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 /* The following variables are implementation specific. */
118 /* Default initialization values to be applied to new associations. */
120 __u16 max_outstreams;
122 /* This is a list of groups of functions for each address
123 * family that we support.
125 struct list_head address_families;
127 /* This is the hash of all endpoints. */
129 struct sctp_hashbucket *ep_hashtable;
131 /* This is the hash of all associations. */
133 struct sctp_hashbucket *assoc_hashtable;
135 /* This is the sctp port control hash. */
137 struct sctp_bind_hashbucket *port_hashtable;
139 /* Flag to indicate whether computing and verifying checksum
141 bool checksum_disable;
144 #define sctp_max_instreams (sctp_globals.max_instreams)
145 #define sctp_max_outstreams (sctp_globals.max_outstreams)
146 #define sctp_address_families (sctp_globals.address_families)
147 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
148 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
149 #define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
150 #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
151 #define sctp_port_hashsize (sctp_globals.port_hashsize)
152 #define sctp_port_hashtable (sctp_globals.port_hashtable)
153 #define sctp_checksum_disable (sctp_globals.checksum_disable)
155 /* SCTP Socket type: UDP or TCP style. */
158 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
160 } sctp_socket_type_t;
162 /* Per socket SCTP information. */
164 /* inet_sock has to be the first member of sctp_sock */
165 struct inet_sock inet;
166 /* What kind of a socket is this? */
167 sctp_socket_type_t type;
169 /* PF_ family specific functions. */
172 /* Access to HMAC transform. */
173 struct crypto_hash *hmac;
176 /* What is our base endpointer? */
177 struct sctp_endpoint *ep;
179 struct sctp_bind_bucket *bind_hash;
180 /* Various Socket Options. */
181 __u16 default_stream;
184 __u32 default_context;
185 __u32 default_timetolive;
186 __u32 default_rcv_context;
189 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
190 * the destination address every heartbeat interval. This value
191 * will be inherited by all new associations.
195 /* This is the max_retrans value for new associations. */
198 /* The initial Path MTU to use for new associations. */
201 /* The default SACK delay timeout for new associations. */
205 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
208 struct sctp_initmsg initmsg;
209 struct sctp_rtoinfo rtoinfo;
210 struct sctp_paddrparams paddrparam;
211 struct sctp_event_subscribe subscribe;
212 struct sctp_assocparams assocparams;
216 __u8 disable_fragments;
218 __u8 frag_interleave;
219 __u32 adaptation_ind;
223 /* Receive to here while partial delivery is in effect. */
224 struct sk_buff_head pd_lobby;
225 struct list_head auto_asconf_list;
229 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
231 return (struct sctp_sock *)sk;
234 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
236 return (struct sock *)sp;
239 #if IS_ENABLED(CONFIG_IPV6)
241 struct sctp_sock sctp;
242 struct ipv6_pinfo inet6;
244 #endif /* CONFIG_IPV6 */
247 /* This is our APPLICATION-SPECIFIC state cookie.
248 * THIS IS NOT DICTATED BY THE SPECIFICATION.
250 /* These are the parts of an association which we send in the cookie.
251 * Most of these are straight out of:
252 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
258 /* My : Tag expected in every inbound packet and sent
259 * Verification: in the INIT or INIT ACK chunk.
264 /* Peer's : Tag expected in every outbound packet except
265 * Verification: in the INIT chunk.
270 /* The rest of these are not from the spec, but really need to
274 /* My Tie Tag : Assist in discovering a restarting association. */
277 /* Peer's Tie Tag: Assist in discovering a restarting association. */
280 /* When does this cookie expire? */
283 /* Number of inbound/outbound streams which are set
284 * and negotiated during the INIT process.
286 __u16 sinit_num_ostreams;
287 __u16 sinit_max_instreams;
289 /* This is the first sequence number I used. */
292 /* This holds the originating address of the INIT packet. */
293 union sctp_addr peer_addr;
296 * Include the source port of the INIT-ACK
302 /* Padding for future use */
305 __u32 adaptation_ind;
307 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
308 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
309 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
311 /* This is a shim for my peer's INIT packet, followed by
312 * a copy of the raw address list of the association.
313 * The length of the raw address list is saved in the
314 * raw_addr_list_len field, which will be used at the time when
315 * the association TCB is re-constructed from the cookie.
317 __u32 raw_addr_list_len;
318 struct sctp_init_chunk peer_init[0];
322 /* The format of our cookie that we send to our peer. */
323 struct sctp_signed_cookie {
324 __u8 signature[SCTP_SECRET_SIZE];
325 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
326 struct sctp_cookie c;
329 /* This is another convenience type to allocate memory for address
330 * params for the maximum size and pass such structures around
333 union sctp_addr_param {
334 struct sctp_paramhdr p;
335 struct sctp_ipv4addr_param v4;
336 struct sctp_ipv6addr_param v6;
339 /* A convenience type to allow walking through the various
340 * parameters and avoid casting all over the place.
344 struct sctp_paramhdr *p;
345 struct sctp_cookie_preserve_param *life;
346 struct sctp_hostname_param *dns;
347 struct sctp_cookie_param *cookie;
348 struct sctp_supported_addrs_param *sat;
349 struct sctp_ipv4addr_param *v4;
350 struct sctp_ipv6addr_param *v6;
351 union sctp_addr_param *addr;
352 struct sctp_adaptation_ind_param *aind;
353 struct sctp_supported_ext_param *ext;
354 struct sctp_random_param *random;
355 struct sctp_chunks_param *chunks;
356 struct sctp_hmac_algo_param *hmac_algo;
357 struct sctp_addip_param *addip;
360 /* RFC 2960. Section 3.3.5 Heartbeat.
361 * Heartbeat Information: variable length
362 * The Sender-specific Heartbeat Info field should normally include
363 * information about the sender's current time when this HEARTBEAT
364 * chunk is sent and the destination transport address to which this
365 * HEARTBEAT is sent (see Section 8.3).
