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 <crypto/sha2.h>
36 #include <linux/ktime.h>
37 #include <linux/generic-radix-tree.h>
38 #include <linux/rhashtable-types.h>
39 #include <linux/socket.h> /* linux/in.h needs this!! */
40 #include <linux/in.h> /* We get struct sockaddr_in. */
41 #include <linux/in6.h> /* We get struct in6_addr */
42 #include <linux/ipv6.h>
43 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
44 #include <linux/atomic.h> /* This gets us atomic counters. */
45 #include <linux/skbuff.h> /* We need sk_buff_head. */
46 #include <linux/workqueue.h> /* We need tq_struct. */
47 #include <linux/sctp.h> /* We need sctp* header structs. */
48 #include <net/sctp/auth.h> /* We need auth specific structs */
49 #include <net/ip.h> /* For inet_skb_parm */
50
51 /* A convenience structure for handling sockaddr structures.
52 * We should wean ourselves off this.
53 */
54 union sctp_addr {
55 struct sockaddr_inet sa; /* Large enough for both address families */
56 struct sockaddr_in v4;
57 struct sockaddr_in6 v6;
58 };
59
60 /* Forward declarations for data structures. */
61 struct sctp_globals;
62 struct sctp_endpoint;
63 struct sctp_association;
64 struct sctp_transport;
65 struct sctp_packet;
66 struct sctp_chunk;
67 struct sctp_inq;
68 struct sctp_outq;
69 struct sctp_bind_addr;
70 struct sctp_ulpq;
71 struct sctp_ep_common;
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 /* What is our base endpointer? */
159 struct sctp_endpoint *ep;
160
161 struct sctp_bind_bucket *bind_hash;
162 /* Various Socket Options. */
163 __u16 default_stream;
164 __u32 default_ppid;
165 __u16 default_flags;
166 __u32 default_context;
167 __u32 default_timetolive;
168 __u32 default_rcv_context;
169 int max_burst;
170
171 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
172 * the destination address every heartbeat interval. This value
173 * will be inherited by all new associations.
174 */
175 __u32 hbinterval;
176 __u32 probe_interval;
177
178 __be16 udp_port;
179 __be16 encap_port;
180
181 /* This is the max_retrans value for new associations. */
182 __u16 pathmaxrxt;
183
184 __u32 flowlabel;
185 __u8 dscp;
186
187 __u16 pf_retrans;
188 __u16 ps_retrans;
189
190 /* The initial Path MTU to use for new associations. */
191 __u32 pathmtu;
192
193 /* The default SACK delay timeout for new associations. */
194 __u32 sackdelay;
195 __u32 sackfreq;
196
197 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
198 __u32 param_flags;
199
200 __u32 default_ss;
201
202 struct sctp_rtoinfo rtoinfo;
203 struct sctp_paddrparams paddrparam;
204 struct sctp_assocparams assocparams;
205
206 /*
207 * These two structures must be grouped together for the usercopy
208 * whitelist region.
209 */
210 __u16 subscribe;
211 struct sctp_initmsg initmsg;
212
213 int user_frag;
214
215 __u32 autoclose;
216 __u32 adaptation_ind;
217 __u32 pd_point;
218 __u16 nodelay:1,
219 pf_expose:2,
220 reuse:1,
221 disable_fragments:1,
222 v4mapped:1,
223 frag_interleave:1,
224 recvrcvinfo:1,
225 recvnxtinfo:1,
226 data_ready_signalled:1,
227 cookie_auth_enable:1;
228
229 atomic_t pd_mode;
230
231 /* Receive to here while partial delivery is in effect. */
232 struct sk_buff_head pd_lobby;
233
234 struct list_head auto_asconf_list;
235 int do_auto_asconf;
236 };
237
238 #define sctp_sk(ptr) container_of_const(ptr, struct sctp_sock, inet.sk)
239
sctp_opt2sk(const struct sctp_sock * sp)240 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
241 {
242 return (struct sock *)sp;
243 }
244
245 #if IS_ENABLED(CONFIG_IPV6)
246 struct sctp6_sock {
247 struct sctp_sock sctp;
248 struct ipv6_pinfo inet6;
249 };
250 #endif /* CONFIG_IPV6 */
251
252
253 /* This is our APPLICATION-SPECIFIC state cookie.
254 * THIS IS NOT DICTATED BY THE SPECIFICATION.
255 */
256 /* These are the parts of an association which we send in the cookie.
257 * Most of these are straight out of:
258 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
259 *
260 */
261
262 struct sctp_cookie {
263
264 /* My : Tag expected in every inbound packet and sent
265 * Verification: in the INIT or INIT ACK chunk.
266 * Tag :
267 */
268 __u32 my_vtag;
269
270 /* Peer's : Tag expected in every outbound packet except
271 * Verification: in the INIT chunk.
272 * Tag :
273 */
274 __u32 peer_vtag;
275
276 /* The rest of these are not from the spec, but really need to
277 * be in the cookie.
278 */
279
280 /* My Tie Tag : Assist in discovering a restarting association. */
281 __u32 my_ttag;
282
283 /* Peer's Tie Tag: Assist in discovering a restarting association. */
284 __u32 peer_ttag;
285
286 /* When does this cookie expire? */
287 ktime_t expiration;
288
289 /* Number of inbound/outbound streams which are set
290 * and negotiated during the INIT process.
291 */
292 __u16 sinit_num_ostreams;
293 __u16 sinit_max_instreams;
294
295 /* This is the first sequence number I used. */
296 __u32 initial_tsn;
297
298 /* This holds the originating address of the INIT packet. */
299 union sctp_addr peer_addr;
300
301 /* IG Section 2.35.3
302 * Include the source port of the INIT-ACK
303 */
304 __u16 my_port;
305
306 __u8 prsctp_capable;
307
308 /* Padding for future use */
309 __u8 padding;
310
311 __u32 adaptation_ind;
312
313 __u8 auth_random[sizeof(struct sctp_paramhdr) +
314 SCTP_AUTH_RANDOM_LENGTH];
315 __u8 auth_hmacs[sizeof(struct sctp_paramhdr) +
316 SCTP_AUTH_NUM_HMACS * sizeof(__u16)];
317 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
318
319 /* This is a shim for my peer's INIT packet, followed by
320 * a copy of the raw address list of the association.
321 * The length of the raw address list is saved in the
322 * raw_addr_list_len field, which will be used at the time when
323 * the association TCB is re-constructed from the cookie.
324 */
325 __u32 raw_addr_list_len;
326 /* struct sctp_init_chunk peer_init[]; */
327 };
328
329
330 /* The format of our cookie that we send to our peer. */
331 struct sctp_signed_cookie {
332 __u8 mac[SCTP_COOKIE_MAC_SIZE];
333 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
334 struct sctp_cookie c;
335 } __packed;
336
337 /* This is another convenience type to allocate memory for address
338 * params for the maximum size and pass such structures around
339 * internally.
340 */
341 union sctp_addr_param {
342 struct sctp_paramhdr p;
343 struct sctp_ipv4addr_param v4;
344 struct sctp_ipv6addr_param v6;
345 };
346
347 /* A convenience type to allow walking through the various
348 * parameters and avoid casting all over the place.
349 */
350 union sctp_params {
351 void *v;
352 struct sctp_paramhdr *p;
353 struct sctp_cookie_preserve_param *life;
354 struct sctp_hostname_param *dns;
355 struct sctp_cookie_param *cookie;
356 struct sctp_supported_addrs_param *sat;
357 struct sctp_ipv4addr_param *v4;
358 struct sctp_ipv6addr_param *v6;
359 union sctp_addr_param *addr;
360 struct sctp_adaptation_ind_param *aind;
361 struct sctp_supported_ext_param *ext;
362 struct sctp_random_param *random;
363 struct sctp_chunks_param *chunks;
364 struct sctp_hmac_algo_param *hmac_algo;
365 struct sctp_addip_param *addip;
366 };
367
368 /* RFC 2960. Section 3.3.5 Heartbeat.
