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, see
23 * <http://www.gnu.org/licenses/>.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <linux-sctp@vger.kernel.org>
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
50 #include <linux/ktime.h>
51 #include <linux/rhashtable.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 sctp port control hash. */
124 struct sctp_bind_hashbucket
*port_hashtable
;
125 /* This is the hash of all transports. */
126 struct rhashtable transport_hashtable
;
128 /* Sizes of above hashtables. */
132 /* Default initialization values to be applied to new associations. */
134 __u16 max_outstreams
;
136 /* Flag to indicate whether computing and verifying checksum
138 bool checksum_disable
;
141 #define sctp_max_instreams (sctp_globals.max_instreams)
142 #define sctp_max_outstreams (sctp_globals.max_outstreams)
143 #define sctp_address_families (sctp_globals.address_families)
144 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
145 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
146 #define sctp_port_hashsize (sctp_globals.port_hashsize)
147 #define sctp_port_hashtable (sctp_globals.port_hashtable)
148 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
149 #define sctp_checksum_disable (sctp_globals.checksum_disable)
151 /* SCTP Socket type: UDP or TCP style. */
154 SCTP_SOCKET_UDP_HIGH_BANDWIDTH
,
156 } sctp_socket_type_t
;
158 /* Per socket SCTP information. */
160 /* inet_sock has to be the first member of sctp_sock */
161 struct inet_sock inet
;
162 /* What kind of a socket is this? */
163 sctp_socket_type_t type
;
165 /* PF_ family specific functions. */
168 /* Access to HMAC transform. */
169 struct crypto_shash
*hmac
;
172 /* What is our base endpointer? */
173 struct sctp_endpoint
*ep
;
175 struct sctp_bind_bucket
*bind_hash
;
176 /* Various Socket Options. */
177 __u16 default_stream
;
180 __u32 default_context
;
181 __u32 default_timetolive
;
182 __u32 default_rcv_context
;
185 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
186 * the destination address every heartbeat interval. This value
187 * will be inherited by all new associations.
191 /* This is the max_retrans value for new associations. */
194 /* The initial Path MTU to use for new associations. */
197 /* The default SACK delay timeout for new associations. */
201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
204 struct sctp_initmsg initmsg
;
205 struct sctp_rtoinfo rtoinfo
;
206 struct sctp_paddrparams paddrparam
;
207 struct sctp_event_subscribe subscribe
;
208 struct sctp_assocparams assocparams
;
213 __u32 adaptation_ind
;
221 data_ready_signalled
:1;
224 /* Receive to here while partial delivery is in effect. */
225 struct sk_buff_head pd_lobby
;
227 /* These must be the last fields, as they will skipped on copies,
228 * like on accept and peeloff operations
230 struct list_head auto_asconf_list
;
234 static inline struct sctp_sock
*sctp_sk(const struct sock
*sk
)
236 return (struct sctp_sock
*)sk
;
239 static inline struct sock
*sctp_opt2sk(const struct sctp_sock
*sp
)
241 return (struct sock
*)sp
;
244 #if IS_ENABLED(CONFIG_IPV6)
246 struct sctp_sock sctp
;
247 struct ipv6_pinfo inet6
;
249 #endif /* CONFIG_IPV6 */
252 /* This is our APPLICATION-SPECIFIC state cookie.
253 * THIS IS NOT DICTATED BY THE SPECIFICATION.
255 /* These are the parts of an association which we send in the cookie.
256 * Most of these are straight out of:
257 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
263 /* My : Tag expected in every inbound packet and sent
264 * Verification: in the INIT or INIT ACK chunk.
269 /* Peer's : Tag expected in every outbound packet except
270 * Verification: in the INIT chunk.
275 /* The rest of these are not from the spec, but really need to
279 /* My Tie Tag : Assist in discovering a restarting association. */
282 /* Peer's Tie Tag: Assist in discovering a restarting association. */
285 /* When does this cookie expire? */
288 /* Number of inbound/outbound streams which are set
289 * and negotiated during the INIT process.
291 __u16 sinit_num_ostreams
;
292 __u16 sinit_max_instreams
;
294 /* This is the first sequence number I used. */
297 /* This holds the originating address of the INIT packet. */
298 union sctp_addr peer_addr
;
301 * Include the source port of the INIT-ACK
307 /* Padding for future use */
310 __u32 adaptation_ind
;
312 __u8 auth_random
[sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
];
313 __u8 auth_hmacs
[SCTP_AUTH_NUM_HMACS
* sizeof(__u16
) + 2];
314 __u8 auth_chunks
[sizeof(sctp_paramhdr_t
) + SCTP_AUTH_MAX_CHUNKS
];
316 /* This is a shim for my peer's INIT packet, followed by
317 * a copy of the raw address list of the association.
318 * The length of the raw address list is saved in the
319 * raw_addr_list_len field, which will be used at the time when
320 * the association TCB is re-constructed from the cookie.
322 __u32 raw_addr_list_len
;
323 struct sctp_init_chunk peer_init
[0];
327 /* The format of our cookie that we send to our peer. */
328 struct sctp_signed_cookie
{
329 __u8 signature
[SCTP_SECRET_SIZE
];
330 __u32 __pad
; /* force sctp_cookie alignment to 64 bits */
331 struct sctp_cookie c
;
334 /* This is another convenience type to allocate memory for address
335 * params for the maximum size and pass such structures around
338 union sctp_addr_param
{
339 struct sctp_paramhdr p
;
340 struct sctp_ipv4addr_param v4
;
341 struct sctp_ipv6addr_param v6
;
344 /* A convenience type to allow walking through the various
345 * parameters and avoid casting all over the place.
349 struct sctp_paramhdr
*p
;
350 struct sctp_cookie_preserve_param
*life
;
351 struct sctp_hostname_param
*dns
;
352 struct sctp_cookie_param
*cookie
;
353 struct sctp_supported_addrs_param
*sat
;
354 struct sctp_ipv4addr_param
*v4
;
355 struct sctp_ipv6addr_param
*v6
;
356 union sctp_addr_param
*addr
;
357 struct sctp_adaptation_ind_param
*aind
;
358 struct sctp_supported_ext_param
*ext
;
359 struct sctp_random_param
*random
;
360 struct sctp_chunks_param
*chunks
;
361 struct sctp_hmac_algo_param
*hmac_algo
;
362 struct sctp_addip_param
*addip
;
365 /* RFC 2960. Section 3.3.5 Heartbeat.
366 * Heartbeat Information: variable length
367 * The Sender-specific Heartbeat Info field should normally include
368 * information about the sender's current time when this HEARTBEAT
369 * chunk is sent and the destination transport address to which this
370 * HEARTBEAT is sent (see Section 8.3).
372 typedef struct sctp_sender_hb_info
{
373 struct sctp_paramhdr param_hdr
;
374 union sctp_addr daddr
;
375 unsigned long sent_at
;
377 } __packed sctp_sender_hb_info_t
;
380 * RFC 2960 1.3.2 Sequenced Delivery within Streams
382 * The term "stream" is used in SCTP to refer to a sequence of user
383 * messages that are to be delivered to the upper-layer protocol in
384 * order with respect to other messages within the same stream. This is
385 * in contrast to its usage in TCP, where it refers to a sequence of
386 * bytes (in this document a byte is assumed to be eight bits).
