1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
8 * This file is part of the SCTP kernel implementation
10 * Please send any bug reports or fixes you make to the
12 * lksctp developers <linux-sctp@vger.kernel.org>
14 * Written or modified by:
15 * Randall Stewart <randall@sctp.chicago.il.us>
16 * Ken Morneau <kmorneau@cisco.com>
17 * Qiaobing Xie <qxie1@email.mot.com>
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Xingang Guo <xingang.guo@intel.com>
22 * Hui Huang <hui.huang@nokia.com>
23 * Sridhar Samudrala <sri@us.ibm.com>
24 * Daisy Chang <daisyc@us.ibm.com>
25 * Dajiang Zhang <dajiang.zhang@nokia.com>
26 * Ardelle Fan <ardelle.fan@intel.com>
27 * Ryan Layer <rmlayer@us.ibm.com>
28 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
29 * Kevin Gao <kevin.gao@intel.com>
32 #ifndef __sctp_structs_h__
33 #define __sctp_structs_h__
35 #include <linux/ktime.h>
36 #include <linux/generic-radix-tree.h>
37 #include <linux/rhashtable-types.h>
38 #include <linux/socket.h> /* linux/in.h needs this!! */
39 #include <linux/in.h> /* We get struct sockaddr_in. */
40 #include <linux/in6.h> /* We get struct in6_addr */
41 #include <linux/ipv6.h>
42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
43 #include <linux/atomic.h> /* This gets us atomic counters. */
44 #include <linux/skbuff.h> /* We need sk_buff_head. */
45 #include <linux/workqueue.h> /* We need tq_struct. */
46 #include <linux/sctp.h> /* We need sctp* header structs. */
47 #include <net/sctp/auth.h> /* We need auth specific structs */
48 #include <net/ip.h> /* For inet_skb_parm */
50 /* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
54 struct sockaddr_in v4
;
55 struct sockaddr_in6 v6
;
59 /* Forward declarations for data structures. */
62 struct sctp_association
;
63 struct sctp_transport
;
68 struct sctp_bind_addr
;
70 struct sctp_ep_common
;
75 #include <net/sctp/tsnmap.h>
76 #include <net/sctp/ulpevent.h>
77 #include <net/sctp/ulpqueue.h>
78 #include <net/sctp/stream_interleave.h>
80 /* Structures useful for managing bind/connect. */
82 struct sctp_bind_bucket
{
84 signed char fastreuse
;
85 signed char fastreuseport
;
87 struct hlist_node node
;
88 struct hlist_head owner
;
92 struct sctp_bind_hashbucket
{
94 struct hlist_head chain
;
97 /* Used for hashing all associations. */
98 struct sctp_hashbucket
{
100 struct hlist_head chain
;
101 } __attribute__((__aligned__(8)));
104 /* The SCTP globals structure. */
105 extern struct sctp_globals
{
106 /* This is a list of groups of functions for each address
107 * family that we support.
109 struct list_head address_families
;
111 /* This is the hash of all endpoints. */
112 struct sctp_hashbucket
*ep_hashtable
;
113 /* This is the sctp port control hash. */
114 struct sctp_bind_hashbucket
*port_hashtable
;
115 /* This is the hash of all transports. */
116 struct rhltable transport_hashtable
;
118 /* Sizes of above hashtables. */
122 /* Default initialization values to be applied to new associations. */
124 __u16 max_outstreams
;
126 /* Flag to indicate whether computing and verifying checksum
128 bool checksum_disable
;
131 #define sctp_max_instreams (sctp_globals.max_instreams)
132 #define sctp_max_outstreams (sctp_globals.max_outstreams)
133 #define sctp_address_families (sctp_globals.address_families)
134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
136 #define sctp_port_hashsize (sctp_globals.port_hashsize)
137 #define sctp_port_hashtable (sctp_globals.port_hashtable)
138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
139 #define sctp_checksum_disable (sctp_globals.checksum_disable)
141 /* SCTP Socket type: UDP or TCP style. */
142 enum sctp_socket_type
{
144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH
,
148 /* Per socket SCTP information. */
150 /* inet_sock has to be the first member of sctp_sock */
151 struct inet_sock inet
;
152 /* What kind of a socket is this? */
153 enum sctp_socket_type type
;
155 /* PF_ family specific functions. */
158 /* Access to HMAC transform. */
159 struct crypto_shash
*hmac
;
162 /* What is our base endpointer? */
163 struct sctp_endpoint
*ep
;
165 struct sctp_bind_bucket
*bind_hash
;
166 /* Various Socket Options. */
167 __u16 default_stream
;
170 __u32 default_context
;
171 __u32 default_timetolive
;
172 __u32 default_rcv_context
;
175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176 * the destination address every heartbeat interval. This value
177 * will be inherited by all new associations.
181 /* This is the max_retrans value for new associations. */
189 /* The initial Path MTU to use for new associations. */
192 /* The default SACK delay timeout for new associations. */
196 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
201 struct sctp_rtoinfo rtoinfo
;
202 struct sctp_paddrparams paddrparam
;
203 struct sctp_assocparams assocparams
;
206 * These two structures must be grouped together for the usercopy
210 struct sctp_initmsg initmsg
;
215 __u32 adaptation_ind
;
224 data_ready_signalled
:1;
227 /* Receive to here while partial delivery is in effect. */
228 struct sk_buff_head pd_lobby
;
230 /* These must be the last fields, as they will skipped on copies,
231 * like on accept and peeloff operations
233 struct list_head auto_asconf_list
;
237 static inline struct sctp_sock
*sctp_sk(const struct sock
*sk
)
239 return (struct sctp_sock
*)sk
;
242 static inline struct sock
*sctp_opt2sk(const struct sctp_sock
*sp
)
244 return (struct sock
*)sp
;
247 #if IS_ENABLED(CONFIG_IPV6)
249 struct sctp_sock sctp
;
250 struct ipv6_pinfo inet6
;
252 #endif /* CONFIG_IPV6 */
255 /* This is our APPLICATION-SPECIFIC state cookie.
256 * THIS IS NOT DICTATED BY THE SPECIFICATION.
258 /* These are the parts of an association which we send in the cookie.
259 * Most of these are straight out of:
260 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
266 /* My : Tag expected in every inbound packet and sent
267 * Verification: in the INIT or INIT ACK chunk.
272 /* Peer's : Tag expected in every outbound packet except
273 * Verification: in the INIT chunk.
278 /* The rest of these are not from the spec, but really need to
282 /* My Tie Tag : Assist in discovering a restarting association. */
285 /* Peer's Tie Tag: Assist in discovering a restarting association. */
288 /* When does this cookie expire? */
291 /* Number of inbound/outbound streams which are set
292 * and negotiated during the INIT process.
294 __u16 sinit_num_ostreams
;
295 __u16 sinit_max_instreams
;
297 /* This is the first sequence number I used. */
300 /* This holds the originating address of the INIT packet. */
301 union sctp_addr peer_addr
;
304 * Include the source port of the INIT-ACK
310 /* Padding for future use */
313 __u32 adaptation_ind
;
315 __u8 auth_random
[sizeof(struct sctp_paramhdr
) +
316 SCTP_AUTH_RANDOM_LENGTH
];
317 __u8 auth_hmacs
[SCTP_AUTH_NUM_HMACS
* sizeof(__u16
) + 2];
318 __u8 auth_chunks
[sizeof(struct sctp_paramhdr
) + SCTP_AUTH_MAX_CHUNKS
];
320 /* This is a shim for my peer's INIT packet, followed by
321 * a copy of the raw address list of the association.
322 * The length of the raw address list is saved in the
323 * raw_addr_list_len field, which will be used at the time when
324 * the association TCB is re-constructed from the cookie.
326 __u32 raw_addr_list_len
;
327 struct sctp_init_chunk peer_init
[0];
331 /* The format of our cookie that we send to our peer. */
332 struct sctp_signed_cookie
{
333 __u8 signature
[SCTP_SECRET_SIZE
];
334 __u32 __pad
; /* force sctp_cookie alignment to 64 bits */
335 struct sctp_cookie c
;
338 /* This is another convenience type to allocate memory for address
339 * params for the maximum size and pass such structures around
342 union sctp_addr_param
{
343 struct sctp_paramhdr p
;
344 struct sctp_ipv4addr_param v4
;
345 struct sctp_ipv6addr_param v6
;
348 /* A convenience type to allow walking through the various
349 * parameters and avoid casting all over the place.
