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. */
202 /* The initial Path MTU to use for new associations. */
205 /* The default SACK delay timeout for new associations. */
209 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
212 struct sctp_rtoinfo rtoinfo;
213 struct sctp_paddrparams paddrparam;
214 struct sctp_assocparams assocparams;
217 * These two structures must be grouped together for the usercopy
220 struct sctp_event_subscribe subscribe;
221 struct sctp_initmsg initmsg;
226 __u32 adaptation_ind;
236 data_ready_signalled:1;
239 /* Receive to here while partial delivery is in effect. */
240 struct sk_buff_head pd_lobby;
242 /* These must be the last fields, as they will skipped on copies,
243 * like on accept and peeloff operations
245 struct list_head auto_asconf_list;
249 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
251 return (struct sctp_sock *)sk;
254 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
256 return (struct sock *)sp;
259 #if IS_ENABLED(CONFIG_IPV6)
261 struct sctp_sock sctp;
262 struct ipv6_pinfo inet6;
264 #endif /* CONFIG_IPV6 */
267 /* This is our APPLICATION-SPECIFIC state cookie.
268 * THIS IS NOT DICTATED BY THE SPECIFICATION.
270 /* These are the parts of an association which we send in the cookie.
271 * Most of these are straight out of:
272 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
278 /* My : Tag expected in every inbound packet and sent
279 * Verification: in the INIT or INIT ACK chunk.
284 /* Peer's : Tag expected in every outbound packet except
285 * Verification: in the INIT chunk.
290 /* The rest of these are not from the spec, but really need to
294 /* My Tie Tag : Assist in discovering a restarting association. */
297 /* Peer's Tie Tag: Assist in discovering a restarting association. */
300 /* When does this cookie expire? */
303 /* Number of inbound/outbound streams which are set
304 * and negotiated during the INIT process.
306 __u16 sinit_num_ostreams;
307 __u16 sinit_max_instreams;
309 /* This is the first sequence number I used. */
312 /* This holds the originating address of the INIT packet. */
313 union sctp_addr peer_addr;
316 * Include the source port of the INIT-ACK
322 /* Padding for future use */
325 __u32 adaptation_ind;
327 __u8 auth_random[sizeof(struct sctp_paramhdr) +
328 SCTP_AUTH_RANDOM_LENGTH];
329 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
330 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
332 /* This is a shim for my peer's INIT packet, followed by
333 * a copy of the raw address list of the association.
334 * The length of the raw address list is saved in the
335 * raw_addr_list_len field, which will be used at the time when
336 * the association TCB is re-constructed from the cookie.
338 __u32 raw_addr_list_len;
339 struct sctp_init_chunk peer_init[0];
343 /* The format of our cookie that we send to our peer. */
344 struct sctp_signed_cookie {
345 __u8 signature[SCTP_SECRET_SIZE];
346 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
347 struct sctp_cookie c;
350 /* This is another convenience type to allocate memory for address
351 * params for the maximum size and pass such structures around
354 union sctp_addr_param {
355 struct sctp_paramhdr p;
356 struct sctp_ipv4addr_param v4;
357 struct sctp_ipv6addr_param v6;
360 /* A convenience type to allow walking through the various
361 * parameters and avoid casting all over the place.
365 struct sctp_paramhdr *p;
366 struct sctp_cookie_preserve_param *life;
367 struct sctp_hostname_param *dns;
368 struct sctp_cookie_param *cookie;
369 struct sctp_supported_addrs_param *sat;
370 struct sctp_ipv4addr_param *v4;
371 struct sctp_ipv6addr_param *v6;
372 union sctp_addr_param *addr;
373 struct sctp_adaptation_ind_param *aind;
374 struct sctp_supported_ext_param *ext;
375 struct sctp_random_param *random;
376 struct sctp_chunks_param *chunks;
377 struct sctp_hmac_algo_param *hmac_algo;
378 struct sctp_addip_param *addip;
381 /* RFC 2960. Section 3.3.5 Heartbeat.
382 * Heartbeat Information: variable length
383 * The Sender-specific Heartbeat Info field should normally include
384 * information about the sender's current time when this HEARTBEAT
385 * chunk is sent and the destination transport address to which this
386 * HEARTBEAT is sent (see Section 8.3).
388 struct sctp_sender_hb_info {
389 struct sctp_paramhdr param_hdr;
390 union sctp_addr daddr;
391 unsigned long sent_at;
395 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
397 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
398 void sctp_stream_free(struct sctp_stream *stream);
399 void sctp_stream_clear(struct sctp_stream *stream);
400 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
402 /* What is the current SSN number for this stream? */
403 #define sctp_ssn_peek(stream, type, sid) \
404 (sctp_stream_##type((stream), (sid))->ssn)
406 /* Return the next SSN number for this stream. */
407 #define sctp_ssn_next(stream, type, sid) \
408 (sctp_stream_##type((stream), (sid))->ssn++)
410 /* Skip over this ssn and all below. */
411 #define sctp_ssn_skip(stream, type, sid, ssn) \
412 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
414 /* What is the current MID number for this stream? */
415 #define sctp_mid_peek(stream, type, sid) \
416 (sctp_stream_##type((stream), (sid))->mid)
418 /* Return the next MID number for this stream. */
419 #define sctp_mid_next(stream, type, sid) \
420 (sctp_stream_##type((stream), (sid))->mid++)
422 /* Skip over this mid and all below. */
423 #define sctp_mid_skip(stream, type, sid, mid) \
424 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
426 /* What is the current MID_uo number for this stream? */
427 #define sctp_mid_uo_peek(stream, type, sid) \
428 (sctp_stream_##type((stream), (sid))->mid_uo)
430 /* Return the next MID_uo number for this stream. */
431 #define sctp_mid_uo_next(stream, type, sid) \
432 (sctp_stream_##type((stream), (sid))->mid_uo++)
435 * Pointers to address related SCTP functions.
436 * (i.e. things that depend on the address family.)
