1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * Please send any bug reports or fixes you make to the
11 * email addresses:
12 *    lksctp developers <linux-sctp@vger.kernel.org>
13 *
14 * Written or modified by:
15 *    Randall Stewart	    <randall@sctp.chicago.il.us>
16 *    Ken Morneau	    <kmorneau@cisco.com>
17 *    Qiaobing Xie	    <qxie1@email.mot.com>
18 *    La Monte H.P. Yarroll <piggy@acm.org>
19 *    Karl Knutson	    <karl@athena.chicago.il.us>
20 *    Jon Grimm		    <jgrimm@us.ibm.com>
21 *    Xingang Guo	    <xingang.guo@intel.com>
22 *    Hui Huang		    <hui.huang@nokia.com>
23 *    Sridhar Samudrala	    <sri@us.ibm.com>
24 *    Daisy Chang	    <daisyc@us.ibm.com>
25 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
26 *    Ardelle Fan	    <ardelle.fan@intel.com>
27 *    Ryan Layer	    <rmlayer@us.ibm.com>
28 *    Anup Pemmaiah	    <pemmaiah@cc.usu.edu>
29 *    Kevin Gao             <kevin.gao@intel.com>
30 */
31
32#ifndef __sctp_structs_h__
33#define __sctp_structs_h__
34
35#include <linux/ktime.h>
36#include <linux/generic-radix-tree.h>
37#include <linux/rhashtable-types.h>
38#include <linux/socket.h>	/* linux/in.h needs this!!    */
39#include <linux/in.h>		/* We get struct sockaddr_in. */
40#include <linux/in6.h>		/* We get struct in6_addr     */
41#include <linux/ipv6.h>
42#include <asm/param.h>		/* We get MAXHOSTNAMELEN.     */
43#include <linux/atomic.h>		/* This gets us atomic counters.  */
44#include <linux/skbuff.h>	/* We need sk_buff_head. */
45#include <linux/workqueue.h>	/* We need tq_struct.	 */
46#include <linux/sctp.h>		/* We need sctp* header structs.  */
47#include <net/sctp/auth.h>	/* We need auth specific structs */
48#include <net/ip.h>		/* For inet_skb_parm */
49
50/* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
52 */
53union sctp_addr {
54	struct sockaddr_in v4;
55	struct sockaddr_in6 v6;
56	struct sockaddr sa;
57};
58
59/* Forward declarations for data structures. */
60struct sctp_globals;
61struct sctp_endpoint;
62struct sctp_association;
63struct sctp_transport;
64struct sctp_packet;
65struct sctp_chunk;
66struct sctp_inq;
67struct sctp_outq;
68struct sctp_bind_addr;
69struct sctp_ulpq;
70struct sctp_ep_common;
71struct crypto_shash;
72struct sctp_stream;
73
74
75#include <net/sctp/tsnmap.h>
76#include <net/sctp/ulpevent.h>
77#include <net/sctp/ulpqueue.h>
78#include <net/sctp/stream_interleave.h>
79
80/* Structures useful for managing bind/connect. */
81
82struct sctp_bind_bucket {
83	unsigned short	port;
84	signed char	fastreuse;
85	signed char	fastreuseport;
86	kuid_t		fastuid;
87	struct hlist_node	node;
88	struct hlist_head	owner;
89	struct net	*net;
90};
91
92struct sctp_bind_hashbucket {
93	spinlock_t	lock;
94	struct hlist_head	chain;
95};
96
97/* Used for hashing all associations.  */
98struct sctp_hashbucket {
99	rwlock_t	lock;
100	struct hlist_head	chain;
101} __attribute__((__aligned__(8)));
102
103
104/* The SCTP globals structure. */
105extern struct sctp_globals {
106	/* This is a list of groups of functions for each address
107	 * family that we support.
108	 */
109	struct list_head address_families;
110
111	/* This is the hash of all endpoints. */
112	struct sctp_hashbucket *ep_hashtable;
113	/* This is the sctp port control hash.	*/
114	struct sctp_bind_hashbucket *port_hashtable;
115	/* This is the hash of all transports. */
116	struct rhltable transport_hashtable;
117
118	/* Sizes of above hashtables. */
119	int ep_hashsize;
120	int port_hashsize;
121
122	/* Default initialization values to be applied to new associations. */
123	__u16 max_instreams;
124	__u16 max_outstreams;
125
126	/* Flag to indicate whether computing and verifying checksum
127	 * is disabled. */
128        bool checksum_disable;
129} sctp_globals;
130
131#define sctp_max_instreams		(sctp_globals.max_instreams)
132#define sctp_max_outstreams		(sctp_globals.max_outstreams)
133#define sctp_address_families		(sctp_globals.address_families)
134#define sctp_ep_hashsize		(sctp_globals.ep_hashsize)
135#define sctp_ep_hashtable		(sctp_globals.ep_hashtable)
136#define sctp_port_hashsize		(sctp_globals.port_hashsize)
137#define sctp_port_hashtable		(sctp_globals.port_hashtable)
138#define sctp_transport_hashtable	(sctp_globals.transport_hashtable)
139#define sctp_checksum_disable		(sctp_globals.checksum_disable)
140
141/* SCTP Socket type: UDP or TCP style. */
142enum sctp_socket_type {
143	SCTP_SOCKET_UDP = 0,
144	SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
145	SCTP_SOCKET_TCP
146};
147
148/* Per socket SCTP information. */
149struct sctp_sock {
150	/* inet_sock has to be the first member of sctp_sock */
151	struct inet_sock inet;
152	/* What kind of a socket is this? */
153	enum sctp_socket_type type;
154
155	/* PF_ family specific functions.  */
156	struct sctp_pf *pf;
157
158	/* Access to HMAC transform. */
159	struct crypto_shash *hmac;
160	char *sctp_hmac_alg;
161
162	/* What is our base endpointer? */
163	struct sctp_endpoint *ep;
164
165	struct sctp_bind_bucket *bind_hash;
166	/* Various Socket Options.  */
167	__u16 default_stream;
168	__u32 default_ppid;
169	__u16 default_flags;
170	__u32 default_context;
171	__u32 default_timetolive;
172	__u32 default_rcv_context;
173	int max_burst;
174
175	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176	 * the destination address every heartbeat interval. This value
177	 * will be inherited by all new associations.
178	 */
179	__u32 hbinterval;
180
181	/* This is the max_retrans value for new associations. */
182	__u16 pathmaxrxt;
183
184	__u32 flowlabel;
185	__u8  dscp;
186
187	__u16 pf_retrans;
188	__u16 ps_retrans;
189
190	/* The initial Path MTU to use for new associations. */
191	__u32 pathmtu;
192
193	/* The default SACK delay timeout for new associations. */
194	__u32 sackdelay;
195	__u32 sackfreq;
196
197	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
198	__u32 param_flags;
199
200	__u32 default_ss;
201
202	struct sctp_rtoinfo rtoinfo;
203	struct sctp_paddrparams paddrparam;
204	struct sctp_assocparams assocparams;
205
206	/*
207	 * These two structures must be grouped together for the usercopy
208	 * whitelist region.
209	 */
210	__u16 subscribe;
211	struct sctp_initmsg initmsg;
212
213	int user_frag;
214
215	__u32 autoclose;
216	__u32 adaptation_ind;
217	__u32 pd_point;
218	__u16	nodelay:1,
219		pf_expose:2,
220		reuse:1,
221		disable_fragments:1,
222		v4mapped:1,
223		frag_interleave:1,
224		recvrcvinfo:1,
225		recvnxtinfo:1,
226		data_ready_signalled:1;
227
228	atomic_t pd_mode;
229
230	/* Fields after this point will be skipped on copies, like on accept
231	 * and peeloff operations
232	 */
233
234	/* Receive to here while partial delivery is in effect. */
235	struct sk_buff_head pd_lobby;
236
237	struct list_head auto_asconf_list;
238	int do_auto_asconf;
239};
240
241static inline struct sctp_sock *sctp_sk(const struct sock *sk)
242{
243       return (struct sctp_sock *)sk;
244}
245
246static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
247{
248       return (struct sock *)sp;
249}
250
251#if IS_ENABLED(CONFIG_IPV6)
252struct sctp6_sock {
253       struct sctp_sock  sctp;
254       struct ipv6_pinfo inet6;
255};
256#endif /* CONFIG_IPV6 */
257
258
259/* This is our APPLICATION-SPECIFIC state cookie.
260 * THIS IS NOT DICTATED BY THE SPECIFICATION.
261 */
262/* These are the parts of an association which we send in the cookie.
263 * Most of these are straight out of:
264 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
265 *
266 */
267
268struct sctp_cookie {
269
270	/* My	       : Tag expected in every inbound packet and sent
271	 * Verification: in the INIT or INIT ACK chunk.
272	 * Tag	       :
273	 */
274	__u32 my_vtag;
275
276	/* Peer's      : Tag expected in every outbound packet except
277	 * Verification: in the INIT chunk.
278	 * Tag	       :
279	 */
280	__u32 peer_vtag;
281
282	/* The rest of these are not from the spec, but really need to
283	 * be in the cookie.
