605
1606		/* active_path
1607		 *   The path that we are currently using to
1608		 *   transmit new data and most control chunks.
1609		 */
1610		struct sctp_transport *active_path;
1611
1612		/* retran_path
1613		 *
1614		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1615		 * ...
1616		 * Furthermore, when its peer is multi-homed, an
1617		 * endpoint SHOULD try to retransmit a chunk to an
1618		 * active destination transport address that is
1619		 * different from the last destination address to
1620		 * which the DATA chunk was sent.
1621		 */
1622		struct sctp_transport *retran_path;
1623
1624		/* Pointer to last transport I have sent on.  */
1625		struct sctp_transport *last_sent_to;
1626
1627		/* This is the last transport I have received DATA on.	*/
1628		struct sctp_transport *last_data_from;
1629
1630		/*
1631		 * Mapping  An array of bits or bytes indicating which out of
1632		 * Array    order TSN's have been received (relative to the
1633		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1634		 *	    order packets have been received, this array
1635		 *	    will be set to all zero. This structure may be
1636		 *	    in the form of a circular buffer or bit array.
1637		 *
1638		 * Last Rcvd   : This is the last TSN received in
1639		 * TSN	       : sequence. This value is set initially by
1640		 *	       : taking the peer's Initial TSN, received in
1641		 *	       : the INIT or INIT ACK chunk, and subtracting
1642		 *	       : one from it.
1643		 *
1644		 * Throughout most of the specification this is called the
1645		 * "Cumulative TSN ACK Point".	In this case, we
1646		 * ignore the advice in 12.2 in favour of the term
1647		 * used in the bulk of the text.  This value is hidden
1648		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1649		 */
1650		struct sctp_tsnmap tsn_map;
1651
1652		/* This mask is used to disable sending the ASCONF chunk
1653		 * with specified parameter to peer.
1654		 */
1655		__be16 addip_disabled_mask;
1656
1657		/* These are capabilities which our peer advertised.  */
1658		__u8	ecn_capable:1,      /* Can peer do ECN? */
1659			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1660			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1661			hostname_address:1, /* Peer understands DNS addresses? */
1662			asconf_capable:1,   /* Does peer support ADDIP? */
1663			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1664			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1665			auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1666
1667		/* sack_needed : This flag indicates if the next received
1668		 *             : packet is to be responded to with a
1669		 *             : SACK. This is initialized to 0.  When a packet
1670		 *             : is received sack_cnt is incremented. If this value
1671		 *             : reaches 2 or more, a SACK is sent and the
1672		 *             : value is reset to 0. Note: This is used only
1673		 *             : when no DATA chunks are received out of
1674		 *             : order.  When DATA chunks are out of order,
1675		 *             : SACK's are not delayed (see Section 6).
1676		 */
1677		__u8    sack_needed:1,     /* Do we need to sack the peer? */
1678			sack_generation:1,
1679			zero_window_announced:1;
1680		__u32	sack_cnt;
1681
 
 
 
 
 
 
 
 
 
1682		__u32   adaptation_ind;	 /* Adaptation Code point. */
1683
 
 
 
 
 
1684		struct sctp_inithdr_host i;
1685		void *cookie;
1686		int cookie_len;
 
1687
1688		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1689		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1690		 * Initial TSN Value minus 1
1691		 */
1692		__u32 addip_serial;
1693
1694		/* SCTP-AUTH: We need to know pears random number, hmac list
1695		 * and authenticated chunk list.  All that is part of the
1696		 * cookie and these are just pointers to those locations
1697		 */
1698		struct sctp_random_param *peer_random;
1699		struct sctp_chunks_param *peer_chunks;
1700		struct sctp_hmac_algo_param *peer_hmacs;
1701	} peer;
1702
1703	/* State       : A state variable indicating what state the
1704	 *	       : association is in, i.e. COOKIE-WAIT,
1705	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1706	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1707	 *
1708	 *		Note: No "CLOSED" state is illustrated since if a
1709	 *		association is "CLOSED" its TCB SHOULD be removed.
1710	 *
1711	 *		In this implementation we DO have a CLOSED
1712	 *		state which is used during initiation and shutdown.
1713	 *
1714	 *		State takes values from SCTP_STATE_*.
1715	 */
1716	enum sctp_state state;
 
 
 