353 struct sctp_paramhdr
*p
;
354 struct sctp_cookie_preserve_param
*life
;
355 struct sctp_hostname_param
*dns
;
356 struct sctp_cookie_param
*cookie
;
357 struct sctp_supported_addrs_param
*sat
;
358 struct sctp_ipv4addr_param
*v4
;
359 struct sctp_ipv6addr_param
*v6
;
360 union sctp_addr_param
*addr
;
361 struct sctp_adaptation_ind_param
*aind
;
362 struct sctp_supported_ext_param
*ext
;
363 struct sctp_random_param
*random
;
364 struct sctp_chunks_param
*chunks
;
365 struct sctp_hmac_algo_param
*hmac_algo
;
366 struct sctp_addip_param
*addip
;
369 /* RFC 2960. Section 3.3.5 Heartbeat.
370 * Heartbeat Information: variable length
371 * The Sender-specific Heartbeat Info field should normally include
372 * information about the sender's current time when this HEARTBEAT
373 * chunk is sent and the destination transport address to which this
374 * HEARTBEAT is sent (see Section 8.3).
376 struct sctp_sender_hb_info
{
377 struct sctp_paramhdr param_hdr
;
378 union sctp_addr daddr
;
379 unsigned long sent_at
;
383 int sctp_stream_init(struct sctp_stream
*stream
, __u16 outcnt
, __u16 incnt
,
385 int sctp_stream_init_ext(struct sctp_stream
*stream
, __u16 sid
);
386 void sctp_stream_free(struct sctp_stream
*stream
);
387 void sctp_stream_clear(struct sctp_stream
*stream
);
388 void sctp_stream_update(struct sctp_stream
*stream
, struct sctp_stream
*new);
390 /* What is the current SSN number for this stream? */
391 #define sctp_ssn_peek(stream, type, sid) \
392 (sctp_stream_##type((stream), (sid))->ssn)
394 /* Return the next SSN number for this stream. */
395 #define sctp_ssn_next(stream, type, sid) \
396 (sctp_stream_##type((stream), (sid))->ssn++)
398 /* Skip over this ssn and all below. */
399 #define sctp_ssn_skip(stream, type, sid, ssn) \
400 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
402 /* What is the current MID number for this stream? */
403 #define sctp_mid_peek(stream, type, sid) \
404 (sctp_stream_##type((stream), (sid))->mid)
406 /* Return the next MID number for this stream. */
407 #define sctp_mid_next(stream, type, sid) \
408 (sctp_stream_##type((stream), (sid))->mid++)
410 /* Skip over this mid and all below. */
411 #define sctp_mid_skip(stream, type, sid, mid) \
412 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
414 /* What is the current MID_uo number for this stream? */
415 #define sctp_mid_uo_peek(stream, type, sid) \
416 (sctp_stream_##type((stream), (sid))->mid_uo)
418 /* Return the next MID_uo number for this stream. */
419 #define sctp_mid_uo_next(stream, type, sid) \
420 (sctp_stream_##type((stream), (sid))->mid_uo++)
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 (*from_addr_param
) (union sctp_addr
*,
468 union sctp_addr_param
*,
469 __be16 port
, int iif
);
470 int (*to_addr_param
) (const union sctp_addr
*,
471 union sctp_addr_param
*);
472 int (*addr_valid
) (union sctp_addr
*,
474 const struct sk_buff
*);
475 enum sctp_scope (*scope
)(union sctp_addr
*);
476 void (*inaddr_any
) (union sctp_addr
*, __be16
);
477 int (*is_any
) (const union sctp_addr
*);
478 int (*available
) (union sctp_addr
*,
480 int (*skb_iif
) (const struct sk_buff
*sk
);
481 int (*is_ce
) (const struct sk_buff
*sk
);
482 void (*seq_dump_addr
)(struct seq_file
*seq
,
483 union sctp_addr
*addr
);
484 void (*ecn_capable
)(struct sock
*sk
);
485 __u16 net_header_len
;
487 int (*ip_options_len
)(struct sock
*sk
);
488 sa_family_t sa_family
;
489 struct list_head list
;
492 struct sctp_af
*sctp_get_af_specific(sa_family_t
);
493 int sctp_register_af(struct sctp_af
*);
495 /* Protocol family functions. */
497 void (*event_msgname
)(struct sctp_ulpevent
*, char *, int *);
498 void (*skb_msgname
) (struct sk_buff
*, char *, int *);
499 int (*af_supported
) (sa_family_t
, struct sctp_sock
*);
500 int (*cmp_addr
) (const union sctp_addr
*,
501 const union sctp_addr
*,
503 int (*bind_verify
) (struct sctp_sock
*, union sctp_addr
*);
504 int (*send_verify
) (struct sctp_sock
*, union sctp_addr
*);
505 int (*supported_addrs
)(const struct sctp_sock
*, __be16
*);
506 struct sock
*(*create_accept_sk
) (struct sock
*sk
,
507 struct sctp_association
*asoc
,
509 int (*addr_to_user
)(struct sctp_sock
*sk
, union sctp_addr
*addr
);
510 void (*to_sk_saddr
)(union sctp_addr
*, struct sock
*sk
);
511 void (*to_sk_daddr
)(union sctp_addr
*, struct sock
*sk
);
512 void (*copy_ip_options
)(struct sock
*sk
, struct sock
*newsk
);
517 /* Structure to track chunk fragments that have been acked, but peer
518 * fragments of the same message have not.
520 struct sctp_datamsg
{
521 /* Chunks waiting to be submitted to lower layer. */
522 struct list_head chunks
;
523 /* Reference counting. */
525 /* When is this message no longer interesting to the peer? */
526 unsigned long expires_at
;
527 /* Did the messenge fail to send? */
530 can_delay
:1, /* should this message be Nagle delayed */
531 abandoned
:1; /* should this message be abandoned */
534 struct sctp_datamsg
*sctp_datamsg_from_user(struct sctp_association
*,
535 struct sctp_sndrcvinfo
*,
537 void sctp_datamsg_free(struct sctp_datamsg
*);
538 void sctp_datamsg_put(struct sctp_datamsg
*);
539 void sctp_chunk_fail(struct sctp_chunk
*, int error
);
540 int sctp_chunk_abandoned(struct sctp_chunk
*);
542 /* RFC2960 1.4 Key Terms
544 * o Chunk: A unit of information within an SCTP packet, consisting of
545 * a chunk header and chunk-specific content.
547 * As a matter of convenience, we remember the SCTP common header for
548 * each chunk as well as a few other header pointers...
551 struct list_head list
;
555 /* How many times this chunk have been sent, for prsctp RTX policy */
559 /* This is our link to the per-transport transmitted list. */
560 struct list_head transmitted_list
;
561 /* List in specific stream outq */
562 struct list_head stream_list
;
565 /* This field is used by chunks that hold fragmented data.
566 * For the first fragment this is the list that holds the rest of
567 * fragments. For the remaining fragments, this is the link to the
568 * frag_list maintained in the first fragment.
570 struct list_head frag_list
;
572 /* This points to the sk_buff containing the actual data. */
576 /* In case of GSO packets, this will store the head one */
577 struct sk_buff
*head_skb
;
578 /* In case of auth enabled, this will point to the shkey */
579 struct sctp_shared_key
*shkey
;
582 /* These are the SCTP headers by reverse order in a packet.
583 * Note that some of these may happen more than once. In that
584 * case, we point at the "current" one, whatever that means
585 * for that level of header.
