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 
sctp_sk(const struct sock * sk)245 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
246 {
247        return (struct sctp_sock *)sk;
248 }
249 
sctp_opt2sk(const struct sctp_sock * sp)250 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
251 {
252        return (struct sock *)sp;
253 }
254 
255 #if IS_ENABLED(CONFIG_IPV6)
256 struct sctp6_sock {
257        struct sctp_sock  sctp;
258        struct ipv6_pinfo inet6;
259 };
260 #endif /* CONFIG_IPV6 */
261 
262 
263 /* This is our APPLICATION-SPECIFIC state cookie.
264  * THIS IS NOT DICTATED BY THE SPECIFICATION.
265  */
266 /* These are the parts of an association which we send in the cookie.
267  * Most of these are straight out of:
268  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
269  *
270  */
271 
272 struct sctp_cookie {
273 
274 	/* My	       : Tag expected in every inbound packet and sent
275 	 * Verification: in the INIT or INIT ACK chunk.
276 	 * Tag	       :
277 	 */
278 	__u32 my_vtag;
279 
280 	/* Peer's      : Tag expected in every outbound packet except
281 	 * Verification: in the INIT chunk.
282 	 * Tag	       :
283 	 */
284 	__u32 peer_vtag;
285 
286 	/* The rest of these are not from the spec, but really need to
287 	 * be in the cookie.
288 	 */
289 
290 	/* My Tie Tag  : Assist in discovering a restarting association. */
291 	__u32 my_ttag;
292 
293 	/* Peer's Tie Tag: Assist in discovering a restarting association. */
294 	__u32 peer_ttag;
295 
296 	/* When does this cookie expire? */
297 	ktime_t expiration;
298 
299 	/* Number of inbound/outbound streams which are set
300 	 * and negotiated during the INIT process.
301 	 */
302 	__u16 sinit_num_ostreams;
303 	__u16 sinit_max_instreams;
304 
305 	/* This is the first sequence number I used.  */
306 	__u32 initial_tsn;
307 
308 	/* This holds the originating address of the INIT packet.  */
309 	union sctp_addr peer_addr;
310 
311 	/* IG Section 2.35.3
312 	 * Include the source port of the INIT-ACK
313 	 */
314 	__u16		my_port;
315 
316 	__u8 prsctp_capable;
317 
318 	/* Padding for future use */
319 	__u8 padding;
320 
321 	__u32 adaptation_ind;
322 
323 	__u8 auth_random[sizeof(struct sctp_paramhdr) +
324 			 SCTP_AUTH_RANDOM_LENGTH];
325 	__u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
326 	__u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
327 
328 	/* This is a shim for my peer's INIT packet, followed by
329 	 * a copy of the raw address list of the association.
330 	 * The length of the raw address list is saved in the
331 	 * raw_addr_list_len field, which will be used at the time when
332 	 * the association TCB is re-constructed from the cookie.
333 	 */
334 	__u32 raw_addr_list_len;
335 	/* struct sctp_init_chunk peer_init[]; */
336 };
337 
338 
339 /* The format of our cookie that we send to our peer. */
340 struct sctp_signed_cookie {
341 	__u8 signature[SCTP_SECRET_SIZE];
342 	__u32 __pad;		/* force sctp_cookie alignment to 64 bits */
343 	struct sctp_cookie c;
344 } __packed;
345 
346 /* This is another convenience type to allocate memory for address
347  * params for the maximum size and pass such structures around
348  * internally.
349  */
350 union sctp_addr_param {
351 	struct sctp_paramhdr p;
352 	struct sctp_ipv4addr_param v4;
353 	struct sctp_ipv6addr_param v6;
354 };
355 
356 /* A convenience type to allow walking through the various
357  * parameters and avoid casting all over the place.
358  */
359 union sctp_params {
360 	void *v;
361 	struct sctp_paramhdr *p;
362 	struct sctp_cookie_preserve_param *life;
363 	struct sctp_hostname_param *dns;
364 	struct sctp_cookie_param *cookie;
365 	struct sctp_supported_addrs_param *sat;
366 	struct sctp_ipv4addr_param *v4;
367 	struct sctp_ipv6addr_param *v6;
368 	union sctp_addr_param *addr;
369 	struct sctp_adaptation_ind_param *aind;
370 	struct sctp_supported_ext_param *ext;
371 	struct sctp_random_param *random;
372 	struct sctp_chunks_param *chunks;
373 	struct sctp_hmac_algo_param *hmac_algo;
374 	struct sctp_addip_param *addip;
375 };
376 
377 /* RFC 2960.  Section 3.3.5 Heartbeat.
378  *    Heartbeat Information: variable length
379  *    The Sender-specific Heartbeat Info field should normally include
380  *    information about the sender's current time when this HEARTBEAT
381  *    chunk is sent and the destination transport address to which this
382  *    HEARTBEAT is sent (see Section 8.3).
383  */
384 struct sctp_sender_hb_info {
385 	struct sctp_paramhdr param_hdr;
386 	union sctp_addr daddr;
387 	unsigned long sent_at;
388 	__u64 hb_nonce;
389 	__u32 probe_size;
390 };
391 
392 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
393 		     gfp_t gfp);
394 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
395 void sctp_stream_free(struct sctp_stream *stream);
396 void sctp_stream_clear(struct sctp_stream *stream);
397 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
398 
399 /* What is the current SSN number for this stream? */
400 #define sctp_ssn_peek(stream, type, sid) \
401 	(sctp_stream_##type((stream), (sid))->ssn)
402 
403 /* Return the next SSN number for this stream.	*/
404 #define sctp_ssn_next(stream, type, sid) \
405 	(sctp_stream_##type((stream), (sid))->ssn++)
406 
407 /* Skip over this ssn and all below. */
408 #define sctp_ssn_skip(stream, type, sid, ssn) \
409 	(sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
410 
411 /* What is the current MID number for this stream? */
412 #define sctp_mid_peek(stream, type, sid) \
413 	(sctp_stream_##type((stream), (sid))->mid)
414 
415 /* Return the next MID number for this stream.  */
416 #define sctp_mid_next(stream, type, sid) \
417 	(sctp_stream_##type((stream), (sid))->mid++)
418 
419 /* Skip over this mid and all below. */
420 #define sctp_mid_skip(stream, type, sid, mid) \
421 	(sctp_stream_##type((stream), (sid))->mid = mid + 1)
422 
423 /* What is the current MID_uo number for this stream? */
424 #define sctp_mid_uo_peek(stream, type, sid) \
425 	(sctp_stream_##type((stream), (sid))->mid_uo)
426 
427 /* Return the next MID_uo number for this stream.  */
428 #define sctp_mid_uo_next(stream, type, sid) \
429 	(sctp_stream_##type((stream), (sid))->mid_uo++)
430 
431 /*
432  * Pointers to address related SCTP functions.
433  * (i.e. things that depend on the address family.)
434  */
435 struct sctp_af {
436 	int		(*sctp_xmit)	(struct sk_buff *skb,
437 					 struct sctp_transport *);
438 	int		(*setsockopt)	(struct sock *sk,
439 					 int level,
440 					 int optname,
441 					 sockptr_t optval,
442 					 unsigned int optlen);
443 	int		(*getsockopt)	(struct sock *sk,
444 					 int level,
445 					 int optname,
446 					 char __user *optval,
447 					 int __user *optlen);
448 	void		(*get_dst)	(struct sctp_transport *t,
449 					 union sctp_addr *saddr,
450 					 struct flowi *fl,
451 					 struct sock *sk);
452 	void		(*get_saddr)	(struct sctp_sock *sk,
453 					 struct sctp_transport *t,
454 					 struct flowi *fl);
455 	void		(*copy_addrlist) (struct list_head *,
456 					  struct net_device *);
457 	int		(*cmp_addr)	(const union sctp_addr *addr1,
458 					 const union sctp_addr *addr2);
459 	void		(*addr_copy)	(union sctp_addr *dst,
460 					 union sctp_addr *src);
461 	void		(*from_skb)	(union sctp_addr *,
462 					 struct sk_buff *skb,
463 					 int saddr);
464 	void		(*from_sk)	(union sctp_addr *,
465 					 struct sock *sk);
466 	bool		(*from_addr_param) (union sctp_addr *,
467 					    union sctp_addr_param *,
468 					    __be16 port, int iif);
469 	int		(*to_addr_param) (const union sctp_addr *,
470 					  union sctp_addr_param *);
471 	int		(*addr_valid)	(union sctp_addr *,
472 					 struct sctp_sock *,
473 					 const struct sk_buff *);
474 	enum sctp_scope	(*scope)(union sctp_addr *);
475 	void		(*inaddr_any)	(union sctp_addr *, __be16);
476 	int		(*is_any)	(const union sctp_addr *);
477 	int		(*available)	(union sctp_addr *,
478 					 struct sctp_sock *);
479 	int		(*skb_iif)	(const struct sk_buff *sk);
480 	int		(*skb_sdif)(const struct sk_buff *sk);
481 	int		(*is_ce)	(const struct sk_buff *sk);
482 	void		(*seq_dump_addr)(struct seq_file *seq,
483 					 union sctp_addr *addr);
484 	void		(*ecn_capable)(struct sock *sk);
485 	__u16		net_header_len;
486 	int		sockaddr_len;
487 	int		(*ip_options_len)(struct sock *sk);
488 	sa_family_t	sa_family;
489 	struct list_head list;
490 };
491 
492 struct sctp_af *sctp_get_af_specific(sa_family_t);
493 int sctp_register_af(struct sctp_af *);
494 
495 /* Protocol family functions. */
496 struct sctp_pf {
497 	void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
498 	void (*skb_msgname)  (struct sk_buff *, char *, int *);
499 	int  (*af_supported) (sa_family_t, struct sctp_sock *);
500 	int  (*cmp_addr) (const union sctp_addr *,
501 			  const union sctp_addr *,
502 			  struct sctp_sock *);
503 	int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
504 	int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
505 	int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
506 	struct sock *(*create_accept_sk) (struct sock *sk,
507 					  struct sctp_association *asoc,
508 					  bool kern);
509 	int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
510 	void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
511 	void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
512 	void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
513 	struct sctp_af *af;
514 };
515 
516 
517 /* Structure to track chunk fragments that have been acked, but peer
518  * fragments of the same message have not.
