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 spinlock_t addr_wq_lock;
214 /* Lock that protects the local_addr_list writers */
215 spinlock_t addr_list_lock;
217 /* Flag to indicate if addip is enabled. */
219 int addip_noauth_enable;
221 /* Flag to indicate if PR-SCTP is enabled. */
224 /* Flag to idicate if SCTP-AUTH is enabled */
228 * Policy to control SCTP IPv4 address scoping
229 * 0 - Disable IPv4 address scoping
230 * 1 - Enable IPv4 address scoping
231 * 2 - Selectively allow only IPv4 private addresses
232 * 3 - Selectively allow only IPv4 link local address
234 int ipv4_scope_policy;
236 /* Flag to indicate whether computing and verifying checksum
238 bool checksum_disable;
240 /* Threshold for rwnd update SACKS. Receive buffer shifted this many
241 * bits is an indicator of when to send and window update SACK.
243 int rwnd_update_shift;
245 /* Threshold for autoclose timeout, in seconds. */
246 unsigned long max_autoclose;
249 #define sctp_rto_initial (sctp_globals.rto_initial)
250 #define sctp_rto_min (sctp_globals.rto_min)
251 #define sctp_rto_max (sctp_globals.rto_max)
252 #define sctp_rto_alpha (sctp_globals.rto_alpha)
253 #define sctp_rto_beta (sctp_globals.rto_beta)
254 #define sctp_max_burst (sctp_globals.max_burst)
255 #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life)
256 #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable)
257 #define sctp_max_retrans_association (sctp_globals.max_retrans_association)
258 #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy)
259 #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy)
260 #define sctp_max_retrans_path (sctp_globals.max_retrans_path)
261 #define sctp_max_retrans_init (sctp_globals.max_retrans_init)
262 #define sctp_sack_timeout (sctp_globals.sack_timeout)
263 #define sctp_hb_interval (sctp_globals.hb_interval)
264 #define sctp_max_instreams (sctp_globals.max_instreams)
265 #define sctp_max_outstreams (sctp_globals.max_outstreams)
266 #define sctp_address_families (sctp_globals.address_families)
267 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
268 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
269 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
270 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
271 #define sctp_port_hashsize (sctp_globals.port_hashsize)
272 #define sctp_port_hashtable (sctp_globals.port_hashtable)
273 #define sctp_local_addr_list (sctp_globals.local_addr_list)
274 #define sctp_local_addr_lock (sctp_globals.addr_list_lock)
275 #define sctp_auto_asconf_splist (sctp_globals.auto_asconf_splist)
276 #define sctp_addr_waitq (sctp_globals.addr_waitq)
277 #define sctp_addr_wq_timer (sctp_globals.addr_wq_timer)
278 #define sctp_addr_wq_lock (sctp_globals.addr_wq_lock)
279 #define sctp_default_auto_asconf (sctp_globals.default_auto_asconf)
280 #define sctp_scope_policy (sctp_globals.ipv4_scope_policy)
281 #define sctp_addip_enable (sctp_globals.addip_enable)
282 #define sctp_addip_noauth (sctp_globals.addip_noauth_enable)
283 #define sctp_prsctp_enable (sctp_globals.prsctp_enable)
284 #define sctp_auth_enable (sctp_globals.auth_enable)
285 #define sctp_checksum_disable (sctp_globals.checksum_disable)
286 #define sctp_rwnd_upd_shift (sctp_globals.rwnd_update_shift)
287 #define sctp_max_autoclose (sctp_globals.max_autoclose)
289 /* SCTP Socket type: UDP or TCP style. */
292 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
294 } sctp_socket_type_t;
296 /* Per socket SCTP information. */
298 /* inet_sock has to be the first member of sctp_sock */
299 struct inet_sock inet;
300 /* What kind of a socket is this? */
301 sctp_socket_type_t type;
303 /* PF_ family specific functions. */
306 /* Access to HMAC transform. */
307 struct crypto_hash *hmac;
309 /* What is our base endpointer? */
310 struct sctp_endpoint *ep;
312 struct sctp_bind_bucket *bind_hash;
313 /* Various Socket Options. */
314 __u16 default_stream;
317 __u32 default_context;
318 __u32 default_timetolive;
319 __u32 default_rcv_context;
322 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
323 * the destination address every heartbeat interval. This value
324 * will be inherited by all new associations.
328 /* This is the max_retrans value for new associations. */
331 /* The initial Path MTU to use for new associations. */
334 /* The default SACK delay timeout for new associations. */
338 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
341 struct sctp_initmsg initmsg;
342 struct sctp_rtoinfo rtoinfo;
343 struct sctp_paddrparams paddrparam;
344 struct sctp_event_subscribe subscribe;
345 struct sctp_assocparams assocparams;
349 __u8 disable_fragments;
351 __u8 frag_interleave;
352 __u32 adaptation_ind;
356 /* Receive to here while partial delivery is in effect. */
357 struct sk_buff_head pd_lobby;
358 struct list_head auto_asconf_list;
362 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
364 return (struct sctp_sock *)sk;
367 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
369 return (struct sock *)sp;
372 #if IS_ENABLED(CONFIG_IPV6)
374 struct sctp_sock sctp;
375 struct ipv6_pinfo inet6;
377 #endif /* CONFIG_IPV6 */
380 /* This is our APPLICATION-SPECIFIC state cookie.
381 * THIS IS NOT DICTATED BY THE SPECIFICATION.
383 /* These are the parts of an association which we send in the cookie.
384 * Most of these are straight out of:
385 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
391 /* My : Tag expected in every inbound packet and sent
392 * Verification: in the INIT or INIT ACK chunk.
397 /* Peer's : Tag expected in every outbound packet except
398 * Verification: in the INIT chunk.
403 /* The rest of these are not from the spec, but really need to
407 /* My Tie Tag : Assist in discovering a restarting association. */
410 /* Peer's Tie Tag: Assist in discovering a restarting association. */
413 /* When does this cookie expire? */
414 struct timeval expiration;
416 /* Number of inbound/outbound streams which are set
417 * and negotiated during the INIT process.
419 __u16 sinit_num_ostreams;
420 __u16 sinit_max_instreams;
422 /* This is the first sequence number I used. */
425 /* This holds the originating address of the INIT packet. */
426 union sctp_addr peer_addr;
429 * Include the source port of the INIT-ACK
435 /* Padding for future use */
438 __u32 adaptation_ind;
440 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
441 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
442 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
444 /* This is a shim for my peer's INIT packet, followed by
445 * a copy of the raw address list of the association.
