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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.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
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)
13 * any later version.
14 *
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.
20 *
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/>.
24 *
25 * Please send any bug reports or fixes you make to the
26 * email addresses:
27 * lksctp developers <linux-sctp@vger.kernel.org>
28 *
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>
45 */
46
47#ifndef __sctp_structs_h__
48#define __sctp_structs_h__
49
50#include <linux/ktime.h>
51#include <linux/socket.h> /* linux/in.h needs this!! */
52#include <linux/in.h> /* We get struct sockaddr_in. */
53#include <linux/in6.h> /* We get struct in6_addr */
54#include <linux/ipv6.h>
55#include <asm/param.h> /* We get MAXHOSTNAMELEN. */
56#include <linux/atomic.h> /* This gets us atomic counters. */
57#include <linux/skbuff.h> /* We need sk_buff_head. */
58#include <linux/workqueue.h> /* We need tq_struct. */
59#include <linux/sctp.h> /* We need sctp* header structs. */
60#include <net/sctp/auth.h> /* We need auth specific structs */
61
62/* A convenience structure for handling sockaddr structures.
63 * We should wean ourselves off this.
64 */
65union sctp_addr {
66 struct sockaddr_in v4;
67 struct sockaddr_in6 v6;
68 struct sockaddr sa;
69};
70
71/* Forward declarations for data structures. */
72struct sctp_globals;
73struct sctp_endpoint;
74struct sctp_association;
75struct sctp_transport;
76struct sctp_packet;
77struct sctp_chunk;
78struct sctp_inq;
79struct sctp_outq;
80struct sctp_bind_addr;
81struct sctp_ulpq;
82struct sctp_ep_common;
83struct sctp_ssnmap;
84struct crypto_hash;
85
86
87#include <net/sctp/tsnmap.h>
88#include <net/sctp/ulpevent.h>
89#include <net/sctp/ulpqueue.h>
90
91/* Structures useful for managing bind/connect. */
92
93struct sctp_bind_bucket {
94 unsigned short port;
95 unsigned short fastreuse;
96 struct hlist_node node;
97 struct hlist_head owner;
98 struct net *net;
99};
100
101struct sctp_bind_hashbucket {
102 spinlock_t lock;
103 struct hlist_head chain;
104};
105
106/* Used for hashing all associations. */
107struct sctp_hashbucket {
108 rwlock_t lock;
109 struct hlist_head chain;
110} __attribute__((__aligned__(8)));
111
112
113/* The SCTP globals structure. */
114extern struct sctp_globals {
115 /* This is a list of groups of functions for each address
116 * family that we support.
117 */
118 struct list_head address_families;
119
120 /* This is the hash of all endpoints. */
121 struct sctp_hashbucket *ep_hashtable;
122 /* This is the hash of all associations. */
123 struct sctp_hashbucket *assoc_hashtable;
124 /* This is the sctp port control hash. */
125 struct sctp_bind_hashbucket *port_hashtable;
126
127 /* Sizes of above hashtables. */
128 int ep_hashsize;
129 int assoc_hashsize;
130 int port_hashsize;
131
132 /* Default initialization values to be applied to new associations. */
133 __u16 max_instreams;
134 __u16 max_outstreams;
135
136 /* Flag to indicate whether computing and verifying checksum
137 * is disabled. */
138 bool checksum_disable;
139} sctp_globals;
140
141#define sctp_max_instreams (sctp_globals.max_instreams)
142#define sctp_max_outstreams (sctp_globals.max_outstreams)
143#define sctp_address_families (sctp_globals.address_families)
144#define sctp_ep_hashsize (sctp_globals.ep_hashsize)
145#define sctp_ep_hashtable (sctp_globals.ep_hashtable)
146#define sctp_assoc_hashsize (sctp_globals.assoc_hashsize)
147#define sctp_assoc_hashtable (sctp_globals.assoc_hashtable)
148#define sctp_port_hashsize (sctp_globals.port_hashsize)
149#define sctp_port_hashtable (sctp_globals.port_hashtable)
150#define sctp_checksum_disable (sctp_globals.checksum_disable)
151
152/* SCTP Socket type: UDP or TCP style. */
153typedef enum {
154 SCTP_SOCKET_UDP = 0,
155 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
156 SCTP_SOCKET_TCP
157} sctp_socket_type_t;
158
159/* Per socket SCTP information. */
160struct sctp_sock {
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;
165
166 /* PF_ family specific functions. */
167 struct sctp_pf *pf;
168
169 /* Access to HMAC transform. */
170 struct crypto_hash *hmac;
171 char *sctp_hmac_alg;
172
173 /* What is our base endpointer? */
174 struct sctp_endpoint *ep;
175
176 struct sctp_bind_bucket *bind_hash;
177 /* Various Socket Options. */
178 __u16 default_stream;
179 __u32 default_ppid;
180 __u16 default_flags;
181 __u32 default_context;
182 __u32 default_timetolive;
183 __u32 default_rcv_context;
184 int max_burst;
185
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.
189 */
190 __u32 hbinterval;
191
192 /* This is the max_retrans value for new associations. */
193 __u16 pathmaxrxt;
194
195 /* The initial Path MTU to use for new associations. */
196 __u32 pathmtu;
197
198 /* The default SACK delay timeout for new associations. */
199 __u32 sackdelay;
200 __u32 sackfreq;
201
202 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
203 __u32 param_flags;
204
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;
210 int user_frag;
211 __u32 autoclose;
212 __u8 nodelay;
213 __u8 disable_fragments;
214 __u8 v4mapped;
215 __u8 frag_interleave;
216 __u32 adaptation_ind;
217 __u32 pd_point;
218
219 atomic_t pd_mode;
220 /* Receive to here while partial delivery is in effect. */
221 struct sk_buff_head pd_lobby;
222 struct list_head auto_asconf_list;
223 int do_auto_asconf;
224};
225
226static inline struct sctp_sock *sctp_sk(const struct sock *sk)
227{
228 return (struct sctp_sock *)sk;
229}
230
231static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
232{
233 return (struct sock *)sp;
234}
235
236#if IS_ENABLED(CONFIG_IPV6)
237struct sctp6_sock {
238 struct sctp_sock sctp;
239 struct ipv6_pinfo inet6;
240};
241#endif /* CONFIG_IPV6 */
242
243
244/* This is our APPLICATION-SPECIFIC state cookie.
245 * THIS IS NOT DICTATED BY THE SPECIFICATION.
246 */
247/* These are the parts of an association which we send in the cookie.
248 * Most of these are straight out of:
249 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
250 *
251 */
252
253struct sctp_cookie {
254
255 /* My : Tag expected in every inbound packet and sent
256 * Verification: in the INIT or INIT ACK chunk.
257 * Tag :
258 */
259 __u32 my_vtag;
260
261 /* Peer's : Tag expected in every outbound packet except
262 * Verification: in the INIT chunk.
263 * Tag :
264 */
265 __u32 peer_vtag;
266
267 /* The rest of these are not from the spec, but really need to
268 * be in the cookie.
269 */
270
271 /* My Tie Tag : Assist in discovering a restarting association. */
272 __u32 my_ttag;
273
274 /* Peer's Tie Tag: Assist in discovering a restarting association. */
275 __u32 peer_ttag;
276
277 /* When does this cookie expire? */
278 ktime_t expiration;
279
280 /* Number of inbound/outbound streams which are set
281 * and negotiated during the INIT process.
282 */
283 __u16 sinit_num_ostreams;
284 __u16 sinit_max_instreams;
285
286 /* This is the first sequence number I used. */
287 __u32 initial_tsn;
288
289 /* This holds the originating address of the INIT packet. */
290 union sctp_addr peer_addr;
291
292 /* IG Section 2.35.3
293 * Include the source port of the INIT-ACK
294 */
295 __u16 my_port;
296
297 __u8 prsctp_capable;
298
299 /* Padding for future use */
300 __u8 padding;
301
302 __u32 adaptation_ind;
303
304 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
305 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
306 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
307
308 /* This is a shim for my peer's INIT packet, followed by
309 * a copy of the raw address list of the association.
310 * The length of the raw address list is saved in the
311 * raw_addr_list_len field, which will be used at the time when
312 * the association TCB is re-constructed from the cookie.
313 */
314 __u32 raw_addr_list_len;
315 struct sctp_init_chunk peer_init[0];
316};
317
318
319/* The format of our cookie that we send to our peer. */
320struct sctp_signed_cookie {
321 __u8 signature[SCTP_SECRET_SIZE];
322 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
323 struct sctp_cookie c;
324} __packed;
325
326/* This is another convenience type to allocate memory for address
327 * params for the maximum size and pass such structures around
328 * internally.
329 */
330union sctp_addr_param {
331 struct sctp_paramhdr p;
332 struct sctp_ipv4addr_param v4;
333 struct sctp_ipv6addr_param v6;
334};
335
336/* A convenience type to allow walking through the various
337 * parameters and avoid casting all over the place.
338 */
339union sctp_params {
340 void *v;
341 struct sctp_paramhdr *p;
342 struct sctp_cookie_preserve_param *life;
343 struct sctp_hostname_param *dns;
344 struct sctp_cookie_param *cookie;
345 struct sctp_supported_addrs_param *sat;
346 struct sctp_ipv4addr_param *v4;
347 struct sctp_ipv6addr_param *v6;
348 union sctp_addr_param *addr;
349 struct sctp_adaptation_ind_param *aind;
350 struct sctp_supported_ext_param *ext;
351 struct sctp_random_param *random;
352 struct sctp_chunks_param *chunks;
353 struct sctp_hmac_algo_param *hmac_algo;
354 struct sctp_addip_param *addip;
355};
356
357/* RFC 2960. Section 3.3.5 Heartbeat.
358 * Heartbeat Information: variable length
359 * The Sender-specific Heartbeat Info field should normally include
360 * information about the sender's current time when this HEARTBEAT
361 * chunk is sent and the destination transport address to which this
362 * HEARTBEAT is sent (see Section 8.3).
363 */
364typedef struct sctp_sender_hb_info {
365 struct sctp_paramhdr param_hdr;
366 union sctp_addr daddr;
367 unsigned long sent_at;
368 __u64 hb_nonce;
369} __packed sctp_sender_hb_info_t;
370
371/*
372 * RFC 2960 1.3.2 Sequenced Delivery within Streams
373 *
374 * The term "stream" is used in SCTP to refer to a sequence of user
375 * messages that are to be delivered to the upper-layer protocol in
376 * order with respect to other messages within the same stream. This is
377 * in contrast to its usage in TCP, where it refers to a sequence of
378 * bytes (in this document a byte is assumed to be eight bits).
379 * ...
380 *
381 * This is the structure we use to track both our outbound and inbound
382 * SSN, or Stream Sequence Numbers.
383 */
384
385struct sctp_stream {
386 __u16 *ssn;
387 unsigned int len;
388};
389
390struct sctp_ssnmap {
391 struct sctp_stream in;
392 struct sctp_stream out;
393};
394
395struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
396 gfp_t gfp);
397void sctp_ssnmap_free(struct sctp_ssnmap *map);
398void sctp_ssnmap_clear(struct sctp_ssnmap *map);
399
400/* What is the current SSN number for this stream? */
401static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
402{
403 return stream->ssn[id];
404}
405
406/* Return the next SSN number for this stream. */
407static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
408{
409 return stream->ssn[id]++;
410}
411
412/* Skip over this ssn and all below. */
413static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
414 __u16 ssn)
415{
416 stream->ssn[id] = ssn+1;
417}
418
419/*
420 * Pointers to address related SCTP functions.
421 * (i.e. things that depend on the address family.)
422 */
423struct sctp_af {
424 int (*sctp_xmit) (struct sk_buff *skb,
425 struct sctp_transport *);
426 int (*setsockopt) (struct sock *sk,
427 int level,
428 int optname,
429 char __user *optval,
430 unsigned int optlen);
431 int (*getsockopt) (struct sock *sk,
432 int level,
433 int optname,
434 char __user *optval,
435 int __user *optlen);
436 int (*compat_setsockopt) (struct sock *sk,
437 int level,
438 int optname,
439 char __user *optval,
440 unsigned int optlen);
441 int (*compat_getsockopt) (struct sock *sk,
442 int level,
443 int optname,
444 char __user *optval,
445 int __user *optlen);
446 void (*get_dst) (struct sctp_transport *t,
447 union sctp_addr *saddr,
448 struct flowi *fl,
449 struct sock *sk);
450 void (*get_saddr) (struct sctp_sock *sk,
451 struct sctp_transport *t,
452 struct flowi *fl);
453 void (*copy_addrlist) (struct list_head *,
454 struct net_device *);
455 int (*cmp_addr) (const union sctp_addr *addr1,
456 const union sctp_addr *addr2);
457 void (*addr_copy) (union sctp_addr *dst,
458 union sctp_addr *src);
459 void (*from_skb) (union sctp_addr *,
460 struct sk_buff *skb,
461 int saddr);
462 void (*from_sk) (union sctp_addr *,
463 struct sock *sk);
464 void (*to_sk_saddr) (union sctp_addr *,
465 struct sock *sk);
466 void (*to_sk_daddr) (union sctp_addr *,
467 struct sock *sk);
468 void (*from_addr_param) (union sctp_addr *,
469 union sctp_addr_param *,
470 __be16 port, int iif);
471 int (*to_addr_param) (const union sctp_addr *,
472 union sctp_addr_param *);
473 int (*addr_valid) (union sctp_addr *,
474 struct sctp_sock *,
475 const struct sk_buff *);
476 sctp_scope_t (*scope) (union sctp_addr *);
477 void (*inaddr_any) (union sctp_addr *, __be16);
478 int (*is_any) (const union sctp_addr *);
479 int (*available) (union sctp_addr *,
480 struct sctp_sock *);
481 int (*skb_iif) (const struct sk_buff *sk);
482 int (*is_ce) (const struct sk_buff *sk);
483 void (*seq_dump_addr)(struct seq_file *seq,
484 union sctp_addr *addr);
485 void (*ecn_capable)(struct sock *sk);
486 __u16 net_header_len;
487 int sockaddr_len;
488 sa_family_t sa_family;
489 struct list_head list;
490};
491
492struct sctp_af *sctp_get_af_specific(sa_family_t);
493int sctp_register_af(struct sctp_af *);
494
495/* Protocol family functions. */
496struct sctp_pf {
497 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
498 void (*skb_msgname) (struct sk_buff *, char *, int *);
499 int (*af_supported) (sa_family_t, struct sctp_sock *);
500 int (*cmp_addr) (const union sctp_addr *,
501 const union sctp_addr *,
502 struct sctp_sock *);
503 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
504 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
505 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
506 struct sock *(*create_accept_sk) (struct sock *sk,
507 struct sctp_association *asoc);
508 void (*addr_v4map) (struct sctp_sock *, union sctp_addr *);
509 struct sctp_af *af;
510};
511
512
513/* Structure to track chunk fragments that have been acked, but peer
514 * fragments of the same message have not.
515 */
516struct sctp_datamsg {
517 /* Chunks waiting to be submitted to lower layer. */
518 struct list_head chunks;
519 /* Reference counting. */
520 atomic_t refcnt;
521 /* When is this message no longer interesting to the peer? */
522 unsigned long expires_at;
523 /* Did the messenge fail to send? */
524 int send_error;
525 u8 send_failed:1,
526 can_abandon:1, /* can chunks from this message can be abandoned. */
527 can_delay; /* should this message be Nagle delayed */
528};
529
530struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
531 struct sctp_sndrcvinfo *,
532 struct msghdr *, int len);
533void sctp_datamsg_free(struct sctp_datamsg *);
534void sctp_datamsg_put(struct sctp_datamsg *);
535void sctp_chunk_fail(struct sctp_chunk *, int error);
536int sctp_chunk_abandoned(struct sctp_chunk *);
537
538/* RFC2960 1.4 Key Terms
539 *
540 * o Chunk: A unit of information within an SCTP packet, consisting of
541 * a chunk header and chunk-specific content.
