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TOMOYO Linux Cross Reference
Linux/include/net/sctp/structs.h

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  1 /* SCTP kernel implementation
  2  * (C) Copyright IBM Corp. 2001, 2004
  3  * Copyright (c) 1999-2000 Cisco, Inc.
  4  * Copyright (c) 1999-2001 Motorola, Inc.
  5  * Copyright (c) 2001 Intel Corp.
  6  *
  7  * This file is part of the SCTP kernel implementation
  8  *
  9  * This SCTP implementation is free software;
 10  * you can redistribute it and/or modify it under the terms of
 11  * the GNU General Public License as published by
 12  * the Free Software Foundation; either version 2, or (at your option)
 13  * any later version.
 14  *
 15  * This SCTP implementation is distributed in the hope that it
 16  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 17  *                 ************************
 18  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 19  * See the GNU General Public License for more details.
 20  *
 21  * You should have received a copy of the GNU General Public License
 22  * along with GNU CC; see the file COPYING.  If not, write to
 23  * the Free Software Foundation, 59 Temple Place - Suite 330,
 24  * Boston, MA 02111-1307, USA.
 25  *
 26  * Please send any bug reports or fixes you make to the
 27  * email addresses:
 28  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 29  *
 30  * Or submit a bug report through the following website:
 31  *    http://www.sf.net/projects/lksctp
 32  *
 33  * Written or modified by:
 34  *    Randall Stewart       <randall@sctp.chicago.il.us>
 35  *    Ken Morneau           <kmorneau@cisco.com>
 36  *    Qiaobing Xie          <qxie1@email.mot.com>
 37  *    La Monte H.P. Yarroll <piggy@acm.org>
 38  *    Karl Knutson          <karl@athena.chicago.il.us>
 39  *    Jon Grimm             <jgrimm@us.ibm.com>
 40  *    Xingang Guo           <xingang.guo@intel.com>
 41  *    Hui Huang             <hui.huang@nokia.com>
 42  *    Sridhar Samudrala     <sri@us.ibm.com>
 43  *    Daisy Chang           <daisyc@us.ibm.com>
 44  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
 45  *    Ardelle Fan           <ardelle.fan@intel.com>
 46  *    Ryan Layer            <rmlayer@us.ibm.com>
 47  *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
 48  *    Kevin Gao             <kevin.gao@intel.com>
 49  *
 50  * Any bugs reported given to us we will try to fix... any fixes shared will
 51  * be incorporated into the next SCTP release.
 52  */
 53 
 54 #ifndef __sctp_structs_h__
 55 #define __sctp_structs_h__
 56 
 57 #include <linux/time.h>         /* We get struct timespec.    */
 58 #include <linux/socket.h>       /* linux/in.h needs this!!    */
 59 #include <linux/in.h>           /* We get struct sockaddr_in. */
 60 #include <linux/in6.h>          /* We get struct in6_addr     */
 61 #include <linux/ipv6.h>
 62 #include <asm/param.h>          /* We get MAXHOSTNAMELEN.     */
 63 #include <asm/atomic.h>         /* This gets us atomic counters.  */
 64 #include <linux/skbuff.h>       /* We need sk_buff_head. */
 65 #include <linux/workqueue.h>    /* We need tq_struct.    */
 66 #include <linux/sctp.h>         /* We need sctp* header structs.  */
 67 #include <net/sctp/auth.h>      /* We need auth specific structs */
 68 
 69 /* A convenience structure for handling sockaddr structures.
 70  * We should wean ourselves off this.
 71  */
 72 union sctp_addr {
 73         struct sockaddr_in v4;
 74         struct sockaddr_in6 v6;
 75         struct sockaddr sa;
 76 };
 77 
 78 /* Forward declarations for data structures. */
 79 struct sctp_globals;
 80 struct sctp_endpoint;
 81 struct sctp_association;
 82 struct sctp_transport;
 83 struct sctp_packet;
 84 struct sctp_chunk;
 85 struct sctp_inq;
 86 struct sctp_outq;
 87 struct sctp_bind_addr;
 88 struct sctp_ulpq;
 89 struct sctp_ep_common;
 90 struct sctp_ssnmap;
 91 struct crypto_hash;
 92 
 93 
 94 #include <net/sctp/tsnmap.h>
 95 #include <net/sctp/ulpevent.h>
 96 #include <net/sctp/ulpqueue.h>
 97 
 98 /* Structures useful for managing bind/connect. */
 99 
100 struct sctp_bind_bucket {
101         unsigned short  port;
102         unsigned short  fastreuse;
103         struct hlist_node       node;
104         struct hlist_head       owner;
105 };
106 
107 struct sctp_bind_hashbucket {
108         spinlock_t      lock;
109         struct hlist_head       chain;
110 };
111 
112 /* Used for hashing all associations.  */
113 struct sctp_hashbucket {
114         rwlock_t        lock;
115         struct hlist_head       chain;
116 } __attribute__((__aligned__(8)));
117 
118 
119 /* The SCTP globals structure. */
120 extern struct sctp_globals {
121         /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values
122          *
123          * The following protocol parameters are RECOMMENDED:
124          *
125          * RTO.Initial              - 3  seconds
126          * RTO.Min                  - 1  second
127          * RTO.Max                 -  60 seconds
128          * RTO.Alpha                - 1/8  (3 when converted to right shifts.)
129          * RTO.Beta                 - 1/4  (2 when converted to right shifts.)
130          */
131         unsigned int rto_initial;
132         unsigned int rto_min;
133         unsigned int rto_max;
134 
135         /* Note: rto_alpha and rto_beta are really defined as inverse
136          * powers of two to facilitate integer operations.
137          */
138         int rto_alpha;
139         int rto_beta;
140 
141         /* Max.Burst                - 4 */
142         int max_burst;
143 
144         /* Whether Cookie Preservative is enabled(1) or not(0) */
145         int cookie_preserve_enable;
146 
147         /* Valid.Cookie.Life        - 60  seconds  */
148         unsigned int valid_cookie_life;
149 
150         /* Delayed SACK timeout  200ms default*/
151         unsigned int sack_timeout;
152 
153         /* HB.interval              - 30 seconds  */
154         unsigned int hb_interval;
155 
156         /* Association.Max.Retrans  - 10 attempts
157          * Path.Max.Retrans         - 5  attempts (per destination address)
158          * Max.Init.Retransmits     - 8  attempts
159          */
160         int max_retrans_association;
161         int max_retrans_path;
162         int max_retrans_init;
163 
164         /*
165          * Policy for preforming sctp/socket accounting
166          * 0   - do socket level accounting, all assocs share sk_sndbuf
167          * 1   - do sctp accounting, each asoc may use sk_sndbuf bytes
168          */
169         int sndbuf_policy;
170 
171         /*
172          * Policy for preforming sctp/socket accounting
173          * 0   - do socket level accounting, all assocs share sk_rcvbuf
174          * 1   - do sctp accounting, each asoc may use sk_rcvbuf bytes
175          */
176         int rcvbuf_policy;
177 
178         /* The following variables are implementation specific.  */
179 
180         /* Default initialization values to be applied to new associations. */
181         __u16 max_instreams;
182         __u16 max_outstreams;
183 
184         /* This is a list of groups of functions for each address
185          * family that we support.
186          */
187         struct list_head address_families;
188 
189         /* This is the hash of all endpoints. */
190         int ep_hashsize;
191         struct sctp_hashbucket *ep_hashtable;
192 
193         /* This is the hash of all associations. */
194         int assoc_hashsize;
195         struct sctp_hashbucket *assoc_hashtable;
196 
197         /* This is the sctp port control hash.  */
198         int port_hashsize;
199         struct sctp_bind_hashbucket *port_hashtable;
200 
201         /* This is the global local address list.
202          * We actively maintain this complete list of addresses on
203          * the system by catching address add/delete events.
204          *
205          * It is a list of sctp_sockaddr_entry.
206          */
207         struct list_head local_addr_list;
208 
209         /* Lock that protects the local_addr_list writers */
210         spinlock_t addr_list_lock;
211         
212         /* Flag to indicate if addip is enabled. */
213         int addip_enable;
214         int addip_noauth_enable;
215 
216         /* Flag to indicate if PR-SCTP is enabled. */
217         int prsctp_enable;
218 
219         /* Flag to idicate if SCTP-AUTH is enabled */
220         int auth_enable;
221 
222         /*
223          * Policy to control SCTP IPv4 address scoping
224          * 0   - Disable IPv4 address scoping
225          * 1   - Enable IPv4 address scoping
226          * 2   - Selectively allow only IPv4 private addresses
227          * 3   - Selectively allow only IPv4 link local address
228          */
229         int ipv4_scope_policy;
230 
231         /* Flag to indicate whether computing and verifying checksum
232          * is disabled. */
233         int checksum_disable;
234 
235         /* Threshold for rwnd update SACKS.  Receive buffer shifted this many
236          * bits is an indicator of when to send and window update SACK.
