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/flex_array.h> /* We need flex_array. */
61 #include <linux/sctp.h> /* We need sctp* header structs. */
62 #include <net/sctp/auth.h> /* We need auth specific structs */
63 #include <net/ip.h> /* For inet_skb_parm */
65 /* A convenience structure for handling sockaddr structures.
66 * We should wean ourselves off this.
69 struct sockaddr_in v4;
70 struct sockaddr_in6 v6;
74 /* Forward declarations for data structures. */
77 struct sctp_association;
78 struct sctp_transport;
83 struct sctp_bind_addr;
85 struct sctp_ep_common;
90 #include <net/sctp/tsnmap.h>
91 #include <net/sctp/ulpevent.h>
92 #include <net/sctp/ulpqueue.h>
93 #include <net/sctp/stream_interleave.h>
95 /* Structures useful for managing bind/connect. */
97 struct sctp_bind_bucket {
99 signed char fastreuse;
100 signed char fastreuseport;
102 struct hlist_node node;
103 struct hlist_head owner;
107 struct sctp_bind_hashbucket {
109 struct hlist_head chain;
112 /* Used for hashing all associations. */
113 struct sctp_hashbucket {
115 struct hlist_head chain;
116 } __attribute__((__aligned__(8)));
119 /* The SCTP globals structure. */
120 extern struct sctp_globals {
121 /* This is a list of groups of functions for each address
122 * family that we support.
124 struct list_head address_families;
126 /* This is the hash of all endpoints. */
127 struct sctp_hashbucket *ep_hashtable;
128 /* This is the sctp port control hash. */
129 struct sctp_bind_hashbucket *port_hashtable;
130 /* This is the hash of all transports. */
131 struct rhltable transport_hashtable;
133 /* Sizes of above hashtables. */
137 /* Default initialization values to be applied to new associations. */
139 __u16 max_outstreams;
141 /* Flag to indicate whether computing and verifying checksum
143 bool checksum_disable;
146 #define sctp_max_instreams (sctp_globals.max_instreams)
147 #define sctp_max_outstreams (sctp_globals.max_outstreams)
148 #define sctp_address_families (sctp_globals.address_families)
149 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
150 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
151 #define sctp_port_hashsize (sctp_globals.port_hashsize)
152 #define sctp_port_hashtable (sctp_globals.port_hashtable)
153 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
154 #define sctp_checksum_disable (sctp_globals.checksum_disable)
156 /* SCTP Socket type: UDP or TCP style. */
157 enum sctp_socket_type {
159 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
163 /* Per socket SCTP information. */
165 /* inet_sock has to be the first member of sctp_sock */
166 struct inet_sock inet;
167 /* What kind of a socket is this? */
168 enum sctp_socket_type type;
170 /* PF_ family specific functions. */
173 /* Access to HMAC transform. */
174 struct crypto_shash *hmac;
177 /* What is our base endpointer? */
178 struct sctp_endpoint *ep;
180 struct sctp_bind_bucket *bind_hash;
181 /* Various Socket Options. */
182 __u16 default_stream;
185 __u32 default_context;
186 __u32 default_timetolive;
187 __u32 default_rcv_context;
190 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
191 * the destination address every heartbeat interval. This value
192 * will be inherited by all new associations.
196 /* This is the max_retrans value for new associations. */
204 /* The initial Path MTU to use for new associations. */
207 /* The default SACK delay timeout for new associations. */
211 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
216 struct sctp_rtoinfo rtoinfo;
217 struct sctp_paddrparams paddrparam;
218 struct sctp_assocparams assocparams;
221 * These two structures must be grouped together for the usercopy
225 struct sctp_initmsg initmsg;
230 __u32 adaptation_ind;
240 data_ready_signalled:1;
243 /* Receive to here while partial delivery is in effect. */
244 struct sk_buff_head pd_lobby;
246 /* These must be the last fields, as they will skipped on copies,
247 * like on accept and peeloff operations
249 struct list_head auto_asconf_list;
253 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
255 return (struct sctp_sock *)sk;
258 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
260 return (struct sock *)sp;
263 #if IS_ENABLED(CONFIG_IPV6)
265 struct sctp_sock sctp;
266 struct ipv6_pinfo inet6;
268 #endif /* CONFIG_IPV6 */
271 /* This is our APPLICATION-SPECIFIC state cookie.
272 * THIS IS NOT DICTATED BY THE SPECIFICATION.
274 /* These are the parts of an association which we send in the cookie.
275 * Most of these are straight out of:
276 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
282 /* My : Tag expected in every inbound packet and sent
283 * Verification: in the INIT or INIT ACK chunk.
288 /* Peer's : Tag expected in every outbound packet except
289 * Verification: in the INIT chunk.
294 /* The rest of these are not from the spec, but really need to
298 /* My Tie Tag : Assist in discovering a restarting association. */
301 /* Peer's Tie Tag: Assist in discovering a restarting association. */
304 /* When does this cookie expire? */
307 /* Number of inbound/outbound streams which are set
308 * and negotiated during the INIT process.
310 __u16 sinit_num_ostreams;
311 __u16 sinit_max_instreams;
313 /* This is the first sequence number I used. */
316 /* This holds the originating address of the INIT packet. */
317 union sctp_addr peer_addr;
320 * Include the source port of the INIT-ACK
326 /* Padding for future use */
329 __u32 adaptation_ind;
331 __u8 auth_random[sizeof(struct sctp_paramhdr) +
332 SCTP_AUTH_RANDOM_LENGTH];
333 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
334 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
336 /* This is a shim for my peer's INIT packet, followed by
337 * a copy of the raw address list of the association.
338 * The length of the raw address list is saved in the
339 * raw_addr_list_len field, which will be used at the time when
340 * the association TCB is re-constructed from the cookie.
342 __u32 raw_addr_list_len;
343 struct sctp_init_chunk peer_init[0];
347 /* The format of our cookie that we send to our peer. */
348 struct sctp_signed_cookie {
349 __u8 signature[SCTP_SECRET_SIZE];
350 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
351 struct sctp_cookie c;
354 /* This is another convenience type to allocate memory for address
355 * params for the maximum size and pass such structures around
358 union sctp_addr_param {
359 struct sctp_paramhdr p;
360 struct sctp_ipv4addr_param v4;
361 struct sctp_ipv6addr_param v6;
364 /* A convenience type to allow walking through the various
365 * parameters and avoid casting all over the place.
369 struct sctp_paramhdr *p;
370 struct sctp_cookie_preserve_param *life;
371 struct sctp_hostname_param *dns;
372 struct sctp_cookie_param *cookie;
373 struct sctp_supported_addrs_param *sat;
374 struct sctp_ipv4addr_param *v4;
375 struct sctp_ipv6addr_param *v6;
376 union sctp_addr_param *addr;
377 struct sctp_adaptation_ind_param *aind;
378 struct sctp_supported_ext_param *ext;
379 struct sctp_random_param *random;
380 struct sctp_chunks_param *chunks;
381 struct sctp_hmac_algo_param *hmac_algo;
382 struct sctp_addip_param *addip;
385 /* RFC 2960. Section 3.3.5 Heartbeat.