389 * This is the structure we use to track both our outbound and inbound
390 * SSN, or Stream Sequence Numbers.
399 struct sctp_stream in
;
400 struct sctp_stream out
;
403 struct sctp_ssnmap
*sctp_ssnmap_new(__u16 in
, __u16 out
,
405 void sctp_ssnmap_free(struct sctp_ssnmap
*map
);
406 void sctp_ssnmap_clear(struct sctp_ssnmap
*map
);
408 /* What is the current SSN number for this stream? */
409 static inline __u16
sctp_ssn_peek(struct sctp_stream
*stream
, __u16 id
)
411 return stream
->ssn
[id
];
414 /* Return the next SSN number for this stream. */
415 static inline __u16
sctp_ssn_next(struct sctp_stream
*stream
, __u16 id
)
417 return stream
->ssn
[id
]++;
420 /* Skip over this ssn and all below. */
421 static inline void sctp_ssn_skip(struct sctp_stream
*stream
, __u16 id
,
424 stream
->ssn
[id
] = ssn
+1;
428 * Pointers to address related SCTP functions.
429 * (i.e. things that depend on the address family.)
432 int (*sctp_xmit
) (struct sk_buff
*skb
,
433 struct sctp_transport
*);
434 int (*setsockopt
) (struct sock
*sk
,
438 unsigned int optlen
);
439 int (*getsockopt
) (struct sock
*sk
,
444 int (*compat_setsockopt
) (struct sock
*sk
,
448 unsigned int optlen
);
449 int (*compat_getsockopt
) (struct sock
*sk
,
454 void (*get_dst
) (struct sctp_transport
*t
,
455 union sctp_addr
*saddr
,
458 void (*get_saddr
) (struct sctp_sock
*sk
,
459 struct sctp_transport
*t
,
461 void (*copy_addrlist
) (struct list_head
*,
462 struct net_device
*);
463 int (*cmp_addr
) (const union sctp_addr
*addr1
,
464 const union sctp_addr
*addr2
);
465 void (*addr_copy
) (union sctp_addr
*dst
,
466 union sctp_addr
*src
);
467 void (*from_skb
) (union sctp_addr
*,
470 void (*from_sk
) (union sctp_addr
*,
472 void (*from_addr_param
) (union sctp_addr
*,
473 union sctp_addr_param
*,
474 __be16 port
, int iif
);
475 int (*to_addr_param
) (const union sctp_addr
*,
476 union sctp_addr_param
*);
477 int (*addr_valid
) (union sctp_addr
*,
479 const struct sk_buff
*);
480 sctp_scope_t (*scope
) (union sctp_addr
*);
481 void (*inaddr_any
) (union sctp_addr
*, __be16
);
482 int (*is_any
) (const union sctp_addr
*);
483 int (*available
) (union sctp_addr
*,
485 int (*skb_iif
) (const struct sk_buff
*sk
);
486 int (*is_ce
) (const struct sk_buff
*sk
);
487 void (*seq_dump_addr
)(struct seq_file
*seq
,
488 union sctp_addr
*addr
);
489 void (*ecn_capable
)(struct sock
*sk
);
490 __u16 net_header_len
;
492 sa_family_t sa_family
;
493 struct list_head list
;
496 struct sctp_af
*sctp_get_af_specific(sa_family_t
);
497 int sctp_register_af(struct sctp_af
*);
499 /* Protocol family functions. */
501 void (*event_msgname
)(struct sctp_ulpevent
*, char *, int *);
502 void (*skb_msgname
) (struct sk_buff
*, char *, int *);
503 int (*af_supported
) (sa_family_t
, struct sctp_sock
*);
504 int (*cmp_addr
) (const union sctp_addr
*,
505 const union sctp_addr
*,
507 int (*bind_verify
) (struct sctp_sock
*, union sctp_addr
*);
508 int (*send_verify
) (struct sctp_sock
*, union sctp_addr
*);
509 int (*supported_addrs
)(const struct sctp_sock
*, __be16
*);
510 struct sock
*(*create_accept_sk
) (struct sock
*sk
,
511 struct sctp_association
*asoc
);
512 int (*addr_to_user
)(struct sctp_sock
*sk
, union sctp_addr
*addr
);
513 void (*to_sk_saddr
)(union sctp_addr
*, struct sock
*sk
);
514 void (*to_sk_daddr
)(union sctp_addr
*, struct sock
*sk
);
519 /* Structure to track chunk fragments that have been acked, but peer
520 * fragments of the same message have not.
522 struct sctp_datamsg
{
523 /* Chunks waiting to be submitted to lower layer. */
524 struct list_head chunks
;
525 /* Reference counting. */
527 /* When is this message no longer interesting to the peer? */
528 unsigned long expires_at
;
529 /* Did the messenge fail to send? */
532 can_abandon
:1, /* can chunks from this message can be abandoned. */
533 can_delay
; /* should this message be Nagle delayed */
536 struct sctp_datamsg
*sctp_datamsg_from_user(struct sctp_association
*,
537 struct sctp_sndrcvinfo
*,
539 void sctp_datamsg_put(struct sctp_datamsg
*);
540 void sctp_chunk_fail(struct sctp_chunk
*, int error
);
541 int sctp_chunk_abandoned(struct sctp_chunk
*);
543 /* RFC2960 1.4 Key Terms
545 * o Chunk: A unit of information within an SCTP packet, consisting of
546 * a chunk header and chunk-specific content.
548 * As a matter of convenience, we remember the SCTP common header for
549 * each chunk as well as a few other header pointers...
552 struct list_head list
;
556 /* This is our link to the per-transport transmitted list. */
557 struct list_head transmitted_list
;
559 /* This field is used by chunks that hold fragmented data.
560 * For the first fragment this is the list that holds the rest of
561 * fragments. For the remaining fragments, this is the link to the
562 * frag_list maintained in the first fragment.
564 struct list_head frag_list
;
566 /* This points to the sk_buff containing the actual data. */
569 /* In case of GSO packets, this will store the head one */
570 struct sk_buff
*head_skb
;
572 /* These are the SCTP headers by reverse order in a packet.
573 * Note that some of these may happen more than once. In that
574 * case, we point at the "current" one, whatever that means
575 * for that level of header.
578 /* We point this at the FIRST TLV parameter to chunk_hdr. */
579 union sctp_params param_hdr
;
582 struct sctp_datahdr
*data_hdr
;
583 struct sctp_inithdr
*init_hdr
;
584 struct sctp_sackhdr
*sack_hdr
;
585 struct sctp_heartbeathdr
*hb_hdr
;
586 struct sctp_sender_hb_info
*hbs_hdr
;
587 struct sctp_shutdownhdr
*shutdown_hdr
;
588 struct sctp_signed_cookie
*cookie_hdr
;
589 struct sctp_ecnehdr
*ecne_hdr
;
590 struct sctp_cwrhdr
*ecn_cwr_hdr
;
591 struct sctp_errhdr
*err_hdr
;
592 struct sctp_addiphdr
*addip_hdr
;
593 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
594 struct sctp_authhdr
*auth_hdr
;
599 struct sctp_chunkhdr
*chunk_hdr
;
600 struct sctphdr
*sctp_hdr
;
602 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
603 struct sctp_sndrcvinfo sinfo
;
605 /* Which association does this belong to? */
606 struct sctp_association
*asoc
;
608 /* What endpoint received this chunk? */
609 struct sctp_ep_common
*rcvr
;
611 /* We fill this in if we are calculating RTT. */
612 unsigned long sent_at
;
614 /* What is the origin IP address for this chunk? */
615 union sctp_addr source
;
616 /* Destination address for this chunk. */
617 union sctp_addr dest
;
619 /* For outbound message, track all fragments for SEND_FAILED. */
620 struct sctp_datamsg
*msg
;
622 /* For an inbound chunk, this tells us where it came from.
