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1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 *		   ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING.  If not, write to
23 * the Free Software Foundation, 59 Temple Place - Suite 330,
24 * Boston, MA 02111-1307, USA.
25 *
26 * Please send any bug reports or fixes you make to the
27 * email addresses:
28 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
29 *
30 * Or submit a bug report through the following website:
31 *    http://www.sf.net/projects/lksctp
32 *
33 * Written or modified by:
34 *    Randall Stewart	    <randall@sctp.chicago.il.us>
35 *    Ken Morneau	    <kmorneau@cisco.com>
36 *    Qiaobing Xie	    <qxie1@email.mot.com>
37 *    La Monte H.P. Yarroll <piggy@acm.org>
38 *    Karl Knutson	    <karl@athena.chicago.il.us>
39 *    Jon Grimm		    <jgrimm@us.ibm.com>
40 *    Xingang Guo	    <xingang.guo@intel.com>
41 *    Hui Huang		    <hui.huang@nokia.com>
42 *    Sridhar Samudrala	    <sri@us.ibm.com>
43 *    Daisy Chang	    <daisyc@us.ibm.com>
44 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
45 *    Ardelle Fan	    <ardelle.fan@intel.com>
46 *    Ryan Layer	    <rmlayer@us.ibm.com>
47 *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
48 *    Kevin Gao             <kevin.gao@intel.com>
49 *
50 * Any bugs reported given to us we will try to fix... any fixes shared will
51 * be incorporated into the next SCTP release.
52 */
53
54#ifndef __sctp_structs_h__
55#define __sctp_structs_h__
56
57#include <linux/time.h>		/* We get struct timespec.    */
58#include <linux/socket.h>	/* linux/in.h needs this!!    */
59#include <linux/in.h>		/* We get struct sockaddr_in. */
60#include <linux/in6.h>		/* We get struct in6_addr     */
61#include <linux/ipv6.h>
62#include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
63#include <asm/atomic.h>		/* This gets us atomic counters.  */
64#include <linux/skbuff.h>	/* We need sk_buff_head. */
65#include <linux/workqueue.h>	/* We need tq_struct.	 */
66#include <linux/sctp.h>		/* We need sctp* header structs.  */
67#include <net/sctp/auth.h>	/* We need auth specific structs */
68
69/* A convenience structure for handling sockaddr structures.
70 * We should wean ourselves off this.
71 */
72union sctp_addr {
73	struct sockaddr_in v4;
74	struct sockaddr_in6 v6;
75	struct sockaddr sa;
76};
77
78/* Forward declarations for data structures. */
79struct sctp_globals;
80struct sctp_endpoint;
81struct sctp_association;
82struct sctp_transport;
83struct sctp_packet;
84struct sctp_chunk;
85struct sctp_inq;
86struct sctp_outq;
87struct sctp_bind_addr;
88struct sctp_ulpq;
89struct sctp_ep_common;
90struct sctp_ssnmap;
91struct crypto_hash;
92
93
94#include <net/sctp/tsnmap.h>
95#include <net/sctp/ulpevent.h>
96#include <net/sctp/ulpqueue.h>
97
98/* Structures useful for managing bind/connect. */
99
100struct sctp_bind_bucket {
101	unsigned short	port;
102	unsigned short	fastreuse;
103	struct hlist_node	node;
104	struct hlist_head	owner;
105};
106
107struct sctp_bind_hashbucket {
108	spinlock_t	lock;
109	struct hlist_head	chain;
110};
111
112/* Used for hashing all associations.  */
113struct sctp_hashbucket {
114	rwlock_t	lock;
115	struct hlist_head	chain;
116} __attribute__((__aligned__(8)));
117
118
119/* The SCTP globals structure. */
120extern struct sctp_globals {
121	/* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values
122	 *
123	 * The following protocol parameters are RECOMMENDED:
124	 *
125	 * RTO.Initial		    - 3	 seconds
126	 * RTO.Min		    - 1	 second
127	 * RTO.Max		   -  60 seconds
128	 * RTO.Alpha		    - 1/8  (3 when converted to right shifts.)
129	 * RTO.Beta		    - 1/4  (2 when converted to right shifts.)
130	 */
131	unsigned int rto_initial;
132	unsigned int rto_min;
133	unsigned int rto_max;
134
135	/* Note: rto_alpha and rto_beta are really defined as inverse
136	 * powers of two to facilitate integer operations.
137	 */
138	int rto_alpha;
139	int rto_beta;
140
141	/* Max.Burst		    - 4 */
142	int max_burst;
143
144	/* Whether Cookie Preservative is enabled(1) or not(0) */
145	int cookie_preserve_enable;
146
147	/* Valid.Cookie.Life	    - 60  seconds  */
148	unsigned int valid_cookie_life;
149
150	/* Delayed SACK timeout  200ms default*/
151	unsigned int sack_timeout;
152
153	/* HB.interval		    - 30 seconds  */
154	unsigned int hb_interval;
155
156	/* Association.Max.Retrans  - 10 attempts
157	 * Path.Max.Retrans	    - 5	 attempts (per destination address)
158	 * Max.Init.Retransmits	    - 8	 attempts
159	 */
160	int max_retrans_association;
161	int max_retrans_path;
162	int max_retrans_init;
163
164	/*
165	 * Policy for preforming sctp/socket accounting
166	 * 0   - do socket level accounting, all assocs share sk_sndbuf
167	 * 1   - do sctp accounting, each asoc may use sk_sndbuf bytes
168	 */
169	int sndbuf_policy;
170
171	/*
172	 * Policy for preforming sctp/socket accounting
173	 * 0   - do socket level accounting, all assocs share sk_rcvbuf
174	 * 1   - do sctp accounting, each asoc may use sk_rcvbuf bytes
175	 */
176	int rcvbuf_policy;
177
178	/* The following variables are implementation specific.	 */
179
180	/* Default initialization values to be applied to new associations. */
181	__u16 max_instreams;
182	__u16 max_outstreams;
183
184	/* This is a list of groups of functions for each address
185	 * family that we support.
186	 */
187	struct list_head address_families;
188
189	/* This is the hash of all endpoints. */
190	int ep_hashsize;
191	struct sctp_hashbucket *ep_hashtable;
192
193	/* This is the hash of all associations. */
194	int assoc_hashsize;
195	struct sctp_hashbucket *assoc_hashtable;
196
197	/* This is the sctp port control hash.	*/
198	int port_hashsize;
199	struct sctp_bind_hashbucket *port_hashtable;
200
201	/* This is the global local address list.
202	 * We actively maintain this complete list of addresses on
203	 * the system by catching address add/delete events.
204	 *
205	 * It is a list of sctp_sockaddr_entry.
206	 */
207	struct list_head local_addr_list;
208
209	/* Lock that protects the local_addr_list writers */
210	spinlock_t addr_list_lock;
211
212	/* Flag to indicate if addip is enabled. */
213	int addip_enable;
214	int addip_noauth_enable;
215
216	/* Flag to indicate if PR-SCTP is enabled. */
217	int prsctp_enable;
218
219	/* Flag to idicate if SCTP-AUTH is enabled */
220	int auth_enable;
221
222	/*
223	 * Policy to control SCTP IPv4 address scoping
224	 * 0   - Disable IPv4 address scoping
225	 * 1   - Enable IPv4 address scoping
226	 * 2   - Selectively allow only IPv4 private addresses
227	 * 3   - Selectively allow only IPv4 link local address
228	 */
229	int ipv4_scope_policy;
230
231	/* Flag to indicate whether computing and verifying checksum
232	 * is disabled. */
233        int checksum_disable;
234
235	/* Threshold for rwnd update SACKS.  Receive buffer shifted this many
236	 * bits is an indicator of when to send and window update SACK.