369 * Heartbeat Information: variable length
370 * The Sender-specific Heartbeat Info field should normally include
371 * information about the sender's current time when this HEARTBEAT
372 * chunk is sent and the destination transport address to which this
373 * HEARTBEAT is sent (see Section 8.3).
374 */
375 struct sctp_sender_hb_info {
376 struct sctp_paramhdr param_hdr;
377 union sctp_addr daddr;
378 unsigned long sent_at;
379 __u64 hb_nonce;
380 __u32 probe_size;
381 };
382
383 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
384 gfp_t gfp);
385 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
386 void sctp_stream_free(struct sctp_stream *stream);
387 void sctp_stream_clear(struct sctp_stream *stream);
388 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
389
390 /* What is the current SSN number for this stream? */
391 #define sctp_ssn_peek(stream, type, sid) \
392 (sctp_stream_##type((stream), (sid))->ssn)
393
394 /* Return the next SSN number for this stream. */
395 #define sctp_ssn_next(stream, type, sid) \
396 (sctp_stream_##type((stream), (sid))->ssn++)
397
398 /* Skip over this ssn and all below. */
399 #define sctp_ssn_skip(stream, type, sid, ssn) \
400 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
401
402 /* What is the current MID number for this stream? */
403 #define sctp_mid_peek(stream, type, sid) \
404 (sctp_stream_##type((stream), (sid))->mid)
405
406 /* Return the next MID number for this stream. */
407 #define sctp_mid_next(stream, type, sid) \
408 (sctp_stream_##type((stream), (sid))->mid++)
409
410 /* Skip over this mid and all below. */
411 #define sctp_mid_skip(stream, type, sid, mid) \
412 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
413
414 /* What is the current MID_uo number for this stream? */
415 #define sctp_mid_uo_peek(stream, type, sid) \
416 (sctp_stream_##type((stream), (sid))->mid_uo)
417
418 /* Return the next MID_uo number for this stream. */
419 #define sctp_mid_uo_next(stream, type, sid) \
420 (sctp_stream_##type((stream), (sid))->mid_uo++)
421
422 /*
423 * Pointers to address related SCTP functions.
424 * (i.e. things that depend on the address family.)
425 */
426 struct sctp_af {
427 int (*sctp_xmit) (struct sk_buff *skb,
428 struct sctp_transport *);
429 int (*setsockopt) (struct sock *sk,
430 int level,
431 int optname,
432 sockptr_t optval,
433 unsigned int optlen);
434 int (*getsockopt) (struct sock *sk,
435 int level,
436 int optname,
437 char __user *optval,
438 int __user *optlen);
439 void (*get_dst) (struct sctp_transport *t,
440 union sctp_addr *saddr,
441 struct flowi *fl,
442 struct sock *sk);
443 void (*get_saddr) (struct sctp_sock *sk,
444 struct sctp_transport *t,
445 struct flowi *fl);
446 void (*copy_addrlist) (struct list_head *,
447 struct net_device *);
448 int (*cmp_addr) (const union sctp_addr *addr1,
449 const union sctp_addr *addr2);
450 void (*addr_copy) (union sctp_addr *dst,
451 union sctp_addr *src);
452 void (*from_skb) (union sctp_addr *,
453 struct sk_buff *skb,
454 int saddr);
455 void (*from_sk) (union sctp_addr *,
456 struct sock *sk);
457 bool (*from_addr_param) (union sctp_addr *,
458 union sctp_addr_param *,
459 __be16 port, int iif);
460 int (*to_addr_param) (const union sctp_addr *,
461 union sctp_addr_param *);
462 int (*addr_valid) (union sctp_addr *,
463 struct sctp_sock *,
464 const struct sk_buff *);
465 enum sctp_scope (*scope)(union sctp_addr *);
466 void (*inaddr_any) (union sctp_addr *, __be16);
467 int (*is_any) (const union sctp_addr *);
468 int (*available) (union sctp_addr *,
469 struct sctp_sock *);
470 int (*skb_iif) (const struct sk_buff *sk);
471 int (*skb_sdif)(const struct sk_buff *sk);
472 int (*is_ce) (const struct sk_buff *sk);
473 void (*seq_dump_addr)(struct seq_file *seq,
474 union sctp_addr *addr);
475 void (*ecn_capable)(struct sock *sk);
476 __u16 net_header_len;
477 int sockaddr_len;
478 int (*ip_options_len)(struct sock *sk);
479 sa_family_t sa_family;
480 struct list_head list;
481 };
482
483 struct sctp_af *sctp_get_af_specific(sa_family_t);
484 int sctp_register_af(struct sctp_af *);
485
486 /* Protocol family functions. */
487 struct sctp_pf {
488 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
489 void (*skb_msgname) (struct sk_buff *, char *, int *);
490 int (*af_supported) (sa_family_t, struct sctp_sock *);
491 int (*cmp_addr) (const union sctp_addr *,
492 const union sctp_addr *,
493 struct sctp_sock *);
494 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
495 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
496 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
497 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
498 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
499 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
500 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
501 struct sctp_af *af;
502 };
503
504
505 /* Structure to track chunk fragments that have been acked, but peer
506 * fragments of the same message have not.
507 */
508 struct sctp_datamsg {
509 /* Chunks waiting to be submitted to lower layer. */
510 struct list_head chunks;
511 /* Reference counting. */
512 refcount_t refcnt;
513 /* When is this message no longer interesting to the peer? */
514 unsigned long expires_at;
515 /* Did the message fail to send? */
516 int send_error;
517 u8 send_failed:1,
518 can_delay:1, /* should this message be Nagle delayed */
519 abandoned:1; /* should this message be abandoned */
520 };
521
522 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
523 struct sctp_sndrcvinfo *,
524 struct iov_iter *);
525 void sctp_datamsg_free(struct sctp_datamsg *);
526 void sctp_datamsg_put(struct sctp_datamsg *);
527 void sctp_chunk_fail(struct sctp_chunk *, int error);
528 int sctp_chunk_abandoned(struct sctp_chunk *);
529
530 /* RFC2960 1.4 Key Terms
531 *
532 * o Chunk: A unit of information within an SCTP packet, consisting of
533 * a chunk header and chunk-specific content.
534 *
535 * As a matter of convenience, we remember the SCTP common header for
536 * each chunk as well as a few other header pointers...
537 */
538 struct sctp_chunk {
539 struct list_head list;
540
541 refcount_t refcnt;
542
543 /* How many times this chunk have been sent, for prsctp RTX policy */
544 int sent_count;
545
546 union {
547 /* This is our link to the per-transport transmitted list. */
548 struct list_head transmitted_list;
549 /* List in specific stream outq */
550 struct list_head stream_list;
551 };
552
553 /* This field is used by chunks that hold fragmented data.
554 * For the first fragment this is the list that holds the rest of
555 * fragments. For the remaining fragments, this is the link to the
556 * frag_list maintained in the first fragment.
557 */
558 struct list_head frag_list;
559
560 /* This points to the sk_buff containing the actual data. */
561 struct sk_buff *skb;
562
563 union {
564 /* In case of GSO packets, this will store the head one */
565 struct sk_buff *head_skb;
566 /* In case of auth enabled, this will point to the shkey */
567 struct sctp_shared_key *shkey;
568 };
569
570 /* These are the SCTP headers by reverse order in a packet.
571 * Note that some of these may happen more than once. In that
572 * case, we point at the "current" one, whatever that means
573 * for that level of header.
