xref: /openbmc/linux/include/net/sctp/structs.h (revision 9c1f8594)
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 <linux/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  */
72 union sctp_addr {
73 	struct sockaddr_in v4;
74 	struct sockaddr_in6 v6;
75 	struct sockaddr sa;
76 };
77 
78 /* Forward declarations for data structures. */
79 struct sctp_globals;
80 struct sctp_endpoint;
81 struct sctp_association;
82 struct sctp_transport;
83 struct sctp_packet;
84 struct sctp_chunk;
85 struct sctp_inq;
86 struct sctp_outq;
87 struct sctp_bind_addr;
88 struct sctp_ulpq;
89 struct sctp_ep_common;
90 struct sctp_ssnmap;
91 struct 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 
100 struct sctp_bind_bucket {
101 	unsigned short	port;
102 	unsigned short	fastreuse;
103 	struct hlist_node	node;
104 	struct hlist_head	owner;
105 };
106 
107 struct sctp_bind_hashbucket {
108 	spinlock_t	lock;
109 	struct hlist_head	chain;
110 };
111 
112 /* Used for hashing all associations.  */
113 struct sctp_hashbucket {
114 	rwlock_t	lock;
115 	struct hlist_head	chain;
116 } __attribute__((__aligned__(8)));
117 
118 
119 /* The SCTP globals structure. */
120 extern 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 	int default_auto_asconf;
209 	struct list_head addr_waitq;
210 	struct timer_list addr_wq_timer;
211 	struct list_head auto_asconf_splist;
212 	spinlock_t addr_wq_lock;
213 
214 	/* Lock that protects the local_addr_list writers */
215 	spinlock_t addr_list_lock;
216 
217 	/* Flag to indicate if addip is enabled. */
218 	int addip_enable;
219 	int addip_noauth_enable;
220 
221 	/* Flag to indicate if PR-SCTP is enabled. */
222 	int prsctp_enable;
223 
224 	/* Flag to idicate if SCTP-AUTH is enabled */
225 	int auth_enable;
226 
227 	/*
228 	 * Policy to control SCTP IPv4 address scoping
229 	 * 0   - Disable IPv4 address scoping
230 	 * 1   - Enable IPv4 address scoping
231 	 * 2   - Selectively allow only IPv4 private addresses
232 	 * 3   - Selectively allow only IPv4 link local address
233 	 */
234 	int ipv4_scope_policy;
235 
236 	/* Flag to indicate whether computing and verifying checksum
237 	 * is disabled. */
238         int checksum_disable;
239 
240 	/* Threshold for rwnd update SACKS.  Receive buffer shifted this many
241 	 * bits is an indicator of when to send and window update SACK.
242 	 */
243 	int rwnd_update_shift;
244 } sctp_globals;
245 
246 #define sctp_rto_initial		(sctp_globals.rto_initial)
247 #define sctp_rto_min			(sctp_globals.rto_min)
248 #define sctp_rto_max			(sctp_globals.rto_max)
249 #define sctp_rto_alpha			(sctp_globals.rto_alpha)
250 #define sctp_rto_beta			(sctp_globals.rto_beta)
251 #define sctp_max_burst			(sctp_globals.max_burst)
252 #define sctp_valid_cookie_life		(sctp_globals.valid_cookie_life)
253 #define sctp_cookie_preserve_enable	(sctp_globals.cookie_preserve_enable)
254 #define sctp_max_retrans_association	(sctp_globals.max_retrans_association)
255 #define sctp_sndbuf_policy	 	(sctp_globals.sndbuf_policy)
256 #define sctp_rcvbuf_policy	 	(sctp_globals.rcvbuf_policy)
257 #define sctp_max_retrans_path		(sctp_globals.max_retrans_path)
258 #define sctp_max_retrans_init		(sctp_globals.max_retrans_init)
259 #define sctp_sack_timeout		(sctp_globals.sack_timeout)
260 #define sctp_hb_interval		(sctp_globals.hb_interval)
261 #define sctp_max_instreams		(sctp_globals.max_instreams)
262 #define sctp_max_outstreams		(sctp_globals.max_outstreams)
263 #define sctp_address_families		(sctp_globals.address_families)
264 #define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
265 #define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
266 #define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
267 #define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
268 #define sctp_port_hashsize		(sctp_globals.port_hashsize)
269 #define sctp_port_hashtable		(sctp_globals.port_hashtable)
270 #define sctp_local_addr_list		(sctp_globals.local_addr_list)
271 #define sctp_local_addr_lock		(sctp_globals.addr_list_lock)
272 #define sctp_auto_asconf_splist		(sctp_globals.auto_asconf_splist)
273 #define sctp_addr_waitq			(sctp_globals.addr_waitq)
274 #define sctp_addr_wq_timer		(sctp_globals.addr_wq_timer)
275 #define sctp_addr_wq_lock		(sctp_globals.addr_wq_lock)
276 #define sctp_default_auto_asconf	(sctp_globals.default_auto_asconf)
277 #define sctp_scope_policy		(sctp_globals.ipv4_scope_policy)
278 #define sctp_addip_enable		(sctp_globals.addip_enable)
279 #define sctp_addip_noauth		(sctp_globals.addip_noauth_enable)
280 #define sctp_prsctp_enable		(sctp_globals.prsctp_enable)
281 #define sctp_auth_enable		(sctp_globals.auth_enable)
282 #define sctp_checksum_disable		(sctp_globals.checksum_disable)
283 #define sctp_rwnd_upd_shift		(sctp_globals.rwnd_update_shift)
284 
285 /* SCTP Socket type: UDP or TCP style. */
286 typedef enum {
287 	SCTP_SOCKET_UDP = 0,
288 	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
289 	SCTP_SOCKET_TCP
290 } sctp_socket_type_t;
291 
292 /* Per socket SCTP information. */
293 struct sctp_sock {
294 	/* inet_sock has to be the first member of sctp_sock */
295 	struct inet_sock inet;
296 	/* What kind of a socket is this? */
297 	sctp_socket_type_t type;
298 
299 	/* PF_ family specific functions.  */
300 	struct sctp_pf *pf;
301 
302 	/* Access to HMAC transform. */
303 	struct crypto_hash *hmac;
304 
305 	/* What is our base endpointer? */
306 	struct sctp_endpoint *ep;
307 
308 	struct sctp_bind_bucket *bind_hash;
309 	/* Various Socket Options.  */
310 	__u16 default_stream;
311 	__u32 default_ppid;
312 	__u16 default_flags;
313 	__u32 default_context;
314 	__u32 default_timetolive;
315 	__u32 default_rcv_context;
316 	int max_burst;
317 
318 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
319 	 * the destination address every heartbeat interval. This value
320 	 * will be inherited by all new associations.
321 	 */
322 	__u32 hbinterval;
323 
324 	/* This is the max_retrans value for new associations. */
325 	__u16 pathmaxrxt;
326 
327 	/* The initial Path MTU to use for new associations. */
328 	__u32 pathmtu;
329 
330 	/* The default SACK delay timeout for new associations. */
331 	__u32 sackdelay;
332 	__u32 sackfreq;
333 
334 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
335 	__u32 param_flags;
336 
337 	struct sctp_initmsg initmsg;
338 	struct sctp_rtoinfo rtoinfo;
339 	struct sctp_paddrparams paddrparam;
340 	struct sctp_event_subscribe subscribe;
341 	struct sctp_assocparams assocparams;
342 	int user_frag;
343 	__u32 autoclose;
344 	__u8 nodelay;
345 	__u8 disable_fragments;
346 	__u8 v4mapped;
347 	__u8 frag_interleave;
348 	__u32 adaptation_ind;
349 	__u32 pd_point;
350 
351 	atomic_t pd_mode;
352 	/* Receive to here while partial delivery is in effect. */
353 	struct sk_buff_head pd_lobby;
354 	struct list_head auto_asconf_list;
355 	int do_auto_asconf;
356 };
357 
358 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
359 {
360        return (struct sctp_sock *)sk;
361 }
362 
363 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
364 {
365        return (struct sock *)sp;
366 }
367 
368 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
369 struct sctp6_sock {
370        struct sctp_sock  sctp;
371        struct ipv6_pinfo inet6;
372 };
373 #endif /* CONFIG_IPV6 */
374 
375 
376 /* This is our APPLICATION-SPECIFIC state cookie.
