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 <[email protected]>
13 *
14 * Written or modified by:
15 * Randall Stewart <[email protected]>
16 * Ken Morneau <[email protected]>
17 * Qiaobing Xie <[email protected]>
18 * La Monte H.P. Yarroll <[email protected]>
19 * Karl Knutson <[email protected]>
20 * Jon Grimm <[email protected]>
21 * Xingang Guo <[email protected]>
22 * Hui Huang <[email protected]>
23 * Sridhar Samudrala <[email protected]>
24 * Daisy Chang <[email protected]>
25 * Dajiang Zhang <[email protected]>
26 * Ardelle Fan <[email protected]>
27 * Ryan Layer <[email protected]>
28 * Anup Pemmaiah <[email protected]>
29 * Kevin Gao <[email protected]>
30 */
31
32 #ifndef __sctp_structs_h__
33 #define __sctp_structs_h__
34
35 #include <linux/ktime.h>
36 #include <linux/generic-radix-tree.h>
37 #include <linux/rhashtable-types.h>
38 #include <linux/socket.h> /* linux/in.h needs this!! */
39 #include <linux/in.h> /* We get struct sockaddr_in. */
40 #include <linux/in6.h> /* We get struct in6_addr */
41 #include <linux/ipv6.h>
42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
43 #include <linux/atomic.h> /* This gets us atomic counters. */
44 #include <linux/skbuff.h> /* We need sk_buff_head. */
45 #include <linux/workqueue.h> /* We need tq_struct. */
46 #include <linux/sctp.h> /* We need sctp* header structs. */
47 #include <net/sctp/auth.h> /* We need auth specific structs */
48 #include <net/ip.h> /* For inet_skb_parm */
49
50 /* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
52 */
53 union sctp_addr {
54 struct sockaddr_in v4;
55 struct sockaddr_in6 v6;
56 struct sockaddr sa;
57 };
58
59 /* Forward declarations for data structures. */
60 struct sctp_globals;
61 struct sctp_endpoint;
62 struct sctp_association;
63 struct sctp_transport;
64 struct sctp_packet;
65 struct sctp_chunk;
66 struct sctp_inq;
67 struct sctp_outq;
68 struct sctp_bind_addr;
69 struct sctp_ulpq;
70 struct sctp_ep_common;
71 struct crypto_shash;
72 struct sctp_stream;
73
74
75 #include <net/sctp/tsnmap.h>
76 #include <net/sctp/ulpevent.h>
77 #include <net/sctp/ulpqueue.h>
78 #include <net/sctp/stream_interleave.h>
79
80 /* Structures useful for managing bind/connect. */
81
82 struct sctp_bind_bucket {
83 unsigned short port;
84 signed char fastreuse;
85 signed char fastreuseport;
86 kuid_t fastuid;
87 struct hlist_node node;
88 struct hlist_head owner;
89 struct net *net;
90 };
91
92 struct sctp_bind_hashbucket {
93 spinlock_t lock;
94 struct hlist_head chain;
95 };
96
97 /* Used for hashing all associations. */
98 struct sctp_hashbucket {
99 rwlock_t lock;
100 struct hlist_head chain;
101 } __attribute__((__aligned__(8)));
102
103
104 /* The SCTP globals structure. */
105 extern struct sctp_globals {
106 /* This is a list of groups of functions for each address
107 * family that we support.