237          */
238         int rwnd_update_shift;
239 } sctp_globals;
240 
241 #define sctp_rto_initial                (sctp_globals.rto_initial)
242 #define sctp_rto_min                    (sctp_globals.rto_min)
243 #define sctp_rto_max                    (sctp_globals.rto_max)
244 #define sctp_rto_alpha                  (sctp_globals.rto_alpha)
245 #define sctp_rto_beta                   (sctp_globals.rto_beta)
246 #define sctp_max_burst                  (sctp_globals.max_burst)
247 #define sctp_valid_cookie_life          (sctp_globals.valid_cookie_life)
248 #define sctp_cookie_preserve_enable     (sctp_globals.cookie_preserve_enable)
249 #define sctp_max_retrans_association    (sctp_globals.max_retrans_association)
250 #define sctp_sndbuf_policy              (sctp_globals.sndbuf_policy)
251 #define sctp_rcvbuf_policy              (sctp_globals.rcvbuf_policy)
252 #define sctp_max_retrans_path           (sctp_globals.max_retrans_path)
253 #define sctp_max_retrans_init           (sctp_globals.max_retrans_init)
254 #define sctp_sack_timeout               (sctp_globals.sack_timeout)
255 #define sctp_hb_interval                (sctp_globals.hb_interval)
256 #define sctp_max_instreams              (sctp_globals.max_instreams)
257 #define sctp_max_outstreams             (sctp_globals.max_outstreams)
258 #define sctp_address_families           (sctp_globals.address_families)
259 #define sctp_ep_hashsize                (sctp_globals.ep_hashsize)
260 #define sctp_ep_hashtable               (sctp_globals.ep_hashtable)
261 #define sctp_assoc_hashsize             (sctp_globals.assoc_hashsize)
262 #define sctp_assoc_hashtable            (sctp_globals.assoc_hashtable)
263 #define sctp_port_hashsize              (sctp_globals.port_hashsize)
264 #define sctp_port_hashtable             (sctp_globals.port_hashtable)
265 #define sctp_local_addr_list            (sctp_globals.local_addr_list)
266 #define sctp_local_addr_lock            (sctp_globals.addr_list_lock)
267 #define sctp_scope_policy               (sctp_globals.ipv4_scope_policy)
268 #define sctp_addip_enable               (sctp_globals.addip_enable)
269 #define sctp_addip_noauth               (sctp_globals.addip_noauth_enable)
270 #define sctp_prsctp_enable              (sctp_globals.prsctp_enable)
271 #define sctp_auth_enable                (sctp_globals.auth_enable)
272 #define sctp_checksum_disable           (sctp_globals.checksum_disable)
273 #define sctp_rwnd_upd_shift             (sctp_globals.rwnd_update_shift)
274 
275 /* SCTP Socket type: UDP or TCP style. */
276 typedef enum {
277         SCTP_SOCKET_UDP = 0,
278         SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
279         SCTP_SOCKET_TCP
280 } sctp_socket_type_t;
281 
282 /* Per socket SCTP information. */
283 struct sctp_sock {
284         /* inet_sock has to be the first member of sctp_sock */
285         struct inet_sock inet;
286         /* What kind of a socket is this? */
287         sctp_socket_type_t type;
288 
289         /* PF_ family specific functions.  */
290         struct sctp_pf *pf;
291 
292         /* Access to HMAC transform. */
293         struct crypto_hash *hmac;
294 
295         /* What is our base endpointer? */
296         struct sctp_endpoint *ep;
297 
298         struct sctp_bind_bucket *bind_hash;
299         /* Various Socket Options.  */
300         __u16 default_stream;
301         __u32 default_ppid;
302         __u16 default_flags;
303         __u32 default_context;
304         __u32 default_timetolive;
305         __u32 default_rcv_context;
306         int max_burst;
307 
308         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
309          * the destination address every heartbeat interval. This value
310          * will be inherited by all new associations.
311          */
312         __u32 hbinterval;
313 
314         /* This is the max_retrans value for new associations. */
315         __u16 pathmaxrxt;
316 
317         /* The initial Path MTU to use for new associations. */
318         __u32 pathmtu;
319 
320         /* The default SACK delay timeout for new associations. */
321         __u32 sackdelay;
322         __u32 sackfreq;
323 
324         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
325         __u32 param_flags;
326 
327         struct sctp_initmsg initmsg;
328         struct sctp_rtoinfo rtoinfo;
329         struct sctp_paddrparams paddrparam;
330         struct sctp_event_subscribe subscribe;
331         struct sctp_assocparams assocparams;
332         int user_frag;
333         __u32 autoclose;
334         __u8 nodelay;
335         __u8 disable_fragments;
336         __u8 v4mapped;
337         __u8 frag_interleave;
338         __u32 adaptation_ind;
339         __u32 pd_point;
340 
341         atomic_t pd_mode;
342         /* Receive to here while partial delivery is in effect. */
343         struct sk_buff_head pd_lobby;
344 };
345 
346 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
347 {
348        return (struct sctp_sock *)sk;
349 }
350 
351 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
352 {
353        return (struct sock *)sp;
354 }
355 
356 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
357 struct sctp6_sock {
358        struct sctp_sock  sctp;
359        struct ipv6_pinfo inet6;
360 };
361 #endif /* CONFIG_IPV6 */
362 
363 
364 /* This is our APPLICATION-SPECIFIC state cookie.
365  * THIS IS NOT DICTATED BY THE SPECIFICATION.
366  */
367 /* These are the parts of an association which we send in the cookie.
368  * Most of these are straight out of:
369  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
370  *
371  */
372 
373 struct sctp_cookie {
374 
375         /* My          : Tag expected in every inbound packet and sent
376          * Verification: in the INIT or INIT ACK chunk.
377          * Tag         :
378          */
379         __u32 my_vtag;
380 
381         /* Peer's      : Tag expected in every outbound packet except
382          * Verification: in the INIT chunk.
383          * Tag         :
384          */
385         __u32 peer_vtag;
386 
387         /* The rest of these are not from the spec, but really need to
388          * be in the cookie.
389          */
390 
391         /* My Tie Tag  : Assist in discovering a restarting association. */
392         __u32 my_ttag;
393 
394         /* Peer's Tie Tag: Assist in discovering a restarting association. */
395         __u32 peer_ttag;
396 
397         /* When does this cookie expire? */
398         struct timeval expiration;
399 
400         /* Number of inbound/outbound streams which are set
401          * and negotiated during the INIT process.
402          */
403         __u16 sinit_num_ostreams;
404         __u16 sinit_max_instreams;
405 
406         /* This is the first sequence number I used.  */
407         __u32 initial_tsn;
408 
409         /* This holds the originating address of the INIT packet.  */
410         union sctp_addr peer_addr;
411 
412         /* IG Section 2.35.3 
413          * Include the source port of the INIT-ACK
414          */
415         __u16           my_port;
416 
417         __u8 prsctp_capable;
418 
419         /* Padding for future use */
420         __u8 padding;           
421 
422         __u32 adaptation_ind;
423 
424         __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
425         __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
426         __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
427 
428         /* This is a shim for my peer's INIT packet, followed by
429          * a copy of the raw address list of the association.
430          * The length of the raw address list is saved in the
431          * raw_addr_list_len field, which will be used at the time when
432          * the association TCB is re-constructed from the cookie.
433          */
434         __u32 raw_addr_list_len;
435         struct sctp_init_chunk peer_init[0];
436 };
437 
438 
439 /* The format of our cookie that we send to our peer. */
440 struct sctp_signed_cookie {
441         __u8 signature[SCTP_SECRET_SIZE];
442         __u32 __pad;            /* force sctp_cookie alignment to 64 bits */
443         struct sctp_cookie c;
444 } __packed;
445 
446 /* This is another convenience type to allocate memory for address
447  * params for the maximum size and pass such structures around
448  * internally.
449  */
450 union sctp_addr_param {
451         struct sctp_paramhdr p;
452         struct sctp_ipv4addr_param v4;
453         struct sctp_ipv6addr_param v6;
454 };
455 
456 /* A convenience type to allow walking through the various
457  * parameters and avoid casting all over the place.
458  */
459 union sctp_params {
460         void *v;
461         struct sctp_paramhdr *p;
462         struct sctp_cookie_preserve_param *life;
463         struct sctp_hostname_param *dns;
464         struct sctp_cookie_param *cookie;
465         struct sctp_supported_addrs_param *sat;
466         struct sctp_ipv4addr_param *v4;
467         struct sctp_ipv6addr_param *v6;
468         union sctp_addr_param *addr;
469         struct sctp_adaptation_ind_param *aind;
470         struct sctp_supported_ext_param *ext;
471         struct sctp_random_param *random;
472         struct sctp_chunks_param *chunks;
473         struct sctp_hmac_algo_param *hmac_algo;
474         struct sctp_addip_param *addip;
475 };
476 
477 /* RFC 2960.  Section 3.3.5 Heartbeat.
478  *    Heartbeat Information: variable length
479  *    The Sender-specific Heartbeat Info field should normally include
480  *    information about the sender's current time when this HEARTBEAT
481  *    chunk is sent and the destination transport address to which this
482  *    HEARTBEAT is sent (see Section 8.3).
