1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
8 * This file is part of the SCTP kernel implementation
10 * Please send any bug reports or fixes you make to the
12 * lksctp developers <linux-sctp@vger.kernel.org>
14 * Written or modified by:
15 * Randall Stewart <randall@sctp.chicago.il.us>
16 * Ken Morneau <kmorneau@cisco.com>
17 * Qiaobing Xie <qxie1@email.mot.com>
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Xingang Guo <xingang.guo@intel.com>
22 * Hui Huang <hui.huang@nokia.com>
23 * Sridhar Samudrala <sri@us.ibm.com>
24 * Daisy Chang <daisyc@us.ibm.com>
25 * Dajiang Zhang <dajiang.zhang@nokia.com>
26 * Ardelle Fan <ardelle.fan@intel.com>
27 * Ryan Layer <rmlayer@us.ibm.com>
28 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
29 * Kevin Gao <kevin.gao@intel.com>
32 #ifndef __sctp_structs_h__
33 #define __sctp_structs_h__
35 #include <linux/ktime.h>
36 #include <linux/generic-radix-tree.h>
37 #include <linux/rhashtable-types.h>
38 #include <linux/socket.h> /* linux/in.h needs this!! */
39 #include <linux/in.h> /* We get struct sockaddr_in. */
40 #include <linux/in6.h> /* We get struct in6_addr */
41 #include <linux/ipv6.h>
42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
43 #include <linux/atomic.h> /* This gets us atomic counters. */
44 #include <linux/skbuff.h> /* We need sk_buff_head. */
45 #include <linux/workqueue.h> /* We need tq_struct. */
46 #include <linux/sctp.h> /* We need sctp* header structs. */
47 #include <net/sctp/auth.h> /* We need auth specific structs */
48 #include <net/ip.h> /* For inet_skb_parm */
50 /* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
54 struct sockaddr_in v4;
55 struct sockaddr_in6 v6;
59 /* Forward declarations for data structures. */
62 struct sctp_association;
63 struct sctp_transport;
68 struct sctp_bind_addr;
70 struct sctp_ep_common;
75 #include <net/sctp/tsnmap.h>
76 #include <net/sctp/ulpevent.h>
77 #include <net/sctp/ulpqueue.h>
78 #include <net/sctp/stream_interleave.h>
80 /* Structures useful for managing bind/connect. */
82 struct sctp_bind_bucket {
84 signed char fastreuse;
85 signed char fastreuseport;
87 struct hlist_node node;
88 struct hlist_head owner;
92 struct sctp_bind_hashbucket {
94 struct hlist_head chain;
97 /* Used for hashing all associations. */
98 struct sctp_hashbucket {
100 struct hlist_head chain;
101 } __attribute__((__aligned__(8)));
104 /* The SCTP globals structure. */
105 extern struct sctp_globals {
106 /* This is a list of groups of functions for each address
107 * family that we support.
109 struct list_head address_families;
111 /* This is the hash of all endpoints. */
112 struct sctp_hashbucket *ep_hashtable;
113 /* This is the sctp port control hash. */
114 struct sctp_bind_hashbucket *port_hashtable;
115 /* This is the hash of all transports. */
116 struct rhltable transport_hashtable;
118 /* Sizes of above hashtables. */
122 /* Default initialization values to be applied to new associations. */
124 __u16 max_outstreams;
126 /* Flag to indicate whether computing and verifying checksum
128 bool checksum_disable;
131 #define sctp_max_instreams (sctp_globals.max_instreams)
132 #define sctp_max_outstreams (sctp_globals.max_outstreams)
133 #define sctp_address_families (sctp_globals.address_families)
134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
136 #define sctp_port_hashsize (sctp_globals.port_hashsize)
137 #define sctp_port_hashtable (sctp_globals.port_hashtable)
138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
139 #define sctp_checksum_disable (sctp_globals.checksum_disable)
141 /* SCTP Socket type: UDP or TCP style. */
142 enum sctp_socket_type {
144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
148 /* Per socket SCTP information. */
150 /* inet_sock has to be the first member of sctp_sock */
151 struct inet_sock inet;
152 /* What kind of a socket is this? */
153 enum sctp_socket_type type;
155 /* PF_ family specific functions. */
158 /* Access to HMAC transform. */
159 struct crypto_shash *hmac;
162 /* What is our base endpointer? */
163 struct sctp_endpoint *ep;
165 struct sctp_bind_bucket *bind_hash;
166 /* Various Socket Options. */
167 __u16 default_stream;
170 __u32 default_context;
171 __u32 default_timetolive;
172 __u32 default_rcv_context;
175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176 * the destination address every heartbeat interval. This value
177 * will be inherited by all new associations.
180 __u32 probe_interval;
185 /* This is the max_retrans value for new associations. */
194 /* The initial Path MTU to use for new associations. */
197 /* The default SACK delay timeout for new associations. */
201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
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
215 struct sctp_initmsg initmsg;
220 __u32 adaptation_ind;
230 data_ready_signalled:1;
234 /* Fields after this point will be skipped on copies, like on accept
235 * and peeloff operations
238 /* Receive to here while partial delivery is in effect. */
239 struct sk_buff_head pd_lobby;
241 struct list_head auto_asconf_list;
245 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
247 return (struct sctp_sock *)sk;
250 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
252 return (struct sock *)sp;
255 #if IS_ENABLED(CONFIG_IPV6)
257 struct sctp_sock sctp;
258 struct ipv6_pinfo inet6;
260 #endif /* CONFIG_IPV6 */
263 /* This is our APPLICATION-SPECIFIC state cookie.
264 * THIS IS NOT DICTATED BY THE SPECIFICATION.
266 /* These are the parts of an association which we send in the cookie.
267 * Most of these are straight out of:
268 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
274 /* My : Tag expected in every inbound packet and sent
275 * Verification: in the INIT or INIT ACK chunk.
280 /* Peer's : Tag expected in every outbound packet except
281 * Verification: in the INIT chunk.
286 /* The rest of these are not from the spec, but really need to
290 /* My Tie Tag : Assist in discovering a restarting association. */
293 /* Peer's Tie Tag: Assist in discovering a restarting association. */
296 /* When does this cookie expire? */
299 /* Number of inbound/outbound streams which are set
300 * and negotiated during the INIT process.
