xref: /linux/include/net/sctp/structs.h (revision 9410645520e9b820069761f3450ef6661418e279)
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 
sctp_opt2sk(const struct sctp_sock * sp)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 
sctp_chunk_stream_no(struct sctp_chunk * ch)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 
sctp_packet_empty(struct sctp_packet * packet)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 		/* RTO-Pending : A flag used to track if one of the DATA
779 		 *		chunks sent to this address is currently being
780 		 *		used to compute a RTT. If this flag is 0,
781 		 *		the next DATA chunk sent to this destination
782 		 *		should be used to compute a RTT and this flag
783 		 *		should be set. Every time the RTT
784 		 *		calculation completes (i.e. the DATA chunk
785 		 *		is SACK'd) clear this flag.
786 		 */
787 	__u32	rto_pending:1,
788 
789 		/*
790 		 * hb_sent : a flag that signals that we have a pending
791 		 * heartbeat.
792 		 */
793 		hb_sent:1,
794 
795 		/* Is the Path MTU update pending on this transport */
796 		pmtu_pending:1,
797 
798 		dst_pending_confirm:1,	/* need to confirm neighbour */
799 
800 		/* Has this transport moved the ctsn since we last sacked */
801 		sack_generation:1;
802 	u32 dst_cookie;
803 
804 	struct flowi fl;
805 
806 	/* This is the peer's IP address and port. */
807 	union sctp_addr ipaddr;
808 
809 	/* These are the functions we call to handle LLP stuff.	 */
810 	struct sctp_af *af_specific;
811 
812 	/* Which association do we belong to?  */
813 	struct sctp_association *asoc;
814 
815 	/* RFC2960
816 	 *
817 	 * 12.3 Per Transport Address Data
818 	 *
819 	 * For each destination transport address in the peer's
820 	 * address list derived from the INIT or INIT ACK chunk, a
821 	 * number of data elements needs to be maintained including:
822 	 */
823 	/* RTO	       : The current retransmission timeout value.  */
824 	unsigned long rto;
825 
826 	__u32 rtt;		/* This is the most recent RTT.	 */
827 
828 	/* RTTVAR      : The current RTT variation.  */
829 	__u32 rttvar;
830 
831 	/* SRTT	       : The current smoothed round trip time.	*/
832 	__u32 srtt;
833 
834 	/*
835 	 * These are the congestion stats.
836 	 */
837 	/* cwnd	       : The current congestion window.	 */
838 	__u32 cwnd;		  /* This is the actual cwnd.  */
839 
840 	/* ssthresh    : The current slow start threshold value.  */
841 	__u32 ssthresh;
842 
843 	/* partial     : The tracking method for increase of cwnd when in
844 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
845 	 */
846 	__u32 partial_bytes_acked;
847 
848 	/* Data that has been sent, but not acknowledged. */
849 	__u32 flight_size;
850 
851 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
852 
853 	/* Destination */
854 	struct dst_entry *dst;
855 	/* Source address. */
856 	union sctp_addr saddr;
857 
858 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
859 	 * the destination address every heartbeat interval.
860 	 */
861 	unsigned long hbinterval;
862 	unsigned long probe_interval;
863 
864 	/* SACK delay timeout */
865 	unsigned long sackdelay;
866 	__u32 sackfreq;
867 
868 	atomic_t mtu_info;
869 
870 	/* When was the last time that we heard from this transport? We use
871 	 * this to pick new active and retran paths.
872 	 */
873 	ktime_t last_time_heard;
874 
875 	/* When was the last time that we sent a chunk using this
876 	 * transport? We use this to check for idle transports
877 	 */
878 	unsigned long last_time_sent;
879 
880 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
881 	 * indication based on ECNE chunk.
882 	 */
883 	unsigned long last_time_ecne_reduced;
884 
885 	__be16 encap_port;
886 
887 	/* This is the max_retrans value for the transport and will
888 	 * be initialized from the assocs value.  This can be changed
889 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
890 	 */
891 	__u16 pathmaxrxt;
892 
893 	__u32 flowlabel;
894 	__u8  dscp;
895 
896 	/* This is the partially failed retrans value for the transport
897 	 * and will be initialized from the assocs value.  This can be changed
898 	 * using the SCTP_PEER_ADDR_THLDS socket option
899 	 */
900 	__u16 pf_retrans;
901 	/* Used for primary path switchover. */
902 	__u16 ps_retrans;
903 	/* PMTU	      : The current known path MTU.  */
904 	__u32 pathmtu;
905 
906 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
907 	__u32 param_flags;
908 
909 	/* The number of times INIT has been sent on this transport. */
910 	int init_sent_count;
911 
912 	/* state       : The current state of this destination,
913 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
914 	 */
915 	int state;
916 
917 	/* These are the error stats for this destination.  */
918 
919 	/* Error count : The current error count for this destination.	*/
920 	unsigned short error_count;
921 
922 	/* Per	       : A timer used by each destination.
923 	 * Destination :
924 	 * Timer       :
925 	 *
926 	 * [Everywhere else in the text this is called T3-rtx. -ed]
927 	 */
928 	struct timer_list T3_rtx_timer;
929 
930 	/* Heartbeat timer is per destination. */
931 	struct timer_list hb_timer;
932 
933 	/* Timer to handle ICMP proto unreachable envets */
934 	struct timer_list proto_unreach_timer;
935 
936 	/* Timer to handler reconf chunk rtx */
937 	struct timer_list reconf_timer;
938 
939 	/* Timer to send a probe HB packet for PLPMTUD */
940 	struct timer_list probe_timer;
941 
942 	/* Since we're using per-destination retransmission timers
943 	 * (see above), we're also using per-destination "transmitted"
944 	 * queues.  This probably ought to be a private struct
945 	 * accessible only within the outqueue, but it's not, yet.
946 	 */
947 	struct list_head transmitted;
948 
949 	/* We build bundle-able packets for this transport here.  */
950 	struct sctp_packet packet;
951 
952 	/* This is the list of transports that have chunks to send.  */
953 	struct list_head send_ready;
954 
955 	/* State information saved for SFR_CACC algorithm. The key
956 	 * idea in SFR_CACC is to maintain state at the sender on a
957 	 * per-destination basis when a changeover happens.