519  */
520 struct sctp_datamsg {
521 	/* Chunks waiting to be submitted to lower layer. */
522 	struct list_head chunks;
523 	/* Reference counting. */
524 	refcount_t refcnt;
525 	/* When is this message no longer interesting to the peer? */
526 	unsigned long expires_at;
527 	/* Did the messenge fail to send? */
528 	int send_error;
529 	u8 send_failed:1,
530 	   can_delay:1,	/* should this message be Nagle delayed */
531 	   abandoned:1;	/* should this message be abandoned */
532 };
533 
534 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
535 					    struct sctp_sndrcvinfo *,
536 					    struct iov_iter *);
537 void sctp_datamsg_free(struct sctp_datamsg *);
538 void sctp_datamsg_put(struct sctp_datamsg *);
539 void sctp_chunk_fail(struct sctp_chunk *, int error);
540 int sctp_chunk_abandoned(struct sctp_chunk *);
541 
542 /* RFC2960 1.4 Key Terms
543  *
544  * o Chunk: A unit of information within an SCTP packet, consisting of
545  * a chunk header and chunk-specific content.
546  *
547  * As a matter of convenience, we remember the SCTP common header for
548  * each chunk as well as a few other header pointers...
549  */
550 struct sctp_chunk {
551 	struct list_head list;
552 
553 	refcount_t refcnt;
554 
555 	/* How many times this chunk have been sent, for prsctp RTX policy */
556 	int sent_count;
557 
558 	union {
559 		/* This is our link to the per-transport transmitted list.  */
560 		struct list_head transmitted_list;
561 		/* List in specific stream outq */
562 		struct list_head stream_list;
563 	};
564 
565 	/* This field is used by chunks that hold fragmented data.
566 	 * For the first fragment this is the list that holds the rest of
567 	 * fragments. For the remaining fragments, this is the link to the
568 	 * frag_list maintained in the first fragment.
569 	 */
570 	struct list_head frag_list;
571 
572 	/* This points to the sk_buff containing the actual data.  */
573 	struct sk_buff *skb;
574 
575 	union {
576 		/* In case of GSO packets, this will store the head one */
577 		struct sk_buff *head_skb;
578 		/* In case of auth enabled, this will point to the shkey */
579 		struct sctp_shared_key *shkey;
580 	};
581 
582 	/* These are the SCTP headers by reverse order in a packet.
583 	 * Note that some of these may happen more than once.  In that
584 	 * case, we point at the "current" one, whatever that means
585 	 * for that level of header.
586 	 */
587 
588 	/* We point this at the FIRST TLV parameter to chunk_hdr.  */
589 	union sctp_params param_hdr;
590 	union {
591 		__u8 *v;
592 		struct sctp_datahdr *data_hdr;
593 		struct sctp_inithdr *init_hdr;
594 		struct sctp_sackhdr *sack_hdr;
595 		struct sctp_heartbeathdr *hb_hdr;
596 		struct sctp_sender_hb_info *hbs_hdr;
597 		struct sctp_shutdownhdr *shutdown_hdr;
598 		struct sctp_signed_cookie *cookie_hdr;
599 		struct sctp_ecnehdr *ecne_hdr;
600 		struct sctp_cwrhdr *ecn_cwr_hdr;
601 		struct sctp_errhdr *err_hdr;
602 		struct sctp_addiphdr *addip_hdr;
603 		struct sctp_fwdtsn_hdr *fwdtsn_hdr;
604 		struct sctp_authhdr *auth_hdr;
605 		struct sctp_idatahdr *idata_hdr;
606 		struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
607 	} subh;
608 
609 	__u8 *chunk_end;
610 
611 	struct sctp_chunkhdr *chunk_hdr;
612 	struct sctphdr *sctp_hdr;
613 
614 	/* This needs to be recoverable for SCTP_SEND_FAILED events. */
615 	struct sctp_sndrcvinfo sinfo;
616 
617 	/* Which association does this belong to?  */
618 	struct sctp_association *asoc;
619 
620 	/* What endpoint received this chunk? */
621 	struct sctp_ep_common *rcvr;
622 
623 	/* We fill this in if we are calculating RTT. */
624 	unsigned long sent_at;
625 
626 	/* What is the origin IP address for this chunk?  */
627 	union sctp_addr source;
628 	/* Destination address for this chunk. */
629 	union sctp_addr dest;
630 
631 	/* For outbound message, track all fragments for SEND_FAILED. */
632 	struct sctp_datamsg *msg;
633 
634 	/* For an inbound chunk, this tells us where it came from.
635 	 * For an outbound chunk, it tells us where we'd like it to
636 	 * go.	It is NULL if we have no preference.
637 	 */
638 	struct sctp_transport *transport;
639 
640 	/* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
641 	 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
642 	 * spec violates the principle premis that all chunks are processed
643 	 * in order.
644 	 */
645 	struct sk_buff *auth_chunk;
646 
647 #define SCTP_CAN_FRTX 0x0
648 #define SCTP_NEED_FRTX 0x1
649 #define SCTP_DONT_FRTX 0x2
650 	__u16	rtt_in_progress:1,	/* This chunk used for RTT calc? */
651 		has_tsn:1,		/* Does this chunk have a TSN yet? */
652 		has_ssn:1,		/* Does this chunk have a SSN yet? */
653 #define has_mid has_ssn
654 		singleton:1,		/* Only chunk in the packet? */
655 		end_of_packet:1,	/* Last chunk in the packet? */
656 		ecn_ce_done:1,		/* Have we processed the ECN CE bit? */
657 		pdiscard:1,		/* Discard the whole packet now? */
658 		tsn_gap_acked:1,	/* Is this chunk acked by a GAP ACK? */
659 		data_accepted:1,	/* At least 1 chunk accepted */
660 		auth:1,			/* IN: was auth'ed | OUT: needs auth */
661 		has_asconf:1,		/* IN: have seen an asconf before */
662 		pmtu_probe:1,		/* Used by PLPMTUD, can be set in s HB chunk */
663 		tsn_missing_report:2,	/* Data chunk missing counter. */
664 		fast_retransmit:2;	/* Is this chunk fast retransmitted? */
665 };
666 
667 #define sctp_chunk_retransmitted(chunk)	(chunk->sent_count > 1)
668 void sctp_chunk_hold(struct sctp_chunk *);
669 void sctp_chunk_put(struct sctp_chunk *);
670 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
671 			  struct iov_iter *from);
672 void sctp_chunk_free(struct sctp_chunk *);
673 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
674 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
675 				 const struct sctp_association *,
676 				 struct sock *, gfp_t gfp);
677 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
678 		     union sctp_addr *);
679 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
680 
sctp_chunk_stream_no(struct sctp_chunk * ch)681 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
682 {
683 	return ntohs(ch->subh.data_hdr->stream);
684 }
685 
686 enum {
687 	SCTP_ADDR_NEW,		/* new address added to assoc/ep */
688 	SCTP_ADDR_SRC,		/* address can be used as source */
689 	SCTP_ADDR_DEL,		/* address about to be deleted */
690 };
691 
692 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
693 struct sctp_sockaddr_entry {
694 	struct list_head list;
695 	struct rcu_head	rcu;
696 	union sctp_addr a;
697 	__u8 state;
698 	__u8 valid;
699 };
700 
701 #define SCTP_ADDRESS_TICK_DELAY	500
702 
703 /* This structure holds lists of chunks as we are assembling for
704  * transmission.
