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 void (*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 (*is_ce) (const struct sk_buff *sk);
481 void (*seq_dump_addr)(struct seq_file *seq,
482 union sctp_addr *addr);
483 void (*ecn_capable)(struct sock *sk);
484 __u16 net_header_len;
486 int (*ip_options_len)(struct sock *sk);
487 sa_family_t sa_family;
488 struct list_head list;
491 struct sctp_af *sctp_get_af_specific(sa_family_t);
492 int sctp_register_af(struct sctp_af *);
494 /* Protocol family functions. */
496 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
497 void (*skb_msgname) (struct sk_buff *, char *, int *);
498 int (*af_supported) (sa_family_t, struct sctp_sock *);
499 int (*cmp_addr) (const union sctp_addr *,
500 const union sctp_addr *,
502 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
503 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
504 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
505 struct sock *(*create_accept_sk) (struct sock *sk,
506 struct sctp_association *asoc,
508 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
509 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
510 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
511 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
516 /* Structure to track chunk fragments that have been acked, but peer
517 * fragments of the same message have not.
519 struct sctp_datamsg {
520 /* Chunks waiting to be submitted to lower layer. */
521 struct list_head chunks;
522 /* Reference counting. */
524 /* When is this message no longer interesting to the peer? */
525 unsigned long expires_at;
526 /* Did the messenge fail to send? */
529 can_delay:1, /* should this message be Nagle delayed */
530 abandoned:1; /* should this message be abandoned */
533 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
534 struct sctp_sndrcvinfo *,
536 void sctp_datamsg_free(struct sctp_datamsg *);
537 void sctp_datamsg_put(struct sctp_datamsg *);
538 void sctp_chunk_fail(struct sctp_chunk *, int error);
539 int sctp_chunk_abandoned(struct sctp_chunk *);
541 /* RFC2960 1.4 Key Terms
543 * o Chunk: A unit of information within an SCTP packet, consisting of
544 * a chunk header and chunk-specific content.
546 * As a matter of convenience, we remember the SCTP common header for
547 * each chunk as well as a few other header pointers...
550 struct list_head list;
554 /* How many times this chunk have been sent, for prsctp RTX policy */
558 /* This is our link to the per-transport transmitted list. */
559 struct list_head transmitted_list;
560 /* List in specific stream outq */
561 struct list_head stream_list;
564 /* This field is used by chunks that hold fragmented data.
565 * For the first fragment this is the list that holds the rest of
566 * fragments. For the remaining fragments, this is the link to the
567 * frag_list maintained in the first fragment.
569 struct list_head frag_list;
571 /* This points to the sk_buff containing the actual data. */
575 /* In case of GSO packets, this will store the head one */
576 struct sk_buff *head_skb;
577 /* In case of auth enabled, this will point to the shkey */
578 struct sctp_shared_key *shkey;
581 /* These are the SCTP headers by reverse order in a packet.
582 * Note that some of these may happen more than once. In that
583 * case, we point at the "current" one, whatever that means
584 * for that level of header.
587 /* We point this at the FIRST TLV parameter to chunk_hdr. */
588 union sctp_params param_hdr;
591 struct sctp_datahdr *data_hdr;
592 struct sctp_inithdr *init_hdr;
593 struct sctp_sackhdr *sack_hdr;
594 struct sctp_heartbeathdr *hb_hdr;
595 struct sctp_sender_hb_info *hbs_hdr;
596 struct sctp_shutdownhdr *shutdown_hdr;
597 struct sctp_signed_cookie *cookie_hdr;
598 struct sctp_ecnehdr *ecne_hdr;
599 struct sctp_cwrhdr *ecn_cwr_hdr;
600 struct sctp_errhdr *err_hdr;
601 struct sctp_addiphdr *addip_hdr;
602 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
603 struct sctp_authhdr *auth_hdr;
604 struct sctp_idatahdr *idata_hdr;
605 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
610 struct sctp_chunkhdr *chunk_hdr;
611 struct sctphdr *sctp_hdr;
613 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
614 struct sctp_sndrcvinfo sinfo;
616 /* Which association does this belong to? */
617 struct sctp_association *asoc;
619 /* What endpoint received this chunk? */
620 struct sctp_ep_common *rcvr;
622 /* We fill this in if we are calculating RTT. */
623 unsigned long sent_at;
625 /* What is the origin IP address for this chunk? */
626 union sctp_addr source;
627 /* Destination address for this chunk. */
628 union sctp_addr dest;
630 /* For outbound message, track all fragments for SEND_FAILED. */
631 struct sctp_datamsg *msg;
633 /* For an inbound chunk, this tells us where it came from.
634 * For an outbound chunk, it tells us where we'd like it to
635 * go. It is NULL if we have no preference.
