1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
7 * This file is part of the SCTP kernel implementation
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, see
23 * <http://www.gnu.org/licenses/>.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <linux-sctp@vger.kernel.org>
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
50 #include <linux/ktime.h>
51 #include <linux/rhashtable.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/sctp.h> /* We need sctp* header structs. */
61 #include <net/sctp/auth.h> /* We need auth specific structs */
62 #include <net/ip.h> /* For inet_skb_parm */
64 /* A convenience structure for handling sockaddr structures.
65 * We should wean ourselves off this.
68 struct sockaddr_in v4;
69 struct sockaddr_in6 v6;
73 /* Forward declarations for data structures. */
76 struct sctp_association;
77 struct sctp_transport;
82 struct sctp_bind_addr;
84 struct sctp_ep_common;
89 #include <net/sctp/tsnmap.h>
90 #include <net/sctp/ulpevent.h>
91 #include <net/sctp/ulpqueue.h>
92 #include <net/sctp/stream_interleave.h>
94 /* Structures useful for managing bind/connect. */
96 struct sctp_bind_bucket {
98 unsigned short fastreuse;
99 struct hlist_node node;
100 struct hlist_head owner;
104 struct sctp_bind_hashbucket {
106 struct hlist_head chain;
109 /* Used for hashing all associations. */
110 struct sctp_hashbucket {
112 struct hlist_head chain;
113 } __attribute__((__aligned__(8)));
116 /* The SCTP globals structure. */
117 extern struct sctp_globals {
118 /* This is a list of groups of functions for each address
119 * family that we support.
121 struct list_head address_families;
123 /* This is the hash of all endpoints. */
124 struct sctp_hashbucket *ep_hashtable;
125 /* This is the sctp port control hash. */
126 struct sctp_bind_hashbucket *port_hashtable;
127 /* This is the hash of all transports. */
128 struct rhltable transport_hashtable;
130 /* Sizes of above hashtables. */
134 /* Default initialization values to be applied to new associations. */
136 __u16 max_outstreams;
138 /* Flag to indicate whether computing and verifying checksum
140 bool checksum_disable;
143 #define sctp_max_instreams (sctp_globals.max_instreams)
144 #define sctp_max_outstreams (sctp_globals.max_outstreams)
145 #define sctp_address_families (sctp_globals.address_families)
146 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
147 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
148 #define sctp_port_hashsize (sctp_globals.port_hashsize)
149 #define sctp_port_hashtable (sctp_globals.port_hashtable)
150 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
151 #define sctp_checksum_disable (sctp_globals.checksum_disable)
153 /* SCTP Socket type: UDP or TCP style. */
154 enum sctp_socket_type {
156 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
160 /* Per socket SCTP information. */
162 /* inet_sock has to be the first member of sctp_sock */
163 struct inet_sock inet;
164 /* What kind of a socket is this? */
165 enum sctp_socket_type type;
167 /* PF_ family specific functions. */
170 /* Access to HMAC transform. */
171 struct crypto_shash *hmac;
174 /* What is our base endpointer? */
175 struct sctp_endpoint *ep;
177 struct sctp_bind_bucket *bind_hash;
178 /* Various Socket Options. */
179 __u16 default_stream;
182 __u32 default_context;
183 __u32 default_timetolive;
184 __u32 default_rcv_context;
187 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
188 * the destination address every heartbeat interval. This value
189 * will be inherited by all new associations.
193 /* This is the max_retrans value for new associations. */
196 /* The initial Path MTU to use for new associations. */
199 /* The default SACK delay timeout for new associations. */
203 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
206 struct sctp_initmsg initmsg;
207 struct sctp_rtoinfo rtoinfo;
208 struct sctp_paddrparams paddrparam;
209 struct sctp_event_subscribe subscribe;
210 struct sctp_assocparams assocparams;
215 __u32 adaptation_ind;
224 data_ready_signalled:1;
227 /* Receive to here while partial delivery is in effect. */
228 struct sk_buff_head pd_lobby;
230 /* These must be the last fields, as they will skipped on copies,
231 * like on accept and peeloff operations
233 struct list_head auto_asconf_list;
237 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
239 return (struct sctp_sock *)sk;
242 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
244 return (struct sock *)sp;
247 #if IS_ENABLED(CONFIG_IPV6)
249 struct sctp_sock sctp;
250 struct ipv6_pinfo inet6;
252 #endif /* CONFIG_IPV6 */
255 /* This is our APPLICATION-SPECIFIC state cookie.
256 * THIS IS NOT DICTATED BY THE SPECIFICATION.
258 /* These are the parts of an association which we send in the cookie.
259 * Most of these are straight out of:
260 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
266 /* My : Tag expected in every inbound packet and sent
267 * Verification: in the INIT or INIT ACK chunk.
272 /* Peer's : Tag expected in every outbound packet except
273 * Verification: in the INIT chunk.
278 /* The rest of these are not from the spec, but really need to
282 /* My Tie Tag : Assist in discovering a restarting association. */
285 /* Peer's Tie Tag: Assist in discovering a restarting association. */
288 /* When does this cookie expire? */
291 /* Number of inbound/outbound streams which are set
292 * and negotiated during the INIT process.
294 __u16 sinit_num_ostreams;
295 __u16 sinit_max_instreams;
297 /* This is the first sequence number I used. */
300 /* This holds the originating address of the INIT packet. */
301 union sctp_addr peer_addr;
304 * Include the source port of the INIT-ACK
310 /* Padding for future use */
313 __u32 adaptation_ind;
315 __u8 auth_random[sizeof(struct sctp_paramhdr) +
316 SCTP_AUTH_RANDOM_LENGTH];
317 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
318 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
320 /* This is a shim for my peer's INIT packet, followed by
321 * a copy of the raw address list of the association.
322 * The length of the raw address list is saved in the
323 * raw_addr_list_len field, which will be used at the time when
324 * the association TCB is re-constructed from the cookie.
326 __u32 raw_addr_list_len;
327 struct sctp_init_chunk peer_init[0];
331 /* The format of our cookie that we send to our peer. */
332 struct sctp_signed_cookie {
333 __u8 signature[SCTP_SECRET_SIZE];
334 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
335 struct sctp_cookie c;
338 /* This is another convenience type to allocate memory for address
339 * params for the maximum size and pass such structures around
342 union sctp_addr_param {
343 struct sctp_paramhdr p;
344 struct sctp_ipv4addr_param v4;
345 struct sctp_ipv6addr_param v6;
348 /* A convenience type to allow walking through the various
349 * parameters and avoid casting all over the place.