705  */
706 struct sctp_packet {
707 	/* These are the SCTP header values (host order) for the packet. */
708 	__u16 source_port;
709 	__u16 destination_port;
710 	__u32 vtag;
711 
712 	/* This contains the payload chunks.  */
713 	struct list_head chunk_list;
714 
715 	/* This is the overhead of the sctp and ip headers. */
716 	size_t overhead;
717 	/* This is the total size of all chunks INCLUDING padding.  */
718 	size_t size;
719 	/* This is the maximum size this packet may have */
720 	size_t max_size;
721 
722 	/* The packet is destined for this transport address.
723 	 * The function we finally use to pass down to the next lower
724 	 * layer lives in the transport structure.
725 	 */
726 	struct sctp_transport *transport;
727 
728 	/* pointer to the auth chunk for this packet */
729 	struct sctp_chunk *auth;
730 
731 	u8  has_cookie_echo:1,	/* This packet contains a COOKIE-ECHO chunk. */
732 	    has_sack:1,		/* This packet contains a SACK chunk. */
733 	    has_auth:1,		/* This packet contains an AUTH chunk */
734 	    has_data:1,		/* This packet contains at least 1 DATA chunk */
735 	    ipfragok:1;		/* So let ip fragment this packet */
736 };
737 
738 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
739 		      __u16 sport, __u16 dport);
740 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
741 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
742 					  struct sctp_chunk *chunk,
743 					  int one_packet, gfp_t gfp);
744 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
745 					struct sctp_chunk *chunk);
746 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
747 void sctp_packet_free(struct sctp_packet *);
748 
sctp_packet_empty(struct sctp_packet * packet)749 static inline int sctp_packet_empty(struct sctp_packet *packet)
750 {
751 	return packet->size == packet->overhead;
752 }
753 
754 /* This represents a remote transport address.
755  * For local transport addresses, we just use union sctp_addr.
756  *
757  * RFC2960 Section 1.4 Key Terms
758  *
759  *   o	Transport address:  A Transport Address is traditionally defined
760  *	by Network Layer address, Transport Layer protocol and Transport
761  *	Layer port number.  In the case of SCTP running over IP, a
762  *	transport address is defined by the combination of an IP address
763  *	and an SCTP port number (where SCTP is the Transport protocol).
764  *
765  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
766  *
767  *   o	The sender keeps a separate congestion control parameter set for
768  *	each of the destination addresses it can send to (not each
769  *	source-destination pair but for each destination).  The parameters
770  *	should decay if the address is not used for a long enough time
771  *	period.
772  *
773  */
774 struct sctp_transport {
775 	/* A list of transports. */
776 	struct list_head transports;
777 	struct rhlist_head node;
778 
779 	/* Reference counting. */
780 	refcount_t refcnt;
781 		/* RTO-Pending : A flag used to track if one of the DATA
782 		 *		chunks sent to this address is currently being
783 		 *		used to compute a RTT. If this flag is 0,
784 		 *		the next DATA chunk sent to this destination
785 		 *		should be used to compute a RTT and this flag
786 		 *		should be set. Every time the RTT
787 		 *		calculation completes (i.e. the DATA chunk
788 		 *		is SACK'd) clear this flag.
789 		 */
790 	__u32	rto_pending:1,
791 
792 		/*
793 		 * hb_sent : a flag that signals that we have a pending
794 		 * heartbeat.
795 		 */
796 		hb_sent:1,
797 
798 		/* Is the Path MTU update pending on this tranport */
799 		pmtu_pending:1,
800 
801 		dst_pending_confirm:1,	/* need to confirm neighbour */
802 
803 		/* Has this transport moved the ctsn since we last sacked */
804 		sack_generation:1;
805 	u32 dst_cookie;
806 
807 	struct flowi fl;
808 
809 	/* This is the peer's IP address and port. */
810 	union sctp_addr ipaddr;
811 
812 	/* These are the functions we call to handle LLP stuff.	 */
813 	struct sctp_af *af_specific;
814 
815 	/* Which association do we belong to?  */
816 	struct sctp_association *asoc;
817 
818 	/* RFC2960
819 	 *
820 	 * 12.3 Per Transport Address Data
821 	 *
822 	 * For each destination transport address in the peer's
823 	 * address list derived from the INIT or INIT ACK chunk, a
824 	 * number of data elements needs to be maintained including:
825 	 */
826 	/* RTO	       : The current retransmission timeout value.  */
827 	unsigned long rto;
828 
829 	__u32 rtt;		/* This is the most recent RTT.	 */
830 
831 	/* RTTVAR      : The current RTT variation.  */
832 	__u32 rttvar;
833 
834 	/* SRTT	       : The current smoothed round trip time.	*/
835 	__u32 srtt;
836 
837 	/*
838 	 * These are the congestion stats.
839 	 */
840 	/* cwnd	       : The current congestion window.	 */
841 	__u32 cwnd;		  /* This is the actual cwnd.  */
842 
843 	/* ssthresh    : The current slow start threshold value.  */
844 	__u32 ssthresh;
845 
846 	/* partial     : The tracking method for increase of cwnd when in
847 	 * bytes acked : congestion avoidance mode (see Section 6.2.2)
848 	 */
849 	__u32 partial_bytes_acked;
850 
851 	/* Data that has been sent, but not acknowledged. */
852 	__u32 flight_size;
853 
854 	__u32 burst_limited;	/* Holds old cwnd when max.burst is applied */
855 
856 	/* Destination */
857 	struct dst_entry *dst;
858 	/* Source address. */
859 	union sctp_addr saddr;
860 
861 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
862 	 * the destination address every heartbeat interval.
863 	 */
864 	unsigned long hbinterval;
865 	unsigned long probe_interval;
866 
867 	/* SACK delay timeout */
868 	unsigned long sackdelay;
869 	__u32 sackfreq;
870 
871 	atomic_t mtu_info;
872 
873 	/* When was the last time that we heard from this transport? We use
874 	 * this to pick new active and retran paths.
875 	 */
876 	ktime_t last_time_heard;
877 
878 	/* When was the last time that we sent a chunk using this
879 	 * transport? We use this to check for idle transports
880 	 */
881 	unsigned long last_time_sent;
882 
883 	/* Last time(in jiffies) when cwnd is reduced due to the congestion
884 	 * indication based on ECNE chunk.
885 	 */
886 	unsigned long last_time_ecne_reduced;
887 
888 	__be16 encap_port;
889 
890 	/* This is the max_retrans value for the transport and will
891 	 * be initialized from the assocs value.  This can be changed
892 	 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
893 	 */
894 	__u16 pathmaxrxt;
895 
896 	__u32 flowlabel;
897 	__u8  dscp;
898 
899 	/* This is the partially failed retrans value for the transport
900 	 * and will be initialized from the assocs value.  This can be changed
901 	 * using the SCTP_PEER_ADDR_THLDS socket option
902 	 */
903 	__u16 pf_retrans;
904 	/* Used for primary path switchover. */
905 	__u16 ps_retrans;
906 	/* PMTU	      : The current known path MTU.  */
907 	__u32 pathmtu;
908 
909 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
910 	__u32 param_flags;
911 
912 	/* The number of times INIT has been sent on this transport. */
913 	int init_sent_count;
914 
915 	/* state       : The current state of this destination,
916 	 *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
917 	 */
918 	int state;
919 
920 	/* These are the error stats for this destination.  */
921 
922 	/* Error count : The current error count for this destination.	*/
923 	unsigned short error_count;
924 
925 	/* Per	       : A timer used by each destination.
926 	 * Destination :
927 	 * Timer       :
928 	 *
929 	 * [Everywhere else in the text this is called T3-rtx. -ed]
930 	 */
931 	struct timer_list T3_rtx_timer;
932 
933 	/* Heartbeat timer is per destination. */
934 	struct timer_list hb_timer;
935 
936 	/* Timer to handle ICMP proto unreachable envets */
937 	struct timer_list proto_unreach_timer;
938 
939 	/* Timer to handler reconf chunk rtx */
940 	struct timer_list reconf_timer;
941 
942 	/* Timer to send a probe HB packet for PLPMTUD */
943 	struct timer_list probe_timer;
944 
945 	/* Since we're using per-destination retransmission timers
946 	 * (see above), we're also using per-destination "transmitted"
947 	 * queues.  This probably ought to be a private struct
948 	 * accessible only within the outqueue, but it's not, yet.
949 	 */
950 	struct list_head transmitted;
951 
952 	/* We build bundle-able packets for this transport here.  */
953 	struct sctp_packet packet;
954 
955 	/* This is the list of transports that have chunks to send.  */
956 	struct list_head send_ready;
957 
958 	/* State information saved for SFR_CACC algorithm. The key
959 	 * idea in SFR_CACC is to maintain state at the sender on a
960 	 * per-destination basis when a changeover happens.
961 	 *	char changeover_active;
962 	 *	char cycling_changeover;
963 	 *	__u32 next_tsn_at_change;
964 	 *	char cacc_saw_newack;
965 	 */
966 	struct {
967 		/* An unsigned integer, which stores the next TSN to be
968 		 * used by the sender, at the moment of changeover.
969 		 */
970 		__u32 next_tsn_at_change;
971 
972 		/* A flag which indicates the occurrence of a changeover */
973 		char changeover_active;
974 
975 		/* A flag which indicates whether the change of primary is
976 		 * the first switch to this destination address during an
977 		 * active switch.
