xref: /linux/include/net/sctp/structs.h (revision 96c63fa7393d0a346acfe5a91e0c7d4c7782641b)
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/rhashtable.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_shash;
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 sctp port control hash.	*/
124 	struct sctp_bind_hashbucket *port_hashtable;
125 	/* This is the hash of all transports. */
126 	struct rhashtable transport_hashtable;
127 
128 	/* Sizes of above hashtables. */
129 	int ep_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_port_hashsize		(sctp_globals.port_hashsize)
147 #define sctp_port_hashtable		(sctp_globals.port_hashtable)
148 #define sctp_transport_hashtable	(sctp_globals.transport_hashtable)
149 #define sctp_checksum_disable		(sctp_globals.checksum_disable)
150 
151 /* SCTP Socket type: UDP or TCP style. */
152 typedef enum {
153 	SCTP_SOCKET_UDP = 0,
154 	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
155 	SCTP_SOCKET_TCP
156 } sctp_socket_type_t;
157 
158 /* Per socket SCTP information. */
159 struct sctp_sock {
160 	/* inet_sock has to be the first member of sctp_sock */
161 	struct inet_sock inet;
162 	/* What kind of a socket is this? */
163 	sctp_socket_type_t type;
164 
165 	/* PF_ family specific functions.  */
166 	struct sctp_pf *pf;
167 
168 	/* Access to HMAC transform. */
169 	struct crypto_shash *hmac;
170 	char *sctp_hmac_alg;
171 
172 	/* What is our base endpointer? */
173 	struct sctp_endpoint *ep;
174 
175 	struct sctp_bind_bucket *bind_hash;
176 	/* Various Socket Options.  */
177 	__u16 default_stream;
178 	__u32 default_ppid;
179 	__u16 default_flags;
180 	__u32 default_context;
181 	__u32 default_timetolive;
182 	__u32 default_rcv_context;
183 	int max_burst;
184 
185 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
186 	 * the destination address every heartbeat interval. This value
187 	 * will be inherited by all new associations.
188 	 */
189 	__u32 hbinterval;
190 
191 	/* This is the max_retrans value for new associations. */
192 	__u16 pathmaxrxt;
193 
194 	/* The initial Path MTU to use for new associations. */
195 	__u32 pathmtu;
196 
197 	/* The default SACK delay timeout for new associations. */
198 	__u32 sackdelay;
199 	__u32 sackfreq;
200 
201 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
202 	__u32 param_flags;
203 
204 	struct sctp_initmsg initmsg;
205 	struct sctp_rtoinfo rtoinfo;
206 	struct sctp_paddrparams paddrparam;
207 	struct sctp_event_subscribe subscribe;
208 	struct sctp_assocparams assocparams;
209 
210 	int user_frag;
211 
212 	__u32 autoclose;
213 	__u32 adaptation_ind;
214 	__u32 pd_point;
215 	__u16	nodelay:1,
216 		disable_fragments:1,
217 		v4mapped:1,
218 		frag_interleave:1,
219 		recvrcvinfo:1,
220 		recvnxtinfo:1,
221 		data_ready_signalled:1;
222 
223 	atomic_t pd_mode;
224 	/* Receive to here while partial delivery is in effect. */
225 	struct sk_buff_head pd_lobby;
226 
227 	/* These must be the last fields, as they will skipped on copies,
228 	 * like on accept and peeloff operations
229 	 */
230 	struct list_head auto_asconf_list;
231 	int do_auto_asconf;
232 };
233 
234 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
235 {
236        return (struct sctp_sock *)sk;
237 }
238 
239 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
240 {
241        return (struct sock *)sp;
242 }
243 
244 #if IS_ENABLED(CONFIG_IPV6)
245 struct sctp6_sock {
246        struct sctp_sock  sctp;
247        struct ipv6_pinfo inet6;
248 };
249 #endif /* CONFIG_IPV6 */
250 
251 
252 /* This is our APPLICATION-SPECIFIC state cookie.
253  * THIS IS NOT DICTATED BY THE SPECIFICATION.
254  */
255 /* These are the parts of an association which we send in the cookie.
256  * Most of these are straight out of:
257  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
258  *
259  */
260 
261 struct sctp_cookie {
262 
263 	/* My	       : Tag expected in every inbound packet and sent
264 	 * Verification: in the INIT or INIT ACK chunk.
265 	 * Tag	       :
266 	 */
267 	__u32 my_vtag;
268 
269 	/* Peer's      : Tag expected in every outbound packet except
270 	 * Verification: in the INIT chunk.
271 	 * Tag	       :
272 	 */
273 	__u32 peer_vtag;
274 
275 	/* The rest of these are not from the spec, but really need to
276 	 * be in the cookie.
277 	 */
278 
279 	/* My Tie Tag  : Assist in discovering a restarting association. */
280 	__u32 my_ttag;
281 
282 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
283 	__u32 peer_ttag;
284 
285 	/* When does this cookie expire? */
286 	ktime_t expiration;
287 
288 	/* Number of inbound/outbound streams which are set
289 	 * and negotiated during the INIT process.
290 	 */
291 	__u16 sinit_num_ostreams;
292 	__u16 sinit_max_instreams;
293 
294 	/* This is the first sequence number I used.  */
295 	__u32 initial_tsn;
296 
297 	/* This holds the originating address of the INIT packet.  */
298 	union sctp_addr peer_addr;
299 
300 	/* IG Section 2.35.3
301 	 * Include the source port of the INIT-ACK
302 	 */
303 	__u16		my_port;
304 
305 	__u8 prsctp_capable;
306 
307 	/* Padding for future use */
308 	__u8 padding;
309 
310 	__u32 adaptation_ind;
311 
312 	__u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
313 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
314 	__u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
315 
316 	/* This is a shim for my peer's INIT packet, followed by
317 	 * a copy of the raw address list of the association.
318 	 * The length of the raw address list is saved in the
319 	 * raw_addr_list_len field, which will be used at the time when
320 	 * the association TCB is re-constructed from the cookie.
321 	 */
322 	__u32 raw_addr_list_len;
323 	struct sctp_init_chunk peer_init[0];
324 };
325 
326 
327 /* The format of our cookie that we send to our peer. */
328 struct sctp_signed_cookie {
329 	__u8 signature[SCTP_SECRET_SIZE];
330 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
331 	struct sctp_cookie c;
332 } __packed;
333 
334 /* This is another convenience type to allocate memory for address
335  * params for the maximum size and pass such structures around
336  * internally.
337  */
338 union sctp_addr_param {
339 	struct sctp_paramhdr p;
340 	struct sctp_ipv4addr_param v4;
341 	struct sctp_ipv6addr_param v6;
342 };
343 
344 /* A convenience type to allow walking through the various
345  * parameters and avoid casting all over the place.
346  */
347 union sctp_params {
348 	void *v;
349 	struct sctp_paramhdr *p;
350 	struct sctp_cookie_preserve_param *life;
351 	struct sctp_hostname_param *dns;
352 	struct sctp_cookie_param *cookie;
353 	struct sctp_supported_addrs_param *sat;
354 	struct sctp_ipv4addr_param *v4;
355 	struct sctp_ipv6addr_param *v6;
356 	union sctp_addr_param *addr;
357 	struct sctp_adaptation_ind_param *aind;
358 	struct sctp_supported_ext_param *ext;
359 	struct sctp_random_param *random;
360 	struct sctp_chunks_param *chunks;
361 	struct sctp_hmac_algo_param *hmac_algo;
362 	struct sctp_addip_param *addip;
363 };
364 
365 /* RFC 2960.  Section 3.3.5 Heartbeat.
366  *    Heartbeat Information: variable length
367  *    The Sender-specific Heartbeat Info field should normally include
368  *    information about the sender's current time when this HEARTBEAT
369  *    chunk is sent and the destination transport address to which this
370  *    HEARTBEAT is sent (see Section 8.3).