302 __u16 sinit_num_ostreams;
303 __u16 sinit_max_instreams;
305 /* This is the first sequence number I used. */
308 /* This holds the originating address of the INIT packet. */
309 union sctp_addr peer_addr;
312 * Include the source port of the INIT-ACK
318 /* Padding for future use */
321 __u32 adaptation_ind;
323 __u8 auth_random[sizeof(struct sctp_paramhdr) +
324 SCTP_AUTH_RANDOM_LENGTH];
325 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
326 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
328 /* This is a shim for my peer's INIT packet, followed by
329 * a copy of the raw address list of the association.
330 * The length of the raw address list is saved in the
331 * raw_addr_list_len field, which will be used at the time when
332 * the association TCB is re-constructed from the cookie.
334 __u32 raw_addr_list_len;
335 struct sctp_init_chunk peer_init[];
339 /* The format of our cookie that we send to our peer. */
340 struct sctp_signed_cookie {
341 __u8 signature[SCTP_SECRET_SIZE];
342 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
343 struct sctp_cookie c;
346 /* This is another convenience type to allocate memory for address
347 * params for the maximum size and pass such structures around
350 union sctp_addr_param {
351 struct sctp_paramhdr p;
352 struct sctp_ipv4addr_param v4;
353 struct sctp_ipv6addr_param v6;
356 /* A convenience type to allow walking through the various
357 * parameters and avoid casting all over the place.
361 struct sctp_paramhdr *p;
362 struct sctp_cookie_preserve_param *life;
363 struct sctp_hostname_param *dns;
364 struct sctp_cookie_param *cookie;
365 struct sctp_supported_addrs_param *sat;
366 struct sctp_ipv4addr_param *v4;
367 struct sctp_ipv6addr_param *v6;
368 union sctp_addr_param *addr;
369 struct sctp_adaptation_ind_param *aind;
370 struct sctp_supported_ext_param *ext;
371 struct sctp_random_param *random;
372 struct sctp_chunks_param *chunks;
373 struct sctp_hmac_algo_param *hmac_algo;
374 struct sctp_addip_param *addip;
377 /* RFC 2960. Section 3.3.5 Heartbeat.
378 * Heartbeat Information: variable length
379 * The Sender-specific Heartbeat Info field should normally include
380 * information about the sender's current time when this HEARTBEAT
381 * chunk is sent and the destination transport address to which this
382 * HEARTBEAT is sent (see Section 8.3).
384 struct sctp_sender_hb_info {
385 struct sctp_paramhdr param_hdr;
386 union sctp_addr daddr;
387 unsigned long sent_at;
392 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
394 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
395 void sctp_stream_free(struct sctp_stream *stream);
396 void sctp_stream_clear(struct sctp_stream *stream);
397 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
399 /* What is the current SSN number for this stream? */
400 #define sctp_ssn_peek(stream, type, sid) \
401 (sctp_stream_##type((stream), (sid))->ssn)
403 /* Return the next SSN number for this stream. */
404 #define sctp_ssn_next(stream, type, sid) \
405 (sctp_stream_##type((stream), (sid))->ssn++)
407 /* Skip over this ssn and all below. */
408 #define sctp_ssn_skip(stream, type, sid, ssn) \
409 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
411 /* What is the current MID number for this stream? */
412 #define sctp_mid_peek(stream, type, sid) \
413 (sctp_stream_##type((stream), (sid))->mid)
415 /* Return the next MID number for this stream. */
416 #define sctp_mid_next(stream, type, sid) \
417 (sctp_stream_##type((stream), (sid))->mid++)
419 /* Skip over this mid and all below. */
420 #define sctp_mid_skip(stream, type, sid, mid) \
421 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
423 /* What is the current MID_uo number for this stream? */
424 #define sctp_mid_uo_peek(stream, type, sid) \
425 (sctp_stream_##type((stream), (sid))->mid_uo)
427 /* Return the next MID_uo number for this stream. */
428 #define sctp_mid_uo_next(stream, type, sid) \
429 (sctp_stream_##type((stream), (sid))->mid_uo++)
432 * Pointers to address related SCTP functions.
433 * (i.e. things that depend on the address family.)
436 int (*sctp_xmit) (struct sk_buff *skb,
437 struct sctp_transport *);
438 int (*setsockopt) (struct sock *sk,
442 unsigned int optlen);
443 int (*getsockopt) (struct sock *sk,
448 void (*get_dst) (struct sctp_transport *t,
449 union sctp_addr *saddr,
452 void (*get_saddr) (struct sctp_sock *sk,
453 struct sctp_transport *t,
455 void (*copy_addrlist) (struct list_head *,
456 struct net_device *);
457 int (*cmp_addr) (const union sctp_addr *addr1,
458 const union sctp_addr *addr2);
459 void (*addr_copy) (union sctp_addr *dst,
460 union sctp_addr *src);
461 void (*from_skb) (union sctp_addr *,
464 void (*from_sk) (union sctp_addr *,
466 bool (*from_addr_param) (union sctp_addr *,
467 union sctp_addr_param *,
468 __be16 port, int iif);
469 int (*to_addr_param) (const union sctp_addr *,
470 union sctp_addr_param *);
471 int (*addr_valid) (union sctp_addr *,
473 const struct sk_buff *);
474 enum sctp_scope (*scope)(union sctp_addr *);
475 void (*inaddr_any) (union sctp_addr *, __be16);
476 int (*is_any) (const union sctp_addr *);
477 int (*available) (union sctp_addr *,
479 int (*skb_iif) (const struct sk_buff *sk);
480 int (*skb_sdif)(const struct sk_buff *sk);
481 int (*is_ce) (const struct sk_buff *sk);
482 void (*seq_dump_addr)(struct seq_file *seq,
483 union sctp_addr *addr);
484 void (*ecn_capable)(struct sock *sk);
485 __u16 net_header_len;
487 int (*ip_options_len)(struct sock *sk);
488 sa_family_t sa_family;
489 struct list_head list;
492 struct sctp_af *sctp_get_af_specific(sa_family_t);
493 int sctp_register_af(struct sctp_af *);
495 /* Protocol family functions. */
497 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
498 void (*skb_msgname) (struct sk_buff *, char *, int *);
499 int (*af_supported) (sa_family_t, struct sctp_sock *);
500 int (*cmp_addr) (const union sctp_addr *,
501 const union sctp_addr *,
503 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
504 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
505 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
506 struct sock *(*create_accept_sk) (struct sock *sk,
507 struct sctp_association *asoc,
509 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
510 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
511 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
512 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
517 /* Structure to track chunk fragments that have been acked, but peer
518 * fragments of the same message have not.
