1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
7 * This file is part of the SCTP kernel implementation
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, see
23 * <http://www.gnu.org/licenses/>.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <linux-sctp@vger.kernel.org>
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
50 #include <linux/ktime.h>
51 #include <linux/rhashtable.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/sctp.h> /* We need sctp* header structs. */
61 #include <net/sctp/auth.h> /* We need auth specific structs */
62 #include <net/ip.h> /* For inet_skb_parm */
64 /* A convenience structure for handling sockaddr structures.
65 * We should wean ourselves off this.
68 struct sockaddr_in v4;
69 struct sockaddr_in6 v6;
73 /* Forward declarations for data structures. */
76 struct sctp_association;
77 struct sctp_transport;
82 struct sctp_bind_addr;
84 struct sctp_ep_common;
89 #include <net/sctp/tsnmap.h>
90 #include <net/sctp/ulpevent.h>
91 #include <net/sctp/ulpqueue.h>
93 /* Structures useful for managing bind/connect. */
95 struct sctp_bind_bucket {
97 unsigned short fastreuse;
98 struct hlist_node node;
99 struct hlist_head owner;
103 struct sctp_bind_hashbucket {
105 struct hlist_head chain;
108 /* Used for hashing all associations. */
109 struct sctp_hashbucket {
111 struct hlist_head chain;
112 } __attribute__((__aligned__(8)));
115 /* The SCTP globals structure. */
116 extern struct sctp_globals {
117 /* This is a list of groups of functions for each address
118 * family that we support.
120 struct list_head address_families;
122 /* This is the hash of all endpoints. */
123 struct sctp_hashbucket *ep_hashtable;
124 /* This is the sctp port control hash. */
125 struct sctp_bind_hashbucket *port_hashtable;
126 /* This is the hash of all transports. */
127 struct rhltable transport_hashtable;
129 /* Sizes of above hashtables. */
133 /* Default initialization values to be applied to new associations. */
135 __u16 max_outstreams;
137 /* Flag to indicate whether computing and verifying checksum
139 bool checksum_disable;
142 #define sctp_max_instreams (sctp_globals.max_instreams)
143 #define sctp_max_outstreams (sctp_globals.max_outstreams)
144 #define sctp_address_families (sctp_globals.address_families)
145 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
146 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
147 #define sctp_port_hashsize (sctp_globals.port_hashsize)
148 #define sctp_port_hashtable (sctp_globals.port_hashtable)
149 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
150 #define sctp_checksum_disable (sctp_globals.checksum_disable)
152 /* SCTP Socket type: UDP or TCP style. */
155 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
157 } sctp_socket_type_t;
159 /* Per socket SCTP information. */
161 /* inet_sock has to be the first member of sctp_sock */
162 struct inet_sock inet;
163 /* What kind of a socket is this? */
164 sctp_socket_type_t type;
166 /* PF_ family specific functions. */
169 /* Access to HMAC transform. */
170 struct crypto_shash *hmac;
173 /* What is our base endpointer? */
174 struct sctp_endpoint *ep;
176 struct sctp_bind_bucket *bind_hash;
177 /* Various Socket Options. */
178 __u16 default_stream;
181 __u32 default_context;
182 __u32 default_timetolive;
183 __u32 default_rcv_context;
186 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
187 * the destination address every heartbeat interval. This value
188 * will be inherited by all new associations.
192 /* This is the max_retrans value for new associations. */
195 /* The initial Path MTU to use for new associations. */
198 /* The default SACK delay timeout for new associations. */
202 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
205 struct sctp_initmsg initmsg;
206 struct sctp_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_event_subscribe subscribe;
209 struct sctp_assocparams assocparams;
214 __u32 adaptation_ind;
222 data_ready_signalled:1;
225 /* Receive to here while partial delivery is in effect. */
226 struct sk_buff_head pd_lobby;
228 /* These must be the last fields, as they will skipped on copies,
229 * like on accept and peeloff operations
231 struct list_head auto_asconf_list;
235 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
237 return (struct sctp_sock *)sk;
240 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
242 return (struct sock *)sp;
245 #if IS_ENABLED(CONFIG_IPV6)
247 struct sctp_sock sctp;
248 struct ipv6_pinfo inet6;
250 #endif /* CONFIG_IPV6 */
253 /* This is our APPLICATION-SPECIFIC state cookie.
254 * THIS IS NOT DICTATED BY THE SPECIFICATION.
256 /* These are the parts of an association which we send in the cookie.
257 * Most of these are straight out of:
258 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
264 /* My : Tag expected in every inbound packet and sent
265 * Verification: in the INIT or INIT ACK chunk.
270 /* Peer's : Tag expected in every outbound packet except
271 * Verification: in the INIT chunk.
276 /* The rest of these are not from the spec, but really need to
280 /* My Tie Tag : Assist in discovering a restarting association. */
283 /* Peer's Tie Tag: Assist in discovering a restarting association. */
286 /* When does this cookie expire? */
289 /* Number of inbound/outbound streams which are set
290 * and negotiated during the INIT process.
292 __u16 sinit_num_ostreams;
293 __u16 sinit_max_instreams;
295 /* This is the first sequence number I used. */
298 /* This holds the originating address of the INIT packet. */
299 union sctp_addr peer_addr;
302 * Include the source port of the INIT-ACK
308 /* Padding for future use */
311 __u32 adaptation_ind;
313 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
314 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
315 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
317 /* This is a shim for my peer's INIT packet, followed by
318 * a copy of the raw address list of the association.
319 * The length of the raw address list is saved in the
320 * raw_addr_list_len field, which will be used at the time when
321 * the association TCB is re-constructed from the cookie.
323 __u32 raw_addr_list_len;
324 struct sctp_init_chunk peer_init[0];
328 /* The format of our cookie that we send to our peer. */
329 struct sctp_signed_cookie {
330 __u8 signature[SCTP_SECRET_SIZE];
331 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
332 struct sctp_cookie c;
335 /* This is another convenience type to allocate memory for address
336 * params for the maximum size and pass such structures around
339 union sctp_addr_param {
340 struct sctp_paramhdr p;
341 struct sctp_ipv4addr_param v4;
342 struct sctp_ipv6addr_param v6;
345 /* A convenience type to allow walking through the various
346 * parameters and avoid casting all over the place.
