xref: /openbmc/linux/include/net/sctp/structs.h (revision 95b384f9)
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 	/* These are the SCTP headers by reverse order in a packet.
570 	 * Note that some of these may happen more than once.  In that
571 	 * case, we point at the "current" one, whatever that means
572 	 * for that level of header.
573 	 */
574 
575 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
576 	union sctp_params param_hdr;
577 	union {
578 		__u8 *v;
579 		struct sctp_datahdr *data_hdr;
580 		struct sctp_inithdr *init_hdr;
581 		struct sctp_sackhdr *sack_hdr;
582 		struct sctp_heartbeathdr *hb_hdr;
583 		struct sctp_sender_hb_info *hbs_hdr;
584 		struct sctp_shutdownhdr *shutdown_hdr;
585 		struct sctp_signed_cookie *cookie_hdr;
586 		struct sctp_ecnehdr *ecne_hdr;
587 		struct sctp_cwrhdr *ecn_cwr_hdr;
588 		struct sctp_errhdr *err_hdr;
589 		struct sctp_addiphdr *addip_hdr;
590 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
591 		struct sctp_authhdr *auth_hdr;
592 	} subh;
593 
594 	__u8 *chunk_end;
595 
596 	struct sctp_chunkhdr *chunk_hdr;
597 	struct sctphdr *sctp_hdr;
598 
599 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
600 	struct sctp_sndrcvinfo sinfo;
601 
602 	/* Which association does this belong to?  */
603 	struct sctp_association *asoc;
604 
605 	/* What endpoint received this chunk? */
606 	struct sctp_ep_common *rcvr;
607 
608 	/* We fill this in if we are calculating RTT. */
609 	unsigned long sent_at;
610 
611 	/* What is the origin IP address for this chunk?  */
612 	union sctp_addr source;
613 	/* Destination address for this chunk. */
614 	union sctp_addr dest;
615 
616 	/* For outbound message, track all fragments for SEND_FAILED. */
617 	struct sctp_datamsg *msg;
618 
619 	/* For an inbound chunk, this tells us where it came from.
620 	 * For an outbound chunk, it tells us where we'd like it to
621 	 * go.	It is NULL if we have no preference.
622 	 */
623 	struct sctp_transport *transport;
624 
625 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
626 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
627 	 * spec violates the principle premis that all chunks are processed
628 	 * in order.
629 	 */
630 	struct sk_buff *auth_chunk;
631 
632 #define SCTP_CAN_FRTX 0x0
633 #define SCTP_NEED_FRTX 0x1
634 #define SCTP_DONT_FRTX 0x2
635 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
636 		resent:1,		/* Has this chunk ever been resent. */
637 		has_tsn:1,		/* Does this chunk have a TSN yet? */
638 		has_ssn:1,		/* Does this chunk have a SSN yet? */
639 		singleton:1,		/* Only chunk in the packet? */
640 		end_of_packet:1,	/* Last chunk in the packet? */
641 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
642 		pdiscard:1,		/* Discard the whole packet now? */
643 		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
644 		data_accepted:1,	/* At least 1 chunk accepted */
645 		auth:1,			/* IN: was auth'ed | OUT: needs auth */
646 		has_asconf:1,		/* IN: have seen an asconf before */
647 		tsn_missing_report:2,	/* Data chunk missing counter. */
648 		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
649 };
650 
651 void sctp_chunk_hold(struct sctp_chunk *);
652 void sctp_chunk_put(struct sctp_chunk *);
653 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
654 			  struct iov_iter *from);
655 void sctp_chunk_free(struct sctp_chunk *);
656 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
657 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
658 				 const struct sctp_association *,
659 				 struct sock *, gfp_t gfp);
660 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
661 		     union sctp_addr *);
662 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
663 
664 enum {
665 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
666 	SCTP_ADDR_SRC,		/* address can be used as source */
667 	SCTP_ADDR_DEL,		/* address about to be deleted */
668 };
669 
670 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
671 struct sctp_sockaddr_entry {
672 	struct list_head list;
673 	struct rcu_head	rcu;
674 	union sctp_addr a;
675 	__u8 state;
676 	__u8 valid;
677 };
678 
679 #define SCTP_ADDRESS_TICK_DELAY	500
680 
681 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
682 
683 /* This structure holds lists of chunks as we are assembling for
684  * transmission.
685  */
686 struct sctp_packet {
687 	/* These are the SCTP header values (host order) for the packet. */
688 	__u16 source_port;
689 	__u16 destination_port;
690 	__u32 vtag;
691 
692 	/* This contains the payload chunks.  */
693 	struct list_head chunk_list;
694 
695 	/* This is the overhead of the sctp and ip headers. */
696 	size_t overhead;
697 	/* This is the total size of all chunks INCLUDING padding.  */
698 	size_t size;
699 
700 	/* The packet is destined for this transport address.
701 	 * The function we finally use to pass down to the next lower
702 	 * layer lives in the transport structure.
703 	 */
704 	struct sctp_transport *transport;
705 
706 	/* pointer to the auth chunk for this packet */
707 	struct sctp_chunk *auth;
708 
709 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
710 	    has_sack:1,		/* This packet contains a SACK chunk. */
711 	    has_auth:1,		/* This packet contains an AUTH chunk */
712 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
713 	    ipfragok:1;		/* So let ip fragment this packet */
714 };
715 
716 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
717 				     struct sctp_transport *,
718 				     __u16 sport, __u16 dport);
719 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
720 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
721 				       struct sctp_chunk *, int, gfp_t);
722 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
723                                      struct sctp_chunk *);
724 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
725 void sctp_packet_free(struct sctp_packet *);
726 
727 static inline int sctp_packet_empty(struct sctp_packet *packet)
728 {
729 	return packet->size == packet->overhead;
730 }
731 
732 /* This represents a remote transport address.
733  * For local transport addresses, we just use union sctp_addr.
734  *
735  * RFC2960 Section 1.4 Key Terms
736  *
737  *   o	Transport address:  A Transport Address is traditionally defined
738  *	by Network Layer address, Transport Layer protocol and Transport
739  *	Layer port number.  In the case of SCTP running over IP, a
740  *	transport address is defined by the combination of an IP address
741  *	and an SCTP port number (where SCTP is the Transport protocol).
