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 <linux-sctp@vger.kernel.org>
30 * Written or modified by:
31 * Randall Stewart <randall@sctp.chicago.il.us>
32 * Ken Morneau <kmorneau@cisco.com>
33 * Qiaobing Xie <qxie1@email.mot.com>
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Jon Grimm <jgrimm@us.ibm.com>
37 * Xingang Guo <xingang.guo@intel.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Dajiang Zhang <dajiang.zhang@nokia.com>
42 * Ardelle Fan <ardelle.fan@intel.com>
43 * Ryan Layer <rmlayer@us.ibm.com>
44 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
45 * Kevin Gao <kevin.gao@intel.com>
48 #ifndef __sctp_structs_h__
49 #define __sctp_structs_h__
51 #include <linux/ktime.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/sctp.h> /* We need sctp* header structs. */
61 #include <net/sctp/auth.h> /* We need auth specific structs */
63 /* A convenience structure for handling sockaddr structures.
64 * We should wean ourselves off this.
67 struct sockaddr_in v4;
68 struct sockaddr_in6 v6;
72 /* Forward declarations for data structures. */
75 struct sctp_association;
76 struct sctp_transport;
81 struct sctp_bind_addr;
83 struct sctp_ep_common;
88 #include <net/sctp/tsnmap.h>
89 #include <net/sctp/ulpevent.h>
90 #include <net/sctp/ulpqueue.h>
92 /* Structures useful for managing bind/connect. */
94 struct sctp_bind_bucket {
96 unsigned short fastreuse;
97 struct hlist_node node;
98 struct hlist_head owner;
102 struct sctp_bind_hashbucket {
104 struct hlist_head chain;
107 /* Used for hashing all associations. */
108 struct sctp_hashbucket {
110 struct hlist_head chain;
111 } __attribute__((__aligned__(8)));
114 /* The SCTP globals structure. */
115 extern struct sctp_globals {
116 /* This is a list of groups of functions for each address
117 * family that we support.
119 struct list_head address_families;
121 /* This is the hash of all endpoints. */
122 struct sctp_hashbucket *ep_hashtable;
123 /* This is the hash of all associations. */
124 struct sctp_hashbucket *assoc_hashtable;
125 /* This is the sctp port control hash. */
126 struct sctp_bind_hashbucket *port_hashtable;
128 /* Sizes of above hashtables. */
133 /* Default initialization values to be applied to new associations. */
135 __u16 max_outstreams;
137 /* Flag to indicate whether computing and verifying checksum
139 bool checksum_disable;
142 #define sctp_max_instreams (sctp_globals.max_instreams)
143 #define sctp_max_outstreams (sctp_globals.max_outstreams)
144 #define sctp_address_families (sctp_globals.address_families)
145 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
146 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
147 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
148 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
149 #define sctp_port_hashsize (sctp_globals.port_hashsize)
150 #define sctp_port_hashtable (sctp_globals.port_hashtable)
151 #define sctp_checksum_disable (sctp_globals.checksum_disable)
153 /* SCTP Socket type: UDP or TCP style. */
156 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
158 } sctp_socket_type_t;
160 /* Per socket SCTP information. */
162 /* inet_sock has to be the first member of sctp_sock */
163 struct inet_sock inet;
164 /* What kind of a socket is this? */
165 sctp_socket_type_t type;
167 /* PF_ family specific functions. */
170 /* Access to HMAC transform. */
171 struct crypto_hash *hmac;
174 /* What is our base endpointer? */
175 struct sctp_endpoint *ep;
177 struct sctp_bind_bucket *bind_hash;
178 /* Various Socket Options. */
179 __u16 default_stream;
182 __u32 default_context;
183 __u32 default_timetolive;
184 __u32 default_rcv_context;
187 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
188 * the destination address every heartbeat interval. This value
189 * will be inherited by all new associations.
193 /* This is the max_retrans value for new associations. */
196 /* The initial Path MTU to use for new associations. */
199 /* The default SACK delay timeout for new associations. */
203 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
206 struct sctp_initmsg initmsg;
207 struct sctp_rtoinfo rtoinfo;
208 struct sctp_paddrparams paddrparam;
209 struct sctp_event_subscribe subscribe;
210 struct sctp_assocparams assocparams;
214 __u8 disable_fragments;
216 __u8 frag_interleave;
217 __u32 adaptation_ind;
221 /* Receive to here while partial delivery is in effect. */
222 struct sk_buff_head pd_lobby;
223 struct list_head auto_asconf_list;
227 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
229 return (struct sctp_sock *)sk;
232 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
234 return (struct sock *)sp;
237 #if IS_ENABLED(CONFIG_IPV6)
239 struct sctp_sock sctp;
240 struct ipv6_pinfo inet6;
242 #endif /* CONFIG_IPV6 */
245 /* This is our APPLICATION-SPECIFIC state cookie.
246 * THIS IS NOT DICTATED BY THE SPECIFICATION.
248 /* These are the parts of an association which we send in the cookie.
249 * Most of these are straight out of:
250 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
256 /* My : Tag expected in every inbound packet and sent
257 * Verification: in the INIT or INIT ACK chunk.
262 /* Peer's : Tag expected in every outbound packet except
263 * Verification: in the INIT chunk.
268 /* The rest of these are not from the spec, but really need to
272 /* My Tie Tag : Assist in discovering a restarting association. */
275 /* Peer's Tie Tag: Assist in discovering a restarting association. */
278 /* When does this cookie expire? */
281 /* Number of inbound/outbound streams which are set
282 * and negotiated during the INIT process.
284 __u16 sinit_num_ostreams;
285 __u16 sinit_max_instreams;
287 /* This is the first sequence number I used. */
290 /* This holds the originating address of the INIT packet. */
291 union sctp_addr peer_addr;
294 * Include the source port of the INIT-ACK
300 /* Padding for future use */
303 __u32 adaptation_ind;
305 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
306 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
307 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
309 /* This is a shim for my peer's INIT packet, followed by
310 * a copy of the raw address list of the association.
311 * The length of the raw address list is saved in the
312 * raw_addr_list_len field, which will be used at the time when
313 * the association TCB is re-constructed from the cookie.
