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.
7 * This file is part of the SCTP kernel implementation
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)
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.
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.
26 * Please send any bug reports or fixes you make to the
28 * lksctp developers <lksctp-developers@lists.sourceforge.net>
30 * Or submit a bug report through the following website:
31 * http://www.sf.net/projects/lksctp
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>
50 * Any bugs reported given to us we will try to fix... any fixes shared will
51 * be incorporated into the next SCTP release.
54 #ifndef __sctp_structs_h__
55 #define __sctp_structs_h__
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 <linux/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 */
69 /* A convenience structure for handling sockaddr structures.
70 * We should wean ourselves off this.
73 struct sockaddr_in v4;
74 struct sockaddr_in6 v6;
78 /* Forward declarations for data structures. */
81 struct sctp_association;
82 struct sctp_transport;
87 struct sctp_bind_addr;
89 struct sctp_ep_common;
94 #include <net/sctp/tsnmap.h>
95 #include <net/sctp/ulpevent.h>
96 #include <net/sctp/ulpqueue.h>
98 /* Structures useful for managing bind/connect. */
100 struct sctp_bind_bucket {
102 unsigned short fastreuse;
103 struct hlist_node node;
104 struct hlist_head owner;
107 struct sctp_bind_hashbucket {
109 struct hlist_head chain;
112 /* Used for hashing all associations. */
113 struct sctp_hashbucket {
115 struct hlist_head chain;
116 } __attribute__((__aligned__(8)));
119 /* The SCTP globals structure. */
120 extern struct sctp_globals {
121 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values
123 * The following protocol parameters are RECOMMENDED:
125 * RTO.Initial - 3 seconds
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.)
131 unsigned int rto_initial;
132 unsigned int rto_min;
133 unsigned int rto_max;
135 /* Note: rto_alpha and rto_beta are really defined as inverse
136 * powers of two to facilitate integer operations.
144 /* Whether Cookie Preservative is enabled(1) or not(0) */
145 int cookie_preserve_enable;
147 /* Valid.Cookie.Life - 60 seconds */
148 unsigned int valid_cookie_life;
150 /* Delayed SACK timeout 200ms default*/
151 unsigned int sack_timeout;
153 /* HB.interval - 30 seconds */
154 unsigned int hb_interval;
156 /* Association.Max.Retrans - 10 attempts
157 * Path.Max.Retrans - 5 attempts (per destination address)
158 * Max.Init.Retransmits - 8 attempts
160 int max_retrans_association;
161 int max_retrans_path;
162 int max_retrans_init;
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
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
178 /* The following variables are implementation specific. */
180 /* Default initialization values to be applied to new associations. */
182 __u16 max_outstreams;
184 /* This is a list of groups of functions for each address
185 * family that we support.
187 struct list_head address_families;
189 /* This is the hash of all endpoints. */
191 struct sctp_hashbucket *ep_hashtable;
193 /* This is the hash of all associations. */
195 struct sctp_hashbucket *assoc_hashtable;
197 /* This is the sctp port control hash. */
199 struct sctp_bind_hashbucket *port_hashtable;
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.
205 * It is a list of sctp_sockaddr_entry.
207 struct list_head local_addr_list;
208 int default_auto_asconf;
209 struct list_head addr_waitq;
210 struct timer_list addr_wq_timer;
211 struct list_head auto_asconf_splist;
212 /* Lock that protects both addr_waitq and auto_asconf_splist */
213 spinlock_t addr_wq_lock;
215 /* Lock that protects the local_addr_list writers */
216 spinlock_t addr_list_lock;
218 /* Flag to indicate if addip is enabled. */
220 int addip_noauth_enable;
222 /* Flag to indicate if PR-SCTP is enabled. */
225 /* Flag to idicate if SCTP-AUTH is enabled */
229 * Policy to control SCTP IPv4 address scoping
230 * 0 - Disable IPv4 address scoping
231 * 1 - Enable IPv4 address scoping
232 * 2 - Selectively allow only IPv4 private addresses
233 * 3 - Selectively allow only IPv4 link local address
235 int ipv4_scope_policy;
237 /* Flag to indicate whether computing and verifying checksum
239 int checksum_disable;
241 /* Threshold for rwnd update SACKS. Receive buffer shifted this many
242 * bits is an indicator of when to send and window update SACK.
244 int rwnd_update_shift;
246 /* Threshold for autoclose timeout, in seconds. */
247 unsigned long max_autoclose;
250 #define sctp_rto_initial (sctp_globals.rto_initial)
251 #define sctp_rto_min (sctp_globals.rto_min)
252 #define sctp_rto_max (sctp_globals.rto_max)
253 #define sctp_rto_alpha (sctp_globals.rto_alpha)
254 #define sctp_rto_beta (sctp_globals.rto_beta)
255 #define sctp_max_burst (sctp_globals.max_burst)
256 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life)
257 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable)
258 #define sctp_max_retrans_association (sctp_globals.max_retrans_association)
259 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy)
260 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy)
261 #define sctp_max_retrans_path (sctp_globals.max_retrans_path)
262 #define sctp_max_retrans_init (sctp_globals.max_retrans_init)
263 #define sctp_sack_timeout (sctp_globals.sack_timeout)
264 #define sctp_hb_interval (sctp_globals.hb_interval)
265 #define sctp_max_instreams (sctp_globals.max_instreams)
266 #define sctp_max_outstreams (sctp_globals.max_outstreams)
267 #define sctp_address_families (sctp_globals.address_families)
268 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
269 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
270 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
271 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
272 #define sctp_port_hashsize (sctp_globals.port_hashsize)
273 #define sctp_port_hashtable (sctp_globals.port_hashtable)
274 #define sctp_local_addr_list (sctp_globals.local_addr_list)
275 #define sctp_local_addr_lock (sctp_globals.addr_list_lock)
276 #define sctp_auto_asconf_splist (sctp_globals.auto_asconf_splist)
277 #define sctp_addr_waitq (sctp_globals.addr_waitq)
278 #define sctp_addr_wq_timer (sctp_globals.addr_wq_timer)
279 #define sctp_addr_wq_lock (sctp_globals.addr_wq_lock)
280 #define sctp_default_auto_asconf (sctp_globals.default_auto_asconf)
281 #define sctp_scope_policy (sctp_globals.ipv4_scope_policy)
282 #define sctp_addip_enable (sctp_globals.addip_enable)
283 #define sctp_addip_noauth (sctp_globals.addip_noauth_enable)
284 #define sctp_prsctp_enable (sctp_globals.prsctp_enable)
285 #define sctp_auth_enable (sctp_globals.auth_enable)
286 #define sctp_checksum_disable (sctp_globals.checksum_disable)
287 #define sctp_rwnd_upd_shift (sctp_globals.rwnd_update_shift)
288 #define sctp_max_autoclose (sctp_globals.max_autoclose)
290 /* SCTP Socket type: UDP or TCP style. */
293 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
295 } sctp_socket_type_t;
297 /* Per socket SCTP information. */
299 /* inet_sock has to be the first member of sctp_sock */
300 struct inet_sock inet;
301 /* What kind of a socket is this? */
302 sctp_socket_type_t type;
304 /* PF_ family specific functions. */
307 /* Access to HMAC transform. */
308 struct crypto_hash *hmac;
310 /* What is our base endpointer? */
311 struct sctp_endpoint *ep;
313 struct sctp_bind_bucket *bind_hash;
314 /* Various Socket Options. */
315 __u16 default_stream;
318 __u32 default_context;
319 __u32 default_timetolive;
320 __u32 default_rcv_context;
323 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
324 * the destination address every heartbeat interval. This value
325 * will be inherited by all new associations.