377  * THIS IS NOT DICTATED BY THE SPECIFICATION.
378  */
379 /* These are the parts of an association which we send in the cookie.
380  * Most of these are straight out of:
381  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
382  *
383  */
384 
385 struct sctp_cookie {
386 
387 	/* My	       : Tag expected in every inbound packet and sent
388 	 * Verification: in the INIT or INIT ACK chunk.
389 	 * Tag	       :
390 	 */
391 	__u32 my_vtag;
392 
393 	/* Peer's      : Tag expected in every outbound packet except
394 	 * Verification: in the INIT chunk.
395 	 * Tag	       :
396 	 */
397 	__u32 peer_vtag;
398 
399 	/* The rest of these are not from the spec, but really need to
400 	 * be in the cookie.
401 	 */
402 
403 	/* My Tie Tag  : Assist in discovering a restarting association. */
404 	__u32 my_ttag;
405 
406 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
407 	__u32 peer_ttag;
408 
409 	/* When does this cookie expire? */
410 	struct timeval expiration;
411 
412 	/* Number of inbound/outbound streams which are set
413 	 * and negotiated during the INIT process.
414 	 */
415 	__u16 sinit_num_ostreams;
416 	__u16 sinit_max_instreams;
417 
418 	/* This is the first sequence number I used.  */
419 	__u32 initial_tsn;
420 
421 	/* This holds the originating address of the INIT packet.  */
422 	union sctp_addr peer_addr;
423 
424 	/* IG Section 2.35.3
425 	 * Include the source port of the INIT-ACK
426 	 */
427 	__u16		my_port;
428 
429 	__u8 prsctp_capable;
430 
431 	/* Padding for future use */
432 	__u8 padding;
433 
434 	__u32 adaptation_ind;
435 
436 	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
437 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
438 	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
439 
440 	/* This is a shim for my peer's INIT packet, followed by
441 	 * a copy of the raw address list of the association.
442 	 * The length of the raw address list is saved in the
443 	 * raw_addr_list_len field, which will be used at the time when
444 	 * the association TCB is re-constructed from the cookie.
445 	 */
446 	__u32 raw_addr_list_len;
447 	struct sctp_init_chunk peer_init[0];
448 };
449 
450 
451 /* The format of our cookie that we send to our peer. */
452 struct sctp_signed_cookie {
453 	__u8 signature[SCTP_SECRET_SIZE];
454 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
455 	struct sctp_cookie c;
456 } __packed;
457 
458 /* This is another convenience type to allocate memory for address
459  * params for the maximum size and pass such structures around
460  * internally.
461  */
462 union sctp_addr_param {
463 	struct sctp_paramhdr p;
464 	struct sctp_ipv4addr_param v4;
465 	struct sctp_ipv6addr_param v6;
466 };
467 
468 /* A convenience type to allow walking through the various
469  * parameters and avoid casting all over the place.
470  */
471 union sctp_params {
472 	void *v;
473 	struct sctp_paramhdr *p;
474 	struct sctp_cookie_preserve_param *life;
475 	struct sctp_hostname_param *dns;
476 	struct sctp_cookie_param *cookie;
477 	struct sctp_supported_addrs_param *sat;
478 	struct sctp_ipv4addr_param *v4;
479 	struct sctp_ipv6addr_param *v6;
480 	union sctp_addr_param *addr;
481 	struct sctp_adaptation_ind_param *aind;
482 	struct sctp_supported_ext_param *ext;
483 	struct sctp_random_param *random;
484 	struct sctp_chunks_param *chunks;
485 	struct sctp_hmac_algo_param *hmac_algo;
486 	struct sctp_addip_param *addip;
487 };
488 
489 /* RFC 2960.  Section 3.3.5 Heartbeat.
490  *    Heartbeat Information: variable length
491  *    The Sender-specific Heartbeat Info field should normally include
492  *    information about the sender's current time when this HEARTBEAT
493  *    chunk is sent and the destination transport address to which this
494  *    HEARTBEAT is sent (see Section 8.3).
495  */
496 typedef struct sctp_sender_hb_info {
497 	struct sctp_paramhdr param_hdr;
498 	union sctp_addr daddr;
499 	unsigned long sent_at;
500 	__u64 hb_nonce;
501 } __packed sctp_sender_hb_info_t;
502 
503 /*
504  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
505  *
506  *  The term "stream" is used in SCTP to refer to a sequence of user
507  *  messages that are to be delivered to the upper-layer protocol in
508  *  order with respect to other messages within the same stream.  This is
509  *  in contrast to its usage in TCP, where it refers to a sequence of
510  *  bytes (in this document a byte is assumed to be eight bits).
511  *  ...
512  *
513  *  This is the structure we use to track both our outbound and inbound
514  *  SSN, or Stream Sequence Numbers.
515  */
516 
517 struct sctp_stream {
518 	__u16 *ssn;
519 	unsigned int len;
520 };
521 
522 struct sctp_ssnmap {
523 	struct sctp_stream in;
524 	struct sctp_stream out;
525 	int malloced;
526 };
527 
528 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
529 				    gfp_t gfp);
530 void sctp_ssnmap_free(struct sctp_ssnmap *map);
531 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
532 
533 /* What is the current SSN number for this stream? */
534 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
535 {
536 	return stream->ssn[id];
537 }
538 
539 /* Return the next SSN number for this stream.	*/
540 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
541 {
542 	return stream->ssn[id]++;
543 }
544 
545 /* Skip over this ssn and all below. */
546 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
547 				 __u16 ssn)
548 {
549 	stream->ssn[id] = ssn+1;
550 }
551 
552 /*
553  * Pointers to address related SCTP functions.
554  * (i.e. things that depend on the address family.)
555  */
556 struct sctp_af {
557 	int		(*sctp_xmit)	(struct sk_buff *skb,
558 					 struct sctp_transport *);
559 	int		(*setsockopt)	(struct sock *sk,
560 					 int level,
561 					 int optname,
562 					 char __user *optval,
563 					 unsigned int optlen);
564 	int		(*getsockopt)	(struct sock *sk,
565 					 int level,
566 					 int optname,
567 					 char __user *optval,
568 					 int __user *optlen);
569 	int		(*compat_setsockopt)	(struct sock *sk,
570 					 int level,
571 					 int optname,
572 					 char __user *optval,
573 					 unsigned int optlen);
574 	int		(*compat_getsockopt)	(struct sock *sk,
575 					 int level,
576 					 int optname,
577 					 char __user *optval,
578 					 int __user *optlen);
579 	void		(*get_dst)	(struct sctp_transport *t,
580 					 union sctp_addr *saddr,
581 					 struct flowi *fl,
582 					 struct sock *sk);
583 	void		(*get_saddr)	(struct sctp_sock *sk,
584 					 struct sctp_transport *t,
585 					 struct flowi *fl);
586 	void		(*copy_addrlist) (struct list_head *,
587 					  struct net_device *);
588 	int		(*cmp_addr)	(const union sctp_addr *addr1,
589 					 const union sctp_addr *addr2);
590 	void		(*addr_copy)	(union sctp_addr *dst,
591 					 union sctp_addr *src);
592 	void		(*from_skb)	(union sctp_addr *,
593 					 struct sk_buff *skb,
594 					 int saddr);
595 	void		(*from_sk)	(union sctp_addr *,
596 					 struct sock *sk);
597 	void		(*to_sk_saddr)	(union sctp_addr *,
598 					 struct sock *sk);
599 	void		(*to_sk_daddr)	(union sctp_addr *,
600 					 struct sock *sk);
601 	void		(*from_addr_param) (union sctp_addr *,
602 					    union sctp_addr_param *,
603 					    __be16 port, int iif);
604 	int		(*to_addr_param) (const union sctp_addr *,
605 					  union sctp_addr_param *);
606 	int		(*addr_valid)	(union sctp_addr *,
607 					 struct sctp_sock *,
608 					 const struct sk_buff *);
609 	sctp_scope_t	(*scope) (union sctp_addr *);
610 	void		(*inaddr_any)	(union sctp_addr *, __be16);
611 	int		(*is_any)	(const union sctp_addr *);
612 	int		(*available)	(union sctp_addr *,
613 					 struct sctp_sock *);
614 	int		(*skb_iif)	(const struct sk_buff *sk);
615 	int		(*is_ce)	(const struct sk_buff *sk);
616 	void		(*seq_dump_addr)(struct seq_file *seq,
617 					 union sctp_addr *addr);
618 	void		(*ecn_capable)(struct sock *sk);
619 	__u16		net_header_len;
620 	int		sockaddr_len;
621 	sa_family_t	sa_family;
622 	struct list_head list;
623 };
624 
625 struct sctp_af *sctp_get_af_specific(sa_family_t);
626 int sctp_register_af(struct sctp_af *);
627 
628 /* Protocol family functions. */
629 struct sctp_pf {
630 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
631 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
632 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
633 	int  (*cmp_addr) (const union sctp_addr *,
634 			  const union sctp_addr *,
635 			  struct sctp_sock *);
636 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
637 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
638 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
639 	struct sock *(*create_accept_sk) (struct sock *sk,
640 					  struct sctp_association *asoc);
641 	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
642 	struct sctp_af *af;
643 };
644 
645 
646 /* Structure to track chunk fragments that have been acked, but peer
647  * fragments of the same message have not.