315 __u32 raw_addr_list_len;
316 struct sctp_init_chunk peer_init[0];
320 /* The format of our cookie that we send to our peer. */
321 struct sctp_signed_cookie {
322 __u8 signature[SCTP_SECRET_SIZE];
323 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
324 struct sctp_cookie c;
327 /* This is another convenience type to allocate memory for address
328 * params for the maximum size and pass such structures around
331 union sctp_addr_param {
332 struct sctp_paramhdr p;
333 struct sctp_ipv4addr_param v4;
334 struct sctp_ipv6addr_param v6;
337 /* A convenience type to allow walking through the various
338 * parameters and avoid casting all over the place.
342 struct sctp_paramhdr *p;
343 struct sctp_cookie_preserve_param *life;
344 struct sctp_hostname_param *dns;
345 struct sctp_cookie_param *cookie;
346 struct sctp_supported_addrs_param *sat;
347 struct sctp_ipv4addr_param *v4;
348 struct sctp_ipv6addr_param *v6;
349 union sctp_addr_param *addr;
350 struct sctp_adaptation_ind_param *aind;
351 struct sctp_supported_ext_param *ext;
352 struct sctp_random_param *random;
353 struct sctp_chunks_param *chunks;
354 struct sctp_hmac_algo_param *hmac_algo;
355 struct sctp_addip_param *addip;
358 /* RFC 2960. Section 3.3.5 Heartbeat.
359 * Heartbeat Information: variable length
360 * The Sender-specific Heartbeat Info field should normally include
361 * information about the sender's current time when this HEARTBEAT
362 * chunk is sent and the destination transport address to which this
363 * HEARTBEAT is sent (see Section 8.3).
365 typedef struct sctp_sender_hb_info {
366 struct sctp_paramhdr param_hdr;
367 union sctp_addr daddr;
368 unsigned long sent_at;
370 } __packed sctp_sender_hb_info_t;
373 * RFC 2960 1.3.2 Sequenced Delivery within Streams
375 * The term "stream" is used in SCTP to refer to a sequence of user
376 * messages that are to be delivered to the upper-layer protocol in
377 * order with respect to other messages within the same stream. This is
378 * in contrast to its usage in TCP, where it refers to a sequence of
379 * bytes (in this document a byte is assumed to be eight bits).
382 * This is the structure we use to track both our outbound and inbound
383 * SSN, or Stream Sequence Numbers.
392 struct sctp_stream in;
393 struct sctp_stream out;
396 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
398 void sctp_ssnmap_free(struct sctp_ssnmap *map);
399 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
401 /* What is the current SSN number for this stream? */
402 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
404 return stream->ssn[id];
407 /* Return the next SSN number for this stream. */
408 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
410 return stream->ssn[id]++;
413 /* Skip over this ssn and all below. */
414 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
417 stream->ssn[id] = ssn+1;
421 * Pointers to address related SCTP functions.
422 * (i.e. things that depend on the address family.)
425 int (*sctp_xmit) (struct sk_buff *skb,
426 struct sctp_transport *);
427 int (*setsockopt) (struct sock *sk,
431 unsigned int optlen);
432 int (*getsockopt) (struct sock *sk,
437 int (*compat_setsockopt) (struct sock *sk,
441 unsigned int optlen);
442 int (*compat_getsockopt) (struct sock *sk,
447 void (*get_dst) (struct sctp_transport *t,
448 union sctp_addr *saddr,
451 void (*get_saddr) (struct sctp_sock *sk,
452 struct sctp_transport *t,
454 void (*copy_addrlist) (struct list_head *,
455 struct net_device *);
456 int (*cmp_addr) (const union sctp_addr *addr1,
457 const union sctp_addr *addr2);
458 void (*addr_copy) (union sctp_addr *dst,
459 union sctp_addr *src);
460 void (*from_skb) (union sctp_addr *,
463 void (*from_sk) (union sctp_addr *,
465 void (*to_sk_saddr) (union sctp_addr *,
467 void (*to_sk_daddr) (union sctp_addr *,
469 void (*from_addr_param) (union sctp_addr *,
470 union sctp_addr_param *,
471 __be16 port, int iif);
472 int (*to_addr_param) (const union sctp_addr *,
473 union sctp_addr_param *);
474 int (*addr_valid) (union sctp_addr *,
476 const struct sk_buff *);
477 sctp_scope_t (*scope) (union sctp_addr *);
478 void (*inaddr_any) (union sctp_addr *, __be16);
479 int (*is_any) (const union sctp_addr *);
480 int (*available) (union sctp_addr *,
482 int (*skb_iif) (const struct sk_buff *sk);
483 int (*is_ce) (const struct sk_buff *sk);
484 void (*seq_dump_addr)(struct seq_file *seq,
485 union sctp_addr *addr);
486 void (*ecn_capable)(struct sock *sk);
487 __u16 net_header_len;
489 sa_family_t sa_family;
490 struct list_head list;
493 struct sctp_af *sctp_get_af_specific(sa_family_t);
494 int sctp_register_af(struct sctp_af *);
496 /* Protocol family functions. */
498 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
499 void (*skb_msgname) (struct sk_buff *, char *, int *);
500 int (*af_supported) (sa_family_t, struct sctp_sock *);
501 int (*cmp_addr) (const union sctp_addr *,
502 const union sctp_addr *,
504 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
505 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
506 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
507 struct sock *(*create_accept_sk) (struct sock *sk,
508 struct sctp_association *asoc);
509 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
514 /* Structure to track chunk fragments that have been acked, but peer
515 * fragments of the same message have not.
517 struct sctp_datamsg {
518 /* Chunks waiting to be submitted to lower layer. */
519 struct list_head chunks;
520 /* Reference counting. */
522 /* When is this message no longer interesting to the peer? */
523 unsigned long expires_at;
524 /* Did the messenge fail to send? */
527 can_abandon:1, /* can chunks from this message can be abandoned. */
528 can_delay; /* should this message be Nagle delayed */
531 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
532 struct sctp_sndrcvinfo *,
533 struct msghdr *, int len);
534 void sctp_datamsg_free(struct sctp_datamsg *);
535 void sctp_datamsg_put(struct sctp_datamsg *);
536 void sctp_chunk_fail(struct sctp_chunk *, int error);
537 int sctp_chunk_abandoned(struct sctp_chunk *);
539 /* RFC2960 1.4 Key Terms
541 * o Chunk: A unit of information within an SCTP packet, consisting of
542 * a chunk header and chunk-specific content.
544 * As a matter of convenience, we remember the SCTP common header for
545 * each chunk as well as a few other header pointers...