574 */
575
576 /* We point this at the FIRST TLV parameter to chunk_hdr. */
577 union sctp_params param_hdr;
578 union {
579 __u8 *v;
580 struct sctp_datahdr *data_hdr;
581 struct sctp_inithdr *init_hdr;
582 struct sctp_sackhdr *sack_hdr;
583 struct sctp_heartbeathdr *hb_hdr;
584 struct sctp_sender_hb_info *hbs_hdr;
585 struct sctp_shutdownhdr *shutdown_hdr;
586 struct sctp_signed_cookie *cookie_hdr;
587 struct sctp_ecnehdr *ecne_hdr;
588 struct sctp_cwrhdr *ecn_cwr_hdr;
589 struct sctp_errhdr *err_hdr;
590 struct sctp_addiphdr *addip_hdr;
591 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
592 struct sctp_authhdr *auth_hdr;
593 struct sctp_idatahdr *idata_hdr;
594 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
595 } subh;
596
597 __u8 *chunk_end;
598
599 struct sctp_chunkhdr *chunk_hdr;
600 struct sctphdr *sctp_hdr;
601
602 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
603 struct sctp_sndrcvinfo sinfo;
604
605 /* Which association does this belong to? */
606 struct sctp_association *asoc;
607
608 /* What endpoint received this chunk? */
609 struct sctp_ep_common *rcvr;
610
611 /* We fill this in if we are calculating RTT. */
612 unsigned long sent_at;
613
614 /* What is the origin IP address for this chunk? */
615 union sctp_addr source;
616 /* Destination address for this chunk. */
617 union sctp_addr dest;
618
619 /* For outbound message, track all fragments for SEND_FAILED. */
620 struct sctp_datamsg *msg;
621
622 /* For an inbound chunk, this tells us where it came from.
623 * For an outbound chunk, it tells us where we'd like it to
624 * go. It is NULL if we have no preference.
625 */
626 struct sctp_transport *transport;
627
628 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
629 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
630 * spec violates the principle premis that all chunks are processed
631 * in order.
632 */
633 struct sk_buff *auth_chunk;
634
635 #define SCTP_CAN_FRTX 0x0
636 #define SCTP_NEED_FRTX 0x1
637 #define SCTP_DONT_FRTX 0x2
638 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
639 has_tsn:1, /* Does this chunk have a TSN yet? */
640 has_ssn:1, /* Does this chunk have a SSN yet? */
641 #define has_mid has_ssn
642 singleton:1, /* Only chunk in the packet? */
643 end_of_packet:1, /* Last chunk in the packet? */
644 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
645 pdiscard:1, /* Discard the whole packet now? */
646 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
647 data_accepted:1, /* At least 1 chunk accepted */
648 auth:1, /* IN: was auth'ed | OUT: needs auth */
649 has_asconf:1, /* IN: have seen an asconf before */
650 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */
651 tsn_missing_report:2, /* Data chunk missing counter. */
652 fast_retransmit:2; /* Is this chunk fast retransmitted? */
653 };
654
655 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
656 void sctp_chunk_hold(struct sctp_chunk *);
657 void sctp_chunk_put(struct sctp_chunk *);
658 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
659 struct iov_iter *from);
660 void sctp_chunk_free(struct sctp_chunk *);
661 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
662 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
663 const struct sctp_association *,
664 struct sock *, gfp_t gfp);
665 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
666 union sctp_addr *);
667 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
668
sctp_chunk_stream_no(struct sctp_chunk * ch)669 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
670 {
671 return ntohs(ch->subh.data_hdr->stream);
672 }
673
674 enum {
675 SCTP_ADDR_NEW, /* new address added to assoc/ep */
676 SCTP_ADDR_SRC, /* address can be used as source */
677 SCTP_ADDR_DEL, /* address about to be deleted */
678 };
679
680 /* This is a structure for holding either an IPv6 or an IPv4 address. */
681 struct sctp_sockaddr_entry {
682 struct list_head list;
683 struct rcu_head rcu;
684 union sctp_addr a;
685 __u8 state;
686 __u8 valid;
687 };
688
689 #define SCTP_ADDRESS_TICK_DELAY 500
690
691 /* This structure holds lists of chunks as we are assembling for
692 * transmission.
693 */
694 struct sctp_packet {
695 /* These are the SCTP header values (host order) for the packet. */
696 __u16 source_port;
697 __u16 destination_port;
698 __u32 vtag;
699
700 /* This contains the payload chunks. */
701 struct list_head chunk_list;
702
703 /* This is the overhead of the sctp and ip headers. */
704 size_t overhead;
705 /* This is the total size of all chunks INCLUDING padding. */
706 size_t size;
707 /* This is the maximum size this packet may have */
708 size_t max_size;
709
710 /* The packet is destined for this transport address.
711 * The function we finally use to pass down to the next lower
712 * layer lives in the transport structure.
713 */
714 struct sctp_transport *transport;
715
716 /* pointer to the auth chunk for this packet */
717 struct sctp_chunk *auth;
718
719 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
720 has_sack:1, /* This packet contains a SACK chunk. */
721 has_auth:1, /* This packet contains an AUTH chunk */
722 has_data:1, /* This packet contains at least 1 DATA chunk */
723 ipfragok:1; /* So let ip fragment this packet */
724 };
725
726 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
727 __u16 sport, __u16 dport);
728 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
729 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
730 struct sctp_chunk *chunk,
731 int one_packet, gfp_t gfp);
732 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
733 struct sctp_chunk *chunk);
734 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
735 void sctp_packet_free(struct sctp_packet *);
736
sctp_packet_empty(struct sctp_packet * packet)737 static inline int sctp_packet_empty(struct sctp_packet *packet)
738 {
739 return packet->size == packet->overhead;
740 }
741
742 /* This represents a remote transport address.
743 * For local transport addresses, we just use union sctp_addr.
744 *
745 * RFC2960 Section 1.4 Key Terms
746 *
747 * o Transport address: A Transport Address is traditionally defined
748 * by Network Layer address, Transport Layer protocol and Transport
749 * Layer port number. In the case of SCTP running over IP, a
750 * transport address is defined by the combination of an IP address
751 * and an SCTP port number (where SCTP is the Transport protocol).
752 *
753 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
754 *
755 * o The sender keeps a separate congestion control parameter set for
756 * each of the destination addresses it can send to (not each
757 * source-destination pair but for each destination). The parameters
758 * should decay if the address is not used for a long enough time
759 * period.
760 *
761 */
762 struct sctp_transport {
763 /* A list of transports. */
764 struct list_head transports;
765 struct rhlist_head node;
766
767 /* Reference counting. */
768 refcount_t refcnt;
769 __u32 dead:1,
770 /* RTO-Pending : A flag used to track if one of the DATA
771 * chunks sent to this address is currently being
772 * used to compute a RTT. If this flag is 0,
773 * the next DATA chunk sent to this destination
774 * should be used to compute a RTT and this flag
775 * should be set. Every time the RTT
776 * calculation completes (i.e. the DATA chunk
777 * is SACK'd) clear this flag.
778 */
779 rto_pending:1,
780
781 /*
782 * hb_sent : a flag that signals that we have a pending
783 * heartbeat.
784 */
785 hb_sent:1,
786
787 /* Is the Path MTU update pending on this transport */
788 pmtu_pending:1,
789
790 dst_pending_confirm:1, /* need to confirm neighbour */
791
792 /* Has this transport moved the ctsn since we last sacked */
793 sack_generation:1;
794 u32 dst_cookie;
795
796 struct flowi fl;
797
798 /* This is the peer's IP address and port. */
799 union sctp_addr ipaddr;
800
801 /* These are the functions we call to handle LLP stuff. */
802 struct sctp_af *af_specific;
803
804 /* Which association do we belong to? */
805 struct sctp_association *asoc;
806
807 /* RFC2960
808 *
809 * 12.3 Per Transport Address Data
810 *
811 * For each destination transport address in the peer's
812 * address list derived from the INIT or INIT ACK chunk, a
813 * number of data elements needs to be maintained including:
814 */
815 /* RTO : The current retransmission timeout value. */
816 unsigned long rto;
817
818 __u32 rtt; /* This is the most recent RTT. */
819
820 /* RTTVAR : The current RTT variation. */
821 __u32 rttvar;
822
823 /* SRTT : The current smoothed round trip time. */
824 __u32 srtt;
825
826 /*
827 * These are the congestion stats.
828 */
829 /* cwnd : The current congestion window. */
830 __u32 cwnd; /* This is the actual cwnd. */
831
832 /* ssthresh : The current slow start threshold value. */
833 __u32 ssthresh;
834
835 /* partial : The tracking method for increase of cwnd when in
836 * bytes acked : congestion avoidance mode (see Section 6.2.2)
837 */
838 __u32 partial_bytes_acked;
839
840 /* Data that has been sent, but not acknowledged. */
841 __u32 flight_size;
842
843 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
844
845 /* Destination */
846 struct dst_entry *dst;
847 /* Source address. */
848 union sctp_addr saddr;
849
850 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
851 * the destination address every heartbeat interval.