353 struct sctp_paramhdr *p;
354 struct sctp_cookie_preserve_param *life;
355 struct sctp_hostname_param *dns;
356 struct sctp_cookie_param *cookie;
357 struct sctp_supported_addrs_param *sat;
358 struct sctp_ipv4addr_param *v4;
359 struct sctp_ipv6addr_param *v6;
360 union sctp_addr_param *addr;
361 struct sctp_adaptation_ind_param *aind;
362 struct sctp_supported_ext_param *ext;
363 struct sctp_random_param *random;
364 struct sctp_chunks_param *chunks;
365 struct sctp_hmac_algo_param *hmac_algo;
366 struct sctp_addip_param *addip;
369 /* RFC 2960. Section 3.3.5 Heartbeat.
370 * Heartbeat Information: variable length
371 * The Sender-specific Heartbeat Info field should normally include
372 * information about the sender's current time when this HEARTBEAT
373 * chunk is sent and the destination transport address to which this
374 * HEARTBEAT is sent (see Section 8.3).
376 struct sctp_sender_hb_info {
377 struct sctp_paramhdr param_hdr;
378 union sctp_addr daddr;
379 unsigned long sent_at;
383 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
385 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
386 void sctp_stream_free(struct sctp_stream *stream);
387 void sctp_stream_clear(struct sctp_stream *stream);
388 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
390 /* What is the current SSN number for this stream? */
391 #define sctp_ssn_peek(stream, type, sid) \
392 ((stream)->type[sid].ssn)
394 /* Return the next SSN number for this stream. */
395 #define sctp_ssn_next(stream, type, sid) \
396 ((stream)->type[sid].ssn++)
398 /* Skip over this ssn and all below. */
399 #define sctp_ssn_skip(stream, type, sid, ssn) \
400 ((stream)->type[sid].ssn = ssn + 1)
402 /* What is the current MID number for this stream? */
403 #define sctp_mid_peek(stream, type, sid) \
404 ((stream)->type[sid].mid)
406 /* Return the next MID number for this stream. */
407 #define sctp_mid_next(stream, type, sid) \
408 ((stream)->type[sid].mid++)
410 /* Skip over this mid and all below. */
411 #define sctp_mid_skip(stream, type, sid, mid) \
412 ((stream)->type[sid].mid = mid + 1)
415 * Pointers to address related SCTP functions.
416 * (i.e. things that depend on the address family.)
419 int (*sctp_xmit) (struct sk_buff *skb,
420 struct sctp_transport *);
421 int (*setsockopt) (struct sock *sk,
425 unsigned int optlen);
426 int (*getsockopt) (struct sock *sk,
431 int (*compat_setsockopt) (struct sock *sk,
435 unsigned int optlen);
436 int (*compat_getsockopt) (struct sock *sk,
441 void (*get_dst) (struct sctp_transport *t,
442 union sctp_addr *saddr,
445 void (*get_saddr) (struct sctp_sock *sk,
446 struct sctp_transport *t,
448 void (*copy_addrlist) (struct list_head *,
449 struct net_device *);
450 int (*cmp_addr) (const union sctp_addr *addr1,
451 const union sctp_addr *addr2);
452 void (*addr_copy) (union sctp_addr *dst,
453 union sctp_addr *src);
454 void (*from_skb) (union sctp_addr *,
457 void (*from_sk) (union sctp_addr *,
459 void (*from_addr_param) (union sctp_addr *,
460 union sctp_addr_param *,
461 __be16 port, int iif);
462 int (*to_addr_param) (const union sctp_addr *,
463 union sctp_addr_param *);
464 int (*addr_valid) (union sctp_addr *,
466 const struct sk_buff *);
467 enum sctp_scope (*scope)(union sctp_addr *);
468 void (*inaddr_any) (union sctp_addr *, __be16);
469 int (*is_any) (const union sctp_addr *);
470 int (*available) (union sctp_addr *,
472 int (*skb_iif) (const struct sk_buff *sk);
473 int (*is_ce) (const struct sk_buff *sk);
474 void (*seq_dump_addr)(struct seq_file *seq,
475 union sctp_addr *addr);
476 void (*ecn_capable)(struct sock *sk);
477 __u16 net_header_len;
479 sa_family_t sa_family;
480 struct list_head list;
483 struct sctp_af *sctp_get_af_specific(sa_family_t);
484 int sctp_register_af(struct sctp_af *);
486 /* Protocol family functions. */
488 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
489 void (*skb_msgname) (struct sk_buff *, char *, int *);
490 int (*af_supported) (sa_family_t, struct sctp_sock *);
491 int (*cmp_addr) (const union sctp_addr *,
492 const union sctp_addr *,
494 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
495 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
496 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
497 struct sock *(*create_accept_sk) (struct sock *sk,
498 struct sctp_association *asoc,
500 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
501 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
502 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
507 /* Structure to track chunk fragments that have been acked, but peer
508 * fragments of the same message have not.
510 struct sctp_datamsg {
511 /* Chunks waiting to be submitted to lower layer. */
512 struct list_head chunks;
513 /* Reference counting. */
515 /* When is this message no longer interesting to the peer? */
516 unsigned long expires_at;
517 /* Did the messenge fail to send? */
520 can_delay:1, /* should this message be Nagle delayed */
521 abandoned:1; /* should this message be abandoned */
524 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
525 struct sctp_sndrcvinfo *,
527 void sctp_datamsg_free(struct sctp_datamsg *);
528 void sctp_datamsg_put(struct sctp_datamsg *);
529 void sctp_chunk_fail(struct sctp_chunk *, int error);
530 int sctp_chunk_abandoned(struct sctp_chunk *);
532 /* RFC2960 1.4 Key Terms
534 * o Chunk: A unit of information within an SCTP packet, consisting of
535 * a chunk header and chunk-specific content.
537 * As a matter of convenience, we remember the SCTP common header for
538 * each chunk as well as a few other header pointers...
541 struct list_head list;
545 /* How many times this chunk have been sent, for prsctp RTX policy */
549 /* This is our link to the per-transport transmitted list. */
550 struct list_head transmitted_list;
551 /* List in specific stream outq */
552 struct list_head stream_list;
555 /* This field is used by chunks that hold fragmented data.
556 * For the first fragment this is the list that holds the rest of
557 * fragments. For the remaining fragments, this is the link to the
558 * frag_list maintained in the first fragment.
560 struct list_head frag_list;
562 /* This points to the sk_buff containing the actual data. */
565 /* In case of GSO packets, this will store the head one */
566 struct sk_buff *head_skb;
568 /* These are the SCTP headers by reverse order in a packet.
569 * Note that some of these may happen more than once. In that
570 * case, we point at the "current" one, whatever that means
571 * for that level of header.
