1 /* SCTP kernel reference 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 reference Implementation
9 * The SCTP reference 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 * The SCTP reference 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 <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. */
68 /* A convenience structure for handling sockaddr structures.
69 * We should wean ourselves off this.
72 struct sockaddr_in v4;
73 struct sockaddr_in6 v6;
77 /* Forward declarations for data structures. */
80 struct sctp_association;
81 struct sctp_transport;
86 struct sctp_bind_addr;
88 struct sctp_ep_common;
92 #include <net/sctp/tsnmap.h>
93 #include <net/sctp/ulpevent.h>
94 #include <net/sctp/ulpqueue.h>
96 /* Structures useful for managing bind/connect. */
98 struct sctp_bind_bucket {
100 unsigned short fastreuse;
101 struct sctp_bind_bucket *next;
102 struct sctp_bind_bucket **pprev;
103 struct hlist_head owner;
106 struct sctp_bind_hashbucket {
108 struct sctp_bind_bucket *chain;
111 /* Used for hashing all associations. */
112 struct sctp_hashbucket {
114 struct sctp_ep_common *chain;
115 } __attribute__((__aligned__(8)));
118 /* The SCTP globals structure. */
119 extern struct sctp_globals {
120 /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values
122 * The following protocol parameters are RECOMMENDED:
124 * RTO.Initial - 3 seconds
126 * RTO.Max - 60 seconds
127 * RTO.Alpha - 1/8 (3 when converted to right shifts.)
128 * RTO.Beta - 1/4 (2 when converted to right shifts.)
134 /* Note: rto_alpha and rto_beta are really defined as inverse
135 * powers of two to facilitate integer operations.
143 /* Valid.Cookie.Life - 60 seconds */
144 int valid_cookie_life;
146 /* Whether Cookie Preservative is enabled(1) or not(0) */
147 int cookie_preserve_enable;
149 /* Association.Max.Retrans - 10 attempts
150 * Path.Max.Retrans - 5 attempts (per destination address)
151 * Max.Init.Retransmits - 8 attempts
153 int max_retrans_association;
154 int max_retrans_path;
155 int max_retrans_init;
158 * Policy for preforming sctp/socket accounting
159 * 0 - do socket level accounting, all assocs share sk_sndbuf
160 * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes
165 * Policy for preforming sctp/socket accounting
166 * 0 - do socket level accounting, all assocs share sk_rcvbuf
167 * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes
171 /* Delayed SACK timeout 200ms default*/
174 /* HB.interval - 30 seconds */
177 /* The following variables are implementation specific. */
179 /* Default initialization values to be applied to new associations. */
181 __u16 max_outstreams;
183 /* This is a list of groups of functions for each address
184 * family that we support.
186 struct list_head address_families;
188 /* This is the hash of all endpoints. */
190 struct sctp_hashbucket *ep_hashtable;
192 /* This is the hash of all associations. */
194 struct sctp_hashbucket *assoc_hashtable;
196 /* This is the sctp port control hash. */
199 spinlock_t port_alloc_lock; /* Protects port_rover. */
200 struct sctp_bind_hashbucket *port_hashtable;
202 /* This is the global local address list.
203 * We actively maintain this complete list of interfaces on
204 * the system by catching routing events.
206 * It is a list of sctp_sockaddr_entry.
208 struct list_head local_addr_list;
209 spinlock_t local_addr_lock;
211 /* Flag to indicate if addip is enabled. */
214 /* Flag to indicate if PR-SCTP is enabled. */
218 #define sctp_rto_initial (sctp_globals.rto_initial)
219 #define sctp_rto_min (sctp_globals.rto_min)
220 #define sctp_rto_max (sctp_globals.rto_max)
221 #define sctp_rto_alpha (sctp_globals.rto_alpha)
222 #define sctp_rto_beta (sctp_globals.rto_beta)
223 #define sctp_max_burst (sctp_globals.max_burst)
224 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life)
225 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable)
226 #define sctp_max_retrans_association (sctp_globals.max_retrans_association)
227 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy)
228 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy)
229 #define sctp_max_retrans_path (sctp_globals.max_retrans_path)
230 #define sctp_max_retrans_init (sctp_globals.max_retrans_init)
231 #define sctp_sack_timeout (sctp_globals.sack_timeout)
232 #define sctp_hb_interval (sctp_globals.hb_interval)
233 #define sctp_max_instreams (sctp_globals.max_instreams)
234 #define sctp_max_outstreams (sctp_globals.max_outstreams)
235 #define sctp_address_families (sctp_globals.address_families)
236 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
237 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
238 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
239 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
240 #define sctp_port_hashsize (sctp_globals.port_hashsize)
241 #define sctp_port_rover (sctp_globals.port_rover)
242 #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock)
243 #define sctp_port_hashtable (sctp_globals.port_hashtable)
244 #define sctp_local_addr_list (sctp_globals.local_addr_list)
245 #define sctp_local_addr_lock (sctp_globals.local_addr_lock)
246 #define sctp_addip_enable (sctp_globals.addip_enable)
247 #define sctp_prsctp_enable (sctp_globals.prsctp_enable)
249 /* SCTP Socket type: UDP or TCP style. */
252 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
254 } sctp_socket_type_t;
256 /* Per socket SCTP information. */
258 /* inet_sock has to be the first member of sctp_sock */
259 struct inet_sock inet;
260 /* What kind of a socket is this? */
261 sctp_socket_type_t type;
263 /* PF_ family specific functions. */
266 /* Access to HMAC transform. */
267 struct crypto_tfm *hmac;
269 /* What is our base endpointer? */
270 struct sctp_endpoint *ep;
272 struct sctp_bind_bucket *bind_hash;
273 /* Various Socket Options. */
274 __u16 default_stream;
277 __u32 default_context;
278 __u32 default_timetolive;
280 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
281 * the destination address every heartbeat interval. This value
282 * will be inherited by all new associations.
