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 rhashtable 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(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
314 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
315 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
317 /* This is a shim for my peer's INIT packet, followed by
318 * a copy of the raw address list of the association.
319 * The length of the raw address list is saved in the
320 * raw_addr_list_len field, which will be used at the time when
321 * the association TCB is re-constructed from the cookie.
323 __u32 raw_addr_list_len;
324 struct sctp_init_chunk peer_init[0];
328 /* The format of our cookie that we send to our peer. */
329 struct sctp_signed_cookie {
330 __u8 signature[SCTP_SECRET_SIZE];
331 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
332 struct sctp_cookie c;
335 /* This is another convenience type to allocate memory for address
336 * params for the maximum size and pass such structures around
339 union sctp_addr_param {
340 struct sctp_paramhdr p;
341 struct sctp_ipv4addr_param v4;
342 struct sctp_ipv6addr_param v6;
345 /* A convenience type to allow walking through the various
346 * parameters and avoid casting all over the place.
350 struct sctp_paramhdr *p;
351 struct sctp_cookie_preserve_param *life;
352 struct sctp_hostname_param *dns;
353 struct sctp_cookie_param *cookie;
354 struct sctp_supported_addrs_param *sat;
355 struct sctp_ipv4addr_param *v4;
356 struct sctp_ipv6addr_param *v6;
357 union sctp_addr_param *addr;
358 struct sctp_adaptation_ind_param *aind;
359 struct sctp_supported_ext_param *ext;
360 struct sctp_random_param *random;
361 struct sctp_chunks_param *chunks;
362 struct sctp_hmac_algo_param *hmac_algo;
363 struct sctp_addip_param *addip;
366 /* RFC 2960. Section 3.3.5 Heartbeat.
367 * Heartbeat Information: variable length
368 * The Sender-specific Heartbeat Info field should normally include
369 * information about the sender's current time when this HEARTBEAT
370 * chunk is sent and the destination transport address to which this
371 * HEARTBEAT is sent (see Section 8.3).
373 typedef struct sctp_sender_hb_info {
374 struct sctp_paramhdr param_hdr;
375 union sctp_addr daddr;
376 unsigned long sent_at;
378 } __packed sctp_sender_hb_info_t;
381 * RFC 2960 1.3.2 Sequenced Delivery within Streams
383 * The term "stream" is used in SCTP to refer to a sequence of user
384 * messages that are to be delivered to the upper-layer protocol in
385 * order with respect to other messages within the same stream. This is
386 * in contrast to its usage in TCP, where it refers to a sequence of
387 * bytes (in this document a byte is assumed to be eight bits).
390 * This is the structure we use to track both our outbound and inbound
391 * SSN, or Stream Sequence Numbers.
400 struct sctp_stream in;
401 struct sctp_stream out;
404 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
406 void sctp_ssnmap_free(struct sctp_ssnmap *map);
407 void sctp_ssnmap_clear(struct sctp_ssnmap *map);
409 /* What is the current SSN number for this stream? */
410 static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
412 return stream->ssn[id];
415 /* Return the next SSN number for this stream. */
416 static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
418 return stream->ssn[id]++;
421 /* Skip over this ssn and all below. */
422 static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
425 stream->ssn[id] = ssn+1;
429 * Pointers to address related SCTP functions.
430 * (i.e. things that depend on the address family.)
433 int (*sctp_xmit) (struct sk_buff *skb,
434 struct sctp_transport *);
435 int (*setsockopt) (struct sock *sk,
439 unsigned int optlen);
440 int (*getsockopt) (struct sock *sk,
445 int (*compat_setsockopt) (struct sock *sk,
449 unsigned int optlen);
450 int (*compat_getsockopt) (struct sock *sk,
455 void (*get_dst) (struct sctp_transport *t,
456 union sctp_addr *saddr,
459 void (*get_saddr) (struct sctp_sock *sk,
460 struct sctp_transport *t,
462 void (*copy_addrlist) (struct list_head *,
463 struct net_device *);
464 int (*cmp_addr) (const union sctp_addr *addr1,
465 const union sctp_addr *addr2);
466 void (*addr_copy) (union sctp_addr *dst,
467 union sctp_addr *src);
468 void (*from_skb) (union sctp_addr *,
471 void (*from_sk) (union sctp_addr *,
473 void (*from_addr_param) (union sctp_addr *,
474 union sctp_addr_param *,
475 __be16 port, int iif);
476 int (*to_addr_param) (const union sctp_addr *,
477 union sctp_addr_param *);
478 int (*addr_valid) (union sctp_addr *,
480 const struct sk_buff *);
481 sctp_scope_t (*scope) (union sctp_addr *);
482 void (*inaddr_any) (union sctp_addr *, __be16);
483 int (*is_any) (const union sctp_addr *);
484 int (*available) (union sctp_addr *,
486 int (*skb_iif) (const struct sk_buff *sk);
487 int (*is_ce) (const struct sk_buff *sk);
488 void (*seq_dump_addr)(struct seq_file *seq,
489 union sctp_addr *addr);
490 void (*ecn_capable)(struct sock *sk);
491 __u16 net_header_len;
493 sa_family_t sa_family;
494 struct list_head list;
497 struct sctp_af *sctp_get_af_specific(sa_family_t);
498 int sctp_register_af(struct sctp_af *);
500 /* Protocol family functions. */
502 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
503 void (*skb_msgname) (struct sk_buff *, char *, int *);
504 int (*af_supported) (sa_family_t, struct sctp_sock *);
505 int (*cmp_addr) (const union sctp_addr *,
506 const union sctp_addr *,
508 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
509 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
510 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
511 struct sock *(*create_accept_sk) (struct sock *sk,
512 struct sctp_association *asoc);
513 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
514 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
515 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
520 /* Structure to track chunk fragments that have been acked, but peer
521 * fragments of the same message have not.