446 * The length of the raw address list is saved in the
447 * raw_addr_list_len field, which will be used at the time when
448 * the association TCB is re-constructed from the cookie.
450 __u32 raw_addr_list_len;
451 struct sctp_init_chunk peer_init[0];
455 /* The format of our cookie that we send to our peer. */
456 struct sctp_signed_cookie {
457 __u8 signature[SCTP_SECRET_SIZE];
458 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
459 struct sctp_cookie c;
462 /* This is another convenience type to allocate memory for address
463 * params for the maximum size and pass such structures around
466 union sctp_addr_param {
467 struct sctp_paramhdr p;
468 struct sctp_ipv4addr_param v4;
469 struct sctp_ipv6addr_param v6;
472 /* A convenience type to allow walking through the various
473 * parameters and avoid casting all over the place.
477 struct sctp_paramhdr *p;
478 struct sctp_cookie_preserve_param *life;
479 struct sctp_hostname_param *dns;
480 struct sctp_cookie_param *cookie;
481 struct sctp_supported_addrs_param *sat;
482 struct sctp_ipv4addr_param *v4;
483 struct sctp_ipv6addr_param *v6;
484 union sctp_addr_param *addr;
485 struct sctp_adaptation_ind_param *aind;
486 struct sctp_supported_ext_param *ext;
487 struct sctp_random_param *random;
488 struct sctp_chunks_param *chunks;
489 struct sctp_hmac_algo_param *hmac_algo;
490 struct sctp_addip_param *addip;
493 /* RFC 2960. Section 3.3.5 Heartbeat.
494 * Heartbeat Information: variable length
495 * The Sender-specific Heartbeat Info field should normally include
496 * information about the sender's current time when this HEARTBEAT
497 * chunk is sent and the destination transport address to which this
498 * HEARTBEAT is sent (see Section 8.3).
500 typedef struct sctp_sender_hb_info {
501 struct sctp_paramhdr param_hdr;
502 union sctp_addr daddr;
503 unsigned long sent_at;
505 } __packed sctp_sender_hb_info_t;
508 * RFC 2960 1.3.2 Sequenced Delivery within Streams
510 * The term "stream" is used in SCTP to refer to a sequence of user
511 * messages that are to be delivered to the upper-layer protocol in
512 * order with respect to other messages within the same stream. This is
513 * in contrast to its usage in TCP, where it refers to a sequence of
514 * bytes (in this document a byte is assumed to be eight bits).
517 * This is the structure we use to track both our outbound and inbound
518 * SSN, or Stream Sequence Numbers.
527 struct sctp_stream in;
528 struct sctp_stream out;
532 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
534 void sctp_ssnmap_free(struct sctp_ssnmap *map);
535 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
537 /* What is the current SSN number for this stream? */
538 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
540 return stream->ssn[id];
543 /* Return the next SSN number for this stream. */
544 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
546 return stream->ssn[id]++;
549 /* Skip over this ssn and all below. */
550 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
553 stream->ssn[id] = ssn+1;
557 * Pointers to address related SCTP functions.
558 * (i.e. things that depend on the address family.)
561 int (*sctp_xmit) (struct sk_buff *skb,
562 struct sctp_transport *);
563 int (*setsockopt) (struct sock *sk,
567 unsigned int optlen);
568 int (*getsockopt) (struct sock *sk,
573 int (*compat_setsockopt) (struct sock *sk,
577 unsigned int optlen);
578 int (*compat_getsockopt) (struct sock *sk,
583 void (*get_dst) (struct sctp_transport *t,
584 union sctp_addr *saddr,
587 void (*get_saddr) (struct sctp_sock *sk,
588 struct sctp_transport *t,
590 void (*copy_addrlist) (struct list_head *,
591 struct net_device *);
592 int (*cmp_addr) (const union sctp_addr *addr1,
593 const union sctp_addr *addr2);
594 void (*addr_copy) (union sctp_addr *dst,
595 union sctp_addr *src);
596 void (*from_skb) (union sctp_addr *,
599 void (*from_sk) (union sctp_addr *,
601 void (*to_sk_saddr) (union sctp_addr *,
603 void (*to_sk_daddr) (union sctp_addr *,
605 void (*from_addr_param) (union sctp_addr *,
606 union sctp_addr_param *,
607 __be16 port, int iif);
608 int (*to_addr_param) (const union sctp_addr *,
609 union sctp_addr_param *);
610 int (*addr_valid) (union sctp_addr *,
612 const struct sk_buff *);
613 sctp_scope_t (*scope) (union sctp_addr *);
614 void (*inaddr_any) (union sctp_addr *, __be16);
615 int (*is_any) (const union sctp_addr *);
616 int (*available) (union sctp_addr *,
618 int (*skb_iif) (const struct sk_buff *sk);
619 int (*is_ce) (const struct sk_buff *sk);
620 void (*seq_dump_addr)(struct seq_file *seq,
621 union sctp_addr *addr);
622 void (*ecn_capable)(struct sock *sk);
623 __u16 net_header_len;
625 sa_family_t sa_family;
626 struct list_head list;
629 struct sctp_af *sctp_get_af_specific(sa_family_t);
630 int sctp_register_af(struct sctp_af *);
632 /* Protocol family functions. */
634 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
635 void (*skb_msgname) (struct sk_buff *, char *, int *);
636 int (*af_supported) (sa_family_t, struct sctp_sock *);
637 int (*cmp_addr) (const union sctp_addr *,
638 const union sctp_addr *,
640 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
641 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
642 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
643 struct sock *(*create_accept_sk) (struct sock *sk,
644 struct sctp_association *asoc);
645 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
650 /* Structure to track chunk fragments that have been acked, but peer
651 * fragments of the same message have not.
653 struct sctp_datamsg {
654 /* Chunks waiting to be submitted to lower layer. */
655 struct list_head chunks;
656 /* Reference counting. */
658 /* When is this message no longer interesting to the peer? */
659 unsigned long expires_at;
660 /* Did the messenge fail to send? */
663 can_abandon:1, /* can chunks from this message can be abandoned. */
664 can_delay; /* should this message be Nagle delayed */
667 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
668 struct sctp_sndrcvinfo *,
669 struct msghdr *, int len);
670 void sctp_datamsg_free(struct sctp_datamsg *);
671 void sctp_datamsg_put(struct sctp_datamsg *);
672 void sctp_chunk_fail(struct sctp_chunk *, int error);
673 int sctp_chunk_abandoned(struct sctp_chunk *);
675 /* RFC2960 1.4 Key Terms
677 * o Chunk: A unit of information within an SCTP packet, consisting of
678 * a chunk header and chunk-specific content.