329 /* This is the max_retrans value for new associations. */
332 /* The initial Path MTU to use for new associations. */
335 /* The default SACK delay timeout for new associations. */
339 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
342 struct sctp_initmsg initmsg;
343 struct sctp_rtoinfo rtoinfo;
344 struct sctp_paddrparams paddrparam;
345 struct sctp_event_subscribe subscribe;
346 struct sctp_assocparams assocparams;
350 __u8 disable_fragments;
352 __u8 frag_interleave;
353 __u32 adaptation_ind;
357 /* Receive to here while partial delivery is in effect. */
358 struct sk_buff_head pd_lobby;
360 /* These must be the last fields, as they will skipped on copies,
361 * like on accept and peeloff operations
363 struct list_head auto_asconf_list;
367 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
369 return (struct sctp_sock *)sk;
372 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
374 return (struct sock *)sp;
377 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
379 struct sctp_sock sctp;
380 struct ipv6_pinfo inet6;
382 #endif /* CONFIG_IPV6 */
385 /* This is our APPLICATION-SPECIFIC state cookie.
386 * THIS IS NOT DICTATED BY THE SPECIFICATION.
388 /* These are the parts of an association which we send in the cookie.
389 * Most of these are straight out of:
390 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
396 /* My : Tag expected in every inbound packet and sent
397 * Verification: in the INIT or INIT ACK chunk.
402 /* Peer's : Tag expected in every outbound packet except
403 * Verification: in the INIT chunk.
408 /* The rest of these are not from the spec, but really need to
412 /* My Tie Tag : Assist in discovering a restarting association. */
415 /* Peer's Tie Tag: Assist in discovering a restarting association. */
418 /* When does this cookie expire? */
419 struct timeval expiration;
421 /* Number of inbound/outbound streams which are set
422 * and negotiated during the INIT process.
424 __u16 sinit_num_ostreams;
425 __u16 sinit_max_instreams;
427 /* This is the first sequence number I used. */
430 /* This holds the originating address of the INIT packet. */
431 union sctp_addr peer_addr;
434 * Include the source port of the INIT-ACK
440 /* Padding for future use */
443 __u32 adaptation_ind;
445 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
446 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
447 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
449 /* This is a shim for my peer's INIT packet, followed by
450 * a copy of the raw address list of the association.
451 * The length of the raw address list is saved in the
452 * raw_addr_list_len field, which will be used at the time when
453 * the association TCB is re-constructed from the cookie.
455 __u32 raw_addr_list_len;
456 struct sctp_init_chunk peer_init[0];
460 /* The format of our cookie that we send to our peer. */
461 struct sctp_signed_cookie {
462 __u8 signature[SCTP_SECRET_SIZE];
463 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
464 struct sctp_cookie c;
467 /* This is another convenience type to allocate memory for address
468 * params for the maximum size and pass such structures around
471 union sctp_addr_param {
472 struct sctp_paramhdr p;
473 struct sctp_ipv4addr_param v4;
474 struct sctp_ipv6addr_param v6;
477 /* A convenience type to allow walking through the various
478 * parameters and avoid casting all over the place.
482 struct sctp_paramhdr *p;
483 struct sctp_cookie_preserve_param *life;
484 struct sctp_hostname_param *dns;
485 struct sctp_cookie_param *cookie;
486 struct sctp_supported_addrs_param *sat;
487 struct sctp_ipv4addr_param *v4;
488 struct sctp_ipv6addr_param *v6;
489 union sctp_addr_param *addr;
490 struct sctp_adaptation_ind_param *aind;
491 struct sctp_supported_ext_param *ext;
492 struct sctp_random_param *random;
493 struct sctp_chunks_param *chunks;
494 struct sctp_hmac_algo_param *hmac_algo;
495 struct sctp_addip_param *addip;
498 /* RFC 2960. Section 3.3.5 Heartbeat.
499 * Heartbeat Information: variable length
500 * The Sender-specific Heartbeat Info field should normally include
501 * information about the sender's current time when this HEARTBEAT
502 * chunk is sent and the destination transport address to which this
503 * HEARTBEAT is sent (see Section 8.3).
505 typedef struct sctp_sender_hb_info {
506 struct sctp_paramhdr param_hdr;
507 union sctp_addr daddr;
508 unsigned long sent_at;
510 } __packed sctp_sender_hb_info_t;
513 * RFC 2960 1.3.2 Sequenced Delivery within Streams
515 * The term "stream" is used in SCTP to refer to a sequence of user
516 * messages that are to be delivered to the upper-layer protocol in
517 * order with respect to other messages within the same stream. This is
518 * in contrast to its usage in TCP, where it refers to a sequence of
519 * bytes (in this document a byte is assumed to be eight bits).
522 * This is the structure we use to track both our outbound and inbound
523 * SSN, or Stream Sequence Numbers.
532 struct sctp_stream in;
533 struct sctp_stream out;
537 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
539 void sctp_ssnmap_free(struct sctp_ssnmap *map);
540 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
542 /* What is the current SSN number for this stream? */
543 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
545 return stream->ssn[id];
548 /* Return the next SSN number for this stream. */
549 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
551 return stream->ssn[id]++;
554 /* Skip over this ssn and all below. */
555 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
558 stream->ssn[id] = ssn+1;
562 * Pointers to address related SCTP functions.
563 * (i.e. things that depend on the address family.)