523 struct sctp_datamsg {
524 /* Chunks waiting to be submitted to lower layer. */
525 struct list_head chunks;
526 /* Reference counting. */
528 /* When is this message no longer interesting to the peer? */
529 unsigned long expires_at;
530 /* Did the messenge fail to send? */
533 can_abandon:1, /* can chunks from this message can be abandoned. */
534 can_delay; /* should this message be Nagle delayed */
537 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
538 struct sctp_sndrcvinfo *,
540 void sctp_datamsg_free(struct sctp_datamsg *);
541 void sctp_datamsg_put(struct sctp_datamsg *);
542 void sctp_chunk_fail(struct sctp_chunk *, int error);
543 int sctp_chunk_abandoned(struct sctp_chunk *);
545 /* RFC2960 1.4 Key Terms
547 * o Chunk: A unit of information within an SCTP packet, consisting of
548 * a chunk header and chunk-specific content.
550 * As a matter of convenience, we remember the SCTP common header for
551 * each chunk as well as a few other header pointers...
554 struct list_head list;
558 /* This is our link to the per-transport transmitted list. */
559 struct list_head transmitted_list;
561 /* This field is used by chunks that hold fragmented data.
562 * For the first fragment this is the list that holds the rest of
563 * fragments. For the remaining fragments, this is the link to the
564 * frag_list maintained in the first fragment.
566 struct list_head frag_list;
568 /* This points to the sk_buff containing the actual data. */
571 /* In case of GSO packets, this will store the head one */
572 struct sk_buff *head_skb;
574 /* These are the SCTP headers by reverse order in a packet.
575 * Note that some of these may happen more than once. In that
576 * case, we point at the "current" one, whatever that means
577 * for that level of header.
580 /* We point this at the FIRST TLV parameter to chunk_hdr. */
581 union sctp_params param_hdr;
584 struct sctp_datahdr *data_hdr;
585 struct sctp_inithdr *init_hdr;
586 struct sctp_sackhdr *sack_hdr;
587 struct sctp_heartbeathdr *hb_hdr;
588 struct sctp_sender_hb_info *hbs_hdr;
589 struct sctp_shutdownhdr *shutdown_hdr;
590 struct sctp_signed_cookie *cookie_hdr;
591 struct sctp_ecnehdr *ecne_hdr;
592 struct sctp_cwrhdr *ecn_cwr_hdr;
593 struct sctp_errhdr *err_hdr;
594 struct sctp_addiphdr *addip_hdr;
595 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
596 struct sctp_authhdr *auth_hdr;
601 struct sctp_chunkhdr *chunk_hdr;
602 struct sctphdr *sctp_hdr;
604 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
605 struct sctp_sndrcvinfo sinfo;
607 /* We use this field to record param for prsctp policies,
608 * for TTL policy, it is the time_to_drop of this chunk,
609 * for RTX policy, it is the max_sent_count of this chunk,
610 * for PRIO policy, it is the priority of this chunk.
612 unsigned long prsctp_param;
614 /* How many times this chunk have been sent, for prsctp RTX policy */
617 /* Which association does this belong to? */
618 struct sctp_association *asoc;
620 /* What endpoint received this chunk? */
621 struct sctp_ep_common *rcvr;
623 /* We fill this in if we are calculating RTT. */
624 unsigned long sent_at;
626 /* What is the origin IP address for this chunk? */
627 union sctp_addr source;
628 /* Destination address for this chunk. */
629 union sctp_addr dest;
631 /* For outbound message, track all fragments for SEND_FAILED. */
632 struct sctp_datamsg *msg;
634 /* For an inbound chunk, this tells us where it came from.
635 * For an outbound chunk, it tells us where we'd like it to
636 * go. It is NULL if we have no preference.
638 struct sctp_transport *transport;
640 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
641 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
642 * spec violates the principle premis that all chunks are processed
645 struct sk_buff *auth_chunk;
647 #define SCTP_CAN_FRTX 0x0
648 #define SCTP_NEED_FRTX 0x1
649 #define SCTP_DONT_FRTX 0x2
650 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
651 resent:1, /* Has this chunk ever been resent. */
652 has_tsn:1, /* Does this chunk have a TSN yet? */
653 has_ssn:1, /* Does this chunk have a SSN yet? */
654 singleton:1, /* Only chunk in the packet? */
655 end_of_packet:1, /* Last chunk in the packet? */
656 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
657 pdiscard:1, /* Discard the whole packet now? */
658 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
659 data_accepted:1, /* At least 1 chunk accepted */
660 auth:1, /* IN: was auth'ed | OUT: needs auth */
661 has_asconf:1, /* IN: have seen an asconf before */
662 tsn_missing_report:2, /* Data chunk missing counter. */
663 fast_retransmit:2; /* Is this chunk fast retransmitted? */
666 void sctp_chunk_hold(struct sctp_chunk *);
667 void sctp_chunk_put(struct sctp_chunk *);
668 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
669 struct iov_iter *from);
670 void sctp_chunk_free(struct sctp_chunk *);
671 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
672 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
673 const struct sctp_association *,
674 struct sock *, gfp_t gfp);
675 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
677 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
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 typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
698 /* This structure holds lists of chunks as we are assembling for
702 /* These are the SCTP header values (host order) for the packet. */
704 __u16 destination_port;
707 /* This contains the payload chunks. */
708 struct list_head chunk_list;
710 /* This is the overhead of the sctp and ip headers. */
712 /* This is the total size of all chunks INCLUDING padding. */
714 /* This is the maximum size this packet may have */
717 /* The packet is destined for this transport address.
