1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
7 * This file is part of the SCTP kernel implementation
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, see
23 * <http://www.gnu.org/licenses/>.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <linux-sctp@vger.kernel.org>
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
50 #include <linux/ktime.h>
51 #include <linux/rhashtable.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/sctp.h> /* We need sctp* header structs. */
61 #include <net/sctp/auth.h> /* We need auth specific structs */
62 #include <net/ip.h> /* For inet_skb_parm */
64 /* A convenience structure for handling sockaddr structures.
65 * We should wean ourselves off this.
68 struct sockaddr_in v4;
69 struct sockaddr_in6 v6;
73 /* Forward declarations for data structures. */
76 struct sctp_association;
77 struct sctp_transport;
82 struct sctp_bind_addr;
84 struct sctp_ep_common;
89 #include <net/sctp/tsnmap.h>
90 #include <net/sctp/ulpevent.h>
91 #include <net/sctp/ulpqueue.h>
93 /* Structures useful for managing bind/connect. */
95 struct sctp_bind_bucket {
97 unsigned short fastreuse;
98 struct hlist_node node;
99 struct hlist_head owner;
103 struct sctp_bind_hashbucket {
105 struct hlist_head chain;
108 /* Used for hashing all associations. */
109 struct sctp_hashbucket {
111 struct hlist_head chain;
112 } __attribute__((__aligned__(8)));
115 /* The SCTP globals structure. */
116 extern struct sctp_globals {
117 /* This is a list of groups of functions for each address
118 * family that we support.
120 struct list_head address_families;
122 /* This is the hash of all endpoints. */
123 struct sctp_hashbucket *ep_hashtable;
124 /* This is the sctp port control hash. */
125 struct sctp_bind_hashbucket *port_hashtable;
126 /* This is the hash of all transports. */
127 struct rhltable transport_hashtable;
129 /* Sizes of above hashtables. */
133 /* Default initialization values to be applied to new associations. */
135 __u16 max_outstreams;
137 /* Flag to indicate whether computing and verifying checksum
139 bool checksum_disable;
142 #define sctp_max_instreams (sctp_globals.max_instreams)
143 #define sctp_max_outstreams (sctp_globals.max_outstreams)
144 #define sctp_address_families (sctp_globals.address_families)
145 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
146 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
147 #define sctp_port_hashsize (sctp_globals.port_hashsize)
148 #define sctp_port_hashtable (sctp_globals.port_hashtable)
149 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
150 #define sctp_checksum_disable (sctp_globals.checksum_disable)
152 /* SCTP Socket type: UDP or TCP style. */
155 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
157 } sctp_socket_type_t;
159 /* Per socket SCTP information. */
161 /* inet_sock has to be the first member of sctp_sock */
162 struct inet_sock inet;
163 /* What kind of a socket is this? */
164 sctp_socket_type_t type;
166 /* PF_ family specific functions. */
169 /* Access to HMAC transform. */
170 struct crypto_shash *hmac;
173 /* What is our base endpointer? */
174 struct sctp_endpoint *ep;
176 struct sctp_bind_bucket *bind_hash;
177 /* Various Socket Options. */
178 __u16 default_stream;
181 __u32 default_context;
182 __u32 default_timetolive;
183 __u32 default_rcv_context;
186 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
187 * the destination address every heartbeat interval. This value
188 * will be inherited by all new associations.
192 /* This is the max_retrans value for new associations. */
195 /* The initial Path MTU to use for new associations. */
198 /* The default SACK delay timeout for new associations. */
202 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
205 struct sctp_initmsg initmsg;
206 struct sctp_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_event_subscribe subscribe;
209 struct sctp_assocparams assocparams;
214 __u32 adaptation_ind;
222 data_ready_signalled:1;
225 /* Receive to here while partial delivery is in effect. */
226 struct sk_buff_head pd_lobby;
228 /* These must be the last fields, as they will skipped on copies,
229 * like on accept and peeloff operations
231 struct list_head auto_asconf_list;
235 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
237 return (struct sctp_sock *)sk;
240 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
242 return (struct sock *)sp;
245 #if IS_ENABLED(CONFIG_IPV6)
247 struct sctp_sock sctp;
248 struct ipv6_pinfo inet6;
250 #endif /* CONFIG_IPV6 */
253 /* This is our APPLICATION-SPECIFIC state cookie.
254 * THIS IS NOT DICTATED BY THE SPECIFICATION.
256 /* These are the parts of an association which we send in the cookie.
257 * Most of these are straight out of:
258 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
264 /* My : Tag expected in every inbound packet and sent
265 * Verification: in the INIT or INIT ACK chunk.
270 /* Peer's : Tag expected in every outbound packet except
271 * Verification: in the INIT chunk.
276 /* The rest of these are not from the spec, but really need to
280 /* My Tie Tag : Assist in discovering a restarting association. */
283 /* Peer's Tie Tag: Assist in discovering a restarting association. */
286 /* When does this cookie expire? */
289 /* Number of inbound/outbound streams which are set
290 * and negotiated during the INIT process.
292 __u16 sinit_num_ostreams;
293 __u16 sinit_max_instreams;
295 /* This is the first sequence number I used. */
298 /* This holds the originating address of the INIT packet. */
299 union sctp_addr peer_addr;
302 * Include the source port of the INIT-ACK
308 /* Padding for future use */
311 __u32 adaptation_ind;
313 __u8 auth_random[sizeof(struct sctp_paramhdr) +
314 SCTP_AUTH_RANDOM_LENGTH];
315 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
316 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
318 /* This is a shim for my peer's INIT packet, followed by
319 * a copy of the raw address list of the association.
320 * The length of the raw address list is saved in the
321 * raw_addr_list_len field, which will be used at the time when
322 * the association TCB is re-constructed from the cookie.
324 __u32 raw_addr_list_len;
325 struct sctp_init_chunk peer_init[0];
329 /* The format of our cookie that we send to our peer. */
330 struct sctp_signed_cookie {
331 __u8 signature[SCTP_SECRET_SIZE];
332 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
333 struct sctp_cookie c;
336 /* This is another convenience type to allocate memory for address
337 * params for the maximum size and pass such structures around
340 union sctp_addr_param {
341 struct sctp_paramhdr p;
342 struct sctp_ipv4addr_param v4;
343 struct sctp_ipv6addr_param v6;
346 /* A convenience type to allow walking through the various
347 * parameters and avoid casting all over the place.
