xref: /openbmc/linux/include/net/sctp/structs.h (revision b9031d9d87b24e24cd32ea15b5f4220a1e8da909)
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  */
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 
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 } sctp_globals;
222 
223 #define sctp_rto_initial		(sctp_globals.rto_initial)
224 #define sctp_rto_min			(sctp_globals.rto_min)
225 #define sctp_rto_max			(sctp_globals.rto_max)
226 #define sctp_rto_alpha			(sctp_globals.rto_alpha)
227 #define sctp_rto_beta			(sctp_globals.rto_beta)
228 #define sctp_max_burst			(sctp_globals.max_burst)
229 #define sctp_valid_cookie_life		(sctp_globals.valid_cookie_life)
230 #define sctp_cookie_preserve_enable	(sctp_globals.cookie_preserve_enable)
231 #define sctp_max_retrans_association	(sctp_globals.max_retrans_association)
232 #define sctp_sndbuf_policy	 	(sctp_globals.sndbuf_policy)
233 #define sctp_rcvbuf_policy	 	(sctp_globals.rcvbuf_policy)
234 #define sctp_max_retrans_path		(sctp_globals.max_retrans_path)
235 #define sctp_max_retrans_init		(sctp_globals.max_retrans_init)
236 #define sctp_sack_timeout		(sctp_globals.sack_timeout)
237 #define sctp_hb_interval		(sctp_globals.hb_interval)
238 #define sctp_max_instreams		(sctp_globals.max_instreams)
239 #define sctp_max_outstreams		(sctp_globals.max_outstreams)
240 #define sctp_address_families		(sctp_globals.address_families)
241 #define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
242 #define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
243 #define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
244 #define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
245 #define sctp_port_hashsize		(sctp_globals.port_hashsize)
246 #define sctp_port_rover			(sctp_globals.port_rover)
247 #define sctp_port_alloc_lock		(sctp_globals.port_alloc_lock)
248 #define sctp_port_hashtable		(sctp_globals.port_hashtable)
249 #define sctp_local_addr_list		(sctp_globals.local_addr_list)
250 #define sctp_local_addr_lock		(sctp_globals.addr_list_lock)
251 #define sctp_addip_enable		(sctp_globals.addip_enable)
252 #define sctp_addip_noauth		(sctp_globals.addip_noauth_enable)
253 #define sctp_prsctp_enable		(sctp_globals.prsctp_enable)
254 #define sctp_auth_enable		(sctp_globals.auth_enable)
255 
256 /* SCTP Socket type: UDP or TCP style. */
257 typedef enum {
258 	SCTP_SOCKET_UDP = 0,
259 	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
260 	SCTP_SOCKET_TCP
261 } sctp_socket_type_t;
262 
263 /* Per socket SCTP information. */
264 struct sctp_sock {
265 	/* inet_sock has to be the first member of sctp_sock */
266 	struct inet_sock inet;
267 	/* What kind of a socket is this? */
268 	sctp_socket_type_t type;
269 
270 	/* PF_ family specific functions.  */
271 	struct sctp_pf *pf;
272 
273 	/* Access to HMAC transform. */
274 	struct crypto_hash *hmac;
275 
276 	/* What is our base endpointer? */
277 	struct sctp_endpoint *ep;
278 
279 	struct sctp_bind_bucket *bind_hash;
280 	/* Various Socket Options.  */
281 	__u16 default_stream;
282 	__u32 default_ppid;
283 	__u16 default_flags;
284 	__u32 default_context;
285 	__u32 default_timetolive;
286 	__u32 default_rcv_context;
287 	int max_burst;
288 
289 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
290 	 * the destination address every heartbeat interval. This value
291 	 * will be inherited by all new associations.
292 	 */
293 	__u32 hbinterval;
294 
295 	/* This is the max_retrans value for new associations. */
296 	__u16 pathmaxrxt;
297 
298 	/* The initial Path MTU to use for new associations. */
299 	__u32 pathmtu;
300 
301 	/* The default SACK delay timeout for new associations. */
302 	__u32 sackdelay;
303 
304 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
305 	__u32 param_flags;
306 
307 	struct sctp_initmsg initmsg;
308 	struct sctp_rtoinfo rtoinfo;
309 	struct sctp_paddrparams paddrparam;
310 	struct sctp_event_subscribe subscribe;
311 	struct sctp_assocparams assocparams;
312 	int user_frag;
313 	__u32 autoclose;
314 	__u8 nodelay;
315 	__u8 disable_fragments;
316 	__u8 v4mapped;
317 	__u8 frag_interleave;
318 	__u32 adaptation_ind;
319 	__u32 pd_point;
320 
321 	atomic_t pd_mode;
322 	/* Receive to here while partial delivery is in effect. */
323 	struct sk_buff_head pd_lobby;
324 };
325 
326 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
327 {
328        return (struct sctp_sock *)sk;
329 }
330 
331 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
332 {
333        return (struct sock *)sp;
334 }
335 
336 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
337 struct sctp6_sock {
338        struct sctp_sock  sctp;
339        struct ipv6_pinfo inet6;
340 };
341 #endif /* CONFIG_IPV6 */
342 
343 
344 /* This is our APPLICATION-SPECIFIC state cookie.
345  * THIS IS NOT DICTATED BY THE SPECIFICATION.
346  */
347 /* These are the parts of an association which we send in the cookie.
348  * Most of these are straight out of:
349  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
350  *
351  */
352 
353 struct sctp_cookie {
354 
355 	/* My	       : Tag expected in every inbound packet and sent
356 	 * Verification: in the INIT or INIT ACK chunk.
357 	 * Tag	       :
358 	 */
359 	__u32 my_vtag;
360 
361 	/* Peer's      : Tag expected in every outbound packet except
362 	 * Verification: in the INIT chunk.
363 	 * Tag	       :
364 	 */
365 	__u32 peer_vtag;
366 
367 	/* The rest of these are not from the spec, but really need to
368 	 * be in the cookie.
369 	 */
370 
371 	/* My Tie Tag  : Assist in discovering a restarting association. */
372 	__u32 my_ttag;
373 
374 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
375 	__u32 peer_ttag;
376 
377 	/* When does this cookie expire? */
378 	struct timeval expiration;
379 
380 	/* Number of inbound/outbound streams which are set
381 	 * and negotiated during the INIT process.
382 	 */
383 	__u16 sinit_num_ostreams;
384 	__u16 sinit_max_instreams;
385 
386 	/* This is the first sequence number I used.  */
387 	__u32 initial_tsn;
388 
389 	/* This holds the originating address of the INIT packet.  */
390 	union sctp_addr peer_addr;
391 
392 	/* IG Section 2.35.3
393 	 * Include the source port of the INIT-ACK
394 	 */
395 	__u16		my_port;
396 
397 	__u8 prsctp_capable;
398 
399 	/* Padding for future use */
400 	__u8 padding;
401 
402 	__u32 adaptation_ind;
403 
404 	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
405 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS + 2];
406 	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
407 
408 	/* This is a shim for my peer's INIT packet, followed by
409 	 * a copy of the raw address list of the association.
410 	 * The length of the raw address list is saved in the
411 	 * raw_addr_list_len field, which will be used at the time when
412 	 * the association TCB is re-constructed from the cookie.
413 	 */
414 	__u32 raw_addr_list_len;
415 	struct sctp_init_chunk peer_init[0];
416 };
417 
418 
419 /* The format of our cookie that we send to our peer. */
420 struct sctp_signed_cookie {
421 	__u8 signature[SCTP_SECRET_SIZE];
422 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
423 	struct sctp_cookie c;
424 } __attribute__((packed));
425 
426 /* This is another convenience type to allocate memory for address
427  * params for the maximum size and pass such structures around
428  * internally.
429  */
430 union sctp_addr_param {
431 	struct sctp_paramhdr p;
432 	struct sctp_ipv4addr_param v4;
433 	struct sctp_ipv6addr_param v6;
434 };
435 
436 /* A convenience type to allow walking through the various
437  * parameters and avoid casting all over the place.