542 *
543 * As a matter of convenience, we remember the SCTP common header for
544 * each chunk as well as a few other header pointers...
545 */
546struct sctp_chunk {
547 struct list_head list;
548
549 atomic_t refcnt;
550
551 /* This is our link to the per-transport transmitted list. */
552 struct list_head transmitted_list;
553
554 /* This field is used by chunks that hold fragmented data.
555 * For the first fragment this is the list that holds the rest of
556 * fragments. For the remaining fragments, this is the link to the
557 * frag_list maintained in the first fragment.
558 */
559 struct list_head frag_list;
560
561 /* This points to the sk_buff containing the actual data. */
562 struct sk_buff *skb;
563
564 /* These are the SCTP headers by reverse order in a packet.
565 * Note that some of these may happen more than once. In that
566 * case, we point at the "current" one, whatever that means
567 * for that level of header.
568 */
569
570 /* We point this at the FIRST TLV parameter to chunk_hdr. */
571 union sctp_params param_hdr;
572 union {
573 __u8 *v;
574 struct sctp_datahdr *data_hdr;
575 struct sctp_inithdr *init_hdr;
576 struct sctp_sackhdr *sack_hdr;
577 struct sctp_heartbeathdr *hb_hdr;
578 struct sctp_sender_hb_info *hbs_hdr;
579 struct sctp_shutdownhdr *shutdown_hdr;
580 struct sctp_signed_cookie *cookie_hdr;
581 struct sctp_ecnehdr *ecne_hdr;
582 struct sctp_cwrhdr *ecn_cwr_hdr;
583 struct sctp_errhdr *err_hdr;
584 struct sctp_addiphdr *addip_hdr;
585 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
586 struct sctp_authhdr *auth_hdr;
587 } subh;
588
589 __u8 *chunk_end;
590
591 struct sctp_chunkhdr *chunk_hdr;
592 struct sctphdr *sctp_hdr;
593
594 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
595 struct sctp_sndrcvinfo sinfo;
596
597 /* Which association does this belong to? */
598 struct sctp_association *asoc;
599
600 /* What endpoint received this chunk? */
601 struct sctp_ep_common *rcvr;
602
603 /* We fill this in if we are calculating RTT. */
604 unsigned long sent_at;
605
606 /* What is the origin IP address for this chunk? */
607 union sctp_addr source;
608 /* Destination address for this chunk. */
609 union sctp_addr dest;
610
611 /* For outbound message, track all fragments for SEND_FAILED. */
612 struct sctp_datamsg *msg;
613
614 /* For an inbound chunk, this tells us where it came from.
615 * For an outbound chunk, it tells us where we'd like it to
616 * go. It is NULL if we have no preference.
617 */
618 struct sctp_transport *transport;
619
620 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
621 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
622 * spec violates the principle premis that all chunks are processed
623 * in order.
624 */
625 struct sk_buff *auth_chunk;
626
627#define SCTP_CAN_FRTX 0x0
628#define SCTP_NEED_FRTX 0x1
629#define SCTP_DONT_FRTX 0x2
630 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
631 resent:1, /* Has this chunk ever been resent. */
632 has_tsn:1, /* Does this chunk have a TSN yet? */
633 has_ssn:1, /* Does this chunk have a SSN yet? */
634 singleton:1, /* Only chunk in the packet? */
635 end_of_packet:1, /* Last chunk in the packet? */
636 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
637 pdiscard:1, /* Discard the whole packet now? */
638 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
639 data_accepted:1, /* At least 1 chunk accepted */
640 auth:1, /* IN: was auth'ed | OUT: needs auth */
641 has_asconf:1, /* IN: have seen an asconf before */
642 tsn_missing_report:2, /* Data chunk missing counter. */
643 fast_retransmit:2; /* Is this chunk fast retransmitted? */
644};
645
646void sctp_chunk_hold(struct sctp_chunk *);
647void sctp_chunk_put(struct sctp_chunk *);
648int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
649 struct iovec *data);
650void sctp_chunk_free(struct sctp_chunk *);
651void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
652struct sctp_chunk *sctp_chunkify(struct sk_buff *,
653 const struct sctp_association *,
654 struct sock *);
655void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
656 union sctp_addr *);
657const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
658
659enum {
660 SCTP_ADDR_NEW, /* new address added to assoc/ep */
661 SCTP_ADDR_SRC, /* address can be used as source */
662 SCTP_ADDR_DEL, /* address about to be deleted */
663};
664
665/* This is a structure for holding either an IPv6 or an IPv4 address. */
666struct sctp_sockaddr_entry {
667 struct list_head list;
668 struct rcu_head rcu;
669 union sctp_addr a;
670 __u8 state;
671 __u8 valid;
672};
673
674#define SCTP_ADDRESS_TICK_DELAY 500
675
676typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
677
678/* This structure holds lists of chunks as we are assembling for
679 * transmission.
680 */
681struct sctp_packet {
682 /* These are the SCTP header values (host order) for the packet. */
683 __u16 source_port;
684 __u16 destination_port;
685 __u32 vtag;
686
687 /* This contains the payload chunks. */
688 struct list_head chunk_list;
689
690 /* This is the overhead of the sctp and ip headers. */
691 size_t overhead;
692 /* This is the total size of all chunks INCLUDING padding. */
693 size_t size;
694
695 /* The packet is destined for this transport address.
696 * The function we finally use to pass down to the next lower
697 * layer lives in the transport structure.
698 */
699 struct sctp_transport *transport;
700
701 /* pointer to the auth chunk for this packet */
702 struct sctp_chunk *auth;
703
704 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
705 has_sack:1, /* This packet contains a SACK chunk. */
706 has_auth:1, /* This packet contains an AUTH chunk */
707 has_data:1, /* This packet contains at least 1 DATA chunk */
708 ipfragok:1; /* So let ip fragment this packet */
709};
710
711struct sctp_packet *sctp_packet_init(struct sctp_packet *,
712 struct sctp_transport *,
713 __u16 sport, __u16 dport);
714struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
715sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
716 struct sctp_chunk *, int);
717sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
718 struct sctp_chunk *);
719int sctp_packet_transmit(struct sctp_packet *);
720void sctp_packet_free(struct sctp_packet *);
721
722static inline int sctp_packet_empty(struct sctp_packet *packet)
723{
724 return packet->size == packet->overhead;
725}
726
727/* This represents a remote transport address.
728 * For local transport addresses, we just use union sctp_addr.
729 *
730 * RFC2960 Section 1.4 Key Terms
731 *
732 * o Transport address: A Transport Address is traditionally defined
733 * by Network Layer address, Transport Layer protocol and Transport
734 * Layer port number. In the case of SCTP running over IP, a
735 * transport address is defined by the combination of an IP address
736 * and an SCTP port number (where SCTP is the Transport protocol).
737 *
738 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
739 *
740 * o The sender keeps a separate congestion control parameter set for
741 * each of the destination addresses it can send to (not each
742 * source-destination pair but for each destination). The parameters
743 * should decay if the address is not used for a long enough time
744 * period.
745 *
746 */
747struct sctp_transport {
748 /* A list of transports. */
749 struct list_head transports;
750
751 /* Reference counting. */
752 atomic_t refcnt;
753 __u32 dead:1,
754 /* RTO-Pending : A flag used to track if one of the DATA
755 * chunks sent to this address is currently being
756 * used to compute a RTT. If this flag is 0,
757 * the next DATA chunk sent to this destination
758 * should be used to compute a RTT and this flag
759 * should be set. Every time the RTT
760 * calculation completes (i.e. the DATA chunk
761 * is SACK'd) clear this flag.
762 */
763 rto_pending:1,
764
765 /*
766 * hb_sent : a flag that signals that we have a pending
767 * heartbeat.
768 */
769 hb_sent:1,
770
771 /* Is the Path MTU update pending on this tranport */
772 pmtu_pending:1;
773
774 /* Has this transport moved the ctsn since we last sacked */
775 __u32 sack_generation;
776 u32 dst_cookie;
777
778 struct flowi fl;
779
780 /* This is the peer's IP address and port. */
781 union sctp_addr ipaddr;
782
783 /* These are the functions we call to handle LLP stuff. */
784 struct sctp_af *af_specific;
785
786 /* Which association do we belong to? */
787 struct sctp_association *asoc;
788
789 /* RFC2960
790 *
791 * 12.3 Per Transport Address Data
792 *
793 * For each destination transport address in the peer's
794 * address list derived from the INIT or INIT ACK chunk, a
795 * number of data elements needs to be maintained including:
796 */
797 /* RTO : The current retransmission timeout value. */
798 unsigned long rto;
799
800 __u32 rtt; /* This is the most recent RTT. */
801
802 /* RTTVAR : The current RTT variation. */
803 __u32 rttvar;
804
805 /* SRTT : The current smoothed round trip time. */
806 __u32 srtt;
807
808 /*
809 * These are the congestion stats.
810 */
811 /* cwnd : The current congestion window. */
812 __u32 cwnd; /* This is the actual cwnd. */
813
814 /* ssthresh : The current slow start threshold value. */
815 __u32 ssthresh;
816
817 /* partial : The tracking method for increase of cwnd when in
818 * bytes acked : congestion avoidance mode (see Section 6.2.2)
819 */
820 __u32 partial_bytes_acked;
821
822 /* Data that has been sent, but not acknowledged. */
823 __u32 flight_size;
824
825 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
826
827 /* Destination */
828 struct dst_entry *dst;
829 /* Source address. */
830 union sctp_addr saddr;
831
832 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
833 * the destination address every heartbeat interval.
834 */
835 unsigned long hbinterval;
836
837 /* SACK delay timeout */
838 unsigned long sackdelay;
839 __u32 sackfreq;
840
841 /* When was the last time (in jiffies) that we heard from this
842 * transport? We use this to pick new active and retran paths.
843 */
844 unsigned long last_time_heard;
845
846 /* Last time(in jiffies) when cwnd is reduced due to the congestion
847 * indication based on ECNE chunk.
848 */
849 unsigned long last_time_ecne_reduced;
850
851 /* This is the max_retrans value for the transport and will
852 * be initialized from the assocs value. This can be changed
853 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
854 */
855 __u16 pathmaxrxt;
856
857 /* This is the partially failed retrans value for the transport
858 * and will be initialized from the assocs value. This can be changed
859 * using the SCTP_PEER_ADDR_THLDS socket option
860 */
861 int pf_retrans;
862 /* PMTU : The current known path MTU. */
863 __u32 pathmtu;
864
865 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
866 __u32 param_flags;
867
868 /* The number of times INIT has been sent on this transport. */
869 int init_sent_count;
870
871 /* state : The current state of this destination,
872 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
873 */
874 int state;
875
876 /* These are the error stats for this destination. */
877
878 /* Error count : The current error count for this destination. */
879 unsigned short error_count;
880
881 /* Per : A timer used by each destination.
882 * Destination :
883 * Timer :
884 *
885 * [Everywhere else in the text this is called T3-rtx. -ed]
886 */
887 struct timer_list T3_rtx_timer;
888
889 /* Heartbeat timer is per destination. */
890 struct timer_list hb_timer;
891
892 /* Timer to handle ICMP proto unreachable envets */
893 struct timer_list proto_unreach_timer;
894
895 /* Since we're using per-destination retransmission timers
896 * (see above), we're also using per-destination "transmitted"
897 * queues. This probably ought to be a private struct
898 * accessible only within the outqueue, but it's not, yet.
899 */
900 struct list_head transmitted;
901
902 /* We build bundle-able packets for this transport here. */
903 struct sctp_packet packet;
904
905 /* This is the list of transports that have chunks to send. */
906 struct list_head send_ready;
907
908 /* State information saved for SFR_CACC algorithm. The key
909 * idea in SFR_CACC is to maintain state at the sender on a
910 * per-destination basis when a changeover happens.
911 * char changeover_active;
912 * char cycling_changeover;
913 * __u32 next_tsn_at_change;
914 * char cacc_saw_newack;
915 */
916 struct {
917 /* An unsigned integer, which stores the next TSN to be
918 * used by the sender, at the moment of changeover.
919 */
920 __u32 next_tsn_at_change;
921
922 /* A flag which indicates the occurrence of a changeover */
923 char changeover_active;
924
925 /* A flag which indicates whether the change of primary is
926 * the first switch to this destination address during an
927 * active switch.
928 */
929 char cycling_changeover;
930
931 /* A temporary flag, which is used during the processing of
932 * a SACK to estimate the causative TSN(s)'s group.
933 */
934 char cacc_saw_newack;
935 } cacc;
936
937 /* 64-bit random number sent with heartbeat. */
938 __u64 hb_nonce;
939
940 struct rcu_head rcu;
941};
942
943struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
944 gfp_t);
945void sctp_transport_set_owner(struct sctp_transport *,
946 struct sctp_association *);
947void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
948 struct sctp_sock *);
949void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
950void sctp_transport_free(struct sctp_transport *);
951void sctp_transport_reset_timers(struct sctp_transport *);
952void sctp_transport_hold(struct sctp_transport *);
953void sctp_transport_put(struct sctp_transport *);
954void sctp_transport_update_rto(struct sctp_transport *, __u32);
955void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
956void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
957void sctp_transport_burst_limited(struct sctp_transport *);
958void sctp_transport_burst_reset(struct sctp_transport *);
959unsigned long sctp_transport_timeout(struct sctp_transport *);
960void sctp_transport_reset(struct sctp_transport *);
961void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
962void sctp_transport_immediate_rtx(struct sctp_transport *);
963
964
965/* This is the structure we use to queue packets as they come into
966 * SCTP. We write packets to it and read chunks from it.
967 */
968struct sctp_inq {
969 /* This is actually a queue of sctp_chunk each
970 * containing a partially decoded packet.
971 */
972 struct list_head in_chunk_list;
973 /* This is the packet which is currently off the in queue and is
974 * being worked on through the inbound chunk processing.
975 */
976 struct sctp_chunk *in_progress;
977
978 /* This is the delayed task to finish delivering inbound
979 * messages.
980 */
981 struct work_struct immediate;
982};
983
984void sctp_inq_init(struct sctp_inq *);
985void sctp_inq_free(struct sctp_inq *);
986void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
987struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
988struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
989void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
990
991/* This is the structure we use to hold outbound chunks. You push
992 * chunks in and they automatically pop out the other end as bundled
993 * packets (it calls (*output_handler)()).
994 *
995 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
996 * and 8.2 of the v13 draft.
997 *
998 * It handles retransmissions. The connection to the timeout portion
999 * of the state machine is through sctp_..._timeout() and timeout_handler.
1000 *
1001 * If you feed it SACKs, it will eat them.
1002 *
1003 * If you give it big chunks, it will fragment them.
1004 *
1005 * It assigns TSN's to data chunks. This happens at the last possible
1006 * instant before transmission.
1007 *
1008 * When free()'d, it empties itself out via output_handler().