386 * Heartbeat Information: variable length
387 * The Sender-specific Heartbeat Info field should normally include
388 * information about the sender's current time when this HEARTBEAT
389 * chunk is sent and the destination transport address to which this
390 * HEARTBEAT is sent (see Section 8.3).
392 struct sctp_sender_hb_info {
393 struct sctp_paramhdr param_hdr;
394 union sctp_addr daddr;
395 unsigned long sent_at;
399 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
401 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
402 void sctp_stream_free(struct sctp_stream *stream);
403 void sctp_stream_clear(struct sctp_stream *stream);
404 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
406 /* What is the current SSN number for this stream? */
407 #define sctp_ssn_peek(stream, type, sid) \
408 (sctp_stream_##type((stream), (sid))->ssn)
410 /* Return the next SSN number for this stream. */
411 #define sctp_ssn_next(stream, type, sid) \
412 (sctp_stream_##type((stream), (sid))->ssn++)
414 /* Skip over this ssn and all below. */
415 #define sctp_ssn_skip(stream, type, sid, ssn) \
416 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
418 /* What is the current MID number for this stream? */
419 #define sctp_mid_peek(stream, type, sid) \
420 (sctp_stream_##type((stream), (sid))->mid)
422 /* Return the next MID number for this stream. */
423 #define sctp_mid_next(stream, type, sid) \
424 (sctp_stream_##type((stream), (sid))->mid++)
426 /* Skip over this mid and all below. */
427 #define sctp_mid_skip(stream, type, sid, mid) \
428 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
430 /* What is the current MID_uo number for this stream? */
431 #define sctp_mid_uo_peek(stream, type, sid) \
432 (sctp_stream_##type((stream), (sid))->mid_uo)
434 /* Return the next MID_uo number for this stream. */
435 #define sctp_mid_uo_next(stream, type, sid) \
436 (sctp_stream_##type((stream), (sid))->mid_uo++)
439 * Pointers to address related SCTP functions.
440 * (i.e. things that depend on the address family.)
443 int (*sctp_xmit) (struct sk_buff *skb,
444 struct sctp_transport *);
445 int (*setsockopt) (struct sock *sk,
449 unsigned int optlen);
450 int (*getsockopt) (struct sock *sk,
455 int (*compat_setsockopt) (struct sock *sk,
459 unsigned int optlen);
460 int (*compat_getsockopt) (struct sock *sk,
465 void (*get_dst) (struct sctp_transport *t,
466 union sctp_addr *saddr,
469 void (*get_saddr) (struct sctp_sock *sk,
470 struct sctp_transport *t,
472 void (*copy_addrlist) (struct list_head *,
473 struct net_device *);
474 int (*cmp_addr) (const union sctp_addr *addr1,
475 const union sctp_addr *addr2);
476 void (*addr_copy) (union sctp_addr *dst,
477 union sctp_addr *src);
478 void (*from_skb) (union sctp_addr *,
481 void (*from_sk) (union sctp_addr *,
483 void (*from_addr_param) (union sctp_addr *,
484 union sctp_addr_param *,
485 __be16 port, int iif);
486 int (*to_addr_param) (const union sctp_addr *,
487 union sctp_addr_param *);
488 int (*addr_valid) (union sctp_addr *,
490 const struct sk_buff *);
491 enum sctp_scope (*scope)(union sctp_addr *);
492 void (*inaddr_any) (union sctp_addr *, __be16);
493 int (*is_any) (const union sctp_addr *);
494 int (*available) (union sctp_addr *,
496 int (*skb_iif) (const struct sk_buff *sk);
497 int (*is_ce) (const struct sk_buff *sk);
498 void (*seq_dump_addr)(struct seq_file *seq,
499 union sctp_addr *addr);
500 void (*ecn_capable)(struct sock *sk);
501 __u16 net_header_len;
503 int (*ip_options_len)(struct sock *sk);
504 sa_family_t sa_family;
505 struct list_head list;
508 struct sctp_af *sctp_get_af_specific(sa_family_t);
509 int sctp_register_af(struct sctp_af *);
511 /* Protocol family functions. */
513 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
514 void (*skb_msgname) (struct sk_buff *, char *, int *);
515 int (*af_supported) (sa_family_t, struct sctp_sock *);
516 int (*cmp_addr) (const union sctp_addr *,
517 const union sctp_addr *,
519 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
520 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
521 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
522 struct sock *(*create_accept_sk) (struct sock *sk,
523 struct sctp_association *asoc,
525 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
526 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
527 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
528 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
533 /* Structure to track chunk fragments that have been acked, but peer
534 * fragments of the same message have not.
536 struct sctp_datamsg {
537 /* Chunks waiting to be submitted to lower layer. */
538 struct list_head chunks;
539 /* Reference counting. */
541 /* When is this message no longer interesting to the peer? */
542 unsigned long expires_at;
543 /* Did the messenge fail to send? */
546 can_delay:1, /* should this message be Nagle delayed */
547 abandoned:1; /* should this message be abandoned */
550 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
551 struct sctp_sndrcvinfo *,
553 void sctp_datamsg_free(struct sctp_datamsg *);
554 void sctp_datamsg_put(struct sctp_datamsg *);
555 void sctp_chunk_fail(struct sctp_chunk *, int error);
556 int sctp_chunk_abandoned(struct sctp_chunk *);
558 /* RFC2960 1.4 Key Terms
560 * o Chunk: A unit of information within an SCTP packet, consisting of
561 * a chunk header and chunk-specific content.
563 * As a matter of convenience, we remember the SCTP common header for
564 * each chunk as well as a few other header pointers...
567 struct list_head list;
571 /* How many times this chunk have been sent, for prsctp RTX policy */
575 /* This is our link to the per-transport transmitted list. */
576 struct list_head transmitted_list;
577 /* List in specific stream outq */
578 struct list_head stream_list;
581 /* This field is used by chunks that hold fragmented data.
582 * For the first fragment this is the list that holds the rest of
583 * fragments. For the remaining fragments, this is the link to the
584 * frag_list maintained in the first fragment.
586 struct list_head frag_list;
588 /* This points to the sk_buff containing the actual data. */
592 /* In case of GSO packets, this will store the head one */
593 struct sk_buff *head_skb;
594 /* In case of auth enabled, this will point to the shkey */
595 struct sctp_shared_key *shkey;
598 /* These are the SCTP headers by reverse order in a packet.
599 * Note that some of these may happen more than once. In that
600 * case, we point at the "current" one, whatever that means
601 * for that level of header.