483  */
484 typedef struct sctp_sender_hb_info {
485         struct sctp_paramhdr param_hdr;
486         union sctp_addr daddr;
487         unsigned long sent_at;
488         __u64 hb_nonce;
489 } __packed sctp_sender_hb_info_t;
490 
491 /*
492  *  RFC 2960 1.3.2 Sequenced Delivery within Streams
493  *
494  *  The term "stream" is used in SCTP to refer to a sequence of user
495  *  messages that are to be delivered to the upper-layer protocol in
496  *  order with respect to other messages within the same stream.  This is
497  *  in contrast to its usage in TCP, where it refers to a sequence of
498  *  bytes (in this document a byte is assumed to be eight bits).
499  *  ...
500  *
501  *  This is the structure we use to track both our outbound and inbound
502  *  SSN, or Stream Sequence Numbers.
503  */
504 
505 struct sctp_stream {
506         __u16 *ssn;
507         unsigned int len;
508 };
509 
510 struct sctp_ssnmap {
511         struct sctp_stream in;
512         struct sctp_stream out;
513         int malloced;
514 };
515 
516 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
517                                     gfp_t gfp);
518 void sctp_ssnmap_free(struct sctp_ssnmap *map);
519 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
520 
521 /* What is the current SSN number for this stream? */
522 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
523 {
524         return stream->ssn[id];
525 }
526 
527 /* Return the next SSN number for this stream.  */
528 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
529 {
530         return stream->ssn[id]++;
531 }
532 
533 /* Skip over this ssn and all below. */
534 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, 
535                                  __u16 ssn)
536 {
537         stream->ssn[id] = ssn+1;
538 }
539               
540 /*
541  * Pointers to address related SCTP functions.
542  * (i.e. things that depend on the address family.)
543  */
544 struct sctp_af {
545         int             (*sctp_xmit)    (struct sk_buff *skb,
546                                          struct sctp_transport *);
547         int             (*setsockopt)   (struct sock *sk,
548                                          int level,
549                                          int optname,
550                                          char __user *optval,
551                                          unsigned int optlen);
552         int             (*getsockopt)   (struct sock *sk,
553                                          int level,
554                                          int optname,
555                                          char __user *optval,
556                                          int __user *optlen);
557         int             (*compat_setsockopt)    (struct sock *sk,
558                                          int level,
559                                          int optname,
560                                          char __user *optval,
561                                          unsigned int optlen);
562         int             (*compat_getsockopt)    (struct sock *sk,
563                                          int level,
564                                          int optname,
565                                          char __user *optval,
566                                          int __user *optlen);
567         struct dst_entry *(*get_dst)    (struct sctp_association *asoc,
568                                          union sctp_addr *daddr,
569                                          union sctp_addr *saddr);
570         void            (*get_saddr)    (struct sctp_sock *sk,
571                                          struct sctp_association *asoc,
572                                          struct dst_entry *dst,
573                                          union sctp_addr *daddr,
574                                          union sctp_addr *saddr);
575         void            (*copy_addrlist) (struct list_head *,
576                                           struct net_device *);
577         void            (*dst_saddr)    (union sctp_addr *saddr,
578                                          struct dst_entry *dst,
579                                          __be16 port);
580         int             (*cmp_addr)     (const union sctp_addr *addr1,
581                                          const union sctp_addr *addr2);
582         void            (*addr_copy)    (union sctp_addr *dst,
583                                          union sctp_addr *src);
584         void            (*from_skb)     (union sctp_addr *,
585                                          struct sk_buff *skb,
586                                          int saddr);
587         void            (*from_sk)      (union sctp_addr *,
588                                          struct sock *sk);
589         void            (*to_sk_saddr)  (union sctp_addr *,
590                                          struct sock *sk);
591         void            (*to_sk_daddr)  (union sctp_addr *,
592                                          struct sock *sk);
593         void            (*from_addr_param) (union sctp_addr *,
594                                             union sctp_addr_param *,
595                                             __be16 port, int iif);
596         int             (*to_addr_param) (const union sctp_addr *,
597                                           union sctp_addr_param *); 
598         int             (*addr_valid)   (union sctp_addr *,
599                                          struct sctp_sock *,
600                                          const struct sk_buff *);
601         sctp_scope_t    (*scope) (union sctp_addr *);
602         void            (*inaddr_any)   (union sctp_addr *, __be16);
603         int             (*is_any)       (const union sctp_addr *);
604         int             (*available)    (union sctp_addr *,
605                                          struct sctp_sock *);
606         int             (*skb_iif)      (const struct sk_buff *sk);
607         int             (*is_ce)        (const struct sk_buff *sk);
608         void            (*seq_dump_addr)(struct seq_file *seq,
609                                          union sctp_addr *addr);
610         void            (*ecn_capable)(struct sock *sk);
611         __u16           net_header_len;
612         int             sockaddr_len;
613         sa_family_t     sa_family;
614         struct list_head list;
615 };
616 
617 struct sctp_af *sctp_get_af_specific(sa_family_t);
618 int sctp_register_af(struct sctp_af *);
619 
620 /* Protocol family functions. */
621 struct sctp_pf {
622         void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
623         void (*skb_msgname)  (struct sk_buff *, char *, int *);
624         int  (*af_supported) (sa_family_t, struct sctp_sock *);
625         int  (*cmp_addr) (const union sctp_addr *,
626                           const union sctp_addr *,
627                           struct sctp_sock *);
628         int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
629         int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
630         int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
631         struct sock *(*create_accept_sk) (struct sock *sk,
632                                           struct sctp_association *asoc);
633         void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
634         struct sctp_af *af;
635 };
636 
637 
638 /* Structure to track chunk fragments that have been acked, but peer
639  * fragments of the same message have not.
640  */
641 struct sctp_datamsg {
642         /* Chunks waiting to be submitted to lower layer. */
643         struct list_head chunks;
644         /* Reference counting. */
645         atomic_t refcnt;
646         /* When is this message no longer interesting to the peer? */
647         unsigned long expires_at;
648         /* Did the messenge fail to send? */
649         int send_error;
650         u8 send_failed:1,
651            can_abandon:1,   /* can chunks from this message can be abandoned. */
652            can_delay;       /* should this message be Nagle delayed */
653 };
654 
655 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
656                                             struct sctp_sndrcvinfo *,
657                                             struct msghdr *, int len);
658 void sctp_datamsg_free(struct sctp_datamsg *);
659 void sctp_datamsg_put(struct sctp_datamsg *);
660 void sctp_chunk_fail(struct sctp_chunk *, int error);
661 int sctp_chunk_abandoned(struct sctp_chunk *);
662 
663 /* RFC2960 1.4 Key Terms
664  *
665  * o Chunk: A unit of information within an SCTP packet, consisting of
666  * a chunk header and chunk-specific content.
667  *
668  * As a matter of convenience, we remember the SCTP common header for
669  * each chunk as well as a few other header pointers...
670  */
671 struct sctp_chunk {
672         struct list_head list;
673 
674         atomic_t refcnt;
675 
676         /* This is our link to the per-transport transmitted list.  */
677         struct list_head transmitted_list;
678 
679         /* This field is used by chunks that hold fragmented data.
680          * For the first fragment this is the list that holds the rest of
681          * fragments. For the remaining fragments, this is the link to the
682          * frag_list maintained in the first fragment.
683          */
684         struct list_head frag_list;
685 
686         /* This points to the sk_buff containing the actual data.  */
687         struct sk_buff *skb;
688 
689         /* These are the SCTP headers by reverse order in a packet.
690          * Note that some of these may happen more than once.  In that
691          * case, we point at the "current" one, whatever that means
692          * for that level of header.
693          */
694 
695         /* We point this at the FIRST TLV parameter to chunk_hdr.  */
696         union sctp_params param_hdr;
697         union {
698                 __u8 *v;
699                 struct sctp_datahdr *data_hdr;
700                 struct sctp_inithdr *init_hdr;
701                 struct sctp_sackhdr *sack_hdr;
702                 struct sctp_heartbeathdr *hb_hdr;
703                 struct sctp_sender_hb_info *hbs_hdr;
704                 struct sctp_shutdownhdr *shutdown_hdr;
705                 struct sctp_signed_cookie *cookie_hdr;
706                 struct sctp_ecnehdr *ecne_hdr;
707                 struct sctp_cwrhdr *ecn_cwr_hdr;
708                 struct sctp_errhdr *err_hdr;
709                 struct sctp_addiphdr *addip_hdr;
710                 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
711                 struct sctp_authhdr *auth_hdr;
712         } subh;
713 
714         __u8 *chunk_end;
715 
716         struct sctp_chunkhdr *chunk_hdr;
717         struct sctphdr *sctp_hdr;
718 
719         /* This needs to be recoverable for SCTP_SEND_FAILED events. */
720         struct sctp_sndrcvinfo sinfo;
721 
722         /* Which association does this belong to?  */
723         struct sctp_association *asoc;
724 
725         /* What endpoint received this chunk? */
726         struct sctp_ep_common *rcvr;
727 
728         /* We fill this in if we are calculating RTT. */
729         unsigned long sent_at;
730 
731         /* What is the origin IP address for this chunk?  */
732         union sctp_addr source;
733         /* Destination address for this chunk. */
734         union sctp_addr dest;
735 
736         /* For outbound message, track all fragments for SEND_FAILED. */
737         struct sctp_datamsg *msg;
738 
739         /* For an inbound chunk, this tells us where it came from.