351 struct sctp_paramhdr *p;
352 struct sctp_cookie_preserve_param *life;
353 struct sctp_hostname_param *dns;
354 struct sctp_cookie_param *cookie;
355 struct sctp_supported_addrs_param *sat;
356 struct sctp_ipv4addr_param *v4;
357 struct sctp_ipv6addr_param *v6;
358 union sctp_addr_param *addr;
359 struct sctp_adaptation_ind_param *aind;
360 struct sctp_supported_ext_param *ext;
361 struct sctp_random_param *random;
362 struct sctp_chunks_param *chunks;
363 struct sctp_hmac_algo_param *hmac_algo;
364 struct sctp_addip_param *addip;
367 /* RFC 2960. Section 3.3.5 Heartbeat.
368 * Heartbeat Information: variable length
369 * The Sender-specific Heartbeat Info field should normally include
370 * information about the sender's current time when this HEARTBEAT
371 * chunk is sent and the destination transport address to which this
372 * HEARTBEAT is sent (see Section 8.3).
374 struct sctp_sender_hb_info {
375 struct sctp_paramhdr param_hdr;
376 union sctp_addr daddr;
377 unsigned long sent_at;
381 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
383 void sctp_stream_free(struct sctp_stream *stream);
384 void sctp_stream_clear(struct sctp_stream *stream);
385 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
387 /* What is the current SSN number for this stream? */
388 #define sctp_ssn_peek(stream, type, sid) \
389 ((stream)->type[sid].ssn)
391 /* Return the next SSN number for this stream. */
392 #define sctp_ssn_next(stream, type, sid) \
393 ((stream)->type[sid].ssn++)
395 /* Skip over this ssn and all below. */
396 #define sctp_ssn_skip(stream, type, sid, ssn) \
397 ((stream)->type[sid].ssn = ssn + 1)
400 * Pointers to address related SCTP functions.
401 * (i.e. things that depend on the address family.)
404 int (*sctp_xmit) (struct sk_buff *skb,
405 struct sctp_transport *);
406 int (*setsockopt) (struct sock *sk,
410 unsigned int optlen);
411 int (*getsockopt) (struct sock *sk,
416 int (*compat_setsockopt) (struct sock *sk,
420 unsigned int optlen);
421 int (*compat_getsockopt) (struct sock *sk,
426 void (*get_dst) (struct sctp_transport *t,
427 union sctp_addr *saddr,
430 void (*get_saddr) (struct sctp_sock *sk,
431 struct sctp_transport *t,
433 void (*copy_addrlist) (struct list_head *,
434 struct net_device *);
435 int (*cmp_addr) (const union sctp_addr *addr1,
436 const union sctp_addr *addr2);
437 void (*addr_copy) (union sctp_addr *dst,
438 union sctp_addr *src);
439 void (*from_skb) (union sctp_addr *,
442 void (*from_sk) (union sctp_addr *,
444 void (*from_addr_param) (union sctp_addr *,
445 union sctp_addr_param *,
446 __be16 port, int iif);
447 int (*to_addr_param) (const union sctp_addr *,
448 union sctp_addr_param *);
449 int (*addr_valid) (union sctp_addr *,
451 const struct sk_buff *);
452 enum sctp_scope (*scope)(union sctp_addr *);
453 void (*inaddr_any) (union sctp_addr *, __be16);
454 int (*is_any) (const union sctp_addr *);
455 int (*available) (union sctp_addr *,
457 int (*skb_iif) (const struct sk_buff *sk);
458 int (*is_ce) (const struct sk_buff *sk);
459 void (*seq_dump_addr)(struct seq_file *seq,
460 union sctp_addr *addr);
461 void (*ecn_capable)(struct sock *sk);
462 __u16 net_header_len;
464 sa_family_t sa_family;
465 struct list_head list;
468 struct sctp_af *sctp_get_af_specific(sa_family_t);
469 int sctp_register_af(struct sctp_af *);
471 /* Protocol family functions. */
473 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
474 void (*skb_msgname) (struct sk_buff *, char *, int *);
475 int (*af_supported) (sa_family_t, struct sctp_sock *);
476 int (*cmp_addr) (const union sctp_addr *,
477 const union sctp_addr *,
479 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
480 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
481 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
482 struct sock *(*create_accept_sk) (struct sock *sk,
483 struct sctp_association *asoc,
485 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
486 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
487 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
492 /* Structure to track chunk fragments that have been acked, but peer
493 * fragments of the same message have not.
495 struct sctp_datamsg {
496 /* Chunks waiting to be submitted to lower layer. */
497 struct list_head chunks;
498 /* Reference counting. */
500 /* When is this message no longer interesting to the peer? */
501 unsigned long expires_at;
502 /* Did the messenge fail to send? */
505 can_delay; /* should this message be Nagle delayed */
508 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
509 struct sctp_sndrcvinfo *,
511 void sctp_datamsg_free(struct sctp_datamsg *);
512 void sctp_datamsg_put(struct sctp_datamsg *);
513 void sctp_chunk_fail(struct sctp_chunk *, int error);
514 int sctp_chunk_abandoned(struct sctp_chunk *);
516 /* RFC2960 1.4 Key Terms
518 * o Chunk: A unit of information within an SCTP packet, consisting of
519 * a chunk header and chunk-specific content.
521 * As a matter of convenience, we remember the SCTP common header for
522 * each chunk as well as a few other header pointers...
525 struct list_head list;
529 /* How many times this chunk have been sent, for prsctp RTX policy */
532 /* This is our link to the per-transport transmitted list. */
533 struct list_head transmitted_list;
535 /* This field is used by chunks that hold fragmented data.
536 * For the first fragment this is the list that holds the rest of
537 * fragments. For the remaining fragments, this is the link to the
538 * frag_list maintained in the first fragment.
540 struct list_head frag_list;
542 /* This points to the sk_buff containing the actual data. */
545 /* In case of GSO packets, this will store the head one */
546 struct sk_buff *head_skb;
548 /* These are the SCTP headers by reverse order in a packet.
549 * Note that some of these may happen more than once. In that
550 * case, we point at the "current" one, whatever that means
551 * for that level of header.