680 * As a matter of convenience, we remember the SCTP common header for
681 * each chunk as well as a few other header pointers...
684 struct list_head list;
688 /* This is our link to the per-transport transmitted list. */
689 struct list_head transmitted_list;
691 /* This field is used by chunks that hold fragmented data.
692 * For the first fragment this is the list that holds the rest of
693 * fragments. For the remaining fragments, this is the link to the
694 * frag_list maintained in the first fragment.
696 struct list_head frag_list;
698 /* This points to the sk_buff containing the actual data. */
701 /* These are the SCTP headers by reverse order in a packet.
702 * Note that some of these may happen more than once. In that
703 * case, we point at the "current" one, whatever that means
704 * for that level of header.
707 /* We point this at the FIRST TLV parameter to chunk_hdr. */
708 union sctp_params param_hdr;
711 struct sctp_datahdr *data_hdr;
712 struct sctp_inithdr *init_hdr;
713 struct sctp_sackhdr *sack_hdr;
714 struct sctp_heartbeathdr *hb_hdr;
715 struct sctp_sender_hb_info *hbs_hdr;
716 struct sctp_shutdownhdr *shutdown_hdr;
717 struct sctp_signed_cookie *cookie_hdr;
718 struct sctp_ecnehdr *ecne_hdr;
719 struct sctp_cwrhdr *ecn_cwr_hdr;
720 struct sctp_errhdr *err_hdr;
721 struct sctp_addiphdr *addip_hdr;
722 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
723 struct sctp_authhdr *auth_hdr;
728 struct sctp_chunkhdr *chunk_hdr;
729 struct sctphdr *sctp_hdr;
731 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
732 struct sctp_sndrcvinfo sinfo;
734 /* Which association does this belong to? */
735 struct sctp_association *asoc;
737 /* What endpoint received this chunk? */
738 struct sctp_ep_common *rcvr;
740 /* We fill this in if we are calculating RTT. */
741 unsigned long sent_at;
743 /* What is the origin IP address for this chunk? */
744 union sctp_addr source;
745 /* Destination address for this chunk. */
746 union sctp_addr dest;
748 /* For outbound message, track all fragments for SEND_FAILED. */
749 struct sctp_datamsg *msg;
751 /* For an inbound chunk, this tells us where it came from.
752 * For an outbound chunk, it tells us where we'd like it to
753 * go. It is NULL if we have no preference.
755 struct sctp_transport *transport;
757 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
758 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
759 * spec violates the principle premis that all chunks are processed
762 struct sk_buff *auth_chunk;
764 #define SCTP_CAN_FRTX 0x0
765 #define SCTP_NEED_FRTX 0x1
766 #define SCTP_DONT_FRTX 0x2
767 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
768 has_tsn:1, /* Does this chunk have a TSN yet? */
769 has_ssn:1, /* Does this chunk have a SSN yet? */
770 singleton:1, /* Only chunk in the packet? */
771 end_of_packet:1, /* Last chunk in the packet? */
772 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
773 pdiscard:1, /* Discard the whole packet now? */
774 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
775 data_accepted:1, /* At least 1 chunk accepted */
776 auth:1, /* IN: was auth'ed | OUT: needs auth */
777 has_asconf:1, /* IN: have seen an asconf before */
778 tsn_missing_report:2, /* Data chunk missing counter. */
779 fast_retransmit:2; /* Is this chunk fast retransmitted? */
782 void sctp_chunk_hold(struct sctp_chunk *);
783 void sctp_chunk_put(struct sctp_chunk *);
784 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
786 void sctp_chunk_free(struct sctp_chunk *);
787 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
788 void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
789 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
790 const struct sctp_association *,
792 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
794 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
797 SCTP_ADDR_NEW, /* new address added to assoc/ep */
798 SCTP_ADDR_SRC, /* address can be used as source */
799 SCTP_ADDR_DEL, /* address about to be deleted */
802 /* This is a structure for holding either an IPv6 or an IPv4 address. */
803 struct sctp_sockaddr_entry {
804 struct list_head list;
811 #define SCTP_ADDRESS_TICK_DELAY 500
813 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
815 /* This structure holds lists of chunks as we are assembling for
819 /* These are the SCTP header values (host order) for the packet. */
821 __u16 destination_port;
824 /* This contains the payload chunks. */
825 struct list_head chunk_list;
827 /* This is the overhead of the sctp and ip headers. */
829 /* This is the total size of all chunks INCLUDING padding. */
832 /* The packet is destined for this transport address.
833 * The function we finally use to pass down to the next lower
834 * layer lives in the transport structure.
836 struct sctp_transport *transport;
838 /* pointer to the auth chunk for this packet */
839 struct sctp_chunk *auth;
841 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
842 has_sack:1, /* This packet contains a SACK chunk. */
843 has_auth:1, /* This packet contains an AUTH chunk */
844 has_data:1, /* This packet contains at least 1 DATA chunk */
845 ipfragok:1, /* So let ip fragment this packet */
846 malloced:1; /* Is it malloced? */
849 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
850 struct sctp_transport *,
851 __u16 sport, __u16 dport);
852 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
853 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
854 struct sctp_chunk *, int);
855 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
856 struct sctp_chunk *);
857 int sctp_packet_transmit(struct sctp_packet *);
858 void sctp_packet_free(struct sctp_packet *);
860 static inline int sctp_packet_empty(struct sctp_packet *packet)
862 return packet->size == packet->overhead;
865 /* This represents a remote transport address.
866 * For local transport addresses, we just use union sctp_addr.
868 * RFC2960 Section 1.4 Key Terms
870 * o Transport address: A Transport Address is traditionally defined
871 * by Network Layer address, Transport Layer protocol and Transport
872 * Layer port number. In the case of SCTP running over IP, a
873 * transport address is defined by the combination of an IP address
874 * and an SCTP port number (where SCTP is the Transport protocol).