284	 */
285
286	/* My Tie Tag  : Assist in discovering a restarting association. */
287	__u32 my_ttag;
288
289	/* Peer's Tie Tag: Assist in discovering a restarting association. */
290	__u32 peer_ttag;
291
292	/* When does this cookie expire? */
293	ktime_t expiration;
294
295	/* Number of inbound/outbound streams which are set
296	 * and negotiated during the INIT process.
297	 */
298	__u16 sinit_num_ostreams;
299	__u16 sinit_max_instreams;
300
301	/* This is the first sequence number I used.  */
302	__u32 initial_tsn;
303
304	/* This holds the originating address of the INIT packet.  */
305	union sctp_addr peer_addr;
306
307	/* IG Section 2.35.3
308	 * Include the source port of the INIT-ACK
309	 */
310	__u16		my_port;
311
312	__u8 prsctp_capable;
313
314	/* Padding for future use */
315	__u8 padding;
316
317	__u32 adaptation_ind;
318
319	__u8 auth_random[sizeof(struct sctp_paramhdr) +
320			 SCTP_AUTH_RANDOM_LENGTH];
321	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
322	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
323
324	/* This is a shim for my peer's INIT packet, followed by
325	 * a copy of the raw address list of the association.
326	 * The length of the raw address list is saved in the
327	 * raw_addr_list_len field, which will be used at the time when
328	 * the association TCB is re-constructed from the cookie.
329	 */
330	__u32 raw_addr_list_len;
331	struct sctp_init_chunk peer_init[];
332};
333
334
335/* The format of our cookie that we send to our peer. */
336struct sctp_signed_cookie {
337	__u8 signature[SCTP_SECRET_SIZE];
338	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
339	struct sctp_cookie c;
340} __packed;
341
342/* This is another convenience type to allocate memory for address
343 * params for the maximum size and pass such structures around
344 * internally.
345 */
346union sctp_addr_param {
347	struct sctp_paramhdr p;
348	struct sctp_ipv4addr_param v4;
349	struct sctp_ipv6addr_param v6;
350};
351
352/* A convenience type to allow walking through the various
353 * parameters and avoid casting all over the place.
354 */
355union sctp_params {
356	void *v;
357	struct sctp_paramhdr *p;
358	struct sctp_cookie_preserve_param *life;
359	struct sctp_hostname_param *dns;
360	struct sctp_cookie_param *cookie;
361	struct sctp_supported_addrs_param *sat;
362	struct sctp_ipv4addr_param *v4;
363	struct sctp_ipv6addr_param *v6;
364	union sctp_addr_param *addr;
365	struct sctp_adaptation_ind_param *aind;
366	struct sctp_supported_ext_param *ext;
367	struct sctp_random_param *random;
368	struct sctp_chunks_param *chunks;
369	struct sctp_hmac_algo_param *hmac_algo;
370	struct sctp_addip_param *addip;
371};
372
373/* RFC 2960.  Section 3.3.5 Heartbeat.
374 *    Heartbeat Information: variable length
375 *    The Sender-specific Heartbeat Info field should normally include
376 *    information about the sender's current time when this HEARTBEAT
377 *    chunk is sent and the destination transport address to which this
378 *    HEARTBEAT is sent (see Section 8.3).
379 */
380struct sctp_sender_hb_info {
381	struct sctp_paramhdr param_hdr;
382	union sctp_addr daddr;
383	unsigned long sent_at;
384	__u64 hb_nonce;
385};
386
387int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
388		     gfp_t gfp);
389int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
390void sctp_stream_free(struct sctp_stream *stream);
391void sctp_stream_clear(struct sctp_stream *stream);
392void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
393
394/* What is the current SSN number for this stream? */
395#define sctp_ssn_peek(stream, type, sid) \
396	(sctp_stream_##type((stream), (sid))->ssn)
397
398/* Return the next SSN number for this stream.	*/
399#define sctp_ssn_next(stream, type, sid) \
400	(sctp_stream_##type((stream), (sid))->ssn++)
401
402/* Skip over this ssn and all below. */
403#define sctp_ssn_skip(stream, type, sid, ssn) \
404	(sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
405
406/* What is the current MID number for this stream? */
407#define sctp_mid_peek(stream, type, sid) \
408	(sctp_stream_##type((stream), (sid))->mid)
409
410/* Return the next MID number for this stream.  */
411#define sctp_mid_next(stream, type, sid) \
412	(sctp_stream_##type((stream), (sid))->mid++)
413
414/* Skip over this mid and all below. */
415#define sctp_mid_skip(stream, type, sid, mid) \
416	(sctp_stream_##type((stream), (sid))->mid = mid + 1)
417
418/* What is the current MID_uo number for this stream? */
419#define sctp_mid_uo_peek(stream, type, sid) \
420	(sctp_stream_##type((stream), (sid))->mid_uo)
421
422/* Return the next MID_uo number for this stream.  */
423#define sctp_mid_uo_next(stream, type, sid) \
424	(sctp_stream_##type((stream), (sid))->mid_uo++)
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					 sockptr_t 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	void		(*get_dst)	(struct sctp_transport *t,
444					 union sctp_addr *saddr,
445					 struct flowi *fl,
446					 struct sock *sk);
447	void		(*get_saddr)	(struct sctp_sock *sk,
448					 struct sctp_transport *t,
449					 struct flowi *fl);
450	void		(*copy_addrlist) (struct list_head *,
451					  struct net_device *);
452	int		(*cmp_addr)	(const union sctp_addr *addr1,
453					 const union sctp_addr *addr2);
454	void		(*addr_copy)	(union sctp_addr *dst,
455					 union sctp_addr *src);
456	void		(*from_skb)	(union sctp_addr *,
457					 struct sk_buff *skb,
458					 int saddr);
459	void		(*from_sk)	(union sctp_addr *,
460					 struct sock *sk);
461	bool		(*from_addr_param) (union sctp_addr *,
462					    union sctp_addr_param *,
463					    __be16 port, int iif);
464	int		(*to_addr_param) (const union sctp_addr *,
465					  union sctp_addr_param *);
466	int		(*addr_valid)	(union sctp_addr *,
467					 struct sctp_sock *,
468					 const struct sk_buff *);
469	enum sctp_scope	(*scope)(union sctp_addr *);
470	void		(*inaddr_any)	(union sctp_addr *, __be16);
471	int		(*is_any)	(const union sctp_addr *);
472	int		(*available)	(union sctp_addr *,
473					 struct sctp_sock *);
474	int		(*skb_iif)	(const struct sk_buff *sk);
475	int		(*is_ce)	(const struct sk_buff *sk);
476	void		(*seq_dump_addr)(struct seq_file *seq,
477					 union sctp_addr *addr);
478	void		(*ecn_capable)(struct sock *sk);
479	__u16		net_header_len;
480	int		sockaddr_len;
481	int		(*ip_options_len)(struct sock *sk);
482	sa_family_t	sa_family;
483	struct list_head list;
484};
485
486struct sctp_af *sctp_get_af_specific(sa_family_t);
487int sctp_register_af(struct sctp_af *);
488
489/* Protocol family functions. */
490struct sctp_pf {
491	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
492	void (*skb_msgname)  (struct sk_buff *, char *, int *);
493	int  (*af_supported) (sa_family_t, struct sctp_sock *);
494	int  (*cmp_addr) (const union sctp_addr *,
495			  const union sctp_addr *,
496			  struct sctp_sock *);
497	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
498	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
499	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
500	struct sock *(*create_accept_sk) (struct sock *sk,
501					  struct sctp_association *asoc,
502					  bool kern);
503	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
504	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
505	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
506	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
507	struct sctp_af *af;
508};
509
510
511/* Structure to track chunk fragments that have been acked, but peer
512 * fragments of the same message have not.
513 */
514struct sctp_datamsg {
515	/* Chunks waiting to be submitted to lower layer. */
516	struct list_head chunks;
517	/* Reference counting. */
518	refcount_t refcnt;
519	/* When is this message no longer interesting to the peer? */
520	unsigned long expires_at;
521	/* Did the messenge fail to send? */
522	int send_error;
523	u8 send_failed:1,
524	   can_delay:1,	/* should this message be Nagle delayed */
525	   abandoned:1;	/* should this message be abandoned */
526};
527
528struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
529					    struct sctp_sndrcvinfo *,
530					    struct iov_iter *);
531void sctp_datamsg_free(struct sctp_datamsg *);
532void sctp_datamsg_put(struct sctp_datamsg *);
533void sctp_chunk_fail(struct sctp_chunk *, int error);
534int sctp_chunk_abandoned(struct sctp_chunk *);
535
536/* RFC2960 1.4 Key Terms
537 *
538 * o Chunk: A unit of information within an SCTP packet, consisting of
539 * a chunk header and chunk-specific content.
540 *
541 * As a matter of convenience, we remember the SCTP common header for
542 * each chunk as well as a few other header pointers...