554 /* We point this at the FIRST TLV parameter to chunk_hdr. */
555 union sctp_params param_hdr;
558 struct sctp_datahdr *data_hdr;
559 struct sctp_inithdr *init_hdr;
560 struct sctp_sackhdr *sack_hdr;
561 struct sctp_heartbeathdr *hb_hdr;
562 struct sctp_sender_hb_info *hbs_hdr;
563 struct sctp_shutdownhdr *shutdown_hdr;
564 struct sctp_signed_cookie *cookie_hdr;
565 struct sctp_ecnehdr *ecne_hdr;
566 struct sctp_cwrhdr *ecn_cwr_hdr;
567 struct sctp_errhdr *err_hdr;
568 struct sctp_addiphdr *addip_hdr;
569 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
570 struct sctp_authhdr *auth_hdr;
575 struct sctp_chunkhdr *chunk_hdr;
576 struct sctphdr *sctp_hdr;
578 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
579 struct sctp_sndrcvinfo sinfo;
581 /* Which association does this belong to? */
582 struct sctp_association *asoc;
584 /* What endpoint received this chunk? */
585 struct sctp_ep_common *rcvr;
587 /* We fill this in if we are calculating RTT. */
588 unsigned long sent_at;
590 /* What is the origin IP address for this chunk? */
591 union sctp_addr source;
592 /* Destination address for this chunk. */
593 union sctp_addr dest;
595 /* For outbound message, track all fragments for SEND_FAILED. */
596 struct sctp_datamsg *msg;
598 /* For an inbound chunk, this tells us where it came from.
599 * For an outbound chunk, it tells us where we'd like it to
600 * go. It is NULL if we have no preference.
602 struct sctp_transport *transport;
604 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
605 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
606 * spec violates the principle premis that all chunks are processed
609 struct sk_buff *auth_chunk;
611 #define SCTP_CAN_FRTX 0x0
612 #define SCTP_NEED_FRTX 0x1
613 #define SCTP_DONT_FRTX 0x2
614 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
615 has_tsn:1, /* Does this chunk have a TSN yet? */
616 has_ssn:1, /* Does this chunk have a SSN yet? */
617 singleton:1, /* Only chunk in the packet? */
618 end_of_packet:1, /* Last chunk in the packet? */
619 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
620 pdiscard:1, /* Discard the whole packet now? */
621 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
622 data_accepted:1, /* At least 1 chunk accepted */
623 auth:1, /* IN: was auth'ed | OUT: needs auth */
624 has_asconf:1, /* IN: have seen an asconf before */
625 tsn_missing_report:2, /* Data chunk missing counter. */
626 fast_retransmit:2; /* Is this chunk fast retransmitted? */
629 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
630 void sctp_chunk_hold(struct sctp_chunk *);
631 void sctp_chunk_put(struct sctp_chunk *);
632 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
633 struct iov_iter *from);
634 void sctp_chunk_free(struct sctp_chunk *);
635 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
636 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
637 const struct sctp_association *,
638 struct sock *, gfp_t gfp);
639 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
641 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
644 SCTP_ADDR_NEW, /* new address added to assoc/ep */
645 SCTP_ADDR_SRC, /* address can be used as source */
646 SCTP_ADDR_DEL, /* address about to be deleted */
649 /* This is a structure for holding either an IPv6 or an IPv4 address. */
650 struct sctp_sockaddr_entry {
651 struct list_head list;
658 #define SCTP_ADDRESS_TICK_DELAY 500
660 /* This structure holds lists of chunks as we are assembling for
664 /* These are the SCTP header values (host order) for the packet. */
666 __u16 destination_port;
669 /* This contains the payload chunks. */
670 struct list_head chunk_list;
672 /* This is the overhead of the sctp and ip headers. */
674 /* This is the total size of all chunks INCLUDING padding. */
676 /* This is the maximum size this packet may have */
679 /* The packet is destined for this transport address.
680 * The function we finally use to pass down to the next lower
681 * layer lives in the transport structure.
683 struct sctp_transport *transport;
685 /* pointer to the auth chunk for this packet */
686 struct sctp_chunk *auth;
688 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
689 has_sack:1, /* This packet contains a SACK chunk. */
690 has_auth:1, /* This packet contains an AUTH chunk */
691 has_data:1, /* This packet contains at least 1 DATA chunk */
692 ipfragok:1; /* So let ip fragment this packet */
695 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
696 __u16 sport, __u16 dport);
697 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
698 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
699 struct sctp_chunk *chunk,
700 int one_packet, gfp_t gfp);
701 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
702 struct sctp_chunk *chunk);
703 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
704 void sctp_packet_free(struct sctp_packet *);
706 static inline int sctp_packet_empty(struct sctp_packet *packet)
708 return packet->size == packet->overhead;
711 /* This represents a remote transport address.
712 * For local transport addresses, we just use union sctp_addr.
714 * RFC2960 Section 1.4 Key Terms
716 * o Transport address: A Transport Address is traditionally defined
717 * by Network Layer address, Transport Layer protocol and Transport
718 * Layer port number. In the case of SCTP running over IP, a
719 * transport address is defined by the combination of an IP address
720 * and an SCTP port number (where SCTP is the Transport protocol).
722 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
724 * o The sender keeps a separate congestion control parameter set for
725 * each of the destination addresses it can send to (not each
726 * source-destination pair but for each destination). The parameters
727 * should decay if the address is not used for a long enough time
731 struct sctp_transport {
732 /* A list of transports. */
733 struct list_head transports;
734 struct rhlist_head node;
736 /* Reference counting. */
738 /* RTO-Pending : A flag used to track if one of the DATA
739 * chunks sent to this address is currently being
740 * used to compute a RTT. If this flag is 0,
741 * the next DATA chunk sent to this destination
742 * should be used to compute a RTT and this flag
743 * should be set. Every time the RTT
744 * calculation completes (i.e. the DATA chunk
745 * is SACK'd) clear this flag.
750 * hb_sent : a flag that signals that we have a pending
755 /* Is the Path MTU update pending on this tranport */
758 dst_pending_confirm:1, /* need to confirm neighbour */
760 /* Has this transport moved the ctsn since we last sacked */
766 /* This is the peer's IP address and port. */
767 union sctp_addr ipaddr;
769 /* These are the functions we call to handle LLP stuff. */
770 struct sctp_af *af_specific;
772 /* Which association do we belong to? */
773 struct sctp_association *asoc;
777 * 12.3 Per Transport Address Data
779 * For each destination transport address in the peer's
780 * address list derived from the INIT or INIT ACK chunk, a
781 * number of data elements needs to be maintained including:
783 /* RTO : The current retransmission timeout value. */
786 __u32 rtt; /* This is the most recent RTT. */
788 /* RTTVAR : The current RTT variation. */
791 /* SRTT : The current smoothed round trip time. */
795 * These are the congestion stats.