718 * The function we finally use to pass down to the next lower
719 * layer lives in the transport structure.
721 struct sctp_transport *transport;
723 /* pointer to the auth chunk for this packet */
724 struct sctp_chunk *auth;
726 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
727 has_sack:1, /* This packet contains a SACK chunk. */
728 has_auth:1, /* This packet contains an AUTH chunk */
729 has_data:1, /* This packet contains at least 1 DATA chunk */
730 ipfragok:1; /* So let ip fragment this packet */
733 struct sctp_packet *sctp_packet_init(struct sctp_packet *,
734 struct sctp_transport *,
735 __u16 sport, __u16 dport);
736 struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
737 sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
738 struct sctp_chunk *, int, gfp_t);
739 sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
740 struct sctp_chunk *);
741 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
742 void sctp_packet_free(struct sctp_packet *);
744 static inline int sctp_packet_empty(struct sctp_packet *packet)
746 return packet->size == packet->overhead;
749 /* This represents a remote transport address.
750 * For local transport addresses, we just use union sctp_addr.
752 * RFC2960 Section 1.4 Key Terms
754 * o Transport address: A Transport Address is traditionally defined
755 * by Network Layer address, Transport Layer protocol and Transport
756 * Layer port number. In the case of SCTP running over IP, a
757 * transport address is defined by the combination of an IP address
758 * and an SCTP port number (where SCTP is the Transport protocol).
760 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
762 * o The sender keeps a separate congestion control parameter set for
763 * each of the destination addresses it can send to (not each
764 * source-destination pair but for each destination). The parameters
765 * should decay if the address is not used for a long enough time
769 struct sctp_transport {
770 /* A list of transports. */
771 struct list_head transports;
772 struct rhash_head node;
774 /* Reference counting. */
776 /* RTO-Pending : A flag used to track if one of the DATA
777 * chunks sent to this address is currently being
778 * used to compute a RTT. If this flag is 0,
779 * the next DATA chunk sent to this destination
780 * should be used to compute a RTT and this flag
781 * should be set. Every time the RTT
782 * calculation completes (i.e. the DATA chunk
783 * is SACK'd) clear this flag.
788 * hb_sent : a flag that signals that we have a pending
793 /* Is the Path MTU update pending on this tranport */
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;
863 /* When was the last time that we heard from this transport? We use
864 * this to pick new active and retran paths.
866 ktime_t last_time_heard;
868 /* When was the last time that we sent a chunk using this
869 * transport? We use this to check for idle transports
871 unsigned long last_time_sent;
873 /* Last time(in jiffies) when cwnd is reduced due to the congestion
874 * indication based on ECNE chunk.
876 unsigned long last_time_ecne_reduced;
878 /* This is the max_retrans value for the transport and will
879 * be initialized from the assocs value. This can be changed
880 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
884 /* This is the partially failed retrans value for the transport
885 * and will be initialized from the assocs value. This can be changed
886 * using the SCTP_PEER_ADDR_THLDS socket option
889 /* PMTU : The current known path MTU. */
892 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
895 /* The number of times INIT has been sent on this transport. */
898 /* state : The current state of this destination,
899 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
903 /* These are the error stats for this destination. */
905 /* Error count : The current error count for this destination. */
906 unsigned short error_count;
908 /* Per : A timer used by each destination.
912 * [Everywhere else in the text this is called T3-rtx. -ed]
914 struct timer_list T3_rtx_timer;
916 /* Heartbeat timer is per destination. */
917 struct timer_list hb_timer;
919 /* Timer to handle ICMP proto unreachable envets */
920 struct timer_list proto_unreach_timer;
922 /* Since we're using per-destination retransmission timers
923 * (see above), we're also using per-destination "transmitted"
924 * queues. This probably ought to be a private struct
925 * accessible only within the outqueue, but it's not, yet.
927 struct list_head transmitted;
929 /* We build bundle-able packets for this transport here. */
930 struct sctp_packet packet;
932 /* This is the list of transports that have chunks to send. */
933 struct list_head send_ready;
935 /* State information saved for SFR_CACC algorithm. The key
936 * idea in SFR_CACC is to maintain state at the sender on a
937 * per-destination basis when a changeover happens.
938 * char changeover_active;
939 * char cycling_changeover;
940 * __u32 next_tsn_at_change;
941 * char cacc_saw_newack;
944 /* An unsigned integer, which stores the next TSN to be
945 * used by the sender, at the moment of changeover.
947 __u32 next_tsn_at_change;
949 /* A flag which indicates the occurrence of a changeover */
950 char changeover_active;
952 /* A flag which indicates whether the change of primary is
953 * the first switch to this destination address during an
956 char cycling_changeover;
958 /* A temporary flag, which is used during the processing of
959 * a SACK to estimate the causative TSN(s)'s group.
961 char cacc_saw_newack;
964 /* 64-bit random number sent with heartbeat. */
970 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
972 void sctp_transport_set_owner(struct sctp_transport *,
973 struct sctp_association *);
974 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
976 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
977 void sctp_transport_free(struct sctp_transport *);
978 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
979 void sctp_transport_reset_hb_timer(struct sctp_transport *);
980 int sctp_transport_hold(struct sctp_transport *);
981 void sctp_transport_put(struct sctp_transport *);
982 void sctp_transport_update_rto(struct sctp_transport *, __u32);
983 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
984 void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
985 void sctp_transport_burst_limited(struct sctp_transport *);
986 void sctp_transport_burst_reset(struct sctp_transport *);
987 unsigned long sctp_transport_timeout(struct sctp_transport *);
988 void sctp_transport_reset(struct sctp_transport *);
989 void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
990 void sctp_transport_immediate_rtx(struct sctp_transport *);
993 /* This is the structure we use to queue packets as they come into
994 * SCTP. We write packets to it and read chunks from it.
