xref: /openbmc/linux/include/net/sctp/structs.h (revision 37be287c)
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, see
23  * <http://www.gnu.org/licenses/>.
24  *
25  * Please send any bug reports or fixes you make to the
26  * email addresses:
27  *    lksctp developers <linux-sctp@vger.kernel.org>
28  *
29  * Written or modified by:
30  *    Randall Stewart	    <randall@sctp.chicago.il.us>
31  *    Ken Morneau	    <kmorneau@cisco.com>
32  *    Qiaobing Xie	    <qxie1@email.mot.com>
33  *    La Monte H.P. Yarroll <piggy@acm.org>
34  *    Karl Knutson	    <karl@athena.chicago.il.us>
35  *    Jon Grimm		    <jgrimm@us.ibm.com>
36  *    Xingang Guo	    <xingang.guo@intel.com>
37  *    Hui Huang		    <hui.huang@nokia.com>
38  *    Sridhar Samudrala	    <sri@us.ibm.com>
39  *    Daisy Chang	    <daisyc@us.ibm.com>
40  *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
41  *    Ardelle Fan	    <ardelle.fan@intel.com>
42  *    Ryan Layer	    <rmlayer@us.ibm.com>
43  *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
44  *    Kevin Gao             <kevin.gao@intel.com>
45  */
46 
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
49 
50 #include <linux/ktime.h>
51 #include <linux/socket.h>	/* linux/in.h needs this!!    */
52 #include <linux/in.h>		/* We get struct sockaddr_in. */
53 #include <linux/in6.h>		/* We get struct in6_addr     */
54 #include <linux/ipv6.h>
55 #include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
56 #include <linux/atomic.h>		/* This gets us atomic counters.  */
57 #include <linux/skbuff.h>	/* We need sk_buff_head. */
58 #include <linux/workqueue.h>	/* We need tq_struct.	 */
59 #include <linux/sctp.h>		/* We need sctp* header structs.  */
60 #include <net/sctp/auth.h>	/* We need auth specific structs */
61 
62 /* A convenience structure for handling sockaddr structures.
63  * We should wean ourselves off this.
64  */
65 union sctp_addr {
66 	struct sockaddr_in v4;
67 	struct sockaddr_in6 v6;
68 	struct sockaddr sa;
69 };
70 
71 /* Forward declarations for data structures. */
72 struct sctp_globals;
73 struct sctp_endpoint;
74 struct sctp_association;
75 struct sctp_transport;
76 struct sctp_packet;
77 struct sctp_chunk;
78 struct sctp_inq;
79 struct sctp_outq;
80 struct sctp_bind_addr;
81 struct sctp_ulpq;
82 struct sctp_ep_common;
83 struct sctp_ssnmap;
84 struct crypto_hash;
85 
86 
87 #include <net/sctp/tsnmap.h>
88 #include <net/sctp/ulpevent.h>
89 #include <net/sctp/ulpqueue.h>
90 
91 /* Structures useful for managing bind/connect. */
92 
93 struct sctp_bind_bucket {
94 	unsigned short	port;
95 	unsigned short	fastreuse;
96 	struct hlist_node	node;
97 	struct hlist_head	owner;
98 	struct net	*net;
99 };
100 
101 struct sctp_bind_hashbucket {
102 	spinlock_t	lock;
103 	struct hlist_head	chain;
104 };
105 
106 /* Used for hashing all associations.  */
107 struct sctp_hashbucket {
108 	rwlock_t	lock;
109 	struct hlist_head	chain;
110 } __attribute__((__aligned__(8)));
111 
112 
113 /* The SCTP globals structure. */
114 extern struct sctp_globals {
115 	/* This is a list of groups of functions for each address
116 	 * family that we support.
117 	 */
118 	struct list_head address_families;
119 
120 	/* This is the hash of all endpoints. */
121 	struct sctp_hashbucket *ep_hashtable;
122 	/* This is the hash of all associations. */
123 	struct sctp_hashbucket *assoc_hashtable;
124 	/* This is the sctp port control hash.	*/
125 	struct sctp_bind_hashbucket *port_hashtable;
126 
127 	/* Sizes of above hashtables. */
128 	int ep_hashsize;
129 	int assoc_hashsize;
130 	int port_hashsize;
131 
132 	/* Default initialization values to be applied to new associations. */
133 	__u16 max_instreams;
134 	__u16 max_outstreams;
135 
136 	/* Flag to indicate whether computing and verifying checksum
137 	 * is disabled. */
138         bool checksum_disable;
139 } sctp_globals;
140 
141 #define sctp_max_instreams		(sctp_globals.max_instreams)
142 #define sctp_max_outstreams		(sctp_globals.max_outstreams)
143 #define sctp_address_families		(sctp_globals.address_families)
144 #define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
145 #define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
146 #define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
147 #define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
148 #define sctp_port_hashsize		(sctp_globals.port_hashsize)
149 #define sctp_port_hashtable		(sctp_globals.port_hashtable)
150 #define sctp_checksum_disable		(sctp_globals.checksum_disable)
151 
152 /* SCTP Socket type: UDP or TCP style. */
153 typedef enum {
154 	SCTP_SOCKET_UDP = 0,
155 	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
156 	SCTP_SOCKET_TCP
157 } sctp_socket_type_t;
158 
159 /* Per socket SCTP information. */
160 struct sctp_sock {
161 	/* inet_sock has to be the first member of sctp_sock */
162 	struct inet_sock inet;
163 	/* What kind of a socket is this? */
164 	sctp_socket_type_t type;
165 
166 	/* PF_ family specific functions.  */
167 	struct sctp_pf *pf;
168 
169 	/* Access to HMAC transform. */
170 	struct crypto_hash *hmac;
171 	char *sctp_hmac_alg;
172 
173 	/* What is our base endpointer? */
174 	struct sctp_endpoint *ep;
175 
176 	struct sctp_bind_bucket *bind_hash;
177 	/* Various Socket Options.  */
178 	__u16 default_stream;
179 	__u32 default_ppid;
180 	__u16 default_flags;
181 	__u32 default_context;
182 	__u32 default_timetolive;
183 	__u32 default_rcv_context;
184 	int max_burst;
185 
186 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
187 	 * the destination address every heartbeat interval. This value
188 	 * will be inherited by all new associations.
189 	 */
190 	__u32 hbinterval;
191 
192 	/* This is the max_retrans value for new associations. */
193 	__u16 pathmaxrxt;
194 
195 	/* The initial Path MTU to use for new associations. */
196 	__u32 pathmtu;
197 
198 	/* The default SACK delay timeout for new associations. */
199 	__u32 sackdelay;
200 	__u32 sackfreq;
201 
202 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
203 	__u32 param_flags;
204 
205 	struct sctp_initmsg initmsg;
206 	struct sctp_rtoinfo rtoinfo;
207 	struct sctp_paddrparams paddrparam;
208 	struct sctp_event_subscribe subscribe;
209 	struct sctp_assocparams assocparams;
210 	int user_frag;
211 	__u32 autoclose;
212 	__u8 nodelay;
213 	__u8 disable_fragments;
214 	__u8 v4mapped;
215 	__u8 frag_interleave;
216 	__u32 adaptation_ind;
217 	__u32 pd_point;
218 
219 	atomic_t pd_mode;
220 	/* Receive to here while partial delivery is in effect. */
221 	struct sk_buff_head pd_lobby;
222 	struct list_head auto_asconf_list;
223 	int do_auto_asconf;
224 };
225 
226 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
227 {
228        return (struct sctp_sock *)sk;
229 }
230 
231 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
232 {
233        return (struct sock *)sp;
234 }
235 
236 #if IS_ENABLED(CONFIG_IPV6)
237 struct sctp6_sock {
238        struct sctp_sock  sctp;
239        struct ipv6_pinfo inet6;
240 };
241 #endif /* CONFIG_IPV6 */
242 
243 
244 /* This is our APPLICATION-SPECIFIC state cookie.
245  * THIS IS NOT DICTATED BY THE SPECIFICATION.
246  */
247 /* These are the parts of an association which we send in the cookie.
248  * Most of these are straight out of:
249  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
250  *
251  */
252 
253 struct sctp_cookie {
254 
255 	/* My	       : Tag expected in every inbound packet and sent
256 	 * Verification: in the INIT or INIT ACK chunk.