286 /* This is the max_retrans value for new associations. */
289 /* The initial Path MTU to use for new associations. */
292 /* The default SACK delay timeout for new associations. */
295 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
298 struct sctp_initmsg initmsg;
299 struct sctp_rtoinfo rtoinfo;
300 struct sctp_paddrparams paddrparam;
301 struct sctp_event_subscribe subscribe;
302 struct sctp_assocparams assocparams;
306 __u8 disable_fragments;
311 /* Receive to here while partial delivery is in effect. */
312 struct sk_buff_head pd_lobby;
315 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
317 return (struct sctp_sock *)sk;
320 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
322 return (struct sock *)sp;
325 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
327 struct sctp_sock sctp;
328 struct ipv6_pinfo inet6;
330 #endif /* CONFIG_IPV6 */
333 /* This is our APPLICATION-SPECIFIC state cookie.
334 * THIS IS NOT DICTATED BY THE SPECIFICATION.
336 /* These are the parts of an association which we send in the cookie.
337 * Most of these are straight out of:
338 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
344 /* My : Tag expected in every inbound packet and sent
345 * Verification: in the INIT or INIT ACK chunk.
350 /* Peer's : Tag expected in every outbound packet except
351 * Verification: in the INIT chunk.
356 /* The rest of these are not from the spec, but really need to
360 /* My Tie Tag : Assist in discovering a restarting association. */
363 /* Peer's Tie Tag: Assist in discovering a restarting association. */
366 /* When does this cookie expire? */
367 struct timeval expiration;
369 /* Number of inbound/outbound streams which are set
370 * and negotiated during the INIT process.
372 __u16 sinit_num_ostreams;
373 __u16 sinit_max_instreams;
375 /* This is the first sequence number I used. */
378 /* This holds the originating address of the INIT packet. */
379 union sctp_addr peer_addr;
382 * Include the source port of the INIT-ACK
388 /* Padding for future use */
394 /* This is a shim for my peer's INIT packet, followed by
395 * a copy of the raw address list of the association.
396 * The length of the raw address list is saved in the
397 * raw_addr_list_len field, which will be used at the time when
398 * the association TCB is re-constructed from the cookie.
400 __u32 raw_addr_list_len;
401 struct sctp_init_chunk peer_init[0];
405 /* The format of our cookie that we send to our peer. */
406 struct sctp_signed_cookie {
407 __u8 signature[SCTP_SECRET_SIZE];
408 struct sctp_cookie c;
411 /* This is another convenience type to allocate memory for address
412 * params for the maximum size and pass such structures around
415 union sctp_addr_param {
416 struct sctp_ipv4addr_param v4;
417 struct sctp_ipv6addr_param v6;
420 /* A convenience type to allow walking through the various
421 * parameters and avoid casting all over the place.
425 struct sctp_paramhdr *p;
426 struct sctp_cookie_preserve_param *life;
427 struct sctp_hostname_param *dns;
428 struct sctp_cookie_param *cookie;
429 struct sctp_supported_addrs_param *sat;
430 struct sctp_ipv4addr_param *v4;
431 struct sctp_ipv6addr_param *v6;
432 union sctp_addr_param *addr;
433 struct sctp_adaption_ind_param *aind;
436 /* RFC 2960. Section 3.3.5 Heartbeat.
437 * Heartbeat Information: variable length
438 * The Sender-specific Heartbeat Info field should normally include
439 * information about the sender's current time when this HEARTBEAT
440 * chunk is sent and the destination transport address to which this
441 * HEARTBEAT is sent (see Section 8.3).
443 typedef struct sctp_sender_hb_info {
444 struct sctp_paramhdr param_hdr;
445 union sctp_addr daddr;
446 unsigned long sent_at;
447 } __attribute__((packed)) sctp_sender_hb_info_t;
450 * RFC 2960 1.3.2 Sequenced Delivery within Streams
452 * The term "stream" is used in SCTP to refer to a sequence of user
453 * messages that are to be delivered to the upper-layer protocol in
454 * order with respect to other messages within the same stream. This is
455 * in contrast to its usage in TCP, where it refers to a sequence of
456 * bytes (in this document a byte is assumed to be eight bits).
459 * This is the structure we use to track both our outbound and inbound
460 * SSN, or Stream Sequence Numbers.
469 struct sctp_stream in;
470 struct sctp_stream out;
474 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
476 void sctp_ssnmap_free(struct sctp_ssnmap *map);
477 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
479 /* What is the current SSN number for this stream? */
480 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
482 return stream->ssn[id];
485 /* Return the next SSN number for this stream. */
486 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
488 return stream->ssn[id]++;
491 /* Skip over this ssn and all below. */
492 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
495 stream->ssn[id] = ssn+1;
499 * Pointers to address related SCTP functions.
500 * (i.e. things that depend on the address family.)