588 /* We point this at the FIRST TLV parameter to chunk_hdr. */
589 union sctp_params param_hdr
;
592 struct sctp_datahdr
*data_hdr
;
593 struct sctp_inithdr
*init_hdr
;
594 struct sctp_sackhdr
*sack_hdr
;
595 struct sctp_heartbeathdr
*hb_hdr
;
596 struct sctp_sender_hb_info
*hbs_hdr
;
597 struct sctp_shutdownhdr
*shutdown_hdr
;
598 struct sctp_signed_cookie
*cookie_hdr
;
599 struct sctp_ecnehdr
*ecne_hdr
;
600 struct sctp_cwrhdr
*ecn_cwr_hdr
;
601 struct sctp_errhdr
*err_hdr
;
602 struct sctp_addiphdr
*addip_hdr
;
603 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
604 struct sctp_authhdr
*auth_hdr
;
605 struct sctp_idatahdr
*idata_hdr
;
606 struct sctp_ifwdtsn_hdr
*ifwdtsn_hdr
;
611 struct sctp_chunkhdr
*chunk_hdr
;
612 struct sctphdr
*sctp_hdr
;
614 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
615 struct sctp_sndrcvinfo sinfo
;
617 /* Which association does this belong to? */
618 struct sctp_association
*asoc
;
620 /* What endpoint received this chunk? */
621 struct sctp_ep_common
*rcvr
;
623 /* We fill this in if we are calculating RTT. */
624 unsigned long sent_at
;
626 /* What is the origin IP address for this chunk? */
627 union sctp_addr source
;
628 /* Destination address for this chunk. */
629 union sctp_addr dest
;
631 /* For outbound message, track all fragments for SEND_FAILED. */
632 struct sctp_datamsg
*msg
;
634 /* For an inbound chunk, this tells us where it came from.
635 * For an outbound chunk, it tells us where we'd like it to
636 * go. It is NULL if we have no preference.
638 struct sctp_transport
*transport
;
640 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
641 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
642 * spec violates the principle premis that all chunks are processed
645 struct sk_buff
*auth_chunk
;
647 #define SCTP_CAN_FRTX 0x0
648 #define SCTP_NEED_FRTX 0x1
649 #define SCTP_DONT_FRTX 0x2
650 __u16 rtt_in_progress
:1, /* This chunk used for RTT calc? */
651 has_tsn
:1, /* Does this chunk have a TSN yet? */
652 has_ssn
:1, /* Does this chunk have a SSN yet? */
653 #define has_mid has_ssn
654 singleton
:1, /* Only chunk in the packet? */
655 end_of_packet
:1, /* Last chunk in the packet? */
656 ecn_ce_done
:1, /* Have we processed the ECN CE bit? */
657 pdiscard
:1, /* Discard the whole packet now? */
658 tsn_gap_acked
:1, /* Is this chunk acked by a GAP ACK? */
659 data_accepted
:1, /* At least 1 chunk accepted */
660 auth
:1, /* IN: was auth'ed | OUT: needs auth */
661 has_asconf
:1, /* IN: have seen an asconf before */
662 tsn_missing_report
:2, /* Data chunk missing counter. */
663 fast_retransmit
:2; /* Is this chunk fast retransmitted? */
666 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
667 void sctp_chunk_hold(struct sctp_chunk
*);
668 void sctp_chunk_put(struct sctp_chunk
*);
669 int sctp_user_addto_chunk(struct sctp_chunk
*chunk
, int len
,
670 struct iov_iter
*from
);
671 void sctp_chunk_free(struct sctp_chunk
*);
672 void *sctp_addto_chunk(struct sctp_chunk
*, int len
, const void *data
);
673 struct sctp_chunk
*sctp_chunkify(struct sk_buff
*,
674 const struct sctp_association
*,
675 struct sock
*, gfp_t gfp
);
676 void sctp_init_addrs(struct sctp_chunk
*, union sctp_addr
*,
678 const union sctp_addr
*sctp_source(const struct sctp_chunk
*chunk
);
680 static inline __u16
sctp_chunk_stream_no(struct sctp_chunk
*ch
)
682 return ntohs(ch
->subh
.data_hdr
->stream
);
686 SCTP_ADDR_NEW
, /* new address added to assoc/ep */
687 SCTP_ADDR_SRC
, /* address can be used as source */
688 SCTP_ADDR_DEL
, /* address about to be deleted */
691 /* This is a structure for holding either an IPv6 or an IPv4 address. */
692 struct sctp_sockaddr_entry
{
693 struct list_head list
;
700 #define SCTP_ADDRESS_TICK_DELAY 500
702 /* This structure holds lists of chunks as we are assembling for
706 /* These are the SCTP header values (host order) for the packet. */
708 __u16 destination_port
;
711 /* This contains the payload chunks. */
712 struct list_head chunk_list
;
714 /* This is the overhead of the sctp and ip headers. */
716 /* This is the total size of all chunks INCLUDING padding. */
718 /* This is the maximum size this packet may have */
721 /* The packet is destined for this transport address.
722 * The function we finally use to pass down to the next lower
723 * layer lives in the transport structure.
725 struct sctp_transport
*transport
;
727 /* pointer to the auth chunk for this packet */
728 struct sctp_chunk
*auth
;
730 u8 has_cookie_echo
:1, /* This packet contains a COOKIE-ECHO chunk. */
731 has_sack
:1, /* This packet contains a SACK chunk. */
732 has_auth
:1, /* This packet contains an AUTH chunk */
733 has_data
:1, /* This packet contains at least 1 DATA chunk */
734 ipfragok
:1; /* So let ip fragment this packet */
737 void sctp_packet_init(struct sctp_packet
*, struct sctp_transport
*,
738 __u16 sport
, __u16 dport
);
739 void sctp_packet_config(struct sctp_packet
*, __u32 vtag
, int);
740 enum sctp_xmit
sctp_packet_transmit_chunk(struct sctp_packet
*packet
,
741 struct sctp_chunk
*chunk
,
742 int one_packet
, gfp_t gfp
);
743 enum sctp_xmit
sctp_packet_append_chunk(struct sctp_packet
*packet
,
744 struct sctp_chunk
*chunk
);
745 int sctp_packet_transmit(struct sctp_packet
*, gfp_t
);
746 void sctp_packet_free(struct sctp_packet
*);
748 static inline int sctp_packet_empty(struct sctp_packet
*packet
)
750 return packet
->size
== packet
->overhead
;
753 /* This represents a remote transport address.
754 * For local transport addresses, we just use union sctp_addr.
756 * RFC2960 Section 1.4 Key Terms
758 * o Transport address: A Transport Address is traditionally defined
759 * by Network Layer address, Transport Layer protocol and Transport
760 * Layer port number. In the case of SCTP running over IP, a
761 * transport address is defined by the combination of an IP address
762 * and an SCTP port number (where SCTP is the Transport protocol).
764 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
766 * o The sender keeps a separate congestion control parameter set for
767 * each of the destination addresses it can send to (not each
768 * source-destination pair but for each destination). The parameters
769 * should decay if the address is not used for a long enough time
773 struct sctp_transport
{
774 /* A list of transports. */
775 struct list_head transports
;
776 struct rhlist_head node
;
778 /* Reference counting. */
780 /* RTO-Pending : A flag used to track if one of the DATA
781 * chunks sent to this address is currently being
782 * used to compute a RTT. If this flag is 0,
783 * the next DATA chunk sent to this destination
784 * should be used to compute a RTT and this flag
785 * should be set. Every time the RTT
786 * calculation completes (i.e. the DATA chunk
787 * is SACK'd) clear this flag.
792 * hb_sent : a flag that signals that we have a pending
797 /* Is the Path MTU update pending on this tranport */
800 dst_pending_confirm
:1, /* need to confirm neighbour */
802 /* Has this transport moved the ctsn since we last sacked */
808 /* This is the peer's IP address and port. */
809 union sctp_addr ipaddr
;
811 /* These are the functions we call to handle LLP stuff. */
812 struct sctp_af
*af_specific
;
814 /* Which association do we belong to? */
815 struct sctp_association
*asoc
;
819 * 12.3 Per Transport Address Data
821 * For each destination transport address in the peer's
822 * address list derived from the INIT or INIT ACK chunk, a
823 * number of data elements needs to be maintained including:
825 /* RTO : The current retransmission timeout value. */
828 __u32 rtt
; /* This is the most recent RTT. */
830 /* RTTVAR : The current RTT variation. */
833 /* SRTT : The current smoothed round trip time. */
837 * These are the congestion stats.