371  */
372 typedef struct sctp_sender_hb_info {
373 	struct sctp_paramhdr param_hdr;
374 	union sctp_addr daddr;
375 	unsigned long sent_at;
376 	__u64 hb_nonce;
377 } __packed sctp_sender_hb_info_t;
378 
379 /*
380  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
381  *
382  *  The term "stream" is used in SCTP to refer to a sequence of user
383  *  messages that are to be delivered to the upper-layer protocol in
384  *  order with respect to other messages within the same stream.  This is
385  *  in contrast to its usage in TCP, where it refers to a sequence of
386  *  bytes (in this document a byte is assumed to be eight bits).
387  *  ...
388  *
389  *  This is the structure we use to track both our outbound and inbound
390  *  SSN, or Stream Sequence Numbers.
391  */
392 
393 struct sctp_stream {
394 	__u16 *ssn;
395 	unsigned int len;
396 };
397 
398 struct sctp_ssnmap {
399 	struct sctp_stream in;
400 	struct sctp_stream out;
401 };
402 
403 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
404 				    gfp_t gfp);
405 void sctp_ssnmap_free(struct sctp_ssnmap *map);
406 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
407 
408 /* What is the current SSN number for this stream? */
409 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
410 {
411 	return stream->ssn[id];
412 }
413 
414 /* Return the next SSN number for this stream.	*/
415 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
416 {
417 	return stream->ssn[id]++;
418 }
419 
420 /* Skip over this ssn and all below. */
421 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
422 				 __u16 ssn)
423 {
424 	stream->ssn[id] = ssn+1;
425 }
426 
427 /*
428  * Pointers to address related SCTP functions.
429  * (i.e. things that depend on the address family.)
430  */
431 struct sctp_af {
432 	int		(*sctp_xmit)	(struct sk_buff *skb,
433 					 struct sctp_transport *);
434 	int		(*setsockopt)	(struct sock *sk,
435 					 int level,
436 					 int optname,
437 					 char __user *optval,
438 					 unsigned int optlen);
439 	int		(*getsockopt)	(struct sock *sk,
440 					 int level,
441 					 int optname,
442 					 char __user *optval,
443 					 int __user *optlen);
444 	int		(*compat_setsockopt)	(struct sock *sk,
445 					 int level,
446 					 int optname,
447 					 char __user *optval,
448 					 unsigned int optlen);
449 	int		(*compat_getsockopt)	(struct sock *sk,
450 					 int level,
451 					 int optname,
452 					 char __user *optval,
453 					 int __user *optlen);
454 	void		(*get_dst)	(struct sctp_transport *t,
455 					 union sctp_addr *saddr,
456 					 struct flowi *fl,
457 					 struct sock *sk);
458 	void		(*get_saddr)	(struct sctp_sock *sk,
459 					 struct sctp_transport *t,
460 					 struct flowi *fl);
461 	void		(*copy_addrlist) (struct list_head *,
462 					  struct net_device *);
463 	int		(*cmp_addr)	(const union sctp_addr *addr1,
464 					 const union sctp_addr *addr2);
465 	void		(*addr_copy)	(union sctp_addr *dst,
466 					 union sctp_addr *src);
467 	void		(*from_skb)	(union sctp_addr *,
468 					 struct sk_buff *skb,
469 					 int saddr);
470 	void		(*from_sk)	(union sctp_addr *,
471 					 struct sock *sk);
472 	void		(*from_addr_param) (union sctp_addr *,
473 					    union sctp_addr_param *,
474 					    __be16 port, int iif);
475 	int		(*to_addr_param) (const union sctp_addr *,
476 					  union sctp_addr_param *);
477 	int		(*addr_valid)	(union sctp_addr *,
478 					 struct sctp_sock *,
479 					 const struct sk_buff *);
480 	sctp_scope_t	(*scope) (union sctp_addr *);
481 	void		(*inaddr_any)	(union sctp_addr *, __be16);
482 	int		(*is_any)	(const union sctp_addr *);
483 	int		(*available)	(union sctp_addr *,
484 					 struct sctp_sock *);
485 	int		(*skb_iif)	(const struct sk_buff *sk);
486 	int		(*is_ce)	(const struct sk_buff *sk);
487 	void		(*seq_dump_addr)(struct seq_file *seq,
488 					 union sctp_addr *addr);
489 	void		(*ecn_capable)(struct sock *sk);
490 	__u16		net_header_len;
491 	int		sockaddr_len;
492 	sa_family_t	sa_family;
493 	struct list_head list;
494 };
495 
496 struct sctp_af *sctp_get_af_specific(sa_family_t);
497 int sctp_register_af(struct sctp_af *);
498 
499 /* Protocol family functions. */
500 struct sctp_pf {
501 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
502 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
503 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
504 	int  (*cmp_addr) (const union sctp_addr *,
505 			  const union sctp_addr *,
506 			  struct sctp_sock *);
507 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
508 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
509 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
510 	struct sock *(*create_accept_sk) (struct sock *sk,
511 					  struct sctp_association *asoc);
512 	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
513 	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
514 	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
515 	struct sctp_af *af;
516 };
517 
518 
519 /* Structure to track chunk fragments that have been acked, but peer
520  * fragments of the same message have not.
521  */
522 struct sctp_datamsg {
523 	/* Chunks waiting to be submitted to lower layer. */
524 	struct list_head chunks;
525 	/* Reference counting. */
526 	atomic_t refcnt;
527 	/* When is this message no longer interesting to the peer? */
528 	unsigned long expires_at;
529 	/* Did the messenge fail to send? */
530 	int send_error;
531 	u8 send_failed:1,
532 	   can_abandon:1,   /* can chunks from this message can be abandoned. */
533 	   can_delay;	    /* should this message be Nagle delayed */
534 };
535 
536 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
537 					    struct sctp_sndrcvinfo *,
538 					    struct iov_iter *);
539 void sctp_datamsg_put(struct sctp_datamsg *);
540 void sctp_chunk_fail(struct sctp_chunk *, int error);
541 int sctp_chunk_abandoned(struct sctp_chunk *);
542 
543 /* RFC2960 1.4 Key Terms
544  *
545  * o Chunk: A unit of information within an SCTP packet, consisting of
546  * a chunk header and chunk-specific content.
547  *
548  * As a matter of convenience, we remember the SCTP common header for
549  * each chunk as well as a few other header pointers...
550  */
551 struct sctp_chunk {
552 	struct list_head list;
553 
554 	atomic_t refcnt;
555 
556 	/* This is our link to the per-transport transmitted list.  */
557 	struct list_head transmitted_list;
558 
559 	/* This field is used by chunks that hold fragmented data.
560 	 * For the first fragment this is the list that holds the rest of
561 	 * fragments. For the remaining fragments, this is the link to the
562 	 * frag_list maintained in the first fragment.
563 	 */
564 	struct list_head frag_list;
565 
566 	/* This points to the sk_buff containing the actual data.  */
567 	struct sk_buff *skb;
568 
569 	/* In case of GSO packets, this will store the head one */
570 	struct sk_buff *head_skb;
571 
572 	/* These are the SCTP headers by reverse order in a packet.
573 	 * Note that some of these may happen more than once.  In that
574 	 * case, we point at the "current" one, whatever that means
575 	 * for that level of header.