520 struct sctp_datamsg {
521 /* Chunks waiting to be submitted to lower layer. */
522 struct list_head chunks;
523 /* Reference counting. */
525 /* When is this message no longer interesting to the peer? */
526 unsigned long expires_at;
527 /* Did the messenge fail to send? */
530 can_delay:1, /* should this message be Nagle delayed */
531 abandoned:1; /* should this message be abandoned */
534 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
535 struct sctp_sndrcvinfo *,
537 void sctp_datamsg_free(struct sctp_datamsg *);
538 void sctp_datamsg_put(struct sctp_datamsg *);
539 void sctp_chunk_fail(struct sctp_chunk *, int error);
540 int sctp_chunk_abandoned(struct sctp_chunk *);
542 /* RFC2960 1.4 Key Terms
544 * o Chunk: A unit of information within an SCTP packet, consisting of
545 * a chunk header and chunk-specific content.
547 * As a matter of convenience, we remember the SCTP common header for
548 * each chunk as well as a few other header pointers...
551 struct list_head list;
555 /* How many times this chunk have been sent, for prsctp RTX policy */
559 /* This is our link to the per-transport transmitted list. */
560 struct list_head transmitted_list;
561 /* List in specific stream outq */
562 struct list_head stream_list;
565 /* This field is used by chunks that hold fragmented data.
566 * For the first fragment this is the list that holds the rest of
567 * fragments. For the remaining fragments, this is the link to the
568 * frag_list maintained in the first fragment.
570 struct list_head frag_list;
572 /* This points to the sk_buff containing the actual data. */
576 /* In case of GSO packets, this will store the head one */
577 struct sk_buff *head_skb;
578 /* In case of auth enabled, this will point to the shkey */
579 struct sctp_shared_key *shkey;
582 /* These are the SCTP headers by reverse order in a packet.
583 * Note that some of these may happen more than once. In that
584 * case, we point at the "current" one, whatever that means
585 * for that level of header.
588 /* We point this at the FIRST TLV parameter to chunk_hdr. */
589 union sctp_params param_hdr;
592 struct sctp_datahdr *data_hdr;
593 struct sctp_inithdr *init_hdr;
594 struct sctp_sackhdr *sack_hdr;
595 struct sctp_heartbeathdr *hb_hdr;
596 struct sctp_sender_hb_info *hbs_hdr;
597 struct sctp_shutdownhdr *shutdown_hdr;
598 struct sctp_signed_cookie *cookie_hdr;
599 struct sctp_ecnehdr *ecne_hdr;
600 struct sctp_cwrhdr *ecn_cwr_hdr;
601 struct sctp_errhdr *err_hdr;
602 struct sctp_addiphdr *addip_hdr;
603 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
604 struct sctp_authhdr *auth_hdr;
605 struct sctp_idatahdr *idata_hdr;
606 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
611 struct sctp_chunkhdr *chunk_hdr;
612 struct sctphdr *sctp_hdr;
614 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
615 struct sctp_sndrcvinfo sinfo;
617 /* Which association does this belong to? */
618 struct sctp_association *asoc;
620 /* What endpoint received this chunk? */
621 struct sctp_ep_common *rcvr;
623 /* We fill this in if we are calculating RTT. */
624 unsigned long sent_at;
626 /* What is the origin IP address for this chunk? */
627 union sctp_addr source;
628 /* Destination address for this chunk. */
629 union sctp_addr dest;
631 /* For outbound message, track all fragments for SEND_FAILED. */
632 struct sctp_datamsg *msg;
634 /* For an inbound chunk, this tells us where it came from.
635 * For an outbound chunk, it tells us where we'd like it to
636 * go. It is NULL if we have no preference.
638 struct sctp_transport *transport;
640 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
641 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
642 * spec violates the principle premis that all chunks are processed
645 struct sk_buff *auth_chunk;
647 #define SCTP_CAN_FRTX 0x0
648 #define SCTP_NEED_FRTX 0x1
649 #define SCTP_DONT_FRTX 0x2
650 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
651 has_tsn:1, /* Does this chunk have a TSN yet? */
652 has_ssn:1, /* Does this chunk have a SSN yet? */
653 #define has_mid has_ssn
654 singleton:1, /* Only chunk in the packet? */
655 end_of_packet:1, /* Last chunk in the packet? */
656 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
657 pdiscard:1, /* Discard the whole packet now? */
658 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
659 data_accepted:1, /* At least 1 chunk accepted */
660 auth:1, /* IN: was auth'ed | OUT: needs auth */
661 has_asconf:1, /* IN: have seen an asconf before */
662 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */
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;
865 unsigned long probe_interval;
867 /* SACK delay timeout */
868 unsigned long sackdelay;
873 /* When was the last time that we heard from this transport? We use
874 * this to pick new active and retran paths.
876 ktime_t last_time_heard;
878 /* When was the last time that we sent a chunk using this
879 * transport? We use this to check for idle transports
881 unsigned long last_time_sent;
883 /* Last time(in jiffies) when cwnd is reduced due to the congestion
884 * indication based on ECNE chunk.
886 unsigned long last_time_ecne_reduced;
890 /* This is the max_retrans value for the transport and will
891 * be initialized from the assocs value. This can be changed
892 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
899 /* This is the partially failed retrans value for the transport
900 * and will be initialized from the assocs value. This can be changed
901 * using the SCTP_PEER_ADDR_THLDS socket option
904 /* Used for primary path switchover. */
906 /* PMTU : The current known path MTU. */
909 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
912 /* The number of times INIT has been sent on this transport. */
915 /* state : The current state of this destination,
916 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
920 /* These are the error stats for this destination. */
922 /* Error count : The current error count for this destination. */
923 unsigned short error_count;
925 /* Per : A timer used by each destination.
929 * [Everywhere else in the text this is called T3-rtx. -ed]
931 struct timer_list T3_rtx_timer;
933 /* Heartbeat timer is per destination. */
934 struct timer_list hb_timer;
936 /* Timer to handle ICMP proto unreachable envets */
937 struct timer_list proto_unreach_timer;
939 /* Timer to handler reconf chunk rtx */
940 struct timer_list reconf_timer;
942 /* Timer to send a probe HB packet for PLPMTUD */
943 struct timer_list probe_timer;
945 /* Since we're using per-destination retransmission timers
946 * (see above), we're also using per-destination "transmitted"
947 * queues. This probably ought to be a private struct
948 * accessible only within the outqueue, but it's not, yet.
950 struct list_head transmitted;
952 /* We build bundle-able packets for this transport here. */
953 struct sctp_packet packet;
955 /* This is the list of transports that have chunks to send. */
956 struct list_head send_ready;
958 /* State information saved for SFR_CACC algorithm. The key
959 * idea in SFR_CACC is to maintain state at the sender on a
960 * per-destination basis when a changeover happens.