852 */
853 unsigned long hbinterval;
854 unsigned long probe_interval;
855
856 /* SACK delay timeout */
857 unsigned long sackdelay;
858 __u32 sackfreq;
859
860 atomic_t mtu_info;
861
862 /* When was the last time that we heard from this transport? We use
863 * this to pick new active and retran paths.
864 */
865 ktime_t last_time_heard;
866
867 /* When was the last time that we sent a chunk using this
868 * transport? We use this to check for idle transports
869 */
870 unsigned long last_time_sent;
871
872 /* Last time(in jiffies) when cwnd is reduced due to the congestion
873 * indication based on ECNE chunk.
874 */
875 unsigned long last_time_ecne_reduced;
876
877 __be16 encap_port;
878
879 /* This is the max_retrans value for the transport and will
880 * be initialized from the assocs value. This can be changed
881 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
882 */
883 __u16 pathmaxrxt;
884
885 __u32 flowlabel;
886 __u8 dscp;
887
888 /* This is the partially failed retrans value for the transport
889 * and will be initialized from the assocs value. This can be changed
890 * using the SCTP_PEER_ADDR_THLDS socket option
891 */
892 __u16 pf_retrans;
893 /* Used for primary path switchover. */
894 __u16 ps_retrans;
895 /* PMTU : The current known path MTU. */
896 __u32 pathmtu;
897
898 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
899 __u32 param_flags;
900
901 /* The number of times INIT has been sent on this transport. */
902 int init_sent_count;
903
904 /* state : The current state of this destination,
905 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
906 */
907 int state;
908
909 /* These are the error stats for this destination. */
910
911 /* Error count : The current error count for this destination. */
912 unsigned short error_count;
913
914 /* Per : A timer used by each destination.
915 * Destination :
916 * Timer :
917 *
918 * [Everywhere else in the text this is called T3-rtx. -ed]
919 */
920 struct timer_list T3_rtx_timer;
921
922 /* Heartbeat timer is per destination. */
923 struct timer_list hb_timer;
924
925 /* Timer to handle ICMP proto unreachable envets */
926 struct timer_list proto_unreach_timer;
927
928 /* Timer to handler reconf chunk rtx */
929 struct timer_list reconf_timer;
930
931 /* Timer to send a probe HB packet for PLPMTUD */
932 struct timer_list probe_timer;
933
934 /* Since we're using per-destination retransmission timers
935 * (see above), we're also using per-destination "transmitted"
936 * queues. This probably ought to be a private struct
937 * accessible only within the outqueue, but it's not, yet.
938 */
939 struct list_head transmitted;
940
941 /* We build bundle-able packets for this transport here. */
942 struct sctp_packet packet;
943
944 /* This is the list of transports that have chunks to send. */
945 struct list_head send_ready;
946
947 /* State information saved for SFR_CACC algorithm. The key
948 * idea in SFR_CACC is to maintain state at the sender on a
949 * per-destination basis when a changeover happens.
950 * char changeover_active;
951 * char cycling_changeover;
952 * __u32 next_tsn_at_change;
953 * char cacc_saw_newack;
954 */
955 struct {
956 /* An unsigned integer, which stores the next TSN to be
957 * used by the sender, at the moment of changeover.
958 */
959 __u32 next_tsn_at_change;
960
961 /* A flag which indicates the occurrence of a changeover */
962 char changeover_active;
963
964 /* A flag which indicates whether the change of primary is
965 * the first switch to this destination address during an
966 * active switch.
967 */
968 char cycling_changeover;
969
970 /* A temporary flag, which is used during the processing of
971 * a SACK to estimate the causative TSN(s)'s group.
972 */
973 char cacc_saw_newack;
974 } cacc;
975
976 struct {
977 __u16 pmtu;
978 __u16 probe_size;
979 __u16 probe_high;
980 __u8 probe_count;
981 __u8 state;
982 } pl; /* plpmtud related */
983
984 /* 64-bit random number sent with heartbeat. */
985 __u64 hb_nonce;
986
987 struct rcu_head rcu;
988 };
989
990 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
991 gfp_t);
992 void sctp_transport_set_owner(struct sctp_transport *,
993 struct sctp_association *);
994 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
995 struct sctp_sock *);
996 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
997 void sctp_transport_free(struct sctp_transport *);
998 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
999 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1000 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1001 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1002 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1003 int sctp_transport_hold(struct sctp_transport *);
1004 void sctp_transport_put(struct sctp_transport *);
1005 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1006 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1007 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1008 enum sctp_lower_cwnd reason);
1009 void sctp_transport_burst_limited(struct sctp_transport *);
1010 void sctp_transport_burst_reset(struct sctp_transport *);
1011 unsigned long sctp_transport_timeout(struct sctp_transport *);
1012 void sctp_transport_reset(struct sctp_transport *t);
1013 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1014 void sctp_transport_immediate_rtx(struct sctp_transport *);
1015 void sctp_transport_dst_release(struct sctp_transport *t);
1016 void sctp_transport_dst_confirm(struct sctp_transport *t);
1017 void sctp_transport_pl_send(struct sctp_transport *t);
1018 bool sctp_transport_pl_recv(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 const 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_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1115 enum sctp_retransmit_reason reason);
1116 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1117 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1118 void sctp_prsctp_prune(struct sctp_association *asoc,
1119 struct sctp_sndrcvinfo *sinfo, int msg_len);
1120 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1121 /* Uncork and flush an outqueue. */
sctp_outq_cork(struct sctp_outq * q)1122 static inline void sctp_outq_cork(struct sctp_outq *q)
1123 {
1124 q->cork = 1;
1125 }
1126
1127 /* SCTP skb control block.
1128 * sctp_input_cb is currently used on rx and sock rx queue
1129 */
1130 struct sctp_input_cb {
1131 union {
1132 struct inet_skb_parm h4;
1133 #if IS_ENABLED(CONFIG_IPV6)
1134 struct inet6_skb_parm h6;
1135 #endif
1136 } header;
1137 struct sctp_chunk *chunk;
1138 struct sctp_af *af;
1139 __be16 encap_port;
1140 };
1141 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1142
1143 struct sctp_output_cb {
1144 struct sk_buff *last;
1145 };
1146 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1147
sctp_gso_headskb(const struct sk_buff * skb)1148 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1149 {
1150 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1151
1152 return chunk->head_skb ? : skb;
1153 }
1154
1155 /* These bind address data fields common between endpoints and associations */
1156 struct sctp_bind_addr {
1157
1158 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1159 *
1160 * SCTP Port: The local SCTP port number the endpoint is
1161 * bound to.
1162 */
1163 __u16 port;
1164
1165 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1166 *
1167 * Address List: The list of IP addresses that this instance
1168 * has bound. This information is passed to one's
1169 * peer(s) in INIT and INIT ACK chunks.
1170 */
1171 struct list_head address_list;
1172 };
1173
1174 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1175 void sctp_bind_addr_free(struct sctp_bind_addr *);
1176 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1177 const struct sctp_bind_addr *src,
1178 enum sctp_scope scope, gfp_t gfp,
1179 int flags);
1180 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1181 const struct sctp_bind_addr *src,
1182 gfp_t gfp);
1183 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1184 int new_size, __u8 addr_state, gfp_t gfp);
1185 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1186 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1187 struct sctp_sock *);
1188 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1189 struct sctp_sock *, struct sctp_sock *);
1190 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1191 const union sctp_addr *addr);
1192 int sctp_bind_addrs_check(struct sctp_sock *sp,
1193 struct sctp_sock *sp2, int cnt2);
1194 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1195 const union sctp_addr *addrs,
1196 int addrcnt,
1197 struct sctp_sock *opt);
1198 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1199 int *addrs_len,
1200 gfp_t gfp);
1201 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1202 __u16 port, gfp_t gfp);
1203
1204 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1205 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1206 const enum sctp_scope scope);
1207 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1208 int sctp_is_ep_boundall(struct sock *sk);
1209
1210
1211 /* What type of endpoint? */
1212 enum sctp_endpoint_type {
1213 SCTP_EP_TYPE_SOCKET,
1214 SCTP_EP_TYPE_ASSOCIATION,
1215 };
1216
1217 /*
1218 * A common base class to bridge the implementation view of a
1219 * socket (usually listening) endpoint versus an association's
1220 * local endpoint.
