1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
8 * This file is part of the SCTP kernel implementation
10 * Please send any bug reports or fixes you make to the
12 * lksctp developers <linux-sctp@vger.kernel.org>
14 * Written or modified by:
15 * Randall Stewart <randall@sctp.chicago.il.us>
16 * Ken Morneau <kmorneau@cisco.com>
17 * Qiaobing Xie <qxie1@email.mot.com>
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Xingang Guo <xingang.guo@intel.com>
22 * Hui Huang <hui.huang@nokia.com>
23 * Sridhar Samudrala <sri@us.ibm.com>
24 * Daisy Chang <daisyc@us.ibm.com>
25 * Dajiang Zhang <dajiang.zhang@nokia.com>
26 * Ardelle Fan <ardelle.fan@intel.com>
27 * Ryan Layer <rmlayer@us.ibm.com>
28 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
29 * Kevin Gao <kevin.gao@intel.com>
32 #ifndef __sctp_structs_h__
33 #define __sctp_structs_h__
35 #include <linux/ktime.h>
36 #include <linux/generic-radix-tree.h>
37 #include <linux/rhashtable-types.h>
38 #include <linux/socket.h> /* linux/in.h needs this!! */
39 #include <linux/in.h> /* We get struct sockaddr_in. */
40 #include <linux/in6.h> /* We get struct in6_addr */
41 #include <linux/ipv6.h>
42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
43 #include <linux/atomic.h> /* This gets us atomic counters. */
44 #include <linux/skbuff.h> /* We need sk_buff_head. */
45 #include <linux/workqueue.h> /* We need tq_struct. */
46 #include <linux/sctp.h> /* We need sctp* header structs. */
47 #include <net/sctp/auth.h> /* We need auth specific structs */
48 #include <net/ip.h> /* For inet_skb_parm */
50 /* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
54 struct sockaddr_in v4;
55 struct sockaddr_in6 v6;
59 /* Forward declarations for data structures. */
62 struct sctp_association;
63 struct sctp_transport;
68 struct sctp_bind_addr;
70 struct sctp_ep_common;
75 #include <net/sctp/tsnmap.h>
76 #include <net/sctp/ulpevent.h>
77 #include <net/sctp/ulpqueue.h>
78 #include <net/sctp/stream_interleave.h>
80 /* Structures useful for managing bind/connect. */
82 struct sctp_bind_bucket {
84 signed char fastreuse;
85 signed char fastreuseport;
87 struct hlist_node node;
88 struct hlist_head owner;
92 struct sctp_bind_hashbucket {
94 struct hlist_head chain;
97 /* Used for hashing all associations. */
98 struct sctp_hashbucket {
100 struct hlist_head chain;
101 } __attribute__((__aligned__(8)));
104 /* The SCTP globals structure. */
105 extern struct sctp_globals {
106 /* This is a list of groups of functions for each address
107 * family that we support.
109 struct list_head address_families;
111 /* This is the hash of all endpoints. */
112 struct sctp_hashbucket *ep_hashtable;
113 /* This is the sctp port control hash. */
114 struct sctp_bind_hashbucket *port_hashtable;
115 /* This is the hash of all transports. */
116 struct rhltable transport_hashtable;
118 /* Sizes of above hashtables. */
122 /* Default initialization values to be applied to new associations. */
124 __u16 max_outstreams;
126 /* Flag to indicate whether computing and verifying checksum
128 bool checksum_disable;
131 #define sctp_max_instreams (sctp_globals.max_instreams)
132 #define sctp_max_outstreams (sctp_globals.max_outstreams)
133 #define sctp_address_families (sctp_globals.address_families)
134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
136 #define sctp_port_hashsize (sctp_globals.port_hashsize)
137 #define sctp_port_hashtable (sctp_globals.port_hashtable)
138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
139 #define sctp_checksum_disable (sctp_globals.checksum_disable)
141 /* SCTP Socket type: UDP or TCP style. */
142 enum sctp_socket_type {
144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
148 /* Per socket SCTP information. */
150 /* inet_sock has to be the first member of sctp_sock */
151 struct inet_sock inet;
152 /* What kind of a socket is this? */
153 enum sctp_socket_type type;
155 /* PF_ family specific functions. */
158 /* Access to HMAC transform. */
159 struct crypto_shash *hmac;
162 /* What is our base endpointer? */
163 struct sctp_endpoint *ep;
165 struct sctp_bind_bucket *bind_hash;
166 /* Various Socket Options. */
167 __u16 default_stream;
170 __u32 default_context;
171 __u32 default_timetolive;
172 __u32 default_rcv_context;
175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176 * the destination address every heartbeat interval. This value
177 * will be inherited by all new associations.
181 /* This is the max_retrans value for new associations. */
190 /* The initial Path MTU to use for new associations. */
193 /* The default SACK delay timeout for new associations. */
197 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
202 struct sctp_rtoinfo rtoinfo;
203 struct sctp_paddrparams paddrparam;
204 struct sctp_assocparams assocparams;
207 * These two structures must be grouped together for the usercopy
211 struct sctp_initmsg initmsg;
216 __u32 adaptation_ind;
226 data_ready_signalled:1;
230 /* Fields after this point will be skipped on copies, like on accept
231 * and peeloff operations
234 /* Receive to here while partial delivery is in effect. */
235 struct sk_buff_head pd_lobby;
237 struct list_head auto_asconf_list;
241 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
243 return (struct sctp_sock *)sk;
246 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
248 return (struct sock *)sp;
251 #if IS_ENABLED(CONFIG_IPV6)
253 struct sctp_sock sctp;
254 struct ipv6_pinfo inet6;
256 #endif /* CONFIG_IPV6 */
259 /* This is our APPLICATION-SPECIFIC state cookie.
260 * THIS IS NOT DICTATED BY THE SPECIFICATION.
262 /* These are the parts of an association which we send in the cookie.
263 * Most of these are straight out of:
264 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
270 /* My : Tag expected in every inbound packet and sent
271 * Verification: in the INIT or INIT ACK chunk.
276 /* Peer's : Tag expected in every outbound packet except
277 * Verification: in the INIT chunk.
282 /* The rest of these are not from the spec, but really need to
286 /* My Tie Tag : Assist in discovering a restarting association. */
289 /* Peer's Tie Tag: Assist in discovering a restarting association. */
292 /* When does this cookie expire? */
295 /* Number of inbound/outbound streams which are set
296 * and negotiated during the INIT process.
298 __u16 sinit_num_ostreams;
299 __u16 sinit_max_instreams;
301 /* This is the first sequence number I used. */
304 /* This holds the originating address of the INIT packet. */
305 union sctp_addr peer_addr;
308 * Include the source port of the INIT-ACK
314 /* Padding for future use */
317 __u32 adaptation_ind;
319 __u8 auth_random[sizeof(struct sctp_paramhdr) +
320 SCTP_AUTH_RANDOM_LENGTH];
321 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
322 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
324 /* This is a shim for my peer's INIT packet, followed by
325 * a copy of the raw address list of the association.
326 * The length of the raw address list is saved in the
327 * raw_addr_list_len field, which will be used at the time when
328 * the association TCB is re-constructed from the cookie.