876 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
878 * o The sender keeps a separate congestion control parameter set for
879 * each of the destination addresses it can send to (not each
880 * source-destination pair but for each destination). The parameters
881 * should decay if the address is not used for a long enough time
885 struct sctp_transport {
886 /* A list of transports. */
887 struct list_head transports;
889 /* Reference counting. */
892 /* RTO-Pending : A flag used to track if one of the DATA
893 * chunks sent to this address is currently being
894 * used to compute a RTT. If this flag is 0,
895 * the next DATA chunk sent to this destination
896 * should be used to compute a RTT and this flag
897 * should be set. Every time the RTT
898 * calculation completes (i.e. the DATA chunk
899 * is SACK'd) clear this flag.
904 * hb_sent : a flag that signals that we have a pending
909 /* Is the Path MTU update pending on this tranport */
912 /* Is this structure kfree()able? */
917 /* This is the peer's IP address and port. */
918 union sctp_addr ipaddr;
920 /* These are the functions we call to handle LLP stuff. */
921 struct sctp_af *af_specific;
923 /* Which association do we belong to? */
924 struct sctp_association *asoc;
928 * 12.3 Per Transport Address Data
930 * For each destination transport address in the peer's
931 * address list derived from the INIT or INIT ACK chunk, a
932 * number of data elements needs to be maintained including:
934 /* RTO : The current retransmission timeout value. */
937 __u32 rtt; /* This is the most recent RTT. */
939 /* RTTVAR : The current RTT variation. */
942 /* SRTT : The current smoothed round trip time. */
946 * These are the congestion stats.
948 /* cwnd : The current congestion window. */
949 __u32 cwnd; /* This is the actual cwnd. */
951 /* ssthresh : The current slow start threshold value. */
954 /* partial : The tracking method for increase of cwnd when in
955 * bytes acked : congestion avoidance mode (see Section 6.2.2)
957 __u32 partial_bytes_acked;
959 /* Data that has been sent, but not acknowledged. */
962 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
965 struct dst_entry *dst;
966 /* Source address. */
967 union sctp_addr saddr;
969 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
970 * the destination address every heartbeat interval.
972 unsigned long hbinterval;
974 /* SACK delay timeout */
975 unsigned long sackdelay;
978 /* When was the last time (in jiffies) that we heard from this
979 * transport? We use this to pick new active and retran paths.
981 unsigned long last_time_heard;
983 /* Last time(in jiffies) when cwnd is reduced due to the congestion
984 * indication based on ECNE chunk.
986 unsigned long last_time_ecne_reduced;
988 /* This is the max_retrans value for the transport and will
989 * be initialized from the assocs value. This can be changed
990 * using SCTP_SET_PEER_ADDR_PARAMS socket option.
994 /* PMTU : The current known path MTU. */
997 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1000 /* The number of times INIT has been sent on this transport. */
1001 int init_sent_count;
1003 /* state : The current state of this destination,
1004 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
1008 /* These are the error stats for this destination. */
1010 /* Error count : The current error count for this destination. */
1011 unsigned short error_count;
1013 /* Per : A timer used by each destination.
1017 * [Everywhere else in the text this is called T3-rtx. -ed]
1019 struct timer_list T3_rtx_timer;
1021 /* Heartbeat timer is per destination. */
1022 struct timer_list hb_timer;
1024 /* Timer to handle ICMP proto unreachable envets */
1025 struct timer_list proto_unreach_timer;
1027 /* Since we're using per-destination retransmission timers
1028 * (see above), we're also using per-destination "transmitted"
1029 * queues. This probably ought to be a private struct
1030 * accessible only within the outqueue, but it's not, yet.
1032 struct list_head transmitted;
1034 /* We build bundle-able packets for this transport here. */
1035 struct sctp_packet packet;
1037 /* This is the list of transports that have chunks to send. */
1038 struct list_head send_ready;
1040 /* State information saved for SFR_CACC algorithm. The key
1041 * idea in SFR_CACC is to maintain state at the sender on a
1042 * per-destination basis when a changeover happens.
1043 * char changeover_active;
1044 * char cycling_changeover;
1045 * __u32 next_tsn_at_change;
1046 * char cacc_saw_newack;
1049 /* An unsigned integer, which stores the next TSN to be
1050 * used by the sender, at the moment of changeover.
1052 __u32 next_tsn_at_change;
1054 /* A flag which indicates the occurrence of a changeover */
1055 char changeover_active;
1057 /* A flag which indicates whether the change of primary is
1058 * the first switch to this destination address during an
1061 char cycling_changeover;
1063 /* A temporary flag, which is used during the processing of
1064 * a SACK to estimate the causative TSN(s)'s group.
1066 char cacc_saw_newack;
1069 /* 64-bit random number sent with heartbeat. */
1073 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
1075 void sctp_transport_set_owner(struct sctp_transport *,
1076 struct sctp_association *);
1077 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1078 struct sctp_sock *);
1079 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1080 void sctp_transport_free(struct sctp_transport *);
1081 void sctp_transport_reset_timers(struct sctp_transport *);
1082 void sctp_transport_hold(struct sctp_transport *);
1083 void sctp_transport_put(struct sctp_transport *);
1084 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1085 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1086 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
1087 void sctp_transport_burst_limited(struct sctp_transport *);
1088 void sctp_transport_burst_reset(struct sctp_transport *);
1089 unsigned long sctp_transport_timeout(struct sctp_transport *);
1090 void sctp_transport_reset(struct sctp_transport *);
1091 void sctp_transport_update_pmtu(struct sctp_transport *, u32);
1092 void sctp_transport_immediate_rtx(struct sctp_transport *);
1095 /* This is the structure we use to queue packets as they come into
1096 * SCTP. We write packets to it and read chunks from it.
1099 /* This is actually a queue of sctp_chunk each
1100 * containing a partially decoded packet.
1102 struct list_head in_chunk_list;
1103 /* This is the packet which is currently off the in queue and is
1104 * being worked on through the inbound chunk processing.
1106 struct sctp_chunk *in_progress;
1108 /* This is the delayed task to finish delivering inbound
1111 struct work_struct immediate;
1113 int malloced; /* Is this structure kfree()able? */
1116 void sctp_inq_init(struct sctp_inq *);
1117 void sctp_inq_free(struct sctp_inq *);
1118 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1119 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1120 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1121 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1123 /* This is the structure we use to hold outbound chunks. You push
1124 * chunks in and they automatically pop out the other end as bundled
1125 * packets (it calls (*output_handler)()).