1009 */
1010struct sctp_outq {
1011 struct sctp_association *asoc;
1012
1013 /* Data pending that has never been transmitted. */
1014 struct list_head out_chunk_list;
1015
1016 unsigned int out_qlen; /* Total length of queued data chunks. */
1017
1018 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1019 unsigned int error;
1020
1021 /* These are control chunks we want to send. */
1022 struct list_head control_chunk_list;
1023
1024 /* These are chunks that have been sacked but are above the
1025 * CTSN, or cumulative tsn ack point.
1026 */
1027 struct list_head sacked;
1028
1029 /* Put chunks on this list to schedule them for
1030 * retransmission.
1031 */
1032 struct list_head retransmit;
1033
1034 /* Put chunks on this list to save them for FWD TSN processing as
1035 * they were abandoned.
1036 */
1037 struct list_head abandoned;
1038
1039 /* How many unackd bytes do we have in-flight? */
1040 __u32 outstanding_bytes;
1041
1042 /* Are we doing fast-rtx on this queue */
1043 char fast_rtx;
1044
1045 /* Corked? */
1046 char cork;
1047};
1048
1049void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1050void sctp_outq_teardown(struct sctp_outq *);
1051void sctp_outq_free(struct sctp_outq*);
1052int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk);
1053int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1054int sctp_outq_is_empty(const struct sctp_outq *);
1055void sctp_outq_restart(struct sctp_outq *);
1056
1057void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1058 sctp_retransmit_reason_t);
1059void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1060int sctp_outq_uncork(struct sctp_outq *);
1061/* Uncork and flush an outqueue. */
1062static inline void sctp_outq_cork(struct sctp_outq *q)
1063{
1064 q->cork = 1;
1065}
1066
1067/* These bind address data fields common between endpoints and associations */
1068struct sctp_bind_addr {
1069
1070 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1071 *
1072 * SCTP Port: The local SCTP port number the endpoint is
1073 * bound to.
1074 */
1075 __u16 port;
1076
1077 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1078 *
1079 * Address List: The list of IP addresses that this instance
1080 * has bound. This information is passed to one's
1081 * peer(s) in INIT and INIT ACK chunks.
1082 */
1083 struct list_head address_list;
1084};
1085
1086void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1087void sctp_bind_addr_free(struct sctp_bind_addr *);
1088int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1089 const struct sctp_bind_addr *src,
1090 sctp_scope_t scope, gfp_t gfp,
1091 int flags);
1092int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1093 const struct sctp_bind_addr *src,
1094 gfp_t gfp);
1095int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1096 __u8 addr_state, gfp_t gfp);
1097int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1098int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1099 struct sctp_sock *);
1100int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1101 struct sctp_sock *, struct sctp_sock *);
1102int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1103 const union sctp_addr *addr);
1104union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1105 const union sctp_addr *addrs,
1106 int addrcnt,
1107 struct sctp_sock *opt);
1108union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1109 int *addrs_len,
1110 gfp_t gfp);
1111int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1112 __u16 port, gfp_t gfp);
1113
1114sctp_scope_t sctp_scope(const union sctp_addr *);
1115int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1116int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1117int sctp_addr_is_valid(const union sctp_addr *addr);
1118int sctp_is_ep_boundall(struct sock *sk);
1119
1120
1121/* What type of endpoint? */
1122typedef enum {
1123 SCTP_EP_TYPE_SOCKET,
1124 SCTP_EP_TYPE_ASSOCIATION,
1125} sctp_endpoint_type_t;
1126
1127/*
1128 * A common base class to bridge the implmentation view of a
1129 * socket (usually listening) endpoint versus an association's
1130 * local endpoint.
1131 * This common structure is useful for several purposes:
1132 * 1) Common interface for lookup routines.
1133 * a) Subfunctions work for either endpoint or association
1134 * b) Single interface to lookup allows hiding the lookup lock rather
1135 * than acquiring it externally.
1136 * 2) Common interface for the inbound chunk handling/state machine.
1137 * 3) Common object handling routines for reference counting, etc.
1138 * 4) Disentangle association lookup from endpoint lookup, where we
1139 * do not have to find our endpoint to find our association.
1140 *
1141 */
1142
1143struct sctp_ep_common {
1144 /* Fields to help us manage our entries in the hash tables. */
1145 struct hlist_node node;
1146 int hashent;
1147
1148 /* Runtime type information. What kind of endpoint is this? */
1149 sctp_endpoint_type_t type;
1150
1151 /* Some fields to help us manage this object.
1152 * refcnt - Reference count access to this object.
1153 * dead - Do not attempt to use this object.
1154 */
1155 atomic_t refcnt;
1156 bool dead;
1157
1158 /* What socket does this endpoint belong to? */
1159 struct sock *sk;
1160
1161 /* This is where we receive inbound chunks. */
1162 struct sctp_inq inqueue;
1163
1164 /* This substructure includes the defining parameters of the
1165 * endpoint:
1166 * bind_addr.port is our shared port number.
1167 * bind_addr.address_list is our set of local IP addresses.
1168 */
1169 struct sctp_bind_addr bind_addr;
1170};
1171
1172
1173/* RFC Section 1.4 Key Terms
1174 *
1175 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1176 * multi-homed host, an SCTP endpoint is represented to its peers as a
1177 * combination of a set of eligible destination transport addresses to
1178 * which SCTP packets can be sent and a set of eligible source
1179 * transport addresses from which SCTP packets can be received.
1180 * All transport addresses used by an SCTP endpoint must use the
1181 * same port number, but can use multiple IP addresses. A transport
1182 * address used by an SCTP endpoint must not be used by another
1183 * SCTP endpoint. In other words, a transport address is unique
1184 * to an SCTP endpoint.
1185 *
1186 * From an implementation perspective, each socket has one of these.
1187 * A TCP-style socket will have exactly one association on one of
1188 * these. An UDP-style socket will have multiple associations hanging
1189 * off one of these.
1190 */
1191
1192struct sctp_endpoint {
1193 /* Common substructure for endpoint and association. */
1194 struct sctp_ep_common base;
1195
1196 /* Associations: A list of current associations and mappings
1197 * to the data consumers for each association. This
1198 * may be in the form of a hash table or other
1199 * implementation dependent structure. The data
1200 * consumers may be process identification
1201 * information such as file descriptors, named pipe
1202 * pointer, or table pointers dependent on how SCTP
1203 * is implemented.
1204 */
1205 /* This is really a list of struct sctp_association entries. */
1206 struct list_head asocs;
1207
1208 /* Secret Key: A secret key used by this endpoint to compute
1209 * the MAC. This SHOULD be a cryptographic quality
1210 * random number with a sufficient length.
1211 * Discussion in [RFC1750] can be helpful in
1212 * selection of the key.
1213 */
1214 __u8 secret_key[SCTP_SECRET_SIZE];
1215
1216 /* digest: This is a digest of the sctp cookie. This field is
1217 * only used on the receive path when we try to validate
1218 * that the cookie has not been tampered with. We put
1219 * this here so we pre-allocate this once and can re-use
1220 * on every receive.
1221 */
1222 __u8 *digest;
1223
1224 /* sendbuf acct. policy. */
1225 __u32 sndbuf_policy;
1226
1227 /* rcvbuf acct. policy. */
1228 __u32 rcvbuf_policy;
1229
1230 /* SCTP AUTH: array of the HMACs that will be allocated
1231 * we need this per association so that we don't serialize
1232 */
1233 struct crypto_hash **auth_hmacs;
1234
1235 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1236 struct sctp_hmac_algo_param *auth_hmacs_list;
1237
1238 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1239 struct sctp_chunks_param *auth_chunk_list;
1240
1241 /* SCTP-AUTH: endpoint shared keys */
1242 struct list_head endpoint_shared_keys;
1243 __u16 active_key_id;
1244 __u8 auth_enable;
1245};
1246
1247/* Recover the outter endpoint structure. */
1248static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1249{
1250 struct sctp_endpoint *ep;
1251
1252 ep = container_of(base, struct sctp_endpoint, base);
1253 return ep;
1254}
1255
1256/* These are function signatures for manipulating endpoints. */
1257struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1258void sctp_endpoint_free(struct sctp_endpoint *);
1259void sctp_endpoint_put(struct sctp_endpoint *);
1260void sctp_endpoint_hold(struct sctp_endpoint *);
1261void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1262struct sctp_association *sctp_endpoint_lookup_assoc(
1263 const struct sctp_endpoint *ep,
1264 const union sctp_addr *paddr,
1265 struct sctp_transport **);
1266int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1267 const union sctp_addr *);
1268struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1269 struct net *, const union sctp_addr *);
1270int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1271 const union sctp_addr *paddr);
1272
1273int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1274 const struct sctp_association *asoc,
1275 sctp_cid_t, sctp_init_chunk_t *peer_init,
1276 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1277int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1278 const union sctp_addr *peer,
1279 sctp_init_chunk_t *init, gfp_t gfp);
1280__u32 sctp_generate_tag(const struct sctp_endpoint *);
1281__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1282
1283struct sctp_inithdr_host {
1284 __u32 init_tag;
1285 __u32 a_rwnd;
1286 __u16 num_outbound_streams;
1287 __u16 num_inbound_streams;
1288 __u32 initial_tsn;
1289};
1290
1291/* SCTP_GET_ASSOC_STATS counters */
1292struct sctp_priv_assoc_stats {
1293 /* Maximum observed rto in the association during subsequent
1294 * observations. Value is set to 0 if no RTO measurement took place
1295 * The transport where the max_rto was observed is returned in
1296 * obs_rto_ipaddr
1297 */
1298 struct sockaddr_storage obs_rto_ipaddr;
1299 __u64 max_obs_rto;
1300 /* Total In and Out SACKs received and sent */
1301 __u64 isacks;
1302 __u64 osacks;
1303 /* Total In and Out packets received and sent */
1304 __u64 opackets;
1305 __u64 ipackets;
1306 /* Total retransmitted chunks */
1307 __u64 rtxchunks;
1308 /* TSN received > next expected */
1309 __u64 outofseqtsns;
1310 /* Duplicate Chunks received */
1311 __u64 idupchunks;
1312 /* Gap Ack Blocks received */
1313 __u64 gapcnt;
1314 /* Unordered data chunks sent and received */
1315 __u64 ouodchunks;
1316 __u64 iuodchunks;
1317 /* Ordered data chunks sent and received */
1318 __u64 oodchunks;
1319 __u64 iodchunks;
1320 /* Control chunks sent and received */
1321 __u64 octrlchunks;
1322 __u64 ictrlchunks;
1323};
1324
1325/* RFC2960
1326 *
1327 * 12. Recommended Transmission Control Block (TCB) Parameters
1328 *
1329 * This section details a recommended set of parameters that should
1330 * be contained within the TCB for an implementation. This section is
1331 * for illustrative purposes and should not be deemed as requirements
1332 * on an implementation or as an exhaustive list of all parameters
1333 * inside an SCTP TCB. Each implementation may need its own additional
1334 * parameters for optimization.
1335 */
1336
1337
1338/* Here we have information about each individual association. */
1339struct sctp_association {
1340
1341 /* A base structure common to endpoint and association.
1342 * In this context, it represents the associations's view
1343 * of the local endpoint of the association.
1344 */
1345 struct sctp_ep_common base;
1346
1347 /* Associations on the same socket. */
1348 struct list_head asocs;
1349
1350 /* association id. */
1351 sctp_assoc_t assoc_id;
1352
1353 /* This is our parent endpoint. */
1354 struct sctp_endpoint *ep;
1355
1356 /* These are those association elements needed in the cookie. */
1357 struct sctp_cookie c;
1358
1359 /* This is all information about our peer. */
1360 struct {
1361 /* transport_addr_list
1362 *
1363 * Peer : A list of SCTP transport addresses that the
1364 * Transport : peer is bound to. This information is derived
1365 * Address : from the INIT or INIT ACK and is used to
1366 * List : associate an inbound packet with a given
1367 * : association. Normally this information is
1368 * : hashed or keyed for quick lookup and access
1369 * : of the TCB.
1370 * : The list is also initialized with the list
1371 * : of addresses passed with the sctp_connectx()
1372 * : call.
1373 *
1374 * It is a list of SCTP_transport's.
1375 */
1376 struct list_head transport_addr_list;
1377
1378 /* rwnd
1379 *
1380 * Peer Rwnd : Current calculated value of the peer's rwnd.
1381 */
1382 __u32 rwnd;
1383
1384 /* transport_count
1385 *
1386 * Peer : A count of the number of peer addresses
1387 * Transport : in the Peer Transport Address List.
1388 * Address :
1389 * Count :
1390 */
1391 __u16 transport_count;
1392
1393 /* port
1394 * The transport layer port number.
1395 */
1396 __u16 port;
1397
1398 /* primary_path
1399 *
1400 * Primary : This is the current primary destination
1401 * Path : transport address of the peer endpoint. It
1402 * : may also specify a source transport address
1403 * : on this endpoint.
1404 *
1405 * All of these paths live on transport_addr_list.
1406 *
1407 * At the bakeoffs, we discovered that the intent of
1408 * primaryPath is that it only changes when the ULP
1409 * asks to have it changed. We add the activePath to
1410 * designate the connection we are currently using to
1411 * transmit new data and most control chunks.
1412 */
1413 struct sctp_transport *primary_path;
1414
1415 /* Cache the primary path address here, when we
1416 * need a an address for msg_name.
1417 */
1418 union sctp_addr primary_addr;
1419
1420 /* active_path
1421 * The path that we are currently using to
1422 * transmit new data and most control chunks.
1423 */
1424 struct sctp_transport *active_path;
1425
1426 /* retran_path
1427 *
1428 * RFC2960 6.4 Multi-homed SCTP Endpoints
1429 * ...
1430 * Furthermore, when its peer is multi-homed, an
1431 * endpoint SHOULD try to retransmit a chunk to an
1432 * active destination transport address that is
1433 * different from the last destination address to
1434 * which the DATA chunk was sent.
1435 */
1436 struct sctp_transport *retran_path;
1437
1438 /* Pointer to last transport I have sent on. */
1439 struct sctp_transport *last_sent_to;
1440
1441 /* This is the last transport I have received DATA on. */
1442 struct sctp_transport *last_data_from;
1443
1444 /*
1445 * Mapping An array of bits or bytes indicating which out of
1446 * Array order TSN's have been received (relative to the
1447 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1448 * order packets have been received, this array
1449 * will be set to all zero. This structure may be
1450 * in the form of a circular buffer or bit array.
1451 *
1452 * Last Rcvd : This is the last TSN received in
1453 * TSN : sequence. This value is set initially by
1454 * : taking the peer's Initial TSN, received in
1455 * : the INIT or INIT ACK chunk, and subtracting
1456 * : one from it.
1457 *
1458 * Throughout most of the specification this is called the
1459 * "Cumulative TSN ACK Point". In this case, we
1460 * ignore the advice in 12.2 in favour of the term
1461 * used in the bulk of the text. This value is hidden
1462 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1463 */
1464 struct sctp_tsnmap tsn_map;
1465
1466 /* This mask is used to disable sending the ASCONF chunk
1467 * with specified parameter to peer.
1468 */
1469 __be16 addip_disabled_mask;
1470
1471 /* These are capabilities which our peer advertised. */
1472 __u8 ecn_capable:1, /* Can peer do ECN? */
1473 ipv4_address:1, /* Peer understands IPv4 addresses? */
1474 ipv6_address:1, /* Peer understands IPv6 addresses? */
1475 hostname_address:1, /* Peer understands DNS addresses? */
1476 asconf_capable:1, /* Does peer support ADDIP? */
1477 prsctp_capable:1, /* Can peer do PR-SCTP? */
1478 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1479
1480 /* Ack State : This flag indicates if the next received
1481 * : packet is to be responded to with a
1482 * : SACK. This is initializedto 0. When a packet
1483 * : is received it is incremented. If this value
1484 * : reaches 2 or more, a SACK is sent and the
1485 * : value is reset to 0. Note: This is used only
1486 * : when no DATA chunks are received out of
1487 * : order. When DATA chunks are out of order,
1488 * : SACK's are not delayed (see Section 6).