330 __u32 raw_addr_list_len;
331 struct sctp_init_chunk peer_init[];
335 /* The format of our cookie that we send to our peer. */
336 struct sctp_signed_cookie {
337 __u8 signature[SCTP_SECRET_SIZE];
338 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
339 struct sctp_cookie c;
342 /* This is another convenience type to allocate memory for address
343 * params for the maximum size and pass such structures around
346 union sctp_addr_param {
347 struct sctp_paramhdr p;
348 struct sctp_ipv4addr_param v4;
349 struct sctp_ipv6addr_param v6;
352 /* A convenience type to allow walking through the various
353 * parameters and avoid casting all over the place.
357 struct sctp_paramhdr *p;
358 struct sctp_cookie_preserve_param *life;
359 struct sctp_hostname_param *dns;
360 struct sctp_cookie_param *cookie;
361 struct sctp_supported_addrs_param *sat;
362 struct sctp_ipv4addr_param *v4;
363 struct sctp_ipv6addr_param *v6;
364 union sctp_addr_param *addr;
365 struct sctp_adaptation_ind_param *aind;
366 struct sctp_supported_ext_param *ext;
367 struct sctp_random_param *random;
368 struct sctp_chunks_param *chunks;
369 struct sctp_hmac_algo_param *hmac_algo;
370 struct sctp_addip_param *addip;
373 /* RFC 2960. Section 3.3.5 Heartbeat.
374 * Heartbeat Information: variable length
375 * The Sender-specific Heartbeat Info field should normally include
376 * information about the sender's current time when this HEARTBEAT
377 * chunk is sent and the destination transport address to which this
378 * HEARTBEAT is sent (see Section 8.3).
380 struct sctp_sender_hb_info {
381 struct sctp_paramhdr param_hdr;
382 union sctp_addr daddr;
383 unsigned long sent_at;
387 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
389 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
390 void sctp_stream_free(struct sctp_stream *stream);
391 void sctp_stream_clear(struct sctp_stream *stream);
392 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
394 /* What is the current SSN number for this stream? */
395 #define sctp_ssn_peek(stream, type, sid) \
396 (sctp_stream_##type((stream), (sid))->ssn)
398 /* Return the next SSN number for this stream. */
399 #define sctp_ssn_next(stream, type, sid) \
400 (sctp_stream_##type((stream), (sid))->ssn++)
402 /* Skip over this ssn and all below. */
403 #define sctp_ssn_skip(stream, type, sid, ssn) \
404 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
406 /* What is the current MID number for this stream? */
407 #define sctp_mid_peek(stream, type, sid) \
408 (sctp_stream_##type((stream), (sid))->mid)
410 /* Return the next MID number for this stream. */
411 #define sctp_mid_next(stream, type, sid) \
412 (sctp_stream_##type((stream), (sid))->mid++)
414 /* Skip over this mid and all below. */
415 #define sctp_mid_skip(stream, type, sid, mid) \
416 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
418 /* What is the current MID_uo number for this stream? */
419 #define sctp_mid_uo_peek(stream, type, sid) \
420 (sctp_stream_##type((stream), (sid))->mid_uo)
422 /* Return the next MID_uo number for this stream. */
423 #define sctp_mid_uo_next(stream, type, sid) \
424 (sctp_stream_##type((stream), (sid))->mid_uo++)
427 * Pointers to address related SCTP functions.
428 * (i.e. things that depend on the address family.)
431 int (*sctp_xmit) (struct sk_buff *skb,
432 struct sctp_transport *);
433 int (*setsockopt) (struct sock *sk,
437 unsigned int optlen);
438 int (*getsockopt) (struct sock *sk,
443 void (*get_dst) (struct sctp_transport *t,
444 union sctp_addr *saddr,
447 void (*get_saddr) (struct sctp_sock *sk,
448 struct sctp_transport *t,
450 void (*copy_addrlist) (struct list_head *,
451 struct net_device *);
452 int (*cmp_addr) (const union sctp_addr *addr1,
453 const union sctp_addr *addr2);
454 void (*addr_copy) (union sctp_addr *dst,
455 union sctp_addr *src);
456 void (*from_skb) (union sctp_addr *,
459 void (*from_sk) (union sctp_addr *,
461 bool (*from_addr_param) (union sctp_addr *,
462 union sctp_addr_param *,
463 __be16 port, int iif);
464 int (*to_addr_param) (const union sctp_addr *,
465 union sctp_addr_param *);
466 int (*addr_valid) (union sctp_addr *,
468 const struct sk_buff *);
469 enum sctp_scope (*scope)(union sctp_addr *);
470 void (*inaddr_any) (union sctp_addr *, __be16);
471 int (*is_any) (const union sctp_addr *);
472 int (*available) (union sctp_addr *,
474 int (*skb_iif) (const struct sk_buff *sk);
475 int (*is_ce) (const struct sk_buff *sk);
476 void (*seq_dump_addr)(struct seq_file *seq,
477 union sctp_addr *addr);
478 void (*ecn_capable)(struct sock *sk);
479 __u16 net_header_len;
481 int (*ip_options_len)(struct sock *sk);
482 sa_family_t sa_family;
483 struct list_head list;
486 struct sctp_af *sctp_get_af_specific(sa_family_t);
487 int sctp_register_af(struct sctp_af *);
489 /* Protocol family functions. */
491 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
492 void (*skb_msgname) (struct sk_buff *, char *, int *);
493 int (*af_supported) (sa_family_t, struct sctp_sock *);
494 int (*cmp_addr) (const union sctp_addr *,
495 const union sctp_addr *,
497 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
498 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
499 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
500 struct sock *(*create_accept_sk) (struct sock *sk,
501 struct sctp_association *asoc,
503 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
504 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
505 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
506 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
511 /* Structure to track chunk fragments that have been acked, but peer
512 * fragments of the same message have not.
514 struct sctp_datamsg {
515 /* Chunks waiting to be submitted to lower layer. */
516 struct list_head chunks;
517 /* Reference counting. */
519 /* When is this message no longer interesting to the peer? */
520 unsigned long expires_at;
521 /* Did the messenge fail to send? */
524 can_delay:1, /* should this message be Nagle delayed */
525 abandoned:1; /* should this message be abandoned */
528 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
529 struct sctp_sndrcvinfo *,
531 void sctp_datamsg_free(struct sctp_datamsg *);
532 void sctp_datamsg_put(struct sctp_datamsg *);
533 void sctp_chunk_fail(struct sctp_chunk *, int error);
534 int sctp_chunk_abandoned(struct sctp_chunk *);
536 /* RFC2960 1.4 Key Terms
538 * o Chunk: A unit of information within an SCTP packet, consisting of
539 * a chunk header and chunk-specific content.
541 * As a matter of convenience, we remember the SCTP common header for
542 * each chunk as well as a few other header pointers...
545 struct list_head list;
549 /* How many times this chunk have been sent, for prsctp RTX policy */
553 /* This is our link to the per-transport transmitted list. */
554 struct list_head transmitted_list;
555 /* List in specific stream outq */
556 struct list_head stream_list;
559 /* This field is used by chunks that hold fragmented data.