740          * For an outbound chunk, it tells us where we'd like it to
741          * go.  It is NULL if we have no preference.
742          */
743         struct sctp_transport *transport;
744 
745         /* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
746          * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
747          * spec violates the principle premis that all chunks are processed
748          * in order.
749          */
750         struct sk_buff *auth_chunk;
751 
752 #define SCTP_CAN_FRTX 0x0
753 #define SCTP_NEED_FRTX 0x1
754 #define SCTP_DONT_FRTX 0x2
755         __u16   rtt_in_progress:1,      /* This chunk used for RTT calc? */
756                 has_tsn:1,              /* Does this chunk have a TSN yet? */
757                 has_ssn:1,              /* Does this chunk have a SSN yet? */
758                 singleton:1,            /* Only chunk in the packet? */
759                 end_of_packet:1,        /* Last chunk in the packet? */
760                 ecn_ce_done:1,          /* Have we processed the ECN CE bit? */
761                 pdiscard:1,             /* Discard the whole packet now? */
762                 tsn_gap_acked:1,        /* Is this chunk acked by a GAP ACK? */
763                 data_accepted:1,        /* At least 1 chunk accepted */
764                 auth:1,                 /* IN: was auth'ed | OUT: needs auth */
765                 has_asconf:1,           /* IN: have seen an asconf before */
766                 tsn_missing_report:2,   /* Data chunk missing counter. */
767                 fast_retransmit:2;      /* Is this chunk fast retransmitted? */
768 };
769 
770 void sctp_chunk_hold(struct sctp_chunk *);
771 void sctp_chunk_put(struct sctp_chunk *);
772 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
773                           struct iovec *data);
774 void sctp_chunk_free(struct sctp_chunk *);
775 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
776 void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
777 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
778                                  const struct sctp_association *,
779                                  struct sock *);
780 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
781                      union sctp_addr *);
782 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
783 
784 enum {
785         SCTP_ADDR_NEW,          /* new address added to assoc/ep */
786         SCTP_ADDR_SRC,          /* address can be used as source */
787         SCTP_ADDR_DEL,          /* address about to be deleted */
788 };
789 
790 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
791 struct sctp_sockaddr_entry {
792         struct list_head list;
793         struct rcu_head rcu;
794         union sctp_addr a;
795         __u8 state;
796         __u8 valid;
797 };
798 
799 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
800 
801 /* This structure holds lists of chunks as we are assembling for
802  * transmission.
803  */
804 struct sctp_packet {
805         /* These are the SCTP header values (host order) for the packet. */
806         __u16 source_port;
807         __u16 destination_port;
808         __u32 vtag;
809 
810         /* This contains the payload chunks.  */
811         struct list_head chunk_list;
812 
813         /* This is the overhead of the sctp and ip headers. */
814         size_t overhead;
815         /* This is the total size of all chunks INCLUDING padding.  */
816         size_t size;
817 
818         /* The packet is destined for this transport address.
819          * The function we finally use to pass down to the next lower
820          * layer lives in the transport structure.
821          */
822         struct sctp_transport *transport;
823 
824         /* pointer to the auth chunk for this packet */
825         struct sctp_chunk *auth;
826 
827         u8  has_cookie_echo:1,  /* This packet contains a COOKIE-ECHO chunk. */
828             has_sack:1,         /* This packet contains a SACK chunk. */
829             has_auth:1,         /* This packet contains an AUTH chunk */
830             has_data:1,         /* This packet contains at least 1 DATA chunk */
831             ipfragok:1,         /* So let ip fragment this packet */
832             malloced:1;         /* Is it malloced? */
833 };
834 
835 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
836                                      struct sctp_transport *,
837                                      __u16 sport, __u16 dport);
838 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
839 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
840                                        struct sctp_chunk *, int);
841 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
842                                      struct sctp_chunk *);
843 int sctp_packet_transmit(struct sctp_packet *);
844 void sctp_packet_free(struct sctp_packet *);
845 
846 static inline int sctp_packet_empty(struct sctp_packet *packet)
847 {
848         return packet->size == packet->overhead;
849 }
850 
851 /* This represents a remote transport address.
852  * For local transport addresses, we just use union sctp_addr.
853  *
854  * RFC2960 Section 1.4 Key Terms
855  *
856  *   o  Transport address:  A Transport Address is traditionally defined
857  *      by Network Layer address, Transport Layer protocol and Transport
858  *      Layer port number.  In the case of SCTP running over IP, a
859  *      transport address is defined by the combination of an IP address
860  *      and an SCTP port number (where SCTP is the Transport protocol).
861  *
862  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
863  *
864  *   o  The sender keeps a separate congestion control parameter set for
865  *      each of the destination addresses it can send to (not each
866  *      source-destination pair but for each destination).  The parameters
867  *      should decay if the address is not used for a long enough time
868  *      period.
869  *
870  */
871 struct sctp_transport {
872         /* A list of transports. */
873         struct list_head transports;
874 
875         /* Reference counting. */
876         atomic_t refcnt;
877         __u32    dead:1,
878                 /* RTO-Pending : A flag used to track if one of the DATA
879                  *              chunks sent to this address is currently being
880                  *              used to compute a RTT. If this flag is 0,
881                  *              the next DATA chunk sent to this destination
882                  *              should be used to compute a RTT and this flag
883                  *              should be set. Every time the RTT
884                  *              calculation completes (i.e. the DATA chunk
885                  *              is SACK'd) clear this flag.
886                  */
887                  rto_pending:1,
888 
889                 /*
890                  * hb_sent : a flag that signals that we have a pending
891                  * heartbeat.
892                  */
893                 hb_sent:1,
894 
895                 /* Is the Path MTU update pending on this tranport */
896                 pmtu_pending:1,
897 
898                 /* Is this structure kfree()able? */
899                 malloced:1;
900 
901 
902         /* This is the peer's IP address and port. */
903         union sctp_addr ipaddr;
904 
905         /* These are the functions we call to handle LLP stuff.  */
906         struct sctp_af *af_specific;
907 
908         /* Which association do we belong to?  */
909         struct sctp_association *asoc;
910 
911         /* RFC2960
912          *
913          * 12.3 Per Transport Address Data
914          *
915          * For each destination transport address in the peer's
916          * address list derived from the INIT or INIT ACK chunk, a
917          * number of data elements needs to be maintained including:
918          */
919         /* RTO         : The current retransmission timeout value.  */
920         unsigned long rto;
921 
922         __u32 rtt;              /* This is the most recent RTT.  */
923 
924         /* RTTVAR      : The current RTT variation.  */
925         __u32 rttvar;
926 
927         /* SRTT        : The current smoothed round trip time.  */
928         __u32 srtt;
929 
930         /*
931          * These are the congestion stats.
932          */
933         /* cwnd        : The current congestion window.  */
934         __u32 cwnd;               /* This is the actual cwnd.  */
935 
936         /* ssthresh    : The current slow start threshold value.  */
937         __u32 ssthresh;
938 
939         /* partial     : The tracking method for increase of cwnd when in
940          * bytes acked : congestion avoidance mode (see Section 6.2.2)
941          */
942         __u32 partial_bytes_acked;
943 
944         /* Data that has been sent, but not acknowledged. */
945         __u32 flight_size;
946 
947         __u32 burst_limited;    /* Holds old cwnd when max.burst is applied */
948 
949         /* Destination */
950         struct dst_entry *dst;
951         /* Source address. */
952         union sctp_addr saddr;
953 
954         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
955          * the destination address every heartbeat interval.
956          */
957         unsigned long hbinterval;
958 
959         /* SACK delay timeout */
960         unsigned long sackdelay;
961         __u32 sackfreq;
962 
963         /* When was the last time (in jiffies) that we heard from this
964          * transport?  We use this to pick new active and retran paths.
965          */
966         unsigned long last_time_heard;
967 
968         /* Last time(in jiffies) when cwnd is reduced due to the congestion
969          * indication based on ECNE chunk.
970          */
971         unsigned long last_time_ecne_reduced;
972 
973         /* This is the max_retrans value for the transport and will
974          * be initialized from the assocs value.  This can be changed
975          * using SCTP_SET_PEER_ADDR_PARAMS socket option.