978 		 */
979 		char cycling_changeover;
980 
981 		/* A temporary flag, which is used during the processing of
982 		 * a SACK to estimate the causative TSN(s)'s group.
983 		 */
984 		char cacc_saw_newack;
985 	} cacc;
986 
987 	struct {
988 		__u16 pmtu;
989 		__u16 probe_size;
990 		__u16 probe_high;
991 		__u8 probe_count;
992 		__u8 state;
993 	} pl; /* plpmtud related */
994 
995 	/* 64-bit random number sent with heartbeat. */
996 	__u64 hb_nonce;
997 
998 	struct rcu_head rcu;
999 };
1000 
1001 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1002 					  gfp_t);
1003 void sctp_transport_set_owner(struct sctp_transport *,
1004 			      struct sctp_association *);
1005 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1006 			  struct sctp_sock *);
1007 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1008 void sctp_transport_free(struct sctp_transport *);
1009 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1010 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1011 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1012 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1013 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1014 int sctp_transport_hold(struct sctp_transport *);
1015 void sctp_transport_put(struct sctp_transport *);
1016 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1017 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1018 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1019 			       enum sctp_lower_cwnd reason);
1020 void sctp_transport_burst_limited(struct sctp_transport *);
1021 void sctp_transport_burst_reset(struct sctp_transport *);
1022 unsigned long sctp_transport_timeout(struct sctp_transport *);
1023 void sctp_transport_reset(struct sctp_transport *t);
1024 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1025 void sctp_transport_immediate_rtx(struct sctp_transport *);
1026 void sctp_transport_dst_release(struct sctp_transport *t);
1027 void sctp_transport_dst_confirm(struct sctp_transport *t);
1028 void sctp_transport_pl_send(struct sctp_transport *t);
1029 bool sctp_transport_pl_recv(struct sctp_transport *t);
1030 
1031 
1032 /* This is the structure we use to queue packets as they come into
1033  * SCTP.  We write packets to it and read chunks from it.
1034  */
1035 struct sctp_inq {
1036 	/* This is actually a queue of sctp_chunk each
1037 	 * containing a partially decoded packet.
1038 	 */
1039 	struct list_head in_chunk_list;
1040 	/* This is the packet which is currently off the in queue and is
1041 	 * being worked on through the inbound chunk processing.
1042 	 */
1043 	struct sctp_chunk *in_progress;
1044 
1045 	/* This is the delayed task to finish delivering inbound
1046 	 * messages.
1047 	 */
1048 	struct work_struct immediate;
1049 };
1050 
1051 void sctp_inq_init(struct sctp_inq *);
1052 void sctp_inq_free(struct sctp_inq *);
1053 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1054 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1055 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1056 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1057 
1058 /* This is the structure we use to hold outbound chunks.  You push
1059  * chunks in and they automatically pop out the other end as bundled
1060  * packets (it calls (*output_handler)()).
1061  *
1062  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1063  * and 8.2 of the v13 draft.
1064  *
1065  * It handles retransmissions.	The connection to the timeout portion
1066  * of the state machine is through sctp_..._timeout() and timeout_handler.
1067  *
1068  * If you feed it SACKs, it will eat them.
1069  *
1070  * If you give it big chunks, it will fragment them.
1071  *
1072  * It assigns TSN's to data chunks.  This happens at the last possible
1073  * instant before transmission.
1074  *
1075  * When free()'d, it empties itself out via output_handler().
1076  */
1077 struct sctp_outq {
1078 	struct sctp_association *asoc;
1079 
1080 	/* Data pending that has never been transmitted.  */
1081 	struct list_head out_chunk_list;
1082 
1083 	/* Stream scheduler being used */
1084 	struct sctp_sched_ops *sched;
1085 
1086 	unsigned int out_qlen;	/* Total length of queued data chunks. */
1087 
1088 	/* Error of send failed, may used in SCTP_SEND_FAILED event. */
1089 	unsigned int error;
1090 
1091 	/* These are control chunks we want to send.  */
1092 	struct list_head control_chunk_list;
1093 
1094 	/* These are chunks that have been sacked but are above the
1095 	 * CTSN, or cumulative tsn ack point.
1096 	 */
1097 	struct list_head sacked;
1098 
1099 	/* Put chunks on this list to schedule them for
1100 	 * retransmission.
1101 	 */
1102 	struct list_head retransmit;
1103 
1104 	/* Put chunks on this list to save them for FWD TSN processing as
1105 	 * they were abandoned.
1106 	 */
1107 	struct list_head abandoned;
1108 
1109 	/* How many unackd bytes do we have in-flight?	*/
1110 	__u32 outstanding_bytes;
1111 
1112 	/* Are we doing fast-rtx on this queue */
1113 	char fast_rtx;
1114 
1115 	/* Corked? */
1116 	char cork;
1117 };
1118 
1119 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1120 void sctp_outq_teardown(struct sctp_outq *);
1121 void sctp_outq_free(struct sctp_outq*);
1122 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1123 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1124 int sctp_outq_is_empty(const struct sctp_outq *);
1125 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1126 		     enum sctp_retransmit_reason reason);
1127 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1128 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1129 void sctp_prsctp_prune(struct sctp_association *asoc,
1130 		       struct sctp_sndrcvinfo *sinfo, int msg_len);
1131 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1132 /* Uncork and flush an outqueue.  */
sctp_outq_cork(struct sctp_outq * q)1133 static inline void sctp_outq_cork(struct sctp_outq *q)
1134 {
1135 	q->cork = 1;
1136 }
1137 
1138 /* SCTP skb control block.
1139  * sctp_input_cb is currently used on rx and sock rx queue
1140  */
1141 struct sctp_input_cb {
1142 	union {
1143 		struct inet_skb_parm    h4;
1144 #if IS_ENABLED(CONFIG_IPV6)
1145 		struct inet6_skb_parm   h6;
1146 #endif
1147 	} header;
1148 	struct sctp_chunk *chunk;
1149 	struct sctp_af *af;
1150 	__be16 encap_port;
1151 };
1152 #define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
1153 
1154 struct sctp_output_cb {
1155 	struct sk_buff *last;
1156 };
1157 #define SCTP_OUTPUT_CB(__skb)	((struct sctp_output_cb *)&((__skb)->cb[0]))
1158 
sctp_gso_headskb(const struct sk_buff * skb)1159 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1160 {
1161 	const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1162 
1163 	return chunk->head_skb ? : skb;
1164 }
1165 
1166 /* These bind address data fields common between endpoints and associations */
1167 struct sctp_bind_addr {
1168 
1169 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1170 	 *
1171 	 * SCTP Port:	The local SCTP port number the endpoint is
1172 	 *		bound to.
1173 	 */
1174 	__u16 port;
1175 
1176 	/* RFC 2960 12.1 Parameters necessary for the SCTP instance
1177 	 *
1178 	 * Address List: The list of IP addresses that this instance
1179 	 *	has bound.  This information is passed to one's
1180 	 *	peer(s) in INIT and INIT ACK chunks.
1181 	 */
1182 	struct list_head address_list;
1183 };
1184 
1185 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1186 void sctp_bind_addr_free(struct sctp_bind_addr *);
1187 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1188 			const struct sctp_bind_addr *src,
1189 			enum sctp_scope scope, gfp_t gfp,
1190 			int flags);
1191 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1192 			const struct sctp_bind_addr *src,
1193 			gfp_t gfp);
1194 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1195 		       int new_size, __u8 addr_state, gfp_t gfp);
1196 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1197 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1198 			 struct sctp_sock *);
1199 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1200 			 struct sctp_sock *, struct sctp_sock *);
1201 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1202 			 const union sctp_addr *addr);
1203 int sctp_bind_addrs_check(struct sctp_sock *sp,
1204 			  struct sctp_sock *sp2, int cnt2);
1205 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
1206 					const union sctp_addr	*addrs,
1207 					int			addrcnt,
1208 					struct sctp_sock	*opt);
1209 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1210 					 int *addrs_len,
1211 					 gfp_t gfp);
1212 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1213 			   __u16 port, gfp_t gfp);
1214 
1215 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1216 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1217 		  const enum sctp_scope scope);
1218 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1219 int sctp_is_ep_boundall(struct sock *sk);
1220 
1221 
1222 /* What type of endpoint?  */
1223 enum sctp_endpoint_type {
1224 	SCTP_EP_TYPE_SOCKET,
1225 	SCTP_EP_TYPE_ASSOCIATION,
1226 };
1227 
1228 /*
1229  * A common base class to bridge the implmentation view of a
1230  * socket (usually listening) endpoint versus an association's
1231  * local endpoint.
1232  * This common structure is useful for several purposes:
1233  *   1) Common interface for lookup routines.
1234  *	a) Subfunctions work for either endpoint or association
1235  *	b) Single interface to lookup allows hiding the lookup lock rather
1236  *	   than acquiring it externally.
1237  *   2) Common interface for the inbound chunk handling/state machine.
