xref: /openbmc/linux/include/net/sctp/structs.h (revision b34081f1)
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 <linux-sctp@vger.kernel.org>
29  *
30  * Written or modified by:
31  *    Randall Stewart	    <randall@sctp.chicago.il.us>
32  *    Ken Morneau	    <kmorneau@cisco.com>
33  *    Qiaobing Xie	    <qxie1@email.mot.com>
34  *    La Monte H.P. Yarroll <piggy@acm.org>
35  *    Karl Knutson	    <karl@athena.chicago.il.us>
36  *    Jon Grimm		    <jgrimm@us.ibm.com>
37  *    Xingang Guo	    <xingang.guo@intel.com>
38  *    Hui Huang		    <hui.huang@nokia.com>
39  *    Sridhar Samudrala	    <sri@us.ibm.com>
40  *    Daisy Chang	    <daisyc@us.ibm.com>
41  *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
42  *    Ardelle Fan	    <ardelle.fan@intel.com>
43  *    Ryan Layer	    <rmlayer@us.ibm.com>
44  *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
45  *    Kevin Gao             <kevin.gao@intel.com>
46  */
47 
48 #ifndef __sctp_structs_h__
49 #define __sctp_structs_h__
50 
51 #include <linux/ktime.h>
52 #include <linux/socket.h>	/* linux/in.h needs this!!    */
53 #include <linux/in.h>		/* We get struct sockaddr_in. */
54 #include <linux/in6.h>		/* We get struct in6_addr     */
55 #include <linux/ipv6.h>
56 #include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
57 #include <linux/atomic.h>		/* This gets us atomic counters.  */
58 #include <linux/skbuff.h>	/* We need sk_buff_head. */
59 #include <linux/workqueue.h>	/* We need tq_struct.	 */
60 #include <linux/sctp.h>		/* We need sctp* header structs.  */
61 #include <net/sctp/auth.h>	/* We need auth specific structs */
62 
63 /* A convenience structure for handling sockaddr structures.
64  * We should wean ourselves off this.
65  */
66 union sctp_addr {
67 	struct sockaddr_in v4;
68 	struct sockaddr_in6 v6;
69 	struct sockaddr sa;
70 };
71 
72 /* Forward declarations for data structures. */
73 struct sctp_globals;
74 struct sctp_endpoint;
75 struct sctp_association;
76 struct sctp_transport;
77 struct sctp_packet;
78 struct sctp_chunk;
79 struct sctp_inq;
80 struct sctp_outq;
81 struct sctp_bind_addr;
82 struct sctp_ulpq;
83 struct sctp_ep_common;
84 struct sctp_ssnmap;
85 struct crypto_hash;
86 
87 
88 #include <net/sctp/tsnmap.h>
89 #include <net/sctp/ulpevent.h>
90 #include <net/sctp/ulpqueue.h>
91 
92 /* Structures useful for managing bind/connect. */
93 
94 struct sctp_bind_bucket {
95 	unsigned short	port;
96 	unsigned short	fastreuse;
97 	struct hlist_node	node;
98 	struct hlist_head	owner;
99 	struct net	*net;
100 };
101 
102 struct sctp_bind_hashbucket {
103 	spinlock_t	lock;
104 	struct hlist_head	chain;
105 };
106 
107 /* Used for hashing all associations.  */
108 struct sctp_hashbucket {
109 	rwlock_t	lock;
110 	struct hlist_head	chain;
111 } __attribute__((__aligned__(8)));
112 
113 
114 /* The SCTP globals structure. */
115 extern struct sctp_globals {
116 	/* This is a list of groups of functions for each address
117 	 * family that we support.
118 	 */
119 	struct list_head address_families;
120 
121 	/* This is the hash of all endpoints. */
122 	struct sctp_hashbucket *ep_hashtable;
123 	/* This is the hash of all associations. */
124 	struct sctp_hashbucket *assoc_hashtable;
125 	/* This is the sctp port control hash.	*/
126 	struct sctp_bind_hashbucket *port_hashtable;
127 
128 	/* Sizes of above hashtables. */
129 	int ep_hashsize;
130 	int assoc_hashsize;
131 	int port_hashsize;
132 
133 	/* Default initialization values to be applied to new associations. */
134 	__u16 max_instreams;
135 	__u16 max_outstreams;
136 
137 	/* Flag to indicate whether computing and verifying checksum
138 	 * is disabled. */
139         bool checksum_disable;
140 } sctp_globals;
141 
142 #define sctp_max_instreams		(sctp_globals.max_instreams)
143 #define sctp_max_outstreams		(sctp_globals.max_outstreams)
144 #define sctp_address_families		(sctp_globals.address_families)
145 #define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
146 #define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
147 #define sctp_assoc_hashsize		(sctp_globals.assoc_hashsize)
148 #define sctp_assoc_hashtable		(sctp_globals.assoc_hashtable)
149 #define sctp_port_hashsize		(sctp_globals.port_hashsize)
150 #define sctp_port_hashtable		(sctp_globals.port_hashtable)
151 #define sctp_checksum_disable		(sctp_globals.checksum_disable)
152 
153 /* SCTP Socket type: UDP or TCP style. */
154 typedef enum {
155 	SCTP_SOCKET_UDP = 0,
156 	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
157 	SCTP_SOCKET_TCP
158 } sctp_socket_type_t;
159 
160 /* Per socket SCTP information. */
161 struct sctp_sock {
162 	/* inet_sock has to be the first member of sctp_sock */
163 	struct inet_sock inet;
164 	/* What kind of a socket is this? */
165 	sctp_socket_type_t type;
166 
167 	/* PF_ family specific functions.  */
168 	struct sctp_pf *pf;
169 
170 	/* Access to HMAC transform. */
171 	struct crypto_hash *hmac;
172 	char *sctp_hmac_alg;
173 
174 	/* What is our base endpointer? */
175 	struct sctp_endpoint *ep;
176 
177 	struct sctp_bind_bucket *bind_hash;
178 	/* Various Socket Options.  */
179 	__u16 default_stream;
180 	__u32 default_ppid;
181 	__u16 default_flags;
182 	__u32 default_context;
183 	__u32 default_timetolive;
184 	__u32 default_rcv_context;
185 	int max_burst;
186 
187 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
188 	 * the destination address every heartbeat interval. This value
189 	 * will be inherited by all new associations.
190 	 */
191 	__u32 hbinterval;
192 
193 	/* This is the max_retrans value for new associations. */
194 	__u16 pathmaxrxt;
195 
196 	/* The initial Path MTU to use for new associations. */
197 	__u32 pathmtu;
198 
199 	/* The default SACK delay timeout for new associations. */
200 	__u32 sackdelay;
201 	__u32 sackfreq;
202 
203 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
204 	__u32 param_flags;
205 
206 	struct sctp_initmsg initmsg;
207 	struct sctp_rtoinfo rtoinfo;
208 	struct sctp_paddrparams paddrparam;
209 	struct sctp_event_subscribe subscribe;
210 	struct sctp_assocparams assocparams;
211 	int user_frag;
212 	__u32 autoclose;
213 	__u8 nodelay;
214 	__u8 disable_fragments;
215 	__u8 v4mapped;
216 	__u8 frag_interleave;
217 	__u32 adaptation_ind;
218 	__u32 pd_point;
219 
220 	atomic_t pd_mode;
221 	/* Receive to here while partial delivery is in effect. */
222 	struct sk_buff_head pd_lobby;
223 	struct list_head auto_asconf_list;
224 	int do_auto_asconf;
225 };
226 
227 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
228 {
229        return (struct sctp_sock *)sk;
230 }
231 
232 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
233 {
234        return (struct sock *)sp;
235 }
236 
237 #if IS_ENABLED(CONFIG_IPV6)
238 struct sctp6_sock {
239        struct sctp_sock  sctp;
240        struct ipv6_pinfo inet6;
241 };
242 #endif /* CONFIG_IPV6 */
243 
244 
245 /* This is our APPLICATION-SPECIFIC state cookie.
246  * THIS IS NOT DICTATED BY THE SPECIFICATION.
247  */
248 /* These are the parts of an association which we send in the cookie.
249  * Most of these are straight out of:
250  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
251  *
252  */
253 
254 struct sctp_cookie {
255 
256 	/* My	       : Tag expected in every inbound packet and sent
257 	 * Verification: in the INIT or INIT ACK chunk.