543 */
544struct sctp_chunk {
545	struct list_head list;
546
547	refcount_t refcnt;
548
549	/* How many times this chunk have been sent, for prsctp RTX policy */
550	int sent_count;
551
552	union {
553		/* This is our link to the per-transport transmitted list.  */
554		struct list_head transmitted_list;
555		/* List in specific stream outq */
556		struct list_head stream_list;
557	};
558
559	/* This field is used by chunks that hold fragmented data.
560	 * For the first fragment this is the list that holds the rest of
561	 * fragments. For the remaining fragments, this is the link to the
562	 * frag_list maintained in the first fragment.
563	 */
564	struct list_head frag_list;
565
566	/* This points to the sk_buff containing the actual data.  */
567	struct sk_buff *skb;
568
569	union {
570		/* In case of GSO packets, this will store the head one */
571		struct sk_buff *head_skb;
572		/* In case of auth enabled, this will point to the shkey */
573		struct sctp_shared_key *shkey;
574	};
575
576	/* These are the SCTP headers by reverse order in a packet.
577	 * Note that some of these may happen more than once.  In that
578	 * case, we point at the "current" one, whatever that means
579	 * for that level of header.
580	 */
581
582	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
583	union sctp_params param_hdr;
584	union {
585		__u8 *v;
586		struct sctp_datahdr *data_hdr;
587		struct sctp_inithdr *init_hdr;
588		struct sctp_sackhdr *sack_hdr;
589		struct sctp_heartbeathdr *hb_hdr;
590		struct sctp_sender_hb_info *hbs_hdr;
591		struct sctp_shutdownhdr *shutdown_hdr;
592		struct sctp_signed_cookie *cookie_hdr;
593		struct sctp_ecnehdr *ecne_hdr;
594		struct sctp_cwrhdr *ecn_cwr_hdr;
595		struct sctp_errhdr *err_hdr;
596		struct sctp_addiphdr *addip_hdr;
597		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
598		struct sctp_authhdr *auth_hdr;
599		struct sctp_idatahdr *idata_hdr;
600		struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
601	} subh;
602
603	__u8 *chunk_end;
604
605	struct sctp_chunkhdr *chunk_hdr;
606	struct sctphdr *sctp_hdr;
607
608	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
609	struct sctp_sndrcvinfo sinfo;
610
611	/* Which association does this belong to?  */
612	struct sctp_association *asoc;
613
614	/* What endpoint received this chunk? */
615	struct sctp_ep_common *rcvr;
616
617	/* We fill this in if we are calculating RTT. */
618	unsigned long sent_at;
619
620	/* What is the origin IP address for this chunk?  */
621	union sctp_addr source;
622	/* Destination address for this chunk. */
623	union sctp_addr dest;
624
625	/* For outbound message, track all fragments for SEND_FAILED. */
626	struct sctp_datamsg *msg;
627
628	/* For an inbound chunk, this tells us where it came from.
629	 * For an outbound chunk, it tells us where we'd like it to
630	 * go.	It is NULL if we have no preference.
631	 */
632	struct sctp_transport *transport;
633
634	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
635	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
636	 * spec violates the principle premis that all chunks are processed
637	 * in order.
638	 */
639	struct sk_buff *auth_chunk;
640
641#define SCTP_CAN_FRTX 0x0
642#define SCTP_NEED_FRTX 0x1
643#define SCTP_DONT_FRTX 0x2
644	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
645		has_tsn:1,		/* Does this chunk have a TSN yet? */
646		has_ssn:1,		/* Does this chunk have a SSN yet? */
647#define has_mid has_ssn
648		singleton:1,		/* Only chunk in the packet? */
649		end_of_packet:1,	/* Last chunk in the packet? */
650		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
651		pdiscard:1,		/* Discard the whole packet now? */
652		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
653		data_accepted:1,	/* At least 1 chunk accepted */
654		auth:1,			/* IN: was auth'ed | OUT: needs auth */
655		has_asconf:1,		/* IN: have seen an asconf before */
656		tsn_missing_report:2,	/* Data chunk missing counter. */
657		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
658};
659
660#define sctp_chunk_retransmitted(chunk)	(chunk->sent_count > 1)
661void sctp_chunk_hold(struct sctp_chunk *);
662void sctp_chunk_put(struct sctp_chunk *);
663int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
664			  struct iov_iter *from);
665void sctp_chunk_free(struct sctp_chunk *);
666void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
667struct sctp_chunk *sctp_chunkify(struct sk_buff *,
668				 const struct sctp_association *,
669				 struct sock *, gfp_t gfp);
670void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
671		     union sctp_addr *);
672const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
673
674static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
675{
676	return ntohs(ch->subh.data_hdr->stream);
677}
678
679enum {
680	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
681	SCTP_ADDR_SRC,		/* address can be used as source */
682	SCTP_ADDR_DEL,		/* address about to be deleted */
683};
684
685/* This is a structure for holding either an IPv6 or an IPv4 address.  */
686struct sctp_sockaddr_entry {
687	struct list_head list;
688	struct rcu_head	rcu;
689	union sctp_addr a;
690	__u8 state;
691	__u8 valid;
692};
693
694#define SCTP_ADDRESS_TICK_DELAY	500
695
696/* This structure holds lists of chunks as we are assembling for
697 * transmission.
698 */
699struct sctp_packet {
700	/* These are the SCTP header values (host order) for the packet. */
701	__u16 source_port;
702	__u16 destination_port;
703	__u32 vtag;
704
705	/* This contains the payload chunks.  */
706	struct list_head chunk_list;
707
708	/* This is the overhead of the sctp and ip headers. */
709	size_t overhead;
710	/* This is the total size of all chunks INCLUDING padding.  */
711	size_t size;
712	/* This is the maximum size this packet may have */
713	size_t max_size;
714
715	/* The packet is destined for this transport address.
716	 * The function we finally use to pass down to the next lower
717	 * layer lives in the transport structure.
718	 */
719	struct sctp_transport *transport;
720
721	/* pointer to the auth chunk for this packet */
722	struct sctp_chunk *auth;
723
724	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
725	    has_sack:1,		/* This packet contains a SACK chunk. */
726	    has_auth:1,		/* This packet contains an AUTH chunk */
727	    has_data:1,		/* This packet contains at least 1 DATA chunk */
728	    ipfragok:1;		/* So let ip fragment this packet */
729};
730
731void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
732		      __u16 sport, __u16 dport);
733void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
734enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
735					  struct sctp_chunk *chunk,
736					  int one_packet, gfp_t gfp);
737enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
738					struct sctp_chunk *chunk);
739int sctp_packet_transmit(struct sctp_packet *, gfp_t);
740void sctp_packet_free(struct sctp_packet *);
741
742static inline int sctp_packet_empty(struct sctp_packet *packet)
743{
744	return packet->size == packet->overhead;
745}
746
747/* This represents a remote transport address.
748 * For local transport addresses, we just use union sctp_addr.
749 *
750 * RFC2960 Section 1.4 Key Terms
751 *
752 *   o	Transport address:  A Transport Address is traditionally defined
753 *	by Network Layer address, Transport Layer protocol and Transport
754 *	Layer port number.  In the case of SCTP running over IP, a
755 *	transport address is defined by the combination of an IP address
756 *	and an SCTP port number (where SCTP is the Transport protocol).
757 *
758 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
759 *
760 *   o	The sender keeps a separate congestion control parameter set for
761 *	each of the destination addresses it can send to (not each
762 *	source-destination pair but for each destination).  The parameters
763 *	should decay if the address is not used for a long enough time
764 *	period.
765 *
766 */
767struct sctp_transport {
768	/* A list of transports. */
769	struct list_head transports;
770	struct rhlist_head node;
771
772	/* Reference counting. */
773	refcount_t refcnt;
774		/* RTO-Pending : A flag used to track if one of the DATA
775		 *		chunks sent to this address is currently being
776		 *		used to compute a RTT. If this flag is 0,
777		 *		the next DATA chunk sent to this destination
778		 *		should be used to compute a RTT and this flag
779		 *		should be set. Every time the RTT
780		 *		calculation completes (i.e. the DATA chunk
781		 *		is SACK'd) clear this flag.
782		 */
783	__u32	rto_pending:1,
784
785		/*
786		 * hb_sent : a flag that signals that we have a pending
787		 * heartbeat.
788		 */
789		hb_sent:1,
790
791		/* Is the Path MTU update pending on this tranport */
792		pmtu_pending:1,
793
794		dst_pending_confirm:1,	/* need to confirm neighbour */
795
796		/* Has this transport moved the ctsn since we last sacked */
797		sack_generation:1;
798	u32 dst_cookie;
799
800	struct flowi fl;
801
802	/* This is the peer's IP address and port. */
803	union sctp_addr ipaddr;
804
805	/* These are the functions we call to handle LLP stuff.	 */
806	struct sctp_af *af_specific;
807
808	/* Which association do we belong to?  */
809	struct sctp_association *asoc;
810
811	/* RFC2960
812	 *
813	 * 12.3 Per Transport Address Data
814	 *
815	 * For each destination transport address in the peer's
816	 * address list derived from the INIT or INIT ACK chunk, a
817	 * number of data elements needs to be maintained including:
818	 */
819	/* RTO	       : The current retransmission timeout value.  */
820	unsigned long rto;
821
822	__u32 rtt;		/* This is the most recent RTT.	 */
823
824	/* RTTVAR      : The current RTT variation.  */
825	__u32 rttvar;
826
827	/* SRTT	       : The current smoothed round trip time.	*/
828	__u32 srtt;
829
830	/*
831	 * These are the congestion stats.
