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	__u32 probe_interval;
 181
 182	__be16 udp_port;
 183	__be16 encap_port;
 184
 185	/* This is the max_retrans value for new associations. */
 186	__u16 pathmaxrxt;
 187
 188	__u32 flowlabel;
 189	__u8  dscp;
 190
 191	__u16 pf_retrans;
 192	__u16 ps_retrans;
 193
 194	/* The initial Path MTU to use for new associations. */
 195	__u32 pathmtu;
 196
 197	/* The default SACK delay timeout for new associations. */
 198	__u32 sackdelay;
 199	__u32 sackfreq;
 200
 201	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 202	__u32 param_flags;
 203
 204	__u32 default_ss;
 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	__u16 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		pf_expose:2,
 224		reuse:1,
 225		disable_fragments:1,
 226		v4mapped:1,
 227		frag_interleave:1,
 228		recvrcvinfo:1,
 229		recvnxtinfo:1,
 230		data_ready_signalled:1;
 231
 232	atomic_t pd_mode;
 233
 234	/* Fields after this point will be skipped on copies, like on accept
 235	 * and peeloff operations
 236	 */
 237
 238	/* Receive to here while partial delivery is in effect. */
 239	struct sk_buff_head pd_lobby;
 240
 
 
 
 241	struct list_head auto_asconf_list;
 242	int do_auto_asconf;
 243};
 244
 245static inline struct sctp_sock *sctp_sk(const struct sock *sk)
 246{
 247       return (struct sctp_sock *)sk;
 248}
 249
 250static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
 251{
 252       return (struct sock *)sp;
 253}
 254
 255#if IS_ENABLED(CONFIG_IPV6)
 256struct sctp6_sock {
 257       struct sctp_sock  sctp;
 258       struct ipv6_pinfo inet6;
 259};
 260#endif /* CONFIG_IPV6 */
 261
 262
 263/* This is our APPLICATION-SPECIFIC state cookie.
 264 * THIS IS NOT DICTATED BY THE SPECIFICATION.
 265 */
 266/* These are the parts of an association which we send in the cookie.
 267 * Most of these are straight out of:
 268 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
 269 *
 270 */
 271
 272struct sctp_cookie {
 273
 274	/* My	       : Tag expected in every inbound packet and sent
 275	 * Verification: in the INIT or INIT ACK chunk.
 276	 * Tag	       :
 277	 */
 278	__u32 my_vtag;
 279
 280	/* Peer's      : Tag expected in every outbound packet except
 281	 * Verification: in the INIT chunk.
 282	 * Tag	       :
 283	 */
 284	__u32 peer_vtag;
 285
 286	/* The rest of these are not from the spec, but really need to
 287	 * be in the cookie.
 288	 */
 289
 290	/* My Tie Tag  : Assist in discovering a restarting association. */
 291	__u32 my_ttag;
 292
 293	/* Peer's Tie Tag: Assist in discovering a restarting association. */
 294	__u32 peer_ttag;
 295
 296	/* When does this cookie expire? */
 297	ktime_t expiration;
 298
 299	/* Number of inbound/outbound streams which are set
 300	 * and negotiated during the INIT process.
 301	 */
 302	__u16 sinit_num_ostreams;
 303	__u16 sinit_max_instreams;
 304
 305	/* This is the first sequence number I used.  */
 306	__u32 initial_tsn;
 307
 308	/* This holds the originating address of the INIT packet.  */
 309	union sctp_addr peer_addr;
 310
 311	/* IG Section 2.35.3 
 312	 * Include the source port of the INIT-ACK
 313	 */
 314	__u16		my_port;
 315
 316	__u8 prsctp_capable;
 317
 318	/* Padding for future use */
 319	__u8 padding;  		
 320
 321	__u32 adaptation_ind;
 322
 323	__u8 auth_random[sizeof(struct sctp_paramhdr) +
 324			 SCTP_AUTH_RANDOM_LENGTH];
 325	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
 326	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
 327
 328	/* This is a shim for my peer's INIT packet, followed by
 329	 * a copy of the raw address list of the association.
 330	 * The length of the raw address list is saved in the
 331	 * raw_addr_list_len field, which will be used at the time when
 332	 * the association TCB is re-constructed from the cookie.
 333	 */
 334	__u32 raw_addr_list_len;
 335	struct sctp_init_chunk peer_init[];
 336};
 337
 338
 339/* The format of our cookie that we send to our peer. */
 340struct sctp_signed_cookie {
 341	__u8 signature[SCTP_SECRET_SIZE];
 342	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
 343	struct sctp_cookie c;
 344} __packed;
 345
 346/* This is another convenience type to allocate memory for address
 347 * params for the maximum size and pass such structures around
 348 * internally.
 349 */
 350union sctp_addr_param {
 351	struct sctp_paramhdr p;
 352	struct sctp_ipv4addr_param v4;
 353	struct sctp_ipv6addr_param v6;
 354};
 355
 356/* A convenience type to allow walking through the various
 357 * parameters and avoid casting all over the place.
 358 */
 359union sctp_params {
 360	void *v;
 361	struct sctp_paramhdr *p;
 362	struct sctp_cookie_preserve_param *life;
 363	struct sctp_hostname_param *dns;
 364	struct sctp_cookie_param *cookie;
 365	struct sctp_supported_addrs_param *sat;
 366	struct sctp_ipv4addr_param *v4;
 367	struct sctp_ipv6addr_param *v6;
 368	union sctp_addr_param *addr;
 369	struct sctp_adaptation_ind_param *aind;
 370	struct sctp_supported_ext_param *ext;
 371	struct sctp_random_param *random;
 372	struct sctp_chunks_param *chunks;
 373	struct sctp_hmac_algo_param *hmac_algo;
 374	struct sctp_addip_param *addip;
 375};
 376
 377/* RFC 2960.  Section 3.3.5 Heartbeat.
 378 *    Heartbeat Information: variable length
 379 *    The Sender-specific Heartbeat Info field should normally include
 380 *    information about the sender's current time when this HEARTBEAT
 381 *    chunk is sent and the destination transport address to which this
 382 *    HEARTBEAT is sent (see Section 8.3).
 383 */
 384struct sctp_sender_hb_info {
 385	struct sctp_paramhdr param_hdr;
 386	union sctp_addr daddr;
 387	unsigned long sent_at;
 388	__u64 hb_nonce;
 389	__u32 probe_size;
 390};
 391
 392int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
 393		     gfp_t gfp);
 394int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
 395void sctp_stream_free(struct sctp_stream *stream);
 396void sctp_stream_clear(struct sctp_stream *stream);
 397void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
 398
 399/* What is the current SSN number for this stream? */
 400#define sctp_ssn_peek(stream, type, sid) \
 401	(sctp_stream_##type((stream), (sid))->ssn)
 402
 403/* Return the next SSN number for this stream.	*/
 404#define sctp_ssn_next(stream, type, sid) \
 405	(sctp_stream_##type((stream), (sid))->ssn++)
 406
 407/* Skip over this ssn and all below. */
 408#define sctp_ssn_skip(stream, type, sid, ssn) \
 409	(sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
 410
 411/* What is the current MID number for this stream? */
 412#define sctp_mid_peek(stream, type, sid) \
 413	(sctp_stream_##type((stream), (sid))->mid)
 414
 415/* Return the next MID number for this stream.  */
 416#define sctp_mid_next(stream, type, sid) \
 417	(sctp_stream_##type((stream), (sid))->mid++)
 418
 419/* Skip over this mid and all below. */
 420#define sctp_mid_skip(stream, type, sid, mid) \
 421	(sctp_stream_##type((stream), (sid))->mid = mid + 1)
 422
 423/* What is the current MID_uo number for this stream? */
 424#define sctp_mid_uo_peek(stream, type, sid) \
 425	(sctp_stream_##type((stream), (sid))->mid_uo)
 426
 427/* Return the next MID_uo number for this stream.  */
 428#define sctp_mid_uo_next(stream, type, sid) \
 429	(sctp_stream_##type((stream), (sid))->mid_uo++)
 430
 431/*
 432 * Pointers to address related SCTP functions.