576 	 */
577 
578 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
579 	union sctp_params param_hdr;
580 	union {
581 		__u8 *v;
582 		struct sctp_datahdr *data_hdr;
583 		struct sctp_inithdr *init_hdr;
584 		struct sctp_sackhdr *sack_hdr;
585 		struct sctp_heartbeathdr *hb_hdr;
586 		struct sctp_sender_hb_info *hbs_hdr;
587 		struct sctp_shutdownhdr *shutdown_hdr;
588 		struct sctp_signed_cookie *cookie_hdr;
589 		struct sctp_ecnehdr *ecne_hdr;
590 		struct sctp_cwrhdr *ecn_cwr_hdr;
591 		struct sctp_errhdr *err_hdr;
592 		struct sctp_addiphdr *addip_hdr;
593 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
594 		struct sctp_authhdr *auth_hdr;
595 	} subh;
596 
597 	__u8 *chunk_end;
598 
599 	struct sctp_chunkhdr *chunk_hdr;
600 	struct sctphdr *sctp_hdr;
601 
602 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
603 	struct sctp_sndrcvinfo sinfo;
604 
605 	/* Which association does this belong to?  */
606 	struct sctp_association *asoc;
607 
608 	/* What endpoint received this chunk? */
609 	struct sctp_ep_common *rcvr;
610 
611 	/* We fill this in if we are calculating RTT. */
612 	unsigned long sent_at;
613 
614 	/* What is the origin IP address for this chunk?  */
615 	union sctp_addr source;
616 	/* Destination address for this chunk. */
617 	union sctp_addr dest;
618 
619 	/* For outbound message, track all fragments for SEND_FAILED. */
620 	struct sctp_datamsg *msg;
621 
622 	/* For an inbound chunk, this tells us where it came from.
623 	 * For an outbound chunk, it tells us where we'd like it to
624 	 * go.	It is NULL if we have no preference.
625 	 */
626 	struct sctp_transport *transport;
627 
628 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
629 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
630 	 * spec violates the principle premis that all chunks are processed
631 	 * in order.
632 	 */
633 	struct sk_buff *auth_chunk;
634 
635 #define SCTP_CAN_FRTX 0x0
636 #define SCTP_NEED_FRTX 0x1
637 #define SCTP_DONT_FRTX 0x2
638 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
639 		resent:1,		/* Has this chunk ever been resent. */
640 		has_tsn:1,		/* Does this chunk have a TSN yet? */
641 		has_ssn:1,		/* Does this chunk have a SSN yet? */
642 		singleton:1,		/* Only chunk in the packet? */
643 		end_of_packet:1,	/* Last chunk in the packet? */
644 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
645 		pdiscard:1,		/* Discard the whole packet now? */
646 		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
647 		data_accepted:1,	/* At least 1 chunk accepted */
648 		auth:1,			/* IN: was auth'ed | OUT: needs auth */
649 		has_asconf:1,		/* IN: have seen an asconf before */
650 		tsn_missing_report:2,	/* Data chunk missing counter. */
651 		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
652 };
653 
654 void sctp_chunk_hold(struct sctp_chunk *);
655 void sctp_chunk_put(struct sctp_chunk *);
656 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
657 			  struct iov_iter *from);
658 void sctp_chunk_free(struct sctp_chunk *);
659 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
660 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
661 				 const struct sctp_association *,
662 				 struct sock *, gfp_t gfp);
663 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
664 		     union sctp_addr *);
665 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
666 
667 enum {
668 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
669 	SCTP_ADDR_SRC,		/* address can be used as source */
670 	SCTP_ADDR_DEL,		/* address about to be deleted */
671 };
672 
673 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
674 struct sctp_sockaddr_entry {
675 	struct list_head list;
676 	struct rcu_head	rcu;
677 	union sctp_addr a;
678 	__u8 state;
679 	__u8 valid;
680 };
681 
682 #define SCTP_ADDRESS_TICK_DELAY	500
683 
684 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
685 
686 /* This structure holds lists of chunks as we are assembling for
687  * transmission.
688  */
689 struct sctp_packet {
690 	/* These are the SCTP header values (host order) for the packet. */
691 	__u16 source_port;
692 	__u16 destination_port;
693 	__u32 vtag;
694 
695 	/* This contains the payload chunks.  */
696 	struct list_head chunk_list;
697 
698 	/* This is the overhead of the sctp and ip headers. */
699 	size_t overhead;
700 	/* This is the total size of all chunks INCLUDING padding.  */
701 	size_t size;
702 	/* This is the maximum size this packet may have */
703 	size_t max_size;
704 
705 	/* The packet is destined for this transport address.
706 	 * The function we finally use to pass down to the next lower
707 	 * layer lives in the transport structure.
708 	 */
709 	struct sctp_transport *transport;
710 
711 	/* pointer to the auth chunk for this packet */
712 	struct sctp_chunk *auth;
713 
714 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
715 	    has_sack:1,		/* This packet contains a SACK chunk. */
716 	    has_auth:1,		/* This packet contains an AUTH chunk */
717 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
718 	    ipfragok:1;		/* So let ip fragment this packet */
719 };
720 
721 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
722 				     struct sctp_transport *,
723 				     __u16 sport, __u16 dport);
724 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
725 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
726 				       struct sctp_chunk *, int, gfp_t);
727 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
728                                      struct sctp_chunk *);
729 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
730 void sctp_packet_free(struct sctp_packet *);
731 
732 static inline int sctp_packet_empty(struct sctp_packet *packet)
733 {
734 	return packet->size == packet->overhead;
735 }
736 
737 /* This represents a remote transport address.
738  * For local transport addresses, we just use union sctp_addr.
739  *
740  * RFC2960 Section 1.4 Key Terms
741  *
742  *   o	Transport address:  A Transport Address is traditionally defined
743  *	by Network Layer address, Transport Layer protocol and Transport
744  *	Layer port number.  In the case of SCTP running over IP, a
745  *	transport address is defined by the combination of an IP address
746  *	and an SCTP port number (where SCTP is the Transport protocol).
747  *
748  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
749  *
750  *   o	The sender keeps a separate congestion control parameter set for
751  *	each of the destination addresses it can send to (not each
752  *	source-destination pair but for each destination).  The parameters
753  *	should decay if the address is not used for a long enough time
754  *	period.
755  *
756  */
757 struct sctp_transport {
758 	/* A list of transports. */
759 	struct list_head transports;
760 	struct rhash_head node;
761 
762 	/* Reference counting. */
763 	atomic_t refcnt;
764 		/* RTO-Pending : A flag used to track if one of the DATA
765 		 *		chunks sent to this address is currently being
766 		 *		used to compute a RTT. If this flag is 0,
767 		 *		the next DATA chunk sent to this destination
768 		 *		should be used to compute a RTT and this flag
769 		 *		should be set. Every time the RTT
770 		 *		calculation completes (i.e. the DATA chunk
771 		 *		is SACK'd) clear this flag.
772 		 */
773 	__u32	rto_pending:1,
774 
775 		/*
776 		 * hb_sent : a flag that signals that we have a pending
777 		 * heartbeat.
778 		 */
779 		hb_sent:1,
780 
781 		/* Is the Path MTU update pending on this tranport */
782 		pmtu_pending:1,
783 
784 		/* Has this transport moved the ctsn since we last sacked */
785 		sack_generation:1;
786 	u32 dst_cookie;
787 
788 	struct flowi fl;
789 
790 	/* This is the peer's IP address and port. */
791 	union sctp_addr ipaddr;
792 
793 	/* These are the functions we call to handle LLP stuff.	 */
794 	struct sctp_af *af_specific;
795 
796 	/* Which association do we belong to?  */
797 	struct sctp_association *asoc;
798 
799 	/* RFC2960
800 	 *
801 	 * 12.3 Per Transport Address Data
802 	 *
803 	 * For each destination transport address in the peer's
804 	 * address list derived from the INIT or INIT ACK chunk, a
805 	 * number of data elements needs to be maintained including:
806 	 */
807 	/* RTO	       : The current retransmission timeout value.  */
808 	unsigned long rto;
809 
810 	__u32 rtt;		/* This is the most recent RTT.	 */
811 
812 	/* RTTVAR      : The current RTT variation.  */
813 	__u32 rttvar;
814 
815 	/* SRTT	       : The current smoothed round trip time.	*/
816 	__u32 srtt;
817 
818 	/*
819 	 * These are the congestion stats.