648  */
649 struct sctp_datamsg {
650 	/* Chunks waiting to be submitted to lower layer. */
651 	struct list_head chunks;
652 	/* Reference counting. */
653 	atomic_t refcnt;
654 	/* When is this message no longer interesting to the peer? */
655 	unsigned long expires_at;
656 	/* Did the messenge fail to send? */
657 	int send_error;
658 	u8 send_failed:1,
659 	   can_abandon:1,   /* can chunks from this message can be abandoned. */
660 	   can_delay;	    /* should this message be Nagle delayed */
661 };
662 
663 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
664 					    struct sctp_sndrcvinfo *,
665 					    struct msghdr *, int len);
666 void sctp_datamsg_free(struct sctp_datamsg *);
667 void sctp_datamsg_put(struct sctp_datamsg *);
668 void sctp_chunk_fail(struct sctp_chunk *, int error);
669 int sctp_chunk_abandoned(struct sctp_chunk *);
670 
671 /* RFC2960 1.4 Key Terms
672  *
673  * o Chunk: A unit of information within an SCTP packet, consisting of
674  * a chunk header and chunk-specific content.
675  *
676  * As a matter of convenience, we remember the SCTP common header for
677  * each chunk as well as a few other header pointers...
678  */
679 struct sctp_chunk {
680 	struct list_head list;
681 
682 	atomic_t refcnt;
683 
684 	/* This is our link to the per-transport transmitted list.  */
685 	struct list_head transmitted_list;
686 
687 	/* This field is used by chunks that hold fragmented data.
688 	 * For the first fragment this is the list that holds the rest of
689 	 * fragments. For the remaining fragments, this is the link to the
690 	 * frag_list maintained in the first fragment.
691 	 */
692 	struct list_head frag_list;
693 
694 	/* This points to the sk_buff containing the actual data.  */
695 	struct sk_buff *skb;
696 
697 	/* These are the SCTP headers by reverse order in a packet.
698 	 * Note that some of these may happen more than once.  In that
699 	 * case, we point at the "current" one, whatever that means
700 	 * for that level of header.
701 	 */
702 
703 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
704 	union sctp_params param_hdr;
705 	union {
706 		__u8 *v;
707 		struct sctp_datahdr *data_hdr;
708 		struct sctp_inithdr *init_hdr;
709 		struct sctp_sackhdr *sack_hdr;
710 		struct sctp_heartbeathdr *hb_hdr;
711 		struct sctp_sender_hb_info *hbs_hdr;
712 		struct sctp_shutdownhdr *shutdown_hdr;
713 		struct sctp_signed_cookie *cookie_hdr;
714 		struct sctp_ecnehdr *ecne_hdr;
715 		struct sctp_cwrhdr *ecn_cwr_hdr;
716 		struct sctp_errhdr *err_hdr;
717 		struct sctp_addiphdr *addip_hdr;
718 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
719 		struct sctp_authhdr *auth_hdr;
720 	} subh;
721 
722 	__u8 *chunk_end;
723 
724 	struct sctp_chunkhdr *chunk_hdr;
725 	struct sctphdr *sctp_hdr;
726 
727 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
728 	struct sctp_sndrcvinfo sinfo;
729 
730 	/* Which association does this belong to?  */
731 	struct sctp_association *asoc;
732 
733 	/* What endpoint received this chunk? */
734 	struct sctp_ep_common *rcvr;
735 
736 	/* We fill this in if we are calculating RTT. */
737 	unsigned long sent_at;
738 
739 	/* What is the origin IP address for this chunk?  */
740 	union sctp_addr source;
741 	/* Destination address for this chunk. */
742 	union sctp_addr dest;
743 
744 	/* For outbound message, track all fragments for SEND_FAILED. */
745 	struct sctp_datamsg *msg;
746 
747 	/* For an inbound chunk, this tells us where it came from.
748 	 * For an outbound chunk, it tells us where we'd like it to
749 	 * go.	It is NULL if we have no preference.
750 	 */
751 	struct sctp_transport *transport;
752 
753 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
754 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
755 	 * spec violates the principle premis that all chunks are processed
756 	 * in order.
757 	 */
758 	struct sk_buff *auth_chunk;
759 
760 #define SCTP_CAN_FRTX 0x0
761 #define SCTP_NEED_FRTX 0x1
762 #define SCTP_DONT_FRTX 0x2
763 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
764 		has_tsn:1,		/* Does this chunk have a TSN yet? */
765 		has_ssn:1,		/* Does this chunk have a SSN yet? */
766 		singleton:1,		/* Only chunk in the packet? */
767 		end_of_packet:1,	/* Last chunk in the packet? */
768 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
769 		pdiscard:1,		/* Discard the whole packet now? */
770 		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
771 		data_accepted:1,	/* At least 1 chunk accepted */
772 		auth:1,			/* IN: was auth'ed | OUT: needs auth */
773 		has_asconf:1,		/* IN: have seen an asconf before */
774 		tsn_missing_report:2,	/* Data chunk missing counter. */
775 		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
776 };
777 
778 void sctp_chunk_hold(struct sctp_chunk *);
779 void sctp_chunk_put(struct sctp_chunk *);
780 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
781 			  struct iovec *data);
782 void sctp_chunk_free(struct sctp_chunk *);
783 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
784 void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
785 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
786 				 const struct sctp_association *,
787 				 struct sock *);
788 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
789 		     union sctp_addr *);
790 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
791 
792 enum {
793 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
794 	SCTP_ADDR_SRC,		/* address can be used as source */
795 	SCTP_ADDR_DEL,		/* address about to be deleted */
796 };
797 
798 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
799 struct sctp_sockaddr_entry {
800 	struct list_head list;
801 	struct rcu_head	rcu;
802 	union sctp_addr a;
803 	__u8 state;
804 	__u8 valid;
805 };
806 
807 #define SCTP_ADDRESS_TICK_DELAY	500
808 
809 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
810 
811 /* This structure holds lists of chunks as we are assembling for
812  * transmission.
813  */
814 struct sctp_packet {
815 	/* These are the SCTP header values (host order) for the packet. */
816 	__u16 source_port;
817 	__u16 destination_port;
818 	__u32 vtag;
819 
820 	/* This contains the payload chunks.  */
821 	struct list_head chunk_list;
822 
823 	/* This is the overhead of the sctp and ip headers. */
824 	size_t overhead;
825 	/* This is the total size of all chunks INCLUDING padding.  */
826 	size_t size;
827 
828 	/* The packet is destined for this transport address.
829 	 * The function we finally use to pass down to the next lower
830 	 * layer lives in the transport structure.
831 	 */
832 	struct sctp_transport *transport;
833 
834 	/* pointer to the auth chunk for this packet */
835 	struct sctp_chunk *auth;
836 
837 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
838 	    has_sack:1,		/* This packet contains a SACK chunk. */
839 	    has_auth:1,		/* This packet contains an AUTH chunk */
840 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
841 	    ipfragok:1,		/* So let ip fragment this packet */
842 	    malloced:1;		/* Is it malloced? */
843 };
844 
845 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
846 				     struct sctp_transport *,
847 				     __u16 sport, __u16 dport);
848 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
849 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
850                                        struct sctp_chunk *, int);
851 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
852                                      struct sctp_chunk *);
853 int sctp_packet_transmit(struct sctp_packet *);
854 void sctp_packet_free(struct sctp_packet *);
855 
856 static inline int sctp_packet_empty(struct sctp_packet *packet)
857 {
858 	return packet->size == packet->overhead;
859 }
860 
861 /* This represents a remote transport address.