257 	 * Tag	       :
258 	 */
259 	__u32 my_vtag;
260 
261 	/* Peer's      : Tag expected in every outbound packet except
262 	 * Verification: in the INIT chunk.
263 	 * Tag	       :
264 	 */
265 	__u32 peer_vtag;
266 
267 	/* The rest of these are not from the spec, but really need to
268 	 * be in the cookie.
269 	 */
270 
271 	/* My Tie Tag  : Assist in discovering a restarting association. */
272 	__u32 my_ttag;
273 
274 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
275 	__u32 peer_ttag;
276 
277 	/* When does this cookie expire? */
278 	ktime_t expiration;
279 
280 	/* Number of inbound/outbound streams which are set
281 	 * and negotiated during the INIT process.
282 	 */
283 	__u16 sinit_num_ostreams;
284 	__u16 sinit_max_instreams;
285 
286 	/* This is the first sequence number I used.  */
287 	__u32 initial_tsn;
288 
289 	/* This holds the originating address of the INIT packet.  */
290 	union sctp_addr peer_addr;
291 
292 	/* IG Section 2.35.3
293 	 * Include the source port of the INIT-ACK
294 	 */
295 	__u16		my_port;
296 
297 	__u8 prsctp_capable;
298 
299 	/* Padding for future use */
300 	__u8 padding;
301 
302 	__u32 adaptation_ind;
303 
304 	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
305 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
306 	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
307 
308 	/* This is a shim for my peer's INIT packet, followed by
309 	 * a copy of the raw address list of the association.
310 	 * The length of the raw address list is saved in the
311 	 * raw_addr_list_len field, which will be used at the time when
312 	 * the association TCB is re-constructed from the cookie.
313 	 */
314 	__u32 raw_addr_list_len;
315 	struct sctp_init_chunk peer_init[0];
316 };
317 
318 
319 /* The format of our cookie that we send to our peer. */
320 struct sctp_signed_cookie {
321 	__u8 signature[SCTP_SECRET_SIZE];
322 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
323 	struct sctp_cookie c;
324 } __packed;
325 
326 /* This is another convenience type to allocate memory for address
327  * params for the maximum size and pass such structures around
328  * internally.
329  */
330 union sctp_addr_param {
331 	struct sctp_paramhdr p;
332 	struct sctp_ipv4addr_param v4;
333 	struct sctp_ipv6addr_param v6;
334 };
335 
336 /* A convenience type to allow walking through the various
337  * parameters and avoid casting all over the place.
338  */
339 union sctp_params {
340 	void *v;
341 	struct sctp_paramhdr *p;
342 	struct sctp_cookie_preserve_param *life;
343 	struct sctp_hostname_param *dns;
344 	struct sctp_cookie_param *cookie;
345 	struct sctp_supported_addrs_param *sat;
346 	struct sctp_ipv4addr_param *v4;
347 	struct sctp_ipv6addr_param *v6;
348 	union sctp_addr_param *addr;
349 	struct sctp_adaptation_ind_param *aind;
350 	struct sctp_supported_ext_param *ext;
351 	struct sctp_random_param *random;
352 	struct sctp_chunks_param *chunks;
353 	struct sctp_hmac_algo_param *hmac_algo;
354 	struct sctp_addip_param *addip;
355 };
356 
357 /* RFC 2960.  Section 3.3.5 Heartbeat.
358  *    Heartbeat Information: variable length
359  *    The Sender-specific Heartbeat Info field should normally include
360  *    information about the sender's current time when this HEARTBEAT
361  *    chunk is sent and the destination transport address to which this
362  *    HEARTBEAT is sent (see Section 8.3).
363  */
364 typedef struct sctp_sender_hb_info {
365 	struct sctp_paramhdr param_hdr;
366 	union sctp_addr daddr;
367 	unsigned long sent_at;
368 	__u64 hb_nonce;
369 } __packed sctp_sender_hb_info_t;
370 
371 /*
372  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
373  *
374  *  The term "stream" is used in SCTP to refer to a sequence of user
375  *  messages that are to be delivered to the upper-layer protocol in
376  *  order with respect to other messages within the same stream.  This is
377  *  in contrast to its usage in TCP, where it refers to a sequence of
378  *  bytes (in this document a byte is assumed to be eight bits).
379  *  ...
380  *
381  *  This is the structure we use to track both our outbound and inbound
382  *  SSN, or Stream Sequence Numbers.
383  */
384 
385 struct sctp_stream {
386 	__u16 *ssn;
387 	unsigned int len;
388 };
389 
390 struct sctp_ssnmap {
391 	struct sctp_stream in;
392 	struct sctp_stream out;
393 };
394 
395 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
396 				    gfp_t gfp);
397 void sctp_ssnmap_free(struct sctp_ssnmap *map);
398 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
399 
400 /* What is the current SSN number for this stream? */
401 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
402 {
403 	return stream->ssn[id];
404 }
405 
406 /* Return the next SSN number for this stream.	*/
407 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
408 {
409 	return stream->ssn[id]++;
410 }
411 
412 /* Skip over this ssn and all below. */
413 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
414 				 __u16 ssn)
415 {
416 	stream->ssn[id] = ssn+1;
417 }
418 
419 /*
420  * Pointers to address related SCTP functions.
421  * (i.e. things that depend on the address family.)
422  */
423 struct sctp_af {
424 	int		(*sctp_xmit)	(struct sk_buff *skb,
425 					 struct sctp_transport *);
426 	int		(*setsockopt)	(struct sock *sk,
427 					 int level,
428 					 int optname,
429 					 char __user *optval,
430 					 unsigned int optlen);
431 	int		(*getsockopt)	(struct sock *sk,
432 					 int level,
433 					 int optname,
434 					 char __user *optval,
435 					 int __user *optlen);
436 	int		(*compat_setsockopt)	(struct sock *sk,
437 					 int level,
438 					 int optname,
439 					 char __user *optval,
440 					 unsigned int optlen);
441 	int		(*compat_getsockopt)	(struct sock *sk,
442 					 int level,
443 					 int optname,
444 					 char __user *optval,
445 					 int __user *optlen);
446 	void		(*get_dst)	(struct sctp_transport *t,
447 					 union sctp_addr *saddr,
448 					 struct flowi *fl,
449 					 struct sock *sk);
450 	void		(*get_saddr)	(struct sctp_sock *sk,
451 					 struct sctp_transport *t,
452 					 struct flowi *fl);
453 	void		(*copy_addrlist) (struct list_head *,
454 					  struct net_device *);
455 	int		(*cmp_addr)	(const union sctp_addr *addr1,
456 					 const union sctp_addr *addr2);
457 	void		(*addr_copy)	(union sctp_addr *dst,
458 					 union sctp_addr *src);
459 	void		(*from_skb)	(union sctp_addr *,
460 					 struct sk_buff *skb,
461 					 int saddr);
462 	void		(*from_sk)	(union sctp_addr *,
463 					 struct sock *sk);
464 	void		(*to_sk_saddr)	(union sctp_addr *,
465 					 struct sock *sk);
466 	void		(*to_sk_daddr)	(union sctp_addr *,
467 					 struct sock *sk);
468 	void		(*from_addr_param) (union sctp_addr *,
469 					    union sctp_addr_param *,
470 					    __be16 port, int iif);
471 	int		(*to_addr_param) (const union sctp_addr *,
472 					  union sctp_addr_param *);
473 	int		(*addr_valid)	(union sctp_addr *,
474 					 struct sctp_sock *,
475 					 const struct sk_buff *);
476 	sctp_scope_t	(*scope) (union sctp_addr *);
477 	void		(*inaddr_any)	(union sctp_addr *, __be16);
478 	int		(*is_any)	(const union sctp_addr *);
479 	int		(*available)	(union sctp_addr *,
480 					 struct sctp_sock *);
481 	int		(*skb_iif)	(const struct sk_buff *sk);
482 	int		(*is_ce)	(const struct sk_buff *sk);
483 	void		(*seq_dump_addr)(struct seq_file *seq,
484 					 union sctp_addr *addr);
485 	void		(*ecn_capable)(struct sock *sk);
486 	__u16		net_header_len;
487 	int		sockaddr_len;
488 	sa_family_t	sa_family;
489 	struct list_head list;
490 };
491 
492 struct sctp_af *sctp_get_af_specific(sa_family_t);
493 int sctp_register_af(struct sctp_af *);
494 
495 /* Protocol family functions. */
496 struct sctp_pf {
497 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
498 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
499 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
500 	int  (*cmp_addr) (const union sctp_addr *,
501 			  const union sctp_addr *,
502 			  struct sctp_sock *);
503 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
504 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
505 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
506 	struct sock *(*create_accept_sk) (struct sock *sk,
507 					  struct sctp_association *asoc);
508 	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
509 	struct sctp_af *af;
510 };
511 
512 
513 /* Structure to track chunk fragments that have been acked, but peer
514  * fragments of the same message have not.