258 	 * Tag	       :
259 	 */
260 	__u32 my_vtag;
261 
262 	/* Peer's      : Tag expected in every outbound packet except
263 	 * Verification: in the INIT chunk.
264 	 * Tag	       :
265 	 */
266 	__u32 peer_vtag;
267 
268 	/* The rest of these are not from the spec, but really need to
269 	 * be in the cookie.
270 	 */
271 
272 	/* My Tie Tag  : Assist in discovering a restarting association. */
273 	__u32 my_ttag;
274 
275 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
276 	__u32 peer_ttag;
277 
278 	/* When does this cookie expire? */
279 	ktime_t expiration;
280 
281 	/* Number of inbound/outbound streams which are set
282 	 * and negotiated during the INIT process.
283 	 */
284 	__u16 sinit_num_ostreams;
285 	__u16 sinit_max_instreams;
286 
287 	/* This is the first sequence number I used.  */
288 	__u32 initial_tsn;
289 
290 	/* This holds the originating address of the INIT packet.  */
291 	union sctp_addr peer_addr;
292 
293 	/* IG Section 2.35.3
294 	 * Include the source port of the INIT-ACK
295 	 */
296 	__u16		my_port;
297 
298 	__u8 prsctp_capable;
299 
300 	/* Padding for future use */
301 	__u8 padding;
302 
303 	__u32 adaptation_ind;
304 
305 	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
306 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
307 	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
308 
309 	/* This is a shim for my peer's INIT packet, followed by
310 	 * a copy of the raw address list of the association.
311 	 * The length of the raw address list is saved in the
312 	 * raw_addr_list_len field, which will be used at the time when
313 	 * the association TCB is re-constructed from the cookie.
314 	 */
315 	__u32 raw_addr_list_len;
316 	struct sctp_init_chunk peer_init[0];
317 };
318 
319 
320 /* The format of our cookie that we send to our peer. */
321 struct sctp_signed_cookie {
322 	__u8 signature[SCTP_SECRET_SIZE];
323 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
324 	struct sctp_cookie c;
325 } __packed;
326 
327 /* This is another convenience type to allocate memory for address
328  * params for the maximum size and pass such structures around
329  * internally.
330  */
331 union sctp_addr_param {
332 	struct sctp_paramhdr p;
333 	struct sctp_ipv4addr_param v4;
334 	struct sctp_ipv6addr_param v6;
335 };
336 
337 /* A convenience type to allow walking through the various
338  * parameters and avoid casting all over the place.
339  */
340 union sctp_params {
341 	void *v;
342 	struct sctp_paramhdr *p;
343 	struct sctp_cookie_preserve_param *life;
344 	struct sctp_hostname_param *dns;
345 	struct sctp_cookie_param *cookie;
346 	struct sctp_supported_addrs_param *sat;
347 	struct sctp_ipv4addr_param *v4;
348 	struct sctp_ipv6addr_param *v6;
349 	union sctp_addr_param *addr;
350 	struct sctp_adaptation_ind_param *aind;
351 	struct sctp_supported_ext_param *ext;
352 	struct sctp_random_param *random;
353 	struct sctp_chunks_param *chunks;
354 	struct sctp_hmac_algo_param *hmac_algo;
355 	struct sctp_addip_param *addip;
356 };
357 
358 /* RFC 2960.  Section 3.3.5 Heartbeat.
359  *    Heartbeat Information: variable length
360  *    The Sender-specific Heartbeat Info field should normally include
361  *    information about the sender's current time when this HEARTBEAT
362  *    chunk is sent and the destination transport address to which this
363  *    HEARTBEAT is sent (see Section 8.3).
364  */
365 typedef struct sctp_sender_hb_info {
366 	struct sctp_paramhdr param_hdr;
367 	union sctp_addr daddr;
368 	unsigned long sent_at;
369 	__u64 hb_nonce;
370 } __packed sctp_sender_hb_info_t;
371 
372 /*
373  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
374  *
375  *  The term "stream" is used in SCTP to refer to a sequence of user
376  *  messages that are to be delivered to the upper-layer protocol in
377  *  order with respect to other messages within the same stream.  This is
378  *  in contrast to its usage in TCP, where it refers to a sequence of
379  *  bytes (in this document a byte is assumed to be eight bits).
380  *  ...
381  *
382  *  This is the structure we use to track both our outbound and inbound
383  *  SSN, or Stream Sequence Numbers.
384  */
385 
386 struct sctp_stream {
387 	__u16 *ssn;
388 	unsigned int len;
389 };
390 
391 struct sctp_ssnmap {
392 	struct sctp_stream in;
393 	struct sctp_stream out;
394 };
395 
396 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
397 				    gfp_t gfp);
398 void sctp_ssnmap_free(struct sctp_ssnmap *map);
399 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
400 
401 /* What is the current SSN number for this stream? */
402 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
403 {
404 	return stream->ssn[id];
405 }
406 
407 /* Return the next SSN number for this stream.	*/
408 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
409 {
410 	return stream->ssn[id]++;
411 }
412 
413 /* Skip over this ssn and all below. */
414 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
415 				 __u16 ssn)
416 {
417 	stream->ssn[id] = ssn+1;
418 }
419 
420 /*
421  * Pointers to address related SCTP functions.
422  * (i.e. things that depend on the address family.)
423  */
424 struct sctp_af {
425 	int		(*sctp_xmit)	(struct sk_buff *skb,
426 					 struct sctp_transport *);
427 	int		(*setsockopt)	(struct sock *sk,
428 					 int level,
429 					 int optname,
430 					 char __user *optval,
431 					 unsigned int optlen);
432 	int		(*getsockopt)	(struct sock *sk,
433 					 int level,
434 					 int optname,
435 					 char __user *optval,
436 					 int __user *optlen);
437 	int		(*compat_setsockopt)	(struct sock *sk,
438 					 int level,
439 					 int optname,
440 					 char __user *optval,
441 					 unsigned int optlen);
442 	int		(*compat_getsockopt)	(struct sock *sk,
443 					 int level,
444 					 int optname,
445 					 char __user *optval,
446 					 int __user *optlen);
447 	void		(*get_dst)	(struct sctp_transport *t,
448 					 union sctp_addr *saddr,
449 					 struct flowi *fl,
450 					 struct sock *sk);
451 	void		(*get_saddr)	(struct sctp_sock *sk,
452 					 struct sctp_transport *t,
453 					 struct flowi *fl);
454 	void		(*copy_addrlist) (struct list_head *,
455 					  struct net_device *);
456 	int		(*cmp_addr)	(const union sctp_addr *addr1,
457 					 const union sctp_addr *addr2);
458 	void		(*addr_copy)	(union sctp_addr *dst,
459 					 union sctp_addr *src);
460 	void		(*from_skb)	(union sctp_addr *,
461 					 struct sk_buff *skb,
462 					 int saddr);
463 	void		(*from_sk)	(union sctp_addr *,
464 					 struct sock *sk);
465 	void		(*to_sk_saddr)	(union sctp_addr *,
466 					 struct sock *sk);
467 	void		(*to_sk_daddr)	(union sctp_addr *,
468 					 struct sock *sk);
469 	void		(*from_addr_param) (union sctp_addr *,
470 					    union sctp_addr_param *,
471 					    __be16 port, int iif);
472 	int		(*to_addr_param) (const union sctp_addr *,
473 					  union sctp_addr_param *);
474 	int		(*addr_valid)	(union sctp_addr *,
475 					 struct sctp_sock *,
476 					 const struct sk_buff *);
477 	sctp_scope_t	(*scope) (union sctp_addr *);
478 	void		(*inaddr_any)	(union sctp_addr *, __be16);
479 	int		(*is_any)	(const union sctp_addr *);
480 	int		(*available)	(union sctp_addr *,
481 					 struct sctp_sock *);
482 	int		(*skb_iif)	(const struct sk_buff *sk);
483 	int		(*is_ce)	(const struct sk_buff *sk);
484 	void		(*seq_dump_addr)(struct seq_file *seq,
485 					 union sctp_addr *addr);
486 	void		(*ecn_capable)(struct sock *sk);
487 	__u16		net_header_len;
488 	int		sockaddr_len;
489 	sa_family_t	sa_family;
490 	struct list_head list;
491 };
492 
493 struct sctp_af *sctp_get_af_specific(sa_family_t);
494 int sctp_register_af(struct sctp_af *);
495 
496 /* Protocol family functions. */
497 struct sctp_pf {
498 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
499 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
500 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
501 	int  (*cmp_addr) (const union sctp_addr *,
502 			  const union sctp_addr *,
503 			  struct sctp_sock *);
504 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
505 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
506 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
507 	struct sock *(*create_accept_sk) (struct sock *sk,
508 					  struct sctp_association *asoc);
509 	void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
510 	struct sctp_af *af;
511 };
512 
513 
514 /* Structure to track chunk fragments that have been acked, but peer
515  * fragments of the same message have not.
