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 */
62 #include <net/ip.h> /* For inet_skb_parm */
64 /* A convenience structure for handling sockaddr structures.
65 * We should wean ourselves off this.
68 struct sockaddr_in v4
;
69 struct sockaddr_in6 v6
;
73 /* Forward declarations for data structures. */
76 struct sctp_association
;
77 struct sctp_transport
;
82 struct sctp_bind_addr
;
84 struct sctp_ep_common
;
89 #include <net/sctp/tsnmap.h>
90 #include <net/sctp/ulpevent.h>
91 #include <net/sctp/ulpqueue.h>
92 #include <net/sctp/stream_interleave.h>
94 /* Structures useful for managing bind/connect. */
96 struct sctp_bind_bucket
{
98 unsigned short fastreuse
;
99 struct hlist_node node
;
100 struct hlist_head owner
;
104 struct sctp_bind_hashbucket
{
106 struct hlist_head chain
;
109 /* Used for hashing all associations. */
110 struct sctp_hashbucket
{
112 struct hlist_head chain
;
113 } __attribute__((__aligned__(8)));
116 /* The SCTP globals structure. */
117 extern struct sctp_globals
{
118 /* This is a list of groups of functions for each address
119 * family that we support.
121 struct list_head address_families
;
123 /* This is the hash of all endpoints. */
124 struct sctp_hashbucket
*ep_hashtable
;
125 /* This is the sctp port control hash. */
126 struct sctp_bind_hashbucket
*port_hashtable
;
127 /* This is the hash of all transports. */
128 struct rhltable transport_hashtable
;
130 /* Sizes of above hashtables. */
134 /* Default initialization values to be applied to new associations. */
136 __u16 max_outstreams
;
138 /* Flag to indicate whether computing and verifying checksum
140 bool checksum_disable
;
143 #define sctp_max_instreams (sctp_globals.max_instreams)
144 #define sctp_max_outstreams (sctp_globals.max_outstreams)
145 #define sctp_address_families (sctp_globals.address_families)
146 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
147 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
148 #define sctp_port_hashsize (sctp_globals.port_hashsize)
149 #define sctp_port_hashtable (sctp_globals.port_hashtable)
150 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
151 #define sctp_checksum_disable (sctp_globals.checksum_disable)
153 /* SCTP Socket type: UDP or TCP style. */
154 enum sctp_socket_type
{
156 SCTP_SOCKET_UDP_HIGH_BANDWIDTH
,
160 /* Per socket SCTP information. */
162 /* inet_sock has to be the first member of sctp_sock */
163 struct inet_sock inet
;
164 /* What kind of a socket is this? */
165 enum sctp_socket_type type
;
167 /* PF_ family specific functions. */
170 /* Access to HMAC transform. */
171 struct crypto_shash
*hmac
;
174 /* What is our base endpointer? */
175 struct sctp_endpoint
*ep
;
177 struct sctp_bind_bucket
*bind_hash
;
178 /* Various Socket Options. */
179 __u16 default_stream
;
182 __u32 default_context
;
183 __u32 default_timetolive
;
184 __u32 default_rcv_context
;
187 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
188 * the destination address every heartbeat interval. This value
189 * will be inherited by all new associations.
193 /* This is the max_retrans value for new associations. */
196 /* The initial Path MTU to use for new associations. */
199 /* The default SACK delay timeout for new associations. */
203 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
206 struct sctp_rtoinfo rtoinfo
;
207 struct sctp_paddrparams paddrparam
;
208 struct sctp_assocparams assocparams
;
211 * These two structures must be grouped together for the usercopy
214 struct sctp_event_subscribe subscribe
;
215 struct sctp_initmsg initmsg
;
220 __u32 adaptation_ind
;
229 data_ready_signalled
:1;
232 /* Receive to here while partial delivery is in effect. */
233 struct sk_buff_head pd_lobby
;
235 /* These must be the last fields, as they will skipped on copies,
236 * like on accept and peeloff operations
238 struct list_head auto_asconf_list
;
242 static inline struct sctp_sock
*sctp_sk(const struct sock
*sk
)
244 return (struct sctp_sock
*)sk
;
247 static inline struct sock
*sctp_opt2sk(const struct sctp_sock
*sp
)
249 return (struct sock
*)sp
;
252 #if IS_ENABLED(CONFIG_IPV6)
254 struct sctp_sock sctp
;
255 struct ipv6_pinfo inet6
;
257 #endif /* CONFIG_IPV6 */
260 /* This is our APPLICATION-SPECIFIC state cookie.
261 * THIS IS NOT DICTATED BY THE SPECIFICATION.
263 /* These are the parts of an association which we send in the cookie.
264 * Most of these are straight out of:
265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
271 /* My : Tag expected in every inbound packet and sent
272 * Verification: in the INIT or INIT ACK chunk.
277 /* Peer's : Tag expected in every outbound packet except
278 * Verification: in the INIT chunk.
283 /* The rest of these are not from the spec, but really need to
287 /* My Tie Tag : Assist in discovering a restarting association. */
290 /* Peer's Tie Tag: Assist in discovering a restarting association. */
293 /* When does this cookie expire? */
296 /* Number of inbound/outbound streams which are set
297 * and negotiated during the INIT process.
299 __u16 sinit_num_ostreams
;
300 __u16 sinit_max_instreams
;
302 /* This is the first sequence number I used. */
305 /* This holds the originating address of the INIT packet. */
306 union sctp_addr peer_addr
;
309 * Include the source port of the INIT-ACK
315 /* Padding for future use */
318 __u32 adaptation_ind
;
320 __u8 auth_random
[sizeof(struct sctp_paramhdr
) +
321 SCTP_AUTH_RANDOM_LENGTH
];
322 __u8 auth_hmacs
[SCTP_AUTH_NUM_HMACS
* sizeof(__u16
) + 2];
323 __u8 auth_chunks
[sizeof(struct sctp_paramhdr
) + SCTP_AUTH_MAX_CHUNKS
];
325 /* This is a shim for my peer's INIT packet, followed by
326 * a copy of the raw address list of the association.
327 * The length of the raw address list is saved in the
328 * raw_addr_list_len field, which will be used at the time when
329 * the association TCB is re-constructed from the cookie.
331 __u32 raw_addr_list_len
;
332 struct sctp_init_chunk peer_init
[0];
336 /* The format of our cookie that we send to our peer. */
337 struct sctp_signed_cookie
{
338 __u8 signature
[SCTP_SECRET_SIZE
];
339 __u32 __pad
; /* force sctp_cookie alignment to 64 bits */
340 struct sctp_cookie c
;
343 /* This is another convenience type to allocate memory for address
344 * params for the maximum size and pass such structures around
347 union sctp_addr_param
{
348 struct sctp_paramhdr p
;
349 struct sctp_ipv4addr_param v4
;
350 struct sctp_ipv6addr_param v6
;
353 /* A convenience type to allow walking through the various
354 * parameters and avoid casting all over the place.
358 struct sctp_paramhdr
*p
;
359 struct sctp_cookie_preserve_param
*life
;
360 struct sctp_hostname_param
*dns
;
361 struct sctp_cookie_param
*cookie
;
362 struct sctp_supported_addrs_param
*sat
;
363 struct sctp_ipv4addr_param
*v4
;
364 struct sctp_ipv6addr_param
*v6
;
365 union sctp_addr_param
*addr
;
366 struct sctp_adaptation_ind_param
*aind
;
367 struct sctp_supported_ext_param
*ext
;
368 struct sctp_random_param
*random
;
369 struct sctp_chunks_param
*chunks
;
370 struct sctp_hmac_algo_param
*hmac_algo
;
371 struct sctp_addip_param
*addip
;
374 /* RFC 2960. Section 3.3.5 Heartbeat.
375 * Heartbeat Information: variable length
376 * The Sender-specific Heartbeat Info field should normally include
377 * information about the sender's current time when this HEARTBEAT
378 * chunk is sent and the destination transport address to which this
379 * HEARTBEAT is sent (see Section 8.3).