1238  *   3) Common object handling routines for reference counting, etc.
1239  *   4) Disentangle association lookup from endpoint lookup, where we
1240  *	do not have to find our endpoint to find our association.
1241  *
1242  */
1243 
1244 struct sctp_ep_common {
1245 	/* Runtime type information.  What kind of endpoint is this? */
1246 	enum sctp_endpoint_type type;
1247 
1248 	/* Some fields to help us manage this object.
1249 	 *   refcnt   - Reference count access to this object.
1250 	 *   dead     - Do not attempt to use this object.
1251 	 */
1252 	refcount_t    refcnt;
1253 	bool	    dead;
1254 
1255 	/* What socket does this endpoint belong to?  */
1256 	struct sock *sk;
1257 
1258 	/* Cache netns and it won't change once set */
1259 	struct net *net;
1260 
1261 	/* This is where we receive inbound chunks.  */
1262 	struct sctp_inq	  inqueue;
1263 
1264 	/* This substructure includes the defining parameters of the
1265 	 * endpoint:
1266 	 * bind_addr.port is our shared port number.
1267 	 * bind_addr.address_list is our set of local IP addresses.
1268 	 */
1269 	struct sctp_bind_addr bind_addr;
1270 };
1271 
1272 
1273 /* RFC Section 1.4 Key Terms
1274  *
1275  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1276  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1277  *   combination of a set of eligible destination transport addresses to
1278  *   which SCTP packets can be sent and a set of eligible source
1279  *   transport addresses from which SCTP packets can be received.
1280  *   All transport addresses used by an SCTP endpoint must use the
1281  *   same port number, but can use multiple IP addresses. A transport
1282  *   address used by an SCTP endpoint must not be used by another
1283  *   SCTP endpoint. In other words, a transport address is unique
1284  *   to an SCTP endpoint.
1285  *
1286  * From an implementation perspective, each socket has one of these.
1287  * A TCP-style socket will have exactly one association on one of
1288  * these.  An UDP-style socket will have multiple associations hanging
1289  * off one of these.
1290  */
1291 
1292 struct sctp_endpoint {
1293 	/* Common substructure for endpoint and association. */
1294 	struct sctp_ep_common base;
1295 
1296 	/* Fields to help us manage our entries in the hash tables. */
1297 	struct hlist_node node;
1298 	int hashent;
1299 
1300 	/* Associations: A list of current associations and mappings
1301 	 *	      to the data consumers for each association. This
1302 	 *	      may be in the form of a hash table or other
1303 	 *	      implementation dependent structure. The data
1304 	 *	      consumers may be process identification
1305 	 *	      information such as file descriptors, named pipe
1306 	 *	      pointer, or table pointers dependent on how SCTP
1307 	 *	      is implemented.
1308 	 */
1309 	/* This is really a list of struct sctp_association entries. */
1310 	struct list_head asocs;
1311 
1312 	/* Secret Key: A secret key used by this endpoint to compute
1313 	 *	      the MAC.	This SHOULD be a cryptographic quality
1314 	 *	      random number with a sufficient length.
1315 	 *	      Discussion in [RFC1750] can be helpful in
1316 	 *	      selection of the key.
1317 	 */
1318 	__u8 secret_key[SCTP_SECRET_SIZE];
1319 
1320  	/* digest:  This is a digest of the sctp cookie.  This field is
1321  	 * 	    only used on the receive path when we try to validate
1322  	 * 	    that the cookie has not been tampered with.  We put
1323  	 * 	    this here so we pre-allocate this once and can re-use
1324  	 * 	    on every receive.
1325  	 */
1326  	__u8 *digest;
1327 
1328 	/* sendbuf acct. policy.	*/
1329 	__u32 sndbuf_policy;
1330 
1331 	/* rcvbuf acct. policy.	*/
1332 	__u32 rcvbuf_policy;
1333 
1334 	/* SCTP AUTH: array of the HMACs that will be allocated
1335 	 * we need this per association so that we don't serialize
1336 	 */
1337 	struct crypto_shash **auth_hmacs;
1338 
1339 	/* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1340 	 struct sctp_hmac_algo_param *auth_hmacs_list;
1341 
1342 	/* SCTP-AUTH: chunks to authenticate encoded into parameter */
1343 	struct sctp_chunks_param *auth_chunk_list;
1344 
1345 	/* SCTP-AUTH: endpoint shared keys */
1346 	struct list_head endpoint_shared_keys;
1347 	__u16 active_key_id;
1348 	__u8  ecn_enable:1,
1349 	      auth_enable:1,
1350 	      intl_enable:1,
1351 	      prsctp_enable:1,
1352 	      asconf_enable:1,
1353 	      reconf_enable:1;
1354 
1355 	__u8  strreset_enable;
1356 	struct rcu_head rcu;
1357 };
1358 
1359 /* Recover the outter endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1360 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1361 {
1362 	struct sctp_endpoint *ep;
1363 
1364 	ep = container_of(base, struct sctp_endpoint, base);
1365 	return ep;
1366 }
1367 
1368 /* These are function signatures for manipulating endpoints.  */
1369 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1370 void sctp_endpoint_free(struct sctp_endpoint *);
1371 void sctp_endpoint_put(struct sctp_endpoint *);
1372 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1373 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1374 struct sctp_association *sctp_endpoint_lookup_assoc(
1375 	const struct sctp_endpoint *ep,
1376 	const union sctp_addr *paddr,
1377 	struct sctp_transport **);
1378 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1379 				 const union sctp_addr *paddr);
1380 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1381 					     struct net *net,
1382 					     const union sctp_addr *laddr,
1383 					     int dif, int sdif);
1384 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1385 			  const union sctp_addr *paddr, int dif, int sdif);
1386 
1387 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1388 		     const struct sctp_association *asoc,
1389 		     enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1390 		     struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1391 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1392 		      const union sctp_addr *peer,
1393 		      struct sctp_init_chunk *init, gfp_t gfp);
1394 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1395 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1396 
1397 struct sctp_inithdr_host {
1398 	__u32 init_tag;
1399 	__u32 a_rwnd;
1400 	__u16 num_outbound_streams;
1401 	__u16 num_inbound_streams;
1402 	__u32 initial_tsn;
1403 };
1404 
1405 struct sctp_stream_priorities {
1406 	/* List of priorities scheduled */
1407 	struct list_head prio_sched;
1408 	/* List of streams scheduled */
1409 	struct list_head active;
1410 	/* The next stream in line */
1411 	struct sctp_stream_out_ext *next;
1412 	__u16 prio;
1413 	__u16 users;
1414 };
1415 
1416 struct sctp_stream_out_ext {
1417 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1418 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1419 	struct list_head outq; /* chunks enqueued by this stream */
1420 	union {
1421 		struct {
1422 			/* Scheduled streams list */
1423 			struct list_head prio_list;
1424 			struct sctp_stream_priorities *prio_head;
1425 		};
1426 		/* Fields used by RR scheduler */
1427 		struct {
1428 			struct list_head rr_list;
1429 		};
1430 		struct {
1431 			struct list_head fc_list;
1432 			__u32 fc_length;
1433 			__u16 fc_weight;
1434 		};
1435 	};
1436 };
1437 
1438 struct sctp_stream_out {
1439 	union {
1440 		__u32 mid;
1441 		__u16 ssn;
1442 	};
1443 	__u32 mid_uo;
1444 	struct sctp_stream_out_ext *ext;
1445 	__u8 state;
1446 };
1447 
1448 struct sctp_stream_in {
1449 	union {
1450 		__u32 mid;
1451 		__u16 ssn;
1452 	};
1453 	__u32 mid_uo;
1454 	__u32 fsn;
1455 	__u32 fsn_uo;
1456 	char pd_mode;
1457 	char pd_mode_uo;
1458 };
1459 
1460 struct sctp_stream {
1461 	GENRADIX(struct sctp_stream_out) out;
1462 	GENRADIX(struct sctp_stream_in)	in;
1463 
1464 	__u16 outcnt;
1465 	__u16 incnt;
1466 	/* Current stream being sent, if any */
1467 	struct sctp_stream_out *out_curr;
1468 	union {
1469 		/* Fields used by priority scheduler */
1470 		struct {
1471 			/* List of priorities scheduled */
1472 			struct list_head prio_list;
1473 		};
1474 		/* Fields used by RR scheduler */
1475 		struct {
1476 			/* List of streams scheduled */
1477 			struct list_head rr_list;
1478 			/* The next stream in line */
1479 			struct sctp_stream_out_ext *rr_next;
1480 		};
1481 		struct {
1482 			struct list_head fc_list;
1483 		};
1484 	};
1485 	struct sctp_stream_interleave *si;
1486 };
1487 
sctp_stream_out(struct sctp_stream * stream,__u16 sid)1488 static inline struct sctp_stream_out *sctp_stream_out(
1489 	struct sctp_stream *stream,
1490 	__u16 sid)
1491 {
1492 	return genradix_ptr(&stream->out, sid);
1493 }
1494 
