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	*/
53	union sctp_addr {
54	struct sockaddr_in v4;
55	struct sockaddr_in6 v6;
56	struct sockaddr sa;
57	};
58
59	/* Forward declarations for data structures. */
60	struct sctp_globals;
61	struct sctp_endpoint;
62	struct sctp_association;
63	struct sctp_transport;
64	struct sctp_packet;
65	struct sctp_chunk;
66	struct sctp_inq;
67	struct sctp_outq;
68	struct sctp_bind_addr;
69	struct sctp_ulpq;
70	struct sctp_ep_common;
71	struct crypto_shash;
72	struct 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
82	struct 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
92	struct sctp_bind_hashbucket {
93	spinlock_t lock;
94	struct hlist_head chain;
95	};
96
97	/* Used for hashing all associations. */
98	struct sctp_hashbucket {
99	rwlock_t lock;
100	struct hlist_head chain;
101	} __attribute__((__aligned__(8)));
102
103
104	/* The SCTP globals structure. */
105	extern struct sctp_globals {
106	/* This is a list of groups of functions for each address
107	* family that we support.
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. */
142	enum 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. */
149	struct 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	__u32 probe_interval;
181
182	__be16 udp_port;
183	__be16 encap_port;
184
185	/* This is the max_retrans value for new associations. */
186	__u16 pathmaxrxt;
187
188	__u32 flowlabel;
189	__u8 dscp;
190
191	__u16 pf_retrans;
192	__u16 ps_retrans;
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	__u32 default_ss;
205
206	struct sctp_rtoinfo rtoinfo;
207	struct sctp_paddrparams paddrparam;
208	struct sctp_assocparams assocparams;
209
210	/*
211	* These two structures must be grouped together for the usercopy
212	* whitelist region.
213	*/
214	__u16 subscribe;
215	struct sctp_initmsg initmsg;
216
217	int user_frag;
218
219	__u32 autoclose;
220	__u32 adaptation_ind;
221	__u32 pd_point;
222	__u16 nodelay:1,
223	pf_expose:2,
224	reuse:1,
225	disable_fragments:1,
226	v4mapped:1,
227	frag_interleave:1,
228	recvrcvinfo:1,
229	recvnxtinfo:1,
230	data_ready_signalled:1;
231
232	atomic_t pd_mode;
233
234	/* Fields after this point will be skipped on copies, like on accept
235	* and peeloff operations
236	*/
237
238	/* Receive to here while partial delivery is in effect. */
239	struct sk_buff_head pd_lobby;
240
241	struct list_head auto_asconf_list;
242	int do_auto_asconf;
243	};
244
245	#define sctp_sk(ptr) container_of_const(ptr, struct sctp_sock, inet.sk)
246
247	static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
248	{
249	return (struct sock *)sp;
250	}
251
252	#if IS_ENABLED(CONFIG_IPV6)
253	struct sctp6_sock {
254	struct sctp_sock sctp;
255	struct ipv6_pinfo inet6;
256	};
257	#endif /* CONFIG_IPV6 */
258
259
260	/* This is our APPLICATION-SPECIFIC state cookie.
261	* THIS IS NOT DICTATED BY THE SPECIFICATION.
262	*/
263	/* These are the parts of an association which we send in the cookie.
264	* Most of these are straight out of:
265	* RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
266	*
267	*/
268
269	struct sctp_cookie {
270
271	/* My : Tag expected in every inbound packet and sent
272	* Verification: in the INIT or INIT ACK chunk.
273	* Tag :
274	*/
275	__u32 my_vtag;
276
277	/* Peer's : Tag expected in every outbound packet except
278	* Verification: in the INIT chunk.
279	* Tag :
280	*/
281	__u32 peer_vtag;
282
283	/* The rest of these are not from the spec, but really need to
284	* be in the cookie.
285	*/
286
287	/* My Tie Tag : Assist in discovering a restarting association. */
288	__u32 my_ttag;
289
290	/* Peer's Tie Tag: Assist in discovering a restarting association. */
291	__u32 peer_ttag;
292
293	/* When does this cookie expire? */
294	ktime_t expiration;
295
296	/* Number of inbound/outbound streams which are set
297	* and negotiated during the INIT process.
298	*/
299	__u16 sinit_num_ostreams;
300	__u16 sinit_max_instreams;
301
302	/* This is the first sequence number I used. */
303	__u32 initial_tsn;
304
305	/* This holds the originating address of the INIT packet. */
306	union sctp_addr peer_addr;
307
308	/* IG Section 2.35.3
309	* Include the source port of the INIT-ACK
310	*/
311	__u16 my_port;
312
313	__u8 prsctp_capable;
314
315	/* Padding for future use */
316	__u8 padding;
317
318	__u32 adaptation_ind;
319
320	__u8 auth_random[sizeof(struct sctp_paramhdr) +
321	SCTP_AUTH_RANDOM_LENGTH];
322	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
323	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
324
325	/* This is a shim for my peer's INIT packet, followed by
326	* a copy of the raw address list of the association.
327	* The length of the raw address list is saved in the
328	* raw_addr_list_len field, which will be used at the time when
329	* the association TCB is re-constructed from the cookie.
330	*/
331	__u32 raw_addr_list_len;
332	/* struct sctp_init_chunk peer_init[]; */
333	};
334
335
336	/* The format of our cookie that we send to our peer. */
337	struct sctp_signed_cookie {
338	__u8 signature[SCTP_SECRET_SIZE];
339	__u32 __pad; /* force sctp_cookie alignment to 64 bits */
340	struct sctp_cookie c;
341	} __packed;
342
343	/* This is another convenience type to allocate memory for address
344	* params for the maximum size and pass such structures around
345	* internally.
346	*/
347	union sctp_addr_param {
348	struct sctp_paramhdr p;
349	struct sctp_ipv4addr_param v4;
350	struct sctp_ipv6addr_param v6;
351	};
352
353	/* A convenience type to allow walking through the various
354	* parameters and avoid casting all over the place.
355	*/
356	union sctp_params {
357	void *v;
358	struct sctp_paramhdr *p;
359	struct sctp_cookie_preserve_param *life;
360	struct sctp_hostname_param *dns;
361	struct sctp_cookie_param *cookie;
362	struct sctp_supported_addrs_param *sat;
363	struct sctp_ipv4addr_param *v4;
364	struct sctp_ipv6addr_param *v6;
365	union sctp_addr_param *addr;
366	struct sctp_adaptation_ind_param *aind;
367	struct sctp_supported_ext_param *ext;
368	struct sctp_random_param *random;
369	struct sctp_chunks_param *chunks;
370	struct sctp_hmac_algo_param *hmac_algo;
371	struct sctp_addip_param *addip;
372	};
373
374	/* RFC 2960. Section 3.3.5 Heartbeat.
375	* Heartbeat Information: variable length
376	* The Sender-specific Heartbeat Info field should normally include
377	* information about the sender's current time when this HEARTBEAT
378	* chunk is sent and the destination transport address to which this
379	* HEARTBEAT is sent (see Section 8.3).
380	*/
381	struct sctp_sender_hb_info {
382	struct sctp_paramhdr param_hdr;
383	union sctp_addr daddr;
384	unsigned long sent_at;
385	__u64 hb_nonce;
386	__u32 probe_size;
387	};
388
389	int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
390	gfp_t gfp);
391	int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
392	void sctp_stream_free(struct sctp_stream *stream);
393	void sctp_stream_clear(struct sctp_stream *stream);
394	void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
395
396	/* What is the current SSN number for this stream? */
397	#define sctp_ssn_peek(stream, type, sid) \
398	(sctp_stream_##type((stream), (sid))->ssn)
399
400	/* Return the next SSN number for this stream. */
401	#define sctp_ssn_next(stream, type, sid) \
402	(sctp_stream_##type((stream), (sid))->ssn++)
403
404	/* Skip over this ssn and all below. */
405	#define sctp_ssn_skip(stream, type, sid, ssn) \
406	(sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
407
408	/* What is the current MID number for this stream? */
409	#define sctp_mid_peek(stream, type, sid) \
410	(sctp_stream_##type((stream), (sid))->mid)
411
412	/* Return the next MID number for this stream. */
413	#define sctp_mid_next(stream, type, sid) \
414	(sctp_stream_##type((stream), (sid))->mid++)
415
416	/* Skip over this mid and all below. */
417	#define sctp_mid_skip(stream, type, sid, mid) \
418	(sctp_stream_##type((stream), (sid))->mid = mid + 1)
419
420	/* What is the current MID_uo number for this stream? */
421	#define sctp_mid_uo_peek(stream, type, sid) \
422	(sctp_stream_##type((stream), (sid))->mid_uo)
423
424	/* Return the next MID_uo number for this stream. */
425	#define sctp_mid_uo_next(stream, type, sid) \
426	(sctp_stream_##type((stream), (sid))->mid_uo++)
427
428	/*
429	* Pointers to address related SCTP functions.