1717
1718	/* Overall     : The overall association error count.
1719	 * Error Count : [Clear this any time I get something.]
1720	 */
1721	int overall_error_count;
1722
1723	/* The cookie life I award for any cookie.  */
1724	ktime_t cookie_life;
1725
1726	/* These are the association's initial, max, and min RTO values.
1727	 * These values will be initialized by system defaults, but can
1728	 * be modified via the SCTP_RTOINFO socket option.
1729	 */
1730	unsigned long rto_initial;
1731	unsigned long rto_max;
1732	unsigned long rto_min;
1733
1734	/* Maximum number of new data packets that can be sent in a burst.  */
1735	int max_burst;
1736
1737	/* This is the max_retrans value for the association.  This value will
1738	 * be initialized initialized from system defaults, but can be
1739	 * modified by the SCTP_ASSOCINFO socket option.
1740	 */
1741	int max_retrans;
1742
1743	/* This is the partially failed retrans value for the transport
1744	 * and will be initialized from the assocs value.  This can be
1745	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1746	 */
1747	int pf_retrans;
1748
1749	/* Maximum number of times the endpoint will retransmit INIT  */
1750	__u16 max_init_attempts;
1751
1752	/* How many times have we resent an INIT? */
1753	__u16 init_retries;
1754
1755	/* The largest timeout or RTO value to use in attempting an INIT */
1756	unsigned long max_init_timeo;
1757
1758	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1759	 * the destination address every heartbeat interval. This value
1760	 * will be inherited by all new transports.
1761	 */
1762	unsigned long hbinterval;
1763
1764	/* This is the max_retrans value for new transports in the
1765	 * association.
1766	 */
1767	__u16 pathmaxrxt;
1768
1769	/* Flag that path mtu update is pending */
1770	__u8   pmtu_pending;
1771
1772	/* Association : The smallest PMTU discovered for all of the
1773	 * PMTU	       : peer's transport addresses.
1774	 */
1775	__u32 pathmtu;
1776
1777	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1778	__u32 param_flags;
1779
1780	__u32 sackfreq;
1781	/* SACK delay timeout */
1782	unsigned long sackdelay;
 
 
1783
1784	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1785	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1786
1787	/* Transport to which SHUTDOWN chunk was last sent.  */
1788	struct sctp_transport *shutdown_last_sent_to;
1789
1790	/* Transport to which INIT chunk was last sent.  */
1791	struct sctp_transport *init_last_sent_to;
1792
1793	/* How many times have we resent a SHUTDOWN */
1794	int shutdown_retries;
1795
 
 
 
1796	/* Next TSN    : The next TSN number to be assigned to a new
1797	 *	       : DATA chunk.  This is sent in the INIT or INIT
1798	 *	       : ACK chunk to the peer and incremented each
1799	 *	       : time a DATA chunk is assigned a TSN
1800	 *	       : (normally just prior to transmit or during
1801	 *	       : fragmentation).
1802	 */
1803	__u32 next_tsn;
1804
1805	/*
1806	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1807	 * TSN	       : is set initially by taking the peer's Initial TSN,
1808	 *	       : received in the INIT or INIT ACK chunk, and
1809	 *	       : subtracting one from it.
1810	 *
1811	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1812	 */
1813
1814	__u32 ctsn_ack_point;
1815
1816	/* PR-SCTP Advanced.Peer.Ack.Point */
1817	__u32 adv_peer_ack_point;
1818
1819	/* Highest TSN that is acknowledged by incoming SACKs. */
1820	__u32 highest_sacked;
1821
1822	/* TSN marking the fast recovery exit point */
1823	__u32 fast_recovery_exit;
1824
1825	/* Flag to track the current fast recovery state */
1826	__u8 fast_recovery;
1827
1828	/* The number of unacknowledged data chunks.  Reported through
1829	 * the SCTP_STATUS sockopt.
1830	 */
1831	__u16 unack_data;
1832
1833	/* The total number of data chunks that we've had to retransmit
1834	 * as the result of a T3 timer expiration
1835	 */
1836	__u32 rtx_data_chunks;
1837
1838	/* This is the association's receive buffer space.  This value is used
1839	 * to set a_rwnd field in an INIT or a SACK chunk.
1840	 */
1841	__u32 rwnd;
1842
1843	/* This is the last advertised value of rwnd over a SACK chunk. */
1844	__u32 a_rwnd;
1845
1846	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1847	 * to slop over a maximum of the association's frag_point.
1848	 */
1849	__u32 rwnd_over;
1850
1851	/* Keeps treack of rwnd pressure.  This happens when we have
1852	 * a window, but not recevie buffer (i.e small packets).  This one
1853	 * is releases slowly (1 PMTU at a time ).
1854	 */
1855	__u32 rwnd_press;
1856
1857	/* This is the sndbuf size in use for the association.
1858	 * This corresponds to the sndbuf size for the association,
1859	 * as specified in the sk->sndbuf.
1860	 */
1861	int sndbuf_used;
1862
1863	/* This is the amount of memory that this association has allocated
1864	 * in the receive path at any given time.
1865	 */
1866	atomic_t rmem_alloc;
1867
1868	/* This is the wait queue head for send requests waiting on
1869	 * the association sndbuf space.
1870	 */
1871	wait_queue_head_t	wait;
1872
1873	/* The message size at which SCTP fragmentation will occur. */
1874	__u32 frag_point;
1875	__u32 user_frag;
1876
1877	/* Counter used to count INIT errors. */
1878	int init_err_counter;
1879
1880	/* Count the number of INIT cycles (for doubling timeout). */
1881	int init_cycle;
1882
1883	/* Default send parameters. */
1884	__u16 default_stream;
1885	__u16 default_flags;
1886	__u32 default_ppid;
1887	__u32 default_context;
1888	__u32 default_timetolive;
1889
1890	/* Default receive parameters */
1891	__u32 default_rcv_context;
1892
1893	/* Stream arrays */
1894	struct sctp_stream stream;
1895
1896	/* All outbound chunks go through this structure.  */
1897	struct sctp_outq outqueue;
1898
1899	/* A smart pipe that will handle reordering and fragmentation,
1900	 * as well as handle passing events up to the ULP.
1901	 */
1902	struct sctp_ulpq ulpq;
1903
1904	/* Last TSN that caused an ECNE Chunk to be sent.  */
1905	__u32 last_ecne_tsn;
1906
1907	/* Last TSN that caused a CWR Chunk to be sent.	 */
1908	__u32 last_cwr_tsn;
1909
1910	/* How many duplicated TSNs have we seen?  */
1911	int numduptsns;
1912
 
