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