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-types.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_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_assocparams assocparams;
211 * These two structures must be grouped together for the usercopy
214 struct sctp_event_subscribe subscribe;
215 struct sctp_initmsg initmsg;
220 __u32 adaptation_ind;
229 data_ready_signalled:1;
232 /* Receive to here while partial delivery is in effect. */
233 struct sk_buff_head pd_lobby;
235 /* These must be the last fields, as they will skipped on copies,
236 * like on accept and peeloff operations
238 struct list_head auto_asconf_list;
242 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
244 return (struct sctp_sock *)sk;
247 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
249 return (struct sock *)sp;
252 #if IS_ENABLED(CONFIG_IPV6)
254 struct sctp_sock sctp;
255 struct ipv6_pinfo inet6;
257 #endif /* CONFIG_IPV6 */
260 /* This is our APPLICATION-SPECIFIC state cookie.
261 * THIS IS NOT DICTATED BY THE SPECIFICATION.
263 /* These are the parts of an association which we send in the cookie.
264 * Most of these are straight out of:
265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
271 /* My : Tag expected in every inbound packet and sent
272 * Verification: in the INIT or INIT ACK chunk.
277 /* Peer's : Tag expected in every outbound packet except
278 * Verification: in the INIT chunk.
283 /* The rest of these are not from the spec, but really need to
287 /* My Tie Tag : Assist in discovering a restarting association. */
290 /* Peer's Tie Tag: Assist in discovering a restarting association. */
293 /* When does this cookie expire? */
296 /* Number of inbound/outbound streams which are set
297 * and negotiated during the INIT process.
299 __u16 sinit_num_ostreams;
300 __u16 sinit_max_instreams;
302 /* This is the first sequence number I used. */
305 /* This holds the originating address of the INIT packet. */
306 union sctp_addr peer_addr;
309 * Include the source port of the INIT-ACK
315 /* Padding for future use */
318 __u32 adaptation_ind;
320 __u8 auth_random[sizeof(struct sctp_paramhdr) +
321 SCTP_AUTH_RANDOM_LENGTH];
322 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
323 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
325 /* This is a shim for my peer's INIT packet, followed by
326 * a copy of the raw address list of the association.
327 * The length of the raw address list is saved in the
328 * raw_addr_list_len field, which will be used at the time when
329 * the association TCB is re-constructed from the cookie.
331 __u32 raw_addr_list_len;
332 struct sctp_init_chunk peer_init[0];
336 /* The format of our cookie that we send to our peer. */
337 struct sctp_signed_cookie {
338 __u8 signature[SCTP_SECRET_SIZE];
339 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
340 struct sctp_cookie c;
343 /* This is another convenience type to allocate memory for address
344 * params for the maximum size and pass such structures around
347 union sctp_addr_param {
348 struct sctp_paramhdr p;
349 struct sctp_ipv4addr_param v4;
350 struct sctp_ipv6addr_param v6;
353 /* A convenience type to allow walking through the various
354 * parameters and avoid casting all over the place.
358 struct sctp_paramhdr *p;
359 struct sctp_cookie_preserve_param *life;
360 struct sctp_hostname_param *dns;
361 struct sctp_cookie_param *cookie;
362 struct sctp_supported_addrs_param *sat;
363 struct sctp_ipv4addr_param *v4;
364 struct sctp_ipv6addr_param *v6;
365 union sctp_addr_param *addr;
366 struct sctp_adaptation_ind_param *aind;
367 struct sctp_supported_ext_param *ext;
368 struct sctp_random_param *random;
369 struct sctp_chunks_param *chunks;
370 struct sctp_hmac_algo_param *hmac_algo;
371 struct sctp_addip_param *addip;
374 /* RFC 2960. Section 3.3.5 Heartbeat.
375 * Heartbeat Information: variable length
376 * The Sender-specific Heartbeat Info field should normally include
377 * information about the sender's current time when this HEARTBEAT
378 * chunk is sent and the destination transport address to which this
379 * HEARTBEAT is sent (see Section 8.3).
381 struct sctp_sender_hb_info {
382 struct sctp_paramhdr param_hdr;
383 union sctp_addr daddr;
384 unsigned long sent_at;
388 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
390 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
391 void sctp_stream_free(struct sctp_stream *stream);
392 void sctp_stream_clear(struct sctp_stream *stream);
393 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
395 /* What is the current SSN number for this stream? */
396 #define sctp_ssn_peek(stream, type, sid) \
397 ((stream)->type[sid].ssn)
399 /* Return the next SSN number for this stream. */
400 #define sctp_ssn_next(stream, type, sid) \
401 ((stream)->type[sid].ssn++)
403 /* Skip over this ssn and all below. */
404 #define sctp_ssn_skip(stream, type, sid, ssn) \
405 ((stream)->type[sid].ssn = ssn + 1)
407 /* What is the current MID number for this stream? */
408 #define sctp_mid_peek(stream, type, sid) \
409 ((stream)->type[sid].mid)
411 /* Return the next MID number for this stream. */
412 #define sctp_mid_next(stream, type, sid) \
413 ((stream)->type[sid].mid++)
415 /* Skip over this mid and all below. */
416 #define sctp_mid_skip(stream, type, sid, mid) \
417 ((stream)->type[sid].mid = mid + 1)
419 #define sctp_stream_in(asoc, sid) (&(asoc)->stream.in[sid])
421 /* What is the current MID_uo number for this stream? */
422 #define sctp_mid_uo_peek(stream, type, sid) \
423 ((stream)->type[sid].mid_uo)
425 /* Return the next MID_uo number for this stream. */
426 #define sctp_mid_uo_next(stream, type, sid) \
427 ((stream)->type[sid].mid_uo++)
430 * Pointers to address related SCTP functions.
431 * (i.e. things that depend on the address family.)