430	* (i.e. things that depend on the address family.)
431	*/
432	struct sctp_af {
433	int (*sctp_xmit) (struct sk_buff *skb,
434	struct sctp_transport *);
435	int (*setsockopt) (struct sock *sk,
436	int level,
437	int optname,
438	sockptr_t optval,
439	unsigned int optlen);
440	int (*getsockopt) (struct sock *sk,
441	int level,
442	int optname,
443	char __user *optval,
444	int __user *optlen);
445	void (*get_dst) (struct sctp_transport *t,
446	union sctp_addr *saddr,
447	struct flowi *fl,
448	struct sock *sk);
449	void (*get_saddr) (struct sctp_sock *sk,
450	struct sctp_transport *t,
451	struct flowi *fl);
452	void (*copy_addrlist) (struct list_head *,
453	struct net_device *);
454	int (*cmp_addr) (const union sctp_addr *addr1,
455	const union sctp_addr *addr2);
456	void (*addr_copy) (union sctp_addr *dst,
457	union sctp_addr *src);
458	void (*from_skb) (union sctp_addr *,
459	struct sk_buff *skb,
460	int saddr);
461	void (*from_sk) (union sctp_addr *,
462	struct sock *sk);
463	bool (*from_addr_param) (union sctp_addr *,
464	union sctp_addr_param *,
465	__be16 port, int iif);
466	int (*to_addr_param) (const union sctp_addr *,
467	union sctp_addr_param *);
468	int (*addr_valid) (union sctp_addr *,
469	struct sctp_sock *,
470	const struct sk_buff *);
471	enum sctp_scope (*scope)(union sctp_addr *);
472	void (*inaddr_any) (union sctp_addr *, __be16);
473	int (*is_any) (const union sctp_addr *);
474	int (*available) (union sctp_addr *,
475	struct sctp_sock *);
476	int (*skb_iif) (const struct sk_buff *sk);
477	int (*skb_sdif)(const struct sk_buff *sk);
478	int (*is_ce) (const struct sk_buff *sk);
479	void (*seq_dump_addr)(struct seq_file *seq,
480	union sctp_addr *addr);
481	void (*ecn_capable)(struct sock *sk);
482	__u16 net_header_len;
483	int sockaddr_len;
484	int (*ip_options_len)(struct sock *sk);
485	sa_family_t sa_family;
486	struct list_head list;
487	};
488
489	struct sctp_af *sctp_get_af_specific(sa_family_t);
490	int sctp_register_af(struct sctp_af *);
491
492	/* Protocol family functions. */
493	struct sctp_pf {
494	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
495	void (*skb_msgname) (struct sk_buff *, char *, int *);
496	int (*af_supported) (sa_family_t, struct sctp_sock *);
497	int (*cmp_addr) (const union sctp_addr *,
498	const union sctp_addr *,
499	struct sctp_sock *);
500	int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
501	int (*send_verify) (struct sctp_sock *, union sctp_addr *);
502	int (*supported_addrs)(const struct sctp_sock *, __be16 *);
503	struct sock *(*create_accept_sk) (struct sock *sk,
504	struct sctp_association *asoc,
505	bool kern);
506	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
507	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
508	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
509	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
510	struct sctp_af *af;
511	};
512
513
514	/* Structure to track chunk fragments that have been acked, but peer
515	* fragments of the same message have not.
516	*/
517	struct sctp_datamsg {
518	/* Chunks waiting to be submitted to lower layer. */
519	struct list_head chunks;
520	/* Reference counting. */
521	refcount_t refcnt;
522	/* When is this message no longer interesting to the peer? */
523	unsigned long expires_at;
524	/* Did the message fail to send? */
525	int send_error;
526	u8 send_failed:1,
527	can_delay:1, /* should this message be Nagle delayed */
528	abandoned:1; /* should this message be abandoned */
529	};
530
531	struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
532	struct sctp_sndrcvinfo *,
533	struct iov_iter *);
534	void sctp_datamsg_free(struct sctp_datamsg *);
535	void sctp_datamsg_put(struct sctp_datamsg *);
536	void sctp_chunk_fail(struct sctp_chunk *, int error);
537	int sctp_chunk_abandoned(struct sctp_chunk *);
538
539	/* RFC2960 1.4 Key Terms
540	*
541	* o Chunk: A unit of information within an SCTP packet, consisting of
542	* a chunk header and chunk-specific content.
543	*
544	* As a matter of convenience, we remember the SCTP common header for
545	* each chunk as well as a few other header pointers...
546	*/
547	struct sctp_chunk {
548	struct list_head list;
549
550	refcount_t refcnt;
551
552	/* How many times this chunk have been sent, for prsctp RTX policy */
553	int sent_count;
554
555	union {
556	/* This is our link to the per-transport transmitted list. */
557	struct list_head transmitted_list;
558	/* List in specific stream outq */
559	struct list_head stream_list;
560	};
561
562	/* This field is used by chunks that hold fragmented data.
563	* For the first fragment this is the list that holds the rest of
564	* fragments. For the remaining fragments, this is the link to the
565	* frag_list maintained in the first fragment.
566	*/
567	struct list_head frag_list;
568
569	/* This points to the sk_buff containing the actual data. */
570	struct sk_buff *skb;
571
572	union {
573	/* In case of GSO packets, this will store the head one */
574	struct sk_buff *head_skb;
575	/* In case of auth enabled, this will point to the shkey */
576	struct sctp_shared_key *shkey;
577	};
578
579	/* These are the SCTP headers by reverse order in a packet.
580	* Note that some of these may happen more than once. In that
581	* case, we point at the "current" one, whatever that means
582	* for that level of header.
583	*/
584
585	/* We point this at the FIRST TLV parameter to chunk_hdr. */
586	union sctp_params param_hdr;
587	union {
588	__u8 *v;
589	struct sctp_datahdr *data_hdr;
590	struct sctp_inithdr *init_hdr;
591	struct sctp_sackhdr *sack_hdr;
592	struct sctp_heartbeathdr *hb_hdr;
593	struct sctp_sender_hb_info *hbs_hdr;
594	struct sctp_shutdownhdr *shutdown_hdr;
595	struct sctp_signed_cookie *cookie_hdr;
596	struct sctp_ecnehdr *ecne_hdr;
597	struct sctp_cwrhdr *ecn_cwr_hdr;
598	struct sctp_errhdr *err_hdr;
599	struct sctp_addiphdr *addip_hdr;
600	struct sctp_fwdtsn_hdr *fwdtsn_hdr;
601	struct sctp_authhdr *auth_hdr;
602	struct sctp_idatahdr *idata_hdr;
603	struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
604	} subh;
605
606	__u8 *chunk_end;
607
608	struct sctp_chunkhdr *chunk_hdr;
609	struct sctphdr *sctp_hdr;
610
611	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
612	struct sctp_sndrcvinfo sinfo;
613
614	/* Which association does this belong to? */
615	struct sctp_association *asoc;
616
617	/* What endpoint received this chunk? */
618	struct sctp_ep_common *rcvr;
619
620	/* We fill this in if we are calculating RTT. */
621	unsigned long sent_at;
622
623	/* What is the origin IP address for this chunk? */
624	union sctp_addr source;
625	/* Destination address for this chunk. */
626	union sctp_addr dest;
627
628	/* For outbound message, track all fragments for SEND_FAILED. */
629	struct sctp_datamsg *msg;
630
631	/* For an inbound chunk, this tells us where it came from.
632	* For an outbound chunk, it tells us where we'd like it to
633	* go. It is NULL if we have no preference.
634	*/
635	struct sctp_transport *transport;
636
637	/* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
638	* we need save a pointer to the AUTH chunk, since the SCTP-AUTH
639	* spec violates the principle premis that all chunks are processed
640	* in order.