958 	 *	char changeover_active;
959 	 *	char cycling_changeover;
960 	 *	__u32 next_tsn_at_change;
961 	 *	char cacc_saw_newack;
962 	 */
963 	struct {
964 		/* An unsigned integer, which stores the next TSN to be
965 		 * used by the sender, at the moment of changeover.
966 		 */
967 		__u32 next_tsn_at_change;
968 
969 		/* A flag which indicates the occurrence of a changeover */
970 		char changeover_active;
971 
972 		/* A flag which indicates whether the change of primary is
973 		 * the first switch to this destination address during an
974 		 * active switch.
975 		 */
976 		char cycling_changeover;
977 
978 		/* A temporary flag, which is used during the processing of
979 		 * a SACK to estimate the causative TSN(s)'s group.
980 		 */
981 		char cacc_saw_newack;
982 	} cacc;
983 
984 	struct {
985 		__u16 pmtu;
986 		__u16 probe_size;
987 		__u16 probe_high;
988 		__u8 probe_count;
989 		__u8 state;
990 	} pl; /* plpmtud related */
991 
992 	/* 64-bit random number sent with heartbeat. */
993 	__u64 hb_nonce;
994 
995 	struct rcu_head rcu;
996 };
997 
998 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
999 					  gfp_t);
1000 void sctp_transport_set_owner(struct sctp_transport *,
1001 			      struct sctp_association *);
1002 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1003 			  struct sctp_sock *);
1004 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1005 void sctp_transport_free(struct sctp_transport *);
1006 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1007 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1008 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1009 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1010 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1011 int sctp_transport_hold(struct sctp_transport *);
1012 void sctp_transport_put(struct sctp_transport *);
1013 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1014 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1015 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1016 			       enum sctp_lower_cwnd reason);
1017 void sctp_transport_burst_limited(struct sctp_transport *);
1018 void sctp_transport_burst_reset(struct sctp_transport *);
1019 unsigned long sctp_transport_timeout(struct sctp_transport *);
1020 void sctp_transport_reset(struct sctp_transport *t);
1021 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1022 void sctp_transport_immediate_rtx(struct sctp_transport *);
1023 void sctp_transport_dst_release(struct sctp_transport *t);
1024 void sctp_transport_dst_confirm(struct sctp_transport *t);
1025 void sctp_transport_pl_send(struct sctp_transport *t);
1026 bool sctp_transport_pl_recv(struct sctp_transport *t);
1027 
1028 
1029 /* This is the structure we use to queue packets as they come into
1030  * SCTP.  We write packets to it and read chunks from it.
1031  */
1032 struct sctp_inq {
1033 	/* This is actually a queue of sctp_chunk each
1034 	 * containing a partially decoded packet.
1035 	 */
1036 	struct list_head in_chunk_list;
1037 	/* This is the packet which is currently off the in queue and is
1038 	 * being worked on through the inbound chunk processing.
1039 	 */
1040 	struct sctp_chunk *in_progress;
1041 
1042 	/* This is the delayed task to finish delivering inbound
1043 	 * messages.
1044 	 */
1045 	struct work_struct immediate;
1046 };
1047 
1048 void sctp_inq_init(struct sctp_inq *);
1049 void sctp_inq_free(struct sctp_inq *);
1050 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1051 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1052 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1053 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1054 
1055 /* This is the structure we use to hold outbound chunks.  You push
1056  * chunks in and they automatically pop out the other end as bundled
1057  * packets (it calls (*output_handler)()).
1058  *
1059  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1060  * and 8.2 of the v13 draft.
1061  *
1062  * It handles retransmissions.	The connection to the timeout portion
1063  * of the state machine is through sctp_..._timeout() and timeout_handler.
1064  *
1065  * If you feed it SACKs, it will eat them.
1066  *
1067  * If you give it big chunks, it will fragment them.
1068  *
1069  * It assigns TSN's to data chunks.  This happens at the last possible
1070  * instant before transmission.
1071  *
1072  * When free()'d, it empties itself out via output_handler().
1073  */
1074 struct sctp_outq {
1075 	struct sctp_association *asoc;
1076 
1077 	/* Data pending that has never been transmitted.  */
1078 	struct list_head out_chunk_list;
1079 
1080 	/* Stream scheduler being used */
1081 	struct sctp_sched_ops *sched;
1082 
1083 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1084 
1085 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1086 	unsigned int error;
1087 
1088 	/* These are control chunks we want to send.  */
1089 	struct list_head control_chunk_list;
1090 
1091 	/* These are chunks that have been sacked but are above the
1092 	 * CTSN, or cumulative tsn ack point.
1093 	 */
1094 	struct list_head sacked;
1095 
1096 	/* Put chunks on this list to schedule them for
1097 	 * retransmission.
1098 	 */
1099 	struct list_head retransmit;
1100 
1101 	/* Put chunks on this list to save them for FWD TSN processing as
1102 	 * they were abandoned.
1103 	 */
1104 	struct list_head abandoned;
1105 
1106 	/* How many unackd bytes do we have in-flight?	*/
1107 	__u32 outstanding_bytes;
1108 
1109 	/* Are we doing fast-rtx on this queue */
1110 	char fast_rtx;
1111 
1112 	/* Corked? */
1113 	char cork;
1114 };
1115 
1116 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1117 void sctp_outq_teardown(struct sctp_outq *);
1118 void sctp_outq_free(struct sctp_outq*);
1119 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1120 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1121 int sctp_outq_is_empty(const struct sctp_outq *);
1122 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1123 		     enum sctp_retransmit_reason reason);
1124 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1125 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1126 void sctp_prsctp_prune(struct sctp_association *asoc,
1127 		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1128 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1129 /* Uncork and flush an outqueue.  */
sctp_outq_cork(struct sctp_outq * q)1130 static inline void sctp_outq_cork(struct sctp_outq *q)
1131 {
1132 	q->cork = 1;
1133 }
1134 
1135 /* SCTP skb control block.
