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>
93 /* Structures useful for managing bind/connect. */
95 struct sctp_bind_bucket
{
97 unsigned short fastreuse
;
98 struct hlist_node node
;
99 struct hlist_head owner
;
103 struct sctp_bind_hashbucket
{
105 struct hlist_head chain
;
108 /* Used for hashing all associations. */
109 struct sctp_hashbucket
{
111 struct hlist_head chain
;
112 } __attribute__((__aligned__(8)));
115 /* The SCTP globals structure. */
116 extern struct sctp_globals
{
117 /* This is a list of groups of functions for each address
118 * family that we support.
120 struct list_head address_families
;
122 /* This is the hash of all endpoints. */
123 struct sctp_hashbucket
*ep_hashtable
;
124 /* This is the sctp port control hash. */
125 struct sctp_bind_hashbucket
*port_hashtable
;
126 /* This is the hash of all transports. */
127 struct rhltable transport_hashtable
;
129 /* Sizes of above hashtables. */
133 /* Default initialization values to be applied to new associations. */
135 __u16 max_outstreams
;
137 /* Flag to indicate whether computing and verifying checksum
139 bool checksum_disable
;
142 #define sctp_max_instreams (sctp_globals.max_instreams)
143 #define sctp_max_outstreams (sctp_globals.max_outstreams)
144 #define sctp_address_families (sctp_globals.address_families)
145 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
146 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
147 #define sctp_port_hashsize (sctp_globals.port_hashsize)
148 #define sctp_port_hashtable (sctp_globals.port_hashtable)
149 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
150 #define sctp_checksum_disable (sctp_globals.checksum_disable)
152 /* SCTP Socket type: UDP or TCP style. */
153 enum sctp_socket_type
{
155 SCTP_SOCKET_UDP_HIGH_BANDWIDTH
,
159 /* Per socket SCTP information. */
161 /* inet_sock has to be the first member of sctp_sock */
162 struct inet_sock inet
;
163 /* What kind of a socket is this? */
164 enum sctp_socket_type type
;
166 /* PF_ family specific functions. */
169 /* Access to HMAC transform. */
170 struct crypto_shash
*hmac
;
173 /* What is our base endpointer? */
174 struct sctp_endpoint
*ep
;
176 struct sctp_bind_bucket
*bind_hash
;
177 /* Various Socket Options. */
178 __u16 default_stream
;
181 __u32 default_context
;
182 __u32 default_timetolive
;
183 __u32 default_rcv_context
;
186 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
187 * the destination address every heartbeat interval. This value
188 * will be inherited by all new associations.
192 /* This is the max_retrans value for new associations. */
195 /* The initial Path MTU to use for new associations. */
198 /* The default SACK delay timeout for new associations. */
202 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
205 struct sctp_initmsg initmsg
;
206 struct sctp_rtoinfo rtoinfo
;
207 struct sctp_paddrparams paddrparam
;
208 struct sctp_event_subscribe subscribe
;
209 struct sctp_assocparams assocparams
;
214 __u32 adaptation_ind
;
222 data_ready_signalled
:1;
225 /* Receive to here while partial delivery is in effect. */
226 struct sk_buff_head pd_lobby
;
228 /* These must be the last fields, as they will skipped on copies,
229 * like on accept and peeloff operations
231 struct list_head auto_asconf_list
;
235 static inline struct sctp_sock
*sctp_sk(const struct sock
*sk
)
237 return (struct sctp_sock
*)sk
;
240 static inline struct sock
*sctp_opt2sk(const struct sctp_sock
*sp
)
242 return (struct sock
*)sp
;
245 #if IS_ENABLED(CONFIG_IPV6)
247 struct sctp_sock sctp
;
248 struct ipv6_pinfo inet6
;
250 #endif /* CONFIG_IPV6 */
253 /* This is our APPLICATION-SPECIFIC state cookie.
254 * THIS IS NOT DICTATED BY THE SPECIFICATION.
256 /* These are the parts of an association which we send in the cookie.
257 * Most of these are straight out of:
258 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
264 /* My : Tag expected in every inbound packet and sent
265 * Verification: in the INIT or INIT ACK chunk.
270 /* Peer's : Tag expected in every outbound packet except
271 * Verification: in the INIT chunk.
276 /* The rest of these are not from the spec, but really need to
280 /* My Tie Tag : Assist in discovering a restarting association. */
283 /* Peer's Tie Tag: Assist in discovering a restarting association. */
286 /* When does this cookie expire? */
289 /* Number of inbound/outbound streams which are set
290 * and negotiated during the INIT process.
292 __u16 sinit_num_ostreams
;
293 __u16 sinit_max_instreams
;
295 /* This is the first sequence number I used. */
298 /* This holds the originating address of the INIT packet. */
299 union sctp_addr peer_addr
;
302 * Include the source port of the INIT-ACK
308 /* Padding for future use */
311 __u32 adaptation_ind
;
313 __u8 auth_random
[sizeof(struct sctp_paramhdr
) +
314 SCTP_AUTH_RANDOM_LENGTH
];
315 __u8 auth_hmacs
[SCTP_AUTH_NUM_HMACS
* sizeof(__u16
) + 2];
316 __u8 auth_chunks
[sizeof(struct sctp_paramhdr
) + SCTP_AUTH_MAX_CHUNKS
];
318 /* This is a shim for my peer's INIT packet, followed by
319 * a copy of the raw address list of the association.
320 * The length of the raw address list is saved in the
321 * raw_addr_list_len field, which will be used at the time when
322 * the association TCB is re-constructed from the cookie.
324 __u32 raw_addr_list_len
;
325 struct sctp_init_chunk peer_init
[0];
329 /* The format of our cookie that we send to our peer. */
330 struct sctp_signed_cookie
{
331 __u8 signature
[SCTP_SECRET_SIZE
];
332 __u32 __pad
; /* force sctp_cookie alignment to 64 bits */
333 struct sctp_cookie c
;
336 /* This is another convenience type to allocate memory for address
337 * params for the maximum size and pass such structures around
340 union sctp_addr_param
{
341 struct sctp_paramhdr p
;
342 struct sctp_ipv4addr_param v4
;
343 struct sctp_ipv6addr_param v6
;
346 /* A convenience type to allow walking through the various
347 * parameters and avoid casting all over the place.
351 struct sctp_paramhdr
*p
;
352 struct sctp_cookie_preserve_param
*life
;
353 struct sctp_hostname_param
*dns
;
354 struct sctp_cookie_param
*cookie
;
355 struct sctp_supported_addrs_param
*sat
;
356 struct sctp_ipv4addr_param
*v4
;
357 struct sctp_ipv6addr_param
*v6
;
358 union sctp_addr_param
*addr
;
359 struct sctp_adaptation_ind_param
*aind
;
360 struct sctp_supported_ext_param
*ext
;
361 struct sctp_random_param
*random
;
362 struct sctp_chunks_param
*chunks
;
363 struct sctp_hmac_algo_param
*hmac_algo
;
364 struct sctp_addip_param
*addip
;
367 /* RFC 2960. Section 3.3.5 Heartbeat.
368 * Heartbeat Information: variable length
369 * The Sender-specific Heartbeat Info field should normally include
370 * information about the sender's current time when this HEARTBEAT
371 * chunk is sent and the destination transport address to which this
372 * HEARTBEAT is sent (see Section 8.3).