381 struct sctp_sender_hb_info
{
382 struct sctp_paramhdr param_hdr
;
383 union sctp_addr daddr
;
384 unsigned long sent_at
;
388 int sctp_stream_init(struct sctp_stream
*stream
, __u16 outcnt
, __u16 incnt
,
390 int sctp_stream_init_ext(struct sctp_stream
*stream
, __u16 sid
);
391 void sctp_stream_free(struct sctp_stream
*stream
);
392 void sctp_stream_clear(struct sctp_stream
*stream
);
393 void sctp_stream_update(struct sctp_stream
*stream
, struct sctp_stream
*new);
395 /* What is the current SSN number for this stream? */
396 #define sctp_ssn_peek(stream, type, sid) \
397 ((stream)->type[sid].ssn)
399 /* Return the next SSN number for this stream. */
400 #define sctp_ssn_next(stream, type, sid) \
401 ((stream)->type[sid].ssn++)
403 /* Skip over this ssn and all below. */
404 #define sctp_ssn_skip(stream, type, sid, ssn) \
405 ((stream)->type[sid].ssn = ssn + 1)
407 /* What is the current MID number for this stream? */
408 #define sctp_mid_peek(stream, type, sid) \
409 ((stream)->type[sid].mid)
411 /* Return the next MID number for this stream. */
412 #define sctp_mid_next(stream, type, sid) \
413 ((stream)->type[sid].mid++)
415 /* Skip over this mid and all below. */
416 #define sctp_mid_skip(stream, type, sid, mid) \
417 ((stream)->type[sid].mid = mid + 1)
419 #define sctp_stream_in(asoc, sid) (&(asoc)->stream.in[sid])
421 /* What is the current MID_uo number for this stream? */
422 #define sctp_mid_uo_peek(stream, type, sid) \
423 ((stream)->type[sid].mid_uo)
425 /* Return the next MID_uo number for this stream. */
426 #define sctp_mid_uo_next(stream, type, sid) \
427 ((stream)->type[sid].mid_uo++)
430 * Pointers to address related SCTP functions.
431 * (i.e. things that depend on the address family.)
434 int (*sctp_xmit
) (struct sk_buff
*skb
,
435 struct sctp_transport
*);
436 int (*setsockopt
) (struct sock
*sk
,
440 unsigned int optlen
);
441 int (*getsockopt
) (struct sock
*sk
,
446 int (*compat_setsockopt
) (struct sock
*sk
,
450 unsigned int optlen
);
451 int (*compat_getsockopt
) (struct sock
*sk
,
456 void (*get_dst
) (struct sctp_transport
*t
,
457 union sctp_addr
*saddr
,
460 void (*get_saddr
) (struct sctp_sock
*sk
,
461 struct sctp_transport
*t
,
463 void (*copy_addrlist
) (struct list_head
*,
464 struct net_device
*);
465 int (*cmp_addr
) (const union sctp_addr
*addr1
,
466 const union sctp_addr
*addr2
);
467 void (*addr_copy
) (union sctp_addr
*dst
,
468 union sctp_addr
*src
);
469 void (*from_skb
) (union sctp_addr
*,
472 void (*from_sk
) (union sctp_addr
*,
474 void (*from_addr_param
) (union sctp_addr
*,
475 union sctp_addr_param
*,
476 __be16 port
, int iif
);
477 int (*to_addr_param
) (const union sctp_addr
*,
478 union sctp_addr_param
*);
479 int (*addr_valid
) (union sctp_addr
*,
481 const struct sk_buff
*);
482 enum sctp_scope (*scope
)(union sctp_addr
*);
483 void (*inaddr_any
) (union sctp_addr
*, __be16
);
484 int (*is_any
) (const union sctp_addr
*);
485 int (*available
) (union sctp_addr
*,
487 int (*skb_iif
) (const struct sk_buff
*sk
);
488 int (*is_ce
) (const struct sk_buff
*sk
);
489 void (*seq_dump_addr
)(struct seq_file
*seq
,
490 union sctp_addr
*addr
);
491 void (*ecn_capable
)(struct sock
*sk
);
492 __u16 net_header_len
;
494 sa_family_t sa_family
;
495 struct list_head list
;
498 struct sctp_af
*sctp_get_af_specific(sa_family_t
);
499 int sctp_register_af(struct sctp_af
*);
501 /* Protocol family functions. */
503 void (*event_msgname
)(struct sctp_ulpevent
*, char *, int *);
504 void (*skb_msgname
) (struct sk_buff
*, char *, int *);
505 int (*af_supported
) (sa_family_t
, struct sctp_sock
*);
506 int (*cmp_addr
) (const union sctp_addr
*,
507 const union sctp_addr
*,
509 int (*bind_verify
) (struct sctp_sock
*, union sctp_addr
*);
510 int (*send_verify
) (struct sctp_sock
*, union sctp_addr
*);
511 int (*supported_addrs
)(const struct sctp_sock
*, __be16
*);
512 struct sock
*(*create_accept_sk
) (struct sock
*sk
,
513 struct sctp_association
*asoc
,
515 int (*addr_to_user
)(struct sctp_sock
*sk
, union sctp_addr
*addr
);
516 void (*to_sk_saddr
)(union sctp_addr
*, struct sock
*sk
);
517 void (*to_sk_daddr
)(union sctp_addr
*, struct sock
*sk
);
522 /* Structure to track chunk fragments that have been acked, but peer
523 * fragments of the same message have not.
525 struct sctp_datamsg
{
526 /* Chunks waiting to be submitted to lower layer. */
527 struct list_head chunks
;
528 /* Reference counting. */
530 /* When is this message no longer interesting to the peer? */
531 unsigned long expires_at
;
532 /* Did the messenge fail to send? */
535 can_delay
:1, /* should this message be Nagle delayed */
536 abandoned
:1; /* should this message be abandoned */
539 struct sctp_datamsg
*sctp_datamsg_from_user(struct sctp_association
*,
540 struct sctp_sndrcvinfo
*,
542 void sctp_datamsg_free(struct sctp_datamsg
*);
543 void sctp_datamsg_put(struct sctp_datamsg
*);
544 void sctp_chunk_fail(struct sctp_chunk
*, int error
);
545 int sctp_chunk_abandoned(struct sctp_chunk
*);
547 /* RFC2960 1.4 Key Terms
549 * o Chunk: A unit of information within an SCTP packet, consisting of
550 * a chunk header and chunk-specific content.
552 * As a matter of convenience, we remember the SCTP common header for
553 * each chunk as well as a few other header pointers...
556 struct list_head list
;
560 /* How many times this chunk have been sent, for prsctp RTX policy */
564 /* This is our link to the per-transport transmitted list. */
565 struct list_head transmitted_list
;
566 /* List in specific stream outq */
567 struct list_head stream_list
;
570 /* This field is used by chunks that hold fragmented data.
571 * For the first fragment this is the list that holds the rest of
572 * fragments. For the remaining fragments, this is the link to the
573 * frag_list maintained in the first fragment.
575 struct list_head frag_list
;
577 /* This points to the sk_buff containing the actual data. */
580 /* In case of GSO packets, this will store the head one */
581 struct sk_buff
*head_skb
;
583 /* These are the SCTP headers by reverse order in a packet.
584 * Note that some of these may happen more than once. In that
585 * case, we point at the "current" one, whatever that means
586 * for that level of header.