742  *
743  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
744  *
745  *   o	The sender keeps a separate congestion control parameter set for
746  *	each of the destination addresses it can send to (not each
747  *	source-destination pair but for each destination).  The parameters
748  *	should decay if the address is not used for a long enough time
749  *	period.
750  *
751  */
752 struct sctp_transport {
753 	/* A list of transports. */
754 	struct list_head transports;
755 	struct rhash_head node;
756 
757 	/* Reference counting. */
758 	atomic_t refcnt;
759 		/* RTO-Pending : A flag used to track if one of the DATA
760 		 *		chunks sent to this address is currently being
761 		 *		used to compute a RTT. If this flag is 0,
762 		 *		the next DATA chunk sent to this destination
763 		 *		should be used to compute a RTT and this flag
764 		 *		should be set. Every time the RTT
765 		 *		calculation completes (i.e. the DATA chunk
766 		 *		is SACK'd) clear this flag.
767 		 */
768 	__u32	rto_pending:1,
769 
770 		/*
771 		 * hb_sent : a flag that signals that we have a pending
772 		 * heartbeat.
773 		 */
774 		hb_sent:1,
775 
776 		/* Is the Path MTU update pending on this tranport */
777 		pmtu_pending:1,
778 
779 		/* Has this transport moved the ctsn since we last sacked */
780 		sack_generation:1;
781 	u32 dst_cookie;
782 
783 	struct flowi fl;
784 
785 	/* This is the peer's IP address and port. */
786 	union sctp_addr ipaddr;
787 
788 	/* These are the functions we call to handle LLP stuff.	 */
789 	struct sctp_af *af_specific;
790 
791 	/* Which association do we belong to?  */
792 	struct sctp_association *asoc;
793 
794 	/* RFC2960
795 	 *
796 	 * 12.3 Per Transport Address Data
797 	 *
798 	 * For each destination transport address in the peer's
799 	 * address list derived from the INIT or INIT ACK chunk, a
800 	 * number of data elements needs to be maintained including:
801 	 */
802 	/* RTO	       : The current retransmission timeout value.  */
803 	unsigned long rto;
804 
805 	__u32 rtt;		/* This is the most recent RTT.	 */
806 
807 	/* RTTVAR      : The current RTT variation.  */
808 	__u32 rttvar;
809 
810 	/* SRTT	       : The current smoothed round trip time.	*/
811 	__u32 srtt;
812 
813 	/*
814 	 * These are the congestion stats.
815 	 */
816 	/* cwnd	       : The current congestion window.	 */
817 	__u32 cwnd;		  /* This is the actual cwnd.  */
818 
819 	/* ssthresh    : The current slow start threshold value.  */
820 	__u32 ssthresh;
821 
822 	/* partial     : The tracking method for increase of cwnd when in
823 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
824 	 */
825 	__u32 partial_bytes_acked;
826 
827 	/* Data that has been sent, but not acknowledged. */
828 	__u32 flight_size;
829 
830 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
831 
832 	/* Destination */
833 	struct dst_entry *dst;
834 	/* Source address. */
835 	union sctp_addr saddr;
836 
837 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
838 	 * the destination address every heartbeat interval.
839 	 */
840 	unsigned long hbinterval;
841 
842 	/* SACK delay timeout */
843 	unsigned long sackdelay;
844 	__u32 sackfreq;
845 
846 	/* When was the last time that we heard from this transport? We use
847 	 * this to pick new active and retran paths.
848 	 */
849 	ktime_t last_time_heard;
850 
851 	/* When was the last time that we sent a chunk using this
852 	 * transport? We use this to check for idle transports
853 	 */
854 	unsigned long last_time_sent;
855 
856 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
857 	 * indication based on ECNE chunk.
858 	 */
859 	unsigned long last_time_ecne_reduced;
860 
861 	/* This is the max_retrans value for the transport and will
862 	 * be initialized from the assocs value.  This can be changed
863 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
864 	 */
865 	__u16 pathmaxrxt;
866 
867 	/* This is the partially failed retrans value for the transport
868 	 * and will be initialized from the assocs value.  This can be changed
869 	 * using the SCTP_PEER_ADDR_THLDS socket option
870 	 */
871 	int pf_retrans;
872 	/* PMTU	      : The current known path MTU.  */
873 	__u32 pathmtu;
874 
875 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
876 	__u32 param_flags;
877 
878 	/* The number of times INIT has been sent on this transport. */
879 	int init_sent_count;
880 
881 	/* state       : The current state of this destination,
882 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
883 	 */
884 	int state;
885 
886 	/* These are the error stats for this destination.  */
887 
888 	/* Error count : The current error count for this destination.	*/
889 	unsigned short error_count;
890 
891 	/* Per	       : A timer used by each destination.
892 	 * Destination :
893 	 * Timer       :
894 	 *
895 	 * [Everywhere else in the text this is called T3-rtx. -ed]
896 	 */
897 	struct timer_list T3_rtx_timer;
898 
899 	/* Heartbeat timer is per destination. */
900 	struct timer_list hb_timer;
901 
902 	/* Timer to handle ICMP proto unreachable envets */
903 	struct timer_list proto_unreach_timer;
904 
905 	/* Since we're using per-destination retransmission timers
906 	 * (see above), we're also using per-destination "transmitted"
907 	 * queues.  This probably ought to be a private struct
908 	 * accessible only within the outqueue, but it's not, yet.
909 	 */
910 	struct list_head transmitted;
911 
912 	/* We build bundle-able packets for this transport here.  */
913 	struct sctp_packet packet;
914 
915 	/* This is the list of transports that have chunks to send.  */
916 	struct list_head send_ready;
917 
918 	/* State information saved for SFR_CACC algorithm. The key
919 	 * idea in SFR_CACC is to maintain state at the sender on a
920 	 * per-destination basis when a changeover happens.