1221 * This common structure is useful for several purposes:
1222 * 1) Common interface for lookup routines.
1223 * a) Subfunctions work for either endpoint or association
1224 * b) Single interface to lookup allows hiding the lookup lock rather
1225 * than acquiring it externally.
1226 * 2) Common interface for the inbound chunk handling/state machine.
1227 * 3) Common object handling routines for reference counting, etc.
1228 * 4) Disentangle association lookup from endpoint lookup, where we
1229 * do not have to find our endpoint to find our association.
1230 *
1231 */
1232
1233 struct sctp_ep_common {
1234 /* Runtime type information. What kind of endpoint is this? */
1235 enum sctp_endpoint_type type;
1236
1237 /* Some fields to help us manage this object.
1238 * refcnt - Reference count access to this object.
1239 * dead - Do not attempt to use this object.
1240 */
1241 refcount_t refcnt;
1242 bool dead;
1243
1244 /* What socket does this endpoint belong to? */
1245 struct sock *sk;
1246
1247 /* Cache netns and it won't change once set */
1248 struct net *net;
1249
1250 /* This is where we receive inbound chunks. */
1251 struct sctp_inq inqueue;
1252
1253 /* This substructure includes the defining parameters of the
1254 * endpoint:
1255 * bind_addr.port is our shared port number.
1256 * bind_addr.address_list is our set of local IP addresses.
1257 */
1258 struct sctp_bind_addr bind_addr;
1259 };
1260
1261
1262 /* RFC Section 1.4 Key Terms
1263 *
1264 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1265 * multi-homed host, an SCTP endpoint is represented to its peers as a
1266 * combination of a set of eligible destination transport addresses to
1267 * which SCTP packets can be sent and a set of eligible source
1268 * transport addresses from which SCTP packets can be received.
1269 * All transport addresses used by an SCTP endpoint must use the
1270 * same port number, but can use multiple IP addresses. A transport
1271 * address used by an SCTP endpoint must not be used by another
1272 * SCTP endpoint. In other words, a transport address is unique
1273 * to an SCTP endpoint.
1274 *
1275 * From an implementation perspective, each socket has one of these.
1276 * A TCP-style socket will have exactly one association on one of
1277 * these. An UDP-style socket will have multiple associations hanging
1278 * off one of these.
1279 */
1280
1281 struct sctp_endpoint {
1282 /* Common substructure for endpoint and association. */
1283 struct sctp_ep_common base;
1284
1285 /* Fields to help us manage our entries in the hash tables. */
1286 struct hlist_node node;
1287 int hashent;
1288
1289 /* Associations: A list of current associations and mappings
1290 * to the data consumers for each association. This
1291 * may be in the form of a hash table or other
1292 * implementation dependent structure. The data
1293 * consumers may be process identification
1294 * information such as file descriptors, named pipe
1295 * pointer, or table pointers dependent on how SCTP
1296 * is implemented.
1297 */
1298 /* This is really a list of struct sctp_association entries. */
1299 struct list_head asocs;
1300
1301 /* Cookie authentication key used by this endpoint */
1302 struct hmac_sha256_key cookie_auth_key;
1303
1304 /* sendbuf acct. policy. */
1305 __u32 sndbuf_policy;
1306
1307 /* rcvbuf acct. policy. */
1308 __u32 rcvbuf_policy;
1309
1310 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1311 struct sctp_hmac_algo_param *auth_hmacs_list;
1312
1313 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1314 struct sctp_chunks_param *auth_chunk_list;
1315
1316 /* SCTP-AUTH: endpoint shared keys */
1317 struct list_head endpoint_shared_keys;
1318 __u16 active_key_id;
1319 __u8 ecn_enable:1,
1320 auth_enable:1,
1321 intl_enable:1,
1322 prsctp_enable:1,
1323 asconf_enable:1,
1324 reconf_enable:1;
1325
1326 __u8 strreset_enable;
1327 struct rcu_head rcu;
1328 };
1329
1330 /* Recover the outer endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1331 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1332 {
1333 struct sctp_endpoint *ep;
1334
1335 ep = container_of(base, struct sctp_endpoint, base);
1336 return ep;
1337 }
1338
1339 /* These are function signatures for manipulating endpoints. */
1340 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1341 void sctp_endpoint_free(struct sctp_endpoint *);
1342 void sctp_endpoint_put(struct sctp_endpoint *);
1343 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1344 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1345 struct sctp_association *sctp_endpoint_lookup_assoc(
1346 const struct sctp_endpoint *ep,
1347 const union sctp_addr *paddr,
1348 struct sctp_transport **);
1349 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1350 const union sctp_addr *paddr);
1351 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1352 struct net *net,
1353 const union sctp_addr *laddr,
1354 int dif, int sdif);
1355 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1356 const union sctp_addr *paddr, int dif, int sdif);
1357
1358 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1359 const struct sctp_association *asoc,
1360 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1361 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1362 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1363 const union sctp_addr *peer,
1364 struct sctp_init_chunk *init, gfp_t gfp);
1365 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1366 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1367
1368 struct sctp_inithdr_host {
1369 __u32 init_tag;
1370 __u32 a_rwnd;
1371 __u16 num_outbound_streams;
1372 __u16 num_inbound_streams;
1373 __u32 initial_tsn;
1374 };
1375
1376 struct sctp_stream_priorities {
1377 /* List of priorities scheduled */
1378 struct list_head prio_sched;
1379 /* List of streams scheduled */
1380 struct list_head active;
1381 /* The next stream in line */
1382 struct sctp_stream_out_ext *next;
1383 __u16 prio;
1384 __u16 users;
1385 };
1386
1387 struct sctp_stream_out_ext {
1388 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1389 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1390 struct list_head outq; /* chunks enqueued by this stream */
1391 union {
1392 struct {
1393 /* Scheduled streams list */
1394 struct list_head prio_list;
1395 struct sctp_stream_priorities *prio_head;
1396 };
1397 /* Fields used by RR scheduler */
1398 struct {
1399 struct list_head rr_list;
1400 };
1401 struct {
1402 struct list_head fc_list;
1403 __u32 fc_length;
1404 __u16 fc_weight;
1405 };
1406 };
1407 };
1408
1409 struct sctp_stream_out {
1410 union {
1411 __u32 mid;
1412 __u16 ssn;
1413 };
1414 __u32 mid_uo;
1415 struct sctp_stream_out_ext *ext;
1416 __u8 state;
1417 };
1418
1419 struct sctp_stream_in {
1420 union {
1421 __u32 mid;
1422 __u16 ssn;
1423 };
1424 __u32 mid_uo;
1425 __u32 fsn;
1426 __u32 fsn_uo;
1427 char pd_mode;
1428 char pd_mode_uo;
1429 };
1430
1431 struct sctp_stream {
1432 GENRADIX(struct sctp_stream_out) out;
1433 GENRADIX(struct sctp_stream_in) in;
1434
1435 __u16 outcnt;
1436 __u16 incnt;
1437 /* Current stream being sent, if any */
1438 struct sctp_stream_out *out_curr;
1439 union {
1440 /* Fields used by priority scheduler */
1441 struct {
1442 /* List of priorities scheduled */
1443 struct list_head prio_list;
1444 };
1445 /* Fields used by RR scheduler */
1446 struct {
1447 /* List of streams scheduled */
1448 struct list_head rr_list;
1449 /* The next stream in line */
1450 struct sctp_stream_out_ext *rr_next;
1451 };
1452 struct {
1453 struct list_head fc_list;
1454 };
1455 };
1456 struct sctp_stream_interleave *si;
1457 };
1458
sctp_stream_out(struct sctp_stream * stream,__u16 sid)1459 static inline struct sctp_stream_out *sctp_stream_out(
1460 struct sctp_stream *stream,
1461 __u16 sid)
1462 {
1463 return genradix_ptr(&stream->out, sid);
1464 }
1465
sctp_stream_in(struct sctp_stream * stream,__u16 sid)1466 static inline struct sctp_stream_in *sctp_stream_in(