566 int (*sctp_xmit) (struct sk_buff *skb,
567 struct sctp_transport *);
568 int (*setsockopt) (struct sock *sk,
572 unsigned int optlen);
573 int (*getsockopt) (struct sock *sk,
578 int (*compat_setsockopt) (struct sock *sk,
582 unsigned int optlen);
583 int (*compat_getsockopt) (struct sock *sk,
588 void (*get_dst) (struct sctp_transport *t,
589 union sctp_addr *saddr,
592 void (*get_saddr) (struct sctp_sock *sk,
593 struct sctp_transport *t,
595 void (*copy_addrlist) (struct list_head *,
596 struct net_device *);
597 int (*cmp_addr) (const union sctp_addr *addr1,
598 const union sctp_addr *addr2);
599 void (*addr_copy) (union sctp_addr *dst,
600 union sctp_addr *src);
601 void (*from_skb) (union sctp_addr *,
604 void (*from_sk) (union sctp_addr *,
606 void (*to_sk_saddr) (union sctp_addr *,
608 void (*to_sk_daddr) (union sctp_addr *,
610 void (*from_addr_param) (union sctp_addr *,
611 union sctp_addr_param *,
612 __be16 port, int iif);
613 int (*to_addr_param) (const union sctp_addr *,
614 union sctp_addr_param *);
615 int (*addr_valid) (union sctp_addr *,
617 const struct sk_buff *);
618 sctp_scope_t (*scope) (union sctp_addr *);
619 void (*inaddr_any) (union sctp_addr *, __be16);
620 int (*is_any) (const union sctp_addr *);
621 int (*available) (union sctp_addr *,
623 int (*skb_iif) (const struct sk_buff *sk);
624 int (*is_ce) (const struct sk_buff *sk);
625 void (*seq_dump_addr)(struct seq_file *seq,
626 union sctp_addr *addr);
627 void (*ecn_capable)(struct sock *sk);
628 __u16 net_header_len;
630 sa_family_t sa_family;
631 struct list_head list;
634 struct sctp_af *sctp_get_af_specific(sa_family_t);
635 int sctp_register_af(struct sctp_af *);
637 /* Protocol family functions. */
639 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
640 void (*skb_msgname) (struct sk_buff *, char *, int *);
641 int (*af_supported) (sa_family_t, struct sctp_sock *);
642 int (*cmp_addr) (const union sctp_addr *,
643 const union sctp_addr *,
645 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
646 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
647 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
648 struct sock *(*create_accept_sk) (struct sock *sk,
649 struct sctp_association *asoc);
650 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
655 /* Structure to track chunk fragments that have been acked, but peer
656 * fragments of the same message have not.
658 struct sctp_datamsg {
659 /* Chunks waiting to be submitted to lower layer. */
660 struct list_head chunks;
661 /* Reference counting. */
663 /* When is this message no longer interesting to the peer? */
664 unsigned long expires_at;
665 /* Did the messenge fail to send? */
668 can_abandon:1, /* can chunks from this message can be abandoned. */
669 can_delay; /* should this message be Nagle delayed */
672 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
673 struct sctp_sndrcvinfo *,
674 struct msghdr *, int len);
675 void sctp_datamsg_free(struct sctp_datamsg *);
676 void sctp_datamsg_put(struct sctp_datamsg *);
677 void sctp_chunk_fail(struct sctp_chunk *, int error);
678 int sctp_chunk_abandoned(struct sctp_chunk *);
680 /* RFC2960 1.4 Key Terms
682 * o Chunk: A unit of information within an SCTP packet, consisting of
683 * a chunk header and chunk-specific content.
685 * As a matter of convenience, we remember the SCTP common header for
686 * each chunk as well as a few other header pointers...
689 struct list_head list;
693 /* This is our link to the per-transport transmitted list. */
694 struct list_head transmitted_list;
696 /* This field is used by chunks that hold fragmented data.
697 * For the first fragment this is the list that holds the rest of
698 * fragments. For the remaining fragments, this is the link to the
699 * frag_list maintained in the first fragment.
701 struct list_head frag_list;
703 /* This points to the sk_buff containing the actual data. */
706 /* These are the SCTP headers by reverse order in a packet.
707 * Note that some of these may happen more than once. In that
708 * case, we point at the "current" one, whatever that means
709 * for that level of header.
712 /* We point this at the FIRST TLV parameter to chunk_hdr. */
713 union sctp_params param_hdr;
716 struct sctp_datahdr *data_hdr;
717 struct sctp_inithdr *init_hdr;
718 struct sctp_sackhdr *sack_hdr;
719 struct sctp_heartbeathdr *hb_hdr;
720 struct sctp_sender_hb_info *hbs_hdr;
721 struct sctp_shutdownhdr *shutdown_hdr;
722 struct sctp_signed_cookie *cookie_hdr;
723 struct sctp_ecnehdr *ecne_hdr;
724 struct sctp_cwrhdr *ecn_cwr_hdr;
725 struct sctp_errhdr *err_hdr;
726 struct sctp_addiphdr *addip_hdr;
727 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
728 struct sctp_authhdr *auth_hdr;
733 struct sctp_chunkhdr *chunk_hdr;
734 struct sctphdr *sctp_hdr;
736 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
737 struct sctp_sndrcvinfo sinfo;
739 /* Which association does this belong to? */
740 struct sctp_association *asoc;
742 /* What endpoint received this chunk? */
743 struct sctp_ep_common *rcvr;
745 /* We fill this in if we are calculating RTT. */
746 unsigned long sent_at;
748 /* What is the origin IP address for this chunk? */
749 union sctp_addr source;
750 /* Destination address for this chunk. */
751 union sctp_addr dest;
753 /* For outbound message, track all fragments for SEND_FAILED. */
754 struct sctp_datamsg *msg;
756 /* For an inbound chunk, this tells us where it came from.
757 * For an outbound chunk, it tells us where we'd like it to
758 * go. It is NULL if we have no preference.
760 struct sctp_transport *transport;
762 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
763 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
764 * spec violates the principle premis that all chunks are processed
767 struct sk_buff *auth_chunk;
769 #define SCTP_CAN_FRTX 0x0
770 #define SCTP_NEED_FRTX 0x1
771 #define SCTP_DONT_FRTX 0x2
772 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
773 has_tsn:1, /* Does this chunk have a TSN yet? */
774 has_ssn:1, /* Does this chunk have a SSN yet? */
775 singleton:1, /* Only chunk in the packet? */
776 end_of_packet:1, /* Last chunk in the packet? */
777 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
778 pdiscard:1, /* Discard the whole packet now? */
779 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
780 data_accepted:1, /* At least 1 chunk accepted */
781 auth:1, /* IN: was auth'ed | OUT: needs auth */
782 has_asconf:1, /* IN: have seen an asconf before */
783 tsn_missing_report:2, /* Data chunk missing counter. */
784 fast_retransmit:2; /* Is this chunk fast retransmitted? */
787 void sctp_chunk_hold(struct sctp_chunk *);
788 void sctp_chunk_put(struct sctp_chunk *);
789 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
791 void sctp_chunk_free(struct sctp_chunk *);
792 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
793 void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
794 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
795 const struct sctp_association *,
797 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
799 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
802 SCTP_ADDR_NEW, /* new address added to assoc/ep */
803 SCTP_ADDR_SRC, /* address can be used as source */
804 SCTP_ADDR_DEL, /* address about to be deleted */
807 /* This is a structure for holding either an IPv6 or an IPv4 address. */
808 struct sctp_sockaddr_entry {
809 struct list_head list;
816 #define SCTP_ADDRESS_TICK_DELAY 500
818 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
820 /* This structure holds lists of chunks as we are assembling for
824 /* These are the SCTP header values (host order) for the packet. */
826 __u16 destination_port;
829 /* This contains the payload chunks. */
830 struct list_head chunk_list;
832 /* This is the overhead of the sctp and ip headers. */
834 /* This is the total size of all chunks INCLUDING padding. */
837 /* The packet is destined for this transport address.