237	 */
238	int rwnd_update_shift;
239} sctp_globals;
240
241#define sctp_rto_initial		(sctp_globals.rto_initial)
242#define sctp_rto_min			(sctp_globals.rto_min)
243#define sctp_rto_max			(sctp_globals.rto_max)
244#define sctp_rto_alpha			(sctp_globals.rto_alpha)
245#define sctp_rto_beta			(sctp_globals.rto_beta)
246#define sctp_max_burst			(sctp_globals.max_burst)
247#define sctp_valid_cookie_life		(sctp_globals.valid_cookie_life)
248#define sctp_cookie_preserve_enable	(sctp_globals.cookie_preserve_enable)
249#define sctp_max_retrans_association	(sctp_globals.max_retrans_association)
250#define sctp_sndbuf_policy	 	(sctp_globals.sndbuf_policy)
251#define sctp_rcvbuf_policy	 	(sctp_globals.rcvbuf_policy)
252#define sctp_max_retrans_path		(sctp_globals.max_retrans_path)
253#define sctp_max_retrans_init		(sctp_globals.max_retrans_init)
254#define sctp_sack_timeout		(sctp_globals.sack_timeout)
255#define sctp_hb_interval		(sctp_globals.hb_interval)
256#define sctp_max_instreams		(sctp_globals.max_instreams)
257#define sctp_max_outstreams		(sctp_globals.max_outstreams)
258#define sctp_address_families		(sctp_globals.address_families)
259#define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
260#define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
261#define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
262#define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
263#define sctp_port_hashsize		(sctp_globals.port_hashsize)
264#define sctp_port_rover			(sctp_globals.port_rover)
265#define sctp_port_alloc_lock		(sctp_globals.port_alloc_lock)
266#define sctp_port_hashtable		(sctp_globals.port_hashtable)
267#define sctp_local_addr_list		(sctp_globals.local_addr_list)
268#define sctp_local_addr_lock		(sctp_globals.addr_list_lock)
269#define sctp_scope_policy		(sctp_globals.ipv4_scope_policy)
270#define sctp_addip_enable		(sctp_globals.addip_enable)
271#define sctp_addip_noauth		(sctp_globals.addip_noauth_enable)
272#define sctp_prsctp_enable		(sctp_globals.prsctp_enable)
273#define sctp_auth_enable		(sctp_globals.auth_enable)
274#define sctp_checksum_disable		(sctp_globals.checksum_disable)
275#define sctp_rwnd_upd_shift		(sctp_globals.rwnd_update_shift)
276
277/* SCTP Socket type: UDP or TCP style. */
278typedef enum {
279	SCTP_SOCKET_UDP = 0,
280	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
281	SCTP_SOCKET_TCP
282} sctp_socket_type_t;
283
284/* Per socket SCTP information. */
285struct sctp_sock {
286	/* inet_sock has to be the first member of sctp_sock */
287	struct inet_sock inet;
288	/* What kind of a socket is this? */
289	sctp_socket_type_t type;
290
291	/* PF_ family specific functions.  */
292	struct sctp_pf *pf;
293
294	/* Access to HMAC transform. */
295	struct crypto_hash *hmac;
296
297	/* What is our base endpointer? */
298	struct sctp_endpoint *ep;
299
300	struct sctp_bind_bucket *bind_hash;
301	/* Various Socket Options.  */
302	__u16 default_stream;
303	__u32 default_ppid;
304	__u16 default_flags;
305	__u32 default_context;
306	__u32 default_timetolive;
307	__u32 default_rcv_context;
308	int max_burst;
309
310	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
311	 * the destination address every heartbeat interval. This value
312	 * will be inherited by all new associations.
313	 */
314	__u32 hbinterval;
315
316	/* This is the max_retrans value for new associations. */
317	__u16 pathmaxrxt;
318
319	/* The initial Path MTU to use for new associations. */
320	__u32 pathmtu;
321
322	/* The default SACK delay timeout for new associations. */
323	__u32 sackdelay;
324	__u32 sackfreq;
325
326	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
327	__u32 param_flags;
328
329	struct sctp_initmsg initmsg;
330	struct sctp_rtoinfo rtoinfo;
331	struct sctp_paddrparams paddrparam;
332	struct sctp_event_subscribe subscribe;
333	struct sctp_assocparams assocparams;
334	int user_frag;
335	__u32 autoclose;
336	__u8 nodelay;
337	__u8 disable_fragments;
338	__u8 v4mapped;
339	__u8 frag_interleave;
340	__u32 adaptation_ind;
341	__u32 pd_point;
342
343	atomic_t pd_mode;
344	/* Receive to here while partial delivery is in effect. */
345	struct sk_buff_head pd_lobby;
346};
347
348static inline struct sctp_sock *sctp_sk(const struct sock *sk)
349{
350       return (struct sctp_sock *)sk;
351}
352
353static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
354{
355       return (struct sock *)sp;
356}
357
358#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
359struct sctp6_sock {
360       struct sctp_sock  sctp;
361       struct ipv6_pinfo inet6;
362};
363#endif /* CONFIG_IPV6 */
364
365
366/* This is our APPLICATION-SPECIFIC state cookie.
367 * THIS IS NOT DICTATED BY THE SPECIFICATION.
368 */
369/* These are the parts of an association which we send in the cookie.
370 * Most of these are straight out of:
371 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
372 *
373 */
374
375struct sctp_cookie {
376
377	/* My	       : Tag expected in every inbound packet and sent
378	 * Verification: in the INIT or INIT ACK chunk.
379	 * Tag	       :
380	 */
381	__u32 my_vtag;
382
383	/* Peer's      : Tag expected in every outbound packet except
384	 * Verification: in the INIT chunk.
385	 * Tag	       :
386	 */
387	__u32 peer_vtag;
388
389	/* The rest of these are not from the spec, but really need to
390	 * be in the cookie.
391	 */
392
393	/* My Tie Tag  : Assist in discovering a restarting association. */
394	__u32 my_ttag;
395
396	/* Peer's Tie Tag: Assist in discovering a restarting association. */
397	__u32 peer_ttag;
398
399	/* When does this cookie expire? */
400	struct timeval expiration;
401
402	/* Number of inbound/outbound streams which are set
403	 * and negotiated during the INIT process.
404	 */
405	__u16 sinit_num_ostreams;
406	__u16 sinit_max_instreams;
407
408	/* This is the first sequence number I used.  */
409	__u32 initial_tsn;
410
411	/* This holds the originating address of the INIT packet.  */
412	union sctp_addr peer_addr;
413
414	/* IG Section 2.35.3
415	 * Include the source port of the INIT-ACK
416	 */
417	__u16		my_port;
418
419	__u8 prsctp_capable;
420
421	/* Padding for future use */
422	__u8 padding;
423
424	__u32 adaptation_ind;
425
426	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
427	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS + 2];
428	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
429
430	/* This is a shim for my peer's INIT packet, followed by
431	 * a copy of the raw address list of the association.
432	 * The length of the raw address list is saved in the
433	 * raw_addr_list_len field, which will be used at the time when
434	 * the association TCB is re-constructed from the cookie.
435	 */
436	__u32 raw_addr_list_len;
437	struct sctp_init_chunk peer_init[0];
438};
439
440
441/* The format of our cookie that we send to our peer. */
442struct sctp_signed_cookie {
443	__u8 signature[SCTP_SECRET_SIZE];
444	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
445	struct sctp_cookie c;
446} __packed;
447
448/* This is another convenience type to allocate memory for address
449 * params for the maximum size and pass such structures around
450 * internally.
451 */
452union sctp_addr_param {
453	struct sctp_paramhdr p;
454	struct sctp_ipv4addr_param v4;
455	struct sctp_ipv6addr_param v6;
456};
457
458/* A convenience type to allow walking through the various
459 * parameters and avoid casting all over the place.
460 */
461union sctp_params {
462	void *v;
463	struct sctp_paramhdr *p;
464	struct sctp_cookie_preserve_param *life;
465	struct sctp_hostname_param *dns;
466	struct sctp_cookie_param *cookie;
467	struct sctp_supported_addrs_param *sat;
468	struct sctp_ipv4addr_param *v4;
469	struct sctp_ipv6addr_param *v6;
470	union sctp_addr_param *addr;
471	struct sctp_adaptation_ind_param *aind;
472	struct sctp_supported_ext_param *ext;
473	struct sctp_random_param *random;
474	struct sctp_chunks_param *chunks;
475	struct sctp_hmac_algo_param *hmac_algo;
476	struct sctp_addip_param *addip;
477};
478
479/* RFC 2960.  Section 3.3.5 Heartbeat.
480 *    Heartbeat Information: variable length
481 *    The Sender-specific Heartbeat Info field should normally include
482 *    information about the sender's current time when this HEARTBEAT
483 *    chunk is sent and the destination transport address to which this
484 *    HEARTBEAT is sent (see Section 8.3).
485 */
486typedef struct sctp_sender_hb_info {
487	struct sctp_paramhdr param_hdr;
488	union sctp_addr daddr;
489	unsigned long sent_at;
490	__u64 hb_nonce;
491} __packed sctp_sender_hb_info_t;
492
493/*
494 *  RFC 2960 1.3.2 Sequenced Delivery within Streams
495 *
496 *  The term "stream" is used in SCTP to refer to a sequence of user
497 *  messages that are to be delivered to the upper-layer protocol in
498 *  order with respect to other messages within the same stream.  This is
499 *  in contrast to its usage in TCP, where it refers to a sequence of
500 *  bytes (in this document a byte is assumed to be eight bits).