839 /* cwnd : The current congestion window. */
840 __u32 cwnd
; /* This is the actual cwnd. */
842 /* ssthresh : The current slow start threshold value. */
845 /* partial : The tracking method for increase of cwnd when in
846 * bytes acked : congestion avoidance mode (see Section 6.2.2)
848 __u32 partial_bytes_acked
;
850 /* Data that has been sent, but not acknowledged. */
853 __u32 burst_limited
; /* Holds old cwnd when max.burst is applied */
856 struct dst_entry
*dst
;
857 /* Source address. */
858 union sctp_addr saddr
;
860 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
861 * the destination address every heartbeat interval.
863 unsigned long hbinterval
;
865 /* SACK delay timeout */
866 unsigned long sackdelay
;
871 /* When was the last time that we heard from this transport? We use
872 * this to pick new active and retran paths.
874 ktime_t last_time_heard
;
876 /* When was the last time that we sent a chunk using this
877 * transport? We use this to check for idle transports
879 unsigned long last_time_sent
;
881 /* Last time(in jiffies) when cwnd is reduced due to the congestion
882 * indication based on ECNE chunk.
884 unsigned long last_time_ecne_reduced
;
886 /* This is the max_retrans value for the transport and will
887 * be initialized from the assocs value. This can be changed
888 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
895 /* This is the partially failed retrans value for the transport
896 * and will be initialized from the assocs value. This can be changed
897 * using the SCTP_PEER_ADDR_THLDS socket option
900 /* PMTU : The current known path MTU. */
903 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
906 /* The number of times INIT has been sent on this transport. */
909 /* state : The current state of this destination,
910 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
914 /* These are the error stats for this destination. */
916 /* Error count : The current error count for this destination. */
917 unsigned short error_count
;
919 /* Per : A timer used by each destination.
923 * [Everywhere else in the text this is called T3-rtx. -ed]
925 struct timer_list T3_rtx_timer
;
927 /* Heartbeat timer is per destination. */
928 struct timer_list hb_timer
;
930 /* Timer to handle ICMP proto unreachable envets */
931 struct timer_list proto_unreach_timer
;
933 /* Timer to handler reconf chunk rtx */
934 struct timer_list reconf_timer
;
936 /* Since we're using per-destination retransmission timers
937 * (see above), we're also using per-destination "transmitted"
938 * queues. This probably ought to be a private struct
939 * accessible only within the outqueue, but it's not, yet.
941 struct list_head transmitted
;
943 /* We build bundle-able packets for this transport here. */
944 struct sctp_packet packet
;
946 /* This is the list of transports that have chunks to send. */
947 struct list_head send_ready
;
949 /* State information saved for SFR_CACC algorithm. The key
950 * idea in SFR_CACC is to maintain state at the sender on a
951 * per-destination basis when a changeover happens.
952 * char changeover_active;
953 * char cycling_changeover;
954 * __u32 next_tsn_at_change;
955 * char cacc_saw_newack;
958 /* An unsigned integer, which stores the next TSN to be
959 * used by the sender, at the moment of changeover.
961 __u32 next_tsn_at_change
;
963 /* A flag which indicates the occurrence of a changeover */
964 char changeover_active
;
966 /* A flag which indicates whether the change of primary is
967 * the first switch to this destination address during an
970 char cycling_changeover
;
972 /* A temporary flag, which is used during the processing of
973 * a SACK to estimate the causative TSN(s)'s group.
975 char cacc_saw_newack
;
978 /* 64-bit random number sent with heartbeat. */
984 struct sctp_transport
*sctp_transport_new(struct net
*, const union sctp_addr
*,
986 void sctp_transport_set_owner(struct sctp_transport
*,
987 struct sctp_association
*);
988 void sctp_transport_route(struct sctp_transport
*, union sctp_addr
*,
990 void sctp_transport_pmtu(struct sctp_transport
*, struct sock
*sk
);
991 void sctp_transport_free(struct sctp_transport
*);
992 void sctp_transport_reset_t3_rtx(struct sctp_transport
*);
993 void sctp_transport_reset_hb_timer(struct sctp_transport
*);
994 void sctp_transport_reset_reconf_timer(struct sctp_transport
*transport
);
995 int sctp_transport_hold(struct sctp_transport
*);
996 void sctp_transport_put(struct sctp_transport
*);
997 void sctp_transport_update_rto(struct sctp_transport
*, __u32
);
998 void sctp_transport_raise_cwnd(struct sctp_transport
*, __u32
, __u32
);
999 void sctp_transport_lower_cwnd(struct sctp_transport
*t
,
1000 enum sctp_lower_cwnd reason
);
1001 void sctp_transport_burst_limited(struct sctp_transport
*);
1002 void sctp_transport_burst_reset(struct sctp_transport
*);
1003 unsigned long sctp_transport_timeout(struct sctp_transport
*);
1004 void sctp_transport_reset(struct sctp_transport
*t
);
1005 bool sctp_transport_update_pmtu(struct sctp_transport
*t
, u32 pmtu
);
1006 void sctp_transport_immediate_rtx(struct sctp_transport
*);
1007 void sctp_transport_dst_release(struct sctp_transport
*t
);
1008 void sctp_transport_dst_confirm(struct sctp_transport
*t
);
1011 /* This is the structure we use to queue packets as they come into
1012 * SCTP. We write packets to it and read chunks from it.
1015 /* This is actually a queue of sctp_chunk each
1016 * containing a partially decoded packet.
1018 struct list_head in_chunk_list
;
1019 /* This is the packet which is currently off the in queue and is
1020 * being worked on through the inbound chunk processing.
1022 struct sctp_chunk
*in_progress
;
1024 /* This is the delayed task to finish delivering inbound
1027 struct work_struct immediate
;
1030 void sctp_inq_init(struct sctp_inq
*);
1031 void sctp_inq_free(struct sctp_inq
*);
1032 void sctp_inq_push(struct sctp_inq
*, struct sctp_chunk
*packet
);
1033 struct sctp_chunk
*sctp_inq_pop(struct sctp_inq
*);
1034 struct sctp_chunkhdr
*sctp_inq_peek(struct sctp_inq
*);
1035 void sctp_inq_set_th_handler(struct sctp_inq
*, work_func_t
);
1037 /* This is the structure we use to hold outbound chunks. You push
1038 * chunks in and they automatically pop out the other end as bundled
1039 * packets (it calls (*output_handler)()).
1041 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1042 * and 8.2 of the v13 draft.
1044 * It handles retransmissions. The connection to the timeout portion
1045 * of the state machine is through sctp_..._timeout() and timeout_handler.
1047 * If you feed it SACKs, it will eat them.
1049 * If you give it big chunks, it will fragment them.
1051 * It assigns TSN's to data chunks. This happens at the last possible
1052 * instant before transmission.
1054 * When free()'d, it empties itself out via output_handler().
1057 struct sctp_association
*asoc
;
1059 /* Data pending that has never been transmitted. */
1060 struct list_head out_chunk_list
;
1062 /* Stream scheduler being used */
1063 struct sctp_sched_ops
*sched
;
1065 unsigned int out_qlen
; /* Total length of queued data chunks. */
1067 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1070 /* These are control chunks we want to send. */
1071 struct list_head control_chunk_list
;
1073 /* These are chunks that have been sacked but are above the
1074 * CTSN, or cumulative tsn ack point.
1076 struct list_head sacked
;
1078 /* Put chunks on this list to schedule them for
1081 struct list_head retransmit
;
1083 /* Put chunks on this list to save them for FWD TSN processing as
1084 * they were abandoned.
1086 struct list_head abandoned
;
1088 /* How many unackd bytes do we have in-flight? */
1089 __u32 outstanding_bytes
;
1091 /* Are we doing fast-rtx on this queue */
1098 void sctp_outq_init(struct sctp_association
*, struct sctp_outq
*);
1099 void sctp_outq_teardown(struct sctp_outq
*);
1100 void sctp_outq_free(struct sctp_outq
*);
1101 void sctp_outq_tail(struct sctp_outq
*, struct sctp_chunk
*chunk
, gfp_t
);
1102 int sctp_outq_sack(struct sctp_outq
*, struct sctp_chunk
*);
1103 int sctp_outq_is_empty(const struct sctp_outq
*);
1104 void sctp_outq_restart(struct sctp_outq
*);
1106 void sctp_retransmit(struct sctp_outq
*q
, struct sctp_transport
*transport
,
1107 enum sctp_retransmit_reason reason
);
1108 void sctp_retransmit_mark(struct sctp_outq
*, struct sctp_transport
*, __u8
);
1109 void sctp_outq_uncork(struct sctp_outq
*, gfp_t gfp
);
1110 void sctp_prsctp_prune(struct sctp_association
*asoc
,
1111 struct sctp_sndrcvinfo
*sinfo
, int msg_len
);
1112 void sctp_generate_fwdtsn(struct sctp_outq
*q
, __u32 sack_ctsn
);
1113 /* Uncork and flush an outqueue. */
1114 static inline void sctp_outq_cork(struct sctp_outq
*q
)
1119 /* SCTP skb control block.