350 struct sctp_paramhdr *p;
351 struct sctp_cookie_preserve_param *life;
352 struct sctp_hostname_param *dns;
353 struct sctp_cookie_param *cookie;
354 struct sctp_supported_addrs_param *sat;
355 struct sctp_ipv4addr_param *v4;
356 struct sctp_ipv6addr_param *v6;
357 union sctp_addr_param *addr;
358 struct sctp_adaptation_ind_param *aind;
359 struct sctp_supported_ext_param *ext;
360 struct sctp_random_param *random;
361 struct sctp_chunks_param *chunks;
362 struct sctp_hmac_algo_param *hmac_algo;
363 struct sctp_addip_param *addip;
366 /* RFC 2960. Section 3.3.5 Heartbeat.
367 * Heartbeat Information: variable length
368 * The Sender-specific Heartbeat Info field should normally include
369 * information about the sender's current time when this HEARTBEAT
370 * chunk is sent and the destination transport address to which this
371 * HEARTBEAT is sent (see Section 8.3).
373 typedef struct sctp_sender_hb_info {
374 struct sctp_paramhdr param_hdr;
375 union sctp_addr daddr;
376 unsigned long sent_at;
378 } __packed sctp_sender_hb_info_t;
381 * RFC 2960 1.3.2 Sequenced Delivery within Streams
383 * The term "stream" is used in SCTP to refer to a sequence of user
384 * messages that are to be delivered to the upper-layer protocol in
385 * order with respect to other messages within the same stream. This is
386 * in contrast to its usage in TCP, where it refers to a sequence of
387 * bytes (in this document a byte is assumed to be eight bits).
390 * This is the structure we use to track both our outbound and inbound
391 * SSN, or Stream Sequence Numbers.
400 struct sctp_stream in;
401 struct sctp_stream out;
404 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
406 void sctp_ssnmap_free(struct sctp_ssnmap *map);
407 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
409 /* What is the current SSN number for this stream? */
410 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
412 return stream->ssn[id];
415 /* Return the next SSN number for this stream. */
416 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
418 return stream->ssn[id]++;
421 /* Skip over this ssn and all below. */
422 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
425 stream->ssn[id] = ssn+1;
429 * Pointers to address related SCTP functions.
430 * (i.e. things that depend on the address family.)
433 int (*sctp_xmit) (struct sk_buff *skb,
434 struct sctp_transport *);
435 int (*setsockopt) (struct sock *sk,
439 unsigned int optlen);
440 int (*getsockopt) (struct sock *sk,
445 int (*compat_setsockopt) (struct sock *sk,
449 unsigned int optlen);
450 int (*compat_getsockopt) (struct sock *sk,
455 void (*get_dst) (struct sctp_transport *t,
456 union sctp_addr *saddr,
459 void (*get_saddr) (struct sctp_sock *sk,
460 struct sctp_transport *t,
462 void (*copy_addrlist) (struct list_head *,
463 struct net_device *);
464 int (*cmp_addr) (const union sctp_addr *addr1,
465 const union sctp_addr *addr2);
466 void (*addr_copy) (union sctp_addr *dst,
467 union sctp_addr *src);
468 void (*from_skb) (union sctp_addr *,
471 void (*from_sk) (union sctp_addr *,
473 void (*from_addr_param) (union sctp_addr *,
474 union sctp_addr_param *,
475 __be16 port, int iif);
476 int (*to_addr_param) (const union sctp_addr *,
477 union sctp_addr_param *);
478 int (*addr_valid) (union sctp_addr *,
480 const struct sk_buff *);
481 sctp_scope_t (*scope) (union sctp_addr *);
482 void (*inaddr_any) (union sctp_addr *, __be16);
483 int (*is_any) (const union sctp_addr *);
484 int (*available) (union sctp_addr *,
486 int (*skb_iif) (const struct sk_buff *sk);
487 int (*is_ce) (const struct sk_buff *sk);
488 void (*seq_dump_addr)(struct seq_file *seq,
489 union sctp_addr *addr);
490 void (*ecn_capable)(struct sock *sk);
491 __u16 net_header_len;
493 sa_family_t sa_family;
494 struct list_head list;
497 struct sctp_af *sctp_get_af_specific(sa_family_t);
498 int sctp_register_af(struct sctp_af *);
500 /* Protocol family functions. */
502 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
503 void (*skb_msgname) (struct sk_buff *, char *, int *);
504 int (*af_supported) (sa_family_t, struct sctp_sock *);
505 int (*cmp_addr) (const union sctp_addr *,
506 const union sctp_addr *,
508 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
509 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
510 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
511 struct sock *(*create_accept_sk) (struct sock *sk,
512 struct sctp_association *asoc);
513 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
514 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
515 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
520 /* Structure to track chunk fragments that have been acked, but peer
521 * fragments of the same message have not.
523 struct sctp_datamsg {
524 /* Chunks waiting to be submitted to lower layer. */
525 struct list_head chunks;
526 /* Reference counting. */
528 /* When is this message no longer interesting to the peer? */
529 unsigned long expires_at;
530 /* Did the messenge fail to send? */
533 can_delay; /* should this message be Nagle delayed */
536 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
537 struct sctp_sndrcvinfo *,
539 void sctp_datamsg_free(struct sctp_datamsg *);
540 void sctp_datamsg_put(struct sctp_datamsg *);
541 void sctp_chunk_fail(struct sctp_chunk *, int error);
542 int sctp_chunk_abandoned(struct sctp_chunk *);
544 /* RFC2960 1.4 Key Terms
546 * o Chunk: A unit of information within an SCTP packet, consisting of
547 * a chunk header and chunk-specific content.
549 * As a matter of convenience, we remember the SCTP common header for
550 * each chunk as well as a few other header pointers...