503 int (*sctp_xmit) (struct sk_buff *skb,
504 struct sctp_transport *,
506 int (*setsockopt) (struct sock *sk,
511 int (*getsockopt) (struct sock *sk,
516 struct dst_entry *(*get_dst) (struct sctp_association *asoc,
517 union sctp_addr *daddr,
518 union sctp_addr *saddr);
519 void (*get_saddr) (struct sctp_association *asoc,
520 struct dst_entry *dst,
521 union sctp_addr *daddr,
522 union sctp_addr *saddr);
523 void (*copy_addrlist) (struct list_head *,
524 struct net_device *);
525 void (*dst_saddr) (union sctp_addr *saddr,
526 struct dst_entry *dst,
527 unsigned short port);
528 int (*cmp_addr) (const union sctp_addr *addr1,
529 const union sctp_addr *addr2);
530 void (*addr_copy) (union sctp_addr *dst,
531 union sctp_addr *src);
532 void (*from_skb) (union sctp_addr *,
535 void (*from_sk) (union sctp_addr *,
537 void (*to_sk_saddr) (union sctp_addr *,
539 void (*to_sk_daddr) (union sctp_addr *,
541 void (*from_addr_param) (union sctp_addr *,
542 union sctp_addr_param *,
543 __u16 port, int iif);
544 int (*to_addr_param) (const union sctp_addr *,
545 union sctp_addr_param *);
546 int (*addr_valid) (union sctp_addr *,
548 sctp_scope_t (*scope) (union sctp_addr *);
549 void (*inaddr_any) (union sctp_addr *, unsigned short);
550 int (*is_any) (const union sctp_addr *);
551 int (*available) (union sctp_addr *,
553 int (*skb_iif) (const struct sk_buff *sk);
554 int (*is_ce) (const struct sk_buff *sk);
555 void (*seq_dump_addr)(struct seq_file *seq,
556 union sctp_addr *addr);
557 __u16 net_header_len;
559 sa_family_t sa_family;
560 struct list_head list;
563 struct sctp_af *sctp_get_af_specific(sa_family_t);
564 int sctp_register_af(struct sctp_af *);
566 /* Protocol family functions. */
568 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
569 void (*skb_msgname) (struct sk_buff *, char *, int *);
570 int (*af_supported) (sa_family_t, struct sctp_sock *);
571 int (*cmp_addr) (const union sctp_addr *,
572 const union sctp_addr *,
574 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
575 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
576 int (*supported_addrs)(const struct sctp_sock *, __u16 *);
577 struct sock *(*create_accept_sk) (struct sock *sk,
578 struct sctp_association *asoc);
579 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
584 /* Structure to track chunk fragments that have been acked, but peer
585 * fragments of the same message have not.
587 struct sctp_datamsg {
588 /* Chunks waiting to be submitted to lower layer. */
589 struct list_head chunks;
590 /* Chunks that have been transmitted. */
591 struct list_head track;
592 /* Reference counting. */
594 /* When is this message no longer interesting to the peer? */
595 unsigned long expires_at;
596 /* Did the messenge fail to send? */
599 /* Control whether chunks from this message can be abandoned. */
603 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
604 struct sctp_sndrcvinfo *,
605 struct msghdr *, int len);
606 void sctp_datamsg_put(struct sctp_datamsg *);
607 void sctp_datamsg_free(struct sctp_datamsg *);
608 void sctp_datamsg_track(struct sctp_chunk *);
609 void sctp_chunk_fail(struct sctp_chunk *, int error);
610 int sctp_chunk_abandoned(struct sctp_chunk *);
612 /* RFC2960 1.4 Key Terms
614 * o Chunk: A unit of information within an SCTP packet, consisting of
615 * a chunk header and chunk-specific content.
617 * As a matter of convenience, we remember the SCTP common header for
618 * each chunk as well as a few other header pointers...
621 struct list_head list;
625 /* This is our link to the per-transport transmitted list. */
626 struct list_head transmitted_list;
628 /* This field is used by chunks that hold fragmented data.
629 * For the first fragment this is the list that holds the rest of
630 * fragments. For the remaining fragments, this is the link to the
631 * frag_list maintained in the first fragment.
633 struct list_head frag_list;
635 /* This points to the sk_buff containing the actual data. */
638 /* These are the SCTP headers by reverse order in a packet.
639 * Note that some of these may happen more than once. In that
640 * case, we point at the "current" one, whatever that means
641 * for that level of header.
644 /* We point this at the FIRST TLV parameter to chunk_hdr. */
645 union sctp_params param_hdr;
648 struct sctp_datahdr *data_hdr;
649 struct sctp_inithdr *init_hdr;
650 struct sctp_sackhdr *sack_hdr;
651 struct sctp_heartbeathdr *hb_hdr;
652 struct sctp_sender_hb_info *hbs_hdr;
653 struct sctp_shutdownhdr *shutdown_hdr;
654 struct sctp_signed_cookie *cookie_hdr;
655 struct sctp_ecnehdr *ecne_hdr;
656 struct sctp_cwrhdr *ecn_cwr_hdr;
657 struct sctp_errhdr *err_hdr;
658 struct sctp_addiphdr *addip_hdr;
659 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
664 struct sctp_chunkhdr *chunk_hdr;
665 struct sctphdr *sctp_hdr;
667 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
668 struct sctp_sndrcvinfo sinfo;
670 /* Which association does this belong to? */
671 struct sctp_association *asoc;
673 /* What endpoint received this chunk? */
674 struct sctp_ep_common *rcvr;
676 /* We fill this in if we are calculating RTT. */
677 unsigned long sent_at;
679 /* What is the origin IP address for this chunk? */
680 union sctp_addr source;
681 /* Destination address for this chunk. */
682 union sctp_addr dest;
684 /* For outbound message, track all fragments for SEND_FAILED. */
685 struct sctp_datamsg *msg;
687 /* For an inbound chunk, this tells us where it came from.
688 * For an outbound chunk, it tells us where we'd like it to
689 * go. It is NULL if we have no preference.
691 struct sctp_transport *transport;
693 __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */
694 __u8 resent; /* Has this chunk ever been retransmitted. */
695 __u8 has_tsn; /* Does this chunk have a TSN yet? */
696 __u8 has_ssn; /* Does this chunk have a SSN yet? */
697 __u8 singleton; /* Was this the only chunk in the packet? */
698 __u8 end_of_packet; /* Was this the last chunk in the packet? */
699 __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */
700 __u8 pdiscard; /* Discard the whole packet now? */
701 __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */
702 __u8 fast_retransmit; /* Is this chunk fast retransmitted? */
703 __u8 tsn_missing_report; /* Data chunk missing counter. */
706 void sctp_chunk_hold(struct sctp_chunk *);
707 void sctp_chunk_put(struct sctp_chunk *);
708 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
710 void sctp_chunk_free(struct sctp_chunk *);
711 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
712 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
713 const struct sctp_association *,
715 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
717 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
719 /* This is a structure for holding either an IPv6 or an IPv4 address. */
720 /* sin_family -- AF_INET or AF_INET6
721 * sin_port -- ordinary port number
722 * sin_addr -- cast to either (struct in_addr) or (struct in6_addr)
724 struct sctp_sockaddr_entry {
725 struct list_head list;
729 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
731 /* This structure holds lists of chunks as we are assembling for
735 /* These are the SCTP header values (host order) for the packet. */
737 __u16 destination_port;
740 /* This contains the payload chunks. */
741 struct list_head chunk_list;
743 /* This is the overhead of the sctp and ip headers. */
745 /* This is the total size of all chunks INCLUDING padding. */
748 /* The packet is destined for this transport address.