108 */
109 struct list_head address_families;
110
111 /* This is the hash of all endpoints. */
112 struct sctp_hashbucket *ep_hashtable;
113 /* This is the sctp port control hash. */
114 struct sctp_bind_hashbucket *port_hashtable;
115 /* This is the hash of all transports. */
116 struct rhltable transport_hashtable;
117
118 /* Sizes of above hashtables. */
119 int ep_hashsize;
120 int port_hashsize;
121
122 /* Default initialization values to be applied to new associations. */
123 __u16 max_instreams;
124 __u16 max_outstreams;
125
126 /* Flag to indicate whether computing and verifying checksum
127 * is disabled. */
128 bool checksum_disable;
129 } sctp_globals;
130
131 #define sctp_max_instreams (sctp_globals.max_instreams)
132 #define sctp_max_outstreams (sctp_globals.max_outstreams)
133 #define sctp_address_families (sctp_globals.address_families)
134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
136 #define sctp_port_hashsize (sctp_globals.port_hashsize)
137 #define sctp_port_hashtable (sctp_globals.port_hashtable)
138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
139 #define sctp_checksum_disable (sctp_globals.checksum_disable)
140
141 /* SCTP Socket type: UDP or TCP style. */
142 enum sctp_socket_type {
143 SCTP_SOCKET_UDP = 0,
144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
145 SCTP_SOCKET_TCP
146 };
147
148 /* Per socket SCTP information. */
149 struct sctp_sock {
150 /* inet_sock has to be the first member of sctp_sock */
151 struct inet_sock inet;
152 /* What kind of a socket is this? */
153 enum sctp_socket_type type;
154
155 /* PF_ family specific functions. */
156 struct sctp_pf *pf;
157
158 /* Access to HMAC transform. */
159 struct crypto_shash *hmac;
160 char *sctp_hmac_alg;
161
162 /* What is our base endpointer? */
163 struct sctp_endpoint *ep;
164
165 struct sctp_bind_bucket *bind_hash;
166 /* Various Socket Options. */
167 __u16 default_stream;
168 __u32 default_ppid;
169 __u16 default_flags;
170 __u32 default_context;
171 __u32 default_timetolive;
172 __u32 default_rcv_context;
173 int max_burst;
174
175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176 * the destination address every heartbeat interval. This value
177 * will be inherited by all new associations.
178 */
179 __u32 hbinterval;
180 __u32 probe_interval;
181
182 __be16 udp_port;
183 __be16 encap_port;
184
185 /* This is the max_retrans value for new associations. */
186 __u16 pathmaxrxt;
187
188 __u32 flowlabel;
189 __u8 dscp;
190
191 __u16 pf_retrans;
192 __u16 ps_retrans;
193
194 /* The initial Path MTU to use for new associations. */
195 __u32 pathmtu;
196
197 /* The default SACK delay timeout for new associations. */
198 __u32 sackdelay;
199 __u32 sackfreq;
200
201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
202 __u32 param_flags;
203
204 __u32 default_ss;
205
206 struct sctp_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_assocparams assocparams;
209
210 /*
211 * These two structures must be grouped together for the usercopy
212 * whitelist region.
213 */
214 __u16 subscribe;
215 struct sctp_initmsg initmsg;
216
217 int user_frag;
218
219 __u32 autoclose;
220 __u32 adaptation_ind;
221 __u32 pd_point;
222 __u16 nodelay:1,
223 pf_expose:2,
224 reuse:1,
225 disable_fragments:1,
226 v4mapped:1,
227 frag_interleave:1,
228 recvrcvinfo:1,
229 recvnxtinfo:1,
230 data_ready_signalled:1;
231
232 atomic_t pd_mode;
233
234 /* Fields after this point will be skipped on copies, like on accept
235 * and peeloff operations
236 */
237
238 /* Receive to here while partial delivery is in effect. */
239 struct sk_buff_head pd_lobby;
240
241 struct list_head auto_asconf_list;
242 int do_auto_asconf;
243 };
244
245 #define sctp_sk(ptr) container_of_const(ptr, struct sctp_sock, inet.sk)
246
sctp_opt2sk(const struct sctp_sock * sp)247 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
248 {
249 return (struct sock *)sp;
250 }
251
252 #if IS_ENABLED(CONFIG_IPV6)
253 struct sctp6_sock {
254 struct sctp_sock sctp;
255 struct ipv6_pinfo inet6;
256 };
257 #endif /* CONFIG_IPV6 */
258
259
260 /* This is our APPLICATION-SPECIFIC state cookie.
261 * THIS IS NOT DICTATED BY THE SPECIFICATION.
262 */
263 /* These are the parts of an association which we send in the cookie.