1467 struct sctp_stream *stream,
1468 __u16 sid)
1469 {
1470 return genradix_ptr(&stream->in, sid);
1471 }
1472
1473 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1474 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1475
1476 #define SCTP_STREAM_CLOSED 0x00
1477 #define SCTP_STREAM_OPEN 0x01
1478
sctp_datachk_len(const struct sctp_stream * stream)1479 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1480 {
1481 return stream->si->data_chunk_len;
1482 }
1483
sctp_datahdr_len(const struct sctp_stream * stream)1484 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1485 {
1486 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1487 }
1488
sctp_ftsnchk_len(const struct sctp_stream * stream)1489 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1490 {
1491 return stream->si->ftsn_chunk_len;
1492 }
1493
sctp_ftsnhdr_len(const struct sctp_stream * stream)1494 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1495 {
1496 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1497 }
1498
1499 /* SCTP_GET_ASSOC_STATS counters */
1500 struct sctp_priv_assoc_stats {
1501 /* Maximum observed rto in the association during subsequent
1502 * observations. Value is set to 0 if no RTO measurement took place
1503 * The transport where the max_rto was observed is returned in
1504 * obs_rto_ipaddr
1505 */
1506 struct sockaddr_storage obs_rto_ipaddr;
1507 __u64 max_obs_rto;
1508 /* Total In and Out SACKs received and sent */
1509 __u64 isacks;
1510 __u64 osacks;
1511 /* Total In and Out packets received and sent */
1512 __u64 opackets;
1513 __u64 ipackets;
1514 /* Total retransmitted chunks */
1515 __u64 rtxchunks;
1516 /* TSN received > next expected */
1517 __u64 outofseqtsns;
1518 /* Duplicate Chunks received */
1519 __u64 idupchunks;
1520 /* Gap Ack Blocks received */
1521 __u64 gapcnt;
1522 /* Unordered data chunks sent and received */
1523 __u64 ouodchunks;
1524 __u64 iuodchunks;
1525 /* Ordered data chunks sent and received */
1526 __u64 oodchunks;
1527 __u64 iodchunks;
1528 /* Control chunks sent and received */
1529 __u64 octrlchunks;
1530 __u64 ictrlchunks;
1531 };
1532
1533 /* RFC2960
1534 *
1535 * 12. Recommended Transmission Control Block (TCB) Parameters
1536 *
1537 * This section details a recommended set of parameters that should
1538 * be contained within the TCB for an implementation. This section is
1539 * for illustrative purposes and should not be deemed as requirements
1540 * on an implementation or as an exhaustive list of all parameters
1541 * inside an SCTP TCB. Each implementation may need its own additional
1542 * parameters for optimization.
1543 */
1544
1545
1546 /* Here we have information about each individual association. */
1547 struct sctp_association {
1548
1549 /* A base structure common to endpoint and association.
1550 * In this context, it represents the associations's view
1551 * of the local endpoint of the association.
1552 */
1553 struct sctp_ep_common base;
1554
1555 /* Associations on the same socket. */
1556 struct list_head asocs;
1557
1558 /* association id. */
1559 sctp_assoc_t assoc_id;
1560
1561 /* This is our parent endpoint. */
1562 struct sctp_endpoint *ep;
1563
1564 /* These are those association elements needed in the cookie. */
1565 struct sctp_cookie c;
1566
1567 /* This is all information about our peer. */
1568 struct {
1569 /* transport_addr_list
1570 *
1571 * Peer : A list of SCTP transport addresses that the
1572 * Transport : peer is bound to. This information is derived
1573 * Address : from the INIT or INIT ACK and is used to
1574 * List : associate an inbound packet with a given
1575 * : association. Normally this information is
1576 * : hashed or keyed for quick lookup and access
1577 * : of the TCB.
1578 * : The list is also initialized with the list
1579 * : of addresses passed with the sctp_connectx()
1580 * : call.
1581 *
1582 * It is a list of SCTP_transport's.
1583 */
1584 struct list_head transport_addr_list;
1585
1586 /* rwnd
1587 *
1588 * Peer Rwnd : Current calculated value of the peer's rwnd.
1589 */
1590 __u32 rwnd;
1591
1592 /* transport_count
1593 *
1594 * Peer : A count of the number of peer addresses
1595 * Transport : in the Peer Transport Address List.
1596 * Address :
1597 * Count :
1598 */
1599 __u16 transport_count;
1600
1601 /* port
1602 * The transport layer port number.
1603 */
1604 __u16 port;
1605
1606 /* primary_path
1607 *
1608 * Primary : This is the current primary destination
1609 * Path : transport address of the peer endpoint. It
1610 * : may also specify a source transport address
1611 * : on this endpoint.
1612 *
1613 * All of these paths live on transport_addr_list.
1614 *
1615 * At the bakeoffs, we discovered that the intent of
1616 * primaryPath is that it only changes when the ULP
1617 * asks to have it changed. We add the activePath to
1618 * designate the connection we are currently using to
1619 * transmit new data and most control chunks.
1620 */
1621 struct sctp_transport *primary_path;
1622
1623 /* Cache the primary path address here, when we
1624 * need a an address for msg_name.
1625 */
1626 union sctp_addr primary_addr;
1627
1628 /* active_path
1629 * The path that we are currently using to
1630 * transmit new data and most control chunks.
1631 */
1632 struct sctp_transport *active_path;
1633
1634 /* retran_path
1635 *
1636 * RFC2960 6.4 Multi-homed SCTP Endpoints
1637 * ...
1638 * Furthermore, when its peer is multi-homed, an
1639 * endpoint SHOULD try to retransmit a chunk to an
1640 * active destination transport address that is
1641 * different from the last destination address to
1642 * which the DATA chunk was sent.
1643 */
1644 struct sctp_transport *retran_path;
1645
1646 /* Pointer to last transport I have sent on. */
1647 struct sctp_transport *last_sent_to;
1648
1649 /* This is the last transport I have received DATA on. */
1650 struct sctp_transport *last_data_from;
1651
1652 /*
1653 * Mapping An array of bits or bytes indicating which out of
1654 * Array order TSN's have been received (relative to the
1655 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1656 * order packets have been received, this array
1657 * will be set to all zero. This structure may be
1658 * in the form of a circular buffer or bit array.
1659 *
1660 * Last Rcvd : This is the last TSN received in
1661 * TSN : sequence. This value is set initially by
1662 * : taking the peer's Initial TSN, received in
1663 * : the INIT or INIT ACK chunk, and subtracting
1664 * : one from it.
1665 *
1666 * Throughout most of the specification this is called the
1667 * "Cumulative TSN ACK Point". In this case, we
1668 * ignore the advice in 12.2 in favour of the term
1669 * used in the bulk of the text. This value is hidden
1670 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1671 */
1672 struct sctp_tsnmap tsn_map;
1673
1674 /* This mask is used to disable sending the ASCONF chunk
1675 * with specified parameter to peer.
1676 */
1677 __be16 addip_disabled_mask;
1678
1679 /* These are capabilities which our peer advertised. */
1680 __u16 ecn_capable:1, /* Can peer do ECN? */
1681 ipv4_address:1, /* Peer understands IPv4 addresses? */
1682 ipv6_address:1, /* Peer understands IPv6 addresses? */
1683 asconf_capable:1, /* Does peer support ADDIP? */
1684 prsctp_capable:1, /* Can peer do PR-SCTP? */
1685 reconf_capable:1, /* Can peer do RE-CONFIG? */
1686 intl_capable:1, /* Can peer do INTERLEAVE */
1687 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1688 /* sack_needed:
1689 * This flag indicates if the next received
1690 * packet is to be responded to with a
1691 * SACK. This is initialized to 0. When a packet
1692 * is received sack_cnt is incremented. If this value
1693 * reaches 2 or more, a SACK is sent and the
1694 * value is reset to 0. Note: This is used only
1695 * when no DATA chunks are received out of
1696 * order. When DATA chunks are out of order,
1697 * SACK's are not delayed (see Section 6).