548 struct list_head list;
552 /* This is our link to the per-transport transmitted list. */
553 struct list_head transmitted_list;
555 /* This field is used by chunks that hold fragmented data.
556 * For the first fragment this is the list that holds the rest of
557 * fragments. For the remaining fragments, this is the link to the
558 * frag_list maintained in the first fragment.
560 struct list_head frag_list;
562 /* This points to the sk_buff containing the actual data. */
565 /* These are the SCTP headers by reverse order in a packet.
566 * Note that some of these may happen more than once. In that
567 * case, we point at the "current" one, whatever that means
568 * for that level of header.
571 /* We point this at the FIRST TLV parameter to chunk_hdr. */
572 union sctp_params param_hdr;
575 struct sctp_datahdr *data_hdr;
576 struct sctp_inithdr *init_hdr;
577 struct sctp_sackhdr *sack_hdr;
578 struct sctp_heartbeathdr *hb_hdr;
579 struct sctp_sender_hb_info *hbs_hdr;
580 struct sctp_shutdownhdr *shutdown_hdr;
581 struct sctp_signed_cookie *cookie_hdr;
582 struct sctp_ecnehdr *ecne_hdr;
583 struct sctp_cwrhdr *ecn_cwr_hdr;
584 struct sctp_errhdr *err_hdr;
585 struct sctp_addiphdr *addip_hdr;
586 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
587 struct sctp_authhdr *auth_hdr;
592 struct sctp_chunkhdr *chunk_hdr;
593 struct sctphdr *sctp_hdr;
595 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
596 struct sctp_sndrcvinfo sinfo;
598 /* Which association does this belong to? */
599 struct sctp_association *asoc;
601 /* What endpoint received this chunk? */
602 struct sctp_ep_common *rcvr;
604 /* We fill this in if we are calculating RTT. */
605 unsigned long sent_at;
607 /* What is the origin IP address for this chunk? */
608 union sctp_addr source;
609 /* Destination address for this chunk. */
610 union sctp_addr dest;
612 /* For outbound message, track all fragments for SEND_FAILED. */
613 struct sctp_datamsg *msg;
615 /* For an inbound chunk, this tells us where it came from.
616 * For an outbound chunk, it tells us where we'd like it to
617 * go. It is NULL if we have no preference.
619 struct sctp_transport *transport;
621 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
622 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
623 * spec violates the principle premis that all chunks are processed
626 struct sk_buff *auth_chunk;
628 #define SCTP_CAN_FRTX 0x0
629 #define SCTP_NEED_FRTX 0x1
630 #define SCTP_DONT_FRTX 0x2
631 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
632 resent:1, /* Has this chunk ever been resent. */
633 has_tsn:1, /* Does this chunk have a TSN yet? */
634 has_ssn:1, /* Does this chunk have a SSN yet? */
635 singleton:1, /* Only chunk in the packet? */
636 end_of_packet:1, /* Last chunk in the packet? */
637 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
638 pdiscard:1, /* Discard the whole packet now? */
639 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
640 data_accepted:1, /* At least 1 chunk accepted */
641 auth:1, /* IN: was auth'ed | OUT: needs auth */
642 has_asconf:1, /* IN: have seen an asconf before */
643 tsn_missing_report:2, /* Data chunk missing counter. */
644 fast_retransmit:2; /* Is this chunk fast retransmitted? */
647 void sctp_chunk_hold(struct sctp_chunk *);
648 void sctp_chunk_put(struct sctp_chunk *);
649 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
651 void sctp_chunk_free(struct sctp_chunk *);
652 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
653 void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
654 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
655 const struct sctp_association *,
657 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
659 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
662 SCTP_ADDR_NEW, /* new address added to assoc/ep */
663 SCTP_ADDR_SRC, /* address can be used as source */
664 SCTP_ADDR_DEL, /* address about to be deleted */
667 /* This is a structure for holding either an IPv6 or an IPv4 address. */
668 struct sctp_sockaddr_entry {
669 struct list_head list;
676 #define SCTP_ADDRESS_TICK_DELAY 500
678 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
680 /* This structure holds lists of chunks as we are assembling for
684 /* These are the SCTP header values (host order) for the packet. */
686 __u16 destination_port;
689 /* This contains the payload chunks. */
690 struct list_head chunk_list;
692 /* This is the overhead of the sctp and ip headers. */
694 /* This is the total size of all chunks INCLUDING padding. */
697 /* The packet is destined for this transport address.
698 * The function we finally use to pass down to the next lower
699 * layer lives in the transport structure.
701 struct sctp_transport *transport;
703 /* pointer to the auth chunk for this packet */
704 struct sctp_chunk *auth;
706 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
707 has_sack:1, /* This packet contains a SACK chunk. */
708 has_auth:1, /* This packet contains an AUTH chunk */
709 has_data:1, /* This packet contains at least 1 DATA chunk */
710 ipfragok:1; /* So let ip fragment this packet */
713 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
714 struct sctp_transport *,
715 __u16 sport, __u16 dport);
716 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
717 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
718 struct sctp_chunk *, int);
719 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
720 struct sctp_chunk *);
721 int sctp_packet_transmit(struct sctp_packet *);
722 void sctp_packet_free(struct sctp_packet *);
724 static inline int sctp_packet_empty(struct sctp_packet *packet)
726 return packet->size == packet->overhead;
729 /* This represents a remote transport address.
730 * For local transport addresses, we just use union sctp_addr.
732 * RFC2960 Section 1.4 Key Terms
734 * o Transport address: A Transport Address is traditionally defined
735 * by Network Layer address, Transport Layer protocol and Transport
736 * Layer port number. In the case of SCTP running over IP, a
737 * transport address is defined by the combination of an IP address
738 * and an SCTP port number (where SCTP is the Transport protocol).
740 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
742 * o The sender keeps a separate congestion control parameter set for
743 * each of the destination addresses it can send to (not each
744 * source-destination pair but for each destination). The parameters
745 * should decay if the address is not used for a long enough time
749 struct sctp_transport {
750 /* A list of transports. */
751 struct list_head transports;
753 /* Reference counting. */
756 /* RTO-Pending : A flag used to track if one of the DATA
757 * chunks sent to this address is currently being
758 * used to compute a RTT. If this flag is 0,
759 * the next DATA chunk sent to this destination
760 * should be used to compute a RTT and this flag
761 * should be set. Every time the RTT
762 * calculation completes (i.e. the DATA chunk
763 * is SACK'd) clear this flag.