374 struct sctp_sender_hb_info
{
375 struct sctp_paramhdr param_hdr
;
376 union sctp_addr daddr
;
377 unsigned long sent_at
;
381 int sctp_stream_init(struct sctp_stream
*stream
, __u16 outcnt
, __u16 incnt
,
383 int sctp_stream_init_ext(struct sctp_stream
*stream
, __u16 sid
);
384 void sctp_stream_free(struct sctp_stream
*stream
);
385 void sctp_stream_clear(struct sctp_stream
*stream
);
386 void sctp_stream_update(struct sctp_stream
*stream
, struct sctp_stream
*new);
388 /* What is the current SSN number for this stream? */
389 #define sctp_ssn_peek(stream, type, sid) \
390 ((stream)->type[sid].ssn)
392 /* Return the next SSN number for this stream. */
393 #define sctp_ssn_next(stream, type, sid) \
394 ((stream)->type[sid].ssn++)
396 /* Skip over this ssn and all below. */
397 #define sctp_ssn_skip(stream, type, sid, ssn) \
398 ((stream)->type[sid].ssn = ssn + 1)
401 * Pointers to address related SCTP functions.
402 * (i.e. things that depend on the address family.)
405 int (*sctp_xmit
) (struct sk_buff
*skb
,
406 struct sctp_transport
*);
407 int (*setsockopt
) (struct sock
*sk
,
411 unsigned int optlen
);
412 int (*getsockopt
) (struct sock
*sk
,
417 int (*compat_setsockopt
) (struct sock
*sk
,
421 unsigned int optlen
);
422 int (*compat_getsockopt
) (struct sock
*sk
,
427 void (*get_dst
) (struct sctp_transport
*t
,
428 union sctp_addr
*saddr
,
431 void (*get_saddr
) (struct sctp_sock
*sk
,
432 struct sctp_transport
*t
,
434 void (*copy_addrlist
) (struct list_head
*,
435 struct net_device
*);
436 int (*cmp_addr
) (const union sctp_addr
*addr1
,
437 const union sctp_addr
*addr2
);
438 void (*addr_copy
) (union sctp_addr
*dst
,
439 union sctp_addr
*src
);
440 void (*from_skb
) (union sctp_addr
*,
443 void (*from_sk
) (union sctp_addr
*,
445 void (*from_addr_param
) (union sctp_addr
*,
446 union sctp_addr_param
*,
447 __be16 port
, int iif
);
448 int (*to_addr_param
) (const union sctp_addr
*,
449 union sctp_addr_param
*);
450 int (*addr_valid
) (union sctp_addr
*,
452 const struct sk_buff
*);
453 enum sctp_scope (*scope
)(union sctp_addr
*);
454 void (*inaddr_any
) (union sctp_addr
*, __be16
);
455 int (*is_any
) (const union sctp_addr
*);
456 int (*available
) (union sctp_addr
*,
458 int (*skb_iif
) (const struct sk_buff
*sk
);
459 int (*is_ce
) (const struct sk_buff
*sk
);
460 void (*seq_dump_addr
)(struct seq_file
*seq
,
461 union sctp_addr
*addr
);
462 void (*ecn_capable
)(struct sock
*sk
);
463 __u16 net_header_len
;
465 sa_family_t sa_family
;
466 struct list_head list
;
469 struct sctp_af
*sctp_get_af_specific(sa_family_t
);
470 int sctp_register_af(struct sctp_af
*);
472 /* Protocol family functions. */
474 void (*event_msgname
)(struct sctp_ulpevent
*, char *, int *);
475 void (*skb_msgname
) (struct sk_buff
*, char *, int *);
476 int (*af_supported
) (sa_family_t
, struct sctp_sock
*);
477 int (*cmp_addr
) (const union sctp_addr
*,
478 const union sctp_addr
*,
480 int (*bind_verify
) (struct sctp_sock
*, union sctp_addr
*);
481 int (*send_verify
) (struct sctp_sock
*, union sctp_addr
*);
482 int (*supported_addrs
)(const struct sctp_sock
*, __be16
*);
483 struct sock
*(*create_accept_sk
) (struct sock
*sk
,
484 struct sctp_association
*asoc
,
486 int (*addr_to_user
)(struct sctp_sock
*sk
, union sctp_addr
*addr
);
487 void (*to_sk_saddr
)(union sctp_addr
*, struct sock
*sk
);
488 void (*to_sk_daddr
)(union sctp_addr
*, struct sock
*sk
);
493 /* Structure to track chunk fragments that have been acked, but peer
494 * fragments of the same message have not.
496 struct sctp_datamsg
{
497 /* Chunks waiting to be submitted to lower layer. */
498 struct list_head chunks
;
499 /* Reference counting. */
501 /* When is this message no longer interesting to the peer? */
502 unsigned long expires_at
;
503 /* Did the messenge fail to send? */
506 can_delay
:1, /* should this message be Nagle delayed */
507 abandoned
:1; /* should this message be abandoned */
510 struct sctp_datamsg
*sctp_datamsg_from_user(struct sctp_association
*,
511 struct sctp_sndrcvinfo
*,
513 void sctp_datamsg_free(struct sctp_datamsg
*);
514 void sctp_datamsg_put(struct sctp_datamsg
*);
515 void sctp_chunk_fail(struct sctp_chunk
*, int error
);
516 int sctp_chunk_abandoned(struct sctp_chunk
*);
518 /* RFC2960 1.4 Key Terms
520 * o Chunk: A unit of information within an SCTP packet, consisting of
521 * a chunk header and chunk-specific content.
523 * As a matter of convenience, we remember the SCTP common header for
524 * each chunk as well as a few other header pointers...
527 struct list_head list
;
531 /* How many times this chunk have been sent, for prsctp RTX policy */
535 /* This is our link to the per-transport transmitted list. */
536 struct list_head transmitted_list
;
537 /* List in specific stream outq */
538 struct list_head stream_list
;
541 /* This field is used by chunks that hold fragmented data.
542 * For the first fragment this is the list that holds the rest of
543 * fragments. For the remaining fragments, this is the link to the
544 * frag_list maintained in the first fragment.
546 struct list_head frag_list
;
548 /* This points to the sk_buff containing the actual data. */
551 /* In case of GSO packets, this will store the head one */
552 struct sk_buff
*head_skb
;
554 /* These are the SCTP headers by reverse order in a packet.
555 * Note that some of these may happen more than once. In that
556 * case, we point at the "current" one, whatever that means
557 * for that level of header.
560 /* We point this at the FIRST TLV parameter to chunk_hdr. */
561 union sctp_params param_hdr
;
564 struct sctp_datahdr
*data_hdr
;
565 struct sctp_inithdr
*init_hdr
;
566 struct sctp_sackhdr
*sack_hdr
;
567 struct sctp_heartbeathdr
*hb_hdr
;
568 struct sctp_sender_hb_info
*hbs_hdr
;
569 struct sctp_shutdownhdr
*shutdown_hdr
;
570 struct sctp_signed_cookie
*cookie_hdr
;
571 struct sctp_ecnehdr
*ecne_hdr
;
572 struct sctp_cwrhdr
*ecn_cwr_hdr
;
573 struct sctp_errhdr
*err_hdr
;
574 struct sctp_addiphdr
*addip_hdr
;
575 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
576 struct sctp_authhdr
*auth_hdr
;
581 struct sctp_chunkhdr
*chunk_hdr
;
582 struct sctphdr
*sctp_hdr
;
584 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
585 struct sctp_sndrcvinfo sinfo
;
587 /* Which association does this belong to? */
588 struct sctp_association
*asoc
;
590 /* What endpoint received this chunk? */
591 struct sctp_ep_common
*rcvr
;
593 /* We fill this in if we are calculating RTT. */
594 unsigned long sent_at
;
596 /* What is the origin IP address for this chunk? */
597 union sctp_addr source
;
598 /* Destination address for this chunk. */
599 union sctp_addr dest
;
601 /* For outbound message, track all fragments for SEND_FAILED. */
602 struct sctp_datamsg
*msg
;
604 /* For an inbound chunk, this tells us where it came from.