637 struct sctp_transport *transport;
639 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
640 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
641 * spec violates the principle premis that all chunks are processed
644 struct sk_buff *auth_chunk;
646 #define SCTP_CAN_FRTX 0x0
647 #define SCTP_NEED_FRTX 0x1
648 #define SCTP_DONT_FRTX 0x2
649 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
650 has_tsn:1, /* Does this chunk have a TSN yet? */
651 has_ssn:1, /* Does this chunk have a SSN yet? */
652 #define has_mid has_ssn
653 singleton:1, /* Only chunk in the packet? */
654 end_of_packet:1, /* Last chunk in the packet? */
655 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
656 pdiscard:1, /* Discard the whole packet now? */
657 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
658 data_accepted:1, /* At least 1 chunk accepted */
659 auth:1, /* IN: was auth'ed | OUT: needs auth */
660 has_asconf:1, /* IN: have seen an asconf before */
661 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */
662 tsn_missing_report:2, /* Data chunk missing counter. */
663 fast_retransmit:2; /* Is this chunk fast retransmitted? */
666 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
667 void sctp_chunk_hold(struct sctp_chunk *);
668 void sctp_chunk_put(struct sctp_chunk *);
669 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
670 struct iov_iter *from);
671 void sctp_chunk_free(struct sctp_chunk *);
672 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
673 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
674 const struct sctp_association *,
675 struct sock *, gfp_t gfp);
676 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
678 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
680 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
682 return ntohs(ch->subh.data_hdr->stream);
686 SCTP_ADDR_NEW, /* new address added to assoc/ep */
687 SCTP_ADDR_SRC, /* address can be used as source */
688 SCTP_ADDR_DEL, /* address about to be deleted */
691 /* This is a structure for holding either an IPv6 or an IPv4 address. */
692 struct sctp_sockaddr_entry {
693 struct list_head list;
700 #define SCTP_ADDRESS_TICK_DELAY 500
702 /* This structure holds lists of chunks as we are assembling for
706 /* These are the SCTP header values (host order) for the packet. */
708 __u16 destination_port;
711 /* This contains the payload chunks. */
712 struct list_head chunk_list;
714 /* This is the overhead of the sctp and ip headers. */
716 /* This is the total size of all chunks INCLUDING padding. */
718 /* This is the maximum size this packet may have */
721 /* The packet is destined for this transport address.
722 * The function we finally use to pass down to the next lower
723 * layer lives in the transport structure.
725 struct sctp_transport *transport;
727 /* pointer to the auth chunk for this packet */
728 struct sctp_chunk *auth;
730 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
731 has_sack:1, /* This packet contains a SACK chunk. */
732 has_auth:1, /* This packet contains an AUTH chunk */
733 has_data:1, /* This packet contains at least 1 DATA chunk */
734 ipfragok:1; /* So let ip fragment this packet */
737 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
738 __u16 sport, __u16 dport);
739 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
740 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
741 struct sctp_chunk *chunk,
742 int one_packet, gfp_t gfp);
743 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
744 struct sctp_chunk *chunk);
745 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
746 void sctp_packet_free(struct sctp_packet *);
748 static inline int sctp_packet_empty(struct sctp_packet *packet)
750 return packet->size == packet->overhead;
753 /* This represents a remote transport address.
754 * For local transport addresses, we just use union sctp_addr.
756 * RFC2960 Section 1.4 Key Terms
758 * o Transport address: A Transport Address is traditionally defined
759 * by Network Layer address, Transport Layer protocol and Transport
760 * Layer port number. In the case of SCTP running over IP, a
761 * transport address is defined by the combination of an IP address
762 * and an SCTP port number (where SCTP is the Transport protocol).
764 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
766 * o The sender keeps a separate congestion control parameter set for
767 * each of the destination addresses it can send to (not each
768 * source-destination pair but for each destination). The parameters
769 * should decay if the address is not used for a long enough time
773 struct sctp_transport {
774 /* A list of transports. */
775 struct list_head transports;
776 struct rhlist_head node;
778 /* Reference counting. */
780 /* RTO-Pending : A flag used to track if one of the DATA
781 * chunks sent to this address is currently being
782 * used to compute a RTT. If this flag is 0,
783 * the next DATA chunk sent to this destination
784 * should be used to compute a RTT and this flag
785 * should be set. Every time the RTT
786 * calculation completes (i.e. the DATA chunk
787 * is SACK'd) clear this flag.
792 * hb_sent : a flag that signals that we have a pending
797 /* Is the Path MTU update pending on this tranport */
800 dst_pending_confirm:1, /* need to confirm neighbour */
802 /* Has this transport moved the ctsn since we last sacked */
808 /* This is the peer's IP address and port. */
809 union sctp_addr ipaddr;
811 /* These are the functions we call to handle LLP stuff. */
812 struct sctp_af *af_specific;
814 /* Which association do we belong to? */
815 struct sctp_association *asoc;
819 * 12.3 Per Transport Address Data
821 * For each destination transport address in the peer's
822 * address list derived from the INIT or INIT ACK chunk, a
823 * number of data elements needs to be maintained including:
825 /* RTO : The current retransmission timeout value. */
828 __u32 rtt; /* This is the most recent RTT. */
830 /* RTTVAR : The current RTT variation. */
833 /* SRTT : The current smoothed round trip time. */
837 * These are the congestion stats.
839 /* cwnd : The current congestion window. */
840 __u32 cwnd; /* This is the actual cwnd. */
842 /* ssthresh : The current slow start threshold value. */
845 /* partial : The tracking method for increase of cwnd when in
846 * bytes acked : congestion avoidance mode (see Section 6.2.2)
848 __u32 partial_bytes_acked;
850 /* Data that has been sent, but not acknowledged. */
853 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
856 struct dst_entry *dst;
857 /* Source address. */
858 union sctp_addr saddr;
860 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
861 * the destination address every heartbeat interval.
863 unsigned long hbinterval;
864 unsigned long probe_interval;
866 /* SACK delay timeout */
867 unsigned long sackdelay;
872 /* When was the last time that we heard from this transport? We use
873 * this to pick new active and retran paths.
875 ktime_t last_time_heard;
877 /* When was the last time that we sent a chunk using this
878 * transport? We use this to check for idle transports
880 unsigned long last_time_sent;
882 /* Last time(in jiffies) when cwnd is reduced due to the congestion
883 * indication based on ECNE chunk.