768 * hb_sent : a flag that signals that we have a pending
773 /* Is the Path MTU update pending on this tranport */
776 /* Has this transport moved the ctsn since we last sacked */
777 __u32 sack_generation;
782 /* This is the peer's IP address and port. */
783 union sctp_addr ipaddr;
785 /* These are the functions we call to handle LLP stuff. */
786 struct sctp_af *af_specific;
788 /* Which association do we belong to? */
789 struct sctp_association *asoc;
793 * 12.3 Per Transport Address Data
795 * For each destination transport address in the peer's
796 * address list derived from the INIT or INIT ACK chunk, a
797 * number of data elements needs to be maintained including:
799 /* RTO : The current retransmission timeout value. */
802 __u32 rtt; /* This is the most recent RTT. */
804 /* RTTVAR : The current RTT variation. */
807 /* SRTT : The current smoothed round trip time. */
811 * These are the congestion stats.
813 /* cwnd : The current congestion window. */
814 __u32 cwnd; /* This is the actual cwnd. */
816 /* ssthresh : The current slow start threshold value. */
819 /* partial : The tracking method for increase of cwnd when in
820 * bytes acked : congestion avoidance mode (see Section 6.2.2)
822 __u32 partial_bytes_acked;
824 /* Data that has been sent, but not acknowledged. */
827 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
830 struct dst_entry *dst;
831 /* Source address. */
832 union sctp_addr saddr;
834 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
835 * the destination address every heartbeat interval.
837 unsigned long hbinterval;
839 /* SACK delay timeout */
840 unsigned long sackdelay;
843 /* When was the last time (in jiffies) that we heard from this
844 * transport? We use this to pick new active and retran paths.
846 unsigned long last_time_heard;
848 /* Last time(in jiffies) when cwnd is reduced due to the congestion
849 * indication based on ECNE chunk.
851 unsigned long last_time_ecne_reduced;
853 /* This is the max_retrans value for the transport and will
854 * be initialized from the assocs value. This can be changed
855 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
859 /* This is the partially failed retrans value for the transport
860 * and will be initialized from the assocs value. This can be changed
861 * using the SCTP_PEER_ADDR_THLDS socket option
864 /* PMTU : The current known path MTU. */
867 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
870 /* The number of times INIT has been sent on this transport. */
873 /* state : The current state of this destination,
874 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
878 /* These are the error stats for this destination. */
880 /* Error count : The current error count for this destination. */
881 unsigned short error_count;
883 /* Per : A timer used by each destination.
887 * [Everywhere else in the text this is called T3-rtx. -ed]
889 struct timer_list T3_rtx_timer;
891 /* Heartbeat timer is per destination. */
892 struct timer_list hb_timer;
894 /* Timer to handle ICMP proto unreachable envets */
895 struct timer_list proto_unreach_timer;
897 /* Since we're using per-destination retransmission timers
898 * (see above), we're also using per-destination "transmitted"
899 * queues. This probably ought to be a private struct
900 * accessible only within the outqueue, but it's not, yet.
902 struct list_head transmitted;
904 /* We build bundle-able packets for this transport here. */
905 struct sctp_packet packet;
907 /* This is the list of transports that have chunks to send. */
908 struct list_head send_ready;
910 /* State information saved for SFR_CACC algorithm. The key
911 * idea in SFR_CACC is to maintain state at the sender on a
912 * per-destination basis when a changeover happens.
913 * char changeover_active;
914 * char cycling_changeover;
915 * __u32 next_tsn_at_change;
916 * char cacc_saw_newack;
919 /* An unsigned integer, which stores the next TSN to be
920 * used by the sender, at the moment of changeover.
922 __u32 next_tsn_at_change;
924 /* A flag which indicates the occurrence of a changeover */
925 char changeover_active;
927 /* A flag which indicates whether the change of primary is
928 * the first switch to this destination address during an
931 char cycling_changeover;
933 /* A temporary flag, which is used during the processing of
934 * a SACK to estimate the causative TSN(s)'s group.
936 char cacc_saw_newack;
939 /* 64-bit random number sent with heartbeat. */
945 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
947 void sctp_transport_set_owner(struct sctp_transport *,
948 struct sctp_association *);
949 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
951 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
952 void sctp_transport_free(struct sctp_transport *);
953 void sctp_transport_reset_timers(struct sctp_transport *);
954 void sctp_transport_hold(struct sctp_transport *);
955 void sctp_transport_put(struct sctp_transport *);
956 void sctp_transport_update_rto(struct sctp_transport *, __u32);
957 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
958 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
959 void sctp_transport_burst_limited(struct sctp_transport *);
960 void sctp_transport_burst_reset(struct sctp_transport *);
961 unsigned long sctp_transport_timeout(struct sctp_transport *);
962 void sctp_transport_reset(struct sctp_transport *);
963 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
964 void sctp_transport_immediate_rtx(struct sctp_transport *);
967 /* This is the structure we use to queue packets as they come into
968 * SCTP. We write packets to it and read chunks from it.
971 /* This is actually a queue of sctp_chunk each
972 * containing a partially decoded packet.
974 struct list_head in_chunk_list;
975 /* This is the packet which is currently off the in queue and is
976 * being worked on through the inbound chunk processing.
978 struct sctp_chunk *in_progress;
980 /* This is the delayed task to finish delivering inbound
983 struct work_struct immediate;
986 void sctp_inq_init(struct sctp_inq *);
987 void sctp_inq_free(struct sctp_inq *);
988 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
989 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
990 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
991 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
993 /* This is the structure we use to hold outbound chunks. You push
994 * chunks in and they automatically pop out the other end as bundled
995 * packets (it calls (*output_handler)()).
997 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
998 * and 8.2 of the v13 draft.
1000 * It handles retransmissions. The connection to the timeout portion
1001 * of the state machine is through sctp_..._timeout() and timeout_handler.
1003 * If you feed it SACKs, it will eat them.
1005 * If you give it big chunks, it will fragment them.
1007 * It assigns TSN's to data chunks. This happens at the last possible
1008 * instant before transmission.
1010 * When free()'d, it empties itself out via output_handler().