604 /* We point this at the FIRST TLV parameter to chunk_hdr. */
605 union sctp_params param_hdr;
608 struct sctp_datahdr *data_hdr;
609 struct sctp_inithdr *init_hdr;
610 struct sctp_sackhdr *sack_hdr;
611 struct sctp_heartbeathdr *hb_hdr;
612 struct sctp_sender_hb_info *hbs_hdr;
613 struct sctp_shutdownhdr *shutdown_hdr;
614 struct sctp_signed_cookie *cookie_hdr;
615 struct sctp_ecnehdr *ecne_hdr;
616 struct sctp_cwrhdr *ecn_cwr_hdr;
617 struct sctp_errhdr *err_hdr;
618 struct sctp_addiphdr *addip_hdr;
619 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
620 struct sctp_authhdr *auth_hdr;
621 struct sctp_idatahdr *idata_hdr;
622 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
627 struct sctp_chunkhdr *chunk_hdr;
628 struct sctphdr *sctp_hdr;
630 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
631 struct sctp_sndrcvinfo sinfo;
633 /* Which association does this belong to? */
634 struct sctp_association *asoc;
636 /* What endpoint received this chunk? */
637 struct sctp_ep_common *rcvr;
639 /* We fill this in if we are calculating RTT. */
640 unsigned long sent_at;
642 /* What is the origin IP address for this chunk? */
643 union sctp_addr source;
644 /* Destination address for this chunk. */
645 union sctp_addr dest;
647 /* For outbound message, track all fragments for SEND_FAILED. */
648 struct sctp_datamsg *msg;
650 /* For an inbound chunk, this tells us where it came from.
651 * For an outbound chunk, it tells us where we'd like it to
652 * go. It is NULL if we have no preference.
654 struct sctp_transport *transport;
656 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
657 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
658 * spec violates the principle premis that all chunks are processed
661 struct sk_buff *auth_chunk;
663 #define SCTP_CAN_FRTX 0x0
664 #define SCTP_NEED_FRTX 0x1
665 #define SCTP_DONT_FRTX 0x2
666 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
667 has_tsn:1, /* Does this chunk have a TSN yet? */
668 has_ssn:1, /* Does this chunk have a SSN yet? */
669 #define has_mid has_ssn
670 singleton:1, /* Only chunk in the packet? */
671 end_of_packet:1, /* Last chunk in the packet? */
672 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
673 pdiscard:1, /* Discard the whole packet now? */
674 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
675 data_accepted:1, /* At least 1 chunk accepted */
676 auth:1, /* IN: was auth'ed | OUT: needs auth */
677 has_asconf:1, /* IN: have seen an asconf before */
678 tsn_missing_report:2, /* Data chunk missing counter. */
679 fast_retransmit:2; /* Is this chunk fast retransmitted? */
682 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
683 void sctp_chunk_hold(struct sctp_chunk *);
684 void sctp_chunk_put(struct sctp_chunk *);
685 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
686 struct iov_iter *from);
687 void sctp_chunk_free(struct sctp_chunk *);
688 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
689 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
690 const struct sctp_association *,
691 struct sock *, gfp_t gfp);
692 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
694 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
696 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
698 return ntohs(ch->subh.data_hdr->stream);
702 SCTP_ADDR_NEW, /* new address added to assoc/ep */
703 SCTP_ADDR_SRC, /* address can be used as source */
704 SCTP_ADDR_DEL, /* address about to be deleted */
707 /* This is a structure for holding either an IPv6 or an IPv4 address. */
708 struct sctp_sockaddr_entry {
709 struct list_head list;
716 #define SCTP_ADDRESS_TICK_DELAY 500
718 /* This structure holds lists of chunks as we are assembling for
722 /* These are the SCTP header values (host order) for the packet. */
724 __u16 destination_port;
727 /* This contains the payload chunks. */
728 struct list_head chunk_list;
730 /* This is the overhead of the sctp and ip headers. */
732 /* This is the total size of all chunks INCLUDING padding. */
734 /* This is the maximum size this packet may have */
737 /* The packet is destined for this transport address.
738 * The function we finally use to pass down to the next lower
739 * layer lives in the transport structure.
741 struct sctp_transport *transport;
743 /* pointer to the auth chunk for this packet */
744 struct sctp_chunk *auth;
746 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
747 has_sack:1, /* This packet contains a SACK chunk. */
748 has_auth:1, /* This packet contains an AUTH chunk */
749 has_data:1, /* This packet contains at least 1 DATA chunk */
750 ipfragok:1; /* So let ip fragment this packet */
753 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
754 __u16 sport, __u16 dport);
755 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
756 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
757 struct sctp_chunk *chunk,
758 int one_packet, gfp_t gfp);
759 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
760 struct sctp_chunk *chunk);
761 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
762 void sctp_packet_free(struct sctp_packet *);
764 static inline int sctp_packet_empty(struct sctp_packet *packet)
766 return packet->size == packet->overhead;
769 /* This represents a remote transport address.
770 * For local transport addresses, we just use union sctp_addr.
772 * RFC2960 Section 1.4 Key Terms
774 * o Transport address: A Transport Address is traditionally defined
775 * by Network Layer address, Transport Layer protocol and Transport
776 * Layer port number. In the case of SCTP running over IP, a
777 * transport address is defined by the combination of an IP address
778 * and an SCTP port number (where SCTP is the Transport protocol).
780 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
782 * o The sender keeps a separate congestion control parameter set for
783 * each of the destination addresses it can send to (not each
784 * source-destination pair but for each destination). The parameters
785 * should decay if the address is not used for a long enough time
789 struct sctp_transport {
790 /* A list of transports. */
791 struct list_head transports;
792 struct rhlist_head node;
794 /* Reference counting. */
796 /* RTO-Pending : A flag used to track if one of the DATA
797 * chunks sent to this address is currently being
798 * used to compute a RTT. If this flag is 0,
799 * the next DATA chunk sent to this destination
800 * should be used to compute a RTT and this flag
801 * should be set. Every time the RTT
802 * calculation completes (i.e. the DATA chunk
803 * is SACK'd) clear this flag.
808 * hb_sent : a flag that signals that we have a pending
813 /* Is the Path MTU update pending on this tranport */
816 dst_pending_confirm:1, /* need to confirm neighbour */
818 /* Has this transport moved the ctsn since we last sacked */
824 /* This is the peer's IP address and port. */
825 union sctp_addr ipaddr;
827 /* These are the functions we call to handle LLP stuff. */
828 struct sctp_af *af_specific;
830 /* Which association do we belong to? */
831 struct sctp_association *asoc;
835 * 12.3 Per Transport Address Data
837 * For each destination transport address in the peer's
838 * address list derived from the INIT or INIT ACK chunk, a
839 * number of data elements needs to be maintained including:
841 /* RTO : The current retransmission timeout value. */
844 __u32 rtt; /* This is the most recent RTT. */
846 /* RTTVAR : The current RTT variation. */
849 /* SRTT : The current smoothed round trip time. */
853 * These are the congestion stats.