sctp_stream_in(struct sctp_stream * stream,__u16 sid)1495 static inline struct sctp_stream_in *sctp_stream_in(
1496 	struct sctp_stream *stream,
1497 	__u16 sid)
1498 {
1499 	return genradix_ptr(&stream->in, sid);
1500 }
1501 
1502 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1503 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1504 
1505 #define SCTP_STREAM_CLOSED		0x00
1506 #define SCTP_STREAM_OPEN		0x01
1507 
sctp_datachk_len(const struct sctp_stream * stream)1508 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1509 {
1510 	return stream->si->data_chunk_len;
1511 }
1512 
sctp_datahdr_len(const struct sctp_stream * stream)1513 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1514 {
1515 	return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1516 }
1517 
sctp_ftsnchk_len(const struct sctp_stream * stream)1518 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1519 {
1520 	return stream->si->ftsn_chunk_len;
1521 }
1522 
sctp_ftsnhdr_len(const struct sctp_stream * stream)1523 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1524 {
1525 	return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1526 }
1527 
1528 /* SCTP_GET_ASSOC_STATS counters */
1529 struct sctp_priv_assoc_stats {
1530 	/* Maximum observed rto in the association during subsequent
1531 	 * observations. Value is set to 0 if no RTO measurement took place
1532 	 * The transport where the max_rto was observed is returned in
1533 	 * obs_rto_ipaddr
1534 	 */
1535 	struct sockaddr_storage obs_rto_ipaddr;
1536 	__u64 max_obs_rto;
1537 	/* Total In and Out SACKs received and sent */
1538 	__u64 isacks;
1539 	__u64 osacks;
1540 	/* Total In and Out packets received and sent */
1541 	__u64 opackets;
1542 	__u64 ipackets;
1543 	/* Total retransmitted chunks */
1544 	__u64 rtxchunks;
1545 	/* TSN received > next expected */
1546 	__u64 outofseqtsns;
1547 	/* Duplicate Chunks received */
1548 	__u64 idupchunks;
1549 	/* Gap Ack Blocks received */
1550 	__u64 gapcnt;
1551 	/* Unordered data chunks sent and received */
1552 	__u64 ouodchunks;
1553 	__u64 iuodchunks;
1554 	/* Ordered data chunks sent and received */
1555 	__u64 oodchunks;
1556 	__u64 iodchunks;
1557 	/* Control chunks sent and received */
1558 	__u64 octrlchunks;
1559 	__u64 ictrlchunks;
1560 };
1561 
1562 /* RFC2960
1563  *
1564  * 12. Recommended Transmission Control Block (TCB) Parameters
1565  *
1566  * This section details a recommended set of parameters that should
1567  * be contained within the TCB for an implementation. This section is
1568  * for illustrative purposes and should not be deemed as requirements
1569  * on an implementation or as an exhaustive list of all parameters
1570  * inside an SCTP TCB. Each implementation may need its own additional
1571  * parameters for optimization.
1572  */
1573 
1574 
1575 /* Here we have information about each individual association. */
1576 struct sctp_association {
1577 
1578 	/* A base structure common to endpoint and association.
1579 	 * In this context, it represents the associations's view
1580 	 * of the local endpoint of the association.
1581 	 */
1582 	struct sctp_ep_common base;
1583 
1584 	/* Associations on the same socket. */
1585 	struct list_head asocs;
1586 
1587 	/* association id. */
1588 	sctp_assoc_t assoc_id;
1589 
1590 	/* This is our parent endpoint.	 */
1591 	struct sctp_endpoint *ep;
1592 
1593 	/* These are those association elements needed in the cookie.  */
1594 	struct sctp_cookie c;
1595 
1596 	/* This is all information about our peer.  */
1597 	struct {
1598 		/* transport_addr_list
1599 		 *
1600 		 * Peer	       : A list of SCTP transport addresses that the
1601 		 * Transport   : peer is bound to. This information is derived
1602 		 * Address     : from the INIT or INIT ACK and is used to
1603 		 * List	       : associate an inbound packet with a given
1604 		 *	       : association. Normally this information is
1605 		 *	       : hashed or keyed for quick lookup and access
1606 		 *	       : of the TCB.
1607 		 *	       : The list is also initialized with the list
1608 		 *	       : of addresses passed with the sctp_connectx()
1609 		 *	       : call.
1610 		 *
1611 		 * It is a list of SCTP_transport's.
1612 		 */
1613 		struct list_head transport_addr_list;
1614 
1615 		/* rwnd
1616 		 *
1617 		 * Peer Rwnd   : Current calculated value of the peer's rwnd.
1618 		 */
1619 		__u32 rwnd;
1620 
1621 		/* transport_count
1622 		 *
1623 		 * Peer        : A count of the number of peer addresses
1624 		 * Transport   : in the Peer Transport Address List.
1625 		 * Address     :
1626 		 * Count       :
1627 		 */
1628 		__u16 transport_count;
1629 
1630 		/* port
1631 		 *   The transport layer port number.
1632 		 */
1633 		__u16 port;
1634 
1635 		/* primary_path
1636 		 *
1637 		 * Primary     : This is the current primary destination
1638 		 * Path	       : transport address of the peer endpoint.  It
1639 		 *	       : may also specify a source transport address
1640 		 *	       : on this endpoint.
1641 		 *
1642 		 * All of these paths live on transport_addr_list.
1643 		 *
1644 		 * At the bakeoffs, we discovered that the intent of
1645 		 * primaryPath is that it only changes when the ULP
1646 		 * asks to have it changed.  We add the activePath to
1647 		 * designate the connection we are currently using to
1648 		 * transmit new data and most control chunks.
1649 		 */
1650 		struct sctp_transport *primary_path;
1651 
1652 		/* Cache the primary path address here, when we
1653 		 * need a an address for msg_name.
1654 		 */
1655 		union sctp_addr primary_addr;
1656 
1657 		/* active_path
1658 		 *   The path that we are currently using to
1659 		 *   transmit new data and most control chunks.
1660 		 */
1661 		struct sctp_transport *active_path;
1662 
1663 		/* retran_path
1664 		 *
1665 		 * RFC2960 6.4 Multi-homed SCTP Endpoints
1666 		 * ...
1667 		 * Furthermore, when its peer is multi-homed, an
1668 		 * endpoint SHOULD try to retransmit a chunk to an
1669 		 * active destination transport address that is
1670 		 * different from the last destination address to
1671 		 * which the DATA chunk was sent.
1672 		 */
1673 		struct sctp_transport *retran_path;
1674 
1675 		/* Pointer to last transport I have sent on.  */
1676 		struct sctp_transport *last_sent_to;
1677 
1678 		/* This is the last transport I have received DATA on.	*/
1679 		struct sctp_transport *last_data_from;
1680 
1681 		/*
1682 		 * Mapping  An array of bits or bytes indicating which out of
1683 		 * Array    order TSN's have been received (relative to the
1684 		 *	    Last Rcvd TSN). If no gaps exist, i.e. no out of
1685 		 *	    order packets have been received, this array
1686 		 *	    will be set to all zero. This structure may be
1687 		 *	    in the form of a circular buffer or bit array.
1688 		 *
1689 		 * Last Rcvd   : This is the last TSN received in
1690 		 * TSN	       : sequence. This value is set initially by
1691 		 *	       : taking the peer's Initial TSN, received in
1692 		 *	       : the INIT or INIT ACK chunk, and subtracting
1693 		 *	       : one from it.
1694 		 *
1695 		 * Throughout most of the specification this is called the
1696 		 * "Cumulative TSN ACK Point".	In this case, we
1697 		 * ignore the advice in 12.2 in favour of the term
1698 		 * used in the bulk of the text.  This value is hidden
1699 		 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1700 		 */
1701 		struct sctp_tsnmap tsn_map;
1702 
1703 		/* This mask is used to disable sending the ASCONF chunk
1704 		 * with specified parameter to peer.
1705 		 */
1706 		__be16 addip_disabled_mask;
1707 
1708 		/* These are capabilities which our peer advertised.  */
1709 		__u16	ecn_capable:1,      /* Can peer do ECN? */
1710 			ipv4_address:1,     /* Peer understands IPv4 addresses? */
1711 			ipv6_address:1,     /* Peer understands IPv6 addresses? */
1712 			asconf_capable:1,   /* Does peer support ADDIP? */
1713 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
1714 			reconf_capable:1,   /* Can peer do RE-CONFIG? */
1715 			intl_capable:1,     /* Can peer do INTERLEAVE */
1716 			auth_capable:1,     /* Is peer doing SCTP-AUTH? */
1717 			/* sack_needed:
1718 			 *   This flag indicates if the next received
1719 			 *   packet is to be responded to with a
1720 			 *   SACK. This is initialized to 0.  When a packet
1721 			 *   is received sack_cnt is incremented. If this value
1722 			 *   reaches 2 or more, a SACK is sent and the
1723 			 *   value is reset to 0. Note: This is used only
1724 			 *   when no DATA chunks are received out of
1725 			 *   order.  When DATA chunks are out of order,
1726 			 *   SACK's are not delayed (see Section 6).