997 /* This is actually a queue of sctp_chunk each
998 * containing a partially decoded packet.
1000 struct list_head in_chunk_list;
1001 /* This is the packet which is currently off the in queue and is
1002 * being worked on through the inbound chunk processing.
1004 struct sctp_chunk *in_progress;
1006 /* This is the delayed task to finish delivering inbound
1009 struct work_struct immediate;
1012 void sctp_inq_init(struct sctp_inq *);
1013 void sctp_inq_free(struct sctp_inq *);
1014 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1015 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1016 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1017 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1019 /* This is the structure we use to hold outbound chunks. You push
1020 * chunks in and they automatically pop out the other end as bundled
1021 * packets (it calls (*output_handler)()).
1023 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1024 * and 8.2 of the v13 draft.
1026 * It handles retransmissions. The connection to the timeout portion
1027 * of the state machine is through sctp_..._timeout() and timeout_handler.
1029 * If you feed it SACKs, it will eat them.
1031 * If you give it big chunks, it will fragment them.
1033 * It assigns TSN's to data chunks. This happens at the last possible
1034 * instant before transmission.
1036 * When free()'d, it empties itself out via output_handler().
1039 struct sctp_association *asoc;
1041 /* Data pending that has never been transmitted. */
1042 struct list_head out_chunk_list;
1044 unsigned int out_qlen; /* Total length of queued data chunks. */
1046 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1049 /* These are control chunks we want to send. */
1050 struct list_head control_chunk_list;
1052 /* These are chunks that have been sacked but are above the
1053 * CTSN, or cumulative tsn ack point.
1055 struct list_head sacked;
1057 /* Put chunks on this list to schedule them for
1060 struct list_head retransmit;
1062 /* Put chunks on this list to save them for FWD TSN processing as
1063 * they were abandoned.
1065 struct list_head abandoned;
1067 /* How many unackd bytes do we have in-flight? */
1068 __u32 outstanding_bytes;
1070 /* Are we doing fast-rtx on this queue */
1077 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1078 void sctp_outq_teardown(struct sctp_outq *);
1079 void sctp_outq_free(struct sctp_outq*);
1080 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1081 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1082 int sctp_outq_is_empty(const struct sctp_outq *);
1083 void sctp_outq_restart(struct sctp_outq *);
1085 void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1086 sctp_retransmit_reason_t);
1087 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1088 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1089 void sctp_prsctp_prune(struct sctp_association *asoc,
1090 struct sctp_sndrcvinfo *sinfo, int msg_len);
1091 /* Uncork and flush an outqueue. */
1092 static inline void sctp_outq_cork(struct sctp_outq *q)
1097 /* SCTP skb control block.
1098 * sctp_input_cb is currently used on rx and sock rx queue
1100 struct sctp_input_cb {
1102 struct inet_skb_parm h4;
1103 #if IS_ENABLED(CONFIG_IPV6)
1104 struct inet6_skb_parm h6;
1107 struct sctp_chunk *chunk;
1110 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1112 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1114 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1116 return chunk->head_skb ? : skb;
1119 /* These bind address data fields common between endpoints and associations */
1120 struct sctp_bind_addr {
1122 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1124 * SCTP Port: The local SCTP port number the endpoint is
1129 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1131 * Address List: The list of IP addresses that this instance
1132 * has bound. This information is passed to one's
1133 * peer(s) in INIT and INIT ACK chunks.
1135 struct list_head address_list;
1138 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1139 void sctp_bind_addr_free(struct sctp_bind_addr *);
1140 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1141 const struct sctp_bind_addr *src,
1142 sctp_scope_t scope, gfp_t gfp,
1144 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1145 const struct sctp_bind_addr *src,
1147 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1148 int new_size, __u8 addr_state, gfp_t gfp);
1149 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1150 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1151 struct sctp_sock *);
1152 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1153 struct sctp_sock *, struct sctp_sock *);
1154 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1155 const union sctp_addr *addr);
1156 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1157 const union sctp_addr *addrs,
1159 struct sctp_sock *opt);
1160 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1163 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1164 __u16 port, gfp_t gfp);
1166 sctp_scope_t sctp_scope(const union sctp_addr *);
1167 int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1168 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1169 int sctp_is_ep_boundall(struct sock *sk);
1172 /* What type of endpoint? */
1174 SCTP_EP_TYPE_SOCKET,
1175 SCTP_EP_TYPE_ASSOCIATION,
1176 } sctp_endpoint_type_t;
1179 * A common base class to bridge the implmentation view of a
1180 * socket (usually listening) endpoint versus an association's
1182 * This common structure is useful for several purposes:
1183 * 1) Common interface for lookup routines.
1184 * a) Subfunctions work for either endpoint or association
1185 * b) Single interface to lookup allows hiding the lookup lock rather
1186 * than acquiring it externally.
1187 * 2) Common interface for the inbound chunk handling/state machine.
1188 * 3) Common object handling routines for reference counting, etc.
1189 * 4) Disentangle association lookup from endpoint lookup, where we
1190 * do not have to find our endpoint to find our association.