838 * The function we finally use to pass down to the next lower
839 * layer lives in the transport structure.
841 struct sctp_transport *transport;
843 /* pointer to the auth chunk for this packet */
844 struct sctp_chunk *auth;
846 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
847 has_sack:1, /* This packet contains a SACK chunk. */
848 has_auth:1, /* This packet contains an AUTH chunk */
849 has_data:1, /* This packet contains at least 1 DATA chunk */
850 ipfragok:1, /* So let ip fragment this packet */
851 malloced:1; /* Is it malloced? */
854 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
855 struct sctp_transport *,
856 __u16 sport, __u16 dport);
857 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
858 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
859 struct sctp_chunk *, int);
860 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
861 struct sctp_chunk *);
862 int sctp_packet_transmit(struct sctp_packet *);
863 void sctp_packet_free(struct sctp_packet *);
865 static inline int sctp_packet_empty(struct sctp_packet *packet)
867 return packet->size == packet->overhead;
870 /* This represents a remote transport address.
871 * For local transport addresses, we just use union sctp_addr.
873 * RFC2960 Section 1.4 Key Terms
875 * o Transport address: A Transport Address is traditionally defined
876 * by Network Layer address, Transport Layer protocol and Transport
877 * Layer port number. In the case of SCTP running over IP, a
878 * transport address is defined by the combination of an IP address
879 * and an SCTP port number (where SCTP is the Transport protocol).
881 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
883 * o The sender keeps a separate congestion control parameter set for
884 * each of the destination addresses it can send to (not each
885 * source-destination pair but for each destination). The parameters
886 * should decay if the address is not used for a long enough time
890 struct sctp_transport {
891 /* A list of transports. */
892 struct list_head transports;
894 /* Reference counting. */
897 /* RTO-Pending : A flag used to track if one of the DATA
898 * chunks sent to this address is currently being
899 * used to compute a RTT. If this flag is 0,
900 * the next DATA chunk sent to this destination
901 * should be used to compute a RTT and this flag
902 * should be set. Every time the RTT
903 * calculation completes (i.e. the DATA chunk
904 * is SACK'd) clear this flag.
909 * hb_sent : a flag that signals that we have a pending
914 /* Is the Path MTU update pending on this tranport */
917 /* Is this structure kfree()able? */
922 /* This is the peer's IP address and port. */
923 union sctp_addr ipaddr;
925 /* These are the functions we call to handle LLP stuff. */
926 struct sctp_af *af_specific;
928 /* Which association do we belong to? */
929 struct sctp_association *asoc;
933 * 12.3 Per Transport Address Data
935 * For each destination transport address in the peer's
936 * address list derived from the INIT or INIT ACK chunk, a
937 * number of data elements needs to be maintained including:
939 /* RTO : The current retransmission timeout value. */
942 __u32 rtt; /* This is the most recent RTT. */
944 /* RTTVAR : The current RTT variation. */
947 /* SRTT : The current smoothed round trip time. */
951 * These are the congestion stats.
953 /* cwnd : The current congestion window. */
954 __u32 cwnd; /* This is the actual cwnd. */
956 /* ssthresh : The current slow start threshold value. */
959 /* partial : The tracking method for increase of cwnd when in
960 * bytes acked : congestion avoidance mode (see Section 6.2.2)
962 __u32 partial_bytes_acked;
964 /* Data that has been sent, but not acknowledged. */
967 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
970 struct dst_entry *dst;
971 /* Source address. */
972 union sctp_addr saddr;
974 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
975 * the destination address every heartbeat interval.
977 unsigned long hbinterval;
979 /* SACK delay timeout */
980 unsigned long sackdelay;
983 /* When was the last time (in jiffies) that we heard from this
984 * transport? We use this to pick new active and retran paths.
986 unsigned long last_time_heard;
988 /* Last time(in jiffies) when cwnd is reduced due to the congestion
989 * indication based on ECNE chunk.
991 unsigned long last_time_ecne_reduced;
993 /* This is the max_retrans value for the transport and will
994 * be initialized from the assocs value. This can be changed
995 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
999 /* PMTU : The current known path MTU. */
1002 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1005 /* The number of times INIT has been sent on this transport. */
1006 int init_sent_count;
1008 /* state : The current state of this destination,
1009 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
1013 /* These are the error stats for this destination. */
1015 /* Error count : The current error count for this destination. */
1016 unsigned short error_count;
1018 /* Per : A timer used by each destination.
1022 * [Everywhere else in the text this is called T3-rtx. -ed]
1024 struct timer_list T3_rtx_timer;
1026 /* Heartbeat timer is per destination. */
1027 struct timer_list hb_timer;
1029 /* Timer to handle ICMP proto unreachable envets */
1030 struct timer_list proto_unreach_timer;
1032 /* Since we're using per-destination retransmission timers
1033 * (see above), we're also using per-destination "transmitted"
1034 * queues. This probably ought to be a private struct
1035 * accessible only within the outqueue, but it's not, yet.
1037 struct list_head transmitted;
1039 /* We build bundle-able packets for this transport here. */
1040 struct sctp_packet packet;
1042 /* This is the list of transports that have chunks to send. */
1043 struct list_head send_ready;
1045 /* State information saved for SFR_CACC algorithm. The key
1046 * idea in SFR_CACC is to maintain state at the sender on a
1047 * per-destination basis when a changeover happens.
1048 * char changeover_active;
1049 * char cycling_changeover;
1050 * __u32 next_tsn_at_change;
1051 * char cacc_saw_newack;
1054 /* An unsigned integer, which stores the next TSN to be
1055 * used by the sender, at the moment of changeover.
1057 __u32 next_tsn_at_change;
1059 /* A flag which indicates the occurrence of a changeover */
1060 char changeover_active;
1062 /* A flag which indicates whether the change of primary is
1063 * the first switch to this destination address during an
1066 char cycling_changeover;
1068 /* A temporary flag, which is used during the processing of
1069 * a SACK to estimate the causative TSN(s)'s group.