961 * char changeover_active;
962 * char cycling_changeover;
963 * __u32 next_tsn_at_change;
964 * char cacc_saw_newack;
967 /* An unsigned integer, which stores the next TSN to be
968 * used by the sender, at the moment of changeover.
970 __u32 next_tsn_at_change;
972 /* A flag which indicates the occurrence of a changeover */
973 char changeover_active;
975 /* A flag which indicates whether the change of primary is
976 * the first switch to this destination address during an
979 char cycling_changeover;
981 /* A temporary flag, which is used during the processing of
982 * a SACK to estimate the causative TSN(s)'s group.
984 char cacc_saw_newack;
993 } pl; /* plpmtud related */
995 /* 64-bit random number sent with heartbeat. */
1001 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1003 void sctp_transport_set_owner(struct sctp_transport *,
1004 struct sctp_association *);
1005 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1006 struct sctp_sock *);
1007 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1008 void sctp_transport_free(struct sctp_transport *);
1009 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1010 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1011 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1012 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1013 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1014 int sctp_transport_hold(struct sctp_transport *);
1015 void sctp_transport_put(struct sctp_transport *);
1016 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1017 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1018 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1019 enum sctp_lower_cwnd reason);
1020 void sctp_transport_burst_limited(struct sctp_transport *);
1021 void sctp_transport_burst_reset(struct sctp_transport *);
1022 unsigned long sctp_transport_timeout(struct sctp_transport *);
1023 void sctp_transport_reset(struct sctp_transport *t);
1024 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1025 void sctp_transport_immediate_rtx(struct sctp_transport *);
1026 void sctp_transport_dst_release(struct sctp_transport *t);
1027 void sctp_transport_dst_confirm(struct sctp_transport *t);
1028 void sctp_transport_pl_send(struct sctp_transport *t);
1029 bool sctp_transport_pl_recv(struct sctp_transport *t);
1032 /* This is the structure we use to queue packets as they come into
1033 * SCTP. We write packets to it and read chunks from it.
1036 /* This is actually a queue of sctp_chunk each
1037 * containing a partially decoded packet.
1039 struct list_head in_chunk_list;
1040 /* This is the packet which is currently off the in queue and is
1041 * being worked on through the inbound chunk processing.
1043 struct sctp_chunk *in_progress;
1045 /* This is the delayed task to finish delivering inbound
1048 struct work_struct immediate;
1051 void sctp_inq_init(struct sctp_inq *);
1052 void sctp_inq_free(struct sctp_inq *);
1053 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1054 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1055 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1056 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1058 /* This is the structure we use to hold outbound chunks. You push
1059 * chunks in and they automatically pop out the other end as bundled
1060 * packets (it calls (*output_handler)()).
1062 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1063 * and 8.2 of the v13 draft.
1065 * It handles retransmissions. The connection to the timeout portion
1066 * of the state machine is through sctp_..._timeout() and timeout_handler.
1068 * If you feed it SACKs, it will eat them.
1070 * If you give it big chunks, it will fragment them.
1072 * It assigns TSN's to data chunks. This happens at the last possible
1073 * instant before transmission.
1075 * When free()'d, it empties itself out via output_handler().
1078 struct sctp_association *asoc;
1080 /* Data pending that has never been transmitted. */
1081 struct list_head out_chunk_list;
1083 /* Stream scheduler being used */
1084 struct sctp_sched_ops *sched;
1086 unsigned int out_qlen; /* Total length of queued data chunks. */
1088 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1091 /* These are control chunks we want to send. */
1092 struct list_head control_chunk_list;
1094 /* These are chunks that have been sacked but are above the
1095 * CTSN, or cumulative tsn ack point.
1097 struct list_head sacked;
1099 /* Put chunks on this list to schedule them for
1102 struct list_head retransmit;
1104 /* Put chunks on this list to save them for FWD TSN processing as
1105 * they were abandoned.
1107 struct list_head abandoned;
1109 /* How many unackd bytes do we have in-flight? */
1110 __u32 outstanding_bytes;
1112 /* Are we doing fast-rtx on this queue */
1119 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1120 void sctp_outq_teardown(struct sctp_outq *);
1121 void sctp_outq_free(struct sctp_outq*);
1122 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1123 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1124 int sctp_outq_is_empty(const struct sctp_outq *);
1125 void sctp_outq_restart(struct sctp_outq *);
1127 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1128 enum sctp_retransmit_reason reason);
1129 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1130 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1131 void sctp_prsctp_prune(struct sctp_association *asoc,
1132 struct sctp_sndrcvinfo *sinfo, int msg_len);
1133 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1134 /* Uncork and flush an outqueue. */
1135 static inline void sctp_outq_cork(struct sctp_outq *q)
1140 /* SCTP skb control block.
1141 * sctp_input_cb is currently used on rx and sock rx queue
1143 struct sctp_input_cb {
1145 struct inet_skb_parm h4;
1146 #if IS_ENABLED(CONFIG_IPV6)
1147 struct inet6_skb_parm h6;
1150 struct sctp_chunk *chunk;
1154 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1156 struct sctp_output_cb {
1157 struct sk_buff *last;
1159 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1161 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1163 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1165 return chunk->head_skb ? : skb;
1168 /* These bind address data fields common between endpoints and associations */
1169 struct sctp_bind_addr {
1171 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1173 * SCTP Port: The local SCTP port number the endpoint is
1178 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1180 * Address List: The list of IP addresses that this instance
1181 * has bound. This information is passed to one's
1182 * peer(s) in INIT and INIT ACK chunks.
1184 struct list_head address_list;
1187 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1188 void sctp_bind_addr_free(struct sctp_bind_addr *);
1189 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1190 const struct sctp_bind_addr *src,
1191 enum sctp_scope scope, gfp_t gfp,
1193 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1194 const struct sctp_bind_addr *src,
1196 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1197 int new_size, __u8 addr_state, gfp_t gfp);
1198 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1199 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1200 struct sctp_sock *);
1201 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1202 struct sctp_sock *, struct sctp_sock *);
1203 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1204 const union sctp_addr *addr);
1205 int sctp_bind_addrs_check(struct sctp_sock *sp,
1206 struct sctp_sock *sp2, int cnt2);
1207 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1208 const union sctp_addr *addrs,
1210 struct sctp_sock *opt);
1211 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1214 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1215 __u16 port, gfp_t gfp);
1217 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1218 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1219 const enum sctp_scope scope);
1220 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1221 int sctp_is_ep_boundall(struct sock *sk);
1224 /* What type of endpoint? */
1225 enum sctp_endpoint_type {
1226 SCTP_EP_TYPE_SOCKET,
1227 SCTP_EP_TYPE_ASSOCIATION,
1231 * A common base class to bridge the implmentation view of a
1232 * socket (usually listening) endpoint versus an association's
1234 * This common structure is useful for several purposes:
1235 * 1) Common interface for lookup routines.