367 typedef struct sctp_sender_hb_info {
368 struct sctp_paramhdr param_hdr;
369 union sctp_addr daddr;
370 unsigned long sent_at;
372 } __packed sctp_sender_hb_info_t;
375 * RFC 2960 1.3.2 Sequenced Delivery within Streams
377 * The term "stream" is used in SCTP to refer to a sequence of user
378 * messages that are to be delivered to the upper-layer protocol in
379 * order with respect to other messages within the same stream. This is
380 * in contrast to its usage in TCP, where it refers to a sequence of
381 * bytes (in this document a byte is assumed to be eight bits).
384 * This is the structure we use to track both our outbound and inbound
385 * SSN, or Stream Sequence Numbers.
394 struct sctp_stream in;
395 struct sctp_stream out;
398 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
400 void sctp_ssnmap_free(struct sctp_ssnmap *map);
401 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
403 /* What is the current SSN number for this stream? */
404 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
406 return stream->ssn[id];
409 /* Return the next SSN number for this stream. */
410 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
412 return stream->ssn[id]++;
415 /* Skip over this ssn and all below. */
416 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
419 stream->ssn[id] = ssn+1;
423 * Pointers to address related SCTP functions.
424 * (i.e. things that depend on the address family.)
427 int (*sctp_xmit) (struct sk_buff *skb,
428 struct sctp_transport *);
429 int (*setsockopt) (struct sock *sk,
433 unsigned int optlen);
434 int (*getsockopt) (struct sock *sk,
439 int (*compat_setsockopt) (struct sock *sk,
443 unsigned int optlen);
444 int (*compat_getsockopt) (struct sock *sk,
449 void (*get_dst) (struct sctp_transport *t,
450 union sctp_addr *saddr,
453 void (*get_saddr) (struct sctp_sock *sk,
454 struct sctp_transport *t,
456 void (*copy_addrlist) (struct list_head *,
457 struct net_device *);
458 int (*cmp_addr) (const union sctp_addr *addr1,
459 const union sctp_addr *addr2);
460 void (*addr_copy) (union sctp_addr *dst,
461 union sctp_addr *src);
462 void (*from_skb) (union sctp_addr *,
465 void (*from_sk) (union sctp_addr *,
467 void (*to_sk_saddr) (union sctp_addr *,
469 void (*to_sk_daddr) (union sctp_addr *,
471 void (*from_addr_param) (union sctp_addr *,
472 union sctp_addr_param *,
473 __be16 port, int iif);
474 int (*to_addr_param) (const union sctp_addr *,
475 union sctp_addr_param *);
476 int (*addr_valid) (union sctp_addr *,
478 const struct sk_buff *);
479 sctp_scope_t (*scope) (union sctp_addr *);
480 void (*inaddr_any) (union sctp_addr *, __be16);
481 int (*is_any) (const union sctp_addr *);
482 int (*available) (union sctp_addr *,
484 int (*skb_iif) (const struct sk_buff *sk);
485 int (*is_ce) (const struct sk_buff *sk);
486 void (*seq_dump_addr)(struct seq_file *seq,
487 union sctp_addr *addr);
488 void (*ecn_capable)(struct sock *sk);
489 __u16 net_header_len;
491 sa_family_t sa_family;
492 struct list_head list;
495 struct sctp_af *sctp_get_af_specific(sa_family_t);
496 int sctp_register_af(struct sctp_af *);
498 /* Protocol family functions. */
500 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
501 void (*skb_msgname) (struct sk_buff *, char *, int *);
502 int (*af_supported) (sa_family_t, struct sctp_sock *);
503 int (*cmp_addr) (const union sctp_addr *,
504 const union sctp_addr *,
506 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
507 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
508 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
509 struct sock *(*create_accept_sk) (struct sock *sk,
510 struct sctp_association *asoc);
511 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
516 /* Structure to track chunk fragments that have been acked, but peer
517 * fragments of the same message have not.
519 struct sctp_datamsg {
520 /* Chunks waiting to be submitted to lower layer. */
521 struct list_head chunks;
522 /* Reference counting. */
524 /* When is this message no longer interesting to the peer? */
525 unsigned long expires_at;
526 /* Did the messenge fail to send? */
529 can_abandon:1, /* can chunks from this message can be abandoned. */
530 can_delay; /* should this message be Nagle delayed */
533 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
534 struct sctp_sndrcvinfo *,
535 struct msghdr *, int len);
536 void sctp_datamsg_free(struct sctp_datamsg *);
537 void sctp_datamsg_put(struct sctp_datamsg *);
538 void sctp_chunk_fail(struct sctp_chunk *, int error);
539 int sctp_chunk_abandoned(struct sctp_chunk *);
541 /* RFC2960 1.4 Key Terms
543 * o Chunk: A unit of information within an SCTP packet, consisting of
544 * a chunk header and chunk-specific content.
546 * As a matter of convenience, we remember the SCTP common header for
547 * each chunk as well as a few other header pointers...
550 struct list_head list;
554 /* This is our link to the per-transport transmitted list. */
555 struct list_head transmitted_list;
557 /* This field is used by chunks that hold fragmented data.
558 * For the first fragment this is the list that holds the rest of
559 * fragments. For the remaining fragments, this is the link to the
560 * frag_list maintained in the first fragment.
562 struct list_head frag_list;
564 /* This points to the sk_buff containing the actual data. */
567 /* These are the SCTP headers by reverse order in a packet.
568 * Note that some of these may happen more than once. In that
569 * case, we point at the "current" one, whatever that means
570 * for that level of header.
573 /* We point this at the FIRST TLV parameter to chunk_hdr. */
574 union sctp_params param_hdr;
577 struct sctp_datahdr *data_hdr;
578 struct sctp_inithdr *init_hdr;
579 struct sctp_sackhdr *sack_hdr;
580 struct sctp_heartbeathdr *hb_hdr;
581 struct sctp_sender_hb_info *hbs_hdr;
582 struct sctp_shutdownhdr *shutdown_hdr;
583 struct sctp_signed_cookie *cookie_hdr;
584 struct sctp_ecnehdr *ecne_hdr;
585 struct sctp_cwrhdr *ecn_cwr_hdr;
586 struct sctp_errhdr *err_hdr;
587 struct sctp_addiphdr *addip_hdr;
588 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
589 struct sctp_authhdr *auth_hdr;
594 struct sctp_chunkhdr *chunk_hdr;
595 struct sctphdr *sctp_hdr;
597 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
598 struct sctp_sndrcvinfo sinfo;
600 /* Which association does this belong to? */
601 struct sctp_association *asoc;
603 /* What endpoint received this chunk? */
604 struct sctp_ep_common *rcvr;
606 /* We fill this in if we are calculating RTT. */
607 unsigned long sent_at;
609 /* What is the origin IP address for this chunk? */
610 union sctp_addr source;
611 /* Destination address for this chunk. */
612 union sctp_addr dest;
614 /* For outbound message, track all fragments for SEND_FAILED. */
615 struct sctp_datamsg *msg;
617 /* For an inbound chunk, this tells us where it came from.