 
 
 
 
 
1913	/* These are to support
1914	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1915	 *  and Enforcement of Flow and Message Limits"
1916	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1917	 * or "ADDIP" for short.
1918	 */
1919
1920
1921
1922	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1923	 *
1924	 * R1) One and only one ASCONF Chunk MAY be in transit and
1925	 * unacknowledged at any one time.  If a sender, after sending
1926	 * an ASCONF chunk, decides it needs to transfer another
1927	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1928	 * returns from the previous ASCONF Chunk before sending a
1929	 * subsequent ASCONF. Note this restriction binds each side,
1930	 * so at any time two ASCONF may be in-transit on any given
1931	 * association (one sent from each endpoint).
1932	 *
1933	 * [This is our one-and-only-one ASCONF in flight.  If we do
1934	 * not have an ASCONF in flight, this is NULL.]
1935	 */
1936	struct sctp_chunk *addip_last_asconf;
1937
1938	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1939	 *
1940	 * This is needed to implement itmes E1 - E4 of the updated
1941	 * spec.  Here is the justification:
1942	 *
1943	 * Since the peer may bundle multiple ASCONF chunks toward us,
1944	 * we now need the ability to cache multiple ACKs.  The section
1945	 * describes in detail how they are cached and cleaned up.
1946	 */
1947	struct list_head asconf_ack_list;
1948
1949	/* These ASCONF chunks are waiting to be sent.
1950	 *
1951	 * These chunaks can't be pushed to outqueue until receiving
1952	 * ASCONF_ACK for the previous ASCONF indicated by
1953	 * addip_last_asconf, so as to guarantee that only one ASCONF
1954	 * is in flight at any time.
1955	 *
1956	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1957	 *
1958	 * In defining the ASCONF Chunk transfer procedures, it is
1959	 * essential that these transfers MUST NOT cause congestion
1960	 * within the network.	To achieve this, we place these
1961	 * restrictions on the transfer of ASCONF Chunks:
1962	 *
1963	 * R1) One and only one ASCONF Chunk MAY be in transit and
1964	 * unacknowledged at any one time.  If a sender, after sending
1965	 * an ASCONF chunk, decides it needs to transfer another
1966	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1967	 * returns from the previous ASCONF Chunk before sending a
1968	 * subsequent ASCONF. Note this restriction binds each side,
1969	 * so at any time two ASCONF may be in-transit on any given
1970	 * association (one sent from each endpoint).
1971	 *
1972	 *
1973	 * [I really think this is EXACTLY the sort of intelligence
1974	 *  which already resides in sctp_outq.	 Please move this
1975	 *  queue and its supporting logic down there.	--piggy]
1976	 */
1977	struct list_head addip_chunk_list;
1978
1979	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1980	 *
1981	 * A2) A serial number should be assigned to the Chunk. The
1982	 * serial number SHOULD be a monotonically increasing
1983	 * number. The serial number SHOULD be initialized at
1984	 * the start of the association to the same value as the
1985	 * Initial TSN and every time a new ASCONF chunk is created
1986	 * it is incremented by one after assigning the serial number
1987	 * to the newly created chunk.
1988	 *
1989	 * ADDIP
1990	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1991	 *
1992	 * Serial Number : 32 bits (unsigned integer)
1993	 *
1994	 * This value represents a Serial Number for the ASCONF
1995	 * Chunk. The valid range of Serial Number is from 0 to
1996	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1997	 * after reaching 4294967295.
1998	 */
1999	__u32 addip_serial;
2000	int src_out_of_asoc_ok;
2001	union sctp_addr *asconf_addr_del_pending;
2002	struct sctp_transport *new_transport;
2003
2004	/* SCTP AUTH: list of the endpoint shared keys.  These
2005	 * keys are provided out of band by the user applicaton
2006	 * and can't change during the lifetime of the association
2007	 */
2008	struct list_head endpoint_shared_keys;
2009
2010	/* SCTP AUTH:
2011	 * The current generated assocaition shared key (secret)
2012	 */
2013	struct sctp_auth_bytes *asoc_shared_key;
2014	struct sctp_shared_key *shkey;
2015
2016	/* SCTP AUTH: hmac id of the first peer requested algorithm
2017	 * that we support.
2018	 */
2019	__u16 default_hmac_id;
2020
2021	__u16 active_key_id;
2022
2023	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2024	     temp:1,		/* Is it a temporary association? */