832	 */
833	/* cwnd	       : The current congestion window.	 */
834	__u32 cwnd;		  /* This is the actual cwnd.  */
835
836	/* ssthresh    : The current slow start threshold value.  */
837	__u32 ssthresh;
838
839	/* partial     : The tracking method for increase of cwnd when in
840	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
841	 */
842	__u32 partial_bytes_acked;
843
844	/* Data that has been sent, but not acknowledged. */
845	__u32 flight_size;
846
847	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
848
849	/* Destination */
850	struct dst_entry *dst;
851	/* Source address. */
852	union sctp_addr saddr;
853
854	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
855	 * the destination address every heartbeat interval.
856	 */
857	unsigned long hbinterval;
858
859	/* SACK delay timeout */
860	unsigned long sackdelay;
861	__u32 sackfreq;
862
863	atomic_t mtu_info;
864
865	/* When was the last time that we heard from this transport? We use
866	 * this to pick new active and retran paths.
867	 */
868	ktime_t last_time_heard;
869
870	/* When was the last time that we sent a chunk using this
871	 * transport? We use this to check for idle transports
872	 */
873	unsigned long last_time_sent;
874
875	/* Last time(in jiffies) when cwnd is reduced due to the congestion
876	 * indication based on ECNE chunk.
877	 */
878	unsigned long last_time_ecne_reduced;
879
880	/* This is the max_retrans value for the transport and will
881	 * be initialized from the assocs value.  This can be changed
882	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
883	 */
884	__u16 pathmaxrxt;
885
886	__u32 flowlabel;
887	__u8  dscp;
888
889	/* This is the partially failed retrans value for the transport
890	 * and will be initialized from the assocs value.  This can be changed
891	 * using the SCTP_PEER_ADDR_THLDS socket option
892	 */
893	__u16 pf_retrans;
894	/* Used for primary path switchover. */
895	__u16 ps_retrans;
896	/* PMTU	      : The current known path MTU.  */
897	__u32 pathmtu;
898
899	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
900	__u32 param_flags;
901
902	/* The number of times INIT has been sent on this transport. */
903	int init_sent_count;
904
905	/* state       : The current state of this destination,
906	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
907	 */
908	int state;
909
910	/* These are the error stats for this destination.  */
911
912	/* Error count : The current error count for this destination.	*/
913	unsigned short error_count;
914
915	/* Per	       : A timer used by each destination.
916	 * Destination :
917	 * Timer       :
918	 *
919	 * [Everywhere else in the text this is called T3-rtx. -ed]
920	 */
921	struct timer_list T3_rtx_timer;
922
923	/* Heartbeat timer is per destination. */
924	struct timer_list hb_timer;
925
926	/* Timer to handle ICMP proto unreachable envets */
927	struct timer_list proto_unreach_timer;
928
929	/* Timer to handler reconf chunk rtx */
930	struct timer_list reconf_timer;
931
932	/* Since we're using per-destination retransmission timers
933	 * (see above), we're also using per-destination "transmitted"
934	 * queues.  This probably ought to be a private struct
935	 * accessible only within the outqueue, but it's not, yet.
936	 */
937	struct list_head transmitted;
938
939	/* We build bundle-able packets for this transport here.  */
940	struct sctp_packet packet;
941
942	/* This is the list of transports that have chunks to send.  */
943	struct list_head send_ready;
944
945	/* State information saved for SFR_CACC algorithm. The key
946	 * idea in SFR_CACC is to maintain state at the sender on a
947	 * per-destination basis when a changeover happens.
948	 *	char changeover_active;
949	 *	char cycling_changeover;
950	 *	__u32 next_tsn_at_change;
951	 *	char cacc_saw_newack;
952	 */
953	struct {
954		/* An unsigned integer, which stores the next TSN to be
955		 * used by the sender, at the moment of changeover.
956		 */
957		__u32 next_tsn_at_change;
958
959		/* A flag which indicates the occurrence of a changeover */
960		char changeover_active;
961
962		/* A flag which indicates whether the change of primary is
963		 * the first switch to this destination address during an
964		 * active switch.
965		 */
966		char cycling_changeover;
967
968		/* A temporary flag, which is used during the processing of
969		 * a SACK to estimate the causative TSN(s)'s group.
970		 */
971		char cacc_saw_newack;
972	} cacc;
973
974	/* 64-bit random number sent with heartbeat. */
975	__u64 hb_nonce;
976
977	struct rcu_head rcu;
978};
979
980struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
981					  gfp_t);
982void sctp_transport_set_owner(struct sctp_transport *,
983			      struct sctp_association *);
984void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
985			  struct sctp_sock *);
986void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
987void sctp_transport_free(struct sctp_transport *);
988void sctp_transport_reset_t3_rtx(struct sctp_transport *);
989void sctp_transport_reset_hb_timer(struct sctp_transport *);
990void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
991int sctp_transport_hold(struct sctp_transport *);
992void sctp_transport_put(struct sctp_transport *);
993void sctp_transport_update_rto(struct sctp_transport *, __u32);
994void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
995void sctp_transport_lower_cwnd(struct sctp_transport *t,
996			       enum sctp_lower_cwnd reason);
997void sctp_transport_burst_limited(struct sctp_transport *);
998void sctp_transport_burst_reset(struct sctp_transport *);
999unsigned long sctp_transport_timeout(struct sctp_transport *);
1000void sctp_transport_reset(struct sctp_transport *t);
1001bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1002void sctp_transport_immediate_rtx(struct sctp_transport *);
1003void sctp_transport_dst_release(struct sctp_transport *t);
1004void sctp_transport_dst_confirm(struct sctp_transport *t);
1005
1006
1007/* This is the structure we use to queue packets as they come into
1008 * SCTP.  We write packets to it and read chunks from it.
1009 */
1010struct sctp_inq {
1011	/* This is actually a queue of sctp_chunk each
1012	 * containing a partially decoded packet.
1013	 */
1014	struct list_head in_chunk_list;
1015	/* This is the packet which is currently off the in queue and is
1016	 * being worked on through the inbound chunk processing.
1017	 */
1018	struct sctp_chunk *in_progress;
1019
1020	/* This is the delayed task to finish delivering inbound
1021	 * messages.
1022	 */
1023	struct work_struct immediate;
1024};
1025
1026void sctp_inq_init(struct sctp_inq *);
1027void sctp_inq_free(struct sctp_inq *);
1028void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1029struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1030struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1031void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1032
1033/* This is the structure we use to hold outbound chunks.  You push
1034 * chunks in and they automatically pop out the other end as bundled
1035 * packets (it calls (*output_handler)()).
1036 *
1037 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1038 * and 8.2 of the v13 draft.
1039 *
1040 * It handles retransmissions.	The connection to the timeout portion
1041 * of the state machine is through sctp_..._timeout() and timeout_handler.
1042 *
1043 * If you feed it SACKs, it will eat them.
1044 *
1045 * If you give it big chunks, it will fragment them.
1046 *
1047 * It assigns TSN's to data chunks.  This happens at the last possible
1048 * instant before transmission.
1049 *
1050 * When free()'d, it empties itself out via output_handler().
1051 */
1052struct sctp_outq {
1053	struct sctp_association *asoc;
1054
1055	/* Data pending that has never been transmitted.  */
1056	struct list_head out_chunk_list;
1057
1058	/* Stream scheduler being used */
1059	struct sctp_sched_ops *sched;
1060
1061	unsigned int out_qlen;	/* Total length of queued data chunks. */
1062
1063	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1064	unsigned int error;
1065
1066	/* These are control chunks we want to send.  */
1067	struct list_head control_chunk_list;
1068
1069	/* These are chunks that have been sacked but are above the
1070	 * CTSN, or cumulative tsn ack point.
1071	 */
1072	struct list_head sacked;
1073
1074	/* Put chunks on this list to schedule them for
1075	 * retransmission.
1076	 */
1077	struct list_head retransmit;
1078
1079	/* Put chunks on this list to save them for FWD TSN processing as
1080	 * they were abandoned.
1081	 */
1082	struct list_head abandoned;
1083
1084	/* How many unackd bytes do we have in-flight?	*/
1085	__u32 outstanding_bytes;
1086
1087	/* Are we doing fast-rtx on this queue */
1088	char fast_rtx;
1089
1090	/* Corked? */
1091	char cork;
1092};
1093
1094void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1095void sctp_outq_teardown(struct sctp_outq *);
1096void sctp_outq_free(struct sctp_outq*);
1097void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1098int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1099int sctp_outq_is_empty(const struct sctp_outq *);
1100void sctp_outq_restart(struct sctp_outq *);
1101
1102void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1103		     enum sctp_retransmit_reason reason);
1104void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1105void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1106void sctp_prsctp_prune(struct sctp_association *asoc,
1107		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1108void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1109/* Uncork and flush an outqueue.  */
1110static inline void sctp_outq_cork(struct sctp_outq *q)
1111{
1112	q->cork = 1;
1113}
1114
1115/* SCTP skb control block.