439 int (*sctp_xmit) (struct sk_buff *skb,
440 struct sctp_transport *);
441 int (*setsockopt) (struct sock *sk,
445 unsigned int optlen);
446 int (*getsockopt) (struct sock *sk,
451 int (*compat_setsockopt) (struct sock *sk,
455 unsigned int optlen);
456 int (*compat_getsockopt) (struct sock *sk,
461 void (*get_dst) (struct sctp_transport *t,
462 union sctp_addr *saddr,
465 void (*get_saddr) (struct sctp_sock *sk,
466 struct sctp_transport *t,
468 void (*copy_addrlist) (struct list_head *,
469 struct net_device *);
470 int (*cmp_addr) (const union sctp_addr *addr1,
471 const union sctp_addr *addr2);
472 void (*addr_copy) (union sctp_addr *dst,
473 union sctp_addr *src);
474 void (*from_skb) (union sctp_addr *,
477 void (*from_sk) (union sctp_addr *,
479 void (*from_addr_param) (union sctp_addr *,
480 union sctp_addr_param *,
481 __be16 port, int iif);
482 int (*to_addr_param) (const union sctp_addr *,
483 union sctp_addr_param *);
484 int (*addr_valid) (union sctp_addr *,
486 const struct sk_buff *);
487 enum sctp_scope (*scope)(union sctp_addr *);
488 void (*inaddr_any) (union sctp_addr *, __be16);
489 int (*is_any) (const union sctp_addr *);
490 int (*available) (union sctp_addr *,
492 int (*skb_iif) (const struct sk_buff *sk);
493 int (*is_ce) (const struct sk_buff *sk);
494 void (*seq_dump_addr)(struct seq_file *seq,
495 union sctp_addr *addr);
496 void (*ecn_capable)(struct sock *sk);
497 __u16 net_header_len;
499 int (*ip_options_len)(struct sock *sk);
500 sa_family_t sa_family;
501 struct list_head list;
504 struct sctp_af *sctp_get_af_specific(sa_family_t);
505 int sctp_register_af(struct sctp_af *);
507 /* Protocol family functions. */
509 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
510 void (*skb_msgname) (struct sk_buff *, char *, int *);
511 int (*af_supported) (sa_family_t, struct sctp_sock *);
512 int (*cmp_addr) (const union sctp_addr *,
513 const union sctp_addr *,
515 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
516 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
517 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
518 struct sock *(*create_accept_sk) (struct sock *sk,
519 struct sctp_association *asoc,
521 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
522 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
523 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
524 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
529 /* Structure to track chunk fragments that have been acked, but peer
530 * fragments of the same message have not.
532 struct sctp_datamsg {
533 /* Chunks waiting to be submitted to lower layer. */
534 struct list_head chunks;
535 /* Reference counting. */
537 /* When is this message no longer interesting to the peer? */
538 unsigned long expires_at;
539 /* Did the messenge fail to send? */
542 can_delay:1, /* should this message be Nagle delayed */
543 abandoned:1; /* should this message be abandoned */
546 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
547 struct sctp_sndrcvinfo *,
549 void sctp_datamsg_free(struct sctp_datamsg *);
550 void sctp_datamsg_put(struct sctp_datamsg *);
551 void sctp_chunk_fail(struct sctp_chunk *, int error);
552 int sctp_chunk_abandoned(struct sctp_chunk *);
554 /* RFC2960 1.4 Key Terms
556 * o Chunk: A unit of information within an SCTP packet, consisting of
557 * a chunk header and chunk-specific content.
559 * As a matter of convenience, we remember the SCTP common header for
560 * each chunk as well as a few other header pointers...
563 struct list_head list;
567 /* How many times this chunk have been sent, for prsctp RTX policy */
571 /* This is our link to the per-transport transmitted list. */
572 struct list_head transmitted_list;
573 /* List in specific stream outq */
574 struct list_head stream_list;
577 /* This field is used by chunks that hold fragmented data.
578 * For the first fragment this is the list that holds the rest of
579 * fragments. For the remaining fragments, this is the link to the
580 * frag_list maintained in the first fragment.
582 struct list_head frag_list;
584 /* This points to the sk_buff containing the actual data. */
588 /* In case of GSO packets, this will store the head one */
589 struct sk_buff *head_skb;
590 /* In case of auth enabled, this will point to the shkey */
591 struct sctp_shared_key *shkey;
594 /* These are the SCTP headers by reverse order in a packet.
595 * Note that some of these may happen more than once. In that
596 * case, we point at the "current" one, whatever that means
597 * for that level of header.
600 /* We point this at the FIRST TLV parameter to chunk_hdr. */
601 union sctp_params param_hdr;
604 struct sctp_datahdr *data_hdr;
605 struct sctp_inithdr *init_hdr;
606 struct sctp_sackhdr *sack_hdr;
607 struct sctp_heartbeathdr *hb_hdr;
608 struct sctp_sender_hb_info *hbs_hdr;
609 struct sctp_shutdownhdr *shutdown_hdr;
610 struct sctp_signed_cookie *cookie_hdr;
611 struct sctp_ecnehdr *ecne_hdr;
612 struct sctp_cwrhdr *ecn_cwr_hdr;
613 struct sctp_errhdr *err_hdr;
614 struct sctp_addiphdr *addip_hdr;
615 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
616 struct sctp_authhdr *auth_hdr;
617 struct sctp_idatahdr *idata_hdr;
618 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
623 struct sctp_chunkhdr *chunk_hdr;
624 struct sctphdr *sctp_hdr;
626 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
627 struct sctp_sndrcvinfo sinfo;
629 /* Which association does this belong to? */
630 struct sctp_association *asoc;
632 /* What endpoint received this chunk? */
633 struct sctp_ep_common *rcvr;
635 /* We fill this in if we are calculating RTT. */
636 unsigned long sent_at;
638 /* What is the origin IP address for this chunk? */
639 union sctp_addr source;
640 /* Destination address for this chunk. */
641 union sctp_addr dest;
643 /* For outbound message, track all fragments for SEND_FAILED. */
644 struct sctp_datamsg *msg;
646 /* For an inbound chunk, this tells us where it came from.
647 * For an outbound chunk, it tells us where we'd like it to
648 * go. It is NULL if we have no preference.