855 /* cwnd : The current congestion window. */
856 __u32 cwnd; /* This is the actual cwnd. */
858 /* ssthresh : The current slow start threshold value. */
861 /* partial : The tracking method for increase of cwnd when in
862 * bytes acked : congestion avoidance mode (see Section 6.2.2)
864 __u32 partial_bytes_acked;
866 /* Data that has been sent, but not acknowledged. */
869 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
872 struct dst_entry *dst;
873 /* Source address. */
874 union sctp_addr saddr;
876 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
877 * the destination address every heartbeat interval.
879 unsigned long hbinterval;
881 /* SACK delay timeout */
882 unsigned long sackdelay;
887 /* When was the last time that we heard from this transport? We use
888 * this to pick new active and retran paths.
890 ktime_t last_time_heard;
892 /* When was the last time that we sent a chunk using this
893 * transport? We use this to check for idle transports
895 unsigned long last_time_sent;
897 /* Last time(in jiffies) when cwnd is reduced due to the congestion
898 * indication based on ECNE chunk.
900 unsigned long last_time_ecne_reduced;
902 /* This is the max_retrans value for the transport and will
903 * be initialized from the assocs value. This can be changed
904 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
911 /* This is the partially failed retrans value for the transport
912 * and will be initialized from the assocs value. This can be changed
913 * using the SCTP_PEER_ADDR_THLDS socket option
916 /* PMTU : The current known path MTU. */
919 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
922 /* The number of times INIT has been sent on this transport. */
925 /* state : The current state of this destination,
926 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
930 /* These are the error stats for this destination. */
932 /* Error count : The current error count for this destination. */
933 unsigned short error_count;
935 /* Per : A timer used by each destination.
939 * [Everywhere else in the text this is called T3-rtx. -ed]
941 struct timer_list T3_rtx_timer;
943 /* Heartbeat timer is per destination. */
944 struct timer_list hb_timer;
946 /* Timer to handle ICMP proto unreachable envets */
947 struct timer_list proto_unreach_timer;
949 /* Timer to handler reconf chunk rtx */
950 struct timer_list reconf_timer;
952 /* Since we're using per-destination retransmission timers
953 * (see above), we're also using per-destination "transmitted"
954 * queues. This probably ought to be a private struct
955 * accessible only within the outqueue, but it's not, yet.
957 struct list_head transmitted;
959 /* We build bundle-able packets for this transport here. */
960 struct sctp_packet packet;
962 /* This is the list of transports that have chunks to send. */
963 struct list_head send_ready;
965 /* State information saved for SFR_CACC algorithm. The key
966 * idea in SFR_CACC is to maintain state at the sender on a
967 * per-destination basis when a changeover happens.
968 * char changeover_active;
969 * char cycling_changeover;
970 * __u32 next_tsn_at_change;
971 * char cacc_saw_newack;
974 /* An unsigned integer, which stores the next TSN to be
975 * used by the sender, at the moment of changeover.
977 __u32 next_tsn_at_change;
979 /* A flag which indicates the occurrence of a changeover */
980 char changeover_active;
982 /* A flag which indicates whether the change of primary is
983 * the first switch to this destination address during an
986 char cycling_changeover;
988 /* A temporary flag, which is used during the processing of
989 * a SACK to estimate the causative TSN(s)'s group.
991 char cacc_saw_newack;
994 /* 64-bit random number sent with heartbeat. */
1000 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1002 void sctp_transport_set_owner(struct sctp_transport *,
1003 struct sctp_association *);
1004 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1005 struct sctp_sock *);
1006 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1007 void sctp_transport_free(struct sctp_transport *);
1008 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1009 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1010 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1011 int sctp_transport_hold(struct sctp_transport *);
1012 void sctp_transport_put(struct sctp_transport *);
1013 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1014 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1015 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1016 enum sctp_lower_cwnd reason);
1017 void sctp_transport_burst_limited(struct sctp_transport *);
1018 void sctp_transport_burst_reset(struct sctp_transport *);
1019 unsigned long sctp_transport_timeout(struct sctp_transport *);
1020 void sctp_transport_reset(struct sctp_transport *t);
1021 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1022 void sctp_transport_immediate_rtx(struct sctp_transport *);
1023 void sctp_transport_dst_release(struct sctp_transport *t);
1024 void sctp_transport_dst_confirm(struct sctp_transport *t);
1027 /* This is the structure we use to queue packets as they come into
1028 * SCTP. We write packets to it and read chunks from it.
1031 /* This is actually a queue of sctp_chunk each
1032 * containing a partially decoded packet.
1034 struct list_head in_chunk_list;
1035 /* This is the packet which is currently off the in queue and is
1036 * being worked on through the inbound chunk processing.
1038 struct sctp_chunk *in_progress;
1040 /* This is the delayed task to finish delivering inbound
1043 struct work_struct immediate;
1046 void sctp_inq_init(struct sctp_inq *);
1047 void sctp_inq_free(struct sctp_inq *);
1048 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1049 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1050 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1051 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1053 /* This is the structure we use to hold outbound chunks. You push
1054 * chunks in and they automatically pop out the other end as bundled
1055 * packets (it calls (*output_handler)()).
1057 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1058 * and 8.2 of the v13 draft.
1060 * It handles retransmissions. The connection to the timeout portion
1061 * of the state machine is through sctp_..._timeout() and timeout_handler.
1063 * If you feed it SACKs, it will eat them.
1065 * If you give it big chunks, it will fragment them.
1067 * It assigns TSN's to data chunks. This happens at the last possible
1068 * instant before transmission.
1070 * When free()'d, it empties itself out via output_handler().
1073 struct sctp_association *asoc;
1075 /* Data pending that has never been transmitted. */
1076 struct list_head out_chunk_list;
1078 /* Stream scheduler being used */
1079 struct sctp_sched_ops *sched;
1081 unsigned int out_qlen; /* Total length of queued data chunks. */
1083 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1086 /* These are control chunks we want to send. */
1087 struct list_head control_chunk_list;
1089 /* These are chunks that have been sacked but are above the
1090 * CTSN, or cumulative tsn ack point.
1092 struct list_head sacked;
1094 /* Put chunks on this list to schedule them for
1097 struct list_head retransmit;
1099 /* Put chunks on this list to save them for FWD TSN processing as
1100 * they were abandoned.
1102 struct list_head abandoned;
1104 /* How many unackd bytes do we have in-flight? */
1105 __u32 outstanding_bytes;
1107 /* Are we doing fast-rtx on this queue */
1114 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1115 void sctp_outq_teardown(struct sctp_outq *);
1116 void sctp_outq_free(struct sctp_outq*);
1117 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1118 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1119 int sctp_outq_is_empty(const struct sctp_outq *);
1120 void sctp_outq_restart(struct sctp_outq *);
1122 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1123 enum sctp_retransmit_reason reason);
1124 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1125 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1126 void sctp_prsctp_prune(struct sctp_association *asoc,
1127 struct sctp_sndrcvinfo *sinfo, int msg_len);
1128 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1129 /* Uncork and flush an outqueue. */
1130 static inline void sctp_outq_cork(struct sctp_outq *q)
1135 /* SCTP skb control block.