574 /* We point this at the FIRST TLV parameter to chunk_hdr. */
575 union sctp_params param_hdr;
578 struct sctp_datahdr *data_hdr;
579 struct sctp_inithdr *init_hdr;
580 struct sctp_sackhdr *sack_hdr;
581 struct sctp_heartbeathdr *hb_hdr;
582 struct sctp_sender_hb_info *hbs_hdr;
583 struct sctp_shutdownhdr *shutdown_hdr;
584 struct sctp_signed_cookie *cookie_hdr;
585 struct sctp_ecnehdr *ecne_hdr;
586 struct sctp_cwrhdr *ecn_cwr_hdr;
587 struct sctp_errhdr *err_hdr;
588 struct sctp_addiphdr *addip_hdr;
589 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
590 struct sctp_authhdr *auth_hdr;
591 struct sctp_idatahdr *idata_hdr;
596 struct sctp_chunkhdr *chunk_hdr;
597 struct sctphdr *sctp_hdr;
599 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
600 struct sctp_sndrcvinfo sinfo;
602 /* Which association does this belong to? */
603 struct sctp_association *asoc;
605 /* What endpoint received this chunk? */
606 struct sctp_ep_common *rcvr;
608 /* We fill this in if we are calculating RTT. */
609 unsigned long sent_at;
611 /* What is the origin IP address for this chunk? */
612 union sctp_addr source;
613 /* Destination address for this chunk. */
614 union sctp_addr dest;
616 /* For outbound message, track all fragments for SEND_FAILED. */
617 struct sctp_datamsg *msg;
619 /* For an inbound chunk, this tells us where it came from.
620 * For an outbound chunk, it tells us where we'd like it to
621 * go. It is NULL if we have no preference.
623 struct sctp_transport *transport;
625 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
626 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
627 * spec violates the principle premis that all chunks are processed
630 struct sk_buff *auth_chunk;
632 #define SCTP_CAN_FRTX 0x0
633 #define SCTP_NEED_FRTX 0x1
634 #define SCTP_DONT_FRTX 0x2
635 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
636 has_tsn:1, /* Does this chunk have a TSN yet? */
637 has_ssn:1, /* Does this chunk have a SSN yet? */
638 #define has_mid has_ssn
639 singleton:1, /* Only chunk in the packet? */
640 end_of_packet:1, /* Last chunk in the packet? */
641 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
642 pdiscard:1, /* Discard the whole packet now? */
643 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
644 data_accepted:1, /* At least 1 chunk accepted */
645 auth:1, /* IN: was auth'ed | OUT: needs auth */
646 has_asconf:1, /* IN: have seen an asconf before */
647 tsn_missing_report:2, /* Data chunk missing counter. */
648 fast_retransmit:2; /* Is this chunk fast retransmitted? */
651 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
652 void sctp_chunk_hold(struct sctp_chunk *);
653 void sctp_chunk_put(struct sctp_chunk *);
654 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
655 struct iov_iter *from);
656 void sctp_chunk_free(struct sctp_chunk *);
657 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
658 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
659 const struct sctp_association *,
660 struct sock *, gfp_t gfp);
661 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
663 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
665 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
667 return ntohs(ch->subh.data_hdr->stream);
671 SCTP_ADDR_NEW, /* new address added to assoc/ep */
672 SCTP_ADDR_SRC, /* address can be used as source */
673 SCTP_ADDR_DEL, /* address about to be deleted */
676 /* This is a structure for holding either an IPv6 or an IPv4 address. */
677 struct sctp_sockaddr_entry {
678 struct list_head list;
685 #define SCTP_ADDRESS_TICK_DELAY 500
687 /* This structure holds lists of chunks as we are assembling for
691 /* These are the SCTP header values (host order) for the packet. */
693 __u16 destination_port;
696 /* This contains the payload chunks. */
697 struct list_head chunk_list;
699 /* This is the overhead of the sctp and ip headers. */
701 /* This is the total size of all chunks INCLUDING padding. */
703 /* This is the maximum size this packet may have */
706 /* The packet is destined for this transport address.
707 * The function we finally use to pass down to the next lower
708 * layer lives in the transport structure.
710 struct sctp_transport *transport;
712 /* pointer to the auth chunk for this packet */
713 struct sctp_chunk *auth;
715 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
716 has_sack:1, /* This packet contains a SACK chunk. */
717 has_auth:1, /* This packet contains an AUTH chunk */
718 has_data:1, /* This packet contains at least 1 DATA chunk */
719 ipfragok:1; /* So let ip fragment this packet */
722 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
723 __u16 sport, __u16 dport);
724 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
725 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
726 struct sctp_chunk *chunk,
727 int one_packet, gfp_t gfp);
728 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
729 struct sctp_chunk *chunk);
730 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
731 void sctp_packet_free(struct sctp_packet *);
733 static inline int sctp_packet_empty(struct sctp_packet *packet)
735 return packet->size == packet->overhead;
738 /* This represents a remote transport address.
739 * For local transport addresses, we just use union sctp_addr.
741 * RFC2960 Section 1.4 Key Terms
743 * o Transport address: A Transport Address is traditionally defined
744 * by Network Layer address, Transport Layer protocol and Transport
745 * Layer port number. In the case of SCTP running over IP, a
746 * transport address is defined by the combination of an IP address
747 * and an SCTP port number (where SCTP is the Transport protocol).
749 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
751 * o The sender keeps a separate congestion control parameter set for
752 * each of the destination addresses it can send to (not each
753 * source-destination pair but for each destination). The parameters
754 * should decay if the address is not used for a long enough time
758 struct sctp_transport {
759 /* A list of transports. */
760 struct list_head transports;
761 struct rhlist_head node;
763 /* Reference counting. */
765 /* RTO-Pending : A flag used to track if one of the DATA
766 * chunks sent to this address is currently being
767 * used to compute a RTT. If this flag is 0,
768 * the next DATA chunk sent to this destination
769 * should be used to compute a RTT and this flag
770 * should be set. Every time the RTT
771 * calculation completes (i.e. the DATA chunk
772 * is SACK'd) clear this flag.
777 * hb_sent : a flag that signals that we have a pending
782 /* Is the Path MTU update pending on this tranport */
785 dst_pending_confirm:1, /* need to confirm neighbour */
787 /* Has this transport moved the ctsn since we last sacked */
793 /* This is the peer's IP address and port. */
794 union sctp_addr ipaddr;
796 /* These are the functions we call to handle LLP stuff. */
797 struct sctp_af *af_specific;
799 /* Which association do we belong to? */
800 struct sctp_association *asoc;
804 * 12.3 Per Transport Address Data
806 * For each destination transport address in the peer's
807 * address list derived from the INIT or INIT ACK chunk, a
808 * number of data elements needs to be maintained including:
810 /* RTO : The current retransmission timeout value. */
813 __u32 rtt; /* This is the most recent RTT. */
815 /* RTTVAR : The current RTT variation. */
818 /* SRTT : The current smoothed round trip time. */
822 * These are the congestion stats.
