1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * This SCTP implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * This SCTP implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, see
23 * <http://www.gnu.org/licenses/>.
24 *
25 * Please send any bug reports or fixes you make to the
26 * email addresses:
27 * lksctp developers <linux-sctp@vger.kernel.org>
28 *
29 * Written or modified by:
30 * Randall Stewart <randall@sctp.chicago.il.us>
31 * Ken Morneau <kmorneau@cisco.com>
32 * Qiaobing Xie <qxie1@email.mot.com>
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
44 * Kevin Gao <kevin.gao@intel.com>
45 */
46
47 #ifndef __sctp_structs_h__
48 #define __sctp_structs_h__
49
50 #include <linux/ktime.h>
51 #include <linux/rhashtable-types.h>
52 #include <linux/socket.h> /* linux/in.h needs this!! */
53 #include <linux/in.h> /* We get struct sockaddr_in. */
54 #include <linux/in6.h> /* We get struct in6_addr */
55 #include <linux/ipv6.h>
56 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
57 #include <linux/atomic.h> /* This gets us atomic counters. */
58 #include <linux/skbuff.h> /* We need sk_buff_head. */
59 #include <linux/workqueue.h> /* We need tq_struct. */
60 #include <linux/flex_array.h> /* We need flex_array. */
61 #include <linux/sctp.h> /* We need sctp* header structs. */
62 #include <net/sctp/auth.h> /* We need auth specific structs */
63 #include <net/ip.h> /* For inet_skb_parm */
64
65 /* A convenience structure for handling sockaddr structures.
66 * We should wean ourselves off this.
67 */
68 union sctp_addr {
69 struct sockaddr_in v4;
70 struct sockaddr_in6 v6;
71 struct sockaddr sa;
72 };
73
74 /* Forward declarations for data structures. */
75 struct sctp_globals;
76 struct sctp_endpoint;
77 struct sctp_association;
78 struct sctp_transport;
79 struct sctp_packet;
80 struct sctp_chunk;
81 struct sctp_inq;
82 struct sctp_outq;
83 struct sctp_bind_addr;
84 struct sctp_ulpq;
85 struct sctp_ep_common;
86 struct crypto_shash;
87 struct sctp_stream;
88
89
90 #include <net/sctp/tsnmap.h>
91 #include <net/sctp/ulpevent.h>
92 #include <net/sctp/ulpqueue.h>
93 #include <net/sctp/stream_interleave.h>
94
95 /* Structures useful for managing bind/connect. */
96
97 struct sctp_bind_bucket {
98 unsigned short port;
99 unsigned short fastreuse;
100 struct hlist_node node;
101 struct hlist_head owner;
102 struct net *net;
103 };
104
105 struct sctp_bind_hashbucket {
106 spinlock_t lock;
107 struct hlist_head chain;
108 };
109
110 /* Used for hashing all associations. */
111 struct sctp_hashbucket {
112 rwlock_t lock;
113 struct hlist_head chain;
114 } __attribute__((__aligned__(8)));
115
116
117 /* The SCTP globals structure. */
118 extern struct sctp_globals {
119 /* This is a list of groups of functions for each address
120 * family that we support.
121 */
122 struct list_head address_families;
123
124 /* This is the hash of all endpoints. */
125 struct sctp_hashbucket *ep_hashtable;
126 /* This is the sctp port control hash. */
127 struct sctp_bind_hashbucket *port_hashtable;
128 /* This is the hash of all transports. */
129 struct rhltable transport_hashtable;
130
131 /* Sizes of above hashtables. */
132 int ep_hashsize;
133 int port_hashsize;
134
135 /* Default initialization values to be applied to new associations. */
136 __u16 max_instreams;
137 __u16 max_outstreams;
138
139 /* Flag to indicate whether computing and verifying checksum
140 * is disabled. */
141 bool checksum_disable;
142 } sctp_globals;
143
144 #define sctp_max_instreams (sctp_globals.max_instreams)
145 #define sctp_max_outstreams (sctp_globals.max_outstreams)
146 #define sctp_address_families (sctp_globals.address_families)
147 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
148 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
149 #define sctp_port_hashsize (sctp_globals.port_hashsize)
150 #define sctp_port_hashtable (sctp_globals.port_hashtable)
151 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
152 #define sctp_checksum_disable (sctp_globals.checksum_disable)
153
154 /* SCTP Socket type: UDP or TCP style. */
155 enum sctp_socket_type {
156 SCTP_SOCKET_UDP = 0,
157 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
158 SCTP_SOCKET_TCP
159 };
160
161 /* Per socket SCTP information. */
162 struct sctp_sock {
163 /* inet_sock has to be the first member of sctp_sock */
164 struct inet_sock inet;
165 /* What kind of a socket is this? */
166 enum sctp_socket_type type;
167
168 /* PF_ family specific functions. */
169 struct sctp_pf *pf;
170
171 /* Access to HMAC transform. */
172 struct crypto_shash *hmac;
173 char *sctp_hmac_alg;
174
175 /* What is our base endpointer? */
176 struct sctp_endpoint *ep;
177
178 struct sctp_bind_bucket *bind_hash;
179 /* Various Socket Options. */
180 __u16 default_stream;
181 __u32 default_ppid;
182 __u16 default_flags;
183 __u32 default_context;
184 __u32 default_timetolive;
185 __u32 default_rcv_context;
186 int max_burst;
187
188 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
189 * the destination address every heartbeat interval. This value
190 * will be inherited by all new associations.
191 */
192 __u32 hbinterval;
193
194 /* This is the max_retrans value for new associations. */
195 __u16 pathmaxrxt;
196
197 __u32 flowlabel;
198 __u8 dscp;
199
200 /* The initial Path MTU to use for new associations. */
201 __u32 pathmtu;
202
203 /* The default SACK delay timeout for new associations. */
204 __u32 sackdelay;
205 __u32 sackfreq;
206
207 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
208 __u32 param_flags;
209
210 struct sctp_rtoinfo rtoinfo;
211 struct sctp_paddrparams paddrparam;
212 struct sctp_assocparams assocparams;
213
214 /*
215 * These two structures must be grouped together for the usercopy
216 * whitelist region.
217 */
218 struct sctp_event_subscribe subscribe;
219 struct sctp_initmsg initmsg;
220
221 int user_frag;
222
223 __u32 autoclose;
224 __u32 adaptation_ind;
225 __u32 pd_point;
226 __u16 nodelay:1,
227 reuse:1,
228 disable_fragments:1,
229 v4mapped:1,
230 frag_interleave:1,
231 strm_interleave:1,
232 recvrcvinfo:1,
233 recvnxtinfo:1,
234 data_ready_signalled:1;
235
236 atomic_t pd_mode;
237 /* Receive to here while partial delivery is in effect. */
238 struct sk_buff_head pd_lobby;
239
240 /* These must be the last fields, as they will skipped on copies,
241 * like on accept and peeloff operations
242 */
243 struct list_head auto_asconf_list;
244 int do_auto_asconf;
245 };
246
sctp_sk(const struct sock * sk)247 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
248 {
249 return (struct sctp_sock *)sk;
250 }
251
sctp_opt2sk(const struct sctp_sock * sp)252 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
253 {
254 return (struct sock *)sp;
255 }
256
257 #if IS_ENABLED(CONFIG_IPV6)
258 struct sctp6_sock {
259 struct sctp_sock sctp;
260 struct ipv6_pinfo inet6;
261 };
262 #endif /* CONFIG_IPV6 */
263
264
265 /* This is our APPLICATION-SPECIFIC state cookie.
266 * THIS IS NOT DICTATED BY THE SPECIFICATION.
267 */
268 /* These are the parts of an association which we send in the cookie.
269 * Most of these are straight out of:
270 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
271 *
272 */
273
274 struct sctp_cookie {
275
276 /* My : Tag expected in every inbound packet and sent
277 * Verification: in the INIT or INIT ACK chunk.
278 * Tag :
279 */
280 __u32 my_vtag;
281
282 /* Peer's : Tag expected in every outbound packet except
283 * Verification: in the INIT chunk.
284 * Tag :
285 */
286 __u32 peer_vtag;
287
288 /* The rest of these are not from the spec, but really need to
289 * be in the cookie.
290 */
291
292 /* My Tie Tag : Assist in discovering a restarting association. */
293 __u32 my_ttag;
294
295 /* Peer's Tie Tag: Assist in discovering a restarting association. */
296 __u32 peer_ttag;
297
298 /* When does this cookie expire? */
299 ktime_t expiration;
300
301 /* Number of inbound/outbound streams which are set
302 * and negotiated during the INIT process.