1727 			 */
1728 			sack_needed:1,     /* Do we need to sack the peer? */
1729 			sack_generation:1,
1730 			zero_window_announced:1;
1731 
1732 		__u32	sack_cnt;
1733 
1734 		__u32   adaptation_ind;	 /* Adaptation Code point. */
1735 
1736 		struct sctp_inithdr_host i;
1737 		void *cookie;
1738 		int cookie_len;
1739 
1740 		/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1741 		 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1742 		 * Initial TSN Value minus 1
1743 		 */
1744 		__u32 addip_serial;
1745 
1746 		/* SCTP-AUTH: We need to know pears random number, hmac list
1747 		 * and authenticated chunk list.  All that is part of the
1748 		 * cookie and these are just pointers to those locations
1749 		 */
1750 		struct sctp_random_param *peer_random;
1751 		struct sctp_chunks_param *peer_chunks;
1752 		struct sctp_hmac_algo_param *peer_hmacs;
1753 	} peer;
1754 
1755 	/* State       : A state variable indicating what state the
1756 	 *	       : association is in, i.e. COOKIE-WAIT,
1757 	 *	       : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1758 	 *	       : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1759 	 *
1760 	 *		Note: No "CLOSED" state is illustrated since if a
1761 	 *		association is "CLOSED" its TCB SHOULD be removed.
1762 	 *
1763 	 *		In this implementation we DO have a CLOSED
1764 	 *		state which is used during initiation and shutdown.
1765 	 *
1766 	 *		State takes values from SCTP_STATE_*.
1767 	 */
1768 	enum sctp_state state;
1769 
1770 	/* Overall     : The overall association error count.
1771 	 * Error Count : [Clear this any time I get something.]
1772 	 */
1773 	int overall_error_count;
1774 
1775 	/* The cookie life I award for any cookie.  */
1776 	ktime_t cookie_life;
1777 
1778 	/* These are the association's initial, max, and min RTO values.
1779 	 * These values will be initialized by system defaults, but can
1780 	 * be modified via the SCTP_RTOINFO socket option.
1781 	 */
1782 	unsigned long rto_initial;
1783 	unsigned long rto_max;
1784 	unsigned long rto_min;
1785 
1786 	/* Maximum number of new data packets that can be sent in a burst.  */
1787 	int max_burst;
1788 
1789 	/* This is the max_retrans value for the association.  This value will
1790 	 * be initialized from system defaults, but can be
1791 	 * modified by the SCTP_ASSOCINFO socket option.
1792 	 */
1793 	int max_retrans;
1794 
1795 	/* This is the partially failed retrans value for the transport
1796 	 * and will be initialized from the assocs value.  This can be
1797 	 * changed using the SCTP_PEER_ADDR_THLDS socket option
1798 	 */
1799 	__u16 pf_retrans;
1800 	/* Used for primary path switchover. */
1801 	__u16 ps_retrans;
1802 
1803 	/* Maximum number of times the endpoint will retransmit INIT  */
1804 	__u16 max_init_attempts;
1805 
1806 	/* How many times have we resent an INIT? */
1807 	__u16 init_retries;
1808 
1809 	/* The largest timeout or RTO value to use in attempting an INIT */
1810 	unsigned long max_init_timeo;
1811 
1812 	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1813 	 * the destination address every heartbeat interval. This value
1814 	 * will be inherited by all new transports.
1815 	 */
1816 	unsigned long hbinterval;
1817 	unsigned long probe_interval;
1818 
1819 	__be16 encap_port;
1820 
1821 	/* This is the max_retrans value for new transports in the
1822 	 * association.
1823 	 */
1824 	__u16 pathmaxrxt;
1825 
1826 	__u32 flowlabel;
1827 	__u8  dscp;
1828 
1829 	/* Flag that path mtu update is pending */
1830 	__u8   pmtu_pending;
1831 
1832 	/* Association : The smallest PMTU discovered for all of the
1833 	 * PMTU	       : peer's transport addresses.
1834 	 */
1835 	__u32 pathmtu;
1836 
1837 	/* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1838 	__u32 param_flags;
1839 
1840 	__u32 sackfreq;
1841 	/* SACK delay timeout */
1842 	unsigned long sackdelay;
1843 
1844 	unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1845 	struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1846 
1847 	/* Transport to which SHUTDOWN chunk was last sent.  */
1848 	struct sctp_transport *shutdown_last_sent_to;
1849 
1850 	/* Transport to which INIT chunk was last sent.  */
1851 	struct sctp_transport *init_last_sent_to;
1852 
1853 	/* How many times have we resent a SHUTDOWN */
1854 	int shutdown_retries;
1855 
1856 	/* Next TSN    : The next TSN number to be assigned to a new
1857 	 *	       : DATA chunk.  This is sent in the INIT or INIT
1858 	 *	       : ACK chunk to the peer and incremented each
1859 	 *	       : time a DATA chunk is assigned a TSN
1860 	 *	       : (normally just prior to transmit or during
1861 	 *	       : fragmentation).
1862 	 */
1863 	__u32 next_tsn;
1864 
1865 	/*
1866 	 * Last Rcvd   : This is the last TSN received in sequence.  This value
1867 	 * TSN	       : is set initially by taking the peer's Initial TSN,
1868 	 *	       : received in the INIT or INIT ACK chunk, and
1869 	 *	       : subtracting one from it.
1870 	 *
1871 	 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1872 	 */
1873 
1874 	__u32 ctsn_ack_point;
1875 
1876 	/* PR-SCTP Advanced.Peer.Ack.Point */
1877 	__u32 adv_peer_ack_point;
1878 
1879 	/* Highest TSN that is acknowledged by incoming SACKs. */
1880 	__u32 highest_sacked;
1881 
1882 	/* TSN marking the fast recovery exit point */
1883 	__u32 fast_recovery_exit;
1884 
1885 	/* Flag to track the current fast recovery state */
1886 	__u8 fast_recovery;
1887 
1888 	/* The number of unacknowledged data chunks.  Reported through
1889 	 * the SCTP_STATUS sockopt.
1890 	 */
1891 	__u16 unack_data;
1892 
1893 	/* The total number of data chunks that we've had to retransmit
1894 	 * as the result of a T3 timer expiration
1895 	 */
1896 	__u32 rtx_data_chunks;
1897 
1898 	/* This is the association's receive buffer space.  This value is used
1899 	 * to set a_rwnd field in an INIT or a SACK chunk.
1900 	 */
1901 	__u32 rwnd;
1902 
1903 	/* This is the last advertised value of rwnd over a SACK chunk. */
1904 	__u32 a_rwnd;
1905 
1906 	/* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1907 	 * to slop over a maximum of the association's frag_point.
1908 	 */
1909 	__u32 rwnd_over;
1910 
1911 	/* Keeps treack of rwnd pressure.  This happens when we have
1912 	 * a window, but not recevie buffer (i.e small packets).  This one
1913 	 * is releases slowly (1 PMTU at a time ).
1914 	 */
1915 	__u32 rwnd_press;
1916 
1917 	/* This is the sndbuf size in use for the association.
1918 	 * This corresponds to the sndbuf size for the association,
1919 	 * as specified in the sk->sndbuf.
1920 	 */
1921 	int sndbuf_used;
1922 
1923 	/* This is the amount of memory that this association has allocated
1924 	 * in the receive path at any given time.
1925 	 */
1926 	atomic_t rmem_alloc;
1927 
1928 	/* This is the wait queue head for send requests waiting on
1929 	 * the association sndbuf space.
1930 	 */
1931 	wait_queue_head_t	wait;
1932 
1933 	/* The message size at which SCTP fragmentation will occur. */
1934 	__u32 frag_point;
1935 	__u32 user_frag;
1936 
1937 	/* Counter used to count INIT errors. */
1938 	int init_err_counter;
1939 
1940 	/* Count the number of INIT cycles (for doubling timeout). */
1941 	int init_cycle;
1942 
1943 	/* Default send parameters. */
1944 	__u16 default_stream;
1945 	__u16 default_flags;
1946 	__u32 default_ppid;
1947 	__u32 default_context;
1948 	__u32 default_timetolive;
1949 
1950 	/* Default receive parameters */
1951 	__u32 default_rcv_context;
1952 
1953 	/* Stream arrays */
1954 	struct sctp_stream stream;
1955 
1956 	/* All outbound chunks go through this structure.  */
1957 	struct sctp_outq outqueue;
1958 
1959 	/* A smart pipe that will handle reordering and fragmentation,
1960 	 * as well as handle passing events up to the ULP.
1961 	 */
1962 	struct sctp_ulpq ulpq;
1963 
1964 	/* Last TSN that caused an ECNE Chunk to be sent.  */
1965 	__u32 last_ecne_tsn;
1966 
1967 	/* Last TSN that caused a CWR Chunk to be sent.	 */
1968 	__u32 last_cwr_tsn;
1969 
1970 	/* How many duplicated TSNs have we seen?  */
1971 	int numduptsns;
1972 
1973 	/* These are to support
1974 	 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1975 	 *  and Enforcement of Flow and Message Limits"
1976 	 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1977 	 * or "ADDIP" for short.