976          */
977         __u16 pathmaxrxt;
978 
979         /* PMTU       : The current known path MTU.  */
980         __u32 pathmtu;
981 
982         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
983         __u32 param_flags;
984 
985         /* The number of times INIT has been sent on this transport. */
986         int init_sent_count;
987 
988         /* state       : The current state of this destination,
989          *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
990          */
991         int state;
992 
993         /* These are the error stats for this destination.  */
994 
995         /* Error count : The current error count for this destination.  */
996         unsigned short error_count;
997 
998         /* Per         : A timer used by each destination.
999          * Destination :
1000          * Timer       :
1001          *
1002          * [Everywhere else in the text this is called T3-rtx. -ed]
1003          */
1004         struct timer_list T3_rtx_timer;
1005 
1006         /* Heartbeat timer is per destination. */
1007         struct timer_list hb_timer;
1008 
1009         /* Timer to handle ICMP proto unreachable envets */
1010         struct timer_list proto_unreach_timer;
1011 
1012         /* Since we're using per-destination retransmission timers
1013          * (see above), we're also using per-destination "transmitted"
1014          * queues.  This probably ought to be a private struct
1015          * accessible only within the outqueue, but it's not, yet.
1016          */
1017         struct list_head transmitted;
1018 
1019         /* We build bundle-able packets for this transport here.  */
1020         struct sctp_packet packet;
1021 
1022         /* This is the list of transports that have chunks to send.  */
1023         struct list_head send_ready;
1024 
1025         /* State information saved for SFR_CACC algorithm. The key
1026          * idea in SFR_CACC is to maintain state at the sender on a
1027          * per-destination basis when a changeover happens.
1028          *      char changeover_active;
1029          *      char cycling_changeover;
1030          *      __u32 next_tsn_at_change;
1031          *      char cacc_saw_newack;
1032          */
1033         struct {
1034                 /* An unsigned integer, which stores the next TSN to be
1035                  * used by the sender, at the moment of changeover.
1036                  */
1037                 __u32 next_tsn_at_change;
1038 
1039                 /* A flag which indicates the occurrence of a changeover */
1040                 char changeover_active;
1041 
1042                 /* A flag which indicates whether the change of primary is
1043                  * the first switch to this destination address during an
1044                  * active switch.
1045                  */
1046                 char cycling_changeover;
1047 
1048                 /* A temporary flag, which is used during the processing of
1049                  * a SACK to estimate the causative TSN(s)'s group.
1050                  */
1051                 char cacc_saw_newack;
1052         } cacc;
1053 
1054         /* 64-bit random number sent with heartbeat. */
1055         __u64 hb_nonce;
1056 };
1057 
1058 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1059                                           gfp_t);
1060 void sctp_transport_set_owner(struct sctp_transport *,
1061                               struct sctp_association *);
1062 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1063                           struct sctp_sock *);
1064 void sctp_transport_pmtu(struct sctp_transport *);
1065 void sctp_transport_free(struct sctp_transport *);
1066 void sctp_transport_reset_timers(struct sctp_transport *);
1067 void sctp_transport_hold(struct sctp_transport *);
1068 void sctp_transport_put(struct sctp_transport *);
1069 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1070 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1071 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1072 void sctp_transport_burst_limited(struct sctp_transport *);
1073 void sctp_transport_burst_reset(struct sctp_transport *);
1074 unsigned long sctp_transport_timeout(struct sctp_transport *);
1075 void sctp_transport_reset(struct sctp_transport *);
1076 void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1077 
1078 
1079 /* This is the structure we use to queue packets as they come into
1080  * SCTP.  We write packets to it and read chunks from it.
1081  */
1082 struct sctp_inq {
1083         /* This is actually a queue of sctp_chunk each
1084          * containing a partially decoded packet.
1085          */
1086         struct list_head in_chunk_list;
1087         /* This is the packet which is currently off the in queue and is
1088          * being worked on through the inbound chunk processing.
1089          */
1090         struct sctp_chunk *in_progress;
1091 
1092         /* This is the delayed task to finish delivering inbound
1093          * messages.
1094          */
1095         struct work_struct immediate;
1096 
1097         int malloced;        /* Is this structure kfree()able?  */
1098 };
1099 
1100 void sctp_inq_init(struct sctp_inq *);
1101 void sctp_inq_free(struct sctp_inq *);
1102 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1103 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1104 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1105 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1106 
1107 /* This is the structure we use to hold outbound chunks.  You push
1108  * chunks in and they automatically pop out the other end as bundled
1109  * packets (it calls (*output_handler)()).
1110  *
1111  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1112  * and 8.2 of the v13 draft.
1113  *
1114  * It handles retransmissions.  The connection to the timeout portion
1115  * of the state machine is through sctp_..._timeout() and timeout_handler.
1116  *
1117  * If you feed it SACKs, it will eat them.
1118  *
1119  * If you give it big chunks, it will fragment them.
1120  *
1121  * It assigns TSN's to data chunks.  This happens at the last possible
1122  * instant before transmission.
1123  *
1124  * When free()'d, it empties itself out via output_handler().
1125  */
1126 struct sctp_outq {
1127         struct sctp_association *asoc;
1128 
1129         /* Data pending that has never been transmitted.  */
1130         struct list_head out_chunk_list;
1131 
1132         unsigned out_qlen;      /* Total length of queued data chunks. */
1133 
1134         /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1135         unsigned error;
1136 
1137         /* These are control chunks we want to send.  */
1138         struct list_head control_chunk_list;
1139 
1140         /* These are chunks that have been sacked but are above the
1141          * CTSN, or cumulative tsn ack point.
1142          */
1143         struct list_head sacked;
1144 
1145         /* Put chunks on this list to schedule them for
1146          * retransmission.
1147          */
1148         struct list_head retransmit;
1149 
1150         /* Put chunks on this list to save them for FWD TSN processing as
1151          * they were abandoned.
1152          */
1153         struct list_head abandoned;
1154 
1155         /* How many unackd bytes do we have in-flight?  */
1156         __u32 outstanding_bytes;
1157 
1158         /* Are we doing fast-rtx on this queue */
1159         char fast_rtx;
1160 
1161         /* Corked? */
1162         char cork;
1163 
1164         /* Is this structure empty?  */
1165         char empty;
1166 
1167         /* Are we kfree()able? */
1168         char malloced;
1169 };
1170 
1171 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1172 void sctp_outq_teardown(struct sctp_outq *);
1173 void sctp_outq_free(struct sctp_outq*);
1174 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1175 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1176 int sctp_outq_is_empty(const struct sctp_outq *);
1177 void sctp_outq_restart(struct sctp_outq *);
1178 
1179 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1180                      sctp_retransmit_reason_t);
1181 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1182 int sctp_outq_uncork(struct sctp_outq *);
1183 /* Uncork and flush an outqueue.  */
1184 static inline void sctp_outq_cork(struct sctp_outq *q)
1185 {
1186         q->cork = 1;
1187 }
1188 
1189 /* These bind address data fields common between endpoints and associations */
1190 struct sctp_bind_addr {
1191 
1192         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1193          *
1194          * SCTP Port:   The local SCTP port number the endpoint is
1195          *              bound to.
1196          */
1197         __u16 port;
1198 
1199         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1200          *
1201          * Address List: The list of IP addresses that this instance
1202          *      has bound.  This information is passed to one's
1203          *      peer(s) in INIT and INIT ACK chunks.
1204          */
1205         struct list_head address_list;
1206 
1207         int malloced;        /* Are we kfree()able?  */
1208 };
1209 
1210 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1211 void sctp_bind_addr_free(struct sctp_bind_addr *);
1212 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1213                         const struct sctp_bind_addr *src,
1214                         sctp_scope_t scope, gfp_t gfp,
1215                         int flags);
1216 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1217                         const struct sctp_bind_addr *src,
1218                         gfp_t gfp);
1219 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1220                        __u8 addr_state, gfp_t gfp);
1221 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1222 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1223                          struct sctp_sock *);
1224 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1225                          struct sctp_sock *, struct sctp_sock *);
1226 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1227                          const union sctp_addr *addr);
1228 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
1229                                         const union sctp_addr   *addrs,
1230                                         int                     addrcnt,
1231                                         struct sctp_sock        *opt);
1232 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1233                                          int *addrs_len,
1234                                          gfp_t gfp);
1235 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1236                            __u16 port, gfp_t gfp);
1237 
1238 sctp_scope_t sctp_scope(const union sctp_addr *);
1239 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1240 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1241 int sctp_addr_is_valid(const union sctp_addr *addr);
1242 
1243 
1244 /* What type of endpoint?  */
1245 typedef enum {
1246         SCTP_EP_TYPE_SOCKET,
1247         SCTP_EP_TYPE_ASSOCIATION,
1248 } sctp_endpoint_type_t;
1249 
1250 /*
1251  * A common base class to bridge the implmentation view of a
1252  * socket (usually listening) endpoint versus an association's
1253  * local endpoint.
1254  * This common structure is useful for several purposes:
1255  *   1) Common interface for lookup routines.
1256  *      a) Subfunctions work for either endpoint or association
1257  *      b) Single interface to lookup allows hiding the lookup lock rather
1258  *         than acquiring it externally.
1259  *   2) Common interface for the inbound chunk handling/state machine.