862  * For local transport addresses, we just use union sctp_addr.
863  *
864  * RFC2960 Section 1.4 Key Terms
865  *
866  *   o	Transport address:  A Transport Address is traditionally defined
867  *	by Network Layer address, Transport Layer protocol and Transport
868  *	Layer port number.  In the case of SCTP running over IP, a
869  *	transport address is defined by the combination of an IP address
870  *	and an SCTP port number (where SCTP is the Transport protocol).
871  *
872  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
873  *
874  *   o	The sender keeps a separate congestion control parameter set for
875  *	each of the destination addresses it can send to (not each
876  *	source-destination pair but for each destination).  The parameters
877  *	should decay if the address is not used for a long enough time
878  *	period.
879  *
880  */
881 struct sctp_transport {
882 	/* A list of transports. */
883 	struct list_head transports;
884 
885 	/* Reference counting. */
886 	atomic_t refcnt;
887 	__u32	 dead:1,
888 		/* RTO-Pending : A flag used to track if one of the DATA
889 		 *		chunks sent to this address is currently being
890 		 *		used to compute a RTT. If this flag is 0,
891 		 *		the next DATA chunk sent to this destination
892 		 *		should be used to compute a RTT and this flag
893 		 *		should be set. Every time the RTT
894 		 *		calculation completes (i.e. the DATA chunk
895 		 *		is SACK'd) clear this flag.
896 		 */
897 		 rto_pending:1,
898 
899 		/*
900 		 * hb_sent : a flag that signals that we have a pending
901 		 * heartbeat.
902 		 */
903 		hb_sent:1,
904 
905 		/* Is the Path MTU update pending on this tranport */
906 		pmtu_pending:1,
907 
908 		/* Is this structure kfree()able? */
909 		malloced:1;
910 
911 	struct flowi fl;
912 
913 	/* This is the peer's IP address and port. */
914 	union sctp_addr ipaddr;
915 
916 	/* These are the functions we call to handle LLP stuff.	 */
917 	struct sctp_af *af_specific;
918 
919 	/* Which association do we belong to?  */
920 	struct sctp_association *asoc;
921 
922 	/* RFC2960
923 	 *
924 	 * 12.3 Per Transport Address Data
925 	 *
926 	 * For each destination transport address in the peer's
927 	 * address list derived from the INIT or INIT ACK chunk, a
928 	 * number of data elements needs to be maintained including:
929 	 */
930 	/* RTO	       : The current retransmission timeout value.  */
931 	unsigned long rto;
932 
933 	__u32 rtt;		/* This is the most recent RTT.	 */
934 
935 	/* RTTVAR      : The current RTT variation.  */
936 	__u32 rttvar;
937 
938 	/* SRTT	       : The current smoothed round trip time.	*/
939 	__u32 srtt;
940 
941 	/*
942 	 * These are the congestion stats.
943 	 */
944 	/* cwnd	       : The current congestion window.	 */
945 	__u32 cwnd;		  /* This is the actual cwnd.  */
946 
947 	/* ssthresh    : The current slow start threshold value.  */
948 	__u32 ssthresh;
949 
950 	/* partial     : The tracking method for increase of cwnd when in
951 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
952 	 */
953 	__u32 partial_bytes_acked;
954 
955 	/* Data that has been sent, but not acknowledged. */
956 	__u32 flight_size;
957 
958 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
959 
960 	/* Destination */
961 	struct dst_entry *dst;
962 	/* Source address. */
963 	union sctp_addr saddr;
964 
965 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
966 	 * the destination address every heartbeat interval.
967 	 */
968 	unsigned long hbinterval;
969 
970 	/* SACK delay timeout */
971 	unsigned long sackdelay;
972 	__u32 sackfreq;
973 
974 	/* When was the last time (in jiffies) that we heard from this
975 	 * transport?  We use this to pick new active and retran paths.
976 	 */
977 	unsigned long last_time_heard;
978 
979 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
980 	 * indication based on ECNE chunk.
981 	 */
982 	unsigned long last_time_ecne_reduced;
983 
984 	/* This is the max_retrans value for the transport and will
985 	 * be initialized from the assocs value.  This can be changed
986 	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
987 	 */
988 	__u16 pathmaxrxt;
989 
990 	/* PMTU	      : The current known path MTU.  */
991 	__u32 pathmtu;
992 
993 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
994 	__u32 param_flags;
995 
996 	/* The number of times INIT has been sent on this transport. */
997 	int init_sent_count;
998 
999 	/* state       : The current state of this destination,
1000 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
1001 	 */
1002 	int state;
1003 
1004 	/* These are the error stats for this destination.  */
1005 
1006 	/* Error count : The current error count for this destination.	*/
1007 	unsigned short error_count;
1008 
1009 	/* Per	       : A timer used by each destination.
1010 	 * Destination :
1011 	 * Timer       :
1012 	 *
1013 	 * [Everywhere else in the text this is called T3-rtx. -ed]
1014 	 */
1015 	struct timer_list T3_rtx_timer;
1016 
1017 	/* Heartbeat timer is per destination. */
1018 	struct timer_list hb_timer;
1019 
1020 	/* Timer to handle ICMP proto unreachable envets */
1021 	struct timer_list proto_unreach_timer;
1022 
1023 	/* Since we're using per-destination retransmission timers
1024 	 * (see above), we're also using per-destination "transmitted"
1025 	 * queues.  This probably ought to be a private struct
1026 	 * accessible only within the outqueue, but it's not, yet.
1027 	 */
1028 	struct list_head transmitted;
1029 
1030 	/* We build bundle-able packets for this transport here.  */
1031 	struct sctp_packet packet;
1032 
1033 	/* This is the list of transports that have chunks to send.  */
1034 	struct list_head send_ready;
1035 
1036 	/* State information saved for SFR_CACC algorithm. The key
1037 	 * idea in SFR_CACC is to maintain state at the sender on a
1038 	 * per-destination basis when a changeover happens.
1039 	 *	char changeover_active;
1040 	 *	char cycling_changeover;
1041 	 *	__u32 next_tsn_at_change;
1042 	 *	char cacc_saw_newack;
1043 	 */
1044 	struct {
1045 		/* An unsigned integer, which stores the next TSN to be
1046 		 * used by the sender, at the moment of changeover.
1047 		 */
1048 		__u32 next_tsn_at_change;
1049 
1050 		/* A flag which indicates the occurrence of a changeover */
1051 		char changeover_active;
1052 
1053 		/* A flag which indicates whether the change of primary is
1054 		 * the first switch to this destination address during an
1055 		 * active switch.
1056 		 */
1057 		char cycling_changeover;
1058 
1059 		/* A temporary flag, which is used during the processing of
1060 		 * a SACK to estimate the causative TSN(s)'s group.
1061 		 */
1062 		char cacc_saw_newack;
1063 	} cacc;
1064 
1065 	/* 64-bit random number sent with heartbeat. */
1066 	__u64 hb_nonce;
1067 };
1068 
1069 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1070 					  gfp_t);
1071 void sctp_transport_set_owner(struct sctp_transport *,
1072 			      struct sctp_association *);
1073 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1074 			  struct sctp_sock *);
1075 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1076 void sctp_transport_free(struct sctp_transport *);
1077 void sctp_transport_reset_timers(struct sctp_transport *);
1078 void sctp_transport_hold(struct sctp_transport *);
1079 void sctp_transport_put(struct sctp_transport *);
1080 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1081 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1082 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1083 void sctp_transport_burst_limited(struct sctp_transport *);
1084 void sctp_transport_burst_reset(struct sctp_transport *);
1085 unsigned long sctp_transport_timeout(struct sctp_transport *);
1086 void sctp_transport_reset(struct sctp_transport *);
1087 void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1088 
1089 
1090 /* This is the structure we use to queue packets as they come into
1091  * SCTP.  We write packets to it and read chunks from it.
1092  */
1093 struct sctp_inq {
1094 	/* This is actually a queue of sctp_chunk each
1095 	 * containing a partially decoded packet.