501 *  ...
502 *
503 *  This is the structure we use to track both our outbound and inbound
504 *  SSN, or Stream Sequence Numbers.
505 */
506
507struct sctp_stream {
508	__u16 *ssn;
509	unsigned int len;
510};
511
512struct sctp_ssnmap {
513	struct sctp_stream in;
514	struct sctp_stream out;
515	int malloced;
516};
517
518struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
519				    gfp_t gfp);
520void sctp_ssnmap_free(struct sctp_ssnmap *map);
521void sctp_ssnmap_clear(struct sctp_ssnmap *map);
522
523/* What is the current SSN number for this stream? */
524static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
525{
526	return stream->ssn[id];
527}
528
529/* Return the next SSN number for this stream.	*/
530static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
531{
532	return stream->ssn[id]++;
533}
534
535/* Skip over this ssn and all below. */
536static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
537				 __u16 ssn)
538{
539	stream->ssn[id] = ssn+1;
540}
541
542/*
543 * Pointers to address related SCTP functions.
544 * (i.e. things that depend on the address family.)
545 */
546struct sctp_af {
547	int		(*sctp_xmit)	(struct sk_buff *skb,
548					 struct sctp_transport *);
549	int		(*setsockopt)	(struct sock *sk,
550					 int level,
551					 int optname,
552					 char __user *optval,
553					 unsigned int optlen);
554	int		(*getsockopt)	(struct sock *sk,
555					 int level,
556					 int optname,
557					 char __user *optval,
558					 int __user *optlen);
559	int		(*compat_setsockopt)	(struct sock *sk,
560					 int level,
561					 int optname,
562					 char __user *optval,
563					 unsigned int optlen);
564	int		(*compat_getsockopt)	(struct sock *sk,
565					 int level,
566					 int optname,
567					 char __user *optval,
568					 int __user *optlen);
569	struct dst_entry *(*get_dst)	(struct sctp_association *asoc,
570					 union sctp_addr *daddr,
571					 union sctp_addr *saddr);
572	void		(*get_saddr)	(struct sctp_sock *sk,
573					 struct sctp_association *asoc,
574					 struct dst_entry *dst,
575					 union sctp_addr *daddr,
576					 union sctp_addr *saddr);
577	void		(*copy_addrlist) (struct list_head *,
578					  struct net_device *);
579	void		(*dst_saddr)	(union sctp_addr *saddr,
580					 struct dst_entry *dst,
581					 __be16 port);
582	int		(*cmp_addr)	(const union sctp_addr *addr1,
583					 const union sctp_addr *addr2);
584	void		(*addr_copy)	(union sctp_addr *dst,
585					 union sctp_addr *src);
586	void		(*from_skb)	(union sctp_addr *,
587					 struct sk_buff *skb,
588					 int saddr);
589	void		(*from_sk)	(union sctp_addr *,
590					 struct sock *sk);
591	void		(*to_sk_saddr)	(union sctp_addr *,
592					 struct sock *sk);
593	void		(*to_sk_daddr)	(union sctp_addr *,
594					 struct sock *sk);
595	void		(*from_addr_param) (union sctp_addr *,
596					    union sctp_addr_param *,
597					    __be16 port, int iif);
598	int		(*to_addr_param) (const union sctp_addr *,
599					  union sctp_addr_param *);
600	int		(*addr_valid)	(union sctp_addr *,
601					 struct sctp_sock *,
602					 const struct sk_buff *);
603	sctp_scope_t	(*scope) (union sctp_addr *);
604	void		(*inaddr_any)	(union sctp_addr *, __be16);
605	int		(*is_any)	(const union sctp_addr *);
606	int		(*available)	(union sctp_addr *,
607					 struct sctp_sock *);
608	int		(*skb_iif)	(const struct sk_buff *sk);
609	int		(*is_ce)	(const struct sk_buff *sk);
610	void		(*seq_dump_addr)(struct seq_file *seq,
611					 union sctp_addr *addr);
612	void		(*ecn_capable)(struct sock *sk);
613	__u16		net_header_len;
614	int		sockaddr_len;
615	sa_family_t	sa_family;
616	struct list_head list;
617};
618
619struct sctp_af *sctp_get_af_specific(sa_family_t);
620int sctp_register_af(struct sctp_af *);
621
622/* Protocol family functions. */
623struct sctp_pf {
624	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
625	void (*skb_msgname)  (struct sk_buff *, char *, int *);
626	int  (*af_supported) (sa_family_t, struct sctp_sock *);
627	int  (*cmp_addr) (const union sctp_addr *,
628			  const union sctp_addr *,
629			  struct sctp_sock *);
630	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
631	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
632	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
633	struct sock *(*create_accept_sk) (struct sock *sk,
634					  struct sctp_association *asoc);
635	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
636	struct sctp_af *af;
637};
638
639
640/* Structure to track chunk fragments that have been acked, but peer
641 * fragments of the same message have not.
642 */
643struct sctp_datamsg {
644	/* Chunks waiting to be submitted to lower layer. */
645	struct list_head chunks;
646	/* Reference counting. */
647	atomic_t refcnt;
648	/* When is this message no longer interesting to the peer? */
649	unsigned long expires_at;
650	/* Did the messenge fail to send? */
651	int send_error;
652	u8 send_failed:1,
653	   can_abandon:1,   /* can chunks from this message can be abandoned. */
654	   can_delay;	    /* should this message be Nagle delayed */
655};
656
657struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
658					    struct sctp_sndrcvinfo *,
659					    struct msghdr *, int len);
660void sctp_datamsg_free(struct sctp_datamsg *);
661void sctp_datamsg_put(struct sctp_datamsg *);
662void sctp_chunk_fail(struct sctp_chunk *, int error);
663int sctp_chunk_abandoned(struct sctp_chunk *);
664
665/* RFC2960 1.4 Key Terms
666 *
667 * o Chunk: A unit of information within an SCTP packet, consisting of
668 * a chunk header and chunk-specific content.
669 *
670 * As a matter of convenience, we remember the SCTP common header for
671 * each chunk as well as a few other header pointers...
672 */
673struct sctp_chunk {
674	struct list_head list;
675
676	atomic_t refcnt;
677
678	/* This is our link to the per-transport transmitted list.  */
679	struct list_head transmitted_list;
680
681	/* This field is used by chunks that hold fragmented data.
682	 * For the first fragment this is the list that holds the rest of
683	 * fragments. For the remaining fragments, this is the link to the
684	 * frag_list maintained in the first fragment.
685	 */
686	struct list_head frag_list;
687
688	/* This points to the sk_buff containing the actual data.  */
689	struct sk_buff *skb;
690
691	/* These are the SCTP headers by reverse order in a packet.
692	 * Note that some of these may happen more than once.  In that
693	 * case, we point at the "current" one, whatever that means
694	 * for that level of header.
695	 */
696
697	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
698	union sctp_params param_hdr;
699	union {
700		__u8 *v;
701		struct sctp_datahdr *data_hdr;
702		struct sctp_inithdr *init_hdr;
703		struct sctp_sackhdr *sack_hdr;
704		struct sctp_heartbeathdr *hb_hdr;
705		struct sctp_sender_hb_info *hbs_hdr;
706		struct sctp_shutdownhdr *shutdown_hdr;
707		struct sctp_signed_cookie *cookie_hdr;
708		struct sctp_ecnehdr *ecne_hdr;
709		struct sctp_cwrhdr *ecn_cwr_hdr;
710		struct sctp_errhdr *err_hdr;
711		struct sctp_addiphdr *addip_hdr;
712		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
713		struct sctp_authhdr *auth_hdr;
714	} subh;
715
716	__u8 *chunk_end;
717
718	struct sctp_chunkhdr *chunk_hdr;
719	struct sctphdr *sctp_hdr;
720
721	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
722	struct sctp_sndrcvinfo sinfo;
723
724	/* Which association does this belong to?  */
725	struct sctp_association *asoc;
726
727	/* What endpoint received this chunk? */
728	struct sctp_ep_common *rcvr;
729
730	/* We fill this in if we are calculating RTT. */
731	unsigned long sent_at;
732
733	/* What is the origin IP address for this chunk?  */
734	union sctp_addr source;
735	/* Destination address for this chunk. */
736	union sctp_addr dest;
737
738	/* For outbound message, track all fragments for SEND_FAILED. */
739	struct sctp_datamsg *msg;
740
741	/* For an inbound chunk, this tells us where it came from.
742	 * For an outbound chunk, it tells us where we'd like it to
743	 * go.	It is NULL if we have no preference.
744	 */
745	struct sctp_transport *transport;
746
747	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
748	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
749	 * spec violates the principle premis that all chunks are processed
750	 * in order.