1127 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1128 * and 8.2 of the v13 draft.
1130 * It handles retransmissions. The connection to the timeout portion
1131 * of the state machine is through sctp_..._timeout() and timeout_handler.
1133 * If you feed it SACKs, it will eat them.
1135 * If you give it big chunks, it will fragment them.
1137 * It assigns TSN's to data chunks. This happens at the last possible
1138 * instant before transmission.
1140 * When free()'d, it empties itself out via output_handler().
1143 struct sctp_association *asoc;
1145 /* Data pending that has never been transmitted. */
1146 struct list_head out_chunk_list;
1148 unsigned out_qlen; /* Total length of queued data chunks. */
1150 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1153 /* These are control chunks we want to send. */
1154 struct list_head control_chunk_list;
1156 /* These are chunks that have been sacked but are above the
1157 * CTSN, or cumulative tsn ack point.
1159 struct list_head sacked;
1161 /* Put chunks on this list to schedule them for
1164 struct list_head retransmit;
1166 /* Put chunks on this list to save them for FWD TSN processing as
1167 * they were abandoned.
1169 struct list_head abandoned;
1171 /* How many unackd bytes do we have in-flight? */
1172 __u32 outstanding_bytes;
1174 /* Are we doing fast-rtx on this queue */
1180 /* Is this structure empty? */
1183 /* Are we kfree()able? */
1187 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1188 void sctp_outq_teardown(struct sctp_outq *);
1189 void sctp_outq_free(struct sctp_outq*);
1190 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1191 int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *);
1192 int sctp_outq_is_empty(const struct sctp_outq *);
1193 void sctp_outq_restart(struct sctp_outq *);
1195 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1196 sctp_retransmit_reason_t);
1197 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1198 int sctp_outq_uncork(struct sctp_outq *);
1199 /* Uncork and flush an outqueue. */
1200 static inline void sctp_outq_cork(struct sctp_outq *q)
1205 /* These bind address data fields common between endpoints and associations */
1206 struct sctp_bind_addr {
1208 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1210 * SCTP Port: The local SCTP port number the endpoint is
1215 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1217 * Address List: The list of IP addresses that this instance
1218 * has bound. This information is passed to one's
1219 * peer(s) in INIT and INIT ACK chunks.
1221 struct list_head address_list;
1223 int malloced; /* Are we kfree()able? */
1226 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1227 void sctp_bind_addr_free(struct sctp_bind_addr *);
1228 int sctp_bind_addr_copy(struct sctp_bind_addr *dest,
1229 const struct sctp_bind_addr *src,
1230 sctp_scope_t scope, gfp_t gfp,
1232 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1233 const struct sctp_bind_addr *src,
1235 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1236 __u8 addr_state, gfp_t gfp);
1237 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1238 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1239 struct sctp_sock *);
1240 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1241 struct sctp_sock *, struct sctp_sock *);
1242 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1243 const union sctp_addr *addr);
1244 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1245 const union sctp_addr *addrs,
1247 struct sctp_sock *opt);
1248 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1251 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1252 __u16 port, gfp_t gfp);
1254 sctp_scope_t sctp_scope(const union sctp_addr *);
1255 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
1256 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1257 int sctp_addr_is_valid(const union sctp_addr *addr);
1258 int sctp_is_ep_boundall(struct sock *sk);
1261 /* What type of endpoint? */
1263 SCTP_EP_TYPE_SOCKET,
1264 SCTP_EP_TYPE_ASSOCIATION,
1265 } sctp_endpoint_type_t;
1268 * A common base class to bridge the implmentation view of a
1269 * socket (usually listening) endpoint versus an association's
1271 * This common structure is useful for several purposes:
1272 * 1) Common interface for lookup routines.
1273 * a) Subfunctions work for either endpoint or association
1274 * b) Single interface to lookup allows hiding the lookup lock rather
1275 * than acquiring it externally.
1276 * 2) Common interface for the inbound chunk handling/state machine.
1277 * 3) Common object handling routines for reference counting, etc.
1278 * 4) Disentangle association lookup from endpoint lookup, where we
1279 * do not have to find our endpoint to find our association.
1283 struct sctp_ep_common {
1284 /* Fields to help us manage our entries in the hash tables. */
1285 struct hlist_node node;
1288 /* Runtime type information. What kind of endpoint is this? */
1289 sctp_endpoint_type_t type;
1291 /* Some fields to help us manage this object.
1292 * refcnt - Reference count access to this object.
1293 * dead - Do not attempt to use this object.
1294 * malloced - Do we need to kfree this object?
1300 /* What socket does this endpoint belong to? */
1303 /* This is where we receive inbound chunks. */
1304 struct sctp_inq inqueue;
1306 /* This substructure includes the defining parameters of the
1308 * bind_addr.port is our shared port number.
1309 * bind_addr.address_list is our set of local IP addresses.
1311 struct sctp_bind_addr bind_addr;
1315 /* RFC Section 1.4 Key Terms
1317 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1318 * multi-homed host, an SCTP endpoint is represented to its peers as a
1319 * combination of a set of eligible destination transport addresses to
1320 * which SCTP packets can be sent and a set of eligible source
1321 * transport addresses from which SCTP packets can be received.
1322 * All transport addresses used by an SCTP endpoint must use the
1323 * same port number, but can use multiple IP addresses. A transport
1324 * address used by an SCTP endpoint must not be used by another
1325 * SCTP endpoint. In other words, a transport address is unique
1326 * to an SCTP endpoint.
1328 * From an implementation perspective, each socket has one of these.
1329 * A TCP-style socket will have exactly one association on one of
1330 * these. An UDP-style socket will have multiple associations hanging
1334 struct sctp_endpoint {
1335 /* Common substructure for endpoint and association. */
1336 struct sctp_ep_common base;
1338 /* Associations: A list of current associations and mappings
1339 * to the data consumers for each association. This
1340 * may be in the form of a hash table or other
1341 * implementation dependent structure. The data
1342 * consumers may be process identification
1343 * information such as file descriptors, named pipe
1344 * pointer, or table pointers dependent on how SCTP
1347 /* This is really a list of struct sctp_association entries. */
1348 struct list_head asocs;
1350 /* Secret Key: A secret key used by this endpoint to compute
1351 * the MAC. This SHOULD be a cryptographic quality
1352 * random number with a sufficient length.
1353 * Discussion in [RFC1750] can be helpful in
1354 * selection of the key.