921 	 *	char changeover_active;
922 	 *	char cycling_changeover;
923 	 *	__u32 next_tsn_at_change;
924 	 *	char cacc_saw_newack;
925 	 */
926 	struct {
927 		/* An unsigned integer, which stores the next TSN to be
928 		 * used by the sender, at the moment of changeover.
929 		 */
930 		__u32 next_tsn_at_change;
931 
932 		/* A flag which indicates the occurrence of a changeover */
933 		char changeover_active;
934 
935 		/* A flag which indicates whether the change of primary is
936 		 * the first switch to this destination address during an
937 		 * active switch.
938 		 */
939 		char cycling_changeover;
940 
941 		/* A temporary flag, which is used during the processing of
942 		 * a SACK to estimate the causative TSN(s)'s group.
943 		 */
944 		char cacc_saw_newack;
945 	} cacc;
946 
947 	/* 64-bit random number sent with heartbeat. */
948 	__u64 hb_nonce;
949 
950 	struct rcu_head rcu;
951 };
952 
953 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
954 					  gfp_t);
955 void sctp_transport_set_owner(struct sctp_transport *,
956 			      struct sctp_association *);
957 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
958 			  struct sctp_sock *);
959 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
960 void sctp_transport_free(struct sctp_transport *);
961 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
962 void sctp_transport_reset_hb_timer(struct sctp_transport *);
963 int sctp_transport_hold(struct sctp_transport *);
964 void sctp_transport_put(struct sctp_transport *);
965 void sctp_transport_update_rto(struct sctp_transport *, __u32);
966 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
967 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
968 void sctp_transport_burst_limited(struct sctp_transport *);
969 void sctp_transport_burst_reset(struct sctp_transport *);
970 unsigned long sctp_transport_timeout(struct sctp_transport *);
971 void sctp_transport_reset(struct sctp_transport *);
972 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
973 void sctp_transport_immediate_rtx(struct sctp_transport *);
974 
975 
976 /* This is the structure we use to queue packets as they come into
977  * SCTP.  We write packets to it and read chunks from it.
978  */
979 struct sctp_inq {
980 	/* This is actually a queue of sctp_chunk each
981 	 * containing a partially decoded packet.
982 	 */
983 	struct list_head in_chunk_list;
984 	/* This is the packet which is currently off the in queue and is
985 	 * being worked on through the inbound chunk processing.
986 	 */
987 	struct sctp_chunk *in_progress;
988 
989 	/* This is the delayed task to finish delivering inbound
990 	 * messages.
991 	 */
992 	struct work_struct immediate;
993 };
994 
995 void sctp_inq_init(struct sctp_inq *);
996 void sctp_inq_free(struct sctp_inq *);
997 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
998 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
999 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1000 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1001 
1002 /* This is the structure we use to hold outbound chunks.  You push
1003  * chunks in and they automatically pop out the other end as bundled
1004  * packets (it calls (*output_handler)()).
1005  *
1006  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1007  * and 8.2 of the v13 draft.
1008  *
1009  * It handles retransmissions.	The connection to the timeout portion
1010  * of the state machine is through sctp_..._timeout() and timeout_handler.
1011  *
1012  * If you feed it SACKs, it will eat them.
1013  *
1014  * If you give it big chunks, it will fragment them.
1015  *
1016  * It assigns TSN's to data chunks.  This happens at the last possible
1017  * instant before transmission.
1018  *
1019  * When free()'d, it empties itself out via output_handler().
1020  */
1021 struct sctp_outq {
1022 	struct sctp_association *asoc;
1023 
1024 	/* Data pending that has never been transmitted.  */
1025 	struct list_head out_chunk_list;
1026 
1027 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1028 
1029 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1030 	unsigned int error;
1031 
1032 	/* These are control chunks we want to send.  */
1033 	struct list_head control_chunk_list;
1034 
1035 	/* These are chunks that have been sacked but are above the
1036 	 * CTSN, or cumulative tsn ack point.
1037 	 */
1038 	struct list_head sacked;
1039 
1040 	/* Put chunks on this list to schedule them for
1041 	 * retransmission.
1042 	 */
1043 	struct list_head retransmit;
1044 
1045 	/* Put chunks on this list to save them for FWD TSN processing as
1046 	 * they were abandoned.
1047 	 */
1048 	struct list_head abandoned;
1049 
1050 	/* How many unackd bytes do we have in-flight?	*/
1051 	__u32 outstanding_bytes;
1052 
1053 	/* Are we doing fast-rtx on this queue */
1054 	char fast_rtx;
1055 
1056 	/* Corked? */
1057 	char cork;
1058 };
1059 
1060 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1061 void sctp_outq_teardown(struct sctp_outq *);
1062 void sctp_outq_free(struct sctp_outq*);
1063 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1064 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1065 int sctp_outq_is_empty(const struct sctp_outq *);
1066 void sctp_outq_restart(struct sctp_outq *);
1067 
1068 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1069 		     sctp_retransmit_reason_t);
1070 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1071 int sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1072 /* Uncork and flush an outqueue.  */
1073 static inline void sctp_outq_cork(struct sctp_outq *q)
1074 {
1075 	q->cork = 1;
1076 }
1077 
1078 /* These bind address data fields common between endpoints and associations */
1079 struct sctp_bind_addr {
1080 
1081 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1082 	 *
1083 	 * SCTP Port:	The local SCTP port number the endpoint is
1084 	 *		bound to.
1085 	 */
1086 	__u16 port;
1087 
1088 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1089 	 *
1090 	 * Address List: The list of IP addresses that this instance
1091 	 *	has bound.  This information is passed to one's
1092 	 *	peer(s) in INIT and INIT ACK chunks.