303 */
304 __u16 sinit_num_ostreams;
305 __u16 sinit_max_instreams;
306
307 /* This is the first sequence number I used. */
308 __u32 initial_tsn;
309
310 /* This holds the originating address of the INIT packet. */
311 union sctp_addr peer_addr;
312
313 /* IG Section 2.35.3
314 * Include the source port of the INIT-ACK
315 */
316 __u16 my_port;
317
318 __u8 prsctp_capable;
319
320 /* Padding for future use */
321 __u8 padding;
322
323 __u32 adaptation_ind;
324
325 __u8 auth_random[sizeof(struct sctp_paramhdr) +
326 SCTP_AUTH_RANDOM_LENGTH];
327 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
328 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
329
330 /* This is a shim for my peer's INIT packet, followed by
331 * a copy of the raw address list of the association.
332 * The length of the raw address list is saved in the
333 * raw_addr_list_len field, which will be used at the time when
334 * the association TCB is re-constructed from the cookie.
335 */
336 __u32 raw_addr_list_len;
337 struct sctp_init_chunk peer_init[0];
338 };
339
340
341 /* The format of our cookie that we send to our peer. */
342 struct sctp_signed_cookie {
343 __u8 signature[SCTP_SECRET_SIZE];
344 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
345 struct sctp_cookie c;
346 } __packed;
347
348 /* This is another convenience type to allocate memory for address
349 * params for the maximum size and pass such structures around
350 * internally.
351 */
352 union sctp_addr_param {
353 struct sctp_paramhdr p;
354 struct sctp_ipv4addr_param v4;
355 struct sctp_ipv6addr_param v6;
356 };
357
358 /* A convenience type to allow walking through the various
359 * parameters and avoid casting all over the place.
360 */
361 union sctp_params {
362 void *v;
363 struct sctp_paramhdr *p;
364 struct sctp_cookie_preserve_param *life;
365 struct sctp_hostname_param *dns;
366 struct sctp_cookie_param *cookie;
367 struct sctp_supported_addrs_param *sat;
368 struct sctp_ipv4addr_param *v4;
369 struct sctp_ipv6addr_param *v6;
370 union sctp_addr_param *addr;
371 struct sctp_adaptation_ind_param *aind;
372 struct sctp_supported_ext_param *ext;
373 struct sctp_random_param *random;
374 struct sctp_chunks_param *chunks;
375 struct sctp_hmac_algo_param *hmac_algo;
376 struct sctp_addip_param *addip;
377 };
378
379 /* RFC 2960. Section 3.3.5 Heartbeat.
380 * Heartbeat Information: variable length
381 * The Sender-specific Heartbeat Info field should normally include
382 * information about the sender's current time when this HEARTBEAT
383 * chunk is sent and the destination transport address to which this
384 * HEARTBEAT is sent (see Section 8.3).
385 */
386 struct sctp_sender_hb_info {
387 struct sctp_paramhdr param_hdr;
388 union sctp_addr daddr;
389 unsigned long sent_at;
390 __u64 hb_nonce;
391 };
392
393 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
394 gfp_t gfp);
395 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
396 void sctp_stream_free(struct sctp_stream *stream);
397 void sctp_stream_clear(struct sctp_stream *stream);
398 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
399
400 /* What is the current SSN number for this stream? */
401 #define sctp_ssn_peek(stream, type, sid) \
402 (sctp_stream_##type((stream), (sid))->ssn)
403
404 /* Return the next SSN number for this stream. */
405 #define sctp_ssn_next(stream, type, sid) \
406 (sctp_stream_##type((stream), (sid))->ssn++)
407
408 /* Skip over this ssn and all below. */
409 #define sctp_ssn_skip(stream, type, sid, ssn) \
410 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
411
412 /* What is the current MID number for this stream? */
413 #define sctp_mid_peek(stream, type, sid) \
414 (sctp_stream_##type((stream), (sid))->mid)
415
416 /* Return the next MID number for this stream. */
417 #define sctp_mid_next(stream, type, sid) \
418 (sctp_stream_##type((stream), (sid))->mid++)
419
420 /* Skip over this mid and all below. */
421 #define sctp_mid_skip(stream, type, sid, mid) \
422 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
423
424 /* What is the current MID_uo number for this stream? */
425 #define sctp_mid_uo_peek(stream, type, sid) \
426 (sctp_stream_##type((stream), (sid))->mid_uo)
427
428 /* Return the next MID_uo number for this stream. */
429 #define sctp_mid_uo_next(stream, type, sid) \
430 (sctp_stream_##type((stream), (sid))->mid_uo++)
431
432 /*
433 * Pointers to address related SCTP functions.
434 * (i.e. things that depend on the address family.)
435 */
436 struct sctp_af {
437 int (*sctp_xmit) (struct sk_buff *skb,
438 struct sctp_transport *);
439 int (*setsockopt) (struct sock *sk,
440 int level,
441 int optname,
442 char __user *optval,
443 unsigned int optlen);
444 int (*getsockopt) (struct sock *sk,
445 int level,
446 int optname,
447 char __user *optval,
448 int __user *optlen);
449 int (*compat_setsockopt) (struct sock *sk,
450 int level,
451 int optname,
452 char __user *optval,
453 unsigned int optlen);
454 int (*compat_getsockopt) (struct sock *sk,
455 int level,
456 int optname,
457 char __user *optval,
458 int __user *optlen);
459 void (*get_dst) (struct sctp_transport *t,
460 union sctp_addr *saddr,
461 struct flowi *fl,
462 struct sock *sk);
463 void (*get_saddr) (struct sctp_sock *sk,
464 struct sctp_transport *t,
465 struct flowi *fl);
466 void (*copy_addrlist) (struct list_head *,
467 struct net_device *);
468 int (*cmp_addr) (const union sctp_addr *addr1,
469 const union sctp_addr *addr2);
470 void (*addr_copy) (union sctp_addr *dst,
471 union sctp_addr *src);
472 void (*from_skb) (union sctp_addr *,
473 struct sk_buff *skb,
474 int saddr);
475 void (*from_sk) (union sctp_addr *,
476 struct sock *sk);
477 bool (*from_addr_param) (union sctp_addr *,
478 union sctp_addr_param *,
479 __be16 port, int iif);
480 int (*to_addr_param) (const union sctp_addr *,
481 union sctp_addr_param *);
482 int (*addr_valid) (union sctp_addr *,
483 struct sctp_sock *,
484 const struct sk_buff *);
485 enum sctp_scope (*scope)(union sctp_addr *);
486 void (*inaddr_any) (union sctp_addr *, __be16);
487 int (*is_any) (const union sctp_addr *);
488 int (*available) (union sctp_addr *,
489 struct sctp_sock *);
490 int (*skb_iif) (const struct sk_buff *sk);
491 int (*is_ce) (const struct sk_buff *sk);
492 void (*seq_dump_addr)(struct seq_file *seq,
493 union sctp_addr *addr);
494 void (*ecn_capable)(struct sock *sk);
495 __u16 net_header_len;
496 int sockaddr_len;
497 int (*ip_options_len)(struct sock *sk);
498 sa_family_t sa_family;
499 struct list_head list;
500 };
501
502 struct sctp_af *sctp_get_af_specific(sa_family_t);
503 int sctp_register_af(struct sctp_af *);
504
505 /* Protocol family functions. */
506 struct sctp_pf {
507 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
508 void (*skb_msgname) (struct sk_buff *, char *, int *);
509 int (*af_supported) (sa_family_t, struct sctp_sock *);
510 int (*cmp_addr) (const union sctp_addr *,
511 const union sctp_addr *,
512 struct sctp_sock *);
513 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
514 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
515 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
516 struct sock *(*create_accept_sk) (struct sock *sk,
517 struct sctp_association *asoc,
518 bool kern);
519 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
520 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
521 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
522 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
523 struct sctp_af *af;
524 };
525
526
527 /* Structure to track chunk fragments that have been acked, but peer
528 * fragments of the same message have not.
529 */
530 struct sctp_datamsg {
531 /* Chunks waiting to be submitted to lower layer. */
532 struct list_head chunks;
533 /* Reference counting. */
534 refcount_t refcnt;
535 /* When is this message no longer interesting to the peer? */
536 unsigned long expires_at;
537 /* Did the messenge fail to send? */
538 int send_error;
539 u8 send_failed:1,
540 can_delay:1, /* should this message be Nagle delayed */
541 abandoned:1; /* should this message be abandoned */
542 };
543
544 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
545 struct sctp_sndrcvinfo *,
546 struct iov_iter *);
547 void sctp_datamsg_free(struct sctp_datamsg *);
548 void sctp_datamsg_put(struct sctp_datamsg *);
549 void sctp_chunk_fail(struct sctp_chunk *, int error);
550 int sctp_chunk_abandoned(struct sctp_chunk *);
551
552 /* RFC2960 1.4 Key Terms
553 *
554 * o Chunk: A unit of information within an SCTP packet, consisting of
555 * a chunk header and chunk-specific content.
556 *
557 * As a matter of convenience, we remember the SCTP common header for
558 * each chunk as well as a few other header pointers...