751	 */
752	struct sk_buff *auth_chunk;
753
754#define SCTP_CAN_FRTX 0x0
755#define SCTP_NEED_FRTX 0x1
756#define SCTP_DONT_FRTX 0x2
757	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
758		has_tsn:1,		/* Does this chunk have a TSN yet? */
759		has_ssn:1,		/* Does this chunk have a SSN yet? */
760		singleton:1,		/* Only chunk in the packet? */
761		end_of_packet:1,	/* Last chunk in the packet? */
762		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
763		pdiscard:1,		/* Discard the whole packet now? */
764		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
765		data_accepted:1,	/* At least 1 chunk accepted */
766		auth:1,			/* IN: was auth'ed | OUT: needs auth */
767		has_asconf:1,		/* IN: have seen an asconf before */
768		tsn_missing_report:2,	/* Data chunk missing counter. */
769		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
770};
771
772void sctp_chunk_hold(struct sctp_chunk *);
773void sctp_chunk_put(struct sctp_chunk *);
774int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
775			  struct iovec *data);
776void sctp_chunk_free(struct sctp_chunk *);
777void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
778void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
779struct sctp_chunk *sctp_chunkify(struct sk_buff *,
780				 const struct sctp_association *,
781				 struct sock *);
782void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
783		     union sctp_addr *);
784const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
785
786enum {
787	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
788	SCTP_ADDR_SRC,		/* address can be used as source */
789	SCTP_ADDR_DEL,		/* address about to be deleted */
790};
791
792/* This is a structure for holding either an IPv6 or an IPv4 address.  */
793struct sctp_sockaddr_entry {
794	struct list_head list;
795	struct rcu_head	rcu;
796	union sctp_addr a;
797	__u8 state;
798	__u8 valid;
799};
800
801typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
802
803/* This structure holds lists of chunks as we are assembling for
804 * transmission.
805 */
806struct sctp_packet {
807	/* These are the SCTP header values (host order) for the packet. */
808	__u16 source_port;
809	__u16 destination_port;
810	__u32 vtag;
811
812	/* This contains the payload chunks.  */
813	struct list_head chunk_list;
814
815	/* This is the overhead of the sctp and ip headers. */
816	size_t overhead;
817	/* This is the total size of all chunks INCLUDING padding.  */
818	size_t size;
819
820	/* The packet is destined for this transport address.
821	 * The function we finally use to pass down to the next lower
822	 * layer lives in the transport structure.
823	 */
824	struct sctp_transport *transport;
825
826	/* pointer to the auth chunk for this packet */
827	struct sctp_chunk *auth;
828
829	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
830	    has_sack:1,		/* This packet contains a SACK chunk. */
831	    has_auth:1,		/* This packet contains an AUTH chunk */
832	    has_data:1,		/* This packet contains at least 1 DATA chunk */
833	    ipfragok:1,		/* So let ip fragment this packet */
834	    malloced:1;		/* Is it malloced? */
835};
836
837struct sctp_packet *sctp_packet_init(struct sctp_packet *,
838				     struct sctp_transport *,
839				     __u16 sport, __u16 dport);
840struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
841sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
842                                       struct sctp_chunk *, int);
843sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
844                                     struct sctp_chunk *);
845int sctp_packet_transmit(struct sctp_packet *);
846void sctp_packet_free(struct sctp_packet *);
847
848static inline int sctp_packet_empty(struct sctp_packet *packet)
849{
850	return (packet->size == packet->overhead);
851}
852
853/* This represents a remote transport address.
854 * For local transport addresses, we just use union sctp_addr.
855 *
856 * RFC2960 Section 1.4 Key Terms
857 *
858 *   o	Transport address:  A Transport Address is traditionally defined
859 *	by Network Layer address, Transport Layer protocol and Transport
860 *	Layer port number.  In the case of SCTP running over IP, a
861 *	transport address is defined by the combination of an IP address
862 *	and an SCTP port number (where SCTP is the Transport protocol).
863 *
864 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
865 *
866 *   o	The sender keeps a separate congestion control parameter set for
867 *	each of the destination addresses it can send to (not each
868 *	source-destination pair but for each destination).  The parameters
869 *	should decay if the address is not used for a long enough time
870 *	period.
871 *
872 */
873struct sctp_transport {
874	/* A list of transports. */
875	struct list_head transports;
876
877	/* Reference counting. */
878	atomic_t refcnt;
879	__u32	 dead:1,
880		/* RTO-Pending : A flag used to track if one of the DATA
881		 *		chunks sent to this address is currently being
882		 *		used to compute a RTT. If this flag is 0,
883		 *		the next DATA chunk sent to this destination
884		 *		should be used to compute a RTT and this flag
885		 *		should be set. Every time the RTT
886		 *		calculation completes (i.e. the DATA chunk
887		 *		is SACK'd) clear this flag.
888		 */
889		 rto_pending:1,
890
891		/*
892		 * hb_sent : a flag that signals that we have a pending
893		 * heartbeat.
894		 */
895		hb_sent:1,
896
897		/* Is the Path MTU update pending on this tranport */
898		pmtu_pending:1,
899
900		/* Is this structure kfree()able? */
901		malloced:1;
902
903
904	/* This is the peer's IP address and port. */
905	union sctp_addr ipaddr;
906
907	/* These are the functions we call to handle LLP stuff.	 */
908	struct sctp_af *af_specific;
909
910	/* Which association do we belong to?  */
911	struct sctp_association *asoc;
912
913	/* RFC2960
914	 *
915	 * 12.3 Per Transport Address Data
916	 *
917	 * For each destination transport address in the peer's
918	 * address list derived from the INIT or INIT ACK chunk, a
919	 * number of data elements needs to be maintained including:
920	 */
921	/* RTO	       : The current retransmission timeout value.  */
922	unsigned long rto;
923
924	__u32 rtt;		/* This is the most recent RTT.	 */
925
926	/* RTTVAR      : The current RTT variation.  */
927	__u32 rttvar;
928
929	/* SRTT	       : The current smoothed round trip time.	*/
930	__u32 srtt;
931
932	/*
933	 * These are the congestion stats.
934	 */
935	/* cwnd	       : The current congestion window.	 */
936	__u32 cwnd;		  /* This is the actual cwnd.  */
937
938	/* ssthresh    : The current slow start threshold value.  */
939	__u32 ssthresh;
940
941	/* partial     : The tracking method for increase of cwnd when in
942	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
943	 */
944	__u32 partial_bytes_acked;
945
946	/* Data that has been sent, but not acknowledged. */
947	__u32 flight_size;
948
949	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
950
951	/* Destination */
952	struct dst_entry *dst;
953	/* Source address. */
954	union sctp_addr saddr;
955
956	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
957	 * the destination address every heartbeat interval.
958	 */
959	unsigned long hbinterval;
960
961	/* SACK delay timeout */
962	unsigned long sackdelay;
963	__u32 sackfreq;
964
965	/* When was the last time (in jiffies) that we heard from this
966	 * transport?  We use this to pick new active and retran paths.
967	 */
968	unsigned long last_time_heard;
969
970	/* Last time(in jiffies) when cwnd is reduced due to the congestion
971	 * indication based on ECNE chunk.
972	 */
973	unsigned long last_time_ecne_reduced;
974
975	/* This is the max_retrans value for the transport and will
976	 * be initialized from the assocs value.  This can be changed
977	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
978	 */
979	__u16 pathmaxrxt;
980
981	/* PMTU	      : The current known path MTU.  */
982	__u32 pathmtu;
983
984	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
985	__u32 param_flags;
986
987	/* The number of times INIT has been sent on this transport. */
988	int init_sent_count;
989
990	/* state       : The current state of this destination,
991	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
992	 */
993	int state;
994
995	/* These are the error stats for this destination.  */
996
997	/* Error count : The current error count for this destination.	*/
998	unsigned short error_count;
999
1000	/* Per	       : A timer used by each destination.
1001	 * Destination :
1002	 * Timer       :
1003	 *
1004	 * [Everywhere else in the text this is called T3-rtx. -ed]
1005	 */
1006	struct timer_list T3_rtx_timer;
1007
1008	/* Heartbeat timer is per destination. */
1009	struct timer_list hb_timer;
1010
1011	/* Timer to handle ICMP proto unreachable envets */
1012	struct timer_list proto_unreach_timer;
1013
1014	/* Since we're using per-destination retransmission timers
1015	 * (see above), we're also using per-destination "transmitted"
1016	 * queues.  This probably ought to be a private struct
1017	 * accessible only within the outqueue, but it's not, yet.