553 struct list_head list;
557 /* How many times this chunk have been sent, for prsctp RTX policy */
560 /* This is our link to the per-transport transmitted list. */
561 struct list_head transmitted_list;
563 /* This field is used by chunks that hold fragmented data.
564 * For the first fragment this is the list that holds the rest of
565 * fragments. For the remaining fragments, this is the link to the
566 * frag_list maintained in the first fragment.
568 struct list_head frag_list;
570 /* This points to the sk_buff containing the actual data. */
573 /* In case of GSO packets, this will store the head one */
574 struct sk_buff *head_skb;
576 /* These are the SCTP headers by reverse order in a packet.
577 * Note that some of these may happen more than once. In that
578 * case, we point at the "current" one, whatever that means
579 * for that level of header.
582 /* We point this at the FIRST TLV parameter to chunk_hdr. */
583 union sctp_params param_hdr;
586 struct sctp_datahdr *data_hdr;
587 struct sctp_inithdr *init_hdr;
588 struct sctp_sackhdr *sack_hdr;
589 struct sctp_heartbeathdr *hb_hdr;
590 struct sctp_sender_hb_info *hbs_hdr;
591 struct sctp_shutdownhdr *shutdown_hdr;
592 struct sctp_signed_cookie *cookie_hdr;
593 struct sctp_ecnehdr *ecne_hdr;
594 struct sctp_cwrhdr *ecn_cwr_hdr;
595 struct sctp_errhdr *err_hdr;
596 struct sctp_addiphdr *addip_hdr;
597 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
598 struct sctp_authhdr *auth_hdr;
603 struct sctp_chunkhdr *chunk_hdr;
604 struct sctphdr *sctp_hdr;
606 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
607 struct sctp_sndrcvinfo sinfo;
609 /* Which association does this belong to? */
610 struct sctp_association *asoc;
612 /* What endpoint received this chunk? */
613 struct sctp_ep_common *rcvr;
615 /* We fill this in if we are calculating RTT. */
616 unsigned long sent_at;
618 /* What is the origin IP address for this chunk? */
619 union sctp_addr source;
620 /* Destination address for this chunk. */
621 union sctp_addr dest;
623 /* For outbound message, track all fragments for SEND_FAILED. */
624 struct sctp_datamsg *msg;
626 /* For an inbound chunk, this tells us where it came from.
627 * For an outbound chunk, it tells us where we'd like it to
628 * go. It is NULL if we have no preference.
630 struct sctp_transport *transport;
632 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
633 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
634 * spec violates the principle premis that all chunks are processed
637 struct sk_buff *auth_chunk;
639 #define SCTP_CAN_FRTX 0x0
640 #define SCTP_NEED_FRTX 0x1
641 #define SCTP_DONT_FRTX 0x2
642 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
643 has_tsn:1, /* Does this chunk have a TSN yet? */
644 has_ssn:1, /* Does this chunk have a SSN yet? */
645 singleton:1, /* Only chunk in the packet? */
646 end_of_packet:1, /* Last chunk in the packet? */
647 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
648 pdiscard:1, /* Discard the whole packet now? */
649 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
650 data_accepted:1, /* At least 1 chunk accepted */
651 auth:1, /* IN: was auth'ed | OUT: needs auth */
652 has_asconf:1, /* IN: have seen an asconf before */
653 tsn_missing_report:2, /* Data chunk missing counter. */
654 fast_retransmit:2; /* Is this chunk fast retransmitted? */
657 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
658 void sctp_chunk_hold(struct sctp_chunk *);
659 void sctp_chunk_put(struct sctp_chunk *);
660 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
661 struct iov_iter *from);
662 void sctp_chunk_free(struct sctp_chunk *);
663 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
664 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
665 const struct sctp_association *,
666 struct sock *, gfp_t gfp);
667 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
669 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
672 SCTP_ADDR_NEW, /* new address added to assoc/ep */
673 SCTP_ADDR_SRC, /* address can be used as source */
674 SCTP_ADDR_DEL, /* address about to be deleted */
677 /* This is a structure for holding either an IPv6 or an IPv4 address. */
678 struct sctp_sockaddr_entry {
679 struct list_head list;
686 #define SCTP_ADDRESS_TICK_DELAY 500
688 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
690 /* This structure holds lists of chunks as we are assembling for
694 /* These are the SCTP header values (host order) for the packet. */
696 __u16 destination_port;
699 /* This contains the payload chunks. */
700 struct list_head chunk_list;
702 /* This is the overhead of the sctp and ip headers. */
704 /* This is the total size of all chunks INCLUDING padding. */
706 /* This is the maximum size this packet may have */
709 /* The packet is destined for this transport address.
710 * The function we finally use to pass down to the next lower
711 * layer lives in the transport structure.
713 struct sctp_transport *transport;
715 /* pointer to the auth chunk for this packet */
716 struct sctp_chunk *auth;
718 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
719 has_sack:1, /* This packet contains a SACK chunk. */
720 has_auth:1, /* This packet contains an AUTH chunk */
721 has_data:1, /* This packet contains at least 1 DATA chunk */
722 ipfragok:1; /* So let ip fragment this packet */
725 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
726 __u16 sport, __u16 dport);
727 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
728 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
729 struct sctp_chunk *, int, gfp_t);
730 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
731 struct sctp_chunk *);
732 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
733 void sctp_packet_free(struct sctp_packet *);
735 static inline int sctp_packet_empty(struct sctp_packet *packet)
737 return packet->size == packet->overhead;
740 /* This represents a remote transport address.
741 * For local transport addresses, we just use union sctp_addr.
743 * RFC2960 Section 1.4 Key Terms
745 * o Transport address: A Transport Address is traditionally defined
746 * by Network Layer address, Transport Layer protocol and Transport
747 * Layer port number. In the case of SCTP running over IP, a
748 * transport address is defined by the combination of an IP address
749 * and an SCTP port number (where SCTP is the Transport protocol).