1260  *   3) Common object handling routines for reference counting, etc.
1261  *   4) Disentangle association lookup from endpoint lookup, where we
1262  *      do not have to find our endpoint to find our association.
1263  *
1264  */
1265 
1266 struct sctp_ep_common {
1267         /* Fields to help us manage our entries in the hash tables. */
1268         struct hlist_node node;
1269         int hashent;
1270 
1271         /* Runtime type information.  What kind of endpoint is this? */
1272         sctp_endpoint_type_t type;
1273 
1274         /* Some fields to help us manage this object.
1275          *   refcnt   - Reference count access to this object.
1276          *   dead     - Do not attempt to use this object.
1277          *   malloced - Do we need to kfree this object?
1278          */
1279         atomic_t    refcnt;
1280         char        dead;
1281         char        malloced;
1282 
1283         /* What socket does this endpoint belong to?  */
1284         struct sock *sk;
1285 
1286         /* This is where we receive inbound chunks.  */
1287         struct sctp_inq   inqueue;
1288 
1289         /* This substructure includes the defining parameters of the
1290          * endpoint:
1291          * bind_addr.port is our shared port number.
1292          * bind_addr.address_list is our set of local IP addresses.
1293          */
1294         struct sctp_bind_addr bind_addr;
1295 };
1296 
1297 
1298 /* RFC Section 1.4 Key Terms
1299  *
1300  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1301  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1302  *   combination of a set of eligible destination transport addresses to
1303  *   which SCTP packets can be sent and a set of eligible source
1304  *   transport addresses from which SCTP packets can be received.
1305  *   All transport addresses used by an SCTP endpoint must use the
1306  *   same port number, but can use multiple IP addresses. A transport
1307  *   address used by an SCTP endpoint must not be used by another
1308  *   SCTP endpoint. In other words, a transport address is unique
1309  *   to an SCTP endpoint.
1310  *
1311  * From an implementation perspective, each socket has one of these.
1312  * A TCP-style socket will have exactly one association on one of
1313  * these.  An UDP-style socket will have multiple associations hanging
1314  * off one of these.
1315  */
1316 
1317 struct sctp_endpoint {
1318         /* Common substructure for endpoint and association. */
1319         struct sctp_ep_common base;
1320 
1321         /* Associations: A list of current associations and mappings
1322          *            to the data consumers for each association. This
1323          *            may be in the form of a hash table or other
1324          *            implementation dependent structure. The data
1325          *            consumers may be process identification
1326          *            information such as file descriptors, named pipe
1327          *            pointer, or table pointers dependent on how SCTP
1328          *            is implemented.
1329          */
1330         /* This is really a list of struct sctp_association entries. */
1331         struct list_head asocs;
1332 
1333         /* Secret Key: A secret key used by this endpoint to compute
1334          *            the MAC.  This SHOULD be a cryptographic quality
1335          *            random number with a sufficient length.
1336          *            Discussion in [RFC1750] can be helpful in
1337          *            selection of the key.
1338          */
1339         __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1340         int current_key;
1341         int last_key;
1342         int key_changed_at;
1343 
1344         /* digest:  This is a digest of the sctp cookie.  This field is
1345          *          only used on the receive path when we try to validate
1346          *          that the cookie has not been tampered with.  We put
1347          *          this here so we pre-allocate this once and can re-use
1348          *          on every receive.
1349          */
1350         __u8 *digest;
1351  
1352         /* sendbuf acct. policy.        */
1353         __u32 sndbuf_policy;
1354 
1355         /* rcvbuf acct. policy. */
1356         __u32 rcvbuf_policy;
1357 
1358         /* SCTP AUTH: array of the HMACs that will be allocated
1359          * we need this per association so that we don't serialize
1360          */
1361         struct crypto_hash **auth_hmacs;
1362 
1363         /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1364          struct sctp_hmac_algo_param *auth_hmacs_list;
1365 
1366         /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1367         struct sctp_chunks_param *auth_chunk_list;
1368 
1369         /* SCTP-AUTH: endpoint shared keys */
1370         struct list_head endpoint_shared_keys;
1371         __u16 active_key_id;
1372 };
1373 
1374 /* Recover the outter endpoint structure. */
1375 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1376 {
1377         struct sctp_endpoint *ep;
1378 
1379         ep = container_of(base, struct sctp_endpoint, base);
1380         return ep;
1381 }
1382 
1383 /* These are function signatures for manipulating endpoints.  */
1384 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1385 void sctp_endpoint_free(struct sctp_endpoint *);
1386 void sctp_endpoint_put(struct sctp_endpoint *);
1387 void sctp_endpoint_hold(struct sctp_endpoint *);
1388 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1389 struct sctp_association *sctp_endpoint_lookup_assoc(
1390         const struct sctp_endpoint *ep,
1391         const union sctp_addr *paddr,
1392         struct sctp_transport **);
1393 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1394                                 const union sctp_addr *);
1395 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1396                                         const union sctp_addr *);
1397 int sctp_has_association(const union sctp_addr *laddr,
1398                          const union sctp_addr *paddr);
1399 
1400 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1401                      sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1402                      struct sctp_chunk **err_chunk);
1403 int sctp_process_init(struct sctp_association *, sctp_cid_t cid,
1404                       const union sctp_addr *peer,
1405                       sctp_init_chunk_t *init, gfp_t gfp);
1406 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1407 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1408 
1409 struct sctp_inithdr_host {
1410         __u32 init_tag;
1411         __u32 a_rwnd;
1412         __u16 num_outbound_streams;
1413         __u16 num_inbound_streams;
1414         __u32 initial_tsn;
1415 };
1416 
1417 /* RFC2960
1418  *
1419  * 12. Recommended Transmission Control Block (TCB) Parameters
1420  *
1421  * This section details a recommended set of parameters that should
1422  * be contained within the TCB for an implementation. This section is
1423  * for illustrative purposes and should not be deemed as requirements
1424  * on an implementation or as an exhaustive list of all parameters
1425  * inside an SCTP TCB. Each implementation may need its own additional
1426  * parameters for optimization.
1427  */
1428 
1429 
1430 /* Here we have information about each individual association. */
1431 struct sctp_association {
1432 
1433         /* A base structure common to endpoint and association.
1434          * In this context, it represents the associations's view
1435          * of the local endpoint of the association.
1436          */
1437         struct sctp_ep_common base;
1438 
1439         /* Associations on the same socket. */
1440         struct list_head asocs;
1441 
1442         /* association id. */
1443         sctp_assoc_t assoc_id;
1444 
1445         /* This is our parent endpoint.  */
1446         struct sctp_endpoint *ep;
1447 
1448         /* These are those association elements needed in the cookie.  */
1449         struct sctp_cookie c;
1450 
1451         /* This is all information about our peer.  */
1452         struct {
1453                 /* rwnd
1454                  *
1455                  * Peer Rwnd   : Current calculated value of the peer's rwnd.
1456                  */
1457                 __u32 rwnd;
1458 
1459                 /* transport_addr_list
1460                  *
1461                  * Peer        : A list of SCTP transport addresses that the
1462                  * Transport   : peer is bound to. This information is derived
1463                  * Address     : from the INIT or INIT ACK and is used to
1464                  * List        : associate an inbound packet with a given
1465                  *             : association. Normally this information is
1466                  *             : hashed or keyed for quick lookup and access
1467                  *             : of the TCB.
1468                  *             : The list is also initialized with the list
1469                  *             : of addresses passed with the sctp_connectx()
1470                  *             : call.
1471                  *
1472                  * It is a list of SCTP_transport's.
1473                  */
1474                 struct list_head transport_addr_list;
1475 
1476                 /* transport_count
1477                  *
1478                  * Peer        : A count of the number of peer addresses
1479                  * Transport   : in the Peer Transport Address List.
1480                  * Address     :
1481                  * Count       :
1482                  */
1483                 __u16 transport_count;
1484 
1485                 /* port
1486                  *   The transport layer port number.
1487                  */
1488                 __u16 port;
1489 
1490                 /* primary_path
1491                  *
1492                  * Primary     : This is the current primary destination
1493                  * Path        : transport address of the peer endpoint.  It
1494                  *             : may also specify a source transport address
1495                  *             : on this endpoint.
1496                  *
1497                  * All of these paths live on transport_addr_list.
1498                  *
1499                  * At the bakeoffs, we discovered that the intent of
1500                  * primaryPath is that it only changes when the ULP
1501                  * asks to have it changed.  We add the activePath to
1502                  * designate the connection we are currently using to
1503                  * transmit new data and most control chunks.
1504                  */
1505                 struct sctp_transport *primary_path;
1506 
1507                 /* Cache the primary path address here, when we
1508                  * need a an address for msg_name.
1509                  */
1510                 union sctp_addr primary_addr;
1511 
1512                 /* active_path
1513                  *   The path that we are currently using to
1514                  *   transmit new data and most control chunks.
1515                  */
1516                 struct sctp_transport *active_path;
1517 
1518                 /* retran_path
1519                  *
1520                  * RFC2960 6.4 Multi-homed SCTP Endpoints
1521                  * ...