1236 * a) Subfunctions work for either endpoint or association
1237 * b) Single interface to lookup allows hiding the lookup lock rather
1238 * than acquiring it externally.
1239 * 2) Common interface for the inbound chunk handling/state machine.
1240 * 3) Common object handling routines for reference counting, etc.
1241 * 4) Disentangle association lookup from endpoint lookup, where we
1242 * do not have to find our endpoint to find our association.
1246 struct sctp_ep_common {
1247 /* Runtime type information. What kind of endpoint is this? */
1248 enum sctp_endpoint_type type;
1250 /* Some fields to help us manage this object.
1251 * refcnt - Reference count access to this object.
1252 * dead - Do not attempt to use this object.
1257 /* What socket does this endpoint belong to? */
1260 /* Cache netns and it won't change once set */
1263 /* This is where we receive inbound chunks. */
1264 struct sctp_inq inqueue;
1266 /* This substructure includes the defining parameters of the
1268 * bind_addr.port is our shared port number.
1269 * bind_addr.address_list is our set of local IP addresses.
1271 struct sctp_bind_addr bind_addr;
1275 /* RFC Section 1.4 Key Terms
1277 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1278 * multi-homed host, an SCTP endpoint is represented to its peers as a
1279 * combination of a set of eligible destination transport addresses to
1280 * which SCTP packets can be sent and a set of eligible source
1281 * transport addresses from which SCTP packets can be received.
1282 * All transport addresses used by an SCTP endpoint must use the
1283 * same port number, but can use multiple IP addresses. A transport
1284 * address used by an SCTP endpoint must not be used by another
1285 * SCTP endpoint. In other words, a transport address is unique
1286 * to an SCTP endpoint.
1288 * From an implementation perspective, each socket has one of these.
1289 * A TCP-style socket will have exactly one association on one of
1290 * these. An UDP-style socket will have multiple associations hanging
1294 struct sctp_endpoint {
1295 /* Common substructure for endpoint and association. */
1296 struct sctp_ep_common base;
1298 /* Fields to help us manage our entries in the hash tables. */
1299 struct hlist_node node;
1302 /* Associations: A list of current associations and mappings
1303 * to the data consumers for each association. This
1304 * may be in the form of a hash table or other
1305 * implementation dependent structure. The data
1306 * consumers may be process identification
1307 * information such as file descriptors, named pipe
1308 * pointer, or table pointers dependent on how SCTP
1311 /* This is really a list of struct sctp_association entries. */
1312 struct list_head asocs;
1314 /* Secret Key: A secret key used by this endpoint to compute
1315 * the MAC. This SHOULD be a cryptographic quality
1316 * random number with a sufficient length.
1317 * Discussion in [RFC1750] can be helpful in
1318 * selection of the key.
1320 __u8 secret_key[SCTP_SECRET_SIZE];
1322 /* digest: This is a digest of the sctp cookie. This field is
1323 * only used on the receive path when we try to validate
1324 * that the cookie has not been tampered with. We put
1325 * this here so we pre-allocate this once and can re-use
1330 /* sendbuf acct. policy. */
1331 __u32 sndbuf_policy;
1333 /* rcvbuf acct. policy. */
1334 __u32 rcvbuf_policy;
1336 /* SCTP AUTH: array of the HMACs that will be allocated
1337 * we need this per association so that we don't serialize
1339 struct crypto_shash **auth_hmacs;
1341 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1342 struct sctp_hmac_algo_param *auth_hmacs_list;
1344 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1345 struct sctp_chunks_param *auth_chunk_list;
1347 /* SCTP-AUTH: endpoint shared keys */
1348 struct list_head endpoint_shared_keys;
1349 __u16 active_key_id;
1357 __u8 strreset_enable;
1358 struct rcu_head rcu;
1361 /* Recover the outter endpoint structure. */
1362 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1364 struct sctp_endpoint *ep;
1366 ep = container_of(base, struct sctp_endpoint, base);
1370 /* These are function signatures for manipulating endpoints. */
1371 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1372 void sctp_endpoint_free(struct sctp_endpoint *);
1373 void sctp_endpoint_put(struct sctp_endpoint *);
1374 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1375 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1376 struct sctp_association *sctp_endpoint_lookup_assoc(
1377 const struct sctp_endpoint *ep,
1378 const union sctp_addr *paddr,
1379 struct sctp_transport **);
1380 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1381 const union sctp_addr *paddr);
1382 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1384 const union sctp_addr *laddr,
1386 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1387 const union sctp_addr *paddr, int dif, int sdif);
1389 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1390 const struct sctp_association *asoc,
1391 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1392 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1393 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1394 const union sctp_addr *peer,
1395 struct sctp_init_chunk *init, gfp_t gfp);
1396 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1397 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1399 struct sctp_inithdr_host {
1402 __u16 num_outbound_streams;
1403 __u16 num_inbound_streams;
1407 struct sctp_stream_priorities {
1408 /* List of priorities scheduled */
1409 struct list_head prio_sched;
1410 /* List of streams scheduled */
1411 struct list_head active;
1412 /* The next stream in line */
1413 struct sctp_stream_out_ext *next;
1418 struct sctp_stream_out_ext {
1419 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1420 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1421 struct list_head outq; /* chunks enqueued by this stream */
1424 /* Scheduled streams list */
1425 struct list_head prio_list;
1426 struct sctp_stream_priorities *prio_head;
1428 /* Fields used by RR scheduler */
1430 struct list_head rr_list;
1433 struct list_head fc_list;
1440 struct sctp_stream_out {
1446 struct sctp_stream_out_ext *ext;
1450 struct sctp_stream_in {
1462 struct sctp_stream {
1463 GENRADIX(struct sctp_stream_out) out;
1464 GENRADIX(struct sctp_stream_in) in;
1468 /* Current stream being sent, if any */
1469 struct sctp_stream_out *out_curr;
1471 /* Fields used by priority scheduler */
1473 /* List of priorities scheduled */
1474 struct list_head prio_list;
1476 /* Fields used by RR scheduler */
1478 /* List of streams scheduled */
1479 struct list_head rr_list;
1480 /* The next stream in line */
1481 struct sctp_stream_out_ext *rr_next;
1484 struct list_head fc_list;
1487 struct sctp_stream_interleave *si;