885 unsigned long last_time_ecne_reduced;
889 /* This is the max_retrans value for the transport and will
890 * be initialized from the assocs value. This can be changed
891 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
898 /* This is the partially failed retrans value for the transport
899 * and will be initialized from the assocs value. This can be changed
900 * using the SCTP_PEER_ADDR_THLDS socket option
903 /* Used for primary path switchover. */
905 /* PMTU : The current known path MTU. */
908 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
911 /* The number of times INIT has been sent on this transport. */
914 /* state : The current state of this destination,
915 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
919 /* These are the error stats for this destination. */
921 /* Error count : The current error count for this destination. */
922 unsigned short error_count;
924 /* Per : A timer used by each destination.
928 * [Everywhere else in the text this is called T3-rtx. -ed]
930 struct timer_list T3_rtx_timer;
932 /* Heartbeat timer is per destination. */
933 struct timer_list hb_timer;
935 /* Timer to handle ICMP proto unreachable envets */
936 struct timer_list proto_unreach_timer;
938 /* Timer to handler reconf chunk rtx */
939 struct timer_list reconf_timer;
941 /* Timer to send a probe HB packet for PLPMTUD */
942 struct timer_list probe_timer;
944 /* Since we're using per-destination retransmission timers
945 * (see above), we're also using per-destination "transmitted"
946 * queues. This probably ought to be a private struct
947 * accessible only within the outqueue, but it's not, yet.
949 struct list_head transmitted;
951 /* We build bundle-able packets for this transport here. */
952 struct sctp_packet packet;
954 /* This is the list of transports that have chunks to send. */
955 struct list_head send_ready;
957 /* State information saved for SFR_CACC algorithm. The key
958 * idea in SFR_CACC is to maintain state at the sender on a
959 * per-destination basis when a changeover happens.
960 * char changeover_active;
961 * char cycling_changeover;
962 * __u32 next_tsn_at_change;
963 * char cacc_saw_newack;
966 /* An unsigned integer, which stores the next TSN to be
967 * used by the sender, at the moment of changeover.
969 __u32 next_tsn_at_change;
971 /* A flag which indicates the occurrence of a changeover */
972 char changeover_active;
974 /* A flag which indicates whether the change of primary is
975 * the first switch to this destination address during an
978 char cycling_changeover;
980 /* A temporary flag, which is used during the processing of
981 * a SACK to estimate the causative TSN(s)'s group.
983 char cacc_saw_newack;
992 } pl; /* plpmtud related */
994 /* 64-bit random number sent with heartbeat. */
1000 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1002 void sctp_transport_set_owner(struct sctp_transport *,
1003 struct sctp_association *);
1004 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1005 struct sctp_sock *);
1006 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1007 void sctp_transport_free(struct sctp_transport *);
1008 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1009 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1010 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1011 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1012 int sctp_transport_hold(struct sctp_transport *);
1013 void sctp_transport_put(struct sctp_transport *);
1014 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1015 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1016 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1017 enum sctp_lower_cwnd reason);
1018 void sctp_transport_burst_limited(struct sctp_transport *);
1019 void sctp_transport_burst_reset(struct sctp_transport *);
1020 unsigned long sctp_transport_timeout(struct sctp_transport *);
1021 void sctp_transport_reset(struct sctp_transport *t);
1022 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1023 void sctp_transport_immediate_rtx(struct sctp_transport *);
1024 void sctp_transport_dst_release(struct sctp_transport *t);
1025 void sctp_transport_dst_confirm(struct sctp_transport *t);
1026 void sctp_transport_pl_send(struct sctp_transport *t);
1027 void sctp_transport_pl_recv(struct sctp_transport *t);
1030 /* This is the structure we use to queue packets as they come into
1031 * SCTP. We write packets to it and read chunks from it.
1034 /* This is actually a queue of sctp_chunk each
1035 * containing a partially decoded packet.
1037 struct list_head in_chunk_list;
1038 /* This is the packet which is currently off the in queue and is
1039 * being worked on through the inbound chunk processing.
1041 struct sctp_chunk *in_progress;
1043 /* This is the delayed task to finish delivering inbound
1046 struct work_struct immediate;
1049 void sctp_inq_init(struct sctp_inq *);
1050 void sctp_inq_free(struct sctp_inq *);
1051 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1052 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1053 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1054 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1056 /* This is the structure we use to hold outbound chunks. You push
1057 * chunks in and they automatically pop out the other end as bundled
1058 * packets (it calls (*output_handler)()).
1060 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1061 * and 8.2 of the v13 draft.
1063 * It handles retransmissions. The connection to the timeout portion
1064 * of the state machine is through sctp_..._timeout() and timeout_handler.
1066 * If you feed it SACKs, it will eat them.
1068 * If you give it big chunks, it will fragment them.
1070 * It assigns TSN's to data chunks. This happens at the last possible
1071 * instant before transmission.
1073 * When free()'d, it empties itself out via output_handler().
1076 struct sctp_association *asoc;
1078 /* Data pending that has never been transmitted. */
1079 struct list_head out_chunk_list;
1081 /* Stream scheduler being used */
1082 struct sctp_sched_ops *sched;
1084 unsigned int out_qlen; /* Total length of queued data chunks. */
1086 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1089 /* These are control chunks we want to send. */
1090 struct list_head control_chunk_list;
1092 /* These are chunks that have been sacked but are above the
1093 * CTSN, or cumulative tsn ack point.
1095 struct list_head sacked;
1097 /* Put chunks on this list to schedule them for
1100 struct list_head retransmit;
1102 /* Put chunks on this list to save them for FWD TSN processing as
1103 * they were abandoned.