1522                  * Furthermore, when its peer is multi-homed, an
1523                  * endpoint SHOULD try to retransmit a chunk to an
1524                  * active destination transport address that is
1525                  * different from the last destination address to
1526                  * which the DATA chunk was sent.
1527                  */
1528                 struct sctp_transport *retran_path;
1529 
1530                 /* Pointer to last transport I have sent on.  */
1531                 struct sctp_transport *last_sent_to;
1532 
1533                 /* This is the last transport I have received DATA on.  */
1534                 struct sctp_transport *last_data_from;
1535 
1536                 /*
1537                  * Mapping  An array of bits or bytes indicating which out of
1538                  * Array    order TSN's have been received (relative to the
1539                  *          Last Rcvd TSN). If no gaps exist, i.e. no out of
1540                  *          order packets have been received, this array
1541                  *          will be set to all zero. This structure may be
1542                  *          in the form of a circular buffer or bit array.
1543                  *
1544                  * Last Rcvd   : This is the last TSN received in
1545                  * TSN         : sequence. This value is set initially by
1546                  *             : taking the peer's Initial TSN, received in
1547                  *             : the INIT or INIT ACK chunk, and subtracting
1548                  *             : one from it.
1549                  *
1550                  * Throughout most of the specification this is called the
1551                  * "Cumulative TSN ACK Point".  In this case, we
1552                  * ignore the advice in 12.2 in favour of the term
1553                  * used in the bulk of the text.  This value is hidden
1554                  * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1555                  */
1556                 struct sctp_tsnmap tsn_map;
1557 
1558                 /* Ack State   : This flag indicates if the next received
1559                  *             : packet is to be responded to with a
1560                  *             : SACK. This is initializedto 0.  When a packet
1561                  *             : is received it is incremented. If this value
1562                  *             : reaches 2 or more, a SACK is sent and the
1563                  *             : value is reset to 0. Note: This is used only
1564                  *             : when no DATA chunks are received out of
1565                  *             : order.  When DATA chunks are out of order,
1566                  *             : SACK's are not delayed (see Section 6).
1567                  */
1568                 __u8    sack_needed;     /* Do we need to sack the peer? */
1569                 __u32   sack_cnt;
1570 
1571                 /* These are capabilities which our peer advertised.  */
1572                 __u8    ecn_capable:1,      /* Can peer do ECN? */
1573                         ipv4_address:1,     /* Peer understands IPv4 addresses? */
1574                         ipv6_address:1,     /* Peer understands IPv6 addresses? */
1575                         hostname_address:1, /* Peer understands DNS addresses? */
1576                         asconf_capable:1,   /* Does peer support ADDIP? */
1577                         prsctp_capable:1,   /* Can peer do PR-SCTP? */
1578                         auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1579 
1580                 __u32   adaptation_ind;  /* Adaptation Code point. */
1581 
1582                 /* This mask is used to disable sending the ASCONF chunk
1583                  * with specified parameter to peer.
1584                  */
1585                 __be16 addip_disabled_mask;
1586 
1587                 struct sctp_inithdr_host i;
1588                 int cookie_len;
1589                 void *cookie;
1590 
1591                 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1592                  * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1593                  * Initial TSN Value minus 1
1594                  */
1595                 __u32 addip_serial;
1596 
1597                 /* SCTP-AUTH: We need to know pears random number, hmac list
1598                  * and authenticated chunk list.  All that is part of the
1599                  * cookie and these are just pointers to those locations
1600                  */
1601                 sctp_random_param_t *peer_random;
1602                 sctp_chunks_param_t *peer_chunks;
1603                 sctp_hmac_algo_param_t *peer_hmacs;
1604         } peer;
1605 
1606         /* State       : A state variable indicating what state the
1607          *             : association is in, i.e. COOKIE-WAIT,
1608          *             : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1609          *             : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1610          *
1611          *              Note: No "CLOSED" state is illustrated since if a
1612          *              association is "CLOSED" its TCB SHOULD be removed.
1613          *
1614          *              In this implementation we DO have a CLOSED
1615          *              state which is used during initiation and shutdown.
1616          *
1617          *              State takes values from SCTP_STATE_*.
1618          */
1619         sctp_state_t state;
1620 
1621         /* The cookie life I award for any cookie.  */
1622         struct timeval cookie_life;
1623 
1624         /* Overall     : The overall association error count.
1625          * Error Count : [Clear this any time I get something.]
1626          */
1627         int overall_error_count;
1628 
1629         /* These are the association's initial, max, and min RTO values.
1630          * These values will be initialized by system defaults, but can
1631          * be modified via the SCTP_RTOINFO socket option.
1632          */
1633         unsigned long rto_initial;
1634         unsigned long rto_max;
1635         unsigned long rto_min;
1636 
1637         /* Maximum number of new data packets that can be sent in a burst.  */
1638         int max_burst;
1639 
1640         /* This is the max_retrans value for the association.  This value will
1641          * be initialized initialized from system defaults, but can be
1642          * modified by the SCTP_ASSOCINFO socket option.
1643          */
1644         int max_retrans;
1645 
1646         /* Maximum number of times the endpoint will retransmit INIT  */
1647         __u16 max_init_attempts;
1648 
1649         /* How many times have we resent an INIT? */
1650         __u16 init_retries;
1651 
1652         /* The largest timeout or RTO value to use in attempting an INIT */
1653         unsigned long max_init_timeo;
1654 
1655         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1656          * the destination address every heartbeat interval. This value
1657          * will be inherited by all new transports.
1658          */
1659         unsigned long hbinterval;
1660 
1661         /* This is the max_retrans value for new transports in the
1662          * association.
1663          */
1664         __u16 pathmaxrxt;
1665 
1666         /* Flag that path mtu update is pending */
1667         __u8   pmtu_pending;
1668 
1669         /* Association : The smallest PMTU discovered for all of the
1670          * PMTU        : peer's transport addresses.
1671          */
1672         __u32 pathmtu;
1673 
1674         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1675         __u32 param_flags;
1676 
1677         /* SACK delay timeout */
1678         unsigned long sackdelay;
1679         __u32 sackfreq;
1680 
1681 
1682         unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1683         struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1684 
1685         /* Transport to which SHUTDOWN chunk was last sent.  */
1686         struct sctp_transport *shutdown_last_sent_to;
1687 
1688         /* How many times have we resent a SHUTDOWN */
1689         int shutdown_retries;
1690 
1691         /* Transport to which INIT chunk was last sent.  */
1692         struct sctp_transport *init_last_sent_to;
1693 
1694         /* Next TSN    : The next TSN number to be assigned to a new
1695          *             : DATA chunk.  This is sent in the INIT or INIT
1696          *             : ACK chunk to the peer and incremented each
1697          *             : time a DATA chunk is assigned a TSN
1698          *             : (normally just prior to transmit or during
1699          *             : fragmentation).
1700          */
1701         __u32 next_tsn;
1702 
1703         /*
1704          * Last Rcvd   : This is the last TSN received in sequence.  This value
1705          * TSN         : is set initially by taking the peer's Initial TSN,
1706          *             : received in the INIT or INIT ACK chunk, and
1707          *             : subtracting one from it.
1708          *
1709          * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1710          */
1711 
1712         __u32 ctsn_ack_point;
1713 
1714         /* PR-SCTP Advanced.Peer.Ack.Point */
1715         __u32 adv_peer_ack_point;
1716 
1717         /* Highest TSN that is acknowledged by incoming SACKs. */
1718         __u32 highest_sacked;
1719 
1720         /* TSN marking the fast recovery exit point */
1721         __u32 fast_recovery_exit;
1722 
1723         /* Flag to track the current fast recovery state */
1724         __u8 fast_recovery;
1725 
1726         /* The number of unacknowledged data chunks.  Reported through
1727          * the SCTP_STATUS sockopt.
1728          */
1729         __u16 unack_data;
1730 
1731         /* The total number of data chunks that we've had to retransmit
1732          * as the result of a T3 timer expiration
1733          */
1734         __u32 rtx_data_chunks;
1735 
1736         /* This is the association's receive buffer space.  This value is used
1737          * to set a_rwnd field in an INIT or a SACK chunk.
1738          */
1739         __u32 rwnd;
1740 
1741         /* This is the last advertised value of rwnd over a SACK chunk. */
1742         __u32 a_rwnd;
1743 
1744         /* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1745          * to slop over a maximum of the association's frag_point.
1746          */
1747         __u32 rwnd_over;
1748 
1749         /* Keeps treack of rwnd pressure.  This happens when we have
1750          * a window, but not recevie buffer (i.e small packets).  This one
1751          * is releases slowly (1 PMTU at a time ).
1752          */
1753         __u32 rwnd_press;
1754 
1755         /* This is the sndbuf size in use for the association.
1756          * This corresponds to the sndbuf size for the association,
1757          * as specified in the sk->sndbuf.
1758          */
1759         int sndbuf_used;
1760 
1761         /* This is the amount of memory that this association has allocated
1762          * in the receive path at any given time.