1093 	 */
1094 	struct list_head address_list;
1095 };
1096 
1097 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1098 void sctp_bind_addr_free(struct sctp_bind_addr *);
1099 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1100 			const struct sctp_bind_addr *src,
1101 			sctp_scope_t scope, gfp_t gfp,
1102 			int flags);
1103 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1104 			const struct sctp_bind_addr *src,
1105 			gfp_t gfp);
1106 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1107 		       int new_size, __u8 addr_state, gfp_t gfp);
1108 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1109 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1110 			 struct sctp_sock *);
1111 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1112 			 struct sctp_sock *, struct sctp_sock *);
1113 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1114 			 const union sctp_addr *addr);
1115 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1116 					const union sctp_addr	*addrs,
1117 					int			addrcnt,
1118 					struct sctp_sock	*opt);
1119 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1120 					 int *addrs_len,
1121 					 gfp_t gfp);
1122 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1123 			   __u16 port, gfp_t gfp);
1124 
1125 sctp_scope_t sctp_scope(const union sctp_addr *);
1126 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1127 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1128 int sctp_is_ep_boundall(struct sock *sk);
1129 
1130 
1131 /* What type of endpoint?  */
1132 typedef enum {
1133 	SCTP_EP_TYPE_SOCKET,
1134 	SCTP_EP_TYPE_ASSOCIATION,
1135 } sctp_endpoint_type_t;
1136 
1137 /*
1138  * A common base class to bridge the implmentation view of a
1139  * socket (usually listening) endpoint versus an association's
1140  * local endpoint.
1141  * This common structure is useful for several purposes:
1142  *   1) Common interface for lookup routines.
1143  *	a) Subfunctions work for either endpoint or association
1144  *	b) Single interface to lookup allows hiding the lookup lock rather
1145  *	   than acquiring it externally.
1146  *   2) Common interface for the inbound chunk handling/state machine.
1147  *   3) Common object handling routines for reference counting, etc.
1148  *   4) Disentangle association lookup from endpoint lookup, where we
1149  *	do not have to find our endpoint to find our association.
1150  *
1151  */
1152 
1153 struct sctp_ep_common {
1154 	/* Fields to help us manage our entries in the hash tables. */
1155 	struct hlist_node node;
1156 	int hashent;
1157 
1158 	/* Runtime type information.  What kind of endpoint is this? */
1159 	sctp_endpoint_type_t type;
1160 
1161 	/* Some fields to help us manage this object.
1162 	 *   refcnt   - Reference count access to this object.
1163 	 *   dead     - Do not attempt to use this object.
1164 	 */
1165 	atomic_t    refcnt;
1166 	bool	    dead;
1167 
1168 	/* What socket does this endpoint belong to?  */
1169 	struct sock *sk;
1170 
1171 	/* This is where we receive inbound chunks.  */
1172 	struct sctp_inq	  inqueue;
1173 
1174 	/* This substructure includes the defining parameters of the
1175 	 * endpoint:
1176 	 * bind_addr.port is our shared port number.
1177 	 * bind_addr.address_list is our set of local IP addresses.
1178 	 */
1179 	struct sctp_bind_addr bind_addr;
1180 };
1181 
1182 
1183 /* RFC Section 1.4 Key Terms
1184  *
1185  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1186  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1187  *   combination of a set of eligible destination transport addresses to
1188  *   which SCTP packets can be sent and a set of eligible source
1189  *   transport addresses from which SCTP packets can be received.
1190  *   All transport addresses used by an SCTP endpoint must use the
1191  *   same port number, but can use multiple IP addresses. A transport
1192  *   address used by an SCTP endpoint must not be used by another
1193  *   SCTP endpoint. In other words, a transport address is unique
1194  *   to an SCTP endpoint.
1195  *
1196  * From an implementation perspective, each socket has one of these.
1197  * A TCP-style socket will have exactly one association on one of
1198  * these.  An UDP-style socket will have multiple associations hanging
1199  * off one of these.
1200  */
1201 
1202 struct sctp_endpoint {
1203 	/* Common substructure for endpoint and association. */
1204 	struct sctp_ep_common base;
1205 
1206 	/* Associations: A list of current associations and mappings
1207 	 *	      to the data consumers for each association. This
1208 	 *	      may be in the form of a hash table or other
1209 	 *	      implementation dependent structure. The data
1210 	 *	      consumers may be process identification
1211 	 *	      information such as file descriptors, named pipe
1212 	 *	      pointer, or table pointers dependent on how SCTP
1213 	 *	      is implemented.
1214 	 */
1215 	/* This is really a list of struct sctp_association entries. */
1216 	struct list_head asocs;
1217 
1218 	/* Secret Key: A secret key used by this endpoint to compute
1219 	 *	      the MAC.	This SHOULD be a cryptographic quality
1220 	 *	      random number with a sufficient length.
1221 	 *	      Discussion in [RFC1750] can be helpful in
1222 	 *	      selection of the key.
1223 	 */
1224 	__u8 secret_key[SCTP_SECRET_SIZE];
1225 
1226  	/* digest:  This is a digest of the sctp cookie.  This field is
1227  	 * 	    only used on the receive path when we try to validate
1228  	 * 	    that the cookie has not been tampered with.  We put
1229  	 * 	    this here so we pre-allocate this once and can re-use
1230  	 * 	    on every receive.