1136  * sctp_input_cb is currently used on rx and sock rx queue
1137  */
1138 struct sctp_input_cb {
1139 	union {
1140 		struct inet_skb_parm    h4;
1141 #if IS_ENABLED(CONFIG_IPV6)
1142 		struct inet6_skb_parm   h6;
1143 #endif
1144 	} header;
1145 	struct sctp_chunk *chunk;
1146 	struct sctp_af *af;
1147 	__be16 encap_port;
1148 };
1149 #define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1150 
1151 struct sctp_output_cb {
1152 	struct sk_buff *last;
1153 };
1154 #define SCTP_OUTPUT_CB(__skb)	((struct sctp_output_cb *)&((__skb)->cb[0]))
1155 
sctp_gso_headskb(const struct sk_buff * skb)1156 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1157 {
1158 	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1159 
1160 	return chunk->head_skb ? : skb;
1161 }
1162 
1163 /* These bind address data fields common between endpoints and associations */
1164 struct sctp_bind_addr {
1165 
1166 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1167 	 *
1168 	 * SCTP Port:	The local SCTP port number the endpoint is
1169 	 *		bound to.
1170 	 */
1171 	__u16 port;
1172 
1173 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1174 	 *
1175 	 * Address List: The list of IP addresses that this instance
1176 	 *	has bound.  This information is passed to one's
1177 	 *	peer(s) in INIT and INIT ACK chunks.
1178 	 */
1179 	struct list_head address_list;
1180 };
1181 
1182 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1183 void sctp_bind_addr_free(struct sctp_bind_addr *);
1184 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1185 			const struct sctp_bind_addr *src,
1186 			enum sctp_scope scope, gfp_t gfp,
1187 			int flags);
1188 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1189 			const struct sctp_bind_addr *src,
1190 			gfp_t gfp);
1191 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1192 		       int new_size, __u8 addr_state, gfp_t gfp);
1193 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1194 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1195 			 struct sctp_sock *);
1196 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1197 			 struct sctp_sock *, struct sctp_sock *);
1198 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1199 			 const union sctp_addr *addr);
1200 int sctp_bind_addrs_check(struct sctp_sock *sp,
1201 			  struct sctp_sock *sp2, int cnt2);
1202 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1203 					const union sctp_addr	*addrs,
1204 					int			addrcnt,
1205 					struct sctp_sock	*opt);
1206 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1207 					 int *addrs_len,
1208 					 gfp_t gfp);
1209 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1210 			   __u16 port, gfp_t gfp);
1211 
1212 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1213 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1214 		  const enum sctp_scope scope);
1215 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1216 int sctp_is_ep_boundall(struct sock *sk);
1217 
1218 
1219 /* What type of endpoint?  */
1220 enum sctp_endpoint_type {
1221 	SCTP_EP_TYPE_SOCKET,
1222 	SCTP_EP_TYPE_ASSOCIATION,
1223 };
1224 
1225 /*
1226  * A common base class to bridge the implementation view of a
1227  * socket (usually listening) endpoint versus an association's
1228  * local endpoint.
1229  * This common structure is useful for several purposes:
1230  *   1) Common interface for lookup routines.
1231  *	a) Subfunctions work for either endpoint or association
1232  *	b) Single interface to lookup allows hiding the lookup lock rather
1233  *	   than acquiring it externally.
1234  *   2) Common interface for the inbound chunk handling/state machine.
1235  *   3) Common object handling routines for reference counting, etc.
1236  *   4) Disentangle association lookup from endpoint lookup, where we
1237  *	do not have to find our endpoint to find our association.
1238  *
1239  */
1240 
1241 struct sctp_ep_common {
1242 	/* Runtime type information.  What kind of endpoint is this? */
1243 	enum sctp_endpoint_type type;
1244 
1245 	/* Some fields to help us manage this object.
1246 	 *   refcnt   - Reference count access to this object.
1247 	 *   dead     - Do not attempt to use this object.
1248 	 */
1249 	refcount_t    refcnt;
1250 	bool	    dead;
1251 
1252 	/* What socket does this endpoint belong to?  */
1253 	struct sock *sk;
1254 
1255 	/* Cache netns and it won't change once set */
1256 	struct net *net;
1257 
1258 	/* This is where we receive inbound chunks.  */
1259 	struct sctp_inq	  inqueue;
1260 
1261 	/* This substructure includes the defining parameters of the
1262 	 * endpoint:
1263 	 * bind_addr.port is our shared port number.
1264 	 * bind_addr.address_list is our set of local IP addresses.
1265 	 */
1266 	struct sctp_bind_addr bind_addr;
1267 };
1268 
1269 
1270 /* RFC Section 1.4 Key Terms
1271  *
1272  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1273  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1274  *   combination of a set of eligible destination transport addresses to
1275  *   which SCTP packets can be sent and a set of eligible source
1276  *   transport addresses from which SCTP packets can be received.
1277  *   All transport addresses used by an SCTP endpoint must use the
1278  *   same port number, but can use multiple IP addresses. A transport
1279  *   address used by an SCTP endpoint must not be used by another
1280  *   SCTP endpoint. In other words, a transport address is unique
1281  *   to an SCTP endpoint.
1282  *
1283  * From an implementation perspective, each socket has one of these.
1284  * A TCP-style socket will have exactly one association on one of
1285  * these.  An UDP-style socket will have multiple associations hanging
1286  * off one of these.
1287  */
1288 
1289 struct sctp_endpoint {
1290 	/* Common substructure for endpoint and association. */
1291 	struct sctp_ep_common base;
1292 
1293 	/* Fields to help us manage our entries in the hash tables. */
1294 	struct hlist_node node;
1295 	int hashent;
1296 
1297 	/* Associations: A list of current associations and mappings
1298 	 *	      to the data consumers for each association. This
1299 	 *	      may be in the form of a hash table or other
1300 	 *	      implementation dependent structure. The data
1301 	 *	      consumers may be process identification
1302 	 *	      information such as file descriptors, named pipe
1303 	 *	      pointer, or table pointers dependent on how SCTP
1304 	 *	      is implemented.
1305 	 */
1306 	/* This is really a list of struct sctp_association entries. */
1307 	struct list_head asocs;
1308 
1309 	/* Secret Key: A secret key used by this endpoint to compute
1310 	 *	      the MAC.	This SHOULD be a cryptographic quality
1311 	 *	      random number with a sufficient length.
1312 	 *	      Discussion in [RFC1750] can be helpful in
1313 	 *	      selection of the key.
1314 	 */
1315 	__u8 secret_key[SCTP_SECRET_SIZE];
1316 
1317  	/* digest:  This is a digest of the sctp cookie.  This field is
1318  	 * 	    only used on the receive path when we try to validate
1319  	 * 	    that the cookie has not been tampered with.  We put
1320  	 * 	    this here so we pre-allocate this once and can re-use
1321  	 * 	    on every receive.