438  */
439 union sctp_params {
440 	void *v;
441 	struct sctp_paramhdr *p;
442 	struct sctp_cookie_preserve_param *life;
443 	struct sctp_hostname_param *dns;
444 	struct sctp_cookie_param *cookie;
445 	struct sctp_supported_addrs_param *sat;
446 	struct sctp_ipv4addr_param *v4;
447 	struct sctp_ipv6addr_param *v6;
448 	union sctp_addr_param *addr;
449 	struct sctp_adaptation_ind_param *aind;
450 	struct sctp_supported_ext_param *ext;
451 	struct sctp_random_param *random;
452 	struct sctp_chunks_param *chunks;
453 	struct sctp_hmac_algo_param *hmac_algo;
454 	struct sctp_addip_param *addip;
455 };
456 
457 /* RFC 2960.  Section 3.3.5 Heartbeat.
458  *    Heartbeat Information: variable length
459  *    The Sender-specific Heartbeat Info field should normally include
460  *    information about the sender's current time when this HEARTBEAT
461  *    chunk is sent and the destination transport address to which this
462  *    HEARTBEAT is sent (see Section 8.3).
463  */
464 typedef struct sctp_sender_hb_info {
465 	struct sctp_paramhdr param_hdr;
466 	union sctp_addr daddr;
467 	unsigned long sent_at;
468 	__u64 hb_nonce;
469 } __attribute__((packed)) sctp_sender_hb_info_t;
470 
471 /*
472  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
473  *
474  *  The term "stream" is used in SCTP to refer to a sequence of user
475  *  messages that are to be delivered to the upper-layer protocol in
476  *  order with respect to other messages within the same stream.  This is
477  *  in contrast to its usage in TCP, where it refers to a sequence of
478  *  bytes (in this document a byte is assumed to be eight bits).
479  *  ...
480  *
481  *  This is the structure we use to track both our outbound and inbound
482  *  SSN, or Stream Sequence Numbers.
483  */
484 
485 struct sctp_stream {
486 	__u16 *ssn;
487 	unsigned int len;
488 };
489 
490 struct sctp_ssnmap {
491 	struct sctp_stream in;
492 	struct sctp_stream out;
493 	int malloced;
494 };
495 
496 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
497 				    gfp_t gfp);
498 void sctp_ssnmap_free(struct sctp_ssnmap *map);
499 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
500 
501 /* What is the current SSN number for this stream? */
502 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
503 {
504 	return stream->ssn[id];
505 }
506 
507 /* Return the next SSN number for this stream.	*/
508 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
509 {
510 	return stream->ssn[id]++;
511 }
512 
513 /* Skip over this ssn and all below. */
514 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
515 				 __u16 ssn)
516 {
517 	stream->ssn[id] = ssn+1;
518 }
519 
520 /*
521  * Pointers to address related SCTP functions.
522  * (i.e. things that depend on the address family.)
523  */
524 struct sctp_af {
525 	int		(*sctp_xmit)	(struct sk_buff *skb,
526 					 struct sctp_transport *,
527 					 int ipfragok);
528 	int		(*setsockopt)	(struct sock *sk,
529 					 int level,
530 					 int optname,
531 					 char __user *optval,
532 					 int optlen);
533 	int		(*getsockopt)	(struct sock *sk,
534 					 int level,
535 					 int optname,
536 					 char __user *optval,
537 					 int __user *optlen);
538 	int		(*compat_setsockopt)	(struct sock *sk,
539 					 int level,
540 					 int optname,
541 					 char __user *optval,
542 					 int optlen);
543 	int		(*compat_getsockopt)	(struct sock *sk,
544 					 int level,
545 					 int optname,
546 					 char __user *optval,
547 					 int __user *optlen);
548 	struct dst_entry *(*get_dst)	(struct sctp_association *asoc,
549 					 union sctp_addr *daddr,
550 					 union sctp_addr *saddr);
551 	void		(*get_saddr)	(struct sctp_sock *sk,
552 					 struct sctp_association *asoc,
553 					 struct dst_entry *dst,
554 					 union sctp_addr *daddr,
555 					 union sctp_addr *saddr);
556 	void		(*copy_addrlist) (struct list_head *,
557 					  struct net_device *);
558 	void		(*dst_saddr)	(union sctp_addr *saddr,
559 					 struct dst_entry *dst,
560 					 __be16 port);
561 	int		(*cmp_addr)	(const union sctp_addr *addr1,
562 					 const union sctp_addr *addr2);
563 	void		(*addr_copy)	(union sctp_addr *dst,
564 					 union sctp_addr *src);
565 	void		(*from_skb)	(union sctp_addr *,
566 					 struct sk_buff *skb,
567 					 int saddr);
568 	void		(*from_sk)	(union sctp_addr *,
569 					 struct sock *sk);
570 	void		(*to_sk_saddr)	(union sctp_addr *,
571 					 struct sock *sk);
572 	void		(*to_sk_daddr)	(union sctp_addr *,
573 					 struct sock *sk);
574 	void		(*from_addr_param) (union sctp_addr *,
575 					    union sctp_addr_param *,
576 					    __be16 port, int iif);
577 	int		(*to_addr_param) (const union sctp_addr *,
578 					  union sctp_addr_param *);
579 	int		(*addr_valid)	(union sctp_addr *,
580 					 struct sctp_sock *,
581 					 const struct sk_buff *);
582 	sctp_scope_t	(*scope) (union sctp_addr *);
583 	void		(*inaddr_any)	(union sctp_addr *, __be16);
584 	int		(*is_any)	(const union sctp_addr *);
585 	int		(*available)	(union sctp_addr *,
586 					 struct sctp_sock *);
587 	int		(*skb_iif)	(const struct sk_buff *sk);
588 	int		(*is_ce)	(const struct sk_buff *sk);
589 	void		(*seq_dump_addr)(struct seq_file *seq,
590 					 union sctp_addr *addr);
591 	void		(*ecn_capable)(struct sock *sk);
592 	__u16		net_header_len;
593 	int		sockaddr_len;
594 	sa_family_t	sa_family;
595 	struct list_head list;
596 };
597 
598 struct sctp_af *sctp_get_af_specific(sa_family_t);
599 int sctp_register_af(struct sctp_af *);
600 
601 /* Protocol family functions. */
602 struct sctp_pf {
603 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
604 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
605 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
606 	int  (*cmp_addr) (const union sctp_addr *,
607 			  const union sctp_addr *,
608 			  struct sctp_sock *);
609 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
610 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
611 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
612 	struct sock *(*create_accept_sk) (struct sock *sk,
613 					  struct sctp_association *asoc);
614 	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
615 	struct sctp_af *af;
616 };
617 
618 
619 /* Structure to track chunk fragments that have been acked, but peer
620  * fragments of the same message have not.
621  */
622 struct sctp_datamsg {
623 	/* Chunks waiting to be submitted to lower layer. */
624 	struct list_head chunks;
625 	/* Chunks that have been transmitted. */
626 	struct list_head track;
627 	/* Reference counting. */
628 	atomic_t refcnt;
629 	/* When is this message no longer interesting to the peer? */
630 	unsigned long expires_at;
631 	/* Did the messenge fail to send? */
632 	int send_error;
633 	char send_failed;
634 	/* Control whether chunks from this message can be abandoned. */
635 	char can_abandon;
636 };
637 
638 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
639 					    struct sctp_sndrcvinfo *,
640 					    struct msghdr *, int len);
641 void sctp_datamsg_put(struct sctp_datamsg *);
642 void sctp_chunk_fail(struct sctp_chunk *, int error);
643 int sctp_chunk_abandoned(struct sctp_chunk *);
644 
645 /* RFC2960 1.4 Key Terms
646  *
647  * o Chunk: A unit of information within an SCTP packet, consisting of
648  * a chunk header and chunk-specific content.