434 int (*sctp_xmit) (struct sk_buff *skb,
435 struct sctp_transport *);
436 int (*setsockopt) (struct sock *sk,
440 unsigned int optlen);
441 int (*getsockopt) (struct sock *sk,
446 int (*compat_setsockopt) (struct sock *sk,
450 unsigned int optlen);
451 int (*compat_getsockopt) (struct sock *sk,
456 void (*get_dst) (struct sctp_transport *t,
457 union sctp_addr *saddr,
460 void (*get_saddr) (struct sctp_sock *sk,
461 struct sctp_transport *t,
463 void (*copy_addrlist) (struct list_head *,
464 struct net_device *);
465 int (*cmp_addr) (const union sctp_addr *addr1,
466 const union sctp_addr *addr2);
467 void (*addr_copy) (union sctp_addr *dst,
468 union sctp_addr *src);
469 void (*from_skb) (union sctp_addr *,
472 void (*from_sk) (union sctp_addr *,
474 void (*from_addr_param) (union sctp_addr *,
475 union sctp_addr_param *,
476 __be16 port, int iif);
477 int (*to_addr_param) (const union sctp_addr *,
478 union sctp_addr_param *);
479 int (*addr_valid) (union sctp_addr *,
481 const struct sk_buff *);
482 enum sctp_scope (*scope)(union sctp_addr *);
483 void (*inaddr_any) (union sctp_addr *, __be16);
484 int (*is_any) (const union sctp_addr *);
485 int (*available) (union sctp_addr *,
487 int (*skb_iif) (const struct sk_buff *sk);
488 int (*is_ce) (const struct sk_buff *sk);
489 void (*seq_dump_addr)(struct seq_file *seq,
490 union sctp_addr *addr);
491 void (*ecn_capable)(struct sock *sk);
492 __u16 net_header_len;
494 int (*ip_options_len)(struct sock *sk);
495 sa_family_t sa_family;
496 struct list_head list;
499 struct sctp_af *sctp_get_af_specific(sa_family_t);
500 int sctp_register_af(struct sctp_af *);
502 /* Protocol family functions. */
504 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
505 void (*skb_msgname) (struct sk_buff *, char *, int *);
506 int (*af_supported) (sa_family_t, struct sctp_sock *);
507 int (*cmp_addr) (const union sctp_addr *,
508 const union sctp_addr *,
510 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
511 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
512 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
513 struct sock *(*create_accept_sk) (struct sock *sk,
514 struct sctp_association *asoc,
516 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
517 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
518 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
519 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
524 /* Structure to track chunk fragments that have been acked, but peer
525 * fragments of the same message have not.
527 struct sctp_datamsg {
528 /* Chunks waiting to be submitted to lower layer. */
529 struct list_head chunks;
530 /* Reference counting. */
532 /* When is this message no longer interesting to the peer? */
533 unsigned long expires_at;
534 /* Did the messenge fail to send? */
537 can_delay:1, /* should this message be Nagle delayed */
538 abandoned:1; /* should this message be abandoned */
541 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
542 struct sctp_sndrcvinfo *,
544 void sctp_datamsg_free(struct sctp_datamsg *);
545 void sctp_datamsg_put(struct sctp_datamsg *);
546 void sctp_chunk_fail(struct sctp_chunk *, int error);
547 int sctp_chunk_abandoned(struct sctp_chunk *);
549 /* RFC2960 1.4 Key Terms
551 * o Chunk: A unit of information within an SCTP packet, consisting of
552 * a chunk header and chunk-specific content.
554 * As a matter of convenience, we remember the SCTP common header for
555 * each chunk as well as a few other header pointers...
558 struct list_head list;
562 /* How many times this chunk have been sent, for prsctp RTX policy */
566 /* This is our link to the per-transport transmitted list. */
567 struct list_head transmitted_list;
568 /* List in specific stream outq */
569 struct list_head stream_list;
572 /* This field is used by chunks that hold fragmented data.
573 * For the first fragment this is the list that holds the rest of
574 * fragments. For the remaining fragments, this is the link to the
575 * frag_list maintained in the first fragment.
577 struct list_head frag_list;
579 /* This points to the sk_buff containing the actual data. */
583 /* In case of GSO packets, this will store the head one */
584 struct sk_buff *head_skb;
585 /* In case of auth enabled, this will point to the shkey */
586 struct sctp_shared_key *shkey;
589 /* These are the SCTP headers by reverse order in a packet.
590 * Note that some of these may happen more than once. In that
591 * case, we point at the "current" one, whatever that means
592 * for that level of header.
595 /* We point this at the FIRST TLV parameter to chunk_hdr. */
596 union sctp_params param_hdr;
599 struct sctp_datahdr *data_hdr;
600 struct sctp_inithdr *init_hdr;
601 struct sctp_sackhdr *sack_hdr;
602 struct sctp_heartbeathdr *hb_hdr;
603 struct sctp_sender_hb_info *hbs_hdr;
604 struct sctp_shutdownhdr *shutdown_hdr;
605 struct sctp_signed_cookie *cookie_hdr;
606 struct sctp_ecnehdr *ecne_hdr;
607 struct sctp_cwrhdr *ecn_cwr_hdr;
608 struct sctp_errhdr *err_hdr;
609 struct sctp_addiphdr *addip_hdr;
610 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
611 struct sctp_authhdr *auth_hdr;
612 struct sctp_idatahdr *idata_hdr;
613 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
618 struct sctp_chunkhdr *chunk_hdr;
619 struct sctphdr *sctp_hdr;
621 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
622 struct sctp_sndrcvinfo sinfo;
624 /* Which association does this belong to? */
625 struct sctp_association *asoc;
627 /* What endpoint received this chunk? */
628 struct sctp_ep_common *rcvr;
630 /* We fill this in if we are calculating RTT. */
631 unsigned long sent_at;
633 /* What is the origin IP address for this chunk? */
634 union sctp_addr source;
635 /* Destination address for this chunk. */
636 union sctp_addr dest;
638 /* For outbound message, track all fragments for SEND_FAILED. */
639 struct sctp_datamsg *msg;
641 /* For an inbound chunk, this tells us where it came from.
642 * For an outbound chunk, it tells us where we'd like it to
643 * go. It is NULL if we have no preference.