1105 struct list_head abandoned;
1107 /* How many unackd bytes do we have in-flight? */
1108 __u32 outstanding_bytes;
1110 /* Are we doing fast-rtx on this queue */
1117 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1118 void sctp_outq_teardown(struct sctp_outq *);
1119 void sctp_outq_free(struct sctp_outq*);
1120 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1121 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1122 int sctp_outq_is_empty(const struct sctp_outq *);
1123 void sctp_outq_restart(struct sctp_outq *);
1125 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1126 enum sctp_retransmit_reason reason);
1127 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1128 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1129 void sctp_prsctp_prune(struct sctp_association *asoc,
1130 struct sctp_sndrcvinfo *sinfo, int msg_len);
1131 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1132 /* Uncork and flush an outqueue. */
1133 static inline void sctp_outq_cork(struct sctp_outq *q)
1138 /* SCTP skb control block.
1139 * sctp_input_cb is currently used on rx and sock rx queue
1141 struct sctp_input_cb {
1143 struct inet_skb_parm h4;
1144 #if IS_ENABLED(CONFIG_IPV6)
1145 struct inet6_skb_parm h6;
1148 struct sctp_chunk *chunk;
1152 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1154 struct sctp_output_cb {
1155 struct sk_buff *last;
1157 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1159 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1161 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1163 return chunk->head_skb ? : skb;
1166 /* These bind address data fields common between endpoints and associations */
1167 struct sctp_bind_addr {
1169 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1171 * SCTP Port: The local SCTP port number the endpoint is
1176 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1178 * Address List: The list of IP addresses that this instance
1179 * has bound. This information is passed to one's
1180 * peer(s) in INIT and INIT ACK chunks.
1182 struct list_head address_list;
1185 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1186 void sctp_bind_addr_free(struct sctp_bind_addr *);
1187 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1188 const struct sctp_bind_addr *src,
1189 enum sctp_scope scope, gfp_t gfp,
1191 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1192 const struct sctp_bind_addr *src,
1194 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1195 int new_size, __u8 addr_state, gfp_t gfp);
1196 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1197 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1198 struct sctp_sock *);
1199 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1200 struct sctp_sock *, struct sctp_sock *);
1201 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1202 const union sctp_addr *addr);
1203 int sctp_bind_addrs_check(struct sctp_sock *sp,
1204 struct sctp_sock *sp2, int cnt2);
1205 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1206 const union sctp_addr *addrs,
1208 struct sctp_sock *opt);
1209 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1212 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1213 __u16 port, gfp_t gfp);
1215 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1216 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1217 const enum sctp_scope scope);
1218 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1219 int sctp_is_ep_boundall(struct sock *sk);
1222 /* What type of endpoint? */
1223 enum sctp_endpoint_type {
1224 SCTP_EP_TYPE_SOCKET,
1225 SCTP_EP_TYPE_ASSOCIATION,
1229 * A common base class to bridge the implmentation view of a
1230 * socket (usually listening) endpoint versus an association's
1232 * This common structure is useful for several purposes:
1233 * 1) Common interface for lookup routines.
1234 * a) Subfunctions work for either endpoint or association
1235 * b) Single interface to lookup allows hiding the lookup lock rather
1236 * than acquiring it externally.
1237 * 2) Common interface for the inbound chunk handling/state machine.
1238 * 3) Common object handling routines for reference counting, etc.
1239 * 4) Disentangle association lookup from endpoint lookup, where we
1240 * do not have to find our endpoint to find our association.
1244 struct sctp_ep_common {
1245 /* Fields to help us manage our entries in the hash tables. */
1246 struct hlist_node node;
1249 /* Runtime type information. What kind of endpoint is this? */
1250 enum sctp_endpoint_type type;
1252 /* Some fields to help us manage this object.
1253 * refcnt - Reference count access to this object.
1254 * dead - Do not attempt to use this object.
1259 /* What socket does this endpoint belong to? */
1262 /* Cache netns and it won't change once set */
1265 /* This is where we receive inbound chunks. */
1266 struct sctp_inq inqueue;
1268 /* This substructure includes the defining parameters of the
1270 * bind_addr.port is our shared port number.
1271 * bind_addr.address_list is our set of local IP addresses.
1273 struct sctp_bind_addr bind_addr;
1277 /* RFC Section 1.4 Key Terms
1279 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1280 * multi-homed host, an SCTP endpoint is represented to its peers as a
1281 * combination of a set of eligible destination transport addresses to
1282 * which SCTP packets can be sent and a set of eligible source
1283 * transport addresses from which SCTP packets can be received.
1284 * All transport addresses used by an SCTP endpoint must use the
1285 * same port number, but can use multiple IP addresses. A transport
1286 * address used by an SCTP endpoint must not be used by another
1287 * SCTP endpoint. In other words, a transport address is unique
1288 * to an SCTP endpoint.
1290 * From an implementation perspective, each socket has one of these.
1291 * A TCP-style socket will have exactly one association on one of
1292 * these. An UDP-style socket will have multiple associations hanging
1296 struct sctp_endpoint {
1297 /* Common substructure for endpoint and association. */
1298 struct sctp_ep_common base;
1300 /* Associations: A list of current associations and mappings
1301 * to the data consumers for each association. This
1302 * may be in the form of a hash table or other
1303 * implementation dependent structure. The data
1304 * consumers may be process identification
1305 * information such as file descriptors, named pipe
1306 * pointer, or table pointers dependent on how SCTP
1309 /* This is really a list of struct sctp_association entries. */
1310 struct list_head asocs;
1312 /* Secret Key: A secret key used by this endpoint to compute
1313 * the MAC. This SHOULD be a cryptographic quality
1314 * random number with a sufficient length.
1315 * Discussion in [RFC1750] can be helpful in
1316 * selection of the key.