824 /* cwnd : The current congestion window. */
825 __u32 cwnd; /* This is the actual cwnd. */
827 /* ssthresh : The current slow start threshold value. */
830 /* partial : The tracking method for increase of cwnd when in
831 * bytes acked : congestion avoidance mode (see Section 6.2.2)
833 __u32 partial_bytes_acked;
835 /* Data that has been sent, but not acknowledged. */
838 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
841 struct dst_entry *dst;
842 /* Source address. */
843 union sctp_addr saddr;
845 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
846 * the destination address every heartbeat interval.
848 unsigned long hbinterval;
850 /* SACK delay timeout */
851 unsigned long sackdelay;
854 /* When was the last time that we heard from this transport? We use
855 * this to pick new active and retran paths.
857 ktime_t last_time_heard;
859 /* When was the last time that we sent a chunk using this
860 * transport? We use this to check for idle transports
862 unsigned long last_time_sent;
864 /* Last time(in jiffies) when cwnd is reduced due to the congestion
865 * indication based on ECNE chunk.
867 unsigned long last_time_ecne_reduced;
869 /* This is the max_retrans value for the transport and will
870 * be initialized from the assocs value. This can be changed
871 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
875 /* This is the partially failed retrans value for the transport
876 * and will be initialized from the assocs value. This can be changed
877 * using the SCTP_PEER_ADDR_THLDS socket option
880 /* PMTU : The current known path MTU. */
883 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
886 /* The number of times INIT has been sent on this transport. */
889 /* state : The current state of this destination,
890 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
894 /* These are the error stats for this destination. */
896 /* Error count : The current error count for this destination. */
897 unsigned short error_count;
899 /* Per : A timer used by each destination.
903 * [Everywhere else in the text this is called T3-rtx. -ed]
905 struct timer_list T3_rtx_timer;
907 /* Heartbeat timer is per destination. */
908 struct timer_list hb_timer;
910 /* Timer to handle ICMP proto unreachable envets */
911 struct timer_list proto_unreach_timer;
913 /* Timer to handler reconf chunk rtx */
914 struct timer_list reconf_timer;
916 /* Since we're using per-destination retransmission timers
917 * (see above), we're also using per-destination "transmitted"
918 * queues. This probably ought to be a private struct
919 * accessible only within the outqueue, but it's not, yet.
921 struct list_head transmitted;
923 /* We build bundle-able packets for this transport here. */
924 struct sctp_packet packet;
926 /* This is the list of transports that have chunks to send. */
927 struct list_head send_ready;
929 /* State information saved for SFR_CACC algorithm. The key
930 * idea in SFR_CACC is to maintain state at the sender on a
931 * per-destination basis when a changeover happens.
932 * char changeover_active;
933 * char cycling_changeover;
934 * __u32 next_tsn_at_change;
935 * char cacc_saw_newack;
938 /* An unsigned integer, which stores the next TSN to be
939 * used by the sender, at the moment of changeover.
941 __u32 next_tsn_at_change;
943 /* A flag which indicates the occurrence of a changeover */
944 char changeover_active;
946 /* A flag which indicates whether the change of primary is
947 * the first switch to this destination address during an
950 char cycling_changeover;
952 /* A temporary flag, which is used during the processing of
953 * a SACK to estimate the causative TSN(s)'s group.
955 char cacc_saw_newack;
958 /* 64-bit random number sent with heartbeat. */
964 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
966 void sctp_transport_set_owner(struct sctp_transport *,
967 struct sctp_association *);
968 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
970 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
971 void sctp_transport_free(struct sctp_transport *);
972 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
973 void sctp_transport_reset_hb_timer(struct sctp_transport *);
974 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
975 int sctp_transport_hold(struct sctp_transport *);
976 void sctp_transport_put(struct sctp_transport *);
977 void sctp_transport_update_rto(struct sctp_transport *, __u32);
978 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
979 void sctp_transport_lower_cwnd(struct sctp_transport *t,
980 enum sctp_lower_cwnd reason);
981 void sctp_transport_burst_limited(struct sctp_transport *);
982 void sctp_transport_burst_reset(struct sctp_transport *);
983 unsigned long sctp_transport_timeout(struct sctp_transport *);
984 void sctp_transport_reset(struct sctp_transport *t);
985 void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
986 void sctp_transport_immediate_rtx(struct sctp_transport *);
987 void sctp_transport_dst_release(struct sctp_transport *t);
988 void sctp_transport_dst_confirm(struct sctp_transport *t);
991 /* This is the structure we use to queue packets as they come into
992 * SCTP. We write packets to it and read chunks from it.
995 /* This is actually a queue of sctp_chunk each
996 * containing a partially decoded packet.
998 struct list_head in_chunk_list;
999 /* This is the packet which is currently off the in queue and is
1000 * being worked on through the inbound chunk processing.
1002 struct sctp_chunk *in_progress;
1004 /* This is the delayed task to finish delivering inbound
1007 struct work_struct immediate;
1010 void sctp_inq_init(struct sctp_inq *);
1011 void sctp_inq_free(struct sctp_inq *);
1012 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1013 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1014 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1015 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1017 /* This is the structure we use to hold outbound chunks. You push
1018 * chunks in and they automatically pop out the other end as bundled
1019 * packets (it calls (*output_handler)()).
1021 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1022 * and 8.2 of the v13 draft.
1024 * It handles retransmissions. The connection to the timeout portion
1025 * of the state machine is through sctp_..._timeout() and timeout_handler.
1027 * If you feed it SACKs, it will eat them.
1029 * If you give it big chunks, it will fragment them.
1031 * It assigns TSN's to data chunks. This happens at the last possible
1032 * instant before transmission.
1034 * When free()'d, it empties itself out via output_handler().
1037 struct sctp_association *asoc;
1039 /* Data pending that has never been transmitted. */
1040 struct list_head out_chunk_list;
1042 /* Stream scheduler being used */
1043 struct sctp_sched_ops *sched;
1045 unsigned int out_qlen; /* Total length of queued data chunks. */
1047 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1050 /* These are control chunks we want to send. */
1051 struct list_head control_chunk_list;
1053 /* These are chunks that have been sacked but are above the
1054 * CTSN, or cumulative tsn ack point.
1056 struct list_head sacked;
1058 /* Put chunks on this list to schedule them for
1061 struct list_head retransmit;
1063 /* Put chunks on this list to save them for FWD TSN processing as
1064 * they were abandoned.