1322  	 */
1323  	__u8 *digest;
1324 
1325 	/* sendbuf acct. policy.	*/
1326 	__u32 sndbuf_policy;
1327 
1328 	/* rcvbuf acct. policy.	*/
1329 	__u32 rcvbuf_policy;
1330 
1331 	/* SCTP AUTH: array of the HMACs that will be allocated
1332 	 * we need this per association so that we don't serialize
1333 	 */
1334 	struct crypto_shash **auth_hmacs;
1335 
1336 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1337 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1338 
1339 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1340 	struct sctp_chunks_param *auth_chunk_list;
1341 
1342 	/* SCTP-AUTH: endpoint shared keys */
1343 	struct list_head endpoint_shared_keys;
1344 	__u16 active_key_id;
1345 	__u8  ecn_enable:1,
1346 	      auth_enable:1,
1347 	      intl_enable:1,
1348 	      prsctp_enable:1,
1349 	      asconf_enable:1,
1350 	      reconf_enable:1;
1351 
1352 	__u8  strreset_enable;
1353 	struct rcu_head rcu;
1354 };
1355 
1356 /* Recover the outer endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1357 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1358 {
1359 	struct sctp_endpoint *ep;
1360 
1361 	ep = container_of(base, struct sctp_endpoint, base);
1362 	return ep;
1363 }
1364 
1365 /* These are function signatures for manipulating endpoints.  */
1366 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1367 void sctp_endpoint_free(struct sctp_endpoint *);
1368 void sctp_endpoint_put(struct sctp_endpoint *);
1369 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1370 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1371 struct sctp_association *sctp_endpoint_lookup_assoc(
1372 	const struct sctp_endpoint *ep,
1373 	const union sctp_addr *paddr,
1374 	struct sctp_transport **);
1375 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1376 				 const union sctp_addr *paddr);
1377 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1378 					     struct net *net,
1379 					     const union sctp_addr *laddr,
1380 					     int dif, int sdif);
1381 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1382 			  const union sctp_addr *paddr, int dif, int sdif);
1383 
1384 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1385 		     const struct sctp_association *asoc,
1386 		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1387 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1388 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1389 		      const union sctp_addr *peer,
1390 		      struct sctp_init_chunk *init, gfp_t gfp);
1391 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1392 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1393 
1394 struct sctp_inithdr_host {
1395 	__u32 init_tag;
1396 	__u32 a_rwnd;
1397 	__u16 num_outbound_streams;
1398 	__u16 num_inbound_streams;
1399 	__u32 initial_tsn;
1400 };
1401 
1402 struct sctp_stream_priorities {
1403 	/* List of priorities scheduled */
1404 	struct list_head prio_sched;
1405 	/* List of streams scheduled */
1406 	struct list_head active;
1407 	/* The next stream in line */
1408 	struct sctp_stream_out_ext *next;
1409 	__u16 prio;
1410 	__u16 users;
1411 };
1412 
1413 struct sctp_stream_out_ext {
1414 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1415 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1416 	struct list_head outq; /* chunks enqueued by this stream */
1417 	union {
1418 		struct {
1419 			/* Scheduled streams list */
1420 			struct list_head prio_list;
1421 			struct sctp_stream_priorities *prio_head;
1422 		};
1423 		/* Fields used by RR scheduler */
1424 		struct {
1425 			struct list_head rr_list;
1426 		};
1427 		struct {
1428 			struct list_head fc_list;
1429 			__u32 fc_length;
1430 			__u16 fc_weight;
1431 		};
1432 	};
1433 };
1434 
1435 struct sctp_stream_out {
1436 	union {
1437 		__u32 mid;
1438 		__u16 ssn;
1439 	};
1440 	__u32 mid_uo;
1441 	struct sctp_stream_out_ext *ext;
1442 	__u8 state;
1443 };
1444 
1445 struct sctp_stream_in {
1446 	union {
1447 		__u32 mid;
1448 		__u16 ssn;
1449 	};
1450 	__u32 mid_uo;
1451 	__u32 fsn;
1452 	__u32 fsn_uo;
1453 	char pd_mode;
1454 	char pd_mode_uo;
1455 };
1456 
1457 struct sctp_stream {
1458 	GENRADIX(struct sctp_stream_out) out;
1459 	GENRADIX(struct sctp_stream_in)	in;
1460 
1461 	__u16 outcnt;
1462 	__u16 incnt;
1463 	/* Current stream being sent, if any */
1464 	struct sctp_stream_out *out_curr;
1465 	union {
1466 		/* Fields used by priority scheduler */
1467 		struct {
1468 			/* List of priorities scheduled */
1469 			struct list_head prio_list;
1470 		};
1471 		/* Fields used by RR scheduler */
1472 		struct {
1473 			/* List of streams scheduled */
1474 			struct list_head rr_list;
1475 			/* The next stream in line */
1476 			struct sctp_stream_out_ext *rr_next;
1477 		};
1478 		struct {
1479 			struct list_head fc_list;
1480 		};
1481 	};
1482 	struct sctp_stream_interleave *si;
1483 };
1484 
sctp_stream_out(struct sctp_stream * stream,__u16 sid)1485 static inline struct sctp_stream_out *sctp_stream_out(
1486 	struct sctp_stream *stream,
1487 	__u16 sid)
1488 {
1489 	return genradix_ptr(&stream->out, sid);
1490 }
1491 
sctp_stream_in(struct sctp_stream * stream,__u16 sid)1492 static inline struct sctp_stream_in *sctp_stream_in(
1493 	struct sctp_stream *stream,
1494 	__u16 sid)
1495 {
1496 	return genradix_ptr(&stream->in, sid);
1497 }
1498 
1499 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1500 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1501 
1502 #define SCTP_STREAM_CLOSED		0x00
1503 #define SCTP_STREAM_OPEN		0x01
1504 
sctp_datachk_len(const struct sctp_stream * stream)1505 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1506 {
1507 	return stream->si->data_chunk_len;
1508 }
1509 
sctp_datahdr_len(const struct sctp_stream * stream)1510 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1511 {
1512 	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1513 }
1514 
sctp_ftsnchk_len(const struct sctp_stream * stream)1515 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1516 {