645 struct sctp_transport *transport;
647 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
648 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
649 * spec violates the principle premis that all chunks are processed
652 struct sk_buff *auth_chunk;
654 #define SCTP_CAN_FRTX 0x0
655 #define SCTP_NEED_FRTX 0x1
656 #define SCTP_DONT_FRTX 0x2
657 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
658 has_tsn:1, /* Does this chunk have a TSN yet? */
659 has_ssn:1, /* Does this chunk have a SSN yet? */
660 #define has_mid has_ssn
661 singleton:1, /* Only chunk in the packet? */
662 end_of_packet:1, /* Last chunk in the packet? */
663 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
664 pdiscard:1, /* Discard the whole packet now? */
665 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
666 data_accepted:1, /* At least 1 chunk accepted */
667 auth:1, /* IN: was auth'ed | OUT: needs auth */
668 has_asconf:1, /* IN: have seen an asconf before */
669 tsn_missing_report:2, /* Data chunk missing counter. */
670 fast_retransmit:2; /* Is this chunk fast retransmitted? */
673 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
674 void sctp_chunk_hold(struct sctp_chunk *);
675 void sctp_chunk_put(struct sctp_chunk *);
676 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
677 struct iov_iter *from);
678 void sctp_chunk_free(struct sctp_chunk *);
679 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
680 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
681 const struct sctp_association *,
682 struct sock *, gfp_t gfp);
683 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
685 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
687 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
689 return ntohs(ch->subh.data_hdr->stream);
693 SCTP_ADDR_NEW, /* new address added to assoc/ep */
694 SCTP_ADDR_SRC, /* address can be used as source */
695 SCTP_ADDR_DEL, /* address about to be deleted */
698 /* This is a structure for holding either an IPv6 or an IPv4 address. */
699 struct sctp_sockaddr_entry {
700 struct list_head list;
707 #define SCTP_ADDRESS_TICK_DELAY 500
709 /* This structure holds lists of chunks as we are assembling for
713 /* These are the SCTP header values (host order) for the packet. */
715 __u16 destination_port;
718 /* This contains the payload chunks. */
719 struct list_head chunk_list;
721 /* This is the overhead of the sctp and ip headers. */
723 /* This is the total size of all chunks INCLUDING padding. */
725 /* This is the maximum size this packet may have */
728 /* The packet is destined for this transport address.
729 * The function we finally use to pass down to the next lower
730 * layer lives in the transport structure.
732 struct sctp_transport *transport;
734 /* pointer to the auth chunk for this packet */
735 struct sctp_chunk *auth;
737 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
738 has_sack:1, /* This packet contains a SACK chunk. */
739 has_auth:1, /* This packet contains an AUTH chunk */
740 has_data:1, /* This packet contains at least 1 DATA chunk */
741 ipfragok:1; /* So let ip fragment this packet */
744 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
745 __u16 sport, __u16 dport);
746 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
747 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
748 struct sctp_chunk *chunk,
749 int one_packet, gfp_t gfp);
750 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
751 struct sctp_chunk *chunk);
752 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
753 void sctp_packet_free(struct sctp_packet *);
755 static inline int sctp_packet_empty(struct sctp_packet *packet)
757 return packet->size == packet->overhead;
760 /* This represents a remote transport address.
761 * For local transport addresses, we just use union sctp_addr.
763 * RFC2960 Section 1.4 Key Terms
765 * o Transport address: A Transport Address is traditionally defined
766 * by Network Layer address, Transport Layer protocol and Transport
767 * Layer port number. In the case of SCTP running over IP, a
768 * transport address is defined by the combination of an IP address
769 * and an SCTP port number (where SCTP is the Transport protocol).
771 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
773 * o The sender keeps a separate congestion control parameter set for
774 * each of the destination addresses it can send to (not each
775 * source-destination pair but for each destination). The parameters
776 * should decay if the address is not used for a long enough time
780 struct sctp_transport {
781 /* A list of transports. */
782 struct list_head transports;
783 struct rhlist_head node;
785 /* Reference counting. */
787 /* RTO-Pending : A flag used to track if one of the DATA
788 * chunks sent to this address is currently being
789 * used to compute a RTT. If this flag is 0,
790 * the next DATA chunk sent to this destination
791 * should be used to compute a RTT and this flag
792 * should be set. Every time the RTT
793 * calculation completes (i.e. the DATA chunk
794 * is SACK'd) clear this flag.
799 * hb_sent : a flag that signals that we have a pending
804 /* Is the Path MTU update pending on this tranport */
807 dst_pending_confirm:1, /* need to confirm neighbour */
809 /* Has this transport moved the ctsn since we last sacked */
815 /* This is the peer's IP address and port. */
816 union sctp_addr ipaddr;
818 /* These are the functions we call to handle LLP stuff. */
819 struct sctp_af *af_specific;
821 /* Which association do we belong to? */
822 struct sctp_association *asoc;
826 * 12.3 Per Transport Address Data
828 * For each destination transport address in the peer's
829 * address list derived from the INIT or INIT ACK chunk, a
830 * number of data elements needs to be maintained including:
832 /* RTO : The current retransmission timeout value. */
835 __u32 rtt; /* This is the most recent RTT. */
837 /* RTTVAR : The current RTT variation. */
840 /* SRTT : The current smoothed round trip time. */
844 * These are the congestion stats.
846 /* cwnd : The current congestion window. */
847 __u32 cwnd; /* This is the actual cwnd. */
849 /* ssthresh : The current slow start threshold value. */
852 /* partial : The tracking method for increase of cwnd when in
853 * bytes acked : congestion avoidance mode (see Section 6.2.2)
855 __u32 partial_bytes_acked;
857 /* Data that has been sent, but not acknowledged. */
860 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
863 struct dst_entry *dst;
864 /* Source address. */
865 union sctp_addr saddr;
867 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
868 * the destination address every heartbeat interval.
870 unsigned long hbinterval;
872 /* SACK delay timeout */
873 unsigned long sackdelay;
876 /* When was the last time that we heard from this transport? We use
877 * this to pick new active and retran paths.
879 ktime_t last_time_heard;
881 /* When was the last time that we sent a chunk using this
882 * transport? We use this to check for idle transports
884 unsigned long last_time_sent;
886 /* Last time(in jiffies) when cwnd is reduced due to the congestion
887 * indication based on ECNE chunk.
889 unsigned long last_time_ecne_reduced;
891 /* This is the max_retrans value for the transport and will
892 * be initialized from the assocs value. This can be changed
893 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
897 /* This is the partially failed retrans value for the transport
898 * and will be initialized from the assocs value. This can be changed
899 * using the SCTP_PEER_ADDR_THLDS socket option
902 /* PMTU : The current known path MTU. */
905 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
908 /* The number of times INIT has been sent on this transport. */
911 /* state : The current state of this destination,
912 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
916 /* These are the error stats for this destination. */
918 /* Error count : The current error count for this destination. */
919 unsigned short error_count;
921 /* Per : A timer used by each destination.
925 * [Everywhere else in the text this is called T3-rtx. -ed]
927 struct timer_list T3_rtx_timer;
929 /* Heartbeat timer is per destination. */
930 struct timer_list hb_timer;
932 /* Timer to handle ICMP proto unreachable envets */
933 struct timer_list proto_unreach_timer;
935 /* Timer to handler reconf chunk rtx */
936 struct timer_list reconf_timer;
938 /* Since we're using per-destination retransmission timers
939 * (see above), we're also using per-destination "transmitted"
940 * queues. This probably ought to be a private struct
941 * accessible only within the outqueue, but it's not, yet.