749 * The function we finally use to pass down to the next lower
750 * layer lives in the transport structure.
752 struct sctp_transport *transport;
754 /* This packet contains a COOKIE-ECHO chunk. */
755 char has_cookie_echo;
757 /* This packet containsa SACK chunk. */
760 /* SCTP cannot fragment this packet. So let ip fragment it. */
766 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
767 struct sctp_transport *,
768 __u16 sport, __u16 dport);
769 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
770 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
771 struct sctp_chunk *);
772 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
773 struct sctp_chunk *);
774 int sctp_packet_transmit(struct sctp_packet *);
775 void sctp_packet_free(struct sctp_packet *);
777 static inline int sctp_packet_empty(struct sctp_packet *packet)
779 return (packet->size == packet->overhead);
782 /* This represents a remote transport address.
783 * For local transport addresses, we just use union sctp_addr.
785 * RFC2960 Section 1.4 Key Terms
787 * o Transport address: A Transport Address is traditionally defined
788 * by Network Layer address, Transport Layer protocol and Transport
789 * Layer port number. In the case of SCTP running over IP, a
790 * transport address is defined by the combination of an IP address
791 * and an SCTP port number (where SCTP is the Transport protocol).
793 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
795 * o The sender keeps a separate congestion control parameter set for
796 * each of the destination addresses it can send to (not each
797 * source-destination pair but for each destination). The parameters
798 * should decay if the address is not used for a long enough time
802 struct sctp_transport {
803 /* A list of transports. */
804 struct list_head transports;
806 /* Reference counting. */
810 /* This is the peer's IP address and port. */
811 union sctp_addr ipaddr;
813 /* These are the functions we call to handle LLP stuff. */
814 struct sctp_af *af_specific;
816 /* Which association do we belong to? */
817 struct sctp_association *asoc;
821 * 12.3 Per Transport Address Data
823 * For each destination transport address in the peer's
824 * address list derived from the INIT or INIT ACK chunk, a
825 * number of data elements needs to be maintained including:
827 __u32 rtt; /* This is the most recent RTT. */
829 /* RTO : The current retransmission timeout value. */
832 /* RTTVAR : The current RTT variation. */
835 /* SRTT : The current smoothed round trip time. */
838 /* RTO-Pending : A flag used to track if one of the DATA
839 * chunks sent to this address is currently being
840 * used to compute a RTT. If this flag is 0,
841 * the next DATA chunk sent to this destination
842 * should be used to compute a RTT and this flag
843 * should be set. Every time the RTT
844 * calculation completes (i.e. the DATA chunk
845 * is SACK'd) clear this flag.
850 * These are the congestion stats.
852 /* cwnd : The current congestion window. */
853 __u32 cwnd; /* This is the actual cwnd. */
855 /* ssthresh : The current slow start threshold value. */
858 /* partial : The tracking method for increase of cwnd when in
859 * bytes acked : congestion avoidance mode (see Section 6.2.2)
861 __u32 partial_bytes_acked;
863 /* Data that has been sent, but not acknowledged. */
867 struct dst_entry *dst;
868 /* Source address. */
869 union sctp_addr saddr;
871 /* When was the last time(in jiffies) that a data packet was sent on
872 * this transport? This is used to adjust the cwnd when the transport
875 unsigned long last_time_used;
877 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
878 * the destination address every heartbeat interval.
882 /* This is the max_retrans value for the transport and will
883 * be initialized from the assocs value. This can be changed
884 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
888 /* PMTU : The current known path MTU. */
891 /* SACK delay timeout */
894 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
897 /* When was the last time (in jiffies) that we heard from this
898 * transport? We use this to pick new active and retran paths.
900 unsigned long last_time_heard;
902 /* Last time(in jiffies) when cwnd is reduced due to the congestion
903 * indication based on ECNE chunk.
905 unsigned long last_time_ecne_reduced;
907 /* The number of times INIT has been sent on this transport. */
910 /* state : The current state of this destination,
911 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKOWN.
915 /* These are the error stats for this destination. */
917 /* Error count : The current error count for this destination. */
918 unsigned short error_count;
920 /* Per : A timer used by each destination.
924 * [Everywhere else in the text this is called T3-rtx. -ed]
926 struct timer_list T3_rtx_timer;
928 /* Heartbeat timer is per destination. */
929 struct timer_list hb_timer;
931 /* Since we're using per-destination retransmission timers
932 * (see above), we're also using per-destination "transmitted"
933 * queues. This probably ought to be a private struct
934 * accessible only within the outqueue, but it's not, yet.
936 struct list_head transmitted;
938 /* We build bundle-able packets for this transport here. */
939 struct sctp_packet packet;
941 /* This is the list of transports that have chunks to send. */
942 struct list_head send_ready;
944 int malloced; /* Is this structure kfree()able? */
946 /* State information saved for SFR_CACC algorithm. The key
947 * idea in SFR_CACC is to maintain state at the sender on a
948 * per-destination basis when a changeover happens.
949 * char changeover_active;
950 * char cycling_changeover;
951 * __u32 next_tsn_at_change;
952 * char cacc_saw_newack;
955 /* An unsigned integer, which stores the next TSN to be
956 * used by the sender, at the moment of changeover.
958 __u32 next_tsn_at_change;
960 /* A flag which indicates the occurrence of a changeover */
961 char changeover_active;
963 /* A flag which indicates whether the change of primary is
964 * the first switch to this destination address during an
967 char cycling_changeover;
969 /* A temporary flag, which is used during the processing of
970 * a SACK to estimate the causative TSN(s)'s group.