1489 */
1490 __u8 sack_needed; /* Do we need to sack the peer? */
1491 __u32 sack_cnt;
1492 __u32 sack_generation;
1493
1494 __u32 adaptation_ind; /* Adaptation Code point. */
1495
1496 struct sctp_inithdr_host i;
1497 void *cookie;
1498 int cookie_len;
1499
1500 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1501 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1502 * Initial TSN Value minus 1
1503 */
1504 __u32 addip_serial;
1505
1506 /* SCTP-AUTH: We need to know pears random number, hmac list
1507 * and authenticated chunk list. All that is part of the
1508 * cookie and these are just pointers to those locations
1509 */
1510 sctp_random_param_t *peer_random;
1511 sctp_chunks_param_t *peer_chunks;
1512 sctp_hmac_algo_param_t *peer_hmacs;
1513 } peer;
1514
1515 /* State : A state variable indicating what state the
1516 * : association is in, i.e. COOKIE-WAIT,
1517 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1518 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1519 *
1520 * Note: No "CLOSED" state is illustrated since if a
1521 * association is "CLOSED" its TCB SHOULD be removed.
1522 *
1523 * In this implementation we DO have a CLOSED
1524 * state which is used during initiation and shutdown.
1525 *
1526 * State takes values from SCTP_STATE_*.
1527 */
1528 sctp_state_t state;
1529
1530 /* Overall : The overall association error count.
1531 * Error Count : [Clear this any time I get something.]
1532 */
1533 int overall_error_count;
1534
1535 /* The cookie life I award for any cookie. */
1536 ktime_t cookie_life;
1537
1538 /* These are the association's initial, max, and min RTO values.
1539 * These values will be initialized by system defaults, but can
1540 * be modified via the SCTP_RTOINFO socket option.
1541 */
1542 unsigned long rto_initial;
1543 unsigned long rto_max;
1544 unsigned long rto_min;
1545
1546 /* Maximum number of new data packets that can be sent in a burst. */
1547 int max_burst;
1548
1549 /* This is the max_retrans value for the association. This value will
1550 * be initialized initialized from system defaults, but can be
1551 * modified by the SCTP_ASSOCINFO socket option.
1552 */
1553 int max_retrans;
1554
1555 /* This is the partially failed retrans value for the transport
1556 * and will be initialized from the assocs value. This can be
1557 * changed using the SCTP_PEER_ADDR_THLDS socket option
1558 */
1559 int pf_retrans;
1560
1561 /* Maximum number of times the endpoint will retransmit INIT */
1562 __u16 max_init_attempts;
1563
1564 /* How many times have we resent an INIT? */
1565 __u16 init_retries;
1566
1567 /* The largest timeout or RTO value to use in attempting an INIT */
1568 unsigned long max_init_timeo;
1569
1570 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1571 * the destination address every heartbeat interval. This value
1572 * will be inherited by all new transports.
1573 */
1574 unsigned long hbinterval;
1575
1576 /* This is the max_retrans value for new transports in the
1577 * association.
1578 */
1579 __u16 pathmaxrxt;
1580
1581 /* Flag that path mtu update is pending */
1582 __u8 pmtu_pending;
1583
1584 /* Association : The smallest PMTU discovered for all of the
1585 * PMTU : peer's transport addresses.
1586 */
1587 __u32 pathmtu;
1588
1589 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1590 __u32 param_flags;
1591
1592 __u32 sackfreq;
1593 /* SACK delay timeout */
1594 unsigned long sackdelay;
1595
1596 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1597 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1598
1599 /* Transport to which SHUTDOWN chunk was last sent. */
1600 struct sctp_transport *shutdown_last_sent_to;
1601
1602 /* Transport to which INIT chunk was last sent. */
1603 struct sctp_transport *init_last_sent_to;
1604
1605 /* How many times have we resent a SHUTDOWN */
1606 int shutdown_retries;
1607
1608 /* Next TSN : The next TSN number to be assigned to a new
1609 * : DATA chunk. This is sent in the INIT or INIT
1610 * : ACK chunk to the peer and incremented each
1611 * : time a DATA chunk is assigned a TSN
1612 * : (normally just prior to transmit or during
1613 * : fragmentation).
1614 */
1615 __u32 next_tsn;
1616
1617 /*
1618 * Last Rcvd : This is the last TSN received in sequence. This value
1619 * TSN : is set initially by taking the peer's Initial TSN,
1620 * : received in the INIT or INIT ACK chunk, and
1621 * : subtracting one from it.
1622 *
1623 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1624 */
1625
1626 __u32 ctsn_ack_point;
1627
1628 /* PR-SCTP Advanced.Peer.Ack.Point */
1629 __u32 adv_peer_ack_point;
1630
1631 /* Highest TSN that is acknowledged by incoming SACKs. */
1632 __u32 highest_sacked;
1633
1634 /* TSN marking the fast recovery exit point */
1635 __u32 fast_recovery_exit;
1636
1637 /* Flag to track the current fast recovery state */
1638 __u8 fast_recovery;
1639
1640 /* The number of unacknowledged data chunks. Reported through
1641 * the SCTP_STATUS sockopt.
1642 */
1643 __u16 unack_data;
1644
1645 /* The total number of data chunks that we've had to retransmit
1646 * as the result of a T3 timer expiration
1647 */
1648 __u32 rtx_data_chunks;
1649
1650 /* This is the association's receive buffer space. This value is used
1651 * to set a_rwnd field in an INIT or a SACK chunk.
1652 */
1653 __u32 rwnd;
1654
1655 /* This is the last advertised value of rwnd over a SACK chunk. */
1656 __u32 a_rwnd;
1657
1658 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1659 * to slop over a maximum of the association's frag_point.
1660 */
1661 __u32 rwnd_over;
1662
1663 /* Keeps treack of rwnd pressure. This happens when we have
1664 * a window, but not recevie buffer (i.e small packets). This one
1665 * is releases slowly (1 PMTU at a time ).
1666 */
1667 __u32 rwnd_press;
1668
1669 /* This is the sndbuf size in use for the association.
1670 * This corresponds to the sndbuf size for the association,
1671 * as specified in the sk->sndbuf.
1672 */
1673 int sndbuf_used;
1674
1675 /* This is the amount of memory that this association has allocated
1676 * in the receive path at any given time.
1677 */
1678 atomic_t rmem_alloc;
1679
1680 /* This is the wait queue head for send requests waiting on
1681 * the association sndbuf space.
1682 */
1683 wait_queue_head_t wait;
1684
1685 /* The message size at which SCTP fragmentation will occur. */
1686 __u32 frag_point;
1687 __u32 user_frag;
1688
1689 /* Counter used to count INIT errors. */
1690 int init_err_counter;
1691
1692 /* Count the number of INIT cycles (for doubling timeout). */
1693 int init_cycle;
1694
1695 /* Default send parameters. */
1696 __u16 default_stream;
1697 __u16 default_flags;
1698 __u32 default_ppid;
1699 __u32 default_context;
1700 __u32 default_timetolive;
1701
1702 /* Default receive parameters */
1703 __u32 default_rcv_context;
1704
1705 /* This tracks outbound ssn for a given stream. */
1706 struct sctp_ssnmap *ssnmap;
1707
1708 /* All outbound chunks go through this structure. */
1709 struct sctp_outq outqueue;
1710
1711 /* A smart pipe that will handle reordering and fragmentation,
1712 * as well as handle passing events up to the ULP.
1713 */
1714 struct sctp_ulpq ulpq;
1715
1716 /* Last TSN that caused an ECNE Chunk to be sent. */
1717 __u32 last_ecne_tsn;
1718
1719 /* Last TSN that caused a CWR Chunk to be sent. */
1720 __u32 last_cwr_tsn;
1721
1722 /* How many duplicated TSNs have we seen? */
1723 int numduptsns;
1724
1725 /* These are to support
1726 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1727 * and Enforcement of Flow and Message Limits"
1728 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1729 * or "ADDIP" for short.
1730 */
1731
1732
1733
1734 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1735 *
1736 * R1) One and only one ASCONF Chunk MAY be in transit and
1737 * unacknowledged at any one time. If a sender, after sending
1738 * an ASCONF chunk, decides it needs to transfer another
1739 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1740 * returns from the previous ASCONF Chunk before sending a
1741 * subsequent ASCONF. Note this restriction binds each side,
1742 * so at any time two ASCONF may be in-transit on any given
1743 * association (one sent from each endpoint).
1744 *
1745 * [This is our one-and-only-one ASCONF in flight. If we do
1746 * not have an ASCONF in flight, this is NULL.]
1747 */
1748 struct sctp_chunk *addip_last_asconf;
1749
1750 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1751 *
1752 * This is needed to implement itmes E1 - E4 of the updated
1753 * spec. Here is the justification:
1754 *
1755 * Since the peer may bundle multiple ASCONF chunks toward us,
1756 * we now need the ability to cache multiple ACKs. The section
1757 * describes in detail how they are cached and cleaned up.
1758 */
1759 struct list_head asconf_ack_list;
1760
1761 /* These ASCONF chunks are waiting to be sent.
1762 *
1763 * These chunaks can't be pushed to outqueue until receiving
1764 * ASCONF_ACK for the previous ASCONF indicated by
1765 * addip_last_asconf, so as to guarantee that only one ASCONF
1766 * is in flight at any time.
1767 *
1768 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1769 *
1770 * In defining the ASCONF Chunk transfer procedures, it is
1771 * essential that these transfers MUST NOT cause congestion
1772 * within the network. To achieve this, we place these
1773 * restrictions on the transfer of ASCONF Chunks:
1774 *
1775 * R1) One and only one ASCONF Chunk MAY be in transit and
1776 * unacknowledged at any one time. If a sender, after sending
1777 * an ASCONF chunk, decides it needs to transfer another
1778 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1779 * returns from the previous ASCONF Chunk before sending a
1780 * subsequent ASCONF. Note this restriction binds each side,
1781 * so at any time two ASCONF may be in-transit on any given
1782 * association (one sent from each endpoint).
1783 *
1784 *
1785 * [I really think this is EXACTLY the sort of intelligence
1786 * which already resides in sctp_outq. Please move this
1787 * queue and its supporting logic down there. --piggy]
1788 */
1789 struct list_head addip_chunk_list;
1790
1791 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1792 *
1793 * A2) A serial number should be assigned to the Chunk. The
1794 * serial number SHOULD be a monotonically increasing
1795 * number. The serial number SHOULD be initialized at
1796 * the start of the association to the same value as the
1797 * Initial TSN and every time a new ASCONF chunk is created
1798 * it is incremented by one after assigning the serial number
1799 * to the newly created chunk.
1800 *
1801 * ADDIP
1802 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1803 *
1804 * Serial Number : 32 bits (unsigned integer)
1805 *
1806 * This value represents a Serial Number for the ASCONF
1807 * Chunk. The valid range of Serial Number is from 0 to
1808 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1809 * after reaching 4294967295.
1810 */
1811 __u32 addip_serial;
1812 int src_out_of_asoc_ok;
1813 union sctp_addr *asconf_addr_del_pending;
1814 struct sctp_transport *new_transport;
1815
1816 /* SCTP AUTH: list of the endpoint shared keys. These
1817 * keys are provided out of band by the user applicaton
1818 * and can't change during the lifetime of the association
1819 */
1820 struct list_head endpoint_shared_keys;
1821
1822 /* SCTP AUTH:
1823 * The current generated assocaition shared key (secret)
1824 */
1825 struct sctp_auth_bytes *asoc_shared_key;
1826
1827 /* SCTP AUTH: hmac id of the first peer requested algorithm
1828 * that we support.
1829 */
1830 __u16 default_hmac_id;
1831
1832 __u16 active_key_id;
1833
1834 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1835 temp:1; /* Is it a temporary association? */
1836
1837 struct sctp_priv_assoc_stats stats;
1838};
1839
1840
1841/* An eyecatcher for determining if we are really looking at an
1842 * association data structure.
1843 */
1844enum {
1845 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1846};
1847
1848/* Recover the outter association structure. */
1849static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1850{
1851 struct sctp_association *asoc;
1852
1853 asoc = container_of(base, struct sctp_association, base);
1854 return asoc;
1855}
1856
1857/* These are function signatures for manipulating associations. */
1858
1859
1860struct sctp_association *
1861sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1862 sctp_scope_t scope, gfp_t gfp);
1863void sctp_association_free(struct sctp_association *);
1864void sctp_association_put(struct sctp_association *);
1865void sctp_association_hold(struct sctp_association *);
1866
1867struct sctp_transport *sctp_assoc_choose_alter_transport(
1868 struct sctp_association *, struct sctp_transport *);
1869void sctp_assoc_update_retran_path(struct sctp_association *);
1870struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1871 const union sctp_addr *);
1872int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1873 const union sctp_addr *laddr);
1874struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1875 const union sctp_addr *address,
1876 const gfp_t gfp,
1877 const int peer_state);
1878void sctp_assoc_del_peer(struct sctp_association *asoc,
1879 const union sctp_addr *addr);
1880void sctp_assoc_rm_peer(struct sctp_association *asoc,
1881 struct sctp_transport *peer);
1882void sctp_assoc_control_transport(struct sctp_association *,
1883 struct sctp_transport *,
1884 sctp_transport_cmd_t, sctp_sn_error_t);
1885struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1886struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1887 struct net *,
1888 const union sctp_addr *,
1889 const union sctp_addr *);
1890void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1891void sctp_assoc_update(struct sctp_association *old,
1892 struct sctp_association *new);
1893
1894__u32 sctp_association_get_next_tsn(struct sctp_association *);
1895
1896void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1897void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1898void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1899void sctp_assoc_set_primary(struct sctp_association *,
1900 struct sctp_transport *);
1901void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1902 struct sctp_transport *);
1903int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1904 sctp_scope_t, gfp_t);
1905int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1906 struct sctp_cookie*,
1907 gfp_t gfp);
1908int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1909void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1910struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1911 const struct sctp_association *asoc,
1912 __be32 serial);
1913void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1914
1915int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1916 const union sctp_addr *ss2);
1917struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1918
1919/* A convenience structure to parse out SCTP specific CMSGs. */
1920typedef struct sctp_cmsgs {
1921 struct sctp_initmsg *init;
1922 struct sctp_sndrcvinfo *info;
1923} sctp_cmsgs_t;
1924
1925/* Structure for tracking memory objects */
1926typedef struct {
1927 char *label;
1928 atomic_t *counter;
1929} sctp_dbg_objcnt_entry_t;
1930
1931#endif /* __sctp_structs_h__ */
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.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
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)
13 * any later version.
14 *
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.
20 *
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/>.
24 *
25 * Please send any bug reports or fixes you make to the
26 * email addresses:
27 * lksctp developers <linux-sctp@vger.kernel.org>
28 *
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>
45 */
46
47#ifndef __sctp_structs_h__
48#define __sctp_structs_h__
49
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
63/* A convenience structure for handling sockaddr structures.
64 * We should wean ourselves off this.