 433 * (i.e. things that depend on the address family.)
 434 */
 435struct sctp_af {
 436	int		(*sctp_xmit)	(struct sk_buff *skb,
 437					 struct sctp_transport *);
 438	int		(*setsockopt)	(struct sock *sk,
 439					 int level,
 440					 int optname,
 441					 sockptr_t optval,
 442					 unsigned int optlen);
 443	int		(*getsockopt)	(struct sock *sk,
 444					 int level,
 445					 int optname,
 446					 char __user *optval,
 447					 int __user *optlen);
 
 
 
 
 
 
 
 
 
 
 448	void		(*get_dst)	(struct sctp_transport *t,
 449					 union sctp_addr *saddr,
 450					 struct flowi *fl,
 451					 struct sock *sk);
 452	void		(*get_saddr)	(struct sctp_sock *sk,
 453					 struct sctp_transport *t,
 454					 struct flowi *fl);
 455	void		(*copy_addrlist) (struct list_head *,
 456					  struct net_device *);
 457	int		(*cmp_addr)	(const union sctp_addr *addr1,
 458					 const union sctp_addr *addr2);
 459	void		(*addr_copy)	(union sctp_addr *dst,
 460					 union sctp_addr *src);
 461	void		(*from_skb)	(union sctp_addr *,
 462					 struct sk_buff *skb,
 463					 int saddr);
 464	void		(*from_sk)	(union sctp_addr *,
 465					 struct sock *sk);
 466	bool		(*from_addr_param) (union sctp_addr *,
 467					    union sctp_addr_param *,
 468					    __be16 port, int iif);
 469	int		(*to_addr_param) (const union sctp_addr *,
 470					  union sctp_addr_param *); 
 471	int		(*addr_valid)	(union sctp_addr *,
 472					 struct sctp_sock *,
 473					 const struct sk_buff *);
 474	enum sctp_scope	(*scope)(union sctp_addr *);
 475	void		(*inaddr_any)	(union sctp_addr *, __be16);
 476	int		(*is_any)	(const union sctp_addr *);
 477	int		(*available)	(union sctp_addr *,
 478					 struct sctp_sock *);
 479	int		(*skb_iif)	(const struct sk_buff *sk);
 480	int		(*is_ce)	(const struct sk_buff *sk);
 481	void		(*seq_dump_addr)(struct seq_file *seq,
 482					 union sctp_addr *addr);
 483	void		(*ecn_capable)(struct sock *sk);
 484	__u16		net_header_len;
 485	int		sockaddr_len;
 486	int		(*ip_options_len)(struct sock *sk);
 487	sa_family_t	sa_family;
 488	struct list_head list;
 489};
 490
 491struct sctp_af *sctp_get_af_specific(sa_family_t);
 492int sctp_register_af(struct sctp_af *);
 493
 494/* Protocol family functions. */
 495struct sctp_pf {
 496	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
 497	void (*skb_msgname)  (struct sk_buff *, char *, int *);
 498	int  (*af_supported) (sa_family_t, struct sctp_sock *);
 499	int  (*cmp_addr) (const union sctp_addr *,
 500			  const union sctp_addr *,
 501			  struct sctp_sock *);
 502	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
 503	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
 504	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
 505	struct sock *(*create_accept_sk) (struct sock *sk,
 506					  struct sctp_association *asoc,
 507					  bool kern);
 508	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
 509	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
 510	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
 511	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
 512	struct sctp_af *af;
 513};
 514
 515
 516/* Structure to track chunk fragments that have been acked, but peer
 517 * fragments of the same message have not.
 518 */
 519struct sctp_datamsg {
 520	/* Chunks waiting to be submitted to lower layer. */
 521	struct list_head chunks;
 522	/* Reference counting. */
 523	refcount_t refcnt;
 524	/* When is this message no longer interesting to the peer? */
 525	unsigned long expires_at;
 526	/* Did the messenge fail to send? */
 527	int send_error;
 528	u8 send_failed:1,
 529	   can_delay:1,	/* should this message be Nagle delayed */
 530	   abandoned:1;	/* should this message be abandoned */
 531};
 532
 533struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
 534					    struct sctp_sndrcvinfo *,
 535					    struct iov_iter *);
 536void sctp_datamsg_free(struct sctp_datamsg *);
 537void sctp_datamsg_put(struct sctp_datamsg *);
 538void sctp_chunk_fail(struct sctp_chunk *, int error);
 539int sctp_chunk_abandoned(struct sctp_chunk *);
 540
 541/* RFC2960 1.4 Key Terms
 542 *
 543 * o Chunk: A unit of information within an SCTP packet, consisting of
 544 * a chunk header and chunk-specific content.
 545 *
 546 * As a matter of convenience, we remember the SCTP common header for
 547 * each chunk as well as a few other header pointers...
 548 */
 549struct sctp_chunk {
 550	struct list_head list;
 551
 552	refcount_t refcnt;
 553
 554	/* How many times this chunk have been sent, for prsctp RTX policy */
 555	int sent_count;
 556
 557	union {
 558		/* This is our link to the per-transport transmitted list.  */
 559		struct list_head transmitted_list;
 560		/* List in specific stream outq */
 561		struct list_head stream_list;
 562	};
 563
 564	/* This field is used by chunks that hold fragmented data.
 565	 * For the first fragment this is the list that holds the rest of
 566	 * fragments. For the remaining fragments, this is the link to the
 567	 * frag_list maintained in the first fragment.
 568	 */
 569	struct list_head frag_list;
 570
 571	/* This points to the sk_buff containing the actual data.  */
 572	struct sk_buff *skb;
 573
 574	union {
 575		/* In case of GSO packets, this will store the head one */
 576		struct sk_buff *head_skb;
 577		/* In case of auth enabled, this will point to the shkey */
 578		struct sctp_shared_key *shkey;
 579	};
 580
 581	/* These are the SCTP headers by reverse order in a packet.
 582	 * Note that some of these may happen more than once.  In that
 583	 * case, we point at the "current" one, whatever that means
 584	 * for that level of header.
 585	 */
 586
 587	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
 588	union sctp_params param_hdr;
 589	union {
 590		__u8 *v;
 591		struct sctp_datahdr *data_hdr;
 592		struct sctp_inithdr *init_hdr;
 593		struct sctp_sackhdr *sack_hdr;
 594		struct sctp_heartbeathdr *hb_hdr;
 595		struct sctp_sender_hb_info *hbs_hdr;
 596		struct sctp_shutdownhdr *shutdown_hdr;
 597		struct sctp_signed_cookie *cookie_hdr;
 598		struct sctp_ecnehdr *ecne_hdr;
 599		struct sctp_cwrhdr *ecn_cwr_hdr;
 600		struct sctp_errhdr *err_hdr;
 601		struct sctp_addiphdr *addip_hdr;
 602		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
 603		struct sctp_authhdr *auth_hdr;
 604		struct sctp_idatahdr *idata_hdr;
 605		struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
 606	} subh;
 607
 608	__u8 *chunk_end;
 609
 610	struct sctp_chunkhdr *chunk_hdr;
 611	struct sctphdr *sctp_hdr;
 612
 613	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
 614	struct sctp_sndrcvinfo sinfo;
 615
 616	/* Which association does this belong to?  */
 617	struct sctp_association *asoc;
 618
 619	/* What endpoint received this chunk? */
 620	struct sctp_ep_common *rcvr;
 621
 622	/* We fill this in if we are calculating RTT. */
 623	unsigned long sent_at;
 624
 625	/* What is the origin IP address for this chunk?  */
 626	union sctp_addr source;
 627	/* Destination address for this chunk. */
 628	union sctp_addr dest;
 629
 630	/* For outbound message, track all fragments for SEND_FAILED. */
 631	struct sctp_datamsg *msg;
 632
 633	/* For an inbound chunk, this tells us where it came from.