1517 	return stream->si->ftsn_chunk_len;
1518 }
1519 
sctp_ftsnhdr_len(const struct sctp_stream * stream)1520 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1521 {
1522 	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1523 }
1524 
1525 /* SCTP_GET_ASSOC_STATS counters */
1526 struct sctp_priv_assoc_stats {
1527 	/* Maximum observed rto in the association during subsequent
1528 	 * observations. Value is set to 0 if no RTO measurement took place
1529 	 * The transport where the max_rto was observed is returned in
1530 	 * obs_rto_ipaddr
1531 	 */
1532 	struct sockaddr_storage obs_rto_ipaddr;
1533 	__u64 max_obs_rto;
1534 	/* Total In and Out SACKs received and sent */
1535 	__u64 isacks;
1536 	__u64 osacks;
1537 	/* Total In and Out packets received and sent */
1538 	__u64 opackets;
1539 	__u64 ipackets;
1540 	/* Total retransmitted chunks */
1541 	__u64 rtxchunks;
1542 	/* TSN received > next expected */
1543 	__u64 outofseqtsns;
1544 	/* Duplicate Chunks received */
1545 	__u64 idupchunks;
1546 	/* Gap Ack Blocks received */
1547 	__u64 gapcnt;
1548 	/* Unordered data chunks sent and received */
1549 	__u64 ouodchunks;
1550 	__u64 iuodchunks;
1551 	/* Ordered data chunks sent and received */
1552 	__u64 oodchunks;
1553 	__u64 iodchunks;
1554 	/* Control chunks sent and received */
1555 	__u64 octrlchunks;
1556 	__u64 ictrlchunks;
1557 };
1558 
1559 /* RFC2960
1560  *
1561  * 12. Recommended Transmission Control Block (TCB) Parameters
1562  *
1563  * This section details a recommended set of parameters that should
1564  * be contained within the TCB for an implementation. This section is
1565  * for illustrative purposes and should not be deemed as requirements
1566  * on an implementation or as an exhaustive list of all parameters
1567  * inside an SCTP TCB. Each implementation may need its own additional
1568  * parameters for optimization.
1569  */
1570 
1571 
1572 /* Here we have information about each individual association. */
1573 struct sctp_association {
1574 
1575 	/* A base structure common to endpoint and association.
1576 	 * In this context, it represents the associations's view
1577 	 * of the local endpoint of the association.
1578 	 */
1579 	struct sctp_ep_common base;
1580 
1581 	/* Associations on the same socket. */
1582 	struct list_head asocs;
1583 
1584 	/* association id. */
1585 	sctp_assoc_t assoc_id;
1586 
1587 	/* This is our parent endpoint.	 */
1588 	struct sctp_endpoint *ep;
1589 
1590 	/* These are those association elements needed in the cookie.  */
1591 	struct sctp_cookie c;
1592 
1593 	/* This is all information about our peer.  */
1594 	struct {
1595 		/* transport_addr_list
1596 		 *
1597 		 * Peer	       : A list of SCTP transport addresses that the
1598 		 * Transport   : peer is bound to. This information is derived
1599 		 * Address     : from the INIT or INIT ACK and is used to
1600 		 * List	       : associate an inbound packet with a given
1601 		 *	       : association. Normally this information is
1602 		 *	       : hashed or keyed for quick lookup and access
1603 		 *	       : of the TCB.
1604 		 *	       : The list is also initialized with the list
1605 		 *	       : of addresses passed with the sctp_connectx()
1606 		 *	       : call.
1607 		 *
1608 		 * It is a list of SCTP_transport's.
1609 		 */
1610 		struct list_head transport_addr_list;
1611 
1612 		/* rwnd
1613 		 *
1614 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1615 		 */
1616 		__u32 rwnd;
1617 
1618 		/* transport_count
1619 		 *
1620 		 * Peer        : A count of the number of peer addresses
1621 		 * Transport   : in the Peer Transport Address List.
1622 		 * Address     :
1623 		 * Count       :
1624 		 */
1625 		__u16 transport_count;
1626 
1627 		/* port
1628 		 *   The transport layer port number.
1629 		 */
1630 		__u16 port;
1631 
1632 		/* primary_path
1633 		 *
1634 		 * Primary     : This is the current primary destination
1635 		 * Path	       : transport address of the peer endpoint.  It
1636 		 *	       : may also specify a source transport address
1637 		 *	       : on this endpoint.
1638 		 *
1639 		 * All of these paths live on transport_addr_list.
1640 		 *
1641 		 * At the bakeoffs, we discovered that the intent of
1642 		 * primaryPath is that it only changes when the ULP
1643 		 * asks to have it changed.  We add the activePath to
1644 		 * designate the connection we are currently using to
1645 		 * transmit new data and most control chunks.
1646 		 */
1647 		struct sctp_transport *primary_path;
1648 
1649 		/* Cache the primary path address here, when we
1650 		 * need a an address for msg_name.
1651 		 */
1652 		union sctp_addr primary_addr;
1653 
1654 		/* active_path
1655 		 *   The path that we are currently using to
1656 		 *   transmit new data and most control chunks.
1657 		 */
1658 		struct sctp_transport *active_path;
1659 
1660 		/* retran_path
1661 		 *
1662 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1663 		 * ...
1664 		 * Furthermore, when its peer is multi-homed, an
1665 		 * endpoint SHOULD try to retransmit a chunk to an
1666 		 * active destination transport address that is
1667 		 * different from the last destination address to
1668 		 * which the DATA chunk was sent.
1669 		 */
1670 		struct sctp_transport *retran_path;
1671 
1672 		/* Pointer to last transport I have sent on.  */
1673 		struct sctp_transport *last_sent_to;
1674 
1675 		/* This is the last transport I have received DATA on.	*/
1676 		struct sctp_transport *last_data_from;
1677 
1678 		/*
1679 		 * Mapping  An array of bits or bytes indicating which out of
1680 		 * Array    order TSN's have been received (relative to the
1681 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1682 		 *	    order packets have been received, this array
1683 		 *	    will be set to all zero. This structure may be
1684 		 *	    in the form of a circular buffer or bit array.