1096 	 */
1097 	struct list_head in_chunk_list;
1098 	/* This is the packet which is currently off the in queue and is
1099 	 * being worked on through the inbound chunk processing.
1100 	 */
1101 	struct sctp_chunk *in_progress;
1102 
1103 	/* This is the delayed task to finish delivering inbound
1104 	 * messages.
1105 	 */
1106 	struct work_struct immediate;
1107 
1108 	int malloced;	     /* Is this structure kfree()able?	*/
1109 };
1110 
1111 void sctp_inq_init(struct sctp_inq *);
1112 void sctp_inq_free(struct sctp_inq *);
1113 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1114 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1115 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1116 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1117 
1118 /* This is the structure we use to hold outbound chunks.  You push
1119  * chunks in and they automatically pop out the other end as bundled
1120  * packets (it calls (*output_handler)()).
1121  *
1122  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1123  * and 8.2 of the v13 draft.
1124  *
1125  * It handles retransmissions.	The connection to the timeout portion
1126  * of the state machine is through sctp_..._timeout() and timeout_handler.
1127  *
1128  * If you feed it SACKs, it will eat them.
1129  *
1130  * If you give it big chunks, it will fragment them.
1131  *
1132  * It assigns TSN's to data chunks.  This happens at the last possible
1133  * instant before transmission.
1134  *
1135  * When free()'d, it empties itself out via output_handler().
1136  */
1137 struct sctp_outq {
1138 	struct sctp_association *asoc;
1139 
1140 	/* Data pending that has never been transmitted.  */
1141 	struct list_head out_chunk_list;
1142 
1143 	unsigned out_qlen;	/* Total length of queued data chunks. */
1144 
1145 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1146 	unsigned error;
1147 
1148 	/* These are control chunks we want to send.  */
1149 	struct list_head control_chunk_list;
1150 
1151 	/* These are chunks that have been sacked but are above the
1152 	 * CTSN, or cumulative tsn ack point.
1153 	 */
1154 	struct list_head sacked;
1155 
1156 	/* Put chunks on this list to schedule them for
1157 	 * retransmission.
1158 	 */
1159 	struct list_head retransmit;
1160 
1161 	/* Put chunks on this list to save them for FWD TSN processing as
1162 	 * they were abandoned.
1163 	 */
1164 	struct list_head abandoned;
1165 
1166 	/* How many unackd bytes do we have in-flight?	*/
1167 	__u32 outstanding_bytes;
1168 
1169 	/* Are we doing fast-rtx on this queue */
1170 	char fast_rtx;
1171 
1172 	/* Corked? */
1173 	char cork;
1174 
1175 	/* Is this structure empty?  */
1176 	char empty;
1177 
1178 	/* Are we kfree()able? */
1179 	char malloced;
1180 };
1181 
1182 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1183 void sctp_outq_teardown(struct sctp_outq *);
1184 void sctp_outq_free(struct sctp_outq*);
1185 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1186 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1187 int sctp_outq_is_empty(const struct sctp_outq *);
1188 void sctp_outq_restart(struct sctp_outq *);
1189 
1190 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1191 		     sctp_retransmit_reason_t);
1192 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1193 int sctp_outq_uncork(struct sctp_outq *);
1194 /* Uncork and flush an outqueue.  */
1195 static inline void sctp_outq_cork(struct sctp_outq *q)
1196 {
1197 	q->cork = 1;
1198 }
1199 
1200 /* These bind address data fields common between endpoints and associations */
1201 struct sctp_bind_addr {
1202 
1203 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1204 	 *
1205 	 * SCTP Port:	The local SCTP port number the endpoint is
1206 	 *		bound to.
1207 	 */
1208 	__u16 port;
1209 
1210 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1211 	 *
1212 	 * Address List: The list of IP addresses that this instance
1213 	 *	has bound.  This information is passed to one's
1214 	 *	peer(s) in INIT and INIT ACK chunks.
1215 	 */
1216 	struct list_head address_list;
1217 
1218 	int malloced;	     /* Are we kfree()able?  */
1219 };
1220 
1221 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1222 void sctp_bind_addr_free(struct sctp_bind_addr *);
1223 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1224 			const struct sctp_bind_addr *src,
1225 			sctp_scope_t scope, gfp_t gfp,
1226 			int flags);
1227 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1228 			const struct sctp_bind_addr *src,
1229 			gfp_t gfp);
1230 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1231 		       __u8 addr_state, gfp_t gfp);
1232 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1233 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1234 			 struct sctp_sock *);
1235 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1236 			 struct sctp_sock *, struct sctp_sock *);
1237 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1238 			 const union sctp_addr *addr);
1239 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1240 					const union sctp_addr	*addrs,
1241 					int			addrcnt,
1242 					struct sctp_sock	*opt);
1243 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1244 					 int *addrs_len,
1245 					 gfp_t gfp);
1246 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1247 			   __u16 port, gfp_t gfp);
1248 
1249 sctp_scope_t sctp_scope(const union sctp_addr *);
1250 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1251 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1252 int sctp_addr_is_valid(const union sctp_addr *addr);
1253 int sctp_is_ep_boundall(struct sock *sk);
1254 
1255 
1256 /* What type of endpoint?  */
1257 typedef enum {
1258 	SCTP_EP_TYPE_SOCKET,
1259 	SCTP_EP_TYPE_ASSOCIATION,
1260 } sctp_endpoint_type_t;
1261 
1262 /*
1263  * A common base class to bridge the implmentation view of a
1264  * socket (usually listening) endpoint versus an association's
1265  * local endpoint.
1266  * This common structure is useful for several purposes:
1267  *   1) Common interface for lookup routines.
1268  *	a) Subfunctions work for either endpoint or association
1269  *	b) Single interface to lookup allows hiding the lookup lock rather
1270  *	   than acquiring it externally.
1271  *   2) Common interface for the inbound chunk handling/state machine.
1272  *   3) Common object handling routines for reference counting, etc.
1273  *   4) Disentangle association lookup from endpoint lookup, where we
1274  *	do not have to find our endpoint to find our association.
1275  *
1276  */
1277 
1278 struct sctp_ep_common {
1279 	/* Fields to help us manage our entries in the hash tables. */
1280 	struct hlist_node node;
1281 	int hashent;
1282 
1283 	/* Runtime type information.  What kind of endpoint is this? */
1284 	sctp_endpoint_type_t type;
1285 
1286 	/* Some fields to help us manage this object.
1287 	 *   refcnt   - Reference count access to this object.
1288 	 *   dead     - Do not attempt to use this object.
1289 	 *   malloced - Do we need to kfree this object?
1290 	 */
1291 	atomic_t    refcnt;
1292 	char	    dead;
1293 	char	    malloced;
1294 
1295 	/* What socket does this endpoint belong to?  */
1296 	struct sock *sk;
1297 
1298 	/* This is where we receive inbound chunks.  */
1299 	struct sctp_inq	  inqueue;
1300 
1301 	/* This substructure includes the defining parameters of the
1302 	 * endpoint:
1303 	 * bind_addr.port is our shared port number.
1304 	 * bind_addr.address_list is our set of local IP addresses.
1305 	 */
1306 	struct sctp_bind_addr bind_addr;
1307 };
1308 
1309 
1310 /* RFC Section 1.4 Key Terms
1311  *
1312  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1313  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1314  *   combination of a set of eligible destination transport addresses to
1315  *   which SCTP packets can be sent and a set of eligible source
1316  *   transport addresses from which SCTP packets can be received.
1317  *   All transport addresses used by an SCTP endpoint must use the
1318  *   same port number, but can use multiple IP addresses. A transport
1319  *   address used by an SCTP endpoint must not be used by another
1320  *   SCTP endpoint. In other words, a transport address is unique
1321  *   to an SCTP endpoint.
1322  *
1323  * From an implementation perspective, each socket has one of these.
1324  * A TCP-style socket will have exactly one association on one of
1325  * these.  An UDP-style socket will have multiple associations hanging
1326  * off one of these.
1327  */
1328 
1329 struct sctp_endpoint {
1330 	/* Common substructure for endpoint and association. */
1331 	struct sctp_ep_common base;
1332 
1333 	/* Associations: A list of current associations and mappings
1334 	 *	      to the data consumers for each association. This
1335 	 *	      may be in the form of a hash table or other
1336 	 *	      implementation dependent structure. The data
1337 	 *	      consumers may be process identification
1338 	 *	      information such as file descriptors, named pipe
1339 	 *	      pointer, or table pointers dependent on how SCTP
1340 	 *	      is implemented.