264 * Most of these are straight out of:
265 * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
266 *
267 */
268
269 struct sctp_cookie {
270
271 /* My : Tag expected in every inbound packet and sent
272 * Verification: in the INIT or INIT ACK chunk.
273 * Tag :
274 */
275 __u32 my_vtag;
276
277 /* Peer's : Tag expected in every outbound packet except
278 * Verification: in the INIT chunk.
279 * Tag :
280 */
281 __u32 peer_vtag;
282
283 /* The rest of these are not from the spec, but really need to
284 * be in the cookie.
285 */
286
287 /* My Tie Tag : Assist in discovering a restarting association. */
288 __u32 my_ttag;
289
290 /* Peer's Tie Tag: Assist in discovering a restarting association. */
291 __u32 peer_ttag;
292
293 /* When does this cookie expire? */
294 ktime_t expiration;
295
296 /* Number of inbound/outbound streams which are set
297 * and negotiated during the INIT process.
298 */
299 __u16 sinit_num_ostreams;
300 __u16 sinit_max_instreams;
301
302 /* This is the first sequence number I used. */
303 __u32 initial_tsn;
304
305 /* This holds the originating address of the INIT packet. */
306 union sctp_addr peer_addr;
307
308 /* IG Section 2.35.3
309 * Include the source port of the INIT-ACK
310 */
311 __u16 my_port;
312
313 __u8 prsctp_capable;
314
315 /* Padding for future use */
316 __u8 padding;
317
318 __u32 adaptation_ind;
319
320 __u8 auth_random[sizeof(struct sctp_paramhdr) +
321 SCTP_AUTH_RANDOM_LENGTH];
322 __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
323 __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
324
325 /* This is a shim for my peer's INIT packet, followed by
326 * a copy of the raw address list of the association.
327 * The length of the raw address list is saved in the
328 * raw_addr_list_len field, which will be used at the time when
329 * the association TCB is re-constructed from the cookie.
330 */
331 __u32 raw_addr_list_len;
332 /* struct sctp_init_chunk peer_init[]; */
333 };
334
335
336 /* The format of our cookie that we send to our peer. */
337 struct sctp_signed_cookie {
338 __u8 signature[SCTP_SECRET_SIZE];
339 __u32 __pad; /* force sctp_cookie alignment to 64 bits */
340 struct sctp_cookie c;
341 } __packed;
342
343 /* This is another convenience type to allocate memory for address
344 * params for the maximum size and pass such structures around
345 * internally.
346 */
347 union sctp_addr_param {
348 struct sctp_paramhdr p;
349 struct sctp_ipv4addr_param v4;
350 struct sctp_ipv6addr_param v6;
351 };
352
353 /* A convenience type to allow walking through the various
354 * parameters and avoid casting all over the place.
355 */
356 union sctp_params {
357 void *v;
358 struct sctp_paramhdr *p;
359 struct sctp_cookie_preserve_param *life;
360 struct sctp_hostname_param *dns;
361 struct sctp_cookie_param *cookie;
362 struct sctp_supported_addrs_param *sat;
363 struct sctp_ipv4addr_param *v4;
364 struct sctp_ipv6addr_param *v6;
365 union sctp_addr_param *addr;
366 struct sctp_adaptation_ind_param *aind;
367 struct sctp_supported_ext_param *ext;
368 struct sctp_random_param *random;
369 struct sctp_chunks_param *chunks;
370 struct sctp_hmac_algo_param *hmac_algo;
371 struct sctp_addip_param *addip;
372 };
373
374 /* RFC 2960. Section 3.3.5 Heartbeat.
375 * Heartbeat Information: variable length
376 * The Sender-specific Heartbeat Info field should normally include
377 * information about the sender's current time when this HEARTBEAT
378 * chunk is sent and the destination transport address to which this
379 * HEARTBEAT is sent (see Section 8.3).