1231  	 */
1232  	__u8 *digest;
1233 
1234 	/* sendbuf acct. policy.	*/
1235 	__u32 sndbuf_policy;
1236 
1237 	/* rcvbuf acct. policy.	*/
1238 	__u32 rcvbuf_policy;
1239 
1240 	/* SCTP AUTH: array of the HMACs that will be allocated
1241 	 * we need this per association so that we don't serialize
1242 	 */
1243 	struct crypto_shash **auth_hmacs;
1244 
1245 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1246 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1247 
1248 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1249 	struct sctp_chunks_param *auth_chunk_list;
1250 
1251 	/* SCTP-AUTH: endpoint shared keys */
1252 	struct list_head endpoint_shared_keys;
1253 	__u16 active_key_id;
1254 	__u8  auth_enable;
1255 };
1256 
1257 /* Recover the outter endpoint structure. */
1258 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1259 {
1260 	struct sctp_endpoint *ep;
1261 
1262 	ep = container_of(base, struct sctp_endpoint, base);
1263 	return ep;
1264 }
1265 
1266 /* These are function signatures for manipulating endpoints.  */
1267 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1268 void sctp_endpoint_free(struct sctp_endpoint *);
1269 void sctp_endpoint_put(struct sctp_endpoint *);
1270 void sctp_endpoint_hold(struct sctp_endpoint *);
1271 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1272 struct sctp_association *sctp_endpoint_lookup_assoc(
1273 	const struct sctp_endpoint *ep,
1274 	const union sctp_addr *paddr,
1275 	struct sctp_transport **);
1276 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1277 				const union sctp_addr *);
1278 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1279 					struct net *, const union sctp_addr *);
1280 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1281 			 const union sctp_addr *paddr);
1282 
1283 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1284 		     const struct sctp_association *asoc,
1285 		     sctp_cid_t, sctp_init_chunk_t *peer_init,
1286 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1287 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1288 		      const union sctp_addr *peer,
1289 		      sctp_init_chunk_t *init, gfp_t gfp);
1290 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1291 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1292 
1293 struct sctp_inithdr_host {
1294 	__u32 init_tag;
1295 	__u32 a_rwnd;
1296 	__u16 num_outbound_streams;
1297 	__u16 num_inbound_streams;
1298 	__u32 initial_tsn;
1299 };
1300 
1301 /* SCTP_GET_ASSOC_STATS counters */
1302 struct sctp_priv_assoc_stats {
1303 	/* Maximum observed rto in the association during subsequent
1304 	 * observations. Value is set to 0 if no RTO measurement took place
1305 	 * The transport where the max_rto was observed is returned in
1306 	 * obs_rto_ipaddr
1307 	 */
1308 	struct sockaddr_storage obs_rto_ipaddr;
1309 	__u64 max_obs_rto;
1310 	/* Total In and Out SACKs received and sent */
1311 	__u64 isacks;
1312 	__u64 osacks;
1313 	/* Total In and Out packets received and sent */
1314 	__u64 opackets;
1315 	__u64 ipackets;
1316 	/* Total retransmitted chunks */
1317 	__u64 rtxchunks;
1318 	/* TSN received > next expected */
1319 	__u64 outofseqtsns;
1320 	/* Duplicate Chunks received */
1321 	__u64 idupchunks;
1322 	/* Gap Ack Blocks received */
1323 	__u64 gapcnt;
1324 	/* Unordered data chunks sent and received */
1325 	__u64 ouodchunks;
1326 	__u64 iuodchunks;
1327 	/* Ordered data chunks sent and received */
1328 	__u64 oodchunks;
1329 	__u64 iodchunks;
1330 	/* Control chunks sent and received */
1331 	__u64 octrlchunks;
1332 	__u64 ictrlchunks;
1333 };
1334 
1335 /* RFC2960
1336  *
1337  * 12. Recommended Transmission Control Block (TCB) Parameters
1338  *
1339  * This section details a recommended set of parameters that should
1340  * be contained within the TCB for an implementation. This section is
1341  * for illustrative purposes and should not be deemed as requirements
1342  * on an implementation or as an exhaustive list of all parameters
1343  * inside an SCTP TCB. Each implementation may need its own additional
1344  * parameters for optimization.
1345  */
1346 
1347 
1348 /* Here we have information about each individual association. */
1349 struct sctp_association {
1350 
1351 	/* A base structure common to endpoint and association.
1352 	 * In this context, it represents the associations's view
1353 	 * of the local endpoint of the association.
1354 	 */
1355 	struct sctp_ep_common base;
1356 
1357 	/* Associations on the same socket. */
1358 	struct list_head asocs;
1359 
1360 	/* association id. */
1361 	sctp_assoc_t assoc_id;
1362 
1363 	/* This is our parent endpoint.	 */
1364 	struct sctp_endpoint *ep;
1365 
1366 	/* These are those association elements needed in the cookie.  */
1367 	struct sctp_cookie c;
1368 
1369 	/* This is all information about our peer.  */
1370 	struct {
1371 		/* transport_addr_list
1372 		 *
1373 		 * Peer	       : A list of SCTP transport addresses that the
1374 		 * Transport   : peer is bound to. This information is derived
1375 		 * Address     : from the INIT or INIT ACK and is used to
1376 		 * List	       : associate an inbound packet with a given
1377 		 *	       : association. Normally this information is
1378 		 *	       : hashed or keyed for quick lookup and access
1379 		 *	       : of the TCB.
1380 		 *	       : The list is also initialized with the list
1381 		 *	       : of addresses passed with the sctp_connectx()
1382 		 *	       : call.
1383 		 *
1384 		 * It is a list of SCTP_transport's.
1385 		 */
1386 		struct list_head transport_addr_list;
1387 
1388 		/* rwnd
1389 		 *
1390 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1391 		 */
1392 		__u32 rwnd;
1393 
1394 		/* transport_count
1395 		 *
1396 		 * Peer        : A count of the number of peer addresses
1397 		 * Transport   : in the Peer Transport Address List.
1398 		 * Address     :
1399 		 * Count       :
1400 		 */
1401 		__u16 transport_count;
1402 
1403 		/* port
1404 		 *   The transport layer port number.
1405 		 */
1406 		__u16 port;
1407 
1408 		/* primary_path
1409 		 *
1410 		 * Primary     : This is the current primary destination
1411 		 * Path	       : transport address of the peer endpoint.  It
1412 		 *	       : may also specify a source transport address
1413 		 *	       : on this endpoint.
1414 		 *
1415 		 * All of these paths live on transport_addr_list.
1416 		 *
1417 		 * At the bakeoffs, we discovered that the intent of
1418 		 * primaryPath is that it only changes when the ULP
1419 		 * asks to have it changed.  We add the activePath to
1420 		 * designate the connection we are currently using to
1421 		 * transmit new data and most control chunks.
1422 		 */
1423 		struct sctp_transport *primary_path;
1424 
1425 		/* Cache the primary path address here, when we
1426 		 * need a an address for msg_name.
1427 		 */
1428 		union sctp_addr primary_addr;
1429 
1430 		/* active_path
1431 		 *   The path that we are currently using to
1432 		 *   transmit new data and most control chunks.
1433 		 */
1434 		struct sctp_transport *active_path;
1435 
1436 		/* retran_path
1437 		 *
1438 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1439 		 * ...