559 */
560 struct sctp_chunk {
561 struct list_head list;
562
563 refcount_t refcnt;
564
565 /* How many times this chunk have been sent, for prsctp RTX policy */
566 int sent_count;
567
568 union {
569 /* This is our link to the per-transport transmitted list. */
570 struct list_head transmitted_list;
571 /* List in specific stream outq */
572 struct list_head stream_list;
573 };
574
575 /* This field is used by chunks that hold fragmented data.
576 * For the first fragment this is the list that holds the rest of
577 * fragments. For the remaining fragments, this is the link to the
578 * frag_list maintained in the first fragment.
579 */
580 struct list_head frag_list;
581
582 /* This points to the sk_buff containing the actual data. */
583 struct sk_buff *skb;
584
585 union {
586 /* In case of GSO packets, this will store the head one */
587 struct sk_buff *head_skb;
588 /* In case of auth enabled, this will point to the shkey */
589 struct sctp_shared_key *shkey;
590 };
591
592 /* These are the SCTP headers by reverse order in a packet.
593 * Note that some of these may happen more than once. In that
594 * case, we point at the "current" one, whatever that means
595 * for that level of header.
596 */
597
598 /* We point this at the FIRST TLV parameter to chunk_hdr. */
599 union sctp_params param_hdr;
600 union {
601 __u8 *v;
602 struct sctp_datahdr *data_hdr;
603 struct sctp_inithdr *init_hdr;
604 struct sctp_sackhdr *sack_hdr;
605 struct sctp_heartbeathdr *hb_hdr;
606 struct sctp_sender_hb_info *hbs_hdr;
607 struct sctp_shutdownhdr *shutdown_hdr;
608 struct sctp_signed_cookie *cookie_hdr;
609 struct sctp_ecnehdr *ecne_hdr;
610 struct sctp_cwrhdr *ecn_cwr_hdr;
611 struct sctp_errhdr *err_hdr;
612 struct sctp_addiphdr *addip_hdr;
613 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
614 struct sctp_authhdr *auth_hdr;
615 struct sctp_idatahdr *idata_hdr;
616 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
617 } subh;
618
619 __u8 *chunk_end;
620
621 struct sctp_chunkhdr *chunk_hdr;
622 struct sctphdr *sctp_hdr;
623
624 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
625 struct sctp_sndrcvinfo sinfo;
626
627 /* Which association does this belong to? */
628 struct sctp_association *asoc;
629
630 /* What endpoint received this chunk? */
631 struct sctp_ep_common *rcvr;
632
633 /* We fill this in if we are calculating RTT. */
634 unsigned long sent_at;
635
636 /* What is the origin IP address for this chunk? */
637 union sctp_addr source;
638 /* Destination address for this chunk. */
639 union sctp_addr dest;
640
641 /* For outbound message, track all fragments for SEND_FAILED. */
642 struct sctp_datamsg *msg;
643
644 /* For an inbound chunk, this tells us where it came from.
645 * For an outbound chunk, it tells us where we'd like it to
646 * go. It is NULL if we have no preference.
647 */
648 struct sctp_transport *transport;
649
650 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
651 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
652 * spec violates the principle premis that all chunks are processed
653 * in order.
654 */
655 struct sk_buff *auth_chunk;
656
657 #define SCTP_CAN_FRTX 0x0
658 #define SCTP_NEED_FRTX 0x1
659 #define SCTP_DONT_FRTX 0x2
660 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
661 has_tsn:1, /* Does this chunk have a TSN yet? */
662 has_ssn:1, /* Does this chunk have a SSN yet? */
663 #define has_mid has_ssn
664 singleton:1, /* Only chunk in the packet? */
665 end_of_packet:1, /* Last chunk in the packet? */
666 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
667 pdiscard:1, /* Discard the whole packet now? */
668 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
669 data_accepted:1, /* At least 1 chunk accepted */
670 auth:1, /* IN: was auth'ed | OUT: needs auth */
671 has_asconf:1, /* IN: have seen an asconf before */
672 tsn_missing_report:2, /* Data chunk missing counter. */
673 fast_retransmit:2; /* Is this chunk fast retransmitted? */
674 };
675
676 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
677 void sctp_chunk_hold(struct sctp_chunk *);
678 void sctp_chunk_put(struct sctp_chunk *);
679 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
680 struct iov_iter *from);
681 void sctp_chunk_free(struct sctp_chunk *);
682 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
683 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
684 const struct sctp_association *,
685 struct sock *, gfp_t gfp);
686 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
687 union sctp_addr *);
688 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
689
sctp_chunk_stream_no(struct sctp_chunk * ch)690 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
691 {
692 return ntohs(ch->subh.data_hdr->stream);
693 }
694
695 enum {
696 SCTP_ADDR_NEW, /* new address added to assoc/ep */
697 SCTP_ADDR_SRC, /* address can be used as source */
698 SCTP_ADDR_DEL, /* address about to be deleted */
699 };
700
701 /* This is a structure for holding either an IPv6 or an IPv4 address. */
702 struct sctp_sockaddr_entry {
703 struct list_head list;
704 struct rcu_head rcu;
705 union sctp_addr a;
706 __u8 state;
707 __u8 valid;
708 };
709
710 #define SCTP_ADDRESS_TICK_DELAY 500
711
712 /* This structure holds lists of chunks as we are assembling for
713 * transmission.
714 */
715 struct sctp_packet {
716 /* These are the SCTP header values (host order) for the packet. */
717 __u16 source_port;
718 __u16 destination_port;
719 __u32 vtag;
720
721 /* This contains the payload chunks. */
722 struct list_head chunk_list;
723
724 /* This is the overhead of the sctp and ip headers. */
725 size_t overhead;
726 /* This is the total size of all chunks INCLUDING padding. */
727 size_t size;
728 /* This is the maximum size this packet may have */
729 size_t max_size;
730
731 /* The packet is destined for this transport address.
732 * The function we finally use to pass down to the next lower
733 * layer lives in the transport structure.
734 */
735 struct sctp_transport *transport;
736
737 /* pointer to the auth chunk for this packet */
738 struct sctp_chunk *auth;
739
740 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
741 has_sack:1, /* This packet contains a SACK chunk. */
742 has_auth:1, /* This packet contains an AUTH chunk */
743 has_data:1, /* This packet contains at least 1 DATA chunk */
744 ipfragok:1; /* So let ip fragment this packet */
745 };
746
747 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
748 __u16 sport, __u16 dport);
749 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
750 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
751 struct sctp_chunk *chunk,
752 int one_packet, gfp_t gfp);
753 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
754 struct sctp_chunk *chunk);
755 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
756 void sctp_packet_free(struct sctp_packet *);
757
sctp_packet_empty(struct sctp_packet * packet)758 static inline int sctp_packet_empty(struct sctp_packet *packet)
759 {
760 return packet->size == packet->overhead;
761 }
762
763 /* This represents a remote transport address.
764 * For local transport addresses, we just use union sctp_addr.
765 *
766 * RFC2960 Section 1.4 Key Terms
767 *
768 * o Transport address: A Transport Address is traditionally defined
769 * by Network Layer address, Transport Layer protocol and Transport
770 * Layer port number. In the case of SCTP running over IP, a
771 * transport address is defined by the combination of an IP address
772 * and an SCTP port number (where SCTP is the Transport protocol).
773 *
774 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
775 *
776 * o The sender keeps a separate congestion control parameter set for
777 * each of the destination addresses it can send to (not each
778 * source-destination pair but for each destination). The parameters
779 * should decay if the address is not used for a long enough time
780 * period.
781 *
782 */
783 struct sctp_transport {
784 /* A list of transports. */
785 struct list_head transports;
786 struct rhlist_head node;
787
788 /* Reference counting. */
789 refcount_t refcnt;
790 /* RTO-Pending : A flag used to track if one of the DATA
791 * chunks sent to this address is currently being
792 * used to compute a RTT. If this flag is 0,
793 * the next DATA chunk sent to this destination
794 * should be used to compute a RTT and this flag
795 * should be set. Every time the RTT
796 * calculation completes (i.e. the DATA chunk
797 * is SACK'd) clear this flag.
798 */
799 __u32 rto_pending:1,
800
801 /*
802 * hb_sent : a flag that signals that we have a pending
803 * heartbeat.