1763          */
1764         atomic_t rmem_alloc;
1765 
1766         /* This is the wait queue head for send requests waiting on
1767          * the association sndbuf space.
1768          */
1769         wait_queue_head_t       wait;
1770 
1771         /* The message size at which SCTP fragmentation will occur. */
1772         __u32 frag_point;
1773         __u32 user_frag;
1774 
1775         /* Counter used to count INIT errors. */
1776         int init_err_counter;
1777 
1778         /* Count the number of INIT cycles (for doubling timeout). */
1779         int init_cycle;
1780 
1781         /* Default send parameters. */
1782         __u16 default_stream;
1783         __u16 default_flags;
1784         __u32 default_ppid;
1785         __u32 default_context;
1786         __u32 default_timetolive;
1787 
1788         /* Default receive parameters */
1789         __u32 default_rcv_context;
1790 
1791         /* This tracks outbound ssn for a given stream.  */
1792         struct sctp_ssnmap *ssnmap;
1793 
1794         /* All outbound chunks go through this structure.  */
1795         struct sctp_outq outqueue;
1796 
1797         /* A smart pipe that will handle reordering and fragmentation,
1798          * as well as handle passing events up to the ULP.
1799          */
1800         struct sctp_ulpq ulpq;
1801 
1802         /* Last TSN that caused an ECNE Chunk to be sent.  */
1803         __u32 last_ecne_tsn;
1804 
1805         /* Last TSN that caused a CWR Chunk to be sent.  */
1806         __u32 last_cwr_tsn;
1807 
1808         /* How many duplicated TSNs have we seen?  */
1809         int numduptsns;
1810 
1811         /* Number of seconds of idle time before an association is closed.
1812          * In the association context, this is really used as a boolean
1813          * since the real timeout is stored in the timeouts array
1814          */
1815         __u32 autoclose;
1816 
1817         /* These are to support
1818          * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1819          *  and Enforcement of Flow and Message Limits"
1820          * <draft-ietf-tsvwg-addip-sctp-02.txt>
1821          * or "ADDIP" for short.
1822          */
1823 
1824 
1825 
1826         /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1827          *
1828          * R1) One and only one ASCONF Chunk MAY be in transit and
1829          * unacknowledged at any one time.  If a sender, after sending
1830          * an ASCONF chunk, decides it needs to transfer another
1831          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1832          * returns from the previous ASCONF Chunk before sending a
1833          * subsequent ASCONF. Note this restriction binds each side,
1834          * so at any time two ASCONF may be in-transit on any given
1835          * association (one sent from each endpoint).
1836          *
1837          * [This is our one-and-only-one ASCONF in flight.  If we do
1838          * not have an ASCONF in flight, this is NULL.]
1839          */
1840         struct sctp_chunk *addip_last_asconf;
1841 
1842         /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1843          *
1844          * This is needed to implement itmes E1 - E4 of the updated
1845          * spec.  Here is the justification:
1846          *
1847          * Since the peer may bundle multiple ASCONF chunks toward us,
1848          * we now need the ability to cache multiple ACKs.  The section
1849          * describes in detail how they are cached and cleaned up.
1850          */
1851         struct list_head asconf_ack_list;
1852 
1853         /* These ASCONF chunks are waiting to be sent.
1854          *
1855          * These chunaks can't be pushed to outqueue until receiving
1856          * ASCONF_ACK for the previous ASCONF indicated by
1857          * addip_last_asconf, so as to guarantee that only one ASCONF
1858          * is in flight at any time.
1859          *
1860          * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1861          *
1862          * In defining the ASCONF Chunk transfer procedures, it is
1863          * essential that these transfers MUST NOT cause congestion
1864          * within the network.  To achieve this, we place these
1865          * restrictions on the transfer of ASCONF Chunks:
1866          *
1867          * R1) One and only one ASCONF Chunk MAY be in transit and
1868          * unacknowledged at any one time.  If a sender, after sending
1869          * an ASCONF chunk, decides it needs to transfer another
1870          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1871          * returns from the previous ASCONF Chunk before sending a
1872          * subsequent ASCONF. Note this restriction binds each side,
1873          * so at any time two ASCONF may be in-transit on any given
1874          * association (one sent from each endpoint).
1875          *
1876          *
1877          * [I really think this is EXACTLY the sort of intelligence
1878          *  which already resides in sctp_outq.  Please move this
1879          *  queue and its supporting logic down there.  --piggy]
1880          */
1881         struct list_head addip_chunk_list;
1882 
1883         /* ADDIP Section 4.1 ASCONF Chunk Procedures
1884          *
1885          * A2) A serial number should be assigned to the Chunk. The
1886          * serial number SHOULD be a monotonically increasing
1887          * number. The serial number SHOULD be initialized at
1888          * the start of the association to the same value as the
1889          * Initial TSN and every time a new ASCONF chunk is created
1890          * it is incremented by one after assigning the serial number
1891          * to the newly created chunk.
1892          *
1893          * ADDIP
1894          * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
1895          *
1896          * Serial Number : 32 bits (unsigned integer)
1897          *
1898          * This value represents a Serial Number for the ASCONF
1899          * Chunk. The valid range of Serial Number is from 0 to
1900          * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
1901          * after reaching 4294967295.
1902          */
1903         __u32 addip_serial;
1904 
1905         /* SCTP AUTH: list of the endpoint shared keys.  These
1906          * keys are provided out of band by the user applicaton
1907          * and can't change during the lifetime of the association
1908          */
1909         struct list_head endpoint_shared_keys;
1910 
1911         /* SCTP AUTH:
1912          * The current generated assocaition shared key (secret)
1913          */
1914         struct sctp_auth_bytes *asoc_shared_key;
1915 
1916         /* SCTP AUTH: hmac id of the first peer requested algorithm
1917          * that we support.
1918          */
1919         __u16 default_hmac_id;
1920 
1921         __u16 active_key_id;
1922 
1923         __u8 need_ecne:1,       /* Need to send an ECNE Chunk? */
1924              temp:1;            /* Is it a temporary association? */
1925 };
1926 
1927 
1928 /* An eyecatcher for determining if we are really looking at an
1929  * association data structure.
1930  */
1931 enum {
1932         SCTP_ASSOC_EYECATCHER = 0xa550c123,
1933 };
1934 
1935 /* Recover the outter association structure. */
1936 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1937 {
1938         struct sctp_association *asoc;
1939 
1940         asoc = container_of(base, struct sctp_association, base);
1941         return asoc;
1942 }
1943 
1944 /* These are function signatures for manipulating associations.  */
1945 
1946 
1947 struct sctp_association *
1948 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1949                      sctp_scope_t scope, gfp_t gfp);
1950 void sctp_association_free(struct sctp_association *);
1951 void sctp_association_put(struct sctp_association *);
1952 void sctp_association_hold(struct sctp_association *);
1953 
1954 struct sctp_transport *sctp_assoc_choose_alter_transport(
1955         struct sctp_association *, struct sctp_transport *);
1956 void sctp_assoc_update_retran_path(struct sctp_association *);
1957 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1958                                           const union sctp_addr *);
1959 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1960                             const union sctp_addr *laddr);
1961 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1962                                      const union sctp_addr *address,
1963                                      const gfp_t gfp,
1964                                      const int peer_state);
1965 void sctp_assoc_del_peer(struct sctp_association *asoc,
1966                          const union sctp_addr *addr);
1967 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1968                          struct sctp_transport *peer);
1969 void sctp_assoc_control_transport(struct sctp_association *,
1970                                   struct sctp_transport *,
1971                                   sctp_transport_cmd_t, sctp_sn_error_t);
1972 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1973 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1974                                            const union sctp_addr *,
1975                                            const union sctp_addr *);
1976 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1977 void sctp_assoc_update(struct sctp_association *old,
1978                        struct sctp_association *new);
1979 
1980 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1981 
1982 void sctp_assoc_sync_pmtu(struct sctp_association *);
1983 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1984 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1985 void sctp_assoc_set_primary(struct sctp_association *,
1986                             struct sctp_transport *);
1987 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1988                                     struct sctp_transport *);
1989 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1990                                      sctp_scope_t, gfp_t);
1991 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1992                                          struct sctp_cookie*,
1993                                          gfp_t gfp);
1994 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1995 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1996 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1997                                         const struct sctp_association *asoc,
1998                                         __be32 serial);
1999 
2000 
2001 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2002                         const union sctp_addr *ss2);
2003 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2004 
2005 /* A convenience structure to parse out SCTP specific CMSGs. */
2006 typedef struct sctp_cmsgs {
2007         struct sctp_initmsg *init;
2008         struct sctp_sndrcvinfo *info;
2009 } sctp_cmsgs_t;
2010 
2011 /* Structure for tracking memory objects */
2012 typedef struct {
2013         char *label;
2014         atomic_t *counter;
2015 } sctp_dbg_objcnt_entry_t;
2016 
2017 #endif /* __sctp_structs_h__ */
2018 

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