623 * For an outbound chunk, it tells us where we'd like it to
624 * go. It is NULL if we have no preference.
626 struct sctp_transport
*transport
;
628 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
629 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
630 * spec violates the principle premis that all chunks are processed
633 struct sk_buff
*auth_chunk
;
635 #define SCTP_CAN_FRTX 0x0
636 #define SCTP_NEED_FRTX 0x1
637 #define SCTP_DONT_FRTX 0x2
638 __u16 rtt_in_progress
:1, /* This chunk used for RTT calc? */
639 resent
:1, /* Has this chunk ever been resent. */
640 has_tsn
:1, /* Does this chunk have a TSN yet? */
641 has_ssn
:1, /* Does this chunk have a SSN yet? */
642 singleton
:1, /* Only chunk in the packet? */
643 end_of_packet
:1, /* Last chunk in the packet? */
644 ecn_ce_done
:1, /* Have we processed the ECN CE bit? */
645 pdiscard
:1, /* Discard the whole packet now? */
646 tsn_gap_acked
:1, /* Is this chunk acked by a GAP ACK? */
647 data_accepted
:1, /* At least 1 chunk accepted */
648 auth
:1, /* IN: was auth'ed | OUT: needs auth */
649 has_asconf
:1, /* IN: have seen an asconf before */
650 tsn_missing_report
:2, /* Data chunk missing counter. */
651 fast_retransmit
:2; /* Is this chunk fast retransmitted? */
654 void sctp_chunk_hold(struct sctp_chunk
*);
655 void sctp_chunk_put(struct sctp_chunk
*);
656 int sctp_user_addto_chunk(struct sctp_chunk
*chunk
, int len
,
657 struct iov_iter
*from
);
658 void sctp_chunk_free(struct sctp_chunk
*);
659 void *sctp_addto_chunk(struct sctp_chunk
*, int len
, const void *data
);
660 struct sctp_chunk
*sctp_chunkify(struct sk_buff
*,
661 const struct sctp_association
*,
662 struct sock
*, gfp_t gfp
);
663 void sctp_init_addrs(struct sctp_chunk
*, union sctp_addr
*,
665 const union sctp_addr
*sctp_source(const struct sctp_chunk
*chunk
);
668 SCTP_ADDR_NEW
, /* new address added to assoc/ep */
669 SCTP_ADDR_SRC
, /* address can be used as source */
670 SCTP_ADDR_DEL
, /* address about to be deleted */
673 /* This is a structure for holding either an IPv6 or an IPv4 address. */
674 struct sctp_sockaddr_entry
{
675 struct list_head list
;
682 #define SCTP_ADDRESS_TICK_DELAY 500
684 typedef struct sctp_chunk
*(sctp_packet_phandler_t
)(struct sctp_association
*);
686 /* This structure holds lists of chunks as we are assembling for
690 /* These are the SCTP header values (host order) for the packet. */
692 __u16 destination_port
;
695 /* This contains the payload chunks. */
696 struct list_head chunk_list
;
698 /* This is the overhead of the sctp and ip headers. */
700 /* This is the total size of all chunks INCLUDING padding. */
702 /* This is the maximum size this packet may have */
705 /* The packet is destined for this transport address.
706 * The function we finally use to pass down to the next lower
707 * layer lives in the transport structure.
709 struct sctp_transport
*transport
;
711 /* pointer to the auth chunk for this packet */
712 struct sctp_chunk
*auth
;
714 u8 has_cookie_echo
:1, /* This packet contains a COOKIE-ECHO chunk. */
715 has_sack
:1, /* This packet contains a SACK chunk. */
716 has_auth
:1, /* This packet contains an AUTH chunk */
717 has_data
:1, /* This packet contains at least 1 DATA chunk */
718 ipfragok
:1; /* So let ip fragment this packet */
721 struct sctp_packet
*sctp_packet_init(struct sctp_packet
*,
722 struct sctp_transport
*,
723 __u16 sport
, __u16 dport
);
724 struct sctp_packet
*sctp_packet_config(struct sctp_packet
*, __u32 vtag
, int);
725 sctp_xmit_t
sctp_packet_transmit_chunk(struct sctp_packet
*,
726 struct sctp_chunk
*, int, gfp_t
);
727 sctp_xmit_t
sctp_packet_append_chunk(struct sctp_packet
*,
728 struct sctp_chunk
*);
729 int sctp_packet_transmit(struct sctp_packet
*, gfp_t
);
730 void sctp_packet_free(struct sctp_packet
*);
732 static inline int sctp_packet_empty(struct sctp_packet
*packet
)
734 return packet
->size
== packet
->overhead
;
737 /* This represents a remote transport address.
738 * For local transport addresses, we just use union sctp_addr.
740 * RFC2960 Section 1.4 Key Terms
742 * o Transport address: A Transport Address is traditionally defined
743 * by Network Layer address, Transport Layer protocol and Transport
744 * Layer port number. In the case of SCTP running over IP, a
745 * transport address is defined by the combination of an IP address
746 * and an SCTP port number (where SCTP is the Transport protocol).
748 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
750 * o The sender keeps a separate congestion control parameter set for
751 * each of the destination addresses it can send to (not each
752 * source-destination pair but for each destination). The parameters
753 * should decay if the address is not used for a long enough time
757 struct sctp_transport
{
758 /* A list of transports. */
759 struct list_head transports
;
760 struct rhash_head node
;
762 /* Reference counting. */
764 /* RTO-Pending : A flag used to track if one of the DATA
765 * chunks sent to this address is currently being
766 * used to compute a RTT. If this flag is 0,
767 * the next DATA chunk sent to this destination
768 * should be used to compute a RTT and this flag
769 * should be set. Every time the RTT
770 * calculation completes (i.e. the DATA chunk
771 * is SACK'd) clear this flag.
776 * hb_sent : a flag that signals that we have a pending
781 /* Is the Path MTU update pending on this tranport */
784 /* Has this transport moved the ctsn since we last sacked */
790 /* This is the peer's IP address and port. */
791 union sctp_addr ipaddr
;
793 /* These are the functions we call to handle LLP stuff. */
794 struct sctp_af
*af_specific
;
796 /* Which association do we belong to? */
797 struct sctp_association
*asoc
;
801 * 12.3 Per Transport Address Data
803 * For each destination transport address in the peer's
804 * address list derived from the INIT or INIT ACK chunk, a
805 * number of data elements needs to be maintained including:
807 /* RTO : The current retransmission timeout value. */
810 __u32 rtt
; /* This is the most recent RTT. */
812 /* RTTVAR : The current RTT variation. */
815 /* SRTT : The current smoothed round trip time. */
819 * These are the congestion stats.