1013 struct sctp_association *asoc;
1015 /* Data pending that has never been transmitted. */
1016 struct list_head out_chunk_list;
1018 unsigned int out_qlen; /* Total length of queued data chunks. */
1020 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1023 /* These are control chunks we want to send. */
1024 struct list_head control_chunk_list;
1026 /* These are chunks that have been sacked but are above the
1027 * CTSN, or cumulative tsn ack point.
1029 struct list_head sacked;
1031 /* Put chunks on this list to schedule them for
1034 struct list_head retransmit;
1036 /* Put chunks on this list to save them for FWD TSN processing as
1037 * they were abandoned.
1039 struct list_head abandoned;
1041 /* How many unackd bytes do we have in-flight? */
1042 __u32 outstanding_bytes;
1044 /* Are we doing fast-rtx on this queue */
1050 /* Is this structure empty? */
1054 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1055 void sctp_outq_teardown(struct sctp_outq *);
1056 void sctp_outq_free(struct sctp_outq*);
1057 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1058 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1059 int sctp_outq_is_empty(const struct sctp_outq *);
1060 void sctp_outq_restart(struct sctp_outq *);
1062 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1063 sctp_retransmit_reason_t);
1064 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1065 int sctp_outq_uncork(struct sctp_outq *);
1066 /* Uncork and flush an outqueue. */
1067 static inline void sctp_outq_cork(struct sctp_outq *q)
1072 /* These bind address data fields common between endpoints and associations */
1073 struct sctp_bind_addr {
1075 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1077 * SCTP Port: The local SCTP port number the endpoint is
1082 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1084 * Address List: The list of IP addresses that this instance
1085 * has bound. This information is passed to one's
1086 * peer(s) in INIT and INIT ACK chunks.
1088 struct list_head address_list;
1091 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1092 void sctp_bind_addr_free(struct sctp_bind_addr *);
1093 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1094 const struct sctp_bind_addr *src,
1095 sctp_scope_t scope, gfp_t gfp,
1097 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1098 const struct sctp_bind_addr *src,
1100 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1101 __u8 addr_state, gfp_t gfp);
1102 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1103 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1104 struct sctp_sock *);
1105 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1106 struct sctp_sock *, struct sctp_sock *);
1107 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1108 const union sctp_addr *addr);
1109 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1110 const union sctp_addr *addrs,
1112 struct sctp_sock *opt);
1113 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1116 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1117 __u16 port, gfp_t gfp);
1119 sctp_scope_t sctp_scope(const union sctp_addr *);
1120 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1121 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1122 int sctp_addr_is_valid(const union sctp_addr *addr);
1123 int sctp_is_ep_boundall(struct sock *sk);
1126 /* What type of endpoint? */
1128 SCTP_EP_TYPE_SOCKET,
1129 SCTP_EP_TYPE_ASSOCIATION,
1130 } sctp_endpoint_type_t;
1133 * A common base class to bridge the implmentation view of a
1134 * socket (usually listening) endpoint versus an association's
1136 * This common structure is useful for several purposes:
1137 * 1) Common interface for lookup routines.
1138 * a) Subfunctions work for either endpoint or association
1139 * b) Single interface to lookup allows hiding the lookup lock rather
1140 * than acquiring it externally.
1141 * 2) Common interface for the inbound chunk handling/state machine.
1142 * 3) Common object handling routines for reference counting, etc.
1143 * 4) Disentangle association lookup from endpoint lookup, where we
1144 * do not have to find our endpoint to find our association.
1148 struct sctp_ep_common {
1149 /* Fields to help us manage our entries in the hash tables. */
1150 struct hlist_node node;
1153 /* Runtime type information. What kind of endpoint is this? */
1154 sctp_endpoint_type_t type;
1156 /* Some fields to help us manage this object.
1157 * refcnt - Reference count access to this object.
1158 * dead - Do not attempt to use this object.
1163 /* What socket does this endpoint belong to? */
1166 /* This is where we receive inbound chunks. */
1167 struct sctp_inq inqueue;
1169 /* This substructure includes the defining parameters of the
1171 * bind_addr.port is our shared port number.
1172 * bind_addr.address_list is our set of local IP addresses.
1174 struct sctp_bind_addr bind_addr;
1178 /* RFC Section 1.4 Key Terms
1180 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1181 * multi-homed host, an SCTP endpoint is represented to its peers as a
1182 * combination of a set of eligible destination transport addresses to
1183 * which SCTP packets can be sent and a set of eligible source
1184 * transport addresses from which SCTP packets can be received.
1185 * All transport addresses used by an SCTP endpoint must use the
1186 * same port number, but can use multiple IP addresses. A transport
1187 * address used by an SCTP endpoint must not be used by another
1188 * SCTP endpoint. In other words, a transport address is unique
1189 * to an SCTP endpoint.
1191 * From an implementation perspective, each socket has one of these.
1192 * A TCP-style socket will have exactly one association on one of
1193 * these. An UDP-style socket will have multiple associations hanging
1197 struct sctp_endpoint {
1198 /* Common substructure for endpoint and association. */
1199 struct sctp_ep_common base;
1201 /* Associations: A list of current associations and mappings
1202 * to the data consumers for each association. This
1203 * may be in the form of a hash table or other
1204 * implementation dependent structure. The data
1205 * consumers may be process identification
1206 * information such as file descriptors, named pipe
1207 * pointer, or table pointers dependent on how SCTP
1210 /* This is really a list of struct sctp_association entries. */
1211 struct list_head asocs;
1213 /* Secret Key: A secret key used by this endpoint to compute
1214 * the MAC. This SHOULD be a cryptographic quality
1215 * random number with a sufficient length.
1216 * Discussion in [RFC1750] can be helpful in
1217 * selection of the key.