1066 struct list_head abandoned;
1068 /* How many unackd bytes do we have in-flight? */
1069 __u32 outstanding_bytes;
1071 /* Are we doing fast-rtx on this queue */
1078 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1079 void sctp_outq_teardown(struct sctp_outq *);
1080 void sctp_outq_free(struct sctp_outq*);
1081 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1082 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1083 int sctp_outq_is_empty(const struct sctp_outq *);
1084 void sctp_outq_restart(struct sctp_outq *);
1086 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1087 enum sctp_retransmit_reason reason);
1088 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1089 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1090 void sctp_prsctp_prune(struct sctp_association *asoc,
1091 struct sctp_sndrcvinfo *sinfo, int msg_len);
1092 /* Uncork and flush an outqueue. */
1093 static inline void sctp_outq_cork(struct sctp_outq *q)
1098 /* SCTP skb control block.
1099 * sctp_input_cb is currently used on rx and sock rx queue
1101 struct sctp_input_cb {
1103 struct inet_skb_parm h4;
1104 #if IS_ENABLED(CONFIG_IPV6)
1105 struct inet6_skb_parm h6;
1108 struct sctp_chunk *chunk;
1111 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1113 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1115 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1117 return chunk->head_skb ? : skb;
1120 /* These bind address data fields common between endpoints and associations */
1121 struct sctp_bind_addr {
1123 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1125 * SCTP Port: The local SCTP port number the endpoint is
1130 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1132 * Address List: The list of IP addresses that this instance
1133 * has bound. This information is passed to one's
1134 * peer(s) in INIT and INIT ACK chunks.
1136 struct list_head address_list;
1139 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1140 void sctp_bind_addr_free(struct sctp_bind_addr *);
1141 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1142 const struct sctp_bind_addr *src,
1143 enum sctp_scope scope, gfp_t gfp,
1145 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1146 const struct sctp_bind_addr *src,
1148 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1149 int new_size, __u8 addr_state, gfp_t gfp);
1150 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1151 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1152 struct sctp_sock *);
1153 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1154 struct sctp_sock *, struct sctp_sock *);
1155 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1156 const union sctp_addr *addr);
1157 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1158 const union sctp_addr *addrs,
1160 struct sctp_sock *opt);
1161 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1164 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1165 __u16 port, gfp_t gfp);
1167 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1168 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1169 const enum sctp_scope scope);
1170 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1171 int sctp_is_ep_boundall(struct sock *sk);
1174 /* What type of endpoint? */
1175 enum sctp_endpoint_type {
1176 SCTP_EP_TYPE_SOCKET,
1177 SCTP_EP_TYPE_ASSOCIATION,
1181 * A common base class to bridge the implmentation view of a
1182 * socket (usually listening) endpoint versus an association's
1184 * This common structure is useful for several purposes:
1185 * 1) Common interface for lookup routines.
1186 * a) Subfunctions work for either endpoint or association
1187 * b) Single interface to lookup allows hiding the lookup lock rather
1188 * than acquiring it externally.
1189 * 2) Common interface for the inbound chunk handling/state machine.
1190 * 3) Common object handling routines for reference counting, etc.
1191 * 4) Disentangle association lookup from endpoint lookup, where we
1192 * do not have to find our endpoint to find our association.
1196 struct sctp_ep_common {
1197 /* Fields to help us manage our entries in the hash tables. */
1198 struct hlist_node node;
1201 /* Runtime type information. What kind of endpoint is this? */
1202 enum sctp_endpoint_type type;
1204 /* Some fields to help us manage this object.
1205 * refcnt - Reference count access to this object.
1206 * dead - Do not attempt to use this object.
1211 /* What socket does this endpoint belong to? */
1214 /* This is where we receive inbound chunks. */
1215 struct sctp_inq inqueue;
1217 /* This substructure includes the defining parameters of the
1219 * bind_addr.port is our shared port number.
1220 * bind_addr.address_list is our set of local IP addresses.
1222 struct sctp_bind_addr bind_addr;
1226 /* RFC Section 1.4 Key Terms
1228 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1229 * multi-homed host, an SCTP endpoint is represented to its peers as a
1230 * combination of a set of eligible destination transport addresses to
1231 * which SCTP packets can be sent and a set of eligible source
1232 * transport addresses from which SCTP packets can be received.
1233 * All transport addresses used by an SCTP endpoint must use the
1234 * same port number, but can use multiple IP addresses. A transport
1235 * address used by an SCTP endpoint must not be used by another
1236 * SCTP endpoint. In other words, a transport address is unique
1237 * to an SCTP endpoint.
1239 * From an implementation perspective, each socket has one of these.
1240 * A TCP-style socket will have exactly one association on one of
1241 * these. An UDP-style socket will have multiple associations hanging
1245 struct sctp_endpoint {
1246 /* Common substructure for endpoint and association. */
1247 struct sctp_ep_common base;
1249 /* Associations: A list of current associations and mappings
1250 * to the data consumers for each association. This
1251 * may be in the form of a hash table or other
1252 * implementation dependent structure. The data
1253 * consumers may be process identification
1254 * information such as file descriptors, named pipe
1255 * pointer, or table pointers dependent on how SCTP
1258 /* This is really a list of struct sctp_association entries. */
1259 struct list_head asocs;
1261 /* Secret Key: A secret key used by this endpoint to compute
1262 * the MAC. This SHOULD be a cryptographic quality
1263 * random number with a sufficient length.
1264 * Discussion in [RFC1750] can be helpful in
1265 * selection of the key.