1116 * sctp_input_cb is currently used on rx and sock rx queue
1117 */
1118struct sctp_input_cb {
1119	union {
1120		struct inet_skb_parm	h4;
1121#if IS_ENABLED(CONFIG_IPV6)
1122		struct inet6_skb_parm	h6;
1123#endif
1124	} header;
1125	struct sctp_chunk *chunk;
1126	struct sctp_af *af;
1127};
1128#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1129
1130struct sctp_output_cb {
1131	struct sk_buff *last;
1132};
1133#define SCTP_OUTPUT_CB(__skb)	((struct sctp_output_cb *)&((__skb)->cb[0]))
1134
1135static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1136{
1137	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1138
1139	return chunk->head_skb ? : skb;
1140}
1141
1142/* These bind address data fields common between endpoints and associations */
1143struct sctp_bind_addr {
1144
1145	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1146	 *
1147	 * SCTP Port:	The local SCTP port number the endpoint is
1148	 *		bound to.
1149	 */
1150	__u16 port;
1151
1152	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1153	 *
1154	 * Address List: The list of IP addresses that this instance
1155	 *	has bound.  This information is passed to one's
1156	 *	peer(s) in INIT and INIT ACK chunks.
1157	 */
1158	struct list_head address_list;
1159};
1160
1161void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1162void sctp_bind_addr_free(struct sctp_bind_addr *);
1163int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1164			const struct sctp_bind_addr *src,
1165			enum sctp_scope scope, gfp_t gfp,
1166			int flags);
1167int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1168			const struct sctp_bind_addr *src,
1169			gfp_t gfp);
1170int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1171		       int new_size, __u8 addr_state, gfp_t gfp);
1172int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1173int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1174			 struct sctp_sock *);
1175int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1176			 struct sctp_sock *, struct sctp_sock *);
1177int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1178			 const union sctp_addr *addr);
1179int sctp_bind_addrs_check(struct sctp_sock *sp,
1180			  struct sctp_sock *sp2, int cnt2);
1181union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1182					const union sctp_addr	*addrs,
1183					int			addrcnt,
1184					struct sctp_sock	*opt);
1185union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1186					 int *addrs_len,
1187					 gfp_t gfp);
1188int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1189			   __u16 port, gfp_t gfp);
1190
1191enum sctp_scope sctp_scope(const union sctp_addr *addr);
1192int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1193		  const enum sctp_scope scope);
1194int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1195int sctp_is_ep_boundall(struct sock *sk);
1196
1197
1198/* What type of endpoint?  */
1199enum sctp_endpoint_type {
1200	SCTP_EP_TYPE_SOCKET,
1201	SCTP_EP_TYPE_ASSOCIATION,
1202};
1203
1204/*
1205 * A common base class to bridge the implmentation view of a
1206 * socket (usually listening) endpoint versus an association's
1207 * local endpoint.
1208 * This common structure is useful for several purposes:
1209 *   1) Common interface for lookup routines.
1210 *	a) Subfunctions work for either endpoint or association
1211 *	b) Single interface to lookup allows hiding the lookup lock rather
1212 *	   than acquiring it externally.
1213 *   2) Common interface for the inbound chunk handling/state machine.
1214 *   3) Common object handling routines for reference counting, etc.
1215 *   4) Disentangle association lookup from endpoint lookup, where we
1216 *	do not have to find our endpoint to find our association.
1217 *
1218 */
1219
1220struct sctp_ep_common {
1221	/* Fields to help us manage our entries in the hash tables. */
1222	struct hlist_node node;
1223	int hashent;
1224
1225	/* Runtime type information.  What kind of endpoint is this? */
1226	enum sctp_endpoint_type type;
1227
1228	/* Some fields to help us manage this object.
1229	 *   refcnt   - Reference count access to this object.
1230	 *   dead     - Do not attempt to use this object.
1231	 */
1232	refcount_t    refcnt;
1233	bool	    dead;
1234
1235	/* What socket does this endpoint belong to?  */
1236	struct sock *sk;
1237
1238	/* Cache netns and it won't change once set */
1239	struct net *net;
1240
1241	/* This is where we receive inbound chunks.  */
1242	struct sctp_inq	  inqueue;
1243
1244	/* This substructure includes the defining parameters of the
1245	 * endpoint:
1246	 * bind_addr.port is our shared port number.
1247	 * bind_addr.address_list is our set of local IP addresses.
1248	 */
1249	struct sctp_bind_addr bind_addr;
1250};
1251
1252
1253/* RFC Section 1.4 Key Terms
1254 *
1255 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1256 *   multi-homed host, an SCTP endpoint is represented to its peers as a
1257 *   combination of a set of eligible destination transport addresses to
1258 *   which SCTP packets can be sent and a set of eligible source
1259 *   transport addresses from which SCTP packets can be received.
1260 *   All transport addresses used by an SCTP endpoint must use the
1261 *   same port number, but can use multiple IP addresses. A transport
1262 *   address used by an SCTP endpoint must not be used by another
1263 *   SCTP endpoint. In other words, a transport address is unique
1264 *   to an SCTP endpoint.
1265 *
1266 * From an implementation perspective, each socket has one of these.
1267 * A TCP-style socket will have exactly one association on one of
1268 * these.  An UDP-style socket will have multiple associations hanging
1269 * off one of these.
1270 */
1271
1272struct sctp_endpoint {
1273	/* Common substructure for endpoint and association. */
1274	struct sctp_ep_common base;
1275
1276	/* Associations: A list of current associations and mappings
1277	 *	      to the data consumers for each association. This
1278	 *	      may be in the form of a hash table or other
1279	 *	      implementation dependent structure. The data
1280	 *	      consumers may be process identification
1281	 *	      information such as file descriptors, named pipe
1282	 *	      pointer, or table pointers dependent on how SCTP
1283	 *	      is implemented.
1284	 */
1285	/* This is really a list of struct sctp_association entries. */
1286	struct list_head asocs;
1287
1288	/* Secret Key: A secret key used by this endpoint to compute
1289	 *	      the MAC.	This SHOULD be a cryptographic quality
1290	 *	      random number with a sufficient length.
1291	 *	      Discussion in [RFC1750] can be helpful in
1292	 *	      selection of the key.
1293	 */
1294	__u8 secret_key[SCTP_SECRET_SIZE];
1295
1296 	/* digest:  This is a digest of the sctp cookie.  This field is
1297 	 * 	    only used on the receive path when we try to validate
1298 	 * 	    that the cookie has not been tampered with.  We put
1299 	 * 	    this here so we pre-allocate this once and can re-use
1300 	 * 	    on every receive.
1301 	 */
1302 	__u8 *digest;
1303
1304	/* sendbuf acct. policy.	*/
1305	__u32 sndbuf_policy;
1306
1307	/* rcvbuf acct. policy.	*/
1308	__u32 rcvbuf_policy;
1309
1310	/* SCTP AUTH: array of the HMACs that will be allocated
1311	 * we need this per association so that we don't serialize
1312	 */
1313	struct crypto_shash **auth_hmacs;
1314
1315	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1316	 struct sctp_hmac_algo_param *auth_hmacs_list;
1317
1318	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1319	struct sctp_chunks_param *auth_chunk_list;
1320
1321	/* SCTP-AUTH: endpoint shared keys */
1322	struct list_head endpoint_shared_keys;
1323	__u16 active_key_id;
1324	__u8  ecn_enable:1,
1325	      auth_enable:1,
1326	      intl_enable:1,
1327	      prsctp_enable:1,
1328	      asconf_enable:1,
1329	      reconf_enable:1;
1330
1331	__u8  strreset_enable;
1332
1333	/* Security identifiers from incoming (INIT). These are set by
1334	 * security_sctp_assoc_request(). These will only be used by
1335	 * SCTP TCP type sockets and peeled off connections as they
1336	 * cause a new socket to be generated. security_sctp_sk_clone()
1337	 * will then plug these into the new socket.
