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