797 /* cwnd : The current congestion window. */
798 __u32 cwnd; /* This is the actual cwnd. */
800 /* ssthresh : The current slow start threshold value. */
803 /* partial : The tracking method for increase of cwnd when in
804 * bytes acked : congestion avoidance mode (see Section 6.2.2)
806 __u32 partial_bytes_acked;
808 /* Data that has been sent, but not acknowledged. */
811 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
814 struct dst_entry *dst;
815 /* Source address. */
816 union sctp_addr saddr;
818 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
819 * the destination address every heartbeat interval.
821 unsigned long hbinterval;
823 /* SACK delay timeout */
824 unsigned long sackdelay;
827 /* When was the last time that we heard from this transport? We use
828 * this to pick new active and retran paths.
830 ktime_t last_time_heard;
832 /* When was the last time that we sent a chunk using this
833 * transport? We use this to check for idle transports
835 unsigned long last_time_sent;
837 /* Last time(in jiffies) when cwnd is reduced due to the congestion
838 * indication based on ECNE chunk.
840 unsigned long last_time_ecne_reduced;
842 /* This is the max_retrans value for the transport and will
843 * be initialized from the assocs value. This can be changed
844 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
848 /* This is the partially failed retrans value for the transport
849 * and will be initialized from the assocs value. This can be changed
850 * using the SCTP_PEER_ADDR_THLDS socket option
853 /* PMTU : The current known path MTU. */
856 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
859 /* The number of times INIT has been sent on this transport. */
862 /* state : The current state of this destination,
863 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
867 /* These are the error stats for this destination. */
869 /* Error count : The current error count for this destination. */
870 unsigned short error_count;
872 /* Per : A timer used by each destination.
876 * [Everywhere else in the text this is called T3-rtx. -ed]
878 struct timer_list T3_rtx_timer;
880 /* Heartbeat timer is per destination. */
881 struct timer_list hb_timer;
883 /* Timer to handle ICMP proto unreachable envets */
884 struct timer_list proto_unreach_timer;
886 /* Timer to handler reconf chunk rtx */
887 struct timer_list reconf_timer;
889 /* Since we're using per-destination retransmission timers
890 * (see above), we're also using per-destination "transmitted"
891 * queues. This probably ought to be a private struct
892 * accessible only within the outqueue, but it's not, yet.
894 struct list_head transmitted;
896 /* We build bundle-able packets for this transport here. */
897 struct sctp_packet packet;
899 /* This is the list of transports that have chunks to send. */
900 struct list_head send_ready;
902 /* State information saved for SFR_CACC algorithm. The key
903 * idea in SFR_CACC is to maintain state at the sender on a
904 * per-destination basis when a changeover happens.
905 * char changeover_active;
906 * char cycling_changeover;
907 * __u32 next_tsn_at_change;
908 * char cacc_saw_newack;
911 /* An unsigned integer, which stores the next TSN to be
912 * used by the sender, at the moment of changeover.
914 __u32 next_tsn_at_change;
916 /* A flag which indicates the occurrence of a changeover */
917 char changeover_active;
919 /* A flag which indicates whether the change of primary is
920 * the first switch to this destination address during an
923 char cycling_changeover;
925 /* A temporary flag, which is used during the processing of
926 * a SACK to estimate the causative TSN(s)'s group.
928 char cacc_saw_newack;
931 /* 64-bit random number sent with heartbeat. */
937 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
939 void sctp_transport_set_owner(struct sctp_transport *,
940 struct sctp_association *);
941 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
943 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
944 void sctp_transport_free(struct sctp_transport *);
945 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
946 void sctp_transport_reset_hb_timer(struct sctp_transport *);
947 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
948 int sctp_transport_hold(struct sctp_transport *);
949 void sctp_transport_put(struct sctp_transport *);
950 void sctp_transport_update_rto(struct sctp_transport *, __u32);
951 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
952 void sctp_transport_lower_cwnd(struct sctp_transport *t,
953 enum sctp_lower_cwnd reason);
954 void sctp_transport_burst_limited(struct sctp_transport *);
955 void sctp_transport_burst_reset(struct sctp_transport *);
956 unsigned long sctp_transport_timeout(struct sctp_transport *);
957 void sctp_transport_reset(struct sctp_transport *t);
958 void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
959 void sctp_transport_immediate_rtx(struct sctp_transport *);
960 void sctp_transport_dst_release(struct sctp_transport *t);
961 void sctp_transport_dst_confirm(struct sctp_transport *t);
964 /* This is the structure we use to queue packets as they come into
965 * SCTP. We write packets to it and read chunks from it.
968 /* This is actually a queue of sctp_chunk each
969 * containing a partially decoded packet.
971 struct list_head in_chunk_list;
972 /* This is the packet which is currently off the in queue and is
973 * being worked on through the inbound chunk processing.
975 struct sctp_chunk *in_progress;
977 /* This is the delayed task to finish delivering inbound
980 struct work_struct immediate;
983 void sctp_inq_init(struct sctp_inq *);
984 void sctp_inq_free(struct sctp_inq *);
985 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
986 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
987 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
988 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
990 /* This is the structure we use to hold outbound chunks. You push
991 * chunks in and they automatically pop out the other end as bundled
992 * packets (it calls (*output_handler)()).
994 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
995 * and 8.2 of the v13 draft.
997 * It handles retransmissions. The connection to the timeout portion
998 * of the state machine is through sctp_..._timeout() and timeout_handler.
1000 * If you feed it SACKs, it will eat them.
1002 * If you give it big chunks, it will fragment them.
1004 * It assigns TSN's to data chunks. This happens at the last possible
1005 * instant before transmission.
1007 * When free()'d, it empties itself out via output_handler().
1010 struct sctp_association *asoc;
1012 /* Data pending that has never been transmitted. */
1013 struct list_head out_chunk_list;
1015 unsigned int out_qlen; /* Total length of queued data chunks. */
1017 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1020 /* These are control chunks we want to send. */
1021 struct list_head control_chunk_list;
1023 /* These are chunks that have been sacked but are above the
1024 * CTSN, or cumulative tsn ack point.
1026 struct list_head sacked;
1028 /* Put chunks on this list to schedule them for
1031 struct list_head retransmit;
1033 /* Put chunks on this list to save them for FWD TSN processing as
1034 * they were abandoned.