1318 __u8 secret_key[SCTP_SECRET_SIZE];
1320 /* digest: This is a digest of the sctp cookie. This field is
1321 * only used on the receive path when we try to validate
1322 * that the cookie has not been tampered with. We put
1323 * this here so we pre-allocate this once and can re-use
1328 /* sendbuf acct. policy. */
1329 __u32 sndbuf_policy;
1331 /* rcvbuf acct. policy. */
1332 __u32 rcvbuf_policy;
1334 /* SCTP AUTH: array of the HMACs that will be allocated
1335 * we need this per association so that we don't serialize
1337 struct crypto_shash **auth_hmacs;
1339 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1340 struct sctp_hmac_algo_param *auth_hmacs_list;
1342 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1343 struct sctp_chunks_param *auth_chunk_list;
1345 /* SCTP-AUTH: endpoint shared keys */
1346 struct list_head endpoint_shared_keys;
1347 __u16 active_key_id;
1355 __u8 strreset_enable;
1357 /* Security identifiers from incoming (INIT). These are set by
1358 * security_sctp_assoc_request(). These will only be used by
1359 * SCTP TCP type sockets and peeled off connections as they
1360 * cause a new socket to be generated. security_sctp_sk_clone()
1361 * will then plug these into the new socket.
1368 /* Recover the outter endpoint structure. */
1369 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1371 struct sctp_endpoint *ep;
1373 ep = container_of(base, struct sctp_endpoint, base);
1377 /* These are function signatures for manipulating endpoints. */
1378 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1379 void sctp_endpoint_free(struct sctp_endpoint *);
1380 void sctp_endpoint_put(struct sctp_endpoint *);
1381 void sctp_endpoint_hold(struct sctp_endpoint *);
1382 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1383 struct sctp_association *sctp_endpoint_lookup_assoc(
1384 const struct sctp_endpoint *ep,
1385 const union sctp_addr *paddr,
1386 struct sctp_transport **);
1387 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1388 const union sctp_addr *paddr);
1389 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1390 struct net *, const union sctp_addr *);
1391 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1392 const union sctp_addr *paddr);
1394 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1395 const struct sctp_association *asoc,
1396 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1397 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1398 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1399 const union sctp_addr *peer,
1400 struct sctp_init_chunk *init, gfp_t gfp);
1401 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1402 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1404 struct sctp_inithdr_host {
1407 __u16 num_outbound_streams;
1408 __u16 num_inbound_streams;
1412 struct sctp_stream_priorities {
1413 /* List of priorities scheduled */
1414 struct list_head prio_sched;
1415 /* List of streams scheduled */
1416 struct list_head active;
1417 /* The next stream in line */
1418 struct sctp_stream_out_ext *next;
1422 struct sctp_stream_out_ext {
1423 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1424 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1425 struct list_head outq; /* chunks enqueued by this stream */
1428 /* Scheduled streams list */
1429 struct list_head prio_list;
1430 struct sctp_stream_priorities *prio_head;
1432 /* Fields used by RR scheduler */
1434 struct list_head rr_list;
1439 struct sctp_stream_out {
1445 struct sctp_stream_out_ext *ext;
1449 struct sctp_stream_in {
1461 struct sctp_stream {
1462 GENRADIX(struct sctp_stream_out) out;
1463 GENRADIX(struct sctp_stream_in) in;
1467 /* Current stream being sent, if any */
1468 struct sctp_stream_out *out_curr;
1470 /* Fields used by priority scheduler */
1472 /* List of priorities scheduled */
1473 struct list_head prio_list;
1475 /* Fields used by RR scheduler */
1477 /* List of streams scheduled */
1478 struct list_head rr_list;
1479 /* The next stream in line */
1480 struct sctp_stream_out_ext *rr_next;
1483 struct sctp_stream_interleave *si;
1486 static inline struct sctp_stream_out *sctp_stream_out(
1487 struct sctp_stream *stream,
1490 return genradix_ptr(&stream->out, sid);
1493 static inline struct sctp_stream_in *sctp_stream_in(
1494 struct sctp_stream *stream,
1497 return genradix_ptr(&stream->in, sid);
1500 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1501 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1503 #define SCTP_STREAM_CLOSED 0x00
1504 #define SCTP_STREAM_OPEN 0x01
1506 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1508 return stream->si->data_chunk_len;
1511 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1513 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1516 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1518 return stream->si->ftsn_chunk_len;
1521 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1523 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1526 /* SCTP_GET_ASSOC_STATS counters */
1527 struct sctp_priv_assoc_stats {
1528 /* Maximum observed rto in the association during subsequent
1529 * observations. Value is set to 0 if no RTO measurement took place
1530 * The transport where the max_rto was observed is returned in
1533 struct sockaddr_storage obs_rto_ipaddr;
1535 /* Total In and Out SACKs received and sent */
1538 /* Total In and Out packets received and sent */
1541 /* Total retransmitted chunks */
1543 /* TSN received > next expected */
1545 /* Duplicate Chunks received */
1547 /* Gap Ack Blocks received */
1549 /* Unordered data chunks sent and received */
1552 /* Ordered data chunks sent and received */
1555 /* Control chunks sent and received */
1562 * 12. Recommended Transmission Control Block (TCB) Parameters
1564 * This section details a recommended set of parameters that should
1565 * be contained within the TCB for an implementation. This section is
1566 * for illustrative purposes and should not be deemed as requirements
1567 * on an implementation or as an exhaustive list of all parameters
1568 * inside an SCTP TCB. Each implementation may need its own additional
1569 * parameters for optimization.
1573 /* Here we have information about each individual association. */
1574 struct sctp_association {
1576 /* A base structure common to endpoint and association.
1577 * In this context, it represents the associations's view
1578 * of the local endpoint of the association.