560 * For the first fragment this is the list that holds the rest of
561 * fragments. For the remaining fragments, this is the link to the
562 * frag_list maintained in the first fragment.
564 struct list_head frag_list;
566 /* This points to the sk_buff containing the actual data. */
570 /* In case of GSO packets, this will store the head one */
571 struct sk_buff *head_skb;
572 /* In case of auth enabled, this will point to the shkey */
573 struct sctp_shared_key *shkey;
576 /* These are the SCTP headers by reverse order in a packet.
577 * Note that some of these may happen more than once. In that
578 * case, we point at the "current" one, whatever that means
579 * for that level of header.
582 /* We point this at the FIRST TLV parameter to chunk_hdr. */
583 union sctp_params param_hdr;
586 struct sctp_datahdr *data_hdr;
587 struct sctp_inithdr *init_hdr;
588 struct sctp_sackhdr *sack_hdr;
589 struct sctp_heartbeathdr *hb_hdr;
590 struct sctp_sender_hb_info *hbs_hdr;
591 struct sctp_shutdownhdr *shutdown_hdr;
592 struct sctp_signed_cookie *cookie_hdr;
593 struct sctp_ecnehdr *ecne_hdr;
594 struct sctp_cwrhdr *ecn_cwr_hdr;
595 struct sctp_errhdr *err_hdr;
596 struct sctp_addiphdr *addip_hdr;
597 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
598 struct sctp_authhdr *auth_hdr;
599 struct sctp_idatahdr *idata_hdr;
600 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
605 struct sctp_chunkhdr *chunk_hdr;
606 struct sctphdr *sctp_hdr;
608 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
609 struct sctp_sndrcvinfo sinfo;
611 /* Which association does this belong to? */
612 struct sctp_association *asoc;
614 /* What endpoint received this chunk? */
615 struct sctp_ep_common *rcvr;
617 /* We fill this in if we are calculating RTT. */
618 unsigned long sent_at;
620 /* What is the origin IP address for this chunk? */
621 union sctp_addr source;
622 /* Destination address for this chunk. */
623 union sctp_addr dest;
625 /* For outbound message, track all fragments for SEND_FAILED. */
626 struct sctp_datamsg *msg;
628 /* For an inbound chunk, this tells us where it came from.
629 * For an outbound chunk, it tells us where we'd like it to
630 * go. It is NULL if we have no preference.
632 struct sctp_transport *transport;
634 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
635 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
636 * spec violates the principle premis that all chunks are processed
639 struct sk_buff *auth_chunk;
641 #define SCTP_CAN_FRTX 0x0
642 #define SCTP_NEED_FRTX 0x1
643 #define SCTP_DONT_FRTX 0x2
644 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
645 has_tsn:1, /* Does this chunk have a TSN yet? */
646 has_ssn:1, /* Does this chunk have a SSN yet? */
647 #define has_mid has_ssn
648 singleton:1, /* Only chunk in the packet? */
649 end_of_packet:1, /* Last chunk in the packet? */
650 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
651 pdiscard:1, /* Discard the whole packet now? */
652 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
653 data_accepted:1, /* At least 1 chunk accepted */
654 auth:1, /* IN: was auth'ed | OUT: needs auth */
655 has_asconf:1, /* IN: have seen an asconf before */
656 tsn_missing_report:2, /* Data chunk missing counter. */
657 fast_retransmit:2; /* Is this chunk fast retransmitted? */
660 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
661 void sctp_chunk_hold(struct sctp_chunk *);
662 void sctp_chunk_put(struct sctp_chunk *);
663 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
664 struct iov_iter *from);
665 void sctp_chunk_free(struct sctp_chunk *);
666 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
667 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
668 const struct sctp_association *,
669 struct sock *, gfp_t gfp);
670 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
672 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
674 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
676 return ntohs(ch->subh.data_hdr->stream);
680 SCTP_ADDR_NEW, /* new address added to assoc/ep */
681 SCTP_ADDR_SRC, /* address can be used as source */
682 SCTP_ADDR_DEL, /* address about to be deleted */
685 /* This is a structure for holding either an IPv6 or an IPv4 address. */
686 struct sctp_sockaddr_entry {
687 struct list_head list;
694 #define SCTP_ADDRESS_TICK_DELAY 500
696 /* This structure holds lists of chunks as we are assembling for
700 /* These are the SCTP header values (host order) for the packet. */
702 __u16 destination_port;
705 /* This contains the payload chunks. */
706 struct list_head chunk_list;
708 /* This is the overhead of the sctp and ip headers. */
710 /* This is the total size of all chunks INCLUDING padding. */
712 /* This is the maximum size this packet may have */
715 /* The packet is destined for this transport address.
716 * The function we finally use to pass down to the next lower
717 * layer lives in the transport structure.
719 struct sctp_transport *transport;
721 /* pointer to the auth chunk for this packet */
722 struct sctp_chunk *auth;
724 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
725 has_sack:1, /* This packet contains a SACK chunk. */
726 has_auth:1, /* This packet contains an AUTH chunk */
727 has_data:1, /* This packet contains at least 1 DATA chunk */
728 ipfragok:1; /* So let ip fragment this packet */
731 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
732 __u16 sport, __u16 dport);
733 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
734 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
735 struct sctp_chunk *chunk,
736 int one_packet, gfp_t gfp);
737 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
738 struct sctp_chunk *chunk);
739 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
740 void sctp_packet_free(struct sctp_packet *);
742 static inline int sctp_packet_empty(struct sctp_packet *packet)
744 return packet->size == packet->overhead;
747 /* This represents a remote transport address.
748 * For local transport addresses, we just use union sctp_addr.
750 * RFC2960 Section 1.4 Key Terms
752 * o Transport address: A Transport Address is traditionally defined
753 * by Network Layer address, Transport Layer protocol and Transport
754 * Layer port number. In the case of SCTP running over IP, a
755 * transport address is defined by the combination of an IP address
756 * and an SCTP port number (where SCTP is the Transport protocol).
758 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
760 * o The sender keeps a separate congestion control parameter set for
761 * each of the destination addresses it can send to (not each
762 * source-destination pair but for each destination). The parameters
763 * should decay if the address is not used for a long enough time
767 struct sctp_transport {
768 /* A list of transports. */
769 struct list_head transports;
770 struct rhlist_head node;
772 /* Reference counting. */
774 /* RTO-Pending : A flag used to track if one of the DATA
775 * chunks sent to this address is currently being
776 * used to compute a RTT. If this flag is 0,
777 * the next DATA chunk sent to this destination
778 * should be used to compute a RTT and this flag
779 * should be set. Every time the RTT
780 * calculation completes (i.e. the DATA chunk
781 * is SACK'd) clear this flag.