65 */
66union sctp_addr {
67 struct sockaddr_in v4;
68 struct sockaddr_in6 v6;
69 struct sockaddr sa;
70};
71
72/* Forward declarations for data structures. */
73struct sctp_globals;
74struct sctp_endpoint;
75struct sctp_association;
76struct sctp_transport;
77struct sctp_packet;
78struct sctp_chunk;
79struct sctp_inq;
80struct sctp_outq;
81struct sctp_bind_addr;
82struct sctp_ulpq;
83struct sctp_ep_common;
84struct sctp_ssnmap;
85struct crypto_shash;
86
87
88#include <net/sctp/tsnmap.h>
89#include <net/sctp/ulpevent.h>
90#include <net/sctp/ulpqueue.h>
91
92/* Structures useful for managing bind/connect. */
93
94struct sctp_bind_bucket {
95 unsigned short port;
96 unsigned short fastreuse;
97 struct hlist_node node;
98 struct hlist_head owner;
99 struct net *net;
100};
101
102struct sctp_bind_hashbucket {
103 spinlock_t lock;
104 struct hlist_head chain;
105};
106
107/* Used for hashing all associations. */
108struct sctp_hashbucket {
109 rwlock_t lock;
110 struct hlist_head chain;
111} __attribute__((__aligned__(8)));
112
113
114/* The SCTP globals structure. */
115extern struct sctp_globals {
116 /* This is a list of groups of functions for each address
117 * family that we support.
118 */
119 struct list_head address_families;
120
121 /* This is the hash of all endpoints. */
122 struct sctp_hashbucket *ep_hashtable;
123 /* This is the sctp port control hash. */
124 struct sctp_bind_hashbucket *port_hashtable;
125 /* This is the hash of all transports. */
126 struct rhashtable transport_hashtable;
127
128 /* Sizes of above hashtables. */
129 int ep_hashsize;
130 int port_hashsize;
131
132 /* Default initialization values to be applied to new associations. */
133 __u16 max_instreams;
134 __u16 max_outstreams;
135
136 /* Flag to indicate whether computing and verifying checksum
137 * is disabled. */
138 bool checksum_disable;
139} sctp_globals;
140
141#define sctp_max_instreams (sctp_globals.max_instreams)
142#define sctp_max_outstreams (sctp_globals.max_outstreams)
143#define sctp_address_families (sctp_globals.address_families)
144#define sctp_ep_hashsize (sctp_globals.ep_hashsize)
145#define sctp_ep_hashtable (sctp_globals.ep_hashtable)
146#define sctp_port_hashsize (sctp_globals.port_hashsize)
147#define sctp_port_hashtable (sctp_globals.port_hashtable)
148#define sctp_transport_hashtable (sctp_globals.transport_hashtable)
149#define sctp_checksum_disable (sctp_globals.checksum_disable)
150
151/* SCTP Socket type: UDP or TCP style. */
152typedef enum {
153 SCTP_SOCKET_UDP = 0,
154 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
155 SCTP_SOCKET_TCP
156} sctp_socket_type_t;
157
158/* Per socket SCTP information. */
159struct sctp_sock {
160 /* inet_sock has to be the first member of sctp_sock */
161 struct inet_sock inet;
162 /* What kind of a socket is this? */
163 sctp_socket_type_t type;
164
165 /* PF_ family specific functions. */
166 struct sctp_pf *pf;
167
168 /* Access to HMAC transform. */
169 struct crypto_shash *hmac;
170 char *sctp_hmac_alg;
171
172 /* What is our base endpointer? */
173 struct sctp_endpoint *ep;
174
175 struct sctp_bind_bucket *bind_hash;
176 /* Various Socket Options. */
177 __u16 default_stream;
178 __u32 default_ppid;
179 __u16 default_flags;
180 __u32 default_context;
181 __u32 default_timetolive;
182 __u32 default_rcv_context;
183 int max_burst;
184
185 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
186 * the destination address every heartbeat interval. This value
187 * will be inherited by all new associations.
188 */
189 __u32 hbinterval;
190
191 /* This is the max_retrans value for new associations. */
192 __u16 pathmaxrxt;
193
194 /* The initial Path MTU to use for new associations. */
195 __u32 pathmtu;
196
197 /* The default SACK delay timeout for new associations. */
198 __u32 sackdelay;
199 __u32 sackfreq;
200
201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
202 __u32 param_flags;
203
204 struct sctp_initmsg initmsg;
205 struct sctp_rtoinfo rtoinfo;
206 struct sctp_paddrparams paddrparam;
207 struct sctp_event_subscribe subscribe;
208 struct sctp_assocparams assocparams;
209
210 int user_frag;
211
212 __u32 autoclose;
213 __u8 nodelay;
214 __u8 disable_fragments;
215 __u8 v4mapped;
216 __u8 frag_interleave;
217 __u32 adaptation_ind;
218 __u32 pd_point;
219 __u8 recvrcvinfo;
220 __u8 recvnxtinfo;
221
222 atomic_t pd_mode;
223 /* Receive to here while partial delivery is in effect. */
224 struct sk_buff_head pd_lobby;
225
226 /* These must be the last fields, as they will skipped on copies,
227 * like on accept and peeloff operations
228 */
229 struct list_head auto_asconf_list;
230 int do_auto_asconf;
231};
232
233static inline struct sctp_sock *sctp_sk(const struct sock *sk)
234{
235 return (struct sctp_sock *)sk;
236}
237
238static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
239{
240 return (struct sock *)sp;
241}
242
243#if IS_ENABLED(CONFIG_IPV6)
244struct sctp6_sock {
245 struct sctp_sock sctp;
246 struct ipv6_pinfo inet6;
247};
248#endif /* CONFIG_IPV6 */
249
250
251/* This is our APPLICATION-SPECIFIC state cookie.
252 * THIS IS NOT DICTATED BY THE SPECIFICATION.
253 */
254/* These are the parts of an association which we send in the cookie.
255 * Most of these are straight out of:
256 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
257 *
258 */
259
260struct sctp_cookie {
261
262 /* My : Tag expected in every inbound packet and sent
263 * Verification: in the INIT or INIT ACK chunk.
264 * Tag :
265 */
266 __u32 my_vtag;
267
268 /* Peer's : Tag expected in every outbound packet except
269 * Verification: in the INIT chunk.
270 * Tag :
271 */
272 __u32 peer_vtag;
273
274 /* The rest of these are not from the spec, but really need to
275 * be in the cookie.
276 */
277
278 /* My Tie Tag : Assist in discovering a restarting association. */
279 __u32 my_ttag;
280
281 /* Peer's Tie Tag: Assist in discovering a restarting association. */
282 __u32 peer_ttag;
283
284 /* When does this cookie expire? */
285 ktime_t expiration;
286
287 /* Number of inbound/outbound streams which are set
288 * and negotiated during the INIT process.
289 */
290 __u16 sinit_num_ostreams;
291 __u16 sinit_max_instreams;
292
293 /* This is the first sequence number I used. */
294 __u32 initial_tsn;
295
296 /* This holds the originating address of the INIT packet. */
297 union sctp_addr peer_addr;
298
299 /* IG Section 2.35.3
300 * Include the source port of the INIT-ACK
301 */
302 __u16 my_port;
303
304 __u8 prsctp_capable;
305
306 /* Padding for future use */
307 __u8 padding;
308
309 __u32 adaptation_ind;
310
311 __u8 auth_random[sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH];
312 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
313 __u8 auth_chunks[sizeof(sctp_paramhdr_t) + SCTP_AUTH_MAX_CHUNKS];
314
315 /* This is a shim for my peer's INIT packet, followed by
316 * a copy of the raw address list of the association.
317 * The length of the raw address list is saved in the
318 * raw_addr_list_len field, which will be used at the time when
319 * the association TCB is re-constructed from the cookie.
320 */
321 __u32 raw_addr_list_len;
322 struct sctp_init_chunk peer_init[0];
323};
324
325
326/* The format of our cookie that we send to our peer. */
327struct sctp_signed_cookie {
328 __u8 signature[SCTP_SECRET_SIZE];
329 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
330 struct sctp_cookie c;
331} __packed;
332
333/* This is another convenience type to allocate memory for address
334 * params for the maximum size and pass such structures around
335 * internally.
336 */
337union sctp_addr_param {
338 struct sctp_paramhdr p;
339 struct sctp_ipv4addr_param v4;
340 struct sctp_ipv6addr_param v6;
341};
342
343/* A convenience type to allow walking through the various
344 * parameters and avoid casting all over the place.
345 */
346union sctp_params {
347 void *v;
348 struct sctp_paramhdr *p;
349 struct sctp_cookie_preserve_param *life;
350 struct sctp_hostname_param *dns;
351 struct sctp_cookie_param *cookie;
352 struct sctp_supported_addrs_param *sat;
353 struct sctp_ipv4addr_param *v4;
354 struct sctp_ipv6addr_param *v6;
355 union sctp_addr_param *addr;
356 struct sctp_adaptation_ind_param *aind;
357 struct sctp_supported_ext_param *ext;
358 struct sctp_random_param *random;
359 struct sctp_chunks_param *chunks;
360 struct sctp_hmac_algo_param *hmac_algo;
361 struct sctp_addip_param *addip;
362};
363
364/* RFC 2960. Section 3.3.5 Heartbeat.
365 * Heartbeat Information: variable length
366 * The Sender-specific Heartbeat Info field should normally include
367 * information about the sender's current time when this HEARTBEAT
368 * chunk is sent and the destination transport address to which this
369 * HEARTBEAT is sent (see Section 8.3).
370 */
371typedef struct sctp_sender_hb_info {
372 struct sctp_paramhdr param_hdr;
373 union sctp_addr daddr;
374 unsigned long sent_at;
375 __u64 hb_nonce;
376} __packed sctp_sender_hb_info_t;
377
378/*
379 * RFC 2960 1.3.2 Sequenced Delivery within Streams
380 *
381 * The term "stream" is used in SCTP to refer to a sequence of user
382 * messages that are to be delivered to the upper-layer protocol in
383 * order with respect to other messages within the same stream. This is
384 * in contrast to its usage in TCP, where it refers to a sequence of
385 * bytes (in this document a byte is assumed to be eight bits).
386 * ...
387 *
388 * This is the structure we use to track both our outbound and inbound
389 * SSN, or Stream Sequence Numbers.
390 */
391
392struct sctp_stream {
393 __u16 *ssn;
394 unsigned int len;
395};
396
397struct sctp_ssnmap {
398 struct sctp_stream in;
399 struct sctp_stream out;
400};
401
402struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
403 gfp_t gfp);
404void sctp_ssnmap_free(struct sctp_ssnmap *map);
405void sctp_ssnmap_clear(struct sctp_ssnmap *map);
406
407/* What is the current SSN number for this stream? */
408static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
409{
410 return stream->ssn[id];
411}
412
413/* Return the next SSN number for this stream. */
414static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
415{
416 return stream->ssn[id]++;
417}
418
419/* Skip over this ssn and all below. */
420static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
421 __u16 ssn)
422{
423 stream->ssn[id] = ssn+1;
424}
425
426/*
427 * Pointers to address related SCTP functions.
428 * (i.e. things that depend on the address family.)
429 */
430struct sctp_af {
431 int (*sctp_xmit) (struct sk_buff *skb,
432 struct sctp_transport *);
433 int (*setsockopt) (struct sock *sk,
434 int level,
435 int optname,
436 char __user *optval,
437 unsigned int optlen);
438 int (*getsockopt) (struct sock *sk,
439 int level,
440 int optname,
441 char __user *optval,
442 int __user *optlen);
443 int (*compat_setsockopt) (struct sock *sk,
444 int level,
445 int optname,
446 char __user *optval,
447 unsigned int optlen);
448 int (*compat_getsockopt) (struct sock *sk,
449 int level,
450 int optname,
451 char __user *optval,
452 int __user *optlen);
453 void (*get_dst) (struct sctp_transport *t,
454 union sctp_addr *saddr,
455 struct flowi *fl,
456 struct sock *sk);
457 void (*get_saddr) (struct sctp_sock *sk,
458 struct sctp_transport *t,
459 struct flowi *fl);
460 void (*copy_addrlist) (struct list_head *,
461 struct net_device *);
462 int (*cmp_addr) (const union sctp_addr *addr1,
463 const union sctp_addr *addr2);
464 void (*addr_copy) (union sctp_addr *dst,
465 union sctp_addr *src);
466 void (*from_skb) (union sctp_addr *,
467 struct sk_buff *skb,
468 int saddr);
469 void (*from_sk) (union sctp_addr *,
470 struct sock *sk);
471 void (*from_addr_param) (union sctp_addr *,
472 union sctp_addr_param *,
473 __be16 port, int iif);
474 int (*to_addr_param) (const union sctp_addr *,
475 union sctp_addr_param *);
476 int (*addr_valid) (union sctp_addr *,
477 struct sctp_sock *,
478 const struct sk_buff *);
479 sctp_scope_t (*scope) (union sctp_addr *);
480 void (*inaddr_any) (union sctp_addr *, __be16);
481 int (*is_any) (const union sctp_addr *);
482 int (*available) (union sctp_addr *,
483 struct sctp_sock *);
484 int (*skb_iif) (const struct sk_buff *sk);
485 int (*is_ce) (const struct sk_buff *sk);
486 void (*seq_dump_addr)(struct seq_file *seq,
487 union sctp_addr *addr);
488 void (*ecn_capable)(struct sock *sk);
489 __u16 net_header_len;
490 int sockaddr_len;
491 sa_family_t sa_family;
492 struct list_head list;
493};
494
495struct sctp_af *sctp_get_af_specific(sa_family_t);
496int sctp_register_af(struct sctp_af *);
497
498/* Protocol family functions. */
499struct sctp_pf {
500 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
501 void (*skb_msgname) (struct sk_buff *, char *, int *);
502 int (*af_supported) (sa_family_t, struct sctp_sock *);
503 int (*cmp_addr) (const union sctp_addr *,
504 const union sctp_addr *,
505 struct sctp_sock *);
506 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
507 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
508 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
509 struct sock *(*create_accept_sk) (struct sock *sk,
510 struct sctp_association *asoc);
511 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
512 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
513 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
514 struct sctp_af *af;
515};
516
517
518/* Structure to track chunk fragments that have been acked, but peer
519 * fragments of the same message have not.
520 */
521struct sctp_datamsg {
522 /* Chunks waiting to be submitted to lower layer. */
523 struct list_head chunks;
524 /* Reference counting. */
525 atomic_t refcnt;
526 /* When is this message no longer interesting to the peer? */
527 unsigned long expires_at;
528 /* Did the messenge fail to send? */
529 int send_error;
530 u8 send_failed:1,
531 can_abandon:1, /* can chunks from this message can be abandoned. */
532 can_delay; /* should this message be Nagle delayed */
533};
534
535struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
536 struct sctp_sndrcvinfo *,
537 struct iov_iter *);
538void sctp_datamsg_put(struct sctp_datamsg *);
539void sctp_chunk_fail(struct sctp_chunk *, int error);
540int sctp_chunk_abandoned(struct sctp_chunk *);
541
542/* RFC2960 1.4 Key Terms
543 *
544 * o Chunk: A unit of information within an SCTP packet, consisting of
545 * a chunk header and chunk-specific content.
546 *
547 * As a matter of convenience, we remember the SCTP common header for
548 * each chunk as well as a few other header pointers...
549 */
550struct sctp_chunk {
551 struct list_head list;
552
553 atomic_t refcnt;
554
555 /* This is our link to the per-transport transmitted list. */
556 struct list_head transmitted_list;
557
558 /* This field is used by chunks that hold fragmented data.