516  */
517 struct sctp_datamsg {
518 	/* Chunks waiting to be submitted to lower layer. */
519 	struct list_head chunks;
520 	/* Reference counting. */
521 	atomic_t refcnt;
522 	/* When is this message no longer interesting to the peer? */
523 	unsigned long expires_at;
524 	/* Did the messenge fail to send? */
525 	int send_error;
526 	u8 send_failed:1,
527 	   can_abandon:1,   /* can chunks from this message can be abandoned. */
528 	   can_delay;	    /* should this message be Nagle delayed */
529 };
530 
531 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
532 					    struct sctp_sndrcvinfo *,
533 					    struct msghdr *, int len);
534 void sctp_datamsg_free(struct sctp_datamsg *);
535 void sctp_datamsg_put(struct sctp_datamsg *);
536 void sctp_chunk_fail(struct sctp_chunk *, int error);
537 int sctp_chunk_abandoned(struct sctp_chunk *);
538 
539 /* RFC2960 1.4 Key Terms
540  *
541  * o Chunk: A unit of information within an SCTP packet, consisting of
542  * a chunk header and chunk-specific content.
543  *
544  * As a matter of convenience, we remember the SCTP common header for
545  * each chunk as well as a few other header pointers...
546  */
547 struct sctp_chunk {
548 	struct list_head list;
549 
550 	atomic_t refcnt;
551 
552 	/* This is our link to the per-transport transmitted list.  */
553 	struct list_head transmitted_list;
554 
555 	/* This field is used by chunks that hold fragmented data.
556 	 * For the first fragment this is the list that holds the rest of
557 	 * fragments. For the remaining fragments, this is the link to the
558 	 * frag_list maintained in the first fragment.
559 	 */
560 	struct list_head frag_list;
561 
562 	/* This points to the sk_buff containing the actual data.  */
563 	struct sk_buff *skb;
564 
565 	/* These are the SCTP headers by reverse order in a packet.
566 	 * Note that some of these may happen more than once.  In that
567 	 * case, we point at the "current" one, whatever that means
568 	 * for that level of header.
569 	 */
570 
571 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
572 	union sctp_params param_hdr;
573 	union {
574 		__u8 *v;
575 		struct sctp_datahdr *data_hdr;
576 		struct sctp_inithdr *init_hdr;
577 		struct sctp_sackhdr *sack_hdr;
578 		struct sctp_heartbeathdr *hb_hdr;
579 		struct sctp_sender_hb_info *hbs_hdr;
580 		struct sctp_shutdownhdr *shutdown_hdr;
581 		struct sctp_signed_cookie *cookie_hdr;
582 		struct sctp_ecnehdr *ecne_hdr;
583 		struct sctp_cwrhdr *ecn_cwr_hdr;
584 		struct sctp_errhdr *err_hdr;
585 		struct sctp_addiphdr *addip_hdr;
586 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
587 		struct sctp_authhdr *auth_hdr;
588 	} subh;
589 
590 	__u8 *chunk_end;
591 
592 	struct sctp_chunkhdr *chunk_hdr;
593 	struct sctphdr *sctp_hdr;
594 
595 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
596 	struct sctp_sndrcvinfo sinfo;
597 
598 	/* Which association does this belong to?  */
599 	struct sctp_association *asoc;
600 
601 	/* What endpoint received this chunk? */
602 	struct sctp_ep_common *rcvr;
603 
604 	/* We fill this in if we are calculating RTT. */
605 	unsigned long sent_at;
606 
607 	/* What is the origin IP address for this chunk?  */
608 	union sctp_addr source;
609 	/* Destination address for this chunk. */
610 	union sctp_addr dest;
611 
612 	/* For outbound message, track all fragments for SEND_FAILED. */
613 	struct sctp_datamsg *msg;
614 
615 	/* For an inbound chunk, this tells us where it came from.
616 	 * For an outbound chunk, it tells us where we'd like it to
617 	 * go.	It is NULL if we have no preference.
618 	 */
619 	struct sctp_transport *transport;
620 
621 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
622 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
623 	 * spec violates the principle premis that all chunks are processed
624 	 * in order.
625 	 */
626 	struct sk_buff *auth_chunk;
627 
628 #define SCTP_CAN_FRTX 0x0
629 #define SCTP_NEED_FRTX 0x1
630 #define SCTP_DONT_FRTX 0x2
631 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
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 void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
653 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
654 				 const struct sctp_association *,
655 				 struct sock *);
656 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
657 		     union sctp_addr *);
658 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
659 
660 enum {
661 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
662 	SCTP_ADDR_SRC,		/* address can be used as source */
663 	SCTP_ADDR_DEL,		/* address about to be deleted */
664 };
665 
666 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
667 struct sctp_sockaddr_entry {
668 	struct list_head list;
669 	struct rcu_head	rcu;
670 	union sctp_addr a;
671 	__u8 state;
672 	__u8 valid;
673 };
674 
675 #define SCTP_ADDRESS_TICK_DELAY	500
676 
677 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
678 
679 /* This structure holds lists of chunks as we are assembling for
680  * transmission.
681  */
682 struct sctp_packet {
683 	/* These are the SCTP header values (host order) for the packet. */
684 	__u16 source_port;
685 	__u16 destination_port;
686 	__u32 vtag;
687 
688 	/* This contains the payload chunks.  */
689 	struct list_head chunk_list;
690 
691 	/* This is the overhead of the sctp and ip headers. */
692 	size_t overhead;
693 	/* This is the total size of all chunks INCLUDING padding.  */
694 	size_t size;
695 
696 	/* The packet is destined for this transport address.
697 	 * The function we finally use to pass down to the next lower
698 	 * layer lives in the transport structure.
699 	 */
700 	struct sctp_transport *transport;
701 
702 	/* pointer to the auth chunk for this packet */
703 	struct sctp_chunk *auth;
704 
705 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
706 	    has_sack:1,		/* This packet contains a SACK chunk. */
707 	    has_auth:1,		/* This packet contains an AUTH chunk */
708 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
709 	    ipfragok:1;		/* So let ip fragment this packet */
710 };
711 
712 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
713 				     struct sctp_transport *,
714 				     __u16 sport, __u16 dport);
715 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
716 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
717                                        struct sctp_chunk *, int);
718 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
719                                      struct sctp_chunk *);
720 int sctp_packet_transmit(struct sctp_packet *);
721 void sctp_packet_free(struct sctp_packet *);
722 
723 static inline int sctp_packet_empty(struct sctp_packet *packet)
724 {
725 	return packet->size == packet->overhead;
726 }
727 
728 /* This represents a remote transport address.
729  * For local transport addresses, we just use union sctp_addr.
730  *
731  * RFC2960 Section 1.4 Key Terms
732  *
733  *   o	Transport address:  A Transport Address is traditionally defined
734  *	by Network Layer address, Transport Layer protocol and Transport
735  *	Layer port number.  In the case of SCTP running over IP, a
736  *	transport address is defined by the combination of an IP address
737  *	and an SCTP port number (where SCTP is the Transport protocol).
738  *
739  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
740  *
741  *   o	The sender keeps a separate congestion control parameter set for
742  *	each of the destination addresses it can send to (not each
743  *	source-destination pair but for each destination).  The parameters
744  *	should decay if the address is not used for a long enough time
745  *	period.
746  *
747  */
748 struct sctp_transport {
749 	/* A list of transports. */
750 	struct list_head transports;
751 
752 	/* Reference counting. */
753 	atomic_t refcnt;
754 	__u32	 dead:1,
755 		/* RTO-Pending : A flag used to track if one of the DATA
756 		 *		chunks sent to this address is currently being
757 		 *		used to compute a RTT. If this flag is 0,
758 		 *		the next DATA chunk sent to this destination
759 		 *		should be used to compute a RTT and this flag
760 		 *		should be set. Every time the RTT
761 		 *		calculation completes (i.e. the DATA chunk
762 		 *		is SACK'd) clear this flag.