1018	 */
1019	struct list_head transmitted;
1020
1021	/* We build bundle-able packets for this transport here.  */
1022	struct sctp_packet packet;
1023
1024	/* This is the list of transports that have chunks to send.  */
1025	struct list_head send_ready;
1026
1027	/* State information saved for SFR_CACC algorithm. The key
1028	 * idea in SFR_CACC is to maintain state at the sender on a
1029	 * per-destination basis when a changeover happens.
1030	 *	char changeover_active;
1031	 *	char cycling_changeover;
1032	 *	__u32 next_tsn_at_change;
1033	 *	char cacc_saw_newack;
1034	 */
1035	struct {
1036		/* An unsigned integer, which stores the next TSN to be
1037		 * used by the sender, at the moment of changeover.
1038		 */
1039		__u32 next_tsn_at_change;
1040
1041		/* A flag which indicates the occurrence of a changeover */
1042		char changeover_active;
1043
1044		/* A flag which indicates whether the change of primary is
1045		 * the first switch to this destination address during an
1046		 * active switch.
1047		 */
1048		char cycling_changeover;
1049
1050		/* A temporary flag, which is used during the processing of
1051		 * a SACK to estimate the causative TSN(s)'s group.
1052		 */
1053		char cacc_saw_newack;
1054	} cacc;
1055
1056	/* 64-bit random number sent with heartbeat. */
1057	__u64 hb_nonce;
1058};
1059
1060struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1061					  gfp_t);
1062void sctp_transport_set_owner(struct sctp_transport *,
1063			      struct sctp_association *);
1064void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1065			  struct sctp_sock *);
1066void sctp_transport_pmtu(struct sctp_transport *);
1067void sctp_transport_free(struct sctp_transport *);
1068void sctp_transport_reset_timers(struct sctp_transport *);
1069void sctp_transport_hold(struct sctp_transport *);
1070void sctp_transport_put(struct sctp_transport *);
1071void sctp_transport_update_rto(struct sctp_transport *, __u32);
1072void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1073void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1074void sctp_transport_burst_limited(struct sctp_transport *);
1075void sctp_transport_burst_reset(struct sctp_transport *);
1076unsigned long sctp_transport_timeout(struct sctp_transport *);
1077void sctp_transport_reset(struct sctp_transport *);
1078void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1079
1080
1081/* This is the structure we use to queue packets as they come into
1082 * SCTP.  We write packets to it and read chunks from it.
1083 */
1084struct sctp_inq {
1085	/* This is actually a queue of sctp_chunk each
1086	 * containing a partially decoded packet.
1087	 */
1088	struct list_head in_chunk_list;
1089	/* This is the packet which is currently off the in queue and is
1090	 * being worked on through the inbound chunk processing.
1091	 */
1092	struct sctp_chunk *in_progress;
1093
1094	/* This is the delayed task to finish delivering inbound
1095	 * messages.
1096	 */
1097	struct work_struct immediate;
1098
1099	int malloced;	     /* Is this structure kfree()able?	*/
1100};
1101
1102void sctp_inq_init(struct sctp_inq *);
1103void sctp_inq_free(struct sctp_inq *);
1104void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1105struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1106struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1107void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1108
1109/* This is the structure we use to hold outbound chunks.  You push
1110 * chunks in and they automatically pop out the other end as bundled
1111 * packets (it calls (*output_handler)()).
1112 *
1113 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1114 * and 8.2 of the v13 draft.
1115 *
1116 * It handles retransmissions.	The connection to the timeout portion
1117 * of the state machine is through sctp_..._timeout() and timeout_handler.
1118 *
1119 * If you feed it SACKs, it will eat them.
1120 *
1121 * If you give it big chunks, it will fragment them.
1122 *
1123 * It assigns TSN's to data chunks.  This happens at the last possible
1124 * instant before transmission.
1125 *
1126 * When free()'d, it empties itself out via output_handler().
1127 */
1128struct sctp_outq {
1129	struct sctp_association *asoc;
1130
1131	/* Data pending that has never been transmitted.  */
1132	struct list_head out_chunk_list;
1133
1134	unsigned out_qlen;	/* Total length of queued data chunks. */
1135
1136	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1137	unsigned error;
1138
1139	/* These are control chunks we want to send.  */
1140	struct list_head control_chunk_list;
1141
1142	/* These are chunks that have been sacked but are above the
1143	 * CTSN, or cumulative tsn ack point.
1144	 */
1145	struct list_head sacked;
1146
1147	/* Put chunks on this list to schedule them for
1148	 * retransmission.
1149	 */
1150	struct list_head retransmit;
1151
1152	/* Put chunks on this list to save them for FWD TSN processing as
1153	 * they were abandoned.
1154	 */
1155	struct list_head abandoned;
1156
1157	/* How many unackd bytes do we have in-flight?	*/
1158	__u32 outstanding_bytes;
1159
1160	/* Are we doing fast-rtx on this queue */
1161	char fast_rtx;
1162
1163	/* Corked? */
1164	char cork;
1165
1166	/* Is this structure empty?  */
1167	char empty;
1168
1169	/* Are we kfree()able? */
1170	char malloced;
1171};
1172
1173void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1174void sctp_outq_teardown(struct sctp_outq *);
1175void sctp_outq_free(struct sctp_outq*);
1176int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1177int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1178int sctp_outq_is_empty(const struct sctp_outq *);
1179void sctp_outq_restart(struct sctp_outq *);
1180
1181void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1182		     sctp_retransmit_reason_t);
1183void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1184int sctp_outq_uncork(struct sctp_outq *);
1185/* Uncork and flush an outqueue.  */
1186static inline void sctp_outq_cork(struct sctp_outq *q)
1187{
1188	q->cork = 1;
1189}
1190
1191/* These bind address data fields common between endpoints and associations */
1192struct sctp_bind_addr {
1193
1194	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1195	 *
1196	 * SCTP Port:	The local SCTP port number the endpoint is
1197	 *		bound to.
1198	 */
1199	__u16 port;
1200
1201	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1202	 *
1203	 * Address List: The list of IP addresses that this instance
1204	 *	has bound.  This information is passed to one's
1205	 *	peer(s) in INIT and INIT ACK chunks.
1206	 */
1207	struct list_head address_list;
1208
1209	int malloced;	     /* Are we kfree()able?  */
1210};
1211
1212void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1213void sctp_bind_addr_free(struct sctp_bind_addr *);
1214int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1215			const struct sctp_bind_addr *src,
1216			sctp_scope_t scope, gfp_t gfp,
1217			int flags);
1218int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1219			const struct sctp_bind_addr *src,
1220			gfp_t gfp);
1221int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1222		       __u8 addr_state, gfp_t gfp);
1223int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1224int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1225			 struct sctp_sock *);
1226int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1227			 struct sctp_sock *, struct sctp_sock *);
1228int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1229			 const union sctp_addr *addr);
1230union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1231					const union sctp_addr	*addrs,
1232					int			addrcnt,
1233					struct sctp_sock	*opt);
1234union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1235					 int *addrs_len,
1236					 gfp_t gfp);
1237int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1238			   __u16 port, gfp_t gfp);
1239
1240sctp_scope_t sctp_scope(const union sctp_addr *);
1241int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1242int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1243int sctp_addr_is_valid(const union sctp_addr *addr);
1244
1245
1246/* What type of endpoint?  */
1247typedef enum {
1248	SCTP_EP_TYPE_SOCKET,
1249	SCTP_EP_TYPE_ASSOCIATION,
1250} sctp_endpoint_type_t;
1251
1252/*
1253 * A common base class to bridge the implmentation view of a
1254 * socket (usually listening) endpoint versus an association's
1255 * local endpoint.
1256 * This common structure is useful for several purposes:
1257 *   1) Common interface for lookup routines.
1258 *	a) Subfunctions work for either endpoint or association
1259 *	b) Single interface to lookup allows hiding the lookup lock rather
1260 *	   than acquiring it externally.
1261 *   2) Common interface for the inbound chunk handling/state machine.
1262 *   3) Common object handling routines for reference counting, etc.
1263 *   4) Disentangle association lookup from endpoint lookup, where we
1264 *	do not have to find our endpoint to find our association.
1265 *
1266 */
1267
1268struct sctp_ep_common {
1269	/* Fields to help us manage our entries in the hash tables. */
1270	struct hlist_node node;
1271	int hashent;
1272
1273	/* Runtime type information.  What kind of endpoint is this? */
1274	sctp_endpoint_type_t type;
1275
1276	/* Some fields to help us manage this object.
1277	 *   refcnt   - Reference count access to this object.
1278	 *   dead     - Do not attempt to use this object.
1279	 *   malloced - Do we need to kfree this object?