751 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
753 * o The sender keeps a separate congestion control parameter set for
754 * each of the destination addresses it can send to (not each
755 * source-destination pair but for each destination). The parameters
756 * should decay if the address is not used for a long enough time
760 struct sctp_transport {
761 /* A list of transports. */
762 struct list_head transports;
763 struct rhlist_head node;
765 /* Reference counting. */
767 /* RTO-Pending : A flag used to track if one of the DATA
768 * chunks sent to this address is currently being
769 * used to compute a RTT. If this flag is 0,
770 * the next DATA chunk sent to this destination
771 * should be used to compute a RTT and this flag
772 * should be set. Every time the RTT
773 * calculation completes (i.e. the DATA chunk
774 * is SACK'd) clear this flag.
779 * hb_sent : a flag that signals that we have a pending
784 /* Is the Path MTU update pending on this tranport */
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 /* Since we're using per-destination retransmission timers
914 * (see above), we're also using per-destination "transmitted"
915 * queues. This probably ought to be a private struct
916 * accessible only within the outqueue, but it's not, yet.
918 struct list_head transmitted;
920 /* We build bundle-able packets for this transport here. */
921 struct sctp_packet packet;
923 /* This is the list of transports that have chunks to send. */
924 struct list_head send_ready;
926 /* State information saved for SFR_CACC algorithm. The key
927 * idea in SFR_CACC is to maintain state at the sender on a
928 * per-destination basis when a changeover happens.
929 * char changeover_active;
930 * char cycling_changeover;
931 * __u32 next_tsn_at_change;
932 * char cacc_saw_newack;
935 /* An unsigned integer, which stores the next TSN to be
936 * used by the sender, at the moment of changeover.
938 __u32 next_tsn_at_change;
940 /* A flag which indicates the occurrence of a changeover */
941 char changeover_active;
943 /* A flag which indicates whether the change of primary is
944 * the first switch to this destination address during an
947 char cycling_changeover;
949 /* A temporary flag, which is used during the processing of
950 * a SACK to estimate the causative TSN(s)'s group.
952 char cacc_saw_newack;
955 /* 64-bit random number sent with heartbeat. */
961 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
963 void sctp_transport_set_owner(struct sctp_transport *,
964 struct sctp_association *);
965 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
967 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
968 void sctp_transport_free(struct sctp_transport *);
969 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
970 void sctp_transport_reset_hb_timer(struct sctp_transport *);
971 int sctp_transport_hold(struct sctp_transport *);
972 void sctp_transport_put(struct sctp_transport *);
973 void sctp_transport_update_rto(struct sctp_transport *, __u32);
974 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
975 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
976 void sctp_transport_burst_limited(struct sctp_transport *);
977 void sctp_transport_burst_reset(struct sctp_transport *);
978 unsigned long sctp_transport_timeout(struct sctp_transport *);
979 void sctp_transport_reset(struct sctp_transport *);
980 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
981 void sctp_transport_immediate_rtx(struct sctp_transport *);
984 /* This is the structure we use to queue packets as they come into
985 * SCTP. We write packets to it and read chunks from it.
988 /* This is actually a queue of sctp_chunk each
989 * containing a partially decoded packet.
991 struct list_head in_chunk_list;
992 /* This is the packet which is currently off the in queue and is
993 * being worked on through the inbound chunk processing.
995 struct sctp_chunk *in_progress;
997 /* This is the delayed task to finish delivering inbound
1000 struct work_struct immediate;
1003 void sctp_inq_init(struct sctp_inq *);
1004 void sctp_inq_free(struct sctp_inq *);
1005 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1006 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1007 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1008 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1010 /* This is the structure we use to hold outbound chunks. You push
1011 * chunks in and they automatically pop out the other end as bundled
1012 * packets (it calls (*output_handler)()).
1014 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1015 * and 8.2 of the v13 draft.
1017 * It handles retransmissions. The connection to the timeout portion
1018 * of the state machine is through sctp_..._timeout() and timeout_handler.
1020 * If you feed it SACKs, it will eat them.
1022 * If you give it big chunks, it will fragment them.
1024 * It assigns TSN's to data chunks. This happens at the last possible
1025 * instant before transmission.
1027 * When free()'d, it empties itself out via output_handler().
1030 struct sctp_association *asoc;
1032 /* Data pending that has never been transmitted. */
1033 struct list_head out_chunk_list;
1035 unsigned int out_qlen; /* Total length of queued data chunks. */
1037 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1040 /* These are control chunks we want to send. */
1041 struct list_head control_chunk_list;
1043 /* These are chunks that have been sacked but are above the
1044 * CTSN, or cumulative tsn ack point.
1046 struct list_head sacked;
1048 /* Put chunks on this list to schedule them for
1051 struct list_head retransmit;
1053 /* Put chunks on this list to save them for FWD TSN processing as
1054 * they were abandoned.
1056 struct list_head abandoned;
1058 /* How many unackd bytes do we have in-flight? */
1059 __u32 outstanding_bytes;
1061 /* Are we doing fast-rtx on this queue */
1068 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1069 void sctp_outq_teardown(struct sctp_outq *);
1070 void sctp_outq_free(struct sctp_outq*);
1071 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1072 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1073 int sctp_outq_is_empty(const struct sctp_outq *);
1074 void sctp_outq_restart(struct sctp_outq *);
1076 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1077 sctp_retransmit_reason_t);
1078 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1079 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1080 void sctp_prsctp_prune(struct sctp_association *asoc,
1081 struct sctp_sndrcvinfo *sinfo, int msg_len);
1082 /* Uncork and flush an outqueue. */
1083 static inline void sctp_outq_cork(struct sctp_outq *q)
1088 /* SCTP skb control block.
1089 * sctp_input_cb is currently used on rx and sock rx queue
1091 struct sctp_input_cb {
1093 struct inet_skb_parm h4;
1094 #if IS_ENABLED(CONFIG_IPV6)
1095 struct inet6_skb_parm h6;
1098 struct sctp_chunk *chunk;
1101 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1103 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1105 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1107 return chunk->head_skb ? : skb;
1110 /* These bind address data fields common between endpoints and associations */
1111 struct sctp_bind_addr {
1113 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1115 * SCTP Port: The local SCTP port number the endpoint is
1120 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1122 * Address List: The list of IP addresses that this instance
1123 * has bound. This information is passed to one's
1124 * peer(s) in INIT and INIT ACK chunks.