804 */
805 hb_sent:1,
806
807 /* Is the Path MTU update pending on this tranport */
808 pmtu_pending:1,
809
810 dst_pending_confirm:1, /* need to confirm neighbour */
811
812 /* Has this transport moved the ctsn since we last sacked */
813 sack_generation:1;
814 u32 dst_cookie;
815
816 struct flowi fl;
817
818 /* This is the peer's IP address and port. */
819 union sctp_addr ipaddr;
820
821 /* These are the functions we call to handle LLP stuff. */
822 struct sctp_af *af_specific;
823
824 /* Which association do we belong to? */
825 struct sctp_association *asoc;
826
827 /* RFC2960
828 *
829 * 12.3 Per Transport Address Data
830 *
831 * For each destination transport address in the peer's
832 * address list derived from the INIT or INIT ACK chunk, a
833 * number of data elements needs to be maintained including:
834 */
835 /* RTO : The current retransmission timeout value. */
836 unsigned long rto;
837
838 __u32 rtt; /* This is the most recent RTT. */
839
840 /* RTTVAR : The current RTT variation. */
841 __u32 rttvar;
842
843 /* SRTT : The current smoothed round trip time. */
844 __u32 srtt;
845
846 /*
847 * These are the congestion stats.
848 */
849 /* cwnd : The current congestion window. */
850 __u32 cwnd; /* This is the actual cwnd. */
851
852 /* ssthresh : The current slow start threshold value. */
853 __u32 ssthresh;
854
855 /* partial : The tracking method for increase of cwnd when in
856 * bytes acked : congestion avoidance mode (see Section 6.2.2)
857 */
858 __u32 partial_bytes_acked;
859
860 /* Data that has been sent, but not acknowledged. */
861 __u32 flight_size;
862
863 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
864
865 /* Destination */
866 struct dst_entry *dst;
867 /* Source address. */
868 union sctp_addr saddr;
869
870 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
871 * the destination address every heartbeat interval.
872 */
873 unsigned long hbinterval;
874
875 /* SACK delay timeout */
876 unsigned long sackdelay;
877 __u32 sackfreq;
878
879 atomic_t mtu_info;
880
881 /* When was the last time that we heard from this transport? We use
882 * this to pick new active and retran paths.
883 */
884 ktime_t last_time_heard;
885
886 /* When was the last time that we sent a chunk using this
887 * transport? We use this to check for idle transports
888 */
889 unsigned long last_time_sent;
890
891 /* Last time(in jiffies) when cwnd is reduced due to the congestion
892 * indication based on ECNE chunk.
893 */
894 unsigned long last_time_ecne_reduced;
895
896 /* This is the max_retrans value for the transport and will
897 * be initialized from the assocs value. This can be changed
898 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
899 */
900 __u16 pathmaxrxt;
901
902 __u32 flowlabel;
903 __u8 dscp;
904
905 /* This is the partially failed retrans value for the transport
906 * and will be initialized from the assocs value. This can be changed
907 * using the SCTP_PEER_ADDR_THLDS socket option
908 */
909 int pf_retrans;
910 /* PMTU : The current known path MTU. */
911 __u32 pathmtu;
912
913 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
914 __u32 param_flags;
915
916 /* The number of times INIT has been sent on this transport. */
917 int init_sent_count;
918
919 /* state : The current state of this destination,
920 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
921 */
922 int state;
923
924 /* These are the error stats for this destination. */
925
926 /* Error count : The current error count for this destination. */
927 unsigned short error_count;
928
929 /* Per : A timer used by each destination.
930 * Destination :
931 * Timer :
932 *
933 * [Everywhere else in the text this is called T3-rtx. -ed]
934 */
935 struct timer_list T3_rtx_timer;
936
937 /* Heartbeat timer is per destination. */
938 struct timer_list hb_timer;
939
940 /* Timer to handle ICMP proto unreachable envets */
941 struct timer_list proto_unreach_timer;
942
943 /* Timer to handler reconf chunk rtx */
944 struct timer_list reconf_timer;
945
946 /* Since we're using per-destination retransmission timers
947 * (see above), we're also using per-destination "transmitted"
948 * queues. This probably ought to be a private struct
949 * accessible only within the outqueue, but it's not, yet.
950 */
951 struct list_head transmitted;
952
953 /* We build bundle-able packets for this transport here. */
954 struct sctp_packet packet;
955
956 /* This is the list of transports that have chunks to send. */
957 struct list_head send_ready;
958
959 /* State information saved for SFR_CACC algorithm. The key
960 * idea in SFR_CACC is to maintain state at the sender on a
961 * per-destination basis when a changeover happens.
962 * char changeover_active;
963 * char cycling_changeover;
964 * __u32 next_tsn_at_change;
965 * char cacc_saw_newack;
966 */
967 struct {
968 /* An unsigned integer, which stores the next TSN to be
969 * used by the sender, at the moment of changeover.
970 */
971 __u32 next_tsn_at_change;
972
973 /* A flag which indicates the occurrence of a changeover */
974 char changeover_active;
975
976 /* A flag which indicates whether the change of primary is
977 * the first switch to this destination address during an
978 * active switch.
979 */
980 char cycling_changeover;
981
982 /* A temporary flag, which is used during the processing of
983 * a SACK to estimate the causative TSN(s)'s group.
984 */
985 char cacc_saw_newack;
986 } cacc;
987
988 /* 64-bit random number sent with heartbeat. */
989 __u64 hb_nonce;
990
991 struct rcu_head rcu;
992 };
993
994 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
995 gfp_t);
996 void sctp_transport_set_owner(struct sctp_transport *,
997 struct sctp_association *);
998 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
999 struct sctp_sock *);
1000 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1001 void sctp_transport_free(struct sctp_transport *);
1002 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1003 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1004 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1005 int sctp_transport_hold(struct sctp_transport *);
1006 void sctp_transport_put(struct sctp_transport *);
1007 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1008 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1009 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1010 enum sctp_lower_cwnd reason);
1011 void sctp_transport_burst_limited(struct sctp_transport *);
1012 void sctp_transport_burst_reset(struct sctp_transport *);
1013 unsigned long sctp_transport_timeout(struct sctp_transport *);
1014 void sctp_transport_reset(struct sctp_transport *t);
1015 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1016 void sctp_transport_immediate_rtx(struct sctp_transport *);
1017 void sctp_transport_dst_release(struct sctp_transport *t);
1018 void sctp_transport_dst_confirm(struct sctp_transport *t);
1019
1020
1021 /* This is the structure we use to queue packets as they come into
1022 * SCTP. We write packets to it and read chunks from it.
1023 */
1024 struct sctp_inq {
1025 /* This is actually a queue of sctp_chunk each
1026 * containing a partially decoded packet.
1027 */
1028 struct list_head in_chunk_list;
1029 /* This is the packet which is currently off the in queue and is
1030 * being worked on through the inbound chunk processing.
1031 */
1032 struct sctp_chunk *in_progress;
1033
1034 /* This is the delayed task to finish delivering inbound
1035 * messages.
1036 */
1037 struct work_struct immediate;
1038 };
1039
1040 void sctp_inq_init(struct sctp_inq *);
1041 void sctp_inq_free(struct sctp_inq *);
1042 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1043 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1044 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1045 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1046
1047 /* This is the structure we use to hold outbound chunks. You push
1048 * chunks in and they automatically pop out the other end as bundled
1049 * packets (it calls (*output_handler)()).
1050 *
1051 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1052 * and 8.2 of the v13 draft.
1053 *
1054 * It handles retransmissions. The connection to the timeout portion
1055 * of the state machine is through sctp_..._timeout() and timeout_handler.
1056 *
1057 * If you feed it SACKs, it will eat them.
1058 *
1059 * If you give it big chunks, it will fragment them.
1060 *
1061 * It assigns TSN's to data chunks. This happens at the last possible
1062 * instant before transmission.
1063 *
1064 * When free()'d, it empties itself out via output_handler().
1065 */
1066 struct sctp_outq {
1067 struct sctp_association *asoc;
1068
1069 /* Data pending that has never been transmitted. */
1070 struct list_head out_chunk_list;
1071
1072 /* Stream scheduler being used */
1073 struct sctp_sched_ops *sched;
1074
1075 unsigned int out_qlen; /* Total length of queued data chunks. */
1076
1077 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1078 unsigned int error;
1079
1080 /* These are control chunks we want to send. */
1081 struct list_head control_chunk_list;
1082
1083 /* These are chunks that have been sacked but are above the
1084 * CTSN, or cumulative tsn ack point.
1085 */
1086 struct list_head sacked;
1087
1088 /* Put chunks on this list to schedule them for
1089 * retransmission.
1090 */
1091 struct list_head retransmit;
1092
1093 /* Put chunks on this list to save them for FWD TSN processing as
1094 * they were abandoned.