1490 static inline struct sctp_stream_out *sctp_stream_out(
1491 struct sctp_stream *stream,
1494 return genradix_ptr(&stream->out, sid);
1497 static inline struct sctp_stream_in *sctp_stream_in(
1498 struct sctp_stream *stream,
1501 return genradix_ptr(&stream->in, sid);
1504 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1505 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1507 #define SCTP_STREAM_CLOSED 0x00
1508 #define SCTP_STREAM_OPEN 0x01
1510 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1512 return stream->si->data_chunk_len;
1515 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1517 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1520 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1522 return stream->si->ftsn_chunk_len;
1525 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1527 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1530 /* SCTP_GET_ASSOC_STATS counters */
1531 struct sctp_priv_assoc_stats {
1532 /* Maximum observed rto in the association during subsequent
1533 * observations. Value is set to 0 if no RTO measurement took place
1534 * The transport where the max_rto was observed is returned in
1537 struct sockaddr_storage obs_rto_ipaddr;
1539 /* Total In and Out SACKs received and sent */
1542 /* Total In and Out packets received and sent */
1545 /* Total retransmitted chunks */
1547 /* TSN received > next expected */
1549 /* Duplicate Chunks received */
1551 /* Gap Ack Blocks received */
1553 /* Unordered data chunks sent and received */
1556 /* Ordered data chunks sent and received */
1559 /* Control chunks sent and received */
1566 * 12. Recommended Transmission Control Block (TCB) Parameters
1568 * This section details a recommended set of parameters that should
1569 * be contained within the TCB for an implementation. This section is
1570 * for illustrative purposes and should not be deemed as requirements
1571 * on an implementation or as an exhaustive list of all parameters
1572 * inside an SCTP TCB. Each implementation may need its own additional
1573 * parameters for optimization.
1577 /* Here we have information about each individual association. */
1578 struct sctp_association {
1580 /* A base structure common to endpoint and association.
1581 * In this context, it represents the associations's view
1582 * of the local endpoint of the association.
1584 struct sctp_ep_common base;
1586 /* Associations on the same socket. */
1587 struct list_head asocs;
1589 /* association id. */
1590 sctp_assoc_t assoc_id;
1592 /* This is our parent endpoint. */
1593 struct sctp_endpoint *ep;
1595 /* These are those association elements needed in the cookie. */
1596 struct sctp_cookie c;
1598 /* This is all information about our peer. */
1600 /* transport_addr_list
1602 * Peer : A list of SCTP transport addresses that the
1603 * Transport : peer is bound to. This information is derived
1604 * Address : from the INIT or INIT ACK and is used to
1605 * List : associate an inbound packet with a given
1606 * : association. Normally this information is
1607 * : hashed or keyed for quick lookup and access
1609 * : The list is also initialized with the list
1610 * : of addresses passed with the sctp_connectx()
1613 * It is a list of SCTP_transport's.
1615 struct list_head transport_addr_list;
1619 * Peer Rwnd : Current calculated value of the peer's rwnd.
1625 * Peer : A count of the number of peer addresses
1626 * Transport : in the Peer Transport Address List.
1630 __u16 transport_count;
1633 * The transport layer port number.
1639 * Primary : This is the current primary destination
1640 * Path : transport address of the peer endpoint. It
1641 * : may also specify a source transport address
1642 * : on this endpoint.
1644 * All of these paths live on transport_addr_list.
1646 * At the bakeoffs, we discovered that the intent of
1647 * primaryPath is that it only changes when the ULP
1648 * asks to have it changed. We add the activePath to
1649 * designate the connection we are currently using to
1650 * transmit new data and most control chunks.
1652 struct sctp_transport *primary_path;
1654 /* Cache the primary path address here, when we
1655 * need a an address for msg_name.
1657 union sctp_addr primary_addr;
1660 * The path that we are currently using to
1661 * transmit new data and most control chunks.
1663 struct sctp_transport *active_path;
1667 * RFC2960 6.4 Multi-homed SCTP Endpoints
1669 * Furthermore, when its peer is multi-homed, an
1670 * endpoint SHOULD try to retransmit a chunk to an
1671 * active destination transport address that is
1672 * different from the last destination address to
1673 * which the DATA chunk was sent.
1675 struct sctp_transport *retran_path;
1677 /* Pointer to last transport I have sent on. */
1678 struct sctp_transport *last_sent_to;
1680 /* This is the last transport I have received DATA on. */
1681 struct sctp_transport *last_data_from;
1684 * Mapping An array of bits or bytes indicating which out of
1685 * Array order TSN's have been received (relative to the
1686 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1687 * order packets have been received, this array
1688 * will be set to all zero. This structure may be
1689 * in the form of a circular buffer or bit array.
1691 * Last Rcvd : This is the last TSN received in
1692 * TSN : sequence. This value is set initially by
1693 * : taking the peer's Initial TSN, received in
1694 * : the INIT or INIT ACK chunk, and subtracting
1697 * Throughout most of the specification this is called the
1698 * "Cumulative TSN ACK Point". In this case, we
1699 * ignore the advice in 12.2 in favour of the term
1700 * used in the bulk of the text. This value is hidden
1701 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1703 struct sctp_tsnmap tsn_map;
1705 /* This mask is used to disable sending the ASCONF chunk
1706 * with specified parameter to peer.
1708 __be16 addip_disabled_mask;
1710 /* These are capabilities which our peer advertised. */
1711 __u16 ecn_capable:1, /* Can peer do ECN? */
1712 ipv4_address:1, /* Peer understands IPv4 addresses? */
1713 ipv6_address:1, /* Peer understands IPv6 addresses? */
1714 asconf_capable:1, /* Does peer support ADDIP? */
1715 prsctp_capable:1, /* Can peer do PR-SCTP? */
1716 reconf_capable:1, /* Can peer do RE-CONFIG? */
1717 intl_capable:1, /* Can peer do INTERLEAVE */
1718 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1720 * This flag indicates if the next received
1721 * packet is to be responded to with a
1722 * SACK. This is initialized to 0. When a packet
1723 * is received sack_cnt is incremented. If this value
1724 * reaches 2 or more, a SACK is sent and the
1725 * value is reset to 0. Note: This is used only
1726 * when no DATA chunks are received out of
1727 * order. When DATA chunks are out of order,
1728 * SACK's are not delayed (see Section 6).