589 /* We point this at the FIRST TLV parameter to chunk_hdr. */
590 union sctp_params param_hdr
;
593 struct sctp_datahdr
*data_hdr
;
594 struct sctp_inithdr
*init_hdr
;
595 struct sctp_sackhdr
*sack_hdr
;
596 struct sctp_heartbeathdr
*hb_hdr
;
597 struct sctp_sender_hb_info
*hbs_hdr
;
598 struct sctp_shutdownhdr
*shutdown_hdr
;
599 struct sctp_signed_cookie
*cookie_hdr
;
600 struct sctp_ecnehdr
*ecne_hdr
;
601 struct sctp_cwrhdr
*ecn_cwr_hdr
;
602 struct sctp_errhdr
*err_hdr
;
603 struct sctp_addiphdr
*addip_hdr
;
604 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
605 struct sctp_authhdr
*auth_hdr
;
606 struct sctp_idatahdr
*idata_hdr
;
607 struct sctp_ifwdtsn_hdr
*ifwdtsn_hdr
;
612 struct sctp_chunkhdr
*chunk_hdr
;
613 struct sctphdr
*sctp_hdr
;
615 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
616 struct sctp_sndrcvinfo sinfo
;
618 /* Which association does this belong to? */
619 struct sctp_association
*asoc
;
621 /* What endpoint received this chunk? */
622 struct sctp_ep_common
*rcvr
;
624 /* We fill this in if we are calculating RTT. */
625 unsigned long sent_at
;
627 /* What is the origin IP address for this chunk? */
628 union sctp_addr source
;
629 /* Destination address for this chunk. */
630 union sctp_addr dest
;
632 /* For outbound message, track all fragments for SEND_FAILED. */
633 struct sctp_datamsg
*msg
;
635 /* For an inbound chunk, this tells us where it came from.
636 * For an outbound chunk, it tells us where we'd like it to
637 * go. It is NULL if we have no preference.
639 struct sctp_transport
*transport
;
641 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
642 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
643 * spec violates the principle premis that all chunks are processed
646 struct sk_buff
*auth_chunk
;
648 #define SCTP_CAN_FRTX 0x0
649 #define SCTP_NEED_FRTX 0x1
650 #define SCTP_DONT_FRTX 0x2
651 __u16 rtt_in_progress
:1, /* This chunk used for RTT calc? */
652 has_tsn
:1, /* Does this chunk have a TSN yet? */
653 has_ssn
:1, /* Does this chunk have a SSN yet? */
654 #define has_mid has_ssn
655 singleton
:1, /* Only chunk in the packet? */
656 end_of_packet
:1, /* Last chunk in the packet? */
657 ecn_ce_done
:1, /* Have we processed the ECN CE bit? */
658 pdiscard
:1, /* Discard the whole packet now? */
659 tsn_gap_acked
:1, /* Is this chunk acked by a GAP ACK? */
660 data_accepted
:1, /* At least 1 chunk accepted */
661 auth
:1, /* IN: was auth'ed | OUT: needs auth */
662 has_asconf
:1, /* IN: have seen an asconf before */
663 tsn_missing_report
:2, /* Data chunk missing counter. */
664 fast_retransmit
:2; /* Is this chunk fast retransmitted? */
667 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
668 void sctp_chunk_hold(struct sctp_chunk
*);
669 void sctp_chunk_put(struct sctp_chunk
*);
670 int sctp_user_addto_chunk(struct sctp_chunk
*chunk
, int len
,
671 struct iov_iter
*from
);
672 void sctp_chunk_free(struct sctp_chunk
*);
673 void *sctp_addto_chunk(struct sctp_chunk
*, int len
, const void *data
);
674 struct sctp_chunk
*sctp_chunkify(struct sk_buff
*,
675 const struct sctp_association
*,
676 struct sock
*, gfp_t gfp
);
677 void sctp_init_addrs(struct sctp_chunk
*, union sctp_addr
*,
679 const union sctp_addr
*sctp_source(const struct sctp_chunk
*chunk
);
681 static inline __u16
sctp_chunk_stream_no(struct sctp_chunk
*ch
)
683 return ntohs(ch
->subh
.data_hdr
->stream
);
687 SCTP_ADDR_NEW
, /* new address added to assoc/ep */
688 SCTP_ADDR_SRC
, /* address can be used as source */
689 SCTP_ADDR_DEL
, /* address about to be deleted */
692 /* This is a structure for holding either an IPv6 or an IPv4 address. */
693 struct sctp_sockaddr_entry
{
694 struct list_head list
;
701 #define SCTP_ADDRESS_TICK_DELAY 500
703 /* This structure holds lists of chunks as we are assembling for
707 /* These are the SCTP header values (host order) for the packet. */
709 __u16 destination_port
;
712 /* This contains the payload chunks. */
713 struct list_head chunk_list
;
715 /* This is the overhead of the sctp and ip headers. */
717 /* This is the total size of all chunks INCLUDING padding. */
719 /* This is the maximum size this packet may have */
722 /* The packet is destined for this transport address.
723 * The function we finally use to pass down to the next lower
724 * layer lives in the transport structure.
726 struct sctp_transport
*transport
;
728 /* pointer to the auth chunk for this packet */
729 struct sctp_chunk
*auth
;
731 u8 has_cookie_echo
:1, /* This packet contains a COOKIE-ECHO chunk. */
732 has_sack
:1, /* This packet contains a SACK chunk. */
733 has_auth
:1, /* This packet contains an AUTH chunk */
734 has_data
:1, /* This packet contains at least 1 DATA chunk */
735 ipfragok
:1; /* So let ip fragment this packet */
738 void sctp_packet_init(struct sctp_packet
*, struct sctp_transport
*,
739 __u16 sport
, __u16 dport
);
740 void sctp_packet_config(struct sctp_packet
*, __u32 vtag
, int);
741 enum sctp_xmit
sctp_packet_transmit_chunk(struct sctp_packet
*packet
,
742 struct sctp_chunk
*chunk
,
743 int one_packet
, gfp_t gfp
);
744 enum sctp_xmit
sctp_packet_append_chunk(struct sctp_packet
*packet
,
745 struct sctp_chunk
*chunk
);
746 int sctp_packet_transmit(struct sctp_packet
*, gfp_t
);
747 void sctp_packet_free(struct sctp_packet
*);
749 static inline int sctp_packet_empty(struct sctp_packet
*packet
)
751 return packet
->size
== packet
->overhead
;
754 /* This represents a remote transport address.
755 * For local transport addresses, we just use union sctp_addr.
757 * RFC2960 Section 1.4 Key Terms
759 * o Transport address: A Transport Address is traditionally defined
760 * by Network Layer address, Transport Layer protocol and Transport
761 * Layer port number. In the case of SCTP running over IP, a
762 * transport address is defined by the combination of an IP address
763 * and an SCTP port number (where SCTP is the Transport protocol).
765 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
767 * o The sender keeps a separate congestion control parameter set for
768 * each of the destination addresses it can send to (not each
769 * source-destination pair but for each destination). The parameters
770 * should decay if the address is not used for a long enough time
774 struct sctp_transport
{
775 /* A list of transports. */
776 struct list_head transports
;
777 struct rhlist_head node
;
779 /* Reference counting. */
781 /* RTO-Pending : A flag used to track if one of the DATA
782 * chunks sent to this address is currently being
783 * used to compute a RTT. If this flag is 0,
784 * the next DATA chunk sent to this destination
785 * should be used to compute a RTT and this flag
786 * should be set. Every time the RTT
787 * calculation completes (i.e. the DATA chunk
788 * is SACK'd) clear this flag.
793 * hb_sent : a flag that signals that we have a pending
798 /* Is the Path MTU update pending on this tranport */
801 dst_pending_confirm
:1, /* need to confirm neighbour */
803 /* Has this transport moved the ctsn since we last sacked */
809 /* This is the peer's IP address and port. */
810 union sctp_addr ipaddr
;
812 /* These are the functions we call to handle LLP stuff. */
813 struct sctp_af
*af_specific
;
815 /* Which association do we belong to? */
816 struct sctp_association
*asoc
;
820 * 12.3 Per Transport Address Data
822 * For each destination transport address in the peer's
823 * address list derived from the INIT or INIT ACK chunk, a
824 * number of data elements needs to be maintained including:
826 /* RTO : The current retransmission timeout value. */
829 __u32 rtt
; /* This is the most recent RTT. */
831 /* RTTVAR : The current RTT variation. */
834 /* SRTT : The current smoothed round trip time. */
838 * These are the congestion stats.