650 struct sctp_transport *transport;
652 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
653 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
654 * spec violates the principle premis that all chunks are processed
657 struct sk_buff *auth_chunk;
659 #define SCTP_CAN_FRTX 0x0
660 #define SCTP_NEED_FRTX 0x1
661 #define SCTP_DONT_FRTX 0x2
662 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
663 has_tsn:1, /* Does this chunk have a TSN yet? */
664 has_ssn:1, /* Does this chunk have a SSN yet? */
665 #define has_mid has_ssn
666 singleton:1, /* Only chunk in the packet? */
667 end_of_packet:1, /* Last chunk in the packet? */
668 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
669 pdiscard:1, /* Discard the whole packet now? */
670 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
671 data_accepted:1, /* At least 1 chunk accepted */
672 auth:1, /* IN: was auth'ed | OUT: needs auth */
673 has_asconf:1, /* IN: have seen an asconf before */
674 tsn_missing_report:2, /* Data chunk missing counter. */
675 fast_retransmit:2; /* Is this chunk fast retransmitted? */
678 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
679 void sctp_chunk_hold(struct sctp_chunk *);
680 void sctp_chunk_put(struct sctp_chunk *);
681 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
682 struct iov_iter *from);
683 void sctp_chunk_free(struct sctp_chunk *);
684 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
685 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
686 const struct sctp_association *,
687 struct sock *, gfp_t gfp);
688 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
690 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
692 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
694 return ntohs(ch->subh.data_hdr->stream);
698 SCTP_ADDR_NEW, /* new address added to assoc/ep */
699 SCTP_ADDR_SRC, /* address can be used as source */
700 SCTP_ADDR_DEL, /* address about to be deleted */
703 /* This is a structure for holding either an IPv6 or an IPv4 address. */
704 struct sctp_sockaddr_entry {
705 struct list_head list;
712 #define SCTP_ADDRESS_TICK_DELAY 500
714 /* This structure holds lists of chunks as we are assembling for
718 /* These are the SCTP header values (host order) for the packet. */
720 __u16 destination_port;
723 /* This contains the payload chunks. */
724 struct list_head chunk_list;
726 /* This is the overhead of the sctp and ip headers. */
728 /* This is the total size of all chunks INCLUDING padding. */
730 /* This is the maximum size this packet may have */
733 /* The packet is destined for this transport address.
734 * The function we finally use to pass down to the next lower
735 * layer lives in the transport structure.
737 struct sctp_transport *transport;
739 /* pointer to the auth chunk for this packet */
740 struct sctp_chunk *auth;
742 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
743 has_sack:1, /* This packet contains a SACK chunk. */
744 has_auth:1, /* This packet contains an AUTH chunk */
745 has_data:1, /* This packet contains at least 1 DATA chunk */
746 ipfragok:1; /* So let ip fragment this packet */
749 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
750 __u16 sport, __u16 dport);
751 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
752 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
753 struct sctp_chunk *chunk,
754 int one_packet, gfp_t gfp);
755 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
756 struct sctp_chunk *chunk);
757 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
758 void sctp_packet_free(struct sctp_packet *);
760 static inline int sctp_packet_empty(struct sctp_packet *packet)
762 return packet->size == packet->overhead;
765 /* This represents a remote transport address.
766 * For local transport addresses, we just use union sctp_addr.
768 * RFC2960 Section 1.4 Key Terms
770 * o Transport address: A Transport Address is traditionally defined
771 * by Network Layer address, Transport Layer protocol and Transport
772 * Layer port number. In the case of SCTP running over IP, a
773 * transport address is defined by the combination of an IP address
774 * and an SCTP port number (where SCTP is the Transport protocol).
776 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
778 * o The sender keeps a separate congestion control parameter set for
779 * each of the destination addresses it can send to (not each
780 * source-destination pair but for each destination). The parameters
781 * should decay if the address is not used for a long enough time
785 struct sctp_transport {
786 /* A list of transports. */
787 struct list_head transports;
788 struct rhlist_head node;
790 /* Reference counting. */
792 /* RTO-Pending : A flag used to track if one of the DATA
793 * chunks sent to this address is currently being
794 * used to compute a RTT. If this flag is 0,
795 * the next DATA chunk sent to this destination
796 * should be used to compute a RTT and this flag
797 * should be set. Every time the RTT
798 * calculation completes (i.e. the DATA chunk
799 * is SACK'd) clear this flag.
804 * hb_sent : a flag that signals that we have a pending
809 /* Is the Path MTU update pending on this tranport */
812 dst_pending_confirm:1, /* need to confirm neighbour */
814 /* Has this transport moved the ctsn since we last sacked */
820 /* This is the peer's IP address and port. */
821 union sctp_addr ipaddr;
823 /* These are the functions we call to handle LLP stuff. */
824 struct sctp_af *af_specific;
826 /* Which association do we belong to? */
827 struct sctp_association *asoc;
831 * 12.3 Per Transport Address Data
833 * For each destination transport address in the peer's
834 * address list derived from the INIT or INIT ACK chunk, a
835 * number of data elements needs to be maintained including:
837 /* RTO : The current retransmission timeout value. */
840 __u32 rtt; /* This is the most recent RTT. */
842 /* RTTVAR : The current RTT variation. */
845 /* SRTT : The current smoothed round trip time. */
849 * These are the congestion stats.
851 /* cwnd : The current congestion window. */
852 __u32 cwnd; /* This is the actual cwnd. */
854 /* ssthresh : The current slow start threshold value. */
857 /* partial : The tracking method for increase of cwnd when in
858 * bytes acked : congestion avoidance mode (see Section 6.2.2)
860 __u32 partial_bytes_acked;
862 /* Data that has been sent, but not acknowledged. */
865 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
868 struct dst_entry *dst;
869 /* Source address. */
870 union sctp_addr saddr;
872 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
873 * the destination address every heartbeat interval.
875 unsigned long hbinterval;
877 /* SACK delay timeout */
878 unsigned long sackdelay;
883 /* When was the last time that we heard from this transport? We use
884 * this to pick new active and retran paths.
886 ktime_t last_time_heard;
888 /* When was the last time that we sent a chunk using this
889 * transport? We use this to check for idle transports
891 unsigned long last_time_sent;
893 /* Last time(in jiffies) when cwnd is reduced due to the congestion
894 * indication based on ECNE chunk.
896 unsigned long last_time_ecne_reduced;
898 /* This is the max_retrans value for the transport and will
899 * be initialized from the assocs value. This can be changed
900 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
907 /* This is the partially failed retrans value for the transport
908 * and will be initialized from the assocs value. This can be changed
909 * using the SCTP_PEER_ADDR_THLDS socket option
912 /* PMTU : The current known path MTU. */
915 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
918 /* The number of times INIT has been sent on this transport. */
921 /* state : The current state of this destination,
922 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
926 /* These are the error stats for this destination. */
928 /* Error count : The current error count for this destination. */
929 unsigned short error_count;
931 /* Per : A timer used by each destination.
935 * [Everywhere else in the text this is called T3-rtx. -ed]
937 struct timer_list T3_rtx_timer;
939 /* Heartbeat timer is per destination. */
940 struct timer_list hb_timer;
942 /* Timer to handle ICMP proto unreachable envets */
943 struct timer_list proto_unreach_timer;
945 /* Timer to handler reconf chunk rtx */
946 struct timer_list reconf_timer;
948 /* Since we're using per-destination retransmission timers
949 * (see above), we're also using per-destination "transmitted"
950 * queues. This probably ought to be a private struct
951 * accessible only within the outqueue, but it's not, yet.