821 /* cwnd : The current congestion window. */
822 __u32 cwnd
; /* This is the actual cwnd. */
824 /* ssthresh : The current slow start threshold value. */
827 /* partial : The tracking method for increase of cwnd when in
828 * bytes acked : congestion avoidance mode (see Section 6.2.2)
830 __u32 partial_bytes_acked
;
832 /* Data that has been sent, but not acknowledged. */
835 __u32 burst_limited
; /* Holds old cwnd when max.burst is applied */
838 struct dst_entry
*dst
;
839 /* Source address. */
840 union sctp_addr saddr
;
842 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
843 * the destination address every heartbeat interval.
845 unsigned long hbinterval
;
847 /* SACK delay timeout */
848 unsigned long sackdelay
;
851 /* When was the last time that we heard from this transport? We use
852 * this to pick new active and retran paths.
854 ktime_t last_time_heard
;
856 /* When was the last time that we sent a chunk using this
857 * transport? We use this to check for idle transports
859 unsigned long last_time_sent
;
861 /* Last time(in jiffies) when cwnd is reduced due to the congestion
862 * indication based on ECNE chunk.
864 unsigned long last_time_ecne_reduced
;
866 /* This is the max_retrans value for the transport and will
867 * be initialized from the assocs value. This can be changed
868 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
872 /* This is the partially failed retrans value for the transport
873 * and will be initialized from the assocs value. This can be changed
874 * using the SCTP_PEER_ADDR_THLDS socket option
877 /* PMTU : The current known path MTU. */
880 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
883 /* The number of times INIT has been sent on this transport. */
886 /* state : The current state of this destination,
887 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
891 /* These are the error stats for this destination. */
893 /* Error count : The current error count for this destination. */
894 unsigned short error_count
;
896 /* Per : A timer used by each destination.
900 * [Everywhere else in the text this is called T3-rtx. -ed]
902 struct timer_list T3_rtx_timer
;
904 /* Heartbeat timer is per destination. */
905 struct timer_list hb_timer
;
907 /* Timer to handle ICMP proto unreachable envets */
908 struct timer_list proto_unreach_timer
;
910 /* Since we're using per-destination retransmission timers
911 * (see above), we're also using per-destination "transmitted"
912 * queues. This probably ought to be a private struct
913 * accessible only within the outqueue, but it's not, yet.
915 struct list_head transmitted
;
917 /* We build bundle-able packets for this transport here. */
918 struct sctp_packet packet
;
920 /* This is the list of transports that have chunks to send. */
921 struct list_head send_ready
;
923 /* State information saved for SFR_CACC algorithm. The key
924 * idea in SFR_CACC is to maintain state at the sender on a
925 * per-destination basis when a changeover happens.
926 * char changeover_active;
927 * char cycling_changeover;
928 * __u32 next_tsn_at_change;
929 * char cacc_saw_newack;
932 /* An unsigned integer, which stores the next TSN to be
933 * used by the sender, at the moment of changeover.
935 __u32 next_tsn_at_change
;
937 /* A flag which indicates the occurrence of a changeover */
938 char changeover_active
;
940 /* A flag which indicates whether the change of primary is
941 * the first switch to this destination address during an
944 char cycling_changeover
;
946 /* A temporary flag, which is used during the processing of
947 * a SACK to estimate the causative TSN(s)'s group.
949 char cacc_saw_newack
;
952 /* 64-bit random number sent with heartbeat. */
958 struct sctp_transport
*sctp_transport_new(struct net
*, const union sctp_addr
*,
960 void sctp_transport_set_owner(struct sctp_transport
*,
961 struct sctp_association
*);
962 void sctp_transport_route(struct sctp_transport
*, union sctp_addr
*,
964 void sctp_transport_pmtu(struct sctp_transport
*, struct sock
*sk
);
965 void sctp_transport_free(struct sctp_transport
*);
966 void sctp_transport_reset_t3_rtx(struct sctp_transport
*);
967 void sctp_transport_reset_hb_timer(struct sctp_transport
*);
968 int sctp_transport_hold(struct sctp_transport
*);
969 void sctp_transport_put(struct sctp_transport
*);
970 void sctp_transport_update_rto(struct sctp_transport
*, __u32
);
971 void sctp_transport_raise_cwnd(struct sctp_transport
*, __u32
, __u32
);
972 void sctp_transport_lower_cwnd(struct sctp_transport
*, sctp_lower_cwnd_t
);
973 void sctp_transport_burst_limited(struct sctp_transport
*);
974 void sctp_transport_burst_reset(struct sctp_transport
*);
975 unsigned long sctp_transport_timeout(struct sctp_transport
*);
976 void sctp_transport_reset(struct sctp_transport
*);
977 void sctp_transport_update_pmtu(struct sock
*, struct sctp_transport
*, u32
);
978 void sctp_transport_immediate_rtx(struct sctp_transport
*);
981 /* This is the structure we use to queue packets as they come into
982 * SCTP. We write packets to it and read chunks from it.
985 /* This is actually a queue of sctp_chunk each
986 * containing a partially decoded packet.
988 struct list_head in_chunk_list
;
989 /* This is the packet which is currently off the in queue and is
990 * being worked on through the inbound chunk processing.
992 struct sctp_chunk
*in_progress
;
994 /* This is the delayed task to finish delivering inbound
997 struct work_struct immediate
;
1000 void sctp_inq_init(struct sctp_inq
*);
1001 void sctp_inq_free(struct sctp_inq
*);
1002 void sctp_inq_push(struct sctp_inq
*, struct sctp_chunk
*packet
);
1003 struct sctp_chunk
*sctp_inq_pop(struct sctp_inq
*);
1004 struct sctp_chunkhdr
*sctp_inq_peek(struct sctp_inq
*);
1005 void sctp_inq_set_th_handler(struct sctp_inq
*, work_func_t
);
1007 /* This is the structure we use to hold outbound chunks. You push
1008 * chunks in and they automatically pop out the other end as bundled
1009 * packets (it calls (*output_handler)()).
1011 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1012 * and 8.2 of the v13 draft.
1014 * It handles retransmissions. The connection to the timeout portion
1015 * of the state machine is through sctp_..._timeout() and timeout_handler.
1017 * If you feed it SACKs, it will eat them.
1019 * If you give it big chunks, it will fragment them.
1021 * It assigns TSN's to data chunks. This happens at the last possible
1022 * instant before transmission.
1024 * When free()'d, it empties itself out via output_handler().
1027 struct sctp_association
*asoc
;
1029 /* Data pending that has never been transmitted. */
1030 struct list_head out_chunk_list
;
1032 unsigned int out_qlen
; /* Total length of queued data chunks. */
1034 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1037 /* These are control chunks we want to send. */
1038 struct list_head control_chunk_list
;
1040 /* These are chunks that have been sacked but are above the
1041 * CTSN, or cumulative tsn ack point.
1043 struct list_head sacked
;
1045 /* Put chunks on this list to schedule them for
1048 struct list_head retransmit
;
1050 /* Put chunks on this list to save them for FWD TSN processing as
1051 * they were abandoned.