618 * For an outbound chunk, it tells us where we'd like it to
619 * go. It is NULL if we have no preference.
621 struct sctp_transport *transport;
623 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
624 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
625 * spec violates the principle premis that all chunks are processed
628 struct sk_buff *auth_chunk;
630 #define SCTP_CAN_FRTX 0x0
631 #define SCTP_NEED_FRTX 0x1
632 #define SCTP_DONT_FRTX 0x2
633 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
634 has_tsn:1, /* Does this chunk have a TSN yet? */
635 has_ssn:1, /* Does this chunk have a SSN yet? */
636 singleton:1, /* Only chunk in the packet? */
637 end_of_packet:1, /* Last chunk in the packet? */
638 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
639 pdiscard:1, /* Discard the whole packet now? */
640 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
641 data_accepted:1, /* At least 1 chunk accepted */
642 auth:1, /* IN: was auth'ed | OUT: needs auth */
643 has_asconf:1, /* IN: have seen an asconf before */
644 tsn_missing_report:2, /* Data chunk missing counter. */
645 fast_retransmit:2; /* Is this chunk fast retransmitted? */
648 void sctp_chunk_hold(struct sctp_chunk *);
649 void sctp_chunk_put(struct sctp_chunk *);
650 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
652 void sctp_chunk_free(struct sctp_chunk *);
653 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
654 void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, const void *data);
655 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
656 const struct sctp_association *,
658 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
660 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
663 SCTP_ADDR_NEW, /* new address added to assoc/ep */
664 SCTP_ADDR_SRC, /* address can be used as source */
665 SCTP_ADDR_DEL, /* address about to be deleted */
668 /* This is a structure for holding either an IPv6 or an IPv4 address. */
669 struct sctp_sockaddr_entry {
670 struct list_head list;
677 #define SCTP_ADDRESS_TICK_DELAY 500
679 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
681 /* This structure holds lists of chunks as we are assembling for
685 /* These are the SCTP header values (host order) for the packet. */
687 __u16 destination_port;
690 /* This contains the payload chunks. */
691 struct list_head chunk_list;
693 /* This is the overhead of the sctp and ip headers. */
695 /* This is the total size of all chunks INCLUDING padding. */
698 /* The packet is destined for this transport address.
699 * The function we finally use to pass down to the next lower
700 * layer lives in the transport structure.
702 struct sctp_transport *transport;
704 /* pointer to the auth chunk for this packet */
705 struct sctp_chunk *auth;
707 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
708 has_sack:1, /* This packet contains a SACK chunk. */
709 has_auth:1, /* This packet contains an AUTH chunk */
710 has_data:1, /* This packet contains at least 1 DATA chunk */
711 ipfragok:1; /* So let ip fragment this packet */
714 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
715 struct sctp_transport *,
716 __u16 sport, __u16 dport);
717 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
718 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
719 struct sctp_chunk *, int);
720 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
721 struct sctp_chunk *);
722 int sctp_packet_transmit(struct sctp_packet *);
723 void sctp_packet_free(struct sctp_packet *);
725 static inline int sctp_packet_empty(struct sctp_packet *packet)
727 return packet->size == packet->overhead;
730 /* This represents a remote transport address.
731 * For local transport addresses, we just use union sctp_addr.
733 * RFC2960 Section 1.4 Key Terms
735 * o Transport address: A Transport Address is traditionally defined
736 * by Network Layer address, Transport Layer protocol and Transport
737 * Layer port number. In the case of SCTP running over IP, a
738 * transport address is defined by the combination of an IP address
739 * and an SCTP port number (where SCTP is the Transport protocol).
741 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
743 * o The sender keeps a separate congestion control parameter set for
744 * each of the destination addresses it can send to (not each
745 * source-destination pair but for each destination). The parameters
746 * should decay if the address is not used for a long enough time
750 struct sctp_transport {
751 /* A list of transports. */
752 struct list_head transports;
754 /* Reference counting. */
757 /* RTO-Pending : A flag used to track if one of the DATA
758 * chunks sent to this address is currently being
759 * used to compute a RTT. If this flag is 0,
760 * the next DATA chunk sent to this destination
761 * should be used to compute a RTT and this flag
762 * should be set. Every time the RTT
763 * calculation completes (i.e. the DATA chunk
764 * is SACK'd) clear this flag.
769 * hb_sent : a flag that signals that we have a pending
774 /* Is the Path MTU update pending on this tranport */
777 /* Has this transport moved the ctsn since we last sacked */
778 __u32 sack_generation;
783 /* This is the peer's IP address and port. */
784 union sctp_addr ipaddr;
786 /* These are the functions we call to handle LLP stuff. */
787 struct sctp_af *af_specific;
789 /* Which association do we belong to? */
790 struct sctp_association *asoc;
794 * 12.3 Per Transport Address Data
796 * For each destination transport address in the peer's
797 * address list derived from the INIT or INIT ACK chunk, a
798 * number of data elements needs to be maintained including:
800 /* RTO : The current retransmission timeout value. */
803 __u32 rtt; /* This is the most recent RTT. */
805 /* RTTVAR : The current RTT variation. */
808 /* SRTT : The current smoothed round trip time. */
812 * These are the congestion stats.