953 struct list_head transmitted;
955 /* We build bundle-able packets for this transport here. */
956 struct sctp_packet packet;
958 /* This is the list of transports that have chunks to send. */
959 struct list_head send_ready;
961 /* State information saved for SFR_CACC algorithm. The key
962 * idea in SFR_CACC is to maintain state at the sender on a
963 * per-destination basis when a changeover happens.
964 * char changeover_active;
965 * char cycling_changeover;
966 * __u32 next_tsn_at_change;
967 * char cacc_saw_newack;
970 /* An unsigned integer, which stores the next TSN to be
971 * used by the sender, at the moment of changeover.
973 __u32 next_tsn_at_change;
975 /* A flag which indicates the occurrence of a changeover */
976 char changeover_active;
978 /* A flag which indicates whether the change of primary is
979 * the first switch to this destination address during an
982 char cycling_changeover;
984 /* A temporary flag, which is used during the processing of
985 * a SACK to estimate the causative TSN(s)'s group.
987 char cacc_saw_newack;
990 /* 64-bit random number sent with heartbeat. */
996 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
998 void sctp_transport_set_owner(struct sctp_transport *,
999 struct sctp_association *);
1000 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1001 struct sctp_sock *);
1002 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1003 void sctp_transport_free(struct sctp_transport *);
1004 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1005 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1006 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1007 int sctp_transport_hold(struct sctp_transport *);
1008 void sctp_transport_put(struct sctp_transport *);
1009 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1010 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1011 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1012 enum sctp_lower_cwnd reason);
1013 void sctp_transport_burst_limited(struct sctp_transport *);
1014 void sctp_transport_burst_reset(struct sctp_transport *);
1015 unsigned long sctp_transport_timeout(struct sctp_transport *);
1016 void sctp_transport_reset(struct sctp_transport *t);
1017 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1018 void sctp_transport_immediate_rtx(struct sctp_transport *);
1019 void sctp_transport_dst_release(struct sctp_transport *t);
1020 void sctp_transport_dst_confirm(struct sctp_transport *t);
1023 /* This is the structure we use to queue packets as they come into
1024 * SCTP. We write packets to it and read chunks from it.
1027 /* This is actually a queue of sctp_chunk each
1028 * containing a partially decoded packet.
1030 struct list_head in_chunk_list;
1031 /* This is the packet which is currently off the in queue and is
1032 * being worked on through the inbound chunk processing.
1034 struct sctp_chunk *in_progress;
1036 /* This is the delayed task to finish delivering inbound
1039 struct work_struct immediate;
1042 void sctp_inq_init(struct sctp_inq *);
1043 void sctp_inq_free(struct sctp_inq *);
1044 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1045 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1046 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1047 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1049 /* This is the structure we use to hold outbound chunks. You push
1050 * chunks in and they automatically pop out the other end as bundled
1051 * packets (it calls (*output_handler)()).
1053 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1054 * and 8.2 of the v13 draft.
1056 * It handles retransmissions. The connection to the timeout portion
1057 * of the state machine is through sctp_..._timeout() and timeout_handler.
1059 * If you feed it SACKs, it will eat them.
1061 * If you give it big chunks, it will fragment them.
1063 * It assigns TSN's to data chunks. This happens at the last possible
1064 * instant before transmission.
1066 * When free()'d, it empties itself out via output_handler().
1069 struct sctp_association *asoc;
1071 /* Data pending that has never been transmitted. */
1072 struct list_head out_chunk_list;
1074 /* Stream scheduler being used */
1075 struct sctp_sched_ops *sched;
1077 unsigned int out_qlen; /* Total length of queued data chunks. */
1079 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1082 /* These are control chunks we want to send. */
1083 struct list_head control_chunk_list;
1085 /* These are chunks that have been sacked but are above the
1086 * CTSN, or cumulative tsn ack point.
1088 struct list_head sacked;
1090 /* Put chunks on this list to schedule them for
1093 struct list_head retransmit;
1095 /* Put chunks on this list to save them for FWD TSN processing as
1096 * they were abandoned.
1098 struct list_head abandoned;
1100 /* How many unackd bytes do we have in-flight? */
1101 __u32 outstanding_bytes;
1103 /* Are we doing fast-rtx on this queue */
1110 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1111 void sctp_outq_teardown(struct sctp_outq *);
1112 void sctp_outq_free(struct sctp_outq*);
1113 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1114 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1115 int sctp_outq_is_empty(const struct sctp_outq *);
1116 void sctp_outq_restart(struct sctp_outq *);
1118 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1119 enum sctp_retransmit_reason reason);
1120 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1121 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1122 void sctp_prsctp_prune(struct sctp_association *asoc,
1123 struct sctp_sndrcvinfo *sinfo, int msg_len);
1124 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1125 /* Uncork and flush an outqueue. */
1126 static inline void sctp_outq_cork(struct sctp_outq *q)
1131 /* SCTP skb control block.
1132 * sctp_input_cb is currently used on rx and sock rx queue
1134 struct sctp_input_cb {
1136 struct inet_skb_parm h4;
1137 #if IS_ENABLED(CONFIG_IPV6)
1138 struct inet6_skb_parm h6;
1141 struct sctp_chunk *chunk;
1144 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1146 struct sctp_output_cb {
1147 struct sk_buff *last;
1149 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1151 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1153 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1155 return chunk->head_skb ? : skb;
1158 /* These bind address data fields common between endpoints and associations */
1159 struct sctp_bind_addr {
1161 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1163 * SCTP Port: The local SCTP port number the endpoint is
1168 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1170 * Address List: The list of IP addresses that this instance
1171 * has bound. This information is passed to one's
1172 * peer(s) in INIT and INIT ACK chunks.