641	*/
642	struct sk_buff *auth_chunk;
643
644	#define SCTP_CAN_FRTX 0x0
645	#define SCTP_NEED_FRTX 0x1
646	#define SCTP_DONT_FRTX 0x2
647	__u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
648	has_tsn:1, /* Does this chunk have a TSN yet? */
649	has_ssn:1, /* Does this chunk have a SSN yet? */
650	#define has_mid has_ssn
651	singleton:1, /* Only chunk in the packet? */
652	end_of_packet:1, /* Last chunk in the packet? */
653	ecn_ce_done:1, /* Have we processed the ECN CE bit? */
654	pdiscard:1, /* Discard the whole packet now? */
655	tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
656	data_accepted:1, /* At least 1 chunk accepted */
657	auth:1, /* IN: was auth'ed | OUT: needs auth */
658	has_asconf:1, /* IN: have seen an asconf before */
659	pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */
660	tsn_missing_report:2, /* Data chunk missing counter. */
661	fast_retransmit:2; /* Is this chunk fast retransmitted? */
662	};
663
664	#define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
665	void sctp_chunk_hold(struct sctp_chunk *);
666	void sctp_chunk_put(struct sctp_chunk *);
667	int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
668	struct iov_iter *from);
669	void sctp_chunk_free(struct sctp_chunk *);
670	void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
671	struct sctp_chunk *sctp_chunkify(struct sk_buff *,
672	const struct sctp_association *,
673	struct sock *, gfp_t gfp);
674	void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
675	union sctp_addr *);
676	const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
677
678	static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
679	{
680	return ntohs(ch->subh.data_hdr->stream);
681	}
682
683	enum {
684	SCTP_ADDR_NEW, /* new address added to assoc/ep */
685	SCTP_ADDR_SRC, /* address can be used as source */
686	SCTP_ADDR_DEL, /* address about to be deleted */
687	};
688
689	/* This is a structure for holding either an IPv6 or an IPv4 address. */
690	struct sctp_sockaddr_entry {
691	struct list_head list;
692	struct rcu_head rcu;
693	union sctp_addr a;
694	__u8 state;
695	__u8 valid;
696	};
697
698	#define SCTP_ADDRESS_TICK_DELAY 500
699
700	/* This structure holds lists of chunks as we are assembling for
701	* transmission.
702	*/
703	struct sctp_packet {
704	/* These are the SCTP header values (host order) for the packet. */
705	__u16 source_port;
706	__u16 destination_port;
707	__u32 vtag;
708
709	/* This contains the payload chunks. */
710	struct list_head chunk_list;
711
712	/* This is the overhead of the sctp and ip headers. */
713	size_t overhead;
714	/* This is the total size of all chunks INCLUDING padding. */
715	size_t size;
716	/* This is the maximum size this packet may have */
717	size_t max_size;
718
719	/* The packet is destined for this transport address.
720	* The function we finally use to pass down to the next lower
721	* layer lives in the transport structure.
722	*/
723	struct sctp_transport *transport;
724
725	/* pointer to the auth chunk for this packet */
726	struct sctp_chunk *auth;
727
728	u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
729	has_sack:1, /* This packet contains a SACK chunk. */
730	has_auth:1, /* This packet contains an AUTH chunk */
731	has_data:1, /* This packet contains at least 1 DATA chunk */
732	ipfragok:1; /* So let ip fragment this packet */
733	};
734
735	void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
736	__u16 sport, __u16 dport);
737	void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
738	enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
739	struct sctp_chunk *chunk,
740	int one_packet, gfp_t gfp);
741	enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
742	struct sctp_chunk *chunk);
743	int sctp_packet_transmit(struct sctp_packet *, gfp_t);
744	void sctp_packet_free(struct sctp_packet *);
745
746	static inline int sctp_packet_empty(struct sctp_packet *packet)
747	{
748	return packet->size == packet->overhead;
749	}
750
751	/* This represents a remote transport address.
752	* For local transport addresses, we just use union sctp_addr.
753	*
754	* RFC2960 Section 1.4 Key Terms
755	*
756	* o Transport address: A Transport Address is traditionally defined
757	* by Network Layer address, Transport Layer protocol and Transport
758	* Layer port number. In the case of SCTP running over IP, a
759	* transport address is defined by the combination of an IP address
760	* and an SCTP port number (where SCTP is the Transport protocol).
761	*
762	* RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
763	*
764	* o The sender keeps a separate congestion control parameter set for
765	* each of the destination addresses it can send to (not each
766	* source-destination pair but for each destination). The parameters
767	* should decay if the address is not used for a long enough time
768	* period.
769	*
770	*/
771	struct sctp_transport {
772	/* A list of transports. */
773	struct list_head transports;
774	struct rhlist_head node;
775
776	/* Reference counting. */
777	refcount_t refcnt;
778	__u32 dead:1,
779	/* RTO-Pending : A flag used to track if one of the DATA
780	* chunks sent to this address is currently being
781	* used to compute a RTT. If this flag is 0,
782	* the next DATA chunk sent to this destination
783	* should be used to compute a RTT and this flag
784	* should be set. Every time the RTT
785	* calculation completes (i.e. the DATA chunk
786	* is SACK'd) clear this flag.
787	*/
788	rto_pending:1,
789
790	/*
791	* hb_sent : a flag that signals that we have a pending
792	* heartbeat.
793	*/
794	hb_sent:1,
795
796	/* Is the Path MTU update pending on this transport */
797	pmtu_pending:1,
798
799	dst_pending_confirm:1, /* need to confirm neighbour */
800
801	/* Has this transport moved the ctsn since we last sacked */
802	sack_generation:1;
803	u32 dst_cookie;
804
805	struct flowi fl;
806
807	/* This is the peer's IP address and port. */
808	union sctp_addr ipaddr;
809
810	/* These are the functions we call to handle LLP stuff. */
811	struct sctp_af *af_specific;
812
813	/* Which association do we belong to? */
814	struct sctp_association *asoc;
815
816	/* RFC2960
817	*
818	* 12.3 Per Transport Address Data
819	*
820	* For each destination transport address in the peer's
821	* address list derived from the INIT or INIT ACK chunk, a
822	* number of data elements needs to be maintained including:
823	*/
824	/* RTO : The current retransmission timeout value. */
825	unsigned long rto;
826
827	__u32 rtt; /* This is the most recent RTT. */
828
829	/* RTTVAR : The current RTT variation. */
830	__u32 rttvar;
831
832	/* SRTT : The current smoothed round trip time. */
833	__u32 srtt;
834
835	/*
836	* These are the congestion stats.
837	*/
838	/* cwnd : The current congestion window. */
839	__u32 cwnd; /* This is the actual cwnd. */
840
841	/* ssthresh : The current slow start threshold value. */
842	__u32 ssthresh;
843
844	/* partial : The tracking method for increase of cwnd when in
845	* bytes acked : congestion avoidance mode (see Section 6.2.2)
846	*/
847	__u32 partial_bytes_acked;
848
849	/* Data that has been sent, but not acknowledged. */
850	__u32 flight_size;
851
852	__u32 burst_limited; /* Holds old cwnd when max.burst is applied */
853
854	/* Destination */
855	struct dst_entry *dst;
856	/* Source address. */
857	union sctp_addr saddr;
858
859	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
860	* the destination address every heartbeat interval.
861	*/
862	unsigned long hbinterval;
863	unsigned long probe_interval;
864
865	/* SACK delay timeout */
866	unsigned long sackdelay;
867	__u32 sackfreq;
868
869	atomic_t mtu_info;
870
871	/* When was the last time that we heard from this transport? We use
872	* this to pick new active and retran paths.
873	*/
874	ktime_t last_time_heard;
875
876	/* When was the last time that we sent a chunk using this
877	* transport? We use this to check for idle transports
878	*/
879	unsigned long last_time_sent;
880
881	/* Last time(in jiffies) when cwnd is reduced due to the congestion
882	* indication based on ECNE chunk.
883	*/
884	unsigned long last_time_ecne_reduced;
885
886	__be16 encap_port;
887
888	/* This is the max_retrans value for the transport and will
889	* be initialized from the assocs value. This can be changed
890	* using the SCTP_SET_PEER_ADDR_PARAMS socket option.
891	*/
892	__u16 pathmaxrxt;
893
894	__u32 flowlabel;
895	__u8 dscp;
896
897	/* This is the partially failed retrans value for the transport
898	* and will be initialized from the assocs value. This can be changed
899	* using the SCTP_PEER_ADDR_THLDS socket option
900	*/
901	__u16 pf_retrans;
902	/* Used for primary path switchover. */
903	__u16 ps_retrans;
904	/* PMTU : The current known path MTU. */
905	__u32 pathmtu;
906
907	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
908	__u32 param_flags;
909
910	/* The number of times INIT has been sent on this transport. */
911	int init_sent_count;
912
913	/* state : The current state of this destination,
914	* : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
915	*/
916	int state;
917
918	/* These are the error stats for this destination. */
919
920	/* Error count : The current error count for this destination. */
921	unsigned short error_count;
922
923	/* Per : A timer used by each destination.