1685 		 *
1686 		 * Last Rcvd   : This is the last TSN received in
1687 		 * TSN	       : sequence. This value is set initially by
1688 		 *	       : taking the peer's Initial TSN, received in
1689 		 *	       : the INIT or INIT ACK chunk, and subtracting
1690 		 *	       : one from it.
1691 		 *
1692 		 * Throughout most of the specification this is called the
1693 		 * "Cumulative TSN ACK Point".	In this case, we
1694 		 * ignore the advice in 12.2 in favour of the term
1695 		 * used in the bulk of the text.  This value is hidden
1696 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1697 		 */
1698 		struct sctp_tsnmap tsn_map;
1699 
1700 		/* This mask is used to disable sending the ASCONF chunk
1701 		 * with specified parameter to peer.
1702 		 */
1703 		__be16 addip_disabled_mask;
1704 
1705 		/* These are capabilities which our peer advertised.  */
1706 		__u16	ecn_capable:1,      /* Can peer do ECN? */
1707 			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1708 			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1709 			asconf_capable:1,   /* Does peer support ADDIP? */
1710 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1711 			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1712 			intl_capable:1,     /* Can peer do INTERLEAVE */
1713 			auth_capable:1,     /* Is peer doing SCTP-AUTH? */
1714 			/* sack_needed:
1715 			 *   This flag indicates if the next received
1716 			 *   packet is to be responded to with a
1717 			 *   SACK. This is initialized to 0.  When a packet
1718 			 *   is received sack_cnt is incremented. If this value
1719 			 *   reaches 2 or more, a SACK is sent and the
1720 			 *   value is reset to 0. Note: This is used only
1721 			 *   when no DATA chunks are received out of
1722 			 *   order.  When DATA chunks are out of order,
1723 			 *   SACK's are not delayed (see Section 6).
1724 			 */
1725 			sack_needed:1,     /* Do we need to sack the peer? */
1726 			sack_generation:1,
1727 			zero_window_announced:1;
1728 
1729 		__u32	sack_cnt;
1730 
1731 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1732 
1733 		struct sctp_inithdr_host i;
1734 		void *cookie;
1735 		int cookie_len;
1736 
1737 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1738 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1739 		 * Initial TSN Value minus 1
1740 		 */
1741 		__u32 addip_serial;
1742 
1743 		/* SCTP-AUTH: We need to know pears random number, hmac list
1744 		 * and authenticated chunk list.  All that is part of the
1745 		 * cookie and these are just pointers to those locations
1746 		 */
1747 		struct sctp_random_param *peer_random;
1748 		struct sctp_chunks_param *peer_chunks;
1749 		struct sctp_hmac_algo_param *peer_hmacs;
1750 	} peer;
1751 
1752 	/* State       : A state variable indicating what state the
1753 	 *	       : association is in, i.e. COOKIE-WAIT,
1754 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1755 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1756 	 *
1757 	 *		Note: No "CLOSED" state is illustrated since if a
1758 	 *		association is "CLOSED" its TCB SHOULD be removed.
1759 	 *
1760 	 *		In this implementation we DO have a CLOSED
1761 	 *		state which is used during initiation and shutdown.
1762 	 *
1763 	 *		State takes values from SCTP_STATE_*.
1764 	 */
1765 	enum sctp_state state;
1766 
1767 	/* Overall     : The overall association error count.
1768 	 * Error Count : [Clear this any time I get something.]
1769 	 */
1770 	int overall_error_count;
1771 
1772 	/* The cookie life I award for any cookie.  */
1773 	ktime_t cookie_life;
1774 
1775 	/* These are the association's initial, max, and min RTO values.
1776 	 * These values will be initialized by system defaults, but can
1777 	 * be modified via the SCTP_RTOINFO socket option.
1778 	 */
1779 	unsigned long rto_initial;
1780 	unsigned long rto_max;
1781 	unsigned long rto_min;
1782 
1783 	/* Maximum number of new data packets that can be sent in a burst.  */
1784 	int max_burst;
1785 
1786 	/* This is the max_retrans value for the association.  This value will
1787 	 * be initialized from system defaults, but can be
1788 	 * modified by the SCTP_ASSOCINFO socket option.
1789 	 */
1790 	int max_retrans;
1791 
1792 	/* This is the partially failed retrans value for the transport
1793 	 * and will be initialized from the assocs value.  This can be
1794 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1795 	 */
1796 	__u16 pf_retrans;
1797 	/* Used for primary path switchover. */
1798 	__u16 ps_retrans;
1799 
1800 	/* Maximum number of times the endpoint will retransmit INIT  */
1801 	__u16 max_init_attempts;
1802 
1803 	/* How many times have we resent an INIT? */
1804 	__u16 init_retries;
1805 
1806 	/* The largest timeout or RTO value to use in attempting an INIT */
1807 	unsigned long max_init_timeo;
1808 
1809 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1810 	 * the destination address every heartbeat interval. This value
1811 	 * will be inherited by all new transports.
1812 	 */
1813 	unsigned long hbinterval;
1814 	unsigned long probe_interval;
1815 
1816 	__be16 encap_port;
1817 
1818 	/* This is the max_retrans value for new transports in the
1819 	 * association.
1820 	 */
1821 	__u16 pathmaxrxt;
1822 
1823 	__u32 flowlabel;
1824 	__u8  dscp;
1825 
1826 	/* Flag that path mtu update is pending */
1827 	__u8   pmtu_pending;
1828 
1829 	/* Association : The smallest PMTU discovered for all of the
1830 	 * PMTU	       : peer's transport addresses.
1831 	 */
1832 	__u32 pathmtu;
1833 
1834 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1835 	__u32 param_flags;
1836 
1837 	__u32 sackfreq;
1838 	/* SACK delay timeout */
1839 	unsigned long sackdelay;
1840 
1841 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1842 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1843 
1844 	/* Transport to which SHUTDOWN chunk was last sent.  */
1845 	struct sctp_transport *shutdown_last_sent_to;
1846 
1847 	/* Transport to which INIT chunk was last sent.  */
1848 	struct sctp_transport *init_last_sent_to;
1849 
1850 	/* How many times have we resent a SHUTDOWN */
1851 	int shutdown_retries;
1852 
1853 	/* Next TSN    : The next TSN number to be assigned to a new
1854 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1855 	 *	       : ACK chunk to the peer and incremented each
1856 	 *	       : time a DATA chunk is assigned a TSN
1857 	 *	       : (normally just prior to transmit or during
1858 	 *	       : fragmentation).