1126 struct list_head address_list;
1129 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1130 void sctp_bind_addr_free(struct sctp_bind_addr *);
1131 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1132 const struct sctp_bind_addr *src,
1133 sctp_scope_t scope, gfp_t gfp,
1135 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1136 const struct sctp_bind_addr *src,
1138 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1139 int new_size, __u8 addr_state, gfp_t gfp);
1140 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1141 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1142 struct sctp_sock *);
1143 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1144 struct sctp_sock *, struct sctp_sock *);
1145 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1146 const union sctp_addr *addr);
1147 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1148 const union sctp_addr *addrs,
1150 struct sctp_sock *opt);
1151 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1154 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1155 __u16 port, gfp_t gfp);
1157 sctp_scope_t sctp_scope(const union sctp_addr *);
1158 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1159 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1160 int sctp_is_ep_boundall(struct sock *sk);
1163 /* What type of endpoint? */
1165 SCTP_EP_TYPE_SOCKET,
1166 SCTP_EP_TYPE_ASSOCIATION,
1167 } sctp_endpoint_type_t;
1170 * A common base class to bridge the implmentation view of a
1171 * socket (usually listening) endpoint versus an association's
1173 * This common structure is useful for several purposes:
1174 * 1) Common interface for lookup routines.
1175 * a) Subfunctions work for either endpoint or association
1176 * b) Single interface to lookup allows hiding the lookup lock rather
1177 * than acquiring it externally.
1178 * 2) Common interface for the inbound chunk handling/state machine.
1179 * 3) Common object handling routines for reference counting, etc.
1180 * 4) Disentangle association lookup from endpoint lookup, where we
1181 * do not have to find our endpoint to find our association.
1185 struct sctp_ep_common {
1186 /* Fields to help us manage our entries in the hash tables. */
1187 struct hlist_node node;
1190 /* Runtime type information. What kind of endpoint is this? */
1191 sctp_endpoint_type_t type;
1193 /* Some fields to help us manage this object.
1194 * refcnt - Reference count access to this object.
1195 * dead - Do not attempt to use this object.
1200 /* What socket does this endpoint belong to? */
1203 /* This is where we receive inbound chunks. */
1204 struct sctp_inq inqueue;
1206 /* This substructure includes the defining parameters of the
1208 * bind_addr.port is our shared port number.
1209 * bind_addr.address_list is our set of local IP addresses.
1211 struct sctp_bind_addr bind_addr;
1215 /* RFC Section 1.4 Key Terms
1217 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1218 * multi-homed host, an SCTP endpoint is represented to its peers as a
1219 * combination of a set of eligible destination transport addresses to
1220 * which SCTP packets can be sent and a set of eligible source
1221 * transport addresses from which SCTP packets can be received.
1222 * All transport addresses used by an SCTP endpoint must use the
1223 * same port number, but can use multiple IP addresses. A transport
1224 * address used by an SCTP endpoint must not be used by another
1225 * SCTP endpoint. In other words, a transport address is unique
1226 * to an SCTP endpoint.
1228 * From an implementation perspective, each socket has one of these.
1229 * A TCP-style socket will have exactly one association on one of
1230 * these. An UDP-style socket will have multiple associations hanging
1234 struct sctp_endpoint {
1235 /* Common substructure for endpoint and association. */
1236 struct sctp_ep_common base;
1238 /* Associations: A list of current associations and mappings
1239 * to the data consumers for each association. This
1240 * may be in the form of a hash table or other
1241 * implementation dependent structure. The data
1242 * consumers may be process identification
1243 * information such as file descriptors, named pipe
1244 * pointer, or table pointers dependent on how SCTP
1247 /* This is really a list of struct sctp_association entries. */
1248 struct list_head asocs;
1250 /* Secret Key: A secret key used by this endpoint to compute
1251 * the MAC. This SHOULD be a cryptographic quality
1252 * random number with a sufficient length.
1253 * Discussion in [RFC1750] can be helpful in
1254 * selection of the key.
1256 __u8 secret_key[SCTP_SECRET_SIZE];
1258 /* digest: This is a digest of the sctp cookie. This field is
1259 * only used on the receive path when we try to validate
1260 * that the cookie has not been tampered with. We put
1261 * this here so we pre-allocate this once and can re-use
1266 /* sendbuf acct. policy. */
1267 __u32 sndbuf_policy;
1269 /* rcvbuf acct. policy. */
1270 __u32 rcvbuf_policy;
1272 /* SCTP AUTH: array of the HMACs that will be allocated
1273 * we need this per association so that we don't serialize
1275 struct crypto_shash **auth_hmacs;
1277 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1278 struct sctp_hmac_algo_param *auth_hmacs_list;
1280 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1281 struct sctp_chunks_param *auth_chunk_list;
1283 /* SCTP-AUTH: endpoint shared keys */
1284 struct list_head endpoint_shared_keys;
1285 __u16 active_key_id;
1290 /* Recover the outter endpoint structure. */
1291 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1293 struct sctp_endpoint *ep;
1295 ep = container_of(base, struct sctp_endpoint, base);
1299 /* These are function signatures for manipulating endpoints. */
1300 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1301 void sctp_endpoint_free(struct sctp_endpoint *);
1302 void sctp_endpoint_put(struct sctp_endpoint *);
1303 void sctp_endpoint_hold(struct sctp_endpoint *);
1304 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1305 struct sctp_association *sctp_endpoint_lookup_assoc(
1306 const struct sctp_endpoint *ep,
1307 const union sctp_addr *paddr,
1308 struct sctp_transport **);
1309 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1310 const union sctp_addr *);
1311 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1312 struct net *, const union sctp_addr *);
1313 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1314 const union sctp_addr *paddr);
1316 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1317 const struct sctp_association *asoc,
1318 sctp_cid_t, sctp_init_chunk_t *peer_init,
1319 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1320 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1321 const union sctp_addr *peer,
1322 sctp_init_chunk_t *init, gfp_t gfp);
1323 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1324 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1326 struct sctp_inithdr_host {
1329 __u16 num_outbound_streams;
1330 __u16 num_inbound_streams;
1334 /* SCTP_GET_ASSOC_STATS counters */
1335 struct sctp_priv_assoc_stats {
1336 /* Maximum observed rto in the association during subsequent
1337 * observations. Value is set to 0 if no RTO measurement took place
1338 * The transport where the max_rto was observed is returned in
1341 struct sockaddr_storage obs_rto_ipaddr;
1343 /* Total In and Out SACKs received and sent */
1346 /* Total In and Out packets received and sent */
1349 /* Total retransmitted chunks */
1351 /* TSN received > next expected */
1353 /* Duplicate Chunks received */
1355 /* Gap Ack Blocks received */
1357 /* Unordered data chunks sent and received */
1360 /* Ordered data chunks sent and received */
1363 /* Control chunks sent and received */
1370 * 12. Recommended Transmission Control Block (TCB) Parameters
1372 * This section details a recommended set of parameters that should
1373 * be contained within the TCB for an implementation. This section is
1374 * for illustrative purposes and should not be deemed as requirements
1375 * on an implementation or as an exhaustive list of all parameters
1376 * inside an SCTP TCB. Each implementation may need its own additional
1377 * parameters for optimization.