1194 struct sctp_ep_common {
1195 /* Fields to help us manage our entries in the hash tables. */
1196 struct hlist_node node;
1199 /* Runtime type information. What kind of endpoint is this? */
1200 sctp_endpoint_type_t type;
1202 /* Some fields to help us manage this object.
1203 * refcnt - Reference count access to this object.
1204 * dead - Do not attempt to use this object.
1209 /* What socket does this endpoint belong to? */
1212 /* This is where we receive inbound chunks. */
1213 struct sctp_inq inqueue;
1215 /* This substructure includes the defining parameters of the
1217 * bind_addr.port is our shared port number.
1218 * bind_addr.address_list is our set of local IP addresses.
1220 struct sctp_bind_addr bind_addr;
1224 /* RFC Section 1.4 Key Terms
1226 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1227 * multi-homed host, an SCTP endpoint is represented to its peers as a
1228 * combination of a set of eligible destination transport addresses to
1229 * which SCTP packets can be sent and a set of eligible source
1230 * transport addresses from which SCTP packets can be received.
1231 * All transport addresses used by an SCTP endpoint must use the
1232 * same port number, but can use multiple IP addresses. A transport
1233 * address used by an SCTP endpoint must not be used by another
1234 * SCTP endpoint. In other words, a transport address is unique
1235 * to an SCTP endpoint.
1237 * From an implementation perspective, each socket has one of these.
1238 * A TCP-style socket will have exactly one association on one of
1239 * these. An UDP-style socket will have multiple associations hanging
1243 struct sctp_endpoint {
1244 /* Common substructure for endpoint and association. */
1245 struct sctp_ep_common base;
1247 /* Associations: A list of current associations and mappings
1248 * to the data consumers for each association. This
1249 * may be in the form of a hash table or other
1250 * implementation dependent structure. The data
1251 * consumers may be process identification
1252 * information such as file descriptors, named pipe
1253 * pointer, or table pointers dependent on how SCTP
1256 /* This is really a list of struct sctp_association entries. */
1257 struct list_head asocs;
1259 /* Secret Key: A secret key used by this endpoint to compute
1260 * the MAC. This SHOULD be a cryptographic quality
1261 * random number with a sufficient length.
1262 * Discussion in [RFC1750] can be helpful in
1263 * selection of the key.
1265 __u8 secret_key[SCTP_SECRET_SIZE];
1267 /* digest: This is a digest of the sctp cookie. This field is
1268 * only used on the receive path when we try to validate
1269 * that the cookie has not been tampered with. We put
1270 * this here so we pre-allocate this once and can re-use
1275 /* sendbuf acct. policy. */
1276 __u32 sndbuf_policy;
1278 /* rcvbuf acct. policy. */
1279 __u32 rcvbuf_policy;
1281 /* SCTP AUTH: array of the HMACs that will be allocated
1282 * we need this per association so that we don't serialize
1284 struct crypto_shash **auth_hmacs;
1286 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1287 struct sctp_hmac_algo_param *auth_hmacs_list;
1289 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1290 struct sctp_chunks_param *auth_chunk_list;
1292 /* SCTP-AUTH: endpoint shared keys */
1293 struct list_head endpoint_shared_keys;
1294 __u16 active_key_id;
1299 /* Recover the outter endpoint structure. */
1300 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1302 struct sctp_endpoint *ep;
1304 ep = container_of(base, struct sctp_endpoint, base);
1308 /* These are function signatures for manipulating endpoints. */
1309 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1310 void sctp_endpoint_free(struct sctp_endpoint *);
1311 void sctp_endpoint_put(struct sctp_endpoint *);
1312 void sctp_endpoint_hold(struct sctp_endpoint *);
1313 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1314 struct sctp_association *sctp_endpoint_lookup_assoc(
1315 const struct sctp_endpoint *ep,
1316 const union sctp_addr *paddr,
1317 struct sctp_transport **);
1318 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1319 const union sctp_addr *);
1320 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1321 struct net *, const union sctp_addr *);
1322 int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1323 const union sctp_addr *paddr);
1325 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1326 const struct sctp_association *asoc,
1327 sctp_cid_t, sctp_init_chunk_t *peer_init,
1328 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1329 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1330 const union sctp_addr *peer,
1331 sctp_init_chunk_t *init, gfp_t gfp);
1332 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1333 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1335 struct sctp_inithdr_host {
1338 __u16 num_outbound_streams;
1339 __u16 num_inbound_streams;
1343 /* SCTP_GET_ASSOC_STATS counters */
1344 struct sctp_priv_assoc_stats {
1345 /* Maximum observed rto in the association during subsequent
1346 * observations. Value is set to 0 if no RTO measurement took place
1347 * The transport where the max_rto was observed is returned in
1350 struct sockaddr_storage obs_rto_ipaddr;
1352 /* Total In and Out SACKs received and sent */
1355 /* Total In and Out packets received and sent */
1358 /* Total retransmitted chunks */
1360 /* TSN received > next expected */
1362 /* Duplicate Chunks received */
1364 /* Gap Ack Blocks received */
1366 /* Unordered data chunks sent and received */
1369 /* Ordered data chunks sent and received */
1372 /* Control chunks sent and received */
1379 * 12. Recommended Transmission Control Block (TCB) Parameters
1381 * This section details a recommended set of parameters that should
1382 * be contained within the TCB for an implementation. This section is
1383 * for illustrative purposes and should not be deemed as requirements
1384 * on an implementation or as an exhaustive list of all parameters
1385 * inside an SCTP TCB. Each implementation may need its own additional
1386 * parameters for optimization.
1390 /* Here we have information about each individual association. */
1391 struct sctp_association {
1393 /* A base structure common to endpoint and association.