943 struct list_head transmitted;
945 /* We build bundle-able packets for this transport here. */
946 struct sctp_packet packet;
948 /* This is the list of transports that have chunks to send. */
949 struct list_head send_ready;
951 /* State information saved for SFR_CACC algorithm. The key
952 * idea in SFR_CACC is to maintain state at the sender on a
953 * per-destination basis when a changeover happens.
954 * char changeover_active;
955 * char cycling_changeover;
956 * __u32 next_tsn_at_change;
957 * char cacc_saw_newack;
960 /* An unsigned integer, which stores the next TSN to be
961 * used by the sender, at the moment of changeover.
963 __u32 next_tsn_at_change;
965 /* A flag which indicates the occurrence of a changeover */
966 char changeover_active;
968 /* A flag which indicates whether the change of primary is
969 * the first switch to this destination address during an
972 char cycling_changeover;
974 /* A temporary flag, which is used during the processing of
975 * a SACK to estimate the causative TSN(s)'s group.
977 char cacc_saw_newack;
980 /* 64-bit random number sent with heartbeat. */
986 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
988 void sctp_transport_set_owner(struct sctp_transport *,
989 struct sctp_association *);
990 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
992 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
993 void sctp_transport_free(struct sctp_transport *);
994 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
995 void sctp_transport_reset_hb_timer(struct sctp_transport *);
996 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
997 int sctp_transport_hold(struct sctp_transport *);
998 void sctp_transport_put(struct sctp_transport *);
999 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1000 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1001 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1002 enum sctp_lower_cwnd reason);
1003 void sctp_transport_burst_limited(struct sctp_transport *);
1004 void sctp_transport_burst_reset(struct sctp_transport *);
1005 unsigned long sctp_transport_timeout(struct sctp_transport *);
1006 void sctp_transport_reset(struct sctp_transport *t);
1007 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1008 void sctp_transport_immediate_rtx(struct sctp_transport *);
1009 void sctp_transport_dst_release(struct sctp_transport *t);
1010 void sctp_transport_dst_confirm(struct sctp_transport *t);
1013 /* This is the structure we use to queue packets as they come into
1014 * SCTP. We write packets to it and read chunks from it.
1017 /* This is actually a queue of sctp_chunk each
1018 * containing a partially decoded packet.
1020 struct list_head in_chunk_list;
1021 /* This is the packet which is currently off the in queue and is
1022 * being worked on through the inbound chunk processing.
1024 struct sctp_chunk *in_progress;
1026 /* This is the delayed task to finish delivering inbound
1029 struct work_struct immediate;
1032 void sctp_inq_init(struct sctp_inq *);
1033 void sctp_inq_free(struct sctp_inq *);
1034 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1035 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1036 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1037 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1039 /* This is the structure we use to hold outbound chunks. You push
1040 * chunks in and they automatically pop out the other end as bundled
1041 * packets (it calls (*output_handler)()).
1043 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1044 * and 8.2 of the v13 draft.
1046 * It handles retransmissions. The connection to the timeout portion
1047 * of the state machine is through sctp_..._timeout() and timeout_handler.
1049 * If you feed it SACKs, it will eat them.
1051 * If you give it big chunks, it will fragment them.
1053 * It assigns TSN's to data chunks. This happens at the last possible
1054 * instant before transmission.
1056 * When free()'d, it empties itself out via output_handler().
1059 struct sctp_association *asoc;
1061 /* Data pending that has never been transmitted. */
1062 struct list_head out_chunk_list;
1064 /* Stream scheduler being used */
1065 struct sctp_sched_ops *sched;
1067 unsigned int out_qlen; /* Total length of queued data chunks. */
1069 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1072 /* These are control chunks we want to send. */
1073 struct list_head control_chunk_list;
1075 /* These are chunks that have been sacked but are above the
1076 * CTSN, or cumulative tsn ack point.
1078 struct list_head sacked;
1080 /* Put chunks on this list to schedule them for
1083 struct list_head retransmit;
1085 /* Put chunks on this list to save them for FWD TSN processing as
1086 * they were abandoned.
1088 struct list_head abandoned;
1090 /* How many unackd bytes do we have in-flight? */
1091 __u32 outstanding_bytes;
1093 /* Are we doing fast-rtx on this queue */
1100 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1101 void sctp_outq_teardown(struct sctp_outq *);
1102 void sctp_outq_free(struct sctp_outq*);
1103 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1104 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1105 int sctp_outq_is_empty(const struct sctp_outq *);
1106 void sctp_outq_restart(struct sctp_outq *);
1108 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1109 enum sctp_retransmit_reason reason);
1110 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1111 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1112 void sctp_prsctp_prune(struct sctp_association *asoc,
1113 struct sctp_sndrcvinfo *sinfo, int msg_len);
1114 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1115 /* Uncork and flush an outqueue. */
1116 static inline void sctp_outq_cork(struct sctp_outq *q)
1121 /* SCTP skb control block.
1122 * sctp_input_cb is currently used on rx and sock rx queue
1124 struct sctp_input_cb {
1126 struct inet_skb_parm h4;
1127 #if IS_ENABLED(CONFIG_IPV6)
1128 struct inet6_skb_parm h6;
1131 struct sctp_chunk *chunk;
1134 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1136 struct sctp_output_cb {
1137 struct sk_buff *last;
1139 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1141 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1143 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1145 return chunk->head_skb ? : skb;
1148 /* These bind address data fields common between endpoints and associations */
1149 struct sctp_bind_addr {
1151 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1153 * SCTP Port: The local SCTP port number the endpoint is
1158 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1160 * Address List: The list of IP addresses that this instance
1161 * has bound. This information is passed to one's
1162 * peer(s) in INIT and INIT ACK chunks.