1219 __u8 secret_key[SCTP_SECRET_SIZE];
1221 /* digest: This is a digest of the sctp cookie. This field is
1222 * only used on the receive path when we try to validate
1223 * that the cookie has not been tampered with. We put
1224 * this here so we pre-allocate this once and can re-use
1229 /* sendbuf acct. policy. */
1230 __u32 sndbuf_policy;
1232 /* rcvbuf acct. policy. */
1233 __u32 rcvbuf_policy;
1235 /* SCTP AUTH: array of the HMACs that will be allocated
1236 * we need this per association so that we don't serialize
1238 struct crypto_hash **auth_hmacs;
1240 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1241 struct sctp_hmac_algo_param *auth_hmacs_list;
1243 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1244 struct sctp_chunks_param *auth_chunk_list;
1246 /* SCTP-AUTH: endpoint shared keys */
1247 struct list_head endpoint_shared_keys;
1248 __u16 active_key_id;
1251 /* Recover the outter endpoint structure. */
1252 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1254 struct sctp_endpoint *ep;
1256 ep = container_of(base, struct sctp_endpoint, base);
1260 /* These are function signatures for manipulating endpoints. */
1261 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1262 void sctp_endpoint_free(struct sctp_endpoint *);
1263 void sctp_endpoint_put(struct sctp_endpoint *);
1264 void sctp_endpoint_hold(struct sctp_endpoint *);
1265 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1266 struct sctp_association *sctp_endpoint_lookup_assoc(
1267 const struct sctp_endpoint *ep,
1268 const union sctp_addr *paddr,
1269 struct sctp_transport **);
1270 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1271 const union sctp_addr *);
1272 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1273 struct net *, const union sctp_addr *);
1274 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1275 const union sctp_addr *paddr);
1277 int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
1278 sctp_cid_t, sctp_init_chunk_t *peer_init,
1279 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1280 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1281 const union sctp_addr *peer,
1282 sctp_init_chunk_t *init, gfp_t gfp);
1283 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1284 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1286 struct sctp_inithdr_host {
1289 __u16 num_outbound_streams;
1290 __u16 num_inbound_streams;
1294 /* SCTP_GET_ASSOC_STATS counters */
1295 struct sctp_priv_assoc_stats {
1296 /* Maximum observed rto in the association during subsequent
1297 * observations. Value is set to 0 if no RTO measurement took place
1298 * The transport where the max_rto was observed is returned in
1301 struct sockaddr_storage obs_rto_ipaddr;
1303 /* Total In and Out SACKs received and sent */
1306 /* Total In and Out packets received and sent */
1309 /* Total retransmitted chunks */
1311 /* TSN received > next expected */
1313 /* Duplicate Chunks received */
1315 /* Gap Ack Blocks received */
1317 /* Unordered data chunks sent and received */
1320 /* Ordered data chunks sent and received */
1323 /* Control chunks sent and received */
1330 * 12. Recommended Transmission Control Block (TCB) Parameters
1332 * This section details a recommended set of parameters that should
1333 * be contained within the TCB for an implementation. This section is
1334 * for illustrative purposes and should not be deemed as requirements
1335 * on an implementation or as an exhaustive list of all parameters
1336 * inside an SCTP TCB. Each implementation may need its own additional
1337 * parameters for optimization.
1341 /* Here we have information about each individual association. */
1342 struct sctp_association {
1344 /* A base structure common to endpoint and association.
1345 * In this context, it represents the associations's view
1346 * of the local endpoint of the association.
1348 struct sctp_ep_common base;
1350 /* Associations on the same socket. */
1351 struct list_head asocs;
1353 /* association id. */
1354 sctp_assoc_t assoc_id;
1356 /* This is our parent endpoint. */
1357 struct sctp_endpoint *ep;
1359 /* These are those association elements needed in the cookie. */
1360 struct sctp_cookie c;
1362 /* This is all information about our peer. */
1366 * Peer Rwnd : Current calculated value of the peer's rwnd.
1370 /* transport_addr_list
1372 * Peer : A list of SCTP transport addresses that the
1373 * Transport : peer is bound to. This information is derived
1374 * Address : from the INIT or INIT ACK and is used to
1375 * List : associate an inbound packet with a given
1376 * : association. Normally this information is
1377 * : hashed or keyed for quick lookup and access
1379 * : The list is also initialized with the list
1380 * : of addresses passed with the sctp_connectx()
1383 * It is a list of SCTP_transport's.
1385 struct list_head transport_addr_list;
1389 * Peer : A count of the number of peer addresses
1390 * Transport : in the Peer Transport Address List.
1394 __u16 transport_count;
1397 * The transport layer port number.
1403 * Primary : This is the current primary destination
1404 * Path : transport address of the peer endpoint. It
1405 * : may also specify a source transport address
1406 * : on this endpoint.
1408 * All of these paths live on transport_addr_list.
1410 * At the bakeoffs, we discovered that the intent of
1411 * primaryPath is that it only changes when the ULP
1412 * asks to have it changed. We add the activePath to
1413 * designate the connection we are currently using to
1414 * transmit new data and most control chunks.
1416 struct sctp_transport *primary_path;
1418 /* Cache the primary path address here, when we
1419 * need a an address for msg_name.
1421 union sctp_addr primary_addr;
1424 * The path that we are currently using to
1425 * transmit new data and most control chunks.
1427 struct sctp_transport *active_path;
1431 * RFC2960 6.4 Multi-homed SCTP Endpoints
1433 * Furthermore, when its peer is multi-homed, an
1434 * endpoint SHOULD try to retransmit a chunk to an
1435 * active destination transport address that is
1436 * different from the last destination address to
1437 * which the DATA chunk was sent.
1439 struct sctp_transport *retran_path;
1441 /* Pointer to last transport I have sent on. */
1442 struct sctp_transport *last_sent_to;
1444 /* This is the last transport I have received DATA on. */
1445 struct sctp_transport *last_data_from;
1448 * Mapping An array of bits or bytes indicating which out of
1449 * Array order TSN's have been received (relative to the
1450 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1451 * order packets have been received, this array
1452 * will be set to all zero. This structure may be
1453 * in the form of a circular buffer or bit array.
1455 * Last Rcvd : This is the last TSN received in
1456 * TSN : sequence. This value is set initially by
1457 * : taking the peer's Initial TSN, received in
1458 * : the INIT or INIT ACK chunk, and subtracting
1461 * Throughout most of the specification this is called the
1462 * "Cumulative TSN ACK Point". In this case, we
1463 * ignore the advice in 12.2 in favour of the term
1464 * used in the bulk of the text. This value is hidden
1465 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1467 struct sctp_tsnmap tsn_map;
1469 /* Ack State : This flag indicates if the next received
1470 * : packet is to be responded to with a
1471 * : SACK. This is initializedto 0. When a packet
1472 * : is received it is incremented. If this value
1473 * : reaches 2 or more, a SACK is sent and the
1474 * : value is reset to 0. Note: This is used only
1475 * : when no DATA chunks are received out of
1476 * : order. When DATA chunks are out of order,
1477 * : SACK's are not delayed (see Section 6).