1338	 */
1339
1340	u32 secid;
1341	u32 peer_secid;
1342	struct rcu_head rcu;
1343};
1344
1345/* Recover the outter endpoint structure. */
1346static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1347{
1348	struct sctp_endpoint *ep;
1349
1350	ep = container_of(base, struct sctp_endpoint, base);
1351	return ep;
1352}
1353
1354/* These are function signatures for manipulating endpoints.  */
1355struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1356void sctp_endpoint_free(struct sctp_endpoint *);
1357void sctp_endpoint_put(struct sctp_endpoint *);
1358int sctp_endpoint_hold(struct sctp_endpoint *ep);
1359void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1360struct sctp_association *sctp_endpoint_lookup_assoc(
1361	const struct sctp_endpoint *ep,
1362	const union sctp_addr *paddr,
1363	struct sctp_transport **);
1364bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1365				 const union sctp_addr *paddr);
1366struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1367					struct net *, const union sctp_addr *);
1368bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1369			  const union sctp_addr *paddr);
1370
1371int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1372		     const struct sctp_association *asoc,
1373		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1374		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1375int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1376		      const union sctp_addr *peer,
1377		      struct sctp_init_chunk *init, gfp_t gfp);
1378__u32 sctp_generate_tag(const struct sctp_endpoint *);
1379__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1380
1381struct sctp_inithdr_host {
1382	__u32 init_tag;
1383	__u32 a_rwnd;
1384	__u16 num_outbound_streams;
1385	__u16 num_inbound_streams;
1386	__u32 initial_tsn;
1387};
1388
1389struct sctp_stream_priorities {
1390	/* List of priorities scheduled */
1391	struct list_head prio_sched;
1392	/* List of streams scheduled */
1393	struct list_head active;
1394	/* The next stream in line */
1395	struct sctp_stream_out_ext *next;
1396	__u16 prio;
1397	__u16 users;
1398};
1399
1400struct sctp_stream_out_ext {
1401	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1402	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1403	struct list_head outq; /* chunks enqueued by this stream */
1404	union {
1405		struct {
1406			/* Scheduled streams list */
1407			struct list_head prio_list;
1408			struct sctp_stream_priorities *prio_head;
1409		};
1410		/* Fields used by RR scheduler */
1411		struct {
1412			struct list_head rr_list;
1413		};
1414	};
1415};
1416
1417struct sctp_stream_out {
1418	union {
1419		__u32 mid;
1420		__u16 ssn;
1421	};
1422	__u32 mid_uo;
1423	struct sctp_stream_out_ext *ext;
1424	__u8 state;
1425};
1426
1427struct sctp_stream_in {
1428	union {
1429		__u32 mid;
1430		__u16 ssn;
1431	};
1432	__u32 mid_uo;
1433	__u32 fsn;
1434	__u32 fsn_uo;
1435	char pd_mode;
1436	char pd_mode_uo;
1437};
1438
1439struct sctp_stream {
1440	GENRADIX(struct sctp_stream_out) out;
1441	GENRADIX(struct sctp_stream_in)	in;
1442
1443	__u16 outcnt;
1444	__u16 incnt;
1445	/* Current stream being sent, if any */
1446	struct sctp_stream_out *out_curr;
1447	union {
1448		/* Fields used by priority scheduler */
1449		struct {
1450			/* List of priorities scheduled */
1451			struct list_head prio_list;
1452		};
1453		/* Fields used by RR scheduler */
1454		struct {
1455			/* List of streams scheduled */
1456			struct list_head rr_list;
1457			/* The next stream in line */
1458			struct sctp_stream_out_ext *rr_next;
1459		};
1460	};
1461	struct sctp_stream_interleave *si;
1462};
1463
1464static inline struct sctp_stream_out *sctp_stream_out(
1465	struct sctp_stream *stream,
1466	__u16 sid)
1467{
1468	return genradix_ptr(&stream->out, sid);
1469}
1470
1471static inline struct sctp_stream_in *sctp_stream_in(
1472	struct sctp_stream *stream,
1473	__u16 sid)
1474{
1475	return genradix_ptr(&stream->in, sid);
1476}
1477
1478#define SCTP_SO(s, i) sctp_stream_out((s), (i))
1479#define SCTP_SI(s, i) sctp_stream_in((s), (i))
1480
1481#define SCTP_STREAM_CLOSED		0x00
1482#define SCTP_STREAM_OPEN		0x01
1483
1484static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1485{
1486	return stream->si->data_chunk_len;
1487}
1488
1489static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1490{
1491	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1492}
1493
1494static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1495{
1496	return stream->si->ftsn_chunk_len;
1497}
1498
1499static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1500{
1501	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1502}
1503
1504/* SCTP_GET_ASSOC_STATS counters */
1505struct sctp_priv_assoc_stats {
1506	/* Maximum observed rto in the association during subsequent
1507	 * observations. Value is set to 0 if no RTO measurement took place
1508	 * The transport where the max_rto was observed is returned in
1509	 * obs_rto_ipaddr
1510	 */
1511	struct sockaddr_storage obs_rto_ipaddr;
1512	__u64 max_obs_rto;
1513	/* Total In and Out SACKs received and sent */
1514	__u64 isacks;
1515	__u64 osacks;
1516	/* Total In and Out packets received and sent */
1517	__u64 opackets;
1518	__u64 ipackets;
1519	/* Total retransmitted chunks */
1520	__u64 rtxchunks;
1521	/* TSN received > next expected */
1522	__u64 outofseqtsns;
1523	/* Duplicate Chunks received */
1524	__u64 idupchunks;
1525	/* Gap Ack Blocks received */
1526	__u64 gapcnt;
1527	/* Unordered data chunks sent and received */
1528	__u64 ouodchunks;
1529	__u64 iuodchunks;
1530	/* Ordered data chunks sent and received */
1531	__u64 oodchunks;
1532	__u64 iodchunks;
1533	/* Control chunks sent and received */
1534	__u64 octrlchunks;
1535	__u64 ictrlchunks;
1536};
1537
1538/* RFC2960
1539 *
1540 * 12. Recommended Transmission Control Block (TCB) Parameters
1541 *
1542 * This section details a recommended set of parameters that should
1543 * be contained within the TCB for an implementation. This section is
1544 * for illustrative purposes and should not be deemed as requirements
1545 * on an implementation or as an exhaustive list of all parameters
1546 * inside an SCTP TCB. Each implementation may need its own additional
1547 * parameters for optimization.
1548 */
1549
1550
1551/* Here we have information about each individual association. */
1552struct sctp_association {
1553
1554	/* A base structure common to endpoint and association.
1555	 * In this context, it represents the associations's view
1556	 * of the local endpoint of the association.
1557	 */
1558	struct sctp_ep_common base;
1559
1560	/* Associations on the same socket. */
1561	struct list_head asocs;
1562
1563	/* association id. */
1564	sctp_assoc_t assoc_id;
1565
1566	/* This is our parent endpoint.	 */
1567	struct sctp_endpoint *ep;
1568
1569	/* These are those association elements needed in the cookie.  */
1570	struct sctp_cookie c;
1571
1572	/* This is all information about our peer.  */
1573	struct {
1574		/* transport_addr_list
1575		 *
1576		 * Peer	       : A list of SCTP transport addresses that the
1577		 * Transport   : peer is bound to. This information is derived
1578		 * Address     : from the INIT or INIT ACK and is used to
1579		 * List	       : associate an inbound packet with a given
1580		 *	       : association. Normally this information is
1581		 *	       : hashed or keyed for quick lookup and access
1582		 *	       : of the TCB.
1583		 *	       : The list is also initialized with the list
1584		 *	       : of addresses passed with the sctp_connectx()
1585		 *	       : call.
1586		 *
1587		 * It is a list of SCTP_transport's.
1588		 */
1589		struct list_head transport_addr_list;
1590
1591		/* rwnd
1592		 *
1593		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1594		 */
1595		__u32 rwnd;
1596
1597		/* transport_count
1598		 *
1599		 * Peer        : A count of the number of peer addresses
1600		 * Transport   : in the Peer Transport Address List.
1601		 * Address     :
1602		 * Count       :
1603		 */
1604		__u16 transport_count;
1605
1606		/* port
1607		 *   The transport layer port number.
1608		 */
1609		__u16 port;
1610
1611		/* primary_path
1612		 *
1613		 * Primary     : This is the current primary destination
1614		 * Path	       : transport address of the peer endpoint.  It
1615		 *	       : may also specify a source transport address
1616		 *	       : on this endpoint.
1617		 *
1618		 * All of these paths live on transport_addr_list.
1619		 *
1620		 * At the bakeoffs, we discovered that the intent of
1621		 * primaryPath is that it only changes when the ULP
1622		 * asks to have it changed.  We add the activePath to
1623		 * designate the connection we are currently using to
1624		 * transmit new data and most control chunks.
1625		 */
1626		struct sctp_transport *primary_path;
1627
1628		/* Cache the primary path address here, when we
1629		 * need a an address for msg_name.
1630		 */
1631		union sctp_addr primary_addr;
1632
1633		/* active_path
1634		 *   The path that we are currently using to
1635		 *   transmit new data and most control chunks.
1636		 */
1637		struct sctp_transport *active_path;
1638
1639		/* retran_path
1640		 *
1641		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1642		 * ...
1643		 * Furthermore, when its peer is multi-homed, an
1644		 * endpoint SHOULD try to retransmit a chunk to an
1645		 * active destination transport address that is
1646		 * different from the last destination address to
1647		 * which the DATA chunk was sent.