840 /* cwnd : The current congestion window. */
841 __u32 cwnd
; /* This is the actual cwnd. */
843 /* ssthresh : The current slow start threshold value. */
846 /* partial : The tracking method for increase of cwnd when in
847 * bytes acked : congestion avoidance mode (see Section 6.2.2)
849 __u32 partial_bytes_acked
;
851 /* Data that has been sent, but not acknowledged. */
854 __u32 burst_limited
; /* Holds old cwnd when max.burst is applied */
857 struct dst_entry
*dst
;
858 /* Source address. */
859 union sctp_addr saddr
;
861 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
862 * the destination address every heartbeat interval.
864 unsigned long hbinterval
;
866 /* SACK delay timeout */
867 unsigned long sackdelay
;
870 /* When was the last time that we heard from this transport? We use
871 * this to pick new active and retran paths.
873 ktime_t last_time_heard
;
875 /* When was the last time that we sent a chunk using this
876 * transport? We use this to check for idle transports
878 unsigned long last_time_sent
;
880 /* Last time(in jiffies) when cwnd is reduced due to the congestion
881 * indication based on ECNE chunk.
883 unsigned long last_time_ecne_reduced
;
885 /* This is the max_retrans value for the transport and will
886 * be initialized from the assocs value. This can be changed
887 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
891 /* This is the partially failed retrans value for the transport
892 * and will be initialized from the assocs value. This can be changed
893 * using the SCTP_PEER_ADDR_THLDS socket option
896 /* PMTU : The current known path MTU. */
899 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
902 /* The number of times INIT has been sent on this transport. */
905 /* state : The current state of this destination,
906 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
910 /* These are the error stats for this destination. */
912 /* Error count : The current error count for this destination. */
913 unsigned short error_count
;
915 /* Per : A timer used by each destination.
919 * [Everywhere else in the text this is called T3-rtx. -ed]
921 struct timer_list T3_rtx_timer
;
923 /* Heartbeat timer is per destination. */
924 struct timer_list hb_timer
;
926 /* Timer to handle ICMP proto unreachable envets */
927 struct timer_list proto_unreach_timer
;
929 /* Timer to handler reconf chunk rtx */
930 struct timer_list reconf_timer
;
932 /* Since we're using per-destination retransmission timers
933 * (see above), we're also using per-destination "transmitted"
934 * queues. This probably ought to be a private struct
935 * accessible only within the outqueue, but it's not, yet.
937 struct list_head transmitted
;
939 /* We build bundle-able packets for this transport here. */
940 struct sctp_packet packet
;
942 /* This is the list of transports that have chunks to send. */
943 struct list_head send_ready
;
945 /* State information saved for SFR_CACC algorithm. The key
946 * idea in SFR_CACC is to maintain state at the sender on a
947 * per-destination basis when a changeover happens.
948 * char changeover_active;
949 * char cycling_changeover;
950 * __u32 next_tsn_at_change;
951 * char cacc_saw_newack;
954 /* An unsigned integer, which stores the next TSN to be
955 * used by the sender, at the moment of changeover.
957 __u32 next_tsn_at_change
;
959 /* A flag which indicates the occurrence of a changeover */
960 char changeover_active
;
962 /* A flag which indicates whether the change of primary is
963 * the first switch to this destination address during an
966 char cycling_changeover
;
968 /* A temporary flag, which is used during the processing of
969 * a SACK to estimate the causative TSN(s)'s group.
971 char cacc_saw_newack
;
974 /* 64-bit random number sent with heartbeat. */
980 struct sctp_transport
*sctp_transport_new(struct net
*, const union sctp_addr
*,
982 void sctp_transport_set_owner(struct sctp_transport
*,
983 struct sctp_association
*);
984 void sctp_transport_route(struct sctp_transport
*, union sctp_addr
*,
986 void sctp_transport_pmtu(struct sctp_transport
*, struct sock
*sk
);
987 void sctp_transport_free(struct sctp_transport
*);
988 void sctp_transport_reset_t3_rtx(struct sctp_transport
*);
989 void sctp_transport_reset_hb_timer(struct sctp_transport
*);
990 void sctp_transport_reset_reconf_timer(struct sctp_transport
*transport
);
991 int sctp_transport_hold(struct sctp_transport
*);
992 void sctp_transport_put(struct sctp_transport
*);
993 void sctp_transport_update_rto(struct sctp_transport
*, __u32
);
994 void sctp_transport_raise_cwnd(struct sctp_transport
*, __u32
, __u32
);
995 void sctp_transport_lower_cwnd(struct sctp_transport
*t
,
996 enum sctp_lower_cwnd reason
);
997 void sctp_transport_burst_limited(struct sctp_transport
*);
998 void sctp_transport_burst_reset(struct sctp_transport
*);
999 unsigned long sctp_transport_timeout(struct sctp_transport
*);
1000 void sctp_transport_reset(struct sctp_transport
*t
);
1001 bool sctp_transport_update_pmtu(struct sctp_transport
*t
, u32 pmtu
);
1002 void sctp_transport_immediate_rtx(struct sctp_transport
*);
1003 void sctp_transport_dst_release(struct sctp_transport
*t
);
1004 void sctp_transport_dst_confirm(struct sctp_transport
*t
);
1007 /* This is the structure we use to queue packets as they come into
1008 * SCTP. We write packets to it and read chunks from it.
1011 /* This is actually a queue of sctp_chunk each
1012 * containing a partially decoded packet.
1014 struct list_head in_chunk_list
;
1015 /* This is the packet which is currently off the in queue and is
1016 * being worked on through the inbound chunk processing.
1018 struct sctp_chunk
*in_progress
;
1020 /* This is the delayed task to finish delivering inbound
1023 struct work_struct immediate
;
1026 void sctp_inq_init(struct sctp_inq
*);
1027 void sctp_inq_free(struct sctp_inq
*);
1028 void sctp_inq_push(struct sctp_inq
*, struct sctp_chunk
*packet
);
1029 struct sctp_chunk
*sctp_inq_pop(struct sctp_inq
*);
1030 struct sctp_chunkhdr
*sctp_inq_peek(struct sctp_inq
*);
1031 void sctp_inq_set_th_handler(struct sctp_inq
*, work_func_t
);
1033 /* This is the structure we use to hold outbound chunks. You push
1034 * chunks in and they automatically pop out the other end as bundled
1035 * packets (it calls (*output_handler)()).
1037 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1038 * and 8.2 of the v13 draft.
1040 * It handles retransmissions. The connection to the timeout portion
1041 * of the state machine is through sctp_..._timeout() and timeout_handler.
1043 * If you feed it SACKs, it will eat them.
1045 * If you give it big chunks, it will fragment them.
1047 * It assigns TSN's to data chunks. This happens at the last possible
1048 * instant before transmission.
1050 * When free()'d, it empties itself out via output_handler().
1053 struct sctp_association
*asoc
;
1055 /* Data pending that has never been transmitted. */
1056 struct list_head out_chunk_list
;
1058 /* Stream scheduler being used */
1059 struct sctp_sched_ops
*sched
;
1061 unsigned int out_qlen
; /* Total length of queued data chunks. */
1063 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1066 /* These are control chunks we want to send. */
1067 struct list_head control_chunk_list
;
1069 /* These are chunks that have been sacked but are above the
1070 * CTSN, or cumulative tsn ack point.
1072 struct list_head sacked
;
1074 /* Put chunks on this list to schedule them for
1077 struct list_head retransmit
;
1079 /* Put chunks on this list to save them for FWD TSN processing as
1080 * they were abandoned.