1394 * In this context, it represents the associations's view
1395 * of the local endpoint of the association.
1397 struct sctp_ep_common base;
1399 /* Associations on the same socket. */
1400 struct list_head asocs;
1402 /* association id. */
1403 sctp_assoc_t assoc_id;
1405 /* This is our parent endpoint. */
1406 struct sctp_endpoint *ep;
1408 /* These are those association elements needed in the cookie. */
1409 struct sctp_cookie c;
1411 /* This is all information about our peer. */
1413 /* transport_addr_list
1415 * Peer : A list of SCTP transport addresses that the
1416 * Transport : peer is bound to. This information is derived
1417 * Address : from the INIT or INIT ACK and is used to
1418 * List : associate an inbound packet with a given
1419 * : association. Normally this information is
1420 * : hashed or keyed for quick lookup and access
1422 * : The list is also initialized with the list
1423 * : of addresses passed with the sctp_connectx()
1426 * It is a list of SCTP_transport's.
1428 struct list_head transport_addr_list;
1432 * Peer Rwnd : Current calculated value of the peer's rwnd.
1438 * Peer : A count of the number of peer addresses
1439 * Transport : in the Peer Transport Address List.
1443 __u16 transport_count;
1446 * The transport layer port number.
1452 * Primary : This is the current primary destination
1453 * Path : transport address of the peer endpoint. It
1454 * : may also specify a source transport address
1455 * : on this endpoint.
1457 * All of these paths live on transport_addr_list.
1459 * At the bakeoffs, we discovered that the intent of
1460 * primaryPath is that it only changes when the ULP
1461 * asks to have it changed. We add the activePath to
1462 * designate the connection we are currently using to
1463 * transmit new data and most control chunks.
1465 struct sctp_transport *primary_path;
1467 /* Cache the primary path address here, when we
1468 * need a an address for msg_name.
1470 union sctp_addr primary_addr;
1473 * The path that we are currently using to
1474 * transmit new data and most control chunks.
1476 struct sctp_transport *active_path;
1480 * RFC2960 6.4 Multi-homed SCTP Endpoints
1482 * Furthermore, when its peer is multi-homed, an
1483 * endpoint SHOULD try to retransmit a chunk to an
1484 * active destination transport address that is
1485 * different from the last destination address to
1486 * which the DATA chunk was sent.
1488 struct sctp_transport *retran_path;
1490 /* Pointer to last transport I have sent on. */
1491 struct sctp_transport *last_sent_to;
1493 /* This is the last transport I have received DATA on. */
1494 struct sctp_transport *last_data_from;
1497 * Mapping An array of bits or bytes indicating which out of
1498 * Array order TSN's have been received (relative to the
1499 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1500 * order packets have been received, this array
1501 * will be set to all zero. This structure may be
1502 * in the form of a circular buffer or bit array.
1504 * Last Rcvd : This is the last TSN received in
1505 * TSN : sequence. This value is set initially by
1506 * : taking the peer's Initial TSN, received in
1507 * : the INIT or INIT ACK chunk, and subtracting
1510 * Throughout most of the specification this is called the
1511 * "Cumulative TSN ACK Point". In this case, we
1512 * ignore the advice in 12.2 in favour of the term
1513 * used in the bulk of the text. This value is hidden
1514 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1516 struct sctp_tsnmap tsn_map;
1518 /* This mask is used to disable sending the ASCONF chunk
1519 * with specified parameter to peer.
1521 __be16 addip_disabled_mask;
1523 /* These are capabilities which our peer advertised. */
1524 __u8 ecn_capable:1, /* Can peer do ECN? */
1525 ipv4_address:1, /* Peer understands IPv4 addresses? */
1526 ipv6_address:1, /* Peer understands IPv6 addresses? */
1527 hostname_address:1, /* Peer understands DNS addresses? */
1528 asconf_capable:1, /* Does peer support ADDIP? */
1529 prsctp_capable:1, /* Can peer do PR-SCTP? */
1530 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1532 /* sack_needed : This flag indicates if the next received
1533 * : packet is to be responded to with a
1534 * : SACK. This is initialized to 0. When a packet
1535 * : is received sack_cnt is incremented. If this value
1536 * : reaches 2 or more, a SACK is sent and the
1537 * : value is reset to 0. Note: This is used only
1538 * : when no DATA chunks are received out of
1539 * : order. When DATA chunks are out of order,
1540 * : SACK's are not delayed (see Section 6).
1542 __u8 sack_needed:1, /* Do we need to sack the peer? */
1544 zero_window_announced:1;
1547 __u32 adaptation_ind; /* Adaptation Code point. */
1549 struct sctp_inithdr_host i;
1553 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1554 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1555 * Initial TSN Value minus 1
1559 /* SCTP-AUTH: We need to know pears random number, hmac list
1560 * and authenticated chunk list. All that is part of the
1561 * cookie and these are just pointers to those locations
1563 sctp_random_param_t *peer_random;
1564 sctp_chunks_param_t *peer_chunks;
1565 sctp_hmac_algo_param_t *peer_hmacs;
1568 /* State : A state variable indicating what state the
1569 * : association is in, i.e. COOKIE-WAIT,
1570 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1571 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1573 * Note: No "CLOSED" state is illustrated since if a
1574 * association is "CLOSED" its TCB SHOULD be removed.
1576 * In this implementation we DO have a CLOSED
1577 * state which is used during initiation and shutdown.
1579 * State takes values from SCTP_STATE_*.
1583 /* Overall : The overall association error count.
1584 * Error Count : [Clear this any time I get something.]