515  */
516 struct sctp_datamsg {
517 	/* Chunks waiting to be submitted to lower layer. */
518 	struct list_head chunks;
519 	/* Reference counting. */
520 	atomic_t refcnt;
521 	/* When is this message no longer interesting to the peer? */
522 	unsigned long expires_at;
523 	/* Did the messenge fail to send? */
524 	int send_error;
525 	u8 send_failed:1,
526 	   can_abandon:1,   /* can chunks from this message can be abandoned. */
527 	   can_delay;	    /* should this message be Nagle delayed */
528 };
529 
530 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
531 					    struct sctp_sndrcvinfo *,
532 					    struct msghdr *, int len);
533 void sctp_datamsg_free(struct sctp_datamsg *);
534 void sctp_datamsg_put(struct sctp_datamsg *);
535 void sctp_chunk_fail(struct sctp_chunk *, int error);
536 int sctp_chunk_abandoned(struct sctp_chunk *);
537 
538 /* RFC2960 1.4 Key Terms
539  *
540  * o Chunk: A unit of information within an SCTP packet, consisting of
541  * a chunk header and chunk-specific content.
542  *
543  * As a matter of convenience, we remember the SCTP common header for
544  * each chunk as well as a few other header pointers...
545  */
546 struct sctp_chunk {
547 	struct list_head list;
548 
549 	atomic_t refcnt;
550 
551 	/* This is our link to the per-transport transmitted list.  */
552 	struct list_head transmitted_list;
553 
554 	/* This field is used by chunks that hold fragmented data.
555 	 * For the first fragment this is the list that holds the rest of
556 	 * fragments. For the remaining fragments, this is the link to the
557 	 * frag_list maintained in the first fragment.
558 	 */
559 	struct list_head frag_list;
560 
561 	/* This points to the sk_buff containing the actual data.  */
562 	struct sk_buff *skb;
563 
564 	/* These are the SCTP headers by reverse order in a packet.
565 	 * Note that some of these may happen more than once.  In that
566 	 * case, we point at the "current" one, whatever that means
567 	 * for that level of header.
568 	 */
569 
570 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
571 	union sctp_params param_hdr;
572 	union {
573 		__u8 *v;
574 		struct sctp_datahdr *data_hdr;
575 		struct sctp_inithdr *init_hdr;
576 		struct sctp_sackhdr *sack_hdr;
577 		struct sctp_heartbeathdr *hb_hdr;
578 		struct sctp_sender_hb_info *hbs_hdr;
579 		struct sctp_shutdownhdr *shutdown_hdr;
580 		struct sctp_signed_cookie *cookie_hdr;
581 		struct sctp_ecnehdr *ecne_hdr;
582 		struct sctp_cwrhdr *ecn_cwr_hdr;
583 		struct sctp_errhdr *err_hdr;
584 		struct sctp_addiphdr *addip_hdr;
585 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
586 		struct sctp_authhdr *auth_hdr;
587 	} subh;
588 
589 	__u8 *chunk_end;
590 
591 	struct sctp_chunkhdr *chunk_hdr;
592 	struct sctphdr *sctp_hdr;
593 
594 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
595 	struct sctp_sndrcvinfo sinfo;
596 
597 	/* Which association does this belong to?  */
598 	struct sctp_association *asoc;
599 
600 	/* What endpoint received this chunk? */
601 	struct sctp_ep_common *rcvr;
602 
603 	/* We fill this in if we are calculating RTT. */
604 	unsigned long sent_at;
605 
606 	/* What is the origin IP address for this chunk?  */
607 	union sctp_addr source;
608 	/* Destination address for this chunk. */
609 	union sctp_addr dest;
610 
611 	/* For outbound message, track all fragments for SEND_FAILED. */
612 	struct sctp_datamsg *msg;
613 
614 	/* For an inbound chunk, this tells us where it came from.
615 	 * For an outbound chunk, it tells us where we'd like it to
616 	 * go.	It is NULL if we have no preference.
617 	 */
618 	struct sctp_transport *transport;
619 
620 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
621 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
622 	 * spec violates the principle premis that all chunks are processed
623 	 * in order.
624 	 */
625 	struct sk_buff *auth_chunk;
626 
627 #define SCTP_CAN_FRTX 0x0
628 #define SCTP_NEED_FRTX 0x1
629 #define SCTP_DONT_FRTX 0x2
630 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
631 		resent:1,		/* Has this chunk ever been resent. */
632 		has_tsn:1,		/* Does this chunk have a TSN yet? */
633 		has_ssn:1,		/* Does this chunk have a SSN yet? */
634 		singleton:1,		/* Only chunk in the packet? */
635 		end_of_packet:1,	/* Last chunk in the packet? */
636 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
637 		pdiscard:1,		/* Discard the whole packet now? */
638 		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
639 		data_accepted:1,	/* At least 1 chunk accepted */
640 		auth:1,			/* IN: was auth'ed | OUT: needs auth */
641 		has_asconf:1,		/* IN: have seen an asconf before */
642 		tsn_missing_report:2,	/* Data chunk missing counter. */
643 		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
644 };
645 
646 void sctp_chunk_hold(struct sctp_chunk *);
647 void sctp_chunk_put(struct sctp_chunk *);
648 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
649 			  struct iovec *data);
650 void sctp_chunk_free(struct sctp_chunk *);
651 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
652 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
653 				 const struct sctp_association *,
654 				 struct sock *);
655 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
656 		     union sctp_addr *);
657 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
658 
659 enum {
660 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
661 	SCTP_ADDR_SRC,		/* address can be used as source */
662 	SCTP_ADDR_DEL,		/* address about to be deleted */
663 };
664 
665 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
666 struct sctp_sockaddr_entry {
667 	struct list_head list;
668 	struct rcu_head	rcu;
669 	union sctp_addr a;
670 	__u8 state;
671 	__u8 valid;
672 };
673 
674 #define SCTP_ADDRESS_TICK_DELAY	500
675 
676 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
677 
678 /* This structure holds lists of chunks as we are assembling for
679  * transmission.
680  */
681 struct sctp_packet {
682 	/* These are the SCTP header values (host order) for the packet. */
683 	__u16 source_port;
684 	__u16 destination_port;
685 	__u32 vtag;
686 
687 	/* This contains the payload chunks.  */
688 	struct list_head chunk_list;
689 
690 	/* This is the overhead of the sctp and ip headers. */
691 	size_t overhead;
692 	/* This is the total size of all chunks INCLUDING padding.  */
693 	size_t size;
694 
695 	/* The packet is destined for this transport address.
696 	 * The function we finally use to pass down to the next lower
697 	 * layer lives in the transport structure.
698 	 */
699 	struct sctp_transport *transport;
700 
701 	/* pointer to the auth chunk for this packet */
702 	struct sctp_chunk *auth;
703 
704 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
705 	    has_sack:1,		/* This packet contains a SACK chunk. */
706 	    has_auth:1,		/* This packet contains an AUTH chunk */
707 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
708 	    ipfragok:1;		/* So let ip fragment this packet */
709 };
710 
711 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
712 				     struct sctp_transport *,
713 				     __u16 sport, __u16 dport);
714 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
715 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
716                                        struct sctp_chunk *, int);
717 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
718                                      struct sctp_chunk *);
719 int sctp_packet_transmit(struct sctp_packet *);
720 void sctp_packet_free(struct sctp_packet *);
721 
722 static inline int sctp_packet_empty(struct sctp_packet *packet)
723 {
724 	return packet->size == packet->overhead;
725 }
726 
727 /* This represents a remote transport address.
728  * For local transport addresses, we just use union sctp_addr.
729  *
730  * RFC2960 Section 1.4 Key Terms
731  *
732  *   o	Transport address:  A Transport Address is traditionally defined
733  *	by Network Layer address, Transport Layer protocol and Transport
734  *	Layer port number.  In the case of SCTP running over IP, a
735  *	transport address is defined by the combination of an IP address
736  *	and an SCTP port number (where SCTP is the Transport protocol).