1136 * sctp_input_cb is currently used on rx and sock rx queue
1138 struct sctp_input_cb {
1140 struct inet_skb_parm h4;
1141 #if IS_ENABLED(CONFIG_IPV6)
1142 struct inet6_skb_parm h6;
1145 struct sctp_chunk *chunk;
1148 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1150 struct sctp_output_cb {
1151 struct sk_buff *last;
1153 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1155 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1157 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1159 return chunk->head_skb ? : skb;
1162 /* These bind address data fields common between endpoints and associations */
1163 struct sctp_bind_addr {
1165 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1167 * SCTP Port: The local SCTP port number the endpoint is
1172 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1174 * Address List: The list of IP addresses that this instance
1175 * has bound. This information is passed to one's
1176 * peer(s) in INIT and INIT ACK chunks.
1178 struct list_head address_list;
1181 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1182 void sctp_bind_addr_free(struct sctp_bind_addr *);
1183 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1184 const struct sctp_bind_addr *src,
1185 enum sctp_scope scope, gfp_t gfp,
1187 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1188 const struct sctp_bind_addr *src,
1190 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1191 int new_size, __u8 addr_state, gfp_t gfp);
1192 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1193 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1194 struct sctp_sock *);
1195 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1196 struct sctp_sock *, struct sctp_sock *);
1197 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1198 const union sctp_addr *addr);
1199 int sctp_bind_addrs_check(struct sctp_sock *sp,
1200 struct sctp_sock *sp2, int cnt2);
1201 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1202 const union sctp_addr *addrs,
1204 struct sctp_sock *opt);
1205 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1208 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1209 __u16 port, gfp_t gfp);
1211 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1212 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1213 const enum sctp_scope scope);
1214 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1215 int sctp_is_ep_boundall(struct sock *sk);
1218 /* What type of endpoint? */
1219 enum sctp_endpoint_type {
1220 SCTP_EP_TYPE_SOCKET,
1221 SCTP_EP_TYPE_ASSOCIATION,
1225 * A common base class to bridge the implmentation view of a
1226 * socket (usually listening) endpoint versus an association's
1228 * This common structure is useful for several purposes:
1229 * 1) Common interface for lookup routines.
1230 * a) Subfunctions work for either endpoint or association
1231 * b) Single interface to lookup allows hiding the lookup lock rather
1232 * than acquiring it externally.
1233 * 2) Common interface for the inbound chunk handling/state machine.
1234 * 3) Common object handling routines for reference counting, etc.
1235 * 4) Disentangle association lookup from endpoint lookup, where we
1236 * do not have to find our endpoint to find our association.
1240 struct sctp_ep_common {
1241 /* Fields to help us manage our entries in the hash tables. */
1242 struct hlist_node node;
1245 /* Runtime type information. What kind of endpoint is this? */
1246 enum sctp_endpoint_type type;
1248 /* Some fields to help us manage this object.
1249 * refcnt - Reference count access to this object.
1250 * dead - Do not attempt to use this object.
1255 /* What socket does this endpoint belong to? */
1258 /* This is where we receive inbound chunks. */
1259 struct sctp_inq inqueue;
1261 /* This substructure includes the defining parameters of the
1263 * bind_addr.port is our shared port number.
1264 * bind_addr.address_list is our set of local IP addresses.
1266 struct sctp_bind_addr bind_addr;
1270 /* RFC Section 1.4 Key Terms
1272 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1273 * multi-homed host, an SCTP endpoint is represented to its peers as a
1274 * combination of a set of eligible destination transport addresses to
1275 * which SCTP packets can be sent and a set of eligible source
1276 * transport addresses from which SCTP packets can be received.
1277 * All transport addresses used by an SCTP endpoint must use the
1278 * same port number, but can use multiple IP addresses. A transport
1279 * address used by an SCTP endpoint must not be used by another
1280 * SCTP endpoint. In other words, a transport address is unique
1281 * to an SCTP endpoint.
1283 * From an implementation perspective, each socket has one of these.
1284 * A TCP-style socket will have exactly one association on one of
1285 * these. An UDP-style socket will have multiple associations hanging
1289 struct sctp_endpoint {
1290 /* Common substructure for endpoint and association. */
1291 struct sctp_ep_common base;
1293 /* Associations: A list of current associations and mappings
1294 * to the data consumers for each association. This
1295 * may be in the form of a hash table or other
1296 * implementation dependent structure. The data
1297 * consumers may be process identification
1298 * information such as file descriptors, named pipe
1299 * pointer, or table pointers dependent on how SCTP
1302 /* This is really a list of struct sctp_association entries. */
1303 struct list_head asocs;
1305 /* Secret Key: A secret key used by this endpoint to compute
1306 * the MAC. This SHOULD be a cryptographic quality
1307 * random number with a sufficient length.
1308 * Discussion in [RFC1750] can be helpful in
1309 * selection of the key.
1311 __u8 secret_key[SCTP_SECRET_SIZE];
1313 /* digest: This is a digest of the sctp cookie. This field is
1314 * only used on the receive path when we try to validate
1315 * that the cookie has not been tampered with. We put
1316 * this here so we pre-allocate this once and can re-use
1321 /* sendbuf acct. policy. */
1322 __u32 sndbuf_policy;
1324 /* rcvbuf acct. policy. */
1325 __u32 rcvbuf_policy;
1327 /* SCTP AUTH: array of the HMACs that will be allocated
1328 * we need this per association so that we don't serialize
1330 struct crypto_shash **auth_hmacs;
1332 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1333 struct sctp_hmac_algo_param *auth_hmacs_list;
1335 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1336 struct sctp_chunks_param *auth_chunk_list;
1338 /* SCTP-AUTH: endpoint shared keys */
1339 struct list_head endpoint_shared_keys;
1340 __u16 active_key_id;
1345 __u8 strreset_enable;
1347 /* Security identifiers from incoming (INIT). These are set by
1348 * security_sctp_assoc_request(). These will only be used by
1349 * SCTP TCP type sockets and peeled off connections as they
1350 * cause a new socket to be generated. security_sctp_sk_clone()
1351 * will then plug these into the new socket.