1082 struct list_head abandoned
;
1084 /* How many unackd bytes do we have in-flight? */
1085 __u32 outstanding_bytes
;
1087 /* Are we doing fast-rtx on this queue */
1094 void sctp_outq_init(struct sctp_association
*, struct sctp_outq
*);
1095 void sctp_outq_teardown(struct sctp_outq
*);
1096 void sctp_outq_free(struct sctp_outq
*);
1097 void sctp_outq_tail(struct sctp_outq
*, struct sctp_chunk
*chunk
, gfp_t
);
1098 int sctp_outq_sack(struct sctp_outq
*, struct sctp_chunk
*);
1099 int sctp_outq_is_empty(const struct sctp_outq
*);
1100 void sctp_outq_restart(struct sctp_outq
*);
1102 void sctp_retransmit(struct sctp_outq
*q
, struct sctp_transport
*transport
,
1103 enum sctp_retransmit_reason reason
);
1104 void sctp_retransmit_mark(struct sctp_outq
*, struct sctp_transport
*, __u8
);
1105 void sctp_outq_uncork(struct sctp_outq
*, gfp_t gfp
);
1106 void sctp_prsctp_prune(struct sctp_association
*asoc
,
1107 struct sctp_sndrcvinfo
*sinfo
, int msg_len
);
1108 void sctp_generate_fwdtsn(struct sctp_outq
*q
, __u32 sack_ctsn
);
1109 /* Uncork and flush an outqueue. */
1110 static inline void sctp_outq_cork(struct sctp_outq
*q
)
1115 /* SCTP skb control block.
1116 * sctp_input_cb is currently used on rx and sock rx queue
1118 struct sctp_input_cb
{
1120 struct inet_skb_parm h4
;
1121 #if IS_ENABLED(CONFIG_IPV6)
1122 struct inet6_skb_parm h6
;
1125 struct sctp_chunk
*chunk
;
1128 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1130 static inline const struct sk_buff
*sctp_gso_headskb(const struct sk_buff
*skb
)
1132 const struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
1134 return chunk
->head_skb
? : skb
;
1137 /* These bind address data fields common between endpoints and associations */
1138 struct sctp_bind_addr
{
1140 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1142 * SCTP Port: The local SCTP port number the endpoint is
1147 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1149 * Address List: The list of IP addresses that this instance
1150 * has bound. This information is passed to one's
1151 * peer(s) in INIT and INIT ACK chunks.
1153 struct list_head address_list
;
1156 void sctp_bind_addr_init(struct sctp_bind_addr
*, __u16 port
);
1157 void sctp_bind_addr_free(struct sctp_bind_addr
*);
1158 int sctp_bind_addr_copy(struct net
*net
, struct sctp_bind_addr
*dest
,
1159 const struct sctp_bind_addr
*src
,
1160 enum sctp_scope scope
, gfp_t gfp
,
1162 int sctp_bind_addr_dup(struct sctp_bind_addr
*dest
,
1163 const struct sctp_bind_addr
*src
,
1165 int sctp_add_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*,
1166 int new_size
, __u8 addr_state
, gfp_t gfp
);
1167 int sctp_del_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*);
1168 int sctp_bind_addr_match(struct sctp_bind_addr
*, const union sctp_addr
*,
1169 struct sctp_sock
*);
1170 int sctp_bind_addr_conflict(struct sctp_bind_addr
*, const union sctp_addr
*,
1171 struct sctp_sock
*, struct sctp_sock
*);
1172 int sctp_bind_addr_state(const struct sctp_bind_addr
*bp
,
1173 const union sctp_addr
*addr
);
1174 union sctp_addr
*sctp_find_unmatch_addr(struct sctp_bind_addr
*bp
,
1175 const union sctp_addr
*addrs
,
1177 struct sctp_sock
*opt
);
1178 union sctp_params
sctp_bind_addrs_to_raw(const struct sctp_bind_addr
*bp
,
1181 int sctp_raw_to_bind_addrs(struct sctp_bind_addr
*bp
, __u8
*raw
, int len
,
1182 __u16 port
, gfp_t gfp
);
1184 enum sctp_scope
sctp_scope(const union sctp_addr
*addr
);
1185 int sctp_in_scope(struct net
*net
, const union sctp_addr
*addr
,
1186 const enum sctp_scope scope
);
1187 int sctp_is_any(struct sock
*sk
, const union sctp_addr
*addr
);
1188 int sctp_is_ep_boundall(struct sock
*sk
);
1191 /* What type of endpoint? */
1192 enum sctp_endpoint_type
{
1193 SCTP_EP_TYPE_SOCKET
,
1194 SCTP_EP_TYPE_ASSOCIATION
,
1198 * A common base class to bridge the implmentation view of a
1199 * socket (usually listening) endpoint versus an association's
1201 * This common structure is useful for several purposes:
1202 * 1) Common interface for lookup routines.
1203 * a) Subfunctions work for either endpoint or association
1204 * b) Single interface to lookup allows hiding the lookup lock rather
1205 * than acquiring it externally.
1206 * 2) Common interface for the inbound chunk handling/state machine.
1207 * 3) Common object handling routines for reference counting, etc.
1208 * 4) Disentangle association lookup from endpoint lookup, where we
1209 * do not have to find our endpoint to find our association.
1213 struct sctp_ep_common
{
1214 /* Fields to help us manage our entries in the hash tables. */
1215 struct hlist_node node
;
1218 /* Runtime type information. What kind of endpoint is this? */
1219 enum sctp_endpoint_type type
;
1221 /* Some fields to help us manage this object.
1222 * refcnt - Reference count access to this object.
1223 * dead - Do not attempt to use this object.
1228 /* What socket does this endpoint belong to? */
1231 /* This is where we receive inbound chunks. */
1232 struct sctp_inq inqueue
;
1234 /* This substructure includes the defining parameters of the
1236 * bind_addr.port is our shared port number.
1237 * bind_addr.address_list is our set of local IP addresses.
1239 struct sctp_bind_addr bind_addr
;
1243 /* RFC Section 1.4 Key Terms
1245 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1246 * multi-homed host, an SCTP endpoint is represented to its peers as a
1247 * combination of a set of eligible destination transport addresses to
1248 * which SCTP packets can be sent and a set of eligible source
1249 * transport addresses from which SCTP packets can be received.
1250 * All transport addresses used by an SCTP endpoint must use the
1251 * same port number, but can use multiple IP addresses. A transport
1252 * address used by an SCTP endpoint must not be used by another
1253 * SCTP endpoint. In other words, a transport address is unique
1254 * to an SCTP endpoint.
1256 * From an implementation perspective, each socket has one of these.
1257 * A TCP-style socket will have exactly one association on one of
1258 * these. An UDP-style socket will have multiple associations hanging
1262 struct sctp_endpoint
{
1263 /* Common substructure for endpoint and association. */
1264 struct sctp_ep_common base
;
1266 /* Associations: A list of current associations and mappings
1267 * to the data consumers for each association. This
1268 * may be in the form of a hash table or other
1269 * implementation dependent structure. The data
1270 * consumers may be process identification
1271 * information such as file descriptors, named pipe
1272 * pointer, or table pointers dependent on how SCTP
1275 /* This is really a list of struct sctp_association entries. */
1276 struct list_head asocs
;
1278 /* Secret Key: A secret key used by this endpoint to compute
1279 * the MAC. This SHOULD be a cryptographic quality
1280 * random number with a sufficient length.
1281 * Discussion in [RFC1750] can be helpful in
1282 * selection of the key.