737  *
738  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
739  *
740  *   o	The sender keeps a separate congestion control parameter set for
741  *	each of the destination addresses it can send to (not each
742  *	source-destination pair but for each destination).  The parameters
743  *	should decay if the address is not used for a long enough time
744  *	period.
745  *
746  */
747 struct sctp_transport {
748 	/* A list of transports. */
749 	struct list_head transports;
750 
751 	/* Reference counting. */
752 	atomic_t refcnt;
753 	__u32	 dead:1,
754 		/* RTO-Pending : A flag used to track if one of the DATA
755 		 *		chunks sent to this address is currently being
756 		 *		used to compute a RTT. If this flag is 0,
757 		 *		the next DATA chunk sent to this destination
758 		 *		should be used to compute a RTT and this flag
759 		 *		should be set. Every time the RTT
760 		 *		calculation completes (i.e. the DATA chunk
761 		 *		is SACK'd) clear this flag.
762 		 */
763 		 rto_pending:1,
764 
765 		/*
766 		 * hb_sent : a flag that signals that we have a pending
767 		 * heartbeat.
768 		 */
769 		hb_sent:1,
770 
771 		/* Is the Path MTU update pending on this tranport */
772 		pmtu_pending:1;
773 
774 	/* Has this transport moved the ctsn since we last sacked */
775 	__u32 sack_generation;
776 	u32 dst_cookie;
777 
778 	struct flowi fl;
779 
780 	/* This is the peer's IP address and port. */
781 	union sctp_addr ipaddr;
782 
783 	/* These are the functions we call to handle LLP stuff.	 */
784 	struct sctp_af *af_specific;
785 
786 	/* Which association do we belong to?  */
787 	struct sctp_association *asoc;
788 
789 	/* RFC2960
790 	 *
791 	 * 12.3 Per Transport Address Data
792 	 *
793 	 * For each destination transport address in the peer's
794 	 * address list derived from the INIT or INIT ACK chunk, a
795 	 * number of data elements needs to be maintained including:
796 	 */
797 	/* RTO	       : The current retransmission timeout value.  */
798 	unsigned long rto;
799 
800 	__u32 rtt;		/* This is the most recent RTT.	 */
801 
802 	/* RTTVAR      : The current RTT variation.  */
803 	__u32 rttvar;
804 
805 	/* SRTT	       : The current smoothed round trip time.	*/
806 	__u32 srtt;
807 
808 	/*
809 	 * These are the congestion stats.
810 	 */
811 	/* cwnd	       : The current congestion window.	 */
812 	__u32 cwnd;		  /* This is the actual cwnd.  */
813 
814 	/* ssthresh    : The current slow start threshold value.  */
815 	__u32 ssthresh;
816 
817 	/* partial     : The tracking method for increase of cwnd when in
818 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
819 	 */
820 	__u32 partial_bytes_acked;
821 
822 	/* Data that has been sent, but not acknowledged. */
823 	__u32 flight_size;
824 
825 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
826 
827 	/* Destination */
828 	struct dst_entry *dst;
829 	/* Source address. */
830 	union sctp_addr saddr;
831 
832 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
833 	 * the destination address every heartbeat interval.
834 	 */
835 	unsigned long hbinterval;
836 
837 	/* SACK delay timeout */
838 	unsigned long sackdelay;
839 	__u32 sackfreq;
840 
841 	/* When was the last time (in jiffies) that we heard from this
842 	 * transport?  We use this to pick new active and retran paths.
843 	 */
844 	unsigned long last_time_heard;
845 
846 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
847 	 * indication based on ECNE chunk.
848 	 */
849 	unsigned long last_time_ecne_reduced;
850 
851 	/* This is the max_retrans value for the transport and will
852 	 * be initialized from the assocs value.  This can be changed
853 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
854 	 */
855 	__u16 pathmaxrxt;
856 
857 	/* This is the partially failed retrans value for the transport
858 	 * and will be initialized from the assocs value.  This can be changed
859 	 * using the SCTP_PEER_ADDR_THLDS socket option
860 	 */
861 	int pf_retrans;
862 	/* PMTU	      : The current known path MTU.  */
863 	__u32 pathmtu;
864 
865 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
866 	__u32 param_flags;
867 
868 	/* The number of times INIT has been sent on this transport. */
869 	int init_sent_count;
870 
871 	/* state       : The current state of this destination,
872 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
873 	 */
874 	int state;
875 
876 	/* These are the error stats for this destination.  */
877 
878 	/* Error count : The current error count for this destination.	*/
879 	unsigned short error_count;
880 
881 	/* Per	       : A timer used by each destination.
882 	 * Destination :
883 	 * Timer       :
884 	 *
885 	 * [Everywhere else in the text this is called T3-rtx. -ed]
886 	 */
887 	struct timer_list T3_rtx_timer;
888 
889 	/* Heartbeat timer is per destination. */
890 	struct timer_list hb_timer;
891 
892 	/* Timer to handle ICMP proto unreachable envets */
893 	struct timer_list proto_unreach_timer;
894 
895 	/* Since we're using per-destination retransmission timers
896 	 * (see above), we're also using per-destination "transmitted"
897 	 * queues.  This probably ought to be a private struct
898 	 * accessible only within the outqueue, but it's not, yet.
899 	 */
900 	struct list_head transmitted;
901 
902 	/* We build bundle-able packets for this transport here.  */
903 	struct sctp_packet packet;
904 
905 	/* This is the list of transports that have chunks to send.  */
906 	struct list_head send_ready;
907 
908 	/* State information saved for SFR_CACC algorithm. The key
909 	 * idea in SFR_CACC is to maintain state at the sender on a
910 	 * per-destination basis when a changeover happens.
911 	 *	char changeover_active;
912 	 *	char cycling_changeover;
913 	 *	__u32 next_tsn_at_change;
914 	 *	char cacc_saw_newack;
915 	 */
916 	struct {
917 		/* An unsigned integer, which stores the next TSN to be
918 		 * used by the sender, at the moment of changeover.
919 		 */
920 		__u32 next_tsn_at_change;
921 
922 		/* A flag which indicates the occurrence of a changeover */
923 		char changeover_active;
924 
925 		/* A flag which indicates whether the change of primary is
926 		 * the first switch to this destination address during an
927 		 * active switch.
928 		 */
929 		char cycling_changeover;
930 
931 		/* A temporary flag, which is used during the processing of
932 		 * a SACK to estimate the causative TSN(s)'s group.
933 		 */
934 		char cacc_saw_newack;
935 	} cacc;
936 
937 	/* 64-bit random number sent with heartbeat. */
938 	__u64 hb_nonce;
939 
940 	struct rcu_head rcu;
941 };
942 
943 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
944 					  gfp_t);
945 void sctp_transport_set_owner(struct sctp_transport *,
946 			      struct sctp_association *);
947 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
948 			  struct sctp_sock *);
949 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
950 void sctp_transport_free(struct sctp_transport *);
951 void sctp_transport_reset_timers(struct sctp_transport *);
952 void sctp_transport_hold(struct sctp_transport *);
953 void sctp_transport_put(struct sctp_transport *);
954 void sctp_transport_update_rto(struct sctp_transport *, __u32);
955 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
956 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
957 void sctp_transport_burst_limited(struct sctp_transport *);
958 void sctp_transport_burst_reset(struct sctp_transport *);
959 unsigned long sctp_transport_timeout(struct sctp_transport *);
960 void sctp_transport_reset(struct sctp_transport *);
961 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
962 void sctp_transport_immediate_rtx(struct sctp_transport *);
963 
964 
965 /* This is the structure we use to queue packets as they come into
966  * SCTP.  We write packets to it and read chunks from it.
967  */
968 struct sctp_inq {
969 	/* This is actually a queue of sctp_chunk each
970 	 * containing a partially decoded packet.
971 	 */
972 	struct list_head in_chunk_list;
973 	/* This is the packet which is currently off the in queue and is
974 	 * being worked on through the inbound chunk processing.
975 	 */
976 	struct sctp_chunk *in_progress;
977 
978 	/* This is the delayed task to finish delivering inbound
979 	 * messages.