1730 sack_needed:1, /* Do we need to sack the peer? */
1732 zero_window_announced:1;
1736 __u32 adaptation_ind; /* Adaptation Code point. */
1738 struct sctp_inithdr_host i;
1742 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1743 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1744 * Initial TSN Value minus 1
1748 /* SCTP-AUTH: We need to know pears random number, hmac list
1749 * and authenticated chunk list. All that is part of the
1750 * cookie and these are just pointers to those locations
1752 struct sctp_random_param *peer_random;
1753 struct sctp_chunks_param *peer_chunks;
1754 struct sctp_hmac_algo_param *peer_hmacs;
1757 /* State : A state variable indicating what state the
1758 * : association is in, i.e. COOKIE-WAIT,
1759 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1760 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1762 * Note: No "CLOSED" state is illustrated since if a
1763 * association is "CLOSED" its TCB SHOULD be removed.
1765 * In this implementation we DO have a CLOSED
1766 * state which is used during initiation and shutdown.
1768 * State takes values from SCTP_STATE_*.
1770 enum sctp_state state;
1772 /* Overall : The overall association error count.
1773 * Error Count : [Clear this any time I get something.]
1775 int overall_error_count;
1777 /* The cookie life I award for any cookie. */
1778 ktime_t cookie_life;
1780 /* These are the association's initial, max, and min RTO values.
1781 * These values will be initialized by system defaults, but can
1782 * be modified via the SCTP_RTOINFO socket option.
1784 unsigned long rto_initial;
1785 unsigned long rto_max;
1786 unsigned long rto_min;
1788 /* Maximum number of new data packets that can be sent in a burst. */
1791 /* This is the max_retrans value for the association. This value will
1792 * be initialized from system defaults, but can be
1793 * modified by the SCTP_ASSOCINFO socket option.
1797 /* This is the partially failed retrans value for the transport
1798 * and will be initialized from the assocs value. This can be
1799 * changed using the SCTP_PEER_ADDR_THLDS socket option
1802 /* Used for primary path switchover. */
1805 /* Maximum number of times the endpoint will retransmit INIT */
1806 __u16 max_init_attempts;
1808 /* How many times have we resent an INIT? */
1811 /* The largest timeout or RTO value to use in attempting an INIT */
1812 unsigned long max_init_timeo;
1814 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1815 * the destination address every heartbeat interval. This value
1816 * will be inherited by all new transports.
1818 unsigned long hbinterval;
1819 unsigned long probe_interval;
1823 /* This is the max_retrans value for new transports in the
1831 /* Flag that path mtu update is pending */
1834 /* Association : The smallest PMTU discovered for all of the
1835 * PMTU : peer's transport addresses.
1839 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1843 /* SACK delay timeout */
1844 unsigned long sackdelay;
1846 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1847 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1849 /* Transport to which SHUTDOWN chunk was last sent. */
1850 struct sctp_transport *shutdown_last_sent_to;
1852 /* Transport to which INIT chunk was last sent. */
1853 struct sctp_transport *init_last_sent_to;
1855 /* How many times have we resent a SHUTDOWN */
1856 int shutdown_retries;
1858 /* Next TSN : The next TSN number to be assigned to a new
1859 * : DATA chunk. This is sent in the INIT or INIT
1860 * : ACK chunk to the peer and incremented each
1861 * : time a DATA chunk is assigned a TSN
1862 * : (normally just prior to transmit or during
1868 * Last Rcvd : This is the last TSN received in sequence. This value
1869 * TSN : is set initially by taking the peer's Initial TSN,
1870 * : received in the INIT or INIT ACK chunk, and
1871 * : subtracting one from it.
1873 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1876 __u32 ctsn_ack_point;
1878 /* PR-SCTP Advanced.Peer.Ack.Point */
1879 __u32 adv_peer_ack_point;
1881 /* Highest TSN that is acknowledged by incoming SACKs. */
1882 __u32 highest_sacked;
1884 /* TSN marking the fast recovery exit point */
1885 __u32 fast_recovery_exit;
1887 /* Flag to track the current fast recovery state */
1890 /* The number of unacknowledged data chunks. Reported through
1891 * the SCTP_STATUS sockopt.
1895 /* The total number of data chunks that we've had to retransmit
1896 * as the result of a T3 timer expiration
1898 __u32 rtx_data_chunks;
1900 /* This is the association's receive buffer space. This value is used
1901 * to set a_rwnd field in an INIT or a SACK chunk.
1905 /* This is the last advertised value of rwnd over a SACK chunk. */
1908 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1909 * to slop over a maximum of the association's frag_point.
1913 /* Keeps treack of rwnd pressure. This happens when we have
1914 * a window, but not recevie buffer (i.e small packets). This one
1915 * is releases slowly (1 PMTU at a time ).
1919 /* This is the sndbuf size in use for the association.
1920 * This corresponds to the sndbuf size for the association,
1921 * as specified in the sk->sndbuf.
1925 /* This is the amount of memory that this association has allocated
1926 * in the receive path at any given time.
1928 atomic_t rmem_alloc;
1930 /* This is the wait queue head for send requests waiting on
1931 * the association sndbuf space.
1933 wait_queue_head_t wait;
1935 /* The message size at which SCTP fragmentation will occur. */
1939 /* Counter used to count INIT errors. */
1940 int init_err_counter;
1942 /* Count the number of INIT cycles (for doubling timeout). */
1945 /* Default send parameters. */
1946 __u16 default_stream;
1947 __u16 default_flags;
1949 __u32 default_context;
1950 __u32 default_timetolive;
1952 /* Default receive parameters */
1953 __u32 default_rcv_context;
1956 struct sctp_stream stream;
1958 /* All outbound chunks go through this structure. */
1959 struct sctp_outq outqueue;
1961 /* A smart pipe that will handle reordering and fragmentation,
1962 * as well as handle passing events up to the ULP.
1964 struct sctp_ulpq ulpq;
1966 /* Last TSN that caused an ECNE Chunk to be sent. */
1967 __u32 last_ecne_tsn;
1969 /* Last TSN that caused a CWR Chunk to be sent. */
1972 /* How many duplicated TSNs have we seen? */
1975 /* These are to support
1976 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1977 * and Enforcement of Flow and Message Limits"
1978 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1979 * or "ADDIP" for short.
1984 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1986 * R1) One and only one ASCONF Chunk MAY be in transit and
1987 * unacknowledged at any one time. If a sender, after sending
1988 * an ASCONF chunk, decides it needs to transfer another
1989 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1990 * returns from the previous ASCONF Chunk before sending a
1991 * subsequent ASCONF. Note this restriction binds each side,
1992 * so at any time two ASCONF may be in-transit on any given
1993 * association (one sent from each endpoint).