1120 * sctp_input_cb is currently used on rx and sock rx queue
1122 struct sctp_input_cb
{
1124 struct inet_skb_parm h4
;
1125 #if IS_ENABLED(CONFIG_IPV6)
1126 struct inet6_skb_parm h6
;
1129 struct sctp_chunk
*chunk
;
1132 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1134 struct sctp_output_cb
{
1135 struct sk_buff
*last
;
1137 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1139 static inline const struct sk_buff
*sctp_gso_headskb(const struct sk_buff
*skb
)
1141 const struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
1143 return chunk
->head_skb
? : skb
;
1146 /* These bind address data fields common between endpoints and associations */
1147 struct sctp_bind_addr
{
1149 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1151 * SCTP Port: The local SCTP port number the endpoint is
1156 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1158 * Address List: The list of IP addresses that this instance
1159 * has bound. This information is passed to one's
1160 * peer(s) in INIT and INIT ACK chunks.
1162 struct list_head address_list
;
1165 void sctp_bind_addr_init(struct sctp_bind_addr
*, __u16 port
);
1166 void sctp_bind_addr_free(struct sctp_bind_addr
*);
1167 int sctp_bind_addr_copy(struct net
*net
, struct sctp_bind_addr
*dest
,
1168 const struct sctp_bind_addr
*src
,
1169 enum sctp_scope scope
, gfp_t gfp
,
1171 int sctp_bind_addr_dup(struct sctp_bind_addr
*dest
,
1172 const struct sctp_bind_addr
*src
,
1174 int sctp_add_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*,
1175 int new_size
, __u8 addr_state
, gfp_t gfp
);
1176 int sctp_del_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*);
1177 int sctp_bind_addr_match(struct sctp_bind_addr
*, const union sctp_addr
*,
1178 struct sctp_sock
*);
1179 int sctp_bind_addr_conflict(struct sctp_bind_addr
*, const union sctp_addr
*,
1180 struct sctp_sock
*, struct sctp_sock
*);
1181 int sctp_bind_addr_state(const struct sctp_bind_addr
*bp
,
1182 const union sctp_addr
*addr
);
1183 int sctp_bind_addrs_check(struct sctp_sock
*sp
,
1184 struct sctp_sock
*sp2
, int cnt2
);
1185 union sctp_addr
*sctp_find_unmatch_addr(struct sctp_bind_addr
*bp
,
1186 const union sctp_addr
*addrs
,
1188 struct sctp_sock
*opt
);
1189 union sctp_params
sctp_bind_addrs_to_raw(const struct sctp_bind_addr
*bp
,
1192 int sctp_raw_to_bind_addrs(struct sctp_bind_addr
*bp
, __u8
*raw
, int len
,
1193 __u16 port
, gfp_t gfp
);
1195 enum sctp_scope
sctp_scope(const union sctp_addr
*addr
);
1196 int sctp_in_scope(struct net
*net
, const union sctp_addr
*addr
,
1197 const enum sctp_scope scope
);
1198 int sctp_is_any(struct sock
*sk
, const union sctp_addr
*addr
);
1199 int sctp_is_ep_boundall(struct sock
*sk
);
1202 /* What type of endpoint? */
1203 enum sctp_endpoint_type
{
1204 SCTP_EP_TYPE_SOCKET
,
1205 SCTP_EP_TYPE_ASSOCIATION
,
1209 * A common base class to bridge the implmentation view of a
1210 * socket (usually listening) endpoint versus an association's
1212 * This common structure is useful for several purposes:
1213 * 1) Common interface for lookup routines.
1214 * a) Subfunctions work for either endpoint or association
1215 * b) Single interface to lookup allows hiding the lookup lock rather
1216 * than acquiring it externally.
1217 * 2) Common interface for the inbound chunk handling/state machine.
1218 * 3) Common object handling routines for reference counting, etc.
1219 * 4) Disentangle association lookup from endpoint lookup, where we
1220 * do not have to find our endpoint to find our association.
1224 struct sctp_ep_common
{
1225 /* Fields to help us manage our entries in the hash tables. */
1226 struct hlist_node node
;
1229 /* Runtime type information. What kind of endpoint is this? */
1230 enum sctp_endpoint_type type
;
1232 /* Some fields to help us manage this object.
1233 * refcnt - Reference count access to this object.
1234 * dead - Do not attempt to use this object.
1239 /* What socket does this endpoint belong to? */
1242 /* Cache netns and it won't change once set */
1245 /* This is where we receive inbound chunks. */
1246 struct sctp_inq inqueue
;
1248 /* This substructure includes the defining parameters of the
1250 * bind_addr.port is our shared port number.
1251 * bind_addr.address_list is our set of local IP addresses.
1253 struct sctp_bind_addr bind_addr
;
1257 /* RFC Section 1.4 Key Terms
1259 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1260 * multi-homed host, an SCTP endpoint is represented to its peers as a
1261 * combination of a set of eligible destination transport addresses to
1262 * which SCTP packets can be sent and a set of eligible source
1263 * transport addresses from which SCTP packets can be received.
1264 * All transport addresses used by an SCTP endpoint must use the
1265 * same port number, but can use multiple IP addresses. A transport
1266 * address used by an SCTP endpoint must not be used by another
1267 * SCTP endpoint. In other words, a transport address is unique
1268 * to an SCTP endpoint.
1270 * From an implementation perspective, each socket has one of these.
1271 * A TCP-style socket will have exactly one association on one of
1272 * these. An UDP-style socket will have multiple associations hanging
1276 struct sctp_endpoint
{
1277 /* Common substructure for endpoint and association. */
1278 struct sctp_ep_common base
;
1280 /* Associations: A list of current associations and mappings
1281 * to the data consumers for each association. This
1282 * may be in the form of a hash table or other
1283 * implementation dependent structure. The data
1284 * consumers may be process identification
1285 * information such as file descriptors, named pipe
1286 * pointer, or table pointers dependent on how SCTP
1289 /* This is really a list of struct sctp_association entries. */
1290 struct list_head asocs
;
1292 /* Secret Key: A secret key used by this endpoint to compute
1293 * the MAC. This SHOULD be a cryptographic quality
1294 * random number with a sufficient length.
1295 * Discussion in [RFC1750] can be helpful in
1296 * selection of the key.
1298 __u8 secret_key
[SCTP_SECRET_SIZE
];
1300 /* digest: This is a digest of the sctp cookie. This field is
1301 * only used on the receive path when we try to validate
1302 * that the cookie has not been tampered with. We put
1303 * this here so we pre-allocate this once and can re-use
1308 /* sendbuf acct. policy. */
1309 __u32 sndbuf_policy
;
1311 /* rcvbuf acct. policy. */
1312 __u32 rcvbuf_policy
;
1314 /* SCTP AUTH: array of the HMACs that will be allocated
1315 * we need this per association so that we don't serialize
1317 struct crypto_shash
**auth_hmacs
;
1319 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1320 struct sctp_hmac_algo_param
*auth_hmacs_list
;
1322 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1323 struct sctp_chunks_param
*auth_chunk_list
;
1325 /* SCTP-AUTH: endpoint shared keys */
1326 struct list_head endpoint_shared_keys
;
1327 __u16 active_key_id
;
1335 __u8 strreset_enable
;
1337 /* Security identifiers from incoming (INIT). These are set by
1338 * security_sctp_assoc_request(). These will only be used by
1339 * SCTP TCP type sockets and peeled off connections as they
1340 * cause a new socket to be generated. security_sctp_sk_clone()
1341 * will then plug these into the new socket.