 634	 * For an outbound chunk, it tells us where we'd like it to
 635	 * go.	It is NULL if we have no preference.
 636	 */
 637	struct sctp_transport *transport;
 638
 639	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
 640	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
 641	 * spec violates the principle premis that all chunks are processed
 642	 * in order.
 643	 */
 644	struct sk_buff *auth_chunk;
 645
 646#define SCTP_CAN_FRTX 0x0
 647#define SCTP_NEED_FRTX 0x1
 648#define SCTP_DONT_FRTX 0x2
 649	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
 650		has_tsn:1,		/* Does this chunk have a TSN yet? */
 651		has_ssn:1,		/* Does this chunk have a SSN yet? */
 652#define has_mid has_ssn
 653		singleton:1,		/* Only chunk in the packet? */
 654		end_of_packet:1,	/* Last chunk in the packet? */
 655		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
 656		pdiscard:1,		/* Discard the whole packet now? */
 657		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
 658		data_accepted:1,	/* At least 1 chunk accepted */
 659		auth:1,			/* IN: was auth'ed | OUT: needs auth */
 660		has_asconf:1,		/* IN: have seen an asconf before */
 661		pmtu_probe:1,		/* Used by PLPMTUD, can be set in s HB chunk */
 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	unsigned long probe_interval;
 865
 866	/* SACK delay timeout */
 867	unsigned long sackdelay;
 868	__u32 sackfreq;
 869
 870	atomic_t mtu_info;
 871
 872	/* When was the last time that we heard from this transport? We use
 873	 * this to pick new active and retran paths.
 874	 */
 875	ktime_t last_time_heard;
 876
 877	/* When was the last time that we sent a chunk using this
 878	 * transport? We use this to check for idle transports
 879	 */
 880	unsigned long last_time_sent;
 881
 882	/* Last time(in jiffies) when cwnd is reduced due to the congestion
 883	 * indication based on ECNE chunk.
 884	 */
 885	unsigned long last_time_ecne_reduced;
 886
 887	__be16 encap_port;
 888
 889	/* This is the max_retrans value for the transport and will
 890	 * be initialized from the assocs value.  This can be changed
 891	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
 892	 */
 893	__u16 pathmaxrxt;
 894
 895	__u32 flowlabel;
 896	__u8  dscp;
 897
 898	/* This is the partially failed retrans value for the transport
 899	 * and will be initialized from the assocs value.  This can be changed
 900	 * using the SCTP_PEER_ADDR_THLDS socket option
 901	 */
 902	__u16 pf_retrans;
 903	/* Used for primary path switchover. */
 904	__u16 ps_retrans;
 905	/* PMTU	      : The current known path MTU.  */
 906	__u32 pathmtu;
 907
 908	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
 909	__u32 param_flags;
 910
 911	/* The number of times INIT has been sent on this transport. */
 912	int init_sent_count;
 913
 914	/* state       : The current state of this destination,
 915	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
 916	 */
 917	int state;
 918
 919	/* These are the error stats for this destination.  */
 920
 921	/* Error count : The current error count for this destination.	*/
 922	unsigned short error_count;
 923
 924	/* Per	       : A timer used by each destination.
 925	 * Destination :
 926	 * Timer       :
 927	 *
 928	 * [Everywhere else in the text this is called T3-rtx. -ed]
 929	 */
 930	struct timer_list T3_rtx_timer;
 931
 932	/* Heartbeat timer is per destination. */
 933	struct timer_list hb_timer;
 934
 935	/* Timer to handle ICMP proto unreachable envets */
 936	struct timer_list proto_unreach_timer;
 937
 938	/* Timer to handler reconf chunk rtx */
 939	struct timer_list reconf_timer;
 940
 941	/* Timer to send a probe HB packet for PLPMTUD */
 942	struct timer_list probe_timer;
 943
 944	/* Since we're using per-destination retransmission timers
 945	 * (see above), we're also using per-destination "transmitted"
 946	 * queues.  This probably ought to be a private struct
 947	 * accessible only within the outqueue, but it's not, yet.
 948	 */
 949	struct list_head transmitted;
 950
 951	/* We build bundle-able packets for this transport here.  */
 952	struct sctp_packet packet;
 953
 954	/* This is the list of transports that have chunks to send.  */
 955	struct list_head send_ready;
 956
 957	/* State information saved for SFR_CACC algorithm. The key
 958	 * idea in SFR_CACC is to maintain state at the sender on a
 959	 * per-destination basis when a changeover happens.
 960	 *	char changeover_active;
 961	 *	char cycling_changeover;
 962	 *	__u32 next_tsn_at_change;
 963	 *	char cacc_saw_newack;
 964	 */
 965	struct {
 966		/* An unsigned integer, which stores the next TSN to be
 967		 * used by the sender, at the moment of changeover.
 968		 */
 969		__u32 next_tsn_at_change;
 970
 971		/* A flag which indicates the occurrence of a changeover */
 972		char changeover_active;
 973
 974		/* A flag which indicates whether the change of primary is
 975		 * the first switch to this destination address during an
 976		 * active switch.
 977		 */
 978		char cycling_changeover;
 979
 980		/* A temporary flag, which is used during the processing of
 981		 * a SACK to estimate the causative TSN(s)'s group.
 982		 */
 983		char cacc_saw_newack;
 984	} cacc;
 985
 986	struct {
 987		__u32 last_rtx_chunks;
 988		__u16 pmtu;
 989		__u16 probe_size;
 990		__u16 probe_high;
 991		__u8 probe_count:3;
 992		__u8 raise_count:5;
 993		__u8 state;
 994	} pl; /* plpmtud related */
 995
 996	/* 64-bit random number sent with heartbeat. */
 997	__u64 hb_nonce;
 998
 999	struct rcu_head rcu;
1000};
1001
1002struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1003					  gfp_t);
1004void sctp_transport_set_owner(struct sctp_transport *,
1005			      struct sctp_association *);
1006void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1007			  struct sctp_sock *);
1008void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1009void sctp_transport_free(struct sctp_transport *);
1010void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1011void sctp_transport_reset_hb_timer(struct sctp_transport *);
1012void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1013void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1014int sctp_transport_hold(struct sctp_transport *);
1015void sctp_transport_put(struct sctp_transport *);
1016void sctp_transport_update_rto(struct sctp_transport *, __u32);
1017void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1018void sctp_transport_lower_cwnd(struct sctp_transport *t,
1019			       enum sctp_lower_cwnd reason);
1020void sctp_transport_burst_limited(struct sctp_transport *);
1021void sctp_transport_burst_reset(struct sctp_transport *);
1022unsigned long sctp_transport_timeout(struct sctp_transport *);
1023void sctp_transport_reset(struct sctp_transport *t);
1024bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1025void sctp_transport_immediate_rtx(struct sctp_transport *);
1026void sctp_transport_dst_release(struct sctp_transport *t);
1027void sctp_transport_dst_confirm(struct sctp_transport *t);
1028bool sctp_transport_pl_send(struct sctp_transport *t);
1029bool sctp_transport_pl_recv(struct sctp_transport *t);
1030
1031
1032/* This is the structure we use to queue packets as they come into
1033 * SCTP.  We write packets to it and read chunks from it.
1034 */
1035struct sctp_inq {
1036	/* This is actually a queue of sctp_chunk each
1037	 * containing a partially decoded packet.
1038	 */
1039	struct list_head in_chunk_list;
1040	/* This is the packet which is currently off the in queue and is
1041	 * being worked on through the inbound chunk processing.