1341 	 */
1342 	/* This is really a list of struct sctp_association entries. */
1343 	struct list_head asocs;
1344 
1345 	/* Secret Key: A secret key used by this endpoint to compute
1346 	 *	      the MAC.	This SHOULD be a cryptographic quality
1347 	 *	      random number with a sufficient length.
1348 	 *	      Discussion in [RFC1750] can be helpful in
1349 	 *	      selection of the key.
1350 	 */
1351 	__u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1352 	int current_key;
1353 	int last_key;
1354 	int key_changed_at;
1355 
1356  	/* digest:  This is a digest of the sctp cookie.  This field is
1357  	 * 	    only used on the receive path when we try to validate
1358  	 * 	    that the cookie has not been tampered with.  We put
1359  	 * 	    this here so we pre-allocate this once and can re-use
1360  	 * 	    on every receive.
1361  	 */
1362  	__u8 *digest;
1363 
1364 	/* sendbuf acct. policy.	*/
1365 	__u32 sndbuf_policy;
1366 
1367 	/* rcvbuf acct. policy.	*/
1368 	__u32 rcvbuf_policy;
1369 
1370 	/* SCTP AUTH: array of the HMACs that will be allocated
1371 	 * we need this per association so that we don't serialize
1372 	 */
1373 	struct crypto_hash **auth_hmacs;
1374 
1375 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1376 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1377 
1378 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1379 	struct sctp_chunks_param *auth_chunk_list;
1380 
1381 	/* SCTP-AUTH: endpoint shared keys */
1382 	struct list_head endpoint_shared_keys;
1383 	__u16 active_key_id;
1384 };
1385 
1386 /* Recover the outter endpoint structure. */
1387 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1388 {
1389 	struct sctp_endpoint *ep;
1390 
1391 	ep = container_of(base, struct sctp_endpoint, base);
1392 	return ep;
1393 }
1394 
1395 /* These are function signatures for manipulating endpoints.  */
1396 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1397 void sctp_endpoint_free(struct sctp_endpoint *);
1398 void sctp_endpoint_put(struct sctp_endpoint *);
1399 void sctp_endpoint_hold(struct sctp_endpoint *);
1400 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1401 struct sctp_association *sctp_endpoint_lookup_assoc(
1402 	const struct sctp_endpoint *ep,
1403 	const union sctp_addr *paddr,
1404 	struct sctp_transport **);
1405 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1406 				const union sctp_addr *);
1407 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1408 					const union sctp_addr *);
1409 int sctp_has_association(const union sctp_addr *laddr,
1410 			 const union sctp_addr *paddr);
1411 
1412 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1413 		     sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1414 		     struct sctp_chunk **err_chunk);
1415 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1416 		      const union sctp_addr *peer,
1417 		      sctp_init_chunk_t *init, gfp_t gfp);
1418 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1419 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1420 
1421 struct sctp_inithdr_host {
1422 	__u32 init_tag;
1423 	__u32 a_rwnd;
1424 	__u16 num_outbound_streams;
1425 	__u16 num_inbound_streams;
1426 	__u32 initial_tsn;
1427 };
1428 
1429 /* RFC2960
1430  *
1431  * 12. Recommended Transmission Control Block (TCB) Parameters
1432  *
1433  * This section details a recommended set of parameters that should
1434  * be contained within the TCB for an implementation. This section is
1435  * for illustrative purposes and should not be deemed as requirements
1436  * on an implementation or as an exhaustive list of all parameters
1437  * inside an SCTP TCB. Each implementation may need its own additional
1438  * parameters for optimization.
1439  */
1440 
1441 
1442 /* Here we have information about each individual association. */
1443 struct sctp_association {
1444 
1445 	/* A base structure common to endpoint and association.
1446 	 * In this context, it represents the associations's view
1447 	 * of the local endpoint of the association.
1448 	 */
1449 	struct sctp_ep_common base;
1450 
1451 	/* Associations on the same socket. */
1452 	struct list_head asocs;
1453 
1454 	/* association id. */
1455 	sctp_assoc_t assoc_id;
1456 
1457 	/* This is our parent endpoint.	 */
1458 	struct sctp_endpoint *ep;
1459 
1460 	/* These are those association elements needed in the cookie.  */
1461 	struct sctp_cookie c;
1462 
1463 	/* This is all information about our peer.  */
1464 	struct {
1465 		/* rwnd
1466 		 *
1467 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1468 		 */
1469 		__u32 rwnd;
1470 
1471 		/* transport_addr_list
1472 		 *
1473 		 * Peer	       : A list of SCTP transport addresses that the
1474 		 * Transport   : peer is bound to. This information is derived
1475 		 * Address     : from the INIT or INIT ACK and is used to
1476 		 * List	       : associate an inbound packet with a given
1477 		 *	       : association. Normally this information is
1478 		 *	       : hashed or keyed for quick lookup and access
1479 		 *	       : of the TCB.
1480 		 *	       : The list is also initialized with the list
1481 		 *	       : of addresses passed with the sctp_connectx()
1482 		 *	       : call.
1483 		 *
1484 		 * It is a list of SCTP_transport's.
1485 		 */
1486 		struct list_head transport_addr_list;
1487 
1488 		/* transport_count
1489 		 *
1490 		 * Peer        : A count of the number of peer addresses
1491 		 * Transport   : in the Peer Transport Address List.
1492 		 * Address     :
1493 		 * Count       :
1494 		 */
1495 		__u16 transport_count;
1496 
1497 		/* port
1498 		 *   The transport layer port number.
1499 		 */
1500 		__u16 port;
1501 
1502 		/* primary_path
1503 		 *
1504 		 * Primary     : This is the current primary destination
1505 		 * Path	       : transport address of the peer endpoint.  It
1506 		 *	       : may also specify a source transport address
1507 		 *	       : on this endpoint.
1508 		 *
1509 		 * All of these paths live on transport_addr_list.
1510 		 *
1511 		 * At the bakeoffs, we discovered that the intent of
1512 		 * primaryPath is that it only changes when the ULP
1513 		 * asks to have it changed.  We add the activePath to
1514 		 * designate the connection we are currently using to
1515 		 * transmit new data and most control chunks.
1516 		 */
1517 		struct sctp_transport *primary_path;
1518 
1519 		/* Cache the primary path address here, when we
1520 		 * need a an address for msg_name.
1521 		 */
1522 		union sctp_addr primary_addr;
1523 
1524 		/* active_path
1525 		 *   The path that we are currently using to
1526 		 *   transmit new data and most control chunks.
1527 		 */
1528 		struct sctp_transport *active_path;
1529 
1530 		/* retran_path
1531 		 *
1532 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1533 		 * ...
1534 		 * Furthermore, when its peer is multi-homed, an
1535 		 * endpoint SHOULD try to retransmit a chunk to an
1536 		 * active destination transport address that is
1537 		 * different from the last destination address to
1538 		 * which the DATA chunk was sent.
1539 		 */
1540 		struct sctp_transport *retran_path;
1541 
1542 		/* Pointer to last transport I have sent on.  */
1543 		struct sctp_transport *last_sent_to;
1544 
1545 		/* This is the last transport I have received DATA on.	*/
1546 		struct sctp_transport *last_data_from;
1547 
1548 		/*
1549 		 * Mapping  An array of bits or bytes indicating which out of
1550 		 * Array    order TSN's have been received (relative to the
1551 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1552 		 *	    order packets have been received, this array
1553 		 *	    will be set to all zero. This structure may be
1554 		 *	    in the form of a circular buffer or bit array.
1555 		 *
1556 		 * Last Rcvd   : This is the last TSN received in
1557 		 * TSN	       : sequence. This value is set initially by
1558 		 *	       : taking the peer's Initial TSN, received in
1559 		 *	       : the INIT or INIT ACK chunk, and subtracting
1560 		 *	       : one from it.