2025	     force_delay:1,
2026	     intl_enable:1,
2027	     prsctp_enable:1,
2028	     reconf_enable:1;
2029
2030	__u8 strreset_enable;
2031	__u8 strreset_outstanding; /* request param count on the fly */
2032
2033	__u32 strreset_outseq; /* Update after receiving response */
2034	__u32 strreset_inseq; /* Update after receiving request */
2035	__u32 strreset_result[2]; /* save the results of last 2 responses */
2036
2037	struct sctp_chunk *strreset_chunk; /* save request chunk */
2038
2039	struct sctp_priv_assoc_stats stats;
2040
2041	int sent_cnt_removable;
2042
2043	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2044	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2045};
2046
2047
2048/* An eyecatcher for determining if we are really looking at an
2049 * association data structure.
2050 */
2051enum {
2052	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2053};
2054
2055/* Recover the outter association structure. */
2056static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2057{
2058	struct sctp_association *asoc;
2059
2060	asoc = container_of(base, struct sctp_association, base);
2061	return asoc;
2062}
2063
2064/* These are function signatures for manipulating associations.	 */
2065
2066
2067struct sctp_association *
2068sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2069		     enum sctp_scope scope, gfp_t gfp);
2070void sctp_association_free(struct sctp_association *);
2071void sctp_association_put(struct sctp_association *);
2072void sctp_association_hold(struct sctp_association *);
2073
2074struct sctp_transport *sctp_assoc_choose_alter_transport(
2075	struct sctp_association *, struct sctp_transport *);
2076void sctp_assoc_update_retran_path(struct sctp_association *);
2077struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2078					  const union sctp_addr *);
2079int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2080			    const union sctp_addr *laddr);
2081struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2082				     const union sctp_addr *address,
2083				     const gfp_t gfp,
2084				     const int peer_state);
2085void sctp_assoc_del_peer(struct sctp_association *asoc,
2086			 const union sctp_addr *addr);
2087void sctp_assoc_rm_peer(struct sctp_association *asoc,
2088			 struct sctp_transport *peer);
2089void sctp_assoc_control_transport(struct sctp_association *asoc,
2090				  struct sctp_transport *transport,
2091				  enum sctp_transport_cmd command,
2092				  sctp_sn_error_t error);
2093struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2094struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
2095					   struct net *,
2096					   const union sctp_addr *,
2097					   const union sctp_addr *);
2098void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2099int sctp_assoc_update(struct sctp_association *old,
2100		      struct sctp_association *new);
2101
2102__u32 sctp_association_get_next_tsn(struct sctp_association *);
2103
2104void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2105void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2106void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2107void sctp_assoc_set_primary(struct sctp_association *,
2108			    struct sctp_transport *);
2109void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2110				    struct sctp_transport *);
2111int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2112				     enum sctp_scope scope, gfp_t gfp);
2113int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2114					 struct sctp_cookie*,
2115					 gfp_t gfp);
2116int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2117void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2118struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2119					const struct sctp_association *asoc,
2120					__be32 serial);
2121void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2122
2123int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2124			const union sctp_addr *ss2);
2125struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2126
2127/* A convenience structure to parse out SCTP specific CMSGs. */
2128struct sctp_cmsgs {
2129	struct sctp_initmsg *init;
2130	struct sctp_sndrcvinfo *srinfo;
2131	struct sctp_sndinfo *sinfo;
2132	struct sctp_prinfo *prinfo;
2133	struct sctp_authinfo *authinfo;
2134	struct msghdr *addrs_msg;
2135};
2136
2137/* Structure for tracking memory objects */
2138struct sctp_dbg_objcnt_entry {
2139	char *label;
2140	atomic_t *counter;
2141};
2142
2143#endif /* __sctp_structs_h__ */