980 	 */
981 	struct work_struct immediate;
982 };
983 
984 void sctp_inq_init(struct sctp_inq *);
985 void sctp_inq_free(struct sctp_inq *);
986 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
987 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
988 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
989 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
990 
991 /* This is the structure we use to hold outbound chunks.  You push
992  * chunks in and they automatically pop out the other end as bundled
993  * packets (it calls (*output_handler)()).
994  *
995  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
996  * and 8.2 of the v13 draft.
997  *
998  * It handles retransmissions.	The connection to the timeout portion
999  * of the state machine is through sctp_..._timeout() and timeout_handler.
1000  *
1001  * If you feed it SACKs, it will eat them.
1002  *
1003  * If you give it big chunks, it will fragment them.
1004  *
1005  * It assigns TSN's to data chunks.  This happens at the last possible
1006  * instant before transmission.
1007  *
1008  * When free()'d, it empties itself out via output_handler().
1009  */
1010 struct sctp_outq {
1011 	struct sctp_association *asoc;
1012 
1013 	/* Data pending that has never been transmitted.  */
1014 	struct list_head out_chunk_list;
1015 
1016 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1017 
1018 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1019 	unsigned int error;
1020 
1021 	/* These are control chunks we want to send.  */
1022 	struct list_head control_chunk_list;
1023 
1024 	/* These are chunks that have been sacked but are above the
1025 	 * CTSN, or cumulative tsn ack point.
1026 	 */
1027 	struct list_head sacked;
1028 
1029 	/* Put chunks on this list to schedule them for
1030 	 * retransmission.
1031 	 */
1032 	struct list_head retransmit;
1033 
1034 	/* Put chunks on this list to save them for FWD TSN processing as
1035 	 * they were abandoned.
1036 	 */
1037 	struct list_head abandoned;
1038 
1039 	/* How many unackd bytes do we have in-flight?	*/
1040 	__u32 outstanding_bytes;
1041 
1042 	/* Are we doing fast-rtx on this queue */
1043 	char fast_rtx;
1044 
1045 	/* Corked? */
1046 	char cork;
1047 };
1048 
1049 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1050 void sctp_outq_teardown(struct sctp_outq *);
1051 void sctp_outq_free(struct sctp_outq*);
1052 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1053 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1054 int sctp_outq_is_empty(const struct sctp_outq *);
1055 void sctp_outq_restart(struct sctp_outq *);
1056 
1057 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1058 		     sctp_retransmit_reason_t);
1059 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1060 int sctp_outq_uncork(struct sctp_outq *);
1061 /* Uncork and flush an outqueue.  */
1062 static inline void sctp_outq_cork(struct sctp_outq *q)
1063 {
1064 	q->cork = 1;
1065 }
1066 
1067 /* These bind address data fields common between endpoints and associations */
1068 struct sctp_bind_addr {
1069 
1070 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1071 	 *
1072 	 * SCTP Port:	The local SCTP port number the endpoint is
1073 	 *		bound to.
1074 	 */
1075 	__u16 port;
1076 
1077 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1078 	 *
1079 	 * Address List: The list of IP addresses that this instance
1080 	 *	has bound.  This information is passed to one's
1081 	 *	peer(s) in INIT and INIT ACK chunks.
1082 	 */
1083 	struct list_head address_list;
1084 };
1085 
1086 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1087 void sctp_bind_addr_free(struct sctp_bind_addr *);
1088 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1089 			const struct sctp_bind_addr *src,
1090 			sctp_scope_t scope, gfp_t gfp,
1091 			int flags);
1092 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1093 			const struct sctp_bind_addr *src,
1094 			gfp_t gfp);
1095 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1096 		       __u8 addr_state, gfp_t gfp);
1097 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1098 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1099 			 struct sctp_sock *);
1100 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1101 			 struct sctp_sock *, struct sctp_sock *);
1102 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1103 			 const union sctp_addr *addr);
1104 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1105 					const union sctp_addr	*addrs,
1106 					int			addrcnt,
1107 					struct sctp_sock	*opt);
1108 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1109 					 int *addrs_len,
1110 					 gfp_t gfp);
1111 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1112 			   __u16 port, gfp_t gfp);
1113 
1114 sctp_scope_t sctp_scope(const union sctp_addr *);
1115 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1116 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1117 int sctp_addr_is_valid(const union sctp_addr *addr);
1118 int sctp_is_ep_boundall(struct sock *sk);
1119 
1120 
1121 /* What type of endpoint?  */
1122 typedef enum {
1123 	SCTP_EP_TYPE_SOCKET,
1124 	SCTP_EP_TYPE_ASSOCIATION,
1125 } sctp_endpoint_type_t;
1126 
1127 /*
1128  * A common base class to bridge the implmentation view of a
1129  * socket (usually listening) endpoint versus an association's
1130  * local endpoint.
1131  * This common structure is useful for several purposes:
1132  *   1) Common interface for lookup routines.
1133  *	a) Subfunctions work for either endpoint or association
1134  *	b) Single interface to lookup allows hiding the lookup lock rather
1135  *	   than acquiring it externally.
1136  *   2) Common interface for the inbound chunk handling/state machine.
1137  *   3) Common object handling routines for reference counting, etc.
1138  *   4) Disentangle association lookup from endpoint lookup, where we
1139  *	do not have to find our endpoint to find our association.
1140  *
1141  */
1142 
1143 struct sctp_ep_common {
1144 	/* Fields to help us manage our entries in the hash tables. */
1145 	struct hlist_node node;
1146 	int hashent;
1147 
1148 	/* Runtime type information.  What kind of endpoint is this? */
1149 	sctp_endpoint_type_t type;
1150 
1151 	/* Some fields to help us manage this object.
1152 	 *   refcnt   - Reference count access to this object.
1153 	 *   dead     - Do not attempt to use this object.
1154 	 */
1155 	atomic_t    refcnt;
1156 	bool	    dead;
1157 
1158 	/* What socket does this endpoint belong to?  */
1159 	struct sock *sk;
1160 
1161 	/* This is where we receive inbound chunks.  */
1162 	struct sctp_inq	  inqueue;
1163 
1164 	/* This substructure includes the defining parameters of the
1165 	 * endpoint:
1166 	 * bind_addr.port is our shared port number.
1167 	 * bind_addr.address_list is our set of local IP addresses.
1168 	 */
1169 	struct sctp_bind_addr bind_addr;
1170 };
1171 
1172 
1173 /* RFC Section 1.4 Key Terms
1174  *
1175  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1176  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1177  *   combination of a set of eligible destination transport addresses to
1178  *   which SCTP packets can be sent and a set of eligible source
1179  *   transport addresses from which SCTP packets can be received.
1180  *   All transport addresses used by an SCTP endpoint must use the
1181  *   same port number, but can use multiple IP addresses. A transport
1182  *   address used by an SCTP endpoint must not be used by another
1183  *   SCTP endpoint. In other words, a transport address is unique
1184  *   to an SCTP endpoint.
1185  *
1186  * From an implementation perspective, each socket has one of these.
1187  * A TCP-style socket will have exactly one association on one of
1188  * these.  An UDP-style socket will have multiple associations hanging
1189  * off one of these.
1190  */
1191 
1192 struct sctp_endpoint {
1193 	/* Common substructure for endpoint and association. */
1194 	struct sctp_ep_common base;
1195 
1196 	/* Associations: A list of current associations and mappings
1197 	 *	      to the data consumers for each association. This
1198 	 *	      may be in the form of a hash table or other
1199 	 *	      implementation dependent structure. The data
1200 	 *	      consumers may be process identification
1201 	 *	      information such as file descriptors, named pipe
1202 	 *	      pointer, or table pointers dependent on how SCTP
1203 	 *	      is implemented.
1204 	 */
1205 	/* This is really a list of struct sctp_association entries. */
1206 	struct list_head asocs;
1207 
1208 	/* Secret Key: A secret key used by this endpoint to compute
1209 	 *	      the MAC.	This SHOULD be a cryptographic quality
1210 	 *	      random number with a sufficient length.
1211 	 *	      Discussion in [RFC1750] can be helpful in
1212 	 *	      selection of the key.
1213 	 */
1214 	__u8 secret_key[SCTP_SECRET_SIZE];
1215 
1216  	/* digest:  This is a digest of the sctp cookie.  This field is
1217  	 * 	    only used on the receive path when we try to validate
1218  	 * 	    that the cookie has not been tampered with.  We put
1219  	 * 	    this here so we pre-allocate this once and can re-use
1220  	 * 	    on every receive.