763 		 */
764 		 rto_pending:1,
765 
766 		/*
767 		 * hb_sent : a flag that signals that we have a pending
768 		 * heartbeat.
769 		 */
770 		hb_sent:1,
771 
772 		/* Is the Path MTU update pending on this tranport */
773 		pmtu_pending:1;
774 
775 	/* Has this transport moved the ctsn since we last sacked */
776 	__u32 sack_generation;
777 	u32 dst_cookie;
778 
779 	struct flowi fl;
780 
781 	/* This is the peer's IP address and port. */
782 	union sctp_addr ipaddr;
783 
784 	/* These are the functions we call to handle LLP stuff.	 */
785 	struct sctp_af *af_specific;
786 
787 	/* Which association do we belong to?  */
788 	struct sctp_association *asoc;
789 
790 	/* RFC2960
791 	 *
792 	 * 12.3 Per Transport Address Data
793 	 *
794 	 * For each destination transport address in the peer's
795 	 * address list derived from the INIT or INIT ACK chunk, a
796 	 * number of data elements needs to be maintained including:
797 	 */
798 	/* RTO	       : The current retransmission timeout value.  */
799 	unsigned long rto;
800 
801 	__u32 rtt;		/* This is the most recent RTT.	 */
802 
803 	/* RTTVAR      : The current RTT variation.  */
804 	__u32 rttvar;
805 
806 	/* SRTT	       : The current smoothed round trip time.	*/
807 	__u32 srtt;
808 
809 	/*
810 	 * These are the congestion stats.
811 	 */
812 	/* cwnd	       : The current congestion window.	 */
813 	__u32 cwnd;		  /* This is the actual cwnd.  */
814 
815 	/* ssthresh    : The current slow start threshold value.  */
816 	__u32 ssthresh;
817 
818 	/* partial     : The tracking method for increase of cwnd when in
819 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
820 	 */
821 	__u32 partial_bytes_acked;
822 
823 	/* Data that has been sent, but not acknowledged. */
824 	__u32 flight_size;
825 
826 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
827 
828 	/* Destination */
829 	struct dst_entry *dst;
830 	/* Source address. */
831 	union sctp_addr saddr;
832 
833 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
834 	 * the destination address every heartbeat interval.
835 	 */
836 	unsigned long hbinterval;
837 
838 	/* SACK delay timeout */
839 	unsigned long sackdelay;
840 	__u32 sackfreq;
841 
842 	/* When was the last time (in jiffies) that we heard from this
843 	 * transport?  We use this to pick new active and retran paths.
844 	 */
845 	unsigned long last_time_heard;
846 
847 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
848 	 * indication based on ECNE chunk.
849 	 */
850 	unsigned long last_time_ecne_reduced;
851 
852 	/* This is the max_retrans value for the transport and will
853 	 * be initialized from the assocs value.  This can be changed
854 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
855 	 */
856 	__u16 pathmaxrxt;
857 
858 	/* This is the partially failed retrans value for the transport
859 	 * and will be initialized from the assocs value.  This can be changed
860 	 * using the SCTP_PEER_ADDR_THLDS socket option
861 	 */
862 	int pf_retrans;
863 	/* PMTU	      : The current known path MTU.  */
864 	__u32 pathmtu;
865 
866 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
867 	__u32 param_flags;
868 
869 	/* The number of times INIT has been sent on this transport. */
870 	int init_sent_count;
871 
872 	/* state       : The current state of this destination,
873 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
874 	 */
875 	int state;
876 
877 	/* These are the error stats for this destination.  */
878 
879 	/* Error count : The current error count for this destination.	*/
880 	unsigned short error_count;
881 
882 	/* Per	       : A timer used by each destination.
883 	 * Destination :
884 	 * Timer       :
885 	 *
886 	 * [Everywhere else in the text this is called T3-rtx. -ed]
887 	 */
888 	struct timer_list T3_rtx_timer;
889 
890 	/* Heartbeat timer is per destination. */
891 	struct timer_list hb_timer;
892 
893 	/* Timer to handle ICMP proto unreachable envets */
894 	struct timer_list proto_unreach_timer;
895 
896 	/* Since we're using per-destination retransmission timers
897 	 * (see above), we're also using per-destination "transmitted"
898 	 * queues.  This probably ought to be a private struct
899 	 * accessible only within the outqueue, but it's not, yet.
900 	 */
901 	struct list_head transmitted;
902 
903 	/* We build bundle-able packets for this transport here.  */
904 	struct sctp_packet packet;
905 
906 	/* This is the list of transports that have chunks to send.  */
907 	struct list_head send_ready;
908 
909 	/* State information saved for SFR_CACC algorithm. The key
910 	 * idea in SFR_CACC is to maintain state at the sender on a
911 	 * per-destination basis when a changeover happens.
912 	 *	char changeover_active;
913 	 *	char cycling_changeover;
914 	 *	__u32 next_tsn_at_change;
915 	 *	char cacc_saw_newack;
916 	 */
917 	struct {
918 		/* An unsigned integer, which stores the next TSN to be
919 		 * used by the sender, at the moment of changeover.
920 		 */
921 		__u32 next_tsn_at_change;
922 
923 		/* A flag which indicates the occurrence of a changeover */
924 		char changeover_active;
925 
926 		/* A flag which indicates whether the change of primary is
927 		 * the first switch to this destination address during an
928 		 * active switch.
929 		 */
930 		char cycling_changeover;
931 
932 		/* A temporary flag, which is used during the processing of
933 		 * a SACK to estimate the causative TSN(s)'s group.
934 		 */
935 		char cacc_saw_newack;
936 	} cacc;
937 
938 	/* 64-bit random number sent with heartbeat. */
939 	__u64 hb_nonce;
940 
941 	struct rcu_head rcu;
942 };
943 
944 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
945 					  gfp_t);
946 void sctp_transport_set_owner(struct sctp_transport *,
947 			      struct sctp_association *);
948 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
949 			  struct sctp_sock *);
950 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
951 void sctp_transport_free(struct sctp_transport *);
952 void sctp_transport_reset_timers(struct sctp_transport *);
953 void sctp_transport_hold(struct sctp_transport *);
954 void sctp_transport_put(struct sctp_transport *);
955 void sctp_transport_update_rto(struct sctp_transport *, __u32);
956 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
957 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
958 void sctp_transport_burst_limited(struct sctp_transport *);
959 void sctp_transport_burst_reset(struct sctp_transport *);
960 unsigned long sctp_transport_timeout(struct sctp_transport *);
961 void sctp_transport_reset(struct sctp_transport *);
962 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
963 void sctp_transport_immediate_rtx(struct sctp_transport *);
964 
965 
966 /* This is the structure we use to queue packets as they come into
967  * SCTP.  We write packets to it and read chunks from it.
968  */
969 struct sctp_inq {
970 	/* This is actually a queue of sctp_chunk each
971 	 * containing a partially decoded packet.
972 	 */
973 	struct list_head in_chunk_list;
974 	/* This is the packet which is currently off the in queue and is
975 	 * being worked on through the inbound chunk processing.
976 	 */
977 	struct sctp_chunk *in_progress;
978 
979 	/* This is the delayed task to finish delivering inbound
980 	 * messages.
981 	 */
982 	struct work_struct immediate;
983 };
984 
985 void sctp_inq_init(struct sctp_inq *);
986 void sctp_inq_free(struct sctp_inq *);
987 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
988 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
989 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
990 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
991 
992 /* This is the structure we use to hold outbound chunks.  You push
993  * chunks in and they automatically pop out the other end as bundled
994  * packets (it calls (*output_handler)()).
995  *
996  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
997  * and 8.2 of the v13 draft.
998  *
999  * It handles retransmissions.	The connection to the timeout portion
1000  * of the state machine is through sctp_..._timeout() and timeout_handler.
1001  *
1002  * If you feed it SACKs, it will eat them.
1003  *
1004  * If you give it big chunks, it will fragment them.
1005  *
1006  * It assigns TSN's to data chunks.  This happens at the last possible
1007  * instant before transmission.