820 	 */
821 	/* cwnd	       : The current congestion window.	 */
822 	__u32 cwnd;		  /* This is the actual cwnd.  */
823 
824 	/* ssthresh    : The current slow start threshold value.  */
825 	__u32 ssthresh;
826 
827 	/* partial     : The tracking method for increase of cwnd when in
828 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
829 	 */
830 	__u32 partial_bytes_acked;
831 
832 	/* Data that has been sent, but not acknowledged. */
833 	__u32 flight_size;
834 
835 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
836 
837 	/* Destination */
838 	struct dst_entry *dst;
839 	/* Source address. */
840 	union sctp_addr saddr;
841 
842 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
843 	 * the destination address every heartbeat interval.
844 	 */
845 	unsigned long hbinterval;
846 
847 	/* SACK delay timeout */
848 	unsigned long sackdelay;
849 	__u32 sackfreq;
850 
851 	/* When was the last time that we heard from this transport? We use
852 	 * this to pick new active and retran paths.
853 	 */
854 	ktime_t last_time_heard;
855 
856 	/* When was the last time that we sent a chunk using this
857 	 * transport? We use this to check for idle transports
858 	 */
859 	unsigned long last_time_sent;
860 
861 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
862 	 * indication based on ECNE chunk.
863 	 */
864 	unsigned long last_time_ecne_reduced;
865 
866 	/* This is the max_retrans value for the transport and will
867 	 * be initialized from the assocs value.  This can be changed
868 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
869 	 */
870 	__u16 pathmaxrxt;
871 
872 	/* This is the partially failed retrans value for the transport
873 	 * and will be initialized from the assocs value.  This can be changed
874 	 * using the SCTP_PEER_ADDR_THLDS socket option
875 	 */
876 	int pf_retrans;
877 	/* PMTU	      : The current known path MTU.  */
878 	__u32 pathmtu;
879 
880 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
881 	__u32 param_flags;
882 
883 	/* The number of times INIT has been sent on this transport. */
884 	int init_sent_count;
885 
886 	/* state       : The current state of this destination,
887 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
888 	 */
889 	int state;
890 
891 	/* These are the error stats for this destination.  */
892 
893 	/* Error count : The current error count for this destination.	*/
894 	unsigned short error_count;
895 
896 	/* Per	       : A timer used by each destination.
897 	 * Destination :
898 	 * Timer       :
899 	 *
900 	 * [Everywhere else in the text this is called T3-rtx. -ed]
901 	 */
902 	struct timer_list T3_rtx_timer;
903 
904 	/* Heartbeat timer is per destination. */
905 	struct timer_list hb_timer;
906 
907 	/* Timer to handle ICMP proto unreachable envets */
908 	struct timer_list proto_unreach_timer;
909 
910 	/* Since we're using per-destination retransmission timers
911 	 * (see above), we're also using per-destination "transmitted"
912 	 * queues.  This probably ought to be a private struct
913 	 * accessible only within the outqueue, but it's not, yet.
914 	 */
915 	struct list_head transmitted;
916 
917 	/* We build bundle-able packets for this transport here.  */
918 	struct sctp_packet packet;
919 
920 	/* This is the list of transports that have chunks to send.  */
921 	struct list_head send_ready;
922 
923 	/* State information saved for SFR_CACC algorithm. The key
924 	 * idea in SFR_CACC is to maintain state at the sender on a
925 	 * per-destination basis when a changeover happens.
926 	 *	char changeover_active;
927 	 *	char cycling_changeover;
928 	 *	__u32 next_tsn_at_change;
929 	 *	char cacc_saw_newack;
930 	 */
931 	struct {
932 		/* An unsigned integer, which stores the next TSN to be
933 		 * used by the sender, at the moment of changeover.
934 		 */
935 		__u32 next_tsn_at_change;
936 
937 		/* A flag which indicates the occurrence of a changeover */
938 		char changeover_active;
939 
940 		/* A flag which indicates whether the change of primary is
941 		 * the first switch to this destination address during an
942 		 * active switch.
943 		 */
944 		char cycling_changeover;
945 
946 		/* A temporary flag, which is used during the processing of
947 		 * a SACK to estimate the causative TSN(s)'s group.
948 		 */
949 		char cacc_saw_newack;
950 	} cacc;
951 
952 	/* 64-bit random number sent with heartbeat. */
953 	__u64 hb_nonce;
954 
955 	struct rcu_head rcu;
956 };
957 
958 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
959 					  gfp_t);
960 void sctp_transport_set_owner(struct sctp_transport *,
961 			      struct sctp_association *);
962 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
963 			  struct sctp_sock *);
964 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
965 void sctp_transport_free(struct sctp_transport *);
966 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
967 void sctp_transport_reset_hb_timer(struct sctp_transport *);
968 int sctp_transport_hold(struct sctp_transport *);
969 void sctp_transport_put(struct sctp_transport *);
970 void sctp_transport_update_rto(struct sctp_transport *, __u32);
971 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
972 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
973 void sctp_transport_burst_limited(struct sctp_transport *);
974 void sctp_transport_burst_reset(struct sctp_transport *);
975 unsigned long sctp_transport_timeout(struct sctp_transport *);
976 void sctp_transport_reset(struct sctp_transport *);
977 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
978 void sctp_transport_immediate_rtx(struct sctp_transport *);
979 
980 
981 /* This is the structure we use to queue packets as they come into
982  * SCTP.  We write packets to it and read chunks from it.
983  */
984 struct sctp_inq {
985 	/* This is actually a queue of sctp_chunk each
986 	 * containing a partially decoded packet.
987 	 */
988 	struct list_head in_chunk_list;
989 	/* This is the packet which is currently off the in queue and is
990 	 * being worked on through the inbound chunk processing.
991 	 */
992 	struct sctp_chunk *in_progress;
993 
994 	/* This is the delayed task to finish delivering inbound
995 	 * messages.
996 	 */
997 	struct work_struct immediate;
998 };
999 
1000 void sctp_inq_init(struct sctp_inq *);
1001 void sctp_inq_free(struct sctp_inq *);
1002 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1003 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1004 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1005 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1006 
1007 /* This is the structure we use to hold outbound chunks.  You push
1008  * chunks in and they automatically pop out the other end as bundled
1009  * packets (it calls (*output_handler)()).
1010  *
1011  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1012  * and 8.2 of the v13 draft.
1013  *
1014  * It handles retransmissions.	The connection to the timeout portion
1015  * of the state machine is through sctp_..._timeout() and timeout_handler.
1016  *
1017  * If you feed it SACKs, it will eat them.
1018  *
1019  * If you give it big chunks, it will fragment them.
1020  *
1021  * It assigns TSN's to data chunks.  This happens at the last possible
1022  * instant before transmission.
1023  *
1024  * When free()'d, it empties itself out via output_handler().
1025  */
1026 struct sctp_outq {
1027 	struct sctp_association *asoc;
1028 
1029 	/* Data pending that has never been transmitted.  */
1030 	struct list_head out_chunk_list;
1031 
1032 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1033 
1034 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1035 	unsigned int error;
1036 
1037 	/* These are control chunks we want to send.  */
1038 	struct list_head control_chunk_list;
1039 
1040 	/* These are chunks that have been sacked but are above the
1041 	 * CTSN, or cumulative tsn ack point.
1042 	 */
1043 	struct list_head sacked;
1044 
1045 	/* Put chunks on this list to schedule them for
1046 	 * retransmission.
1047 	 */
1048 	struct list_head retransmit;
1049 
1050 	/* Put chunks on this list to save them for FWD TSN processing as
1051 	 * they were abandoned.