1348 /* Recover the outter endpoint structure. */
1349 static inline struct sctp_endpoint
*sctp_ep(struct sctp_ep_common
*base
)
1351 struct sctp_endpoint
*ep
;
1353 ep
= container_of(base
, struct sctp_endpoint
, base
);
1357 /* These are function signatures for manipulating endpoints. */
1358 struct sctp_endpoint
*sctp_endpoint_new(struct sock
*, gfp_t
);
1359 void sctp_endpoint_free(struct sctp_endpoint
*);
1360 void sctp_endpoint_put(struct sctp_endpoint
*);
1361 void sctp_endpoint_hold(struct sctp_endpoint
*);
1362 void sctp_endpoint_add_asoc(struct sctp_endpoint
*, struct sctp_association
*);
1363 struct sctp_association
*sctp_endpoint_lookup_assoc(
1364 const struct sctp_endpoint
*ep
,
1365 const union sctp_addr
*paddr
,
1366 struct sctp_transport
**);
1367 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint
*ep
,
1368 const union sctp_addr
*paddr
);
1369 struct sctp_endpoint
*sctp_endpoint_is_match(struct sctp_endpoint
*,
1370 struct net
*, const union sctp_addr
*);
1371 bool sctp_has_association(struct net
*net
, const union sctp_addr
*laddr
,
1372 const union sctp_addr
*paddr
);
1374 int sctp_verify_init(struct net
*net
, const struct sctp_endpoint
*ep
,
1375 const struct sctp_association
*asoc
,
1376 enum sctp_cid cid
, struct sctp_init_chunk
*peer_init
,
1377 struct sctp_chunk
*chunk
, struct sctp_chunk
**err_chunk
);
1378 int sctp_process_init(struct sctp_association
*, struct sctp_chunk
*chunk
,
1379 const union sctp_addr
*peer
,
1380 struct sctp_init_chunk
*init
, gfp_t gfp
);
1381 __u32
sctp_generate_tag(const struct sctp_endpoint
*);
1382 __u32
sctp_generate_tsn(const struct sctp_endpoint
*);
1384 struct sctp_inithdr_host
{
1387 __u16 num_outbound_streams
;
1388 __u16 num_inbound_streams
;
1392 struct sctp_stream_priorities
{
1393 /* List of priorities scheduled */
1394 struct list_head prio_sched
;
1395 /* List of streams scheduled */
1396 struct list_head active
;
1397 /* The next stream stream in line */
1398 struct sctp_stream_out_ext
*next
;
1402 struct sctp_stream_out_ext
{
1403 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
1404 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
1405 struct list_head outq
; /* chunks enqueued by this stream */
1408 /* Scheduled streams list */
1409 struct list_head prio_list
;
1410 struct sctp_stream_priorities
*prio_head
;
1412 /* Fields used by RR scheduler */
1414 struct list_head rr_list
;
1419 struct sctp_stream_out
{
1425 struct sctp_stream_out_ext
*ext
;
1429 struct sctp_stream_in
{
1441 struct sctp_stream
{
1442 GENRADIX(struct sctp_stream_out
) out
;
1443 GENRADIX(struct sctp_stream_in
) in
;
1447 /* Current stream being sent, if any */
1448 struct sctp_stream_out
*out_curr
;
1450 /* Fields used by priority scheduler */
1452 /* List of priorities scheduled */
1453 struct list_head prio_list
;
1455 /* Fields used by RR scheduler */
1457 /* List of streams scheduled */
1458 struct list_head rr_list
;
1459 /* The next stream stream in line */
1460 struct sctp_stream_out_ext
*rr_next
;
1463 struct sctp_stream_interleave
*si
;
1466 static inline struct sctp_stream_out
*sctp_stream_out(
1467 struct sctp_stream
*stream
,
1470 return genradix_ptr(&stream
->out
, sid
);
1473 static inline struct sctp_stream_in
*sctp_stream_in(
1474 struct sctp_stream
*stream
,
1477 return genradix_ptr(&stream
->in
, sid
);
1480 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1481 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1483 #define SCTP_STREAM_CLOSED 0x00
1484 #define SCTP_STREAM_OPEN 0x01
1486 static inline __u16
sctp_datachk_len(const struct sctp_stream
*stream
)
1488 return stream
->si
->data_chunk_len
;
1491 static inline __u16
sctp_datahdr_len(const struct sctp_stream
*stream
)
1493 return stream
->si
->data_chunk_len
- sizeof(struct sctp_chunkhdr
);
1496 static inline __u16
sctp_ftsnchk_len(const struct sctp_stream
*stream
)
1498 return stream
->si
->ftsn_chunk_len
;
1501 static inline __u16
sctp_ftsnhdr_len(const struct sctp_stream
*stream
)
1503 return stream
->si
->ftsn_chunk_len
- sizeof(struct sctp_chunkhdr
);
1506 /* SCTP_GET_ASSOC_STATS counters */
1507 struct sctp_priv_assoc_stats
{
1508 /* Maximum observed rto in the association during subsequent
1509 * observations. Value is set to 0 if no RTO measurement took place
1510 * The transport where the max_rto was observed is returned in
1513 struct sockaddr_storage obs_rto_ipaddr
;
1515 /* Total In and Out SACKs received and sent */
1518 /* Total In and Out packets received and sent */
1521 /* Total retransmitted chunks */
1523 /* TSN received > next expected */
1525 /* Duplicate Chunks received */
1527 /* Gap Ack Blocks received */
1529 /* Unordered data chunks sent and received */
1532 /* Ordered data chunks sent and received */
1535 /* Control chunks sent and received */
1542 * 12. Recommended Transmission Control Block (TCB) Parameters
1544 * This section details a recommended set of parameters that should
1545 * be contained within the TCB for an implementation. This section is
1546 * for illustrative purposes and should not be deemed as requirements
1547 * on an implementation or as an exhaustive list of all parameters
1548 * inside an SCTP TCB. Each implementation may need its own additional
1549 * parameters for optimization.
1553 /* Here we have information about each individual association. */
1554 struct sctp_association
{
1556 /* A base structure common to endpoint and association.
1557 * In this context, it represents the associations's view
1558 * of the local endpoint of the association.
1560 struct sctp_ep_common base
;
1562 /* Associations on the same socket. */
1563 struct list_head asocs
;
1565 /* association id. */
1566 sctp_assoc_t assoc_id
;
1568 /* This is our parent endpoint. */
1569 struct sctp_endpoint
*ep
;
1571 /* These are those association elements needed in the cookie. */
1572 struct sctp_cookie c
;
1574 /* This is all information about our peer. */
1576 /* transport_addr_list
1578 * Peer : A list of SCTP transport addresses that the
1579 * Transport : peer is bound to. This information is derived
1580 * Address : from the INIT or INIT ACK and is used to
1581 * List : associate an inbound packet with a given
1582 * : association. Normally this information is
1583 * : hashed or keyed for quick lookup and access
1585 * : The list is also initialized with the list
1586 * : of addresses passed with the sctp_connectx()
1589 * It is a list of SCTP_transport's.
1591 struct list_head transport_addr_list
;
1595 * Peer Rwnd : Current calculated value of the peer's rwnd.
1601 * Peer : A count of the number of peer addresses
1602 * Transport : in the Peer Transport Address List.
1606 __u16 transport_count
;
1609 * The transport layer port number.
1615 * Primary : This is the current primary destination
1616 * Path : transport address of the peer endpoint. It
1617 * : may also specify a source transport address
1618 * : on this endpoint.
1620 * All of these paths live on transport_addr_list.
1622 * At the bakeoffs, we discovered that the intent of
1623 * primaryPath is that it only changes when the ULP
1624 * asks to have it changed. We add the activePath to
1625 * designate the connection we are currently using to
1626 * transmit new data and most control chunks.
1628 struct sctp_transport
*primary_path
;
1630 /* Cache the primary path address here, when we
1631 * need a an address for msg_name.
1633 union sctp_addr primary_addr
;
1636 * The path that we are currently using to
1637 * transmit new data and most control chunks.
1639 struct sctp_transport
*active_path
;
1643 * RFC2960 6.4 Multi-homed SCTP Endpoints
1645 * Furthermore, when its peer is multi-homed, an
1646 * endpoint SHOULD try to retransmit a chunk to an
1647 * active destination transport address that is
1648 * different from the last destination address to
1649 * which the DATA chunk was sent.