605 * For an outbound chunk, it tells us where we'd like it to
606 * go. It is NULL if we have no preference.
608 struct sctp_transport
*transport
;
610 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
611 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
612 * spec violates the principle premis that all chunks are processed
615 struct sk_buff
*auth_chunk
;
617 #define SCTP_CAN_FRTX 0x0
618 #define SCTP_NEED_FRTX 0x1
619 #define SCTP_DONT_FRTX 0x2
620 __u16 rtt_in_progress
:1, /* This chunk used for RTT calc? */
621 has_tsn
:1, /* Does this chunk have a TSN yet? */
622 has_ssn
:1, /* Does this chunk have a SSN yet? */
623 singleton
:1, /* Only chunk in the packet? */
624 end_of_packet
:1, /* Last chunk in the packet? */
625 ecn_ce_done
:1, /* Have we processed the ECN CE bit? */
626 pdiscard
:1, /* Discard the whole packet now? */
627 tsn_gap_acked
:1, /* Is this chunk acked by a GAP ACK? */
628 data_accepted
:1, /* At least 1 chunk accepted */
629 auth
:1, /* IN: was auth'ed | OUT: needs auth */
630 has_asconf
:1, /* IN: have seen an asconf before */
631 tsn_missing_report
:2, /* Data chunk missing counter. */
632 fast_retransmit
:2; /* Is this chunk fast retransmitted? */
635 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
636 void sctp_chunk_hold(struct sctp_chunk
*);
637 void sctp_chunk_put(struct sctp_chunk
*);
638 int sctp_user_addto_chunk(struct sctp_chunk
*chunk
, int len
,
639 struct iov_iter
*from
);
640 void sctp_chunk_free(struct sctp_chunk
*);
641 void *sctp_addto_chunk(struct sctp_chunk
*, int len
, const void *data
);
642 struct sctp_chunk
*sctp_chunkify(struct sk_buff
*,
643 const struct sctp_association
*,
644 struct sock
*, gfp_t gfp
);
645 void sctp_init_addrs(struct sctp_chunk
*, union sctp_addr
*,
647 const union sctp_addr
*sctp_source(const struct sctp_chunk
*chunk
);
649 static inline __u16
sctp_chunk_stream_no(struct sctp_chunk
*ch
)
651 return ntohs(ch
->subh
.data_hdr
->stream
);
655 SCTP_ADDR_NEW
, /* new address added to assoc/ep */
656 SCTP_ADDR_SRC
, /* address can be used as source */
657 SCTP_ADDR_DEL
, /* address about to be deleted */
660 /* This is a structure for holding either an IPv6 or an IPv4 address. */
661 struct sctp_sockaddr_entry
{
662 struct list_head list
;
669 #define SCTP_ADDRESS_TICK_DELAY 500
671 /* This structure holds lists of chunks as we are assembling for
675 /* These are the SCTP header values (host order) for the packet. */
677 __u16 destination_port
;
680 /* This contains the payload chunks. */
681 struct list_head chunk_list
;
683 /* This is the overhead of the sctp and ip headers. */
685 /* This is the total size of all chunks INCLUDING padding. */
687 /* This is the maximum size this packet may have */
690 /* The packet is destined for this transport address.
691 * The function we finally use to pass down to the next lower
692 * layer lives in the transport structure.
694 struct sctp_transport
*transport
;
696 /* pointer to the auth chunk for this packet */
697 struct sctp_chunk
*auth
;
699 u8 has_cookie_echo
:1, /* This packet contains a COOKIE-ECHO chunk. */
700 has_sack
:1, /* This packet contains a SACK chunk. */
701 has_auth
:1, /* This packet contains an AUTH chunk */
702 has_data
:1, /* This packet contains at least 1 DATA chunk */
703 ipfragok
:1; /* So let ip fragment this packet */
706 void sctp_packet_init(struct sctp_packet
*, struct sctp_transport
*,
707 __u16 sport
, __u16 dport
);
708 void sctp_packet_config(struct sctp_packet
*, __u32 vtag
, int);
709 enum sctp_xmit
sctp_packet_transmit_chunk(struct sctp_packet
*packet
,
710 struct sctp_chunk
*chunk
,
711 int one_packet
, gfp_t gfp
);
712 enum sctp_xmit
sctp_packet_append_chunk(struct sctp_packet
*packet
,
713 struct sctp_chunk
*chunk
);
714 int sctp_packet_transmit(struct sctp_packet
*, gfp_t
);
715 void sctp_packet_free(struct sctp_packet
*);
717 static inline int sctp_packet_empty(struct sctp_packet
*packet
)
719 return packet
->size
== packet
->overhead
;
722 /* This represents a remote transport address.
723 * For local transport addresses, we just use union sctp_addr.
725 * RFC2960 Section 1.4 Key Terms
727 * o Transport address: A Transport Address is traditionally defined
728 * by Network Layer address, Transport Layer protocol and Transport
729 * Layer port number. In the case of SCTP running over IP, a
730 * transport address is defined by the combination of an IP address
731 * and an SCTP port number (where SCTP is the Transport protocol).
733 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
735 * o The sender keeps a separate congestion control parameter set for
736 * each of the destination addresses it can send to (not each
737 * source-destination pair but for each destination). The parameters
738 * should decay if the address is not used for a long enough time
742 struct sctp_transport
{
743 /* A list of transports. */
744 struct list_head transports
;
745 struct rhlist_head node
;
747 /* Reference counting. */
749 /* RTO-Pending : A flag used to track if one of the DATA
750 * chunks sent to this address is currently being
751 * used to compute a RTT. If this flag is 0,
752 * the next DATA chunk sent to this destination
753 * should be used to compute a RTT and this flag
754 * should be set. Every time the RTT
755 * calculation completes (i.e. the DATA chunk
756 * is SACK'd) clear this flag.
761 * hb_sent : a flag that signals that we have a pending
766 /* Is the Path MTU update pending on this tranport */
769 dst_pending_confirm
:1, /* need to confirm neighbour */
771 /* Has this transport moved the ctsn since we last sacked */
777 /* This is the peer's IP address and port. */
778 union sctp_addr ipaddr
;
780 /* These are the functions we call to handle LLP stuff. */
781 struct sctp_af
*af_specific
;
783 /* Which association do we belong to? */
784 struct sctp_association
*asoc
;
788 * 12.3 Per Transport Address Data
790 * For each destination transport address in the peer's
791 * address list derived from the INIT or INIT ACK chunk, a
792 * number of data elements needs to be maintained including:
794 /* RTO : The current retransmission timeout value. */
797 __u32 rtt
; /* This is the most recent RTT. */
799 /* RTTVAR : The current RTT variation. */
802 /* SRTT : The current smoothed round trip time. */
806 * These are the congestion stats.
808 /* cwnd : The current congestion window. */
809 __u32 cwnd
; /* This is the actual cwnd. */
811 /* ssthresh : The current slow start threshold value. */
814 /* partial : The tracking method for increase of cwnd when in
815 * bytes acked : congestion avoidance mode (see Section 6.2.2)
817 __u32 partial_bytes_acked
;
819 /* Data that has been sent, but not acknowledged. */
822 __u32 burst_limited
; /* Holds old cwnd when max.burst is applied */
825 struct dst_entry
*dst
;
826 /* Source address. */
827 union sctp_addr saddr
;
829 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
830 * the destination address every heartbeat interval.
832 unsigned long hbinterval
;
834 /* SACK delay timeout */
835 unsigned long sackdelay
;
838 /* When was the last time that we heard from this transport? We use
839 * this to pick new active and retran paths.