559 * For the first fragment this is the list that holds the rest of
560 * fragments. For the remaining fragments, this is the link to the
561 * frag_list maintained in the first fragment.
562 */
563 struct list_head frag_list;
564
565 /* This points to the sk_buff containing the actual data. */
566 struct sk_buff *skb;
567
568 /* These are the SCTP headers by reverse order in a packet.
569 * Note that some of these may happen more than once. In that
570 * case, we point at the "current" one, whatever that means
571 * for that level of header.
572 */
573
574 /* We point this at the FIRST TLV parameter to chunk_hdr. */
575 union sctp_params param_hdr;
576 union {
577 __u8 *v;
578 struct sctp_datahdr *data_hdr;
579 struct sctp_inithdr *init_hdr;
580 struct sctp_sackhdr *sack_hdr;
581 struct sctp_heartbeathdr *hb_hdr;
582 struct sctp_sender_hb_info *hbs_hdr;
583 struct sctp_shutdownhdr *shutdown_hdr;
584 struct sctp_signed_cookie *cookie_hdr;
585 struct sctp_ecnehdr *ecne_hdr;
586 struct sctp_cwrhdr *ecn_cwr_hdr;
587 struct sctp_errhdr *err_hdr;
588 struct sctp_addiphdr *addip_hdr;
589 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
590 struct sctp_authhdr *auth_hdr;
591 } subh;
592
593 __u8 *chunk_end;
594
595 struct sctp_chunkhdr *chunk_hdr;
596 struct sctphdr *sctp_hdr;
597
598 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
599 struct sctp_sndrcvinfo sinfo;
600
601 /* Which association does this belong to? */
602 struct sctp_association *asoc;
603
604 /* What endpoint received this chunk? */
605 struct sctp_ep_common *rcvr;
606
607 /* We fill this in if we are calculating RTT. */
608 unsigned long sent_at;
609
610 /* What is the origin IP address for this chunk? */
611 union sctp_addr source;
612 /* Destination address for this chunk. */
613 union sctp_addr dest;
614
615 /* For outbound message, track all fragments for SEND_FAILED. */
616 struct sctp_datamsg *msg;
617
618 /* For an inbound chunk, this tells us where it came from.
619 * For an outbound chunk, it tells us where we'd like it to
620 * go. It is NULL if we have no preference.
621 */
622 struct sctp_transport *transport;
623
624 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
625 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
626 * spec violates the principle premis that all chunks are processed
627 * in order.
628 */
629 struct sk_buff *auth_chunk;
630
631#define SCTP_CAN_FRTX 0x0
632#define SCTP_NEED_FRTX 0x1
633#define SCTP_DONT_FRTX 0x2
634 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
635 resent:1, /* Has this chunk ever been resent. */
636 has_tsn:1, /* Does this chunk have a TSN yet? */
637 has_ssn:1, /* Does this chunk have a SSN yet? */
638 singleton:1, /* Only chunk in the packet? */
639 end_of_packet:1, /* Last chunk in the packet? */
640 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
641 pdiscard:1, /* Discard the whole packet now? */
642 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
643 data_accepted:1, /* At least 1 chunk accepted */
644 auth:1, /* IN: was auth'ed | OUT: needs auth */
645 has_asconf:1, /* IN: have seen an asconf before */
646 tsn_missing_report:2, /* Data chunk missing counter. */
647 fast_retransmit:2; /* Is this chunk fast retransmitted? */
648};
649
650void sctp_chunk_hold(struct sctp_chunk *);
651void sctp_chunk_put(struct sctp_chunk *);
652int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
653 struct iov_iter *from);
654void sctp_chunk_free(struct sctp_chunk *);
655void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
656struct sctp_chunk *sctp_chunkify(struct sk_buff *,
657 const struct sctp_association *,
658 struct sock *, gfp_t gfp);
659void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
660 union sctp_addr *);
661const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
662
663enum {
664 SCTP_ADDR_NEW, /* new address added to assoc/ep */
665 SCTP_ADDR_SRC, /* address can be used as source */
666 SCTP_ADDR_DEL, /* address about to be deleted */
667};
668
669/* This is a structure for holding either an IPv6 or an IPv4 address. */
670struct sctp_sockaddr_entry {
671 struct list_head list;
672 struct rcu_head rcu;
673 union sctp_addr a;
674 __u8 state;
675 __u8 valid;
676};
677
678#define SCTP_ADDRESS_TICK_DELAY 500
679
680typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
681
682/* This structure holds lists of chunks as we are assembling for
683 * transmission.
684 */
685struct sctp_packet {
686 /* These are the SCTP header values (host order) for the packet. */
687 __u16 source_port;
688 __u16 destination_port;
689 __u32 vtag;
690
691 /* This contains the payload chunks. */
692 struct list_head chunk_list;
693
694 /* This is the overhead of the sctp and ip headers. */
695 size_t overhead;
696 /* This is the total size of all chunks INCLUDING padding. */
697 size_t size;
698
699 /* The packet is destined for this transport address.
700 * The function we finally use to pass down to the next lower
701 * layer lives in the transport structure.
702 */
703 struct sctp_transport *transport;
704
705 /* pointer to the auth chunk for this packet */
706 struct sctp_chunk *auth;
707
708 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
709 has_sack:1, /* This packet contains a SACK chunk. */
710 has_auth:1, /* This packet contains an AUTH chunk */
711 has_data:1, /* This packet contains at least 1 DATA chunk */
712 ipfragok:1; /* So let ip fragment this packet */
713};
714
715struct sctp_packet *sctp_packet_init(struct sctp_packet *,
716 struct sctp_transport *,
717 __u16 sport, __u16 dport);
718struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
719sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *,
720 struct sctp_chunk *, int, gfp_t);
721sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *,
722 struct sctp_chunk *);
723int sctp_packet_transmit(struct sctp_packet *, gfp_t);
724void sctp_packet_free(struct sctp_packet *);
725
726static inline int sctp_packet_empty(struct sctp_packet *packet)
727{
728 return packet->size == packet->overhead;
729}
730
731/* This represents a remote transport address.
732 * For local transport addresses, we just use union sctp_addr.
733 *
734 * RFC2960 Section 1.4 Key Terms
735 *
736 * o Transport address: A Transport Address is traditionally defined
737 * by Network Layer address, Transport Layer protocol and Transport
738 * Layer port number. In the case of SCTP running over IP, a
739 * transport address is defined by the combination of an IP address
740 * and an SCTP port number (where SCTP is the Transport protocol).
741 *
742 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
743 *
744 * o The sender keeps a separate congestion control parameter set for
745 * each of the destination addresses it can send to (not each
746 * source-destination pair but for each destination). The parameters
747 * should decay if the address is not used for a long enough time
748 * period.
749 *
750 */
751struct sctp_transport {
752 /* A list of transports. */
753 struct list_head transports;
754 struct rhash_head node;
755
756 /* Reference counting. */
757 atomic_t refcnt;
758 /* RTO-Pending : A flag used to track if one of the DATA
759 * chunks sent to this address is currently being
760 * used to compute a RTT. If this flag is 0,
761 * the next DATA chunk sent to this destination
762 * should be used to compute a RTT and this flag
763 * should be set. Every time the RTT
764 * calculation completes (i.e. the DATA chunk
765 * is SACK'd) clear this flag.
766 */
767 __u32 rto_pending:1,
768
769 /*
770 * hb_sent : a flag that signals that we have a pending
771 * heartbeat.
772 */
773 hb_sent:1,
774
775 /* Is the Path MTU update pending on this tranport */
776 pmtu_pending:1,
777
778 /* Has this transport moved the ctsn since we last sacked */
779 sack_generation:1;
780 u32 dst_cookie;
781
782 struct flowi fl;
783
784 /* This is the peer's IP address and port. */
785 union sctp_addr ipaddr;
786
787 /* These are the functions we call to handle LLP stuff. */
788 struct sctp_af *af_specific;
789
790 /* Which association do we belong to? */
791 struct sctp_association *asoc;
792
793 /* RFC2960
794 *
795 * 12.3 Per Transport Address Data
796 *
797 * For each destination transport address in the peer's
798 * address list derived from the INIT or INIT ACK chunk, a
799 * number of data elements needs to be maintained including:
800 */
801 /* RTO : The current retransmission timeout value. */
802 unsigned long rto;
803
804 __u32 rtt; /* This is the most recent RTT. */
805
806 /* RTTVAR : The current RTT variation. */
807 __u32 rttvar;
808
809 /* SRTT : The current smoothed round trip time. */
810 __u32 srtt;
811
812 /*
813 * These are the congestion stats.
814 */
815 /* cwnd : The current congestion window. */
816 __u32 cwnd; /* This is the actual cwnd. */
817
818 /* ssthresh : The current slow start threshold value. */
819 __u32 ssthresh;
820
821 /* partial : The tracking method for increase of cwnd when in
822 * bytes acked : congestion avoidance mode (see Section 6.2.2)
823 */
824 __u32 partial_bytes_acked;
825
826 /* Data that has been sent, but not acknowledged. */
827 __u32 flight_size;
828
829 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
830
831 /* Destination */
832 struct dst_entry *dst;
833 /* Source address. */
834 union sctp_addr saddr;
835
836 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
837 * the destination address every heartbeat interval.
838 */
839 unsigned long hbinterval;
840
841 /* SACK delay timeout */
842 unsigned long sackdelay;
843 __u32 sackfreq;
844
845 /* When was the last time that we heard from this transport? We use
846 * this to pick new active and retran paths.
847 */
848 ktime_t last_time_heard;
849
850 /* When was the last time that we sent a chunk using this
851 * transport? We use this to check for idle transports
852 */
853 unsigned long last_time_sent;
854
855 /* Last time(in jiffies) when cwnd is reduced due to the congestion
856 * indication based on ECNE chunk.
857 */
858 unsigned long last_time_ecne_reduced;
859
860 /* This is the max_retrans value for the transport and will
861 * be initialized from the assocs value. This can be changed
862 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
863 */
864 __u16 pathmaxrxt;
865
866 /* This is the partially failed retrans value for the transport
867 * and will be initialized from the assocs value. This can be changed
868 * using the SCTP_PEER_ADDR_THLDS socket option
869 */
870 int pf_retrans;
871 /* PMTU : The current known path MTU. */
872 __u32 pathmtu;
873
874 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
875 __u32 param_flags;
876
877 /* The number of times INIT has been sent on this transport. */
878 int init_sent_count;
879
880 /* state : The current state of this destination,
881 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
882 */
883 int state;
884
885 /* These are the error stats for this destination. */
886
887 /* Error count : The current error count for this destination. */
888 unsigned short error_count;
889
890 /* Per : A timer used by each destination.
891 * Destination :
892 * Timer :
893 *
894 * [Everywhere else in the text this is called T3-rtx. -ed]
895 */
896 struct timer_list T3_rtx_timer;
897
898 /* Heartbeat timer is per destination. */
899 struct timer_list hb_timer;
900
901 /* Timer to handle ICMP proto unreachable envets */
902 struct timer_list proto_unreach_timer;
903
904 /* Since we're using per-destination retransmission timers
905 * (see above), we're also using per-destination "transmitted"
906 * queues. This probably ought to be a private struct
907 * accessible only within the outqueue, but it's not, yet.
908 */
909 struct list_head transmitted;
910
911 /* We build bundle-able packets for this transport here. */
912 struct sctp_packet packet;
913
914 /* This is the list of transports that have chunks to send. */
915 struct list_head send_ready;
916
917 /* State information saved for SFR_CACC algorithm. The key
918 * idea in SFR_CACC is to maintain state at the sender on a
919 * per-destination basis when a changeover happens.
920 * char changeover_active;
921 * char cycling_changeover;
922 * __u32 next_tsn_at_change;
923 * char cacc_saw_newack;
924 */
925 struct {
926 /* An unsigned integer, which stores the next TSN to be
927 * used by the sender, at the moment of changeover.
928 */
929 __u32 next_tsn_at_change;
930
931 /* A flag which indicates the occurrence of a changeover */
932 char changeover_active;
933
934 /* A flag which indicates whether the change of primary is
935 * the first switch to this destination address during an
936 * active switch.
937 */
938 char cycling_changeover;
939
940 /* A temporary flag, which is used during the processing of
941 * a SACK to estimate the causative TSN(s)'s group.
942 */
943 char cacc_saw_newack;
944 } cacc;
945
946 /* 64-bit random number sent with heartbeat. */
947 __u64 hb_nonce;
948
949 struct rcu_head rcu;
950};
951
952struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
953 gfp_t);
954void sctp_transport_set_owner(struct sctp_transport *,
955 struct sctp_association *);
956void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
957 struct sctp_sock *);
958void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
959void sctp_transport_free(struct sctp_transport *);
960void sctp_transport_reset_t3_rtx(struct sctp_transport *);
961void sctp_transport_reset_hb_timer(struct sctp_transport *);
962int sctp_transport_hold(struct sctp_transport *);
963void sctp_transport_put(struct sctp_transport *);
964void sctp_transport_update_rto(struct sctp_transport *, __u32);
965void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
966void sctp_transport_lower_cwnd(struct sctp_transport *, sctp_lower_cwnd_t);
967void sctp_transport_burst_limited(struct sctp_transport *);
968void sctp_transport_burst_reset(struct sctp_transport *);
969unsigned long sctp_transport_timeout(struct sctp_transport *);
970void sctp_transport_reset(struct sctp_transport *);
971void sctp_transport_update_pmtu(struct sock *, struct sctp_transport *, u32);
972void sctp_transport_immediate_rtx(struct sctp_transport *);
973
974
975/* This is the structure we use to queue packets as they come into
976 * SCTP. We write packets to it and read chunks from it.
977 */
978struct sctp_inq {
979 /* This is actually a queue of sctp_chunk each
980 * containing a partially decoded packet.
981 */
982 struct list_head in_chunk_list;
983 /* This is the packet which is currently off the in queue and is
984 * being worked on through the inbound chunk processing.
985 */
986 struct sctp_chunk *in_progress;
987
988 /* This is the delayed task to finish delivering inbound
989 * messages.
990 */
991 struct work_struct immediate;
992};
993
994void sctp_inq_init(struct sctp_inq *);
995void sctp_inq_free(struct sctp_inq *);
996void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
997struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
998struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
999void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1000
1001/* This is the structure we use to hold outbound chunks. You push
1002 * chunks in and they automatically pop out the other end as bundled
1003 * packets (it calls (*output_handler)()).
1004 *
1005 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1006 * and 8.2 of the v13 draft.
1007 *
1008 * It handles retransmissions. The connection to the timeout portion
1009 * of the state machine is through sctp_..._timeout() and timeout_handler.
1010 *
1011 * If you feed it SACKs, it will eat them.
1012 *
1013 * If you give it big chunks, it will fragment them.
1014 *
1015 * It assigns TSN's to data chunks. This happens at the last possible
1016 * instant before transmission.
1017 *
1018 * When free()'d, it empties itself out via output_handler().
1019 */
1020struct sctp_outq {
1021 struct sctp_association *asoc;
1022
1023 /* Data pending that has never been transmitted. */
1024 struct list_head out_chunk_list;
1025
1026 unsigned int out_qlen; /* Total length of queued data chunks. */
1027
1028 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1029 unsigned int error;
1030
1031 /* These are control chunks we want to send. */
1032 struct list_head control_chunk_list;
1033
1034 /* These are chunks that have been sacked but are above the
1035 * CTSN, or cumulative tsn ack point.