1440 		 * Furthermore, when its peer is multi-homed, an
1441 		 * endpoint SHOULD try to retransmit a chunk to an
1442 		 * active destination transport address that is
1443 		 * different from the last destination address to
1444 		 * which the DATA chunk was sent.
1445 		 */
1446 		struct sctp_transport *retran_path;
1447 
1448 		/* Pointer to last transport I have sent on.  */
1449 		struct sctp_transport *last_sent_to;
1450 
1451 		/* This is the last transport I have received DATA on.	*/
1452 		struct sctp_transport *last_data_from;
1453 
1454 		/*
1455 		 * Mapping  An array of bits or bytes indicating which out of
1456 		 * Array    order TSN's have been received (relative to the
1457 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1458 		 *	    order packets have been received, this array
1459 		 *	    will be set to all zero. This structure may be
1460 		 *	    in the form of a circular buffer or bit array.
1461 		 *
1462 		 * Last Rcvd   : This is the last TSN received in
1463 		 * TSN	       : sequence. This value is set initially by
1464 		 *	       : taking the peer's Initial TSN, received in
1465 		 *	       : the INIT or INIT ACK chunk, and subtracting
1466 		 *	       : one from it.
1467 		 *
1468 		 * Throughout most of the specification this is called the
1469 		 * "Cumulative TSN ACK Point".	In this case, we
1470 		 * ignore the advice in 12.2 in favour of the term
1471 		 * used in the bulk of the text.  This value is hidden
1472 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1473 		 */
1474 		struct sctp_tsnmap tsn_map;
1475 
1476 		/* This mask is used to disable sending the ASCONF chunk
1477 		 * with specified parameter to peer.
1478 		 */
1479 		__be16 addip_disabled_mask;
1480 
1481 		/* These are capabilities which our peer advertised.  */
1482 		__u8	ecn_capable:1,      /* Can peer do ECN? */
1483 			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1484 			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1485 			hostname_address:1, /* Peer understands DNS addresses? */
1486 			asconf_capable:1,   /* Does peer support ADDIP? */
1487 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1488 			auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1489 
1490 		/* sack_needed : This flag indicates if the next received
1491 		 *             : packet is to be responded to with a
1492 		 *             : SACK. This is initialized to 0.  When a packet
1493 		 *             : is received sack_cnt is incremented. If this value
1494 		 *             : reaches 2 or more, a SACK is sent and the
1495 		 *             : value is reset to 0. Note: This is used only
1496 		 *             : when no DATA chunks are received out of
1497 		 *             : order.  When DATA chunks are out of order,
1498 		 *             : SACK's are not delayed (see Section 6).
1499 		 */
1500 		__u8    sack_needed:1,     /* Do we need to sack the peer? */
1501 			sack_generation:1,
1502 			zero_window_announced:1;
1503 		__u32	sack_cnt;
1504 
1505 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1506 
1507 		struct sctp_inithdr_host i;
1508 		void *cookie;
1509 		int cookie_len;
1510 
1511 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1512 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1513 		 * Initial TSN Value minus 1
1514 		 */
1515 		__u32 addip_serial;
1516 
1517 		/* SCTP-AUTH: We need to know pears random number, hmac list
1518 		 * and authenticated chunk list.  All that is part of the
1519 		 * cookie and these are just pointers to those locations
1520 		 */
1521 		sctp_random_param_t *peer_random;
1522 		sctp_chunks_param_t *peer_chunks;
1523 		sctp_hmac_algo_param_t *peer_hmacs;
1524 	} peer;
1525 
1526 	/* State       : A state variable indicating what state the
1527 	 *	       : association is in, i.e. COOKIE-WAIT,
1528 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1529 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1530 	 *
1531 	 *		Note: No "CLOSED" state is illustrated since if a
1532 	 *		association is "CLOSED" its TCB SHOULD be removed.
1533 	 *
1534 	 *		In this implementation we DO have a CLOSED
1535 	 *		state which is used during initiation and shutdown.
1536 	 *
1537 	 *		State takes values from SCTP_STATE_*.
1538 	 */
1539 	sctp_state_t state;
1540 
1541 	/* Overall     : The overall association error count.
1542 	 * Error Count : [Clear this any time I get something.]
1543 	 */
1544 	int overall_error_count;
1545 
1546 	/* The cookie life I award for any cookie.  */
1547 	ktime_t cookie_life;
1548 
1549 	/* These are the association's initial, max, and min RTO values.
1550 	 * These values will be initialized by system defaults, but can
1551 	 * be modified via the SCTP_RTOINFO socket option.
1552 	 */
1553 	unsigned long rto_initial;
1554 	unsigned long rto_max;
1555 	unsigned long rto_min;
1556 
1557 	/* Maximum number of new data packets that can be sent in a burst.  */
1558 	int max_burst;
1559 
1560 	/* This is the max_retrans value for the association.  This value will
1561 	 * be initialized initialized from system defaults, but can be
1562 	 * modified by the SCTP_ASSOCINFO socket option.
1563 	 */
1564 	int max_retrans;
1565 
1566 	/* This is the partially failed retrans value for the transport
1567 	 * and will be initialized from the assocs value.  This can be
1568 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1569 	 */
1570 	int pf_retrans;
1571 
1572 	/* Maximum number of times the endpoint will retransmit INIT  */
1573 	__u16 max_init_attempts;
1574 
1575 	/* How many times have we resent an INIT? */
1576 	__u16 init_retries;
1577 
1578 	/* The largest timeout or RTO value to use in attempting an INIT */
1579 	unsigned long max_init_timeo;
1580 
1581 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1582 	 * the destination address every heartbeat interval. This value
1583 	 * will be inherited by all new transports.
1584 	 */
1585 	unsigned long hbinterval;
1586 
1587 	/* This is the max_retrans value for new transports in the
1588 	 * association.
1589 	 */
1590 	__u16 pathmaxrxt;
1591 
1592 	/* Flag that path mtu update is pending */
1593 	__u8   pmtu_pending;
1594 
1595 	/* Association : The smallest PMTU discovered for all of the
1596 	 * PMTU	       : peer's transport addresses.