841 ktime_t last_time_heard
;
843 /* When was the last time that we sent a chunk using this
844 * transport? We use this to check for idle transports
846 unsigned long last_time_sent
;
848 /* Last time(in jiffies) when cwnd is reduced due to the congestion
849 * indication based on ECNE chunk.
851 unsigned long last_time_ecne_reduced
;
853 /* This is the max_retrans value for the transport and will
854 * be initialized from the assocs value. This can be changed
855 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
859 /* This is the partially failed retrans value for the transport
860 * and will be initialized from the assocs value. This can be changed
861 * using the SCTP_PEER_ADDR_THLDS socket option
864 /* PMTU : The current known path MTU. */
867 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
870 /* The number of times INIT has been sent on this transport. */
873 /* state : The current state of this destination,
874 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
878 /* These are the error stats for this destination. */
880 /* Error count : The current error count for this destination. */
881 unsigned short error_count
;
883 /* Per : A timer used by each destination.
887 * [Everywhere else in the text this is called T3-rtx. -ed]
889 struct timer_list T3_rtx_timer
;
891 /* Heartbeat timer is per destination. */
892 struct timer_list hb_timer
;
894 /* Timer to handle ICMP proto unreachable envets */
895 struct timer_list proto_unreach_timer
;
897 /* Timer to handler reconf chunk rtx */
898 struct timer_list reconf_timer
;
900 /* Since we're using per-destination retransmission timers
901 * (see above), we're also using per-destination "transmitted"
902 * queues. This probably ought to be a private struct
903 * accessible only within the outqueue, but it's not, yet.
905 struct list_head transmitted
;
907 /* We build bundle-able packets for this transport here. */
908 struct sctp_packet packet
;
910 /* This is the list of transports that have chunks to send. */
911 struct list_head send_ready
;
913 /* State information saved for SFR_CACC algorithm. The key
914 * idea in SFR_CACC is to maintain state at the sender on a
915 * per-destination basis when a changeover happens.
916 * char changeover_active;
917 * char cycling_changeover;
918 * __u32 next_tsn_at_change;
919 * char cacc_saw_newack;
922 /* An unsigned integer, which stores the next TSN to be
923 * used by the sender, at the moment of changeover.
925 __u32 next_tsn_at_change
;
927 /* A flag which indicates the occurrence of a changeover */
928 char changeover_active
;
930 /* A flag which indicates whether the change of primary is
931 * the first switch to this destination address during an
934 char cycling_changeover
;
936 /* A temporary flag, which is used during the processing of
937 * a SACK to estimate the causative TSN(s)'s group.
939 char cacc_saw_newack
;
942 /* 64-bit random number sent with heartbeat. */
948 struct sctp_transport
*sctp_transport_new(struct net
*, const union sctp_addr
*,
950 void sctp_transport_set_owner(struct sctp_transport
*,
951 struct sctp_association
*);
952 void sctp_transport_route(struct sctp_transport
*, union sctp_addr
*,
954 void sctp_transport_pmtu(struct sctp_transport
*, struct sock
*sk
);
955 void sctp_transport_free(struct sctp_transport
*);
956 void sctp_transport_reset_t3_rtx(struct sctp_transport
*);
957 void sctp_transport_reset_hb_timer(struct sctp_transport
*);
958 void sctp_transport_reset_reconf_timer(struct sctp_transport
*transport
);
959 int sctp_transport_hold(struct sctp_transport
*);
960 void sctp_transport_put(struct sctp_transport
*);
961 void sctp_transport_update_rto(struct sctp_transport
*, __u32
);
962 void sctp_transport_raise_cwnd(struct sctp_transport
*, __u32
, __u32
);
963 void sctp_transport_lower_cwnd(struct sctp_transport
*t
,
964 enum sctp_lower_cwnd reason
);
965 void sctp_transport_burst_limited(struct sctp_transport
*);
966 void sctp_transport_burst_reset(struct sctp_transport
*);
967 unsigned long sctp_transport_timeout(struct sctp_transport
*);
968 void sctp_transport_reset(struct sctp_transport
*t
);
969 bool sctp_transport_update_pmtu(struct sctp_transport
*t
, u32 pmtu
);
970 void sctp_transport_immediate_rtx(struct sctp_transport
*);
971 void sctp_transport_dst_release(struct sctp_transport
*t
);
972 void sctp_transport_dst_confirm(struct sctp_transport
*t
);
975 /* This is the structure we use to queue packets as they come into
976 * SCTP. We write packets to it and read chunks from it.
979 /* This is actually a queue of sctp_chunk each
980 * containing a partially decoded packet.
982 struct list_head in_chunk_list
;
983 /* This is the packet which is currently off the in queue and is
984 * being worked on through the inbound chunk processing.
986 struct sctp_chunk
*in_progress
;
988 /* This is the delayed task to finish delivering inbound
991 struct work_struct immediate
;
994 void sctp_inq_init(struct sctp_inq
*);
995 void sctp_inq_free(struct sctp_inq
*);
996 void sctp_inq_push(struct sctp_inq
*, struct sctp_chunk
*packet
);
997 struct sctp_chunk
*sctp_inq_pop(struct sctp_inq
*);
998 struct sctp_chunkhdr
*sctp_inq_peek(struct sctp_inq
*);
999 void sctp_inq_set_th_handler(struct sctp_inq
*, work_func_t
);
1001 /* This is the structure we use to hold outbound chunks. You push
1002 * chunks in and they automatically pop out the other end as bundled
1003 * packets (it calls (*output_handler)()).
1005 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1006 * and 8.2 of the v13 draft.
1008 * It handles retransmissions. The connection to the timeout portion
1009 * of the state machine is through sctp_..._timeout() and timeout_handler.
1011 * If you feed it SACKs, it will eat them.
1013 * If you give it big chunks, it will fragment them.
1015 * It assigns TSN's to data chunks. This happens at the last possible
1016 * instant before transmission.
1018 * When free()'d, it empties itself out via output_handler().
1021 struct sctp_association
*asoc
;
1023 /* Data pending that has never been transmitted. */
1024 struct list_head out_chunk_list
;
1026 /* Stream scheduler being used */
1027 struct sctp_sched_ops
*sched
;
1029 unsigned int out_qlen
; /* Total length of queued data chunks. */
1031 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1034 /* These are control chunks we want to send. */
1035 struct list_head control_chunk_list
;
1037 /* These are chunks that have been sacked but are above the
1038 * CTSN, or cumulative tsn ack point.
1040 struct list_head sacked
;
1042 /* Put chunks on this list to schedule them for
1045 struct list_head retransmit
;
1047 /* Put chunks on this list to save them for FWD TSN processing as
1048 * they were abandoned.
1050 struct list_head abandoned
;
1052 /* How many unackd bytes do we have in-flight? */
1053 __u32 outstanding_bytes
;
1055 /* Are we doing fast-rtx on this queue */
1062 void sctp_outq_init(struct sctp_association
*, struct sctp_outq
*);
1063 void sctp_outq_teardown(struct sctp_outq
*);
1064 void sctp_outq_free(struct sctp_outq
*);
1065 void sctp_outq_tail(struct sctp_outq
*, struct sctp_chunk
*chunk
, gfp_t
);
1066 int sctp_outq_sack(struct sctp_outq
*, struct sctp_chunk
*);
1067 int sctp_outq_is_empty(const struct sctp_outq
*);
1068 void sctp_outq_restart(struct sctp_outq
*);
1070 void sctp_retransmit(struct sctp_outq
*q
, struct sctp_transport
*transport
,
1071 enum sctp_retransmit_reason reason
);
1072 void sctp_retransmit_mark(struct sctp_outq
*, struct sctp_transport
*, __u8
);
1073 void sctp_outq_uncork(struct sctp_outq
*, gfp_t gfp
);
1074 void sctp_prsctp_prune(struct sctp_association
*asoc
,
1075 struct sctp_sndrcvinfo
*sinfo
, int msg_len
);
1076 /* Uncork and flush an outqueue. */
1077 static inline void sctp_outq_cork(struct sctp_outq
*q
)
1082 /* SCTP skb control block.