1036 struct list_head abandoned;
1038 /* How many unackd bytes do we have in-flight? */
1039 __u32 outstanding_bytes;
1041 /* Are we doing fast-rtx on this queue */
1048 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1049 void sctp_outq_teardown(struct sctp_outq *);
1050 void sctp_outq_free(struct sctp_outq*);
1051 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1052 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1053 int sctp_outq_is_empty(const struct sctp_outq *);
1054 void sctp_outq_restart(struct sctp_outq *);
1056 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1057 enum sctp_retransmit_reason reason);
1058 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1059 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1060 void sctp_prsctp_prune(struct sctp_association *asoc,
1061 struct sctp_sndrcvinfo *sinfo, int msg_len);
1062 /* Uncork and flush an outqueue. */
1063 static inline void sctp_outq_cork(struct sctp_outq *q)
1068 /* SCTP skb control block.
1069 * sctp_input_cb is currently used on rx and sock rx queue
1071 struct sctp_input_cb {
1073 struct inet_skb_parm h4;
1074 #if IS_ENABLED(CONFIG_IPV6)
1075 struct inet6_skb_parm h6;
1078 struct sctp_chunk *chunk;
1081 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1083 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1085 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1087 return chunk->head_skb ? : skb;
1090 /* These bind address data fields common between endpoints and associations */
1091 struct sctp_bind_addr {
1093 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1095 * SCTP Port: The local SCTP port number the endpoint is
1100 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1102 * Address List: The list of IP addresses that this instance
1103 * has bound. This information is passed to one's
1104 * peer(s) in INIT and INIT ACK chunks.
1106 struct list_head address_list;
1109 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1110 void sctp_bind_addr_free(struct sctp_bind_addr *);
1111 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1112 const struct sctp_bind_addr *src,
1113 enum sctp_scope scope, gfp_t gfp,
1115 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1116 const struct sctp_bind_addr *src,
1118 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1119 int new_size, __u8 addr_state, gfp_t gfp);
1120 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1121 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1122 struct sctp_sock *);
1123 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1124 struct sctp_sock *, struct sctp_sock *);
1125 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1126 const union sctp_addr *addr);
1127 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1128 const union sctp_addr *addrs,
1130 struct sctp_sock *opt);
1131 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1134 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1135 __u16 port, gfp_t gfp);
1137 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1138 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1139 const enum sctp_scope scope);
1140 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1141 int sctp_is_ep_boundall(struct sock *sk);
1144 /* What type of endpoint? */
1145 enum sctp_endpoint_type {
1146 SCTP_EP_TYPE_SOCKET,
1147 SCTP_EP_TYPE_ASSOCIATION,
1151 * A common base class to bridge the implmentation view of a
1152 * socket (usually listening) endpoint versus an association's
1154 * This common structure is useful for several purposes:
1155 * 1) Common interface for lookup routines.
1156 * a) Subfunctions work for either endpoint or association
1157 * b) Single interface to lookup allows hiding the lookup lock rather
1158 * than acquiring it externally.
1159 * 2) Common interface for the inbound chunk handling/state machine.
1160 * 3) Common object handling routines for reference counting, etc.
1161 * 4) Disentangle association lookup from endpoint lookup, where we
1162 * do not have to find our endpoint to find our association.
1166 struct sctp_ep_common {
1167 /* Fields to help us manage our entries in the hash tables. */
1168 struct hlist_node node;
1171 /* Runtime type information. What kind of endpoint is this? */
1172 enum sctp_endpoint_type type;
1174 /* Some fields to help us manage this object.
1175 * refcnt - Reference count access to this object.
1176 * dead - Do not attempt to use this object.
1181 /* What socket does this endpoint belong to? */
1184 /* This is where we receive inbound chunks. */
1185 struct sctp_inq inqueue;
1187 /* This substructure includes the defining parameters of the
1189 * bind_addr.port is our shared port number.
1190 * bind_addr.address_list is our set of local IP addresses.
1192 struct sctp_bind_addr bind_addr;
1196 /* RFC Section 1.4 Key Terms
1198 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1199 * multi-homed host, an SCTP endpoint is represented to its peers as a
1200 * combination of a set of eligible destination transport addresses to
1201 * which SCTP packets can be sent and a set of eligible source
1202 * transport addresses from which SCTP packets can be received.
1203 * All transport addresses used by an SCTP endpoint must use the
1204 * same port number, but can use multiple IP addresses. A transport
1205 * address used by an SCTP endpoint must not be used by another
1206 * SCTP endpoint. In other words, a transport address is unique
1207 * to an SCTP endpoint.
1209 * From an implementation perspective, each socket has one of these.
1210 * A TCP-style socket will have exactly one association on one of
1211 * these. An UDP-style socket will have multiple associations hanging
1215 struct sctp_endpoint {
1216 /* Common substructure for endpoint and association. */
1217 struct sctp_ep_common base;
1219 /* Associations: A list of current associations and mappings
1220 * to the data consumers for each association. This
1221 * may be in the form of a hash table or other
1222 * implementation dependent structure. The data
1223 * consumers may be process identification
1224 * information such as file descriptors, named pipe
1225 * pointer, or table pointers dependent on how SCTP
1228 /* This is really a list of struct sctp_association entries. */
1229 struct list_head asocs;
1231 /* Secret Key: A secret key used by this endpoint to compute
1232 * the MAC. This SHOULD be a cryptographic quality
1233 * random number with a sufficient length.
1234 * Discussion in [RFC1750] can be helpful in
1235 * selection of the key.