1284 __u8 secret_key
[SCTP_SECRET_SIZE
];
1286 /* digest: This is a digest of the sctp cookie. This field is
1287 * only used on the receive path when we try to validate
1288 * that the cookie has not been tampered with. We put
1289 * this here so we pre-allocate this once and can re-use
1294 /* sendbuf acct. policy. */
1295 __u32 sndbuf_policy
;
1297 /* rcvbuf acct. policy. */
1298 __u32 rcvbuf_policy
;
1300 /* SCTP AUTH: array of the HMACs that will be allocated
1301 * we need this per association so that we don't serialize
1303 struct crypto_shash
**auth_hmacs
;
1305 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1306 struct sctp_hmac_algo_param
*auth_hmacs_list
;
1308 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1309 struct sctp_chunks_param
*auth_chunk_list
;
1311 /* SCTP-AUTH: endpoint shared keys */
1312 struct list_head endpoint_shared_keys
;
1313 __u16 active_key_id
;
1318 __u8 strreset_enable
;
1321 /* Recover the outter endpoint structure. */
1322 static inline struct sctp_endpoint
*sctp_ep(struct sctp_ep_common
*base
)
1324 struct sctp_endpoint
*ep
;
1326 ep
= container_of(base
, struct sctp_endpoint
, base
);
1330 /* These are function signatures for manipulating endpoints. */
1331 struct sctp_endpoint
*sctp_endpoint_new(struct sock
*, gfp_t
);
1332 void sctp_endpoint_free(struct sctp_endpoint
*);
1333 void sctp_endpoint_put(struct sctp_endpoint
*);
1334 void sctp_endpoint_hold(struct sctp_endpoint
*);
1335 void sctp_endpoint_add_asoc(struct sctp_endpoint
*, struct sctp_association
*);
1336 struct sctp_association
*sctp_endpoint_lookup_assoc(
1337 const struct sctp_endpoint
*ep
,
1338 const union sctp_addr
*paddr
,
1339 struct sctp_transport
**);
1340 int sctp_endpoint_is_peeled_off(struct sctp_endpoint
*,
1341 const union sctp_addr
*);
1342 struct sctp_endpoint
*sctp_endpoint_is_match(struct sctp_endpoint
*,
1343 struct net
*, const union sctp_addr
*);
1344 int sctp_has_association(struct net
*net
, const union sctp_addr
*laddr
,
1345 const union sctp_addr
*paddr
);
1347 int sctp_verify_init(struct net
*net
, const struct sctp_endpoint
*ep
,
1348 const struct sctp_association
*asoc
,
1349 enum sctp_cid cid
, struct sctp_init_chunk
*peer_init
,
1350 struct sctp_chunk
*chunk
, struct sctp_chunk
**err_chunk
);
1351 int sctp_process_init(struct sctp_association
*, struct sctp_chunk
*chunk
,
1352 const union sctp_addr
*peer
,
1353 struct sctp_init_chunk
*init
, gfp_t gfp
);
1354 __u32
sctp_generate_tag(const struct sctp_endpoint
*);
1355 __u32
sctp_generate_tsn(const struct sctp_endpoint
*);
1357 struct sctp_inithdr_host
{
1360 __u16 num_outbound_streams
;
1361 __u16 num_inbound_streams
;
1365 struct sctp_stream_priorities
{
1366 /* List of priorities scheduled */
1367 struct list_head prio_sched
;
1368 /* List of streams scheduled */
1369 struct list_head active
;
1370 /* The next stream stream in line */
1371 struct sctp_stream_out_ext
*next
;
1375 struct sctp_stream_out_ext
{
1376 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
1377 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
1378 struct list_head outq
; /* chunks enqueued by this stream */
1381 /* Scheduled streams list */
1382 struct list_head prio_list
;
1383 struct sctp_stream_priorities
*prio_head
;
1385 /* Fields used by RR scheduler */
1387 struct list_head rr_list
;
1392 struct sctp_stream_out
{
1398 struct sctp_stream_out_ext
*ext
;
1402 struct sctp_stream_in
{
1414 struct sctp_stream
{
1415 struct sctp_stream_out
*out
;
1416 struct sctp_stream_in
*in
;
1419 /* Current stream being sent, if any */
1420 struct sctp_stream_out
*out_curr
;
1422 /* Fields used by priority scheduler */
1424 /* List of priorities scheduled */
1425 struct list_head prio_list
;
1427 /* Fields used by RR scheduler */
1429 /* List of streams scheduled */
1430 struct list_head rr_list
;
1431 /* The next stream stream in line */
1432 struct sctp_stream_out_ext
*rr_next
;
1435 struct sctp_stream_interleave
*si
;
1438 #define SCTP_STREAM_CLOSED 0x00
1439 #define SCTP_STREAM_OPEN 0x01
1441 static inline __u16
sctp_datachk_len(const struct sctp_stream
*stream
)
1443 return stream
->si
->data_chunk_len
;
1446 static inline __u16
sctp_datahdr_len(const struct sctp_stream
*stream
)
1448 return stream
->si
->data_chunk_len
- sizeof(struct sctp_chunkhdr
);
1451 static inline __u16
sctp_ftsnchk_len(const struct sctp_stream
*stream
)
1453 return stream
->si
->ftsn_chunk_len
;
1456 static inline __u16
sctp_ftsnhdr_len(const struct sctp_stream
*stream
)
1458 return stream
->si
->ftsn_chunk_len
- sizeof(struct sctp_chunkhdr
);
1461 /* SCTP_GET_ASSOC_STATS counters */
1462 struct sctp_priv_assoc_stats
{
1463 /* Maximum observed rto in the association during subsequent
1464 * observations. Value is set to 0 if no RTO measurement took place
1465 * The transport where the max_rto was observed is returned in
1468 struct sockaddr_storage obs_rto_ipaddr
;
1470 /* Total In and Out SACKs received and sent */
1473 /* Total In and Out packets received and sent */
1476 /* Total retransmitted chunks */
1478 /* TSN received > next expected */
1480 /* Duplicate Chunks received */
1482 /* Gap Ack Blocks received */
1484 /* Unordered data chunks sent and received */
1487 /* Ordered data chunks sent and received */
1490 /* Control chunks sent and received */
1497 * 12. Recommended Transmission Control Block (TCB) Parameters
1499 * This section details a recommended set of parameters that should
1500 * be contained within the TCB for an implementation. This section is
1501 * for illustrative purposes and should not be deemed as requirements
1502 * on an implementation or as an exhaustive list of all parameters
1503 * inside an SCTP TCB. Each implementation may need its own additional
1504 * parameters for optimization.
1508 /* Here we have information about each individual association. */
1509 struct sctp_association
{
1511 /* A base structure common to endpoint and association.
1512 * In this context, it represents the associations's view
1513 * of the local endpoint of the association.
1515 struct sctp_ep_common base
;
1517 /* Associations on the same socket. */
1518 struct list_head asocs
;
1520 /* association id. */
1521 sctp_assoc_t assoc_id
;
1523 /* This is our parent endpoint. */
1524 struct sctp_endpoint
*ep
;
1526 /* These are those association elements needed in the cookie. */
1527 struct sctp_cookie c
;
1529 /* This is all information about our peer. */
1531 /* transport_addr_list
1533 * Peer : A list of SCTP transport addresses that the
1534 * Transport : peer is bound to. This information is derived
1535 * Address : from the INIT or INIT ACK and is used to
1536 * List : associate an inbound packet with a given
1537 * : association. Normally this information is
1538 * : hashed or keyed for quick lookup and access
1540 * : The list is also initialized with the list
1541 * : of addresses passed with the sctp_connectx()
1544 * It is a list of SCTP_transport's.
1546 struct list_head transport_addr_list
;
1550 * Peer Rwnd : Current calculated value of the peer's rwnd.
1556 * Peer : A count of the number of peer addresses
1557 * Transport : in the Peer Transport Address List.
1561 __u16 transport_count
;
1564 * The transport layer port number.
1570 * Primary : This is the current primary destination
1571 * Path : transport address of the peer endpoint. It
1572 * : may also specify a source transport address
1573 * : on this endpoint.
1575 * All of these paths live on transport_addr_list.
1577 * At the bakeoffs, we discovered that the intent of
1578 * primaryPath is that it only changes when the ULP
1579 * asks to have it changed. We add the activePath to
1580 * designate the connection we are currently using to
1581 * transmit new data and most control chunks.
1583 struct sctp_transport
*primary_path
;
1585 /* Cache the primary path address here, when we
1586 * need a an address for msg_name.
1588 union sctp_addr primary_addr
;
1591 * The path that we are currently using to
1592 * transmit new data and most control chunks.
1594 struct sctp_transport
*active_path
;
1598 * RFC2960 6.4 Multi-homed SCTP Endpoints
1600 * Furthermore, when its peer is multi-homed, an
1601 * endpoint SHOULD try to retransmit a chunk to an
1602 * active destination transport address that is
1603 * different from the last destination address to
1604 * which the DATA chunk was sent.