924	* Destination :
925	* Timer :
926	*
927	* [Everywhere else in the text this is called T3-rtx. -ed]
928	*/
929	struct timer_list T3_rtx_timer;
930
931	/* Heartbeat timer is per destination. */
932	struct timer_list hb_timer;
933
934	/* Timer to handle ICMP proto unreachable envets */
935	struct timer_list proto_unreach_timer;
936
937	/* Timer to handler reconf chunk rtx */
938	struct timer_list reconf_timer;
939
940	/* Timer to send a probe HB packet for PLPMTUD */
941	struct timer_list probe_timer;
942
943	/* Since we're using per-destination retransmission timers
944	* (see above), we're also using per-destination "transmitted"
945	* queues. This probably ought to be a private struct
946	* accessible only within the outqueue, but it's not, yet.
947	*/
948	struct list_head transmitted;
949
950	/* We build bundle-able packets for this transport here. */
951	struct sctp_packet packet;
952
953	/* This is the list of transports that have chunks to send. */
954	struct list_head send_ready;
955
956	/* State information saved for SFR_CACC algorithm. The key
957	* idea in SFR_CACC is to maintain state at the sender on a
958	* per-destination basis when a changeover happens.
959	* char changeover_active;
960	* char cycling_changeover;
961	* __u32 next_tsn_at_change;
962	* char cacc_saw_newack;
963	*/
964	struct {
965	/* An unsigned integer, which stores the next TSN to be
966	* used by the sender, at the moment of changeover.
967	*/
968	__u32 next_tsn_at_change;
969
970	/* A flag which indicates the occurrence of a changeover */
971	char changeover_active;
972
973	/* A flag which indicates whether the change of primary is
974	* the first switch to this destination address during an
975	* active switch.
976	*/
977	char cycling_changeover;
978
979	/* A temporary flag, which is used during the processing of
980	* a SACK to estimate the causative TSN(s)'s group.
981	*/
982	char cacc_saw_newack;
983	} cacc;
984
985	struct {
986	__u16 pmtu;
987	__u16 probe_size;
988	__u16 probe_high;
989	__u8 probe_count;
990	__u8 state;
991	} pl; /* plpmtud related */
992
993	/* 64-bit random number sent with heartbeat. */
994	__u64 hb_nonce;
995
996	struct rcu_head rcu;
997	};
998
999	struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1000	gfp_t);
1001	void sctp_transport_set_owner(struct sctp_transport *,
1002	struct sctp_association *);
1003	void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1004	struct sctp_sock *);
1005	void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1006	void sctp_transport_free(struct sctp_transport *);
1007	void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1008	void sctp_transport_reset_hb_timer(struct sctp_transport *);
1009	void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1010	void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1011	void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1012	int sctp_transport_hold(struct sctp_transport *);
1013	void sctp_transport_put(struct sctp_transport *);
1014	void sctp_transport_update_rto(struct sctp_transport *, __u32);
1015	void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1016	void sctp_transport_lower_cwnd(struct sctp_transport *t,
1017	enum sctp_lower_cwnd reason);
1018	void sctp_transport_burst_limited(struct sctp_transport *);
1019	void sctp_transport_burst_reset(struct sctp_transport *);
1020	unsigned long sctp_transport_timeout(struct sctp_transport *);
1021	void sctp_transport_reset(struct sctp_transport *t);
1022	bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1023	void sctp_transport_immediate_rtx(struct sctp_transport *);
1024	void sctp_transport_dst_release(struct sctp_transport *t);
1025	void sctp_transport_dst_confirm(struct sctp_transport *t);
1026	void sctp_transport_pl_send(struct sctp_transport *t);
1027	bool sctp_transport_pl_recv(struct sctp_transport *t);
1028
1029
1030	/* This is the structure we use to queue packets as they come into
1031	* SCTP. We write packets to it and read chunks from it.
1032	*/
1033	struct sctp_inq {
1034	/* This is actually a queue of sctp_chunk each
1035	* containing a partially decoded packet.
1036	*/
1037	struct list_head in_chunk_list;
1038	/* This is the packet which is currently off the in queue and is
1039	* being worked on through the inbound chunk processing.
1040	*/
1041	struct sctp_chunk *in_progress;
1042
1043	/* This is the delayed task to finish delivering inbound
1044	* messages.
1045	*/
1046	struct work_struct immediate;
1047	};
1048
1049	void sctp_inq_init(struct sctp_inq *);
1050	void sctp_inq_free(struct sctp_inq *);
1051	void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1052	struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1053	struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1054	void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1055
1056	/* This is the structure we use to hold outbound chunks. You push
1057	* chunks in and they automatically pop out the other end as bundled
1058	* packets (it calls (*output_handler)()).
1059	*
1060	* This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1061	* and 8.2 of the v13 draft.
1062	*
1063	* It handles retransmissions. The connection to the timeout portion
1064	* of the state machine is through sctp_..._timeout() and timeout_handler.
1065	*
1066	* If you feed it SACKs, it will eat them.
1067	*
1068	* If you give it big chunks, it will fragment them.
1069	*
1070	* It assigns TSN's to data chunks. This happens at the last possible
1071	* instant before transmission.
1072	*
1073	* When free()'d, it empties itself out via output_handler().
1074	*/
1075	struct sctp_outq {
1076	struct sctp_association *asoc;
1077
1078	/* Data pending that has never been transmitted. */
1079	struct list_head out_chunk_list;
1080
1081	/* Stream scheduler being used */
1082	struct sctp_sched_ops *sched;
1083
1084	unsigned int out_qlen; /* Total length of queued data chunks. */
1085
1086	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1087	unsigned int error;
1088
1089	/* These are control chunks we want to send. */
1090	struct list_head control_chunk_list;
1091
1092	/* These are chunks that have been sacked but are above the
1093	* CTSN, or cumulative tsn ack point.
1094	*/
1095	struct list_head sacked;
1096
1097	/* Put chunks on this list to schedule them for
1098	* retransmission.
1099	*/
1100	struct list_head retransmit;
1101
1102	/* Put chunks on this list to save them for FWD TSN processing as
1103	* they were abandoned.
1104	*/
1105	struct list_head abandoned;
1106
1107	/* How many unackd bytes do we have in-flight? */
1108	__u32 outstanding_bytes;
1109
1110	/* Are we doing fast-rtx on this queue */
1111	char fast_rtx;
1112
1113	/* Corked? */
1114	char cork;
1115	};
1116
1117	void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1118	void sctp_outq_teardown(struct sctp_outq *);
1119	void sctp_outq_free(struct sctp_outq*);
1120	void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1121	int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1122	int sctp_outq_is_empty(const struct sctp_outq *);
1123	void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1124	enum sctp_retransmit_reason reason);
1125	void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1126	void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1127	void sctp_prsctp_prune(struct sctp_association *asoc,
1128	struct sctp_sndrcvinfo *sinfo, int msg_len);
1129	void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1130	/* Uncork and flush an outqueue. */
1131	static inline void sctp_outq_cork(struct sctp_outq *q)
1132	{
1133	q->cork = 1;
1134	}
1135
1136	/* SCTP skb control block.
1137	* sctp_input_cb is currently used on rx and sock rx queue
1138	*/
1139	struct sctp_input_cb {
1140	union {
1141	struct inet_skb_parm h4;
1142	#if IS_ENABLED(CONFIG_IPV6)
1143	struct inet6_skb_parm h6;
1144	#endif
1145	} header;
1146	struct sctp_chunk *chunk;
1147	struct sctp_af *af;
1148	__be16 encap_port;
1149	};
1150	#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1151
1152	struct sctp_output_cb {
1153	struct sk_buff *last;
1154	};
1155	#define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1156
1157	static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1158	{
1159	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1160
1161	return chunk->head_skb ? : skb;
1162	}
1163
1164	/* These bind address data fields common between endpoints and associations */
1165	struct sctp_bind_addr {
1166
1167	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1168	*
1169	* SCTP Port: The local SCTP port number the endpoint is
1170	* bound to.
1171	*/
1172	__u16 port;
1173
1174	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1175	*
1176	* Address List: The list of IP addresses that this instance
1177	* has bound. This information is passed to one's
1178	* peer(s) in INIT and INIT ACK chunks.