1237 __u8 secret_key[SCTP_SECRET_SIZE];
1239 /* digest: This is a digest of the sctp cookie. This field is
1240 * only used on the receive path when we try to validate
1241 * that the cookie has not been tampered with. We put
1242 * this here so we pre-allocate this once and can re-use
1247 /* sendbuf acct. policy. */
1248 __u32 sndbuf_policy;
1250 /* rcvbuf acct. policy. */
1251 __u32 rcvbuf_policy;
1253 /* SCTP AUTH: array of the HMACs that will be allocated
1254 * we need this per association so that we don't serialize
1256 struct crypto_shash **auth_hmacs;
1258 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1259 struct sctp_hmac_algo_param *auth_hmacs_list;
1261 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1262 struct sctp_chunks_param *auth_chunk_list;
1264 /* SCTP-AUTH: endpoint shared keys */
1265 struct list_head endpoint_shared_keys;
1266 __u16 active_key_id;
1271 __u8 strreset_enable;
1274 /* Recover the outter endpoint structure. */
1275 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1277 struct sctp_endpoint *ep;
1279 ep = container_of(base, struct sctp_endpoint, base);
1283 /* These are function signatures for manipulating endpoints. */
1284 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1285 void sctp_endpoint_free(struct sctp_endpoint *);
1286 void sctp_endpoint_put(struct sctp_endpoint *);
1287 void sctp_endpoint_hold(struct sctp_endpoint *);
1288 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1289 struct sctp_association *sctp_endpoint_lookup_assoc(
1290 const struct sctp_endpoint *ep,
1291 const union sctp_addr *paddr,
1292 struct sctp_transport **);
1293 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1294 const union sctp_addr *);
1295 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1296 struct net *, const union sctp_addr *);
1297 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1298 const union sctp_addr *paddr);
1300 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1301 const struct sctp_association *asoc,
1302 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1303 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1304 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1305 const union sctp_addr *peer,
1306 struct sctp_init_chunk *init, gfp_t gfp);
1307 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1308 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1310 struct sctp_inithdr_host {
1313 __u16 num_outbound_streams;
1314 __u16 num_inbound_streams;
1318 struct sctp_stream_out {
1321 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1322 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1325 struct sctp_stream_in {
1329 struct sctp_stream {
1330 struct sctp_stream_out *out;
1331 struct sctp_stream_in *in;
1336 #define SCTP_STREAM_CLOSED 0x00
1337 #define SCTP_STREAM_OPEN 0x01
1339 /* SCTP_GET_ASSOC_STATS counters */
1340 struct sctp_priv_assoc_stats {
1341 /* Maximum observed rto in the association during subsequent
1342 * observations. Value is set to 0 if no RTO measurement took place
1343 * The transport where the max_rto was observed is returned in
1346 struct sockaddr_storage obs_rto_ipaddr;
1348 /* Total In and Out SACKs received and sent */
1351 /* Total In and Out packets received and sent */
1354 /* Total retransmitted chunks */
1356 /* TSN received > next expected */
1358 /* Duplicate Chunks received */
1360 /* Gap Ack Blocks received */
1362 /* Unordered data chunks sent and received */
1365 /* Ordered data chunks sent and received */
1368 /* Control chunks sent and received */
1375 * 12. Recommended Transmission Control Block (TCB) Parameters
1377 * This section details a recommended set of parameters that should
1378 * be contained within the TCB for an implementation. This section is
1379 * for illustrative purposes and should not be deemed as requirements
1380 * on an implementation or as an exhaustive list of all parameters
1381 * inside an SCTP TCB. Each implementation may need its own additional
1382 * parameters for optimization.
1386 /* Here we have information about each individual association. */
1387 struct sctp_association {
1389 /* A base structure common to endpoint and association.
1390 * In this context, it represents the associations's view
1391 * of the local endpoint of the association.
1393 struct sctp_ep_common base;
1395 /* Associations on the same socket. */
1396 struct list_head asocs;
1398 /* association id. */
1399 sctp_assoc_t assoc_id;
1401 /* This is our parent endpoint. */
1402 struct sctp_endpoint *ep;
1404 /* These are those association elements needed in the cookie. */
1405 struct sctp_cookie c;
1407 /* This is all information about our peer. */
1409 /* transport_addr_list
1411 * Peer : A list of SCTP transport addresses that the
1412 * Transport : peer is bound to. This information is derived
1413 * Address : from the INIT or INIT ACK and is used to
1414 * List : associate an inbound packet with a given
1415 * : association. Normally this information is
1416 * : hashed or keyed for quick lookup and access
1418 * : The list is also initialized with the list
1419 * : of addresses passed with the sctp_connectx()
1422 * It is a list of SCTP_transport's.
1424 struct list_head transport_addr_list;
1428 * Peer Rwnd : Current calculated value of the peer's rwnd.
1434 * Peer : A count of the number of peer addresses
1435 * Transport : in the Peer Transport Address List.
1439 __u16 transport_count;
1442 * The transport layer port number.
1448 * Primary : This is the current primary destination
1449 * Path : transport address of the peer endpoint. It
1450 * : may also specify a source transport address
1451 * : on this endpoint.
1453 * All of these paths live on transport_addr_list.
1455 * At the bakeoffs, we discovered that the intent of
1456 * primaryPath is that it only changes when the ULP
1457 * asks to have it changed. We add the activePath to
1458 * designate the connection we are currently using to
1459 * transmit new data and most control chunks.
1461 struct sctp_transport *primary_path;
1463 /* Cache the primary path address here, when we
1464 * need a an address for msg_name.
1466 union sctp_addr primary_addr;
1469 * The path that we are currently using to
1470 * transmit new data and most control chunks.
1472 struct sctp_transport *active_path;
1476 * RFC2960 6.4 Multi-homed SCTP Endpoints
1478 * Furthermore, when its peer is multi-homed, an
1479 * endpoint SHOULD try to retransmit a chunk to an
1480 * active destination transport address that is
1481 * different from the last destination address to
1482 * which the DATA chunk was sent.
1484 struct sctp_transport *retran_path;
1486 /* Pointer to last transport I have sent on. */
1487 struct sctp_transport *last_sent_to;
1489 /* This is the last transport I have received DATA on. */
1490 struct sctp_transport *last_data_from;
1493 * Mapping An array of bits or bytes indicating which out of
1494 * Array order TSN's have been received (relative to the
1495 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1496 * order packets have been received, this array
1497 * will be set to all zero. This structure may be
1498 * in the form of a circular buffer or bit array.
1500 * Last Rcvd : This is the last TSN received in
1501 * TSN : sequence. This value is set initially by
1502 * : taking the peer's Initial TSN, received in
1503 * : the INIT or INIT ACK chunk, and subtracting
1506 * Throughout most of the specification this is called the
1507 * "Cumulative TSN ACK Point". In this case, we
1508 * ignore the advice in 12.2 in favour of the term
1509 * used in the bulk of the text. This value is hidden
1510 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1512 struct sctp_tsnmap tsn_map;
1514 /* This mask is used to disable sending the ASCONF chunk
1515 * with specified parameter to peer.
1517 __be16 addip_disabled_mask;
1519 /* These are capabilities which our peer advertised. */
1520 __u8 ecn_capable:1, /* Can peer do ECN? */
1521 ipv4_address:1, /* Peer understands IPv4 addresses? */
1522 ipv6_address:1, /* Peer understands IPv6 addresses? */
1523 hostname_address:1, /* Peer understands DNS addresses? */
1524 asconf_capable:1, /* Does peer support ADDIP? */
1525 prsctp_capable:1, /* Can peer do PR-SCTP? */
1526 reconf_capable:1, /* Can peer do RE-CONFIG? */
1527 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1529 /* sack_needed : This flag indicates if the next received
1530 * : packet is to be responded to with a
1531 * : SACK. This is initialized to 0. When a packet
1532 * : is received sack_cnt is incremented. If this value
1533 * : reaches 2 or more, a SACK is sent and the
1534 * : value is reset to 0. Note: This is used only
1535 * : when no DATA chunks are received out of
1536 * : order. When DATA chunks are out of order,
1537 * : SACK's are not delayed (see Section 6).