1095 */
1096 struct list_head abandoned;
1097
1098 /* How many unackd bytes do we have in-flight? */
1099 __u32 outstanding_bytes;
1100
1101 /* Are we doing fast-rtx on this queue */
1102 char fast_rtx;
1103
1104 /* Corked? */
1105 char cork;
1106 };
1107
1108 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1109 void sctp_outq_teardown(struct sctp_outq *);
1110 void sctp_outq_free(struct sctp_outq*);
1111 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1112 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1113 int sctp_outq_is_empty(const struct sctp_outq *);
1114 void sctp_outq_restart(struct sctp_outq *);
1115
1116 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1117 enum sctp_retransmit_reason reason);
1118 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1119 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1120 void sctp_prsctp_prune(struct sctp_association *asoc,
1121 struct sctp_sndrcvinfo *sinfo, int msg_len);
1122 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1123 /* Uncork and flush an outqueue. */
sctp_outq_cork(struct sctp_outq * q)1124 static inline void sctp_outq_cork(struct sctp_outq *q)
1125 {
1126 q->cork = 1;
1127 }
1128
1129 /* SCTP skb control block.
1130 * sctp_input_cb is currently used on rx and sock rx queue
1131 */
1132 struct sctp_input_cb {
1133 union {
1134 struct inet_skb_parm h4;
1135 #if IS_ENABLED(CONFIG_IPV6)
1136 struct inet6_skb_parm h6;
1137 #endif
1138 } header;
1139 struct sctp_chunk *chunk;
1140 struct sctp_af *af;
1141 };
1142 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1143
1144 struct sctp_output_cb {
1145 struct sk_buff *last;
1146 };
1147 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1148
sctp_gso_headskb(const struct sk_buff * skb)1149 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1150 {
1151 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1152
1153 return chunk->head_skb ? : skb;
1154 }
1155
1156 /* These bind address data fields common between endpoints and associations */
1157 struct sctp_bind_addr {
1158
1159 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1160 *
1161 * SCTP Port: The local SCTP port number the endpoint is
1162 * bound to.
1163 */
1164 __u16 port;
1165
1166 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1167 *
1168 * Address List: The list of IP addresses that this instance
1169 * has bound. This information is passed to one's
1170 * peer(s) in INIT and INIT ACK chunks.
1171 */
1172 struct list_head address_list;
1173 };
1174
1175 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1176 void sctp_bind_addr_free(struct sctp_bind_addr *);
1177 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1178 const struct sctp_bind_addr *src,
1179 enum sctp_scope scope, gfp_t gfp,
1180 int flags);
1181 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1182 const struct sctp_bind_addr *src,
1183 gfp_t gfp);
1184 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1185 int new_size, __u8 addr_state, gfp_t gfp);
1186 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1187 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1188 struct sctp_sock *);
1189 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1190 struct sctp_sock *, struct sctp_sock *);
1191 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1192 const union sctp_addr *addr);
1193 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1194 const union sctp_addr *addrs,
1195 int addrcnt,
1196 struct sctp_sock *opt);
1197 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1198 int *addrs_len,
1199 gfp_t gfp);
1200 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1201 __u16 port, gfp_t gfp);
1202
1203 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1204 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1205 const enum sctp_scope scope);
1206 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1207 int sctp_is_ep_boundall(struct sock *sk);
1208
1209
1210 /* What type of endpoint? */
1211 enum sctp_endpoint_type {
1212 SCTP_EP_TYPE_SOCKET,
1213 SCTP_EP_TYPE_ASSOCIATION,
1214 };
1215
1216 /*
1217 * A common base class to bridge the implmentation view of a
1218 * socket (usually listening) endpoint versus an association's
1219 * local endpoint.
1220 * This common structure is useful for several purposes:
1221 * 1) Common interface for lookup routines.
1222 * a) Subfunctions work for either endpoint or association
1223 * b) Single interface to lookup allows hiding the lookup lock rather
1224 * than acquiring it externally.
1225 * 2) Common interface for the inbound chunk handling/state machine.
1226 * 3) Common object handling routines for reference counting, etc.
1227 * 4) Disentangle association lookup from endpoint lookup, where we
1228 * do not have to find our endpoint to find our association.
1229 *
1230 */
1231
1232 struct sctp_ep_common {
1233 /* Fields to help us manage our entries in the hash tables. */
1234 struct hlist_node node;
1235 int hashent;
1236
1237 /* Runtime type information. What kind of endpoint is this? */
1238 enum sctp_endpoint_type type;
1239
1240 /* Some fields to help us manage this object.
1241 * refcnt - Reference count access to this object.
1242 * dead - Do not attempt to use this object.
1243 */
1244 refcount_t refcnt;
1245 bool dead;
1246
1247 /* What socket does this endpoint belong to? */
1248 struct sock *sk;
1249
1250 /* Cache netns and it won't change once set */
1251 struct net *net;
1252
1253 /* This is where we receive inbound chunks. */
1254 struct sctp_inq inqueue;
1255
1256 /* This substructure includes the defining parameters of the
1257 * endpoint:
1258 * bind_addr.port is our shared port number.
1259 * bind_addr.address_list is our set of local IP addresses.
1260 */
1261 struct sctp_bind_addr bind_addr;
1262 };
1263
1264
1265 /* RFC Section 1.4 Key Terms
1266 *
1267 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1268 * multi-homed host, an SCTP endpoint is represented to its peers as a
1269 * combination of a set of eligible destination transport addresses to
1270 * which SCTP packets can be sent and a set of eligible source
1271 * transport addresses from which SCTP packets can be received.
1272 * All transport addresses used by an SCTP endpoint must use the
1273 * same port number, but can use multiple IP addresses. A transport
1274 * address used by an SCTP endpoint must not be used by another
1275 * SCTP endpoint. In other words, a transport address is unique
1276 * to an SCTP endpoint.
1277 *
1278 * From an implementation perspective, each socket has one of these.
1279 * A TCP-style socket will have exactly one association on one of
1280 * these. An UDP-style socket will have multiple associations hanging
1281 * off one of these.
1282 */
1283
1284 struct sctp_endpoint {
1285 /* Common substructure for endpoint and association. */
1286 struct sctp_ep_common base;
1287
1288 /* Associations: A list of current associations and mappings
1289 * to the data consumers for each association. This
1290 * may be in the form of a hash table or other
1291 * implementation dependent structure. The data
1292 * consumers may be process identification
1293 * information such as file descriptors, named pipe
1294 * pointer, or table pointers dependent on how SCTP
1295 * is implemented.
1296 */
1297 /* This is really a list of struct sctp_association entries. */
1298 struct list_head asocs;
1299
1300 /* Secret Key: A secret key used by this endpoint to compute
1301 * the MAC. This SHOULD be a cryptographic quality
1302 * random number with a sufficient length.
1303 * Discussion in [RFC1750] can be helpful in
1304 * selection of the key.
1305 */
1306 __u8 secret_key[SCTP_SECRET_SIZE];
1307
1308 /* digest: This is a digest of the sctp cookie. This field is
1309 * only used on the receive path when we try to validate
1310 * that the cookie has not been tampered with. We put
1311 * this here so we pre-allocate this once and can re-use
1312 * on every receive.
1313 */
1314 __u8 *digest;
1315
1316 /* sendbuf acct. policy. */
1317 __u32 sndbuf_policy;
1318
1319 /* rcvbuf acct. policy. */
1320 __u32 rcvbuf_policy;
1321
1322 /* SCTP AUTH: array of the HMACs that will be allocated
1323 * we need this per association so that we don't serialize
1324 */
1325 struct crypto_shash **auth_hmacs;
1326
1327 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1328 struct sctp_hmac_algo_param *auth_hmacs_list;
1329
1330 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1331 struct sctp_chunks_param *auth_chunk_list;
1332
1333 /* SCTP-AUTH: endpoint shared keys */
1334 struct list_head endpoint_shared_keys;
1335 __u16 active_key_id;
1336 __u8 auth_enable:1,
1337 prsctp_enable:1,
1338 reconf_enable:1;
1339
1340 __u8 strreset_enable;
1341
1342 /* Security identifiers from incoming (INIT). These are set by
1343 * security_sctp_assoc_request(). These will only be used by
1344 * SCTP TCP type sockets and peeled off connections as they
1345 * cause a new socket to be generated. security_sctp_sk_clone()
1346 * will then plug these into the new socket.