1036 */
1037 struct list_head sacked;
1038
1039 /* Put chunks on this list to schedule them for
1040 * retransmission.
1041 */
1042 struct list_head retransmit;
1043
1044 /* Put chunks on this list to save them for FWD TSN processing as
1045 * they were abandoned.
1046 */
1047 struct list_head abandoned;
1048
1049 /* How many unackd bytes do we have in-flight? */
1050 __u32 outstanding_bytes;
1051
1052 /* Are we doing fast-rtx on this queue */
1053 char fast_rtx;
1054
1055 /* Corked? */
1056 char cork;
1057};
1058
1059void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1060void sctp_outq_teardown(struct sctp_outq *);
1061void sctp_outq_free(struct sctp_outq*);
1062int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1063int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1064int sctp_outq_is_empty(const struct sctp_outq *);
1065void sctp_outq_restart(struct sctp_outq *);
1066
1067void sctp_retransmit(struct sctp_outq *, struct sctp_transport *,
1068 sctp_retransmit_reason_t);
1069void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1070int sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1071/* Uncork and flush an outqueue. */
1072static inline void sctp_outq_cork(struct sctp_outq *q)
1073{
1074 q->cork = 1;
1075}
1076
1077/* These bind address data fields common between endpoints and associations */
1078struct sctp_bind_addr {
1079
1080 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1081 *
1082 * SCTP Port: The local SCTP port number the endpoint is
1083 * bound to.
1084 */
1085 __u16 port;
1086
1087 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1088 *
1089 * Address List: The list of IP addresses that this instance
1090 * has bound. This information is passed to one's
1091 * peer(s) in INIT and INIT ACK chunks.
1092 */
1093 struct list_head address_list;
1094};
1095
1096void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1097void sctp_bind_addr_free(struct sctp_bind_addr *);
1098int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1099 const struct sctp_bind_addr *src,
1100 sctp_scope_t scope, gfp_t gfp,
1101 int flags);
1102int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1103 const struct sctp_bind_addr *src,
1104 gfp_t gfp);
1105int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1106 int new_size, __u8 addr_state, gfp_t gfp);
1107int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1108int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1109 struct sctp_sock *);
1110int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1111 struct sctp_sock *, struct sctp_sock *);
1112int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1113 const union sctp_addr *addr);
1114union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1115 const union sctp_addr *addrs,
1116 int addrcnt,
1117 struct sctp_sock *opt);
1118union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1119 int *addrs_len,
1120 gfp_t gfp);
1121int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1122 __u16 port, gfp_t gfp);
1123
1124sctp_scope_t sctp_scope(const union sctp_addr *);
1125int sctp_in_scope(struct net *net, const union sctp_addr *addr, const sctp_scope_t scope);
1126int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1127int sctp_is_ep_boundall(struct sock *sk);
1128
1129
1130/* What type of endpoint? */
1131typedef enum {
1132 SCTP_EP_TYPE_SOCKET,
1133 SCTP_EP_TYPE_ASSOCIATION,
1134} sctp_endpoint_type_t;
1135
1136/*
1137 * A common base class to bridge the implmentation view of a
1138 * socket (usually listening) endpoint versus an association's
1139 * local endpoint.
1140 * This common structure is useful for several purposes:
1141 * 1) Common interface for lookup routines.
1142 * a) Subfunctions work for either endpoint or association
1143 * b) Single interface to lookup allows hiding the lookup lock rather
1144 * than acquiring it externally.
1145 * 2) Common interface for the inbound chunk handling/state machine.
1146 * 3) Common object handling routines for reference counting, etc.
1147 * 4) Disentangle association lookup from endpoint lookup, where we
1148 * do not have to find our endpoint to find our association.
1149 *
1150 */
1151
1152struct sctp_ep_common {
1153 /* Fields to help us manage our entries in the hash tables. */
1154 struct hlist_node node;
1155 int hashent;
1156
1157 /* Runtime type information. What kind of endpoint is this? */
1158 sctp_endpoint_type_t type;
1159
1160 /* Some fields to help us manage this object.
1161 * refcnt - Reference count access to this object.
1162 * dead - Do not attempt to use this object.
1163 */
1164 atomic_t refcnt;
1165 bool dead;
1166
1167 /* What socket does this endpoint belong to? */
1168 struct sock *sk;
1169
1170 /* This is where we receive inbound chunks. */
1171 struct sctp_inq inqueue;
1172
1173 /* This substructure includes the defining parameters of the
1174 * endpoint:
1175 * bind_addr.port is our shared port number.
1176 * bind_addr.address_list is our set of local IP addresses.
1177 */
1178 struct sctp_bind_addr bind_addr;
1179};
1180
1181
1182/* RFC Section 1.4 Key Terms
1183 *
1184 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1185 * multi-homed host, an SCTP endpoint is represented to its peers as a
1186 * combination of a set of eligible destination transport addresses to
1187 * which SCTP packets can be sent and a set of eligible source
1188 * transport addresses from which SCTP packets can be received.
1189 * All transport addresses used by an SCTP endpoint must use the
1190 * same port number, but can use multiple IP addresses. A transport
1191 * address used by an SCTP endpoint must not be used by another
1192 * SCTP endpoint. In other words, a transport address is unique
1193 * to an SCTP endpoint.
1194 *
1195 * From an implementation perspective, each socket has one of these.
1196 * A TCP-style socket will have exactly one association on one of
1197 * these. An UDP-style socket will have multiple associations hanging
1198 * off one of these.
1199 */
1200
1201struct sctp_endpoint {
1202 /* Common substructure for endpoint and association. */
1203 struct sctp_ep_common base;
1204
1205 /* Associations: A list of current associations and mappings
1206 * to the data consumers for each association. This
1207 * may be in the form of a hash table or other
1208 * implementation dependent structure. The data
1209 * consumers may be process identification
1210 * information such as file descriptors, named pipe
1211 * pointer, or table pointers dependent on how SCTP
1212 * is implemented.
1213 */
1214 /* This is really a list of struct sctp_association entries. */
1215 struct list_head asocs;
1216
1217 /* Secret Key: A secret key used by this endpoint to compute
1218 * the MAC. This SHOULD be a cryptographic quality
1219 * random number with a sufficient length.
1220 * Discussion in [RFC1750] can be helpful in
1221 * selection of the key.
1222 */
1223 __u8 secret_key[SCTP_SECRET_SIZE];
1224
1225 /* digest: This is a digest of the sctp cookie. This field is
1226 * only used on the receive path when we try to validate
1227 * that the cookie has not been tampered with. We put
1228 * this here so we pre-allocate this once and can re-use
1229 * on every receive.
1230 */
1231 __u8 *digest;
1232
1233 /* sendbuf acct. policy. */
1234 __u32 sndbuf_policy;
1235
1236 /* rcvbuf acct. policy. */
1237 __u32 rcvbuf_policy;
1238
1239 /* SCTP AUTH: array of the HMACs that will be allocated
1240 * we need this per association so that we don't serialize
1241 */
1242 struct crypto_shash **auth_hmacs;
1243
1244 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1245 struct sctp_hmac_algo_param *auth_hmacs_list;
1246
1247 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1248 struct sctp_chunks_param *auth_chunk_list;
1249
1250 /* SCTP-AUTH: endpoint shared keys */
1251 struct list_head endpoint_shared_keys;
1252 __u16 active_key_id;
1253 __u8 auth_enable;
1254};
1255
1256/* Recover the outter endpoint structure. */
1257static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1258{
1259 struct sctp_endpoint *ep;
1260
1261 ep = container_of(base, struct sctp_endpoint, base);
1262 return ep;
1263}
1264
1265/* These are function signatures for manipulating endpoints. */
1266struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1267void sctp_endpoint_free(struct sctp_endpoint *);
1268void sctp_endpoint_put(struct sctp_endpoint *);
1269void sctp_endpoint_hold(struct sctp_endpoint *);
1270void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1271struct sctp_association *sctp_endpoint_lookup_assoc(
1272 const struct sctp_endpoint *ep,
1273 const union sctp_addr *paddr,
1274 struct sctp_transport **);
1275int sctp_endpoint_is_peeled_off(struct sctp_endpoint *,
1276 const union sctp_addr *);
1277struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1278 struct net *, const union sctp_addr *);
1279int sctp_has_association(struct net *net, const union sctp_addr *laddr,
1280 const union sctp_addr *paddr);
1281
1282int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1283 const struct sctp_association *asoc,
1284 sctp_cid_t, sctp_init_chunk_t *peer_init,
1285 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1286int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1287 const union sctp_addr *peer,
1288 sctp_init_chunk_t *init, gfp_t gfp);
1289__u32 sctp_generate_tag(const struct sctp_endpoint *);
1290__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1291
1292struct sctp_inithdr_host {
1293 __u32 init_tag;
1294 __u32 a_rwnd;
1295 __u16 num_outbound_streams;
1296 __u16 num_inbound_streams;
1297 __u32 initial_tsn;
1298};
1299
1300/* SCTP_GET_ASSOC_STATS counters */
1301struct sctp_priv_assoc_stats {
1302 /* Maximum observed rto in the association during subsequent
1303 * observations. Value is set to 0 if no RTO measurement took place
1304 * The transport where the max_rto was observed is returned in
1305 * obs_rto_ipaddr
1306 */
1307 struct sockaddr_storage obs_rto_ipaddr;
1308 __u64 max_obs_rto;
1309 /* Total In and Out SACKs received and sent */
1310 __u64 isacks;
1311 __u64 osacks;
1312 /* Total In and Out packets received and sent */
1313 __u64 opackets;
1314 __u64 ipackets;
1315 /* Total retransmitted chunks */
1316 __u64 rtxchunks;
1317 /* TSN received > next expected */
1318 __u64 outofseqtsns;
1319 /* Duplicate Chunks received */
1320 __u64 idupchunks;
1321 /* Gap Ack Blocks received */
1322 __u64 gapcnt;
1323 /* Unordered data chunks sent and received */
1324 __u64 ouodchunks;
1325 __u64 iuodchunks;
1326 /* Ordered data chunks sent and received */
1327 __u64 oodchunks;
1328 __u64 iodchunks;
1329 /* Control chunks sent and received */
1330 __u64 octrlchunks;
1331 __u64 ictrlchunks;
1332};
1333
1334/* RFC2960
1335 *
1336 * 12. Recommended Transmission Control Block (TCB) Parameters
1337 *
1338 * This section details a recommended set of parameters that should
1339 * be contained within the TCB for an implementation. This section is
1340 * for illustrative purposes and should not be deemed as requirements
1341 * on an implementation or as an exhaustive list of all parameters
1342 * inside an SCTP TCB. Each implementation may need its own additional
1343 * parameters for optimization.
1344 */
1345
1346
1347/* Here we have information about each individual association. */
1348struct sctp_association {
1349
1350 /* A base structure common to endpoint and association.
1351 * In this context, it represents the associations's view
1352 * of the local endpoint of the association.
1353 */
1354 struct sctp_ep_common base;
1355
1356 /* Associations on the same socket. */
1357 struct list_head asocs;
1358
1359 /* association id. */
1360 sctp_assoc_t assoc_id;
1361
1362 /* This is our parent endpoint. */
1363 struct sctp_endpoint *ep;
1364
1365 /* These are those association elements needed in the cookie. */
1366 struct sctp_cookie c;
1367
1368 /* This is all information about our peer. */
1369 struct {
1370 /* transport_addr_list
1371 *
1372 * Peer : A list of SCTP transport addresses that the
1373 * Transport : peer is bound to. This information is derived
1374 * Address : from the INIT or INIT ACK and is used to
1375 * List : associate an inbound packet with a given
1376 * : association. Normally this information is
1377 * : hashed or keyed for quick lookup and access
1378 * : of the TCB.
1379 * : The list is also initialized with the list
1380 * : of addresses passed with the sctp_connectx()
1381 * : call.
1382 *
1383 * It is a list of SCTP_transport's.
1384 */
1385 struct list_head transport_addr_list;
1386
1387 /* rwnd
1388 *
1389 * Peer Rwnd : Current calculated value of the peer's rwnd.
1390 */
1391 __u32 rwnd;
1392
1393 /* transport_count
1394 *
1395 * Peer : A count of the number of peer addresses
1396 * Transport : in the Peer Transport Address List.
1397 * Address :
1398 * Count :
1399 */
1400 __u16 transport_count;
1401
1402 /* port
1403 * The transport layer port number.
1404 */
1405 __u16 port;
1406
1407 /* primary_path
1408 *
1409 * Primary : This is the current primary destination
1410 * Path : transport address of the peer endpoint. It
1411 * : may also specify a source transport address
1412 * : on this endpoint.
1413 *
1414 * All of these paths live on transport_addr_list.
1415 *
1416 * At the bakeoffs, we discovered that the intent of
1417 * primaryPath is that it only changes when the ULP
1418 * asks to have it changed. We add the activePath to
1419 * designate the connection we are currently using to
1420 * transmit new data and most control chunks.
1421 */
1422 struct sctp_transport *primary_path;
1423
1424 /* Cache the primary path address here, when we
1425 * need a an address for msg_name.
1426 */
1427 union sctp_addr primary_addr;
1428
1429 /* active_path
1430 * The path that we are currently using to
1431 * transmit new data and most control chunks.
1432 */
1433 struct sctp_transport *active_path;
1434
1435 /* retran_path
1436 *
1437 * RFC2960 6.4 Multi-homed SCTP Endpoints
1438 * ...
1439 * Furthermore, when its peer is multi-homed, an
1440 * endpoint SHOULD try to retransmit a chunk to an
1441 * active destination transport address that is
1442 * different from the last destination address to
1443 * which the DATA chunk was sent.
1444 */
1445 struct sctp_transport *retran_path;
1446
1447 /* Pointer to last transport I have sent on. */
1448 struct sctp_transport *last_sent_to;
1449
1450 /* This is the last transport I have received DATA on. */
1451 struct sctp_transport *last_data_from;
1452
1453 /*
1454 * Mapping An array of bits or bytes indicating which out of
1455 * Array order TSN's have been received (relative to the
1456 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1457 * order packets have been received, this array
1458 * will be set to all zero. This structure may be
1459 * in the form of a circular buffer or bit array.
1460 *
1461 * Last Rcvd : This is the last TSN received in
1462 * TSN : sequence. This value is set initially by
1463 * : taking the peer's Initial TSN, received in
1464 * : the INIT or INIT ACK chunk, and subtracting
1465 * : one from it.
1466 *
1467 * Throughout most of the specification this is called the
1468 * "Cumulative TSN ACK Point". In this case, we
1469 * ignore the advice in 12.2 in favour of the term
1470 * used in the bulk of the text. This value is hidden
1471 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1472 */
1473 struct sctp_tsnmap tsn_map;
1474
1475 /* This mask is used to disable sending the ASCONF chunk
1476 * with specified parameter to peer.
1477 */
1478 __be16 addip_disabled_mask;
1479
1480 /* These are capabilities which our peer advertised. */
1481 __u8 ecn_capable:1, /* Can peer do ECN? */
1482 ipv4_address:1, /* Peer understands IPv4 addresses? */
1483 ipv6_address:1, /* Peer understands IPv6 addresses? */
1484 hostname_address:1, /* Peer understands DNS addresses? */
1485 asconf_capable:1, /* Does peer support ADDIP? */
1486 prsctp_capable:1, /* Can peer do PR-SCTP? */
1487 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1488
1489 /* sack_needed : This flag indicates if the next received
1490 * : packet is to be responded to with a
1491 * : SACK. This is initialized to 0. When a packet
1492 * : is received sack_cnt is incremented. If this value
1493 * : reaches 2 or more, a SACK is sent and the
1494 * : value is reset to 0. Note: This is used only
1495 * : when no DATA chunks are received out of
1496 * : order. When DATA chunks are out of order,
1497 * : SACK's are not delayed (see Section 6).