380 */
381 struct sctp_sender_hb_info {
382 struct sctp_paramhdr param_hdr;
383 union sctp_addr daddr;
384 unsigned long sent_at;
385 __u64 hb_nonce;
386 __u32 probe_size;
387 };
388
389 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
390 gfp_t gfp);
391 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
392 void sctp_stream_free(struct sctp_stream *stream);
393 void sctp_stream_clear(struct sctp_stream *stream);
394 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
395
396 /* What is the current SSN number for this stream? */
397 #define sctp_ssn_peek(stream, type, sid) \
398 (sctp_stream_##type((stream), (sid))->ssn)
399
400 /* Return the next SSN number for this stream. */
401 #define sctp_ssn_next(stream, type, sid) \
402 (sctp_stream_##type((stream), (sid))->ssn++)
403
404 /* Skip over this ssn and all below. */
405 #define sctp_ssn_skip(stream, type, sid, ssn) \
406 (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
407
408 /* What is the current MID number for this stream? */
409 #define sctp_mid_peek(stream, type, sid) \
410 (sctp_stream_##type((stream), (sid))->mid)
411
412 /* Return the next MID number for this stream. */
413 #define sctp_mid_next(stream, type, sid) \
414 (sctp_stream_##type((stream), (sid))->mid++)
415
416 /* Skip over this mid and all below. */
417 #define sctp_mid_skip(stream, type, sid, mid) \
418 (sctp_stream_##type((stream), (sid))->mid = mid + 1)
419
420 /* What is the current MID_uo number for this stream? */
421 #define sctp_mid_uo_peek(stream, type, sid) \
422 (sctp_stream_##type((stream), (sid))->mid_uo)
423
424 /* Return the next MID_uo number for this stream. */
425 #define sctp_mid_uo_next(stream, type, sid) \
426 (sctp_stream_##type((stream), (sid))->mid_uo++)
427
428 /*
429 * Pointers to address related SCTP functions.
430 * (i.e. things that depend on the address family.)
431 */
432 struct sctp_af {
433 int (*sctp_xmit) (struct sk_buff *skb,
434 struct sctp_transport *);
435 int (*setsockopt) (struct sock *sk,
436 int level,
437 int optname,
438 sockptr_t optval,
439 unsigned int optlen);
440 int (*getsockopt) (struct sock *sk,
441 int level,
442 int optname,
443 char __user *optval,
444 int __user *optlen);
445 void (*get_dst) (struct sctp_transport *t,
446 union sctp_addr *saddr,
447 struct flowi *fl,
448 struct sock *sk);
449 void (*get_saddr) (struct sctp_sock *sk,
450 struct sctp_transport *t,
451 struct flowi *fl);
452 void (*copy_addrlist) (struct list_head *,
453 struct net_device *);
454 int (*cmp_addr) (const union sctp_addr *addr1,
455 const union sctp_addr *addr2);
456 void (*addr_copy) (union sctp_addr *dst,
457 union sctp_addr *src);
458 void (*from_skb) (union sctp_addr *,
459 struct sk_buff *skb,
460 int saddr);
461 void (*from_sk) (union sctp_addr *,
462 struct sock *sk);
463 bool (*from_addr_param) (union sctp_addr *,
464 union sctp_addr_param *,
465 __be16 port, int iif);
466 int (*to_addr_param) (const union sctp_addr *,
467 union sctp_addr_param *);
468 int (*addr_valid) (union sctp_addr *,
469 struct sctp_sock *,
470 const struct sk_buff *);
471 enum sctp_scope (*scope)(union sctp_addr *);
472 void (*inaddr_any) (union sctp_addr *, __be16);
473 int (*is_any) (const union sctp_addr *);
474 int (*available) (union sctp_addr *,
475 struct sctp_sock *);
476 int (*skb_iif) (const struct sk_buff *sk);
477 int (*skb_sdif)(const struct sk_buff *sk);
478 int (*is_ce) (const struct sk_buff *sk);
479 void (*seq_dump_addr)(struct seq_file *seq,
480 union sctp_addr *addr);
481 void (*ecn_capable)(struct sock *sk);
482 __u16 net_header_len;
483 int sockaddr_len;
484 int (*ip_options_len)(struct sock *sk);
485 sa_family_t sa_family;
486 struct list_head list;
487 };
488
489 struct sctp_af *sctp_get_af_specific(sa_family_t);