649  *
650  * As a matter of convenience, we remember the SCTP common header for
651  * each chunk as well as a few other header pointers...
652  */
653 struct sctp_chunk {
654 	struct list_head list;
655 
656 	atomic_t refcnt;
657 
658 	/* This is our link to the per-transport transmitted list.  */
659 	struct list_head transmitted_list;
660 
661 	/* This field is used by chunks that hold fragmented data.
662 	 * For the first fragment this is the list that holds the rest of
663 	 * fragments. For the remaining fragments, this is the link to the
664 	 * frag_list maintained in the first fragment.
665 	 */
666 	struct list_head frag_list;
667 
668 	/* This points to the sk_buff containing the actual data.  */
669 	struct sk_buff *skb;
670 
671 	/* These are the SCTP headers by reverse order in a packet.
672 	 * Note that some of these may happen more than once.  In that
673 	 * case, we point at the "current" one, whatever that means
674 	 * for that level of header.
675 	 */
676 
677 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
678 	union sctp_params param_hdr;
679 	union {
680 		__u8 *v;
681 		struct sctp_datahdr *data_hdr;
682 		struct sctp_inithdr *init_hdr;
683 		struct sctp_sackhdr *sack_hdr;
684 		struct sctp_heartbeathdr *hb_hdr;
685 		struct sctp_sender_hb_info *hbs_hdr;
686 		struct sctp_shutdownhdr *shutdown_hdr;
687 		struct sctp_signed_cookie *cookie_hdr;
688 		struct sctp_ecnehdr *ecne_hdr;
689 		struct sctp_cwrhdr *ecn_cwr_hdr;
690 		struct sctp_errhdr *err_hdr;
691 		struct sctp_addiphdr *addip_hdr;
692 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
693 		struct sctp_authhdr *auth_hdr;
694 	} subh;
695 
696 	__u8 *chunk_end;
697 
698 	struct sctp_chunkhdr *chunk_hdr;
699 	struct sctphdr *sctp_hdr;
700 
701 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
702 	struct sctp_sndrcvinfo sinfo;
703 
704 	/* Which association does this belong to?  */
705 	struct sctp_association *asoc;
706 
707 	/* What endpoint received this chunk? */
708 	struct sctp_ep_common *rcvr;
709 
710 	/* We fill this in if we are calculating RTT. */
711 	unsigned long sent_at;
712 
713 	/* What is the origin IP address for this chunk?  */
714 	union sctp_addr source;
715 	/* Destination address for this chunk. */
716 	union sctp_addr dest;
717 
718 	/* For outbound message, track all fragments for SEND_FAILED. */
719 	struct sctp_datamsg *msg;
720 
721 	/* For an inbound chunk, this tells us where it came from.
722 	 * For an outbound chunk, it tells us where we'd like it to
723 	 * go.	It is NULL if we have no preference.
724 	 */
725 	struct sctp_transport *transport;
726 
727 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
728 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
729 	 * spec violates the principle premis that all chunks are processed
730 	 * in order.
731 	 */
732 	struct sk_buff *auth_chunk;
733 
734 	__u8 rtt_in_progress;	/* Is this chunk used for RTT calculation? */
735 	__u8 resent;		/* Has this chunk ever been retransmitted. */
736 	__u8 has_tsn;		/* Does this chunk have a TSN yet? */
737 	__u8 has_ssn;		/* Does this chunk have a SSN yet? */
738 	__u8 singleton;		/* Was this the only chunk in the packet? */
739 	__u8 end_of_packet;	/* Was this the last chunk in the packet? */
740 	__u8 ecn_ce_done;	/* Have we processed the ECN CE bit? */
741 	__u8 pdiscard;		/* Discard the whole packet now? */
742 	__u8 tsn_gap_acked;	/* Is this chunk acked by a GAP ACK? */
743 	__s8 fast_retransmit;	 /* Is this chunk fast retransmitted? */
744 	__u8 tsn_missing_report; /* Data chunk missing counter. */
745 	__u8 data_accepted; 	/* At least 1 chunk in this packet accepted */
746 	__u8 auth;		/* IN: was auth'ed | OUT: needs auth */
747 	__u8 has_asconf;	/* IN: have seen an asconf before */
748 };
749 
750 void sctp_chunk_hold(struct sctp_chunk *);
751 void sctp_chunk_put(struct sctp_chunk *);
752 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
753 			  struct iovec *data);
754 void sctp_chunk_free(struct sctp_chunk *);
755 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
756 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
757 				 const struct sctp_association *,
758 				 struct sock *);
759 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
760 		     union sctp_addr *);
761 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
762 
763 enum {
764 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
765 	SCTP_ADDR_SRC,		/* address can be used as source */
766 	SCTP_ADDR_DEL,		/* address about to be deleted */
767 };
768 
769 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
770 struct sctp_sockaddr_entry {
771 	struct list_head list;
772 	struct rcu_head	rcu;
773 	union sctp_addr a;
774 	__u8 state;
775 	__u8 valid;
776 };
777 
778 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
779 
780 /* This structure holds lists of chunks as we are assembling for
781  * transmission.
782  */
783 struct sctp_packet {
784 	/* These are the SCTP header values (host order) for the packet. */
785 	__u16 source_port;
786 	__u16 destination_port;
787 	__u32 vtag;
788 
789 	/* This contains the payload chunks.  */
790 	struct list_head chunk_list;
791 
792 	/* This is the overhead of the sctp and ip headers. */
793 	size_t overhead;
794 	/* This is the total size of all chunks INCLUDING padding.  */
795 	size_t size;
796 
797 	/* The packet is destined for this transport address.
798 	 * The function we finally use to pass down to the next lower
799 	 * layer lives in the transport structure.
800 	 */
801 	struct sctp_transport *transport;
802 
803 	/* pointer to the auth chunk for this packet */
804 	struct sctp_chunk *auth;
805 
806 	/* This packet contains a COOKIE-ECHO chunk. */
807 	__u8 has_cookie_echo;
808 
809 	/* This packet contains a SACK chunk. */
810 	__u8 has_sack;
811 
812 	/* This packet contains an AUTH chunk */
813 	__u8 has_auth;
814 
815 	/* This packet contains at least 1 DATA chunk */
816 	__u8 has_data;
817 
818 	/* SCTP cannot fragment this packet. So let ip fragment it. */
819 	__u8 ipfragok;
820 
821 	__u8 malloced;
822 };
823 
824 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
825 				     struct sctp_transport *,
826 				     __u16 sport, __u16 dport);
827 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
828 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
829                                        struct sctp_chunk *);
830 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
831                                      struct sctp_chunk *);
832 int sctp_packet_transmit(struct sctp_packet *);
833 void sctp_packet_free(struct sctp_packet *);
834 
835 static inline int sctp_packet_empty(struct sctp_packet *packet)
836 {
837 	return (packet->size == packet->overhead);
838 }
839 
840 /* This represents a remote transport address.
841  * For local transport addresses, we just use union sctp_addr.
842  *
843  * RFC2960 Section 1.4 Key Terms
844  *
845  *   o	Transport address:  A Transport Address is traditionally defined
846  *	by Network Layer address, Transport Layer protocol and Transport
847  *	Layer port number.  In the case of SCTP running over IP, a
848  *	transport address is defined by the combination of an IP address
849  *	and an SCTP port number (where SCTP is the Transport protocol).
850  *
851  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
852  *
853  *   o	The sender keeps a separate congestion control parameter set for
854  *	each of the destination addresses it can send to (not each
855  *	source-destination pair but for each destination).  The parameters
856  *	should decay if the address is not used for a long enough time
857  *	period.