1995 * [This is our one-and-only-one ASCONF in flight. If we do
1996 * not have an ASCONF in flight, this is NULL.]
1998 struct sctp_chunk *addip_last_asconf;
2000 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
2002 * This is needed to implement itmes E1 - E4 of the updated
2003 * spec. Here is the justification:
2005 * Since the peer may bundle multiple ASCONF chunks toward us,
2006 * we now need the ability to cache multiple ACKs. The section
2007 * describes in detail how they are cached and cleaned up.
2009 struct list_head asconf_ack_list;
2011 /* These ASCONF chunks are waiting to be sent.
2013 * These chunaks can't be pushed to outqueue until receiving
2014 * ASCONF_ACK for the previous ASCONF indicated by
2015 * addip_last_asconf, so as to guarantee that only one ASCONF
2016 * is in flight at any time.
2018 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2020 * In defining the ASCONF Chunk transfer procedures, it is
2021 * essential that these transfers MUST NOT cause congestion
2022 * within the network. To achieve this, we place these
2023 * restrictions on the transfer of ASCONF Chunks:
2025 * R1) One and only one ASCONF Chunk MAY be in transit and
2026 * unacknowledged at any one time. If a sender, after sending
2027 * an ASCONF chunk, decides it needs to transfer another
2028 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2029 * returns from the previous ASCONF Chunk before sending a
2030 * subsequent ASCONF. Note this restriction binds each side,
2031 * so at any time two ASCONF may be in-transit on any given
2032 * association (one sent from each endpoint).
2035 * [I really think this is EXACTLY the sort of intelligence
2036 * which already resides in sctp_outq. Please move this
2037 * queue and its supporting logic down there. --piggy]
2039 struct list_head addip_chunk_list;
2041 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2043 * A2) A serial number should be assigned to the Chunk. The
2044 * serial number SHOULD be a monotonically increasing
2045 * number. The serial number SHOULD be initialized at
2046 * the start of the association to the same value as the
2047 * Initial TSN and every time a new ASCONF chunk is created
2048 * it is incremented by one after assigning the serial number
2049 * to the newly created chunk.
2052 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2054 * Serial Number : 32 bits (unsigned integer)
2056 * This value represents a Serial Number for the ASCONF
2057 * Chunk. The valid range of Serial Number is from 0 to
2058 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2059 * after reaching 4294967295.
2062 int src_out_of_asoc_ok;
2063 union sctp_addr *asconf_addr_del_pending;
2064 struct sctp_transport *new_transport;
2066 /* SCTP AUTH: list of the endpoint shared keys. These
2067 * keys are provided out of band by the user applicaton
2068 * and can't change during the lifetime of the association
2070 struct list_head endpoint_shared_keys;
2073 * The current generated assocaition shared key (secret)
2075 struct sctp_auth_bytes *asoc_shared_key;
2076 struct sctp_shared_key *shkey;
2078 /* SCTP AUTH: hmac id of the first peer requested algorithm
2081 __u16 default_hmac_id;
2083 __u16 active_key_id;
2085 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2086 temp:1, /* Is it a temporary association? */
2087 pf_expose:2, /* Expose pf state? */
2090 __u8 strreset_enable;
2091 __u8 strreset_outstanding; /* request param count on the fly */
2093 __u32 strreset_outseq; /* Update after receiving response */
2094 __u32 strreset_inseq; /* Update after receiving request */
2095 __u32 strreset_result[2]; /* save the results of last 2 responses */
2097 struct sctp_chunk *strreset_chunk; /* save request chunk */
2099 struct sctp_priv_assoc_stats stats;
2101 int sent_cnt_removable;
2105 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2106 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2108 /* Security identifiers from incoming (INIT). These are set by
2109 * security_sctp_assoc_request(). These will only be used by
2110 * SCTP TCP type sockets and peeled off connections as they
2111 * cause a new socket to be generated. security_sctp_sk_clone()
2112 * will then plug these into the new socket.
2118 struct rcu_head rcu;
2122 /* An eyecatcher for determining if we are really looking at an
2123 * association data structure.
2126 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2129 /* Recover the outter association structure. */
2130 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2132 struct sctp_association *asoc;
2134 asoc = container_of(base, struct sctp_association, base);
2138 /* These are function signatures for manipulating associations. */
2141 struct sctp_association *
2142 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2143 enum sctp_scope scope, gfp_t gfp);
2144 void sctp_association_free(struct sctp_association *);
2145 void sctp_association_put(struct sctp_association *);
2146 void sctp_association_hold(struct sctp_association *);
2148 struct sctp_transport *sctp_assoc_choose_alter_transport(
2149 struct sctp_association *, struct sctp_transport *);
2150 void sctp_assoc_update_retran_path(struct sctp_association *);
2151 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2152 const union sctp_addr *);
2153 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2154 const union sctp_addr *laddr);
2155 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2156 const union sctp_addr *address,
2158 const int peer_state);
2159 void sctp_assoc_del_peer(struct sctp_association *asoc,
2160 const union sctp_addr *addr);
2161 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2162 struct sctp_transport *peer);
2163 void sctp_assoc_control_transport(struct sctp_association *asoc,
2164 struct sctp_transport *transport,
2165 enum sctp_transport_cmd command,
2166 sctp_sn_error_t error);
2167 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2168 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2169 int sctp_assoc_update(struct sctp_association *old,
2170 struct sctp_association *new);
2172 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2174 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2175 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2176 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2177 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2178 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2179 void sctp_assoc_set_primary(struct sctp_association *,
2180 struct sctp_transport *);
2181 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2182 struct sctp_transport *);
2183 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2184 enum sctp_scope scope, gfp_t gfp);
2185 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2186 struct sctp_cookie*,
2188 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2189 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2190 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2191 const struct sctp_association *asoc,
2193 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2195 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2196 const union sctp_addr *ss2);
2197 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2199 /* A convenience structure to parse out SCTP specific CMSGs. */
2201 struct sctp_initmsg *init;
2202 struct sctp_sndrcvinfo *srinfo;
2203 struct sctp_sndinfo *sinfo;
2204 struct sctp_prinfo *prinfo;
2205 struct sctp_authinfo *authinfo;
2206 struct msghdr *addrs_msg;
2209 /* Structure for tracking memory objects */
2210 struct sctp_dbg_objcnt_entry {
2215 #endif /* __sctp_structs_h__ */