1539 __u8 sack_needed:1, /* Do we need to sack the peer? */
1541 zero_window_announced:1;
1544 __u32 adaptation_ind; /* Adaptation Code point. */
1546 struct sctp_inithdr_host i;
1550 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1551 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1552 * Initial TSN Value minus 1
1556 /* SCTP-AUTH: We need to know pears random number, hmac list
1557 * and authenticated chunk list. All that is part of the
1558 * cookie and these are just pointers to those locations
1560 struct sctp_random_param *peer_random;
1561 struct sctp_chunks_param *peer_chunks;
1562 struct sctp_hmac_algo_param *peer_hmacs;
1565 /* State : A state variable indicating what state the
1566 * : association is in, i.e. COOKIE-WAIT,
1567 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1568 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1570 * Note: No "CLOSED" state is illustrated since if a
1571 * association is "CLOSED" its TCB SHOULD be removed.
1573 * In this implementation we DO have a CLOSED
1574 * state which is used during initiation and shutdown.
1576 * State takes values from SCTP_STATE_*.
1578 enum sctp_state state;
1580 /* Overall : The overall association error count.
1581 * Error Count : [Clear this any time I get something.]
1583 int overall_error_count;
1585 /* The cookie life I award for any cookie. */
1586 ktime_t cookie_life;
1588 /* These are the association's initial, max, and min RTO values.
1589 * These values will be initialized by system defaults, but can
1590 * be modified via the SCTP_RTOINFO socket option.
1592 unsigned long rto_initial;
1593 unsigned long rto_max;
1594 unsigned long rto_min;
1596 /* Maximum number of new data packets that can be sent in a burst. */
1599 /* This is the max_retrans value for the association. This value will
1600 * be initialized initialized from system defaults, but can be
1601 * modified by the SCTP_ASSOCINFO socket option.
1605 /* This is the partially failed retrans value for the transport
1606 * and will be initialized from the assocs value. This can be
1607 * changed using the SCTP_PEER_ADDR_THLDS socket option
1611 /* Maximum number of times the endpoint will retransmit INIT */
1612 __u16 max_init_attempts;
1614 /* How many times have we resent an INIT? */
1617 /* The largest timeout or RTO value to use in attempting an INIT */
1618 unsigned long max_init_timeo;
1620 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1621 * the destination address every heartbeat interval. This value
1622 * will be inherited by all new transports.
1624 unsigned long hbinterval;
1626 /* This is the max_retrans value for new transports in the
1631 /* Flag that path mtu update is pending */
1634 /* Association : The smallest PMTU discovered for all of the
1635 * PMTU : peer's transport addresses.
1639 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1643 /* SACK delay timeout */
1644 unsigned long sackdelay;
1646 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1647 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1649 /* Transport to which SHUTDOWN chunk was last sent. */
1650 struct sctp_transport *shutdown_last_sent_to;
1652 /* Transport to which INIT chunk was last sent. */
1653 struct sctp_transport *init_last_sent_to;
1655 /* How many times have we resent a SHUTDOWN */
1656 int shutdown_retries;
1658 /* Next TSN : The next TSN number to be assigned to a new
1659 * : DATA chunk. This is sent in the INIT or INIT
1660 * : ACK chunk to the peer and incremented each
1661 * : time a DATA chunk is assigned a TSN
1662 * : (normally just prior to transmit or during
1668 * Last Rcvd : This is the last TSN received in sequence. This value
1669 * TSN : is set initially by taking the peer's Initial TSN,
1670 * : received in the INIT or INIT ACK chunk, and
1671 * : subtracting one from it.
1673 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1676 __u32 ctsn_ack_point;
1678 /* PR-SCTP Advanced.Peer.Ack.Point */
1679 __u32 adv_peer_ack_point;
1681 /* Highest TSN that is acknowledged by incoming SACKs. */
1682 __u32 highest_sacked;
1684 /* TSN marking the fast recovery exit point */
1685 __u32 fast_recovery_exit;
1687 /* Flag to track the current fast recovery state */
1690 /* The number of unacknowledged data chunks. Reported through
1691 * the SCTP_STATUS sockopt.
1695 /* The total number of data chunks that we've had to retransmit
1696 * as the result of a T3 timer expiration
1698 __u32 rtx_data_chunks;
1700 /* This is the association's receive buffer space. This value is used
1701 * to set a_rwnd field in an INIT or a SACK chunk.
1705 /* This is the last advertised value of rwnd over a SACK chunk. */
1708 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1709 * to slop over a maximum of the association's frag_point.
1713 /* Keeps treack of rwnd pressure. This happens when we have
1714 * a window, but not recevie buffer (i.e small packets). This one
1715 * is releases slowly (1 PMTU at a time ).
1719 /* This is the sndbuf size in use for the association.
1720 * This corresponds to the sndbuf size for the association,
1721 * as specified in the sk->sndbuf.
1725 /* This is the amount of memory that this association has allocated
1726 * in the receive path at any given time.
1728 atomic_t rmem_alloc;
1730 /* This is the wait queue head for send requests waiting on
1731 * the association sndbuf space.
1733 wait_queue_head_t wait;
1735 /* The message size at which SCTP fragmentation will occur. */
1739 /* Counter used to count INIT errors. */
1740 int init_err_counter;
1742 /* Count the number of INIT cycles (for doubling timeout). */
1745 /* Default send parameters. */
1746 __u16 default_stream;
1747 __u16 default_flags;
1749 __u32 default_context;
1750 __u32 default_timetolive;
1752 /* Default receive parameters */
1753 __u32 default_rcv_context;
1756 struct sctp_stream stream;
1758 /* All outbound chunks go through this structure. */
1759 struct sctp_outq outqueue;
1761 /* A smart pipe that will handle reordering and fragmentation,
1762 * as well as handle passing events up to the ULP.
1764 struct sctp_ulpq ulpq;
1766 /* Last TSN that caused an ECNE Chunk to be sent. */
1767 __u32 last_ecne_tsn;
1769 /* Last TSN that caused a CWR Chunk to be sent. */
1772 /* How many duplicated TSNs have we seen? */
1775 /* These are to support
1776 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1777 * and Enforcement of Flow and Message Limits"
1778 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1779 * or "ADDIP" for short.