1174 struct list_head address_list;
1177 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1178 void sctp_bind_addr_free(struct sctp_bind_addr *);
1179 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1180 const struct sctp_bind_addr *src,
1181 enum sctp_scope scope, gfp_t gfp,
1183 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1184 const struct sctp_bind_addr *src,
1186 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1187 int new_size, __u8 addr_state, gfp_t gfp);
1188 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1189 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1190 struct sctp_sock *);
1191 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1192 struct sctp_sock *, struct sctp_sock *);
1193 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1194 const union sctp_addr *addr);
1195 int sctp_bind_addrs_check(struct sctp_sock *sp,
1196 struct sctp_sock *sp2, int cnt2);
1197 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1198 const union sctp_addr *addrs,
1200 struct sctp_sock *opt);
1201 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1204 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1205 __u16 port, gfp_t gfp);
1207 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1208 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1209 const enum sctp_scope scope);
1210 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1211 int sctp_is_ep_boundall(struct sock *sk);
1214 /* What type of endpoint? */
1215 enum sctp_endpoint_type {
1216 SCTP_EP_TYPE_SOCKET,
1217 SCTP_EP_TYPE_ASSOCIATION,
1221 * A common base class to bridge the implmentation view of a
1222 * socket (usually listening) endpoint versus an association's
1224 * This common structure is useful for several purposes:
1225 * 1) Common interface for lookup routines.
1226 * a) Subfunctions work for either endpoint or association
1227 * b) Single interface to lookup allows hiding the lookup lock rather
1228 * than acquiring it externally.
1229 * 2) Common interface for the inbound chunk handling/state machine.
1230 * 3) Common object handling routines for reference counting, etc.
1231 * 4) Disentangle association lookup from endpoint lookup, where we
1232 * do not have to find our endpoint to find our association.
1236 struct sctp_ep_common {
1237 /* Fields to help us manage our entries in the hash tables. */
1238 struct hlist_node node;
1241 /* Runtime type information. What kind of endpoint is this? */
1242 enum sctp_endpoint_type type;
1244 /* Some fields to help us manage this object.
1245 * refcnt - Reference count access to this object.
1246 * dead - Do not attempt to use this object.
1251 /* What socket does this endpoint belong to? */
1254 /* This is where we receive inbound chunks. */
1255 struct sctp_inq inqueue;
1257 /* This substructure includes the defining parameters of the
1259 * bind_addr.port is our shared port number.
1260 * bind_addr.address_list is our set of local IP addresses.
1262 struct sctp_bind_addr bind_addr;
1266 /* RFC Section 1.4 Key Terms
1268 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1269 * multi-homed host, an SCTP endpoint is represented to its peers as a
1270 * combination of a set of eligible destination transport addresses to
1271 * which SCTP packets can be sent and a set of eligible source
1272 * transport addresses from which SCTP packets can be received.
1273 * All transport addresses used by an SCTP endpoint must use the
1274 * same port number, but can use multiple IP addresses. A transport
1275 * address used by an SCTP endpoint must not be used by another
1276 * SCTP endpoint. In other words, a transport address is unique
1277 * to an SCTP endpoint.
1279 * From an implementation perspective, each socket has one of these.
1280 * A TCP-style socket will have exactly one association on one of
1281 * these. An UDP-style socket will have multiple associations hanging
1285 struct sctp_endpoint {
1286 /* Common substructure for endpoint and association. */
1287 struct sctp_ep_common base;
1289 /* Associations: A list of current associations and mappings
1290 * to the data consumers for each association. This
1291 * may be in the form of a hash table or other
1292 * implementation dependent structure. The data
1293 * consumers may be process identification
1294 * information such as file descriptors, named pipe
1295 * pointer, or table pointers dependent on how SCTP
1298 /* This is really a list of struct sctp_association entries. */
1299 struct list_head asocs;
1301 /* Secret Key: A secret key used by this endpoint to compute
1302 * the MAC. This SHOULD be a cryptographic quality
1303 * random number with a sufficient length.
1304 * Discussion in [RFC1750] can be helpful in
1305 * selection of the key.
1307 __u8 secret_key[SCTP_SECRET_SIZE];
1309 /* digest: This is a digest of the sctp cookie. This field is
1310 * only used on the receive path when we try to validate
1311 * that the cookie has not been tampered with. We put
1312 * this here so we pre-allocate this once and can re-use
1317 /* sendbuf acct. policy. */
1318 __u32 sndbuf_policy;
1320 /* rcvbuf acct. policy. */
1321 __u32 rcvbuf_policy;
1323 /* SCTP AUTH: array of the HMACs that will be allocated
1324 * we need this per association so that we don't serialize
1326 struct crypto_shash **auth_hmacs;
1328 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1329 struct sctp_hmac_algo_param *auth_hmacs_list;
1331 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1332 struct sctp_chunks_param *auth_chunk_list;
1334 /* SCTP-AUTH: endpoint shared keys */
1335 struct list_head endpoint_shared_keys;
1336 __u16 active_key_id;
1341 __u8 strreset_enable;
1343 /* Security identifiers from incoming (INIT). These are set by
1344 * security_sctp_assoc_request(). These will only be used by
1345 * SCTP TCP type sockets and peeled off connections as they
1346 * cause a new socket to be generated. security_sctp_sk_clone()
1347 * will then plug these into the new socket.