1597 	 */
1598 	__u32 pathmtu;
1599 
1600 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1601 	__u32 param_flags;
1602 
1603 	__u32 sackfreq;
1604 	/* SACK delay timeout */
1605 	unsigned long sackdelay;
1606 
1607 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1608 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1609 
1610 	/* Transport to which SHUTDOWN chunk was last sent.  */
1611 	struct sctp_transport *shutdown_last_sent_to;
1612 
1613 	/* Transport to which INIT chunk was last sent.  */
1614 	struct sctp_transport *init_last_sent_to;
1615 
1616 	/* How many times have we resent a SHUTDOWN */
1617 	int shutdown_retries;
1618 
1619 	/* Next TSN    : The next TSN number to be assigned to a new
1620 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1621 	 *	       : ACK chunk to the peer and incremented each
1622 	 *	       : time a DATA chunk is assigned a TSN
1623 	 *	       : (normally just prior to transmit or during
1624 	 *	       : fragmentation).
1625 	 */
1626 	__u32 next_tsn;
1627 
1628 	/*
1629 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1630 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1631 	 *	       : received in the INIT or INIT ACK chunk, and
1632 	 *	       : subtracting one from it.
1633 	 *
1634 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1635 	 */
1636 
1637 	__u32 ctsn_ack_point;
1638 
1639 	/* PR-SCTP Advanced.Peer.Ack.Point */
1640 	__u32 adv_peer_ack_point;
1641 
1642 	/* Highest TSN that is acknowledged by incoming SACKs. */
1643 	__u32 highest_sacked;
1644 
1645 	/* TSN marking the fast recovery exit point */
1646 	__u32 fast_recovery_exit;
1647 
1648 	/* Flag to track the current fast recovery state */
1649 	__u8 fast_recovery;
1650 
1651 	/* The number of unacknowledged data chunks.  Reported through
1652 	 * the SCTP_STATUS sockopt.
1653 	 */
1654 	__u16 unack_data;
1655 
1656 	/* The total number of data chunks that we've had to retransmit
1657 	 * as the result of a T3 timer expiration
1658 	 */
1659 	__u32 rtx_data_chunks;
1660 
1661 	/* This is the association's receive buffer space.  This value is used
1662 	 * to set a_rwnd field in an INIT or a SACK chunk.
1663 	 */
1664 	__u32 rwnd;
1665 
1666 	/* This is the last advertised value of rwnd over a SACK chunk. */
1667 	__u32 a_rwnd;
1668 
1669 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1670 	 * to slop over a maximum of the association's frag_point.
1671 	 */
1672 	__u32 rwnd_over;
1673 
1674 	/* Keeps treack of rwnd pressure.  This happens when we have
1675 	 * a window, but not recevie buffer (i.e small packets).  This one
1676 	 * is releases slowly (1 PMTU at a time ).
1677 	 */
1678 	__u32 rwnd_press;
1679 
1680 	/* This is the sndbuf size in use for the association.
1681 	 * This corresponds to the sndbuf size for the association,
1682 	 * as specified in the sk->sndbuf.
1683 	 */
1684 	int sndbuf_used;
1685 
1686 	/* This is the amount of memory that this association has allocated
1687 	 * in the receive path at any given time.
1688 	 */
1689 	atomic_t rmem_alloc;
1690 
1691 	/* This is the wait queue head for send requests waiting on
1692 	 * the association sndbuf space.
1693 	 */
1694 	wait_queue_head_t	wait;
1695 
1696 	/* The message size at which SCTP fragmentation will occur. */
1697 	__u32 frag_point;
1698 	__u32 user_frag;
1699 
1700 	/* Counter used to count INIT errors. */
1701 	int init_err_counter;
1702 
1703 	/* Count the number of INIT cycles (for doubling timeout). */
1704 	int init_cycle;
1705 
1706 	/* Default send parameters. */
1707 	__u16 default_stream;
1708 	__u16 default_flags;
1709 	__u32 default_ppid;
1710 	__u32 default_context;
1711 	__u32 default_timetolive;
1712 
1713 	/* Default receive parameters */
1714 	__u32 default_rcv_context;
1715 
1716 	/* This tracks outbound ssn for a given stream.	 */
1717 	struct sctp_ssnmap *ssnmap;
1718 
1719 	/* All outbound chunks go through this structure.  */
1720 	struct sctp_outq outqueue;
1721 
1722 	/* A smart pipe that will handle reordering and fragmentation,
1723 	 * as well as handle passing events up to the ULP.
1724 	 */
1725 	struct sctp_ulpq ulpq;
1726 
1727 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1728 	__u32 last_ecne_tsn;
1729 
1730 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1731 	__u32 last_cwr_tsn;
1732 
1733 	/* How many duplicated TSNs have we seen?  */
1734 	int numduptsns;
1735 
1736 	/* These are to support
1737 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1738 	 *  and Enforcement of Flow and Message Limits"
1739 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1740 	 * or "ADDIP" for short.
1741 	 */
1742 
1743 
1744 
1745 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1746 	 *
1747 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1748 	 * unacknowledged at any one time.  If a sender, after sending
1749 	 * an ASCONF chunk, decides it needs to transfer another
1750 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1751 	 * returns from the previous ASCONF Chunk before sending a
1752 	 * subsequent ASCONF. Note this restriction binds each side,
1753 	 * so at any time two ASCONF may be in-transit on any given
1754 	 * association (one sent from each endpoint).
1755 	 *
1756 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1757 	 * not have an ASCONF in flight, this is NULL.]
1758 	 */
1759 	struct sctp_chunk *addip_last_asconf;
1760 
1761 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1762 	 *
1763 	 * This is needed to implement itmes E1 - E4 of the updated
1764 	 * spec.  Here is the justification:
1765 	 *
1766 	 * Since the peer may bundle multiple ASCONF chunks toward us,
1767 	 * we now need the ability to cache multiple ACKs.  The section
1768 	 * describes in detail how they are cached and cleaned up.
1769 	 */
1770 	struct list_head asconf_ack_list;
1771 
1772 	/* These ASCONF chunks are waiting to be sent.