1648		 */
1649		struct sctp_transport *retran_path;
1650
1651		/* Pointer to last transport I have sent on.  */
1652		struct sctp_transport *last_sent_to;
1653
1654		/* This is the last transport I have received DATA on.	*/
1655		struct sctp_transport *last_data_from;
1656
1657		/*
1658		 * Mapping  An array of bits or bytes indicating which out of
1659		 * Array    order TSN's have been received (relative to the
1660		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1661		 *	    order packets have been received, this array
1662		 *	    will be set to all zero. This structure may be
1663		 *	    in the form of a circular buffer or bit array.
1664		 *
1665		 * Last Rcvd   : This is the last TSN received in
1666		 * TSN	       : sequence. This value is set initially by
1667		 *	       : taking the peer's Initial TSN, received in
1668		 *	       : the INIT or INIT ACK chunk, and subtracting
1669		 *	       : one from it.
1670		 *
1671		 * Throughout most of the specification this is called the
1672		 * "Cumulative TSN ACK Point".	In this case, we
1673		 * ignore the advice in 12.2 in favour of the term
1674		 * used in the bulk of the text.  This value is hidden
1675		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1676		 */
1677		struct sctp_tsnmap tsn_map;
1678
1679		/* This mask is used to disable sending the ASCONF chunk
1680		 * with specified parameter to peer.
1681		 */
1682		__be16 addip_disabled_mask;
1683
1684		/* These are capabilities which our peer advertised.  */
1685		__u16	ecn_capable:1,      /* Can peer do ECN? */
1686			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1687			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1688			hostname_address:1, /* Peer understands DNS addresses? */
1689			asconf_capable:1,   /* Does peer support ADDIP? */
1690			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1691			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1692			intl_capable:1,     /* Can peer do INTERLEAVE */
1693			auth_capable:1,     /* Is peer doing SCTP-AUTH? */
1694			/* sack_needed:
1695			 *   This flag indicates if the next received
1696			 *   packet is to be responded to with a
1697			 *   SACK. This is initialized to 0.  When a packet
1698			 *   is received sack_cnt is incremented. If this value
1699			 *   reaches 2 or more, a SACK is sent and the
1700			 *   value is reset to 0. Note: This is used only
1701			 *   when no DATA chunks are received out of
1702			 *   order.  When DATA chunks are out of order,
1703			 *   SACK's are not delayed (see Section 6).
1704			 */
1705			sack_needed:1,     /* Do we need to sack the peer? */
1706			sack_generation:1,
1707			zero_window_announced:1;
1708
1709		__u32	sack_cnt;
1710
1711		__u32   adaptation_ind;	 /* Adaptation Code point. */
1712
1713		struct sctp_inithdr_host i;
1714		void *cookie;
1715		int cookie_len;
1716
1717		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1718		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1719		 * Initial TSN Value minus 1
1720		 */
1721		__u32 addip_serial;
1722
1723		/* SCTP-AUTH: We need to know pears random number, hmac list
1724		 * and authenticated chunk list.  All that is part of the
1725		 * cookie and these are just pointers to those locations
1726		 */
1727		struct sctp_random_param *peer_random;
1728		struct sctp_chunks_param *peer_chunks;
1729		struct sctp_hmac_algo_param *peer_hmacs;
1730	} peer;
1731
1732	/* State       : A state variable indicating what state the
1733	 *	       : association is in, i.e. COOKIE-WAIT,
1734	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1735	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1736	 *
1737	 *		Note: No "CLOSED" state is illustrated since if a
1738	 *		association is "CLOSED" its TCB SHOULD be removed.
1739	 *
1740	 *		In this implementation we DO have a CLOSED
1741	 *		state which is used during initiation and shutdown.
1742	 *
1743	 *		State takes values from SCTP_STATE_*.
1744	 */
1745	enum sctp_state state;
1746
1747	/* Overall     : The overall association error count.
1748	 * Error Count : [Clear this any time I get something.]
1749	 */
1750	int overall_error_count;
1751
1752	/* The cookie life I award for any cookie.  */
1753	ktime_t cookie_life;
1754
1755	/* These are the association's initial, max, and min RTO values.
1756	 * These values will be initialized by system defaults, but can
1757	 * be modified via the SCTP_RTOINFO socket option.
1758	 */
1759	unsigned long rto_initial;
1760	unsigned long rto_max;
1761	unsigned long rto_min;
1762
1763	/* Maximum number of new data packets that can be sent in a burst.  */
1764	int max_burst;
1765
1766	/* This is the max_retrans value for the association.  This value will
1767	 * be initialized from system defaults, but can be
1768	 * modified by the SCTP_ASSOCINFO socket option.
1769	 */
1770	int max_retrans;
1771
1772	/* This is the partially failed retrans value for the transport
1773	 * and will be initialized from the assocs value.  This can be
1774	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1775	 */
1776	__u16 pf_retrans;
1777	/* Used for primary path switchover. */
1778	__u16 ps_retrans;
1779
1780	/* Maximum number of times the endpoint will retransmit INIT  */
1781	__u16 max_init_attempts;
1782
1783	/* How many times have we resent an INIT? */
1784	__u16 init_retries;
1785
1786	/* The largest timeout or RTO value to use in attempting an INIT */
1787	unsigned long max_init_timeo;
1788
1789	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1790	 * the destination address every heartbeat interval. This value
1791	 * will be inherited by all new transports.
1792	 */
1793	unsigned long hbinterval;
1794
1795	/* This is the max_retrans value for new transports in the
1796	 * association.
1797	 */
1798	__u16 pathmaxrxt;
1799
1800	__u32 flowlabel;
1801	__u8  dscp;
1802
1803	/* Flag that path mtu update is pending */
1804	__u8   pmtu_pending;
1805
1806	/* Association : The smallest PMTU discovered for all of the
1807	 * PMTU	       : peer's transport addresses.
1808	 */
1809	__u32 pathmtu;
1810
1811	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1812	__u32 param_flags;
1813
1814	__u32 sackfreq;
1815	/* SACK delay timeout */
1816	unsigned long sackdelay;
1817
1818	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1819	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1820
1821	/* Transport to which SHUTDOWN chunk was last sent.  */
1822	struct sctp_transport *shutdown_last_sent_to;
1823
1824	/* Transport to which INIT chunk was last sent.  */
1825	struct sctp_transport *init_last_sent_to;
1826
1827	/* How many times have we resent a SHUTDOWN */
1828	int shutdown_retries;
1829
1830	/* Next TSN    : The next TSN number to be assigned to a new
1831	 *	       : DATA chunk.  This is sent in the INIT or INIT
1832	 *	       : ACK chunk to the peer and incremented each
1833	 *	       : time a DATA chunk is assigned a TSN
1834	 *	       : (normally just prior to transmit or during
1835	 *	       : fragmentation).
1836	 */
1837	__u32 next_tsn;
1838
1839	/*
1840	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1841	 * TSN	       : is set initially by taking the peer's Initial TSN,
1842	 *	       : received in the INIT or INIT ACK chunk, and
1843	 *	       : subtracting one from it.
1844	 *
1845	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1846	 */
1847
1848	__u32 ctsn_ack_point;
1849
1850	/* PR-SCTP Advanced.Peer.Ack.Point */
1851	__u32 adv_peer_ack_point;
1852
1853	/* Highest TSN that is acknowledged by incoming SACKs. */
1854	__u32 highest_sacked;
1855
1856	/* TSN marking the fast recovery exit point */
1857	__u32 fast_recovery_exit;
1858
1859	/* Flag to track the current fast recovery state */
1860	__u8 fast_recovery;
1861
1862	/* The number of unacknowledged data chunks.  Reported through
1863	 * the SCTP_STATUS sockopt.
1864	 */
1865	__u16 unack_data;
1866
1867	/* The total number of data chunks that we've had to retransmit
1868	 * as the result of a T3 timer expiration
1869	 */
1870	__u32 rtx_data_chunks;
1871
1872	/* This is the association's receive buffer space.  This value is used
1873	 * to set a_rwnd field in an INIT or a SACK chunk.
1874	 */
1875	__u32 rwnd;
1876
1877	/* This is the last advertised value of rwnd over a SACK chunk. */
1878	__u32 a_rwnd;
1879
1880	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1881	 * to slop over a maximum of the association's frag_point.
1882	 */
1883	__u32 rwnd_over;
1884
1885	/* Keeps treack of rwnd pressure.  This happens when we have
1886	 * a window, but not recevie buffer (i.e small packets).  This one
1887	 * is releases slowly (1 PMTU at a time ).
1888	 */
1889	__u32 rwnd_press;
1890
1891	/* This is the sndbuf size in use for the association.
1892	 * This corresponds to the sndbuf size for the association,
1893	 * as specified in the sk->sndbuf.
1894	 */
1895	int sndbuf_used;
1896
1897	/* This is the amount of memory that this association has allocated
1898	 * in the receive path at any given time.
1899	 */
1900	atomic_t rmem_alloc;
1901
1902	/* This is the wait queue head for send requests waiting on
1903	 * the association sndbuf space.