1354 /* Recover the outter endpoint structure. */
1355 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1357 struct sctp_endpoint *ep;
1359 ep = container_of(base, struct sctp_endpoint, base);
1363 /* These are function signatures for manipulating endpoints. */
1364 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1365 void sctp_endpoint_free(struct sctp_endpoint *);
1366 void sctp_endpoint_put(struct sctp_endpoint *);
1367 void sctp_endpoint_hold(struct sctp_endpoint *);
1368 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1369 struct sctp_association *sctp_endpoint_lookup_assoc(
1370 const struct sctp_endpoint *ep,
1371 const union sctp_addr *paddr,
1372 struct sctp_transport **);
1373 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1374 const union sctp_addr *paddr);
1375 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1376 struct net *, const union sctp_addr *);
1377 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1378 const union sctp_addr *paddr);
1380 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1381 const struct sctp_association *asoc,
1382 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1383 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1384 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1385 const union sctp_addr *peer,
1386 struct sctp_init_chunk *init, gfp_t gfp);
1387 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1388 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1390 struct sctp_inithdr_host {
1393 __u16 num_outbound_streams;
1394 __u16 num_inbound_streams;
1398 struct sctp_stream_priorities {
1399 /* List of priorities scheduled */
1400 struct list_head prio_sched;
1401 /* List of streams scheduled */
1402 struct list_head active;
1403 /* The next stream stream in line */
1404 struct sctp_stream_out_ext *next;
1408 struct sctp_stream_out_ext {
1409 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1410 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1411 struct list_head outq; /* chunks enqueued by this stream */
1414 /* Scheduled streams list */
1415 struct list_head prio_list;
1416 struct sctp_stream_priorities *prio_head;
1418 /* Fields used by RR scheduler */
1420 struct list_head rr_list;
1425 struct sctp_stream_out {
1431 struct sctp_stream_out_ext *ext;
1435 struct sctp_stream_in {
1447 struct sctp_stream {
1448 struct flex_array *out;
1449 struct flex_array *in;
1452 /* Current stream being sent, if any */
1453 struct sctp_stream_out *out_curr;
1455 /* Fields used by priority scheduler */
1457 /* List of priorities scheduled */
1458 struct list_head prio_list;
1460 /* Fields used by RR scheduler */
1462 /* List of streams scheduled */
1463 struct list_head rr_list;
1464 /* The next stream stream in line */
1465 struct sctp_stream_out_ext *rr_next;
1468 struct sctp_stream_interleave *si;
1471 static inline struct sctp_stream_out *sctp_stream_out(
1472 const struct sctp_stream *stream,
1475 return flex_array_get(stream->out, sid);
1478 static inline struct sctp_stream_in *sctp_stream_in(
1479 const struct sctp_stream *stream,
1482 return flex_array_get(stream->in, sid);
1485 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1486 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1488 #define SCTP_STREAM_CLOSED 0x00
1489 #define SCTP_STREAM_OPEN 0x01
1491 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1493 return stream->si->data_chunk_len;
1496 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1498 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1501 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1503 return stream->si->ftsn_chunk_len;
1506 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1508 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1511 /* SCTP_GET_ASSOC_STATS counters */
1512 struct sctp_priv_assoc_stats {
1513 /* Maximum observed rto in the association during subsequent
1514 * observations. Value is set to 0 if no RTO measurement took place
1515 * The transport where the max_rto was observed is returned in
1518 struct sockaddr_storage obs_rto_ipaddr;
1520 /* Total In and Out SACKs received and sent */
1523 /* Total In and Out packets received and sent */
1526 /* Total retransmitted chunks */
1528 /* TSN received > next expected */
1530 /* Duplicate Chunks received */
1532 /* Gap Ack Blocks received */
1534 /* Unordered data chunks sent and received */
1537 /* Ordered data chunks sent and received */
1540 /* Control chunks sent and received */
1547 * 12. Recommended Transmission Control Block (TCB) Parameters
1549 * This section details a recommended set of parameters that should
1550 * be contained within the TCB for an implementation. This section is
1551 * for illustrative purposes and should not be deemed as requirements
1552 * on an implementation or as an exhaustive list of all parameters
1553 * inside an SCTP TCB. Each implementation may need its own additional
1554 * parameters for optimization.
1558 /* Here we have information about each individual association. */
1559 struct sctp_association {
1561 /* A base structure common to endpoint and association.
1562 * In this context, it represents the associations's view
1563 * of the local endpoint of the association.
1565 struct sctp_ep_common base;
1567 /* Associations on the same socket. */
1568 struct list_head asocs;
1570 /* association id. */
1571 sctp_assoc_t assoc_id;
1573 /* This is our parent endpoint. */
1574 struct sctp_endpoint *ep;
1576 /* These are those association elements needed in the cookie. */
1577 struct sctp_cookie c;
1579 /* This is all information about our peer. */
1581 /* transport_addr_list
1583 * Peer : A list of SCTP transport addresses that the
1584 * Transport : peer is bound to. This information is derived
1585 * Address : from the INIT or INIT ACK and is used to
1586 * List : associate an inbound packet with a given
1587 * : association. Normally this information is
1588 * : hashed or keyed for quick lookup and access
1590 * : The list is also initialized with the list
1591 * : of addresses passed with the sctp_connectx()
1594 * It is a list of SCTP_transport's.
1596 struct list_head transport_addr_list;
1600 * Peer Rwnd : Current calculated value of the peer's rwnd.
1606 * Peer : A count of the number of peer addresses
1607 * Transport : in the Peer Transport Address List.
1611 __u16 transport_count;
1614 * The transport layer port number.
1620 * Primary : This is the current primary destination
1621 * Path : transport address of the peer endpoint. It
1622 * : may also specify a source transport address
1623 * : on this endpoint.
1625 * All of these paths live on transport_addr_list.
1627 * At the bakeoffs, we discovered that the intent of
1628 * primaryPath is that it only changes when the ULP
1629 * asks to have it changed. We add the activePath to
1630 * designate the connection we are currently using to
1631 * transmit new data and most control chunks.
1633 struct sctp_transport *primary_path;
1635 /* Cache the primary path address here, when we
1636 * need a an address for msg_name.
1638 union sctp_addr primary_addr;
1641 * The path that we are currently using to
1642 * transmit new data and most control chunks.
1644 struct sctp_transport *active_path;
1648 * RFC2960 6.4 Multi-homed SCTP Endpoints
1650 * Furthermore, when its peer is multi-homed, an
1651 * endpoint SHOULD try to retransmit a chunk to an
1652 * active destination transport address that is
1653 * different from the last destination address to
1654 * which the DATA chunk was sent.
1656 struct sctp_transport *retran_path;
1658 /* Pointer to last transport I have sent on. */
1659 struct sctp_transport *last_sent_to;
1661 /* This is the last transport I have received DATA on. */
1662 struct sctp_transport *last_data_from;
1665 * Mapping An array of bits or bytes indicating which out of
1666 * Array order TSN's have been received (relative to the
1667 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1668 * order packets have been received, this array
1669 * will be set to all zero. This structure may be
1670 * in the form of a circular buffer or bit array.
1672 * Last Rcvd : This is the last TSN received in
1673 * TSN : sequence. This value is set initially by
1674 * : taking the peer's Initial TSN, received in
1675 * : the INIT or INIT ACK chunk, and subtracting
1678 * Throughout most of the specification this is called the
1679 * "Cumulative TSN ACK Point". In this case, we
1680 * ignore the advice in 12.2 in favour of the term
1681 * used in the bulk of the text. This value is hidden
1682 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1684 struct sctp_tsnmap tsn_map;
1686 /* This mask is used to disable sending the ASCONF chunk
1687 * with specified parameter to peer.
1689 __be16 addip_disabled_mask;
1691 /* These are capabilities which our peer advertised. */
1692 __u8 ecn_capable:1, /* Can peer do ECN? */
1693 ipv4_address:1, /* Peer understands IPv4 addresses? */
1694 ipv6_address:1, /* Peer understands IPv6 addresses? */
1695 hostname_address:1, /* Peer understands DNS addresses? */
1696 asconf_capable:1, /* Does peer support ADDIP? */
1697 prsctp_capable:1, /* Can peer do PR-SCTP? */
1698 reconf_capable:1, /* Can peer do RE-CONFIG? */
1699 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1701 /* sack_needed : This flag indicates if the next received
1702 * : packet is to be responded to with a
1703 * : SACK. This is initialized to 0. When a packet
1704 * : is received sack_cnt is incremented. If this value
1705 * : reaches 2 or more, a SACK is sent and the
1706 * : value is reset to 0. Note: This is used only
1707 * : when no DATA chunks are received out of
1708 * : order. When DATA chunks are out of order,
1709 * : SACK's are not delayed (see Section 6).