1280	 */
1281	atomic_t    refcnt;
1282	char	    dead;
1283	char	    malloced;
1284
1285	/* What socket does this endpoint belong to?  */
1286	struct sock *sk;
1287
1288	/* This is where we receive inbound chunks.  */
1289	struct sctp_inq	  inqueue;
1290
1291	/* This substructure includes the defining parameters of the
1292	 * endpoint:
1293	 * bind_addr.port is our shared port number.
1294	 * bind_addr.address_list is our set of local IP addresses.
1295	 */
1296	struct sctp_bind_addr bind_addr;
1297};
1298
1299
1300/* RFC Section 1.4 Key Terms
1301 *
1302 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1303 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1304 *   combination of a set of eligible destination transport addresses to
1305 *   which SCTP packets can be sent and a set of eligible source
1306 *   transport addresses from which SCTP packets can be received.
1307 *   All transport addresses used by an SCTP endpoint must use the
1308 *   same port number, but can use multiple IP addresses. A transport
1309 *   address used by an SCTP endpoint must not be used by another
1310 *   SCTP endpoint. In other words, a transport address is unique
1311 *   to an SCTP endpoint.
1312 *
1313 * From an implementation perspective, each socket has one of these.
1314 * A TCP-style socket will have exactly one association on one of
1315 * these.  An UDP-style socket will have multiple associations hanging
1316 * off one of these.
1317 */
1318
1319struct sctp_endpoint {
1320	/* Common substructure for endpoint and association. */
1321	struct sctp_ep_common base;
1322
1323	/* Associations: A list of current associations and mappings
1324	 *	      to the data consumers for each association. This
1325	 *	      may be in the form of a hash table or other
1326	 *	      implementation dependent structure. The data
1327	 *	      consumers may be process identification
1328	 *	      information such as file descriptors, named pipe
1329	 *	      pointer, or table pointers dependent on how SCTP
1330	 *	      is implemented.
1331	 */
1332	/* This is really a list of struct sctp_association entries. */
1333	struct list_head asocs;
1334
1335	/* Secret Key: A secret key used by this endpoint to compute
1336	 *	      the MAC.	This SHOULD be a cryptographic quality
1337	 *	      random number with a sufficient length.
1338	 *	      Discussion in [RFC1750] can be helpful in
1339	 *	      selection of the key.
1340	 */
1341	__u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1342	int current_key;
1343	int last_key;
1344	int key_changed_at;
1345
1346 	/* digest:  This is a digest of the sctp cookie.  This field is
1347 	 * 	    only used on the receive path when we try to validate
1348 	 * 	    that the cookie has not been tampered with.  We put
1349 	 * 	    this here so we pre-allocate this once and can re-use
1350 	 * 	    on every receive.
1351 	 */
1352 	__u8 *digest;
1353
1354	/* sendbuf acct. policy.	*/
1355	__u32 sndbuf_policy;
1356
1357	/* rcvbuf acct. policy.	*/
1358	__u32 rcvbuf_policy;
1359
1360	/* SCTP AUTH: array of the HMACs that will be allocated
1361	 * we need this per association so that we don't serialize
1362	 */
1363	struct crypto_hash **auth_hmacs;
1364
1365	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1366	 struct sctp_hmac_algo_param *auth_hmacs_list;
1367
1368	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1369	struct sctp_chunks_param *auth_chunk_list;
1370
1371	/* SCTP-AUTH: endpoint shared keys */
1372	struct list_head endpoint_shared_keys;
1373	__u16 active_key_id;
1374};
1375
1376/* Recover the outter endpoint structure. */
1377static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1378{
1379	struct sctp_endpoint *ep;
1380
1381	ep = container_of(base, struct sctp_endpoint, base);
1382	return ep;
1383}
1384
1385/* These are function signatures for manipulating endpoints.  */
1386struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1387void sctp_endpoint_free(struct sctp_endpoint *);
1388void sctp_endpoint_put(struct sctp_endpoint *);
1389void sctp_endpoint_hold(struct sctp_endpoint *);
1390void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1391struct sctp_association *sctp_endpoint_lookup_assoc(
1392	const struct sctp_endpoint *ep,
1393	const union sctp_addr *paddr,
1394	struct sctp_transport **);
1395int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1396				const union sctp_addr *);
1397struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1398					const union sctp_addr *);
1399int sctp_has_association(const union sctp_addr *laddr,
1400			 const union sctp_addr *paddr);
1401
1402int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1403		     sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1404		     struct sctp_chunk **err_chunk);
1405int sctp_process_init(struct sctp_association *, sctp_cid_t cid,
1406		      const union sctp_addr *peer,
1407		      sctp_init_chunk_t *init, gfp_t gfp);
1408__u32 sctp_generate_tag(const struct sctp_endpoint *);
1409__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1410
1411struct sctp_inithdr_host {
1412	__u32 init_tag;
1413	__u32 a_rwnd;
1414	__u16 num_outbound_streams;
1415	__u16 num_inbound_streams;
1416	__u32 initial_tsn;
1417};
1418
1419/* RFC2960
1420 *
1421 * 12. Recommended Transmission Control Block (TCB) Parameters
1422 *
1423 * This section details a recommended set of parameters that should
1424 * be contained within the TCB for an implementation. This section is
1425 * for illustrative purposes and should not be deemed as requirements
1426 * on an implementation or as an exhaustive list of all parameters
1427 * inside an SCTP TCB. Each implementation may need its own additional
1428 * parameters for optimization.
1429 */
1430
1431
1432/* Here we have information about each individual association. */
1433struct sctp_association {
1434
1435	/* A base structure common to endpoint and association.
1436	 * In this context, it represents the associations's view
1437	 * of the local endpoint of the association.
1438	 */
1439	struct sctp_ep_common base;
1440
1441	/* Associations on the same socket. */
1442	struct list_head asocs;
1443
1444	/* association id. */
1445	sctp_assoc_t assoc_id;
1446
1447	/* This is our parent endpoint.	 */
1448	struct sctp_endpoint *ep;
1449
1450	/* These are those association elements needed in the cookie.  */
1451	struct sctp_cookie c;
1452
1453	/* This is all information about our peer.  */
1454	struct {
1455		/* rwnd
1456		 *
1457		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1458		 */
1459		__u32 rwnd;
1460
1461		/* transport_addr_list
1462		 *
1463		 * Peer	       : A list of SCTP transport addresses that the
1464		 * Transport   : peer is bound to. This information is derived
1465		 * Address     : from the INIT or INIT ACK and is used to
1466		 * List	       : associate an inbound packet with a given
1467		 *	       : association. Normally this information is
1468		 *	       : hashed or keyed for quick lookup and access
1469		 *	       : of the TCB.
1470		 *	       : The list is also initialized with the list
1471		 *	       : of addresses passed with the sctp_connectx()
1472		 *	       : call.
1473		 *
1474		 * It is a list of SCTP_transport's.
1475		 */
1476		struct list_head transport_addr_list;
1477
1478		/* transport_count
1479		 *
1480		 * Peer        : A count of the number of peer addresses
1481		 * Transport   : in the Peer Transport Address List.
1482		 * Address     :
1483		 * Count       :
1484		 */
1485		__u16 transport_count;
1486
1487		/* port
1488		 *   The transport layer port number.
1489		 */
1490		__u16 port;
1491
1492		/* primary_path
1493		 *
1494		 * Primary     : This is the current primary destination
1495		 * Path	       : transport address of the peer endpoint.  It
1496		 *	       : may also specify a source transport address
1497		 *	       : on this endpoint.
1498		 *
1499		 * All of these paths live on transport_addr_list.
1500		 *
1501		 * At the bakeoffs, we discovered that the intent of
1502		 * primaryPath is that it only changes when the ULP
1503		 * asks to have it changed.  We add the activePath to
1504		 * designate the connection we are currently using to
1505		 * transmit new data and most control chunks.
1506		 */
1507		struct sctp_transport *primary_path;
1508
1509		/* Cache the primary path address here, when we
1510		 * need a an address for msg_name.
1511		 */
1512		union sctp_addr primary_addr;
1513
1514		/* active_path
1515		 *   The path that we are currently using to
1516		 *   transmit new data and most control chunks.
1517		 */
1518		struct sctp_transport *active_path;
1519
1520		/* retran_path
1521		 *
1522		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1523		 * ...
1524		 * Furthermore, when its peer is multi-homed, an
1525		 * endpoint SHOULD try to retransmit a chunk to an
1526		 * active destination transport address that is
1527		 * different from the last destination address to
1528		 * which the DATA chunk was sent.