972 char cacc_saw_newack;
976 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
978 void sctp_transport_set_owner(struct sctp_transport *,
979 struct sctp_association *);
980 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
982 void sctp_transport_pmtu(struct sctp_transport *);
983 void sctp_transport_free(struct sctp_transport *);
984 void sctp_transport_reset_timers(struct sctp_transport *);
985 void sctp_transport_hold(struct sctp_transport *);
986 void sctp_transport_put(struct sctp_transport *);
987 void sctp_transport_update_rto(struct sctp_transport *, __u32);
988 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
989 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
990 unsigned long sctp_transport_timeout(struct sctp_transport *);
993 /* This is the structure we use to queue packets as they come into
994 * SCTP. We write packets to it and read chunks from it.
997 /* This is actually a queue of sctp_chunk each
998 * containing a partially decoded packet.
1000 struct list_head in_chunk_list;
1001 /* This is the packet which is currently off the in queue and is
1002 * being worked on through the inbound chunk processing.
1004 struct sctp_chunk *in_progress;
1006 /* This is the delayed task to finish delivering inbound
1009 struct work_struct immediate;
1011 int malloced; /* Is this structure kfree()able? */
1014 void sctp_inq_init(struct sctp_inq *);
1015 void sctp_inq_free(struct sctp_inq *);
1016 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1017 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1018 void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *);
1020 /* This is the structure we use to hold outbound chunks. You push
1021 * chunks in and they automatically pop out the other end as bundled
1022 * packets (it calls (*output_handler)()).
1024 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1025 * and 8.2 of the v13 draft.
1027 * It handles retransmissions. The connection to the timeout portion
1028 * of the state machine is through sctp_..._timeout() and timeout_handler.
1030 * If you feed it SACKs, it will eat them.
1032 * If you give it big chunks, it will fragment them.
1034 * It assigns TSN's to data chunks. This happens at the last possible
1035 * instant before transmission.
1037 * When free()'d, it empties itself out via output_handler().
1040 struct sctp_association *asoc;
1042 /* Data pending that has never been transmitted. */
1043 struct list_head out_chunk_list;
1045 unsigned out_qlen; /* Total length of queued data chunks. */
1047 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1050 /* These are control chunks we want to send. */
1051 struct list_head control_chunk_list;
1053 /* These are chunks that have been sacked but are above the
1054 * CTSN, or cumulative tsn ack point.
1056 struct list_head sacked;
1058 /* Put chunks on this list to schedule them for
1061 struct list_head retransmit;
1063 /* Put chunks on this list to save them for FWD TSN processing as
1064 * they were abandoned.
1066 struct list_head abandoned;
1068 /* How many unackd bytes do we have in-flight? */
1069 __u32 outstanding_bytes;
1074 /* Is this structure empty? */
1077 /* Are we kfree()able? */
1081 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1082 void sctp_outq_teardown(struct sctp_outq *);
1083 void sctp_outq_free(struct sctp_outq*);
1084 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1085 int sctp_outq_flush(struct sctp_outq *, int);
1086 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1087 int sctp_outq_is_empty(const struct sctp_outq *);
1088 void sctp_outq_restart(struct sctp_outq *);
1090 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1091 sctp_retransmit_reason_t);
1092 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1093 int sctp_outq_uncork(struct sctp_outq *);
1094 /* Uncork and flush an outqueue. */
1095 static inline void sctp_outq_cork(struct sctp_outq *q)
1100 /* These bind address data fields common between endpoints and associations */
1101 struct sctp_bind_addr {
1103 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1105 * SCTP Port: The local SCTP port number the endpoint is
1110 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1112 * Address List: The list of IP addresses that this instance
1113 * has bound. This information is passed to one's
1114 * peer(s) in INIT and INIT ACK chunks.
1116 struct list_head address_list;
1118 int malloced; /* Are we kfree()able? */
1121 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1122 void sctp_bind_addr_free(struct sctp_bind_addr *);
1123 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1124 const struct sctp_bind_addr *src,
1125 sctp_scope_t scope, gfp_t gfp,
1127 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1129 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1130 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1131 struct sctp_sock *);
1132 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1133 const union sctp_addr *addrs,
1135 struct sctp_sock *opt);
1136 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1139 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1140 __u16 port, gfp_t gfp);
1142 sctp_scope_t sctp_scope(const union sctp_addr *);
1143 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1144 int sctp_is_any(const union sctp_addr *addr);
1145 int sctp_addr_is_valid(const union sctp_addr *addr);
1148 /* What type of endpoint? */
1150 SCTP_EP_TYPE_SOCKET,
1151 SCTP_EP_TYPE_ASSOCIATION,
1152 } sctp_endpoint_type_t;
1155 * A common base class to bridge the implmentation view of a
1156 * socket (usually listening) endpoint versus an association's
1158 * This common structure is useful for several purposes:
1159 * 1) Common interface for lookup routines.
1160 * a) Subfunctions work for either endpoint or association
1161 * b) Single interface to lookup allows hiding the lookup lock rather
1162 * than acquiring it externally.
1163 * 2) Common interface for the inbound chunk handling/state machine.
1164 * 3) Common object handling routines for reference counting, etc.
1165 * 4) Disentangle association lookup from endpoint lookup, where we
1166 * do not have to find our endpoint to find our association.
1170 struct sctp_ep_common {
1171 /* Fields to help us manage our entries in the hash tables. */
1172 struct sctp_ep_common *next;
1173 struct sctp_ep_common **pprev;
1176 /* Runtime type information. What kind of endpoint is this? */
1177 sctp_endpoint_type_t type;
1179 /* Some fields to help us manage this object.
1180 * refcnt - Reference count access to this object.
1181 * dead - Do not attempt to use this object.
1182 * malloced - Do we need to kfree this object?
1188 /* What socket does this endpoint belong to? */
1191 /* This is where we receive inbound chunks. */
1192 struct sctp_inq inqueue;
1194 /* This substructure includes the defining parameters of the
1196 * bind_addr.port is our shared port number.
1197 * bind_addr.address_list is our set of local IP addresses.