1008  *
1009  * When free()'d, it empties itself out via output_handler().
1010  */
1011 struct sctp_outq {
1012 	struct sctp_association *asoc;
1013 
1014 	/* Data pending that has never been transmitted.  */
1015 	struct list_head out_chunk_list;
1016 
1017 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1018 
1019 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1020 	unsigned int error;
1021 
1022 	/* These are control chunks we want to send.  */
1023 	struct list_head control_chunk_list;
1024 
1025 	/* These are chunks that have been sacked but are above the
1026 	 * CTSN, or cumulative tsn ack point.
1027 	 */
1028 	struct list_head sacked;
1029 
1030 	/* Put chunks on this list to schedule them for
1031 	 * retransmission.
1032 	 */
1033 	struct list_head retransmit;
1034 
1035 	/* Put chunks on this list to save them for FWD TSN processing as
1036 	 * they were abandoned.
1037 	 */
1038 	struct list_head abandoned;
1039 
1040 	/* How many unackd bytes do we have in-flight?	*/
1041 	__u32 outstanding_bytes;
1042 
1043 	/* Are we doing fast-rtx on this queue */
1044 	char fast_rtx;
1045 
1046 	/* Corked? */
1047 	char cork;
1048 
1049 	/* Is this structure empty?  */
1050 	char empty;
1051 };
1052 
1053 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1054 void sctp_outq_teardown(struct sctp_outq *);
1055 void sctp_outq_free(struct sctp_outq*);
1056 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1057 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1058 int sctp_outq_is_empty(const struct sctp_outq *);
1059 void sctp_outq_restart(struct sctp_outq *);
1060 
1061 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1062 		     sctp_retransmit_reason_t);
1063 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1064 int sctp_outq_uncork(struct sctp_outq *);
1065 /* Uncork and flush an outqueue.  */
1066 static inline void sctp_outq_cork(struct sctp_outq *q)
1067 {
1068 	q->cork = 1;
1069 }
1070 
1071 /* These bind address data fields common between endpoints and associations */
1072 struct sctp_bind_addr {
1073 
1074 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1075 	 *
1076 	 * SCTP Port:	The local SCTP port number the endpoint is
1077 	 *		bound to.
1078 	 */
1079 	__u16 port;
1080 
1081 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1082 	 *
1083 	 * Address List: The list of IP addresses that this instance
1084 	 *	has bound.  This information is passed to one's
1085 	 *	peer(s) in INIT and INIT ACK chunks.
1086 	 */
1087 	struct list_head address_list;
1088 };
1089 
1090 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1091 void sctp_bind_addr_free(struct sctp_bind_addr *);
1092 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1093 			const struct sctp_bind_addr *src,
1094 			sctp_scope_t scope, gfp_t gfp,
1095 			int flags);
1096 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1097 			const struct sctp_bind_addr *src,
1098 			gfp_t gfp);
1099 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1100 		       __u8 addr_state, gfp_t gfp);
1101 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1102 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1103 			 struct sctp_sock *);
1104 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1105 			 struct sctp_sock *, struct sctp_sock *);
1106 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1107 			 const union sctp_addr *addr);
1108 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1109 					const union sctp_addr	*addrs,
1110 					int			addrcnt,
1111 					struct sctp_sock	*opt);
1112 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1113 					 int *addrs_len,
1114 					 gfp_t gfp);
1115 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1116 			   __u16 port, gfp_t gfp);
1117 
1118 sctp_scope_t sctp_scope(const union sctp_addr *);
1119 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1120 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1121 int sctp_addr_is_valid(const union sctp_addr *addr);
1122 int sctp_is_ep_boundall(struct sock *sk);
1123 
1124 
1125 /* What type of endpoint?  */
1126 typedef enum {
1127 	SCTP_EP_TYPE_SOCKET,
1128 	SCTP_EP_TYPE_ASSOCIATION,
1129 } sctp_endpoint_type_t;
1130 
1131 /*
1132  * A common base class to bridge the implmentation view of a
1133  * socket (usually listening) endpoint versus an association's
1134  * local endpoint.
1135  * This common structure is useful for several purposes:
1136  *   1) Common interface for lookup routines.
1137  *	a) Subfunctions work for either endpoint or association
1138  *	b) Single interface to lookup allows hiding the lookup lock rather
1139  *	   than acquiring it externally.
1140  *   2) Common interface for the inbound chunk handling/state machine.
1141  *   3) Common object handling routines for reference counting, etc.
1142  *   4) Disentangle association lookup from endpoint lookup, where we
1143  *	do not have to find our endpoint to find our association.
1144  *
1145  */
1146 
1147 struct sctp_ep_common {
1148 	/* Fields to help us manage our entries in the hash tables. */
1149 	struct hlist_node node;
1150 	int hashent;
1151 
1152 	/* Runtime type information.  What kind of endpoint is this? */
1153 	sctp_endpoint_type_t type;
1154 
1155 	/* Some fields to help us manage this object.
1156 	 *   refcnt   - Reference count access to this object.
1157 	 *   dead     - Do not attempt to use this object.
1158 	 */
1159 	atomic_t    refcnt;
1160 	bool	    dead;
1161 
1162 	/* What socket does this endpoint belong to?  */
1163 	struct sock *sk;
1164 
1165 	/* This is where we receive inbound chunks.  */
1166 	struct sctp_inq	  inqueue;
1167 
1168 	/* This substructure includes the defining parameters of the
1169 	 * endpoint:
1170 	 * bind_addr.port is our shared port number.
1171 	 * bind_addr.address_list is our set of local IP addresses.
1172 	 */
1173 	struct sctp_bind_addr bind_addr;
1174 };
1175 
1176 
1177 /* RFC Section 1.4 Key Terms
1178  *
1179  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1180  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1181  *   combination of a set of eligible destination transport addresses to
1182  *   which SCTP packets can be sent and a set of eligible source
1183  *   transport addresses from which SCTP packets can be received.
1184  *   All transport addresses used by an SCTP endpoint must use the
1185  *   same port number, but can use multiple IP addresses. A transport
1186  *   address used by an SCTP endpoint must not be used by another
1187  *   SCTP endpoint. In other words, a transport address is unique
1188  *   to an SCTP endpoint.
1189  *
1190  * From an implementation perspective, each socket has one of these.
1191  * A TCP-style socket will have exactly one association on one of
1192  * these.  An UDP-style socket will have multiple associations hanging
1193  * off one of these.
1194  */
1195 
1196 struct sctp_endpoint {
1197 	/* Common substructure for endpoint and association. */
1198 	struct sctp_ep_common base;
1199 
1200 	/* Associations: A list of current associations and mappings
1201 	 *	      to the data consumers for each association. This
1202 	 *	      may be in the form of a hash table or other
1203 	 *	      implementation dependent structure. The data
1204 	 *	      consumers may be process identification
1205 	 *	      information such as file descriptors, named pipe
1206 	 *	      pointer, or table pointers dependent on how SCTP
1207 	 *	      is implemented.
1208 	 */
1209 	/* This is really a list of struct sctp_association entries. */
1210 	struct list_head asocs;
1211 
1212 	/* Secret Key: A secret key used by this endpoint to compute
1213 	 *	      the MAC.	This SHOULD be a cryptographic quality
1214 	 *	      random number with a sufficient length.
1215 	 *	      Discussion in [RFC1750] can be helpful in
1216 	 *	      selection of the key.
1217 	 */
1218 	__u8 secret_key[SCTP_SECRET_SIZE];
1219 
1220  	/* digest:  This is a digest of the sctp cookie.  This field is
1221  	 * 	    only used on the receive path when we try to validate
1222  	 * 	    that the cookie has not been tampered with.  We put
1223  	 * 	    this here so we pre-allocate this once and can re-use
1224  	 * 	    on every receive.