1606 struct sctp_transport
*retran_path
;
1608 /* Pointer to last transport I have sent on. */
1609 struct sctp_transport
*last_sent_to
;
1611 /* This is the last transport I have received DATA on. */
1612 struct sctp_transport
*last_data_from
;
1615 * Mapping An array of bits or bytes indicating which out of
1616 * Array order TSN's have been received (relative to the
1617 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1618 * order packets have been received, this array
1619 * will be set to all zero. This structure may be
1620 * in the form of a circular buffer or bit array.
1622 * Last Rcvd : This is the last TSN received in
1623 * TSN : sequence. This value is set initially by
1624 * : taking the peer's Initial TSN, received in
1625 * : the INIT or INIT ACK chunk, and subtracting
1628 * Throughout most of the specification this is called the
1629 * "Cumulative TSN ACK Point". In this case, we
1630 * ignore the advice in 12.2 in favour of the term
1631 * used in the bulk of the text. This value is hidden
1632 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1634 struct sctp_tsnmap tsn_map
;
1636 /* This mask is used to disable sending the ASCONF chunk
1637 * with specified parameter to peer.
1639 __be16 addip_disabled_mask
;
1641 /* These are capabilities which our peer advertised. */
1642 __u8 ecn_capable
:1, /* Can peer do ECN? */
1643 ipv4_address
:1, /* Peer understands IPv4 addresses? */
1644 ipv6_address
:1, /* Peer understands IPv6 addresses? */
1645 hostname_address
:1, /* Peer understands DNS addresses? */
1646 asconf_capable
:1, /* Does peer support ADDIP? */
1647 prsctp_capable
:1, /* Can peer do PR-SCTP? */
1648 reconf_capable
:1, /* Can peer do RE-CONFIG? */
1649 auth_capable
:1; /* Is peer doing SCTP-AUTH? */
1651 /* sack_needed : This flag indicates if the next received
1652 * : packet is to be responded to with a
1653 * : SACK. This is initialized to 0. When a packet
1654 * : is received sack_cnt is incremented. If this value
1655 * : reaches 2 or more, a SACK is sent and the
1656 * : value is reset to 0. Note: This is used only
1657 * : when no DATA chunks are received out of
1658 * : order. When DATA chunks are out of order,
1659 * : SACK's are not delayed (see Section 6).
1661 __u8 sack_needed
:1, /* Do we need to sack the peer? */
1663 zero_window_announced
:1;
1666 __u32 adaptation_ind
; /* Adaptation Code point. */
1668 struct sctp_inithdr_host i
;
1672 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1673 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1674 * Initial TSN Value minus 1
1678 /* SCTP-AUTH: We need to know pears random number, hmac list
1679 * and authenticated chunk list. All that is part of the
1680 * cookie and these are just pointers to those locations
1682 struct sctp_random_param
*peer_random
;
1683 struct sctp_chunks_param
*peer_chunks
;
1684 struct sctp_hmac_algo_param
*peer_hmacs
;
1687 /* State : A state variable indicating what state the
1688 * : association is in, i.e. COOKIE-WAIT,
1689 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1690 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1692 * Note: No "CLOSED" state is illustrated since if a
1693 * association is "CLOSED" its TCB SHOULD be removed.
1695 * In this implementation we DO have a CLOSED
1696 * state which is used during initiation and shutdown.
1698 * State takes values from SCTP_STATE_*.
1700 enum sctp_state state
;
1702 /* Overall : The overall association error count.
1703 * Error Count : [Clear this any time I get something.]
1705 int overall_error_count
;
1707 /* The cookie life I award for any cookie. */
1708 ktime_t cookie_life
;
1710 /* These are the association's initial, max, and min RTO values.
1711 * These values will be initialized by system defaults, but can
1712 * be modified via the SCTP_RTOINFO socket option.
1714 unsigned long rto_initial
;
1715 unsigned long rto_max
;
1716 unsigned long rto_min
;
1718 /* Maximum number of new data packets that can be sent in a burst. */
1721 /* This is the max_retrans value for the association. This value will
1722 * be initialized initialized from system defaults, but can be
1723 * modified by the SCTP_ASSOCINFO socket option.
1727 /* This is the partially failed retrans value for the transport
1728 * and will be initialized from the assocs value. This can be
1729 * changed using the SCTP_PEER_ADDR_THLDS socket option
1733 /* Maximum number of times the endpoint will retransmit INIT */
1734 __u16 max_init_attempts
;
1736 /* How many times have we resent an INIT? */
1739 /* The largest timeout or RTO value to use in attempting an INIT */
1740 unsigned long max_init_timeo
;
1742 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1743 * the destination address every heartbeat interval. This value
1744 * will be inherited by all new transports.
1746 unsigned long hbinterval
;
1748 /* This is the max_retrans value for new transports in the
1753 /* Flag that path mtu update is pending */
1756 /* Association : The smallest PMTU discovered for all of the
1757 * PMTU : peer's transport addresses.
1761 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1765 /* SACK delay timeout */
1766 unsigned long sackdelay
;
1768 unsigned long timeouts
[SCTP_NUM_TIMEOUT_TYPES
];
1769 struct timer_list timers
[SCTP_NUM_TIMEOUT_TYPES
];
1771 /* Transport to which SHUTDOWN chunk was last sent. */
1772 struct sctp_transport
*shutdown_last_sent_to
;
1774 /* Transport to which INIT chunk was last sent. */
1775 struct sctp_transport
*init_last_sent_to
;
1777 /* How many times have we resent a SHUTDOWN */
1778 int shutdown_retries
;
1780 /* Next TSN : The next TSN number to be assigned to a new
1781 * : DATA chunk. This is sent in the INIT or INIT
1782 * : ACK chunk to the peer and incremented each
1783 * : time a DATA chunk is assigned a TSN
1784 * : (normally just prior to transmit or during
1790 * Last Rcvd : This is the last TSN received in sequence. This value
1791 * TSN : is set initially by taking the peer's Initial TSN,
1792 * : received in the INIT or INIT ACK chunk, and
1793 * : subtracting one from it.
1795 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1798 __u32 ctsn_ack_point
;
1800 /* PR-SCTP Advanced.Peer.Ack.Point */
1801 __u32 adv_peer_ack_point
;
1803 /* Highest TSN that is acknowledged by incoming SACKs. */
1804 __u32 highest_sacked
;
1806 /* TSN marking the fast recovery exit point */
1807 __u32 fast_recovery_exit
;
1809 /* Flag to track the current fast recovery state */
1812 /* The number of unacknowledged data chunks. Reported through
1813 * the SCTP_STATUS sockopt.
1817 /* The total number of data chunks that we've had to retransmit
1818 * as the result of a T3 timer expiration
1820 __u32 rtx_data_chunks
;
1822 /* This is the association's receive buffer space. This value is used
1823 * to set a_rwnd field in an INIT or a SACK chunk.
1827 /* This is the last advertised value of rwnd over a SACK chunk. */
1830 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1831 * to slop over a maximum of the association's frag_point.
1835 /* Keeps treack of rwnd pressure. This happens when we have
1836 * a window, but not recevie buffer (i.e small packets). This one
1837 * is releases slowly (1 PMTU at a time ).
1841 /* This is the sndbuf size in use for the association.
1842 * This corresponds to the sndbuf size for the association,
1843 * as specified in the sk->sndbuf.
1847 /* This is the amount of memory that this association has allocated
1848 * in the receive path at any given time.
1850 atomic_t rmem_alloc
;
1852 /* This is the wait queue head for send requests waiting on
1853 * the association sndbuf space.
1855 wait_queue_head_t wait
;
1857 /* The message size at which SCTP fragmentation will occur. */
1861 /* Counter used to count INIT errors. */
1862 int init_err_counter
;
1864 /* Count the number of INIT cycles (for doubling timeout). */
1867 /* Default send parameters. */
1868 __u16 default_stream
;
1869 __u16 default_flags
;
1871 __u32 default_context
;
1872 __u32 default_timetolive
;
1874 /* Default receive parameters */
1875 __u32 default_rcv_context
;
1878 struct sctp_stream stream
;
1880 /* All outbound chunks go through this structure. */
1881 struct sctp_outq outqueue
;
1883 /* A smart pipe that will handle reordering and fragmentation,
1884 * as well as handle passing events up to the ULP.