786 * hb_sent : a flag that signals that we have a pending
791 /* Is the Path MTU update pending on this tranport */
794 dst_pending_confirm:1, /* need to confirm neighbour */
796 /* Has this transport moved the ctsn since we last sacked */
802 /* This is the peer's IP address and port. */
803 union sctp_addr ipaddr;
805 /* These are the functions we call to handle LLP stuff. */
806 struct sctp_af *af_specific;
808 /* Which association do we belong to? */
809 struct sctp_association *asoc;
813 * 12.3 Per Transport Address Data
815 * For each destination transport address in the peer's
816 * address list derived from the INIT or INIT ACK chunk, a
817 * number of data elements needs to be maintained including:
819 /* RTO : The current retransmission timeout value. */
822 __u32 rtt; /* This is the most recent RTT. */
824 /* RTTVAR : The current RTT variation. */
827 /* SRTT : The current smoothed round trip time. */
831 * These are the congestion stats.
833 /* cwnd : The current congestion window. */
834 __u32 cwnd; /* This is the actual cwnd. */
836 /* ssthresh : The current slow start threshold value. */
839 /* partial : The tracking method for increase of cwnd when in
840 * bytes acked : congestion avoidance mode (see Section 6.2.2)
842 __u32 partial_bytes_acked;
844 /* Data that has been sent, but not acknowledged. */
847 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
850 struct dst_entry *dst;
851 /* Source address. */
852 union sctp_addr saddr;
854 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
855 * the destination address every heartbeat interval.
857 unsigned long hbinterval;
859 /* SACK delay timeout */
860 unsigned long sackdelay;
865 /* When was the last time that we heard from this transport? We use
866 * this to pick new active and retran paths.
868 ktime_t last_time_heard;
870 /* When was the last time that we sent a chunk using this
871 * transport? We use this to check for idle transports
873 unsigned long last_time_sent;
875 /* Last time(in jiffies) when cwnd is reduced due to the congestion
876 * indication based on ECNE chunk.
878 unsigned long last_time_ecne_reduced;
880 /* This is the max_retrans value for the transport and will
881 * be initialized from the assocs value. This can be changed
882 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
889 /* This is the partially failed retrans value for the transport
890 * and will be initialized from the assocs value. This can be changed
891 * using the SCTP_PEER_ADDR_THLDS socket option
894 /* Used for primary path switchover. */
896 /* PMTU : The current known path MTU. */
899 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
902 /* The number of times INIT has been sent on this transport. */
905 /* state : The current state of this destination,
906 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
910 /* These are the error stats for this destination. */
912 /* Error count : The current error count for this destination. */
913 unsigned short error_count;
915 /* Per : A timer used by each destination.
919 * [Everywhere else in the text this is called T3-rtx. -ed]
921 struct timer_list T3_rtx_timer;
923 /* Heartbeat timer is per destination. */
924 struct timer_list hb_timer;
926 /* Timer to handle ICMP proto unreachable envets */
927 struct timer_list proto_unreach_timer;
929 /* Timer to handler reconf chunk rtx */
930 struct timer_list reconf_timer;
932 /* Since we're using per-destination retransmission timers
933 * (see above), we're also using per-destination "transmitted"
934 * queues. This probably ought to be a private struct
935 * accessible only within the outqueue, but it's not, yet.
937 struct list_head transmitted;
939 /* We build bundle-able packets for this transport here. */
940 struct sctp_packet packet;
942 /* This is the list of transports that have chunks to send. */
943 struct list_head send_ready;
945 /* State information saved for SFR_CACC algorithm. The key
946 * idea in SFR_CACC is to maintain state at the sender on a
947 * per-destination basis when a changeover happens.
948 * char changeover_active;
949 * char cycling_changeover;
950 * __u32 next_tsn_at_change;
951 * char cacc_saw_newack;
954 /* An unsigned integer, which stores the next TSN to be
955 * used by the sender, at the moment of changeover.
957 __u32 next_tsn_at_change;
959 /* A flag which indicates the occurrence of a changeover */
960 char changeover_active;
962 /* A flag which indicates whether the change of primary is
963 * the first switch to this destination address during an
966 char cycling_changeover;
968 /* A temporary flag, which is used during the processing of
969 * a SACK to estimate the causative TSN(s)'s group.
971 char cacc_saw_newack;
974 /* 64-bit random number sent with heartbeat. */
980 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
982 void sctp_transport_set_owner(struct sctp_transport *,
983 struct sctp_association *);
984 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
986 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
987 void sctp_transport_free(struct sctp_transport *);
988 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
989 void sctp_transport_reset_hb_timer(struct sctp_transport *);
990 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
991 int sctp_transport_hold(struct sctp_transport *);
992 void sctp_transport_put(struct sctp_transport *);
993 void sctp_transport_update_rto(struct sctp_transport *, __u32);
994 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
995 void sctp_transport_lower_cwnd(struct sctp_transport *t,
996 enum sctp_lower_cwnd reason);
997 void sctp_transport_burst_limited(struct sctp_transport *);
998 void sctp_transport_burst_reset(struct sctp_transport *);
999 unsigned long sctp_transport_timeout(struct sctp_transport *);
1000 void sctp_transport_reset(struct sctp_transport *t);
1001 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1002 void sctp_transport_immediate_rtx(struct sctp_transport *);
1003 void sctp_transport_dst_release(struct sctp_transport *t);
1004 void sctp_transport_dst_confirm(struct sctp_transport *t);
1007 /* This is the structure we use to queue packets as they come into
1008 * SCTP. We write packets to it and read chunks from it.
1011 /* This is actually a queue of sctp_chunk each
1012 * containing a partially decoded packet.
1014 struct list_head in_chunk_list;
1015 /* This is the packet which is currently off the in queue and is
1016 * being worked on through the inbound chunk processing.
1018 struct sctp_chunk *in_progress;
1020 /* This is the delayed task to finish delivering inbound
1023 struct work_struct immediate;
1026 void sctp_inq_init(struct sctp_inq *);
1027 void sctp_inq_free(struct sctp_inq *);
1028 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1029 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1030 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1031 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1033 /* This is the structure we use to hold outbound chunks. You push
1034 * chunks in and they automatically pop out the other end as bundled
1035 * packets (it calls (*output_handler)()).
1037 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1038 * and 8.2 of the v13 draft.
1040 * It handles retransmissions. The connection to the timeout portion
1041 * of the state machine is through sctp_..._timeout() and timeout_handler.
1043 * If you feed it SACKs, it will eat them.
1045 * If you give it big chunks, it will fragment them.
1047 * It assigns TSN's to data chunks. This happens at the last possible
1048 * instant before transmission.
1050 * When free()'d, it empties itself out via output_handler().
1053 struct sctp_association *asoc;
1055 /* Data pending that has never been transmitted. */
1056 struct list_head out_chunk_list;
1058 /* Stream scheduler being used */
1059 struct sctp_sched_ops *sched;
1061 unsigned int out_qlen; /* Total length of queued data chunks. */
1063 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1066 /* These are control chunks we want to send. */
1067 struct list_head control_chunk_list;
1069 /* These are chunks that have been sacked but are above the
1070 * CTSN, or cumulative tsn ack point.
1072 struct list_head sacked;
1074 /* Put chunks on this list to schedule them for
1077 struct list_head retransmit;
1079 /* Put chunks on this list to save them for FWD TSN processing as
1080 * they were abandoned.