1529		 */
1530		struct sctp_transport *retran_path;
1531
1532		/* Pointer to last transport I have sent on.  */
1533		struct sctp_transport *last_sent_to;
1534
1535		/* This is the last transport I have received DATA on.	*/
1536		struct sctp_transport *last_data_from;
1537
1538		/*
1539		 * Mapping  An array of bits or bytes indicating which out of
1540		 * Array    order TSN's have been received (relative to the
1541		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1542		 *	    order packets have been received, this array
1543		 *	    will be set to all zero. This structure may be
1544		 *	    in the form of a circular buffer or bit array.
1545		 *
1546		 * Last Rcvd   : This is the last TSN received in
1547		 * TSN	       : sequence. This value is set initially by
1548		 *	       : taking the peer's Initial TSN, received in
1549		 *	       : the INIT or INIT ACK chunk, and subtracting
1550		 *	       : one from it.
1551		 *
1552		 * Throughout most of the specification this is called the
1553		 * "Cumulative TSN ACK Point".	In this case, we
1554		 * ignore the advice in 12.2 in favour of the term
1555		 * used in the bulk of the text.  This value is hidden
1556		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1557		 */
1558		struct sctp_tsnmap tsn_map;
1559
1560		/* Ack State   : This flag indicates if the next received
1561		 *             : packet is to be responded to with a
1562		 *             : SACK. This is initializedto 0.  When a packet
1563		 *             : is received it is incremented. If this value
1564		 *             : reaches 2 or more, a SACK is sent and the
1565		 *             : value is reset to 0. Note: This is used only
1566		 *             : when no DATA chunks are received out of
1567		 *             : order.  When DATA chunks are out of order,
1568		 *             : SACK's are not delayed (see Section 6).
1569		 */
1570		__u8    sack_needed;     /* Do we need to sack the peer? */
1571		__u32	sack_cnt;
1572
1573		/* These are capabilities which our peer advertised.  */
1574		__u8	ecn_capable:1,	    /* Can peer do ECN? */
1575			ipv4_address:1,	    /* Peer understands IPv4 addresses? */
1576			ipv6_address:1,	    /* Peer understands IPv6 addresses? */
1577			hostname_address:1, /* Peer understands DNS addresses? */
1578			asconf_capable:1,   /* Does peer support ADDIP? */
1579			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1580			auth_capable:1;	    /* Is peer doing SCTP-AUTH? */
1581
1582		__u32   adaptation_ind;	 /* Adaptation Code point. */
1583
1584		/* This mask is used to disable sending the ASCONF chunk
1585		 * with specified parameter to peer.
1586		 */
1587		__be16 addip_disabled_mask;
1588
1589		struct sctp_inithdr_host i;
1590		int cookie_len;
1591		void *cookie;
1592
1593		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1594		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1595		 * Initial TSN Value minus 1
1596		 */
1597		__u32 addip_serial;
1598
1599		/* SCTP-AUTH: We need to know pears random number, hmac list
1600		 * and authenticated chunk list.  All that is part of the
1601		 * cookie and these are just pointers to those locations
1602		 */
1603		sctp_random_param_t *peer_random;
1604		sctp_chunks_param_t *peer_chunks;
1605		sctp_hmac_algo_param_t *peer_hmacs;
1606	} peer;
1607
1608	/* State       : A state variable indicating what state the
1609	 *	       : association is in, i.e. COOKIE-WAIT,
1610	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1611	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1612	 *
1613	 *		Note: No "CLOSED" state is illustrated since if a
1614	 *		association is "CLOSED" its TCB SHOULD be removed.
1615	 *
1616	 *		In this implementation we DO have a CLOSED
1617	 *		state which is used during initiation and shutdown.
1618	 *
1619	 *		State takes values from SCTP_STATE_*.
1620	 */
1621	sctp_state_t state;
1622
1623	/* The cookie life I award for any cookie.  */
1624	struct timeval cookie_life;
1625
1626	/* Overall     : The overall association error count.
1627	 * Error Count : [Clear this any time I get something.]
1628	 */
1629	int overall_error_count;
1630
1631	/* These are the association's initial, max, and min RTO values.
1632	 * These values will be initialized by system defaults, but can
1633	 * be modified via the SCTP_RTOINFO socket option.
1634	 */
1635	unsigned long rto_initial;
1636	unsigned long rto_max;
1637	unsigned long rto_min;
1638
1639	/* Maximum number of new data packets that can be sent in a burst.  */
1640	int max_burst;
1641
1642	/* This is the max_retrans value for the association.  This value will
1643	 * be initialized initialized from system defaults, but can be
1644	 * modified by the SCTP_ASSOCINFO socket option.
1645	 */
1646	int max_retrans;
1647
1648	/* Maximum number of times the endpoint will retransmit INIT  */
1649	__u16 max_init_attempts;
1650
1651	/* How many times have we resent an INIT? */
1652	__u16 init_retries;
1653
1654	/* The largest timeout or RTO value to use in attempting an INIT */
1655	unsigned long max_init_timeo;
1656
1657	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1658	 * the destination address every heartbeat interval. This value
1659	 * will be inherited by all new transports.
1660	 */
1661	unsigned long hbinterval;
1662
1663	/* This is the max_retrans value for new transports in the
1664	 * association.
1665	 */
1666	__u16 pathmaxrxt;
1667
1668	/* Flag that path mtu update is pending */
1669	__u8   pmtu_pending;
1670
1671	/* Association : The smallest PMTU discovered for all of the
1672	 * PMTU	       : peer's transport addresses.
1673	 */
1674	__u32 pathmtu;
1675
1676	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1677	__u32 param_flags;
1678
1679	/* SACK delay timeout */
1680	unsigned long sackdelay;
1681	__u32 sackfreq;
1682
1683
1684	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1685	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1686
1687	/* Transport to which SHUTDOWN chunk was last sent.  */
1688	struct sctp_transport *shutdown_last_sent_to;
1689
1690	/* How many times have we resent a SHUTDOWN */
1691	int shutdown_retries;
1692
1693	/* Transport to which INIT chunk was last sent.  */
1694	struct sctp_transport *init_last_sent_to;
1695
1696	/* Next TSN    : The next TSN number to be assigned to a new
1697	 *	       : DATA chunk.  This is sent in the INIT or INIT
1698	 *	       : ACK chunk to the peer and incremented each
1699	 *	       : time a DATA chunk is assigned a TSN
1700	 *	       : (normally just prior to transmit or during
1701	 *	       : fragmentation).
1702	 */
1703	__u32 next_tsn;
1704
1705	/*
1706	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1707	 * TSN	       : is set initially by taking the peer's Initial TSN,
1708	 *	       : received in the INIT or INIT ACK chunk, and
1709	 *	       : subtracting one from it.
1710	 *
1711	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1712	 */
1713
1714	__u32 ctsn_ack_point;
1715
1716	/* PR-SCTP Advanced.Peer.Ack.Point */
1717	__u32 adv_peer_ack_point;
1718
1719	/* Highest TSN that is acknowledged by incoming SACKs. */
1720	__u32 highest_sacked;
1721
1722	/* TSN marking the fast recovery exit point */
1723	__u32 fast_recovery_exit;
1724
1725	/* Flag to track the current fast recovery state */
1726	__u8 fast_recovery;
1727
1728	/* The number of unacknowledged data chunks.  Reported through
1729	 * the SCTP_STATUS sockopt.
1730	 */
1731	__u16 unack_data;
1732
1733	/* The total number of data chunks that we've had to retransmit
1734	 * as the result of a T3 timer expiration
1735	 */
1736	__u32 rtx_data_chunks;
1737
1738	/* This is the association's receive buffer space.  This value is used
1739	 * to set a_rwnd field in an INIT or a SACK chunk.
1740	 */
1741	__u32 rwnd;
1742
1743	/* This is the last advertised value of rwnd over a SACK chunk. */
1744	__u32 a_rwnd;
1745
1746	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1747	 * to slop over a maximum of the association's frag_point.
1748	 */
1749	__u32 rwnd_over;
1750
1751	/* Keeps treack of rwnd pressure.  This happens when we have
1752	 * a window, but not recevie buffer (i.e small packets).  This one
1753	 * is releases slowly (1 PMTU at a time ).
1754	 */
1755	__u32 rwnd_press;
1756
1757	/* This is the sndbuf size in use for the association.
1758	 * This corresponds to the sndbuf size for the association,
1759	 * as specified in the sk->sndbuf.
1760	 */
1761	int sndbuf_used;
1762
1763	/* This is the amount of memory that this association has allocated
1764	 * in the receive path at any given time.
1765	 */
1766	atomic_t rmem_alloc;
1767
1768	/* This is the wait queue head for send requests waiting on
1769	 * the association sndbuf space.