1347 */
1348
1349 u32 secid;
1350 u32 peer_secid;
1351 struct rcu_head rcu;
1352 };
1353
1354 /* Recover the outter endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1355 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1356 {
1357 struct sctp_endpoint *ep;
1358
1359 ep = container_of(base, struct sctp_endpoint, base);
1360 return ep;
1361 }
1362
1363 /* These are function signatures for manipulating endpoints. */
1364 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1365 void sctp_endpoint_free(struct sctp_endpoint *);
1366 void sctp_endpoint_put(struct sctp_endpoint *);
1367 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1368 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1369 struct sctp_association *sctp_endpoint_lookup_assoc(
1370 const struct sctp_endpoint *ep,
1371 const union sctp_addr *paddr,
1372 struct sctp_transport **);
1373 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1374 const union sctp_addr *paddr);
1375 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1376 struct net *, const union sctp_addr *);
1377 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1378 const union sctp_addr *paddr);
1379
1380 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1381 const struct sctp_association *asoc,
1382 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1383 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1384 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1385 const union sctp_addr *peer,
1386 struct sctp_init_chunk *init, gfp_t gfp);
1387 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1388 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1389
1390 struct sctp_inithdr_host {
1391 __u32 init_tag;
1392 __u32 a_rwnd;
1393 __u16 num_outbound_streams;
1394 __u16 num_inbound_streams;
1395 __u32 initial_tsn;
1396 };
1397
1398 struct sctp_stream_priorities {
1399 /* List of priorities scheduled */
1400 struct list_head prio_sched;
1401 /* List of streams scheduled */
1402 struct list_head active;
1403 /* The next stream stream in line */
1404 struct sctp_stream_out_ext *next;
1405 __u16 prio;
1406 };
1407
1408 struct sctp_stream_out_ext {
1409 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1410 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1411 struct list_head outq; /* chunks enqueued by this stream */
1412 union {
1413 struct {
1414 /* Scheduled streams list */
1415 struct list_head prio_list;
1416 struct sctp_stream_priorities *prio_head;
1417 };
1418 /* Fields used by RR scheduler */
1419 struct {
1420 struct list_head rr_list;
1421 };
1422 };
1423 };
1424
1425 struct sctp_stream_out {
1426 union {
1427 __u32 mid;
1428 __u16 ssn;
1429 };
1430 __u32 mid_uo;
1431 struct sctp_stream_out_ext *ext;
1432 __u8 state;
1433 };
1434
1435 struct sctp_stream_in {
1436 union {
1437 __u32 mid;
1438 __u16 ssn;
1439 };
1440 __u32 mid_uo;
1441 __u32 fsn;
1442 __u32 fsn_uo;
1443 char pd_mode;
1444 char pd_mode_uo;
1445 };
1446
1447 struct sctp_stream {
1448 struct flex_array *out;
1449 struct flex_array *in;
1450 __u16 outcnt;
1451 __u16 incnt;
1452 /* Current stream being sent, if any */
1453 struct sctp_stream_out *out_curr;
1454 union {
1455 /* Fields used by priority scheduler */
1456 struct {
1457 /* List of priorities scheduled */
1458 struct list_head prio_list;
1459 };
1460 /* Fields used by RR scheduler */
1461 struct {
1462 /* List of streams scheduled */
1463 struct list_head rr_list;
1464 /* The next stream stream in line */
1465 struct sctp_stream_out_ext *rr_next;
1466 };
1467 };
1468 struct sctp_stream_interleave *si;
1469 };
1470
sctp_stream_out(const struct sctp_stream * stream,__u16 sid)1471 static inline struct sctp_stream_out *sctp_stream_out(
1472 const struct sctp_stream *stream,
1473 __u16 sid)
1474 {
1475 return flex_array_get(stream->out, sid);
1476 }
1477
sctp_stream_in(const struct sctp_stream * stream,__u16 sid)1478 static inline struct sctp_stream_in *sctp_stream_in(
1479 const struct sctp_stream *stream,
1480 __u16 sid)
1481 {
1482 return flex_array_get(stream->in, sid);
1483 }
1484
1485 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1486 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1487
1488 #define SCTP_STREAM_CLOSED 0x00
1489 #define SCTP_STREAM_OPEN 0x01
1490
sctp_datachk_len(const struct sctp_stream * stream)1491 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1492 {
1493 return stream->si->data_chunk_len;
1494 }
1495
sctp_datahdr_len(const struct sctp_stream * stream)1496 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1497 {
1498 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1499 }
1500
sctp_ftsnchk_len(const struct sctp_stream * stream)1501 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1502 {
1503 return stream->si->ftsn_chunk_len;
1504 }
1505
sctp_ftsnhdr_len(const struct sctp_stream * stream)1506 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1507 {
1508 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1509 }
1510
1511 /* SCTP_GET_ASSOC_STATS counters */
1512 struct sctp_priv_assoc_stats {
1513 /* Maximum observed rto in the association during subsequent
1514 * observations. Value is set to 0 if no RTO measurement took place
1515 * The transport where the max_rto was observed is returned in
1516 * obs_rto_ipaddr
1517 */
1518 struct sockaddr_storage obs_rto_ipaddr;
1519 __u64 max_obs_rto;
1520 /* Total In and Out SACKs received and sent */
1521 __u64 isacks;
1522 __u64 osacks;
1523 /* Total In and Out packets received and sent */
1524 __u64 opackets;
1525 __u64 ipackets;
1526 /* Total retransmitted chunks */
1527 __u64 rtxchunks;
1528 /* TSN received > next expected */
1529 __u64 outofseqtsns;
1530 /* Duplicate Chunks received */
1531 __u64 idupchunks;
1532 /* Gap Ack Blocks received */
1533 __u64 gapcnt;
1534 /* Unordered data chunks sent and received */
1535 __u64 ouodchunks;
1536 __u64 iuodchunks;
1537 /* Ordered data chunks sent and received */
1538 __u64 oodchunks;
1539 __u64 iodchunks;
1540 /* Control chunks sent and received */
1541 __u64 octrlchunks;
1542 __u64 ictrlchunks;
1543 };
1544
1545 /* RFC2960
1546 *
1547 * 12. Recommended Transmission Control Block (TCB) Parameters
1548 *
1549 * This section details a recommended set of parameters that should
1550 * be contained within the TCB for an implementation. This section is
1551 * for illustrative purposes and should not be deemed as requirements
1552 * on an implementation or as an exhaustive list of all parameters
1553 * inside an SCTP TCB. Each implementation may need its own additional
1554 * parameters for optimization.
1555 */
1556
1557
1558 /* Here we have information about each individual association. */
1559 struct sctp_association {
1560
1561 /* A base structure common to endpoint and association.
1562 * In this context, it represents the associations's view
1563 * of the local endpoint of the association.
1564 */
1565 struct sctp_ep_common base;
1566
1567 /* Associations on the same socket. */
1568 struct list_head asocs;
1569
1570 /* association id. */
1571 sctp_assoc_t assoc_id;
1572
1573 /* This is our parent endpoint. */
1574 struct sctp_endpoint *ep;
1575
1576 /* These are those association elements needed in the cookie. */
1577 struct sctp_cookie c;
1578
1579 /* This is all information about our peer. */
1580 struct {
1581 /* transport_addr_list
1582 *
1583 * Peer : A list of SCTP transport addresses that the
1584 * Transport : peer is bound to. This information is derived
1585 * Address : from the INIT or INIT ACK and is used to
1586 * List : associate an inbound packet with a given
1587 * : association. Normally this information is
1588 * : hashed or keyed for quick lookup and access
1589 * : of the TCB.
1590 * : The list is also initialized with the list
1591 * : of addresses passed with the sctp_connectx()
1592 * : call.
1593 *
1594 * It is a list of SCTP_transport's.
1595 */
1596 struct list_head transport_addr_list;
1597
1598 /* rwnd
1599 *
1600 * Peer Rwnd : Current calculated value of the peer's rwnd.
1601 */
1602 __u32 rwnd;
1603
1604 /* transport_count
1605 *
1606 * Peer : A count of the number of peer addresses
1607 * Transport : in the Peer Transport Address List.
1608 * Address :
1609 * Count :
1610 */
1611 __u16 transport_count;
1612
1613 /* port
1614 * The transport layer port number.
1615 */
1616 __u16 port;
1617
1618 /* primary_path
1619 *
1620 * Primary : This is the current primary destination
1621 * Path : transport address of the peer endpoint. It
1622 * : may also specify a source transport address
1623 * : on this endpoint.
1624 *
1625 * All of these paths live on transport_addr_list.
1626 *
1627 * At the bakeoffs, we discovered that the intent of
1628 * primaryPath is that it only changes when the ULP
1629 * asks to have it changed. We add the activePath to
1630 * designate the connection we are currently using to
1631 * transmit new data and most control chunks.
1632 */
1633 struct sctp_transport *primary_path;
1634
1635 /* Cache the primary path address here, when we
1636 * need a an address for msg_name.
1637 */
1638 union sctp_addr primary_addr;
1639
1640 /* active_path
1641 * The path that we are currently using to
1642 * transmit new data and most control chunks.
1643 */
1644 struct sctp_transport *active_path;
1645
1646 /* retran_path
1647 *
1648 * RFC2960 6.4 Multi-homed SCTP Endpoints
1649 * ...
1650 * Furthermore, when its peer is multi-homed, an
1651 * endpoint SHOULD try to retransmit a chunk to an
1652 * active destination transport address that is
1653 * different from the last destination address to
1654 * which the DATA chunk was sent.