1083 * sctp_input_cb is currently used on rx and sock rx queue
1085 struct sctp_input_cb
{
1087 struct inet_skb_parm h4
;
1088 #if IS_ENABLED(CONFIG_IPV6)
1089 struct inet6_skb_parm h6
;
1092 struct sctp_chunk
*chunk
;
1095 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1097 static inline const struct sk_buff
*sctp_gso_headskb(const struct sk_buff
*skb
)
1099 const struct sctp_chunk
*chunk
= SCTP_INPUT_CB(skb
)->chunk
;
1101 return chunk
->head_skb
? : skb
;
1104 /* These bind address data fields common between endpoints and associations */
1105 struct sctp_bind_addr
{
1107 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1109 * SCTP Port: The local SCTP port number the endpoint is
1114 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1116 * Address List: The list of IP addresses that this instance
1117 * has bound. This information is passed to one's
1118 * peer(s) in INIT and INIT ACK chunks.
1120 struct list_head address_list
;
1123 void sctp_bind_addr_init(struct sctp_bind_addr
*, __u16 port
);
1124 void sctp_bind_addr_free(struct sctp_bind_addr
*);
1125 int sctp_bind_addr_copy(struct net
*net
, struct sctp_bind_addr
*dest
,
1126 const struct sctp_bind_addr
*src
,
1127 enum sctp_scope scope
, gfp_t gfp
,
1129 int sctp_bind_addr_dup(struct sctp_bind_addr
*dest
,
1130 const struct sctp_bind_addr
*src
,
1132 int sctp_add_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*,
1133 int new_size
, __u8 addr_state
, gfp_t gfp
);
1134 int sctp_del_bind_addr(struct sctp_bind_addr
*, union sctp_addr
*);
1135 int sctp_bind_addr_match(struct sctp_bind_addr
*, const union sctp_addr
*,
1136 struct sctp_sock
*);
1137 int sctp_bind_addr_conflict(struct sctp_bind_addr
*, const union sctp_addr
*,
1138 struct sctp_sock
*, struct sctp_sock
*);
1139 int sctp_bind_addr_state(const struct sctp_bind_addr
*bp
,
1140 const union sctp_addr
*addr
);
1141 union sctp_addr
*sctp_find_unmatch_addr(struct sctp_bind_addr
*bp
,
1142 const union sctp_addr
*addrs
,
1144 struct sctp_sock
*opt
);
1145 union sctp_params
sctp_bind_addrs_to_raw(const struct sctp_bind_addr
*bp
,
1148 int sctp_raw_to_bind_addrs(struct sctp_bind_addr
*bp
, __u8
*raw
, int len
,
1149 __u16 port
, gfp_t gfp
);
1151 enum sctp_scope
sctp_scope(const union sctp_addr
*addr
);
1152 int sctp_in_scope(struct net
*net
, const union sctp_addr
*addr
,
1153 const enum sctp_scope scope
);
1154 int sctp_is_any(struct sock
*sk
, const union sctp_addr
*addr
);
1155 int sctp_is_ep_boundall(struct sock
*sk
);
1158 /* What type of endpoint? */
1159 enum sctp_endpoint_type
{
1160 SCTP_EP_TYPE_SOCKET
,
1161 SCTP_EP_TYPE_ASSOCIATION
,
1165 * A common base class to bridge the implmentation view of a
1166 * socket (usually listening) endpoint versus an association's
1168 * This common structure is useful for several purposes:
1169 * 1) Common interface for lookup routines.
1170 * a) Subfunctions work for either endpoint or association
1171 * b) Single interface to lookup allows hiding the lookup lock rather
1172 * than acquiring it externally.
1173 * 2) Common interface for the inbound chunk handling/state machine.
1174 * 3) Common object handling routines for reference counting, etc.
1175 * 4) Disentangle association lookup from endpoint lookup, where we
1176 * do not have to find our endpoint to find our association.
1180 struct sctp_ep_common
{
1181 /* Fields to help us manage our entries in the hash tables. */
1182 struct hlist_node node
;
1185 /* Runtime type information. What kind of endpoint is this? */
1186 enum sctp_endpoint_type type
;
1188 /* Some fields to help us manage this object.
1189 * refcnt - Reference count access to this object.
1190 * dead - Do not attempt to use this object.
1195 /* What socket does this endpoint belong to? */
1198 /* This is where we receive inbound chunks. */
1199 struct sctp_inq inqueue
;
1201 /* This substructure includes the defining parameters of the
1203 * bind_addr.port is our shared port number.
1204 * bind_addr.address_list is our set of local IP addresses.
1206 struct sctp_bind_addr bind_addr
;
1210 /* RFC Section 1.4 Key Terms
1212 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1213 * multi-homed host, an SCTP endpoint is represented to its peers as a
1214 * combination of a set of eligible destination transport addresses to
1215 * which SCTP packets can be sent and a set of eligible source
1216 * transport addresses from which SCTP packets can be received.
1217 * All transport addresses used by an SCTP endpoint must use the
1218 * same port number, but can use multiple IP addresses. A transport
1219 * address used by an SCTP endpoint must not be used by another
1220 * SCTP endpoint. In other words, a transport address is unique
1221 * to an SCTP endpoint.
1223 * From an implementation perspective, each socket has one of these.
1224 * A TCP-style socket will have exactly one association on one of
1225 * these. An UDP-style socket will have multiple associations hanging
1229 struct sctp_endpoint
{
1230 /* Common substructure for endpoint and association. */
1231 struct sctp_ep_common base
;
1233 /* Associations: A list of current associations and mappings
1234 * to the data consumers for each association. This
1235 * may be in the form of a hash table or other
1236 * implementation dependent structure. The data
1237 * consumers may be process identification
1238 * information such as file descriptors, named pipe
1239 * pointer, or table pointers dependent on how SCTP
1242 /* This is really a list of struct sctp_association entries. */
1243 struct list_head asocs
;
1245 /* Secret Key: A secret key used by this endpoint to compute
1246 * the MAC. This SHOULD be a cryptographic quality
1247 * random number with a sufficient length.
1248 * Discussion in [RFC1750] can be helpful in
1249 * selection of the key.