1053 struct list_head abandoned
;
1055 /* How many unackd bytes do we have in-flight? */
1056 __u32 outstanding_bytes
;
1058 /* Are we doing fast-rtx on this queue */
1065 void sctp_outq_init(struct sctp_association
*, struct sctp_outq
*);
1066 void sctp_outq_teardown(struct sctp_outq
*);
1067 void sctp_outq_free(struct sctp_outq
*);
1068 int sctp_outq_tail(struct sctp_outq
*, struct sctp_chunk
*chunk
, gfp_t
);
1069 int sctp_outq_sack(struct sctp_outq
*, struct sctp_chunk
*);
1070 int sctp_outq_is_empty(const struct sctp_outq
*);
1071 void sctp_outq_restart(struct sctp_outq
*);
1073 void sctp_retransmit(struct sctp_outq
*, struct sctp_transport
*,
1074 sctp_retransmit_reason_t
);
1075 void sctp_retransmit_mark(struct sctp_outq
*, struct sctp_transport
*, __u8
);
1076 int sctp_outq_uncork(struct sctp_outq
*, gfp_t gfp
);
1077 /* Uncork and flush an outqueue. */
1078 static inline void sctp_outq_cork(struct sctp_outq
*q
)
1083 /* These bind address data fields common between endpoints and associations */
1084 struct sctp_bind_addr
{
1086 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1088 * SCTP Port: The local SCTP port number the endpoint is
1093 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1095 * Address List: The list of IP addresses that this instance
1096 * has bound. This information is passed to one's
1097 * peer(s) in INIT and INIT ACK chunks.
1099 struct list_head address_list
;
1102 void sctp_bind_addr_init(struct sctp_bind_addr
*, __u16 port
);
1103 void sctp_bind_addr_free(struct sctp_bind_addr
*);
1104 int sctp_bind_addr_copy(struct net
*net
, struct sctp_bind_addr
*dest
,
1105 const struct sctp_bind_addr
*src
,
1106 sctp_scope_t scope
, gfp_t gfp
,
1108 int sctp_bind_addr_dup(struct sctp_bind_addr
*dest
,
1109 const struct sctp_bind_addr
*src
,
1111 int sctp_add_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*,
1112 int new_size
, __u8 addr_state
, gfp_t gfp
);
1113 int sctp_del_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*);
1114 int sctp_bind_addr_match(struct sctp_bind_addr
*, const union sctp_addr
*,
1115 struct sctp_sock
*);
1116 int sctp_bind_addr_conflict(struct sctp_bind_addr
*, const union sctp_addr
*,
1117 struct sctp_sock
*, struct sctp_sock
*);
1118 int sctp_bind_addr_state(const struct sctp_bind_addr
*bp
,
1119 const union sctp_addr
*addr
);
1120 union sctp_addr
*sctp_find_unmatch_addr(struct sctp_bind_addr
*bp
,
1121 const union sctp_addr
*addrs
,
1123 struct sctp_sock
*opt
);
1124 union sctp_params
sctp_bind_addrs_to_raw(const struct sctp_bind_addr
*bp
,
1127 int sctp_raw_to_bind_addrs(struct sctp_bind_addr
*bp
, __u8
*raw
, int len
,
1128 __u16 port
, gfp_t gfp
);
1130 sctp_scope_t
sctp_scope(const union sctp_addr
*);
1131 int sctp_in_scope(struct net
*net
, const union sctp_addr
*addr
, const sctp_scope_t scope
);
1132 int sctp_is_any(struct sock
*sk
, const union sctp_addr
*addr
);
1133 int sctp_is_ep_boundall(struct sock
*sk
);
1136 /* What type of endpoint? */
1138 SCTP_EP_TYPE_SOCKET
,
1139 SCTP_EP_TYPE_ASSOCIATION
,
1140 } sctp_endpoint_type_t
;
1143 * A common base class to bridge the implmentation view of a
1144 * socket (usually listening) endpoint versus an association's
1146 * This common structure is useful for several purposes:
1147 * 1) Common interface for lookup routines.
1148 * a) Subfunctions work for either endpoint or association
1149 * b) Single interface to lookup allows hiding the lookup lock rather
1150 * than acquiring it externally.
1151 * 2) Common interface for the inbound chunk handling/state machine.
1152 * 3) Common object handling routines for reference counting, etc.
1153 * 4) Disentangle association lookup from endpoint lookup, where we
1154 * do not have to find our endpoint to find our association.
1158 struct sctp_ep_common
{
1159 /* Fields to help us manage our entries in the hash tables. */
1160 struct hlist_node node
;
1163 /* Runtime type information. What kind of endpoint is this? */
1164 sctp_endpoint_type_t type
;
1166 /* Some fields to help us manage this object.
1167 * refcnt - Reference count access to this object.
1168 * dead - Do not attempt to use this object.
1173 /* What socket does this endpoint belong to? */
1176 /* This is where we receive inbound chunks. */
1177 struct sctp_inq inqueue
;
1179 /* This substructure includes the defining parameters of the
1181 * bind_addr.port is our shared port number.
1182 * bind_addr.address_list is our set of local IP addresses.
1184 struct sctp_bind_addr bind_addr
;
1188 /* RFC Section 1.4 Key Terms
1190 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1191 * multi-homed host, an SCTP endpoint is represented to its peers as a
1192 * combination of a set of eligible destination transport addresses to
1193 * which SCTP packets can be sent and a set of eligible source
1194 * transport addresses from which SCTP packets can be received.
1195 * All transport addresses used by an SCTP endpoint must use the
1196 * same port number, but can use multiple IP addresses. A transport
1197 * address used by an SCTP endpoint must not be used by another
1198 * SCTP endpoint. In other words, a transport address is unique
1199 * to an SCTP endpoint.
1201 * From an implementation perspective, each socket has one of these.
1202 * A TCP-style socket will have exactly one association on one of
1203 * these. An UDP-style socket will have multiple associations hanging
1207 struct sctp_endpoint
{
1208 /* Common substructure for endpoint and association. */
1209 struct sctp_ep_common base
;
1211 /* Associations: A list of current associations and mappings
1212 * to the data consumers for each association. This
1213 * may be in the form of a hash table or other
1214 * implementation dependent structure. The data
1215 * consumers may be process identification
1216 * information such as file descriptors, named pipe
1217 * pointer, or table pointers dependent on how SCTP
1220 /* This is really a list of struct sctp_association entries. */
1221 struct list_head asocs
;
1223 /* Secret Key: A secret key used by this endpoint to compute
1224 * the MAC. This SHOULD be a cryptographic quality
1225 * random number with a sufficient length.
1226 * Discussion in [RFC1750] can be helpful in
1227 * selection of the key.