1042	 */
1043	struct sctp_chunk *in_progress;
1044
1045	/* This is the delayed task to finish delivering inbound
1046	 * messages.
1047	 */
1048	struct work_struct immediate;
1049};
1050
1051void sctp_inq_init(struct sctp_inq *);
1052void sctp_inq_free(struct sctp_inq *);
1053void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1054struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1055struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1056void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1057
1058/* This is the structure we use to hold outbound chunks.  You push
1059 * chunks in and they automatically pop out the other end as bundled
1060 * packets (it calls (*output_handler)()).
1061 *
1062 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1063 * and 8.2 of the v13 draft.
1064 *
1065 * It handles retransmissions.	The connection to the timeout portion
1066 * of the state machine is through sctp_..._timeout() and timeout_handler.
1067 *
1068 * If you feed it SACKs, it will eat them.
1069 *
1070 * If you give it big chunks, it will fragment them.
1071 *
1072 * It assigns TSN's to data chunks.  This happens at the last possible
1073 * instant before transmission.
1074 *
1075 * When free()'d, it empties itself out via output_handler().
1076 */
1077struct sctp_outq {
1078	struct sctp_association *asoc;
1079
1080	/* Data pending that has never been transmitted.  */
1081	struct list_head out_chunk_list;
1082
1083	/* Stream scheduler being used */
1084	struct sctp_sched_ops *sched;
1085
1086	unsigned int out_qlen;	/* Total length of queued data chunks. */
1087
1088	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1089	unsigned int error;
1090
1091	/* These are control chunks we want to send.  */
1092	struct list_head control_chunk_list;
1093
1094	/* These are chunks that have been sacked but are above the
1095	 * CTSN, or cumulative tsn ack point.
1096	 */
1097	struct list_head sacked;
1098
1099	/* Put chunks on this list to schedule them for
1100	 * retransmission.
1101	 */
1102	struct list_head retransmit;
1103
1104	/* Put chunks on this list to save them for FWD TSN processing as
1105	 * they were abandoned.
1106	 */
1107	struct list_head abandoned;
1108
1109	/* How many unackd bytes do we have in-flight?	*/
1110	__u32 outstanding_bytes;
1111
1112	/* Are we doing fast-rtx on this queue */
1113	char fast_rtx;
1114
1115	/* Corked? */
1116	char cork;
1117};
1118
1119void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1120void sctp_outq_teardown(struct sctp_outq *);
1121void sctp_outq_free(struct sctp_outq*);
1122void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1123int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1124int sctp_outq_is_empty(const struct sctp_outq *);
1125void sctp_outq_restart(struct sctp_outq *);
1126
1127void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1128		     enum sctp_retransmit_reason reason);
1129void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1130void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1131void sctp_prsctp_prune(struct sctp_association *asoc,
1132		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1133void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1134/* Uncork and flush an outqueue.  */
1135static inline void sctp_outq_cork(struct sctp_outq *q)
1136{
1137	q->cork = 1;
1138}
1139
1140/* SCTP skb control block.
1141 * sctp_input_cb is currently used on rx and sock rx queue
1142 */
1143struct sctp_input_cb {
1144	union {
1145		struct inet_skb_parm    h4;
1146#if IS_ENABLED(CONFIG_IPV6)
1147		struct inet6_skb_parm   h6;
1148#endif
1149	} header;
1150	struct sctp_chunk *chunk;
1151	struct sctp_af *af;
1152	__be16 encap_port;
1153};
1154#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1155
1156struct sctp_output_cb {
1157	struct sk_buff *last;
1158};
1159#define SCTP_OUTPUT_CB(__skb)	((struct sctp_output_cb *)&((__skb)->cb[0]))
1160
1161static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1162{
1163	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1164
1165	return chunk->head_skb ? : skb;
1166}
1167
1168/* These bind address data fields common between endpoints and associations */
1169struct sctp_bind_addr {
1170
1171	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1172	 *
1173	 * SCTP Port:	The local SCTP port number the endpoint is
1174	 *		bound to.
1175	 */
1176	__u16 port;
1177
1178	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1179	 *
1180	 * Address List: The list of IP addresses that this instance
1181	 *	has bound.  This information is passed to one's
1182	 *	peer(s) in INIT and INIT ACK chunks.
1183	 */
1184	struct list_head address_list;
1185};
1186
1187void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1188void sctp_bind_addr_free(struct sctp_bind_addr *);
1189int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1190			const struct sctp_bind_addr *src,
1191			enum sctp_scope scope, gfp_t gfp,
1192			int flags);
1193int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1194			const struct sctp_bind_addr *src,
1195			gfp_t gfp);
1196int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1197		       int new_size, __u8 addr_state, gfp_t gfp);
1198int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1199int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1200			 struct sctp_sock *);
1201int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1202			 struct sctp_sock *, struct sctp_sock *);
1203int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1204			 const union sctp_addr *addr);
1205int sctp_bind_addrs_check(struct sctp_sock *sp,
1206			  struct sctp_sock *sp2, int cnt2);
1207union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1208					const union sctp_addr	*addrs,
1209					int			addrcnt,
1210					struct sctp_sock	*opt);
1211union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1212					 int *addrs_len,
1213					 gfp_t gfp);
1214int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1215			   __u16 port, gfp_t gfp);
1216
1217enum sctp_scope sctp_scope(const union sctp_addr *addr);
1218int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1219		  const enum sctp_scope scope);
1220int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1221int sctp_is_ep_boundall(struct sock *sk);
1222
1223
1224/* What type of endpoint?  */
1225enum sctp_endpoint_type {
1226	SCTP_EP_TYPE_SOCKET,
1227	SCTP_EP_TYPE_ASSOCIATION,
1228};
1229
1230/*
1231 * A common base class to bridge the implmentation view of a
1232 * socket (usually listening) endpoint versus an association's
1233 * local endpoint.
1234 * This common structure is useful for several purposes:
1235 *   1) Common interface for lookup routines.
1236 *	a) Subfunctions work for either endpoint or association
1237 *	b) Single interface to lookup allows hiding the lookup lock rather
1238 *	   than acquiring it externally.
1239 *   2) Common interface for the inbound chunk handling/state machine.
1240 *   3) Common object handling routines for reference counting, etc.
1241 *   4) Disentangle association lookup from endpoint lookup, where we
1242 *	do not have to find our endpoint to find our association.
1243 *
1244 */
1245
1246struct sctp_ep_common {
1247	/* Fields to help us manage our entries in the hash tables. */
1248	struct hlist_node node;
1249	int hashent;
1250
1251	/* Runtime type information.  What kind of endpoint is this? */
1252	enum sctp_endpoint_type type;
1253
1254	/* Some fields to help us manage this object.
1255	 *   refcnt   - Reference count access to this object.
1256	 *   dead     - Do not attempt to use this object.
1257	 */
1258	refcount_t    refcnt;
1259	bool	    dead;
1260
1261	/* What socket does this endpoint belong to?  */
1262	struct sock *sk;
1263
1264	/* Cache netns and it won't change once set */
1265	struct net *net;
1266
1267	/* This is where we receive inbound chunks.  */
1268	struct sctp_inq	  inqueue;
1269
1270	/* This substructure includes the defining parameters of the
1271	 * endpoint:
1272	 * bind_addr.port is our shared port number.
1273	 * bind_addr.address_list is our set of local IP addresses.
1274	 */
1275	struct sctp_bind_addr bind_addr;
1276};
1277
1278
1279/* RFC Section 1.4 Key Terms
1280 *
1281 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1282 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1283 *   combination of a set of eligible destination transport addresses to
1284 *   which SCTP packets can be sent and a set of eligible source
1285 *   transport addresses from which SCTP packets can be received.