1580 struct sctp_ep_common base;
1582 /* Associations on the same socket. */
1583 struct list_head asocs;
1585 /* association id. */
1586 sctp_assoc_t assoc_id;
1588 /* This is our parent endpoint. */
1589 struct sctp_endpoint *ep;
1591 /* These are those association elements needed in the cookie. */
1592 struct sctp_cookie c;
1594 /* This is all information about our peer. */
1596 /* transport_addr_list
1598 * Peer : A list of SCTP transport addresses that the
1599 * Transport : peer is bound to. This information is derived
1600 * Address : from the INIT or INIT ACK and is used to
1601 * List : associate an inbound packet with a given
1602 * : association. Normally this information is
1603 * : hashed or keyed for quick lookup and access
1605 * : The list is also initialized with the list
1606 * : of addresses passed with the sctp_connectx()
1609 * It is a list of SCTP_transport's.
1611 struct list_head transport_addr_list;
1615 * Peer Rwnd : Current calculated value of the peer's rwnd.
1621 * Peer : A count of the number of peer addresses
1622 * Transport : in the Peer Transport Address List.
1626 __u16 transport_count;
1629 * The transport layer port number.
1635 * Primary : This is the current primary destination
1636 * Path : transport address of the peer endpoint. It
1637 * : may also specify a source transport address
1638 * : on this endpoint.
1640 * All of these paths live on transport_addr_list.
1642 * At the bakeoffs, we discovered that the intent of
1643 * primaryPath is that it only changes when the ULP
1644 * asks to have it changed. We add the activePath to
1645 * designate the connection we are currently using to
1646 * transmit new data and most control chunks.
1648 struct sctp_transport *primary_path;
1650 /* Cache the primary path address here, when we
1651 * need a an address for msg_name.
1653 union sctp_addr primary_addr;
1656 * The path that we are currently using to
1657 * transmit new data and most control chunks.
1659 struct sctp_transport *active_path;
1663 * RFC2960 6.4 Multi-homed SCTP Endpoints
1665 * Furthermore, when its peer is multi-homed, an
1666 * endpoint SHOULD try to retransmit a chunk to an
1667 * active destination transport address that is
1668 * different from the last destination address to
1669 * which the DATA chunk was sent.
1671 struct sctp_transport *retran_path;
1673 /* Pointer to last transport I have sent on. */
1674 struct sctp_transport *last_sent_to;
1676 /* This is the last transport I have received DATA on. */
1677 struct sctp_transport *last_data_from;
1680 * Mapping An array of bits or bytes indicating which out of
1681 * Array order TSN's have been received (relative to the
1682 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1683 * order packets have been received, this array
1684 * will be set to all zero. This structure may be
1685 * in the form of a circular buffer or bit array.
1687 * Last Rcvd : This is the last TSN received in
1688 * TSN : sequence. This value is set initially by
1689 * : taking the peer's Initial TSN, received in
1690 * : the INIT or INIT ACK chunk, and subtracting
1693 * Throughout most of the specification this is called the
1694 * "Cumulative TSN ACK Point". In this case, we
1695 * ignore the advice in 12.2 in favour of the term
1696 * used in the bulk of the text. This value is hidden
1697 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1699 struct sctp_tsnmap tsn_map;
1701 /* This mask is used to disable sending the ASCONF chunk
1702 * with specified parameter to peer.
1704 __be16 addip_disabled_mask;
1706 /* These are capabilities which our peer advertised. */
1707 __u16 ecn_capable:1, /* Can peer do ECN? */
1708 ipv4_address:1, /* Peer understands IPv4 addresses? */
1709 ipv6_address:1, /* Peer understands IPv6 addresses? */
1710 hostname_address:1, /* Peer understands DNS addresses? */
1711 asconf_capable:1, /* Does peer support ADDIP? */
1712 prsctp_capable:1, /* Can peer do PR-SCTP? */
1713 reconf_capable:1, /* Can peer do RE-CONFIG? */
1714 intl_capable:1, /* Can peer do INTERLEAVE */
1715 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1717 * This flag indicates if the next received
1718 * packet is to be responded to with a
1719 * SACK. This is initialized to 0. When a packet
1720 * is received sack_cnt is incremented. If this value
1721 * reaches 2 or more, a SACK is sent and the
1722 * value is reset to 0. Note: This is used only
1723 * when no DATA chunks are received out of
1724 * order. When DATA chunks are out of order,
1725 * SACK's are not delayed (see Section 6).
1727 sack_needed:1, /* Do we need to sack the peer? */
1729 zero_window_announced:1;
1733 __u32 adaptation_ind; /* Adaptation Code point. */
1735 struct sctp_inithdr_host i;
1739 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1740 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1741 * Initial TSN Value minus 1
1745 /* SCTP-AUTH: We need to know pears random number, hmac list
1746 * and authenticated chunk list. All that is part of the
1747 * cookie and these are just pointers to those locations
1749 struct sctp_random_param *peer_random;
1750 struct sctp_chunks_param *peer_chunks;
1751 struct sctp_hmac_algo_param *peer_hmacs;
1754 /* State : A state variable indicating what state the
1755 * : association is in, i.e. COOKIE-WAIT,
1756 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1757 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1759 * Note: No "CLOSED" state is illustrated since if a
1760 * association is "CLOSED" its TCB SHOULD be removed.
1762 * In this implementation we DO have a CLOSED
1763 * state which is used during initiation and shutdown.
1765 * State takes values from SCTP_STATE_*.
1767 enum sctp_state state;
1769 /* Overall : The overall association error count.
1770 * Error Count : [Clear this any time I get something.]
1772 int overall_error_count;
1774 /* The cookie life I award for any cookie. */
1775 ktime_t cookie_life;
1777 /* These are the association's initial, max, and min RTO values.
1778 * These values will be initialized by system defaults, but can
1779 * be modified via the SCTP_RTOINFO socket option.