1358 /* Recover the outter endpoint structure. */
1359 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1361 struct sctp_endpoint *ep;
1363 ep = container_of(base, struct sctp_endpoint, base);
1367 /* These are function signatures for manipulating endpoints. */
1368 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1369 void sctp_endpoint_free(struct sctp_endpoint *);
1370 void sctp_endpoint_put(struct sctp_endpoint *);
1371 void sctp_endpoint_hold(struct sctp_endpoint *);
1372 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1373 struct sctp_association *sctp_endpoint_lookup_assoc(
1374 const struct sctp_endpoint *ep,
1375 const union sctp_addr *paddr,
1376 struct sctp_transport **);
1377 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1378 const union sctp_addr *paddr);
1379 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1380 struct net *, const union sctp_addr *);
1381 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1382 const union sctp_addr *paddr);
1384 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1385 const struct sctp_association *asoc,
1386 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1387 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1388 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1389 const union sctp_addr *peer,
1390 struct sctp_init_chunk *init, gfp_t gfp);
1391 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1392 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1394 struct sctp_inithdr_host {
1397 __u16 num_outbound_streams;
1398 __u16 num_inbound_streams;
1402 struct sctp_stream_priorities {
1403 /* List of priorities scheduled */
1404 struct list_head prio_sched;
1405 /* List of streams scheduled */
1406 struct list_head active;
1407 /* The next stream stream in line */
1408 struct sctp_stream_out_ext *next;
1412 struct sctp_stream_out_ext {
1413 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1414 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1415 struct list_head outq; /* chunks enqueued by this stream */
1418 /* Scheduled streams list */
1419 struct list_head prio_list;
1420 struct sctp_stream_priorities *prio_head;
1422 /* Fields used by RR scheduler */
1424 struct list_head rr_list;
1429 struct sctp_stream_out {
1435 struct sctp_stream_out_ext *ext;
1439 struct sctp_stream_in {
1451 struct sctp_stream {
1452 struct flex_array *out;
1453 struct flex_array *in;
1456 /* Current stream being sent, if any */
1457 struct sctp_stream_out *out_curr;
1459 /* Fields used by priority scheduler */
1461 /* List of priorities scheduled */
1462 struct list_head prio_list;
1464 /* Fields used by RR scheduler */
1466 /* List of streams scheduled */
1467 struct list_head rr_list;
1468 /* The next stream stream in line */
1469 struct sctp_stream_out_ext *rr_next;
1472 struct sctp_stream_interleave *si;
1475 static inline struct sctp_stream_out *sctp_stream_out(
1476 const struct sctp_stream *stream,
1479 return flex_array_get(stream->out, sid);
1482 static inline struct sctp_stream_in *sctp_stream_in(
1483 const struct sctp_stream *stream,
1486 return flex_array_get(stream->in, sid);
1489 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1490 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1492 #define SCTP_STREAM_CLOSED 0x00
1493 #define SCTP_STREAM_OPEN 0x01
1495 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1497 return stream->si->data_chunk_len;
1500 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1502 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1505 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1507 return stream->si->ftsn_chunk_len;
1510 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1512 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1515 /* SCTP_GET_ASSOC_STATS counters */
1516 struct sctp_priv_assoc_stats {
1517 /* Maximum observed rto in the association during subsequent
1518 * observations. Value is set to 0 if no RTO measurement took place
1519 * The transport where the max_rto was observed is returned in
1522 struct sockaddr_storage obs_rto_ipaddr;
1524 /* Total In and Out SACKs received and sent */
1527 /* Total In and Out packets received and sent */
1530 /* Total retransmitted chunks */
1532 /* TSN received > next expected */
1534 /* Duplicate Chunks received */
1536 /* Gap Ack Blocks received */
1538 /* Unordered data chunks sent and received */
1541 /* Ordered data chunks sent and received */
1544 /* Control chunks sent and received */
1551 * 12. Recommended Transmission Control Block (TCB) Parameters
1553 * This section details a recommended set of parameters that should
1554 * be contained within the TCB for an implementation. This section is
1555 * for illustrative purposes and should not be deemed as requirements
1556 * on an implementation or as an exhaustive list of all parameters
1557 * inside an SCTP TCB. Each implementation may need its own additional
1558 * parameters for optimization.
1562 /* Here we have information about each individual association. */
1563 struct sctp_association {
1565 /* A base structure common to endpoint and association.
1566 * In this context, it represents the associations's view
1567 * of the local endpoint of the association.
1569 struct sctp_ep_common base;
1571 /* Associations on the same socket. */
1572 struct list_head asocs;
1574 /* association id. */
1575 sctp_assoc_t assoc_id;
1577 /* This is our parent endpoint. */
1578 struct sctp_endpoint *ep;
1580 /* These are those association elements needed in the cookie. */
1581 struct sctp_cookie c;
1583 /* This is all information about our peer. */
1585 /* transport_addr_list
1587 * Peer : A list of SCTP transport addresses that the
1588 * Transport : peer is bound to. This information is derived
1589 * Address : from the INIT or INIT ACK and is used to
1590 * List : associate an inbound packet with a given
1591 * : association. Normally this information is
1592 * : hashed or keyed for quick lookup and access
1594 * : The list is also initialized with the list
1595 * : of addresses passed with the sctp_connectx()
1598 * It is a list of SCTP_transport's.
1600 struct list_head transport_addr_list;
1604 * Peer Rwnd : Current calculated value of the peer's rwnd.
1610 * Peer : A count of the number of peer addresses
1611 * Transport : in the Peer Transport Address List.
1615 __u16 transport_count;
1618 * The transport layer port number.
1624 * Primary : This is the current primary destination
1625 * Path : transport address of the peer endpoint. It
1626 * : may also specify a source transport address
1627 * : on this endpoint.
1629 * All of these paths live on transport_addr_list.
1631 * At the bakeoffs, we discovered that the intent of
1632 * primaryPath is that it only changes when the ULP
1633 * asks to have it changed. We add the activePath to
1634 * designate the connection we are currently using to
1635 * transmit new data and most control chunks.
1637 struct sctp_transport *primary_path;
1639 /* Cache the primary path address here, when we
1640 * need a an address for msg_name.
1642 union sctp_addr primary_addr;
1645 * The path that we are currently using to
1646 * transmit new data and most control chunks.
1648 struct sctp_transport *active_path;
1652 * RFC2960 6.4 Multi-homed SCTP Endpoints
1654 * Furthermore, when its peer is multi-homed, an
1655 * endpoint SHOULD try to retransmit a chunk to an
1656 * active destination transport address that is
1657 * different from the last destination address to
1658 * which the DATA chunk was sent.
1660 struct sctp_transport *retran_path;
1662 /* Pointer to last transport I have sent on. */
1663 struct sctp_transport *last_sent_to;
1665 /* This is the last transport I have received DATA on. */
1666 struct sctp_transport *last_data_from;
1669 * Mapping An array of bits or bytes indicating which out of
1670 * Array order TSN's have been received (relative to the
1671 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1672 * order packets have been received, this array
1673 * will be set to all zero. This structure may be
1674 * in the form of a circular buffer or bit array.
1676 * Last Rcvd : This is the last TSN received in
1677 * TSN : sequence. This value is set initially by
1678 * : taking the peer's Initial TSN, received in
1679 * : the INIT or INIT ACK chunk, and subtracting
1682 * Throughout most of the specification this is called the
1683 * "Cumulative TSN ACK Point". In this case, we
1684 * ignore the advice in 12.2 in favour of the term
1685 * used in the bulk of the text. This value is hidden
1686 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1688 struct sctp_tsnmap tsn_map;
1690 /* This mask is used to disable sending the ASCONF chunk
1691 * with specified parameter to peer.