858  *
859  */
860 struct sctp_transport {
861 	/* A list of transports. */
862 	struct list_head transports;
863 
864 	/* Reference counting. */
865 	atomic_t refcnt;
866 	int	 dead;
867 
868 	/* This is the peer's IP address and port. */
869 	union sctp_addr ipaddr;
870 
871 	/* These are the functions we call to handle LLP stuff.	 */
872 	struct sctp_af *af_specific;
873 
874 	/* Which association do we belong to?  */
875 	struct sctp_association *asoc;
876 
877 	/* RFC2960
878 	 *
879 	 * 12.3 Per Transport Address Data
880 	 *
881 	 * For each destination transport address in the peer's
882 	 * address list derived from the INIT or INIT ACK chunk, a
883 	 * number of data elements needs to be maintained including:
884 	 */
885 	/* RTO	       : The current retransmission timeout value.  */
886 	unsigned long rto;
887 	unsigned long last_rto;
888 
889 	__u32 rtt;		/* This is the most recent RTT.	 */
890 
891 	/* RTTVAR      : The current RTT variation.  */
892 	__u32 rttvar;
893 
894 	/* SRTT	       : The current smoothed round trip time.	*/
895 	__u32 srtt;
896 
897 	/* RTO-Pending : A flag used to track if one of the DATA
898 	 *		chunks sent to this address is currently being
899 	 *		used to compute a RTT. If this flag is 0,
900 	 *		the next DATA chunk sent to this destination
901 	 *		should be used to compute a RTT and this flag
902 	 *		should be set. Every time the RTT
903 	 *		calculation completes (i.e. the DATA chunk
904 	 *		is SACK'd) clear this flag.
905 	 */
906 	__u8 rto_pending;
907 
908 	/* Flag to track the current fast recovery state */
909 	__u8 fast_recovery;
910 
911 	/*
912 	 * These are the congestion stats.
913 	 */
914 	/* cwnd	       : The current congestion window.	 */
915 	__u32 cwnd;		  /* This is the actual cwnd.  */
916 
917 	/* ssthresh    : The current slow start threshold value.  */
918 	__u32 ssthresh;
919 
920 	/* partial     : The tracking method for increase of cwnd when in
921 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
922 	 */
923 	__u32 partial_bytes_acked;
924 
925 	/* Data that has been sent, but not acknowledged. */
926 	__u32 flight_size;
927 
928 	/* TSN marking the fast recovery exit point */
929 	__u32 fast_recovery_exit;
930 
931 	/* Destination */
932 	struct dst_entry *dst;
933 	/* Source address. */
934 	union sctp_addr saddr;
935 
936 	/* When was the last time(in jiffies) that a data packet was sent on
937 	 * this transport?  This is used to adjust the cwnd when the transport
938 	 * becomes inactive.
939 	 */
940 	unsigned long last_time_used;
941 
942 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
943 	 * the destination address every heartbeat interval.
944 	 */
945 	unsigned long hbinterval;
946 
947 	/* SACK delay timeout */
948 	unsigned long sackdelay;
949 
950 	/* When was the last time (in jiffies) that we heard from this
951 	 * transport?  We use this to pick new active and retran paths.
952 	 */
953 	unsigned long last_time_heard;
954 
955 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
956 	 * indication based on ECNE chunk.
957 	 */
958 	unsigned long last_time_ecne_reduced;
959 
960 	/* This is the max_retrans value for the transport and will
961 	 * be initialized from the assocs value.  This can be changed
962 	 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
963 	 */
964 	__u16 pathmaxrxt;
965 
966 	/* is the Path MTU update pending on this tranport */
967 	__u8 pmtu_pending;
968 
969 	/* PMTU	      : The current known path MTU.  */
970 	__u32 pathmtu;
971 
972 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
973 	__u32 param_flags;
974 
975 	/* The number of times INIT has been sent on this transport. */
976 	int init_sent_count;
977 
978 	/* state       : The current state of this destination,
979 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN.
980 	 */
981 	int state;
982 
983 	/* These are the error stats for this destination.  */
984 
985 	/* Error count : The current error count for this destination.	*/
986 	unsigned short error_count;
987 
988 	/* Per	       : A timer used by each destination.
989 	 * Destination :
990 	 * Timer       :
991 	 *
992 	 * [Everywhere else in the text this is called T3-rtx. -ed]
993 	 */
994 	struct timer_list T3_rtx_timer;
995 
996 	/* Heartbeat timer is per destination. */
997 	struct timer_list hb_timer;
998 
999 	/* Since we're using per-destination retransmission timers
1000 	 * (see above), we're also using per-destination "transmitted"
1001 	 * queues.  This probably ought to be a private struct
1002 	 * accessible only within the outqueue, but it's not, yet.
1003 	 */
1004 	struct list_head transmitted;
1005 
1006 	/* We build bundle-able packets for this transport here.  */
1007 	struct sctp_packet packet;
1008 
1009 	/* This is the list of transports that have chunks to send.  */
1010 	struct list_head send_ready;
1011 
1012 	int malloced; /* Is this structure kfree()able? */
1013 
1014 	/* State information saved for SFR_CACC algorithm. The key
1015 	 * idea in SFR_CACC is to maintain state at the sender on a
1016 	 * per-destination basis when a changeover happens.
1017 	 *	char changeover_active;
1018 	 *	char cycling_changeover;
1019 	 *	__u32 next_tsn_at_change;
1020 	 *	char cacc_saw_newack;
1021 	 */
1022 	struct {
1023 		/* An unsigned integer, which stores the next TSN to be
1024 		 * used by the sender, at the moment of changeover.
1025 		 */
1026 		__u32 next_tsn_at_change;
1027 
1028 		/* A flag which indicates the occurrence of a changeover */
1029 		char changeover_active;
1030 
1031 		/* A flag which indicates whether the change of primary is
1032 		 * the first switch to this destination address during an
1033 		 * active switch.
1034 		 */
1035 		char cycling_changeover;
1036 
1037 		/* A temporary flag, which is used during the processing of
1038 		 * a SACK to estimate the causative TSN(s)'s group.
1039 		 */
1040 		char cacc_saw_newack;
1041 	} cacc;
1042 
1043 	/* 64-bit random number sent with heartbeat. */
1044 	__u64 hb_nonce;
1045 };
1046 
1047 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1048 					  gfp_t);
1049 void sctp_transport_set_owner(struct sctp_transport *,
1050 			      struct sctp_association *);
1051 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1052 			  struct sctp_sock *);
1053 void sctp_transport_pmtu(struct sctp_transport *);
1054 void sctp_transport_free(struct sctp_transport *);
1055 void sctp_transport_reset_timers(struct sctp_transport *, int);
1056 void sctp_transport_hold(struct sctp_transport *);
1057 void sctp_transport_put(struct sctp_transport *);
1058 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1059 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1060 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1061 unsigned long sctp_transport_timeout(struct sctp_transport *);
1062 void sctp_transport_reset(struct sctp_transport *);
1063 void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1064 
1065 
1066 /* This is the structure we use to queue packets as they come into
1067  * SCTP.  We write packets to it and read chunks from it.
1068  */
1069 struct sctp_inq {
1070 	/* This is actually a queue of sctp_chunk each
1071 	 * containing a partially decoded packet.
1072 	 */
1073 	struct list_head in_chunk_list;
1074 	/* This is the packet which is currently off the in queue and is
1075 	 * being worked on through the inbound chunk processing.
1076 	 */
1077 	struct sctp_chunk *in_progress;
1078 
1079 	/* This is the delayed task to finish delivering inbound
1080 	 * messages.
1081 	 */
1082 	struct work_struct immediate;
1083 
1084 	int malloced;	     /* Is this structure kfree()able?	*/
1085 };
1086 
1087 void sctp_inq_init(struct sctp_inq *);
1088 void sctp_inq_free(struct sctp_inq *);
1089 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1090 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1091 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1092 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1093 
1094 /* This is the structure we use to hold outbound chunks.  You push
1095  * chunks in and they automatically pop out the other end as bundled
1096  * packets (it calls (*output_handler)()).
1097  *
1098  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1099  * and 8.2 of the v13 draft.
1100  *
1101  * It handles retransmissions.	The connection to the timeout portion
1102  * of the state machine is through sctp_..._timeout() and timeout_handler.