1286 *   All transport addresses used by an SCTP endpoint must use the
1287 *   same port number, but can use multiple IP addresses. A transport
1288 *   address used by an SCTP endpoint must not be used by another
1289 *   SCTP endpoint. In other words, a transport address is unique
1290 *   to an SCTP endpoint.
1291 *
1292 * From an implementation perspective, each socket has one of these.
1293 * A TCP-style socket will have exactly one association on one of
1294 * these.  An UDP-style socket will have multiple associations hanging
1295 * off one of these.
1296 */
1297
1298struct sctp_endpoint {
1299	/* Common substructure for endpoint and association. */
1300	struct sctp_ep_common base;
1301
1302	/* Associations: A list of current associations and mappings
1303	 *	      to the data consumers for each association. This
1304	 *	      may be in the form of a hash table or other
1305	 *	      implementation dependent structure. The data
1306	 *	      consumers may be process identification
1307	 *	      information such as file descriptors, named pipe
1308	 *	      pointer, or table pointers dependent on how SCTP
1309	 *	      is implemented.
1310	 */
1311	/* This is really a list of struct sctp_association entries. */
1312	struct list_head asocs;
1313
1314	/* Secret Key: A secret key used by this endpoint to compute
1315	 *	      the MAC.	This SHOULD be a cryptographic quality
1316	 *	      random number with a sufficient length.
1317	 *	      Discussion in [RFC1750] can be helpful in
1318	 *	      selection of the key.
1319	 */
1320	__u8 secret_key[SCTP_SECRET_SIZE];
1321
1322 	/* digest:  This is a digest of the sctp cookie.  This field is
1323 	 * 	    only used on the receive path when we try to validate
1324 	 * 	    that the cookie has not been tampered with.  We put
1325 	 * 	    this here so we pre-allocate this once and can re-use
1326 	 * 	    on every receive.
1327 	 */
1328 	__u8 *digest;
1329 
1330	/* sendbuf acct. policy.	*/
1331	__u32 sndbuf_policy;
1332
1333	/* rcvbuf acct. policy.	*/
1334	__u32 rcvbuf_policy;
1335
1336	/* SCTP AUTH: array of the HMACs that will be allocated
1337	 * we need this per association so that we don't serialize
1338	 */
1339	struct crypto_shash **auth_hmacs;
1340
1341	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1342	 struct sctp_hmac_algo_param *auth_hmacs_list;
1343
1344	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1345	struct sctp_chunks_param *auth_chunk_list;
1346
1347	/* SCTP-AUTH: endpoint shared keys */
1348	struct list_head endpoint_shared_keys;
1349	__u16 active_key_id;
1350	__u8  ecn_enable:1,
1351	      auth_enable:1,
1352	      intl_enable:1,
1353	      prsctp_enable:1,
1354	      asconf_enable:1,
1355	      reconf_enable:1;
1356
1357	__u8  strreset_enable;
1358
1359	/* Security identifiers from incoming (INIT). These are set by
1360	 * security_sctp_assoc_request(). These will only be used by
1361	 * SCTP TCP type sockets and peeled off connections as they
1362	 * cause a new socket to be generated. security_sctp_sk_clone()
1363	 * will then plug these into the new socket.
1364	 */
1365
1366	u32 secid;
1367	u32 peer_secid;
1368};
1369
1370/* Recover the outter endpoint structure. */
1371static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1372{
1373	struct sctp_endpoint *ep;
1374
1375	ep = container_of(base, struct sctp_endpoint, base);
1376	return ep;
1377}
1378
1379/* These are function signatures for manipulating endpoints.  */
1380struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1381void sctp_endpoint_free(struct sctp_endpoint *);
1382void sctp_endpoint_put(struct sctp_endpoint *);
1383void sctp_endpoint_hold(struct sctp_endpoint *);
1384void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1385struct sctp_association *sctp_endpoint_lookup_assoc(
1386	const struct sctp_endpoint *ep,
1387	const union sctp_addr *paddr,
1388	struct sctp_transport **);
1389bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1390				 const union sctp_addr *paddr);
1391struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1392					struct net *, const union sctp_addr *);
1393bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1394			  const union sctp_addr *paddr);
1395
1396int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1397		     const struct sctp_association *asoc,
1398		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1399		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1400int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1401		      const union sctp_addr *peer,
1402		      struct sctp_init_chunk *init, gfp_t gfp);
1403__u32 sctp_generate_tag(const struct sctp_endpoint *);
1404__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1405
1406struct sctp_inithdr_host {
1407	__u32 init_tag;
1408	__u32 a_rwnd;
1409	__u16 num_outbound_streams;
1410	__u16 num_inbound_streams;
1411	__u32 initial_tsn;
1412};
1413
1414struct sctp_stream_priorities {
1415	/* List of priorities scheduled */
1416	struct list_head prio_sched;
1417	/* List of streams scheduled */
1418	struct list_head active;
1419	/* The next stream in line */
1420	struct sctp_stream_out_ext *next;
1421	__u16 prio;
1422};
1423
1424struct sctp_stream_out_ext {
1425	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1426	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1427	struct list_head outq; /* chunks enqueued by this stream */
1428	union {
1429		struct {
1430			/* Scheduled streams list */
1431			struct list_head prio_list;
1432			struct sctp_stream_priorities *prio_head;
1433		};
1434		/* Fields used by RR scheduler */
1435		struct {
1436			struct list_head rr_list;
1437		};
1438	};
1439};
1440
1441struct sctp_stream_out {
1442	union {
1443		__u32 mid;
1444		__u16 ssn;
1445	};
1446	__u32 mid_uo;
1447	struct sctp_stream_out_ext *ext;
1448	__u8 state;
1449};
1450
1451struct sctp_stream_in {
1452	union {
1453		__u32 mid;
1454		__u16 ssn;
1455	};
1456	__u32 mid_uo;
1457	__u32 fsn;
1458	__u32 fsn_uo;
1459	char pd_mode;
1460	char pd_mode_uo;
1461};
1462
1463struct sctp_stream {
1464	GENRADIX(struct sctp_stream_out) out;
1465	GENRADIX(struct sctp_stream_in)	in;
1466
1467	__u16 outcnt;
1468	__u16 incnt;
1469	/* Current stream being sent, if any */
1470	struct sctp_stream_out *out_curr;
1471	union {
1472		/* Fields used by priority scheduler */
1473		struct {
1474			/* List of priorities scheduled */
1475			struct list_head prio_list;
1476		};
1477		/* Fields used by RR scheduler */
1478		struct {
1479			/* List of streams scheduled */
1480			struct list_head rr_list;
1481			/* The next stream in line */
1482			struct sctp_stream_out_ext *rr_next;
1483		};
1484	};
1485	struct sctp_stream_interleave *si;
1486};
1487
1488static inline struct sctp_stream_out *sctp_stream_out(
1489	struct sctp_stream *stream,
1490	__u16 sid)
1491{
1492	return genradix_ptr(&stream->out, sid);
1493}
1494
1495static inline struct sctp_stream_in *sctp_stream_in(
1496	struct sctp_stream *stream,
1497	__u16 sid)
1498{
1499	return genradix_ptr(&stream->in, sid);
1500}
1501
1502#define SCTP_SO(s, i) sctp_stream_out((s), (i))
1503#define SCTP_SI(s, i) sctp_stream_in((s), (i))
1504
1505#define SCTP_STREAM_CLOSED		0x00
1506#define SCTP_STREAM_OPEN		0x01
1507
1508static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1509{
1510	return stream->si->data_chunk_len;
1511}
1512
1513static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1514{
1515	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1516}
1517
1518static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1519{
1520	return stream->si->ftsn_chunk_len;
1521}
1522
1523static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1524{
1525	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1526}
1527
1528/* SCTP_GET_ASSOC_STATS counters */
1529struct sctp_priv_assoc_stats {
1530	/* Maximum observed rto in the association during subsequent
1531	 * observations. Value is set to 0 if no RTO measurement took place
1532	 * The transport where the max_rto was observed is returned in
1533	 * obs_rto_ipaddr
1534	 */
1535	struct sockaddr_storage obs_rto_ipaddr;
1536	__u64 max_obs_rto;
1537	/* Total In and Out SACKs received and sent */
1538	__u64 isacks;
1539	__u64 osacks;
1540	/* Total In and Out packets received and sent */
1541	__u64 opackets;
1542	__u64 ipackets;
1543	/* Total retransmitted chunks */
1544	__u64 rtxchunks;
1545	/* TSN received > next expected */
1546	__u64 outofseqtsns;
1547	/* Duplicate Chunks received */
1548	__u64 idupchunks;
1549	/* Gap Ack Blocks received */
1550	__u64 gapcnt;
1551	/* Unordered data chunks sent and received */
1552	__u64 ouodchunks;
1553	__u64 iuodchunks;
1554	/* Ordered data chunks sent and received */
1555	__u64 oodchunks;
1556	__u64 iodchunks;
1557	/* Control chunks sent and received */
1558	__u64 octrlchunks;
1559	__u64 ictrlchunks;
1560};
1561
1562/* RFC2960
1563 *
1564 * 12. Recommended Transmission Control Block (TCB) Parameters
1565 *
1566 * This section details a recommended set of parameters that should
1567 * be contained within the TCB for an implementation. This section is
1568 * for illustrative purposes and should not be deemed as requirements
1569 * on an implementation or as an exhaustive list of all parameters
1570 * inside an SCTP TCB. Each implementation may need its own additional
1571 * parameters for optimization.