1199 struct sctp_bind_addr bind_addr;
1201 /* Protection during address list comparisons. */
1206 /* RFC Section 1.4 Key Terms
1208 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1209 * multi-homed host, an SCTP endpoint is represented to its peers as a
1210 * combination of a set of eligible destination transport addresses to
1211 * which SCTP packets can be sent and a set of eligible source
1212 * transport addresses from which SCTP packets can be received.
1213 * All transport addresses used by an SCTP endpoint must use the
1214 * same port number, but can use multiple IP addresses. A transport
1215 * address used by an SCTP endpoint must not be used by another
1216 * SCTP endpoint. In other words, a transport address is unique
1217 * to an SCTP endpoint.
1219 * From an implementation perspective, each socket has one of these.
1220 * A TCP-style socket will have exactly one association on one of
1221 * these. An UDP-style socket will have multiple associations hanging
1225 struct sctp_endpoint {
1226 /* Common substructure for endpoint and association. */
1227 struct sctp_ep_common base;
1229 /* Associations: A list of current associations and mappings
1230 * to the data consumers for each association. This
1231 * may be in the form of a hash table or other
1232 * implementation dependent structure. The data
1233 * consumers may be process identification
1234 * information such as file descriptors, named pipe
1235 * pointer, or table pointers dependent on how SCTP
1238 /* This is really a list of struct sctp_association entries. */
1239 struct list_head asocs;
1241 /* Secret Key: A secret key used by this endpoint to compute
1242 * the MAC. This SHOULD be a cryptographic quality
1243 * random number with a sufficient length.
1244 * Discussion in [RFC1750] can be helpful in
1245 * selection of the key.
1247 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1252 /* sendbuf acct. policy. */
1253 __u32 sndbuf_policy;
1255 /* rcvbuf acct. policy. */
1256 __u32 rcvbuf_policy;
1259 /* Recover the outter endpoint structure. */
1260 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1262 struct sctp_endpoint *ep;
1264 ep = container_of(base, struct sctp_endpoint, base);
1268 /* These are function signatures for manipulating endpoints. */
1269 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1270 void sctp_endpoint_free(struct sctp_endpoint *);
1271 void sctp_endpoint_put(struct sctp_endpoint *);
1272 void sctp_endpoint_hold(struct sctp_endpoint *);
1273 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1274 struct sctp_association *sctp_endpoint_lookup_assoc(
1275 const struct sctp_endpoint *ep,
1276 const union sctp_addr *paddr,
1277 struct sctp_transport **);
1278 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1279 const union sctp_addr *);
1280 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1281 const union sctp_addr *);
1282 int sctp_has_association(const union sctp_addr *laddr,
1283 const union sctp_addr *paddr);
1285 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1286 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1287 struct sctp_chunk **err_chunk);
1288 int sctp_process_init(struct sctp_association *, sctp_cid_t cid,
1289 const union sctp_addr *peer,
1290 sctp_init_chunk_t *init, gfp_t gfp);
1291 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1292 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1297 * 12. Recommended Transmission Control Block (TCB) Parameters
1299 * This section details a recommended set of parameters that should
1300 * be contained within the TCB for an implementation. This section is
1301 * for illustrative purposes and should not be deemed as requirements
1302 * on an implementation or as an exhaustive list of all parameters
1303 * inside an SCTP TCB. Each implementation may need its own additional
1304 * parameters for optimization.
1308 /* Here we have information about each individual association. */
1309 struct sctp_association {
1311 /* A base structure common to endpoint and association.
1312 * In this context, it represents the associations's view
1313 * of the local endpoint of the association.
1315 struct sctp_ep_common base;
1317 /* Associations on the same socket. */
1318 struct list_head asocs;
1320 /* association id. */
1321 sctp_assoc_t assoc_id;
1323 /* This is our parent endpoint. */
1324 struct sctp_endpoint *ep;
1326 /* These are those association elements needed in the cookie. */
1327 struct sctp_cookie c;
1329 /* This is all information about our peer. */
1333 * Peer Rwnd : Current calculated value of the peer's rwnd.
1337 /* transport_addr_list
1339 * Peer : A list of SCTP transport addresses that the
1340 * Transport : peer is bound to. This information is derived
1341 * Address : from the INIT or INIT ACK and is used to
1342 * List : associate an inbound packet with a given
1343 * : association. Normally this information is
1344 * : hashed or keyed for quick lookup and access
1346 * : The list is also initialized with the list
1347 * : of addresses passed with the sctp_connectx()
1350 * It is a list of SCTP_transport's.
1352 struct list_head transport_addr_list;
1356 * Peer : A count of the number of peer addresses
1357 * Transport : in the Peer Transport Address List.
1361 __u16 transport_count;
1364 * The transport layer port number.
1370 * Primary : This is the current primary destination
1371 * Path : transport address of the peer endpoint. It
1372 * : may also specify a source transport address
1373 * : on this endpoint.
1375 * All of these paths live on transport_addr_list.
1377 * At the bakeoffs, we discovered that the intent of
1378 * primaryPath is that it only changes when the ULP
1379 * asks to have it changed. We add the activePath to
1380 * designate the connection we are currently using to
1381 * transmit new data and most control chunks.
1383 struct sctp_transport *primary_path;
1385 /* Cache the primary path address here, when we
1386 * need a an address for msg_name.
1388 union sctp_addr primary_addr;
1391 * The path that we are currently using to
1392 * transmit new data and most control chunks.
1394 struct sctp_transport *active_path;
1398 * RFC2960 6.4 Multi-homed SCTP Endpoints
1400 * Furthermore, when its peer is multi-homed, an
1401 * endpoint SHOULD try to retransmit a chunk to an
1402 * active destination transport address that is
1403 * different from the last destination address to
1404 * which the DATA chunk was sent.
1406 struct sctp_transport *retran_path;
1408 /* Pointer to last transport I have sent on. */
1409 struct sctp_transport *last_sent_to;
1411 /* This is the last transport I have received DATA on. */
1412 struct sctp_transport *last_data_from;
1415 * Mapping An array of bits or bytes indicating which out of
1416 * Array order TSN's have been received (relative to the
1417 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1418 * order packets have been received, this array
1419 * will be set to all zero. This structure may be
1420 * in the form of a circular buffer or bit array.