1103  *
1104  * If you feed it SACKs, it will eat them.
1105  *
1106  * If you give it big chunks, it will fragment them.
1107  *
1108  * It assigns TSN's to data chunks.  This happens at the last possible
1109  * instant before transmission.
1110  *
1111  * When free()'d, it empties itself out via output_handler().
1112  */
1113 struct sctp_outq {
1114 	struct sctp_association *asoc;
1115 
1116 	/* Data pending that has never been transmitted.  */
1117 	struct list_head out_chunk_list;
1118 
1119 	unsigned out_qlen;	/* Total length of queued data chunks. */
1120 
1121 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1122 	unsigned error;
1123 
1124 	/* These are control chunks we want to send.  */
1125 	struct list_head control_chunk_list;
1126 
1127 	/* These are chunks that have been sacked but are above the
1128 	 * CTSN, or cumulative tsn ack point.
1129 	 */
1130 	struct list_head sacked;
1131 
1132 	/* Put chunks on this list to schedule them for
1133 	 * retransmission.
1134 	 */
1135 	struct list_head retransmit;
1136 
1137 	/* Put chunks on this list to save them for FWD TSN processing as
1138 	 * they were abandoned.
1139 	 */
1140 	struct list_head abandoned;
1141 
1142 	/* How many unackd bytes do we have in-flight?	*/
1143 	__u32 outstanding_bytes;
1144 
1145 	/* Are we doing fast-rtx on this queue */
1146 	char fast_rtx;
1147 
1148 	/* Corked? */
1149 	char cork;
1150 
1151 	/* Is this structure empty?  */
1152 	char empty;
1153 
1154 	/* Are we kfree()able? */
1155 	char malloced;
1156 };
1157 
1158 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1159 void sctp_outq_teardown(struct sctp_outq *);
1160 void sctp_outq_free(struct sctp_outq*);
1161 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1162 int sctp_outq_flush(struct sctp_outq *, int);
1163 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1164 int sctp_outq_is_empty(const struct sctp_outq *);
1165 void sctp_outq_restart(struct sctp_outq *);
1166 
1167 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1168 		     sctp_retransmit_reason_t);
1169 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1170 int sctp_outq_uncork(struct sctp_outq *);
1171 /* Uncork and flush an outqueue.  */
1172 static inline void sctp_outq_cork(struct sctp_outq *q)
1173 {
1174 	q->cork = 1;
1175 }
1176 
1177 /* These bind address data fields common between endpoints and associations */
1178 struct sctp_bind_addr {
1179 
1180 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1181 	 *
1182 	 * SCTP Port:	The local SCTP port number the endpoint is
1183 	 *		bound to.
1184 	 */
1185 	__u16 port;
1186 
1187 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1188 	 *
1189 	 * Address List: The list of IP addresses that this instance
1190 	 *	has bound.  This information is passed to one's
1191 	 *	peer(s) in INIT and INIT ACK chunks.
1192 	 */
1193 	struct list_head address_list;
1194 
1195 	int malloced;	     /* Are we kfree()able?  */
1196 };
1197 
1198 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1199 void sctp_bind_addr_free(struct sctp_bind_addr *);
1200 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1201 			const struct sctp_bind_addr *src,
1202 			sctp_scope_t scope, gfp_t gfp,
1203 			int flags);
1204 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1205 			const struct sctp_bind_addr *src,
1206 			gfp_t gfp);
1207 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1208 		       __u8 addr_state, gfp_t gfp);
1209 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1210 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1211 			 struct sctp_sock *);
1212 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1213 			 const union sctp_addr *addr);
1214 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1215 					const union sctp_addr	*addrs,
1216 					int			addrcnt,
1217 					struct sctp_sock	*opt);
1218 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1219 					 int *addrs_len,
1220 					 gfp_t gfp);
1221 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1222 			   __u16 port, gfp_t gfp);
1223 
1224 sctp_scope_t sctp_scope(const union sctp_addr *);
1225 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1226 int sctp_is_any(const union sctp_addr *addr);
1227 int sctp_addr_is_valid(const union sctp_addr *addr);
1228 
1229 
1230 /* What type of endpoint?  */
1231 typedef enum {
1232 	SCTP_EP_TYPE_SOCKET,
1233 	SCTP_EP_TYPE_ASSOCIATION,
1234 } sctp_endpoint_type_t;
1235 
1236 /*
1237  * A common base class to bridge the implmentation view of a
1238  * socket (usually listening) endpoint versus an association's
1239  * local endpoint.
1240  * This common structure is useful for several purposes:
1241  *   1) Common interface for lookup routines.
1242  *	a) Subfunctions work for either endpoint or association
1243  *	b) Single interface to lookup allows hiding the lookup lock rather
1244  *	   than acquiring it externally.
1245  *   2) Common interface for the inbound chunk handling/state machine.
1246  *   3) Common object handling routines for reference counting, etc.
1247  *   4) Disentangle association lookup from endpoint lookup, where we
1248  *	do not have to find our endpoint to find our association.
1249  *
1250  */
1251 
1252 struct sctp_ep_common {
1253 	/* Fields to help us manage our entries in the hash tables. */
1254 	struct hlist_node node;
1255 	int hashent;
1256 
1257 	/* Runtime type information.  What kind of endpoint is this? */
1258 	sctp_endpoint_type_t type;
1259 
1260 	/* Some fields to help us manage this object.
1261 	 *   refcnt   - Reference count access to this object.
1262 	 *   dead     - Do not attempt to use this object.
1263 	 *   malloced - Do we need to kfree this object?
1264 	 */
1265 	atomic_t    refcnt;
1266 	char	    dead;
1267 	char	    malloced;
1268 
1269 	/* What socket does this endpoint belong to?  */
1270 	struct sock *sk;
1271 
1272 	/* This is where we receive inbound chunks.  */
1273 	struct sctp_inq	  inqueue;
1274 
1275 	/* This substructure includes the defining parameters of the
1276 	 * endpoint:
1277 	 * bind_addr.port is our shared port number.
1278 	 * bind_addr.address_list is our set of local IP addresses.
1279 	 */
1280 	struct sctp_bind_addr bind_addr;
1281 };
1282 
1283 
1284 /* RFC Section 1.4 Key Terms
1285  *
1286  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1287  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1288  *   combination of a set of eligible destination transport addresses to
1289  *   which SCTP packets can be sent and a set of eligible source
1290  *   transport addresses from which SCTP packets can be received.
1291  *   All transport addresses used by an SCTP endpoint must use the
1292  *   same port number, but can use multiple IP addresses. A transport
1293  *   address used by an SCTP endpoint must not be used by another
1294  *   SCTP endpoint. In other words, a transport address is unique
1295  *   to an SCTP endpoint.
1296  *
1297  * From an implementation perspective, each socket has one of these.
1298  * A TCP-style socket will have exactly one association on one of
1299  * these.  An UDP-style socket will have multiple associations hanging
1300  * off one of these.
1301  */
1302 
1303 struct sctp_endpoint {
1304 	/* Common substructure for endpoint and association. */
1305 	struct sctp_ep_common base;
1306 
1307 	/* Associations: A list of current associations and mappings
1308 	 *	      to the data consumers for each association. This
1309 	 *	      may be in the form of a hash table or other
1310 	 *	      implementation dependent structure. The data
1311 	 *	      consumers may be process identification
1312 	 *	      information such as file descriptors, named pipe
1313 	 *	      pointer, or table pointers dependent on how SCTP
1314 	 *	      is implemented.
1315 	 */
1316 	/* This is really a list of struct sctp_association entries. */
1317 	struct list_head asocs;
1318 
1319 	/* Secret Key: A secret key used by this endpoint to compute
1320 	 *	      the MAC.	This SHOULD be a cryptographic quality
1321 	 *	      random number with a sufficient length.
1322 	 *	      Discussion in [RFC1750] can be helpful in
1323 	 *	      selection of the key.