1781 unsigned long rto_initial;
1782 unsigned long rto_max;
1783 unsigned long rto_min;
1785 /* Maximum number of new data packets that can be sent in a burst. */
1788 /* This is the max_retrans value for the association. This value will
1789 * be initialized from system defaults, but can be
1790 * modified by the SCTP_ASSOCINFO socket option.
1794 /* This is the partially failed retrans value for the transport
1795 * and will be initialized from the assocs value. This can be
1796 * changed using the SCTP_PEER_ADDR_THLDS socket option
1799 /* Used for primary path switchover. */
1802 /* Maximum number of times the endpoint will retransmit INIT */
1803 __u16 max_init_attempts;
1805 /* How many times have we resent an INIT? */
1808 /* The largest timeout or RTO value to use in attempting an INIT */
1809 unsigned long max_init_timeo;
1811 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1812 * the destination address every heartbeat interval. This value
1813 * will be inherited by all new transports.
1815 unsigned long hbinterval;
1816 unsigned long probe_interval;
1820 /* This is the max_retrans value for new transports in the
1828 /* Flag that path mtu update is pending */
1831 /* Association : The smallest PMTU discovered for all of the
1832 * PMTU : peer's transport addresses.
1836 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1840 /* SACK delay timeout */
1841 unsigned long sackdelay;
1843 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1844 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1846 /* Transport to which SHUTDOWN chunk was last sent. */
1847 struct sctp_transport *shutdown_last_sent_to;
1849 /* Transport to which INIT chunk was last sent. */
1850 struct sctp_transport *init_last_sent_to;
1852 /* How many times have we resent a SHUTDOWN */
1853 int shutdown_retries;
1855 /* Next TSN : The next TSN number to be assigned to a new
1856 * : DATA chunk. This is sent in the INIT or INIT
1857 * : ACK chunk to the peer and incremented each
1858 * : time a DATA chunk is assigned a TSN
1859 * : (normally just prior to transmit or during
1865 * Last Rcvd : This is the last TSN received in sequence. This value
1866 * TSN : is set initially by taking the peer's Initial TSN,
1867 * : received in the INIT or INIT ACK chunk, and
1868 * : subtracting one from it.
1870 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1873 __u32 ctsn_ack_point;
1875 /* PR-SCTP Advanced.Peer.Ack.Point */
1876 __u32 adv_peer_ack_point;
1878 /* Highest TSN that is acknowledged by incoming SACKs. */
1879 __u32 highest_sacked;
1881 /* TSN marking the fast recovery exit point */
1882 __u32 fast_recovery_exit;
1884 /* Flag to track the current fast recovery state */
1887 /* The number of unacknowledged data chunks. Reported through
1888 * the SCTP_STATUS sockopt.
1892 /* The total number of data chunks that we've had to retransmit
1893 * as the result of a T3 timer expiration
1895 __u32 rtx_data_chunks;
1897 /* This is the association's receive buffer space. This value is used
1898 * to set a_rwnd field in an INIT or a SACK chunk.
1902 /* This is the last advertised value of rwnd over a SACK chunk. */
1905 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1906 * to slop over a maximum of the association's frag_point.
1910 /* Keeps treack of rwnd pressure. This happens when we have
1911 * a window, but not recevie buffer (i.e small packets). This one
1912 * is releases slowly (1 PMTU at a time ).
1916 /* This is the sndbuf size in use for the association.
1917 * This corresponds to the sndbuf size for the association,
1918 * as specified in the sk->sndbuf.
1922 /* This is the amount of memory that this association has allocated
1923 * in the receive path at any given time.
1925 atomic_t rmem_alloc;
1927 /* This is the wait queue head for send requests waiting on
1928 * the association sndbuf space.
1930 wait_queue_head_t wait;
1932 /* The message size at which SCTP fragmentation will occur. */
1936 /* Counter used to count INIT errors. */
1937 int init_err_counter;
1939 /* Count the number of INIT cycles (for doubling timeout). */
1942 /* Default send parameters. */
1943 __u16 default_stream;
1944 __u16 default_flags;
1946 __u32 default_context;
1947 __u32 default_timetolive;
1949 /* Default receive parameters */
1950 __u32 default_rcv_context;
1953 struct sctp_stream stream;
1955 /* All outbound chunks go through this structure. */
1956 struct sctp_outq outqueue;
1958 /* A smart pipe that will handle reordering and fragmentation,
1959 * as well as handle passing events up to the ULP.
1961 struct sctp_ulpq ulpq;
1963 /* Last TSN that caused an ECNE Chunk to be sent. */
1964 __u32 last_ecne_tsn;
1966 /* Last TSN that caused a CWR Chunk to be sent. */
1969 /* How many duplicated TSNs have we seen? */
1972 /* These are to support
1973 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1974 * and Enforcement of Flow and Message Limits"
1975 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1976 * or "ADDIP" for short.
1981 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1983 * R1) One and only one ASCONF Chunk MAY be in transit and
1984 * unacknowledged at any one time. If a sender, after sending
1985 * an ASCONF chunk, decides it needs to transfer another
1986 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1987 * returns from the previous ASCONF Chunk before sending a
1988 * subsequent ASCONF. Note this restriction binds each side,
1989 * so at any time two ASCONF may be in-transit on any given
1990 * association (one sent from each endpoint).
1992 * [This is our one-and-only-one ASCONF in flight. If we do
1993 * not have an ASCONF in flight, this is NULL.]
1995 struct sctp_chunk *addip_last_asconf;
1997 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1999 * This is needed to implement itmes E1 - E4 of the updated
2000 * spec. Here is the justification:
2002 * Since the peer may bundle multiple ASCONF chunks toward us,
2003 * we now need the ability to cache multiple ACKs. The section
2004 * describes in detail how they are cached and cleaned up.