1586 int overall_error_count;
1588 /* The cookie life I award for any cookie. */
1589 ktime_t cookie_life;
1591 /* These are the association's initial, max, and min RTO values.
1592 * These values will be initialized by system defaults, but can
1593 * be modified via the SCTP_RTOINFO socket option.
1595 unsigned long rto_initial;
1596 unsigned long rto_max;
1597 unsigned long rto_min;
1599 /* Maximum number of new data packets that can be sent in a burst. */
1602 /* This is the max_retrans value for the association. This value will
1603 * be initialized initialized from system defaults, but can be
1604 * modified by the SCTP_ASSOCINFO socket option.
1608 /* This is the partially failed retrans value for the transport
1609 * and will be initialized from the assocs value. This can be
1610 * changed using the SCTP_PEER_ADDR_THLDS socket option
1614 /* Maximum number of times the endpoint will retransmit INIT */
1615 __u16 max_init_attempts;
1617 /* How many times have we resent an INIT? */
1620 /* The largest timeout or RTO value to use in attempting an INIT */
1621 unsigned long max_init_timeo;
1623 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1624 * the destination address every heartbeat interval. This value
1625 * will be inherited by all new transports.
1627 unsigned long hbinterval;
1629 /* This is the max_retrans value for new transports in the
1634 /* Flag that path mtu update is pending */
1637 /* Association : The smallest PMTU discovered for all of the
1638 * PMTU : peer's transport addresses.
1642 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1646 /* SACK delay timeout */
1647 unsigned long sackdelay;
1649 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1650 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1652 /* Transport to which SHUTDOWN chunk was last sent. */
1653 struct sctp_transport *shutdown_last_sent_to;
1655 /* Transport to which INIT chunk was last sent. */
1656 struct sctp_transport *init_last_sent_to;
1658 /* How many times have we resent a SHUTDOWN */
1659 int shutdown_retries;
1661 /* Next TSN : The next TSN number to be assigned to a new
1662 * : DATA chunk. This is sent in the INIT or INIT
1663 * : ACK chunk to the peer and incremented each
1664 * : time a DATA chunk is assigned a TSN
1665 * : (normally just prior to transmit or during
1671 * Last Rcvd : This is the last TSN received in sequence. This value
1672 * TSN : is set initially by taking the peer's Initial TSN,
1673 * : received in the INIT or INIT ACK chunk, and
1674 * : subtracting one from it.
1676 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1679 __u32 ctsn_ack_point;
1681 /* PR-SCTP Advanced.Peer.Ack.Point */
1682 __u32 adv_peer_ack_point;
1684 /* Highest TSN that is acknowledged by incoming SACKs. */
1685 __u32 highest_sacked;
1687 /* TSN marking the fast recovery exit point */
1688 __u32 fast_recovery_exit;
1690 /* Flag to track the current fast recovery state */
1693 /* The number of unacknowledged data chunks. Reported through
1694 * the SCTP_STATUS sockopt.
1698 /* The total number of data chunks that we've had to retransmit
1699 * as the result of a T3 timer expiration
1701 __u32 rtx_data_chunks;
1703 /* This is the association's receive buffer space. This value is used
1704 * to set a_rwnd field in an INIT or a SACK chunk.
1708 /* This is the last advertised value of rwnd over a SACK chunk. */
1711 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1712 * to slop over a maximum of the association's frag_point.
1716 /* Keeps treack of rwnd pressure. This happens when we have
1717 * a window, but not recevie buffer (i.e small packets). This one
1718 * is releases slowly (1 PMTU at a time ).
1722 /* This is the sndbuf size in use for the association.
1723 * This corresponds to the sndbuf size for the association,
1724 * as specified in the sk->sndbuf.
1728 /* This is the amount of memory that this association has allocated
1729 * in the receive path at any given time.
1731 atomic_t rmem_alloc;
1733 /* This is the wait queue head for send requests waiting on
1734 * the association sndbuf space.
1736 wait_queue_head_t wait;
1738 /* The message size at which SCTP fragmentation will occur. */
1742 /* Counter used to count INIT errors. */
1743 int init_err_counter;
1745 /* Count the number of INIT cycles (for doubling timeout). */
1748 /* Default send parameters. */
1749 __u16 default_stream;
1750 __u16 default_flags;
1752 __u32 default_context;
1753 __u32 default_timetolive;
1755 /* Default receive parameters */
1756 __u32 default_rcv_context;
1758 /* This tracks outbound ssn for a given stream. */
1759 struct sctp_ssnmap *ssnmap;
1761 /* All outbound chunks go through this structure. */
1762 struct sctp_outq outqueue;
1764 /* A smart pipe that will handle reordering and fragmentation,
1765 * as well as handle passing events up to the ULP.
1767 struct sctp_ulpq ulpq;
1769 /* Last TSN that caused an ECNE Chunk to be sent. */
1770 __u32 last_ecne_tsn;
1772 /* Last TSN that caused a CWR Chunk to be sent. */
1775 /* How many duplicated TSNs have we seen? */
1778 /* These are to support
1779 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1780 * and Enforcement of Flow and Message Limits"
1781 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1782 * or "ADDIP" for short.
1787 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1789 * R1) One and only one ASCONF Chunk MAY be in transit and
1790 * unacknowledged at any one time. If a sender, after sending
1791 * an ASCONF chunk, decides it needs to transfer another
1792 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1793 * returns from the previous ASCONF Chunk before sending a
1794 * subsequent ASCONF. Note this restriction binds each side,
1795 * so at any time two ASCONF may be in-transit on any given
1796 * association (one sent from each endpoint).