1381 /* Here we have information about each individual association. */
1382 struct sctp_association {
1384 /* A base structure common to endpoint and association.
1385 * In this context, it represents the associations's view
1386 * of the local endpoint of the association.
1388 struct sctp_ep_common base;
1390 /* Associations on the same socket. */
1391 struct list_head asocs;
1393 /* association id. */
1394 sctp_assoc_t assoc_id;
1396 /* This is our parent endpoint. */
1397 struct sctp_endpoint *ep;
1399 /* These are those association elements needed in the cookie. */
1400 struct sctp_cookie c;
1402 /* This is all information about our peer. */
1404 /* transport_addr_list
1406 * Peer : A list of SCTP transport addresses that the
1407 * Transport : peer is bound to. This information is derived
1408 * Address : from the INIT or INIT ACK and is used to
1409 * List : associate an inbound packet with a given
1410 * : association. Normally this information is
1411 * : hashed or keyed for quick lookup and access
1413 * : The list is also initialized with the list
1414 * : of addresses passed with the sctp_connectx()
1417 * It is a list of SCTP_transport's.
1419 struct list_head transport_addr_list;
1423 * Peer Rwnd : Current calculated value of the peer's rwnd.
1429 * Peer : A count of the number of peer addresses
1430 * Transport : in the Peer Transport Address List.
1434 __u16 transport_count;
1437 * The transport layer port number.
1443 * Primary : This is the current primary destination
1444 * Path : transport address of the peer endpoint. It
1445 * : may also specify a source transport address
1446 * : on this endpoint.
1448 * All of these paths live on transport_addr_list.
1450 * At the bakeoffs, we discovered that the intent of
1451 * primaryPath is that it only changes when the ULP
1452 * asks to have it changed. We add the activePath to
1453 * designate the connection we are currently using to
1454 * transmit new data and most control chunks.
1456 struct sctp_transport *primary_path;
1458 /* Cache the primary path address here, when we
1459 * need a an address for msg_name.
1461 union sctp_addr primary_addr;
1464 * The path that we are currently using to
1465 * transmit new data and most control chunks.
1467 struct sctp_transport *active_path;
1471 * RFC2960 6.4 Multi-homed SCTP Endpoints
1473 * Furthermore, when its peer is multi-homed, an
1474 * endpoint SHOULD try to retransmit a chunk to an
1475 * active destination transport address that is
1476 * different from the last destination address to
1477 * which the DATA chunk was sent.
1479 struct sctp_transport *retran_path;
1481 /* Pointer to last transport I have sent on. */
1482 struct sctp_transport *last_sent_to;
1484 /* This is the last transport I have received DATA on. */
1485 struct sctp_transport *last_data_from;
1488 * Mapping An array of bits or bytes indicating which out of
1489 * Array order TSN's have been received (relative to the
1490 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1491 * order packets have been received, this array
1492 * will be set to all zero. This structure may be
1493 * in the form of a circular buffer or bit array.
1495 * Last Rcvd : This is the last TSN received in
1496 * TSN : sequence. This value is set initially by
1497 * : taking the peer's Initial TSN, received in
1498 * : the INIT or INIT ACK chunk, and subtracting
1501 * Throughout most of the specification this is called the
1502 * "Cumulative TSN ACK Point". In this case, we
1503 * ignore the advice in 12.2 in favour of the term
1504 * used in the bulk of the text. This value is hidden
1505 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1507 struct sctp_tsnmap tsn_map;
1509 /* This mask is used to disable sending the ASCONF chunk
1510 * with specified parameter to peer.
1512 __be16 addip_disabled_mask;
1514 /* These are capabilities which our peer advertised. */
1515 __u8 ecn_capable:1, /* Can peer do ECN? */
1516 ipv4_address:1, /* Peer understands IPv4 addresses? */
1517 ipv6_address:1, /* Peer understands IPv6 addresses? */
1518 hostname_address:1, /* Peer understands DNS addresses? */
1519 asconf_capable:1, /* Does peer support ADDIP? */
1520 prsctp_capable:1, /* Can peer do PR-SCTP? */
1521 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1523 /* sack_needed : This flag indicates if the next received
1524 * : packet is to be responded to with a
1525 * : SACK. This is initialized to 0. When a packet
1526 * : is received sack_cnt is incremented. If this value
1527 * : reaches 2 or more, a SACK is sent and the
1528 * : value is reset to 0. Note: This is used only
1529 * : when no DATA chunks are received out of
1530 * : order. When DATA chunks are out of order,
1531 * : SACK's are not delayed (see Section 6).