1179	*/
1180	struct list_head address_list;
1181	};
1182
1183	void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1184	void sctp_bind_addr_free(struct sctp_bind_addr *);
1185	int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1186	const struct sctp_bind_addr *src,
1187	enum sctp_scope scope, gfp_t gfp,
1188	int flags);
1189	int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1190	const struct sctp_bind_addr *src,
1191	gfp_t gfp);
1192	int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1193	int new_size, __u8 addr_state, gfp_t gfp);
1194	int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1195	int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1196	struct sctp_sock *);
1197	int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1198	struct sctp_sock *, struct sctp_sock *);
1199	int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1200	const union sctp_addr *addr);
1201	int sctp_bind_addrs_check(struct sctp_sock *sp,
1202	struct sctp_sock *sp2, int cnt2);
1203	union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1204	const union sctp_addr *addrs,
1205	int addrcnt,
1206	struct sctp_sock *opt);
1207	union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1208	int *addrs_len,
1209	gfp_t gfp);
1210	int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1211	__u16 port, gfp_t gfp);
1212
1213	enum sctp_scope sctp_scope(const union sctp_addr *addr);
1214	int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1215	const enum sctp_scope scope);
1216	int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1217	int sctp_is_ep_boundall(struct sock *sk);
1218
1219
1220	/* What type of endpoint? */
1221	enum sctp_endpoint_type {
1222	SCTP_EP_TYPE_SOCKET,
1223	SCTP_EP_TYPE_ASSOCIATION,
1224	};
1225
1226	/*
1227	* A common base class to bridge the implementation view of a
1228	* socket (usually listening) endpoint versus an association's
1229	* local endpoint.
1230	* This common structure is useful for several purposes:
1231	* 1) Common interface for lookup routines.
1232	* a) Subfunctions work for either endpoint or association
1233	* b) Single interface to lookup allows hiding the lookup lock rather
1234	* than acquiring it externally.
1235	* 2) Common interface for the inbound chunk handling/state machine.
1236	* 3) Common object handling routines for reference counting, etc.
1237	* 4) Disentangle association lookup from endpoint lookup, where we
1238	* do not have to find our endpoint to find our association.
1239	*
1240	*/
1241
1242	struct sctp_ep_common {
1243	/* Runtime type information. What kind of endpoint is this? */
1244	enum sctp_endpoint_type type;
1245
1246	/* Some fields to help us manage this object.
1247	* refcnt - Reference count access to this object.
1248	* dead - Do not attempt to use this object.
1249	*/
1250	refcount_t refcnt;
1251	bool dead;
1252
1253	/* What socket does this endpoint belong to? */
1254	struct sock *sk;
1255
1256	/* Cache netns and it won't change once set */
1257	struct net *net;
1258
1259	/* This is where we receive inbound chunks. */
1260	struct sctp_inq inqueue;
1261
1262	/* This substructure includes the defining parameters of the
1263	* endpoint:
1264	* bind_addr.port is our shared port number.
1265	* bind_addr.address_list is our set of local IP addresses.
1266	*/
1267	struct sctp_bind_addr bind_addr;
1268	};
1269
1270
1271	/* RFC Section 1.4 Key Terms
1272	*
1273	* o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1274	* multi-homed host, an SCTP endpoint is represented to its peers as a
1275	* combination of a set of eligible destination transport addresses to
1276	* which SCTP packets can be sent and a set of eligible source
1277	* transport addresses from which SCTP packets can be received.
1278	* All transport addresses used by an SCTP endpoint must use the
1279	* same port number, but can use multiple IP addresses. A transport
1280	* address used by an SCTP endpoint must not be used by another
1281	* SCTP endpoint. In other words, a transport address is unique
1282	* to an SCTP endpoint.
1283	*
1284	* From an implementation perspective, each socket has one of these.
1285	* A TCP-style socket will have exactly one association on one of
1286	* these. An UDP-style socket will have multiple associations hanging
1287	* off one of these.
1288	*/
1289
1290	struct sctp_endpoint {
1291	/* Common substructure for endpoint and association. */
1292	struct sctp_ep_common base;
1293
1294	/* Fields to help us manage our entries in the hash tables. */
1295	struct hlist_node node;
1296	int hashent;
1297
1298	/* Associations: A list of current associations and mappings
1299	* to the data consumers for each association. This
1300	* may be in the form of a hash table or other
1301	* implementation dependent structure. The data
1302	* consumers may be process identification
1303	* information such as file descriptors, named pipe
1304	* pointer, or table pointers dependent on how SCTP
1305	* is implemented.
1306	*/
1307	/* This is really a list of struct sctp_association entries. */
1308	struct list_head asocs;
1309
1310	/* Secret Key: A secret key used by this endpoint to compute
1311	* the MAC. This SHOULD be a cryptographic quality
1312	* random number with a sufficient length.
1313	* Discussion in [RFC1750] can be helpful in
1314	* selection of the key.
1315	*/
1316	__u8 secret_key[SCTP_SECRET_SIZE];
1317
1318	/* digest: This is a digest of the sctp cookie. This field is
1319	* only used on the receive path when we try to validate
1320	* that the cookie has not been tampered with. We put
1321	* this here so we pre-allocate this once and can re-use
1322	* on every receive.
1323	*/
1324	__u8 *digest;
1325
1326	/* sendbuf acct. policy. */
1327	__u32 sndbuf_policy;
1328
1329	/* rcvbuf acct. policy. */
1330	__u32 rcvbuf_policy;
1331
1332	/* SCTP AUTH: array of the HMACs that will be allocated
1333	* we need this per association so that we don't serialize
1334	*/
1335	struct crypto_shash **auth_hmacs;
1336
1337	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1338	struct sctp_hmac_algo_param *auth_hmacs_list;
1339
1340	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1341	struct sctp_chunks_param *auth_chunk_list;
1342
1343	/* SCTP-AUTH: endpoint shared keys */
1344	struct list_head endpoint_shared_keys;
1345	__u16 active_key_id;
1346	__u8 ecn_enable:1,
1347	auth_enable:1,
1348	intl_enable:1,
1349	prsctp_enable:1,
1350	asconf_enable:1,
1351	reconf_enable:1;
1352
1353	__u8 strreset_enable;
1354	struct rcu_head rcu;
1355	};
1356
1357	/* Recover the outer endpoint structure. */
1358	static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1359	{
1360	struct sctp_endpoint *ep;
1361
1362	ep = container_of(base, struct sctp_endpoint, base);
1363	return ep;
1364	}
1365
1366	/* These are function signatures for manipulating endpoints. */
1367	struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1368	void sctp_endpoint_free(struct sctp_endpoint *);
1369	void sctp_endpoint_put(struct sctp_endpoint *);
1370	int sctp_endpoint_hold(struct sctp_endpoint *ep);
1371	void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1372	struct sctp_association *sctp_endpoint_lookup_assoc(
1373	const struct sctp_endpoint *ep,
1374	const union sctp_addr *paddr,
1375	struct sctp_transport **);
1376	bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1377	const union sctp_addr *paddr);
1378	struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1379	struct net *net,
1380	const union sctp_addr *laddr,
1381	int dif, int sdif);
1382	bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1383	const union sctp_addr *paddr, int dif, int sdif);
1384
1385	int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1386	const struct sctp_association *asoc,
1387	enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1388	struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1389	int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1390	const union sctp_addr *peer,
1391	struct sctp_init_chunk *init, gfp_t gfp);
1392	__u32 sctp_generate_tag(const struct sctp_endpoint *);
1393	__u32 sctp_generate_tsn(const struct sctp_endpoint *);
1394
1395	struct sctp_inithdr_host {
1396	__u32 init_tag;
1397	__u32 a_rwnd;
1398	__u16 num_outbound_streams;
1399	__u16 num_inbound_streams;
1400	__u32 initial_tsn;
1401	};
1402
1403	struct sctp_stream_priorities {
1404	/* List of priorities scheduled */
1405	struct list_head prio_sched;
1406	/* List of streams scheduled */
1407	struct list_head active;
1408	/* The next stream in line */
1409	struct sctp_stream_out_ext *next;
1410	__u16 prio;
1411	__u16 users;
1412	};
1413