1572 */
1573
1574
1575/* Here we have information about each individual association. */
1576struct sctp_association {
1577
1578	/* A base structure common to endpoint and association.
1579	 * In this context, it represents the associations's view
1580	 * of the local endpoint of the association.
1581	 */
1582	struct sctp_ep_common base;
1583
1584	/* Associations on the same socket. */
1585	struct list_head asocs;
1586
1587	/* association id. */
1588	sctp_assoc_t assoc_id;
1589
1590	/* This is our parent endpoint.	 */
1591	struct sctp_endpoint *ep;
1592
1593	/* These are those association elements needed in the cookie.  */
1594	struct sctp_cookie c;
1595
1596	/* This is all information about our peer.  */
1597	struct {
1598		/* transport_addr_list
1599		 *
1600		 * Peer	       : A list of SCTP transport addresses that the
1601		 * Transport   : peer is bound to. This information is derived
1602		 * Address     : from the INIT or INIT ACK and is used to
1603		 * List	       : associate an inbound packet with a given
1604		 *	       : association. Normally this information is
1605		 *	       : hashed or keyed for quick lookup and access
1606		 *	       : of the TCB.
1607		 *	       : The list is also initialized with the list
1608		 *	       : of addresses passed with the sctp_connectx()
1609		 *	       : call.
1610		 *
1611		 * It is a list of SCTP_transport's.
1612		 */
1613		struct list_head transport_addr_list;
1614
1615		/* rwnd
1616		 *
1617		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1618		 */
1619		__u32 rwnd;
1620
1621		/* transport_count
1622		 *
1623		 * Peer        : A count of the number of peer addresses
1624		 * Transport   : in the Peer Transport Address List.
1625		 * Address     :
1626		 * Count       :
1627		 */
1628		__u16 transport_count;
1629
1630		/* port
1631		 *   The transport layer port number.
1632		 */
1633		__u16 port;
1634
1635		/* primary_path
1636		 *
1637		 * Primary     : This is the current primary destination
1638		 * Path	       : transport address of the peer endpoint.  It
1639		 *	       : may also specify a source transport address
1640		 *	       : on this endpoint.
1641		 *
1642		 * All of these paths live on transport_addr_list.
1643		 *
1644		 * At the bakeoffs, we discovered that the intent of
1645		 * primaryPath is that it only changes when the ULP
1646		 * asks to have it changed.  We add the activePath to
1647		 * designate the connection we are currently using to
1648		 * transmit new data and most control chunks.
1649		 */
1650		struct sctp_transport *primary_path;
1651
1652		/* Cache the primary path address here, when we
1653		 * need a an address for msg_name.
1654		 */
1655		union sctp_addr primary_addr;
1656
1657		/* active_path
1658		 *   The path that we are currently using to
1659		 *   transmit new data and most control chunks.
1660		 */
1661		struct sctp_transport *active_path;
1662
1663		/* retran_path
1664		 *
1665		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1666		 * ...
1667		 * Furthermore, when its peer is multi-homed, an
1668		 * endpoint SHOULD try to retransmit a chunk to an
1669		 * active destination transport address that is
1670		 * different from the last destination address to
1671		 * which the DATA chunk was sent.
1672		 */
1673		struct sctp_transport *retran_path;
1674
1675		/* Pointer to last transport I have sent on.  */
1676		struct sctp_transport *last_sent_to;
1677
1678		/* This is the last transport I have received DATA on.	*/
1679		struct sctp_transport *last_data_from;
1680
1681		/*
1682		 * Mapping  An array of bits or bytes indicating which out of
1683		 * Array    order TSN's have been received (relative to the
1684		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1685		 *	    order packets have been received, this array
1686		 *	    will be set to all zero. This structure may be
1687		 *	    in the form of a circular buffer or bit array.
1688		 *
1689		 * Last Rcvd   : This is the last TSN received in
1690		 * TSN	       : sequence. This value is set initially by
1691		 *	       : taking the peer's Initial TSN, received in
1692		 *	       : the INIT or INIT ACK chunk, and subtracting
1693		 *	       : one from it.
1694		 *
1695		 * Throughout most of the specification this is called the
1696		 * "Cumulative TSN ACK Point".	In this case, we
1697		 * ignore the advice in 12.2 in favour of the term
1698		 * used in the bulk of the text.  This value is hidden
1699		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1700		 */
1701		struct sctp_tsnmap tsn_map;
1702
1703		/* This mask is used to disable sending the ASCONF chunk
1704		 * with specified parameter to peer.
1705		 */
1706		__be16 addip_disabled_mask;
1707
1708		/* These are capabilities which our peer advertised.  */
1709		__u16	ecn_capable:1,      /* Can peer do ECN? */
1710			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1711			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1712			hostname_address:1, /* Peer understands DNS addresses? */
1713			asconf_capable:1,   /* Does peer support ADDIP? */
1714			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1715			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1716			intl_capable:1,     /* Can peer do INTERLEAVE */
1717			auth_capable:1,     /* Is peer doing SCTP-AUTH? */
1718			/* sack_needed:
1719			 *   This flag indicates if the next received
1720			 *   packet is to be responded to with a
1721			 *   SACK. This is initialized to 0.  When a packet
1722			 *   is received sack_cnt is incremented. If this value
1723			 *   reaches 2 or more, a SACK is sent and the
1724			 *   value is reset to 0. Note: This is used only
1725			 *   when no DATA chunks are received out of
1726			 *   order.  When DATA chunks are out of order,
1727			 *   SACK's are not delayed (see Section 6).