814 /* cwnd : The current congestion window. */
815 __u32 cwnd; /* This is the actual cwnd. */
817 /* ssthresh : The current slow start threshold value. */
820 /* partial : The tracking method for increase of cwnd when in
821 * bytes acked : congestion avoidance mode (see Section 6.2.2)
823 __u32 partial_bytes_acked;
825 /* Data that has been sent, but not acknowledged. */
828 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
831 struct dst_entry *dst;
832 /* Source address. */
833 union sctp_addr saddr;
835 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
836 * the destination address every heartbeat interval.
838 unsigned long hbinterval;
840 /* SACK delay timeout */
841 unsigned long sackdelay;
844 /* When was the last time (in jiffies) that we heard from this
845 * transport? We use this to pick new active and retran paths.
847 unsigned long last_time_heard;
849 /* Last time(in jiffies) when cwnd is reduced due to the congestion
850 * indication based on ECNE chunk.
852 unsigned long last_time_ecne_reduced;
854 /* This is the max_retrans value for the transport and will
855 * be initialized from the assocs value. This can be changed
856 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
860 /* This is the partially failed retrans value for the transport
861 * and will be initialized from the assocs value. This can be changed
862 * using the SCTP_PEER_ADDR_THLDS socket option
865 /* PMTU : The current known path MTU. */
868 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
871 /* The number of times INIT has been sent on this transport. */
874 /* state : The current state of this destination,
875 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
879 /* These are the error stats for this destination. */
881 /* Error count : The current error count for this destination. */
882 unsigned short error_count;
884 /* Per : A timer used by each destination.
888 * [Everywhere else in the text this is called T3-rtx. -ed]
890 struct timer_list T3_rtx_timer;
892 /* Heartbeat timer is per destination. */
893 struct timer_list hb_timer;
895 /* Timer to handle ICMP proto unreachable envets */
896 struct timer_list proto_unreach_timer;
898 /* Since we're using per-destination retransmission timers
899 * (see above), we're also using per-destination "transmitted"
900 * queues. This probably ought to be a private struct
901 * accessible only within the outqueue, but it's not, yet.
903 struct list_head transmitted;
905 /* We build bundle-able packets for this transport here. */
906 struct sctp_packet packet;
908 /* This is the list of transports that have chunks to send. */
909 struct list_head send_ready;
911 /* State information saved for SFR_CACC algorithm. The key
912 * idea in SFR_CACC is to maintain state at the sender on a
913 * per-destination basis when a changeover happens.
914 * char changeover_active;
915 * char cycling_changeover;
916 * __u32 next_tsn_at_change;
917 * char cacc_saw_newack;
920 /* An unsigned integer, which stores the next TSN to be
921 * used by the sender, at the moment of changeover.
923 __u32 next_tsn_at_change;
925 /* A flag which indicates the occurrence of a changeover */
926 char changeover_active;
928 /* A flag which indicates whether the change of primary is
929 * the first switch to this destination address during an
932 char cycling_changeover;
934 /* A temporary flag, which is used during the processing of
935 * a SACK to estimate the causative TSN(s)'s group.
937 char cacc_saw_newack;
940 /* 64-bit random number sent with heartbeat. */
946 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
948 void sctp_transport_set_owner(struct sctp_transport *,
949 struct sctp_association *);
950 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
952 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
953 void sctp_transport_free(struct sctp_transport *);
954 void sctp_transport_reset_timers(struct sctp_transport *);
955 void sctp_transport_hold(struct sctp_transport *);
956 void sctp_transport_put(struct sctp_transport *);
957 void sctp_transport_update_rto(struct sctp_transport *, __u32);
958 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
959 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
960 void sctp_transport_burst_limited(struct sctp_transport *);
961 void sctp_transport_burst_reset(struct sctp_transport *);
962 unsigned long sctp_transport_timeout(struct sctp_transport *);
963 void sctp_transport_reset(struct sctp_transport *);
964 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
965 void sctp_transport_immediate_rtx(struct sctp_transport *);
968 /* This is the structure we use to queue packets as they come into
969 * SCTP. We write packets to it and read chunks from it.
972 /* This is actually a queue of sctp_chunk each
973 * containing a partially decoded packet.
975 struct list_head in_chunk_list;
976 /* This is the packet which is currently off the in queue and is
977 * being worked on through the inbound chunk processing.
979 struct sctp_chunk *in_progress;
981 /* This is the delayed task to finish delivering inbound
984 struct work_struct immediate;
987 void sctp_inq_init(struct sctp_inq *);
988 void sctp_inq_free(struct sctp_inq *);
989 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
990 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
991 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
992 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
994 /* This is the structure we use to hold outbound chunks. You push
995 * chunks in and they automatically pop out the other end as bundled
996 * packets (it calls (*output_handler)()).
998 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
999 * and 8.2 of the v13 draft.
1001 * It handles retransmissions. The connection to the timeout portion
1002 * of the state machine is through sctp_..._timeout() and timeout_handler.
1004 * If you feed it SACKs, it will eat them.
1006 * If you give it big chunks, it will fragment them.
1008 * It assigns TSN's to data chunks. This happens at the last possible
1009 * instant before transmission.
1011 * When free()'d, it empties itself out via output_handler().
1014 struct sctp_association *asoc;
1016 /* Data pending that has never been transmitted. */
1017 struct list_head out_chunk_list;
1019 unsigned int out_qlen; /* Total length of queued data chunks. */
1021 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1024 /* These are control chunks we want to send. */
1025 struct list_head control_chunk_list;
1027 /* These are chunks that have been sacked but are above the
1028 * CTSN, or cumulative tsn ack point.
1030 struct list_head sacked;
1032 /* Put chunks on this list to schedule them for
1035 struct list_head retransmit;
1037 /* Put chunks on this list to save them for FWD TSN processing as
1038 * they were abandoned.