1859 	 */
1860 	__u32 next_tsn;
1861 
1862 	/*
1863 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1864 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1865 	 *	       : received in the INIT or INIT ACK chunk, and
1866 	 *	       : subtracting one from it.
1867 	 *
1868 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1869 	 */
1870 
1871 	__u32 ctsn_ack_point;
1872 
1873 	/* PR-SCTP Advanced.Peer.Ack.Point */
1874 	__u32 adv_peer_ack_point;
1875 
1876 	/* Highest TSN that is acknowledged by incoming SACKs. */
1877 	__u32 highest_sacked;
1878 
1879 	/* TSN marking the fast recovery exit point */
1880 	__u32 fast_recovery_exit;
1881 
1882 	/* Flag to track the current fast recovery state */
1883 	__u8 fast_recovery;
1884 
1885 	/* The number of unacknowledged data chunks.  Reported through
1886 	 * the SCTP_STATUS sockopt.
1887 	 */
1888 	__u16 unack_data;
1889 
1890 	/* The total number of data chunks that we've had to retransmit
1891 	 * as the result of a T3 timer expiration
1892 	 */
1893 	__u32 rtx_data_chunks;
1894 
1895 	/* This is the association's receive buffer space.  This value is used
1896 	 * to set a_rwnd field in an INIT or a SACK chunk.
1897 	 */
1898 	__u32 rwnd;
1899 
1900 	/* This is the last advertised value of rwnd over a SACK chunk. */
1901 	__u32 a_rwnd;
1902 
1903 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1904 	 * to slop over a maximum of the association's frag_point.
1905 	 */
1906 	__u32 rwnd_over;
1907 
1908 	/* Keeps treack of rwnd pressure.  This happens when we have
1909 	 * a window, but not receive buffer (i.e small packets).  This one
1910 	 * is releases slowly (1 PMTU at a time ).
1911 	 */
1912 	__u32 rwnd_press;
1913 
1914 	/* This is the sndbuf size in use for the association.
1915 	 * This corresponds to the sndbuf size for the association,
1916 	 * as specified in the sk->sndbuf.
1917 	 */
1918 	int sndbuf_used;
1919 
1920 	/* This is the amount of memory that this association has allocated
1921 	 * in the receive path at any given time.
1922 	 */
1923 	atomic_t rmem_alloc;
1924 
1925 	/* This is the wait queue head for send requests waiting on
1926 	 * the association sndbuf space.
1927 	 */
1928 	wait_queue_head_t	wait;
1929 
1930 	/* The message size at which SCTP fragmentation will occur. */
1931 	__u32 frag_point;
1932 	__u32 user_frag;
1933 
1934 	/* Counter used to count INIT errors. */
1935 	int init_err_counter;
1936 
1937 	/* Count the number of INIT cycles (for doubling timeout). */
1938 	int init_cycle;
1939 
1940 	/* Default send parameters. */
1941 	__u16 default_stream;
1942 	__u16 default_flags;
1943 	__u32 default_ppid;
1944 	__u32 default_context;
1945 	__u32 default_timetolive;
1946 
1947 	/* Default receive parameters */
1948 	__u32 default_rcv_context;
1949 
1950 	/* Stream arrays */
1951 	struct sctp_stream stream;
1952 
1953 	/* All outbound chunks go through this structure.  */
1954 	struct sctp_outq outqueue;
1955 
1956 	/* A smart pipe that will handle reordering and fragmentation,
1957 	 * as well as handle passing events up to the ULP.
1958 	 */
1959 	struct sctp_ulpq ulpq;
1960 
1961 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1962 	__u32 last_ecne_tsn;
1963 
1964 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1965 	__u32 last_cwr_tsn;
1966 
1967 	/* How many duplicated TSNs have we seen?  */
1968 	int numduptsns;
1969 
1970 	/* These are to support
1971 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1972 	 *  and Enforcement of Flow and Message Limits"
1973 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1974 	 * or "ADDIP" for short.
1975 	 */
1976 
1977 
1978 
1979 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1980 	 *
1981 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1982 	 * unacknowledged at any one time.  If a sender, after sending
1983 	 * an ASCONF chunk, decides it needs to transfer another
1984 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1985 	 * returns from the previous ASCONF Chunk before sending a
1986 	 * subsequent ASCONF. Note this restriction binds each side,
1987 	 * so at any time two ASCONF may be in-transit on any given
1988 	 * association (one sent from each endpoint).
1989 	 *
1990 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1991 	 * not have an ASCONF in flight, this is NULL.]
1992 	 */
1993 	struct sctp_chunk *addip_last_asconf;
1994 
1995 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1996 	 *
1997 	 * This is needed to implement items E1 - E4 of the updated
1998 	 * spec.  Here is the justification:
1999 	 *
2000 	 * Since the peer may bundle multiple ASCONF chunks toward us,
2001 	 * we now need the ability to cache multiple ACKs.  The section
2002 	 * describes in detail how they are cached and cleaned up.
2003 	 */
2004 	struct list_head asconf_ack_list;
2005 
2006 	/* These ASCONF chunks are waiting to be sent.
2007 	 *
2008 	 * These chunks can't be pushed to outqueue until receiving
2009 	 * ASCONF_ACK for the previous ASCONF indicated by
2010 	 * addip_last_asconf, so as to guarantee that only one ASCONF
2011 	 * is in flight at any time.
2012 	 *
2013 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2014 	 *
2015 	 * In defining the ASCONF Chunk transfer procedures, it is
2016 	 * essential that these transfers MUST NOT cause congestion
2017 	 * within the network.	To achieve this, we place these
2018 	 * restrictions on the transfer of ASCONF Chunks:
2019 	 *
2020 	 * R1) One and only one ASCONF Chunk MAY be in transit and
2021 	 * unacknowledged at any one time.  If a sender, after sending
2022 	 * an ASCONF chunk, decides it needs to transfer another
2023 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2024 	 * returns from the previous ASCONF Chunk before sending a
2025 	 * subsequent ASCONF. Note this restriction binds each side,
2026 	 * so at any time two ASCONF may be in-transit on any given
2027 	 * association (one sent from each endpoint).