1267 __u8 secret_key[SCTP_SECRET_SIZE];
1269 /* digest: This is a digest of the sctp cookie. This field is
1270 * only used on the receive path when we try to validate
1271 * that the cookie has not been tampered with. We put
1272 * this here so we pre-allocate this once and can re-use
1277 /* sendbuf acct. policy. */
1278 __u32 sndbuf_policy;
1280 /* rcvbuf acct. policy. */
1281 __u32 rcvbuf_policy;
1283 /* SCTP AUTH: array of the HMACs that will be allocated
1284 * we need this per association so that we don't serialize
1286 struct crypto_shash **auth_hmacs;
1288 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1289 struct sctp_hmac_algo_param *auth_hmacs_list;
1291 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1292 struct sctp_chunks_param *auth_chunk_list;
1294 /* SCTP-AUTH: endpoint shared keys */
1295 struct list_head endpoint_shared_keys;
1296 __u16 active_key_id;
1301 __u8 strreset_enable;
1304 /* Recover the outter endpoint structure. */
1305 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1307 struct sctp_endpoint *ep;
1309 ep = container_of(base, struct sctp_endpoint, base);
1313 /* These are function signatures for manipulating endpoints. */
1314 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1315 void sctp_endpoint_free(struct sctp_endpoint *);
1316 void sctp_endpoint_put(struct sctp_endpoint *);
1317 void sctp_endpoint_hold(struct sctp_endpoint *);
1318 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1319 struct sctp_association *sctp_endpoint_lookup_assoc(
1320 const struct sctp_endpoint *ep,
1321 const union sctp_addr *paddr,
1322 struct sctp_transport **);
1323 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1324 const union sctp_addr *);
1325 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1326 struct net *, const union sctp_addr *);
1327 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1328 const union sctp_addr *paddr);
1330 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1331 const struct sctp_association *asoc,
1332 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1333 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1334 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1335 const union sctp_addr *peer,
1336 struct sctp_init_chunk *init, gfp_t gfp);
1337 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1338 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1340 struct sctp_inithdr_host {
1343 __u16 num_outbound_streams;
1344 __u16 num_inbound_streams;
1348 struct sctp_stream_priorities {
1349 /* List of priorities scheduled */
1350 struct list_head prio_sched;
1351 /* List of streams scheduled */
1352 struct list_head active;
1353 /* The next stream stream in line */
1354 struct sctp_stream_out_ext *next;
1358 struct sctp_stream_out_ext {
1359 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1360 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1361 struct list_head outq; /* chunks enqueued by this stream */
1364 /* Scheduled streams list */
1365 struct list_head prio_list;
1366 struct sctp_stream_priorities *prio_head;
1368 /* Fields used by RR scheduler */
1370 struct list_head rr_list;
1375 struct sctp_stream_out {
1381 struct sctp_stream_out_ext *ext;
1384 struct sctp_stream_in {
1392 struct sctp_stream {
1393 struct sctp_stream_out *out;
1394 struct sctp_stream_in *in;
1397 /* Current stream being sent, if any */
1398 struct sctp_stream_out *out_curr;
1400 /* Fields used by priority scheduler */
1402 /* List of priorities scheduled */
1403 struct list_head prio_list;
1405 /* Fields used by RR scheduler */
1407 /* List of streams scheduled */
1408 struct list_head rr_list;
1409 /* The next stream stream in line */
1410 struct sctp_stream_out_ext *rr_next;
1413 struct sctp_stream_interleave *si;
1416 #define SCTP_STREAM_CLOSED 0x00
1417 #define SCTP_STREAM_OPEN 0x01
1419 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1421 return stream->si->data_chunk_len;
1424 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1426 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1429 /* SCTP_GET_ASSOC_STATS counters */
1430 struct sctp_priv_assoc_stats {
1431 /* Maximum observed rto in the association during subsequent
1432 * observations. Value is set to 0 if no RTO measurement took place
1433 * The transport where the max_rto was observed is returned in
1436 struct sockaddr_storage obs_rto_ipaddr;
1438 /* Total In and Out SACKs received and sent */
1441 /* Total In and Out packets received and sent */
1444 /* Total retransmitted chunks */
1446 /* TSN received > next expected */
1448 /* Duplicate Chunks received */
1450 /* Gap Ack Blocks received */
1452 /* Unordered data chunks sent and received */
1455 /* Ordered data chunks sent and received */
1458 /* Control chunks sent and received */
1465 * 12. Recommended Transmission Control Block (TCB) Parameters
1467 * This section details a recommended set of parameters that should
1468 * be contained within the TCB for an implementation. This section is
1469 * for illustrative purposes and should not be deemed as requirements
1470 * on an implementation or as an exhaustive list of all parameters
1471 * inside an SCTP TCB. Each implementation may need its own additional
1472 * parameters for optimization.
1476 /* Here we have information about each individual association. */
1477 struct sctp_association {
1479 /* A base structure common to endpoint and association.
1480 * In this context, it represents the associations's view
1481 * of the local endpoint of the association.
1483 struct sctp_ep_common base;
1485 /* Associations on the same socket. */
1486 struct list_head asocs;
1488 /* association id. */
1489 sctp_assoc_t assoc_id;
1491 /* This is our parent endpoint. */
1492 struct sctp_endpoint *ep;
1494 /* These are those association elements needed in the cookie. */
1495 struct sctp_cookie c;
1497 /* This is all information about our peer. */
1499 /* transport_addr_list
1501 * Peer : A list of SCTP transport addresses that the
1502 * Transport : peer is bound to. This information is derived
1503 * Address : from the INIT or INIT ACK and is used to
1504 * List : associate an inbound packet with a given
1505 * : association. Normally this information is
1506 * : hashed or keyed for quick lookup and access
1508 * : The list is also initialized with the list
1509 * : of addresses passed with the sctp_connectx()
1512 * It is a list of SCTP_transport's.
1514 struct list_head transport_addr_list;
1518 * Peer Rwnd : Current calculated value of the peer's rwnd.
1524 * Peer : A count of the number of peer addresses
1525 * Transport : in the Peer Transport Address List.
1529 __u16 transport_count;
1532 * The transport layer port number.
1538 * Primary : This is the current primary destination
1539 * Path : transport address of the peer endpoint. It
1540 * : may also specify a source transport address
1541 * : on this endpoint.
1543 * All of these paths live on transport_addr_list.
1545 * At the bakeoffs, we discovered that the intent of
1546 * primaryPath is that it only changes when the ULP
1547 * asks to have it changed. We add the activePath to
1548 * designate the connection we are currently using to
1549 * transmit new data and most control chunks.
1551 struct sctp_transport *primary_path;
1553 /* Cache the primary path address here, when we
1554 * need a an address for msg_name.
1556 union sctp_addr primary_addr;
1559 * The path that we are currently using to
1560 * transmit new data and most control chunks.
1562 struct sctp_transport *active_path;
1566 * RFC2960 6.4 Multi-homed SCTP Endpoints
1568 * Furthermore, when its peer is multi-homed, an
1569 * endpoint SHOULD try to retransmit a chunk to an
1570 * active destination transport address that is
1571 * different from the last destination address to
1572 * which the DATA chunk was sent.
1574 struct sctp_transport *retran_path;
1576 /* Pointer to last transport I have sent on. */
1577 struct sctp_transport *last_sent_to;
1579 /* This is the last transport I have received DATA on. */
1580 struct sctp_transport *last_data_from;
1583 * Mapping An array of bits or bytes indicating which out of
1584 * Array order TSN's have been received (relative to the
1585 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1586 * order packets have been received, this array
1587 * will be set to all zero. This structure may be
1588 * in the form of a circular buffer or bit array.
1590 * Last Rcvd : This is the last TSN received in
1591 * TSN : sequence. This value is set initially by
1592 * : taking the peer's Initial TSN, received in
1593 * : the INIT or INIT ACK chunk, and subtracting
1596 * Throughout most of the specification this is called the
1597 * "Cumulative TSN ACK Point". In this case, we
1598 * ignore the advice in 12.2 in favour of the term
1599 * used in the bulk of the text. This value is hidden
1600 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1602 struct sctp_tsnmap tsn_map;
1604 /* This mask is used to disable sending the ASCONF chunk
1605 * with specified parameter to peer.