1651 struct sctp_transport
*retran_path
;
1653 /* Pointer to last transport I have sent on. */
1654 struct sctp_transport
*last_sent_to
;
1656 /* This is the last transport I have received DATA on. */
1657 struct sctp_transport
*last_data_from
;
1660 * Mapping An array of bits or bytes indicating which out of
1661 * Array order TSN's have been received (relative to the
1662 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1663 * order packets have been received, this array
1664 * will be set to all zero. This structure may be
1665 * in the form of a circular buffer or bit array.
1667 * Last Rcvd : This is the last TSN received in
1668 * TSN : sequence. This value is set initially by
1669 * : taking the peer's Initial TSN, received in
1670 * : the INIT or INIT ACK chunk, and subtracting
1673 * Throughout most of the specification this is called the
1674 * "Cumulative TSN ACK Point". In this case, we
1675 * ignore the advice in 12.2 in favour of the term
1676 * used in the bulk of the text. This value is hidden
1677 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1679 struct sctp_tsnmap tsn_map
;
1681 /* This mask is used to disable sending the ASCONF chunk
1682 * with specified parameter to peer.
1684 __be16 addip_disabled_mask
;
1686 /* These are capabilities which our peer advertised. */
1687 __u16 ecn_capable
:1, /* Can peer do ECN? */
1688 ipv4_address
:1, /* Peer understands IPv4 addresses? */
1689 ipv6_address
:1, /* Peer understands IPv6 addresses? */
1690 hostname_address
:1, /* Peer understands DNS addresses? */
1691 asconf_capable
:1, /* Does peer support ADDIP? */
1692 prsctp_capable
:1, /* Can peer do PR-SCTP? */
1693 reconf_capable
:1, /* Can peer do RE-CONFIG? */
1694 intl_capable
:1, /* Can peer do INTERLEAVE */
1695 auth_capable
:1, /* Is peer doing SCTP-AUTH? */
1697 * This flag indicates if the next received
1698 * packet is to be responded to with a
1699 * SACK. This is initialized to 0. When a packet
1700 * is received sack_cnt is incremented. If this value
1701 * reaches 2 or more, a SACK is sent and the
1702 * value is reset to 0. Note: This is used only
1703 * when no DATA chunks are received out of
1704 * order. When DATA chunks are out of order,
1705 * SACK's are not delayed (see Section 6).
1707 sack_needed
:1, /* Do we need to sack the peer? */
1709 zero_window_announced
:1;
1713 __u32 adaptation_ind
; /* Adaptation Code point. */
1715 struct sctp_inithdr_host i
;
1719 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1720 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1721 * Initial TSN Value minus 1
1725 /* SCTP-AUTH: We need to know pears random number, hmac list
1726 * and authenticated chunk list. All that is part of the
1727 * cookie and these are just pointers to those locations
1729 struct sctp_random_param
*peer_random
;
1730 struct sctp_chunks_param
*peer_chunks
;
1731 struct sctp_hmac_algo_param
*peer_hmacs
;
1734 /* State : A state variable indicating what state the
1735 * : association is in, i.e. COOKIE-WAIT,
1736 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1737 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1739 * Note: No "CLOSED" state is illustrated since if a
1740 * association is "CLOSED" its TCB SHOULD be removed.
1742 * In this implementation we DO have a CLOSED
1743 * state which is used during initiation and shutdown.
1745 * State takes values from SCTP_STATE_*.
1747 enum sctp_state state
;
1749 /* Overall : The overall association error count.
1750 * Error Count : [Clear this any time I get something.]
1752 int overall_error_count
;
1754 /* The cookie life I award for any cookie. */
1755 ktime_t cookie_life
;
1757 /* These are the association's initial, max, and min RTO values.
1758 * These values will be initialized by system defaults, but can
1759 * be modified via the SCTP_RTOINFO socket option.
1761 unsigned long rto_initial
;
1762 unsigned long rto_max
;
1763 unsigned long rto_min
;
1765 /* Maximum number of new data packets that can be sent in a burst. */
1768 /* This is the max_retrans value for the association. This value will
1769 * be initialized initialized from system defaults, but can be
1770 * modified by the SCTP_ASSOCINFO socket option.
1774 /* This is the partially failed retrans value for the transport
1775 * and will be initialized from the assocs value. This can be
1776 * changed using the SCTP_PEER_ADDR_THLDS socket option
1780 /* Maximum number of times the endpoint will retransmit INIT */
1781 __u16 max_init_attempts
;
1783 /* How many times have we resent an INIT? */
1786 /* The largest timeout or RTO value to use in attempting an INIT */
1787 unsigned long max_init_timeo
;
1789 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1790 * the destination address every heartbeat interval. This value
1791 * will be inherited by all new transports.
1793 unsigned long hbinterval
;
1795 /* This is the max_retrans value for new transports in the
1803 /* Flag that path mtu update is pending */
1806 /* Association : The smallest PMTU discovered for all of the
1807 * PMTU : peer's transport addresses.
1811 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1815 /* SACK delay timeout */
1816 unsigned long sackdelay
;
1818 unsigned long timeouts
[SCTP_NUM_TIMEOUT_TYPES
];
1819 struct timer_list timers
[SCTP_NUM_TIMEOUT_TYPES
];
1821 /* Transport to which SHUTDOWN chunk was last sent. */
1822 struct sctp_transport
*shutdown_last_sent_to
;
1824 /* Transport to which INIT chunk was last sent. */
1825 struct sctp_transport
*init_last_sent_to
;
1827 /* How many times have we resent a SHUTDOWN */
1828 int shutdown_retries
;
1830 /* Next TSN : The next TSN number to be assigned to a new
1831 * : DATA chunk. This is sent in the INIT or INIT
1832 * : ACK chunk to the peer and incremented each
1833 * : time a DATA chunk is assigned a TSN
1834 * : (normally just prior to transmit or during
1840 * Last Rcvd : This is the last TSN received in sequence. This value
1841 * TSN : is set initially by taking the peer's Initial TSN,
1842 * : received in the INIT or INIT ACK chunk, and
1843 * : subtracting one from it.
1845 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1848 __u32 ctsn_ack_point
;
1850 /* PR-SCTP Advanced.Peer.Ack.Point */
1851 __u32 adv_peer_ack_point
;
1853 /* Highest TSN that is acknowledged by incoming SACKs. */
1854 __u32 highest_sacked
;
1856 /* TSN marking the fast recovery exit point */
1857 __u32 fast_recovery_exit
;
1859 /* Flag to track the current fast recovery state */
1862 /* The number of unacknowledged data chunks. Reported through
1863 * the SCTP_STATUS sockopt.
1867 /* The total number of data chunks that we've had to retransmit
1868 * as the result of a T3 timer expiration
1870 __u32 rtx_data_chunks
;
1872 /* This is the association's receive buffer space. This value is used
1873 * to set a_rwnd field in an INIT or a SACK chunk.
1877 /* This is the last advertised value of rwnd over a SACK chunk. */
1880 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1881 * to slop over a maximum of the association's frag_point.
1885 /* Keeps treack of rwnd pressure. This happens when we have
1886 * a window, but not recevie buffer (i.e small packets). This one
1887 * is releases slowly (1 PMTU at a time ).
1891 /* This is the sndbuf size in use for the association.
1892 * This corresponds to the sndbuf size for the association,
1893 * as specified in the sk->sndbuf.
1897 /* This is the amount of memory that this association has allocated
1898 * in the receive path at any given time.
1900 atomic_t rmem_alloc
;
1902 /* This is the wait queue head for send requests waiting on
1903 * the association sndbuf space.
1905 wait_queue_head_t wait
;
1907 /* The message size at which SCTP fragmentation will occur. */
1911 /* Counter used to count INIT errors. */
1912 int init_err_counter
;
1914 /* Count the number of INIT cycles (for doubling timeout). */
1917 /* Default send parameters. */
1918 __u16 default_stream
;
1919 __u16 default_flags
;
1921 __u32 default_context
;
1922 __u32 default_timetolive
;
1924 /* Default receive parameters */
1925 __u32 default_rcv_context
;
1928 struct sctp_stream stream
;
1930 /* All outbound chunks go through this structure. */
1931 struct sctp_outq outqueue
;
1933 /* A smart pipe that will handle reordering and fragmentation,
1934 * as well as handle passing events up to the ULP.