1978 	 */
1979 
1980 
1981 
1982 	/* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1983 	 *
1984 	 * R1) One and only one ASCONF Chunk MAY be in transit and
1985 	 * unacknowledged at any one time.  If a sender, after sending
1986 	 * an ASCONF chunk, decides it needs to transfer another
1987 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1988 	 * returns from the previous ASCONF Chunk before sending a
1989 	 * subsequent ASCONF. Note this restriction binds each side,
1990 	 * so at any time two ASCONF may be in-transit on any given
1991 	 * association (one sent from each endpoint).
1992 	 *
1993 	 * [This is our one-and-only-one ASCONF in flight.  If we do
1994 	 * not have an ASCONF in flight, this is NULL.]
1995 	 */
1996 	struct sctp_chunk *addip_last_asconf;
1997 
1998 	/* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1999 	 *
2000 	 * This is needed to implement itmes E1 - E4 of the updated
2001 	 * spec.  Here is the justification:
2002 	 *
2003 	 * Since the peer may bundle multiple ASCONF chunks toward us,
2004 	 * we now need the ability to cache multiple ACKs.  The section
2005 	 * describes in detail how they are cached and cleaned up.
2006 	 */
2007 	struct list_head asconf_ack_list;
2008 
2009 	/* These ASCONF chunks are waiting to be sent.
2010 	 *
2011 	 * These chunaks can't be pushed to outqueue until receiving
2012 	 * ASCONF_ACK for the previous ASCONF indicated by
2013 	 * addip_last_asconf, so as to guarantee that only one ASCONF
2014 	 * is in flight at any time.
2015 	 *
2016 	 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2017 	 *
2018 	 * In defining the ASCONF Chunk transfer procedures, it is
2019 	 * essential that these transfers MUST NOT cause congestion
2020 	 * within the network.	To achieve this, we place these
2021 	 * restrictions on the transfer of ASCONF Chunks:
2022 	 *
2023 	 * R1) One and only one ASCONF Chunk MAY be in transit and
2024 	 * unacknowledged at any one time.  If a sender, after sending
2025 	 * an ASCONF chunk, decides it needs to transfer another
2026 	 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2027 	 * returns from the previous ASCONF Chunk before sending a
2028 	 * subsequent ASCONF. Note this restriction binds each side,
2029 	 * so at any time two ASCONF may be in-transit on any given
2030 	 * association (one sent from each endpoint).
2031 	 *
2032 	 *
2033 	 * [I really think this is EXACTLY the sort of intelligence
2034 	 *  which already resides in sctp_outq.	 Please move this
2035 	 *  queue and its supporting logic down there.	--piggy]
2036 	 */
2037 	struct list_head addip_chunk_list;
2038 
2039 	/* ADDIP Section 4.1 ASCONF Chunk Procedures
2040 	 *
2041 	 * A2) A serial number should be assigned to the Chunk. The
2042 	 * serial number SHOULD be a monotonically increasing
2043 	 * number. The serial number SHOULD be initialized at
2044 	 * the start of the association to the same value as the
2045 	 * Initial TSN and every time a new ASCONF chunk is created
2046 	 * it is incremented by one after assigning the serial number
2047 	 * to the newly created chunk.
2048 	 *
2049 	 * ADDIP
2050 	 * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2051 	 *
2052 	 * Serial Number : 32 bits (unsigned integer)
2053 	 *
2054 	 * This value represents a Serial Number for the ASCONF
2055 	 * Chunk. The valid range of Serial Number is from 0 to
2056 	 * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2057 	 * after reaching 4294967295.
2058 	 */
2059 	__u32 addip_serial;
2060 	int src_out_of_asoc_ok;
2061 	union sctp_addr *asconf_addr_del_pending;
2062 	struct sctp_transport *new_transport;
2063 
2064 	/* SCTP AUTH: list of the endpoint shared keys.  These
2065 	 * keys are provided out of band by the user applicaton
2066 	 * and can't change during the lifetime of the association
2067 	 */
2068 	struct list_head endpoint_shared_keys;
2069 
2070 	/* SCTP AUTH:
2071 	 * The current generated assocaition shared key (secret)
2072 	 */
2073 	struct sctp_auth_bytes *asoc_shared_key;
2074 	struct sctp_shared_key *shkey;
2075 
2076 	/* SCTP AUTH: hmac id of the first peer requested algorithm
2077 	 * that we support.
2078 	 */
2079 	__u16 default_hmac_id;
2080 
2081 	__u16 active_key_id;
2082 
2083 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
2084 	     temp:1,		/* Is it a temporary association? */
2085 	     pf_expose:2,       /* Expose pf state? */
2086 	     force_delay:1;
2087 
2088 	__u8 strreset_enable;
2089 	__u8 strreset_outstanding; /* request param count on the fly */
2090 
2091 	__u32 strreset_outseq; /* Update after receiving response */
2092 	__u32 strreset_inseq; /* Update after receiving request */
2093 	__u32 strreset_result[2]; /* save the results of last 2 responses */
2094 
2095 	struct sctp_chunk *strreset_chunk; /* save request chunk */
2096 
2097 	struct sctp_priv_assoc_stats stats;
2098 
2099 	int sent_cnt_removable;
2100 
2101 	__u16 subscribe;
2102 
2103 	__u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2104 	__u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2105 
2106 	/* Security identifiers from incoming (INIT). These are set by
2107 	 * security_sctp_assoc_request(). These will only be used by
2108 	 * SCTP TCP type sockets and peeled off connections as they
2109 	 * cause a new socket to be generated. security_sctp_sk_clone()
2110 	 * will then plug these into the new socket.
2111 	 */
2112 
2113 	u32 secid;
2114 	u32 peer_secid;
2115 
2116 	struct rcu_head rcu;
2117 };
2118 
2119 
2120 /* An eyecatcher for determining if we are really looking at an
2121  * association data structure.
2122  */
2123 enum {
2124 	SCTP_ASSOC_EYECATCHER = 0xa550c123,
2125 };
2126 
2127 /* Recover the outter association structure. */
sctp_assoc(struct sctp_ep_common * base)2128 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2129 {
2130 	struct sctp_association *asoc;
2131 
2132 	asoc = container_of(base, struct sctp_association, base);
2133 	return asoc;
2134 }
2135 
2136 /* These are function signatures for manipulating associations.	 */
2137 
2138 
2139 struct sctp_association *
2140 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2141 		     enum sctp_scope scope, gfp_t gfp);
2142 void sctp_association_free(struct sctp_association *);
2143 void sctp_association_put(struct sctp_association *);
2144 void sctp_association_hold(struct sctp_association *);
2145 
2146 struct sctp_transport *sctp_assoc_choose_alter_transport(
2147 	struct sctp_association *, struct sctp_transport *);
2148 void sctp_assoc_update_retran_path(struct sctp_association *);
2149 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2150 					  const union sctp_addr *);
2151 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2152 			    const union sctp_addr *laddr);
2153 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2154 				     const union sctp_addr *address,
2155 				     const gfp_t gfp,
2156 				     const int peer_state);
2157 void sctp_assoc_del_peer(struct sctp_association *asoc,
2158 			 const union sctp_addr *addr);
2159 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2160 			 struct sctp_transport *peer);
2161 void sctp_assoc_control_transport(struct sctp_association *asoc,
2162 				  struct sctp_transport *transport,
2163 				  enum sctp_transport_cmd command,
2164 				  sctp_sn_error_t error);
2165 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2166 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2167 int sctp_assoc_update(struct sctp_association *old,
2168 		      struct sctp_association *new);
2169 
2170 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2171 
2172 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2173 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2174 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2175 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2176 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2177 void sctp_assoc_set_primary(struct sctp_association *,
2178 			    struct sctp_transport *);
2179 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2180 				    struct sctp_transport *);
2181 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2182 				     enum sctp_scope scope, gfp_t gfp);
2183 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2184 					 struct sctp_cookie*,
2185 					 gfp_t gfp);
2186 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2187 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2188 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2189 					const struct sctp_association *asoc,
2190 					__be32 serial);
2191 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2192 
2193 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2194 			const union sctp_addr *ss2);
2195 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2196 
2197 /* A convenience structure to parse out SCTP specific CMSGs. */
2198 struct sctp_cmsgs {
2199 	struct sctp_initmsg *init;
2200 	struct sctp_sndrcvinfo *srinfo;
2201 	struct sctp_sndinfo *sinfo;
2202 	struct sctp_prinfo *prinfo;
2203 	struct sctp_authinfo *authinfo;
2204 	struct msghdr *addrs_msg;
2205 };
2206 
2207 /* Structure for tracking memory objects */
2208 struct sctp_dbg_objcnt_entry {
2209 	char *label;
2210 	atomic_t *counter;
2211 };
2212 
2213 #endif /* __sctp_structs_h__ */
2214