1693 __be16 addip_disabled_mask;
1695 /* These are capabilities which our peer advertised. */
1696 __u8 ecn_capable:1, /* Can peer do ECN? */
1697 ipv4_address:1, /* Peer understands IPv4 addresses? */
1698 ipv6_address:1, /* Peer understands IPv6 addresses? */
1699 hostname_address:1, /* Peer understands DNS addresses? */
1700 asconf_capable:1, /* Does peer support ADDIP? */
1701 prsctp_capable:1, /* Can peer do PR-SCTP? */
1702 reconf_capable:1, /* Can peer do RE-CONFIG? */
1703 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1705 /* sack_needed : This flag indicates if the next received
1706 * : packet is to be responded to with a
1707 * : SACK. This is initialized to 0. When a packet
1708 * : is received sack_cnt is incremented. If this value
1709 * : reaches 2 or more, a SACK is sent and the
1710 * : value is reset to 0. Note: This is used only
1711 * : when no DATA chunks are received out of
1712 * : order. When DATA chunks are out of order,
1713 * : SACK's are not delayed (see Section 6).
1715 __u8 sack_needed:1, /* Do we need to sack the peer? */
1717 zero_window_announced:1;
1720 __u32 adaptation_ind; /* Adaptation Code point. */
1722 struct sctp_inithdr_host i;
1726 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1727 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1728 * Initial TSN Value minus 1
1732 /* SCTP-AUTH: We need to know pears random number, hmac list
1733 * and authenticated chunk list. All that is part of the
1734 * cookie and these are just pointers to those locations
1736 struct sctp_random_param *peer_random;
1737 struct sctp_chunks_param *peer_chunks;
1738 struct sctp_hmac_algo_param *peer_hmacs;
1741 /* State : A state variable indicating what state the
1742 * : association is in, i.e. COOKIE-WAIT,
1743 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1744 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1746 * Note: No "CLOSED" state is illustrated since if a
1747 * association is "CLOSED" its TCB SHOULD be removed.
1749 * In this implementation we DO have a CLOSED
1750 * state which is used during initiation and shutdown.
1752 * State takes values from SCTP_STATE_*.
1754 enum sctp_state state;
1756 /* Overall : The overall association error count.
1757 * Error Count : [Clear this any time I get something.]
1759 int overall_error_count;
1761 /* The cookie life I award for any cookie. */
1762 ktime_t cookie_life;
1764 /* These are the association's initial, max, and min RTO values.
1765 * These values will be initialized by system defaults, but can
1766 * be modified via the SCTP_RTOINFO socket option.
1768 unsigned long rto_initial;
1769 unsigned long rto_max;
1770 unsigned long rto_min;
1772 /* Maximum number of new data packets that can be sent in a burst. */
1775 /* This is the max_retrans value for the association. This value will
1776 * be initialized initialized from system defaults, but can be
1777 * modified by the SCTP_ASSOCINFO socket option.
1781 /* This is the partially failed retrans value for the transport
1782 * and will be initialized from the assocs value. This can be
1783 * changed using the SCTP_PEER_ADDR_THLDS socket option
1787 /* Maximum number of times the endpoint will retransmit INIT */
1788 __u16 max_init_attempts;
1790 /* How many times have we resent an INIT? */
1793 /* The largest timeout or RTO value to use in attempting an INIT */
1794 unsigned long max_init_timeo;
1796 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1797 * the destination address every heartbeat interval. This value
1798 * will be inherited by all new transports.
1800 unsigned long hbinterval;
1802 /* This is the max_retrans value for new transports in the
1810 /* Flag that path mtu update is pending */
1813 /* Association : The smallest PMTU discovered for all of the
1814 * PMTU : peer's transport addresses.
1818 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1822 /* SACK delay timeout */
1823 unsigned long sackdelay;
1825 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1826 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1828 /* Transport to which SHUTDOWN chunk was last sent. */
1829 struct sctp_transport *shutdown_last_sent_to;
1831 /* Transport to which INIT chunk was last sent. */
1832 struct sctp_transport *init_last_sent_to;
1834 /* How many times have we resent a SHUTDOWN */
1835 int shutdown_retries;
1837 /* Next TSN : The next TSN number to be assigned to a new
1838 * : DATA chunk. This is sent in the INIT or INIT
1839 * : ACK chunk to the peer and incremented each
1840 * : time a DATA chunk is assigned a TSN
1841 * : (normally just prior to transmit or during
1847 * Last Rcvd : This is the last TSN received in sequence. This value
1848 * TSN : is set initially by taking the peer's Initial TSN,
1849 * : received in the INIT or INIT ACK chunk, and
1850 * : subtracting one from it.
1852 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1855 __u32 ctsn_ack_point;
1857 /* PR-SCTP Advanced.Peer.Ack.Point */
1858 __u32 adv_peer_ack_point;
1860 /* Highest TSN that is acknowledged by incoming SACKs. */
1861 __u32 highest_sacked;
1863 /* TSN marking the fast recovery exit point */
1864 __u32 fast_recovery_exit;
1866 /* Flag to track the current fast recovery state */
1869 /* The number of unacknowledged data chunks. Reported through
1870 * the SCTP_STATUS sockopt.
1874 /* The total number of data chunks that we've had to retransmit
1875 * as the result of a T3 timer expiration
1877 __u32 rtx_data_chunks;
1879 /* This is the association's receive buffer space. This value is used
1880 * to set a_rwnd field in an INIT or a SACK chunk.
1884 /* This is the last advertised value of rwnd over a SACK chunk. */
1887 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1888 * to slop over a maximum of the association's frag_point.
1892 /* Keeps treack of rwnd pressure. This happens when we have
1893 * a window, but not recevie buffer (i.e small packets). This one
1894 * is releases slowly (1 PMTU at a time ).
1898 /* This is the sndbuf size in use for the association.
1899 * This corresponds to the sndbuf size for the association,
1900 * as specified in the sk->sndbuf.
1904 /* This is the amount of memory that this association has allocated
1905 * in the receive path at any given time.
1907 atomic_t rmem_alloc;
1909 /* This is the wait queue head for send requests waiting on
1910 * the association sndbuf space.
1912 wait_queue_head_t wait;
1914 /* The message size at which SCTP fragmentation will occur. */
1918 /* Counter used to count INIT errors. */
1919 int init_err_counter;
1921 /* Count the number of INIT cycles (for doubling timeout). */
1924 /* Default send parameters. */
1925 __u16 default_stream;
1926 __u16 default_flags;
1928 __u32 default_context;
1929 __u32 default_timetolive;
1931 /* Default receive parameters */
1932 __u32 default_rcv_context;
1935 struct sctp_stream stream;
1937 /* All outbound chunks go through this structure. */
1938 struct sctp_outq outqueue;
1940 /* A smart pipe that will handle reordering and fragmentation,
1941 * as well as handle passing events up to the ULP.