1422 * Last Rcvd : This is the last TSN received in
1423 * TSN : sequence. This value is set initially by
1424 * : taking the peer's Initial TSN, received in
1425 * : the INIT or INIT ACK chunk, and subtracting
1428 * Throughout most of the specification this is called the
1429 * "Cumulative TSN ACK Point". In this case, we
1430 * ignore the advice in 12.2 in favour of the term
1431 * used in the bulk of the text. This value is hidden
1432 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1434 struct sctp_tsnmap tsn_map;
1435 __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)];
1437 /* Ack State : This flag indicates if the next received
1438 * : packet is to be responded to with a
1439 * : SACK. This is initializedto 0. When a packet
1440 * : is received it is incremented. If this value
1441 * : reaches 2 or more, a SACK is sent and the
1442 * : value is reset to 0. Note: This is used only
1443 * : when no DATA chunks are received out of
1444 * : order. When DATA chunks are out of order,
1445 * : SACK's are not delayed (see Section 6).
1447 __u8 sack_needed; /* Do we need to sack the peer? */
1449 /* These are capabilities which our peer advertised. */
1450 __u8 ecn_capable; /* Can peer do ECN? */
1451 __u8 ipv4_address; /* Peer understands IPv4 addresses? */
1452 __u8 ipv6_address; /* Peer understands IPv6 addresses? */
1453 __u8 hostname_address;/* Peer understands DNS addresses? */
1454 __u8 asconf_capable; /* Does peer support ADDIP? */
1455 __u8 prsctp_capable; /* Can peer do PR-SCTP? */
1457 __u32 adaption_ind; /* Adaption Code point. */
1459 /* This mask is used to disable sending the ASCONF chunk
1460 * with specified parameter to peer.
1462 __u16 addip_disabled_mask;
1464 struct sctp_inithdr i;
1468 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1469 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1470 * Initial TSN Value minus 1
1475 /* State : A state variable indicating what state the
1476 * : association is in, i.e. COOKIE-WAIT,
1477 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1478 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1480 * Note: No "CLOSED" state is illustrated since if a
1481 * association is "CLOSED" its TCB SHOULD be removed.
1483 * In this implementation we DO have a CLOSED
1484 * state which is used during initiation and shutdown.
1486 * State takes values from SCTP_STATE_*.
1490 /* The cookie life I award for any cookie. */
1491 struct timeval cookie_life;
1493 /* Overall : The overall association error count.
1494 * Error Count : [Clear this any time I get something.]
1496 int overall_error_count;
1498 /* These are the association's initial, max, and min RTO values.
1499 * These values will be initialized by system defaults, but can
1500 * be modified via the SCTP_RTOINFO socket option.
1506 /* Maximum number of new data packets that can be sent in a burst. */
1509 /* This is the max_retrans value for the association. This value will
1510 * be initialized initialized from system defaults, but can be
1511 * modified by the SCTP_ASSOCINFO socket option.
1515 /* Maximum number of times the endpoint will retransmit INIT */
1516 __u16 max_init_attempts;
1518 /* How many times have we resent an INIT? */
1521 /* The largest timeout or RTO value to use in attempting an INIT */
1522 __u16 max_init_timeo;
1524 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1525 * the destination address every heartbeat interval. This value
1526 * will be inherited by all new transports.
1530 /* This is the max_retrans value for new transports in the
1535 /* Association : The smallest PMTU discovered for all of the
1536 * PMTU : peer's transport addresses.
1540 /* SACK delay timeout */
1543 /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */
1546 int timeouts[SCTP_NUM_TIMEOUT_TYPES];
1547 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1549 /* Transport to which SHUTDOWN chunk was last sent. */
1550 struct sctp_transport *shutdown_last_sent_to;
1552 /* Transport to which INIT chunk was last sent. */
1553 struct sctp_transport *init_last_sent_to;
1555 /* Next TSN : The next TSN number to be assigned to a new
1556 * : DATA chunk. This is sent in the INIT or INIT
1557 * : ACK chunk to the peer and incremented each
1558 * : time a DATA chunk is assigned a TSN
1559 * : (normally just prior to transmit or during
1565 * Last Rcvd : This is the last TSN received in sequence. This value
1566 * TSN : is set initially by taking the peer's Initial TSN,
1567 * : received in the INIT or INIT ACK chunk, and
1568 * : subtracting one from it.
1570 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1573 __u32 ctsn_ack_point;
1575 /* PR-SCTP Advanced.Peer.Ack.Point */
1576 __u32 adv_peer_ack_point;
1578 /* Highest TSN that is acknowledged by incoming SACKs. */
1579 __u32 highest_sacked;
1581 /* The number of unacknowledged data chunks. Reported through
1582 * the SCTP_STATUS sockopt.
1586 /* This is the association's receive buffer space. This value is used
1587 * to set a_rwnd field in an INIT or a SACK chunk.
1591 /* This is the last advertised value of rwnd over a SACK chunk. */
1594 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1595 * to slop over a maximum of the association's frag_point.
1599 /* This is the sndbuf size in use for the association.
1600 * This corresponds to the sndbuf size for the association,
1601 * as specified in the sk->sndbuf.
1605 /* This is the amount of memory that this association has allocated
1606 * in the receive path at any given time.
1608 atomic_t rmem_alloc;
1610 /* This is the wait queue head for send requests waiting on
1611 * the association sndbuf space.
1613 wait_queue_head_t wait;
1615 /* The message size at which SCTP fragmentation will occur. */
1618 /* Counter used to count INIT errors. */
1619 int init_err_counter;
1621 /* Count the number of INIT cycles (for doubling timeout). */
1624 /* Default send parameters. */
1625 __u16 default_stream;
1626 __u16 default_flags;
1628 __u32 default_context;
1629 __u32 default_timetolive;
1631 /* This tracks outbound ssn for a given stream. */
1632 struct sctp_ssnmap *ssnmap;
1634 /* All outbound chunks go through this structure. */
1635 struct sctp_outq outqueue;
1637 /* A smart pipe that will handle reordering and fragmentation,
1638 * as well as handle passing events up to the ULP.