1229 __u8 secret_key
[SCTP_SECRET_SIZE
];
1231 /* digest: This is a digest of the sctp cookie. This field is
1232 * only used on the receive path when we try to validate
1233 * that the cookie has not been tampered with. We put
1234 * this here so we pre-allocate this once and can re-use
1239 /* sendbuf acct. policy. */
1240 __u32 sndbuf_policy
;
1242 /* rcvbuf acct. policy. */
1243 __u32 rcvbuf_policy
;
1245 /* SCTP AUTH: array of the HMACs that will be allocated
1246 * we need this per association so that we don't serialize
1248 struct crypto_shash
**auth_hmacs
;
1250 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1251 struct sctp_hmac_algo_param
*auth_hmacs_list
;
1253 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1254 struct sctp_chunks_param
*auth_chunk_list
;
1256 /* SCTP-AUTH: endpoint shared keys */
1257 struct list_head endpoint_shared_keys
;
1258 __u16 active_key_id
;
1262 /* Recover the outter endpoint structure. */
1263 static inline struct sctp_endpoint
*sctp_ep(struct sctp_ep_common
*base
)
1265 struct sctp_endpoint
*ep
;
1267 ep
= container_of(base
, struct sctp_endpoint
, base
);
1271 /* These are function signatures for manipulating endpoints. */
1272 struct sctp_endpoint
*sctp_endpoint_new(struct sock
*, gfp_t
);
1273 void sctp_endpoint_free(struct sctp_endpoint
*);
1274 void sctp_endpoint_put(struct sctp_endpoint
*);
1275 void sctp_endpoint_hold(struct sctp_endpoint
*);
1276 void sctp_endpoint_add_asoc(struct sctp_endpoint
*, struct sctp_association
*);
1277 struct sctp_association
*sctp_endpoint_lookup_assoc(
1278 const struct sctp_endpoint
*ep
,
1279 const union sctp_addr
*paddr
,
1280 struct sctp_transport
**);
1281 int sctp_endpoint_is_peeled_off(struct sctp_endpoint
*,
1282 const union sctp_addr
*);
1283 struct sctp_endpoint
*sctp_endpoint_is_match(struct sctp_endpoint
*,
1284 struct net
*, const union sctp_addr
*);
1285 int sctp_has_association(struct net
*net
, const union sctp_addr
*laddr
,
1286 const union sctp_addr
*paddr
);
1288 int sctp_verify_init(struct net
*net
, const struct sctp_endpoint
*ep
,
1289 const struct sctp_association
*asoc
,
1290 sctp_cid_t
, sctp_init_chunk_t
*peer_init
,
1291 struct sctp_chunk
*chunk
, struct sctp_chunk
**err_chunk
);
1292 int sctp_process_init(struct sctp_association
*, struct sctp_chunk
*chunk
,
1293 const union sctp_addr
*peer
,
1294 sctp_init_chunk_t
*init
, gfp_t gfp
);
1295 __u32
sctp_generate_tag(const struct sctp_endpoint
*);
1296 __u32
sctp_generate_tsn(const struct sctp_endpoint
*);
1298 struct sctp_inithdr_host
{
1301 __u16 num_outbound_streams
;
1302 __u16 num_inbound_streams
;
1306 /* SCTP_GET_ASSOC_STATS counters */
1307 struct sctp_priv_assoc_stats
{
1308 /* Maximum observed rto in the association during subsequent
1309 * observations. Value is set to 0 if no RTO measurement took place
1310 * The transport where the max_rto was observed is returned in
1313 struct sockaddr_storage obs_rto_ipaddr
;
1315 /* Total In and Out SACKs received and sent */
1318 /* Total In and Out packets received and sent */
1321 /* Total retransmitted chunks */
1323 /* TSN received > next expected */
1325 /* Duplicate Chunks received */
1327 /* Gap Ack Blocks received */
1329 /* Unordered data chunks sent and received */
1332 /* Ordered data chunks sent and received */
1335 /* Control chunks sent and received */
1342 * 12. Recommended Transmission Control Block (TCB) Parameters
1344 * This section details a recommended set of parameters that should
1345 * be contained within the TCB for an implementation. This section is
1346 * for illustrative purposes and should not be deemed as requirements
1347 * on an implementation or as an exhaustive list of all parameters
1348 * inside an SCTP TCB. Each implementation may need its own additional
1349 * parameters for optimization.
1353 /* Here we have information about each individual association. */
1354 struct sctp_association
{
1356 /* A base structure common to endpoint and association.
1357 * In this context, it represents the associations's view
1358 * of the local endpoint of the association.
1360 struct sctp_ep_common base
;
1362 /* Associations on the same socket. */
1363 struct list_head asocs
;
1365 /* association id. */
1366 sctp_assoc_t assoc_id
;
1368 /* This is our parent endpoint. */
1369 struct sctp_endpoint
*ep
;
1371 /* These are those association elements needed in the cookie. */
1372 struct sctp_cookie c
;
1374 /* This is all information about our peer. */
1376 /* transport_addr_list
1378 * Peer : A list of SCTP transport addresses that the
1379 * Transport : peer is bound to. This information is derived
1380 * Address : from the INIT or INIT ACK and is used to
1381 * List : associate an inbound packet with a given
1382 * : association. Normally this information is
1383 * : hashed or keyed for quick lookup and access
1385 * : The list is also initialized with the list
1386 * : of addresses passed with the sctp_connectx()
1389 * It is a list of SCTP_transport's.
1391 struct list_head transport_addr_list
;
1395 * Peer Rwnd : Current calculated value of the peer's rwnd.
1401 * Peer : A count of the number of peer addresses
1402 * Transport : in the Peer Transport Address List.
1406 __u16 transport_count
;
1409 * The transport layer port number.
1415 * Primary : This is the current primary destination
1416 * Path : transport address of the peer endpoint. It
1417 * : may also specify a source transport address
1418 * : on this endpoint.
1420 * All of these paths live on transport_addr_list.
1422 * At the bakeoffs, we discovered that the intent of
1423 * primaryPath is that it only changes when the ULP
1424 * asks to have it changed. We add the activePath to
1425 * designate the connection we are currently using to
1426 * transmit new data and most control chunks.
1428 struct sctp_transport
*primary_path
;
1430 /* Cache the primary path address here, when we
1431 * need a an address for msg_name.
1433 union sctp_addr primary_addr
;
1436 * The path that we are currently using to
1437 * transmit new data and most control chunks.
1439 struct sctp_transport
*active_path
;
1443 * RFC2960 6.4 Multi-homed SCTP Endpoints
1445 * Furthermore, when its peer is multi-homed, an
1446 * endpoint SHOULD try to retransmit a chunk to an
1447 * active destination transport address that is
1448 * different from the last destination address to
1449 * which the DATA chunk was sent.
1451 struct sctp_transport
*retran_path
;
1453 /* Pointer to last transport I have sent on. */
1454 struct sctp_transport
*last_sent_to
;
1456 /* This is the last transport I have received DATA on. */
1457 struct sctp_transport
*last_data_from
;
1460 * Mapping An array of bits or bytes indicating which out of
1461 * Array order TSN's have been received (relative to the
1462 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1463 * order packets have been received, this array
1464 * will be set to all zero. This structure may be
1465 * in the form of a circular buffer or bit array.
1467 * Last Rcvd : This is the last TSN received in
1468 * TSN : sequence. This value is set initially by
1469 * : taking the peer's Initial TSN, received in
1470 * : the INIT or INIT ACK chunk, and subtracting
1473 * Throughout most of the specification this is called the
1474 * "Cumulative TSN ACK Point". In this case, we
1475 * ignore the advice in 12.2 in favour of the term
1476 * used in the bulk of the text. This value is hidden
1477 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1479 struct sctp_tsnmap tsn_map
;
1481 /* This mask is used to disable sending the ASCONF chunk
1482 * with specified parameter to peer.