1052 	 */
1053 	struct list_head abandoned;
1054 
1055 	/* How many unackd bytes do we have in-flight?	*/
1056 	__u32 outstanding_bytes;
1057 
1058 	/* Are we doing fast-rtx on this queue */
1059 	char fast_rtx;
1060 
1061 	/* Corked? */
1062 	char cork;
1063 };
1064 
1065 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1066 void sctp_outq_teardown(struct sctp_outq *);
1067 void sctp_outq_free(struct sctp_outq*);
1068 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1069 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1070 int sctp_outq_is_empty(const struct sctp_outq *);
1071 void sctp_outq_restart(struct sctp_outq *);
1072 
1073 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1074 		     sctp_retransmit_reason_t);
1075 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1076 int sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1077 /* Uncork and flush an outqueue.  */
1078 static inline void sctp_outq_cork(struct sctp_outq *q)
1079 {
1080 	q->cork = 1;
1081 }
1082 
1083 /* These bind address data fields common between endpoints and associations */
1084 struct sctp_bind_addr {
1085 
1086 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1087 	 *
1088 	 * SCTP Port:	The local SCTP port number the endpoint is
1089 	 *		bound to.
1090 	 */
1091 	__u16 port;
1092 
1093 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1094 	 *
1095 	 * Address List: The list of IP addresses that this instance
1096 	 *	has bound.  This information is passed to one's
1097 	 *	peer(s) in INIT and INIT ACK chunks.
1098 	 */
1099 	struct list_head address_list;
1100 };
1101 
1102 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1103 void sctp_bind_addr_free(struct sctp_bind_addr *);
1104 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1105 			const struct sctp_bind_addr *src,
1106 			sctp_scope_t scope, gfp_t gfp,
1107 			int flags);
1108 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1109 			const struct sctp_bind_addr *src,
1110 			gfp_t gfp);
1111 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1112 		       int new_size, __u8 addr_state, gfp_t gfp);
1113 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1114 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1115 			 struct sctp_sock *);
1116 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1117 			 struct sctp_sock *, struct sctp_sock *);
1118 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1119 			 const union sctp_addr *addr);
1120 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1121 					const union sctp_addr	*addrs,
1122 					int			addrcnt,
1123 					struct sctp_sock	*opt);
1124 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1125 					 int *addrs_len,
1126 					 gfp_t gfp);
1127 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1128 			   __u16 port, gfp_t gfp);
1129 
1130 sctp_scope_t sctp_scope(const union sctp_addr *);
1131 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1132 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1133 int sctp_is_ep_boundall(struct sock *sk);
1134 
1135 
1136 /* What type of endpoint?  */
1137 typedef enum {
1138 	SCTP_EP_TYPE_SOCKET,
1139 	SCTP_EP_TYPE_ASSOCIATION,
1140 } sctp_endpoint_type_t;
1141 
1142 /*
1143  * A common base class to bridge the implmentation view of a
1144  * socket (usually listening) endpoint versus an association's
1145  * local endpoint.
1146  * This common structure is useful for several purposes:
1147  *   1) Common interface for lookup routines.
1148  *	a) Subfunctions work for either endpoint or association
1149  *	b) Single interface to lookup allows hiding the lookup lock rather
1150  *	   than acquiring it externally.
1151  *   2) Common interface for the inbound chunk handling/state machine.
1152  *   3) Common object handling routines for reference counting, etc.
1153  *   4) Disentangle association lookup from endpoint lookup, where we
1154  *	do not have to find our endpoint to find our association.
1155  *
1156  */
1157 
1158 struct sctp_ep_common {
1159 	/* Fields to help us manage our entries in the hash tables. */
1160 	struct hlist_node node;
1161 	int hashent;
1162 
1163 	/* Runtime type information.  What kind of endpoint is this? */
1164 	sctp_endpoint_type_t type;
1165 
1166 	/* Some fields to help us manage this object.
1167 	 *   refcnt   - Reference count access to this object.
1168 	 *   dead     - Do not attempt to use this object.
1169 	 */
1170 	atomic_t    refcnt;
1171 	bool	    dead;
1172 
1173 	/* What socket does this endpoint belong to?  */
1174 	struct sock *sk;
1175 
1176 	/* This is where we receive inbound chunks.  */
1177 	struct sctp_inq	  inqueue;
1178 
1179 	/* This substructure includes the defining parameters of the
1180 	 * endpoint:
1181 	 * bind_addr.port is our shared port number.
1182 	 * bind_addr.address_list is our set of local IP addresses.
1183 	 */
1184 	struct sctp_bind_addr bind_addr;
1185 };
1186 
1187 
1188 /* RFC Section 1.4 Key Terms
1189  *
1190  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1191  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1192  *   combination of a set of eligible destination transport addresses to
1193  *   which SCTP packets can be sent and a set of eligible source
1194  *   transport addresses from which SCTP packets can be received.
1195  *   All transport addresses used by an SCTP endpoint must use the
1196  *   same port number, but can use multiple IP addresses. A transport
1197  *   address used by an SCTP endpoint must not be used by another
1198  *   SCTP endpoint. In other words, a transport address is unique
1199  *   to an SCTP endpoint.
1200  *
1201  * From an implementation perspective, each socket has one of these.
1202  * A TCP-style socket will have exactly one association on one of
1203  * these.  An UDP-style socket will have multiple associations hanging
1204  * off one of these.
1205  */
1206 
1207 struct sctp_endpoint {
1208 	/* Common substructure for endpoint and association. */
1209 	struct sctp_ep_common base;
1210 
1211 	/* Associations: A list of current associations and mappings
1212 	 *	      to the data consumers for each association. This
1213 	 *	      may be in the form of a hash table or other
1214 	 *	      implementation dependent structure. The data
1215 	 *	      consumers may be process identification
1216 	 *	      information such as file descriptors, named pipe
1217 	 *	      pointer, or table pointers dependent on how SCTP
1218 	 *	      is implemented.
1219 	 */
1220 	/* This is really a list of struct sctp_association entries. */
1221 	struct list_head asocs;
1222 
1223 	/* Secret Key: A secret key used by this endpoint to compute
1224 	 *	      the MAC.	This SHOULD be a cryptographic quality
1225 	 *	      random number with a sufficient length.
1226 	 *	      Discussion in [RFC1750] can be helpful in
1227 	 *	      selection of the key.
1228 	 */
1229 	__u8 secret_key[SCTP_SECRET_SIZE];
1230 
1231  	/* digest:  This is a digest of the sctp cookie.  This field is
1232  	 * 	    only used on the receive path when we try to validate
1233  	 * 	    that the cookie has not been tampered with.  We put
1234  	 * 	    this here so we pre-allocate this once and can re-use
1235  	 * 	    on every receive.