1640 struct sctp_ulpq ulpq;
1642 /* Last TSN that caused an ECNE Chunk to be sent. */
1643 __u32 last_ecne_tsn;
1645 /* Last TSN that caused a CWR Chunk to be sent. */
1648 /* How many duplicated TSNs have we seen? */
1651 /* Number of seconds of idle time before an association is closed. */
1654 /* These are to support
1655 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1656 * and Enforcement of Flow and Message Limits"
1657 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1658 * or "ADDIP" for short.
1663 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1665 * R1) One and only one ASCONF Chunk MAY be in transit and
1666 * unacknowledged at any one time. If a sender, after sending
1667 * an ASCONF chunk, decides it needs to transfer another
1668 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1669 * returns from the previous ASCONF Chunk before sending a
1670 * subsequent ASCONF. Note this restriction binds each side,
1671 * so at any time two ASCONF may be in-transit on any given
1672 * association (one sent from each endpoint).
1674 * [This is our one-and-only-one ASCONF in flight. If we do
1675 * not have an ASCONF in flight, this is NULL.]
1677 struct sctp_chunk *addip_last_asconf;
1679 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1681 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
1682 * to save the last ASCONF-ACK for some predetermined period
1683 * of time and instead of re-processing the ASCONF (with the
1684 * same serial number) it may just re-transmit the
1685 * ASCONF-ACK. It may wish to use the arrival of a new serial
1686 * number to discard the previously saved ASCONF-ACK or any
1687 * other means it may choose to expire the saved ASCONF-ACK.
1689 * [This is our saved ASCONF-ACK. We invalidate it when a new
1690 * ASCONF serial number arrives.]
1692 struct sctp_chunk *addip_last_asconf_ack;
1694 /* These ASCONF chunks are waiting to be sent.
1696 * These chunaks can't be pushed to outqueue until receiving
1697 * ASCONF_ACK for the previous ASCONF indicated by
1698 * addip_last_asconf, so as to guarantee that only one ASCONF
1699 * is in flight at any time.
1701 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1703 * In defining the ASCONF Chunk transfer procedures, it is
1704 * essential that these transfers MUST NOT cause congestion
1705 * within the network. To achieve this, we place these
1706 * restrictions on the transfer of ASCONF Chunks:
1708 * R1) One and only one ASCONF Chunk MAY be in transit and
1709 * unacknowledged at any one time. If a sender, after sending
1710 * an ASCONF chunk, decides it needs to transfer another
1711 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1712 * returns from the previous ASCONF Chunk before sending a
1713 * subsequent ASCONF. Note this restriction binds each side,
1714 * so at any time two ASCONF may be in-transit on any given
1715 * association (one sent from each endpoint).
1718 * [I really think this is EXACTLY the sort of intelligence
1719 * which already resides in sctp_outq. Please move this
1720 * queue and its supporting logic down there. --piggy]
1722 struct list_head addip_chunk_list;
1724 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1726 * A2) A serial number should be assigned to the Chunk. The
1727 * serial number SHOULD be a monotonically increasing
1728 * number. The serial number SHOULD be initialized at
1729 * the start of the association to the same value as the
1730 * Initial TSN and every time a new ASCONF chunk is created
1731 * it is incremented by one after assigning the serial number
1732 * to the newly created chunk.
1735 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1737 * Serial Number : 32 bits (unsigned integer)
1739 * This value represents a Serial Number for the ASCONF
1740 * Chunk. The valid range of Serial Number is from 0 to
1741 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1742 * after reaching 4294967295.
1746 /* Need to send an ECNE Chunk? */
1749 /* Is it a temporary association? */
1754 /* An eyecatcher for determining if we are really looking at an
1755 * association data structure.
1758 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1761 /* Recover the outter association structure. */
1762 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1764 struct sctp_association *asoc;
1766 asoc = container_of(base, struct sctp_association, base);
1770 /* These are function signatures for manipulating associations. */
1773 struct sctp_association *
1774 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1775 sctp_scope_t scope, gfp_t gfp);
1776 void sctp_association_free(struct sctp_association *);
1777 void sctp_association_put(struct sctp_association *);
1778 void sctp_association_hold(struct sctp_association *);
1780 struct sctp_transport *sctp_assoc_choose_init_transport(
1781 struct sctp_association *);
1782 struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1783 struct sctp_association *);
1784 void sctp_assoc_update_retran_path(struct sctp_association *);
1785 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1786 const union sctp_addr *);
1787 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1788 const union sctp_addr *laddr);
1789 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1790 const union sctp_addr *address,
1792 const int peer_state);
1793 void sctp_assoc_del_peer(struct sctp_association *asoc,
1794 const union sctp_addr *addr);
1795 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1796 struct sctp_transport *peer);
1797 void sctp_assoc_control_transport(struct sctp_association *,
1798 struct sctp_transport *,
1799 sctp_transport_cmd_t, sctp_sn_error_t);
1800 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1801 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1802 const union sctp_addr *,
1803 const union sctp_addr *);
1804 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1805 void sctp_assoc_update(struct sctp_association *old,
1806 struct sctp_association *new);
1808 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1810 void sctp_assoc_sync_pmtu(struct sctp_association *);
1811 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
1812 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
1813 void sctp_assoc_set_primary(struct sctp_association *,
1814 struct sctp_transport *);
1815 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1817 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1818 struct sctp_cookie*,
1821 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1822 const union sctp_addr *ss2);
1823 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1825 /* A convenience structure to parse out SCTP specific CMSGs. */
1826 typedef struct sctp_cmsgs {
1827 struct sctp_initmsg *init;
1828 struct sctp_sndrcvinfo *info;
1831 /* Structure for tracking memory objects */
1835 } sctp_dbg_objcnt_entry_t;
1837 #endif /* __sctp_structs_h__ */