1484 __be16 addip_disabled_mask
;
1486 /* These are capabilities which our peer advertised. */
1487 __u8 ecn_capable
:1, /* Can peer do ECN? */
1488 ipv4_address
:1, /* Peer understands IPv4 addresses? */
1489 ipv6_address
:1, /* Peer understands IPv6 addresses? */
1490 hostname_address
:1, /* Peer understands DNS addresses? */
1491 asconf_capable
:1, /* Does peer support ADDIP? */
1492 prsctp_capable
:1, /* Can peer do PR-SCTP? */
1493 auth_capable
:1; /* Is peer doing SCTP-AUTH? */
1495 /* sack_needed : This flag indicates if the next received
1496 * : packet is to be responded to with a
1497 * : SACK. This is initialized to 0. When a packet
1498 * : is received sack_cnt is incremented. If this value
1499 * : reaches 2 or more, a SACK is sent and the
1500 * : value is reset to 0. Note: This is used only
1501 * : when no DATA chunks are received out of
1502 * : order. When DATA chunks are out of order,
1503 * : SACK's are not delayed (see Section 6).
1505 __u8 sack_needed
:1, /* Do we need to sack the peer? */
1507 zero_window_announced
:1;
1510 __u32 adaptation_ind
; /* Adaptation Code point. */
1512 struct sctp_inithdr_host i
;
1516 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1517 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1518 * Initial TSN Value minus 1
1522 /* SCTP-AUTH: We need to know pears random number, hmac list
1523 * and authenticated chunk list. All that is part of the
1524 * cookie and these are just pointers to those locations
1526 sctp_random_param_t
*peer_random
;
1527 sctp_chunks_param_t
*peer_chunks
;
1528 sctp_hmac_algo_param_t
*peer_hmacs
;
1531 /* State : A state variable indicating what state the
1532 * : association is in, i.e. COOKIE-WAIT,
1533 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1534 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1536 * Note: No "CLOSED" state is illustrated since if a
1537 * association is "CLOSED" its TCB SHOULD be removed.
1539 * In this implementation we DO have a CLOSED
1540 * state which is used during initiation and shutdown.
1542 * State takes values from SCTP_STATE_*.
1546 /* Overall : The overall association error count.
1547 * Error Count : [Clear this any time I get something.]
1549 int overall_error_count
;
1551 /* The cookie life I award for any cookie. */
1552 ktime_t cookie_life
;
1554 /* These are the association's initial, max, and min RTO values.
1555 * These values will be initialized by system defaults, but can
1556 * be modified via the SCTP_RTOINFO socket option.
1558 unsigned long rto_initial
;
1559 unsigned long rto_max
;
1560 unsigned long rto_min
;
1562 /* Maximum number of new data packets that can be sent in a burst. */
1565 /* This is the max_retrans value for the association. This value will
1566 * be initialized initialized from system defaults, but can be
1567 * modified by the SCTP_ASSOCINFO socket option.
1571 /* This is the partially failed retrans value for the transport
1572 * and will be initialized from the assocs value. This can be
1573 * changed using the SCTP_PEER_ADDR_THLDS socket option
1577 /* Maximum number of times the endpoint will retransmit INIT */
1578 __u16 max_init_attempts
;
1580 /* How many times have we resent an INIT? */
1583 /* The largest timeout or RTO value to use in attempting an INIT */
1584 unsigned long max_init_timeo
;
1586 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1587 * the destination address every heartbeat interval. This value
1588 * will be inherited by all new transports.
1590 unsigned long hbinterval
;
1592 /* This is the max_retrans value for new transports in the
1597 /* Flag that path mtu update is pending */
1600 /* Association : The smallest PMTU discovered for all of the
1601 * PMTU : peer's transport addresses.
1605 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1609 /* SACK delay timeout */
1610 unsigned long sackdelay
;
1612 unsigned long timeouts
[SCTP_NUM_TIMEOUT_TYPES
];
1613 struct timer_list timers
[SCTP_NUM_TIMEOUT_TYPES
];
1615 /* Transport to which SHUTDOWN chunk was last sent. */
1616 struct sctp_transport
*shutdown_last_sent_to
;
1618 /* Transport to which INIT chunk was last sent. */
1619 struct sctp_transport
*init_last_sent_to
;
1621 /* How many times have we resent a SHUTDOWN */
1622 int shutdown_retries
;
1624 /* Next TSN : The next TSN number to be assigned to a new
1625 * : DATA chunk. This is sent in the INIT or INIT
1626 * : ACK chunk to the peer and incremented each
1627 * : time a DATA chunk is assigned a TSN
1628 * : (normally just prior to transmit or during
1634 * Last Rcvd : This is the last TSN received in sequence. This value
1635 * TSN : is set initially by taking the peer's Initial TSN,
1636 * : received in the INIT or INIT ACK chunk, and
1637 * : subtracting one from it.
1639 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1642 __u32 ctsn_ack_point
;
1644 /* PR-SCTP Advanced.Peer.Ack.Point */
1645 __u32 adv_peer_ack_point
;
1647 /* Highest TSN that is acknowledged by incoming SACKs. */
1648 __u32 highest_sacked
;
1650 /* TSN marking the fast recovery exit point */
1651 __u32 fast_recovery_exit
;
1653 /* Flag to track the current fast recovery state */
1656 /* The number of unacknowledged data chunks. Reported through
1657 * the SCTP_STATUS sockopt.
1661 /* The total number of data chunks that we've had to retransmit
1662 * as the result of a T3 timer expiration
1664 __u32 rtx_data_chunks
;
1666 /* This is the association's receive buffer space. This value is used
1667 * to set a_rwnd field in an INIT or a SACK chunk.
1671 /* This is the last advertised value of rwnd over a SACK chunk. */
1674 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1675 * to slop over a maximum of the association's frag_point.
1679 /* Keeps treack of rwnd pressure. This happens when we have
1680 * a window, but not recevie buffer (i.e small packets). This one
1681 * is releases slowly (1 PMTU at a time ).
1685 /* This is the sndbuf size in use for the association.
1686 * This corresponds to the sndbuf size for the association,
1687 * as specified in the sk->sndbuf.
1691 /* This is the amount of memory that this association has allocated
1692 * in the receive path at any given time.
1694 atomic_t rmem_alloc
;
1696 /* This is the wait queue head for send requests waiting on
1697 * the association sndbuf space.
1699 wait_queue_head_t wait
;
1701 /* The message size at which SCTP fragmentation will occur. */
1705 /* Counter used to count INIT errors. */
1706 int init_err_counter
;
1708 /* Count the number of INIT cycles (for doubling timeout). */
1711 /* Default send parameters. */
1712 __u16 default_stream
;
1713 __u16 default_flags
;
1715 __u32 default_context
;
1716 __u32 default_timetolive
;
1718 /* Default receive parameters */
1719 __u32 default_rcv_context
;
1721 /* This tracks outbound ssn for a given stream. */
1722 struct sctp_ssnmap
*ssnmap
;
1724 /* All outbound chunks go through this structure. */
1725 struct sctp_outq outqueue
;
1727 /* A smart pipe that will handle reordering and fragmentation,
1728 * as well as handle passing events up to the ULP.