1164 struct list_head address_list;
1167 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1168 void sctp_bind_addr_free(struct sctp_bind_addr *);
1169 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1170 const struct sctp_bind_addr *src,
1171 enum sctp_scope scope, gfp_t gfp,
1173 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1174 const struct sctp_bind_addr *src,
1176 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1177 int new_size, __u8 addr_state, gfp_t gfp);
1178 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1179 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1180 struct sctp_sock *);
1181 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1182 struct sctp_sock *, struct sctp_sock *);
1183 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1184 const union sctp_addr *addr);
1185 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1186 const union sctp_addr *addrs,
1188 struct sctp_sock *opt);
1189 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1192 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1193 __u16 port, gfp_t gfp);
1195 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1196 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1197 const enum sctp_scope scope);
1198 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1199 int sctp_is_ep_boundall(struct sock *sk);
1202 /* What type of endpoint? */
1203 enum sctp_endpoint_type {
1204 SCTP_EP_TYPE_SOCKET,
1205 SCTP_EP_TYPE_ASSOCIATION,
1209 * A common base class to bridge the implmentation view of a
1210 * socket (usually listening) endpoint versus an association's
1212 * This common structure is useful for several purposes:
1213 * 1) Common interface for lookup routines.
1214 * a) Subfunctions work for either endpoint or association
1215 * b) Single interface to lookup allows hiding the lookup lock rather
1216 * than acquiring it externally.
1217 * 2) Common interface for the inbound chunk handling/state machine.
1218 * 3) Common object handling routines for reference counting, etc.
1219 * 4) Disentangle association lookup from endpoint lookup, where we
1220 * do not have to find our endpoint to find our association.
1224 struct sctp_ep_common {
1225 /* Fields to help us manage our entries in the hash tables. */
1226 struct hlist_node node;
1229 /* Runtime type information. What kind of endpoint is this? */
1230 enum sctp_endpoint_type type;
1232 /* Some fields to help us manage this object.
1233 * refcnt - Reference count access to this object.
1234 * dead - Do not attempt to use this object.
1239 /* What socket does this endpoint belong to? */
1242 /* This is where we receive inbound chunks. */
1243 struct sctp_inq inqueue;
1245 /* This substructure includes the defining parameters of the
1247 * bind_addr.port is our shared port number.
1248 * bind_addr.address_list is our set of local IP addresses.
1250 struct sctp_bind_addr bind_addr;
1254 /* RFC Section 1.4 Key Terms
1256 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1257 * multi-homed host, an SCTP endpoint is represented to its peers as a
1258 * combination of a set of eligible destination transport addresses to
1259 * which SCTP packets can be sent and a set of eligible source
1260 * transport addresses from which SCTP packets can be received.
1261 * All transport addresses used by an SCTP endpoint must use the
1262 * same port number, but can use multiple IP addresses. A transport
1263 * address used by an SCTP endpoint must not be used by another
1264 * SCTP endpoint. In other words, a transport address is unique
1265 * to an SCTP endpoint.
1267 * From an implementation perspective, each socket has one of these.
1268 * A TCP-style socket will have exactly one association on one of
1269 * these. An UDP-style socket will have multiple associations hanging
1273 struct sctp_endpoint {
1274 /* Common substructure for endpoint and association. */
1275 struct sctp_ep_common base;
1277 /* Associations: A list of current associations and mappings
1278 * to the data consumers for each association. This
1279 * may be in the form of a hash table or other
1280 * implementation dependent structure. The data
1281 * consumers may be process identification
1282 * information such as file descriptors, named pipe
1283 * pointer, or table pointers dependent on how SCTP
1286 /* This is really a list of struct sctp_association entries. */
1287 struct list_head asocs;
1289 /* Secret Key: A secret key used by this endpoint to compute
1290 * the MAC. This SHOULD be a cryptographic quality
1291 * random number with a sufficient length.
1292 * Discussion in [RFC1750] can be helpful in
1293 * selection of the key.
1295 __u8 secret_key[SCTP_SECRET_SIZE];
1297 /* digest: This is a digest of the sctp cookie. This field is
1298 * only used on the receive path when we try to validate
1299 * that the cookie has not been tampered with. We put
1300 * this here so we pre-allocate this once and can re-use
1305 /* sendbuf acct. policy. */
1306 __u32 sndbuf_policy;
1308 /* rcvbuf acct. policy. */
1309 __u32 rcvbuf_policy;
1311 /* SCTP AUTH: array of the HMACs that will be allocated
1312 * we need this per association so that we don't serialize
1314 struct crypto_shash **auth_hmacs;
1316 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1317 struct sctp_hmac_algo_param *auth_hmacs_list;
1319 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1320 struct sctp_chunks_param *auth_chunk_list;
1322 /* SCTP-AUTH: endpoint shared keys */
1323 struct list_head endpoint_shared_keys;
1324 __u16 active_key_id;
1329 __u8 strreset_enable;
1331 /* Security identifiers from incoming (INIT). These are set by
1332 * security_sctp_assoc_request(). These will only be used by
1333 * SCTP TCP type sockets and peeled off connections as they
1334 * cause a new socket to be generated. security_sctp_sk_clone()
1335 * will then plug these into the new socket.