1225  	 */
1226  	__u8 *digest;
1227 
1228 	/* sendbuf acct. policy.	*/
1229 	__u32 sndbuf_policy;
1230 
1231 	/* rcvbuf acct. policy.	*/
1232 	__u32 rcvbuf_policy;
1233 
1234 	/* SCTP AUTH: array of the HMACs that will be allocated
1235 	 * we need this per association so that we don't serialize
1236 	 */
1237 	struct crypto_hash **auth_hmacs;
1238 
1239 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1240 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1241 
1242 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1243 	struct sctp_chunks_param *auth_chunk_list;
1244 
1245 	/* SCTP-AUTH: endpoint shared keys */
1246 	struct list_head endpoint_shared_keys;
1247 	__u16 active_key_id;
1248 };
1249 
1250 /* Recover the outter endpoint structure. */
1251 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1252 {
1253 	struct sctp_endpoint *ep;
1254 
1255 	ep = container_of(base, struct sctp_endpoint, base);
1256 	return ep;
1257 }
1258 
1259 /* These are function signatures for manipulating endpoints.  */
1260 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1261 void sctp_endpoint_free(struct sctp_endpoint *);
1262 void sctp_endpoint_put(struct sctp_endpoint *);
1263 void sctp_endpoint_hold(struct sctp_endpoint *);
1264 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1265 struct sctp_association *sctp_endpoint_lookup_assoc(
1266 	const struct sctp_endpoint *ep,
1267 	const union sctp_addr *paddr,
1268 	struct sctp_transport **);
1269 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1270 				const union sctp_addr *);
1271 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1272 					struct net *, const union sctp_addr *);
1273 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1274 			 const union sctp_addr *paddr);
1275 
1276 int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
1277 		     sctp_cid_t, sctp_init_chunk_t *peer_init,
1278 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1279 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1280 		      const union sctp_addr *peer,
1281 		      sctp_init_chunk_t *init, gfp_t gfp);
1282 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1283 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1284 
1285 struct sctp_inithdr_host {
1286 	__u32 init_tag;
1287 	__u32 a_rwnd;
1288 	__u16 num_outbound_streams;
1289 	__u16 num_inbound_streams;
1290 	__u32 initial_tsn;
1291 };
1292 
1293 /* SCTP_GET_ASSOC_STATS counters */
1294 struct sctp_priv_assoc_stats {
1295 	/* Maximum observed rto in the association during subsequent
1296 	 * observations. Value is set to 0 if no RTO measurement took place
1297 	 * The transport where the max_rto was observed is returned in
1298 	 * obs_rto_ipaddr
1299 	 */
1300 	struct sockaddr_storage obs_rto_ipaddr;
1301 	__u64 max_obs_rto;
1302 	/* Total In and Out SACKs received and sent */
1303 	__u64 isacks;
1304 	__u64 osacks;
1305 	/* Total In and Out packets received and sent */
1306 	__u64 opackets;
1307 	__u64 ipackets;
1308 	/* Total retransmitted chunks */
1309 	__u64 rtxchunks;
1310 	/* TSN received > next expected */
1311 	__u64 outofseqtsns;
1312 	/* Duplicate Chunks received */
1313 	__u64 idupchunks;
1314 	/* Gap Ack Blocks received */
1315 	__u64 gapcnt;
1316 	/* Unordered data chunks sent and received */
1317 	__u64 ouodchunks;
1318 	__u64 iuodchunks;
1319 	/* Ordered data chunks sent and received */
1320 	__u64 oodchunks;
1321 	__u64 iodchunks;
1322 	/* Control chunks sent and received */
1323 	__u64 octrlchunks;
1324 	__u64 ictrlchunks;
1325 };
1326 
1327 /* RFC2960
1328  *
1329  * 12. Recommended Transmission Control Block (TCB) Parameters
1330  *
1331  * This section details a recommended set of parameters that should
1332  * be contained within the TCB for an implementation. This section is
1333  * for illustrative purposes and should not be deemed as requirements
1334  * on an implementation or as an exhaustive list of all parameters
1335  * inside an SCTP TCB. Each implementation may need its own additional
1336  * parameters for optimization.
1337  */
1338 
1339 
1340 /* Here we have information about each individual association. */
1341 struct sctp_association {
1342 
1343 	/* A base structure common to endpoint and association.
1344 	 * In this context, it represents the associations's view
1345 	 * of the local endpoint of the association.
1346 	 */
1347 	struct sctp_ep_common base;
1348 
1349 	/* Associations on the same socket. */
1350 	struct list_head asocs;
1351 
1352 	/* association id. */
1353 	sctp_assoc_t assoc_id;
1354 
1355 	/* This is our parent endpoint.	 */
1356 	struct sctp_endpoint *ep;
1357 
1358 	/* These are those association elements needed in the cookie.  */
1359 	struct sctp_cookie c;
1360 
1361 	/* This is all information about our peer.  */
1362 	struct {
1363 		/* rwnd
1364 		 *
1365 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1366 		 */
1367 		__u32 rwnd;
1368 
1369 		/* transport_addr_list
1370 		 *
1371 		 * Peer	       : A list of SCTP transport addresses that the
1372 		 * Transport   : peer is bound to. This information is derived
1373 		 * Address     : from the INIT or INIT ACK and is used to
1374 		 * List	       : associate an inbound packet with a given
1375 		 *	       : association. Normally this information is
1376 		 *	       : hashed or keyed for quick lookup and access
1377 		 *	       : of the TCB.
1378 		 *	       : The list is also initialized with the list
1379 		 *	       : of addresses passed with the sctp_connectx()
1380 		 *	       : call.
1381 		 *
1382 		 * It is a list of SCTP_transport's.
1383 		 */
1384 		struct list_head transport_addr_list;
1385 
1386 		/* transport_count
1387 		 *
1388 		 * Peer        : A count of the number of peer addresses
1389 		 * Transport   : in the Peer Transport Address List.
1390 		 * Address     :
1391 		 * Count       :
1392 		 */
1393 		__u16 transport_count;
1394 
1395 		/* port
1396 		 *   The transport layer port number.
1397 		 */
1398 		__u16 port;
1399 
1400 		/* primary_path
1401 		 *
1402 		 * Primary     : This is the current primary destination
1403 		 * Path	       : transport address of the peer endpoint.  It
1404 		 *	       : may also specify a source transport address
1405 		 *	       : on this endpoint.
1406 		 *
1407 		 * All of these paths live on transport_addr_list.
1408 		 *
1409 		 * At the bakeoffs, we discovered that the intent of
1410 		 * primaryPath is that it only changes when the ULP
1411 		 * asks to have it changed.  We add the activePath to
1412 		 * designate the connection we are currently using to
1413 		 * transmit new data and most control chunks.
1414 		 */
1415 		struct sctp_transport *primary_path;
1416 
1417 		/* Cache the primary path address here, when we
1418 		 * need a an address for msg_name.
1419 		 */
1420 		union sctp_addr primary_addr;
1421 
1422 		/* active_path
1423 		 *   The path that we are currently using to
1424 		 *   transmit new data and most control chunks.
1425 		 */
1426 		struct sctp_transport *active_path;
1427 
1428 		/* retran_path
1429 		 *
1430 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1431 		 * ...
1432 		 * Furthermore, when its peer is multi-homed, an
1433 		 * endpoint SHOULD try to retransmit a chunk to an
1434 		 * active destination transport address that is
1435 		 * different from the last destination address to
1436 		 * which the DATA chunk was sent.
1437 		 */
1438 		struct sctp_transport *retran_path;
1439 
1440 		/* Pointer to last transport I have sent on.  */
1441 		struct sctp_transport *last_sent_to;
1442 
1443 		/* This is the last transport I have received DATA on.	*/
1444 		struct sctp_transport *last_data_from;
1445 
1446 		/*
1447 		 * Mapping  An array of bits or bytes indicating which out of
1448 		 * Array    order TSN's have been received (relative to the
1449 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1450 		 *	    order packets have been received, this array
1451 		 *	    will be set to all zero. This structure may be
1452 		 *	    in the form of a circular buffer or bit array.
1453 		 *
1454 		 * Last Rcvd   : This is the last TSN received in
1455 		 * TSN	       : sequence. This value is set initially by
1456 		 *	       : taking the peer's Initial TSN, received in
1457 		 *	       : the INIT or INIT ACK chunk, and subtracting
1458 		 *	       : one from it.
1459 		 *
1460 		 * Throughout most of the specification this is called the
1461 		 * "Cumulative TSN ACK Point".	In this case, we
1462 		 * ignore the advice in 12.2 in favour of the term
1463 		 * used in the bulk of the text.  This value is hidden
1464 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1465 		 */
1466 		struct sctp_tsnmap tsn_map;
1467 
1468 		/* Ack State   : This flag indicates if the next received
1469 		 *             : packet is to be responded to with a
1470 		 *             : SACK. This is initializedto 0.  When a packet
1471 		 *             : is received it is incremented. If this value
1472 		 *             : reaches 2 or more, a SACK is sent and the
1473 		 *             : value is reset to 0. Note: This is used only
1474 		 *             : when no DATA chunks are received out of
1475 		 *             : order.  When DATA chunks are out of order,
1476 		 *             : SACK's are not delayed (see Section 6).