1607 __be16 addip_disabled_mask;
1609 /* These are capabilities which our peer advertised. */
1610 __u8 ecn_capable:1, /* Can peer do ECN? */
1611 ipv4_address:1, /* Peer understands IPv4 addresses? */
1612 ipv6_address:1, /* Peer understands IPv6 addresses? */
1613 hostname_address:1, /* Peer understands DNS addresses? */
1614 asconf_capable:1, /* Does peer support ADDIP? */
1615 prsctp_capable:1, /* Can peer do PR-SCTP? */
1616 reconf_capable:1, /* Can peer do RE-CONFIG? */
1617 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1619 /* sack_needed : This flag indicates if the next received
1620 * : packet is to be responded to with a
1621 * : SACK. This is initialized to 0. When a packet
1622 * : is received sack_cnt is incremented. If this value
1623 * : reaches 2 or more, a SACK is sent and the
1624 * : value is reset to 0. Note: This is used only
1625 * : when no DATA chunks are received out of
1626 * : order. When DATA chunks are out of order,
1627 * : SACK's are not delayed (see Section 6).
1629 __u8 sack_needed:1, /* Do we need to sack the peer? */
1631 zero_window_announced:1;
1634 __u32 adaptation_ind; /* Adaptation Code point. */
1636 struct sctp_inithdr_host i;
1640 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1641 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1642 * Initial TSN Value minus 1
1646 /* SCTP-AUTH: We need to know pears random number, hmac list
1647 * and authenticated chunk list. All that is part of the
1648 * cookie and these are just pointers to those locations
1650 struct sctp_random_param *peer_random;
1651 struct sctp_chunks_param *peer_chunks;
1652 struct sctp_hmac_algo_param *peer_hmacs;
1655 /* State : A state variable indicating what state the
1656 * : association is in, i.e. COOKIE-WAIT,
1657 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1658 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1660 * Note: No "CLOSED" state is illustrated since if a
1661 * association is "CLOSED" its TCB SHOULD be removed.
1663 * In this implementation we DO have a CLOSED
1664 * state which is used during initiation and shutdown.
1666 * State takes values from SCTP_STATE_*.
1668 enum sctp_state state;
1670 /* Overall : The overall association error count.
1671 * Error Count : [Clear this any time I get something.]
1673 int overall_error_count;
1675 /* The cookie life I award for any cookie. */
1676 ktime_t cookie_life;
1678 /* These are the association's initial, max, and min RTO values.
1679 * These values will be initialized by system defaults, but can
1680 * be modified via the SCTP_RTOINFO socket option.
1682 unsigned long rto_initial;
1683 unsigned long rto_max;
1684 unsigned long rto_min;
1686 /* Maximum number of new data packets that can be sent in a burst. */
1689 /* This is the max_retrans value for the association. This value will
1690 * be initialized initialized from system defaults, but can be
1691 * modified by the SCTP_ASSOCINFO socket option.
1695 /* This is the partially failed retrans value for the transport
1696 * and will be initialized from the assocs value. This can be
1697 * changed using the SCTP_PEER_ADDR_THLDS socket option
1701 /* Maximum number of times the endpoint will retransmit INIT */
1702 __u16 max_init_attempts;
1704 /* How many times have we resent an INIT? */
1707 /* The largest timeout or RTO value to use in attempting an INIT */
1708 unsigned long max_init_timeo;
1710 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1711 * the destination address every heartbeat interval. This value
1712 * will be inherited by all new transports.
1714 unsigned long hbinterval;
1716 /* This is the max_retrans value for new transports in the
1721 /* Flag that path mtu update is pending */
1724 /* Association : The smallest PMTU discovered for all of the
1725 * PMTU : peer's transport addresses.
1729 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1733 /* SACK delay timeout */
1734 unsigned long sackdelay;
1736 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1737 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1739 /* Transport to which SHUTDOWN chunk was last sent. */
1740 struct sctp_transport *shutdown_last_sent_to;
1742 /* Transport to which INIT chunk was last sent. */
1743 struct sctp_transport *init_last_sent_to;
1745 /* How many times have we resent a SHUTDOWN */
1746 int shutdown_retries;
1748 /* Next TSN : The next TSN number to be assigned to a new
1749 * : DATA chunk. This is sent in the INIT or INIT
1750 * : ACK chunk to the peer and incremented each
1751 * : time a DATA chunk is assigned a TSN
1752 * : (normally just prior to transmit or during
1758 * Last Rcvd : This is the last TSN received in sequence. This value
1759 * TSN : is set initially by taking the peer's Initial TSN,
1760 * : received in the INIT or INIT ACK chunk, and
1761 * : subtracting one from it.
1763 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1766 __u32 ctsn_ack_point;
1768 /* PR-SCTP Advanced.Peer.Ack.Point */
1769 __u32 adv_peer_ack_point;
1771 /* Highest TSN that is acknowledged by incoming SACKs. */
1772 __u32 highest_sacked;
1774 /* TSN marking the fast recovery exit point */
1775 __u32 fast_recovery_exit;
1777 /* Flag to track the current fast recovery state */
1780 /* The number of unacknowledged data chunks. Reported through
1781 * the SCTP_STATUS sockopt.
1785 /* The total number of data chunks that we've had to retransmit
1786 * as the result of a T3 timer expiration
1788 __u32 rtx_data_chunks;
1790 /* This is the association's receive buffer space. This value is used
1791 * to set a_rwnd field in an INIT or a SACK chunk.
1795 /* This is the last advertised value of rwnd over a SACK chunk. */
1798 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1799 * to slop over a maximum of the association's frag_point.
1803 /* Keeps treack of rwnd pressure. This happens when we have
1804 * a window, but not recevie buffer (i.e small packets). This one
1805 * is releases slowly (1 PMTU at a time ).
1809 /* This is the sndbuf size in use for the association.
1810 * This corresponds to the sndbuf size for the association,
1811 * as specified in the sk->sndbuf.
1815 /* This is the amount of memory that this association has allocated
1816 * in the receive path at any given time.
1818 atomic_t rmem_alloc;
1820 /* This is the wait queue head for send requests waiting on
1821 * the association sndbuf space.
1823 wait_queue_head_t wait;
1825 /* The message size at which SCTP fragmentation will occur. */
1829 /* Counter used to count INIT errors. */
1830 int init_err_counter;
1832 /* Count the number of INIT cycles (for doubling timeout). */
1835 /* Default send parameters. */
1836 __u16 default_stream;
1837 __u16 default_flags;
1839 __u32 default_context;
1840 __u32 default_timetolive;
1842 /* Default receive parameters */
1843 __u32 default_rcv_context;
1846 struct sctp_stream stream;
1848 /* All outbound chunks go through this structure. */
1849 struct sctp_outq outqueue;
1851 /* A smart pipe that will handle reordering and fragmentation,
1852 * as well as handle passing events up to the ULP.