1221  	 */
1222  	__u8 *digest;
1223 
1224 	/* sendbuf acct. policy.	*/
1225 	__u32 sndbuf_policy;
1226 
1227 	/* rcvbuf acct. policy.	*/
1228 	__u32 rcvbuf_policy;
1229 
1230 	/* SCTP AUTH: array of the HMACs that will be allocated
1231 	 * we need this per association so that we don't serialize
1232 	 */
1233 	struct crypto_hash **auth_hmacs;
1234 
1235 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1236 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1237 
1238 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1239 	struct sctp_chunks_param *auth_chunk_list;
1240 
1241 	/* SCTP-AUTH: endpoint shared keys */
1242 	struct list_head endpoint_shared_keys;
1243 	__u16 active_key_id;
1244 };
1245 
1246 /* Recover the outter endpoint structure. */
1247 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1248 {
1249 	struct sctp_endpoint *ep;
1250 
1251 	ep = container_of(base, struct sctp_endpoint, base);
1252 	return ep;
1253 }
1254 
1255 /* These are function signatures for manipulating endpoints.  */
1256 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1257 void sctp_endpoint_free(struct sctp_endpoint *);
1258 void sctp_endpoint_put(struct sctp_endpoint *);
1259 void sctp_endpoint_hold(struct sctp_endpoint *);
1260 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1261 struct sctp_association *sctp_endpoint_lookup_assoc(
1262 	const struct sctp_endpoint *ep,
1263 	const union sctp_addr *paddr,
1264 	struct sctp_transport **);
1265 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1266 				const union sctp_addr *);
1267 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1268 					struct net *, const union sctp_addr *);
1269 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1270 			 const union sctp_addr *paddr);
1271 
1272 int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
1273 		     sctp_cid_t, sctp_init_chunk_t *peer_init,
1274 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1275 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1276 		      const union sctp_addr *peer,
1277 		      sctp_init_chunk_t *init, gfp_t gfp);
1278 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1279 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1280 
1281 struct sctp_inithdr_host {
1282 	__u32 init_tag;
1283 	__u32 a_rwnd;
1284 	__u16 num_outbound_streams;
1285 	__u16 num_inbound_streams;
1286 	__u32 initial_tsn;
1287 };
1288 
1289 /* SCTP_GET_ASSOC_STATS counters */
1290 struct sctp_priv_assoc_stats {
1291 	/* Maximum observed rto in the association during subsequent
1292 	 * observations. Value is set to 0 if no RTO measurement took place
1293 	 * The transport where the max_rto was observed is returned in
1294 	 * obs_rto_ipaddr
1295 	 */
1296 	struct sockaddr_storage obs_rto_ipaddr;
1297 	__u64 max_obs_rto;
1298 	/* Total In and Out SACKs received and sent */
1299 	__u64 isacks;
1300 	__u64 osacks;
1301 	/* Total In and Out packets received and sent */
1302 	__u64 opackets;
1303 	__u64 ipackets;
1304 	/* Total retransmitted chunks */
1305 	__u64 rtxchunks;
1306 	/* TSN received > next expected */
1307 	__u64 outofseqtsns;
1308 	/* Duplicate Chunks received */
1309 	__u64 idupchunks;
1310 	/* Gap Ack Blocks received */
1311 	__u64 gapcnt;
1312 	/* Unordered data chunks sent and received */
1313 	__u64 ouodchunks;
1314 	__u64 iuodchunks;
1315 	/* Ordered data chunks sent and received */
1316 	__u64 oodchunks;
1317 	__u64 iodchunks;
1318 	/* Control chunks sent and received */
1319 	__u64 octrlchunks;
1320 	__u64 ictrlchunks;
1321 };
1322 
1323 /* RFC2960
1324  *
1325  * 12. Recommended Transmission Control Block (TCB) Parameters
1326  *
1327  * This section details a recommended set of parameters that should
1328  * be contained within the TCB for an implementation. This section is
1329  * for illustrative purposes and should not be deemed as requirements
1330  * on an implementation or as an exhaustive list of all parameters
1331  * inside an SCTP TCB. Each implementation may need its own additional
1332  * parameters for optimization.
1333  */
1334 
1335 
1336 /* Here we have information about each individual association. */
1337 struct sctp_association {
1338 
1339 	/* A base structure common to endpoint and association.
1340 	 * In this context, it represents the associations's view
1341 	 * of the local endpoint of the association.
1342 	 */
1343 	struct sctp_ep_common base;
1344 
1345 	/* Associations on the same socket. */
1346 	struct list_head asocs;
1347 
1348 	/* association id. */
1349 	sctp_assoc_t assoc_id;
1350 
1351 	/* This is our parent endpoint.	 */
1352 	struct sctp_endpoint *ep;
1353 
1354 	/* These are those association elements needed in the cookie.  */
1355 	struct sctp_cookie c;
1356 
1357 	/* This is all information about our peer.  */
1358 	struct {
1359 		/* transport_addr_list
1360 		 *
1361 		 * Peer	       : A list of SCTP transport addresses that the
1362 		 * Transport   : peer is bound to. This information is derived
1363 		 * Address     : from the INIT or INIT ACK and is used to
1364 		 * List	       : associate an inbound packet with a given
1365 		 *	       : association. Normally this information is
1366 		 *	       : hashed or keyed for quick lookup and access
1367 		 *	       : of the TCB.
1368 		 *	       : The list is also initialized with the list
1369 		 *	       : of addresses passed with the sctp_connectx()
1370 		 *	       : call.
1371 		 *
1372 		 * It is a list of SCTP_transport's.
1373 		 */
1374 		struct list_head transport_addr_list;
1375 
1376 		/* rwnd
1377 		 *
1378 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1379 		 */
1380 		__u32 rwnd;
1381 
1382 		/* transport_count
1383 		 *
1384 		 * Peer        : A count of the number of peer addresses
1385 		 * Transport   : in the Peer Transport Address List.
1386 		 * Address     :
1387 		 * Count       :
1388 		 */
1389 		__u16 transport_count;
1390 
1391 		/* port
1392 		 *   The transport layer port number.
1393 		 */
1394 		__u16 port;
1395 
1396 		/* primary_path
1397 		 *
1398 		 * Primary     : This is the current primary destination
1399 		 * Path	       : transport address of the peer endpoint.  It
1400 		 *	       : may also specify a source transport address
1401 		 *	       : on this endpoint.
1402 		 *
1403 		 * All of these paths live on transport_addr_list.
1404 		 *
1405 		 * At the bakeoffs, we discovered that the intent of
1406 		 * primaryPath is that it only changes when the ULP
1407 		 * asks to have it changed.  We add the activePath to
1408 		 * designate the connection we are currently using to
1409 		 * transmit new data and most control chunks.
1410 		 */
1411 		struct sctp_transport *primary_path;
1412 
1413 		/* Cache the primary path address here, when we
1414 		 * need a an address for msg_name.
1415 		 */
1416 		union sctp_addr primary_addr;
1417 
1418 		/* active_path
1419 		 *   The path that we are currently using to
1420 		 *   transmit new data and most control chunks.
1421 		 */
1422 		struct sctp_transport *active_path;
1423 
1424 		/* retran_path
1425 		 *
1426 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1427 		 * ...
1428 		 * Furthermore, when its peer is multi-homed, an
1429 		 * endpoint SHOULD try to retransmit a chunk to an
1430 		 * active destination transport address that is
1431 		 * different from the last destination address to
1432 		 * which the DATA chunk was sent.
1433 		 */
1434 		struct sctp_transport *retran_path;
1435 
1436 		/* Pointer to last transport I have sent on.  */
1437 		struct sctp_transport *last_sent_to;
1438 
1439 		/* This is the last transport I have received DATA on.	*/
1440 		struct sctp_transport *last_data_from;
1441 
1442 		/*
1443 		 * Mapping  An array of bits or bytes indicating which out of
1444 		 * Array    order TSN's have been received (relative to the
1445 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1446 		 *	    order packets have been received, this array
1447 		 *	    will be set to all zero. This structure may be
1448 		 *	    in the form of a circular buffer or bit array.
1449 		 *
1450 		 * Last Rcvd   : This is the last TSN received in
1451 		 * TSN	       : sequence. This value is set initially by
1452 		 *	       : taking the peer's Initial TSN, received in
1453 		 *	       : the INIT or INIT ACK chunk, and subtracting
1454 		 *	       : one from it.