1071 char cacc_saw_newack;
1074 /* 64-bit random number sent with heartbeat. */
1078 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1080 void sctp_transport_set_owner(struct sctp_transport *,
1081 struct sctp_association *);
1082 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1083 struct sctp_sock *);
1084 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1085 void sctp_transport_free(struct sctp_transport *);
1086 void sctp_transport_reset_timers(struct sctp_transport *);
1087 void sctp_transport_hold(struct sctp_transport *);
1088 void sctp_transport_put(struct sctp_transport *);
1089 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1090 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1091 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1092 void sctp_transport_burst_limited(struct sctp_transport *);
1093 void sctp_transport_burst_reset(struct sctp_transport *);
1094 unsigned long sctp_transport_timeout(struct sctp_transport *);
1095 void sctp_transport_reset(struct sctp_transport *);
1096 void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1099 /* This is the structure we use to queue packets as they come into
1100 * SCTP. We write packets to it and read chunks from it.
1103 /* This is actually a queue of sctp_chunk each
1104 * containing a partially decoded packet.
1106 struct list_head in_chunk_list;
1107 /* This is the packet which is currently off the in queue and is
1108 * being worked on through the inbound chunk processing.
1110 struct sctp_chunk *in_progress;
1112 /* This is the delayed task to finish delivering inbound
1115 struct work_struct immediate;
1117 int malloced; /* Is this structure kfree()able? */
1120 void sctp_inq_init(struct sctp_inq *);
1121 void sctp_inq_free(struct sctp_inq *);
1122 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1123 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1124 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1125 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1127 /* This is the structure we use to hold outbound chunks. You push
1128 * chunks in and they automatically pop out the other end as bundled
1129 * packets (it calls (*output_handler)()).
1131 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1132 * and 8.2 of the v13 draft.
1134 * It handles retransmissions. The connection to the timeout portion
1135 * of the state machine is through sctp_..._timeout() and timeout_handler.
1137 * If you feed it SACKs, it will eat them.
1139 * If you give it big chunks, it will fragment them.
1141 * It assigns TSN's to data chunks. This happens at the last possible
1142 * instant before transmission.
1144 * When free()'d, it empties itself out via output_handler().
1147 struct sctp_association *asoc;
1149 /* Data pending that has never been transmitted. */
1150 struct list_head out_chunk_list;
1152 unsigned out_qlen; /* Total length of queued data chunks. */
1154 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1157 /* These are control chunks we want to send. */
1158 struct list_head control_chunk_list;
1160 /* These are chunks that have been sacked but are above the
1161 * CTSN, or cumulative tsn ack point.
1163 struct list_head sacked;
1165 /* Put chunks on this list to schedule them for
1168 struct list_head retransmit;
1170 /* Put chunks on this list to save them for FWD TSN processing as
1171 * they were abandoned.
1173 struct list_head abandoned;
1175 /* How many unackd bytes do we have in-flight? */
1176 __u32 outstanding_bytes;
1178 /* Are we doing fast-rtx on this queue */
1184 /* Is this structure empty? */
1187 /* Are we kfree()able? */
1191 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1192 void sctp_outq_teardown(struct sctp_outq *);
1193 void sctp_outq_free(struct sctp_outq*);
1194 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1195 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1196 int sctp_outq_is_empty(const struct sctp_outq *);
1197 void sctp_outq_restart(struct sctp_outq *);
1199 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1200 sctp_retransmit_reason_t);
1201 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1202 int sctp_outq_uncork(struct sctp_outq *);
1203 /* Uncork and flush an outqueue. */
1204 static inline void sctp_outq_cork(struct sctp_outq *q)
1209 /* These bind address data fields common between endpoints and associations */
1210 struct sctp_bind_addr {
1212 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1214 * SCTP Port: The local SCTP port number the endpoint is
1219 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1221 * Address List: The list of IP addresses that this instance
1222 * has bound. This information is passed to one's
1223 * peer(s) in INIT and INIT ACK chunks.
1225 struct list_head address_list;
1227 int malloced; /* Are we kfree()able? */
1230 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1231 void sctp_bind_addr_free(struct sctp_bind_addr *);
1232 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1233 const struct sctp_bind_addr *src,
1234 sctp_scope_t scope, gfp_t gfp,
1236 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1237 const struct sctp_bind_addr *src,
1239 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1240 __u8 addr_state, gfp_t gfp);
1241 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1242 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1243 struct sctp_sock *);
1244 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1245 struct sctp_sock *, struct sctp_sock *);
1246 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1247 const union sctp_addr *addr);
1248 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1249 const union sctp_addr *addrs,
1251 struct sctp_sock *opt);
1252 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1255 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1256 __u16 port, gfp_t gfp);
1258 sctp_scope_t sctp_scope(const union sctp_addr *);
1259 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1260 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1261 int sctp_addr_is_valid(const union sctp_addr *addr);
1262 int sctp_is_ep_boundall(struct sock *sk);
1265 /* What type of endpoint? */
1267 SCTP_EP_TYPE_SOCKET,
1268 SCTP_EP_TYPE_ASSOCIATION,
1269 } sctp_endpoint_type_t;
1272 * A common base class to bridge the implmentation view of a
1273 * socket (usually listening) endpoint versus an association's
1275 * This common structure is useful for several purposes:
1276 * 1) Common interface for lookup routines.
1277 * a) Subfunctions work for either endpoint or association
1278 * b) Single interface to lookup allows hiding the lookup lock rather
1279 * than acquiring it externally.
1280 * 2) Common interface for the inbound chunk handling/state machine.
1281 * 3) Common object handling routines for reference counting, etc.
1282 * 4) Disentangle association lookup from endpoint lookup, where we
1283 * do not have to find our endpoint to find our association.
1287 struct sctp_ep_common {
1288 /* Fields to help us manage our entries in the hash tables. */
1289 struct hlist_node node;
1292 /* Runtime type information. What kind of endpoint is this? */
1293 sctp_endpoint_type_t type;
1295 /* Some fields to help us manage this object.
1296 * refcnt - Reference count access to this object.
1297 * dead - Do not attempt to use this object.
1298 * malloced - Do we need to kfree this object?
1304 /* What socket does this endpoint belong to? */
1307 /* This is where we receive inbound chunks. */
1308 struct sctp_inq inqueue;
1310 /* This substructure includes the defining parameters of the
1312 * bind_addr.port is our shared port number.
1313 * bind_addr.address_list is our set of local IP addresses.
1315 struct sctp_bind_addr bind_addr;
1319 /* RFC Section 1.4 Key Terms
1321 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1322 * multi-homed host, an SCTP endpoint is represented to its peers as a
1323 * combination of a set of eligible destination transport addresses to
1324 * which SCTP packets can be sent and a set of eligible source
1325 * transport addresses from which SCTP packets can be received.