1479 __u8 sack_needed; /* Do we need to sack the peer? */
1481 __u32 sack_generation;
1483 /* These are capabilities which our peer advertised. */
1484 __u8 ecn_capable:1, /* Can peer do ECN? */
1485 ipv4_address:1, /* Peer understands IPv4 addresses? */
1486 ipv6_address:1, /* Peer understands IPv6 addresses? */
1487 hostname_address:1, /* Peer understands DNS addresses? */
1488 asconf_capable:1, /* Does peer support ADDIP? */
1489 prsctp_capable:1, /* Can peer do PR-SCTP? */
1490 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1492 __u32 adaptation_ind; /* Adaptation Code point. */
1494 /* This mask is used to disable sending the ASCONF chunk
1495 * with specified parameter to peer.
1497 __be16 addip_disabled_mask;
1499 struct sctp_inithdr_host i;
1503 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1504 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1505 * Initial TSN Value minus 1
1509 /* SCTP-AUTH: We need to know pears random number, hmac list
1510 * and authenticated chunk list. All that is part of the
1511 * cookie and these are just pointers to those locations
1513 sctp_random_param_t *peer_random;
1514 sctp_chunks_param_t *peer_chunks;
1515 sctp_hmac_algo_param_t *peer_hmacs;
1518 /* State : A state variable indicating what state the
1519 * : association is in, i.e. COOKIE-WAIT,
1520 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1521 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1523 * Note: No "CLOSED" state is illustrated since if a
1524 * association is "CLOSED" its TCB SHOULD be removed.
1526 * In this implementation we DO have a CLOSED
1527 * state which is used during initiation and shutdown.
1529 * State takes values from SCTP_STATE_*.
1533 /* The cookie life I award for any cookie. */
1534 ktime_t cookie_life;
1536 /* Overall : The overall association error count.
1537 * Error Count : [Clear this any time I get something.]
1539 int overall_error_count;
1541 /* These are the association's initial, max, and min RTO values.
1542 * These values will be initialized by system defaults, but can
1543 * be modified via the SCTP_RTOINFO socket option.
1545 unsigned long rto_initial;
1546 unsigned long rto_max;
1547 unsigned long rto_min;
1549 /* Maximum number of new data packets that can be sent in a burst. */
1552 /* This is the max_retrans value for the association. This value will
1553 * be initialized initialized from system defaults, but can be
1554 * modified by the SCTP_ASSOCINFO socket option.
1558 /* This is the partially failed retrans value for the transport
1559 * and will be initialized from the assocs value. This can be
1560 * changed using the SCTP_PEER_ADDR_THLDS socket option
1564 /* Maximum number of times the endpoint will retransmit INIT */
1565 __u16 max_init_attempts;
1567 /* How many times have we resent an INIT? */
1570 /* The largest timeout or RTO value to use in attempting an INIT */
1571 unsigned long max_init_timeo;
1573 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1574 * the destination address every heartbeat interval. This value
1575 * will be inherited by all new transports.
1577 unsigned long hbinterval;
1579 /* This is the max_retrans value for new transports in the
1584 /* Flag that path mtu update is pending */
1587 /* Association : The smallest PMTU discovered for all of the
1588 * PMTU : peer's transport addresses.
1592 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1595 /* SACK delay timeout */
1596 unsigned long sackdelay;
1600 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1601 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1603 /* Transport to which SHUTDOWN chunk was last sent. */
1604 struct sctp_transport *shutdown_last_sent_to;
1606 /* How many times have we resent a SHUTDOWN */
1607 int shutdown_retries;
1609 /* Transport to which INIT chunk was last sent. */
1610 struct sctp_transport *init_last_sent_to;
1612 /* Next TSN : The next TSN number to be assigned to a new
1613 * : DATA chunk. This is sent in the INIT or INIT
1614 * : ACK chunk to the peer and incremented each
1615 * : time a DATA chunk is assigned a TSN
1616 * : (normally just prior to transmit or during
1622 * Last Rcvd : This is the last TSN received in sequence. This value
1623 * TSN : is set initially by taking the peer's Initial TSN,
1624 * : received in the INIT or INIT ACK chunk, and
1625 * : subtracting one from it.
1627 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1630 __u32 ctsn_ack_point;
1632 /* PR-SCTP Advanced.Peer.Ack.Point */
1633 __u32 adv_peer_ack_point;
1635 /* Highest TSN that is acknowledged by incoming SACKs. */
1636 __u32 highest_sacked;
1638 /* TSN marking the fast recovery exit point */
1639 __u32 fast_recovery_exit;
1641 /* Flag to track the current fast recovery state */
1644 /* The number of unacknowledged data chunks. Reported through
1645 * the SCTP_STATUS sockopt.
1649 /* The total number of data chunks that we've had to retransmit
1650 * as the result of a T3 timer expiration
1652 __u32 rtx_data_chunks;
1654 /* This is the association's receive buffer space. This value is used
1655 * to set a_rwnd field in an INIT or a SACK chunk.
1659 /* This is the last advertised value of rwnd over a SACK chunk. */
1662 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1663 * to slop over a maximum of the association's frag_point.
1667 /* Keeps treack of rwnd pressure. This happens when we have
1668 * a window, but not recevie buffer (i.e small packets). This one
1669 * is releases slowly (1 PMTU at a time ).
1673 /* This is the sndbuf size in use for the association.
1674 * This corresponds to the sndbuf size for the association,
1675 * as specified in the sk->sndbuf.
1679 /* This is the amount of memory that this association has allocated
1680 * in the receive path at any given time.
1682 atomic_t rmem_alloc;
1684 /* This is the wait queue head for send requests waiting on
1685 * the association sndbuf space.
1687 wait_queue_head_t wait;
1689 /* The message size at which SCTP fragmentation will occur. */
1693 /* Counter used to count INIT errors. */
1694 int init_err_counter;
1696 /* Count the number of INIT cycles (for doubling timeout). */
1699 /* Default send parameters. */
1700 __u16 default_stream;
1701 __u16 default_flags;
1703 __u32 default_context;
1704 __u32 default_timetolive;
1706 /* Default receive parameters */
1707 __u32 default_rcv_context;
1709 /* This tracks outbound ssn for a given stream. */
1710 struct sctp_ssnmap *ssnmap;
1712 /* All outbound chunks go through this structure. */
1713 struct sctp_outq outqueue;
1715 /* A smart pipe that will handle reordering and fragmentation,
1716 * as well as handle passing events up to the ULP.