1936 struct sctp_ulpq ulpq
;
1938 /* Last TSN that caused an ECNE Chunk to be sent. */
1939 __u32 last_ecne_tsn
;
1941 /* Last TSN that caused a CWR Chunk to be sent. */
1944 /* How many duplicated TSNs have we seen? */
1947 /* These are to support
1948 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1949 * and Enforcement of Flow and Message Limits"
1950 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1951 * or "ADDIP" for short.
1956 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1958 * R1) One and only one ASCONF Chunk MAY be in transit and
1959 * unacknowledged at any one time. If a sender, after sending
1960 * an ASCONF chunk, decides it needs to transfer another
1961 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1962 * returns from the previous ASCONF Chunk before sending a
1963 * subsequent ASCONF. Note this restriction binds each side,
1964 * so at any time two ASCONF may be in-transit on any given
1965 * association (one sent from each endpoint).
1967 * [This is our one-and-only-one ASCONF in flight. If we do
1968 * not have an ASCONF in flight, this is NULL.]
1970 struct sctp_chunk
*addip_last_asconf
;
1972 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1974 * This is needed to implement itmes E1 - E4 of the updated
1975 * spec. Here is the justification:
1977 * Since the peer may bundle multiple ASCONF chunks toward us,
1978 * we now need the ability to cache multiple ACKs. The section
1979 * describes in detail how they are cached and cleaned up.
1981 struct list_head asconf_ack_list
;
1983 /* These ASCONF chunks are waiting to be sent.
1985 * These chunaks can't be pushed to outqueue until receiving
1986 * ASCONF_ACK for the previous ASCONF indicated by
1987 * addip_last_asconf, so as to guarantee that only one ASCONF
1988 * is in flight at any time.
1990 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1992 * In defining the ASCONF Chunk transfer procedures, it is
1993 * essential that these transfers MUST NOT cause congestion
1994 * within the network. To achieve this, we place these
1995 * restrictions on the transfer of ASCONF Chunks:
1997 * R1) One and only one ASCONF Chunk MAY be in transit and
1998 * unacknowledged at any one time. If a sender, after sending
1999 * an ASCONF chunk, decides it needs to transfer another
2000 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2001 * returns from the previous ASCONF Chunk before sending a
2002 * subsequent ASCONF. Note this restriction binds each side,
2003 * so at any time two ASCONF may be in-transit on any given
2004 * association (one sent from each endpoint).
2007 * [I really think this is EXACTLY the sort of intelligence
2008 * which already resides in sctp_outq. Please move this
2009 * queue and its supporting logic down there. --piggy]
2011 struct list_head addip_chunk_list
;
2013 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2015 * A2) A serial number should be assigned to the Chunk. The
2016 * serial number SHOULD be a monotonically increasing
2017 * number. The serial number SHOULD be initialized at
2018 * the start of the association to the same value as the
2019 * Initial TSN and every time a new ASCONF chunk is created
2020 * it is incremented by one after assigning the serial number
2021 * to the newly created chunk.
2024 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2026 * Serial Number : 32 bits (unsigned integer)
2028 * This value represents a Serial Number for the ASCONF
2029 * Chunk. The valid range of Serial Number is from 0 to
2030 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2031 * after reaching 4294967295.
2034 int src_out_of_asoc_ok
;
2035 union sctp_addr
*asconf_addr_del_pending
;
2036 struct sctp_transport
*new_transport
;
2038 /* SCTP AUTH: list of the endpoint shared keys. These
2039 * keys are provided out of band by the user applicaton
2040 * and can't change during the lifetime of the association
2042 struct list_head endpoint_shared_keys
;
2045 * The current generated assocaition shared key (secret)
2047 struct sctp_auth_bytes
*asoc_shared_key
;
2048 struct sctp_shared_key
*shkey
;
2050 /* SCTP AUTH: hmac id of the first peer requested algorithm
2053 __u16 default_hmac_id
;
2055 __u16 active_key_id
;
2057 __u8 need_ecne
:1, /* Need to send an ECNE Chunk? */
2058 temp
:1, /* Is it a temporary association? */
2061 __u8 strreset_enable
;
2062 __u8 strreset_outstanding
; /* request param count on the fly */
2064 __u32 strreset_outseq
; /* Update after receiving response */
2065 __u32 strreset_inseq
; /* Update after receiving request */
2066 __u32 strreset_result
[2]; /* save the results of last 2 responses */
2068 struct sctp_chunk
*strreset_chunk
; /* save request chunk */
2070 struct sctp_priv_assoc_stats stats
;
2072 int sent_cnt_removable
;
2076 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
2077 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
2079 struct rcu_head rcu
;
2083 /* An eyecatcher for determining if we are really looking at an
2084 * association data structure.
2087 SCTP_ASSOC_EYECATCHER
= 0xa550c123,
2090 /* Recover the outter association structure. */
2091 static inline struct sctp_association
*sctp_assoc(struct sctp_ep_common
*base
)
2093 struct sctp_association
*asoc
;
2095 asoc
= container_of(base
, struct sctp_association
, base
);
2099 /* These are function signatures for manipulating associations. */
2102 struct sctp_association
*
2103 sctp_association_new(const struct sctp_endpoint
*ep
, const struct sock
*sk
,
2104 enum sctp_scope scope
, gfp_t gfp
);
2105 void sctp_association_free(struct sctp_association
*);
2106 void sctp_association_put(struct sctp_association
*);
2107 void sctp_association_hold(struct sctp_association
*);
2109 struct sctp_transport
*sctp_assoc_choose_alter_transport(
2110 struct sctp_association
*, struct sctp_transport
*);
2111 void sctp_assoc_update_retran_path(struct sctp_association
*);
2112 struct sctp_transport
*sctp_assoc_lookup_paddr(const struct sctp_association
*,
2113 const union sctp_addr
*);
2114 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
2115 const union sctp_addr
*laddr
);
2116 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*,
2117 const union sctp_addr
*address
,
2119 const int peer_state
);
2120 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
2121 const union sctp_addr
*addr
);
2122 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
2123 struct sctp_transport
*peer
);
2124 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
2125 struct sctp_transport
*transport
,
2126 enum sctp_transport_cmd command
,
2127 sctp_sn_error_t error
);
2128 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*, __u32
);
2129 void sctp_assoc_migrate(struct sctp_association
*, struct sock
*);
2130 int sctp_assoc_update(struct sctp_association
*old
,
2131 struct sctp_association
*new);
2133 __u32
sctp_association_get_next_tsn(struct sctp_association
*);
2135 void sctp_assoc_update_frag_point(struct sctp_association
*asoc
);
2136 void sctp_assoc_set_pmtu(struct sctp_association
*asoc
, __u32 pmtu
);
2137 void sctp_assoc_sync_pmtu(struct sctp_association
*asoc
);
2138 void sctp_assoc_rwnd_increase(struct sctp_association
*, unsigned int);
2139 void sctp_assoc_rwnd_decrease(struct sctp_association
*, unsigned int);
2140 void sctp_assoc_set_primary(struct sctp_association
*,
2141 struct sctp_transport
*);
2142 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*,
2143 struct sctp_transport
*);
2144 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
2145 enum sctp_scope scope
, gfp_t gfp
);
2146 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*,
2147 struct sctp_cookie
*,
2149 int sctp_assoc_set_id(struct sctp_association
*, gfp_t
);
2150 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
);
2151 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
2152 const struct sctp_association
*asoc
,
2154 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
);
2156 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
2157 const union sctp_addr
*ss2
);
2158 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
);
2160 /* A convenience structure to parse out SCTP specific CMSGs. */
2162 struct sctp_initmsg
*init
;
2163 struct sctp_sndrcvinfo
*srinfo
;
2164 struct sctp_sndinfo
*sinfo
;
2165 struct sctp_prinfo
*prinfo
;
2166 struct sctp_authinfo
*authinfo
;
2167 struct msghdr
*addrs_msg
;
2170 /* Structure for tracking memory objects */
2171 struct sctp_dbg_objcnt_entry
{
2176 #endif /* __sctp_structs_h__ */