1561 		 *
1562 		 * Throughout most of the specification this is called the
1563 		 * "Cumulative TSN ACK Point".	In this case, we
1564 		 * ignore the advice in 12.2 in favour of the term
1565 		 * used in the bulk of the text.  This value is hidden
1566 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1567 		 */
1568 		struct sctp_tsnmap tsn_map;
1569 
1570 		/* Ack State   : This flag indicates if the next received
1571 		 *             : packet is to be responded to with a
1572 		 *             : SACK. This is initializedto 0.  When a packet
1573 		 *             : is received it is incremented. If this value
1574 		 *             : reaches 2 or more, a SACK is sent and the
1575 		 *             : value is reset to 0. Note: This is used only
1576 		 *             : when no DATA chunks are received out of
1577 		 *             : order.  When DATA chunks are out of order,
1578 		 *             : SACK's are not delayed (see Section 6).
1579 		 */
1580 		__u8    sack_needed;     /* Do we need to sack the peer? */
1581 		__u32	sack_cnt;
1582 
1583 		/* These are capabilities which our peer advertised.  */
1584 		__u8	ecn_capable:1,	    /* Can peer do ECN? */
1585 			ipv4_address:1,	    /* Peer understands IPv4 addresses? */
1586 			ipv6_address:1,	    /* Peer understands IPv6 addresses? */
1587 			hostname_address:1, /* Peer understands DNS addresses? */
1588 			asconf_capable:1,   /* Does peer support ADDIP? */
1589 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1590 			auth_capable:1;	    /* Is peer doing SCTP-AUTH? */
1591 
1592 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1593 
1594 		/* This mask is used to disable sending the ASCONF chunk
1595 		 * with specified parameter to peer.
1596 		 */
1597 		__be16 addip_disabled_mask;
1598 
1599 		struct sctp_inithdr_host i;
1600 		int cookie_len;
1601 		void *cookie;
1602 
1603 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1604 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1605 		 * Initial TSN Value minus 1
1606 		 */
1607 		__u32 addip_serial;
1608 
1609 		/* SCTP-AUTH: We need to know pears random number, hmac list
1610 		 * and authenticated chunk list.  All that is part of the
1611 		 * cookie and these are just pointers to those locations
1612 		 */
1613 		sctp_random_param_t *peer_random;
1614 		sctp_chunks_param_t *peer_chunks;
1615 		sctp_hmac_algo_param_t *peer_hmacs;
1616 	} peer;
1617 
1618 	/* State       : A state variable indicating what state the
1619 	 *	       : association is in, i.e. COOKIE-WAIT,
1620 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1621 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1622 	 *
1623 	 *		Note: No "CLOSED" state is illustrated since if a
1624 	 *		association is "CLOSED" its TCB SHOULD be removed.
1625 	 *
1626 	 *		In this implementation we DO have a CLOSED
1627 	 *		state which is used during initiation and shutdown.
1628 	 *
1629 	 *		State takes values from SCTP_STATE_*.
1630 	 */
1631 	sctp_state_t state;
1632 
1633 	/* The cookie life I award for any cookie.  */
1634 	struct timeval cookie_life;
1635 
1636 	/* Overall     : The overall association error count.
1637 	 * Error Count : [Clear this any time I get something.]
1638 	 */
1639 	int overall_error_count;
1640 
1641 	/* These are the association's initial, max, and min RTO values.
1642 	 * These values will be initialized by system defaults, but can
1643 	 * be modified via the SCTP_RTOINFO socket option.
1644 	 */
1645 	unsigned long rto_initial;
1646 	unsigned long rto_max;
1647 	unsigned long rto_min;
1648 
1649 	/* Maximum number of new data packets that can be sent in a burst.  */
1650 	int max_burst;
1651 
1652 	/* This is the max_retrans value for the association.  This value will
1653 	 * be initialized initialized from system defaults, but can be
1654 	 * modified by the SCTP_ASSOCINFO socket option.
1655 	 */
1656 	int max_retrans;
1657 
1658 	/* Maximum number of times the endpoint will retransmit INIT  */
1659 	__u16 max_init_attempts;
1660 
1661 	/* How many times have we resent an INIT? */
1662 	__u16 init_retries;
1663 
1664 	/* The largest timeout or RTO value to use in attempting an INIT */
1665 	unsigned long max_init_timeo;
1666 
1667 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1668 	 * the destination address every heartbeat interval. This value
1669 	 * will be inherited by all new transports.
1670 	 */
1671 	unsigned long hbinterval;
1672 
1673 	/* This is the max_retrans value for new transports in the
1674 	 * association.
1675 	 */
1676 	__u16 pathmaxrxt;
1677 
1678 	/* Flag that path mtu update is pending */
1679 	__u8   pmtu_pending;
1680 
1681 	/* Association : The smallest PMTU discovered for all of the
1682 	 * PMTU	       : peer's transport addresses.
1683 	 */
1684 	__u32 pathmtu;
1685 
1686 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1687 	__u32 param_flags;
1688 
1689 	/* SACK delay timeout */
1690 	unsigned long sackdelay;
1691 	__u32 sackfreq;
1692 
1693 
1694 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1695 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1696 
1697 	/* Transport to which SHUTDOWN chunk was last sent.  */
1698 	struct sctp_transport *shutdown_last_sent_to;
1699 
1700 	/* How many times have we resent a SHUTDOWN */
1701 	int shutdown_retries;
1702 
1703 	/* Transport to which INIT chunk was last sent.  */
1704 	struct sctp_transport *init_last_sent_to;
1705 
1706 	/* Next TSN    : The next TSN number to be assigned to a new
1707 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1708 	 *	       : ACK chunk to the peer and incremented each
1709 	 *	       : time a DATA chunk is assigned a TSN
1710 	 *	       : (normally just prior to transmit or during
1711 	 *	       : fragmentation).
1712 	 */
1713 	__u32 next_tsn;
1714 
1715 	/*
1716 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1717 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1718 	 *	       : received in the INIT or INIT ACK chunk, and
1719 	 *	       : subtracting one from it.
1720 	 *
1721 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1722 	 */
1723 
1724 	__u32 ctsn_ack_point;
1725 
1726 	/* PR-SCTP Advanced.Peer.Ack.Point */
1727 	__u32 adv_peer_ack_point;
1728 
1729 	/* Highest TSN that is acknowledged by incoming SACKs. */
1730 	__u32 highest_sacked;
1731 
1732 	/* TSN marking the fast recovery exit point */
1733 	__u32 fast_recovery_exit;
1734 
1735 	/* Flag to track the current fast recovery state */
1736 	__u8 fast_recovery;
1737 
1738 	/* The number of unacknowledged data chunks.  Reported through
1739 	 * the SCTP_STATUS sockopt.
1740 	 */
1741 	__u16 unack_data;
1742 
1743 	/* The total number of data chunks that we've had to retransmit
1744 	 * as the result of a T3 timer expiration
1745 	 */
1746 	__u32 rtx_data_chunks;
1747 
1748 	/* This is the association's receive buffer space.  This value is used
1749 	 * to set a_rwnd field in an INIT or a SACK chunk.
1750 	 */
1751 	__u32 rwnd;
1752 
1753 	/* This is the last advertised value of rwnd over a SACK chunk. */
1754 	__u32 a_rwnd;
1755 
1756 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1757 	 * to slop over a maximum of the association's frag_point.
1758 	 */
1759 	__u32 rwnd_over;
1760 
1761 	/* Keeps treack of rwnd pressure.  This happens when we have
1762 	 * a window, but not recevie buffer (i.e small packets).  This one
1763 	 * is releases slowly (1 PMTU at a time ).
1764 	 */
1765 	__u32 rwnd_press;
1766 
1767 	/* This is the sndbuf size in use for the association.
1768 	 * This corresponds to the sndbuf size for the association,
1769 	 * as specified in the sk->sndbuf.
1770 	 */
1771 	int sndbuf_used;
1772 
1773 	/* This is the amount of memory that this association has allocated
1774 	 * in the receive path at any given time.
1775 	 */
1776 	atomic_t rmem_alloc;
1777 
1778 	/* This is the wait queue head for send requests waiting on
1779 	 * the association sndbuf space.