1698 */
1699 sack_needed:1, /* Do we need to sack the peer? */
1700 sack_generation:1,
1701 zero_window_announced:1;
1702
1703 __u32 sack_cnt;
1704
1705 __u32 adaptation_ind; /* Adaptation Code point. */
1706
1707 struct sctp_inithdr_host i;
1708 void *cookie;
1709 int cookie_len;
1710
1711 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1712 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1713 * Initial TSN Value minus 1
1714 */
1715 __u32 addip_serial;
1716
1717 /* SCTP-AUTH: We need to know pears random number, hmac list
1718 * and authenticated chunk list. All that is part of the
1719 * cookie and these are just pointers to those locations
1720 */
1721 struct sctp_random_param *peer_random;
1722 struct sctp_chunks_param *peer_chunks;
1723 struct sctp_hmac_algo_param *peer_hmacs;
1724 } peer;
1725
1726 /* State : A state variable indicating what state the
1727 * : association is in, i.e. COOKIE-WAIT,
1728 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1729 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1730 *
1731 * Note: No "CLOSED" state is illustrated since if a
1732 * association is "CLOSED" its TCB SHOULD be removed.
1733 *
1734 * In this implementation we DO have a CLOSED
1735 * state which is used during initiation and shutdown.
1736 *
1737 * State takes values from SCTP_STATE_*.
1738 */
1739 enum sctp_state state;
1740
1741 /* Overall : The overall association error count.
1742 * Error Count : [Clear this any time I get something.]
1743 */
1744 int overall_error_count;
1745
1746 /* The cookie life I award for any cookie. */
1747 ktime_t cookie_life;
1748
1749 /* These are the association's initial, max, and min RTO values.
1750 * These values will be initialized by system defaults, but can
1751 * be modified via the SCTP_RTOINFO socket option.
1752 */
1753 unsigned long rto_initial;
1754 unsigned long rto_max;
1755 unsigned long rto_min;
1756
1757 /* Maximum number of new data packets that can be sent in a burst. */
1758 int max_burst;
1759
1760 /* This is the max_retrans value for the association. This value will
1761 * be initialized from system defaults, but can be
1762 * modified by the SCTP_ASSOCINFO socket option.
1763 */
1764 int max_retrans;
1765
1766 /* This is the partially failed retrans value for the transport
1767 * and will be initialized from the assocs value. This can be
1768 * changed using the SCTP_PEER_ADDR_THLDS socket option
1769 */
1770 __u16 pf_retrans;
1771 /* Used for primary path switchover. */
1772 __u16 ps_retrans;
1773
1774 /* Maximum number of times the endpoint will retransmit INIT */
1775 __u16 max_init_attempts;
1776
1777 /* How many times have we resent an INIT? */
1778 __u16 init_retries;
1779
1780 /* The largest timeout or RTO value to use in attempting an INIT */
1781 unsigned long max_init_timeo;
1782
1783 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1784 * the destination address every heartbeat interval. This value
1785 * will be inherited by all new transports.
1786 */
1787 unsigned long hbinterval;
1788 unsigned long probe_interval;
1789
1790 __be16 encap_port;
1791
1792 /* This is the max_retrans value for new transports in the
1793 * association.
1794 */
1795 __u16 pathmaxrxt;
1796
1797 __u32 flowlabel;
1798 __u8 dscp;
1799
1800 /* Flag that path mtu update is pending */
1801 __u8 pmtu_pending;
1802
1803 /* Association : The smallest PMTU discovered for all of the
1804 * PMTU : peer's transport addresses.
1805 */
1806 __u32 pathmtu;
1807
1808 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1809 __u32 param_flags;
1810
1811 __u32 sackfreq;
1812 /* SACK delay timeout */
1813 unsigned long sackdelay;
1814
1815 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1816 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1817
1818 /* Transport to which SHUTDOWN chunk was last sent. */
1819 struct sctp_transport *shutdown_last_sent_to;
1820
1821 /* Transport to which INIT chunk was last sent. */
1822 struct sctp_transport *init_last_sent_to;
1823
1824 /* How many times have we resent a SHUTDOWN */
1825 int shutdown_retries;
1826
1827 /* Next TSN : The next TSN number to be assigned to a new
1828 * : DATA chunk. This is sent in the INIT or INIT
1829 * : ACK chunk to the peer and incremented each
1830 * : time a DATA chunk is assigned a TSN
1831 * : (normally just prior to transmit or during
1832 * : fragmentation).
1833 */
1834 __u32 next_tsn;
1835
1836 /*
1837 * Last Rcvd : This is the last TSN received in sequence. This value
1838 * TSN : is set initially by taking the peer's Initial TSN,
1839 * : received in the INIT or INIT ACK chunk, and
1840 * : subtracting one from it.
1841 *
1842 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1843 */
1844
1845 __u32 ctsn_ack_point;
1846
1847 /* PR-SCTP Advanced.Peer.Ack.Point */
1848 __u32 adv_peer_ack_point;
1849
1850 /* Highest TSN that is acknowledged by incoming SACKs. */
1851 __u32 highest_sacked;
1852
1853 /* TSN marking the fast recovery exit point */
1854 __u32 fast_recovery_exit;
1855
1856 /* Flag to track the current fast recovery state */
1857 __u8 fast_recovery;
1858
1859 /* The number of unacknowledged data chunks. Reported through
1860 * the SCTP_STATUS sockopt.
1861 */
1862 __u16 unack_data;
1863
1864 /* The total number of data chunks that we've had to retransmit
1865 * as the result of a T3 timer expiration
1866 */
1867 __u32 rtx_data_chunks;
1868
1869 /* This is the association's receive buffer space. This value is used
1870 * to set a_rwnd field in an INIT or a SACK chunk.
1871 */
1872 __u32 rwnd;
1873
1874 /* This is the last advertised value of rwnd over a SACK chunk. */
1875 __u32 a_rwnd;
1876
1877 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1878 * to slop over a maximum of the association's frag_point.
1879 */
1880 __u32 rwnd_over;
1881
1882 /* Keeps treack of rwnd pressure. This happens when we have
1883 * a window, but not receive buffer (i.e small packets). This one
1884 * is releases slowly (1 PMTU at a time ).
1885 */
1886 __u32 rwnd_press;
1887
1888 /* This is the sndbuf size in use for the association.
1889 * This corresponds to the sndbuf size for the association,
1890 * as specified in the sk->sndbuf.
1891 */
1892 int sndbuf_used;
1893
1894 /* This is the amount of memory that this association has allocated
1895 * in the receive path at any given time.
1896 */
1897 atomic_t rmem_alloc;
1898
1899 /* This is the wait queue head for send requests waiting on
1900 * the association sndbuf space.
1901 */
1902 wait_queue_head_t wait;
1903
1904 /* The message size at which SCTP fragmentation will occur. */
1905 __u32 frag_point;
1906 __u32 user_frag;
1907
1908 /* Counter used to count INIT errors. */
1909 int init_err_counter;
1910
1911 /* Count the number of INIT cycles (for doubling timeout). */
1912 int init_cycle;
1913
1914 /* Default send parameters. */
1915 __u16 default_stream;
1916 __u16 default_flags;
1917 __u32 default_ppid;
1918 __u32 default_context;
1919 __u32 default_timetolive;
1920
1921 /* Default receive parameters */
1922 __u32 default_rcv_context;
1923
1924 /* Stream arrays */
1925 struct sctp_stream stream;
1926
1927 /* All outbound chunks go through this structure. */
1928 struct sctp_outq outqueue;
1929
1930 /* A smart pipe that will handle reordering and fragmentation,
1931 * as well as handle passing events up to the ULP.