1533 __u8 sack_needed:1, /* Do we need to sack the peer? */
1535 zero_window_announced:1;
1538 __u32 adaptation_ind; /* Adaptation Code point. */
1540 struct sctp_inithdr_host i;
1544 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1545 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1546 * Initial TSN Value minus 1
1550 /* SCTP-AUTH: We need to know pears random number, hmac list
1551 * and authenticated chunk list. All that is part of the
1552 * cookie and these are just pointers to those locations
1554 sctp_random_param_t *peer_random;
1555 sctp_chunks_param_t *peer_chunks;
1556 sctp_hmac_algo_param_t *peer_hmacs;
1559 /* State : A state variable indicating what state the
1560 * : association is in, i.e. COOKIE-WAIT,
1561 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1562 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1564 * Note: No "CLOSED" state is illustrated since if a
1565 * association is "CLOSED" its TCB SHOULD be removed.
1567 * In this implementation we DO have a CLOSED
1568 * state which is used during initiation and shutdown.
1570 * State takes values from SCTP_STATE_*.
1574 /* Overall : The overall association error count.
1575 * Error Count : [Clear this any time I get something.]
1577 int overall_error_count;
1579 /* The cookie life I award for any cookie. */
1580 ktime_t cookie_life;
1582 /* These are the association's initial, max, and min RTO values.
1583 * These values will be initialized by system defaults, but can
1584 * be modified via the SCTP_RTOINFO socket option.
1586 unsigned long rto_initial;
1587 unsigned long rto_max;
1588 unsigned long rto_min;
1590 /* Maximum number of new data packets that can be sent in a burst. */
1593 /* This is the max_retrans value for the association. This value will
1594 * be initialized initialized from system defaults, but can be
1595 * modified by the SCTP_ASSOCINFO socket option.
1599 /* This is the partially failed retrans value for the transport
1600 * and will be initialized from the assocs value. This can be
1601 * changed using the SCTP_PEER_ADDR_THLDS socket option
1605 /* Maximum number of times the endpoint will retransmit INIT */
1606 __u16 max_init_attempts;
1608 /* How many times have we resent an INIT? */
1611 /* The largest timeout or RTO value to use in attempting an INIT */
1612 unsigned long max_init_timeo;
1614 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1615 * the destination address every heartbeat interval. This value
1616 * will be inherited by all new transports.
1618 unsigned long hbinterval;
1620 /* This is the max_retrans value for new transports in the
1625 /* Flag that path mtu update is pending */
1628 /* Association : The smallest PMTU discovered for all of the
1629 * PMTU : peer's transport addresses.
1633 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1637 /* SACK delay timeout */
1638 unsigned long sackdelay;
1640 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1641 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1643 /* Transport to which SHUTDOWN chunk was last sent. */
1644 struct sctp_transport *shutdown_last_sent_to;
1646 /* Transport to which INIT chunk was last sent. */
1647 struct sctp_transport *init_last_sent_to;
1649 /* How many times have we resent a SHUTDOWN */
1650 int shutdown_retries;
1652 /* Next TSN : The next TSN number to be assigned to a new
1653 * : DATA chunk. This is sent in the INIT or INIT
1654 * : ACK chunk to the peer and incremented each
1655 * : time a DATA chunk is assigned a TSN
1656 * : (normally just prior to transmit or during
1662 * Last Rcvd : This is the last TSN received in sequence. This value
1663 * TSN : is set initially by taking the peer's Initial TSN,
1664 * : received in the INIT or INIT ACK chunk, and
1665 * : subtracting one from it.
1667 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1670 __u32 ctsn_ack_point;
1672 /* PR-SCTP Advanced.Peer.Ack.Point */
1673 __u32 adv_peer_ack_point;
1675 /* Highest TSN that is acknowledged by incoming SACKs. */
1676 __u32 highest_sacked;
1678 /* TSN marking the fast recovery exit point */
1679 __u32 fast_recovery_exit;
1681 /* Flag to track the current fast recovery state */
1684 /* The number of unacknowledged data chunks. Reported through
1685 * the SCTP_STATUS sockopt.
1689 /* The total number of data chunks that we've had to retransmit
1690 * as the result of a T3 timer expiration
1692 __u32 rtx_data_chunks;
1694 /* This is the association's receive buffer space. This value is used
1695 * to set a_rwnd field in an INIT or a SACK chunk.
1699 /* This is the last advertised value of rwnd over a SACK chunk. */
1702 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1703 * to slop over a maximum of the association's frag_point.
1707 /* Keeps treack of rwnd pressure. This happens when we have
1708 * a window, but not recevie buffer (i.e small packets). This one
1709 * is releases slowly (1 PMTU at a time ).
1713 /* This is the sndbuf size in use for the association.
1714 * This corresponds to the sndbuf size for the association,
1715 * as specified in the sk->sndbuf.
1719 /* This is the amount of memory that this association has allocated
1720 * in the receive path at any given time.
1722 atomic_t rmem_alloc;
1724 /* This is the wait queue head for send requests waiting on
1725 * the association sndbuf space.
1727 wait_queue_head_t wait;
1729 /* The message size at which SCTP fragmentation will occur. */
1733 /* Counter used to count INIT errors. */
1734 int init_err_counter;
1736 /* Count the number of INIT cycles (for doubling timeout). */
1739 /* Default send parameters. */
1740 __u16 default_stream;
1741 __u16 default_flags;
1743 __u32 default_context;
1744 __u32 default_timetolive;
1746 /* Default receive parameters */
1747 __u32 default_rcv_context;
1749 /* This tracks outbound ssn for a given stream. */
1750 struct sctp_ssnmap *ssnmap;
1752 /* All outbound chunks go through this structure. */
1753 struct sctp_outq outqueue;
1755 /* A smart pipe that will handle reordering and fragmentation,
1756 * as well as handle passing events up to the ULP.
1758 struct sctp_ulpq ulpq;
1760 /* Last TSN that caused an ECNE Chunk to be sent. */
1761 __u32 last_ecne_tsn;
1763 /* Last TSN that caused a CWR Chunk to be sent. */
1766 /* How many duplicated TSNs have we seen? */
1769 /* These are to support
1770 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1771 * and Enforcement of Flow and Message Limits"
1772 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1773 * or "ADDIP" for short.