1082 struct list_head abandoned;
1084 /* How many unackd bytes do we have in-flight? */
1085 __u32 outstanding_bytes;
1087 /* Are we doing fast-rtx on this queue */
1094 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1095 void sctp_outq_teardown(struct sctp_outq *);
1096 void sctp_outq_free(struct sctp_outq*);
1097 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1098 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1099 int sctp_outq_is_empty(const struct sctp_outq *);
1100 void sctp_outq_restart(struct sctp_outq *);
1102 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1103 enum sctp_retransmit_reason reason);
1104 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1105 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1106 void sctp_prsctp_prune(struct sctp_association *asoc,
1107 struct sctp_sndrcvinfo *sinfo, int msg_len);
1108 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1109 /* Uncork and flush an outqueue. */
1110 static inline void sctp_outq_cork(struct sctp_outq *q)
1115 /* SCTP skb control block.
1116 * sctp_input_cb is currently used on rx and sock rx queue
1118 struct sctp_input_cb {
1120 struct inet_skb_parm h4;
1121 #if IS_ENABLED(CONFIG_IPV6)
1122 struct inet6_skb_parm h6;
1125 struct sctp_chunk *chunk;
1128 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1130 struct sctp_output_cb {
1131 struct sk_buff *last;
1133 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1135 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1137 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1139 return chunk->head_skb ? : skb;
1142 /* These bind address data fields common between endpoints and associations */
1143 struct sctp_bind_addr {
1145 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1147 * SCTP Port: The local SCTP port number the endpoint is
1152 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1154 * Address List: The list of IP addresses that this instance
1155 * has bound. This information is passed to one's
1156 * peer(s) in INIT and INIT ACK chunks.
1158 struct list_head address_list;
1161 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1162 void sctp_bind_addr_free(struct sctp_bind_addr *);
1163 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1164 const struct sctp_bind_addr *src,
1165 enum sctp_scope scope, gfp_t gfp,
1167 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1168 const struct sctp_bind_addr *src,
1170 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1171 int new_size, __u8 addr_state, gfp_t gfp);
1172 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1173 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1174 struct sctp_sock *);
1175 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1176 struct sctp_sock *, struct sctp_sock *);
1177 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1178 const union sctp_addr *addr);
1179 int sctp_bind_addrs_check(struct sctp_sock *sp,
1180 struct sctp_sock *sp2, int cnt2);
1181 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1182 const union sctp_addr *addrs,
1184 struct sctp_sock *opt);
1185 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1188 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1189 __u16 port, gfp_t gfp);
1191 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1192 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1193 const enum sctp_scope scope);
1194 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1195 int sctp_is_ep_boundall(struct sock *sk);
1198 /* What type of endpoint? */
1199 enum sctp_endpoint_type {
1200 SCTP_EP_TYPE_SOCKET,
1201 SCTP_EP_TYPE_ASSOCIATION,
1205 * A common base class to bridge the implmentation view of a
1206 * socket (usually listening) endpoint versus an association's
1208 * This common structure is useful for several purposes:
1209 * 1) Common interface for lookup routines.
1210 * a) Subfunctions work for either endpoint or association
1211 * b) Single interface to lookup allows hiding the lookup lock rather
1212 * than acquiring it externally.
1213 * 2) Common interface for the inbound chunk handling/state machine.
1214 * 3) Common object handling routines for reference counting, etc.
1215 * 4) Disentangle association lookup from endpoint lookup, where we
1216 * do not have to find our endpoint to find our association.
1220 struct sctp_ep_common {
1221 /* Fields to help us manage our entries in the hash tables. */
1222 struct hlist_node node;
1225 /* Runtime type information. What kind of endpoint is this? */
1226 enum sctp_endpoint_type type;
1228 /* Some fields to help us manage this object.
1229 * refcnt - Reference count access to this object.
1230 * dead - Do not attempt to use this object.
1235 /* What socket does this endpoint belong to? */
1238 /* Cache netns and it won't change once set */
1241 /* This is where we receive inbound chunks. */
1242 struct sctp_inq inqueue;
1244 /* This substructure includes the defining parameters of the
1246 * bind_addr.port is our shared port number.
1247 * bind_addr.address_list is our set of local IP addresses.
1249 struct sctp_bind_addr bind_addr;
1253 /* RFC Section 1.4 Key Terms
1255 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1256 * multi-homed host, an SCTP endpoint is represented to its peers as a
1257 * combination of a set of eligible destination transport addresses to
1258 * which SCTP packets can be sent and a set of eligible source
1259 * transport addresses from which SCTP packets can be received.
1260 * All transport addresses used by an SCTP endpoint must use the
1261 * same port number, but can use multiple IP addresses. A transport
1262 * address used by an SCTP endpoint must not be used by another
1263 * SCTP endpoint. In other words, a transport address is unique
1264 * to an SCTP endpoint.
1266 * From an implementation perspective, each socket has one of these.
1267 * A TCP-style socket will have exactly one association on one of
1268 * these. An UDP-style socket will have multiple associations hanging
1272 struct sctp_endpoint {
1273 /* Common substructure for endpoint and association. */
1274 struct sctp_ep_common base;
1276 /* Associations: A list of current associations and mappings
1277 * to the data consumers for each association. This
1278 * may be in the form of a hash table or other
1279 * implementation dependent structure. The data
1280 * consumers may be process identification
1281 * information such as file descriptors, named pipe
1282 * pointer, or table pointers dependent on how SCTP
1285 /* This is really a list of struct sctp_association entries. */
1286 struct list_head asocs;
1288 /* Secret Key: A secret key used by this endpoint to compute
1289 * the MAC. This SHOULD be a cryptographic quality
1290 * random number with a sufficient length.
1291 * Discussion in [RFC1750] can be helpful in
1292 * selection of the key.
1294 __u8 secret_key[SCTP_SECRET_SIZE];
1296 /* digest: This is a digest of the sctp cookie. This field is
1297 * only used on the receive path when we try to validate
1298 * that the cookie has not been tampered with. We put
1299 * this here so we pre-allocate this once and can re-use
1304 /* sendbuf acct. policy. */
1305 __u32 sndbuf_policy;
1307 /* rcvbuf acct. policy. */
1308 __u32 rcvbuf_policy;
1310 /* SCTP AUTH: array of the HMACs that will be allocated
1311 * we need this per association so that we don't serialize
1313 struct crypto_shash **auth_hmacs;
1315 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1316 struct sctp_hmac_algo_param *auth_hmacs_list;
1318 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1319 struct sctp_chunks_param *auth_chunk_list;
1321 /* SCTP-AUTH: endpoint shared keys */
1322 struct list_head endpoint_shared_keys;
1323 __u16 active_key_id;
1331 __u8 strreset_enable;
1333 /* Security identifiers from incoming (INIT). These are set by
1334 * security_sctp_assoc_request(). These will only be used by
1335 * SCTP TCP type sockets and peeled off connections as they
1336 * cause a new socket to be generated. security_sctp_sk_clone()
1337 * will then plug these into the new socket.