1773 	 *
1774 	 * These chunaks can't be pushed to outqueue until receiving
1775 	 * ASCONF_ACK for the previous ASCONF indicated by
1776 	 * addip_last_asconf, so as to guarantee that only one ASCONF
1777 	 * is in flight at any time.
1778 	 *
1779 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1780 	 *
1781 	 * In defining the ASCONF Chunk transfer procedures, it is
1782 	 * essential that these transfers MUST NOT cause congestion
1783 	 * within the network.	To achieve this, we place these
1784 	 * restrictions on the transfer of ASCONF Chunks:
1785 	 *
1786 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1787 	 * unacknowledged at any one time.  If a sender, after sending
1788 	 * an ASCONF chunk, decides it needs to transfer another
1789 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1790 	 * returns from the previous ASCONF Chunk before sending a
1791 	 * subsequent ASCONF. Note this restriction binds each side,
1792 	 * so at any time two ASCONF may be in-transit on any given
1793 	 * association (one sent from each endpoint).
1794 	 *
1795 	 *
1796 	 * [I really think this is EXACTLY the sort of intelligence
1797 	 *  which already resides in sctp_outq.	 Please move this
1798 	 *  queue and its supporting logic down there.	--piggy]
1799 	 */
1800 	struct list_head addip_chunk_list;
1801 
1802 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
1803 	 *
1804 	 * A2) A serial number should be assigned to the Chunk. The
1805 	 * serial number SHOULD be a monotonically increasing
1806 	 * number. The serial number SHOULD be initialized at
1807 	 * the start of the association to the same value as the
1808 	 * Initial TSN and every time a new ASCONF chunk is created
1809 	 * it is incremented by one after assigning the serial number
1810 	 * to the newly created chunk.
1811 	 *
1812 	 * ADDIP
1813 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1814 	 *
1815 	 * Serial Number : 32 bits (unsigned integer)
1816 	 *
1817 	 * This value represents a Serial Number for the ASCONF
1818 	 * Chunk. The valid range of Serial Number is from 0 to
1819 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1820 	 * after reaching 4294967295.
1821 	 */
1822 	__u32 addip_serial;
1823 	int src_out_of_asoc_ok;
1824 	union sctp_addr *asconf_addr_del_pending;
1825 	struct sctp_transport *new_transport;
1826 
1827 	/* SCTP AUTH: list of the endpoint shared keys.  These
1828 	 * keys are provided out of band by the user applicaton
1829 	 * and can't change during the lifetime of the association
1830 	 */
1831 	struct list_head endpoint_shared_keys;
1832 
1833 	/* SCTP AUTH:
1834 	 * The current generated assocaition shared key (secret)
1835 	 */
1836 	struct sctp_auth_bytes *asoc_shared_key;
1837 
1838 	/* SCTP AUTH: hmac id of the first peer requested algorithm
1839 	 * that we support.
1840 	 */
1841 	__u16 default_hmac_id;
1842 
1843 	__u16 active_key_id;
1844 
1845 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
1846 	     temp:1;		/* Is it a temporary association? */
1847 
1848 	struct sctp_priv_assoc_stats stats;
1849 };
1850 
1851 
1852 /* An eyecatcher for determining if we are really looking at an
1853  * association data structure.
1854  */
1855 enum {
1856 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
1857 };
1858 
1859 /* Recover the outter association structure. */
1860 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1861 {
1862 	struct sctp_association *asoc;
1863 
1864 	asoc = container_of(base, struct sctp_association, base);
1865 	return asoc;
1866 }
1867 
1868 /* These are function signatures for manipulating associations.	 */
1869 
1870 
1871 struct sctp_association *
1872 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1873 		     sctp_scope_t scope, gfp_t gfp);
1874 void sctp_association_free(struct sctp_association *);
1875 void sctp_association_put(struct sctp_association *);
1876 void sctp_association_hold(struct sctp_association *);
1877 
1878 struct sctp_transport *sctp_assoc_choose_alter_transport(
1879 	struct sctp_association *, struct sctp_transport *);
1880 void sctp_assoc_update_retran_path(struct sctp_association *);
1881 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1882 					  const union sctp_addr *);
1883 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1884 			    const union sctp_addr *laddr);
1885 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1886 				     const union sctp_addr *address,
1887 				     const gfp_t gfp,
1888 				     const int peer_state);
1889 void sctp_assoc_del_peer(struct sctp_association *asoc,
1890 			 const union sctp_addr *addr);
1891 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1892 			 struct sctp_transport *peer);
1893 void sctp_assoc_control_transport(struct sctp_association *,
1894 				  struct sctp_transport *,
1895 				  sctp_transport_cmd_t, sctp_sn_error_t);
1896 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1897 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1898 					   struct net *,
1899 					   const union sctp_addr *,
1900 					   const union sctp_addr *);
1901 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1902 void sctp_assoc_update(struct sctp_association *old,
1903 		       struct sctp_association *new);
1904 
1905 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1906 
1907 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1908 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1909 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1910 void sctp_assoc_set_primary(struct sctp_association *,
1911 			    struct sctp_transport *);
1912 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1913 				    struct sctp_transport *);
1914 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1915 				     sctp_scope_t, gfp_t);
1916 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1917 					 struct sctp_cookie*,
1918 					 gfp_t gfp);
1919 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1920 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1921 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1922 					const struct sctp_association *asoc,
1923 					__be32 serial);
1924 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1925 
1926 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1927 			const union sctp_addr *ss2);
1928 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1929 
1930 /* A convenience structure to parse out SCTP specific CMSGs. */
1931 typedef struct sctp_cmsgs {
1932 	struct sctp_initmsg *init;
1933 	struct sctp_sndrcvinfo *srinfo;
1934 	struct sctp_sndinfo *sinfo;
1935 } sctp_cmsgs_t;
1936 
1937 /* Structure for tracking memory objects */
1938 typedef struct {
1939 	char *label;
1940 	atomic_t *counter;
1941 } sctp_dbg_objcnt_entry_t;
1942 
1943 #endif /* __sctp_structs_h__ */
1944