1324 	 */
1325 	__u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1326 	int current_key;
1327 	int last_key;
1328 	int key_changed_at;
1329 
1330  	/* digest:  This is a digest of the sctp cookie.  This field is
1331  	 * 	    only used on the receive path when we try to validate
1332  	 * 	    that the cookie has not been tampered with.  We put
1333  	 * 	    this here so we pre-allocate this once and can re-use
1334  	 * 	    on every receive.
1335  	 */
1336  	__u8 *digest;
1337 
1338 	/* sendbuf acct. policy.	*/
1339 	__u32 sndbuf_policy;
1340 
1341 	/* rcvbuf acct. policy.	*/
1342 	__u32 rcvbuf_policy;
1343 
1344 	/* SCTP AUTH: array of the HMACs that will be allocated
1345 	 * we need this per association so that we don't serialize
1346 	 */
1347 	struct crypto_hash **auth_hmacs;
1348 
1349 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1350 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1351 
1352 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1353 	struct sctp_chunks_param *auth_chunk_list;
1354 
1355 	/* SCTP-AUTH: endpoint shared keys */
1356 	struct list_head endpoint_shared_keys;
1357 	__u16 active_key_id;
1358 };
1359 
1360 /* Recover the outter endpoint structure. */
1361 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1362 {
1363 	struct sctp_endpoint *ep;
1364 
1365 	ep = container_of(base, struct sctp_endpoint, base);
1366 	return ep;
1367 }
1368 
1369 /* These are function signatures for manipulating endpoints.  */
1370 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1371 void sctp_endpoint_free(struct sctp_endpoint *);
1372 void sctp_endpoint_put(struct sctp_endpoint *);
1373 void sctp_endpoint_hold(struct sctp_endpoint *);
1374 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1375 struct sctp_association *sctp_endpoint_lookup_assoc(
1376 	const struct sctp_endpoint *ep,
1377 	const union sctp_addr *paddr,
1378 	struct sctp_transport **);
1379 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1380 				const union sctp_addr *);
1381 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1382 					const union sctp_addr *);
1383 int sctp_has_association(const union sctp_addr *laddr,
1384 			 const union sctp_addr *paddr);
1385 
1386 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1387 		     sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1388 		     struct sctp_chunk **err_chunk);
1389 int sctp_process_init(struct sctp_association *, sctp_cid_t cid,
1390 		      const union sctp_addr *peer,
1391 		      sctp_init_chunk_t *init, gfp_t gfp);
1392 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1393 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1394 
1395 struct sctp_inithdr_host {
1396 	__u32 init_tag;
1397 	__u32 a_rwnd;
1398 	__u16 num_outbound_streams;
1399 	__u16 num_inbound_streams;
1400 	__u32 initial_tsn;
1401 };
1402 
1403 /* RFC2960
1404  *
1405  * 12. Recommended Transmission Control Block (TCB) Parameters
1406  *
1407  * This section details a recommended set of parameters that should
1408  * be contained within the TCB for an implementation. This section is
1409  * for illustrative purposes and should not be deemed as requirements
1410  * on an implementation or as an exhaustive list of all parameters
1411  * inside an SCTP TCB. Each implementation may need its own additional
1412  * parameters for optimization.
1413  */
1414 
1415 
1416 /* Here we have information about each individual association. */
1417 struct sctp_association {
1418 
1419 	/* A base structure common to endpoint and association.
1420 	 * In this context, it represents the associations's view
1421 	 * of the local endpoint of the association.
1422 	 */
1423 	struct sctp_ep_common base;
1424 
1425 	/* Associations on the same socket. */
1426 	struct list_head asocs;
1427 
1428 	/* association id. */
1429 	sctp_assoc_t assoc_id;
1430 
1431 	/* This is our parent endpoint.	 */
1432 	struct sctp_endpoint *ep;
1433 
1434 	/* These are those association elements needed in the cookie.  */
1435 	struct sctp_cookie c;
1436 
1437 	/* This is all information about our peer.  */
1438 	struct {
1439 		/* rwnd
1440 		 *
1441 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1442 		 */
1443 		__u32 rwnd;
1444 
1445 		/* transport_addr_list
1446 		 *
1447 		 * Peer	       : A list of SCTP transport addresses that the
1448 		 * Transport   : peer is bound to. This information is derived
1449 		 * Address     : from the INIT or INIT ACK and is used to
1450 		 * List	       : associate an inbound packet with a given
1451 		 *	       : association. Normally this information is
1452 		 *	       : hashed or keyed for quick lookup and access
1453 		 *	       : of the TCB.
1454 		 *	       : The list is also initialized with the list
1455 		 *	       : of addresses passed with the sctp_connectx()
1456 		 *	       : call.
1457 		 *
1458 		 * It is a list of SCTP_transport's.
1459 		 */
1460 		struct list_head transport_addr_list;
1461 
1462 		/* transport_count
1463 		 *
1464 		 * Peer        : A count of the number of peer addresses
1465 		 * Transport   : in the Peer Transport Address List.
1466 		 * Address     :
1467 		 * Count       :
1468 		 */
1469 		__u16 transport_count;
1470 
1471 		/* port
1472 		 *   The transport layer port number.
1473 		 */
1474 		__u16 port;
1475 
1476 		/* primary_path
1477 		 *
1478 		 * Primary     : This is the current primary destination
1479 		 * Path	       : transport address of the peer endpoint.  It
1480 		 *	       : may also specify a source transport address
1481 		 *	       : on this endpoint.
1482 		 *
1483 		 * All of these paths live on transport_addr_list.
1484 		 *
1485 		 * At the bakeoffs, we discovered that the intent of
1486 		 * primaryPath is that it only changes when the ULP
1487 		 * asks to have it changed.  We add the activePath to
1488 		 * designate the connection we are currently using to
1489 		 * transmit new data and most control chunks.
1490 		 */
1491 		struct sctp_transport *primary_path;
1492 
1493 		/* Cache the primary path address here, when we
1494 		 * need a an address for msg_name.
1495 		 */
1496 		union sctp_addr primary_addr;
1497 
1498 		/* active_path
1499 		 *   The path that we are currently using to
1500 		 *   transmit new data and most control chunks.
1501 		 */
1502 		struct sctp_transport *active_path;
1503 
1504 		/* retran_path
1505 		 *
1506 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1507 		 * ...
1508 		 * Furthermore, when its peer is multi-homed, an
1509 		 * endpoint SHOULD try to retransmit a chunk to an
1510 		 * active destination transport address that is
1511 		 * different from the last destination address to
1512 		 * which the DATA chunk was sent.
1513 		 */
1514 		struct sctp_transport *retran_path;
1515 
1516 		/* Pointer to last transport I have sent on.  */
1517 		struct sctp_transport *last_sent_to;
1518 
1519 		/* This is the last transport I have received DATA on.	*/
1520 		struct sctp_transport *last_data_from;
1521 
1522 		/*
1523 		 * Mapping  An array of bits or bytes indicating which out of
1524 		 * Array    order TSN's have been received (relative to the
1525 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1526 		 *	    order packets have been received, this array
1527 		 *	    will be set to all zero. This structure may be
1528 		 *	    in the form of a circular buffer or bit array.
1529 		 *
1530 		 * Last Rcvd   : This is the last TSN received in
1531 		 * TSN	       : sequence. This value is set initially by
1532 		 *	       : taking the peer's Initial TSN, received in
1533 		 *	       : the INIT or INIT ACK chunk, and subtracting
1534 		 *	       : one from it.
1535 		 *
1536 		 * Throughout most of the specification this is called the
1537 		 * "Cumulative TSN ACK Point".	In this case, we
1538 		 * ignore the advice in 12.2 in favour of the term
1539 		 * used in the bulk of the text.  This value is hidden
1540 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1541 		 */
1542 		struct sctp_tsnmap tsn_map;
1543 		__u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)];
1544 
1545 		/* Ack State   : This flag indicates if the next received
1546 		 *             : packet is to be responded to with a
1547 		 *             : SACK. This is initializedto 0.  When a packet
1548 		 *             : is received it is incremented. If this value
1549 		 *             : reaches 2 or more, a SACK is sent and the
1550 		 *             : value is reset to 0. Note: This is used only
1551 		 *             : when no DATA chunks are received out of
1552 		 *             : order.  When DATA chunks are out of order,
1553 		 *             : SACK's are not delayed (see Section 6).