1326 * All transport addresses used by an SCTP endpoint must use the
1327 * same port number, but can use multiple IP addresses. A transport
1328 * address used by an SCTP endpoint must not be used by another
1329 * SCTP endpoint. In other words, a transport address is unique
1330 * to an SCTP endpoint.
1332 * From an implementation perspective, each socket has one of these.
1333 * A TCP-style socket will have exactly one association on one of
1334 * these. An UDP-style socket will have multiple associations hanging
1338 struct sctp_endpoint {
1339 /* Common substructure for endpoint and association. */
1340 struct sctp_ep_common base;
1342 /* Associations: A list of current associations and mappings
1343 * to the data consumers for each association. This
1344 * may be in the form of a hash table or other
1345 * implementation dependent structure. The data
1346 * consumers may be process identification
1347 * information such as file descriptors, named pipe
1348 * pointer, or table pointers dependent on how SCTP
1351 /* This is really a list of struct sctp_association entries. */
1352 struct list_head asocs;
1354 /* Secret Key: A secret key used by this endpoint to compute
1355 * the MAC. This SHOULD be a cryptographic quality
1356 * random number with a sufficient length.
1357 * Discussion in [RFC1750] can be helpful in
1358 * selection of the key.
1360 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1365 /* digest: This is a digest of the sctp cookie. This field is
1366 * only used on the receive path when we try to validate
1367 * that the cookie has not been tampered with. We put
1368 * this here so we pre-allocate this once and can re-use
1373 /* sendbuf acct. policy. */
1374 __u32 sndbuf_policy;
1376 /* rcvbuf acct. policy. */
1377 __u32 rcvbuf_policy;
1379 /* SCTP AUTH: array of the HMACs that will be allocated
1380 * we need this per association so that we don't serialize
1382 struct crypto_hash **auth_hmacs;
1384 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1385 struct sctp_hmac_algo_param *auth_hmacs_list;
1387 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1388 struct sctp_chunks_param *auth_chunk_list;
1390 /* SCTP-AUTH: endpoint shared keys */
1391 struct list_head endpoint_shared_keys;
1392 __u16 active_key_id;
1395 /* Recover the outter endpoint structure. */
1396 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1398 struct sctp_endpoint *ep;
1400 ep = container_of(base, struct sctp_endpoint, base);
1404 /* These are function signatures for manipulating endpoints. */
1405 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1406 void sctp_endpoint_free(struct sctp_endpoint *);
1407 void sctp_endpoint_put(struct sctp_endpoint *);
1408 void sctp_endpoint_hold(struct sctp_endpoint *);
1409 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1410 struct sctp_association *sctp_endpoint_lookup_assoc(
1411 const struct sctp_endpoint *ep,
1412 const union sctp_addr *paddr,
1413 struct sctp_transport **);
1414 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1415 const union sctp_addr *);
1416 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1417 const union sctp_addr *);
1418 int sctp_has_association(const union sctp_addr *laddr,
1419 const union sctp_addr *paddr);
1421 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1422 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1423 struct sctp_chunk **err_chunk);
1424 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1425 const union sctp_addr *peer,
1426 sctp_init_chunk_t *init, gfp_t gfp);
1427 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1428 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1430 struct sctp_inithdr_host {
1433 __u16 num_outbound_streams;
1434 __u16 num_inbound_streams;
1440 * 12. Recommended Transmission Control Block (TCB) Parameters
1442 * This section details a recommended set of parameters that should
1443 * be contained within the TCB for an implementation. This section is
1444 * for illustrative purposes and should not be deemed as requirements
1445 * on an implementation or as an exhaustive list of all parameters
1446 * inside an SCTP TCB. Each implementation may need its own additional
1447 * parameters for optimization.
1451 /* Here we have information about each individual association. */
1452 struct sctp_association {
1454 /* A base structure common to endpoint and association.
1455 * In this context, it represents the associations's view
1456 * of the local endpoint of the association.
1458 struct sctp_ep_common base;
1460 /* Associations on the same socket. */
1461 struct list_head asocs;
1463 /* association id. */
1464 sctp_assoc_t assoc_id;
1466 /* This is our parent endpoint. */
1467 struct sctp_endpoint *ep;
1469 /* These are those association elements needed in the cookie. */
1470 struct sctp_cookie c;
1472 /* This is all information about our peer. */
1476 * Peer Rwnd : Current calculated value of the peer's rwnd.
1480 /* transport_addr_list
1482 * Peer : A list of SCTP transport addresses that the
1483 * Transport : peer is bound to. This information is derived
1484 * Address : from the INIT or INIT ACK and is used to
1485 * List : associate an inbound packet with a given
1486 * : association. Normally this information is
1487 * : hashed or keyed for quick lookup and access
1489 * : The list is also initialized with the list
1490 * : of addresses passed with the sctp_connectx()
1493 * It is a list of SCTP_transport's.
1495 struct list_head transport_addr_list;
1499 * Peer : A count of the number of peer addresses
1500 * Transport : in the Peer Transport Address List.
1504 __u16 transport_count;
1507 * The transport layer port number.
1513 * Primary : This is the current primary destination
1514 * Path : transport address of the peer endpoint. It
1515 * : may also specify a source transport address
1516 * : on this endpoint.
1518 * All of these paths live on transport_addr_list.
1520 * At the bakeoffs, we discovered that the intent of
1521 * primaryPath is that it only changes when the ULP
1522 * asks to have it changed. We add the activePath to
1523 * designate the connection we are currently using to
1524 * transmit new data and most control chunks.
1526 struct sctp_transport *primary_path;
1528 /* Cache the primary path address here, when we
1529 * need a an address for msg_name.
1531 union sctp_addr primary_addr;
1534 * The path that we are currently using to
1535 * transmit new data and most control chunks.
1537 struct sctp_transport *active_path;
1541 * RFC2960 6.4 Multi-homed SCTP Endpoints
1543 * Furthermore, when its peer is multi-homed, an
1544 * endpoint SHOULD try to retransmit a chunk to an
1545 * active destination transport address that is
1546 * different from the last destination address to
1547 * which the DATA chunk was sent.
1549 struct sctp_transport *retran_path;
1551 /* Pointer to last transport I have sent on. */
1552 struct sctp_transport *last_sent_to;
1554 /* This is the last transport I have received DATA on. */
1555 struct sctp_transport *last_data_from;
1558 * Mapping An array of bits or bytes indicating which out of
1559 * Array order TSN's have been received (relative to the
1560 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1561 * order packets have been received, this array
1562 * will be set to all zero. This structure may be
1563 * in the form of a circular buffer or bit array.