1342 /* Recover the outter endpoint structure. */
1343 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1345 struct sctp_endpoint *ep;
1347 ep = container_of(base, struct sctp_endpoint, base);
1351 /* These are function signatures for manipulating endpoints. */
1352 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1353 void sctp_endpoint_free(struct sctp_endpoint *);
1354 void sctp_endpoint_put(struct sctp_endpoint *);
1355 void sctp_endpoint_hold(struct sctp_endpoint *);
1356 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1357 struct sctp_association *sctp_endpoint_lookup_assoc(
1358 const struct sctp_endpoint *ep,
1359 const union sctp_addr *paddr,
1360 struct sctp_transport **);
1361 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1362 const union sctp_addr *paddr);
1363 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1364 struct net *, const union sctp_addr *);
1365 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1366 const union sctp_addr *paddr);
1368 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1369 const struct sctp_association *asoc,
1370 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1371 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1372 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1373 const union sctp_addr *peer,
1374 struct sctp_init_chunk *init, gfp_t gfp);
1375 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1376 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1378 struct sctp_inithdr_host {
1381 __u16 num_outbound_streams;
1382 __u16 num_inbound_streams;
1386 struct sctp_stream_priorities {
1387 /* List of priorities scheduled */
1388 struct list_head prio_sched;
1389 /* List of streams scheduled */
1390 struct list_head active;
1391 /* The next stream stream in line */
1392 struct sctp_stream_out_ext *next;
1396 struct sctp_stream_out_ext {
1397 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1398 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1399 struct list_head outq; /* chunks enqueued by this stream */
1402 /* Scheduled streams list */
1403 struct list_head prio_list;
1404 struct sctp_stream_priorities *prio_head;
1406 /* Fields used by RR scheduler */
1408 struct list_head rr_list;
1413 struct sctp_stream_out {
1419 struct sctp_stream_out_ext *ext;
1423 struct sctp_stream_in {
1435 struct sctp_stream {
1436 struct sctp_stream_out *out;
1437 struct sctp_stream_in *in;
1440 /* Current stream being sent, if any */
1441 struct sctp_stream_out *out_curr;
1443 /* Fields used by priority scheduler */
1445 /* List of priorities scheduled */
1446 struct list_head prio_list;
1448 /* Fields used by RR scheduler */
1450 /* List of streams scheduled */
1451 struct list_head rr_list;
1452 /* The next stream stream in line */
1453 struct sctp_stream_out_ext *rr_next;
1456 struct sctp_stream_interleave *si;
1459 #define SCTP_STREAM_CLOSED 0x00
1460 #define SCTP_STREAM_OPEN 0x01
1462 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1464 return stream->si->data_chunk_len;
1467 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1469 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1472 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1474 return stream->si->ftsn_chunk_len;
1477 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1479 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1482 /* SCTP_GET_ASSOC_STATS counters */
1483 struct sctp_priv_assoc_stats {
1484 /* Maximum observed rto in the association during subsequent
1485 * observations. Value is set to 0 if no RTO measurement took place
1486 * The transport where the max_rto was observed is returned in
1489 struct sockaddr_storage obs_rto_ipaddr;
1491 /* Total In and Out SACKs received and sent */
1494 /* Total In and Out packets received and sent */
1497 /* Total retransmitted chunks */
1499 /* TSN received > next expected */
1501 /* Duplicate Chunks received */
1503 /* Gap Ack Blocks received */
1505 /* Unordered data chunks sent and received */
1508 /* Ordered data chunks sent and received */
1511 /* Control chunks sent and received */
1518 * 12. Recommended Transmission Control Block (TCB) Parameters
1520 * This section details a recommended set of parameters that should
1521 * be contained within the TCB for an implementation. This section is
1522 * for illustrative purposes and should not be deemed as requirements
1523 * on an implementation or as an exhaustive list of all parameters
1524 * inside an SCTP TCB. Each implementation may need its own additional
1525 * parameters for optimization.
1529 /* Here we have information about each individual association. */
1530 struct sctp_association {
1532 /* A base structure common to endpoint and association.
1533 * In this context, it represents the associations's view
1534 * of the local endpoint of the association.
1536 struct sctp_ep_common base;
1538 /* Associations on the same socket. */
1539 struct list_head asocs;
1541 /* association id. */
1542 sctp_assoc_t assoc_id;
1544 /* This is our parent endpoint. */
1545 struct sctp_endpoint *ep;
1547 /* These are those association elements needed in the cookie. */
1548 struct sctp_cookie c;
1550 /* This is all information about our peer. */
1552 /* transport_addr_list
1554 * Peer : A list of SCTP transport addresses that the
1555 * Transport : peer is bound to. This information is derived
1556 * Address : from the INIT or INIT ACK and is used to
1557 * List : associate an inbound packet with a given
1558 * : association. Normally this information is
1559 * : hashed or keyed for quick lookup and access
1561 * : The list is also initialized with the list
1562 * : of addresses passed with the sctp_connectx()
1565 * It is a list of SCTP_transport's.
1567 struct list_head transport_addr_list;
1571 * Peer Rwnd : Current calculated value of the peer's rwnd.
1577 * Peer : A count of the number of peer addresses
1578 * Transport : in the Peer Transport Address List.
1582 __u16 transport_count;
1585 * The transport layer port number.
1591 * Primary : This is the current primary destination
1592 * Path : transport address of the peer endpoint. It
1593 * : may also specify a source transport address
1594 * : on this endpoint.
1596 * All of these paths live on transport_addr_list.
1598 * At the bakeoffs, we discovered that the intent of
1599 * primaryPath is that it only changes when the ULP
1600 * asks to have it changed. We add the activePath to
1601 * designate the connection we are currently using to
1602 * transmit new data and most control chunks.
1604 struct sctp_transport *primary_path;
1606 /* Cache the primary path address here, when we
1607 * need a an address for msg_name.
1609 union sctp_addr primary_addr;
1612 * The path that we are currently using to
1613 * transmit new data and most control chunks.
1615 struct sctp_transport *active_path;
1619 * RFC2960 6.4 Multi-homed SCTP Endpoints
1621 * Furthermore, when its peer is multi-homed, an
1622 * endpoint SHOULD try to retransmit a chunk to an
1623 * active destination transport address that is
1624 * different from the last destination address to
1625 * which the DATA chunk was sent.
1627 struct sctp_transport *retran_path;
1629 /* Pointer to last transport I have sent on. */
1630 struct sctp_transport *last_sent_to;
1632 /* This is the last transport I have received DATA on. */
1633 struct sctp_transport *last_data_from;
1636 * Mapping An array of bits or bytes indicating which out of
1637 * Array order TSN's have been received (relative to the
1638 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1639 * order packets have been received, this array
1640 * will be set to all zero. This structure may be
1641 * in the form of a circular buffer or bit array.
1643 * Last Rcvd : This is the last TSN received in
1644 * TSN : sequence. This value is set initially by
1645 * : taking the peer's Initial TSN, received in
1646 * : the INIT or INIT ACK chunk, and subtracting
1649 * Throughout most of the specification this is called the
1650 * "Cumulative TSN ACK Point". In this case, we
1651 * ignore the advice in 12.2 in favour of the term
1652 * used in the bulk of the text. This value is hidden
1653 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1655 struct sctp_tsnmap tsn_map;
1657 /* This mask is used to disable sending the ASCONF chunk
1658 * with specified parameter to peer.
1660 __be16 addip_disabled_mask;
1662 /* These are capabilities which our peer advertised. */
1663 __u8 ecn_capable:1, /* Can peer do ECN? */
1664 ipv4_address:1, /* Peer understands IPv4 addresses? */
1665 ipv6_address:1, /* Peer understands IPv6 addresses? */
1666 hostname_address:1, /* Peer understands DNS addresses? */
1667 asconf_capable:1, /* Does peer support ADDIP? */
1668 prsctp_capable:1, /* Can peer do PR-SCTP? */
1669 reconf_capable:1, /* Can peer do RE-CONFIG? */
1670 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1672 /* sack_needed : This flag indicates if the next received
1673 * : packet is to be responded to with a
1674 * : SACK. This is initialized to 0. When a packet
1675 * : is received sack_cnt is incremented. If this value
1676 * : reaches 2 or more, a SACK is sent and the
1677 * : value is reset to 0. Note: This is used only
1678 * : when no DATA chunks are received out of
1679 * : order. When DATA chunks are out of order,
1680 * : SACK's are not delayed (see Section 6).