1778 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1780 * R1) One and only one ASCONF Chunk MAY be in transit and
1781 * unacknowledged at any one time. If a sender, after sending
1782 * an ASCONF chunk, decides it needs to transfer another
1783 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1784 * returns from the previous ASCONF Chunk before sending a
1785 * subsequent ASCONF. Note this restriction binds each side,
1786 * so at any time two ASCONF may be in-transit on any given
1787 * association (one sent from each endpoint).
1789 * [This is our one-and-only-one ASCONF in flight. If we do
1790 * not have an ASCONF in flight, this is NULL.]
1792 struct sctp_chunk *addip_last_asconf;
1794 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1796 * This is needed to implement itmes E1 - E4 of the updated
1797 * spec. Here is the justification:
1799 * Since the peer may bundle multiple ASCONF chunks toward us,
1800 * we now need the ability to cache multiple ACKs. The section
1801 * describes in detail how they are cached and cleaned up.
1803 struct list_head asconf_ack_list;
1805 /* These ASCONF chunks are waiting to be sent.
1807 * These chunaks can't be pushed to outqueue until receiving
1808 * ASCONF_ACK for the previous ASCONF indicated by
1809 * addip_last_asconf, so as to guarantee that only one ASCONF
1810 * is in flight at any time.
1812 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1814 * In defining the ASCONF Chunk transfer procedures, it is
1815 * essential that these transfers MUST NOT cause congestion
1816 * within the network. To achieve this, we place these
1817 * restrictions on the transfer of ASCONF Chunks:
1819 * R1) One and only one ASCONF Chunk MAY be in transit and
1820 * unacknowledged at any one time. If a sender, after sending
1821 * an ASCONF chunk, decides it needs to transfer another
1822 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1823 * returns from the previous ASCONF Chunk before sending a
1824 * subsequent ASCONF. Note this restriction binds each side,
1825 * so at any time two ASCONF may be in-transit on any given
1826 * association (one sent from each endpoint).
1829 * [I really think this is EXACTLY the sort of intelligence
1830 * which already resides in sctp_outq. Please move this
1831 * queue and its supporting logic down there. --piggy]
1833 struct list_head addip_chunk_list;
1835 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1837 * A2) A serial number should be assigned to the Chunk. The
1838 * serial number SHOULD be a monotonically increasing
1839 * number. The serial number SHOULD be initialized at
1840 * the start of the association to the same value as the
1841 * Initial TSN and every time a new ASCONF chunk is created
1842 * it is incremented by one after assigning the serial number
1843 * to the newly created chunk.
1846 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1848 * Serial Number : 32 bits (unsigned integer)
1850 * This value represents a Serial Number for the ASCONF
1851 * Chunk. The valid range of Serial Number is from 0 to
1852 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1853 * after reaching 4294967295.
1856 int src_out_of_asoc_ok;
1857 union sctp_addr *asconf_addr_del_pending;
1858 struct sctp_transport *new_transport;
1860 /* SCTP AUTH: list of the endpoint shared keys. These
1861 * keys are provided out of band by the user applicaton
1862 * and can't change during the lifetime of the association
1864 struct list_head endpoint_shared_keys;
1867 * The current generated assocaition shared key (secret)
1869 struct sctp_auth_bytes *asoc_shared_key;
1871 /* SCTP AUTH: hmac id of the first peer requested algorithm
1874 __u16 default_hmac_id;
1876 __u16 active_key_id;
1878 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1879 temp:1, /* Is it a temporary association? */
1882 struct sctp_priv_assoc_stats stats;
1884 int sent_cnt_removable;
1886 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1887 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1891 /* An eyecatcher for determining if we are really looking at an
1892 * association data structure.
1895 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1898 /* Recover the outter association structure. */
1899 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1901 struct sctp_association *asoc;
1903 asoc = container_of(base, struct sctp_association, base);
1907 /* These are function signatures for manipulating associations. */
1910 struct sctp_association *
1911 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1912 sctp_scope_t scope, gfp_t gfp);
1913 void sctp_association_free(struct sctp_association *);
1914 void sctp_association_put(struct sctp_association *);
1915 void sctp_association_hold(struct sctp_association *);
1917 struct sctp_transport *sctp_assoc_choose_alter_transport(
1918 struct sctp_association *, struct sctp_transport *);
1919 void sctp_assoc_update_retran_path(struct sctp_association *);
1920 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1921 const union sctp_addr *);
1922 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1923 const union sctp_addr *laddr);
1924 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1925 const union sctp_addr *address,
1927 const int peer_state);
1928 void sctp_assoc_del_peer(struct sctp_association *asoc,
1929 const union sctp_addr *addr);
1930 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1931 struct sctp_transport *peer);
1932 void sctp_assoc_control_transport(struct sctp_association *,
1933 struct sctp_transport *,
1934 sctp_transport_cmd_t, sctp_sn_error_t);
1935 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1936 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1938 const union sctp_addr *,
1939 const union sctp_addr *);
1940 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1941 void sctp_assoc_update(struct sctp_association *old,
1942 struct sctp_association *new);
1944 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1946 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1947 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1948 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1949 void sctp_assoc_set_primary(struct sctp_association *,
1950 struct sctp_transport *);
1951 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1952 struct sctp_transport *);
1953 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1954 sctp_scope_t, gfp_t);
1955 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1956 struct sctp_cookie*,
1958 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1959 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1960 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1961 const struct sctp_association *asoc,
1963 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1965 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1966 const union sctp_addr *ss2);
1967 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1969 /* A convenience structure to parse out SCTP specific CMSGs. */
1970 typedef struct sctp_cmsgs {
1971 struct sctp_initmsg *init;
1972 struct sctp_sndrcvinfo *srinfo;
1973 struct sctp_sndinfo *sinfo;
1976 /* Structure for tracking memory objects */
1980 } sctp_dbg_objcnt_entry_t;
1982 #endif /* __sctp_structs_h__ */