2028 	 *
2029 	 *
2030 	 * [I really think this is EXACTLY the sort of intelligence
2031 	 *  which already resides in sctp_outq.	 Please move this
2032 	 *  queue and its supporting logic down there.	--piggy]
2033 	 */
2034 	struct list_head addip_chunk_list;
2035 
2036 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2037 	 *
2038 	 * A2) A serial number should be assigned to the Chunk. The
2039 	 * serial number SHOULD be a monotonically increasing
2040 	 * number. The serial number SHOULD be initialized at
2041 	 * the start of the association to the same value as the
2042 	 * Initial TSN and every time a new ASCONF chunk is created
2043 	 * it is incremented by one after assigning the serial number
2044 	 * to the newly created chunk.
2045 	 *
2046 	 * ADDIP
2047 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2048 	 *
2049 	 * Serial Number : 32 bits (unsigned integer)
2050 	 *
2051 	 * This value represents a Serial Number for the ASCONF
2052 	 * Chunk. The valid range of Serial Number is from 0 to
2053 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2054 	 * after reaching 4294967295.
2055 	 */
2056 	__u32 addip_serial;
2057 	int src_out_of_asoc_ok;
2058 	union sctp_addr *asconf_addr_del_pending;
2059 	struct sctp_transport *new_transport;
2060 
2061 	/* SCTP AUTH: list of the endpoint shared keys.  These
2062 	 * keys are provided out of band by the user application
2063 	 * and can't change during the lifetime of the association
2064 	 */
2065 	struct list_head endpoint_shared_keys;
2066 
2067 	/* SCTP AUTH:
2068 	 * The current generated association shared key (secret)
2069 	 */
2070 	struct sctp_auth_bytes *asoc_shared_key;
2071 	struct sctp_shared_key *shkey;
2072 
2073 	/* SCTP AUTH: hmac id of the first peer requested algorithm
2074 	 * that we support.
2075 	 */
2076 	__u16 default_hmac_id;
2077 
2078 	__u16 active_key_id;
2079 
2080 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2081 	     temp:1,		/* Is it a temporary association? */
2082 	     pf_expose:2,       /* Expose pf state? */
2083 	     force_delay:1;
2084 
2085 	__u8 strreset_enable;
2086 	__u8 strreset_outstanding; /* request param count on the fly */
2087 
2088 	__u32 strreset_outseq; /* Update after receiving response */
2089 	__u32 strreset_inseq; /* Update after receiving request */
2090 	__u32 strreset_result[2]; /* save the results of last 2 responses */
2091 
2092 	struct sctp_chunk *strreset_chunk; /* save request chunk */
2093 
2094 	struct sctp_priv_assoc_stats stats;
2095 
2096 	int sent_cnt_removable;
2097 
2098 	__u16 subscribe;
2099 
2100 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2101 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2102 
2103 	/* Security identifiers from incoming (INIT). These are set by
2104 	 * security_sctp_assoc_request(). These will only be used by
2105 	 * SCTP TCP type sockets and peeled off connections as they
2106 	 * cause a new socket to be generated. security_sctp_sk_clone()
2107 	 * will then plug these into the new socket.
2108 	 */
2109 
2110 	u32 secid;
2111 	u32 peer_secid;
2112 
2113 	struct rcu_head rcu;
2114 };
2115 
2116 
2117 /* An eyecatcher for determining if we are really looking at an
2118  * association data structure.
2119  */
2120 enum {
2121 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2122 };
2123 
2124 /* Recover the outer association structure. */
sctp_assoc(struct sctp_ep_common * base)2125 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2126 {
2127 	struct sctp_association *asoc;
2128 
2129 	asoc = container_of(base, struct sctp_association, base);
2130 	return asoc;
2131 }
2132 
2133 /* These are function signatures for manipulating associations.	 */
2134 
2135 
2136 struct sctp_association *
2137 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2138 		     enum sctp_scope scope, gfp_t gfp);
2139 void sctp_association_free(struct sctp_association *);
2140 void sctp_association_put(struct sctp_association *);
2141 void sctp_association_hold(struct sctp_association *);
2142 
2143 struct sctp_transport *sctp_assoc_choose_alter_transport(
2144 	struct sctp_association *, struct sctp_transport *);
2145 void sctp_assoc_update_retran_path(struct sctp_association *);
2146 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2147 					  const union sctp_addr *);
2148 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2149 			    const union sctp_addr *laddr);
2150 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2151 				     const union sctp_addr *address,
2152 				     const gfp_t gfp,
2153 				     const int peer_state);
2154 void sctp_assoc_del_peer(struct sctp_association *asoc,
2155 			 const union sctp_addr *addr);
2156 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2157 			 struct sctp_transport *peer);
2158 void sctp_assoc_control_transport(struct sctp_association *asoc,
2159 				  struct sctp_transport *transport,
2160 				  enum sctp_transport_cmd command,
2161 				  sctp_sn_error_t error);
2162 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2163 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2164 int sctp_assoc_update(struct sctp_association *old,
2165 		      struct sctp_association *new);
2166 
2167 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2168 
2169 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2170 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2171 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2172 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2173 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2174 void sctp_assoc_set_primary(struct sctp_association *,
2175 			    struct sctp_transport *);
2176 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2177 				    struct sctp_transport *);
2178 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2179 				     enum sctp_scope scope, gfp_t gfp);
2180 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2181 					 struct sctp_cookie*,
2182 					 gfp_t gfp);
2183 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2184 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2185 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2186 					const struct sctp_association *asoc,
2187 					__be32 serial);
2188 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2189 
2190 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2191 			const union sctp_addr *ss2);
2192 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2193 
2194 /* A convenience structure to parse out SCTP specific CMSGs. */
2195 struct sctp_cmsgs {
2196 	struct sctp_initmsg *init;
2197 	struct sctp_sndrcvinfo *srinfo;
2198 	struct sctp_sndinfo *sinfo;
2199 	struct sctp_prinfo *prinfo;
2200 	struct sctp_authinfo *authinfo;
2201 	struct msghdr *addrs_msg;
2202 };
2203 
2204 /* Structure for tracking memory objects */
2205 struct sctp_dbg_objcnt_entry {
2206 	char *label;
2207 	atomic_t *counter;
2208 };
2209 
2210 #endif /* __sctp_structs_h__ */
2211