1784 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1786 * R1) One and only one ASCONF Chunk MAY be in transit and
1787 * unacknowledged at any one time. If a sender, after sending
1788 * an ASCONF chunk, decides it needs to transfer another
1789 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1790 * returns from the previous ASCONF Chunk before sending a
1791 * subsequent ASCONF. Note this restriction binds each side,
1792 * so at any time two ASCONF may be in-transit on any given
1793 * association (one sent from each endpoint).
1795 * [This is our one-and-only-one ASCONF in flight. If we do
1796 * not have an ASCONF in flight, this is NULL.]
1798 struct sctp_chunk *addip_last_asconf;
1800 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1802 * This is needed to implement itmes E1 - E4 of the updated
1803 * spec. Here is the justification:
1805 * Since the peer may bundle multiple ASCONF chunks toward us,
1806 * we now need the ability to cache multiple ACKs. The section
1807 * describes in detail how they are cached and cleaned up.
1809 struct list_head asconf_ack_list;
1811 /* These ASCONF chunks are waiting to be sent.
1813 * These chunaks can't be pushed to outqueue until receiving
1814 * ASCONF_ACK for the previous ASCONF indicated by
1815 * addip_last_asconf, so as to guarantee that only one ASCONF
1816 * is in flight at any time.
1818 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1820 * In defining the ASCONF Chunk transfer procedures, it is
1821 * essential that these transfers MUST NOT cause congestion
1822 * within the network. To achieve this, we place these
1823 * restrictions on the transfer of ASCONF Chunks:
1825 * R1) One and only one ASCONF Chunk MAY be in transit and
1826 * unacknowledged at any one time. If a sender, after sending
1827 * an ASCONF chunk, decides it needs to transfer another
1828 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1829 * returns from the previous ASCONF Chunk before sending a
1830 * subsequent ASCONF. Note this restriction binds each side,
1831 * so at any time two ASCONF may be in-transit on any given
1832 * association (one sent from each endpoint).
1835 * [I really think this is EXACTLY the sort of intelligence
1836 * which already resides in sctp_outq. Please move this
1837 * queue and its supporting logic down there. --piggy]
1839 struct list_head addip_chunk_list;
1841 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1843 * A2) A serial number should be assigned to the Chunk. The
1844 * serial number SHOULD be a monotonically increasing
1845 * number. The serial number SHOULD be initialized at
1846 * the start of the association to the same value as the
1847 * Initial TSN and every time a new ASCONF chunk is created
1848 * it is incremented by one after assigning the serial number
1849 * to the newly created chunk.
1852 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1854 * Serial Number : 32 bits (unsigned integer)
1856 * This value represents a Serial Number for the ASCONF
1857 * Chunk. The valid range of Serial Number is from 0 to
1858 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1859 * after reaching 4294967295.
1862 int src_out_of_asoc_ok;
1863 union sctp_addr *asconf_addr_del_pending;
1864 struct sctp_transport *new_transport;
1866 /* SCTP AUTH: list of the endpoint shared keys. These
1867 * keys are provided out of band by the user applicaton
1868 * and can't change during the lifetime of the association
1870 struct list_head endpoint_shared_keys;
1873 * The current generated assocaition shared key (secret)
1875 struct sctp_auth_bytes *asoc_shared_key;
1877 /* SCTP AUTH: hmac id of the first peer requested algorithm
1880 __u16 default_hmac_id;
1882 __u16 active_key_id;
1884 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1885 temp:1, /* Is it a temporary association? */
1890 __u8 strreset_enable;
1891 __u8 strreset_outstanding; /* request param count on the fly */
1893 __u32 strreset_outseq; /* Update after receiving response */
1894 __u32 strreset_inseq; /* Update after receiving request */
1895 __u32 strreset_result[2]; /* save the results of last 2 responses */
1897 struct sctp_chunk *strreset_chunk; /* save request chunk */
1899 struct sctp_priv_assoc_stats stats;
1901 int sent_cnt_removable;
1903 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1904 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1908 /* An eyecatcher for determining if we are really looking at an
1909 * association data structure.
1912 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1915 /* Recover the outter association structure. */
1916 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1918 struct sctp_association *asoc;
1920 asoc = container_of(base, struct sctp_association, base);
1924 /* These are function signatures for manipulating associations. */
1927 struct sctp_association *
1928 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
1929 enum sctp_scope scope, gfp_t gfp);
1930 void sctp_association_free(struct sctp_association *);
1931 void sctp_association_put(struct sctp_association *);
1932 void sctp_association_hold(struct sctp_association *);
1934 struct sctp_transport *sctp_assoc_choose_alter_transport(
1935 struct sctp_association *, struct sctp_transport *);
1936 void sctp_assoc_update_retran_path(struct sctp_association *);
1937 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1938 const union sctp_addr *);
1939 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1940 const union sctp_addr *laddr);
1941 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1942 const union sctp_addr *address,
1944 const int peer_state);
1945 void sctp_assoc_del_peer(struct sctp_association *asoc,
1946 const union sctp_addr *addr);
1947 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1948 struct sctp_transport *peer);
1949 void sctp_assoc_control_transport(struct sctp_association *asoc,
1950 struct sctp_transport *transport,
1951 enum sctp_transport_cmd command,
1952 sctp_sn_error_t error);
1953 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1954 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1956 const union sctp_addr *,
1957 const union sctp_addr *);
1958 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1959 int sctp_assoc_update(struct sctp_association *old,
1960 struct sctp_association *new);
1962 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1964 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
1965 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1966 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1967 void sctp_assoc_set_primary(struct sctp_association *,
1968 struct sctp_transport *);
1969 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1970 struct sctp_transport *);
1971 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1972 enum sctp_scope scope, gfp_t gfp);
1973 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1974 struct sctp_cookie*,
1976 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1977 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1978 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1979 const struct sctp_association *asoc,
1981 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1983 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1984 const union sctp_addr *ss2);
1985 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1987 /* A convenience structure to parse out SCTP specific CMSGs. */
1989 struct sctp_initmsg *init;
1990 struct sctp_sndrcvinfo *srinfo;
1991 struct sctp_sndinfo *sinfo;
1994 /* Structure for tracking memory objects */
1998 } sctp_dbg_objcnt_entry_t;
2000 #endif /* __sctp_structs_h__ */