1780 	 */
1781 	wait_queue_head_t	wait;
1782 
1783 	/* The message size at which SCTP fragmentation will occur. */
1784 	__u32 frag_point;
1785 	__u32 user_frag;
1786 
1787 	/* Counter used to count INIT errors. */
1788 	int init_err_counter;
1789 
1790 	/* Count the number of INIT cycles (for doubling timeout). */
1791 	int init_cycle;
1792 
1793 	/* Default send parameters. */
1794 	__u16 default_stream;
1795 	__u16 default_flags;
1796 	__u32 default_ppid;
1797 	__u32 default_context;
1798 	__u32 default_timetolive;
1799 
1800 	/* Default receive parameters */
1801 	__u32 default_rcv_context;
1802 
1803 	/* This tracks outbound ssn for a given stream.	 */
1804 	struct sctp_ssnmap *ssnmap;
1805 
1806 	/* All outbound chunks go through this structure.  */
1807 	struct sctp_outq outqueue;
1808 
1809 	/* A smart pipe that will handle reordering and fragmentation,
1810 	 * as well as handle passing events up to the ULP.
1811 	 */
1812 	struct sctp_ulpq ulpq;
1813 
1814 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1815 	__u32 last_ecne_tsn;
1816 
1817 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1818 	__u32 last_cwr_tsn;
1819 
1820 	/* How many duplicated TSNs have we seen?  */
1821 	int numduptsns;
1822 
1823 	/* Number of seconds of idle time before an association is closed.
1824 	 * In the association context, this is really used as a boolean
1825 	 * since the real timeout is stored in the timeouts array
1826 	 */
1827 	__u32 autoclose;
1828 
1829 	/* These are to support
1830 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1831 	 *  and Enforcement of Flow and Message Limits"
1832 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1833 	 * or "ADDIP" for short.
1834 	 */
1835 
1836 
1837 
1838 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1839 	 *
1840 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1841 	 * unacknowledged at any one time.  If a sender, after sending
1842 	 * an ASCONF chunk, decides it needs to transfer another
1843 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1844 	 * returns from the previous ASCONF Chunk before sending a
1845 	 * subsequent ASCONF. Note this restriction binds each side,
1846 	 * so at any time two ASCONF may be in-transit on any given
1847 	 * association (one sent from each endpoint).
1848 	 *
1849 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1850 	 * not have an ASCONF in flight, this is NULL.]
1851 	 */
1852 	struct sctp_chunk *addip_last_asconf;
1853 
1854 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1855 	 *
1856 	 * This is needed to implement itmes E1 - E4 of the updated
1857 	 * spec.  Here is the justification:
1858 	 *
1859 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1860 	 * we now need the ability to cache multiple ACKs.  The section
1861 	 * describes in detail how they are cached and cleaned up.
1862 	 */
1863 	struct list_head asconf_ack_list;
1864 
1865 	/* These ASCONF chunks are waiting to be sent.
1866 	 *
1867 	 * These chunaks can't be pushed to outqueue until receiving
1868 	 * ASCONF_ACK for the previous ASCONF indicated by
1869 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1870 	 * is in flight at any time.
1871 	 *
1872 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1873 	 *
1874 	 * In defining the ASCONF Chunk transfer procedures, it is
1875 	 * essential that these transfers MUST NOT cause congestion
1876 	 * within the network.	To achieve this, we place these
1877 	 * restrictions on the transfer of ASCONF Chunks:
1878 	 *
1879 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1880 	 * unacknowledged at any one time.  If a sender, after sending
1881 	 * an ASCONF chunk, decides it needs to transfer another
1882 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1883 	 * returns from the previous ASCONF Chunk before sending a
1884 	 * subsequent ASCONF. Note this restriction binds each side,
1885 	 * so at any time two ASCONF may be in-transit on any given
1886 	 * association (one sent from each endpoint).
1887 	 *
1888 	 *
1889 	 * [I really think this is EXACTLY the sort of intelligence
1890 	 *  which already resides in sctp_outq.	 Please move this
1891 	 *  queue and its supporting logic down there.	--piggy]
1892 	 */
1893 	struct list_head addip_chunk_list;
1894 
1895 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1896 	 *
1897 	 * A2) A serial number should be assigned to the Chunk. The
1898 	 * serial number SHOULD be a monotonically increasing
1899 	 * number. The serial number SHOULD be initialized at
1900 	 * the start of the association to the same value as the
1901 	 * Initial TSN and every time a new ASCONF chunk is created
1902 	 * it is incremented by one after assigning the serial number
1903 	 * to the newly created chunk.
1904 	 *
1905 	 * ADDIP
1906 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1907 	 *
1908 	 * Serial Number : 32 bits (unsigned integer)
1909 	 *
1910 	 * This value represents a Serial Number for the ASCONF
1911 	 * Chunk. The valid range of Serial Number is from 0 to
1912 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1913 	 * after reaching 4294967295.
1914 	 */
1915 	__u32 addip_serial;
1916 	union sctp_addr *asconf_addr_del_pending;
1917 	int src_out_of_asoc_ok;
1918 
1919 	/* SCTP AUTH: list of the endpoint shared keys.  These
1920 	 * keys are provided out of band by the user applicaton
1921 	 * and can't change during the lifetime of the association
1922 	 */
1923 	struct list_head endpoint_shared_keys;
1924 
1925 	/* SCTP AUTH:
1926 	 * The current generated assocaition shared key (secret)
1927 	 */
1928 	struct sctp_auth_bytes *asoc_shared_key;
1929 
1930 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1931 	 * that we support.
1932 	 */
1933 	__u16 default_hmac_id;
1934 
1935 	__u16 active_key_id;
1936 
1937 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1938 	     temp:1;		/* Is it a temporary association? */
1939 };
1940 
1941 
1942 /* An eyecatcher for determining if we are really looking at an
1943  * association data structure.
1944  */
1945 enum {
1946 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1947 };
1948 
1949 /* Recover the outter association structure. */
1950 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1951 {
1952 	struct sctp_association *asoc;
1953 
1954 	asoc = container_of(base, struct sctp_association, base);
1955 	return asoc;
1956 }
1957 
1958 /* These are function signatures for manipulating associations.	 */
1959 
1960 
1961 struct sctp_association *
1962 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1963 		     sctp_scope_t scope, gfp_t gfp);
1964 void sctp_association_free(struct sctp_association *);
1965 void sctp_association_put(struct sctp_association *);
1966 void sctp_association_hold(struct sctp_association *);
1967 
1968 struct sctp_transport *sctp_assoc_choose_alter_transport(
1969 	struct sctp_association *, struct sctp_transport *);
1970 void sctp_assoc_update_retran_path(struct sctp_association *);
1971 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1972 					  const union sctp_addr *);
1973 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1974 			    const union sctp_addr *laddr);
1975 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1976 				     const union sctp_addr *address,
1977 				     const gfp_t gfp,
1978 				     const int peer_state);
1979 void sctp_assoc_del_peer(struct sctp_association *asoc,
1980 			 const union sctp_addr *addr);
1981 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1982 			 struct sctp_transport *peer);
1983 void sctp_assoc_control_transport(struct sctp_association *,
1984 				  struct sctp_transport *,
1985 				  sctp_transport_cmd_t, sctp_sn_error_t);
1986 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1987 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1988 					   const union sctp_addr *,
1989 					   const union sctp_addr *);
1990 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1991 void sctp_assoc_update(struct sctp_association *old,
1992 		       struct sctp_association *new);
1993 
1994 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1995 
1996 void sctp_assoc_sync_pmtu(struct sctp_association *);
1997 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1998 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1999 void sctp_assoc_set_primary(struct sctp_association *,
2000 			    struct sctp_transport *);
2001 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2002 				    struct sctp_transport *);
2003 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
2004 				     sctp_scope_t, gfp_t);
2005 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2006 					 struct sctp_cookie*,
2007 					 gfp_t gfp);
2008 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2009 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2010 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2011 					const struct sctp_association *asoc,
2012 					__be32 serial);
2013 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2014 
2015 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2016 			const union sctp_addr *ss2);
2017 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2018 
2019 /* A convenience structure to parse out SCTP specific CMSGs. */
2020 typedef struct sctp_cmsgs {
2021 	struct sctp_initmsg *init;
2022 	struct sctp_sndrcvinfo *info;
2023 } sctp_cmsgs_t;
2024 
2025 /* Structure for tracking memory objects */
2026 typedef struct {
2027 	char *label;
2028 	atomic_t *counter;
2029 } sctp_dbg_objcnt_entry_t;
2030 
2031 #endif /* __sctp_structs_h__ */
2032