1251 __u8 secret_key
[SCTP_SECRET_SIZE
];
1253 /* digest: This is a digest of the sctp cookie. This field is
1254 * only used on the receive path when we try to validate
1255 * that the cookie has not been tampered with. We put
1256 * this here so we pre-allocate this once and can re-use
1261 /* sendbuf acct. policy. */
1262 __u32 sndbuf_policy
;
1264 /* rcvbuf acct. policy. */
1265 __u32 rcvbuf_policy
;
1267 /* SCTP AUTH: array of the HMACs that will be allocated
1268 * we need this per association so that we don't serialize
1270 struct crypto_shash
**auth_hmacs
;
1272 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1273 struct sctp_hmac_algo_param
*auth_hmacs_list
;
1275 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1276 struct sctp_chunks_param
*auth_chunk_list
;
1278 /* SCTP-AUTH: endpoint shared keys */
1279 struct list_head endpoint_shared_keys
;
1280 __u16 active_key_id
;
1285 __u8 strreset_enable
;
1288 /* Recover the outter endpoint structure. */
1289 static inline struct sctp_endpoint
*sctp_ep(struct sctp_ep_common
*base
)
1291 struct sctp_endpoint
*ep
;
1293 ep
= container_of(base
, struct sctp_endpoint
, base
);
1297 /* These are function signatures for manipulating endpoints. */
1298 struct sctp_endpoint
*sctp_endpoint_new(struct sock
*, gfp_t
);
1299 void sctp_endpoint_free(struct sctp_endpoint
*);
1300 void sctp_endpoint_put(struct sctp_endpoint
*);
1301 void sctp_endpoint_hold(struct sctp_endpoint
*);
1302 void sctp_endpoint_add_asoc(struct sctp_endpoint
*, struct sctp_association
*);
1303 struct sctp_association
*sctp_endpoint_lookup_assoc(
1304 const struct sctp_endpoint
*ep
,
1305 const union sctp_addr
*paddr
,
1306 struct sctp_transport
**);
1307 int sctp_endpoint_is_peeled_off(struct sctp_endpoint
*,
1308 const union sctp_addr
*);
1309 struct sctp_endpoint
*sctp_endpoint_is_match(struct sctp_endpoint
*,
1310 struct net
*, const union sctp_addr
*);
1311 int sctp_has_association(struct net
*net
, const union sctp_addr
*laddr
,
1312 const union sctp_addr
*paddr
);
1314 int sctp_verify_init(struct net
*net
, const struct sctp_endpoint
*ep
,
1315 const struct sctp_association
*asoc
,
1316 enum sctp_cid cid
, struct sctp_init_chunk
*peer_init
,
1317 struct sctp_chunk
*chunk
, struct sctp_chunk
**err_chunk
);
1318 int sctp_process_init(struct sctp_association
*, struct sctp_chunk
*chunk
,
1319 const union sctp_addr
*peer
,
1320 struct sctp_init_chunk
*init
, gfp_t gfp
);
1321 __u32
sctp_generate_tag(const struct sctp_endpoint
*);
1322 __u32
sctp_generate_tsn(const struct sctp_endpoint
*);
1324 struct sctp_inithdr_host
{
1327 __u16 num_outbound_streams
;
1328 __u16 num_inbound_streams
;
1332 struct sctp_stream_priorities
{
1333 /* List of priorities scheduled */
1334 struct list_head prio_sched
;
1335 /* List of streams scheduled */
1336 struct list_head active
;
1337 /* The next stream stream in line */
1338 struct sctp_stream_out_ext
*next
;
1342 struct sctp_stream_out_ext
{
1343 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
1344 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
1345 struct list_head outq
; /* chunks enqueued by this stream */
1348 /* Scheduled streams list */
1349 struct list_head prio_list
;
1350 struct sctp_stream_priorities
*prio_head
;
1352 /* Fields used by RR scheduler */
1354 struct list_head rr_list
;
1359 struct sctp_stream_out
{
1362 struct sctp_stream_out_ext
*ext
;
1365 struct sctp_stream_in
{
1369 struct sctp_stream
{
1370 struct sctp_stream_out
*out
;
1371 struct sctp_stream_in
*in
;
1374 /* Current stream being sent, if any */
1375 struct sctp_stream_out
*out_curr
;
1377 /* Fields used by priority scheduler */
1379 /* List of priorities scheduled */
1380 struct list_head prio_list
;
1382 /* Fields used by RR scheduler */
1384 /* List of streams scheduled */
1385 struct list_head rr_list
;
1386 /* The next stream stream in line */
1387 struct sctp_stream_out_ext
*rr_next
;
1392 #define SCTP_STREAM_CLOSED 0x00
1393 #define SCTP_STREAM_OPEN 0x01
1395 /* SCTP_GET_ASSOC_STATS counters */
1396 struct sctp_priv_assoc_stats
{
1397 /* Maximum observed rto in the association during subsequent
1398 * observations. Value is set to 0 if no RTO measurement took place
1399 * The transport where the max_rto was observed is returned in
1402 struct sockaddr_storage obs_rto_ipaddr
;
1404 /* Total In and Out SACKs received and sent */
1407 /* Total In and Out packets received and sent */
1410 /* Total retransmitted chunks */
1412 /* TSN received > next expected */
1414 /* Duplicate Chunks received */
1416 /* Gap Ack Blocks received */
1418 /* Unordered data chunks sent and received */
1421 /* Ordered data chunks sent and received */
1424 /* Control chunks sent and received */
1431 * 12. Recommended Transmission Control Block (TCB) Parameters
1433 * This section details a recommended set of parameters that should
1434 * be contained within the TCB for an implementation. This section is
1435 * for illustrative purposes and should not be deemed as requirements
1436 * on an implementation or as an exhaustive list of all parameters
1437 * inside an SCTP TCB. Each implementation may need its own additional
1438 * parameters for optimization.
1442 /* Here we have information about each individual association. */
1443 struct sctp_association
{
1445 /* A base structure common to endpoint and association.
1446 * In this context, it represents the associations's view
1447 * of the local endpoint of the association.
1449 struct sctp_ep_common base
;
1451 /* Associations on the same socket. */
1452 struct list_head asocs
;
1454 /* association id. */
1455 sctp_assoc_t assoc_id
;
1457 /* This is our parent endpoint. */
1458 struct sctp_endpoint
*ep
;
1460 /* These are those association elements needed in the cookie. */
1461 struct sctp_cookie c
;
1463 /* This is all information about our peer. */
1465 /* transport_addr_list
1467 * Peer : A list of SCTP transport addresses that the
1468 * Transport : peer is bound to. This information is derived
1469 * Address : from the INIT or INIT ACK and is used to
1470 * List : associate an inbound packet with a given
1471 * : association. Normally this information is
1472 * : hashed or keyed for quick lookup and access
1474 * : The list is also initialized with the list
1475 * : of addresses passed with the sctp_connectx()
1478 * It is a list of SCTP_transport's.
1480 struct list_head transport_addr_list
;
1484 * Peer Rwnd : Current calculated value of the peer's rwnd.
1490 * Peer : A count of the number of peer addresses
1491 * Transport : in the Peer Transport Address List.
1495 __u16 transport_count
;
1498 * The transport layer port number.
1504 * Primary : This is the current primary destination
1505 * Path : transport address of the peer endpoint. It
1506 * : may also specify a source transport address
1507 * : on this endpoint.
1509 * All of these paths live on transport_addr_list.
1511 * At the bakeoffs, we discovered that the intent of
1512 * primaryPath is that it only changes when the ULP
1513 * asks to have it changed. We add the activePath to
1514 * designate the connection we are currently using to
1515 * transmit new data and most control chunks.
1517 struct sctp_transport
*primary_path
;
1519 /* Cache the primary path address here, when we
1520 * need a an address for msg_name.
1522 union sctp_addr primary_addr
;
1525 * The path that we are currently using to
1526 * transmit new data and most control chunks.
1528 struct sctp_transport
*active_path
;
1532 * RFC2960 6.4 Multi-homed SCTP Endpoints
1534 * Furthermore, when its peer is multi-homed, an
1535 * endpoint SHOULD try to retransmit a chunk to an
1536 * active destination transport address that is
1537 * different from the last destination address to
1538 * which the DATA chunk was sent.
1540 struct sctp_transport
*retran_path
;
1542 /* Pointer to last transport I have sent on. */
1543 struct sctp_transport
*last_sent_to
;
1545 /* This is the last transport I have received DATA on. */
1546 struct sctp_transport
*last_data_from
;
1549 * Mapping An array of bits or bytes indicating which out of
1550 * Array order TSN's have been received (relative to the
1551 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1552 * order packets have been received, this array
1553 * will be set to all zero. This structure may be
1554 * in the form of a circular buffer or bit array.