1730 struct sctp_ulpq ulpq
;
1732 /* Last TSN that caused an ECNE Chunk to be sent. */
1733 __u32 last_ecne_tsn
;
1735 /* Last TSN that caused a CWR Chunk to be sent. */
1738 /* How many duplicated TSNs have we seen? */
1741 /* These are to support
1742 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1743 * and Enforcement of Flow and Message Limits"
1744 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1745 * or "ADDIP" for short.
1750 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1752 * R1) One and only one ASCONF Chunk MAY be in transit and
1753 * unacknowledged at any one time. If a sender, after sending
1754 * an ASCONF chunk, decides it needs to transfer another
1755 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1756 * returns from the previous ASCONF Chunk before sending a
1757 * subsequent ASCONF. Note this restriction binds each side,
1758 * so at any time two ASCONF may be in-transit on any given
1759 * association (one sent from each endpoint).
1761 * [This is our one-and-only-one ASCONF in flight. If we do
1762 * not have an ASCONF in flight, this is NULL.]
1764 struct sctp_chunk
*addip_last_asconf
;
1766 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1768 * This is needed to implement itmes E1 - E4 of the updated
1769 * spec. Here is the justification:
1771 * Since the peer may bundle multiple ASCONF chunks toward us,
1772 * we now need the ability to cache multiple ACKs. The section
1773 * describes in detail how they are cached and cleaned up.
1775 struct list_head asconf_ack_list
;
1777 /* These ASCONF chunks are waiting to be sent.
1779 * These chunaks can't be pushed to outqueue until receiving
1780 * ASCONF_ACK for the previous ASCONF indicated by
1781 * addip_last_asconf, so as to guarantee that only one ASCONF
1782 * is in flight at any time.
1784 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1786 * In defining the ASCONF Chunk transfer procedures, it is
1787 * essential that these transfers MUST NOT cause congestion
1788 * within the network. To achieve this, we place these
1789 * restrictions on the transfer of ASCONF Chunks:
1791 * R1) One and only one ASCONF Chunk MAY be in transit and
1792 * unacknowledged at any one time. If a sender, after sending
1793 * an ASCONF chunk, decides it needs to transfer another
1794 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1795 * returns from the previous ASCONF Chunk before sending a
1796 * subsequent ASCONF. Note this restriction binds each side,
1797 * so at any time two ASCONF may be in-transit on any given
1798 * association (one sent from each endpoint).
1801 * [I really think this is EXACTLY the sort of intelligence
1802 * which already resides in sctp_outq. Please move this
1803 * queue and its supporting logic down there. --piggy]
1805 struct list_head addip_chunk_list
;
1807 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1809 * A2) A serial number should be assigned to the Chunk. The
1810 * serial number SHOULD be a monotonically increasing
1811 * number. The serial number SHOULD be initialized at
1812 * the start of the association to the same value as the
1813 * Initial TSN and every time a new ASCONF chunk is created
1814 * it is incremented by one after assigning the serial number
1815 * to the newly created chunk.
1818 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1820 * Serial Number : 32 bits (unsigned integer)
1822 * This value represents a Serial Number for the ASCONF
1823 * Chunk. The valid range of Serial Number is from 0 to
1824 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1825 * after reaching 4294967295.
1828 int src_out_of_asoc_ok
;
1829 union sctp_addr
*asconf_addr_del_pending
;
1830 struct sctp_transport
*new_transport
;
1832 /* SCTP AUTH: list of the endpoint shared keys. These
1833 * keys are provided out of band by the user applicaton
1834 * and can't change during the lifetime of the association
1836 struct list_head endpoint_shared_keys
;
1839 * The current generated assocaition shared key (secret)
1841 struct sctp_auth_bytes
*asoc_shared_key
;
1843 /* SCTP AUTH: hmac id of the first peer requested algorithm
1846 __u16 default_hmac_id
;
1848 __u16 active_key_id
;
1850 __u8 need_ecne
:1, /* Need to send an ECNE Chunk? */
1851 temp
:1; /* Is it a temporary association? */
1853 struct sctp_priv_assoc_stats stats
;
1857 /* An eyecatcher for determining if we are really looking at an
1858 * association data structure.
1861 SCTP_ASSOC_EYECATCHER
= 0xa550c123,
1864 /* Recover the outter association structure. */
1865 static inline struct sctp_association
*sctp_assoc(struct sctp_ep_common
*base
)
1867 struct sctp_association
*asoc
;
1869 asoc
= container_of(base
, struct sctp_association
, base
);
1873 /* These are function signatures for manipulating associations. */
1876 struct sctp_association
*
1877 sctp_association_new(const struct sctp_endpoint
*, const struct sock
*,
1878 sctp_scope_t scope
, gfp_t gfp
);
1879 void sctp_association_free(struct sctp_association
*);
1880 void sctp_association_put(struct sctp_association
*);
1881 void sctp_association_hold(struct sctp_association
*);
1883 struct sctp_transport
*sctp_assoc_choose_alter_transport(
1884 struct sctp_association
*, struct sctp_transport
*);
1885 void sctp_assoc_update_retran_path(struct sctp_association
*);
1886 struct sctp_transport
*sctp_assoc_lookup_paddr(const struct sctp_association
*,
1887 const union sctp_addr
*);
1888 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1889 const union sctp_addr
*laddr
);
1890 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*,
1891 const union sctp_addr
*address
,
1893 const int peer_state
);
1894 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
1895 const union sctp_addr
*addr
);
1896 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
1897 struct sctp_transport
*peer
);
1898 void sctp_assoc_control_transport(struct sctp_association
*,
1899 struct sctp_transport
*,
1900 sctp_transport_cmd_t
, sctp_sn_error_t
);
1901 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*, __u32
);
1902 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*,
1904 const union sctp_addr
*,
1905 const union sctp_addr
*);
1906 void sctp_assoc_migrate(struct sctp_association
*, struct sock
*);
1907 void sctp_assoc_update(struct sctp_association
*old
,
1908 struct sctp_association
*new);
1910 __u32
sctp_association_get_next_tsn(struct sctp_association
*);
1912 void sctp_assoc_sync_pmtu(struct sock
*, struct sctp_association
*);
1913 void sctp_assoc_rwnd_increase(struct sctp_association
*, unsigned int);
1914 void sctp_assoc_rwnd_decrease(struct sctp_association
*, unsigned int);
1915 void sctp_assoc_set_primary(struct sctp_association
*,
1916 struct sctp_transport
*);
1917 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*,
1918 struct sctp_transport
*);
1919 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*,
1920 sctp_scope_t
, gfp_t
);
1921 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*,
1922 struct sctp_cookie
*,
1924 int sctp_assoc_set_id(struct sctp_association
*, gfp_t
);
1925 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
);
1926 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1927 const struct sctp_association
*asoc
,
1929 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
);
1931 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
1932 const union sctp_addr
*ss2
);
1933 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
);
1935 /* A convenience structure to parse out SCTP specific CMSGs. */
1936 typedef struct sctp_cmsgs
{
1937 struct sctp_initmsg
*init
;
1938 struct sctp_sndrcvinfo
*srinfo
;
1939 struct sctp_sndinfo
*sinfo
;
1942 /* Structure for tracking memory objects */
1946 } sctp_dbg_objcnt_entry_t
;
1948 #endif /* __sctp_structs_h__ */