1455 		 *
1456 		 * Throughout most of the specification this is called the
1457 		 * "Cumulative TSN ACK Point".	In this case, we
1458 		 * ignore the advice in 12.2 in favour of the term
1459 		 * used in the bulk of the text.  This value is hidden
1460 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1461 		 */
1462 		struct sctp_tsnmap tsn_map;
1463 
1464 		/* This mask is used to disable sending the ASCONF chunk
1465 		 * with specified parameter to peer.
1466 		 */
1467 		__be16 addip_disabled_mask;
1468 
1469 		/* These are capabilities which our peer advertised.  */
1470 		__u8	ecn_capable:1,      /* Can peer do ECN? */
1471 			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1472 			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1473 			hostname_address:1, /* Peer understands DNS addresses? */
1474 			asconf_capable:1,   /* Does peer support ADDIP? */
1475 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1476 			auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1477 
1478 		/* Ack State   : This flag indicates if the next received
1479 		 *             : packet is to be responded to with a
1480 		 *             : SACK. This is initializedto 0.  When a packet
1481 		 *             : is received it is incremented. If this value
1482 		 *             : reaches 2 or more, a SACK is sent and the
1483 		 *             : value is reset to 0. Note: This is used only
1484 		 *             : when no DATA chunks are received out of
1485 		 *             : order.  When DATA chunks are out of order,
1486 		 *             : SACK's are not delayed (see Section 6).
1487 		 */
1488 		__u8    sack_needed;     /* Do we need to sack the peer? */
1489 		__u32	sack_cnt;
1490 		__u32	sack_generation;
1491 
1492 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1493 
1494 		struct sctp_inithdr_host i;
1495 		void *cookie;
1496 		int cookie_len;
1497 
1498 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1499 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1500 		 * Initial TSN Value minus 1
1501 		 */
1502 		__u32 addip_serial;
1503 
1504 		/* SCTP-AUTH: We need to know pears random number, hmac list
1505 		 * and authenticated chunk list.  All that is part of the
1506 		 * cookie and these are just pointers to those locations
1507 		 */
1508 		sctp_random_param_t *peer_random;
1509 		sctp_chunks_param_t *peer_chunks;
1510 		sctp_hmac_algo_param_t *peer_hmacs;
1511 	} peer;
1512 
1513 	/* State       : A state variable indicating what state the
1514 	 *	       : association is in, i.e. COOKIE-WAIT,
1515 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1516 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1517 	 *
1518 	 *		Note: No "CLOSED" state is illustrated since if a
1519 	 *		association is "CLOSED" its TCB SHOULD be removed.
1520 	 *
1521 	 *		In this implementation we DO have a CLOSED
1522 	 *		state which is used during initiation and shutdown.
1523 	 *
1524 	 *		State takes values from SCTP_STATE_*.
1525 	 */
1526 	sctp_state_t state;
1527 
1528 	/* Overall     : The overall association error count.
1529 	 * Error Count : [Clear this any time I get something.]
1530 	 */
1531 	int overall_error_count;
1532 
1533 	/* The cookie life I award for any cookie.  */
1534 	ktime_t cookie_life;
1535 
1536 	/* These are the association's initial, max, and min RTO values.
1537 	 * These values will be initialized by system defaults, but can
1538 	 * be modified via the SCTP_RTOINFO socket option.
1539 	 */
1540 	unsigned long rto_initial;
1541 	unsigned long rto_max;
1542 	unsigned long rto_min;
1543 
1544 	/* Maximum number of new data packets that can be sent in a burst.  */
1545 	int max_burst;
1546 
1547 	/* This is the max_retrans value for the association.  This value will
1548 	 * be initialized initialized from system defaults, but can be
1549 	 * modified by the SCTP_ASSOCINFO socket option.
1550 	 */
1551 	int max_retrans;
1552 
1553 	/* This is the partially failed retrans value for the transport
1554 	 * and will be initialized from the assocs value.  This can be
1555 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1556 	 */
1557 	int pf_retrans;
1558 
1559 	/* Maximum number of times the endpoint will retransmit INIT  */
1560 	__u16 max_init_attempts;
1561 
1562 	/* How many times have we resent an INIT? */
1563 	__u16 init_retries;
1564 
1565 	/* The largest timeout or RTO value to use in attempting an INIT */
1566 	unsigned long max_init_timeo;
1567 
1568 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1569 	 * the destination address every heartbeat interval. This value
1570 	 * will be inherited by all new transports.
1571 	 */
1572 	unsigned long hbinterval;
1573 
1574 	/* This is the max_retrans value for new transports in the
1575 	 * association.
1576 	 */
1577 	__u16 pathmaxrxt;
1578 
1579 	/* Flag that path mtu update is pending */
1580 	__u8   pmtu_pending;
1581 
1582 	/* Association : The smallest PMTU discovered for all of the
1583 	 * PMTU	       : peer's transport addresses.
1584 	 */
1585 	__u32 pathmtu;
1586 
1587 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1588 	__u32 param_flags;
1589 
1590 	__u32 sackfreq;
1591 	/* SACK delay timeout */
1592 	unsigned long sackdelay;
1593 
1594 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1595 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1596 
1597 	/* Transport to which SHUTDOWN chunk was last sent.  */
1598 	struct sctp_transport *shutdown_last_sent_to;
1599 
1600 	/* Transport to which INIT chunk was last sent.  */
1601 	struct sctp_transport *init_last_sent_to;
1602 
1603 	/* How many times have we resent a SHUTDOWN */
1604 	int shutdown_retries;
1605 
1606 	/* Next TSN    : The next TSN number to be assigned to a new
1607 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1608 	 *	       : ACK chunk to the peer and incremented each
1609 	 *	       : time a DATA chunk is assigned a TSN
1610 	 *	       : (normally just prior to transmit or during
1611 	 *	       : fragmentation).
1612 	 */
1613 	__u32 next_tsn;
1614 
1615 	/*
1616 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1617 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1618 	 *	       : received in the INIT or INIT ACK chunk, and
1619 	 *	       : subtracting one from it.
1620 	 *
1621 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1622 	 */
1623 
1624 	__u32 ctsn_ack_point;
1625 
1626 	/* PR-SCTP Advanced.Peer.Ack.Point */
1627 	__u32 adv_peer_ack_point;
1628 
1629 	/* Highest TSN that is acknowledged by incoming SACKs. */
1630 	__u32 highest_sacked;
1631 
1632 	/* TSN marking the fast recovery exit point */
1633 	__u32 fast_recovery_exit;
1634 
1635 	/* Flag to track the current fast recovery state */
1636 	__u8 fast_recovery;
1637 
1638 	/* The number of unacknowledged data chunks.  Reported through
1639 	 * the SCTP_STATUS sockopt.
1640 	 */
1641 	__u16 unack_data;
1642 
1643 	/* The total number of data chunks that we've had to retransmit
1644 	 * as the result of a T3 timer expiration
1645 	 */
1646 	__u32 rtx_data_chunks;
1647 
1648 	/* This is the association's receive buffer space.  This value is used
1649 	 * to set a_rwnd field in an INIT or a SACK chunk.
1650 	 */
1651 	__u32 rwnd;
1652 
1653 	/* This is the last advertised value of rwnd over a SACK chunk. */
1654 	__u32 a_rwnd;
1655 
1656 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1657 	 * to slop over a maximum of the association's frag_point.
1658 	 */
1659 	__u32 rwnd_over;
1660 
1661 	/* Keeps treack of rwnd pressure.  This happens when we have
1662 	 * a window, but not recevie buffer (i.e small packets).  This one
1663 	 * is releases slowly (1 PMTU at a time ).
1664 	 */
1665 	__u32 rwnd_press;
1666 
1667 	/* This is the sndbuf size in use for the association.
1668 	 * This corresponds to the sndbuf size for the association,
1669 	 * as specified in the sk->sndbuf.
1670 	 */
1671 	int sndbuf_used;
1672 
1673 	/* This is the amount of memory that this association has allocated
1674 	 * in the receive path at any given time.
1675 	 */
1676 	atomic_t rmem_alloc;
1677 
1678 	/* This is the wait queue head for send requests waiting on
1679 	 * the association sndbuf space.