1414	struct sctp_stream_out_ext {
1415	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1416	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1417	struct list_head outq; /* chunks enqueued by this stream */
1418	union {
1419	struct {
1420	/* Scheduled streams list */
1421	struct list_head prio_list;
1422	struct sctp_stream_priorities *prio_head;
1423	};
1424	/* Fields used by RR scheduler */
1425	struct {
1426	struct list_head rr_list;
1427	};
1428	struct {
1429	struct list_head fc_list;
1430	__u32 fc_length;
1431	__u16 fc_weight;
1432	};
1433	};
1434	};
1435
1436	struct sctp_stream_out {
1437	union {
1438	__u32 mid;
1439	__u16 ssn;
1440	};
1441	__u32 mid_uo;
1442	struct sctp_stream_out_ext *ext;
1443	__u8 state;
1444	};
1445
1446	struct sctp_stream_in {
1447	union {
1448	__u32 mid;
1449	__u16 ssn;
1450	};
1451	__u32 mid_uo;
1452	__u32 fsn;
1453	__u32 fsn_uo;
1454	char pd_mode;
1455	char pd_mode_uo;
1456	};
1457
1458	struct sctp_stream {
1459	GENRADIX(struct sctp_stream_out) out;
1460	GENRADIX(struct sctp_stream_in) in;
1461
1462	__u16 outcnt;
1463	__u16 incnt;
1464	/* Current stream being sent, if any */
1465	struct sctp_stream_out *out_curr;
1466	union {
1467	/* Fields used by priority scheduler */
1468	struct {
1469	/* List of priorities scheduled */
1470	struct list_head prio_list;
1471	};
1472	/* Fields used by RR scheduler */
1473	struct {
1474	/* List of streams scheduled */
1475	struct list_head rr_list;
1476	/* The next stream in line */
1477	struct sctp_stream_out_ext *rr_next;
1478	};
1479	struct {
1480	struct list_head fc_list;
1481	};
1482	};
1483	struct sctp_stream_interleave *si;
1484	};
1485
1486	static inline struct sctp_stream_out *sctp_stream_out(
1487	struct sctp_stream *stream,
1488	__u16 sid)
1489	{
1490	return genradix_ptr(&stream->out, sid);
1491	}
1492
1493	static inline struct sctp_stream_in *sctp_stream_in(
1494	struct sctp_stream *stream,
1495	__u16 sid)
1496	{
1497	return genradix_ptr(&stream->in, sid);
1498	}
1499
1500	#define SCTP_SO(s, i) sctp_stream_out((s), (i))
1501	#define SCTP_SI(s, i) sctp_stream_in((s), (i))
1502
1503	#define SCTP_STREAM_CLOSED 0x00
1504	#define SCTP_STREAM_OPEN 0x01
1505
1506	static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1507	{
1508	return stream->si->data_chunk_len;
1509	}
1510
1511	static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1512	{
1513	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1514	}
1515
1516	static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1517	{
1518	return stream->si->ftsn_chunk_len;
1519	}
1520
1521	static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1522	{
1523	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1524	}
1525
1526	/* SCTP_GET_ASSOC_STATS counters */
1527	struct sctp_priv_assoc_stats {
1528	/* Maximum observed rto in the association during subsequent
1529	* observations. Value is set to 0 if no RTO measurement took place
1530	* The transport where the max_rto was observed is returned in
1531	* obs_rto_ipaddr
1532	*/
1533	struct sockaddr_storage obs_rto_ipaddr;
1534	__u64 max_obs_rto;
1535	/* Total In and Out SACKs received and sent */
1536	__u64 isacks;
1537	__u64 osacks;
1538	/* Total In and Out packets received and sent */
1539	__u64 opackets;
1540	__u64 ipackets;
1541	/* Total retransmitted chunks */
1542	__u64 rtxchunks;
1543	/* TSN received > next expected */
1544	__u64 outofseqtsns;
1545	/* Duplicate Chunks received */
1546	__u64 idupchunks;
1547	/* Gap Ack Blocks received */
1548	__u64 gapcnt;
1549	/* Unordered data chunks sent and received */
1550	__u64 ouodchunks;
1551	__u64 iuodchunks;
1552	/* Ordered data chunks sent and received */
1553	__u64 oodchunks;
1554	__u64 iodchunks;
1555	/* Control chunks sent and received */
1556	__u64 octrlchunks;
1557	__u64 ictrlchunks;
1558	};
1559
1560	/* RFC2960
1561	*
1562	* 12. Recommended Transmission Control Block (TCB) Parameters
1563	*
1564	* This section details a recommended set of parameters that should
1565	* be contained within the TCB for an implementation. This section is
1566	* for illustrative purposes and should not be deemed as requirements
1567	* on an implementation or as an exhaustive list of all parameters
1568	* inside an SCTP TCB. Each implementation may need its own additional
1569	* parameters for optimization.
1570	*/
1571
1572
1573	/* Here we have information about each individual association. */
1574	struct sctp_association {
1575
1576	/* A base structure common to endpoint and association.
1577	* In this context, it represents the associations's view
1578	* of the local endpoint of the association.
1579	*/
1580	struct sctp_ep_common base;
1581
1582	/* Associations on the same socket. */
1583	struct list_head asocs;
1584
1585	/* association id. */
1586	sctp_assoc_t assoc_id;
1587
1588	/* This is our parent endpoint. */
1589	struct sctp_endpoint *ep;
1590
1591	/* These are those association elements needed in the cookie. */
1592	struct sctp_cookie c;
1593
1594	/* This is all information about our peer. */
1595	struct {
1596	/* transport_addr_list
1597	*
1598	* Peer : A list of SCTP transport addresses that the
1599	* Transport : peer is bound to. This information is derived
1600	* Address : from the INIT or INIT ACK and is used to
1601	* List : associate an inbound packet with a given
1602	* : association. Normally this information is
1603	* : hashed or keyed for quick lookup and access
1604	* : of the TCB.
1605	* : The list is also initialized with the list
1606	* : of addresses passed with the sctp_connectx()
1607	* : call.
1608	*
1609	* It is a list of SCTP_transport's.
1610	*/
1611	struct list_head transport_addr_list;
1612
1613	/* rwnd
1614	*
1615	* Peer Rwnd : Current calculated value of the peer's rwnd.
1616	*/
1617	__u32 rwnd;
1618
1619	/* transport_count
1620	*
1621	* Peer : A count of the number of peer addresses
1622	* Transport : in the Peer Transport Address List.
1623	* Address :
1624	* Count :
1625	*/
1626	__u16 transport_count;
1627
1628	/* port
1629	* The transport layer port number.
1630	*/
1631	__u16 port;
1632
1633	/* primary_path
1634	*
1635	* Primary : This is the current primary destination
1636	* Path : transport address of the peer endpoint. It
1637	* : may also specify a source transport address
1638	* : on this endpoint.
1639	*
1640	* All of these paths live on transport_addr_list.
1641	*
1642	* At the bakeoffs, we discovered that the intent of
1643	* primaryPath is that it only changes when the ULP
1644	* asks to have it changed. We add the activePath to
1645	* designate the connection we are currently using to
1646	* transmit new data and most control chunks.
1647	*/
1648	struct sctp_transport *primary_path;
1649
1650	/* Cache the primary path address here, when we
1651	* need a an address for msg_name.
1652	*/
1653	union sctp_addr primary_addr;
1654
1655	/* active_path
1656	* The path that we are currently using to
1657	* transmit new data and most control chunks.
1658	*/
1659	struct sctp_transport *active_path;
1660
1661	/* retran_path
1662	*
1663	* RFC2960 6.4 Multi-homed SCTP Endpoints
1664	* ...
1665	* Furthermore, when its peer is multi-homed, an
1666	* endpoint SHOULD try to retransmit a chunk to an
1667	* active destination transport address that is
1668	* different from the last destination address to
1669	* which the DATA chunk was sent.
1670	*/
1671	struct sctp_transport *retran_path;
1672
1673	/* Pointer to last transport I have sent on. */
1674	struct sctp_transport *last_sent_to;
1675
1676	/* This is the last transport I have received DATA on. */
1677	struct sctp_transport *last_data_from;
1678
1679	/*
1680	* Mapping An array of bits or bytes indicating which out of
1681	* Array order TSN's have been received (relative to the
1682	* Last Rcvd TSN). If no gaps exist, i.e. no out of
1683	* order packets have been received, this array
1684	* will be set to all zero. This structure may be
1685	* in the form of a circular buffer or bit array.
1686	*
1687	* Last Rcvd : This is the last TSN received in
1688	* TSN : sequence. This value is set initially by
1689	* : taking the peer's Initial TSN, received in
1690	* : the INIT or INIT ACK chunk, and subtracting
1691	* : one from it.
1692	*
1693	* Throughout most of the specification this is called the
1694	* "Cumulative TSN ACK Point". In this case, we
1695	* ignore the advice in 12.2 in favour of the term
1696	* used in the bulk of the text. This value is hidden
1697	* in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1698	*/
1699	struct sctp_tsnmap tsn_map;
1700
1701	/* This mask is used to disable sending the ASCONF chunk
1702	* with specified parameter to peer.