2006 struct list_head asconf_ack_list;
2008 /* These ASCONF chunks are waiting to be sent.
2010 * These chunaks can't be pushed to outqueue until receiving
2011 * ASCONF_ACK for the previous ASCONF indicated by
2012 * addip_last_asconf, so as to guarantee that only one ASCONF
2013 * is in flight at any time.
2015 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2017 * In defining the ASCONF Chunk transfer procedures, it is
2018 * essential that these transfers MUST NOT cause congestion
2019 * within the network. To achieve this, we place these
2020 * restrictions on the transfer of ASCONF Chunks:
2022 * R1) One and only one ASCONF Chunk MAY be in transit and
2023 * unacknowledged at any one time. If a sender, after sending
2024 * an ASCONF chunk, decides it needs to transfer another
2025 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2026 * returns from the previous ASCONF Chunk before sending a
2027 * subsequent ASCONF. Note this restriction binds each side,
2028 * so at any time two ASCONF may be in-transit on any given
2029 * association (one sent from each endpoint).
2032 * [I really think this is EXACTLY the sort of intelligence
2033 * which already resides in sctp_outq. Please move this
2034 * queue and its supporting logic down there. --piggy]
2036 struct list_head addip_chunk_list;
2038 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2040 * A2) A serial number should be assigned to the Chunk. The
2041 * serial number SHOULD be a monotonically increasing
2042 * number. The serial number SHOULD be initialized at
2043 * the start of the association to the same value as the
2044 * Initial TSN and every time a new ASCONF chunk is created
2045 * it is incremented by one after assigning the serial number
2046 * to the newly created chunk.
2049 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2051 * Serial Number : 32 bits (unsigned integer)
2053 * This value represents a Serial Number for the ASCONF
2054 * Chunk. The valid range of Serial Number is from 0 to
2055 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2056 * after reaching 4294967295.
2059 int src_out_of_asoc_ok;
2060 union sctp_addr *asconf_addr_del_pending;
2061 struct sctp_transport *new_transport;
2063 /* SCTP AUTH: list of the endpoint shared keys. These
2064 * keys are provided out of band by the user applicaton
2065 * and can't change during the lifetime of the association
2067 struct list_head endpoint_shared_keys;
2070 * The current generated assocaition shared key (secret)
2072 struct sctp_auth_bytes *asoc_shared_key;
2073 struct sctp_shared_key *shkey;
2075 /* SCTP AUTH: hmac id of the first peer requested algorithm
2078 __u16 default_hmac_id;
2080 __u16 active_key_id;
2082 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2083 temp:1, /* Is it a temporary association? */
2084 pf_expose:2, /* Expose pf state? */
2087 __u8 strreset_enable;
2088 __u8 strreset_outstanding; /* request param count on the fly */
2090 __u32 strreset_outseq; /* Update after receiving response */
2091 __u32 strreset_inseq; /* Update after receiving request */
2092 __u32 strreset_result[2]; /* save the results of last 2 responses */
2094 struct sctp_chunk *strreset_chunk; /* save request chunk */
2096 struct sctp_priv_assoc_stats stats;
2098 int sent_cnt_removable;
2102 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2103 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2105 struct rcu_head rcu;
2109 /* An eyecatcher for determining if we are really looking at an
2110 * association data structure.
2113 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2116 /* Recover the outter association structure. */
2117 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2119 struct sctp_association *asoc;
2121 asoc = container_of(base, struct sctp_association, base);
2125 /* These are function signatures for manipulating associations. */
2128 struct sctp_association *
2129 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2130 enum sctp_scope scope, gfp_t gfp);
2131 void sctp_association_free(struct sctp_association *);
2132 void sctp_association_put(struct sctp_association *);
2133 void sctp_association_hold(struct sctp_association *);
2135 struct sctp_transport *sctp_assoc_choose_alter_transport(
2136 struct sctp_association *, struct sctp_transport *);
2137 void sctp_assoc_update_retran_path(struct sctp_association *);
2138 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2139 const union sctp_addr *);
2140 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2141 const union sctp_addr *laddr);
2142 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2143 const union sctp_addr *address,
2145 const int peer_state);
2146 void sctp_assoc_del_peer(struct sctp_association *asoc,
2147 const union sctp_addr *addr);
2148 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2149 struct sctp_transport *peer);
2150 void sctp_assoc_control_transport(struct sctp_association *asoc,
2151 struct sctp_transport *transport,
2152 enum sctp_transport_cmd command,
2153 sctp_sn_error_t error);
2154 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2155 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2156 int sctp_assoc_update(struct sctp_association *old,
2157 struct sctp_association *new);
2159 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2161 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2162 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2163 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2164 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2165 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2166 void sctp_assoc_set_primary(struct sctp_association *,
2167 struct sctp_transport *);
2168 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2169 struct sctp_transport *);
2170 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2171 enum sctp_scope scope, gfp_t gfp);
2172 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2173 struct sctp_cookie*,
2175 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2176 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2177 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2178 const struct sctp_association *asoc,
2180 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2182 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2183 const union sctp_addr *ss2);
2184 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2186 /* A convenience structure to parse out SCTP specific CMSGs. */
2188 struct sctp_initmsg *init;
2189 struct sctp_sndrcvinfo *srinfo;
2190 struct sctp_sndinfo *sinfo;
2191 struct sctp_prinfo *prinfo;
2192 struct sctp_authinfo *authinfo;
2193 struct msghdr *addrs_msg;
2196 /* Structure for tracking memory objects */
2197 struct sctp_dbg_objcnt_entry {
2202 #endif /* __sctp_structs_h__ */