1342 struct rcu_head rcu;
1345 /* Recover the outter endpoint structure. */
1346 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1348 struct sctp_endpoint *ep;
1350 ep = container_of(base, struct sctp_endpoint, base);
1354 /* These are function signatures for manipulating endpoints. */
1355 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1356 void sctp_endpoint_free(struct sctp_endpoint *);
1357 void sctp_endpoint_put(struct sctp_endpoint *);
1358 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1359 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1360 struct sctp_association *sctp_endpoint_lookup_assoc(
1361 const struct sctp_endpoint *ep,
1362 const union sctp_addr *paddr,
1363 struct sctp_transport **);
1364 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1365 const union sctp_addr *paddr);
1366 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1367 struct net *, const union sctp_addr *);
1368 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1369 const union sctp_addr *paddr);
1371 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1372 const struct sctp_association *asoc,
1373 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1374 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1375 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1376 const union sctp_addr *peer,
1377 struct sctp_init_chunk *init, gfp_t gfp);
1378 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1379 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1381 struct sctp_inithdr_host {
1384 __u16 num_outbound_streams;
1385 __u16 num_inbound_streams;
1389 struct sctp_stream_priorities {
1390 /* List of priorities scheduled */
1391 struct list_head prio_sched;
1392 /* List of streams scheduled */
1393 struct list_head active;
1394 /* The next stream in line */
1395 struct sctp_stream_out_ext *next;
1400 struct sctp_stream_out_ext {
1401 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1402 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1403 struct list_head outq; /* chunks enqueued by this stream */
1406 /* Scheduled streams list */
1407 struct list_head prio_list;
1408 struct sctp_stream_priorities *prio_head;
1410 /* Fields used by RR scheduler */
1412 struct list_head rr_list;
1417 struct sctp_stream_out {
1423 struct sctp_stream_out_ext *ext;
1427 struct sctp_stream_in {
1439 struct sctp_stream {
1440 GENRADIX(struct sctp_stream_out) out;
1441 GENRADIX(struct sctp_stream_in) in;
1445 /* Current stream being sent, if any */
1446 struct sctp_stream_out *out_curr;
1448 /* Fields used by priority scheduler */
1450 /* List of priorities scheduled */
1451 struct list_head prio_list;
1453 /* Fields used by RR scheduler */
1455 /* List of streams scheduled */
1456 struct list_head rr_list;
1457 /* The next stream in line */
1458 struct sctp_stream_out_ext *rr_next;
1461 struct sctp_stream_interleave *si;
1464 static inline struct sctp_stream_out *sctp_stream_out(
1465 struct sctp_stream *stream,
1468 return genradix_ptr(&stream->out, sid);
1471 static inline struct sctp_stream_in *sctp_stream_in(
1472 struct sctp_stream *stream,
1475 return genradix_ptr(&stream->in, sid);
1478 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1479 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1481 #define SCTP_STREAM_CLOSED 0x00
1482 #define SCTP_STREAM_OPEN 0x01
1484 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1486 return stream->si->data_chunk_len;
1489 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1491 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1494 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1496 return stream->si->ftsn_chunk_len;
1499 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1501 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1504 /* SCTP_GET_ASSOC_STATS counters */
1505 struct sctp_priv_assoc_stats {
1506 /* Maximum observed rto in the association during subsequent
1507 * observations. Value is set to 0 if no RTO measurement took place
1508 * The transport where the max_rto was observed is returned in
1511 struct sockaddr_storage obs_rto_ipaddr;
1513 /* Total In and Out SACKs received and sent */
1516 /* Total In and Out packets received and sent */
1519 /* Total retransmitted chunks */
1521 /* TSN received > next expected */
1523 /* Duplicate Chunks received */
1525 /* Gap Ack Blocks received */
1527 /* Unordered data chunks sent and received */
1530 /* Ordered data chunks sent and received */
1533 /* Control chunks sent and received */
1540 * 12. Recommended Transmission Control Block (TCB) Parameters
1542 * This section details a recommended set of parameters that should
1543 * be contained within the TCB for an implementation. This section is
1544 * for illustrative purposes and should not be deemed as requirements
1545 * on an implementation or as an exhaustive list of all parameters
1546 * inside an SCTP TCB. Each implementation may need its own additional
1547 * parameters for optimization.
1551 /* Here we have information about each individual association. */
1552 struct sctp_association {
1554 /* A base structure common to endpoint and association.
1555 * In this context, it represents the associations's view
1556 * of the local endpoint of the association.
1558 struct sctp_ep_common base;
1560 /* Associations on the same socket. */
1561 struct list_head asocs;
1563 /* association id. */
1564 sctp_assoc_t assoc_id;
1566 /* This is our parent endpoint. */
1567 struct sctp_endpoint *ep;
1569 /* These are those association elements needed in the cookie. */
1570 struct sctp_cookie c;
1572 /* This is all information about our peer. */
1574 /* transport_addr_list
1576 * Peer : A list of SCTP transport addresses that the
1577 * Transport : peer is bound to. This information is derived
1578 * Address : from the INIT or INIT ACK and is used to
1579 * List : associate an inbound packet with a given
1580 * : association. Normally this information is
1581 * : hashed or keyed for quick lookup and access
1583 * : The list is also initialized with the list
1584 * : of addresses passed with the sctp_connectx()
1587 * It is a list of SCTP_transport's.
1589 struct list_head transport_addr_list;
1593 * Peer Rwnd : Current calculated value of the peer's rwnd.
1599 * Peer : A count of the number of peer addresses
1600 * Transport : in the Peer Transport Address List.
1604 __u16 transport_count;
1607 * The transport layer port number.
1613 * Primary : This is the current primary destination
1614 * Path : transport address of the peer endpoint. It
1615 * : may also specify a source transport address
1616 * : on this endpoint.
1618 * All of these paths live on transport_addr_list.
1620 * At the bakeoffs, we discovered that the intent of
1621 * primaryPath is that it only changes when the ULP
1622 * asks to have it changed. We add the activePath to
1623 * designate the connection we are currently using to
1624 * transmit new data and most control chunks.
1626 struct sctp_transport *primary_path;
1628 /* Cache the primary path address here, when we
1629 * need a an address for msg_name.
1631 union sctp_addr primary_addr;
1634 * The path that we are currently using to
1635 * transmit new data and most control chunks.
1637 struct sctp_transport *active_path;
1641 * RFC2960 6.4 Multi-homed SCTP Endpoints
1643 * Furthermore, when its peer is multi-homed, an
1644 * endpoint SHOULD try to retransmit a chunk to an
1645 * active destination transport address that is
1646 * different from the last destination address to
1647 * which the DATA chunk was sent.
1649 struct sctp_transport *retran_path;
1651 /* Pointer to last transport I have sent on. */
1652 struct sctp_transport *last_sent_to;
1654 /* This is the last transport I have received DATA on. */
1655 struct sctp_transport *last_data_from;
1658 * Mapping An array of bits or bytes indicating which out of
1659 * Array order TSN's have been received (relative to the
1660 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1661 * order packets have been received, this array
1662 * will be set to all zero. This structure may be
1663 * in the form of a circular buffer or bit array.