1356 __u8 secret_key[SCTP_HOW_MANY_SECRETS][SCTP_SECRET_SIZE];
1361 /* digest: This is a digest of the sctp cookie. This field is
1362 * only used on the receive path when we try to validate
1363 * that the cookie has not been tampered with. We put
1364 * this here so we pre-allocate this once and can re-use
1369 /* sendbuf acct. policy. */
1370 __u32 sndbuf_policy;
1372 /* rcvbuf acct. policy. */
1373 __u32 rcvbuf_policy;
1375 /* SCTP AUTH: array of the HMACs that will be allocated
1376 * we need this per association so that we don't serialize
1378 struct crypto_hash **auth_hmacs;
1380 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1381 struct sctp_hmac_algo_param *auth_hmacs_list;
1383 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1384 struct sctp_chunks_param *auth_chunk_list;
1386 /* SCTP-AUTH: endpoint shared keys */
1387 struct list_head endpoint_shared_keys;
1388 __u16 active_key_id;
1391 /* Recover the outter endpoint structure. */
1392 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1394 struct sctp_endpoint *ep;
1396 ep = container_of(base, struct sctp_endpoint, base);
1400 /* These are function signatures for manipulating endpoints. */
1401 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1402 void sctp_endpoint_free(struct sctp_endpoint *);
1403 void sctp_endpoint_put(struct sctp_endpoint *);
1404 void sctp_endpoint_hold(struct sctp_endpoint *);
1405 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1406 struct sctp_association *sctp_endpoint_lookup_assoc(
1407 const struct sctp_endpoint *ep,
1408 const union sctp_addr *paddr,
1409 struct sctp_transport **);
1410 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1411 const union sctp_addr *);
1412 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1413 const union sctp_addr *);
1414 int sctp_has_association(const union sctp_addr *laddr,
1415 const union sctp_addr *paddr);
1417 int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t,
1418 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
1419 struct sctp_chunk **err_chunk);
1420 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1421 const union sctp_addr *peer,
1422 sctp_init_chunk_t *init, gfp_t gfp);
1423 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1424 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1426 struct sctp_inithdr_host {
1429 __u16 num_outbound_streams;
1430 __u16 num_inbound_streams;
1436 * 12. Recommended Transmission Control Block (TCB) Parameters
1438 * This section details a recommended set of parameters that should
1439 * be contained within the TCB for an implementation. This section is
1440 * for illustrative purposes and should not be deemed as requirements
1441 * on an implementation or as an exhaustive list of all parameters
1442 * inside an SCTP TCB. Each implementation may need its own additional
1443 * parameters for optimization.
1447 /* Here we have information about each individual association. */
1448 struct sctp_association {
1450 /* A base structure common to endpoint and association.
1451 * In this context, it represents the associations's view
1452 * of the local endpoint of the association.
1454 struct sctp_ep_common base;
1456 /* Associations on the same socket. */
1457 struct list_head asocs;
1459 /* association id. */
1460 sctp_assoc_t assoc_id;
1462 /* This is our parent endpoint. */
1463 struct sctp_endpoint *ep;
1465 /* These are those association elements needed in the cookie. */
1466 struct sctp_cookie c;
1468 /* This is all information about our peer. */
1472 * Peer Rwnd : Current calculated value of the peer's rwnd.
1476 /* transport_addr_list
1478 * Peer : A list of SCTP transport addresses that the
1479 * Transport : peer is bound to. This information is derived
1480 * Address : from the INIT or INIT ACK and is used to
1481 * List : associate an inbound packet with a given
1482 * : association. Normally this information is
1483 * : hashed or keyed for quick lookup and access
1485 * : The list is also initialized with the list
1486 * : of addresses passed with the sctp_connectx()
1489 * It is a list of SCTP_transport's.
1491 struct list_head transport_addr_list;
1495 * Peer : A count of the number of peer addresses
1496 * Transport : in the Peer Transport Address List.
1500 __u16 transport_count;
1503 * The transport layer port number.
1509 * Primary : This is the current primary destination
1510 * Path : transport address of the peer endpoint. It
1511 * : may also specify a source transport address
1512 * : on this endpoint.
1514 * All of these paths live on transport_addr_list.
1516 * At the bakeoffs, we discovered that the intent of
1517 * primaryPath is that it only changes when the ULP
1518 * asks to have it changed. We add the activePath to
1519 * designate the connection we are currently using to
1520 * transmit new data and most control chunks.
1522 struct sctp_transport *primary_path;
1524 /* Cache the primary path address here, when we
1525 * need a an address for msg_name.
1527 union sctp_addr primary_addr;
1530 * The path that we are currently using to
1531 * transmit new data and most control chunks.
1533 struct sctp_transport *active_path;
1537 * RFC2960 6.4 Multi-homed SCTP Endpoints
1539 * Furthermore, when its peer is multi-homed, an
1540 * endpoint SHOULD try to retransmit a chunk to an
1541 * active destination transport address that is
1542 * different from the last destination address to
1543 * which the DATA chunk was sent.
1545 struct sctp_transport *retran_path;
1547 /* Pointer to last transport I have sent on. */
1548 struct sctp_transport *last_sent_to;
1550 /* This is the last transport I have received DATA on. */
1551 struct sctp_transport *last_data_from;
1554 * Mapping An array of bits or bytes indicating which out of
1555 * Array order TSN's have been received (relative to the
1556 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1557 * order packets have been received, this array
1558 * will be set to all zero. This structure may be
1559 * in the form of a circular buffer or bit array.
1561 * Last Rcvd : This is the last TSN received in
1562 * TSN : sequence. This value is set initially by
1563 * : taking the peer's Initial TSN, received in
1564 * : the INIT or INIT ACK chunk, and subtracting
1567 * Throughout most of the specification this is called the
1568 * "Cumulative TSN ACK Point". In this case, we
1569 * ignore the advice in 12.2 in favour of the term
1570 * used in the bulk of the text. This value is hidden
1571 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1573 struct sctp_tsnmap tsn_map;
1575 /* Ack State : This flag indicates if the next received
1576 * : packet is to be responded to with a
1577 * : SACK. This is initializedto 0. When a packet
1578 * : is received it is incremented. If this value
1579 * : reaches 2 or more, a SACK is sent and the
1580 * : value is reset to 0. Note: This is used only
1581 * : when no DATA chunks are received out of
1582 * : order. When DATA chunks are out of order,
1583 * : SACK's are not delayed (see Section 6).