1236  	 */
1237  	__u8 *digest;
1238 
1239 	/* sendbuf acct. policy.	*/
1240 	__u32 sndbuf_policy;
1241 
1242 	/* rcvbuf acct. policy.	*/
1243 	__u32 rcvbuf_policy;
1244 
1245 	/* SCTP AUTH: array of the HMACs that will be allocated
1246 	 * we need this per association so that we don't serialize
1247 	 */
1248 	struct crypto_shash **auth_hmacs;
1249 
1250 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1251 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1252 
1253 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1254 	struct sctp_chunks_param *auth_chunk_list;
1255 
1256 	/* SCTP-AUTH: endpoint shared keys */
1257 	struct list_head endpoint_shared_keys;
1258 	__u16 active_key_id;
1259 	__u8  auth_enable;
1260 };
1261 
1262 /* Recover the outter endpoint structure. */
1263 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1264 {
1265 	struct sctp_endpoint *ep;
1266 
1267 	ep = container_of(base, struct sctp_endpoint, base);
1268 	return ep;
1269 }
1270 
1271 /* These are function signatures for manipulating endpoints.  */
1272 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1273 void sctp_endpoint_free(struct sctp_endpoint *);
1274 void sctp_endpoint_put(struct sctp_endpoint *);
1275 void sctp_endpoint_hold(struct sctp_endpoint *);
1276 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1277 struct sctp_association *sctp_endpoint_lookup_assoc(
1278 	const struct sctp_endpoint *ep,
1279 	const union sctp_addr *paddr,
1280 	struct sctp_transport **);
1281 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1282 				const union sctp_addr *);
1283 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1284 					struct net *, const union sctp_addr *);
1285 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1286 			 const union sctp_addr *paddr);
1287 
1288 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1289 		     const struct sctp_association *asoc,
1290 		     sctp_cid_t, sctp_init_chunk_t *peer_init,
1291 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1292 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1293 		      const union sctp_addr *peer,
1294 		      sctp_init_chunk_t *init, gfp_t gfp);
1295 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1296 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1297 
1298 struct sctp_inithdr_host {
1299 	__u32 init_tag;
1300 	__u32 a_rwnd;
1301 	__u16 num_outbound_streams;
1302 	__u16 num_inbound_streams;
1303 	__u32 initial_tsn;
1304 };
1305 
1306 /* SCTP_GET_ASSOC_STATS counters */
1307 struct sctp_priv_assoc_stats {
1308 	/* Maximum observed rto in the association during subsequent
1309 	 * observations. Value is set to 0 if no RTO measurement took place
1310 	 * The transport where the max_rto was observed is returned in
1311 	 * obs_rto_ipaddr
1312 	 */
1313 	struct sockaddr_storage obs_rto_ipaddr;
1314 	__u64 max_obs_rto;
1315 	/* Total In and Out SACKs received and sent */
1316 	__u64 isacks;
1317 	__u64 osacks;
1318 	/* Total In and Out packets received and sent */
1319 	__u64 opackets;
1320 	__u64 ipackets;
1321 	/* Total retransmitted chunks */
1322 	__u64 rtxchunks;
1323 	/* TSN received > next expected */
1324 	__u64 outofseqtsns;
1325 	/* Duplicate Chunks received */
1326 	__u64 idupchunks;
1327 	/* Gap Ack Blocks received */
1328 	__u64 gapcnt;
1329 	/* Unordered data chunks sent and received */
1330 	__u64 ouodchunks;
1331 	__u64 iuodchunks;
1332 	/* Ordered data chunks sent and received */
1333 	__u64 oodchunks;
1334 	__u64 iodchunks;
1335 	/* Control chunks sent and received */
1336 	__u64 octrlchunks;
1337 	__u64 ictrlchunks;
1338 };
1339 
1340 /* RFC2960
1341  *
1342  * 12. Recommended Transmission Control Block (TCB) Parameters
1343  *
1344  * This section details a recommended set of parameters that should
1345  * be contained within the TCB for an implementation. This section is
1346  * for illustrative purposes and should not be deemed as requirements
1347  * on an implementation or as an exhaustive list of all parameters
1348  * inside an SCTP TCB. Each implementation may need its own additional
1349  * parameters for optimization.
1350  */
1351 
1352 
1353 /* Here we have information about each individual association. */
1354 struct sctp_association {
1355 
1356 	/* A base structure common to endpoint and association.
1357 	 * In this context, it represents the associations's view
1358 	 * of the local endpoint of the association.
1359 	 */
1360 	struct sctp_ep_common base;
1361 
1362 	/* Associations on the same socket. */
1363 	struct list_head asocs;
1364 
1365 	/* association id. */
1366 	sctp_assoc_t assoc_id;
1367 
1368 	/* This is our parent endpoint.	 */
1369 	struct sctp_endpoint *ep;
1370 
1371 	/* These are those association elements needed in the cookie.  */
1372 	struct sctp_cookie c;
1373 
1374 	/* This is all information about our peer.  */
1375 	struct {
1376 		/* transport_addr_list
1377 		 *
1378 		 * Peer	       : A list of SCTP transport addresses that the
1379 		 * Transport   : peer is bound to. This information is derived
1380 		 * Address     : from the INIT or INIT ACK and is used to
1381 		 * List	       : associate an inbound packet with a given
1382 		 *	       : association. Normally this information is
1383 		 *	       : hashed or keyed for quick lookup and access
1384 		 *	       : of the TCB.
1385 		 *	       : The list is also initialized with the list
1386 		 *	       : of addresses passed with the sctp_connectx()
1387 		 *	       : call.
1388 		 *
1389 		 * It is a list of SCTP_transport's.
1390 		 */
1391 		struct list_head transport_addr_list;
1392 
1393 		/* rwnd
1394 		 *
1395 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1396 		 */
1397 		__u32 rwnd;
1398 
1399 		/* transport_count
1400 		 *
1401 		 * Peer        : A count of the number of peer addresses
1402 		 * Transport   : in the Peer Transport Address List.
1403 		 * Address     :
1404 		 * Count       :
1405 		 */
1406 		__u16 transport_count;
1407 
1408 		/* port
1409 		 *   The transport layer port number.
1410 		 */
1411 		__u16 port;
1412 
1413 		/* primary_path
1414 		 *
1415 		 * Primary     : This is the current primary destination
1416 		 * Path	       : transport address of the peer endpoint.  It
1417 		 *	       : may also specify a source transport address
1418 		 *	       : on this endpoint.
1419 		 *
1420 		 * All of these paths live on transport_addr_list.
1421 		 *
1422 		 * At the bakeoffs, we discovered that the intent of
1423 		 * primaryPath is that it only changes when the ULP
1424 		 * asks to have it changed.  We add the activePath to
1425 		 * designate the connection we are currently using to
1426 		 * transmit new data and most control chunks.
1427 		 */
1428 		struct sctp_transport *primary_path;
1429 
1430 		/* Cache the primary path address here, when we
1431 		 * need a an address for msg_name.
1432 		 */
1433 		union sctp_addr primary_addr;
1434 
1435 		/* active_path
1436 		 *   The path that we are currently using to
1437 		 *   transmit new data and most control chunks.
1438 		 */
1439 		struct sctp_transport *active_path;
1440 
1441 		/* retran_path
1442 		 *
1443 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1444 		 * ...
1445 		 * Furthermore, when its peer is multi-homed, an
1446 		 * endpoint SHOULD try to retransmit a chunk to an
1447 		 * active destination transport address that is
1448 		 * different from the last destination address to
1449 		 * which the DATA chunk was sent.
1450 		 */
1451 		struct sctp_transport *retran_path;
1452 
1453 		/* Pointer to last transport I have sent on.  */
1454 		struct sctp_transport *last_sent_to;
1455 
1456 		/* This is the last transport I have received DATA on.	*/
1457 		struct sctp_transport *last_data_from;
1458 
1459 		/*
1460 		 * Mapping  An array of bits or bytes indicating which out of
1461 		 * Array    order TSN's have been received (relative to the
1462 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1463 		 *	    order packets have been received, this array
1464 		 *	    will be set to all zero. This structure may be
1465 		 *	    in the form of a circular buffer or bit array.
1466 		 *
1467 		 * Last Rcvd   : This is the last TSN received in
1468 		 * TSN	       : sequence. This value is set initially by
1469 		 *	       : taking the peer's Initial TSN, received in
1470 		 *	       : the INIT or INIT ACK chunk, and subtracting
1471 		 *	       : one from it.
1472 		 *
1473 		 * Throughout most of the specification this is called the
1474 		 * "Cumulative TSN ACK Point".	In this case, we
1475 		 * ignore the advice in 12.2 in favour of the term
1476 		 * used in the bulk of the text.  This value is hidden
1477 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1478 		 */
1479 		struct sctp_tsnmap tsn_map;
1480 
1481 		/* This mask is used to disable sending the ASCONF chunk
1482 		 * with specified parameter to peer.
1483 		 */
1484 		__be16 addip_disabled_mask;
1485 
1486 		/* These are capabilities which our peer advertised.  */
1487 		__u8	ecn_capable:1,      /* Can peer do ECN? */
1488 			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1489 			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1490 			hostname_address:1, /* Peer understands DNS addresses? */
1491 			asconf_capable:1,   /* Does peer support ADDIP? */
1492 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1493 			auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1494 
1495 		/* sack_needed : This flag indicates if the next received
1496 		 *             : packet is to be responded to with a
1497 		 *             : SACK. This is initialized to 0.  When a packet
1498 		 *             : is received sack_cnt is incremented. If this value
1499 		 *             : reaches 2 or more, a SACK is sent and the
1500 		 *             : value is reset to 0. Note: This is used only
1501 		 *             : when no DATA chunks are received out of
1502 		 *             : order.  When DATA chunks are out of order,
1503 		 *             : SACK's are not delayed (see Section 6).