1665 * Last Rcvd : This is the last TSN received in
1666 * TSN : sequence. This value is set initially by
1667 * : taking the peer's Initial TSN, received in
1668 * : the INIT or INIT ACK chunk, and subtracting
1671 * Throughout most of the specification this is called the
1672 * "Cumulative TSN ACK Point". In this case, we
1673 * ignore the advice in 12.2 in favour of the term
1674 * used in the bulk of the text. This value is hidden
1675 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1677 struct sctp_tsnmap tsn_map;
1679 /* This mask is used to disable sending the ASCONF chunk
1680 * with specified parameter to peer.
1682 __be16 addip_disabled_mask;
1684 /* These are capabilities which our peer advertised. */
1685 __u16 ecn_capable:1, /* Can peer do ECN? */
1686 ipv4_address:1, /* Peer understands IPv4 addresses? */
1687 ipv6_address:1, /* Peer understands IPv6 addresses? */
1688 hostname_address:1, /* Peer understands DNS addresses? */
1689 asconf_capable:1, /* Does peer support ADDIP? */
1690 prsctp_capable:1, /* Can peer do PR-SCTP? */
1691 reconf_capable:1, /* Can peer do RE-CONFIG? */
1692 intl_capable:1, /* Can peer do INTERLEAVE */
1693 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1695 * This flag indicates if the next received
1696 * packet is to be responded to with a
1697 * SACK. This is initialized to 0. When a packet
1698 * is received sack_cnt is incremented. If this value
1699 * reaches 2 or more, a SACK is sent and the
1700 * value is reset to 0. Note: This is used only
1701 * when no DATA chunks are received out of
1702 * order. When DATA chunks are out of order,
1703 * SACK's are not delayed (see Section 6).
1705 sack_needed:1, /* Do we need to sack the peer? */
1707 zero_window_announced:1;
1711 __u32 adaptation_ind; /* Adaptation Code point. */
1713 struct sctp_inithdr_host i;
1717 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1718 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1719 * Initial TSN Value minus 1
1723 /* SCTP-AUTH: We need to know pears random number, hmac list
1724 * and authenticated chunk list. All that is part of the
1725 * cookie and these are just pointers to those locations
1727 struct sctp_random_param *peer_random;
1728 struct sctp_chunks_param *peer_chunks;
1729 struct sctp_hmac_algo_param *peer_hmacs;
1732 /* State : A state variable indicating what state the
1733 * : association is in, i.e. COOKIE-WAIT,
1734 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1735 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1737 * Note: No "CLOSED" state is illustrated since if a
1738 * association is "CLOSED" its TCB SHOULD be removed.
1740 * In this implementation we DO have a CLOSED
1741 * state which is used during initiation and shutdown.
1743 * State takes values from SCTP_STATE_*.
1745 enum sctp_state state;
1747 /* Overall : The overall association error count.
1748 * Error Count : [Clear this any time I get something.]
1750 int overall_error_count;
1752 /* The cookie life I award for any cookie. */
1753 ktime_t cookie_life;
1755 /* These are the association's initial, max, and min RTO values.
1756 * These values will be initialized by system defaults, but can
1757 * be modified via the SCTP_RTOINFO socket option.
1759 unsigned long rto_initial;
1760 unsigned long rto_max;
1761 unsigned long rto_min;
1763 /* Maximum number of new data packets that can be sent in a burst. */
1766 /* This is the max_retrans value for the association. This value will
1767 * be initialized from system defaults, but can be
1768 * modified by the SCTP_ASSOCINFO socket option.
1772 /* This is the partially failed retrans value for the transport
1773 * and will be initialized from the assocs value. This can be
1774 * changed using the SCTP_PEER_ADDR_THLDS socket option
1777 /* Used for primary path switchover. */
1780 /* Maximum number of times the endpoint will retransmit INIT */
1781 __u16 max_init_attempts;
1783 /* How many times have we resent an INIT? */
1786 /* The largest timeout or RTO value to use in attempting an INIT */
1787 unsigned long max_init_timeo;
1789 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1790 * the destination address every heartbeat interval. This value
1791 * will be inherited by all new transports.
1793 unsigned long hbinterval;
1795 /* This is the max_retrans value for new transports in the
1803 /* Flag that path mtu update is pending */
1806 /* Association : The smallest PMTU discovered for all of the
1807 * PMTU : peer's transport addresses.
1811 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1815 /* SACK delay timeout */
1816 unsigned long sackdelay;
1818 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1819 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1821 /* Transport to which SHUTDOWN chunk was last sent. */
1822 struct sctp_transport *shutdown_last_sent_to;
1824 /* Transport to which INIT chunk was last sent. */
1825 struct sctp_transport *init_last_sent_to;
1827 /* How many times have we resent a SHUTDOWN */
1828 int shutdown_retries;
1830 /* Next TSN : The next TSN number to be assigned to a new
1831 * : DATA chunk. This is sent in the INIT or INIT
1832 * : ACK chunk to the peer and incremented each
1833 * : time a DATA chunk is assigned a TSN
1834 * : (normally just prior to transmit or during
1840 * Last Rcvd : This is the last TSN received in sequence. This value
1841 * TSN : is set initially by taking the peer's Initial TSN,
1842 * : received in the INIT or INIT ACK chunk, and
1843 * : subtracting one from it.
1845 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1848 __u32 ctsn_ack_point;
1850 /* PR-SCTP Advanced.Peer.Ack.Point */
1851 __u32 adv_peer_ack_point;
1853 /* Highest TSN that is acknowledged by incoming SACKs. */
1854 __u32 highest_sacked;
1856 /* TSN marking the fast recovery exit point */
1857 __u32 fast_recovery_exit;
1859 /* Flag to track the current fast recovery state */
1862 /* The number of unacknowledged data chunks. Reported through
1863 * the SCTP_STATUS sockopt.
1867 /* The total number of data chunks that we've had to retransmit
1868 * as the result of a T3 timer expiration
1870 __u32 rtx_data_chunks;
1872 /* This is the association's receive buffer space. This value is used
1873 * to set a_rwnd field in an INIT or a SACK chunk.
1877 /* This is the last advertised value of rwnd over a SACK chunk. */
1880 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1881 * to slop over a maximum of the association's frag_point.
1885 /* Keeps treack of rwnd pressure. This happens when we have
1886 * a window, but not recevie buffer (i.e small packets). This one
1887 * is releases slowly (1 PMTU at a time ).
1891 /* This is the sndbuf size in use for the association.
1892 * This corresponds to the sndbuf size for the association,
1893 * as specified in the sk->sndbuf.
1897 /* This is the amount of memory that this association has allocated
1898 * in the receive path at any given time.
1900 atomic_t rmem_alloc;
1902 /* This is the wait queue head for send requests waiting on
1903 * the association sndbuf space.
1905 wait_queue_head_t wait;
1907 /* The message size at which SCTP fragmentation will occur. */
1911 /* Counter used to count INIT errors. */
1912 int init_err_counter;
1914 /* Count the number of INIT cycles (for doubling timeout). */
1917 /* Default send parameters. */
1918 __u16 default_stream;
1919 __u16 default_flags;
1921 __u32 default_context;
1922 __u32 default_timetolive;
1924 /* Default receive parameters */
1925 __u32 default_rcv_context;
1928 struct sctp_stream stream;
1930 /* All outbound chunks go through this structure. */
1931 struct sctp_outq outqueue;
1933 /* A smart pipe that will handle reordering and fragmentation,
1934 * as well as handle passing events up to the ULP.