1477 		 */
1478 		__u8    sack_needed;     /* Do we need to sack the peer? */
1479 		__u32	sack_cnt;
1480 		__u32	sack_generation;
1481 
1482 		/* These are capabilities which our peer advertised.  */
1483 		__u8	ecn_capable:1,	    /* Can peer do ECN? */
1484 			ipv4_address:1,	    /* Peer understands IPv4 addresses? */
1485 			ipv6_address:1,	    /* Peer understands IPv6 addresses? */
1486 			hostname_address:1, /* Peer understands DNS addresses? */
1487 			asconf_capable:1,   /* Does peer support ADDIP? */
1488 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1489 			auth_capable:1;	    /* Is peer doing SCTP-AUTH? */
1490 
1491 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1492 
1493 		/* This mask is used to disable sending the ASCONF chunk
1494 		 * with specified parameter to peer.
1495 		 */
1496 		__be16 addip_disabled_mask;
1497 
1498 		struct sctp_inithdr_host i;
1499 		int cookie_len;
1500 		void *cookie;
1501 
1502 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1503 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1504 		 * Initial TSN Value minus 1
1505 		 */
1506 		__u32 addip_serial;
1507 
1508 		/* SCTP-AUTH: We need to know pears random number, hmac list
1509 		 * and authenticated chunk list.  All that is part of the
1510 		 * cookie and these are just pointers to those locations
1511 		 */
1512 		sctp_random_param_t *peer_random;
1513 		sctp_chunks_param_t *peer_chunks;
1514 		sctp_hmac_algo_param_t *peer_hmacs;
1515 	} peer;
1516 
1517 	/* State       : A state variable indicating what state the
1518 	 *	       : association is in, i.e. COOKIE-WAIT,
1519 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1520 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1521 	 *
1522 	 *		Note: No "CLOSED" state is illustrated since if a
1523 	 *		association is "CLOSED" its TCB SHOULD be removed.
1524 	 *
1525 	 *		In this implementation we DO have a CLOSED
1526 	 *		state which is used during initiation and shutdown.
1527 	 *
1528 	 *		State takes values from SCTP_STATE_*.
1529 	 */
1530 	sctp_state_t state;
1531 
1532 	/* The cookie life I award for any cookie.  */
1533 	ktime_t cookie_life;
1534 
1535 	/* Overall     : The overall association error count.
1536 	 * Error Count : [Clear this any time I get something.]
1537 	 */
1538 	int overall_error_count;
1539 
1540 	/* These are the association's initial, max, and min RTO values.
1541 	 * These values will be initialized by system defaults, but can
1542 	 * be modified via the SCTP_RTOINFO socket option.
1543 	 */
1544 	unsigned long rto_initial;
1545 	unsigned long rto_max;
1546 	unsigned long rto_min;
1547 
1548 	/* Maximum number of new data packets that can be sent in a burst.  */
1549 	int max_burst;
1550 
1551 	/* This is the max_retrans value for the association.  This value will
1552 	 * be initialized initialized from system defaults, but can be
1553 	 * modified by the SCTP_ASSOCINFO socket option.
1554 	 */
1555 	int max_retrans;
1556 
1557 	/* This is the partially failed retrans value for the transport
1558 	 * and will be initialized from the assocs value.  This can be
1559 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1560 	 */
1561 	int pf_retrans;
1562 
1563 	/* Maximum number of times the endpoint will retransmit INIT  */
1564 	__u16 max_init_attempts;
1565 
1566 	/* How many times have we resent an INIT? */
1567 	__u16 init_retries;
1568 
1569 	/* The largest timeout or RTO value to use in attempting an INIT */
1570 	unsigned long max_init_timeo;
1571 
1572 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1573 	 * the destination address every heartbeat interval. This value
1574 	 * will be inherited by all new transports.
1575 	 */
1576 	unsigned long hbinterval;
1577 
1578 	/* This is the max_retrans value for new transports in the
1579 	 * association.
1580 	 */
1581 	__u16 pathmaxrxt;
1582 
1583 	/* Flag that path mtu update is pending */
1584 	__u8   pmtu_pending;
1585 
1586 	/* Association : The smallest PMTU discovered for all of the
1587 	 * PMTU	       : peer's transport addresses.
1588 	 */
1589 	__u32 pathmtu;
1590 
1591 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1592 	__u32 param_flags;
1593 
1594 	/* SACK delay timeout */
1595 	unsigned long sackdelay;
1596 	__u32 sackfreq;
1597 
1598 
1599 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1600 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1601 
1602 	/* Transport to which SHUTDOWN chunk was last sent.  */
1603 	struct sctp_transport *shutdown_last_sent_to;
1604 
1605 	/* How many times have we resent a SHUTDOWN */
1606 	int shutdown_retries;
1607 
1608 	/* Transport to which INIT chunk was last sent.  */
1609 	struct sctp_transport *init_last_sent_to;
1610 
1611 	/* Next TSN    : The next TSN number to be assigned to a new
1612 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1613 	 *	       : ACK chunk to the peer and incremented each
1614 	 *	       : time a DATA chunk is assigned a TSN
1615 	 *	       : (normally just prior to transmit or during
1616 	 *	       : fragmentation).
1617 	 */
1618 	__u32 next_tsn;
1619 
1620 	/*
1621 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1622 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1623 	 *	       : received in the INIT or INIT ACK chunk, and
1624 	 *	       : subtracting one from it.
1625 	 *
1626 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1627 	 */
1628 
1629 	__u32 ctsn_ack_point;
1630 
1631 	/* PR-SCTP Advanced.Peer.Ack.Point */
1632 	__u32 adv_peer_ack_point;
1633 
1634 	/* Highest TSN that is acknowledged by incoming SACKs. */
1635 	__u32 highest_sacked;
1636 
1637 	/* TSN marking the fast recovery exit point */
1638 	__u32 fast_recovery_exit;
1639 
1640 	/* Flag to track the current fast recovery state */
1641 	__u8 fast_recovery;
1642 
1643 	/* The number of unacknowledged data chunks.  Reported through
1644 	 * the SCTP_STATUS sockopt.
1645 	 */
1646 	__u16 unack_data;
1647 
1648 	/* The total number of data chunks that we've had to retransmit
1649 	 * as the result of a T3 timer expiration
1650 	 */
1651 	__u32 rtx_data_chunks;
1652 
1653 	/* This is the association's receive buffer space.  This value is used
1654 	 * to set a_rwnd field in an INIT or a SACK chunk.
1655 	 */
1656 	__u32 rwnd;
1657 
1658 	/* This is the last advertised value of rwnd over a SACK chunk. */
1659 	__u32 a_rwnd;
1660 
1661 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1662 	 * to slop over a maximum of the association's frag_point.
1663 	 */
1664 	__u32 rwnd_over;
1665 
1666 	/* Keeps treack of rwnd pressure.  This happens when we have
1667 	 * a window, but not recevie buffer (i.e small packets).  This one
1668 	 * is releases slowly (1 PMTU at a time ).
1669 	 */
1670 	__u32 rwnd_press;
1671 
1672 	/* This is the sndbuf size in use for the association.
1673 	 * This corresponds to the sndbuf size for the association,
1674 	 * as specified in the sk->sndbuf.
1675 	 */
1676 	int sndbuf_used;
1677 
1678 	/* This is the amount of memory that this association has allocated
1679 	 * in the receive path at any given time.
1680 	 */
1681 	atomic_t rmem_alloc;
1682 
1683 	/* This is the wait queue head for send requests waiting on
1684 	 * the association sndbuf space.