1728			 */
1729			sack_needed:1,     /* Do we need to sack the peer? */
1730			sack_generation:1,
1731			zero_window_announced:1;
1732
1733		__u32	sack_cnt;
1734
1735		__u32   adaptation_ind;	 /* Adaptation Code point. */
1736
1737		struct sctp_inithdr_host i;
1738		void *cookie;
1739		int cookie_len;
1740
1741		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1742		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1743		 * Initial TSN Value minus 1
1744		 */
1745		__u32 addip_serial;
1746
1747		/* SCTP-AUTH: We need to know pears random number, hmac list
1748		 * and authenticated chunk list.  All that is part of the
1749		 * cookie and these are just pointers to those locations
1750		 */
1751		struct sctp_random_param *peer_random;
1752		struct sctp_chunks_param *peer_chunks;
1753		struct sctp_hmac_algo_param *peer_hmacs;
1754	} peer;
1755
1756	/* State       : A state variable indicating what state the
1757	 *	       : association is in, i.e. COOKIE-WAIT,
1758	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1759	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1760	 *
1761	 *		Note: No "CLOSED" state is illustrated since if a
1762	 *		association is "CLOSED" its TCB SHOULD be removed.
1763	 *
1764	 *		In this implementation we DO have a CLOSED
1765	 *		state which is used during initiation and shutdown.
1766	 *
1767	 *		State takes values from SCTP_STATE_*.
1768	 */
1769	enum sctp_state state;
1770
1771	/* Overall     : The overall association error count.
1772	 * Error Count : [Clear this any time I get something.]
1773	 */
1774	int overall_error_count;
1775
1776	/* The cookie life I award for any cookie.  */
1777	ktime_t cookie_life;
1778
1779	/* These are the association's initial, max, and min RTO values.
1780	 * These values will be initialized by system defaults, but can
1781	 * be modified via the SCTP_RTOINFO socket option.
1782	 */
1783	unsigned long rto_initial;
1784	unsigned long rto_max;
1785	unsigned long rto_min;
1786
1787	/* Maximum number of new data packets that can be sent in a burst.  */
1788	int max_burst;
1789
1790	/* This is the max_retrans value for the association.  This value will
1791	 * be initialized from system defaults, but can be
1792	 * modified by the SCTP_ASSOCINFO socket option.
1793	 */
1794	int max_retrans;
1795
1796	/* This is the partially failed retrans value for the transport
1797	 * and will be initialized from the assocs value.  This can be
1798	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1799	 */
1800	__u16 pf_retrans;
1801	/* Used for primary path switchover. */
1802	__u16 ps_retrans;
1803
1804	/* Maximum number of times the endpoint will retransmit INIT  */
1805	__u16 max_init_attempts;
1806
1807	/* How many times have we resent an INIT? */
1808	__u16 init_retries;
1809
1810	/* The largest timeout or RTO value to use in attempting an INIT */
1811	unsigned long max_init_timeo;
1812
1813	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1814	 * the destination address every heartbeat interval. This value
1815	 * will be inherited by all new transports.
1816	 */
1817	unsigned long hbinterval;
1818	unsigned long probe_interval;
1819
1820	__be16 encap_port;
1821
1822	/* This is the max_retrans value for new transports in the
1823	 * association.
1824	 */
1825	__u16 pathmaxrxt;
1826
1827	__u32 flowlabel;
1828	__u8  dscp;
1829
1830	/* Flag that path mtu update is pending */
1831	__u8   pmtu_pending;
1832
1833	/* Association : The smallest PMTU discovered for all of the
1834	 * PMTU	       : peer's transport addresses.
1835	 */
1836	__u32 pathmtu;
1837
1838	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1839	__u32 param_flags;
1840
1841	__u32 sackfreq;
1842	/* SACK delay timeout */
1843	unsigned long sackdelay;
1844
1845	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1846	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1847
1848	/* Transport to which SHUTDOWN chunk was last sent.  */
1849	struct sctp_transport *shutdown_last_sent_to;
1850
1851	/* Transport to which INIT chunk was last sent.  */
1852	struct sctp_transport *init_last_sent_to;
1853
1854	/* How many times have we resent a SHUTDOWN */
1855	int shutdown_retries;
1856
1857	/* Next TSN    : The next TSN number to be assigned to a new
1858	 *	       : DATA chunk.  This is sent in the INIT or INIT
1859	 *	       : ACK chunk to the peer and incremented each
1860	 *	       : time a DATA chunk is assigned a TSN
1861	 *	       : (normally just prior to transmit or during
1862	 *	       : fragmentation).
1863	 */
1864	__u32 next_tsn;
1865
1866	/*
1867	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1868	 * TSN	       : is set initially by taking the peer's Initial TSN,
1869	 *	       : received in the INIT or INIT ACK chunk, and
1870	 *	       : subtracting one from it.
1871	 *
1872	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1873	 */
1874
1875	__u32 ctsn_ack_point;
1876
1877	/* PR-SCTP Advanced.Peer.Ack.Point */
1878	__u32 adv_peer_ack_point;
1879
1880	/* Highest TSN that is acknowledged by incoming SACKs. */
1881	__u32 highest_sacked;
1882
1883	/* TSN marking the fast recovery exit point */
1884	__u32 fast_recovery_exit;
1885
1886	/* Flag to track the current fast recovery state */
1887	__u8 fast_recovery;
1888
1889	/* The number of unacknowledged data chunks.  Reported through
1890	 * the SCTP_STATUS sockopt.
1891	 */
1892	__u16 unack_data;
1893
1894	/* The total number of data chunks that we've had to retransmit
1895	 * as the result of a T3 timer expiration
1896	 */
1897	__u32 rtx_data_chunks;
1898
1899	/* This is the association's receive buffer space.  This value is used
1900	 * to set a_rwnd field in an INIT or a SACK chunk.
1901	 */
1902	__u32 rwnd;
1903
1904	/* This is the last advertised value of rwnd over a SACK chunk. */
1905	__u32 a_rwnd;
1906
1907	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1908	 * to slop over a maximum of the association's frag_point.
1909	 */
1910	__u32 rwnd_over;
1911
1912	/* Keeps treack of rwnd pressure.  This happens when we have
1913	 * a window, but not recevie buffer (i.e small packets).  This one
1914	 * is releases slowly (1 PMTU at a time ).
1915	 */
1916	__u32 rwnd_press;
1917
1918	/* This is the sndbuf size in use for the association.
1919	 * This corresponds to the sndbuf size for the association,
1920	 * as specified in the sk->sndbuf.
1921	 */
1922	int sndbuf_used;
1923
1924	/* This is the amount of memory that this association has allocated
1925	 * in the receive path at any given time.
1926	 */
1927	atomic_t rmem_alloc;
1928
1929	/* This is the wait queue head for send requests waiting on
1930	 * the association sndbuf space.
1931	 */
1932	wait_queue_head_t	wait;
1933
1934	/* The message size at which SCTP fragmentation will occur. */
1935	__u32 frag_point;
1936	__u32 user_frag;
1937
1938	/* Counter used to count INIT errors. */
1939	int init_err_counter;
1940
1941	/* Count the number of INIT cycles (for doubling timeout). */
1942	int init_cycle;
1943
1944	/* Default send parameters. */
1945	__u16 default_stream;
1946	__u16 default_flags;
1947	__u32 default_ppid;
1948	__u32 default_context;
1949	__u32 default_timetolive;
1950
1951	/* Default receive parameters */
1952	__u32 default_rcv_context;
1953
1954	/* Stream arrays */
1955	struct sctp_stream stream;
1956
1957	/* All outbound chunks go through this structure.  */
1958	struct sctp_outq outqueue;
1959
1960	/* A smart pipe that will handle reordering and fragmentation,
1961	 * as well as handle passing events up to the ULP.
1962	 */
1963	struct sctp_ulpq ulpq;
1964
1965	/* Last TSN that caused an ECNE Chunk to be sent.  */
1966	__u32 last_ecne_tsn;
1967
1968	/* Last TSN that caused a CWR Chunk to be sent.	 */
1969	__u32 last_cwr_tsn;
1970
1971	/* How many duplicated TSNs have we seen?  */
1972	int numduptsns;
1973
1974	/* These are to support
1975	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1976	 *  and Enforcement of Flow and Message Limits"
1977	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1978	 * or "ADDIP" for short.