1711 __u8 sack_needed:1, /* Do we need to sack the peer? */
1713 zero_window_announced:1;
1716 __u32 adaptation_ind; /* Adaptation Code point. */
1718 struct sctp_inithdr_host i;
1722 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1723 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1724 * Initial TSN Value minus 1
1728 /* SCTP-AUTH: We need to know pears random number, hmac list
1729 * and authenticated chunk list. All that is part of the
1730 * cookie and these are just pointers to those locations
1732 struct sctp_random_param *peer_random;
1733 struct sctp_chunks_param *peer_chunks;
1734 struct sctp_hmac_algo_param *peer_hmacs;
1737 /* State : A state variable indicating what state the
1738 * : association is in, i.e. COOKIE-WAIT,
1739 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1740 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1742 * Note: No "CLOSED" state is illustrated since if a
1743 * association is "CLOSED" its TCB SHOULD be removed.
1745 * In this implementation we DO have a CLOSED
1746 * state which is used during initiation and shutdown.
1748 * State takes values from SCTP_STATE_*.
1750 enum sctp_state state;
1752 /* Overall : The overall association error count.
1753 * Error Count : [Clear this any time I get something.]
1755 int overall_error_count;
1757 /* The cookie life I award for any cookie. */
1758 ktime_t cookie_life;
1760 /* These are the association's initial, max, and min RTO values.
1761 * These values will be initialized by system defaults, but can
1762 * be modified via the SCTP_RTOINFO socket option.
1764 unsigned long rto_initial;
1765 unsigned long rto_max;
1766 unsigned long rto_min;
1768 /* Maximum number of new data packets that can be sent in a burst. */
1771 /* This is the max_retrans value for the association. This value will
1772 * be initialized initialized from system defaults, but can be
1773 * modified by the SCTP_ASSOCINFO socket option.
1777 /* This is the partially failed retrans value for the transport
1778 * and will be initialized from the assocs value. This can be
1779 * changed using the SCTP_PEER_ADDR_THLDS socket option
1783 /* Maximum number of times the endpoint will retransmit INIT */
1784 __u16 max_init_attempts;
1786 /* How many times have we resent an INIT? */
1789 /* The largest timeout or RTO value to use in attempting an INIT */
1790 unsigned long max_init_timeo;
1792 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1793 * the destination address every heartbeat interval. This value
1794 * will be inherited by all new transports.
1796 unsigned long hbinterval;
1798 /* This is the max_retrans value for new transports in the
1806 /* Flag that path mtu update is pending */
1809 /* Association : The smallest PMTU discovered for all of the
1810 * PMTU : peer's transport addresses.
1814 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1818 /* SACK delay timeout */
1819 unsigned long sackdelay;
1821 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1822 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1824 /* Transport to which SHUTDOWN chunk was last sent. */
1825 struct sctp_transport *shutdown_last_sent_to;
1827 /* Transport to which INIT chunk was last sent. */
1828 struct sctp_transport *init_last_sent_to;
1830 /* How many times have we resent a SHUTDOWN */
1831 int shutdown_retries;
1833 /* Next TSN : The next TSN number to be assigned to a new
1834 * : DATA chunk. This is sent in the INIT or INIT
1835 * : ACK chunk to the peer and incremented each
1836 * : time a DATA chunk is assigned a TSN
1837 * : (normally just prior to transmit or during
1843 * Last Rcvd : This is the last TSN received in sequence. This value
1844 * TSN : is set initially by taking the peer's Initial TSN,
1845 * : received in the INIT or INIT ACK chunk, and
1846 * : subtracting one from it.
1848 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1851 __u32 ctsn_ack_point;
1853 /* PR-SCTP Advanced.Peer.Ack.Point */
1854 __u32 adv_peer_ack_point;
1856 /* Highest TSN that is acknowledged by incoming SACKs. */
1857 __u32 highest_sacked;
1859 /* TSN marking the fast recovery exit point */
1860 __u32 fast_recovery_exit;
1862 /* Flag to track the current fast recovery state */
1865 /* The number of unacknowledged data chunks. Reported through
1866 * the SCTP_STATUS sockopt.
1870 /* The total number of data chunks that we've had to retransmit
1871 * as the result of a T3 timer expiration
1873 __u32 rtx_data_chunks;
1875 /* This is the association's receive buffer space. This value is used
1876 * to set a_rwnd field in an INIT or a SACK chunk.
1880 /* This is the last advertised value of rwnd over a SACK chunk. */
1883 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1884 * to slop over a maximum of the association's frag_point.
1888 /* Keeps treack of rwnd pressure. This happens when we have
1889 * a window, but not recevie buffer (i.e small packets). This one
1890 * is releases slowly (1 PMTU at a time ).
1894 /* This is the sndbuf size in use for the association.
1895 * This corresponds to the sndbuf size for the association,
1896 * as specified in the sk->sndbuf.
1900 /* This is the amount of memory that this association has allocated
1901 * in the receive path at any given time.
1903 atomic_t rmem_alloc;
1905 /* This is the wait queue head for send requests waiting on
1906 * the association sndbuf space.
1908 wait_queue_head_t wait;
1910 /* The message size at which SCTP fragmentation will occur. */
1914 /* Counter used to count INIT errors. */
1915 int init_err_counter;
1917 /* Count the number of INIT cycles (for doubling timeout). */
1920 /* Default send parameters. */
1921 __u16 default_stream;
1922 __u16 default_flags;
1924 __u32 default_context;
1925 __u32 default_timetolive;
1927 /* Default receive parameters */
1928 __u32 default_rcv_context;
1931 struct sctp_stream stream;
1933 /* All outbound chunks go through this structure. */
1934 struct sctp_outq outqueue;
1936 /* A smart pipe that will handle reordering and fragmentation,
1937 * as well as handle passing events up to the ULP.
1939 struct sctp_ulpq ulpq;
1941 /* Last TSN that caused an ECNE Chunk to be sent. */
1942 __u32 last_ecne_tsn;
1944 /* Last TSN that caused a CWR Chunk to be sent. */
1947 /* How many duplicated TSNs have we seen? */
1950 /* These are to support
1951 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1952 * and Enforcement of Flow and Message Limits"
1953 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1954 * or "ADDIP" for short.