1585 __u8 sack_needed; /* Do we need to sack the peer? */
1588 /* These are capabilities which our peer advertised. */
1589 __u8 ecn_capable:1, /* Can peer do ECN? */
1590 ipv4_address:1, /* Peer understands IPv4 addresses? */
1591 ipv6_address:1, /* Peer understands IPv6 addresses? */
1592 hostname_address:1, /* Peer understands DNS addresses? */
1593 asconf_capable:1, /* Does peer support ADDIP? */
1594 prsctp_capable:1, /* Can peer do PR-SCTP? */
1595 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1597 __u32 adaptation_ind; /* Adaptation Code point. */
1599 /* This mask is used to disable sending the ASCONF chunk
1600 * with specified parameter to peer.
1602 __be16 addip_disabled_mask;
1604 struct sctp_inithdr_host i;
1608 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1609 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1610 * Initial TSN Value minus 1
1614 /* SCTP-AUTH: We need to know pears random number, hmac list
1615 * and authenticated chunk list. All that is part of the
1616 * cookie and these are just pointers to those locations
1618 sctp_random_param_t *peer_random;
1619 sctp_chunks_param_t *peer_chunks;
1620 sctp_hmac_algo_param_t *peer_hmacs;
1623 /* State : A state variable indicating what state the
1624 * : association is in, i.e. COOKIE-WAIT,
1625 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1626 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1628 * Note: No "CLOSED" state is illustrated since if a
1629 * association is "CLOSED" its TCB SHOULD be removed.
1631 * In this implementation we DO have a CLOSED
1632 * state which is used during initiation and shutdown.
1634 * State takes values from SCTP_STATE_*.
1638 /* The cookie life I award for any cookie. */
1639 struct timeval cookie_life;
1641 /* Overall : The overall association error count.
1642 * Error Count : [Clear this any time I get something.]
1644 int overall_error_count;
1646 /* These are the association's initial, max, and min RTO values.
1647 * These values will be initialized by system defaults, but can
1648 * be modified via the SCTP_RTOINFO socket option.
1650 unsigned long rto_initial;
1651 unsigned long rto_max;
1652 unsigned long rto_min;
1654 /* Maximum number of new data packets that can be sent in a burst. */
1657 /* This is the max_retrans value for the association. This value will
1658 * be initialized initialized from system defaults, but can be
1659 * modified by the SCTP_ASSOCINFO socket option.
1663 /* Maximum number of times the endpoint will retransmit INIT */
1664 __u16 max_init_attempts;
1666 /* How many times have we resent an INIT? */
1669 /* The largest timeout or RTO value to use in attempting an INIT */
1670 unsigned long max_init_timeo;
1672 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1673 * the destination address every heartbeat interval. This value
1674 * will be inherited by all new transports.
1676 unsigned long hbinterval;
1678 /* This is the max_retrans value for new transports in the
1683 /* Flag that path mtu update is pending */
1686 /* Association : The smallest PMTU discovered for all of the
1687 * PMTU : peer's transport addresses.
1691 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1694 /* SACK delay timeout */
1695 unsigned long sackdelay;
1699 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1700 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1702 /* Transport to which SHUTDOWN chunk was last sent. */
1703 struct sctp_transport *shutdown_last_sent_to;
1705 /* How many times have we resent a SHUTDOWN */
1706 int shutdown_retries;
1708 /* Transport to which INIT chunk was last sent. */
1709 struct sctp_transport *init_last_sent_to;
1711 /* Next TSN : The next TSN number to be assigned to a new
1712 * : DATA chunk. This is sent in the INIT or INIT
1713 * : ACK chunk to the peer and incremented each
1714 * : time a DATA chunk is assigned a TSN
1715 * : (normally just prior to transmit or during
1721 * Last Rcvd : This is the last TSN received in sequence. This value
1722 * TSN : is set initially by taking the peer's Initial TSN,
1723 * : received in the INIT or INIT ACK chunk, and
1724 * : subtracting one from it.
1726 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1729 __u32 ctsn_ack_point;
1731 /* PR-SCTP Advanced.Peer.Ack.Point */
1732 __u32 adv_peer_ack_point;
1734 /* Highest TSN that is acknowledged by incoming SACKs. */
1735 __u32 highest_sacked;
1737 /* TSN marking the fast recovery exit point */
1738 __u32 fast_recovery_exit;
1740 /* Flag to track the current fast recovery state */
1743 /* The number of unacknowledged data chunks. Reported through
1744 * the SCTP_STATUS sockopt.
1748 /* The total number of data chunks that we've had to retransmit
1749 * as the result of a T3 timer expiration
1751 __u32 rtx_data_chunks;
1753 /* This is the association's receive buffer space. This value is used
1754 * to set a_rwnd field in an INIT or a SACK chunk.
1758 /* This is the last advertised value of rwnd over a SACK chunk. */
1761 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1762 * to slop over a maximum of the association's frag_point.
1766 /* Keeps treack of rwnd pressure. This happens when we have
1767 * a window, but not recevie buffer (i.e small packets). This one
1768 * is releases slowly (1 PMTU at a time ).
1772 /* This is the sndbuf size in use for the association.
1773 * This corresponds to the sndbuf size for the association,
1774 * as specified in the sk->sndbuf.
1778 /* This is the amount of memory that this association has allocated
1779 * in the receive path at any given time.
1781 atomic_t rmem_alloc;
1783 /* This is the wait queue head for send requests waiting on
1784 * the association sndbuf space.
1786 wait_queue_head_t wait;
1788 /* The message size at which SCTP fragmentation will occur. */
1792 /* Counter used to count INIT errors. */
1793 int init_err_counter;
1795 /* Count the number of INIT cycles (for doubling timeout). */
1798 /* Default send parameters. */
1799 __u16 default_stream;
1800 __u16 default_flags;
1802 __u32 default_context;
1803 __u32 default_timetolive;
1805 /* Default receive parameters */
1806 __u32 default_rcv_context;
1808 /* This tracks outbound ssn for a given stream. */
1809 struct sctp_ssnmap *ssnmap;
1811 /* All outbound chunks go through this structure. */
1812 struct sctp_outq outqueue;
1814 /* A smart pipe that will handle reordering and fragmentation,
1815 * as well as handle passing events up to the ULP.