1040 struct list_head abandoned;
1042 /* How many unackd bytes do we have in-flight? */
1043 __u32 outstanding_bytes;
1045 /* Are we doing fast-rtx on this queue */
1051 /* Is this structure empty? */
1055 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1056 void sctp_outq_teardown(struct sctp_outq *);
1057 void sctp_outq_free(struct sctp_outq*);
1058 int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1059 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1060 int sctp_outq_is_empty(const struct sctp_outq *);
1061 void sctp_outq_restart(struct sctp_outq *);
1063 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1064 sctp_retransmit_reason_t);
1065 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1066 int sctp_outq_uncork(struct sctp_outq *);
1067 /* Uncork and flush an outqueue. */
1068 static inline void sctp_outq_cork(struct sctp_outq *q)
1073 /* These bind address data fields common between endpoints and associations */
1074 struct sctp_bind_addr {
1076 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1078 * SCTP Port: The local SCTP port number the endpoint is
1083 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1085 * Address List: The list of IP addresses that this instance
1086 * has bound. This information is passed to one's
1087 * peer(s) in INIT and INIT ACK chunks.
1089 struct list_head address_list;
1092 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1093 void sctp_bind_addr_free(struct sctp_bind_addr *);
1094 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1095 const struct sctp_bind_addr *src,
1096 sctp_scope_t scope, gfp_t gfp,
1098 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1099 const struct sctp_bind_addr *src,
1101 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1102 __u8 addr_state, gfp_t gfp);
1103 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1104 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1105 struct sctp_sock *);
1106 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1107 struct sctp_sock *, struct sctp_sock *);
1108 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1109 const union sctp_addr *addr);
1110 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1111 const union sctp_addr *addrs,
1113 struct sctp_sock *opt);
1114 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1117 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1118 __u16 port, gfp_t gfp);
1120 sctp_scope_t sctp_scope(const union sctp_addr *);
1121 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1122 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1123 int sctp_addr_is_valid(const union sctp_addr *addr);
1124 int sctp_is_ep_boundall(struct sock *sk);
1127 /* What type of endpoint? */
1129 SCTP_EP_TYPE_SOCKET,
1130 SCTP_EP_TYPE_ASSOCIATION,
1131 } sctp_endpoint_type_t;
1134 * A common base class to bridge the implmentation view of a
1135 * socket (usually listening) endpoint versus an association's
1137 * This common structure is useful for several purposes:
1138 * 1) Common interface for lookup routines.
1139 * a) Subfunctions work for either endpoint or association
1140 * b) Single interface to lookup allows hiding the lookup lock rather
1141 * than acquiring it externally.
1142 * 2) Common interface for the inbound chunk handling/state machine.
1143 * 3) Common object handling routines for reference counting, etc.
1144 * 4) Disentangle association lookup from endpoint lookup, where we
1145 * do not have to find our endpoint to find our association.
1149 struct sctp_ep_common {
1150 /* Fields to help us manage our entries in the hash tables. */
1151 struct hlist_node node;
1154 /* Runtime type information. What kind of endpoint is this? */
1155 sctp_endpoint_type_t type;
1157 /* Some fields to help us manage this object.
1158 * refcnt - Reference count access to this object.
1159 * dead - Do not attempt to use this object.
1164 /* What socket does this endpoint belong to? */
1167 /* This is where we receive inbound chunks. */
1168 struct sctp_inq inqueue;
1170 /* This substructure includes the defining parameters of the
1172 * bind_addr.port is our shared port number.
1173 * bind_addr.address_list is our set of local IP addresses.
1175 struct sctp_bind_addr bind_addr;
1179 /* RFC Section 1.4 Key Terms
1181 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1182 * multi-homed host, an SCTP endpoint is represented to its peers as a
1183 * combination of a set of eligible destination transport addresses to
1184 * which SCTP packets can be sent and a set of eligible source
1185 * transport addresses from which SCTP packets can be received.
1186 * All transport addresses used by an SCTP endpoint must use the
1187 * same port number, but can use multiple IP addresses. A transport
1188 * address used by an SCTP endpoint must not be used by another
1189 * SCTP endpoint. In other words, a transport address is unique
1190 * to an SCTP endpoint.
1192 * From an implementation perspective, each socket has one of these.
1193 * A TCP-style socket will have exactly one association on one of
1194 * these. An UDP-style socket will have multiple associations hanging
1198 struct sctp_endpoint {
1199 /* Common substructure for endpoint and association. */
1200 struct sctp_ep_common base;
1202 /* Associations: A list of current associations and mappings
1203 * to the data consumers for each association. This
1204 * may be in the form of a hash table or other
1205 * implementation dependent structure. The data
1206 * consumers may be process identification
1207 * information such as file descriptors, named pipe
1208 * pointer, or table pointers dependent on how SCTP
1211 /* This is really a list of struct sctp_association entries. */
1212 struct list_head asocs;
1214 /* Secret Key: A secret key used by this endpoint to compute
1215 * the MAC. This SHOULD be a cryptographic quality
1216 * random number with a sufficient length.
1217 * Discussion in [RFC1750] can be helpful in
1218 * selection of the key.