1565 * Last Rcvd : This is the last TSN received in
1566 * TSN : sequence. This value is set initially by
1567 * : taking the peer's Initial TSN, received in
1568 * : the INIT or INIT ACK chunk, and subtracting
1571 * Throughout most of the specification this is called the
1572 * "Cumulative TSN ACK Point". In this case, we
1573 * ignore the advice in 12.2 in favour of the term
1574 * used in the bulk of the text. This value is hidden
1575 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1577 struct sctp_tsnmap tsn_map;
1579 /* Ack State : This flag indicates if the next received
1580 * : packet is to be responded to with a
1581 * : SACK. This is initializedto 0. When a packet
1582 * : is received it is incremented. If this value
1583 * : reaches 2 or more, a SACK is sent and the
1584 * : value is reset to 0. Note: This is used only
1585 * : when no DATA chunks are received out of
1586 * : order. When DATA chunks are out of order,
1587 * : SACK's are not delayed (see Section 6).
1589 __u8 sack_needed:1, /* Do we need to sack the peer? */
1590 zero_window_announced:1;
1593 /* These are capabilities which our peer advertised. */
1594 __u8 ecn_capable:1, /* Can peer do ECN? */
1595 ipv4_address:1, /* Peer understands IPv4 addresses? */
1596 ipv6_address:1, /* Peer understands IPv6 addresses? */
1597 hostname_address:1, /* Peer understands DNS addresses? */
1598 asconf_capable:1, /* Does peer support ADDIP? */
1599 prsctp_capable:1, /* Can peer do PR-SCTP? */
1600 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1602 __u32 adaptation_ind; /* Adaptation Code point. */
1604 /* This mask is used to disable sending the ASCONF chunk
1605 * with specified parameter to peer.
1607 __be16 addip_disabled_mask;
1609 struct sctp_inithdr_host i;
1613 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1614 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1615 * Initial TSN Value minus 1
1619 /* SCTP-AUTH: We need to know pears random number, hmac list
1620 * and authenticated chunk list. All that is part of the
1621 * cookie and these are just pointers to those locations
1623 sctp_random_param_t *peer_random;
1624 sctp_chunks_param_t *peer_chunks;
1625 sctp_hmac_algo_param_t *peer_hmacs;
1628 /* State : A state variable indicating what state the
1629 * : association is in, i.e. COOKIE-WAIT,
1630 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1631 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1633 * Note: No "CLOSED" state is illustrated since if a
1634 * association is "CLOSED" its TCB SHOULD be removed.
1636 * In this implementation we DO have a CLOSED
1637 * state which is used during initiation and shutdown.
1639 * State takes values from SCTP_STATE_*.
1643 /* The cookie life I award for any cookie. */
1644 struct timeval cookie_life;
1646 /* Overall : The overall association error count.
1647 * Error Count : [Clear this any time I get something.]
1649 int overall_error_count;
1651 /* These are the association's initial, max, and min RTO values.
1652 * These values will be initialized by system defaults, but can
1653 * be modified via the SCTP_RTOINFO socket option.
1655 unsigned long rto_initial;
1656 unsigned long rto_max;
1657 unsigned long rto_min;
1659 /* Maximum number of new data packets that can be sent in a burst. */
1662 /* This is the max_retrans value for the association. This value will
1663 * be initialized initialized from system defaults, but can be
1664 * modified by the SCTP_ASSOCINFO socket option.
1668 /* Maximum number of times the endpoint will retransmit INIT */
1669 __u16 max_init_attempts;
1671 /* How many times have we resent an INIT? */
1674 /* The largest timeout or RTO value to use in attempting an INIT */
1675 unsigned long max_init_timeo;
1677 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1678 * the destination address every heartbeat interval. This value
1679 * will be inherited by all new transports.
1681 unsigned long hbinterval;
1683 /* This is the max_retrans value for new transports in the
1688 /* Flag that path mtu update is pending */
1691 /* Association : The smallest PMTU discovered for all of the
1692 * PMTU : peer's transport addresses.
1696 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1699 /* SACK delay timeout */
1700 unsigned long sackdelay;
1704 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1705 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1707 /* Transport to which SHUTDOWN chunk was last sent. */
1708 struct sctp_transport *shutdown_last_sent_to;
1710 /* How many times have we resent a SHUTDOWN */
1711 int shutdown_retries;
1713 /* Transport to which INIT chunk was last sent. */
1714 struct sctp_transport *init_last_sent_to;
1716 /* Next TSN : The next TSN number to be assigned to a new
1717 * : DATA chunk. This is sent in the INIT or INIT
1718 * : ACK chunk to the peer and incremented each
1719 * : time a DATA chunk is assigned a TSN
1720 * : (normally just prior to transmit or during
1726 * Last Rcvd : This is the last TSN received in sequence. This value
1727 * TSN : is set initially by taking the peer's Initial TSN,
1728 * : received in the INIT or INIT ACK chunk, and
1729 * : subtracting one from it.
1731 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1734 __u32 ctsn_ack_point;
1736 /* PR-SCTP Advanced.Peer.Ack.Point */
1737 __u32 adv_peer_ack_point;
1739 /* Highest TSN that is acknowledged by incoming SACKs. */
1740 __u32 highest_sacked;
1742 /* TSN marking the fast recovery exit point */
1743 __u32 fast_recovery_exit;
1745 /* Flag to track the current fast recovery state */
1748 /* The number of unacknowledged data chunks. Reported through
1749 * the SCTP_STATUS sockopt.
1753 /* The total number of data chunks that we've had to retransmit
1754 * as the result of a T3 timer expiration
1756 __u32 rtx_data_chunks;
1758 /* This is the association's receive buffer space. This value is used
1759 * to set a_rwnd field in an INIT or a SACK chunk.
1763 /* This is the last advertised value of rwnd over a SACK chunk. */
1766 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1767 * to slop over a maximum of the association's frag_point.
1771 /* Keeps treack of rwnd pressure. This happens when we have
1772 * a window, but not recevie buffer (i.e small packets). This one
1773 * is releases slowly (1 PMTU at a time ).
1777 /* This is the sndbuf size in use for the association.
1778 * This corresponds to the sndbuf size for the association,
1779 * as specified in the sk->sndbuf.
1783 /* This is the amount of memory that this association has allocated
1784 * in the receive path at any given time.
1786 atomic_t rmem_alloc;
1788 /* This is the wait queue head for send requests waiting on
1789 * the association sndbuf space.
1791 wait_queue_head_t wait;
1793 /* The message size at which SCTP fragmentation will occur. */
1797 /* Counter used to count INIT errors. */
1798 int init_err_counter;
1800 /* Count the number of INIT cycles (for doubling timeout). */
1803 /* Default send parameters. */
1804 __u16 default_stream;
1805 __u16 default_flags;
1807 __u32 default_context;
1808 __u32 default_timetolive;
1810 /* Default receive parameters */
1811 __u32 default_rcv_context;
1813 /* This tracks outbound ssn for a given stream. */
1814 struct sctp_ssnmap *ssnmap;
1816 /* All outbound chunks go through this structure. */
1817 struct sctp_outq outqueue;
1819 /* A smart pipe that will handle reordering and fragmentation,
1820 * as well as handle passing events up to the ULP.