1554 		 */
1555 		__u8    sack_needed;     /* Do we need to sack the peer? */
1556 
1557 		/* These are capabilities which our peer advertised.  */
1558 		__u8	ecn_capable;	 /* Can peer do ECN? */
1559 		__u8	ipv4_address;	 /* Peer understands IPv4 addresses? */
1560 		__u8	ipv6_address;	 /* Peer understands IPv6 addresses? */
1561 		__u8	hostname_address;/* Peer understands DNS addresses? */
1562 		__u8    asconf_capable;  /* Does peer support ADDIP? */
1563 		__u8    prsctp_capable;  /* Can peer do PR-SCTP? */
1564 		__u8	auth_capable;	 /* Is peer doing SCTP-AUTH? */
1565 
1566 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1567 
1568 		/* This mask is used to disable sending the ASCONF chunk
1569 		 * with specified parameter to peer.
1570 		 */
1571 		__be16 addip_disabled_mask;
1572 
1573 		struct sctp_inithdr_host i;
1574 		int cookie_len;
1575 		void *cookie;
1576 
1577 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1578 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1579 		 * Initial TSN Value minus 1
1580 		 */
1581 		__u32 addip_serial;
1582 
1583 		/* SCTP-AUTH: We need to know pears random number, hmac list
1584 		 * and authenticated chunk list.  All that is part of the
1585 		 * cookie and these are just pointers to those locations
1586 		 */
1587 		sctp_random_param_t *peer_random;
1588 		sctp_chunks_param_t *peer_chunks;
1589 		sctp_hmac_algo_param_t *peer_hmacs;
1590 	} peer;
1591 
1592 	/* State       : A state variable indicating what state the
1593 	 *	       : association is in, i.e. COOKIE-WAIT,
1594 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1595 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1596 	 *
1597 	 *		Note: No "CLOSED" state is illustrated since if a
1598 	 *		association is "CLOSED" its TCB SHOULD be removed.
1599 	 *
1600 	 *		In this implementation we DO have a CLOSED
1601 	 *		state which is used during initiation and shutdown.
1602 	 *
1603 	 *		State takes values from SCTP_STATE_*.
1604 	 */
1605 	sctp_state_t state;
1606 
1607 	/* The cookie life I award for any cookie.  */
1608 	struct timeval cookie_life;
1609 
1610 	/* Overall     : The overall association error count.
1611 	 * Error Count : [Clear this any time I get something.]
1612 	 */
1613 	int overall_error_count;
1614 
1615 	/* These are the association's initial, max, and min RTO values.
1616 	 * These values will be initialized by system defaults, but can
1617 	 * be modified via the SCTP_RTOINFO socket option.
1618 	 */
1619 	unsigned long rto_initial;
1620 	unsigned long rto_max;
1621 	unsigned long rto_min;
1622 
1623 	/* Maximum number of new data packets that can be sent in a burst.  */
1624 	int max_burst;
1625 
1626 	/* This is the max_retrans value for the association.  This value will
1627 	 * be initialized initialized from system defaults, but can be
1628 	 * modified by the SCTP_ASSOCINFO socket option.
1629 	 */
1630 	int max_retrans;
1631 
1632 	/* Maximum number of times the endpoint will retransmit INIT  */
1633 	__u16 max_init_attempts;
1634 
1635 	/* How many times have we resent an INIT? */
1636 	__u16 init_retries;
1637 
1638 	/* The largest timeout or RTO value to use in attempting an INIT */
1639 	unsigned long max_init_timeo;
1640 
1641 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1642 	 * the destination address every heartbeat interval. This value
1643 	 * will be inherited by all new transports.
1644 	 */
1645 	unsigned long hbinterval;
1646 
1647 	/* This is the max_retrans value for new transports in the
1648 	 * association.
1649 	 */
1650 	__u16 pathmaxrxt;
1651 
1652 	/* Flag that path mtu update is pending */
1653 	__u8   pmtu_pending;
1654 
1655 	/* Association : The smallest PMTU discovered for all of the
1656 	 * PMTU	       : peer's transport addresses.
1657 	 */
1658 	__u32 pathmtu;
1659 
1660 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1661 	__u32 param_flags;
1662 
1663 	/* SACK delay timeout */
1664 	unsigned long sackdelay;
1665 
1666 
1667 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1668 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1669 
1670 	/* Transport to which SHUTDOWN chunk was last sent.  */
1671 	struct sctp_transport *shutdown_last_sent_to;
1672 
1673 	/* How many times have we resent a SHUTDOWN */
1674 	int shutdown_retries;
1675 
1676 	/* Transport to which INIT chunk was last sent.  */
1677 	struct sctp_transport *init_last_sent_to;
1678 
1679 	/* Next TSN    : The next TSN number to be assigned to a new
1680 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1681 	 *	       : ACK chunk to the peer and incremented each
1682 	 *	       : time a DATA chunk is assigned a TSN
1683 	 *	       : (normally just prior to transmit or during
1684 	 *	       : fragmentation).
1685 	 */
1686 	__u32 next_tsn;
1687 
1688 	/*
1689 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1690 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1691 	 *	       : received in the INIT or INIT ACK chunk, and
1692 	 *	       : subtracting one from it.
1693 	 *
1694 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1695 	 */
1696 
1697 	__u32 ctsn_ack_point;
1698 
1699 	/* PR-SCTP Advanced.Peer.Ack.Point */
1700 	__u32 adv_peer_ack_point;
1701 
1702 	/* Highest TSN that is acknowledged by incoming SACKs. */
1703 	__u32 highest_sacked;
1704 
1705 	/* The number of unacknowledged data chunks.  Reported through
1706 	 * the SCTP_STATUS sockopt.
1707 	 */
1708 	__u16 unack_data;
1709 
1710 	/* The total number of data chunks that we've had to retransmit
1711 	 * as the result of a T3 timer expiration
1712 	 */
1713 	__u32 rtx_data_chunks;
1714 
1715 	/* This is the association's receive buffer space.  This value is used
1716 	 * to set a_rwnd field in an INIT or a SACK chunk.
1717 	 */
1718 	__u32 rwnd;
1719 
1720 	/* This is the last advertised value of rwnd over a SACK chunk. */
1721 	__u32 a_rwnd;
1722 
1723 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1724 	 * to slop over a maximum of the association's frag_point.
1725 	 */
1726 	__u32 rwnd_over;
1727 
1728 	/* This is the sndbuf size in use for the association.
1729 	 * This corresponds to the sndbuf size for the association,
1730 	 * as specified in the sk->sndbuf.
1731 	 */
1732 	int sndbuf_used;
1733 
1734 	/* This is the amount of memory that this association has allocated
1735 	 * in the receive path at any given time.
1736 	 */
1737 	atomic_t rmem_alloc;
1738 
1739 	/* This is the wait queue head for send requests waiting on
1740 	 * the association sndbuf space.
1741 	 */
1742 	wait_queue_head_t	wait;
1743 
1744 	/* The message size at which SCTP fragmentation will occur. */
1745 	__u32 frag_point;
1746 
1747 	/* Counter used to count INIT errors. */
1748 	int init_err_counter;
1749 
1750 	/* Count the number of INIT cycles (for doubling timeout). */
1751 	int init_cycle;
1752 
1753 	/* Default send parameters. */
1754 	__u16 default_stream;
1755 	__u16 default_flags;
1756 	__u32 default_ppid;
1757 	__u32 default_context;
1758 	__u32 default_timetolive;
1759 
1760 	/* Default receive parameters */
1761 	__u32 default_rcv_context;
1762 
1763 	/* This tracks outbound ssn for a given stream.	 */
1764 	struct sctp_ssnmap *ssnmap;
1765 
1766 	/* All outbound chunks go through this structure.  */
1767 	struct sctp_outq outqueue;
1768 
1769 	/* A smart pipe that will handle reordering and fragmentation,
1770 	 * as well as handle passing events up to the ULP.