1770	 */
1771	wait_queue_head_t	wait;
1772
1773	/* The message size at which SCTP fragmentation will occur. */
1774	__u32 frag_point;
1775	__u32 user_frag;
1776
1777	/* Counter used to count INIT errors. */
1778	int init_err_counter;
1779
1780	/* Count the number of INIT cycles (for doubling timeout). */
1781	int init_cycle;
1782
1783	/* Default send parameters. */
1784	__u16 default_stream;
1785	__u16 default_flags;
1786	__u32 default_ppid;
1787	__u32 default_context;
1788	__u32 default_timetolive;
1789
1790	/* Default receive parameters */
1791	__u32 default_rcv_context;
1792
1793	/* This tracks outbound ssn for a given stream.	 */
1794	struct sctp_ssnmap *ssnmap;
1795
1796	/* All outbound chunks go through this structure.  */
1797	struct sctp_outq outqueue;
1798
1799	/* A smart pipe that will handle reordering and fragmentation,
1800	 * as well as handle passing events up to the ULP.
1801	 */
1802	struct sctp_ulpq ulpq;
1803
1804	/* Last TSN that caused an ECNE Chunk to be sent.  */
1805	__u32 last_ecne_tsn;
1806
1807	/* Last TSN that caused a CWR Chunk to be sent.	 */
1808	__u32 last_cwr_tsn;
1809
1810	/* How many duplicated TSNs have we seen?  */
1811	int numduptsns;
1812
1813	/* Number of seconds of idle time before an association is closed.
1814	 * In the association context, this is really used as a boolean
1815	 * since the real timeout is stored in the timeouts array
1816	 */
1817	__u32 autoclose;
1818
1819	/* These are to support
1820	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1821	 *  and Enforcement of Flow and Message Limits"
1822	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1823	 * or "ADDIP" for short.
1824	 */
1825
1826
1827
1828	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1829	 *
1830	 * R1) One and only one ASCONF Chunk MAY be in transit and
1831	 * unacknowledged at any one time.  If a sender, after sending
1832	 * an ASCONF chunk, decides it needs to transfer another
1833	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1834	 * returns from the previous ASCONF Chunk before sending a
1835	 * subsequent ASCONF. Note this restriction binds each side,
1836	 * so at any time two ASCONF may be in-transit on any given
1837	 * association (one sent from each endpoint).
1838	 *
1839	 * [This is our one-and-only-one ASCONF in flight.  If we do
1840	 * not have an ASCONF in flight, this is NULL.]
1841	 */
1842	struct sctp_chunk *addip_last_asconf;
1843
1844	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1845	 *
1846	 * This is needed to implement itmes E1 - E4 of the updated
1847	 * spec.  Here is the justification:
1848	 *
1849	 * Since the peer may bundle multiple ASCONF chunks toward us,
1850	 * we now need the ability to cache multiple ACKs.  The section
1851	 * describes in detail how they are cached and cleaned up.
1852	 */
1853	struct list_head asconf_ack_list;
1854
1855	/* These ASCONF chunks are waiting to be sent.
1856	 *
1857	 * These chunaks can't be pushed to outqueue until receiving
1858	 * ASCONF_ACK for the previous ASCONF indicated by
1859	 * addip_last_asconf, so as to guarantee that only one ASCONF
1860	 * is in flight at any time.
1861	 *
1862	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1863	 *
1864	 * In defining the ASCONF Chunk transfer procedures, it is
1865	 * essential that these transfers MUST NOT cause congestion
1866	 * within the network.	To achieve this, we place these
1867	 * restrictions on the transfer of ASCONF Chunks:
1868	 *
1869	 * R1) One and only one ASCONF Chunk MAY be in transit and
1870	 * unacknowledged at any one time.  If a sender, after sending
1871	 * an ASCONF chunk, decides it needs to transfer another
1872	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1873	 * returns from the previous ASCONF Chunk before sending a
1874	 * subsequent ASCONF. Note this restriction binds each side,
1875	 * so at any time two ASCONF may be in-transit on any given
1876	 * association (one sent from each endpoint).
1877	 *
1878	 *
1879	 * [I really think this is EXACTLY the sort of intelligence
1880	 *  which already resides in sctp_outq.	 Please move this
1881	 *  queue and its supporting logic down there.	--piggy]
1882	 */
1883	struct list_head addip_chunk_list;
1884
1885	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1886	 *
1887	 * A2) A serial number should be assigned to the Chunk. The
1888	 * serial number SHOULD be a monotonically increasing
1889	 * number. The serial number SHOULD be initialized at
1890	 * the start of the association to the same value as the
1891	 * Initial TSN and every time a new ASCONF chunk is created
1892	 * it is incremented by one after assigning the serial number
1893	 * to the newly created chunk.
1894	 *
1895	 * ADDIP
1896	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1897	 *
1898	 * Serial Number : 32 bits (unsigned integer)
1899	 *
1900	 * This value represents a Serial Number for the ASCONF
1901	 * Chunk. The valid range of Serial Number is from 0 to
1902	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1903	 * after reaching 4294967295.
1904	 */
1905	__u32 addip_serial;
1906
1907	/* SCTP AUTH: list of the endpoint shared keys.  These
1908	 * keys are provided out of band by the user applicaton
1909	 * and can't change during the lifetime of the association
1910	 */
1911	struct list_head endpoint_shared_keys;
1912
1913	/* SCTP AUTH:
1914	 * The current generated assocaition shared key (secret)
1915	 */
1916	struct sctp_auth_bytes *asoc_shared_key;
1917
1918	/* SCTP AUTH: hmac id of the first peer requested algorithm
1919	 * that we support.
1920	 */
1921	__u16 default_hmac_id;
1922
1923	__u16 active_key_id;
1924
1925	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1926	     temp:1;		/* Is it a temporary association? */
1927};
1928
1929
1930/* An eyecatcher for determining if we are really looking at an
1931 * association data structure.
1932 */
1933enum {
1934	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1935};
1936
1937/* Recover the outter association structure. */
1938static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1939{
1940	struct sctp_association *asoc;
1941
1942	asoc = container_of(base, struct sctp_association, base);
1943	return asoc;
1944}
1945
1946/* These are function signatures for manipulating associations.	 */
1947
1948
1949struct sctp_association *
1950sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1951		     sctp_scope_t scope, gfp_t gfp);
1952void sctp_association_free(struct sctp_association *);
1953void sctp_association_put(struct sctp_association *);
1954void sctp_association_hold(struct sctp_association *);
1955
1956struct sctp_transport *sctp_assoc_choose_alter_transport(
1957	struct sctp_association *, struct sctp_transport *);
1958void sctp_assoc_update_retran_path(struct sctp_association *);
1959struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1960					  const union sctp_addr *);
1961int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1962			    const union sctp_addr *laddr);
1963struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1964				     const union sctp_addr *address,
1965				     const gfp_t gfp,
1966				     const int peer_state);
1967void sctp_assoc_del_peer(struct sctp_association *asoc,
1968			 const union sctp_addr *addr);
1969void sctp_assoc_rm_peer(struct sctp_association *asoc,
1970			 struct sctp_transport *peer);
1971void sctp_assoc_control_transport(struct sctp_association *,
1972				  struct sctp_transport *,
1973				  sctp_transport_cmd_t, sctp_sn_error_t);
1974struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1975struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1976					   const union sctp_addr *,
1977					   const union sctp_addr *);
1978void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1979void sctp_assoc_update(struct sctp_association *old,
1980		       struct sctp_association *new);
1981
1982__u32 sctp_association_get_next_tsn(struct sctp_association *);
1983
1984void sctp_assoc_sync_pmtu(struct sctp_association *);
1985void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1986void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1987void sctp_assoc_set_primary(struct sctp_association *,
1988			    struct sctp_transport *);
1989void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1990				    struct sctp_transport *);
1991int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1992				     sctp_scope_t, gfp_t);
1993int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1994					 struct sctp_cookie*,
1995					 gfp_t gfp);
1996int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1997void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1998struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1999					const struct sctp_association *asoc,
2000					__be32 serial);
2001
2002
2003int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2004			const union sctp_addr *ss2);
2005struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2006
2007/* A convenience structure to parse out SCTP specific CMSGs. */
2008typedef struct sctp_cmsgs {
2009	struct sctp_initmsg *init;
2010	struct sctp_sndrcvinfo *info;
2011} sctp_cmsgs_t;
2012
2013/* Structure for tracking memory objects */
2014typedef struct {
2015	char *label;
2016	atomic_t *counter;
2017} sctp_dbg_objcnt_entry_t;
2018
2019#endif /* __sctp_structs_h__ */
2020