1682 __u8 sack_needed:1, /* Do we need to sack the peer? */
1684 zero_window_announced:1;
1687 __u32 adaptation_ind; /* Adaptation Code point. */
1689 struct sctp_inithdr_host i;
1693 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1694 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1695 * Initial TSN Value minus 1
1699 /* SCTP-AUTH: We need to know pears random number, hmac list
1700 * and authenticated chunk list. All that is part of the
1701 * cookie and these are just pointers to those locations
1703 struct sctp_random_param *peer_random;
1704 struct sctp_chunks_param *peer_chunks;
1705 struct sctp_hmac_algo_param *peer_hmacs;
1708 /* State : A state variable indicating what state the
1709 * : association is in, i.e. COOKIE-WAIT,
1710 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1711 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1713 * Note: No "CLOSED" state is illustrated since if a
1714 * association is "CLOSED" its TCB SHOULD be removed.
1716 * In this implementation we DO have a CLOSED
1717 * state which is used during initiation and shutdown.
1719 * State takes values from SCTP_STATE_*.
1721 enum sctp_state state;
1723 /* Overall : The overall association error count.
1724 * Error Count : [Clear this any time I get something.]
1726 int overall_error_count;
1728 /* The cookie life I award for any cookie. */
1729 ktime_t cookie_life;
1731 /* These are the association's initial, max, and min RTO values.
1732 * These values will be initialized by system defaults, but can
1733 * be modified via the SCTP_RTOINFO socket option.
1735 unsigned long rto_initial;
1736 unsigned long rto_max;
1737 unsigned long rto_min;
1739 /* Maximum number of new data packets that can be sent in a burst. */
1742 /* This is the max_retrans value for the association. This value will
1743 * be initialized initialized from system defaults, but can be
1744 * modified by the SCTP_ASSOCINFO socket option.
1748 /* This is the partially failed retrans value for the transport
1749 * and will be initialized from the assocs value. This can be
1750 * changed using the SCTP_PEER_ADDR_THLDS socket option
1754 /* Maximum number of times the endpoint will retransmit INIT */
1755 __u16 max_init_attempts;
1757 /* How many times have we resent an INIT? */
1760 /* The largest timeout or RTO value to use in attempting an INIT */
1761 unsigned long max_init_timeo;
1763 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1764 * the destination address every heartbeat interval. This value
1765 * will be inherited by all new transports.
1767 unsigned long hbinterval;
1769 /* This is the max_retrans value for new transports in the
1774 /* Flag that path mtu update is pending */
1777 /* Association : The smallest PMTU discovered for all of the
1778 * PMTU : peer's transport addresses.
1782 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1786 /* SACK delay timeout */
1787 unsigned long sackdelay;
1789 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1790 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1792 /* Transport to which SHUTDOWN chunk was last sent. */
1793 struct sctp_transport *shutdown_last_sent_to;
1795 /* Transport to which INIT chunk was last sent. */
1796 struct sctp_transport *init_last_sent_to;
1798 /* How many times have we resent a SHUTDOWN */
1799 int shutdown_retries;
1801 /* Next TSN : The next TSN number to be assigned to a new
1802 * : DATA chunk. This is sent in the INIT or INIT
1803 * : ACK chunk to the peer and incremented each
1804 * : time a DATA chunk is assigned a TSN
1805 * : (normally just prior to transmit or during
1811 * Last Rcvd : This is the last TSN received in sequence. This value
1812 * TSN : is set initially by taking the peer's Initial TSN,
1813 * : received in the INIT or INIT ACK chunk, and
1814 * : subtracting one from it.
1816 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1819 __u32 ctsn_ack_point;
1821 /* PR-SCTP Advanced.Peer.Ack.Point */
1822 __u32 adv_peer_ack_point;
1824 /* Highest TSN that is acknowledged by incoming SACKs. */
1825 __u32 highest_sacked;
1827 /* TSN marking the fast recovery exit point */
1828 __u32 fast_recovery_exit;
1830 /* Flag to track the current fast recovery state */
1833 /* The number of unacknowledged data chunks. Reported through
1834 * the SCTP_STATUS sockopt.
1838 /* The total number of data chunks that we've had to retransmit
1839 * as the result of a T3 timer expiration
1841 __u32 rtx_data_chunks;
1843 /* This is the association's receive buffer space. This value is used
1844 * to set a_rwnd field in an INIT or a SACK chunk.
1848 /* This is the last advertised value of rwnd over a SACK chunk. */
1851 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1852 * to slop over a maximum of the association's frag_point.
1856 /* Keeps treack of rwnd pressure. This happens when we have
1857 * a window, but not recevie buffer (i.e small packets). This one
1858 * is releases slowly (1 PMTU at a time ).
1862 /* This is the sndbuf size in use for the association.
1863 * This corresponds to the sndbuf size for the association,
1864 * as specified in the sk->sndbuf.
1868 /* This is the amount of memory that this association has allocated
1869 * in the receive path at any given time.
1871 atomic_t rmem_alloc;
1873 /* This is the wait queue head for send requests waiting on
1874 * the association sndbuf space.
1876 wait_queue_head_t wait;
1878 /* The message size at which SCTP fragmentation will occur. */
1882 /* Counter used to count INIT errors. */
1883 int init_err_counter;
1885 /* Count the number of INIT cycles (for doubling timeout). */
1888 /* Default send parameters. */
1889 __u16 default_stream;
1890 __u16 default_flags;
1892 __u32 default_context;
1893 __u32 default_timetolive;
1895 /* Default receive parameters */
1896 __u32 default_rcv_context;
1899 struct sctp_stream stream;
1901 /* All outbound chunks go through this structure. */
1902 struct sctp_outq outqueue;
1904 /* A smart pipe that will handle reordering and fragmentation,
1905 * as well as handle passing events up to the ULP.
1907 struct sctp_ulpq ulpq;
1909 /* Last TSN that caused an ECNE Chunk to be sent. */
1910 __u32 last_ecne_tsn;
1912 /* Last TSN that caused a CWR Chunk to be sent. */
1915 /* How many duplicated TSNs have we seen? */
1918 /* These are to support
1919 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1920 * and Enforcement of Flow and Message Limits"
1921 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1922 * or "ADDIP" for short.