1771 	 */
1772 	struct sctp_ulpq ulpq;
1773 
1774 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1775 	__u32 last_ecne_tsn;
1776 
1777 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1778 	__u32 last_cwr_tsn;
1779 
1780 	/* How many duplicated TSNs have we seen?  */
1781 	int numduptsns;
1782 
1783 	/* Number of seconds of idle time before an association is closed.
1784 	 * In the association context, this is really used as a boolean
1785 	 * since the real timeout is stored in the timeouts array
1786 	 */
1787 	__u32 autoclose;
1788 
1789 	/* These are to support
1790 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1791 	 *  and Enforcement of Flow and Message Limits"
1792 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1793 	 * or "ADDIP" for short.
1794 	 */
1795 
1796 
1797 
1798 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1799 	 *
1800 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1801 	 * unacknowledged at any one time.  If a sender, after sending
1802 	 * an ASCONF chunk, decides it needs to transfer another
1803 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1804 	 * returns from the previous ASCONF Chunk before sending a
1805 	 * subsequent ASCONF. Note this restriction binds each side,
1806 	 * so at any time two ASCONF may be in-transit on any given
1807 	 * association (one sent from each endpoint).
1808 	 *
1809 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1810 	 * not have an ASCONF in flight, this is NULL.]
1811 	 */
1812 	struct sctp_chunk *addip_last_asconf;
1813 
1814 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1815 	 *
1816 	 * This is needed to implement itmes E1 - E4 of the updated
1817 	 * spec.  Here is the justification:
1818 	 *
1819 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1820 	 * we now need the ability to cache multiple ACKs.  The section
1821 	 * describes in detail how they are cached and cleaned up.
1822 	 */
1823 	struct list_head asconf_ack_list;
1824 
1825 	/* These ASCONF chunks are waiting to be sent.
1826 	 *
1827 	 * These chunaks can't be pushed to outqueue until receiving
1828 	 * ASCONF_ACK for the previous ASCONF indicated by
1829 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1830 	 * is in flight at any time.
1831 	 *
1832 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1833 	 *
1834 	 * In defining the ASCONF Chunk transfer procedures, it is
1835 	 * essential that these transfers MUST NOT cause congestion
1836 	 * within the network.	To achieve this, we place these
1837 	 * restrictions on the transfer of ASCONF Chunks:
1838 	 *
1839 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1840 	 * unacknowledged at any one time.  If a sender, after sending
1841 	 * an ASCONF chunk, decides it needs to transfer another
1842 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1843 	 * returns from the previous ASCONF Chunk before sending a
1844 	 * subsequent ASCONF. Note this restriction binds each side,
1845 	 * so at any time two ASCONF may be in-transit on any given
1846 	 * association (one sent from each endpoint).
1847 	 *
1848 	 *
1849 	 * [I really think this is EXACTLY the sort of intelligence
1850 	 *  which already resides in sctp_outq.	 Please move this
1851 	 *  queue and its supporting logic down there.	--piggy]
1852 	 */
1853 	struct list_head addip_chunk_list;
1854 
1855 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1856 	 *
1857 	 * A2) A serial number should be assigned to the Chunk. The
1858 	 * serial number SHOULD be a monotonically increasing
1859 	 * number. The serial number SHOULD be initialized at
1860 	 * the start of the association to the same value as the
1861 	 * Initial TSN and every time a new ASCONF chunk is created
1862 	 * it is incremented by one after assigning the serial number
1863 	 * to the newly created chunk.
1864 	 *
1865 	 * ADDIP
1866 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1867 	 *
1868 	 * Serial Number : 32 bits (unsigned integer)
1869 	 *
1870 	 * This value represents a Serial Number for the ASCONF
1871 	 * Chunk. The valid range of Serial Number is from 0 to
1872 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1873 	 * after reaching 4294967295.
1874 	 */
1875 	__u32 addip_serial;
1876 
1877 	/* SCTP AUTH: list of the endpoint shared keys.  These
1878 	 * keys are provided out of band by the user applicaton
1879 	 * and can't change during the lifetime of the association
1880 	 */
1881 	struct list_head endpoint_shared_keys;
1882 
1883 	/* SCTP AUTH:
1884 	 * The current generated assocaition shared key (secret)
1885 	 */
1886 	struct sctp_auth_bytes *asoc_shared_key;
1887 
1888 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1889 	 * that we support.
1890 	 */
1891 	__u16 default_hmac_id;
1892 
1893 	__u16 active_key_id;
1894 
1895 	/* Need to send an ECNE Chunk? */
1896 	char need_ecne;
1897 
1898 	/* Is it a temporary association? */
1899 	char temp;
1900 };
1901 
1902 
1903 /* An eyecatcher for determining if we are really looking at an
1904  * association data structure.
1905  */
1906 enum {
1907 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1908 };
1909 
1910 /* Recover the outter association structure. */
1911 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1912 {
1913 	struct sctp_association *asoc;
1914 
1915 	asoc = container_of(base, struct sctp_association, base);
1916 	return asoc;
1917 }
1918 
1919 /* These are function signatures for manipulating associations.	 */
1920 
1921 
1922 struct sctp_association *
1923 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1924 		     sctp_scope_t scope, gfp_t gfp);
1925 void sctp_association_free(struct sctp_association *);
1926 void sctp_association_put(struct sctp_association *);
1927 void sctp_association_hold(struct sctp_association *);
1928 
1929 struct sctp_transport *sctp_assoc_choose_init_transport(
1930 	struct sctp_association *);
1931 struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1932 	struct sctp_association *);
1933 void sctp_assoc_update_retran_path(struct sctp_association *);
1934 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1935 					  const union sctp_addr *);
1936 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1937 			    const union sctp_addr *laddr);
1938 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1939 				     const union sctp_addr *address,
1940 				     const gfp_t gfp,
1941 				     const int peer_state);
1942 void sctp_assoc_del_peer(struct sctp_association *asoc,
1943 			 const union sctp_addr *addr);
1944 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1945 			 struct sctp_transport *peer);
1946 void sctp_assoc_control_transport(struct sctp_association *,
1947 				  struct sctp_transport *,
1948 				  sctp_transport_cmd_t, sctp_sn_error_t);
1949 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1950 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1951 					   const union sctp_addr *,
1952 					   const union sctp_addr *);
1953 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1954 void sctp_assoc_update(struct sctp_association *old,
1955 		       struct sctp_association *new);
1956 
1957 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1958 
1959 void sctp_assoc_sync_pmtu(struct sctp_association *);
1960 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1961 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1962 void sctp_assoc_set_primary(struct sctp_association *,
1963 			    struct sctp_transport *);
1964 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1965 				    struct sctp_transport *);
1966 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1967 				     gfp_t);
1968 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1969 					 struct sctp_cookie*,
1970 					 gfp_t gfp);
1971 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1972 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1973 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1974 					const struct sctp_association *asoc,
1975 					__be32 serial);
1976 
1977 
1978 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1979 			const union sctp_addr *ss2);
1980 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1981 
1982 /* A convenience structure to parse out SCTP specific CMSGs. */
1983 typedef struct sctp_cmsgs {
1984 	struct sctp_initmsg *init;
1985 	struct sctp_sndrcvinfo *info;
1986 } sctp_cmsgs_t;
1987 
1988 /* Structure for tracking memory objects */
1989 typedef struct {
1990 	char *label;
1991 	atomic_t *counter;
1992 } sctp_dbg_objcnt_entry_t;
1993 
1994 #endif /* __sctp_structs_h__ */
1995