1932 */
1933 struct sctp_ulpq ulpq;
1934
1935 /* Last TSN that caused an ECNE Chunk to be sent. */
1936 __u32 last_ecne_tsn;
1937
1938 /* Last TSN that caused a CWR Chunk to be sent. */
1939 __u32 last_cwr_tsn;
1940
1941 /* How many duplicated TSNs have we seen? */
1942 int numduptsns;
1943
1944 /* These are to support
1945 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1946 * and Enforcement of Flow and Message Limits"
1947 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1948 * or "ADDIP" for short.
1949 */
1950
1951
1952
1953 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1954 *
1955 * R1) One and only one ASCONF Chunk MAY be in transit and
1956 * unacknowledged at any one time. If a sender, after sending
1957 * an ASCONF chunk, decides it needs to transfer another
1958 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1959 * returns from the previous ASCONF Chunk before sending a
1960 * subsequent ASCONF. Note this restriction binds each side,
1961 * so at any time two ASCONF may be in-transit on any given
1962 * association (one sent from each endpoint).
1963 *
1964 * [This is our one-and-only-one ASCONF in flight. If we do
1965 * not have an ASCONF in flight, this is NULL.]
1966 */
1967 struct sctp_chunk *addip_last_asconf;
1968
1969 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1970 *
1971 * This is needed to implement items E1 - E4 of the updated
1972 * spec. Here is the justification:
1973 *
1974 * Since the peer may bundle multiple ASCONF chunks toward us,
1975 * we now need the ability to cache multiple ACKs. The section
1976 * describes in detail how they are cached and cleaned up.
1977 */
1978 struct list_head asconf_ack_list;
1979
1980 /* These ASCONF chunks are waiting to be sent.
1981 *
1982 * These chunks can't be pushed to outqueue until receiving
1983 * ASCONF_ACK for the previous ASCONF indicated by
1984 * addip_last_asconf, so as to guarantee that only one ASCONF
1985 * is in flight at any time.
1986 *
1987 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1988 *
1989 * In defining the ASCONF Chunk transfer procedures, it is
1990 * essential that these transfers MUST NOT cause congestion
1991 * within the network. To achieve this, we place these
1992 * restrictions on the transfer of ASCONF Chunks:
1993 *
1994 * R1) One and only one ASCONF Chunk MAY be in transit and
1995 * unacknowledged at any one time. If a sender, after sending
1996 * an ASCONF chunk, decides it needs to transfer another
1997 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1998 * returns from the previous ASCONF Chunk before sending a
1999 * subsequent ASCONF. Note this restriction binds each side,
2000 * so at any time two ASCONF may be in-transit on any given
2001 * association (one sent from each endpoint).
2002 *
2003 *
2004 * [I really think this is EXACTLY the sort of intelligence
2005 * which already resides in sctp_outq. Please move this
2006 * queue and its supporting logic down there. --piggy]
2007 */
2008 struct list_head addip_chunk_list;
2009
2010 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2011 *
2012 * A2) A serial number should be assigned to the Chunk. The
2013 * serial number SHOULD be a monotonically increasing
2014 * number. The serial number SHOULD be initialized at
2015 * the start of the association to the same value as the
2016 * Initial TSN and every time a new ASCONF chunk is created
2017 * it is incremented by one after assigning the serial number
2018 * to the newly created chunk.
2019 *
2020 * ADDIP
2021 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2022 *
2023 * Serial Number : 32 bits (unsigned integer)
2024 *
2025 * This value represents a Serial Number for the ASCONF
2026 * Chunk. The valid range of Serial Number is from 0 to
2027 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2028 * after reaching 4294967295.
2029 */
2030 __u32 addip_serial;
2031 int src_out_of_asoc_ok;
2032 union sctp_addr *asconf_addr_del_pending;
2033 struct sctp_transport *new_transport;
2034
2035 /* SCTP AUTH: list of the endpoint shared keys. These
2036 * keys are provided out of band by the user application
2037 * and can't change during the lifetime of the association
2038 */
2039 struct list_head endpoint_shared_keys;
2040
2041 /* SCTP AUTH:
2042 * The current generated association shared key (secret)
2043 */
2044 struct sctp_auth_bytes *asoc_shared_key;
2045 struct sctp_shared_key *shkey;
2046
2047 /* SCTP AUTH: hmac id of the first peer requested algorithm
2048 * that we support.
2049 */
2050 __u16 default_hmac_id;
2051
2052 __u16 active_key_id;
2053
2054 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2055 temp:1, /* Is it a temporary association? */
2056 pf_expose:2, /* Expose pf state? */
2057 force_delay:1;
2058
2059 __u8 strreset_enable;
2060 __u8 strreset_outstanding; /* request param count on the fly */
2061
2062 __u32 strreset_outseq; /* Update after receiving response */
2063 __u32 strreset_inseq; /* Update after receiving request */
2064 __u32 strreset_result[2]; /* save the results of last 2 responses */
2065
2066 struct sctp_chunk *strreset_chunk; /* save request chunk */
2067
2068 struct sctp_priv_assoc_stats stats;
2069
2070 int sent_cnt_removable;
2071
2072 __u16 subscribe;
2073
2074 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2075 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2076
2077 /* Security identifiers from incoming (INIT). These are set by
2078 * security_sctp_assoc_request(). These will only be used by
2079 * SCTP TCP type sockets and peeled off connections as they
2080 * cause a new socket to be generated. security_sctp_sk_clone()
2081 * will then plug these into the new socket.
2082 */
2083
2084 u32 secid;
2085 u32 peer_secid;
2086
2087 struct rcu_head rcu;
2088 };
2089
2090
2091 /* An eyecatcher for determining if we are really looking at an
2092 * association data structure.
2093 */
2094 enum {
2095 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2096 };
2097
2098 /* Recover the outer association structure. */
sctp_assoc(struct sctp_ep_common * base)2099 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2100 {
2101 struct sctp_association *asoc;
2102
2103 asoc = container_of(base, struct sctp_association, base);
2104 return asoc;
2105 }
2106
2107 /* These are function signatures for manipulating associations. */
2108
2109
2110 struct sctp_association *
2111 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2112 enum sctp_scope scope, gfp_t gfp);
2113 void sctp_association_free(struct sctp_association *);
2114 void sctp_association_put(struct sctp_association *);
2115 void sctp_association_hold(struct sctp_association *);
2116
2117 struct sctp_transport *sctp_assoc_choose_alter_transport(
2118 struct sctp_association *, struct sctp_transport *);
2119 void sctp_assoc_update_retran_path(struct sctp_association *);
2120 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2121 const union sctp_addr *);
2122 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2123 const union sctp_addr *laddr);
2124 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2125 const union sctp_addr *address,
2126 const gfp_t gfp,
2127 const int peer_state);
2128 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2129 struct sctp_transport *peer);
2130 void sctp_assoc_control_transport(struct sctp_association *asoc,
2131 struct sctp_transport *transport,
2132 enum sctp_transport_cmd command,
2133 sctp_sn_error_t error);
2134 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2135 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2136 int sctp_assoc_update(struct sctp_association *old,
2137 struct sctp_association *new);
2138
2139 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2140
2141 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2142 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2143 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2144 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2145 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2146 void sctp_assoc_set_primary(struct sctp_association *,
2147 struct sctp_transport *);
2148 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2149 struct sctp_transport *);
2150 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2151 enum sctp_scope scope, gfp_t gfp);
2152 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2153 struct sctp_cookie*,
2154 gfp_t gfp);
2155 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2156 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2157 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2158 const struct sctp_association *asoc,
2159 __be32 serial);
2160 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2161
2162 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2163 const union sctp_addr *ss2);
2164 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2165
2166 /* A convenience structure to parse out SCTP specific CMSGs. */
2167 struct sctp_cmsgs {
2168 struct sctp_initmsg *init;
2169 struct sctp_sndrcvinfo *srinfo;
2170 struct sctp_sndinfo *sinfo;
2171 struct sctp_prinfo *prinfo;
2172 struct sctp_authinfo *authinfo;
2173 struct msghdr *addrs_msg;
2174 };
2175
2176 /* Structure for tracking memory objects */
2177 struct sctp_dbg_objcnt_entry {
2178 char *label;
2179 atomic_t *counter;
2180 };
2181
2182 #endif /* __sctp_structs_h__ */
2183