1498 */
1499 __u8 sack_needed:1, /* Do we need to sack the peer? */
1500 sack_generation:1,
1501 zero_window_announced:1;
1502 __u32 sack_cnt;
1503
1504 __u32 adaptation_ind; /* Adaptation Code point. */
1505
1506 struct sctp_inithdr_host i;
1507 void *cookie;
1508 int cookie_len;
1509
1510 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1511 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1512 * Initial TSN Value minus 1
1513 */
1514 __u32 addip_serial;
1515
1516 /* SCTP-AUTH: We need to know pears random number, hmac list
1517 * and authenticated chunk list. All that is part of the
1518 * cookie and these are just pointers to those locations
1519 */
1520 sctp_random_param_t *peer_random;
1521 sctp_chunks_param_t *peer_chunks;
1522 sctp_hmac_algo_param_t *peer_hmacs;
1523 } peer;
1524
1525 /* State : A state variable indicating what state the
1526 * : association is in, i.e. COOKIE-WAIT,
1527 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1528 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1529 *
1530 * Note: No "CLOSED" state is illustrated since if a
1531 * association is "CLOSED" its TCB SHOULD be removed.
1532 *
1533 * In this implementation we DO have a CLOSED
1534 * state which is used during initiation and shutdown.
1535 *
1536 * State takes values from SCTP_STATE_*.
1537 */
1538 sctp_state_t state;
1539
1540 /* Overall : The overall association error count.
1541 * Error Count : [Clear this any time I get something.]
1542 */
1543 int overall_error_count;
1544
1545 /* The cookie life I award for any cookie. */
1546 ktime_t cookie_life;
1547
1548 /* These are the association's initial, max, and min RTO values.
1549 * These values will be initialized by system defaults, but can
1550 * be modified via the SCTP_RTOINFO socket option.
1551 */
1552 unsigned long rto_initial;
1553 unsigned long rto_max;
1554 unsigned long rto_min;
1555
1556 /* Maximum number of new data packets that can be sent in a burst. */
1557 int max_burst;
1558
1559 /* This is the max_retrans value for the association. This value will
1560 * be initialized initialized from system defaults, but can be
1561 * modified by the SCTP_ASSOCINFO socket option.
1562 */
1563 int max_retrans;
1564
1565 /* This is the partially failed retrans value for the transport
1566 * and will be initialized from the assocs value. This can be
1567 * changed using the SCTP_PEER_ADDR_THLDS socket option
1568 */
1569 int pf_retrans;
1570
1571 /* Maximum number of times the endpoint will retransmit INIT */
1572 __u16 max_init_attempts;
1573
1574 /* How many times have we resent an INIT? */
1575 __u16 init_retries;
1576
1577 /* The largest timeout or RTO value to use in attempting an INIT */
1578 unsigned long max_init_timeo;
1579
1580 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1581 * the destination address every heartbeat interval. This value
1582 * will be inherited by all new transports.
1583 */
1584 unsigned long hbinterval;
1585
1586 /* This is the max_retrans value for new transports in the
1587 * association.
1588 */
1589 __u16 pathmaxrxt;
1590
1591 /* Flag that path mtu update is pending */
1592 __u8 pmtu_pending;
1593
1594 /* Association : The smallest PMTU discovered for all of the
1595 * PMTU : peer's transport addresses.
1596 */
1597 __u32 pathmtu;
1598
1599 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1600 __u32 param_flags;
1601
1602 __u32 sackfreq;
1603 /* SACK delay timeout */
1604 unsigned long sackdelay;
1605
1606 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1607 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1608
1609 /* Transport to which SHUTDOWN chunk was last sent. */
1610 struct sctp_transport *shutdown_last_sent_to;
1611
1612 /* Transport to which INIT chunk was last sent. */
1613 struct sctp_transport *init_last_sent_to;
1614
1615 /* How many times have we resent a SHUTDOWN */
1616 int shutdown_retries;
1617
1618 /* Next TSN : The next TSN number to be assigned to a new
1619 * : DATA chunk. This is sent in the INIT or INIT
1620 * : ACK chunk to the peer and incremented each
1621 * : time a DATA chunk is assigned a TSN
1622 * : (normally just prior to transmit or during
1623 * : fragmentation).
1624 */
1625 __u32 next_tsn;
1626
1627 /*
1628 * Last Rcvd : This is the last TSN received in sequence. This value
1629 * TSN : is set initially by taking the peer's Initial TSN,
1630 * : received in the INIT or INIT ACK chunk, and
1631 * : subtracting one from it.
1632 *
1633 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1634 */
1635
1636 __u32 ctsn_ack_point;
1637
1638 /* PR-SCTP Advanced.Peer.Ack.Point */
1639 __u32 adv_peer_ack_point;
1640
1641 /* Highest TSN that is acknowledged by incoming SACKs. */
1642 __u32 highest_sacked;
1643
1644 /* TSN marking the fast recovery exit point */
1645 __u32 fast_recovery_exit;
1646
1647 /* Flag to track the current fast recovery state */
1648 __u8 fast_recovery;
1649
1650 /* The number of unacknowledged data chunks. Reported through
1651 * the SCTP_STATUS sockopt.
1652 */
1653 __u16 unack_data;
1654
1655 /* The total number of data chunks that we've had to retransmit
1656 * as the result of a T3 timer expiration
1657 */
1658 __u32 rtx_data_chunks;
1659
1660 /* This is the association's receive buffer space. This value is used
1661 * to set a_rwnd field in an INIT or a SACK chunk.
1662 */
1663 __u32 rwnd;
1664
1665 /* This is the last advertised value of rwnd over a SACK chunk. */
1666 __u32 a_rwnd;
1667
1668 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1669 * to slop over a maximum of the association's frag_point.
1670 */
1671 __u32 rwnd_over;
1672
1673 /* Keeps treack of rwnd pressure. This happens when we have
1674 * a window, but not recevie buffer (i.e small packets). This one
1675 * is releases slowly (1 PMTU at a time ).
1676 */
1677 __u32 rwnd_press;
1678
1679 /* This is the sndbuf size in use for the association.
1680 * This corresponds to the sndbuf size for the association,
1681 * as specified in the sk->sndbuf.
1682 */
1683 int sndbuf_used;
1684
1685 /* This is the amount of memory that this association has allocated
1686 * in the receive path at any given time.
1687 */
1688 atomic_t rmem_alloc;
1689
1690 /* This is the wait queue head for send requests waiting on
1691 * the association sndbuf space.
1692 */
1693 wait_queue_head_t wait;
1694
1695 /* The message size at which SCTP fragmentation will occur. */
1696 __u32 frag_point;
1697 __u32 user_frag;
1698
1699 /* Counter used to count INIT errors. */
1700 int init_err_counter;
1701
1702 /* Count the number of INIT cycles (for doubling timeout). */
1703 int init_cycle;
1704
1705 /* Default send parameters. */
1706 __u16 default_stream;
1707 __u16 default_flags;
1708 __u32 default_ppid;
1709 __u32 default_context;
1710 __u32 default_timetolive;
1711
1712 /* Default receive parameters */
1713 __u32 default_rcv_context;
1714
1715 /* This tracks outbound ssn for a given stream. */
1716 struct sctp_ssnmap *ssnmap;
1717
1718 /* All outbound chunks go through this structure. */
1719 struct sctp_outq outqueue;
1720
1721 /* A smart pipe that will handle reordering and fragmentation,
1722 * as well as handle passing events up to the ULP.
1723 */
1724 struct sctp_ulpq ulpq;
1725
1726 /* Last TSN that caused an ECNE Chunk to be sent. */
1727 __u32 last_ecne_tsn;
1728
1729 /* Last TSN that caused a CWR Chunk to be sent. */
1730 __u32 last_cwr_tsn;
1731
1732 /* How many duplicated TSNs have we seen? */
1733 int numduptsns;
1734
1735 /* These are to support
1736 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1737 * and Enforcement of Flow and Message Limits"
1738 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1739 * or "ADDIP" for short.
1740 */
1741
1742
1743
1744 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1745 *
1746 * R1) One and only one ASCONF Chunk MAY be in transit and
1747 * unacknowledged at any one time. If a sender, after sending
1748 * an ASCONF chunk, decides it needs to transfer another
1749 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1750 * returns from the previous ASCONF Chunk before sending a
1751 * subsequent ASCONF. Note this restriction binds each side,
1752 * so at any time two ASCONF may be in-transit on any given
1753 * association (one sent from each endpoint).
1754 *
1755 * [This is our one-and-only-one ASCONF in flight. If we do
1756 * not have an ASCONF in flight, this is NULL.]
1757 */
1758 struct sctp_chunk *addip_last_asconf;
1759
1760 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1761 *
1762 * This is needed to implement itmes E1 - E4 of the updated
1763 * spec. Here is the justification:
1764 *
1765 * Since the peer may bundle multiple ASCONF chunks toward us,
1766 * we now need the ability to cache multiple ACKs. The section
1767 * describes in detail how they are cached and cleaned up.
1768 */
1769 struct list_head asconf_ack_list;
1770
1771 /* These ASCONF chunks are waiting to be sent.
1772 *
1773 * These chunaks can't be pushed to outqueue until receiving
1774 * ASCONF_ACK for the previous ASCONF indicated by
1775 * addip_last_asconf, so as to guarantee that only one ASCONF
1776 * is in flight at any time.
1777 *
1778 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1779 *
1780 * In defining the ASCONF Chunk transfer procedures, it is
1781 * essential that these transfers MUST NOT cause congestion
1782 * within the network. To achieve this, we place these
1783 * restrictions on the transfer of ASCONF Chunks:
1784 *
1785 * R1) One and only one ASCONF Chunk MAY be in transit and
1786 * unacknowledged at any one time. If a sender, after sending
1787 * an ASCONF chunk, decides it needs to transfer another
1788 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1789 * returns from the previous ASCONF Chunk before sending a
1790 * subsequent ASCONF. Note this restriction binds each side,
1791 * so at any time two ASCONF may be in-transit on any given
1792 * association (one sent from each endpoint).
1793 *
1794 *
1795 * [I really think this is EXACTLY the sort of intelligence
1796 * which already resides in sctp_outq. Please move this
1797 * queue and its supporting logic down there. --piggy]
1798 */
1799 struct list_head addip_chunk_list;
1800
1801 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1802 *
1803 * A2) A serial number should be assigned to the Chunk. The
1804 * serial number SHOULD be a monotonically increasing
1805 * number. The serial number SHOULD be initialized at
1806 * the start of the association to the same value as the
1807 * Initial TSN and every time a new ASCONF chunk is created
1808 * it is incremented by one after assigning the serial number
1809 * to the newly created chunk.
1810 *
1811 * ADDIP
1812 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
1813 *
1814 * Serial Number : 32 bits (unsigned integer)
1815 *
1816 * This value represents a Serial Number for the ASCONF
1817 * Chunk. The valid range of Serial Number is from 0 to
1818 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
1819 * after reaching 4294967295.
1820 */
1821 __u32 addip_serial;
1822 int src_out_of_asoc_ok;
1823 union sctp_addr *asconf_addr_del_pending;
1824 struct sctp_transport *new_transport;
1825
1826 /* SCTP AUTH: list of the endpoint shared keys. These
1827 * keys are provided out of band by the user applicaton
1828 * and can't change during the lifetime of the association
1829 */
1830 struct list_head endpoint_shared_keys;
1831
1832 /* SCTP AUTH:
1833 * The current generated assocaition shared key (secret)
1834 */
1835 struct sctp_auth_bytes *asoc_shared_key;
1836
1837 /* SCTP AUTH: hmac id of the first peer requested algorithm
1838 * that we support.
1839 */
1840 __u16 default_hmac_id;
1841
1842 __u16 active_key_id;
1843
1844 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
1845 temp:1; /* Is it a temporary association? */
1846
1847 struct sctp_priv_assoc_stats stats;
1848};
1849
1850
1851/* An eyecatcher for determining if we are really looking at an
1852 * association data structure.
1853 */
1854enum {
1855 SCTP_ASSOC_EYECATCHER = 0xa550c123,
1856};
1857
1858/* Recover the outter association structure. */
1859static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
1860{
1861 struct sctp_association *asoc;
1862
1863 asoc = container_of(base, struct sctp_association, base);
1864 return asoc;
1865}
1866
1867/* These are function signatures for manipulating associations. */
1868
1869
1870struct sctp_association *
1871sctp_association_new(const struct sctp_endpoint *, const struct sock *,
1872 sctp_scope_t scope, gfp_t gfp);
1873void sctp_association_free(struct sctp_association *);
1874void sctp_association_put(struct sctp_association *);
1875void sctp_association_hold(struct sctp_association *);
1876
1877struct sctp_transport *sctp_assoc_choose_alter_transport(
1878 struct sctp_association *, struct sctp_transport *);
1879void sctp_assoc_update_retran_path(struct sctp_association *);
1880struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
1881 const union sctp_addr *);
1882int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1883 const union sctp_addr *laddr);
1884struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
1885 const union sctp_addr *address,
1886 const gfp_t gfp,
1887 const int peer_state);
1888void sctp_assoc_del_peer(struct sctp_association *asoc,
1889 const union sctp_addr *addr);
1890void sctp_assoc_rm_peer(struct sctp_association *asoc,
1891 struct sctp_transport *peer);
1892void sctp_assoc_control_transport(struct sctp_association *,
1893 struct sctp_transport *,
1894 sctp_transport_cmd_t, sctp_sn_error_t);
1895struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
1896struct sctp_transport *sctp_assoc_is_match(struct sctp_association *,
1897 struct net *,
1898 const union sctp_addr *,
1899 const union sctp_addr *);
1900void sctp_assoc_migrate(struct sctp_association *, struct sock *);
1901void sctp_assoc_update(struct sctp_association *old,
1902 struct sctp_association *new);
1903
1904__u32 sctp_association_get_next_tsn(struct sctp_association *);
1905
1906void sctp_assoc_sync_pmtu(struct sock *, struct sctp_association *);
1907void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
1908void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
1909void sctp_assoc_set_primary(struct sctp_association *,
1910 struct sctp_transport *);
1911void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
1912 struct sctp_transport *);
1913int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *,
1914 sctp_scope_t, gfp_t);
1915int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
1916 struct sctp_cookie*,
1917 gfp_t gfp);
1918int sctp_assoc_set_id(struct sctp_association *, gfp_t);
1919void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
1920struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1921 const struct sctp_association *asoc,
1922 __be32 serial);
1923void sctp_asconf_queue_teardown(struct sctp_association *asoc);
1924
1925int sctp_cmp_addr_exact(const union sctp_addr *ss1,
1926 const union sctp_addr *ss2);
1927struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
1928
1929/* A convenience structure to parse out SCTP specific CMSGs. */
1930typedef struct sctp_cmsgs {
1931 struct sctp_initmsg *init;
1932 struct sctp_sndrcvinfo *srinfo;
1933 struct sctp_sndinfo *sinfo;
1934} sctp_cmsgs_t;
1935
1936/* Structure for tracking memory objects */
1937typedef struct {
1938 char *label;
1939 atomic_t *counter;
1940} sctp_dbg_objcnt_entry_t;
1941
1942#endif /* __sctp_structs_h__ */