1703	*/
1704	__be16 addip_disabled_mask;
1705
1706	/* These are capabilities which our peer advertised. */
1707	__u16 ecn_capable:1, /* Can peer do ECN? */
1708	ipv4_address:1, /* Peer understands IPv4 addresses? */
1709	ipv6_address:1, /* Peer understands IPv6 addresses? */
1710	asconf_capable:1, /* Does peer support ADDIP? */
1711	prsctp_capable:1, /* Can peer do PR-SCTP? */
1712	reconf_capable:1, /* Can peer do RE-CONFIG? */
1713	intl_capable:1, /* Can peer do INTERLEAVE */
1714	auth_capable:1, /* Is peer doing SCTP-AUTH? */
1715	/* sack_needed:
1716	* This flag indicates if the next received
1717	* packet is to be responded to with a
1718	* SACK. This is initialized to 0. When a packet
1719	* is received sack_cnt is incremented. If this value
1720	* reaches 2 or more, a SACK is sent and the
1721	* value is reset to 0. Note: This is used only
1722	* when no DATA chunks are received out of
1723	* order. When DATA chunks are out of order,
1724	* SACK's are not delayed (see Section 6).
1725	*/
1726	sack_needed:1, /* Do we need to sack the peer? */
1727	sack_generation:1,
1728	zero_window_announced:1;
1729
1730	__u32 sack_cnt;
1731
1732	__u32 adaptation_ind; /* Adaptation Code point. */
1733
1734	struct sctp_inithdr_host i;
1735	void *cookie;
1736	int cookie_len;
1737
1738	/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1739	* C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1740	* Initial TSN Value minus 1
1741	*/
1742	__u32 addip_serial;
1743
1744	/* SCTP-AUTH: We need to know pears random number, hmac list
1745	* and authenticated chunk list. All that is part of the
1746	* cookie and these are just pointers to those locations
1747	*/
1748	struct sctp_random_param *peer_random;
1749	struct sctp_chunks_param *peer_chunks;
1750	struct sctp_hmac_algo_param *peer_hmacs;
1751	} peer;
1752
1753	/* State : A state variable indicating what state the
1754	* : association is in, i.e. COOKIE-WAIT,
1755	* : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1756	* : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1757	*
1758	* Note: No "CLOSED" state is illustrated since if a
1759	* association is "CLOSED" its TCB SHOULD be removed.
1760	*
1761	* In this implementation we DO have a CLOSED
1762	* state which is used during initiation and shutdown.
1763	*
1764	* State takes values from SCTP_STATE_*.
1765	*/
1766	enum sctp_state state;
1767
1768	/* Overall : The overall association error count.
1769	* Error Count : [Clear this any time I get something.]
1770	*/
1771	int overall_error_count;
1772
1773	/* The cookie life I award for any cookie. */
1774	ktime_t cookie_life;
1775
1776	/* These are the association's initial, max, and min RTO values.
1777	* These values will be initialized by system defaults, but can
1778	* be modified via the SCTP_RTOINFO socket option.
1779	*/
1780	unsigned long rto_initial;
1781	unsigned long rto_max;
1782	unsigned long rto_min;
1783
1784	/* Maximum number of new data packets that can be sent in a burst. */
1785	int max_burst;
1786
1787	/* This is the max_retrans value for the association. This value will
1788	* be initialized from system defaults, but can be
1789	* modified by the SCTP_ASSOCINFO socket option.
1790	*/
1791	int max_retrans;
1792
1793	/* This is the partially failed retrans value for the transport
1794	* and will be initialized from the assocs value. This can be
1795	* changed using the SCTP_PEER_ADDR_THLDS socket option
1796	*/
1797	__u16 pf_retrans;
1798	/* Used for primary path switchover. */
1799	__u16 ps_retrans;
1800
1801	/* Maximum number of times the endpoint will retransmit INIT */
1802	__u16 max_init_attempts;
1803
1804	/* How many times have we resent an INIT? */
1805	__u16 init_retries;
1806
1807	/* The largest timeout or RTO value to use in attempting an INIT */
1808	unsigned long max_init_timeo;
1809
1810	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1811	* the destination address every heartbeat interval. This value
1812	* will be inherited by all new transports.
1813	*/
1814	unsigned long hbinterval;
1815	unsigned long probe_interval;
1816
1817	__be16 encap_port;
1818
1819	/* This is the max_retrans value for new transports in the
1820	* association.
1821	*/
1822	__u16 pathmaxrxt;
1823
1824	__u32 flowlabel;
1825	__u8 dscp;
1826
1827	/* Flag that path mtu update is pending */
1828	__u8 pmtu_pending;
1829
1830	/* Association : The smallest PMTU discovered for all of the
1831	* PMTU : peer's transport addresses.
1832	*/
1833	__u32 pathmtu;
1834
1835	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1836	__u32 param_flags;
1837
1838	__u32 sackfreq;
1839	/* SACK delay timeout */
1840	unsigned long sackdelay;
1841
1842	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1843	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1844
1845	/* Transport to which SHUTDOWN chunk was last sent. */
1846	struct sctp_transport *shutdown_last_sent_to;
1847
1848	/* Transport to which INIT chunk was last sent. */
1849	struct sctp_transport *init_last_sent_to;
1850
1851	/* How many times have we resent a SHUTDOWN */
1852	int shutdown_retries;
1853
1854	/* Next TSN : The next TSN number to be assigned to a new
1855	* : DATA chunk. This is sent in the INIT or INIT
1856	* : ACK chunk to the peer and incremented each
1857	* : time a DATA chunk is assigned a TSN
1858	* : (normally just prior to transmit or during
1859	* : fragmentation).
1860	*/
1861	__u32 next_tsn;
1862
1863	/*
1864	* Last Rcvd : This is the last TSN received in sequence. This value
1865	* TSN : is set initially by taking the peer's Initial TSN,
1866	* : received in the INIT or INIT ACK chunk, and
1867	* : subtracting one from it.
1868	*
1869	* Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1870	*/
1871
1872	__u32 ctsn_ack_point;
1873
1874	/* PR-SCTP Advanced.Peer.Ack.Point */
1875	__u32 adv_peer_ack_point;
1876
1877	/* Highest TSN that is acknowledged by incoming SACKs. */
1878	__u32 highest_sacked;
1879
1880	/* TSN marking the fast recovery exit point */
1881	__u32 fast_recovery_exit;
1882
1883	/* Flag to track the current fast recovery state */
1884	__u8 fast_recovery;
1885
1886	/* The number of unacknowledged data chunks. Reported through
1887	* the SCTP_STATUS sockopt.
1888	*/
1889	__u16 unack_data;
1890
1891	/* The total number of data chunks that we've had to retransmit
1892	* as the result of a T3 timer expiration
1893	*/
1894	__u32 rtx_data_chunks;
1895
1896	/* This is the association's receive buffer space. This value is used
1897	* to set a_rwnd field in an INIT or a SACK chunk.
1898	*/
1899	__u32 rwnd;
1900
1901	/* This is the last advertised value of rwnd over a SACK chunk. */
1902	__u32 a_rwnd;
1903
1904	/* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1905	* to slop over a maximum of the association's frag_point.
1906	*/
1907	__u32 rwnd_over;
1908
1909	/* Keeps treack of rwnd pressure. This happens when we have
1910	* a window, but not receive buffer (i.e small packets). This one
1911	* is releases slowly (1 PMTU at a time ).
1912	*/
1913	__u32 rwnd_press;
1914
1915	/* This is the sndbuf size in use for the association.
1916	* This corresponds to the sndbuf size for the association,
1917	* as specified in the sk->sndbuf.
1918	*/
1919	int sndbuf_used;
1920
1921	/* This is the amount of memory that this association has allocated
1922	* in the receive path at any given time.
1923	*/
1924	atomic_t rmem_alloc;
1925
1926	/* This is the wait queue head for send requests waiting on
1927	* the association sndbuf space.
1928	*/
1929	wait_queue_head_t wait;
1930
1931	/* The message size at which SCTP fragmentation will occur. */
1932	__u32 frag_point;
1933	__u32 user_frag;
1934
1935	/* Counter used to count INIT errors. */
1936	int init_err_counter;
1937
1938	/* Count the number of INIT cycles (for doubling timeout). */
1939	int init_cycle;
1940
1941	/* Default send parameters. */
1942	__u16 default_stream;
1943	__u16 default_flags;
1944	__u32 default_ppid;
1945	__u32 default_context;
1946	__u32 default_timetolive;
1947
1948	/* Default receive parameters */
1949	__u32 default_rcv_context;
1950
1951	/* Stream arrays */
1952	struct sctp_stream stream;
1953
1954	/* All outbound chunks go through this structure. */
1955	struct sctp_outq outqueue;
1956
1957	/* A smart pipe that will handle reordering and fragmentation,
1958	* as well as handle passing events up to the ULP.