1718 struct sctp_ulpq ulpq;
1720 /* Last TSN that caused an ECNE Chunk to be sent. */
1721 __u32 last_ecne_tsn;
1723 /* Last TSN that caused a CWR Chunk to be sent. */
1726 /* How many duplicated TSNs have we seen? */
1729 /* Number of seconds of idle time before an association is closed.
1730 * In the association context, this is really used as a boolean
1731 * since the real timeout is stored in the timeouts array
1735 /* These are to support
1736 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1737 * and Enforcement of Flow and Message Limits"
1738 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1739 * or "ADDIP" for short.
1744 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1746 * R1) One and only one ASCONF Chunk MAY be in transit and
1747 * unacknowledged at any one time. If a sender, after sending
1748 * an ASCONF chunk, decides it needs to transfer another
1749 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1750 * returns from the previous ASCONF Chunk before sending a
1751 * subsequent ASCONF. Note this restriction binds each side,
1752 * so at any time two ASCONF may be in-transit on any given
1753 * association (one sent from each endpoint).
1755 * [This is our one-and-only-one ASCONF in flight. If we do
1756 * not have an ASCONF in flight, this is NULL.]
1758 struct sctp_chunk *addip_last_asconf;
1760 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1762 * This is needed to implement itmes E1 - E4 of the updated
1763 * spec. Here is the justification:
1765 * Since the peer may bundle multiple ASCONF chunks toward us,
1766 * we now need the ability to cache multiple ACKs. The section
1767 * describes in detail how they are cached and cleaned up.
1769 struct list_head asconf_ack_list;
1771 /* These ASCONF chunks are waiting to be sent.
1773 * These chunaks can't be pushed to outqueue until receiving
1774 * ASCONF_ACK for the previous ASCONF indicated by
1775 * addip_last_asconf, so as to guarantee that only one ASCONF
1776 * is in flight at any time.
1778 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1780 * In defining the ASCONF Chunk transfer procedures, it is
1781 * essential that these transfers MUST NOT cause congestion
1782 * within the network. To achieve this, we place these
1783 * restrictions on the transfer of ASCONF Chunks:
1785 * R1) One and only one ASCONF Chunk MAY be in transit and
1786 * unacknowledged at any one time. If a sender, after sending
1787 * an ASCONF chunk, decides it needs to transfer another
1788 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1789 * returns from the previous ASCONF Chunk before sending a
1790 * subsequent ASCONF. Note this restriction binds each side,
1791 * so at any time two ASCONF may be in-transit on any given
1792 * association (one sent from each endpoint).
1795 * [I really think this is EXACTLY the sort of intelligence
1796 * which already resides in sctp_outq. Please move this
1797 * queue and its supporting logic down there. --piggy]
1799 struct list_head addip_chunk_list;
1801 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1803 * A2) A serial number should be assigned to the Chunk. The
1804 * serial number SHOULD be a monotonically increasing
1805 * number. The serial number SHOULD be initialized at
1806 * the start of the association to the same value as the
1807 * Initial TSN and every time a new ASCONF chunk is created
1808 * it is incremented by one after assigning the serial number
1809 * to the newly created chunk.
1812 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1814 * Serial Number : 32 bits (unsigned integer)
1816 * This value represents a Serial Number for the ASCONF
1817 * Chunk. The valid range of Serial Number is from 0 to
1818 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1819 * after reaching 4294967295.
1822 union sctp_addr *asconf_addr_del_pending;
1823 int src_out_of_asoc_ok;
1824 struct sctp_transport *new_transport;
1826 /* SCTP AUTH: list of the endpoint shared keys. These
1827 * keys are provided out of band by the user applicaton
1828 * and can't change during the lifetime of the association
1830 struct list_head endpoint_shared_keys;
1833 * The current generated assocaition shared key (secret)
1835 struct sctp_auth_bytes *asoc_shared_key;
1837 /* SCTP AUTH: hmac id of the first peer requested algorithm
1840 __u16 default_hmac_id;
1842 __u16 active_key_id;
1844 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1845 temp:1; /* Is it a temporary association? */
1847 struct sctp_priv_assoc_stats stats;
1851 /* An eyecatcher for determining if we are really looking at an
1852 * association data structure.
1855 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1858 /* Recover the outter association structure. */
1859 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1861 struct sctp_association *asoc;
1863 asoc = container_of(base, struct sctp_association, base);
1867 /* These are function signatures for manipulating associations. */
1870 struct sctp_association *
1871 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1872 sctp_scope_t scope, gfp_t gfp);
1873 void sctp_association_free(struct sctp_association *);
1874 void sctp_association_put(struct sctp_association *);
1875 void sctp_association_hold(struct sctp_association *);
1877 struct sctp_transport *sctp_assoc_choose_alter_transport(
1878 struct sctp_association *, struct sctp_transport *);
1879 void sctp_assoc_update_retran_path(struct sctp_association *);
1880 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1881 const union sctp_addr *);
1882 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1883 const union sctp_addr *laddr);
1884 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1885 const union sctp_addr *address,
1887 const int peer_state);
1888 void sctp_assoc_del_peer(struct sctp_association *asoc,
1889 const union sctp_addr *addr);
1890 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1891 struct sctp_transport *peer);
1892 void sctp_assoc_control_transport(struct sctp_association *,
1893 struct sctp_transport *,
1894 sctp_transport_cmd_t, sctp_sn_error_t);
1895 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1896 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1898 const union sctp_addr *,
1899 const union sctp_addr *);
1900 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1901 void sctp_assoc_update(struct sctp_association *old,
1902 struct sctp_association *new);
1904 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1906 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1907 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1908 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1909 void sctp_assoc_set_primary(struct sctp_association *,
1910 struct sctp_transport *);
1911 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1912 struct sctp_transport *);
1913 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1914 sctp_scope_t, gfp_t);
1915 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1916 struct sctp_cookie*,
1918 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1919 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1920 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1921 const struct sctp_association *asoc,
1923 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1925 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1926 const union sctp_addr *ss2);
1927 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1929 /* A convenience structure to parse out SCTP specific CMSGs. */
1930 typedef struct sctp_cmsgs {
1931 struct sctp_initmsg *init;
1932 struct sctp_sndrcvinfo *info;
1935 /* Structure for tracking memory objects */
1939 } sctp_dbg_objcnt_entry_t;
1941 #endif /* __sctp_structs_h__ */