1504 		 */
1505 		__u8    sack_needed:1,     /* Do we need to sack the peer? */
1506 			sack_generation:1,
1507 			zero_window_announced:1;
1508 		__u32	sack_cnt;
1509 
1510 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1511 
1512 		struct sctp_inithdr_host i;
1513 		void *cookie;
1514 		int cookie_len;
1515 
1516 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1517 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1518 		 * Initial TSN Value minus 1
1519 		 */
1520 		__u32 addip_serial;
1521 
1522 		/* SCTP-AUTH: We need to know pears random number, hmac list
1523 		 * and authenticated chunk list.  All that is part of the
1524 		 * cookie and these are just pointers to those locations
1525 		 */
1526 		sctp_random_param_t *peer_random;
1527 		sctp_chunks_param_t *peer_chunks;
1528 		sctp_hmac_algo_param_t *peer_hmacs;
1529 	} peer;
1530 
1531 	/* State       : A state variable indicating what state the
1532 	 *	       : association is in, i.e. COOKIE-WAIT,
1533 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1534 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1535 	 *
1536 	 *		Note: No "CLOSED" state is illustrated since if a
1537 	 *		association is "CLOSED" its TCB SHOULD be removed.
1538 	 *
1539 	 *		In this implementation we DO have a CLOSED
1540 	 *		state which is used during initiation and shutdown.
1541 	 *
1542 	 *		State takes values from SCTP_STATE_*.
1543 	 */
1544 	sctp_state_t state;
1545 
1546 	/* Overall     : The overall association error count.
1547 	 * Error Count : [Clear this any time I get something.]
1548 	 */
1549 	int overall_error_count;
1550 
1551 	/* The cookie life I award for any cookie.  */
1552 	ktime_t cookie_life;
1553 
1554 	/* These are the association's initial, max, and min RTO values.
1555 	 * These values will be initialized by system defaults, but can
1556 	 * be modified via the SCTP_RTOINFO socket option.
1557 	 */
1558 	unsigned long rto_initial;
1559 	unsigned long rto_max;
1560 	unsigned long rto_min;
1561 
1562 	/* Maximum number of new data packets that can be sent in a burst.  */
1563 	int max_burst;
1564 
1565 	/* This is the max_retrans value for the association.  This value will
1566 	 * be initialized initialized from system defaults, but can be
1567 	 * modified by the SCTP_ASSOCINFO socket option.
1568 	 */
1569 	int max_retrans;
1570 
1571 	/* This is the partially failed retrans value for the transport
1572 	 * and will be initialized from the assocs value.  This can be
1573 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1574 	 */
1575 	int pf_retrans;
1576 
1577 	/* Maximum number of times the endpoint will retransmit INIT  */
1578 	__u16 max_init_attempts;
1579 
1580 	/* How many times have we resent an INIT? */
1581 	__u16 init_retries;
1582 
1583 	/* The largest timeout or RTO value to use in attempting an INIT */
1584 	unsigned long max_init_timeo;
1585 
1586 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1587 	 * the destination address every heartbeat interval. This value
1588 	 * will be inherited by all new transports.
1589 	 */
1590 	unsigned long hbinterval;
1591 
1592 	/* This is the max_retrans value for new transports in the
1593 	 * association.
1594 	 */
1595 	__u16 pathmaxrxt;
1596 
1597 	/* Flag that path mtu update is pending */
1598 	__u8   pmtu_pending;
1599 
1600 	/* Association : The smallest PMTU discovered for all of the
1601 	 * PMTU	       : peer's transport addresses.
1602 	 */
1603 	__u32 pathmtu;
1604 
1605 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1606 	__u32 param_flags;
1607 
1608 	__u32 sackfreq;
1609 	/* SACK delay timeout */
1610 	unsigned long sackdelay;
1611 
1612 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1613 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1614 
1615 	/* Transport to which SHUTDOWN chunk was last sent.  */
1616 	struct sctp_transport *shutdown_last_sent_to;
1617 
1618 	/* Transport to which INIT chunk was last sent.  */
1619 	struct sctp_transport *init_last_sent_to;
1620 
1621 	/* How many times have we resent a SHUTDOWN */
1622 	int shutdown_retries;
1623 
1624 	/* Next TSN    : The next TSN number to be assigned to a new
1625 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1626 	 *	       : ACK chunk to the peer and incremented each
1627 	 *	       : time a DATA chunk is assigned a TSN
1628 	 *	       : (normally just prior to transmit or during
1629 	 *	       : fragmentation).
1630 	 */
1631 	__u32 next_tsn;
1632 
1633 	/*
1634 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1635 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1636 	 *	       : received in the INIT or INIT ACK chunk, and
1637 	 *	       : subtracting one from it.
1638 	 *
1639 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1640 	 */
1641 
1642 	__u32 ctsn_ack_point;
1643 
1644 	/* PR-SCTP Advanced.Peer.Ack.Point */
1645 	__u32 adv_peer_ack_point;
1646 
1647 	/* Highest TSN that is acknowledged by incoming SACKs. */
1648 	__u32 highest_sacked;
1649 
1650 	/* TSN marking the fast recovery exit point */
1651 	__u32 fast_recovery_exit;
1652 
1653 	/* Flag to track the current fast recovery state */
1654 	__u8 fast_recovery;
1655 
1656 	/* The number of unacknowledged data chunks.  Reported through
1657 	 * the SCTP_STATUS sockopt.
1658 	 */
1659 	__u16 unack_data;
1660 
1661 	/* The total number of data chunks that we've had to retransmit
1662 	 * as the result of a T3 timer expiration
1663 	 */
1664 	__u32 rtx_data_chunks;
1665 
1666 	/* This is the association's receive buffer space.  This value is used
1667 	 * to set a_rwnd field in an INIT or a SACK chunk.
1668 	 */
1669 	__u32 rwnd;
1670 
1671 	/* This is the last advertised value of rwnd over a SACK chunk. */
1672 	__u32 a_rwnd;
1673 
1674 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1675 	 * to slop over a maximum of the association's frag_point.
1676 	 */
1677 	__u32 rwnd_over;
1678 
1679 	/* Keeps treack of rwnd pressure.  This happens when we have
1680 	 * a window, but not recevie buffer (i.e small packets).  This one
1681 	 * is releases slowly (1 PMTU at a time ).
1682 	 */
1683 	__u32 rwnd_press;
1684 
1685 	/* This is the sndbuf size in use for the association.
1686 	 * This corresponds to the sndbuf size for the association,
1687 	 * as specified in the sk->sndbuf.
1688 	 */
1689 	int sndbuf_used;
1690 
1691 	/* This is the amount of memory that this association has allocated
1692 	 * in the receive path at any given time.
1693 	 */
1694 	atomic_t rmem_alloc;
1695 
1696 	/* This is the wait queue head for send requests waiting on
1697 	 * the association sndbuf space.
1698 	 */
1699 	wait_queue_head_t	wait;
1700 
1701 	/* The message size at which SCTP fragmentation will occur. */
1702 	__u32 frag_point;
1703 	__u32 user_frag;
1704 
1705 	/* Counter used to count INIT errors. */
1706 	int init_err_counter;
1707 
1708 	/* Count the number of INIT cycles (for doubling timeout). */
1709 	int init_cycle;
1710 
1711 	/* Default send parameters. */
1712 	__u16 default_stream;
1713 	__u16 default_flags;
1714 	__u32 default_ppid;
1715 	__u32 default_context;
1716 	__u32 default_timetolive;
1717 
1718 	/* Default receive parameters */
1719 	__u32 default_rcv_context;
1720 
1721 	/* This tracks outbound ssn for a given stream.	 */
1722 	struct sctp_ssnmap *ssnmap;
1723 
1724 	/* All outbound chunks go through this structure.  */
1725 	struct sctp_outq outqueue;
1726 
1727 	/* A smart pipe that will handle reordering and fragmentation,
1728 	 * as well as handle passing events up to the ULP.