1556 * Last Rcvd : This is the last TSN received in
1557 * TSN : sequence. This value is set initially by
1558 * : taking the peer's Initial TSN, received in
1559 * : the INIT or INIT ACK chunk, and subtracting
1562 * Throughout most of the specification this is called the
1563 * "Cumulative TSN ACK Point". In this case, we
1564 * ignore the advice in 12.2 in favour of the term
1565 * used in the bulk of the text. This value is hidden
1566 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1568 struct sctp_tsnmap tsn_map
;
1570 /* This mask is used to disable sending the ASCONF chunk
1571 * with specified parameter to peer.
1573 __be16 addip_disabled_mask
;
1575 /* These are capabilities which our peer advertised. */
1576 __u8 ecn_capable
:1, /* Can peer do ECN? */
1577 ipv4_address
:1, /* Peer understands IPv4 addresses? */
1578 ipv6_address
:1, /* Peer understands IPv6 addresses? */
1579 hostname_address
:1, /* Peer understands DNS addresses? */
1580 asconf_capable
:1, /* Does peer support ADDIP? */
1581 prsctp_capable
:1, /* Can peer do PR-SCTP? */
1582 reconf_capable
:1, /* Can peer do RE-CONFIG? */
1583 auth_capable
:1; /* Is peer doing SCTP-AUTH? */
1585 /* sack_needed : This flag indicates if the next received
1586 * : packet is to be responded to with a
1587 * : SACK. This is initialized to 0. When a packet
1588 * : is received sack_cnt is incremented. If this value
1589 * : reaches 2 or more, a SACK is sent and the
1590 * : value is reset to 0. Note: This is used only
1591 * : when no DATA chunks are received out of
1592 * : order. When DATA chunks are out of order,
1593 * : SACK's are not delayed (see Section 6).
1595 __u8 sack_needed
:1, /* Do we need to sack the peer? */
1597 zero_window_announced
:1;
1600 __u32 adaptation_ind
; /* Adaptation Code point. */
1602 struct sctp_inithdr_host i
;
1606 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1607 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1608 * Initial TSN Value minus 1
1612 /* SCTP-AUTH: We need to know pears random number, hmac list
1613 * and authenticated chunk list. All that is part of the
1614 * cookie and these are just pointers to those locations
1616 struct sctp_random_param
*peer_random
;
1617 struct sctp_chunks_param
*peer_chunks
;
1618 struct sctp_hmac_algo_param
*peer_hmacs
;
1621 /* State : A state variable indicating what state the
1622 * : association is in, i.e. COOKIE-WAIT,
1623 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1624 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1626 * Note: No "CLOSED" state is illustrated since if a
1627 * association is "CLOSED" its TCB SHOULD be removed.
1629 * In this implementation we DO have a CLOSED
1630 * state which is used during initiation and shutdown.
1632 * State takes values from SCTP_STATE_*.
1634 enum sctp_state state
;
1636 /* Overall : The overall association error count.
1637 * Error Count : [Clear this any time I get something.]
1639 int overall_error_count
;
1641 /* The cookie life I award for any cookie. */
1642 ktime_t cookie_life
;
1644 /* These are the association's initial, max, and min RTO values.
1645 * These values will be initialized by system defaults, but can
1646 * be modified via the SCTP_RTOINFO socket option.
1648 unsigned long rto_initial
;
1649 unsigned long rto_max
;
1650 unsigned long rto_min
;
1652 /* Maximum number of new data packets that can be sent in a burst. */
1655 /* This is the max_retrans value for the association. This value will
1656 * be initialized initialized from system defaults, but can be
1657 * modified by the SCTP_ASSOCINFO socket option.
1661 /* This is the partially failed retrans value for the transport
1662 * and will be initialized from the assocs value. This can be
1663 * changed using the SCTP_PEER_ADDR_THLDS socket option
1667 /* Maximum number of times the endpoint will retransmit INIT */
1668 __u16 max_init_attempts
;
1670 /* How many times have we resent an INIT? */
1673 /* The largest timeout or RTO value to use in attempting an INIT */
1674 unsigned long max_init_timeo
;
1676 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1677 * the destination address every heartbeat interval. This value
1678 * will be inherited by all new transports.
1680 unsigned long hbinterval
;
1682 /* This is the max_retrans value for new transports in the
1687 /* Flag that path mtu update is pending */
1690 /* Association : The smallest PMTU discovered for all of the
1691 * PMTU : peer's transport addresses.
1695 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1699 /* SACK delay timeout */
1700 unsigned long sackdelay
;
1702 unsigned long timeouts
[SCTP_NUM_TIMEOUT_TYPES
];
1703 struct timer_list timers
[SCTP_NUM_TIMEOUT_TYPES
];
1705 /* Transport to which SHUTDOWN chunk was last sent. */
1706 struct sctp_transport
*shutdown_last_sent_to
;
1708 /* Transport to which INIT chunk was last sent. */
1709 struct sctp_transport
*init_last_sent_to
;
1711 /* How many times have we resent a SHUTDOWN */
1712 int shutdown_retries
;
1714 /* Next TSN : The next TSN number to be assigned to a new
1715 * : DATA chunk. This is sent in the INIT or INIT
1716 * : ACK chunk to the peer and incremented each
1717 * : time a DATA chunk is assigned a TSN
1718 * : (normally just prior to transmit or during
1724 * Last Rcvd : This is the last TSN received in sequence. This value
1725 * TSN : is set initially by taking the peer's Initial TSN,
1726 * : received in the INIT or INIT ACK chunk, and
1727 * : subtracting one from it.
1729 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1732 __u32 ctsn_ack_point
;
1734 /* PR-SCTP Advanced.Peer.Ack.Point */
1735 __u32 adv_peer_ack_point
;
1737 /* Highest TSN that is acknowledged by incoming SACKs. */
1738 __u32 highest_sacked
;
1740 /* TSN marking the fast recovery exit point */
1741 __u32 fast_recovery_exit
;
1743 /* Flag to track the current fast recovery state */
1746 /* The number of unacknowledged data chunks. Reported through
1747 * the SCTP_STATUS sockopt.
1751 /* The total number of data chunks that we've had to retransmit
1752 * as the result of a T3 timer expiration
1754 __u32 rtx_data_chunks
;
1756 /* This is the association's receive buffer space. This value is used
1757 * to set a_rwnd field in an INIT or a SACK chunk.
1761 /* This is the last advertised value of rwnd over a SACK chunk. */
1764 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1765 * to slop over a maximum of the association's frag_point.
1769 /* Keeps treack of rwnd pressure. This happens when we have
1770 * a window, but not recevie buffer (i.e small packets). This one
1771 * is releases slowly (1 PMTU at a time ).
1775 /* This is the sndbuf size in use for the association.
1776 * This corresponds to the sndbuf size for the association,
1777 * as specified in the sk->sndbuf.
1781 /* This is the amount of memory that this association has allocated
1782 * in the receive path at any given time.
1784 atomic_t rmem_alloc
;
1786 /* This is the wait queue head for send requests waiting on
1787 * the association sndbuf space.
1789 wait_queue_head_t wait
;
1791 /* The message size at which SCTP fragmentation will occur. */
1795 /* Counter used to count INIT errors. */
1796 int init_err_counter
;
1798 /* Count the number of INIT cycles (for doubling timeout). */
1801 /* Default send parameters. */
1802 __u16 default_stream
;
1803 __u16 default_flags
;
1805 __u32 default_context
;
1806 __u32 default_timetolive
;
1808 /* Default receive parameters */
1809 __u32 default_rcv_context
;
1812 struct sctp_stream stream
;
1814 /* All outbound chunks go through this structure. */
1815 struct sctp_outq outqueue
;
1817 /* A smart pipe that will handle reordering and fragmentation,
1818 * as well as handle passing events up to the ULP.