1959 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1961 * R1) One and only one ASCONF Chunk MAY be in transit and
1962 * unacknowledged at any one time. If a sender, after sending
1963 * an ASCONF chunk, decides it needs to transfer another
1964 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1965 * returns from the previous ASCONF Chunk before sending a
1966 * subsequent ASCONF. Note this restriction binds each side,
1967 * so at any time two ASCONF may be in-transit on any given
1968 * association (one sent from each endpoint).
1970 * [This is our one-and-only-one ASCONF in flight. If we do
1971 * not have an ASCONF in flight, this is NULL.]
1973 struct sctp_chunk *addip_last_asconf;
1975 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1977 * This is needed to implement itmes E1 - E4 of the updated
1978 * spec. Here is the justification:
1980 * Since the peer may bundle multiple ASCONF chunks toward us,
1981 * we now need the ability to cache multiple ACKs. The section
1982 * describes in detail how they are cached and cleaned up.
1984 struct list_head asconf_ack_list;
1986 /* These ASCONF chunks are waiting to be sent.
1988 * These chunaks can't be pushed to outqueue until receiving
1989 * ASCONF_ACK for the previous ASCONF indicated by
1990 * addip_last_asconf, so as to guarantee that only one ASCONF
1991 * is in flight at any time.
1993 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1995 * In defining the ASCONF Chunk transfer procedures, it is
1996 * essential that these transfers MUST NOT cause congestion
1997 * within the network. To achieve this, we place these
1998 * restrictions on the transfer of ASCONF Chunks:
2000 * R1) One and only one ASCONF Chunk MAY be in transit and
2001 * unacknowledged at any one time. If a sender, after sending
2002 * an ASCONF chunk, decides it needs to transfer another
2003 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2004 * returns from the previous ASCONF Chunk before sending a
2005 * subsequent ASCONF. Note this restriction binds each side,
2006 * so at any time two ASCONF may be in-transit on any given
2007 * association (one sent from each endpoint).
2010 * [I really think this is EXACTLY the sort of intelligence
2011 * which already resides in sctp_outq. Please move this
2012 * queue and its supporting logic down there. --piggy]
2014 struct list_head addip_chunk_list;
2016 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2018 * A2) A serial number should be assigned to the Chunk. The
2019 * serial number SHOULD be a monotonically increasing
2020 * number. The serial number SHOULD be initialized at
2021 * the start of the association to the same value as the
2022 * Initial TSN and every time a new ASCONF chunk is created
2023 * it is incremented by one after assigning the serial number
2024 * to the newly created chunk.
2027 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2029 * Serial Number : 32 bits (unsigned integer)
2031 * This value represents a Serial Number for the ASCONF
2032 * Chunk. The valid range of Serial Number is from 0 to
2033 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2034 * after reaching 4294967295.
2037 int src_out_of_asoc_ok;
2038 union sctp_addr *asconf_addr_del_pending;
2039 struct sctp_transport *new_transport;
2041 /* SCTP AUTH: list of the endpoint shared keys. These
2042 * keys are provided out of band by the user applicaton
2043 * and can't change during the lifetime of the association
2045 struct list_head endpoint_shared_keys;
2048 * The current generated assocaition shared key (secret)
2050 struct sctp_auth_bytes *asoc_shared_key;
2051 struct sctp_shared_key *shkey;
2053 /* SCTP AUTH: hmac id of the first peer requested algorithm
2056 __u16 default_hmac_id;
2058 __u16 active_key_id;
2060 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2061 temp:1, /* Is it a temporary association? */
2067 __u8 strreset_enable;
2068 __u8 strreset_outstanding; /* request param count on the fly */
2070 __u32 strreset_outseq; /* Update after receiving response */
2071 __u32 strreset_inseq; /* Update after receiving request */
2072 __u32 strreset_result[2]; /* save the results of last 2 responses */
2074 struct sctp_chunk *strreset_chunk; /* save request chunk */
2076 struct sctp_priv_assoc_stats stats;
2078 int sent_cnt_removable;
2080 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2081 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2085 /* An eyecatcher for determining if we are really looking at an
2086 * association data structure.
2089 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2092 /* Recover the outter association structure. */
2093 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2095 struct sctp_association *asoc;
2097 asoc = container_of(base, struct sctp_association, base);
2101 /* These are function signatures for manipulating associations. */
2104 struct sctp_association *
2105 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2106 enum sctp_scope scope, gfp_t gfp);
2107 void sctp_association_free(struct sctp_association *);
2108 void sctp_association_put(struct sctp_association *);
2109 void sctp_association_hold(struct sctp_association *);
2111 struct sctp_transport *sctp_assoc_choose_alter_transport(
2112 struct sctp_association *, struct sctp_transport *);
2113 void sctp_assoc_update_retran_path(struct sctp_association *);
2114 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2115 const union sctp_addr *);
2116 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2117 const union sctp_addr *laddr);
2118 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2119 const union sctp_addr *address,
2121 const int peer_state);
2122 void sctp_assoc_del_peer(struct sctp_association *asoc,
2123 const union sctp_addr *addr);
2124 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2125 struct sctp_transport *peer);
2126 void sctp_assoc_control_transport(struct sctp_association *asoc,
2127 struct sctp_transport *transport,
2128 enum sctp_transport_cmd command,
2129 sctp_sn_error_t error);
2130 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2131 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2132 int sctp_assoc_update(struct sctp_association *old,
2133 struct sctp_association *new);
2135 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2137 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2138 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2139 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2140 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2141 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2142 void sctp_assoc_set_primary(struct sctp_association *,
2143 struct sctp_transport *);
2144 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2145 struct sctp_transport *);
2146 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2147 enum sctp_scope scope, gfp_t gfp);
2148 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2149 struct sctp_cookie*,
2151 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2152 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2153 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2154 const struct sctp_association *asoc,
2156 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2158 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2159 const union sctp_addr *ss2);
2160 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2162 /* A convenience structure to parse out SCTP specific CMSGs. */
2164 struct sctp_initmsg *init;
2165 struct sctp_sndrcvinfo *srinfo;
2166 struct sctp_sndinfo *sinfo;
2167 struct sctp_prinfo *prinfo;
2168 struct sctp_authinfo *authinfo;
2169 struct msghdr *addrs_msg;
2172 /* Structure for tracking memory objects */
2173 struct sctp_dbg_objcnt_entry {
2178 #endif /* __sctp_structs_h__ */