1904	 */
1905	wait_queue_head_t	wait;
1906
1907	/* The message size at which SCTP fragmentation will occur. */
1908	__u32 frag_point;
1909	__u32 user_frag;
1910
1911	/* Counter used to count INIT errors. */
1912	int init_err_counter;
1913
1914	/* Count the number of INIT cycles (for doubling timeout). */
1915	int init_cycle;
1916
1917	/* Default send parameters. */
1918	__u16 default_stream;
1919	__u16 default_flags;
1920	__u32 default_ppid;
1921	__u32 default_context;
1922	__u32 default_timetolive;
1923
1924	/* Default receive parameters */
1925	__u32 default_rcv_context;
1926
1927	/* Stream arrays */
1928	struct sctp_stream stream;
1929
1930	/* All outbound chunks go through this structure.  */
1931	struct sctp_outq outqueue;
1932
1933	/* A smart pipe that will handle reordering and fragmentation,
1934	 * as well as handle passing events up to the ULP.
1935	 */
1936	struct sctp_ulpq ulpq;
1937
1938	/* Last TSN that caused an ECNE Chunk to be sent.  */
1939	__u32 last_ecne_tsn;
1940
1941	/* Last TSN that caused a CWR Chunk to be sent.	 */
1942	__u32 last_cwr_tsn;
1943
1944	/* How many duplicated TSNs have we seen?  */
1945	int numduptsns;
1946
1947	/* These are to support
1948	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1949	 *  and Enforcement of Flow and Message Limits"
1950	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1951	 * or "ADDIP" for short.
1952	 */
1953
1954
1955
1956	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1957	 *
1958	 * R1) One and only one ASCONF Chunk MAY be in transit and
1959	 * unacknowledged at any one time.  If a sender, after sending
1960	 * an ASCONF chunk, decides it needs to transfer another
1961	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1962	 * returns from the previous ASCONF Chunk before sending a
1963	 * subsequent ASCONF. Note this restriction binds each side,
1964	 * so at any time two ASCONF may be in-transit on any given
1965	 * association (one sent from each endpoint).
1966	 *
1967	 * [This is our one-and-only-one ASCONF in flight.  If we do
1968	 * not have an ASCONF in flight, this is NULL.]
1969	 */
1970	struct sctp_chunk *addip_last_asconf;
1971
1972	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1973	 *
1974	 * This is needed to implement itmes E1 - E4 of the updated
1975	 * spec.  Here is the justification:
1976	 *
1977	 * Since the peer may bundle multiple ASCONF chunks toward us,
1978	 * we now need the ability to cache multiple ACKs.  The section
1979	 * describes in detail how they are cached and cleaned up.
1980	 */
1981	struct list_head asconf_ack_list;
1982
1983	/* These ASCONF chunks are waiting to be sent.
1984	 *
1985	 * These chunaks can't be pushed to outqueue until receiving
1986	 * ASCONF_ACK for the previous ASCONF indicated by
1987	 * addip_last_asconf, so as to guarantee that only one ASCONF
1988	 * is in flight at any time.
1989	 *
1990	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1991	 *
1992	 * In defining the ASCONF Chunk transfer procedures, it is
1993	 * essential that these transfers MUST NOT cause congestion
1994	 * within the network.	To achieve this, we place these
1995	 * restrictions on the transfer of ASCONF Chunks:
1996	 *
1997	 * R1) One and only one ASCONF Chunk MAY be in transit and
1998	 * unacknowledged at any one time.  If a sender, after sending
1999	 * an ASCONF chunk, decides it needs to transfer another
2000	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2001	 * returns from the previous ASCONF Chunk before sending a
2002	 * subsequent ASCONF. Note this restriction binds each side,
2003	 * so at any time two ASCONF may be in-transit on any given
2004	 * association (one sent from each endpoint).
2005	 *
2006	 *
2007	 * [I really think this is EXACTLY the sort of intelligence
2008	 *  which already resides in sctp_outq.	 Please move this
2009	 *  queue and its supporting logic down there.	--piggy]
2010	 */
2011	struct list_head addip_chunk_list;
2012
2013	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2014	 *
2015	 * A2) A serial number should be assigned to the Chunk. The
2016	 * serial number SHOULD be a monotonically increasing
2017	 * number. The serial number SHOULD be initialized at
2018	 * the start of the association to the same value as the
2019	 * Initial TSN and every time a new ASCONF chunk is created
2020	 * it is incremented by one after assigning the serial number
2021	 * to the newly created chunk.
2022	 *
2023	 * ADDIP
2024	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2025	 *
2026	 * Serial Number : 32 bits (unsigned integer)
2027	 *
2028	 * This value represents a Serial Number for the ASCONF
2029	 * Chunk. The valid range of Serial Number is from 0 to
2030	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2031	 * after reaching 4294967295.
2032	 */
2033	__u32 addip_serial;
2034	int src_out_of_asoc_ok;
2035	union sctp_addr *asconf_addr_del_pending;
2036	struct sctp_transport *new_transport;
2037
2038	/* SCTP AUTH: list of the endpoint shared keys.  These
2039	 * keys are provided out of band by the user applicaton
2040	 * and can't change during the lifetime of the association
2041	 */
2042	struct list_head endpoint_shared_keys;
2043
2044	/* SCTP AUTH:
2045	 * The current generated assocaition shared key (secret)
2046	 */
2047	struct sctp_auth_bytes *asoc_shared_key;
2048	struct sctp_shared_key *shkey;
2049
2050	/* SCTP AUTH: hmac id of the first peer requested algorithm
2051	 * that we support.
2052	 */
2053	__u16 default_hmac_id;
2054
2055	__u16 active_key_id;
2056
2057	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2058	     temp:1,		/* Is it a temporary association? */
2059	     pf_expose:2,       /* Expose pf state? */
2060	     force_delay:1;
2061
2062	__u8 strreset_enable;
2063	__u8 strreset_outstanding; /* request param count on the fly */
2064
2065	__u32 strreset_outseq; /* Update after receiving response */
2066	__u32 strreset_inseq; /* Update after receiving request */
2067	__u32 strreset_result[2]; /* save the results of last 2 responses */
2068
2069	struct sctp_chunk *strreset_chunk; /* save request chunk */
2070
2071	struct sctp_priv_assoc_stats stats;
2072
2073	int sent_cnt_removable;
2074
2075	__u16 subscribe;
2076
2077	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2078	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2079
2080	struct rcu_head rcu;
2081};
2082
2083
2084/* An eyecatcher for determining if we are really looking at an
2085 * association data structure.
2086 */
2087enum {
2088	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2089};
2090
2091/* Recover the outter association structure. */
2092static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2093{
2094	struct sctp_association *asoc;
2095
2096	asoc = container_of(base, struct sctp_association, base);
2097	return asoc;
2098}
2099
2100/* These are function signatures for manipulating associations.	 */
2101
2102
2103struct sctp_association *
2104sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2105		     enum sctp_scope scope, gfp_t gfp);
2106void sctp_association_free(struct sctp_association *);
2107void sctp_association_put(struct sctp_association *);
2108void sctp_association_hold(struct sctp_association *);
2109
2110struct sctp_transport *sctp_assoc_choose_alter_transport(
2111	struct sctp_association *, struct sctp_transport *);
2112void sctp_assoc_update_retran_path(struct sctp_association *);
2113struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2114					  const union sctp_addr *);
2115int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2116			    const union sctp_addr *laddr);
2117struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2118				     const union sctp_addr *address,
2119				     const gfp_t gfp,
2120				     const int peer_state);
2121void sctp_assoc_del_peer(struct sctp_association *asoc,
2122			 const union sctp_addr *addr);
2123void sctp_assoc_rm_peer(struct sctp_association *asoc,
2124			 struct sctp_transport *peer);
2125void sctp_assoc_control_transport(struct sctp_association *asoc,
2126				  struct sctp_transport *transport,
2127				  enum sctp_transport_cmd command,
2128				  sctp_sn_error_t error);
2129struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2130void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2131int sctp_assoc_update(struct sctp_association *old,
2132		      struct sctp_association *new);
2133
2134__u32 sctp_association_get_next_tsn(struct sctp_association *);
2135
2136void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2137void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2138void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2139void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2140void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2141void sctp_assoc_set_primary(struct sctp_association *,
2142			    struct sctp_transport *);
2143void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2144				    struct sctp_transport *);
2145int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2146				     enum sctp_scope scope, gfp_t gfp);
2147int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2148					 struct sctp_cookie*,
2149					 gfp_t gfp);
2150int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2151void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2152struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2153					const struct sctp_association *asoc,
2154					__be32 serial);
2155void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2156
2157int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2158			const union sctp_addr *ss2);
2159struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2160
2161/* A convenience structure to parse out SCTP specific CMSGs. */
2162struct sctp_cmsgs {
2163	struct sctp_initmsg *init;
2164	struct sctp_sndrcvinfo *srinfo;
2165	struct sctp_sndinfo *sinfo;
2166	struct sctp_prinfo *prinfo;
2167	struct sctp_authinfo *authinfo;
2168	struct msghdr *addrs_msg;
2169};
2170
2171/* Structure for tracking memory objects */
2172struct sctp_dbg_objcnt_entry {
2173	char *label;
2174	atomic_t *counter;
2175};
2176
2177#endif /* __sctp_structs_h__ */
2178