1220 __u8 secret_key[SCTP_SECRET_SIZE];
1222 /* digest: This is a digest of the sctp cookie. This field is
1223 * only used on the receive path when we try to validate
1224 * that the cookie has not been tampered with. We put
1225 * this here so we pre-allocate this once and can re-use
1230 /* sendbuf acct. policy. */
1231 __u32 sndbuf_policy;
1233 /* rcvbuf acct. policy. */
1234 __u32 rcvbuf_policy;
1236 /* SCTP AUTH: array of the HMACs that will be allocated
1237 * we need this per association so that we don't serialize
1239 struct crypto_hash **auth_hmacs;
1241 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1242 struct sctp_hmac_algo_param *auth_hmacs_list;
1244 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1245 struct sctp_chunks_param *auth_chunk_list;
1247 /* SCTP-AUTH: endpoint shared keys */
1248 struct list_head endpoint_shared_keys;
1249 __u16 active_key_id;
1252 /* Recover the outter endpoint structure. */
1253 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1255 struct sctp_endpoint *ep;
1257 ep = container_of(base, struct sctp_endpoint, base);
1261 /* These are function signatures for manipulating endpoints. */
1262 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1263 void sctp_endpoint_free(struct sctp_endpoint *);
1264 void sctp_endpoint_put(struct sctp_endpoint *);
1265 void sctp_endpoint_hold(struct sctp_endpoint *);
1266 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1267 struct sctp_association *sctp_endpoint_lookup_assoc(
1268 const struct sctp_endpoint *ep,
1269 const union sctp_addr *paddr,
1270 struct sctp_transport **);
1271 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1272 const union sctp_addr *);
1273 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1274 struct net *, const union sctp_addr *);
1275 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1276 const union sctp_addr *paddr);
1278 int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
1279 sctp_cid_t, sctp_init_chunk_t *peer_init,
1280 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1281 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1282 const union sctp_addr *peer,
1283 sctp_init_chunk_t *init, gfp_t gfp);
1284 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1285 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1287 struct sctp_inithdr_host {
1290 __u16 num_outbound_streams;
1291 __u16 num_inbound_streams;
1295 /* SCTP_GET_ASSOC_STATS counters */
1296 struct sctp_priv_assoc_stats {
1297 /* Maximum observed rto in the association during subsequent
1298 * observations. Value is set to 0 if no RTO measurement took place
1299 * The transport where the max_rto was observed is returned in
1302 struct sockaddr_storage obs_rto_ipaddr;
1304 /* Total In and Out SACKs received and sent */
1307 /* Total In and Out packets received and sent */
1310 /* Total retransmitted chunks */
1312 /* TSN received > next expected */
1314 /* Duplicate Chunks received */
1316 /* Gap Ack Blocks received */
1318 /* Unordered data chunks sent and received */
1321 /* Ordered data chunks sent and received */
1324 /* Control chunks sent and received */
1331 * 12. Recommended Transmission Control Block (TCB) Parameters
1333 * This section details a recommended set of parameters that should
1334 * be contained within the TCB for an implementation. This section is
1335 * for illustrative purposes and should not be deemed as requirements
1336 * on an implementation or as an exhaustive list of all parameters
1337 * inside an SCTP TCB. Each implementation may need its own additional
1338 * parameters for optimization.
1342 /* Here we have information about each individual association. */
1343 struct sctp_association {
1345 /* A base structure common to endpoint and association.
1346 * In this context, it represents the associations's view
1347 * of the local endpoint of the association.
1349 struct sctp_ep_common base;
1351 /* Associations on the same socket. */
1352 struct list_head asocs;
1354 /* association id. */
1355 sctp_assoc_t assoc_id;
1357 /* This is our parent endpoint. */
1358 struct sctp_endpoint *ep;
1360 /* These are those association elements needed in the cookie. */
1361 struct sctp_cookie c;
1363 /* This is all information about our peer. */
1367 * Peer Rwnd : Current calculated value of the peer's rwnd.
1371 /* transport_addr_list
1373 * Peer : A list of SCTP transport addresses that the
1374 * Transport : peer is bound to. This information is derived
1375 * Address : from the INIT or INIT ACK and is used to
1376 * List : associate an inbound packet with a given
1377 * : association. Normally this information is
1378 * : hashed or keyed for quick lookup and access
1380 * : The list is also initialized with the list
1381 * : of addresses passed with the sctp_connectx()
1384 * It is a list of SCTP_transport's.
1386 struct list_head transport_addr_list;
1390 * Peer : A count of the number of peer addresses
1391 * Transport : in the Peer Transport Address List.
1395 __u16 transport_count;
1398 * The transport layer port number.
1404 * Primary : This is the current primary destination
1405 * Path : transport address of the peer endpoint. It
1406 * : may also specify a source transport address
1407 * : on this endpoint.
1409 * All of these paths live on transport_addr_list.
1411 * At the bakeoffs, we discovered that the intent of
1412 * primaryPath is that it only changes when the ULP
1413 * asks to have it changed. We add the activePath to
1414 * designate the connection we are currently using to
1415 * transmit new data and most control chunks.
1417 struct sctp_transport *primary_path;
1419 /* Cache the primary path address here, when we
1420 * need a an address for msg_name.
1422 union sctp_addr primary_addr;
1425 * The path that we are currently using to
1426 * transmit new data and most control chunks.
1428 struct sctp_transport *active_path;
1432 * RFC2960 6.4 Multi-homed SCTP Endpoints
1434 * Furthermore, when its peer is multi-homed, an
1435 * endpoint SHOULD try to retransmit a chunk to an
1436 * active destination transport address that is
1437 * different from the last destination address to
1438 * which the DATA chunk was sent.
1440 struct sctp_transport *retran_path;
1442 /* Pointer to last transport I have sent on. */
1443 struct sctp_transport *last_sent_to;
1445 /* This is the last transport I have received DATA on. */
1446 struct sctp_transport *last_data_from;
1449 * Mapping An array of bits or bytes indicating which out of
1450 * Array order TSN's have been received (relative to the
1451 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1452 * order packets have been received, this array
1453 * will be set to all zero. This structure may be
1454 * in the form of a circular buffer or bit array.
1456 * Last Rcvd : This is the last TSN received in
1457 * TSN : sequence. This value is set initially by
1458 * : taking the peer's Initial TSN, received in
1459 * : the INIT or INIT ACK chunk, and subtracting
1462 * Throughout most of the specification this is called the
1463 * "Cumulative TSN ACK Point". In this case, we
1464 * ignore the advice in 12.2 in favour of the term
1465 * used in the bulk of the text. This value is hidden
1466 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1468 struct sctp_tsnmap tsn_map;
1470 /* Ack State : This flag indicates if the next received
1471 * : packet is to be responded to with a
1472 * : SACK. This is initializedto 0. When a packet
1473 * : is received it is incremented. If this value
1474 * : reaches 2 or more, a SACK is sent and the
1475 * : value is reset to 0. Note: This is used only
1476 * : when no DATA chunks are received out of
1477 * : order. When DATA chunks are out of order,
1478 * : SACK's are not delayed (see Section 6).
1480 __u8 sack_needed; /* Do we need to sack the peer? */
1482 __u32 sack_generation;
1484 /* These are capabilities which our peer advertised. */
1485 __u8 ecn_capable:1, /* Can peer do ECN? */
1486 ipv4_address:1, /* Peer understands IPv4 addresses? */
1487 ipv6_address:1, /* Peer understands IPv6 addresses? */
1488 hostname_address:1, /* Peer understands DNS addresses? */
1489 asconf_capable:1, /* Does peer support ADDIP? */
1490 prsctp_capable:1, /* Can peer do PR-SCTP? */
1491 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1493 __u32 adaptation_ind; /* Adaptation Code point. */
1495 /* This mask is used to disable sending the ASCONF chunk
1496 * with specified parameter to peer.