1959	*/
1960	struct sctp_ulpq ulpq;
1961
1962	/* Last TSN that caused an ECNE Chunk to be sent. */
1963	__u32 last_ecne_tsn;
1964
1965	/* Last TSN that caused a CWR Chunk to be sent. */
1966	__u32 last_cwr_tsn;
1967
1968	/* How many duplicated TSNs have we seen? */
1969	int numduptsns;
1970
1971	/* These are to support
1972	* "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1973	* and Enforcement of Flow and Message Limits"
1974	* <draft-ietf-tsvwg-addip-sctp-02.txt>
1975	* or "ADDIP" for short.
1976	*/
1977
1978
1979
1980	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1981	*
1982	* R1) One and only one ASCONF Chunk MAY be in transit and
1983	* unacknowledged at any one time. If a sender, after sending
1984	* an ASCONF chunk, decides it needs to transfer another
1985	* ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1986	* returns from the previous ASCONF Chunk before sending a
1987	* subsequent ASCONF. Note this restriction binds each side,
1988	* so at any time two ASCONF may be in-transit on any given
1989	* association (one sent from each endpoint).
1990	*
1991	* [This is our one-and-only-one ASCONF in flight. If we do
1992	* not have an ASCONF in flight, this is NULL.]
1993	*/
1994	struct sctp_chunk *addip_last_asconf;
1995
1996	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1997	*
1998	* This is needed to implement items E1 - E4 of the updated
1999	* spec. Here is the justification:
2000	*
2001	* Since the peer may bundle multiple ASCONF chunks toward us,
2002	* we now need the ability to cache multiple ACKs. The section
2003	* describes in detail how they are cached and cleaned up.
2004	*/
2005	struct list_head asconf_ack_list;
2006
2007	/* These ASCONF chunks are waiting to be sent.
2008	*
2009	* These chunks can't be pushed to outqueue until receiving
2010	* ASCONF_ACK for the previous ASCONF indicated by
2011	* addip_last_asconf, so as to guarantee that only one ASCONF
2012	* is in flight at any time.
2013	*
2014	* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2015	*
2016	* In defining the ASCONF Chunk transfer procedures, it is
2017	* essential that these transfers MUST NOT cause congestion
2018	* within the network. To achieve this, we place these
2019	* restrictions on the transfer of ASCONF Chunks:
2020	*
2021	* R1) One and only one ASCONF Chunk MAY be in transit and
2022	* unacknowledged at any one time. If a sender, after sending
2023	* an ASCONF chunk, decides it needs to transfer another
2024	* ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2025	* returns from the previous ASCONF Chunk before sending a
2026	* subsequent ASCONF. Note this restriction binds each side,
2027	* so at any time two ASCONF may be in-transit on any given
2028	* association (one sent from each endpoint).
2029	*
2030	*
2031	* [I really think this is EXACTLY the sort of intelligence
2032	* which already resides in sctp_outq. Please move this
2033	* queue and its supporting logic down there. --piggy]
2034	*/
2035	struct list_head addip_chunk_list;
2036
2037	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2038	*
2039	* A2) A serial number should be assigned to the Chunk. The
2040	* serial number SHOULD be a monotonically increasing
2041	* number. The serial number SHOULD be initialized at
2042	* the start of the association to the same value as the
2043	* Initial TSN and every time a new ASCONF chunk is created
2044	* it is incremented by one after assigning the serial number
2045	* to the newly created chunk.
2046	*
2047	* ADDIP
2048	* 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2049	*
2050	* Serial Number : 32 bits (unsigned integer)
2051	*
2052	* This value represents a Serial Number for the ASCONF
2053	* Chunk. The valid range of Serial Number is from 0 to
2054	* 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2055	* after reaching 4294967295.
2056	*/
2057	__u32 addip_serial;
2058	int src_out_of_asoc_ok;
2059	union sctp_addr *asconf_addr_del_pending;
2060	struct sctp_transport *new_transport;
2061
2062	/* SCTP AUTH: list of the endpoint shared keys. These
2063	* keys are provided out of band by the user application
2064	* and can't change during the lifetime of the association
2065	*/
2066	struct list_head endpoint_shared_keys;
2067
2068	/* SCTP AUTH:
2069	* The current generated association shared key (secret)
2070	*/
2071	struct sctp_auth_bytes *asoc_shared_key;
2072	struct sctp_shared_key *shkey;
2073
2074	/* SCTP AUTH: hmac id of the first peer requested algorithm
2075	* that we support.
2076	*/
2077	__u16 default_hmac_id;
2078
2079	__u16 active_key_id;
2080
2081	__u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2082	temp:1, /* Is it a temporary association? */
2083	pf_expose:2, /* Expose pf state? */
2084	force_delay:1;
2085
2086	__u8 strreset_enable;
2087	__u8 strreset_outstanding; /* request param count on the fly */
2088
2089	__u32 strreset_outseq; /* Update after receiving response */
2090	__u32 strreset_inseq; /* Update after receiving request */
2091	__u32 strreset_result[2]; /* save the results of last 2 responses */
2092
2093	struct sctp_chunk *strreset_chunk; /* save request chunk */
2094
2095	struct sctp_priv_assoc_stats stats;
2096
2097	int sent_cnt_removable;
2098
2099	__u16 subscribe;
2100
2101	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2102	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2103
2104	/* Security identifiers from incoming (INIT). These are set by
2105	* security_sctp_assoc_request(). These will only be used by
2106	* SCTP TCP type sockets and peeled off connections as they
2107	* cause a new socket to be generated. security_sctp_sk_clone()
2108	* will then plug these into the new socket.
2109	*/
2110
2111	u32 secid;
2112	u32 peer_secid;
2113
2114	struct rcu_head rcu;
2115	};
2116
2117
2118	/* An eyecatcher for determining if we are really looking at an
2119	* association data structure.
2120	*/
2121	enum {
2122	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2123	};
2124
2125	/* Recover the outer association structure. */
2126	static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2127	{
2128	struct sctp_association *asoc;
2129
2130	asoc = container_of(base, struct sctp_association, base);
2131	return asoc;
2132	}
2133
2134	/* These are function signatures for manipulating associations. */
2135
2136
2137	struct sctp_association *
2138	sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2139	enum sctp_scope scope, gfp_t gfp);
2140	void sctp_association_free(struct sctp_association *);
2141	void sctp_association_put(struct sctp_association *);
2142	void sctp_association_hold(struct sctp_association *);
2143
2144	struct sctp_transport *sctp_assoc_choose_alter_transport(
2145	struct sctp_association *, struct sctp_transport *);
2146	void sctp_assoc_update_retran_path(struct sctp_association *);
2147	struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2148	const union sctp_addr *);
2149	int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2150	const union sctp_addr *laddr);
2151	struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2152	const union sctp_addr *address,
2153	const gfp_t gfp,
2154	const int peer_state);
2155	void sctp_assoc_rm_peer(struct sctp_association *asoc,
2156	struct sctp_transport *peer);
2157	void sctp_assoc_control_transport(struct sctp_association *asoc,
2158	struct sctp_transport *transport,
2159	enum sctp_transport_cmd command,
2160	sctp_sn_error_t error);
2161	struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2162	void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2163	int sctp_assoc_update(struct sctp_association *old,
2164	struct sctp_association *new);
2165
2166	__u32 sctp_association_get_next_tsn(struct sctp_association *);
2167
2168	void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2169	void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2170	void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2171	void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2172	void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2173	void sctp_assoc_set_primary(struct sctp_association *,
2174	struct sctp_transport *);
2175	void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2176	struct sctp_transport *);
2177	int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2178	enum sctp_scope scope, gfp_t gfp);
2179	int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2180	struct sctp_cookie*,
2181	gfp_t gfp);
2182	int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2183	void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2184	struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2185	const struct sctp_association *asoc,
2186	__be32 serial);
2187	void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2188
2189	int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2190	const union sctp_addr *ss2);
2191	struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2192
2193	/* A convenience structure to parse out SCTP specific CMSGs. */
2194	struct sctp_cmsgs {
2195	struct sctp_initmsg *init;
2196	struct sctp_sndrcvinfo *srinfo;
2197	struct sctp_sndinfo *sinfo;
2198	struct sctp_prinfo *prinfo;
2199	struct sctp_authinfo *authinfo;
2200	struct msghdr *addrs_msg;
2201	};
2202
2203	/* Structure for tracking memory objects */
2204	struct sctp_dbg_objcnt_entry {
2205	char *label;
2206	atomic_t *counter;
2207	};
2208
2209	#endif /* __sctp_structs_h__ */
2210