1655 */
1656 struct sctp_transport *retran_path;
1657
1658 /* Pointer to last transport I have sent on. */
1659 struct sctp_transport *last_sent_to;
1660
1661 /* This is the last transport I have received DATA on. */
1662 struct sctp_transport *last_data_from;
1663
1664 /*
1665 * Mapping An array of bits or bytes indicating which out of
1666 * Array order TSN's have been received (relative to the
1667 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1668 * order packets have been received, this array
1669 * will be set to all zero. This structure may be
1670 * in the form of a circular buffer or bit array.
1671 *
1672 * Last Rcvd : This is the last TSN received in
1673 * TSN : sequence. This value is set initially by
1674 * : taking the peer's Initial TSN, received in
1675 * : the INIT or INIT ACK chunk, and subtracting
1676 * : one from it.
1677 *
1678 * Throughout most of the specification this is called the
1679 * "Cumulative TSN ACK Point". In this case, we
1680 * ignore the advice in 12.2 in favour of the term
1681 * used in the bulk of the text. This value is hidden
1682 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1683 */
1684 struct sctp_tsnmap tsn_map;
1685
1686 /* This mask is used to disable sending the ASCONF chunk
1687 * with specified parameter to peer.
1688 */
1689 __be16 addip_disabled_mask;
1690
1691 /* These are capabilities which our peer advertised. */
1692 __u8 ecn_capable:1, /* Can peer do ECN? */
1693 ipv4_address:1, /* Peer understands IPv4 addresses? */
1694 ipv6_address:1, /* Peer understands IPv6 addresses? */
1695 hostname_address:1, /* Peer understands DNS addresses? */
1696 asconf_capable:1, /* Does peer support ADDIP? */
1697 prsctp_capable:1, /* Can peer do PR-SCTP? */
1698 reconf_capable:1, /* Can peer do RE-CONFIG? */
1699 auth_capable:1; /* Is peer doing SCTP-AUTH? */
1700
1701 /* sack_needed : This flag indicates if the next received
1702 * : packet is to be responded to with a
1703 * : SACK. This is initialized to 0. When a packet
1704 * : is received sack_cnt is incremented. If this value
1705 * : reaches 2 or more, a SACK is sent and the
1706 * : value is reset to 0. Note: This is used only
1707 * : when no DATA chunks are received out of
1708 * : order. When DATA chunks are out of order,
1709 * : SACK's are not delayed (see Section 6).
1710 */
1711 __u8 sack_needed:1, /* Do we need to sack the peer? */
1712 sack_generation:1,
1713 zero_window_announced:1;
1714 __u32 sack_cnt;
1715
1716 __u32 adaptation_ind; /* Adaptation Code point. */
1717
1718 struct sctp_inithdr_host i;
1719 void *cookie;
1720 int cookie_len;
1721
1722 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1723 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1724 * Initial TSN Value minus 1
1725 */
1726 __u32 addip_serial;
1727
1728 /* SCTP-AUTH: We need to know pears random number, hmac list
1729 * and authenticated chunk list. All that is part of the
1730 * cookie and these are just pointers to those locations
1731 */
1732 struct sctp_random_param *peer_random;
1733 struct sctp_chunks_param *peer_chunks;
1734 struct sctp_hmac_algo_param *peer_hmacs;
1735 } peer;
1736
1737 /* State : A state variable indicating what state the
1738 * : association is in, i.e. COOKIE-WAIT,
1739 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1740 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1741 *
1742 * Note: No "CLOSED" state is illustrated since if a
1743 * association is "CLOSED" its TCB SHOULD be removed.
1744 *
1745 * In this implementation we DO have a CLOSED
1746 * state which is used during initiation and shutdown.
1747 *
1748 * State takes values from SCTP_STATE_*.
1749 */
1750 enum sctp_state state;
1751
1752 /* Overall : The overall association error count.
1753 * Error Count : [Clear this any time I get something.]
1754 */
1755 int overall_error_count;
1756
1757 /* The cookie life I award for any cookie. */
1758 ktime_t cookie_life;
1759
1760 /* These are the association's initial, max, and min RTO values.
1761 * These values will be initialized by system defaults, but can
1762 * be modified via the SCTP_RTOINFO socket option.
1763 */
1764 unsigned long rto_initial;
1765 unsigned long rto_max;
1766 unsigned long rto_min;
1767
1768 /* Maximum number of new data packets that can be sent in a burst. */
1769 int max_burst;
1770
1771 /* This is the max_retrans value for the association. This value will
1772 * be initialized initialized from system defaults, but can be
1773 * modified by the SCTP_ASSOCINFO socket option.
1774 */
1775 int max_retrans;
1776
1777 /* This is the partially failed retrans value for the transport
1778 * and will be initialized from the assocs value. This can be
1779 * changed using the SCTP_PEER_ADDR_THLDS socket option
1780 */
1781 int pf_retrans;
1782
1783 /* Maximum number of times the endpoint will retransmit INIT */
1784 __u16 max_init_attempts;
1785
1786 /* How many times have we resent an INIT? */
1787 __u16 init_retries;
1788
1789 /* The largest timeout or RTO value to use in attempting an INIT */
1790 unsigned long max_init_timeo;
1791
1792 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1793 * the destination address every heartbeat interval. This value
1794 * will be inherited by all new transports.
1795 */
1796 unsigned long hbinterval;
1797
1798 /* This is the max_retrans value for new transports in the
1799 * association.
1800 */
1801 __u16 pathmaxrxt;
1802
1803 __u32 flowlabel;
1804 __u8 dscp;
1805
1806 /* Flag that path mtu update is pending */
1807 __u8 pmtu_pending;
1808
1809 /* Association : The smallest PMTU discovered for all of the
1810 * PMTU : peer's transport addresses.
1811 */
1812 __u32 pathmtu;
1813
1814 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1815 __u32 param_flags;
1816
1817 __u32 sackfreq;
1818 /* SACK delay timeout */
1819 unsigned long sackdelay;
1820
1821 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1822 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1823
1824 /* Transport to which SHUTDOWN chunk was last sent. */
1825 struct sctp_transport *shutdown_last_sent_to;
1826
1827 /* Transport to which INIT chunk was last sent. */
1828 struct sctp_transport *init_last_sent_to;
1829
1830 /* How many times have we resent a SHUTDOWN */
1831 int shutdown_retries;
1832
1833 /* Next TSN : The next TSN number to be assigned to a new
1834 * : DATA chunk. This is sent in the INIT or INIT
1835 * : ACK chunk to the peer and incremented each
1836 * : time a DATA chunk is assigned a TSN
1837 * : (normally just prior to transmit or during
1838 * : fragmentation).
1839 */
1840 __u32 next_tsn;
1841
1842 /*
1843 * Last Rcvd : This is the last TSN received in sequence. This value
1844 * TSN : is set initially by taking the peer's Initial TSN,
1845 * : received in the INIT or INIT ACK chunk, and
1846 * : subtracting one from it.
1847 *
1848 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1849 */
1850
1851 __u32 ctsn_ack_point;
1852
1853 /* PR-SCTP Advanced.Peer.Ack.Point */
1854 __u32 adv_peer_ack_point;
1855
1856 /* Highest TSN that is acknowledged by incoming SACKs. */
1857 __u32 highest_sacked;
1858
1859 /* TSN marking the fast recovery exit point */
1860 __u32 fast_recovery_exit;
1861
1862 /* Flag to track the current fast recovery state */
1863 __u8 fast_recovery;
1864
1865 /* The number of unacknowledged data chunks. Reported through
1866 * the SCTP_STATUS sockopt.
1867 */
1868 __u16 unack_data;
1869
1870 /* The total number of data chunks that we've had to retransmit
1871 * as the result of a T3 timer expiration
1872 */
1873 __u32 rtx_data_chunks;
1874
1875 /* This is the association's receive buffer space. This value is used
1876 * to set a_rwnd field in an INIT or a SACK chunk.
1877 */
1878 __u32 rwnd;
1879
1880 /* This is the last advertised value of rwnd over a SACK chunk. */
1881 __u32 a_rwnd;
1882
1883 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1884 * to slop over a maximum of the association's frag_point.
1885 */
1886 __u32 rwnd_over;
1887
1888 /* Keeps treack of rwnd pressure. This happens when we have
1889 * a window, but not recevie buffer (i.e small packets). This one
1890 * is releases slowly (1 PMTU at a time ).
1891 */
1892 __u32 rwnd_press;
1893
1894 /* This is the sndbuf size in use for the association.
1895 * This corresponds to the sndbuf size for the association,
1896 * as specified in the sk->sndbuf.
1897 */
1898 int sndbuf_used;
1899
1900 /* This is the amount of memory that this association has allocated
1901 * in the receive path at any given time.
1902 */
1903 atomic_t rmem_alloc;
1904
1905 /* This is the wait queue head for send requests waiting on
1906 * the association sndbuf space.