1886 struct sctp_ulpq ulpq
;
1888 /* Last TSN that caused an ECNE Chunk to be sent. */
1889 __u32 last_ecne_tsn
;
1891 /* Last TSN that caused a CWR Chunk to be sent. */
1894 /* How many duplicated TSNs have we seen? */
1897 /* These are to support
1898 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1899 * and Enforcement of Flow and Message Limits"
1900 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1901 * or "ADDIP" for short.
1906 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1908 * R1) One and only one ASCONF Chunk MAY be in transit and
1909 * unacknowledged at any one time. If a sender, after sending
1910 * an ASCONF chunk, decides it needs to transfer another
1911 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1912 * returns from the previous ASCONF Chunk before sending a
1913 * subsequent ASCONF. Note this restriction binds each side,
1914 * so at any time two ASCONF may be in-transit on any given
1915 * association (one sent from each endpoint).
1917 * [This is our one-and-only-one ASCONF in flight. If we do
1918 * not have an ASCONF in flight, this is NULL.]
1920 struct sctp_chunk
*addip_last_asconf
;
1922 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1924 * This is needed to implement itmes E1 - E4 of the updated
1925 * spec. Here is the justification:
1927 * Since the peer may bundle multiple ASCONF chunks toward us,
1928 * we now need the ability to cache multiple ACKs. The section
1929 * describes in detail how they are cached and cleaned up.
1931 struct list_head asconf_ack_list
;
1933 /* These ASCONF chunks are waiting to be sent.
1935 * These chunaks can't be pushed to outqueue until receiving
1936 * ASCONF_ACK for the previous ASCONF indicated by
1937 * addip_last_asconf, so as to guarantee that only one ASCONF
1938 * is in flight at any time.
1940 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1942 * In defining the ASCONF Chunk transfer procedures, it is
1943 * essential that these transfers MUST NOT cause congestion
1944 * within the network. To achieve this, we place these
1945 * restrictions on the transfer of ASCONF Chunks:
1947 * R1) One and only one ASCONF Chunk MAY be in transit and
1948 * unacknowledged at any one time. If a sender, after sending
1949 * an ASCONF chunk, decides it needs to transfer another
1950 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1951 * returns from the previous ASCONF Chunk before sending a
1952 * subsequent ASCONF. Note this restriction binds each side,
1953 * so at any time two ASCONF may be in-transit on any given
1954 * association (one sent from each endpoint).
1957 * [I really think this is EXACTLY the sort of intelligence
1958 * which already resides in sctp_outq. Please move this
1959 * queue and its supporting logic down there. --piggy]
1961 struct list_head addip_chunk_list
;
1963 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1965 * A2) A serial number should be assigned to the Chunk. The
1966 * serial number SHOULD be a monotonically increasing
1967 * number. The serial number SHOULD be initialized at
1968 * the start of the association to the same value as the
1969 * Initial TSN and every time a new ASCONF chunk is created
1970 * it is incremented by one after assigning the serial number
1971 * to the newly created chunk.
1974 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1976 * Serial Number : 32 bits (unsigned integer)
1978 * This value represents a Serial Number for the ASCONF
1979 * Chunk. The valid range of Serial Number is from 0 to
1980 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1981 * after reaching 4294967295.
1984 int src_out_of_asoc_ok
;
1985 union sctp_addr
*asconf_addr_del_pending
;
1986 struct sctp_transport
*new_transport
;
1988 /* SCTP AUTH: list of the endpoint shared keys. These
1989 * keys are provided out of band by the user applicaton
1990 * and can't change during the lifetime of the association
1992 struct list_head endpoint_shared_keys
;
1995 * The current generated assocaition shared key (secret)
1997 struct sctp_auth_bytes
*asoc_shared_key
;
1999 /* SCTP AUTH: hmac id of the first peer requested algorithm
2002 __u16 default_hmac_id
;
2004 __u16 active_key_id
;
2006 __u8 need_ecne
:1, /* Need to send an ECNE Chunk? */
2007 temp
:1, /* Is it a temporary association? */
2013 __u8 strreset_enable
;
2014 __u8 strreset_outstanding
; /* request param count on the fly */
2016 __u32 strreset_outseq
; /* Update after receiving response */
2017 __u32 strreset_inseq
; /* Update after receiving request */
2018 __u32 strreset_result
[2]; /* save the results of last 2 responses */
2020 struct sctp_chunk
*strreset_chunk
; /* save request chunk */
2022 struct sctp_priv_assoc_stats stats
;
2024 int sent_cnt_removable
;
2026 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
2027 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
2031 /* An eyecatcher for determining if we are really looking at an
2032 * association data structure.
2035 SCTP_ASSOC_EYECATCHER
= 0xa550c123,
2038 /* Recover the outter association structure. */
2039 static inline struct sctp_association
*sctp_assoc(struct sctp_ep_common
*base
)
2041 struct sctp_association
*asoc
;
2043 asoc
= container_of(base
, struct sctp_association
, base
);
2047 /* These are function signatures for manipulating associations. */
2050 struct sctp_association
*
2051 sctp_association_new(const struct sctp_endpoint
*ep
, const struct sock
*sk
,
2052 enum sctp_scope scope
, gfp_t gfp
);
2053 void sctp_association_free(struct sctp_association
*);
2054 void sctp_association_put(struct sctp_association
*);
2055 void sctp_association_hold(struct sctp_association
*);
2057 struct sctp_transport
*sctp_assoc_choose_alter_transport(
2058 struct sctp_association
*, struct sctp_transport
*);
2059 void sctp_assoc_update_retran_path(struct sctp_association
*);
2060 struct sctp_transport
*sctp_assoc_lookup_paddr(const struct sctp_association
*,
2061 const union sctp_addr
*);
2062 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
2063 const union sctp_addr
*laddr
);
2064 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*,
2065 const union sctp_addr
*address
,
2067 const int peer_state
);
2068 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
2069 const union sctp_addr
*addr
);
2070 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
2071 struct sctp_transport
*peer
);
2072 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
2073 struct sctp_transport
*transport
,
2074 enum sctp_transport_cmd command
,
2075 sctp_sn_error_t error
);
2076 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*, __u32
);
2077 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*,
2079 const union sctp_addr
*,
2080 const union sctp_addr
*);
2081 void sctp_assoc_migrate(struct sctp_association
*, struct sock
*);
2082 int sctp_assoc_update(struct sctp_association
*old
,
2083 struct sctp_association
*new);
2085 __u32
sctp_association_get_next_tsn(struct sctp_association
*);
2087 void sctp_assoc_sync_pmtu(struct sctp_association
*asoc
);
2088 void sctp_assoc_rwnd_increase(struct sctp_association
*, unsigned int);
2089 void sctp_assoc_rwnd_decrease(struct sctp_association
*, unsigned int);
2090 void sctp_assoc_set_primary(struct sctp_association
*,
2091 struct sctp_transport
*);
2092 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*,
2093 struct sctp_transport
*);
2094 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
2095 enum sctp_scope scope
, gfp_t gfp
);
2096 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*,
2097 struct sctp_cookie
*,
2099 int sctp_assoc_set_id(struct sctp_association
*, gfp_t
);
2100 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
);
2101 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
2102 const struct sctp_association
*asoc
,
2104 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
);
2106 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
2107 const union sctp_addr
*ss2
);
2108 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
);
2110 /* A convenience structure to parse out SCTP specific CMSGs. */
2112 struct sctp_initmsg
*init
;
2113 struct sctp_sndrcvinfo
*srinfo
;
2114 struct sctp_sndinfo
*sinfo
;
2117 /* Structure for tracking memory objects */
2118 struct sctp_dbg_objcnt_entry
{
2123 #endif /* __sctp_structs_h__ */