1685 	 */
1686 	wait_queue_head_t	wait;
1687 
1688 	/* The message size at which SCTP fragmentation will occur. */
1689 	__u32 frag_point;
1690 	__u32 user_frag;
1691 
1692 	/* Counter used to count INIT errors. */
1693 	int init_err_counter;
1694 
1695 	/* Count the number of INIT cycles (for doubling timeout). */
1696 	int init_cycle;
1697 
1698 	/* Default send parameters. */
1699 	__u16 default_stream;
1700 	__u16 default_flags;
1701 	__u32 default_ppid;
1702 	__u32 default_context;
1703 	__u32 default_timetolive;
1704 
1705 	/* Default receive parameters */
1706 	__u32 default_rcv_context;
1707 
1708 	/* This tracks outbound ssn for a given stream.	 */
1709 	struct sctp_ssnmap *ssnmap;
1710 
1711 	/* All outbound chunks go through this structure.  */
1712 	struct sctp_outq outqueue;
1713 
1714 	/* A smart pipe that will handle reordering and fragmentation,
1715 	 * as well as handle passing events up to the ULP.
1716 	 */
1717 	struct sctp_ulpq ulpq;
1718 
1719 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1720 	__u32 last_ecne_tsn;
1721 
1722 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1723 	__u32 last_cwr_tsn;
1724 
1725 	/* How many duplicated TSNs have we seen?  */
1726 	int numduptsns;
1727 
1728 	/* Number of seconds of idle time before an association is closed.
1729 	 * In the association context, this is really used as a boolean
1730 	 * since the real timeout is stored in the timeouts array
1731 	 */
1732 	__u32 autoclose;
1733 
1734 	/* These are to support
1735 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1736 	 *  and Enforcement of Flow and Message Limits"
1737 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1738 	 * or "ADDIP" for short.
1739 	 */
1740 
1741 
1742 
1743 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1744 	 *
1745 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1746 	 * unacknowledged at any one time.  If a sender, after sending
1747 	 * an ASCONF chunk, decides it needs to transfer another
1748 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1749 	 * returns from the previous ASCONF Chunk before sending a
1750 	 * subsequent ASCONF. Note this restriction binds each side,
1751 	 * so at any time two ASCONF may be in-transit on any given
1752 	 * association (one sent from each endpoint).
1753 	 *
1754 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1755 	 * not have an ASCONF in flight, this is NULL.]
1756 	 */
1757 	struct sctp_chunk *addip_last_asconf;
1758 
1759 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1760 	 *
1761 	 * This is needed to implement itmes E1 - E4 of the updated
1762 	 * spec.  Here is the justification:
1763 	 *
1764 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1765 	 * we now need the ability to cache multiple ACKs.  The section
1766 	 * describes in detail how they are cached and cleaned up.
1767 	 */
1768 	struct list_head asconf_ack_list;
1769 
1770 	/* These ASCONF chunks are waiting to be sent.
1771 	 *
1772 	 * These chunaks can't be pushed to outqueue until receiving
1773 	 * ASCONF_ACK for the previous ASCONF indicated by
1774 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1775 	 * is in flight at any time.
1776 	 *
1777 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1778 	 *
1779 	 * In defining the ASCONF Chunk transfer procedures, it is
1780 	 * essential that these transfers MUST NOT cause congestion
1781 	 * within the network.	To achieve this, we place these
1782 	 * restrictions on the transfer of ASCONF Chunks:
1783 	 *
1784 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1785 	 * unacknowledged at any one time.  If a sender, after sending
1786 	 * an ASCONF chunk, decides it needs to transfer another
1787 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1788 	 * returns from the previous ASCONF Chunk before sending a
1789 	 * subsequent ASCONF. Note this restriction binds each side,
1790 	 * so at any time two ASCONF may be in-transit on any given
1791 	 * association (one sent from each endpoint).
1792 	 *
1793 	 *
1794 	 * [I really think this is EXACTLY the sort of intelligence
1795 	 *  which already resides in sctp_outq.	 Please move this
1796 	 *  queue and its supporting logic down there.	--piggy]
1797 	 */
1798 	struct list_head addip_chunk_list;
1799 
1800 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1801 	 *
1802 	 * A2) A serial number should be assigned to the Chunk. The
1803 	 * serial number SHOULD be a monotonically increasing
1804 	 * number. The serial number SHOULD be initialized at
1805 	 * the start of the association to the same value as the
1806 	 * Initial TSN and every time a new ASCONF chunk is created
1807 	 * it is incremented by one after assigning the serial number
1808 	 * to the newly created chunk.
1809 	 *
1810 	 * ADDIP
1811 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1812 	 *
1813 	 * Serial Number : 32 bits (unsigned integer)
1814 	 *
1815 	 * This value represents a Serial Number for the ASCONF
1816 	 * Chunk. The valid range of Serial Number is from 0 to
1817 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1818 	 * after reaching 4294967295.
1819 	 */
1820 	__u32 addip_serial;
1821 	union sctp_addr *asconf_addr_del_pending;
1822 	int src_out_of_asoc_ok;
1823 	struct sctp_transport *new_transport;
1824 
1825 	/* SCTP AUTH: list of the endpoint shared keys.  These
1826 	 * keys are provided out of band by the user applicaton
1827 	 * and can't change during the lifetime of the association
1828 	 */
1829 	struct list_head endpoint_shared_keys;
1830 
1831 	/* SCTP AUTH:
1832 	 * The current generated assocaition shared key (secret)
1833 	 */
1834 	struct sctp_auth_bytes *asoc_shared_key;
1835 
1836 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1837 	 * that we support.
1838 	 */
1839 	__u16 default_hmac_id;
1840 
1841 	__u16 active_key_id;
1842 
1843 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1844 	     temp:1;		/* Is it a temporary association? */
1845 
1846 	struct sctp_priv_assoc_stats stats;
1847 };
1848 
1849 
1850 /* An eyecatcher for determining if we are really looking at an
1851  * association data structure.
1852  */
1853 enum {
1854 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1855 };
1856 
1857 /* Recover the outter association structure. */
1858 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1859 {
1860 	struct sctp_association *asoc;
1861 
1862 	asoc = container_of(base, struct sctp_association, base);
1863 	return asoc;
1864 }
1865 
1866 /* These are function signatures for manipulating associations.	 */
1867 
1868 
1869 struct sctp_association *
1870 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1871 		     sctp_scope_t scope, gfp_t gfp);
1872 void sctp_association_free(struct sctp_association *);
1873 void sctp_association_put(struct sctp_association *);
1874 void sctp_association_hold(struct sctp_association *);
1875 
1876 struct sctp_transport *sctp_assoc_choose_alter_transport(
1877 	struct sctp_association *, struct sctp_transport *);
1878 void sctp_assoc_update_retran_path(struct sctp_association *);
1879 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1880 					  const union sctp_addr *);
1881 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1882 			    const union sctp_addr *laddr);
1883 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1884 				     const union sctp_addr *address,
1885 				     const gfp_t gfp,
1886 				     const int peer_state);
1887 void sctp_assoc_del_peer(struct sctp_association *asoc,
1888 			 const union sctp_addr *addr);
1889 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1890 			 struct sctp_transport *peer);
1891 void sctp_assoc_control_transport(struct sctp_association *,
1892 				  struct sctp_transport *,
1893 				  sctp_transport_cmd_t, sctp_sn_error_t);
1894 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1895 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1896 					   struct net *,
1897 					   const union sctp_addr *,
1898 					   const union sctp_addr *);
1899 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1900 void sctp_assoc_update(struct sctp_association *old,
1901 		       struct sctp_association *new);
1902 
1903 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1904 
1905 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1906 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1907 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1908 void sctp_assoc_set_primary(struct sctp_association *,
1909 			    struct sctp_transport *);
1910 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1911 				    struct sctp_transport *);
1912 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1913 				     sctp_scope_t, gfp_t);
1914 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1915 					 struct sctp_cookie*,
1916 					 gfp_t gfp);
1917 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1918 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1919 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1920 					const struct sctp_association *asoc,
1921 					__be32 serial);
1922 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1923 
1924 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1925 			const union sctp_addr *ss2);
1926 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1927 
1928 /* A convenience structure to parse out SCTP specific CMSGs. */
1929 typedef struct sctp_cmsgs {
1930 	struct sctp_initmsg *init;
1931 	struct sctp_sndrcvinfo *info;
1932 } sctp_cmsgs_t;
1933 
1934 /* Structure for tracking memory objects */
1935 typedef struct {
1936 	char *label;
1937 	atomic_t *counter;
1938 } sctp_dbg_objcnt_entry_t;
1939 
1940 #endif /* __sctp_structs_h__ */
1941