1907 */
1908 wait_queue_head_t wait;
1909
1910 /* The message size at which SCTP fragmentation will occur. */
1911 __u32 frag_point;
1912 __u32 user_frag;
1913
1914 /* Counter used to count INIT errors. */
1915 int init_err_counter;
1916
1917 /* Count the number of INIT cycles (for doubling timeout). */
1918 int init_cycle;
1919
1920 /* Default send parameters. */
1921 __u16 default_stream;
1922 __u16 default_flags;
1923 __u32 default_ppid;
1924 __u32 default_context;
1925 __u32 default_timetolive;
1926
1927 /* Default receive parameters */
1928 __u32 default_rcv_context;
1929
1930 /* Stream arrays */
1931 struct sctp_stream stream;
1932
1933 /* All outbound chunks go through this structure. */
1934 struct sctp_outq outqueue;
1935
1936 /* A smart pipe that will handle reordering and fragmentation,
1937 * as well as handle passing events up to the ULP.
1938 */
1939 struct sctp_ulpq ulpq;
1940
1941 /* Last TSN that caused an ECNE Chunk to be sent. */
1942 __u32 last_ecne_tsn;
1943
1944 /* Last TSN that caused a CWR Chunk to be sent. */
1945 __u32 last_cwr_tsn;
1946
1947 /* How many duplicated TSNs have we seen? */
1948 int numduptsns;
1949
1950 /* These are to support
1951 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1952 * and Enforcement of Flow and Message Limits"
1953 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1954 * or "ADDIP" for short.
1955 */
1956
1957
1958
1959 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1960 *
1961 * R1) One and only one ASCONF Chunk MAY be in transit and
1962 * unacknowledged at any one time. If a sender, after sending
1963 * an ASCONF chunk, decides it needs to transfer another
1964 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1965 * returns from the previous ASCONF Chunk before sending a
1966 * subsequent ASCONF. Note this restriction binds each side,
1967 * so at any time two ASCONF may be in-transit on any given
1968 * association (one sent from each endpoint).
1969 *
1970 * [This is our one-and-only-one ASCONF in flight. If we do
1971 * not have an ASCONF in flight, this is NULL.]
1972 */
1973 struct sctp_chunk *addip_last_asconf;
1974
1975 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1976 *
1977 * This is needed to implement itmes E1 - E4 of the updated
1978 * spec. Here is the justification:
1979 *
1980 * Since the peer may bundle multiple ASCONF chunks toward us,
1981 * we now need the ability to cache multiple ACKs. The section
1982 * describes in detail how they are cached and cleaned up.
1983 */
1984 struct list_head asconf_ack_list;
1985
1986 /* These ASCONF chunks are waiting to be sent.
1987 *
1988 * These chunaks can't be pushed to outqueue until receiving
1989 * ASCONF_ACK for the previous ASCONF indicated by
1990 * addip_last_asconf, so as to guarantee that only one ASCONF
1991 * is in flight at any time.
1992 *
1993 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1994 *
1995 * In defining the ASCONF Chunk transfer procedures, it is
1996 * essential that these transfers MUST NOT cause congestion
1997 * within the network. To achieve this, we place these
1998 * restrictions on the transfer of ASCONF Chunks:
1999 *
2000 * R1) One and only one ASCONF Chunk MAY be in transit and
2001 * unacknowledged at any one time. If a sender, after sending
2002 * an ASCONF chunk, decides it needs to transfer another
2003 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2004 * returns from the previous ASCONF Chunk before sending a
2005 * subsequent ASCONF. Note this restriction binds each side,
2006 * so at any time two ASCONF may be in-transit on any given
2007 * association (one sent from each endpoint).
2008 *
2009 *
2010 * [I really think this is EXACTLY the sort of intelligence
2011 * which already resides in sctp_outq. Please move this
2012 * queue and its supporting logic down there. --piggy]
2013 */
2014 struct list_head addip_chunk_list;
2015
2016 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2017 *
2018 * A2) A serial number should be assigned to the Chunk. The
2019 * serial number SHOULD be a monotonically increasing
2020 * number. The serial number SHOULD be initialized at
2021 * the start of the association to the same value as the
2022 * Initial TSN and every time a new ASCONF chunk is created
2023 * it is incremented by one after assigning the serial number
2024 * to the newly created chunk.
2025 *
2026 * ADDIP
2027 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2028 *
2029 * Serial Number : 32 bits (unsigned integer)
2030 *
2031 * This value represents a Serial Number for the ASCONF
2032 * Chunk. The valid range of Serial Number is from 0 to
2033 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2034 * after reaching 4294967295.
2035 */
2036 __u32 addip_serial;
2037 int src_out_of_asoc_ok;
2038 union sctp_addr *asconf_addr_del_pending;
2039 struct sctp_transport *new_transport;
2040
2041 /* SCTP AUTH: list of the endpoint shared keys. These
2042 * keys are provided out of band by the user applicaton
2043 * and can't change during the lifetime of the association
2044 */
2045 struct list_head endpoint_shared_keys;
2046
2047 /* SCTP AUTH:
2048 * The current generated assocaition shared key (secret)
2049 */
2050 struct sctp_auth_bytes *asoc_shared_key;
2051 struct sctp_shared_key *shkey;
2052
2053 /* SCTP AUTH: hmac id of the first peer requested algorithm
2054 * that we support.
2055 */
2056 __u16 default_hmac_id;
2057
2058 __u16 active_key_id;
2059
2060 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2061 temp:1, /* Is it a temporary association? */
2062 force_delay:1,
2063 intl_enable:1,
2064 prsctp_enable:1,
2065 reconf_enable:1;
2066
2067 __u8 strreset_enable;
2068 __u8 strreset_outstanding; /* request param count on the fly */
2069
2070 __u32 strreset_outseq; /* Update after receiving response */
2071 __u32 strreset_inseq; /* Update after receiving request */
2072 __u32 strreset_result[2]; /* save the results of last 2 responses */
2073
2074 struct sctp_chunk *strreset_chunk; /* save request chunk */
2075
2076 struct sctp_priv_assoc_stats stats;
2077
2078 int sent_cnt_removable;
2079
2080 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2081 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2082
2083 struct rcu_head rcu;
2084 };
2085
2086
2087 /* An eyecatcher for determining if we are really looking at an
2088 * association data structure.
2089 */
2090 enum {
2091 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2092 };
2093
2094 /* Recover the outter association structure. */
sctp_assoc(struct sctp_ep_common * base)2095 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2096 {
2097 struct sctp_association *asoc;
2098
2099 asoc = container_of(base, struct sctp_association, base);
2100 return asoc;
2101 }
2102
2103 /* These are function signatures for manipulating associations. */
2104
2105
2106 struct sctp_association *
2107 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2108 enum sctp_scope scope, gfp_t gfp);
2109 void sctp_association_free(struct sctp_association *);
2110 void sctp_association_put(struct sctp_association *);
2111 void sctp_association_hold(struct sctp_association *);
2112
2113 struct sctp_transport *sctp_assoc_choose_alter_transport(
2114 struct sctp_association *, struct sctp_transport *);
2115 void sctp_assoc_update_retran_path(struct sctp_association *);
2116 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2117 const union sctp_addr *);
2118 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2119 const union sctp_addr *laddr);
2120 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2121 const union sctp_addr *address,
2122 const gfp_t gfp,
2123 const int peer_state);
2124 void sctp_assoc_del_peer(struct sctp_association *asoc,
2125 const union sctp_addr *addr);
2126 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2127 struct sctp_transport *peer);
2128 void sctp_assoc_control_transport(struct sctp_association *asoc,
2129 struct sctp_transport *transport,
2130 enum sctp_transport_cmd command,
2131 sctp_sn_error_t error);
2132 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2133 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2134 int sctp_assoc_update(struct sctp_association *old,
2135 struct sctp_association *new);
2136
2137 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2138
2139 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2140 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2141 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2142 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2143 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2144 void sctp_assoc_set_primary(struct sctp_association *,
2145 struct sctp_transport *);
2146 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2147 struct sctp_transport *);
2148 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2149 enum sctp_scope scope, gfp_t gfp);
2150 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2151 struct sctp_cookie*,
2152 gfp_t gfp);
2153 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2154 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2155 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2156 const struct sctp_association *asoc,
2157 __be32 serial);
2158 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2159
2160 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2161 const union sctp_addr *ss2);
2162 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2163
2164 /* A convenience structure to parse out SCTP specific CMSGs. */
2165 struct sctp_cmsgs {
2166 struct sctp_initmsg *init;
2167 struct sctp_sndrcvinfo *srinfo;
2168 struct sctp_sndinfo *sinfo;
2169 struct sctp_prinfo *prinfo;
2170 struct sctp_authinfo *authinfo;
2171 struct msghdr *addrs_msg;
2172 };
2173
2174 /* Structure for tracking memory objects */
2175 struct sctp_dbg_objcnt_entry {
2176 char *label;
2177 atomic_t *counter;
2178 };
2179
2180 #endif /* __sctp_structs_h__ */
2181