1498 __be16 addip_disabled_mask;
1500 struct sctp_inithdr_host i;
1504 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1505 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1506 * Initial TSN Value minus 1
1510 /* SCTP-AUTH: We need to know pears random number, hmac list
1511 * and authenticated chunk list. All that is part of the
1512 * cookie and these are just pointers to those locations
1514 sctp_random_param_t *peer_random;
1515 sctp_chunks_param_t *peer_chunks;
1516 sctp_hmac_algo_param_t *peer_hmacs;
1519 /* State : A state variable indicating what state the
1520 * : association is in, i.e. COOKIE-WAIT,
1521 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1522 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1524 * Note: No "CLOSED" state is illustrated since if a
1525 * association is "CLOSED" its TCB SHOULD be removed.
1527 * In this implementation we DO have a CLOSED
1528 * state which is used during initiation and shutdown.
1530 * State takes values from SCTP_STATE_*.
1534 /* The cookie life I award for any cookie. */
1535 ktime_t cookie_life;
1537 /* Overall : The overall association error count.
1538 * Error Count : [Clear this any time I get something.]
1540 int overall_error_count;
1542 /* These are the association's initial, max, and min RTO values.
1543 * These values will be initialized by system defaults, but can
1544 * be modified via the SCTP_RTOINFO socket option.
1546 unsigned long rto_initial;
1547 unsigned long rto_max;
1548 unsigned long rto_min;
1550 /* Maximum number of new data packets that can be sent in a burst. */
1553 /* This is the max_retrans value for the association. This value will
1554 * be initialized initialized from system defaults, but can be
1555 * modified by the SCTP_ASSOCINFO socket option.
1559 /* This is the partially failed retrans value for the transport
1560 * and will be initialized from the assocs value. This can be
1561 * changed using the SCTP_PEER_ADDR_THLDS socket option
1565 /* Maximum number of times the endpoint will retransmit INIT */
1566 __u16 max_init_attempts;
1568 /* How many times have we resent an INIT? */
1571 /* The largest timeout or RTO value to use in attempting an INIT */
1572 unsigned long max_init_timeo;
1574 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1575 * the destination address every heartbeat interval. This value
1576 * will be inherited by all new transports.
1578 unsigned long hbinterval;
1580 /* This is the max_retrans value for new transports in the
1585 /* Flag that path mtu update is pending */
1588 /* Association : The smallest PMTU discovered for all of the
1589 * PMTU : peer's transport addresses.
1593 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1596 /* SACK delay timeout */
1597 unsigned long sackdelay;
1601 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1602 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1604 /* Transport to which SHUTDOWN chunk was last sent. */
1605 struct sctp_transport *shutdown_last_sent_to;
1607 /* How many times have we resent a SHUTDOWN */
1608 int shutdown_retries;
1610 /* Transport to which INIT chunk was last sent. */
1611 struct sctp_transport *init_last_sent_to;
1613 /* Next TSN : The next TSN number to be assigned to a new
1614 * : DATA chunk. This is sent in the INIT or INIT
1615 * : ACK chunk to the peer and incremented each
1616 * : time a DATA chunk is assigned a TSN
1617 * : (normally just prior to transmit or during
1623 * Last Rcvd : This is the last TSN received in sequence. This value
1624 * TSN : is set initially by taking the peer's Initial TSN,
1625 * : received in the INIT or INIT ACK chunk, and
1626 * : subtracting one from it.
1628 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1631 __u32 ctsn_ack_point;
1633 /* PR-SCTP Advanced.Peer.Ack.Point */
1634 __u32 adv_peer_ack_point;
1636 /* Highest TSN that is acknowledged by incoming SACKs. */
1637 __u32 highest_sacked;
1639 /* TSN marking the fast recovery exit point */
1640 __u32 fast_recovery_exit;
1642 /* Flag to track the current fast recovery state */
1645 /* The number of unacknowledged data chunks. Reported through
1646 * the SCTP_STATUS sockopt.
1650 /* The total number of data chunks that we've had to retransmit
1651 * as the result of a T3 timer expiration
1653 __u32 rtx_data_chunks;
1655 /* This is the association's receive buffer space. This value is used
1656 * to set a_rwnd field in an INIT or a SACK chunk.
1660 /* This is the last advertised value of rwnd over a SACK chunk. */
1663 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1664 * to slop over a maximum of the association's frag_point.
1668 /* Keeps treack of rwnd pressure. This happens when we have
1669 * a window, but not recevie buffer (i.e small packets). This one
1670 * is releases slowly (1 PMTU at a time ).
1674 /* This is the sndbuf size in use for the association.
1675 * This corresponds to the sndbuf size for the association,
1676 * as specified in the sk->sndbuf.
1680 /* This is the amount of memory that this association has allocated
1681 * in the receive path at any given time.
1683 atomic_t rmem_alloc;
1685 /* This is the wait queue head for send requests waiting on
1686 * the association sndbuf space.
1688 wait_queue_head_t wait;
1690 /* The message size at which SCTP fragmentation will occur. */
1694 /* Counter used to count INIT errors. */
1695 int init_err_counter;
1697 /* Count the number of INIT cycles (for doubling timeout). */
1700 /* Default send parameters. */
1701 __u16 default_stream;
1702 __u16 default_flags;
1704 __u32 default_context;
1705 __u32 default_timetolive;
1707 /* Default receive parameters */
1708 __u32 default_rcv_context;
1710 /* This tracks outbound ssn for a given stream. */
1711 struct sctp_ssnmap *ssnmap;
1713 /* All outbound chunks go through this structure. */
1714 struct sctp_outq outqueue;
1716 /* A smart pipe that will handle reordering and fragmentation,
1717 * as well as handle passing events up to the ULP.
1719 struct sctp_ulpq ulpq;
1721 /* Last TSN that caused an ECNE Chunk to be sent. */
1722 __u32 last_ecne_tsn;
1724 /* Last TSN that caused a CWR Chunk to be sent. */
1727 /* How many duplicated TSNs have we seen? */
1730 /* Number of seconds of idle time before an association is closed.