1798 * [This is our one-and-only-one ASCONF in flight. If we do
1799 * not have an ASCONF in flight, this is NULL.]
1801 struct sctp_chunk *addip_last_asconf;
1803 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1805 * This is needed to implement itmes E1 - E4 of the updated
1806 * spec. Here is the justification:
1808 * Since the peer may bundle multiple ASCONF chunks toward us,
1809 * we now need the ability to cache multiple ACKs. The section
1810 * describes in detail how they are cached and cleaned up.
1812 struct list_head asconf_ack_list;
1814 /* These ASCONF chunks are waiting to be sent.
1816 * These chunaks can't be pushed to outqueue until receiving
1817 * ASCONF_ACK for the previous ASCONF indicated by
1818 * addip_last_asconf, so as to guarantee that only one ASCONF
1819 * is in flight at any time.
1821 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1823 * In defining the ASCONF Chunk transfer procedures, it is
1824 * essential that these transfers MUST NOT cause congestion
1825 * within the network. To achieve this, we place these
1826 * restrictions on the transfer of ASCONF Chunks:
1828 * R1) One and only one ASCONF Chunk MAY be in transit and
1829 * unacknowledged at any one time. If a sender, after sending
1830 * an ASCONF chunk, decides it needs to transfer another
1831 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1832 * returns from the previous ASCONF Chunk before sending a
1833 * subsequent ASCONF. Note this restriction binds each side,
1834 * so at any time two ASCONF may be in-transit on any given
1835 * association (one sent from each endpoint).
1838 * [I really think this is EXACTLY the sort of intelligence
1839 * which already resides in sctp_outq. Please move this
1840 * queue and its supporting logic down there. --piggy]
1842 struct list_head addip_chunk_list;
1844 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1846 * A2) A serial number should be assigned to the Chunk. The
1847 * serial number SHOULD be a monotonically increasing
1848 * number. The serial number SHOULD be initialized at
1849 * the start of the association to the same value as the
1850 * Initial TSN and every time a new ASCONF chunk is created
1851 * it is incremented by one after assigning the serial number
1852 * to the newly created chunk.
1855 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1857 * Serial Number : 32 bits (unsigned integer)
1859 * This value represents a Serial Number for the ASCONF
1860 * Chunk. The valid range of Serial Number is from 0 to
1861 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1862 * after reaching 4294967295.
1865 int src_out_of_asoc_ok;
1866 union sctp_addr *asconf_addr_del_pending;
1867 struct sctp_transport *new_transport;
1869 /* SCTP AUTH: list of the endpoint shared keys. These
1870 * keys are provided out of band by the user applicaton
1871 * and can't change during the lifetime of the association
1873 struct list_head endpoint_shared_keys;
1876 * The current generated assocaition shared key (secret)
1878 struct sctp_auth_bytes *asoc_shared_key;
1880 /* SCTP AUTH: hmac id of the first peer requested algorithm
1883 __u16 default_hmac_id;
1885 __u16 active_key_id;
1887 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1888 temp:1, /* Is it a temporary association? */
1891 struct sctp_priv_assoc_stats stats;
1893 int sent_cnt_removable;
1895 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1896 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1900 /* An eyecatcher for determining if we are really looking at an
1901 * association data structure.
1904 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1907 /* Recover the outter association structure. */
1908 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1910 struct sctp_association *asoc;
1912 asoc = container_of(base, struct sctp_association, base);
1916 /* These are function signatures for manipulating associations. */
1919 struct sctp_association *
1920 sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1921 sctp_scope_t scope, gfp_t gfp);
1922 void sctp_association_free(struct sctp_association *);
1923 void sctp_association_put(struct sctp_association *);
1924 void sctp_association_hold(struct sctp_association *);
1926 struct sctp_transport *sctp_assoc_choose_alter_transport(
1927 struct sctp_association *, struct sctp_transport *);
1928 void sctp_assoc_update_retran_path(struct sctp_association *);
1929 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1930 const union sctp_addr *);
1931 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1932 const union sctp_addr *laddr);
1933 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1934 const union sctp_addr *address,
1936 const int peer_state);
1937 void sctp_assoc_del_peer(struct sctp_association *asoc,
1938 const union sctp_addr *addr);
1939 void sctp_assoc_rm_peer(struct sctp_association *asoc,
1940 struct sctp_transport *peer);
1941 void sctp_assoc_control_transport(struct sctp_association *,
1942 struct sctp_transport *,
1943 sctp_transport_cmd_t, sctp_sn_error_t);
1944 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1945 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1947 const union sctp_addr *,
1948 const union sctp_addr *);
1949 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1950 void sctp_assoc_update(struct sctp_association *old,
1951 struct sctp_association *new);
1953 __u32 sctp_association_get_next_tsn(struct sctp_association *);
1955 void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1956 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1957 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1958 void sctp_assoc_set_primary(struct sctp_association *,
1959 struct sctp_transport *);
1960 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1961 struct sctp_transport *);
1962 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1963 sctp_scope_t, gfp_t);
1964 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1965 struct sctp_cookie*,
1967 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1968 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1969 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1970 const struct sctp_association *asoc,
1972 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1974 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1975 const union sctp_addr *ss2);
1976 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1978 /* A convenience structure to parse out SCTP specific CMSGs. */
1979 typedef struct sctp_cmsgs {
1980 struct sctp_initmsg *init;
1981 struct sctp_sndrcvinfo *srinfo;
1982 struct sctp_sndinfo *sinfo;
1985 /* Structure for tracking memory objects */
1989 } sctp_dbg_objcnt_entry_t;
1991 #endif /* __sctp_structs_h__ */