1729 	 */
1730 	struct sctp_ulpq ulpq;
1731 
1732 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1733 	__u32 last_ecne_tsn;
1734 
1735 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1736 	__u32 last_cwr_tsn;
1737 
1738 	/* How many duplicated TSNs have we seen?  */
1739 	int numduptsns;
1740 
1741 	/* These are to support
1742 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1743 	 *  and Enforcement of Flow and Message Limits"
1744 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1745 	 * or "ADDIP" for short.
1746 	 */
1747 
1748 
1749 
1750 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1751 	 *
1752 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1753 	 * unacknowledged at any one time.  If a sender, after sending
1754 	 * an ASCONF chunk, decides it needs to transfer another
1755 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1756 	 * returns from the previous ASCONF Chunk before sending a
1757 	 * subsequent ASCONF. Note this restriction binds each side,
1758 	 * so at any time two ASCONF may be in-transit on any given
1759 	 * association (one sent from each endpoint).
1760 	 *
1761 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1762 	 * not have an ASCONF in flight, this is NULL.]
1763 	 */
1764 	struct sctp_chunk *addip_last_asconf;
1765 
1766 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1767 	 *
1768 	 * This is needed to implement itmes E1 - E4 of the updated
1769 	 * spec.  Here is the justification:
1770 	 *
1771 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1772 	 * we now need the ability to cache multiple ACKs.  The section
1773 	 * describes in detail how they are cached and cleaned up.
1774 	 */
1775 	struct list_head asconf_ack_list;
1776 
1777 	/* These ASCONF chunks are waiting to be sent.
1778 	 *
1779 	 * These chunaks can't be pushed to outqueue until receiving
1780 	 * ASCONF_ACK for the previous ASCONF indicated by
1781 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1782 	 * is in flight at any time.
1783 	 *
1784 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1785 	 *
1786 	 * In defining the ASCONF Chunk transfer procedures, it is
1787 	 * essential that these transfers MUST NOT cause congestion
1788 	 * within the network.	To achieve this, we place these
1789 	 * restrictions on the transfer of ASCONF Chunks:
1790 	 *
1791 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1792 	 * unacknowledged at any one time.  If a sender, after sending
1793 	 * an ASCONF chunk, decides it needs to transfer another
1794 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1795 	 * returns from the previous ASCONF Chunk before sending a
1796 	 * subsequent ASCONF. Note this restriction binds each side,
1797 	 * so at any time two ASCONF may be in-transit on any given
1798 	 * association (one sent from each endpoint).
1799 	 *
1800 	 *
1801 	 * [I really think this is EXACTLY the sort of intelligence
1802 	 *  which already resides in sctp_outq.	 Please move this
1803 	 *  queue and its supporting logic down there.	--piggy]
1804 	 */
1805 	struct list_head addip_chunk_list;
1806 
1807 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1808 	 *
1809 	 * A2) A serial number should be assigned to the Chunk. The
1810 	 * serial number SHOULD be a monotonically increasing
1811 	 * number. The serial number SHOULD be initialized at
1812 	 * the start of the association to the same value as the
1813 	 * Initial TSN and every time a new ASCONF chunk is created
1814 	 * it is incremented by one after assigning the serial number
1815 	 * to the newly created chunk.
1816 	 *
1817 	 * ADDIP
1818 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1819 	 *
1820 	 * Serial Number : 32 bits (unsigned integer)
1821 	 *
1822 	 * This value represents a Serial Number for the ASCONF
1823 	 * Chunk. The valid range of Serial Number is from 0 to
1824 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1825 	 * after reaching 4294967295.
1826 	 */
1827 	__u32 addip_serial;
1828 	int src_out_of_asoc_ok;
1829 	union sctp_addr *asconf_addr_del_pending;
1830 	struct sctp_transport *new_transport;
1831 
1832 	/* SCTP AUTH: list of the endpoint shared keys.  These
1833 	 * keys are provided out of band by the user applicaton
1834 	 * and can't change during the lifetime of the association
1835 	 */
1836 	struct list_head endpoint_shared_keys;
1837 
1838 	/* SCTP AUTH:
1839 	 * The current generated assocaition shared key (secret)
1840 	 */
1841 	struct sctp_auth_bytes *asoc_shared_key;
1842 
1843 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1844 	 * that we support.
1845 	 */
1846 	__u16 default_hmac_id;
1847 
1848 	__u16 active_key_id;
1849 
1850 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1851 	     temp:1;		/* Is it a temporary association? */
1852 
1853 	struct sctp_priv_assoc_stats stats;
1854 };
1855 
1856 
1857 /* An eyecatcher for determining if we are really looking at an
1858  * association data structure.
1859  */
1860 enum {
1861 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1862 };
1863 
1864 /* Recover the outter association structure. */
1865 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1866 {
1867 	struct sctp_association *asoc;
1868 
1869 	asoc = container_of(base, struct sctp_association, base);
1870 	return asoc;
1871 }
1872 
1873 /* These are function signatures for manipulating associations.	 */
1874 
1875 
1876 struct sctp_association *
1877 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1878 		     sctp_scope_t scope, gfp_t gfp);
1879 void sctp_association_free(struct sctp_association *);
1880 void sctp_association_put(struct sctp_association *);
1881 void sctp_association_hold(struct sctp_association *);
1882 
1883 struct sctp_transport *sctp_assoc_choose_alter_transport(
1884 	struct sctp_association *, struct sctp_transport *);
1885 void sctp_assoc_update_retran_path(struct sctp_association *);
1886 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1887 					  const union sctp_addr *);
1888 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1889 			    const union sctp_addr *laddr);
1890 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1891 				     const union sctp_addr *address,
1892 				     const gfp_t gfp,
1893 				     const int peer_state);
1894 void sctp_assoc_del_peer(struct sctp_association *asoc,
1895 			 const union sctp_addr *addr);
1896 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1897 			 struct sctp_transport *peer);
1898 void sctp_assoc_control_transport(struct sctp_association *,
1899 				  struct sctp_transport *,
1900 				  sctp_transport_cmd_t, sctp_sn_error_t);
1901 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1902 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1903 					   struct net *,
1904 					   const union sctp_addr *,
1905 					   const union sctp_addr *);
1906 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1907 void sctp_assoc_update(struct sctp_association *old,
1908 		       struct sctp_association *new);
1909 
1910 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1911 
1912 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1913 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1914 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1915 void sctp_assoc_set_primary(struct sctp_association *,
1916 			    struct sctp_transport *);
1917 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1918 				    struct sctp_transport *);
1919 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1920 				     sctp_scope_t, gfp_t);
1921 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1922 					 struct sctp_cookie*,
1923 					 gfp_t gfp);
1924 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1925 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1926 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1927 					const struct sctp_association *asoc,
1928 					__be32 serial);
1929 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1930 
1931 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1932 			const union sctp_addr *ss2);
1933 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1934 
1935 /* A convenience structure to parse out SCTP specific CMSGs. */
1936 typedef struct sctp_cmsgs {
1937 	struct sctp_initmsg *init;
1938 	struct sctp_sndrcvinfo *srinfo;
1939 	struct sctp_sndinfo *sinfo;
1940 } sctp_cmsgs_t;
1941 
1942 /* Structure for tracking memory objects */
1943 typedef struct {
1944 	char *label;
1945 	atomic_t *counter;
1946 } sctp_dbg_objcnt_entry_t;
1947 
1948 #endif /* __sctp_structs_h__ */
1949