1731 * In the association context, this is really used as a boolean
1732 * since the real timeout is stored in the timeouts array
1736 /* These are to support
1737 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1738 * and Enforcement of Flow and Message Limits"
1739 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1740 * or "ADDIP" for short.
1745 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1747 * R1) One and only one ASCONF Chunk MAY be in transit and
1748 * unacknowledged at any one time. If a sender, after sending
1749 * an ASCONF chunk, decides it needs to transfer another
1750 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1751 * returns from the previous ASCONF Chunk before sending a
1752 * subsequent ASCONF. Note this restriction binds each side,
1753 * so at any time two ASCONF may be in-transit on any given
1754 * association (one sent from each endpoint).
1756 * [This is our one-and-only-one ASCONF in flight. If we do
1757 * not have an ASCONF in flight, this is NULL.]
1759 struct sctp_chunk *addip_last_asconf;
1761 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1763 * This is needed to implement itmes E1 - E4 of the updated
1764 * spec. Here is the justification:
1766 * Since the peer may bundle multiple ASCONF chunks toward us,
1767 * we now need the ability to cache multiple ACKs. The section
1768 * describes in detail how they are cached and cleaned up.
1770 struct list_head asconf_ack_list;
1772 /* These ASCONF chunks are waiting to be sent.
1774 * These chunaks can't be pushed to outqueue until receiving
1775 * ASCONF_ACK for the previous ASCONF indicated by
1776 * addip_last_asconf, so as to guarantee that only one ASCONF
1777 * is in flight at any time.
1779 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1781 * In defining the ASCONF Chunk transfer procedures, it is
1782 * essential that these transfers MUST NOT cause congestion
1783 * within the network. To achieve this, we place these
1784 * restrictions on the transfer of ASCONF Chunks:
1786 * R1) One and only one ASCONF Chunk MAY be in transit and
1787 * unacknowledged at any one time. If a sender, after sending
1788 * an ASCONF chunk, decides it needs to transfer another
1789 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1790 * returns from the previous ASCONF Chunk before sending a
1791 * subsequent ASCONF. Note this restriction binds each side,
1792 * so at any time two ASCONF may be in-transit on any given
1793 * association (one sent from each endpoint).
1796 * [I really think this is EXACTLY the sort of intelligence
1797 * which already resides in sctp_outq. Please move this
1798 * queue and its supporting logic down there. --piggy]
1800 struct list_head addip_chunk_list;
1802 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1804 * A2) A serial number should be assigned to the Chunk. The
1805 * serial number SHOULD be a monotonically increasing
1806 * number. The serial number SHOULD be initialized at
1807 * the start of the association to the same value as the
1808 * Initial TSN and every time a new ASCONF chunk is created
1809 * it is incremented by one after assigning the serial number
1810 * to the newly created chunk.
1813 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1815 * Serial Number : 32 bits (unsigned integer)
1817 * This value represents a Serial Number for the ASCONF
1818 * Chunk. The valid range of Serial Number is from 0 to
1819 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1820 * after reaching 4294967295.
1823 union sctp_addr *asconf_addr_del_pending;
1824 int src_out_of_asoc_ok;
1825 struct sctp_transport *new_transport;
1827 /* SCTP AUTH: list of the endpoint shared keys. These
1828 * keys are provided out of band by the user applicaton
1829 * and can't change during the lifetime of the association
1831 struct list_head endpoint_shared_keys;
1834 * The current generated assocaition shared key (secret)
1836 struct sctp_auth_bytes *asoc_shared_key;
1838 /* SCTP AUTH: hmac id of the first peer requested algorithm
1841 __u16 default_hmac_id;
1843 __u16 active_key_id;
1845 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1846 temp:1; /* Is it a temporary association? */
1848 struct sctp_priv_assoc_stats stats;
1852 /* An eyecatcher for determining if we are really looking at an
1853 * association data structure.
1856 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1859 /* Recover the outter association structure. */
1860 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1862 struct sctp_association *asoc;
1864 asoc = container_of(base, struct sctp_association, base);
1868 /* These are function signatures for manipulating associations. */
1871 struct sctp_association *
1872 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1873 sctp_scope_t scope, gfp_t gfp);
1874 void sctp_association_free(struct sctp_association *);
1875 void sctp_association_put(struct sctp_association *);
1876 void sctp_association_hold(struct sctp_association *);
1878 struct sctp_transport *sctp_assoc_choose_alter_transport(
1879 struct sctp_association *, struct sctp_transport *);
1880 void sctp_assoc_update_retran_path(struct sctp_association *);
1881 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1882 const union sctp_addr *);
1883 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1884 const union sctp_addr *laddr);
1885 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1886 const union sctp_addr *address,
1888 const int peer_state);
1889 void sctp_assoc_del_peer(struct sctp_association *asoc,
1890 const union sctp_addr *addr);
1891 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1892 struct sctp_transport *peer);
1893 void sctp_assoc_control_transport(struct sctp_association *,
1894 struct sctp_transport *,
1895 sctp_transport_cmd_t, sctp_sn_error_t);
1896 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1897 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1899 const union sctp_addr *,
1900 const union sctp_addr *);
1901 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1902 void sctp_assoc_update(struct sctp_association *old,
1903 struct sctp_association *new);
1905 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1907 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1908 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1909 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1910 void sctp_assoc_set_primary(struct sctp_association *,
1911 struct sctp_transport *);
1912 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1913 struct sctp_transport *);
1914 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1915 sctp_scope_t, gfp_t);
1916 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1917 struct sctp_cookie*,
1919 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1920 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1921 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1922 const struct sctp_association *asoc,
1924 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1926 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1927 const union sctp_addr *ss2);
1928 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1930 /* A convenience structure to parse out SCTP specific CMSGs. */
1931 typedef struct sctp_cmsgs {
1932 struct sctp_initmsg *init;
1933 struct sctp_sndrcvinfo *info;
1936 /* Structure for tracking memory objects */
1940 } sctp_dbg_objcnt_entry_t;
1942 #endif /* __sctp_structs_h__ */