1854 struct sctp_ulpq ulpq;
1856 /* Last TSN that caused an ECNE Chunk to be sent. */
1857 __u32 last_ecne_tsn;
1859 /* Last TSN that caused a CWR Chunk to be sent. */
1862 /* How many duplicated TSNs have we seen? */
1865 /* These are to support
1866 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1867 * and Enforcement of Flow and Message Limits"
1868 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1869 * or "ADDIP" for short.
1874 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1876 * R1) One and only one ASCONF Chunk MAY be in transit and
1877 * unacknowledged at any one time. If a sender, after sending
1878 * an ASCONF chunk, decides it needs to transfer another
1879 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1880 * returns from the previous ASCONF Chunk before sending a
1881 * subsequent ASCONF. Note this restriction binds each side,
1882 * so at any time two ASCONF may be in-transit on any given
1883 * association (one sent from each endpoint).
1885 * [This is our one-and-only-one ASCONF in flight. If we do
1886 * not have an ASCONF in flight, this is NULL.]
1888 struct sctp_chunk *addip_last_asconf;
1890 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1892 * This is needed to implement itmes E1 - E4 of the updated
1893 * spec. Here is the justification:
1895 * Since the peer may bundle multiple ASCONF chunks toward us,
1896 * we now need the ability to cache multiple ACKs. The section
1897 * describes in detail how they are cached and cleaned up.
1899 struct list_head asconf_ack_list;
1901 /* These ASCONF chunks are waiting to be sent.
1903 * These chunaks can't be pushed to outqueue until receiving
1904 * ASCONF_ACK for the previous ASCONF indicated by
1905 * addip_last_asconf, so as to guarantee that only one ASCONF
1906 * is in flight at any time.
1908 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1910 * In defining the ASCONF Chunk transfer procedures, it is
1911 * essential that these transfers MUST NOT cause congestion
1912 * within the network. To achieve this, we place these
1913 * restrictions on the transfer of ASCONF Chunks:
1915 * R1) One and only one ASCONF Chunk MAY be in transit and
1916 * unacknowledged at any one time. If a sender, after sending
1917 * an ASCONF chunk, decides it needs to transfer another
1918 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1919 * returns from the previous ASCONF Chunk before sending a
1920 * subsequent ASCONF. Note this restriction binds each side,
1921 * so at any time two ASCONF may be in-transit on any given
1922 * association (one sent from each endpoint).
1925 * [I really think this is EXACTLY the sort of intelligence
1926 * which already resides in sctp_outq. Please move this
1927 * queue and its supporting logic down there. --piggy]
1929 struct list_head addip_chunk_list;
1931 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1933 * A2) A serial number should be assigned to the Chunk. The
1934 * serial number SHOULD be a monotonically increasing
1935 * number. The serial number SHOULD be initialized at
1936 * the start of the association to the same value as the
1937 * Initial TSN and every time a new ASCONF chunk is created
1938 * it is incremented by one after assigning the serial number
1939 * to the newly created chunk.
1942 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1944 * Serial Number : 32 bits (unsigned integer)
1946 * This value represents a Serial Number for the ASCONF
1947 * Chunk. The valid range of Serial Number is from 0 to
1948 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1949 * after reaching 4294967295.
1952 int src_out_of_asoc_ok;
1953 union sctp_addr *asconf_addr_del_pending;
1954 struct sctp_transport *new_transport;
1956 /* SCTP AUTH: list of the endpoint shared keys. These
1957 * keys are provided out of band by the user applicaton
1958 * and can't change during the lifetime of the association
1960 struct list_head endpoint_shared_keys;
1963 * The current generated assocaition shared key (secret)
1965 struct sctp_auth_bytes *asoc_shared_key;
1967 /* SCTP AUTH: hmac id of the first peer requested algorithm
1970 __u16 default_hmac_id;
1972 __u16 active_key_id;
1974 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1975 temp:1, /* Is it a temporary association? */
1981 __u8 strreset_enable;
1982 __u8 strreset_outstanding; /* request param count on the fly */
1984 __u32 strreset_outseq; /* Update after receiving response */
1985 __u32 strreset_inseq; /* Update after receiving request */
1986 __u32 strreset_result[2]; /* save the results of last 2 responses */
1988 struct sctp_chunk *strreset_chunk; /* save request chunk */
1990 struct sctp_priv_assoc_stats stats;
1992 int sent_cnt_removable;
1994 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1995 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1999 /* An eyecatcher for determining if we are really looking at an
2000 * association data structure.
2003 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2006 /* Recover the outter association structure. */
2007 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2009 struct sctp_association *asoc;
2011 asoc = container_of(base, struct sctp_association, base);
2015 /* These are function signatures for manipulating associations. */
2018 struct sctp_association *
2019 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2020 enum sctp_scope scope, gfp_t gfp);
2021 void sctp_association_free(struct sctp_association *);
2022 void sctp_association_put(struct sctp_association *);
2023 void sctp_association_hold(struct sctp_association *);
2025 struct sctp_transport *sctp_assoc_choose_alter_transport(
2026 struct sctp_association *, struct sctp_transport *);
2027 void sctp_assoc_update_retran_path(struct sctp_association *);
2028 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2029 const union sctp_addr *);
2030 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2031 const union sctp_addr *laddr);
2032 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2033 const union sctp_addr *address,
2035 const int peer_state);
2036 void sctp_assoc_del_peer(struct sctp_association *asoc,
2037 const union sctp_addr *addr);
2038 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2039 struct sctp_transport *peer);
2040 void sctp_assoc_control_transport(struct sctp_association *asoc,
2041 struct sctp_transport *transport,
2042 enum sctp_transport_cmd command,
2043 sctp_sn_error_t error);
2044 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2045 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
2047 const union sctp_addr *,
2048 const union sctp_addr *);
2049 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2050 int sctp_assoc_update(struct sctp_association *old,
2051 struct sctp_association *new);
2053 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2055 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2056 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2057 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2058 void sctp_assoc_set_primary(struct sctp_association *,
2059 struct sctp_transport *);
2060 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2061 struct sctp_transport *);
2062 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2063 enum sctp_scope scope, gfp_t gfp);
2064 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2065 struct sctp_cookie*,
2067 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2068 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2069 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2070 const struct sctp_association *asoc,
2072 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2074 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2075 const union sctp_addr *ss2);
2076 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2078 /* A convenience structure to parse out SCTP specific CMSGs. */
2080 struct sctp_initmsg *init;
2081 struct sctp_sndrcvinfo *srinfo;
2082 struct sctp_sndinfo *sinfo;
2085 /* Structure for tracking memory objects */
2086 struct sctp_dbg_objcnt_entry {
2091 #endif /* __sctp_structs_h__ */