1822 struct sctp_ulpq ulpq;
1824 /* Last TSN that caused an ECNE Chunk to be sent. */
1825 __u32 last_ecne_tsn;
1827 /* Last TSN that caused a CWR Chunk to be sent. */
1830 /* How many duplicated TSNs have we seen? */
1833 /* Number of seconds of idle time before an association is closed.
1834 * In the association context, this is really used as a boolean
1835 * since the real timeout is stored in the timeouts array
1839 /* These are to support
1840 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1841 * and Enforcement of Flow and Message Limits"
1842 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1843 * or "ADDIP" for short.
1848 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1850 * R1) One and only one ASCONF Chunk MAY be in transit and
1851 * unacknowledged at any one time. If a sender, after sending
1852 * an ASCONF chunk, decides it needs to transfer another
1853 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1854 * returns from the previous ASCONF Chunk before sending a
1855 * subsequent ASCONF. Note this restriction binds each side,
1856 * so at any time two ASCONF may be in-transit on any given
1857 * association (one sent from each endpoint).
1859 * [This is our one-and-only-one ASCONF in flight. If we do
1860 * not have an ASCONF in flight, this is NULL.]
1862 struct sctp_chunk *addip_last_asconf;
1864 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1866 * This is needed to implement itmes E1 - E4 of the updated
1867 * spec. Here is the justification:
1869 * Since the peer may bundle multiple ASCONF chunks toward us,
1870 * we now need the ability to cache multiple ACKs. The section
1871 * describes in detail how they are cached and cleaned up.
1873 struct list_head asconf_ack_list;
1875 /* These ASCONF chunks are waiting to be sent.
1877 * These chunaks can't be pushed to outqueue until receiving
1878 * ASCONF_ACK for the previous ASCONF indicated by
1879 * addip_last_asconf, so as to guarantee that only one ASCONF
1880 * is in flight at any time.
1882 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1884 * In defining the ASCONF Chunk transfer procedures, it is
1885 * essential that these transfers MUST NOT cause congestion
1886 * within the network. To achieve this, we place these
1887 * restrictions on the transfer of ASCONF Chunks:
1889 * R1) One and only one ASCONF Chunk MAY be in transit and
1890 * unacknowledged at any one time. If a sender, after sending
1891 * an ASCONF chunk, decides it needs to transfer another
1892 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1893 * returns from the previous ASCONF Chunk before sending a
1894 * subsequent ASCONF. Note this restriction binds each side,
1895 * so at any time two ASCONF may be in-transit on any given
1896 * association (one sent from each endpoint).
1899 * [I really think this is EXACTLY the sort of intelligence
1900 * which already resides in sctp_outq. Please move this
1901 * queue and its supporting logic down there. --piggy]
1903 struct list_head addip_chunk_list;
1905 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1907 * A2) A serial number should be assigned to the Chunk. The
1908 * serial number SHOULD be a monotonically increasing
1909 * number. The serial number SHOULD be initialized at
1910 * the start of the association to the same value as the
1911 * Initial TSN and every time a new ASCONF chunk is created
1912 * it is incremented by one after assigning the serial number
1913 * to the newly created chunk.
1916 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1918 * Serial Number : 32 bits (unsigned integer)
1920 * This value represents a Serial Number for the ASCONF
1921 * Chunk. The valid range of Serial Number is from 0 to
1922 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1923 * after reaching 4294967295.
1926 union sctp_addr *asconf_addr_del_pending;
1927 int src_out_of_asoc_ok;
1928 struct sctp_transport *new_transport;
1930 /* SCTP AUTH: list of the endpoint shared keys. These
1931 * keys are provided out of band by the user applicaton
1932 * and can't change during the lifetime of the association
1934 struct list_head endpoint_shared_keys;
1937 * The current generated assocaition shared key (secret)
1939 struct sctp_auth_bytes *asoc_shared_key;
1941 /* SCTP AUTH: hmac id of the first peer requested algorithm
1944 __u16 default_hmac_id;
1946 __u16 active_key_id;
1948 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1949 temp:1; /* Is it a temporary association? */
1953 /* An eyecatcher for determining if we are really looking at an
1954 * association data structure.
1957 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1960 /* Recover the outter association structure. */
1961 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1963 struct sctp_association *asoc;
1965 asoc = container_of(base, struct sctp_association, base);
1969 /* These are function signatures for manipulating associations. */
1972 struct sctp_association *
1973 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1974 sctp_scope_t scope, gfp_t gfp);
1975 void sctp_association_free(struct sctp_association *);
1976 void sctp_association_put(struct sctp_association *);
1977 void sctp_association_hold(struct sctp_association *);
1979 struct sctp_transport *sctp_assoc_choose_alter_transport(
1980 struct sctp_association *, struct sctp_transport *);
1981 void sctp_assoc_update_retran_path(struct sctp_association *);
1982 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1983 const union sctp_addr *);
1984 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1985 const union sctp_addr *laddr);
1986 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1987 const union sctp_addr *address,
1989 const int peer_state);
1990 void sctp_assoc_del_peer(struct sctp_association *asoc,
1991 const union sctp_addr *addr);
1992 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1993 struct sctp_transport *peer);
1994 void sctp_assoc_control_transport(struct sctp_association *,
1995 struct sctp_transport *,
1996 sctp_transport_cmd_t, sctp_sn_error_t);
1997 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1998 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1999 const union sctp_addr *,
2000 const union sctp_addr *);
2001 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2002 void sctp_assoc_update(struct sctp_association *old,
2003 struct sctp_association *new);
2005 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2007 void sctp_assoc_sync_pmtu(struct sctp_association *);
2008 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
2009 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
2010 void sctp_assoc_set_primary(struct sctp_association *,
2011 struct sctp_transport *);
2012 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2013 struct sctp_transport *);
2014 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
2015 sctp_scope_t, gfp_t);
2016 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2017 struct sctp_cookie*,
2019 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2020 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2021 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2022 const struct sctp_association *asoc,
2024 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2026 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2027 const union sctp_addr *ss2);
2028 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2030 /* A convenience structure to parse out SCTP specific CMSGs. */
2031 typedef struct sctp_cmsgs {
2032 struct sctp_initmsg *init;
2033 struct sctp_sndrcvinfo *info;
2036 /* Structure for tracking memory objects */
2040 } sctp_dbg_objcnt_entry_t;
2042 #endif /* __sctp_structs_h__ */