1936 struct sctp_ulpq ulpq;
1938 /* Last TSN that caused an ECNE Chunk to be sent. */
1939 __u32 last_ecne_tsn;
1941 /* Last TSN that caused a CWR Chunk to be sent. */
1944 /* How many duplicated TSNs have we seen? */
1947 /* These are to support
1948 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1949 * and Enforcement of Flow and Message Limits"
1950 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1951 * or "ADDIP" for short.
1956 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1958 * R1) One and only one ASCONF Chunk MAY be in transit and
1959 * unacknowledged at any one time. If a sender, after sending
1960 * an ASCONF chunk, decides it needs to transfer another
1961 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1962 * returns from the previous ASCONF Chunk before sending a
1963 * subsequent ASCONF. Note this restriction binds each side,
1964 * so at any time two ASCONF may be in-transit on any given
1965 * association (one sent from each endpoint).
1967 * [This is our one-and-only-one ASCONF in flight. If we do
1968 * not have an ASCONF in flight, this is NULL.]
1970 struct sctp_chunk *addip_last_asconf;
1972 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1974 * This is needed to implement itmes E1 - E4 of the updated
1975 * spec. Here is the justification:
1977 * Since the peer may bundle multiple ASCONF chunks toward us,
1978 * we now need the ability to cache multiple ACKs. The section
1979 * describes in detail how they are cached and cleaned up.
1981 struct list_head asconf_ack_list;
1983 /* These ASCONF chunks are waiting to be sent.
1985 * These chunaks can't be pushed to outqueue until receiving
1986 * ASCONF_ACK for the previous ASCONF indicated by
1987 * addip_last_asconf, so as to guarantee that only one ASCONF
1988 * is in flight at any time.
1990 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1992 * In defining the ASCONF Chunk transfer procedures, it is
1993 * essential that these transfers MUST NOT cause congestion
1994 * within the network. To achieve this, we place these
1995 * restrictions on the transfer of ASCONF Chunks:
1997 * R1) One and only one ASCONF Chunk MAY be in transit and
1998 * unacknowledged at any one time. If a sender, after sending
1999 * an ASCONF chunk, decides it needs to transfer another
2000 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2001 * returns from the previous ASCONF Chunk before sending a
2002 * subsequent ASCONF. Note this restriction binds each side,
2003 * so at any time two ASCONF may be in-transit on any given
2004 * association (one sent from each endpoint).
2007 * [I really think this is EXACTLY the sort of intelligence
2008 * which already resides in sctp_outq. Please move this
2009 * queue and its supporting logic down there. --piggy]
2011 struct list_head addip_chunk_list;
2013 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2015 * A2) A serial number should be assigned to the Chunk. The
2016 * serial number SHOULD be a monotonically increasing
2017 * number. The serial number SHOULD be initialized at
2018 * the start of the association to the same value as the
2019 * Initial TSN and every time a new ASCONF chunk is created
2020 * it is incremented by one after assigning the serial number
2021 * to the newly created chunk.
2024 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2026 * Serial Number : 32 bits (unsigned integer)
2028 * This value represents a Serial Number for the ASCONF
2029 * Chunk. The valid range of Serial Number is from 0 to
2030 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2031 * after reaching 4294967295.
2034 int src_out_of_asoc_ok;
2035 union sctp_addr *asconf_addr_del_pending;
2036 struct sctp_transport *new_transport;
2038 /* SCTP AUTH: list of the endpoint shared keys. These
2039 * keys are provided out of band by the user applicaton
2040 * and can't change during the lifetime of the association
2042 struct list_head endpoint_shared_keys;
2045 * The current generated assocaition shared key (secret)
2047 struct sctp_auth_bytes *asoc_shared_key;
2048 struct sctp_shared_key *shkey;
2050 /* SCTP AUTH: hmac id of the first peer requested algorithm
2053 __u16 default_hmac_id;
2055 __u16 active_key_id;
2057 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2058 temp:1, /* Is it a temporary association? */
2059 pf_expose:2, /* Expose pf state? */
2062 __u8 strreset_enable;
2063 __u8 strreset_outstanding; /* request param count on the fly */
2065 __u32 strreset_outseq; /* Update after receiving response */
2066 __u32 strreset_inseq; /* Update after receiving request */
2067 __u32 strreset_result[2]; /* save the results of last 2 responses */
2069 struct sctp_chunk *strreset_chunk; /* save request chunk */
2071 struct sctp_priv_assoc_stats stats;
2073 int sent_cnt_removable;
2077 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2078 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2080 struct rcu_head rcu;
2084 /* An eyecatcher for determining if we are really looking at an
2085 * association data structure.
2088 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2091 /* Recover the outter association structure. */
2092 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2094 struct sctp_association *asoc;
2096 asoc = container_of(base, struct sctp_association, base);
2100 /* These are function signatures for manipulating associations. */
2103 struct sctp_association *
2104 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2105 enum sctp_scope scope, gfp_t gfp);
2106 void sctp_association_free(struct sctp_association *);
2107 void sctp_association_put(struct sctp_association *);
2108 void sctp_association_hold(struct sctp_association *);
2110 struct sctp_transport *sctp_assoc_choose_alter_transport(
2111 struct sctp_association *, struct sctp_transport *);
2112 void sctp_assoc_update_retran_path(struct sctp_association *);
2113 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2114 const union sctp_addr *);
2115 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2116 const union sctp_addr *laddr);
2117 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2118 const union sctp_addr *address,
2120 const int peer_state);
2121 void sctp_assoc_del_peer(struct sctp_association *asoc,
2122 const union sctp_addr *addr);
2123 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2124 struct sctp_transport *peer);
2125 void sctp_assoc_control_transport(struct sctp_association *asoc,
2126 struct sctp_transport *transport,
2127 enum sctp_transport_cmd command,
2128 sctp_sn_error_t error);
2129 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2130 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2131 int sctp_assoc_update(struct sctp_association *old,
2132 struct sctp_association *new);
2134 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2136 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2137 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2138 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2139 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2140 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2141 void sctp_assoc_set_primary(struct sctp_association *,
2142 struct sctp_transport *);
2143 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2144 struct sctp_transport *);
2145 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2146 enum sctp_scope scope, gfp_t gfp);
2147 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2148 struct sctp_cookie*,
2150 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2151 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2152 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2153 const struct sctp_association *asoc,
2155 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2157 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2158 const union sctp_addr *ss2);
2159 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2161 /* A convenience structure to parse out SCTP specific CMSGs. */
2163 struct sctp_initmsg *init;
2164 struct sctp_sndrcvinfo *srinfo;
2165 struct sctp_sndinfo *sinfo;
2166 struct sctp_prinfo *prinfo;
2167 struct sctp_authinfo *authinfo;
2168 struct msghdr *addrs_msg;
2171 /* Structure for tracking memory objects */
2172 struct sctp_dbg_objcnt_entry {
2177 #endif /* __sctp_structs_h__ */