1680 	 */
1681 	wait_queue_head_t	wait;
1682 
1683 	/* The message size at which SCTP fragmentation will occur. */
1684 	__u32 frag_point;
1685 	__u32 user_frag;
1686 
1687 	/* Counter used to count INIT errors. */
1688 	int init_err_counter;
1689 
1690 	/* Count the number of INIT cycles (for doubling timeout). */
1691 	int init_cycle;
1692 
1693 	/* Default send parameters. */
1694 	__u16 default_stream;
1695 	__u16 default_flags;
1696 	__u32 default_ppid;
1697 	__u32 default_context;
1698 	__u32 default_timetolive;
1699 
1700 	/* Default receive parameters */
1701 	__u32 default_rcv_context;
1702 
1703 	/* This tracks outbound ssn for a given stream.	 */
1704 	struct sctp_ssnmap *ssnmap;
1705 
1706 	/* All outbound chunks go through this structure.  */
1707 	struct sctp_outq outqueue;
1708 
1709 	/* A smart pipe that will handle reordering and fragmentation,
1710 	 * as well as handle passing events up to the ULP.
1711 	 */
1712 	struct sctp_ulpq ulpq;
1713 
1714 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1715 	__u32 last_ecne_tsn;
1716 
1717 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1718 	__u32 last_cwr_tsn;
1719 
1720 	/* How many duplicated TSNs have we seen?  */
1721 	int numduptsns;
1722 
1723 	/* These are to support
1724 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1725 	 *  and Enforcement of Flow and Message Limits"
1726 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1727 	 * or "ADDIP" for short.
1728 	 */
1729 
1730 
1731 
1732 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1733 	 *
1734 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1735 	 * unacknowledged at any one time.  If a sender, after sending
1736 	 * an ASCONF chunk, decides it needs to transfer another
1737 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1738 	 * returns from the previous ASCONF Chunk before sending a
1739 	 * subsequent ASCONF. Note this restriction binds each side,
1740 	 * so at any time two ASCONF may be in-transit on any given
1741 	 * association (one sent from each endpoint).
1742 	 *
1743 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1744 	 * not have an ASCONF in flight, this is NULL.]
1745 	 */
1746 	struct sctp_chunk *addip_last_asconf;
1747 
1748 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1749 	 *
1750 	 * This is needed to implement itmes E1 - E4 of the updated
1751 	 * spec.  Here is the justification:
1752 	 *
1753 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1754 	 * we now need the ability to cache multiple ACKs.  The section
1755 	 * describes in detail how they are cached and cleaned up.
1756 	 */
1757 	struct list_head asconf_ack_list;
1758 
1759 	/* These ASCONF chunks are waiting to be sent.
1760 	 *
1761 	 * These chunaks can't be pushed to outqueue until receiving
1762 	 * ASCONF_ACK for the previous ASCONF indicated by
1763 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1764 	 * is in flight at any time.
1765 	 *
1766 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1767 	 *
1768 	 * In defining the ASCONF Chunk transfer procedures, it is
1769 	 * essential that these transfers MUST NOT cause congestion
1770 	 * within the network.	To achieve this, we place these
1771 	 * restrictions on the transfer of ASCONF Chunks:
1772 	 *
1773 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1774 	 * unacknowledged at any one time.  If a sender, after sending
1775 	 * an ASCONF chunk, decides it needs to transfer another
1776 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1777 	 * returns from the previous ASCONF Chunk before sending a
1778 	 * subsequent ASCONF. Note this restriction binds each side,
1779 	 * so at any time two ASCONF may be in-transit on any given
1780 	 * association (one sent from each endpoint).
1781 	 *
1782 	 *
1783 	 * [I really think this is EXACTLY the sort of intelligence
1784 	 *  which already resides in sctp_outq.	 Please move this
1785 	 *  queue and its supporting logic down there.	--piggy]
1786 	 */
1787 	struct list_head addip_chunk_list;
1788 
1789 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1790 	 *
1791 	 * A2) A serial number should be assigned to the Chunk. The
1792 	 * serial number SHOULD be a monotonically increasing
1793 	 * number. The serial number SHOULD be initialized at
1794 	 * the start of the association to the same value as the
1795 	 * Initial TSN and every time a new ASCONF chunk is created
1796 	 * it is incremented by one after assigning the serial number
1797 	 * to the newly created chunk.
1798 	 *
1799 	 * ADDIP
1800 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1801 	 *
1802 	 * Serial Number : 32 bits (unsigned integer)
1803 	 *
1804 	 * This value represents a Serial Number for the ASCONF
1805 	 * Chunk. The valid range of Serial Number is from 0 to
1806 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1807 	 * after reaching 4294967295.
1808 	 */
1809 	__u32 addip_serial;
1810 	int src_out_of_asoc_ok;
1811 	union sctp_addr *asconf_addr_del_pending;
1812 	struct sctp_transport *new_transport;
1813 
1814 	/* SCTP AUTH: list of the endpoint shared keys.  These
1815 	 * keys are provided out of band by the user applicaton
1816 	 * and can't change during the lifetime of the association
1817 	 */
1818 	struct list_head endpoint_shared_keys;
1819 
1820 	/* SCTP AUTH:
1821 	 * The current generated assocaition shared key (secret)
1822 	 */
1823 	struct sctp_auth_bytes *asoc_shared_key;
1824 
1825 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1826 	 * that we support.
1827 	 */
1828 	__u16 default_hmac_id;
1829 
1830 	__u16 active_key_id;
1831 
1832 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1833 	     temp:1;		/* Is it a temporary association? */
1834 
1835 	struct sctp_priv_assoc_stats stats;
1836 };
1837 
1838 
1839 /* An eyecatcher for determining if we are really looking at an
1840  * association data structure.
1841  */
1842 enum {
1843 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1844 };
1845 
1846 /* Recover the outter association structure. */
1847 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1848 {
1849 	struct sctp_association *asoc;
1850 
1851 	asoc = container_of(base, struct sctp_association, base);
1852 	return asoc;
1853 }
1854 
1855 /* These are function signatures for manipulating associations.	 */
1856 
1857 
1858 struct sctp_association *
1859 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1860 		     sctp_scope_t scope, gfp_t gfp);
1861 void sctp_association_free(struct sctp_association *);
1862 void sctp_association_put(struct sctp_association *);
1863 void sctp_association_hold(struct sctp_association *);
1864 
1865 struct sctp_transport *sctp_assoc_choose_alter_transport(
1866 	struct sctp_association *, struct sctp_transport *);
1867 void sctp_assoc_update_retran_path(struct sctp_association *);
1868 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1869 					  const union sctp_addr *);
1870 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1871 			    const union sctp_addr *laddr);
1872 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1873 				     const union sctp_addr *address,
1874 				     const gfp_t gfp,
1875 				     const int peer_state);
1876 void sctp_assoc_del_peer(struct sctp_association *asoc,
1877 			 const union sctp_addr *addr);
1878 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1879 			 struct sctp_transport *peer);
1880 void sctp_assoc_control_transport(struct sctp_association *,
1881 				  struct sctp_transport *,
1882 				  sctp_transport_cmd_t, sctp_sn_error_t);
1883 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1884 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1885 					   struct net *,
1886 					   const union sctp_addr *,
1887 					   const union sctp_addr *);
1888 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1889 void sctp_assoc_update(struct sctp_association *old,
1890 		       struct sctp_association *new);
1891 
1892 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1893 
1894 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1895 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1896 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1897 void sctp_assoc_set_primary(struct sctp_association *,
1898 			    struct sctp_transport *);
1899 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1900 				    struct sctp_transport *);
1901 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1902 				     sctp_scope_t, gfp_t);
1903 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1904 					 struct sctp_cookie*,
1905 					 gfp_t gfp);
1906 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1907 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1908 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1909 					const struct sctp_association *asoc,
1910 					__be32 serial);
1911 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1912 
1913 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1914 			const union sctp_addr *ss2);
1915 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1916 
1917 /* A convenience structure to parse out SCTP specific CMSGs. */
1918 typedef struct sctp_cmsgs {
1919 	struct sctp_initmsg *init;
1920 	struct sctp_sndrcvinfo *info;
1921 } sctp_cmsgs_t;
1922 
1923 /* Structure for tracking memory objects */
1924 typedef struct {
1925 	char *label;
1926 	atomic_t *counter;
1927 } sctp_dbg_objcnt_entry_t;
1928 
1929 #endif /* __sctp_structs_h__ */
1930