1927 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1929 * R1) One and only one ASCONF Chunk MAY be in transit and
1930 * unacknowledged at any one time. If a sender, after sending
1931 * an ASCONF chunk, decides it needs to transfer another
1932 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1933 * returns from the previous ASCONF Chunk before sending a
1934 * subsequent ASCONF. Note this restriction binds each side,
1935 * so at any time two ASCONF may be in-transit on any given
1936 * association (one sent from each endpoint).
1938 * [This is our one-and-only-one ASCONF in flight. If we do
1939 * not have an ASCONF in flight, this is NULL.]
1941 struct sctp_chunk *addip_last_asconf;
1943 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1945 * This is needed to implement itmes E1 - E4 of the updated
1946 * spec. Here is the justification:
1948 * Since the peer may bundle multiple ASCONF chunks toward us,
1949 * we now need the ability to cache multiple ACKs. The section
1950 * describes in detail how they are cached and cleaned up.
1952 struct list_head asconf_ack_list;
1954 /* These ASCONF chunks are waiting to be sent.
1956 * These chunaks can't be pushed to outqueue until receiving
1957 * ASCONF_ACK for the previous ASCONF indicated by
1958 * addip_last_asconf, so as to guarantee that only one ASCONF
1959 * is in flight at any time.
1961 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1963 * In defining the ASCONF Chunk transfer procedures, it is
1964 * essential that these transfers MUST NOT cause congestion
1965 * within the network. To achieve this, we place these
1966 * restrictions on the transfer of ASCONF Chunks:
1968 * R1) One and only one ASCONF Chunk MAY be in transit and
1969 * unacknowledged at any one time. If a sender, after sending
1970 * an ASCONF chunk, decides it needs to transfer another
1971 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1972 * returns from the previous ASCONF Chunk before sending a
1973 * subsequent ASCONF. Note this restriction binds each side,
1974 * so at any time two ASCONF may be in-transit on any given
1975 * association (one sent from each endpoint).
1978 * [I really think this is EXACTLY the sort of intelligence
1979 * which already resides in sctp_outq. Please move this
1980 * queue and its supporting logic down there. --piggy]
1982 struct list_head addip_chunk_list;
1984 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1986 * A2) A serial number should be assigned to the Chunk. The
1987 * serial number SHOULD be a monotonically increasing
1988 * number. The serial number SHOULD be initialized at
1989 * the start of the association to the same value as the
1990 * Initial TSN and every time a new ASCONF chunk is created
1991 * it is incremented by one after assigning the serial number
1992 * to the newly created chunk.
1995 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1997 * Serial Number : 32 bits (unsigned integer)
1999 * This value represents a Serial Number for the ASCONF
2000 * Chunk. The valid range of Serial Number is from 0 to
2001 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2002 * after reaching 4294967295.
2005 int src_out_of_asoc_ok;
2006 union sctp_addr *asconf_addr_del_pending;
2007 struct sctp_transport *new_transport;
2009 /* SCTP AUTH: list of the endpoint shared keys. These
2010 * keys are provided out of band by the user applicaton
2011 * and can't change during the lifetime of the association
2013 struct list_head endpoint_shared_keys;
2016 * The current generated assocaition shared key (secret)
2018 struct sctp_auth_bytes *asoc_shared_key;
2019 struct sctp_shared_key *shkey;
2021 /* SCTP AUTH: hmac id of the first peer requested algorithm
2024 __u16 default_hmac_id;
2026 __u16 active_key_id;
2028 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2029 temp:1, /* Is it a temporary association? */
2035 __u8 strreset_enable;
2036 __u8 strreset_outstanding; /* request param count on the fly */
2038 __u32 strreset_outseq; /* Update after receiving response */
2039 __u32 strreset_inseq; /* Update after receiving request */
2040 __u32 strreset_result[2]; /* save the results of last 2 responses */
2042 struct sctp_chunk *strreset_chunk; /* save request chunk */
2044 struct sctp_priv_assoc_stats stats;
2046 int sent_cnt_removable;
2048 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2049 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2053 /* An eyecatcher for determining if we are really looking at an
2054 * association data structure.
2057 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2060 /* Recover the outter association structure. */
2061 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2063 struct sctp_association *asoc;
2065 asoc = container_of(base, struct sctp_association, base);
2069 /* These are function signatures for manipulating associations. */
2072 struct sctp_association *
2073 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2074 enum sctp_scope scope, gfp_t gfp);
2075 void sctp_association_free(struct sctp_association *);
2076 void sctp_association_put(struct sctp_association *);
2077 void sctp_association_hold(struct sctp_association *);
2079 struct sctp_transport *sctp_assoc_choose_alter_transport(
2080 struct sctp_association *, struct sctp_transport *);
2081 void sctp_assoc_update_retran_path(struct sctp_association *);
2082 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2083 const union sctp_addr *);
2084 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2085 const union sctp_addr *laddr);
2086 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2087 const union sctp_addr *address,
2089 const int peer_state);
2090 void sctp_assoc_del_peer(struct sctp_association *asoc,
2091 const union sctp_addr *addr);
2092 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2093 struct sctp_transport *peer);
2094 void sctp_assoc_control_transport(struct sctp_association *asoc,
2095 struct sctp_transport *transport,
2096 enum sctp_transport_cmd command,
2097 sctp_sn_error_t error);
2098 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2099 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2100 int sctp_assoc_update(struct sctp_association *old,
2101 struct sctp_association *new);
2103 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2105 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2106 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2107 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2108 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2109 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2110 void sctp_assoc_set_primary(struct sctp_association *,
2111 struct sctp_transport *);
2112 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2113 struct sctp_transport *);
2114 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2115 enum sctp_scope scope, gfp_t gfp);
2116 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2117 struct sctp_cookie*,
2119 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2120 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2121 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2122 const struct sctp_association *asoc,
2124 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2126 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2127 const union sctp_addr *ss2);
2128 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2130 /* A convenience structure to parse out SCTP specific CMSGs. */
2132 struct sctp_initmsg *init;
2133 struct sctp_sndrcvinfo *srinfo;
2134 struct sctp_sndinfo *sinfo;
2135 struct sctp_prinfo *prinfo;
2136 struct sctp_authinfo *authinfo;
2137 struct msghdr *addrs_msg;
2140 /* Structure for tracking memory objects */
2141 struct sctp_dbg_objcnt_entry {
2146 #endif /* __sctp_structs_h__ */