1943 struct sctp_ulpq ulpq;
1945 /* Last TSN that caused an ECNE Chunk to be sent. */
1946 __u32 last_ecne_tsn;
1948 /* Last TSN that caused a CWR Chunk to be sent. */
1951 /* How many duplicated TSNs have we seen? */
1954 /* These are to support
1955 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1956 * and Enforcement of Flow and Message Limits"
1957 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1958 * or "ADDIP" for short.
1963 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1965 * R1) One and only one ASCONF Chunk MAY be in transit and
1966 * unacknowledged at any one time. If a sender, after sending
1967 * an ASCONF chunk, decides it needs to transfer another
1968 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1969 * returns from the previous ASCONF Chunk before sending a
1970 * subsequent ASCONF. Note this restriction binds each side,
1971 * so at any time two ASCONF may be in-transit on any given
1972 * association (one sent from each endpoint).
1974 * [This is our one-and-only-one ASCONF in flight. If we do
1975 * not have an ASCONF in flight, this is NULL.]
1977 struct sctp_chunk *addip_last_asconf;
1979 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1981 * This is needed to implement itmes E1 - E4 of the updated
1982 * spec. Here is the justification:
1984 * Since the peer may bundle multiple ASCONF chunks toward us,
1985 * we now need the ability to cache multiple ACKs. The section
1986 * describes in detail how they are cached and cleaned up.
1988 struct list_head asconf_ack_list;
1990 /* These ASCONF chunks are waiting to be sent.
1992 * These chunaks can't be pushed to outqueue until receiving
1993 * ASCONF_ACK for the previous ASCONF indicated by
1994 * addip_last_asconf, so as to guarantee that only one ASCONF
1995 * is in flight at any time.
1997 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1999 * In defining the ASCONF Chunk transfer procedures, it is
2000 * essential that these transfers MUST NOT cause congestion
2001 * within the network. To achieve this, we place these
2002 * restrictions on the transfer of ASCONF Chunks:
2004 * R1) One and only one ASCONF Chunk MAY be in transit and
2005 * unacknowledged at any one time. If a sender, after sending
2006 * an ASCONF chunk, decides it needs to transfer another
2007 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2008 * returns from the previous ASCONF Chunk before sending a
2009 * subsequent ASCONF. Note this restriction binds each side,
2010 * so at any time two ASCONF may be in-transit on any given
2011 * association (one sent from each endpoint).
2014 * [I really think this is EXACTLY the sort of intelligence
2015 * which already resides in sctp_outq. Please move this
2016 * queue and its supporting logic down there. --piggy]
2018 struct list_head addip_chunk_list;
2020 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2022 * A2) A serial number should be assigned to the Chunk. The
2023 * serial number SHOULD be a monotonically increasing
2024 * number. The serial number SHOULD be initialized at
2025 * the start of the association to the same value as the
2026 * Initial TSN and every time a new ASCONF chunk is created
2027 * it is incremented by one after assigning the serial number
2028 * to the newly created chunk.
2031 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2033 * Serial Number : 32 bits (unsigned integer)
2035 * This value represents a Serial Number for the ASCONF
2036 * Chunk. The valid range of Serial Number is from 0 to
2037 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2038 * after reaching 4294967295.
2041 int src_out_of_asoc_ok;
2042 union sctp_addr *asconf_addr_del_pending;
2043 struct sctp_transport *new_transport;
2045 /* SCTP AUTH: list of the endpoint shared keys. These
2046 * keys are provided out of band by the user applicaton
2047 * and can't change during the lifetime of the association
2049 struct list_head endpoint_shared_keys;
2052 * The current generated assocaition shared key (secret)
2054 struct sctp_auth_bytes *asoc_shared_key;
2055 struct sctp_shared_key *shkey;
2057 /* SCTP AUTH: hmac id of the first peer requested algorithm
2060 __u16 default_hmac_id;
2062 __u16 active_key_id;
2064 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2065 temp:1, /* Is it a temporary association? */
2071 __u8 strreset_enable;
2072 __u8 strreset_outstanding; /* request param count on the fly */
2074 __u32 strreset_outseq; /* Update after receiving response */
2075 __u32 strreset_inseq; /* Update after receiving request */
2076 __u32 strreset_result[2]; /* save the results of last 2 responses */
2078 struct sctp_chunk *strreset_chunk; /* save request chunk */
2080 struct sctp_priv_assoc_stats stats;
2082 int sent_cnt_removable;
2086 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2087 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2089 struct rcu_head rcu;
2093 /* An eyecatcher for determining if we are really looking at an
2094 * association data structure.
2097 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2100 /* Recover the outter association structure. */
2101 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2103 struct sctp_association *asoc;
2105 asoc = container_of(base, struct sctp_association, base);
2109 /* These are function signatures for manipulating associations. */
2112 struct sctp_association *
2113 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2114 enum sctp_scope scope, gfp_t gfp);
2115 void sctp_association_free(struct sctp_association *);
2116 void sctp_association_put(struct sctp_association *);
2117 void sctp_association_hold(struct sctp_association *);
2119 struct sctp_transport *sctp_assoc_choose_alter_transport(
2120 struct sctp_association *, struct sctp_transport *);
2121 void sctp_assoc_update_retran_path(struct sctp_association *);
2122 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2123 const union sctp_addr *);
2124 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2125 const union sctp_addr *laddr);
2126 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2127 const union sctp_addr *address,
2129 const int peer_state);
2130 void sctp_assoc_del_peer(struct sctp_association *asoc,
2131 const union sctp_addr *addr);
2132 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2133 struct sctp_transport *peer);
2134 void sctp_assoc_control_transport(struct sctp_association *asoc,
2135 struct sctp_transport *transport,
2136 enum sctp_transport_cmd command,
2137 sctp_sn_error_t error);
2138 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2139 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2140 int sctp_assoc_update(struct sctp_association *old,
2141 struct sctp_association *new);
2143 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2145 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2146 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2147 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2148 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2149 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2150 void sctp_assoc_set_primary(struct sctp_association *,
2151 struct sctp_transport *);
2152 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2153 struct sctp_transport *);
2154 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2155 enum sctp_scope scope, gfp_t gfp);
2156 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2157 struct sctp_cookie*,
2159 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2160 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2161 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2162 const struct sctp_association *asoc,
2164 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2166 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2167 const union sctp_addr *ss2);
2168 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2170 /* A convenience structure to parse out SCTP specific CMSGs. */
2172 struct sctp_initmsg *init;
2173 struct sctp_sndrcvinfo *srinfo;
2174 struct sctp_sndinfo *sinfo;
2175 struct sctp_prinfo *prinfo;
2176 struct sctp_authinfo *authinfo;
2177 struct msghdr *addrs_msg;
2180 /* Structure for tracking memory objects */
2181 struct sctp_dbg_objcnt_entry {
2186 #endif /* __sctp_structs_h__ */