1820 struct sctp_ulpq ulpq
;
1822 /* Last TSN that caused an ECNE Chunk to be sent. */
1823 __u32 last_ecne_tsn
;
1825 /* Last TSN that caused a CWR Chunk to be sent. */
1828 /* How many duplicated TSNs have we seen? */
1831 /* These are to support
1832 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1833 * and Enforcement of Flow and Message Limits"
1834 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1835 * or "ADDIP" for short.
1840 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1842 * R1) One and only one ASCONF Chunk MAY be in transit and
1843 * unacknowledged at any one time. If a sender, after sending
1844 * an ASCONF chunk, decides it needs to transfer another
1845 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1846 * returns from the previous ASCONF Chunk before sending a
1847 * subsequent ASCONF. Note this restriction binds each side,
1848 * so at any time two ASCONF may be in-transit on any given
1849 * association (one sent from each endpoint).
1851 * [This is our one-and-only-one ASCONF in flight. If we do
1852 * not have an ASCONF in flight, this is NULL.]
1854 struct sctp_chunk
*addip_last_asconf
;
1856 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1858 * This is needed to implement itmes E1 - E4 of the updated
1859 * spec. Here is the justification:
1861 * Since the peer may bundle multiple ASCONF chunks toward us,
1862 * we now need the ability to cache multiple ACKs. The section
1863 * describes in detail how they are cached and cleaned up.
1865 struct list_head asconf_ack_list
;
1867 /* These ASCONF chunks are waiting to be sent.
1869 * These chunaks can't be pushed to outqueue until receiving
1870 * ASCONF_ACK for the previous ASCONF indicated by
1871 * addip_last_asconf, so as to guarantee that only one ASCONF
1872 * is in flight at any time.
1874 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1876 * In defining the ASCONF Chunk transfer procedures, it is
1877 * essential that these transfers MUST NOT cause congestion
1878 * within the network. To achieve this, we place these
1879 * restrictions on the transfer of ASCONF Chunks:
1881 * R1) One and only one ASCONF Chunk MAY be in transit and
1882 * unacknowledged at any one time. If a sender, after sending
1883 * an ASCONF chunk, decides it needs to transfer another
1884 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1885 * returns from the previous ASCONF Chunk before sending a
1886 * subsequent ASCONF. Note this restriction binds each side,
1887 * so at any time two ASCONF may be in-transit on any given
1888 * association (one sent from each endpoint).
1891 * [I really think this is EXACTLY the sort of intelligence
1892 * which already resides in sctp_outq. Please move this
1893 * queue and its supporting logic down there. --piggy]
1895 struct list_head addip_chunk_list
;
1897 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1899 * A2) A serial number should be assigned to the Chunk. The
1900 * serial number SHOULD be a monotonically increasing
1901 * number. The serial number SHOULD be initialized at
1902 * the start of the association to the same value as the
1903 * Initial TSN and every time a new ASCONF chunk is created
1904 * it is incremented by one after assigning the serial number
1905 * to the newly created chunk.
1908 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1910 * Serial Number : 32 bits (unsigned integer)
1912 * This value represents a Serial Number for the ASCONF
1913 * Chunk. The valid range of Serial Number is from 0 to
1914 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1915 * after reaching 4294967295.
1918 int src_out_of_asoc_ok
;
1919 union sctp_addr
*asconf_addr_del_pending
;
1920 struct sctp_transport
*new_transport
;
1922 /* SCTP AUTH: list of the endpoint shared keys. These
1923 * keys are provided out of band by the user applicaton
1924 * and can't change during the lifetime of the association
1926 struct list_head endpoint_shared_keys
;
1929 * The current generated assocaition shared key (secret)
1931 struct sctp_auth_bytes
*asoc_shared_key
;
1933 /* SCTP AUTH: hmac id of the first peer requested algorithm
1936 __u16 default_hmac_id
;
1938 __u16 active_key_id
;
1940 __u8 need_ecne
:1, /* Need to send an ECNE Chunk? */
1941 temp
:1, /* Is it a temporary association? */
1946 __u8 strreset_enable
;
1947 __u8 strreset_outstanding
; /* request param count on the fly */
1949 __u32 strreset_outseq
; /* Update after receiving response */
1950 __u32 strreset_inseq
; /* Update after receiving request */
1951 __u32 strreset_result
[2]; /* save the results of last 2 responses */
1953 struct sctp_chunk
*strreset_chunk
; /* save request chunk */
1955 struct sctp_priv_assoc_stats stats
;
1957 int sent_cnt_removable
;
1959 __u64 abandoned_unsent
[SCTP_PR_INDEX(MAX
) + 1];
1960 __u64 abandoned_sent
[SCTP_PR_INDEX(MAX
) + 1];
1964 /* An eyecatcher for determining if we are really looking at an
1965 * association data structure.
1968 SCTP_ASSOC_EYECATCHER
= 0xa550c123,
1971 /* Recover the outter association structure. */
1972 static inline struct sctp_association
*sctp_assoc(struct sctp_ep_common
*base
)
1974 struct sctp_association
*asoc
;
1976 asoc
= container_of(base
, struct sctp_association
, base
);
1980 /* These are function signatures for manipulating associations. */
1983 struct sctp_association
*
1984 sctp_association_new(const struct sctp_endpoint
*ep
, const struct sock
*sk
,
1985 enum sctp_scope scope
, gfp_t gfp
);
1986 void sctp_association_free(struct sctp_association
*);
1987 void sctp_association_put(struct sctp_association
*);
1988 void sctp_association_hold(struct sctp_association
*);
1990 struct sctp_transport
*sctp_assoc_choose_alter_transport(
1991 struct sctp_association
*, struct sctp_transport
*);
1992 void sctp_assoc_update_retran_path(struct sctp_association
*);
1993 struct sctp_transport
*sctp_assoc_lookup_paddr(const struct sctp_association
*,
1994 const union sctp_addr
*);
1995 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1996 const union sctp_addr
*laddr
);
1997 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*,
1998 const union sctp_addr
*address
,
2000 const int peer_state
);
2001 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
2002 const union sctp_addr
*addr
);
2003 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
2004 struct sctp_transport
*peer
);
2005 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
2006 struct sctp_transport
*transport
,
2007 enum sctp_transport_cmd command
,
2008 sctp_sn_error_t error
);
2009 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*, __u32
);
2010 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*,
2012 const union sctp_addr
*,
2013 const union sctp_addr
*);
2014 void sctp_assoc_migrate(struct sctp_association
*, struct sock
*);
2015 int sctp_assoc_update(struct sctp_association
*old
,
2016 struct sctp_association
*new);
2018 __u32
sctp_association_get_next_tsn(struct sctp_association
*);
2020 void sctp_assoc_sync_pmtu(struct sctp_association
*asoc
);
2021 void sctp_assoc_rwnd_increase(struct sctp_association
*, unsigned int);
2022 void sctp_assoc_rwnd_decrease(struct sctp_association
*, unsigned int);
2023 void sctp_assoc_set_primary(struct sctp_association
*,
2024 struct sctp_transport
*);
2025 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*,
2026 struct sctp_transport
*);
2027 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
2028 enum sctp_scope scope
, gfp_t gfp
);
2029 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*,
2030 struct sctp_cookie
*,
2032 int sctp_assoc_set_id(struct sctp_association
*, gfp_t
);
2033 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
);
2034 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
2035 const struct sctp_association
*asoc
,
2037 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
);
2039 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
2040 const union sctp_addr
*ss2
);
2041 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
);
2043 /* A convenience structure to parse out SCTP specific CMSGs. */
2045 struct sctp_initmsg
*init
;
2046 struct sctp_sndrcvinfo
*srinfo
;
2047 struct sctp_sndinfo
*sinfo
;
2050 /* Structure for tracking memory objects */
2051 struct sctp_dbg_objcnt_entry
{
2056 #endif /* __sctp_structs_h__ */