1817 struct sctp_ulpq ulpq;
1819 /* Last TSN that caused an ECNE Chunk to be sent. */
1820 __u32 last_ecne_tsn;
1822 /* Last TSN that caused a CWR Chunk to be sent. */
1825 /* How many duplicated TSNs have we seen? */
1828 /* Number of seconds of idle time before an association is closed.
1829 * In the association context, this is really used as a boolean
1830 * since the real timeout is stored in the timeouts array
1834 /* These are to support
1835 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1836 * and Enforcement of Flow and Message Limits"
1837 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1838 * or "ADDIP" for short.
1843 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1845 * R1) One and only one ASCONF Chunk MAY be in transit and
1846 * unacknowledged at any one time. If a sender, after sending
1847 * an ASCONF chunk, decides it needs to transfer another
1848 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1849 * returns from the previous ASCONF Chunk before sending a
1850 * subsequent ASCONF. Note this restriction binds each side,
1851 * so at any time two ASCONF may be in-transit on any given
1852 * association (one sent from each endpoint).
1854 * [This is our one-and-only-one ASCONF in flight. If we do
1855 * not have an ASCONF in flight, this is NULL.]
1857 struct sctp_chunk *addip_last_asconf;
1859 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1861 * This is needed to implement itmes E1 - E4 of the updated
1862 * spec. Here is the justification:
1864 * Since the peer may bundle multiple ASCONF chunks toward us,
1865 * we now need the ability to cache multiple ACKs. The section
1866 * describes in detail how they are cached and cleaned up.
1868 struct list_head asconf_ack_list;
1870 /* These ASCONF chunks are waiting to be sent.
1872 * These chunaks can't be pushed to outqueue until receiving
1873 * ASCONF_ACK for the previous ASCONF indicated by
1874 * addip_last_asconf, so as to guarantee that only one ASCONF
1875 * is in flight at any time.
1877 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1879 * In defining the ASCONF Chunk transfer procedures, it is
1880 * essential that these transfers MUST NOT cause congestion
1881 * within the network. To achieve this, we place these
1882 * restrictions on the transfer of ASCONF Chunks:
1884 * R1) One and only one ASCONF Chunk MAY be in transit and
1885 * unacknowledged at any one time. If a sender, after sending
1886 * an ASCONF chunk, decides it needs to transfer another
1887 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1888 * returns from the previous ASCONF Chunk before sending a
1889 * subsequent ASCONF. Note this restriction binds each side,
1890 * so at any time two ASCONF may be in-transit on any given
1891 * association (one sent from each endpoint).
1894 * [I really think this is EXACTLY the sort of intelligence
1895 * which already resides in sctp_outq. Please move this
1896 * queue and its supporting logic down there. --piggy]
1898 struct list_head addip_chunk_list;
1900 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1902 * A2) A serial number should be assigned to the Chunk. The
1903 * serial number SHOULD be a monotonically increasing
1904 * number. The serial number SHOULD be initialized at
1905 * the start of the association to the same value as the
1906 * Initial TSN and every time a new ASCONF chunk is created
1907 * it is incremented by one after assigning the serial number
1908 * to the newly created chunk.
1911 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1913 * Serial Number : 32 bits (unsigned integer)
1915 * This value represents a Serial Number for the ASCONF
1916 * Chunk. The valid range of Serial Number is from 0 to
1917 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1918 * after reaching 4294967295.
1921 union sctp_addr *asconf_addr_del_pending;
1922 int src_out_of_asoc_ok;
1923 struct sctp_transport *new_transport;
1925 /* SCTP AUTH: list of the endpoint shared keys. These
1926 * keys are provided out of band by the user applicaton
1927 * and can't change during the lifetime of the association
1929 struct list_head endpoint_shared_keys;
1932 * The current generated assocaition shared key (secret)
1934 struct sctp_auth_bytes *asoc_shared_key;
1936 /* SCTP AUTH: hmac id of the first peer requested algorithm
1939 __u16 default_hmac_id;
1941 __u16 active_key_id;
1943 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1944 temp:1; /* Is it a temporary association? */
1948 /* An eyecatcher for determining if we are really looking at an
1949 * association data structure.
1952 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1955 /* Recover the outter association structure. */
1956 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1958 struct sctp_association *asoc;
1960 asoc = container_of(base, struct sctp_association, base);
1964 /* These are function signatures for manipulating associations. */
1967 struct sctp_association *
1968 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1969 sctp_scope_t scope, gfp_t gfp);
1970 void sctp_association_free(struct sctp_association *);
1971 void sctp_association_put(struct sctp_association *);
1972 void sctp_association_hold(struct sctp_association *);
1974 struct sctp_transport *sctp_assoc_choose_alter_transport(
1975 struct sctp_association *, struct sctp_transport *);
1976 void sctp_assoc_update_retran_path(struct sctp_association *);
1977 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1978 const union sctp_addr *);
1979 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1980 const union sctp_addr *laddr);
1981 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1982 const union sctp_addr *address,
1984 const int peer_state);
1985 void sctp_assoc_del_peer(struct sctp_association *asoc,
1986 const union sctp_addr *addr);
1987 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1988 struct sctp_transport *peer);
1989 void sctp_assoc_control_transport(struct sctp_association *,
1990 struct sctp_transport *,
1991 sctp_transport_cmd_t, sctp_sn_error_t);
1992 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1993 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1994 const union sctp_addr *,
1995 const union sctp_addr *);
1996 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1997 void sctp_assoc_update(struct sctp_association *old,
1998 struct sctp_association *new);
2000 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2002 void sctp_assoc_sync_pmtu(struct sctp_association *);
2003 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned);
2004 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned);
2005 void sctp_assoc_set_primary(struct sctp_association *,
2006 struct sctp_transport *);
2007 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2008 struct sctp_transport *);
2009 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
2010 sctp_scope_t, gfp_t);
2011 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2012 struct sctp_cookie*,
2014 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2015 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2016 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2017 const struct sctp_association *asoc,
2019 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2021 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2022 const union sctp_addr *ss2);
2023 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2025 /* A convenience structure to parse out SCTP specific CMSGs. */
2026 typedef struct sctp_cmsgs {
2027 struct sctp_initmsg *init;
2028 struct sctp_sndrcvinfo *info;
2031 /* Structure for tracking memory objects */
2035 } sctp_dbg_objcnt_entry_t;
2037 #endif /* __sctp_structs_h__ */