1979	 */
1980
1981
1982
1983	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1984	 *
1985	 * R1) One and only one ASCONF Chunk MAY be in transit and
1986	 * unacknowledged at any one time.  If a sender, after sending
1987	 * an ASCONF chunk, decides it needs to transfer another
1988	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1989	 * returns from the previous ASCONF Chunk before sending a
1990	 * subsequent ASCONF. Note this restriction binds each side,
1991	 * so at any time two ASCONF may be in-transit on any given
1992	 * association (one sent from each endpoint).
1993	 *
1994	 * [This is our one-and-only-one ASCONF in flight.  If we do
1995	 * not have an ASCONF in flight, this is NULL.]
1996	 */
1997	struct sctp_chunk *addip_last_asconf;
1998
1999	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
2000	 *
2001	 * This is needed to implement itmes E1 - E4 of the updated
2002	 * spec.  Here is the justification:
2003	 *
2004	 * Since the peer may bundle multiple ASCONF chunks toward us,
2005	 * we now need the ability to cache multiple ACKs.  The section
2006	 * describes in detail how they are cached and cleaned up.
2007	 */
2008	struct list_head asconf_ack_list;
2009
2010	/* These ASCONF chunks are waiting to be sent.
2011	 *
2012	 * These chunaks can't be pushed to outqueue until receiving
2013	 * ASCONF_ACK for the previous ASCONF indicated by
2014	 * addip_last_asconf, so as to guarantee that only one ASCONF
2015	 * is in flight at any time.
2016	 *
2017	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2018	 *
2019	 * In defining the ASCONF Chunk transfer procedures, it is
2020	 * essential that these transfers MUST NOT cause congestion
2021	 * within the network.	To achieve this, we place these
2022	 * restrictions on the transfer of ASCONF Chunks:
2023	 *
2024	 * R1) One and only one ASCONF Chunk MAY be in transit and
2025	 * unacknowledged at any one time.  If a sender, after sending
2026	 * an ASCONF chunk, decides it needs to transfer another
2027	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2028	 * returns from the previous ASCONF Chunk before sending a
2029	 * subsequent ASCONF. Note this restriction binds each side,
2030	 * so at any time two ASCONF may be in-transit on any given
2031	 * association (one sent from each endpoint).
2032	 *
2033	 *
2034	 * [I really think this is EXACTLY the sort of intelligence
2035	 *  which already resides in sctp_outq.	 Please move this
2036	 *  queue and its supporting logic down there.	--piggy]
2037	 */
2038	struct list_head addip_chunk_list;
2039
2040	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2041	 *
2042	 * A2) A serial number should be assigned to the Chunk. The
2043	 * serial number SHOULD be a monotonically increasing
2044	 * number. The serial number SHOULD be initialized at
2045	 * the start of the association to the same value as the
2046	 * Initial TSN and every time a new ASCONF chunk is created
2047	 * it is incremented by one after assigning the serial number
2048	 * to the newly created chunk.
2049	 *
2050	 * ADDIP
2051	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2052	 *
2053	 * Serial Number : 32 bits (unsigned integer)
2054	 *
2055	 * This value represents a Serial Number for the ASCONF
2056	 * Chunk. The valid range of Serial Number is from 0 to
2057	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2058	 * after reaching 4294967295.
2059	 */
2060	__u32 addip_serial;
2061	int src_out_of_asoc_ok;
2062	union sctp_addr *asconf_addr_del_pending;
2063	struct sctp_transport *new_transport;
2064
2065	/* SCTP AUTH: list of the endpoint shared keys.  These
2066	 * keys are provided out of band by the user applicaton
2067	 * and can't change during the lifetime of the association
2068	 */
2069	struct list_head endpoint_shared_keys;
2070
2071	/* SCTP AUTH:
2072	 * The current generated assocaition shared key (secret)
2073	 */
2074	struct sctp_auth_bytes *asoc_shared_key;
2075	struct sctp_shared_key *shkey;
2076
2077	/* SCTP AUTH: hmac id of the first peer requested algorithm
2078	 * that we support.
2079	 */
2080	__u16 default_hmac_id;
2081
2082	__u16 active_key_id;
2083
2084	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2085	     temp:1,		/* Is it a temporary association? */
2086	     pf_expose:2,       /* Expose pf state? */
2087	     force_delay:1;
2088
2089	__u8 strreset_enable;
2090	__u8 strreset_outstanding; /* request param count on the fly */
2091
2092	__u32 strreset_outseq; /* Update after receiving response */
2093	__u32 strreset_inseq; /* Update after receiving request */
2094	__u32 strreset_result[2]; /* save the results of last 2 responses */
2095
2096	struct sctp_chunk *strreset_chunk; /* save request chunk */
2097
2098	struct sctp_priv_assoc_stats stats;
2099
2100	int sent_cnt_removable;
2101
2102	__u16 subscribe;
2103
2104	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2105	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2106
2107	struct rcu_head rcu;
2108};
2109
2110
2111/* An eyecatcher for determining if we are really looking at an
2112 * association data structure.
2113 */
2114enum {
2115	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2116};
2117
2118/* Recover the outter association structure. */
2119static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2120{
2121	struct sctp_association *asoc;
2122
2123	asoc = container_of(base, struct sctp_association, base);
2124	return asoc;
2125}
2126
2127/* These are function signatures for manipulating associations.	 */
2128
2129
2130struct sctp_association *
2131sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2132		     enum sctp_scope scope, gfp_t gfp);
2133void sctp_association_free(struct sctp_association *);
2134void sctp_association_put(struct sctp_association *);
2135void sctp_association_hold(struct sctp_association *);
2136
2137struct sctp_transport *sctp_assoc_choose_alter_transport(
2138	struct sctp_association *, struct sctp_transport *);
2139void sctp_assoc_update_retran_path(struct sctp_association *);
2140struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2141					  const union sctp_addr *);
2142int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2143			    const union sctp_addr *laddr);
2144struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2145				     const union sctp_addr *address,
2146				     const gfp_t gfp,
2147				     const int peer_state);
2148void sctp_assoc_del_peer(struct sctp_association *asoc,
2149			 const union sctp_addr *addr);
2150void sctp_assoc_rm_peer(struct sctp_association *asoc,
2151			 struct sctp_transport *peer);
2152void sctp_assoc_control_transport(struct sctp_association *asoc,
2153				  struct sctp_transport *transport,
2154				  enum sctp_transport_cmd command,
2155				  sctp_sn_error_t error);
2156struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2157void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2158int sctp_assoc_update(struct sctp_association *old,
2159		      struct sctp_association *new);
2160
2161__u32 sctp_association_get_next_tsn(struct sctp_association *);
2162
2163void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2164void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2165void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2166void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2167void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2168void sctp_assoc_set_primary(struct sctp_association *,
2169			    struct sctp_transport *);
2170void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2171				    struct sctp_transport *);
2172int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2173				     enum sctp_scope scope, gfp_t gfp);
2174int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2175					 struct sctp_cookie*,
2176					 gfp_t gfp);
2177int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2178void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2179struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2180					const struct sctp_association *asoc,
2181					__be32 serial);
2182void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2183
2184int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2185			const union sctp_addr *ss2);
2186struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2187
2188/* A convenience structure to parse out SCTP specific CMSGs. */
2189struct sctp_cmsgs {
2190	struct sctp_initmsg *init;
2191	struct sctp_sndrcvinfo *srinfo;
2192	struct sctp_sndinfo *sinfo;
2193	struct sctp_prinfo *prinfo;
2194	struct sctp_authinfo *authinfo;
2195	struct msghdr *addrs_msg;
2196};
2197
2198/* Structure for tracking memory objects */
2199struct sctp_dbg_objcnt_entry {
2200	char *label;
2201	atomic_t *counter;
2202};
2203
2204#endif /* __sctp_structs_h__ */