490 int sctp_register_af(struct sctp_af *);
491
492 /* Protocol family functions. */
493 struct sctp_pf {
494 void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
495 void (*skb_msgname) (struct sk_buff *, char *, int *);
496 int (*af_supported) (sa_family_t, struct sctp_sock *);
497 int (*cmp_addr) (const union sctp_addr *,
498 const union sctp_addr *,
499 struct sctp_sock *);
500 int (*bind_verify) (struct sctp_sock *, union sctp_addr *);
501 int (*send_verify) (struct sctp_sock *, union sctp_addr *);
502 int (*supported_addrs)(const struct sctp_sock *, __be16 *);
503 struct sock *(*create_accept_sk) (struct sock *sk,
504 struct sctp_association *asoc,
505 bool kern);
506 int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
507 void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
508 void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
509 void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
510 struct sctp_af *af;
511 };
512
513
514 /* Structure to track chunk fragments that have been acked, but peer
515 * fragments of the same message have not.
516 */
517 struct sctp_datamsg {
518 /* Chunks waiting to be submitted to lower layer. */
519 struct list_head chunks;
520 /* Reference counting. */
521 refcount_t refcnt;
522 /* When is this message no longer interesting to the peer? */
523 unsigned long expires_at;
524 /* Did the message fail to send? */
525 int send_error;
526 u8 send_failed:1,
527 can_delay:1, /* should this message be Nagle delayed */
528 abandoned:1; /* should this message be abandoned */
529 };
530
531 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
532 struct sctp_sndrcvinfo *,
533 struct iov_iter *);
534 void sctp_datamsg_free(struct sctp_datamsg *);
535 void sctp_datamsg_put(struct sctp_datamsg *);
536 void sctp_chunk_fail(struct sctp_chunk *, int error);
537 int sctp_chunk_abandoned(struct sctp_chunk *);
538
539 /* RFC2960 1.4 Key Terms
540 *
541 * o Chunk: A unit of information within an SCTP packet, consisting of
542 * a chunk header and chunk-specific content.
543 *
544 * As a matter of convenience, we remember the SCTP common header for
545 * each chunk as well as a few other header pointers...
546 */
547 struct sctp_chunk {
548 struct list_head list;
549
550 refcount_t refcnt;
551
552 /* How many times this chunk have been sent, for prsctp RTX policy */
553 int sent_count;
554
555 union {
556 /* This is our link to the per-transport transmitted list. */
557 struct list_head transmitted_list;
558 /* List in specific stream outq */
559 struct list_head stream_list;
560 };
561
562 /* This field is used by chunks that hold fragmented data.
563 * For the first fragment this is the list that holds the rest of
564 * fragments. For the remaining fragments, this is the link to the
565 * frag_list maintained in the first fragment.
566 */
567 struct list_head frag_list;
568
569 /* This points to the sk_buff containing the actual data. */
570 struct sk_buff *skb;
571
572 union {
573 /* In case of GSO packets, this will store the head one */
574 struct sk_buff *head_skb;
575 /* In case of auth enabled, this will point to the shkey */
576 struct sctp_shared_key *shkey;
577 };
578
579 /* These are the SCTP headers by reverse order in a packet.
580 * Note that some of these may happen more than once. In that
581 * case, we point at the "current" one, whatever that means
582 * for that level of header.
583 */
584
585 /* We point this at the FIRST TLV parameter to chunk_hdr. */
586 union sctp_params param_hdr;
587 union {
588 __u8 *v;
589 struct sctp_datahdr *data_hdr;
590 struct sctp_inithdr *init_hdr;
591 struct sctp_sackhdr *sack_hdr;
592 struct sctp_heartbeathdr *hb_hdr;
593 struct sctp_sender_hb_info *hbs_hdr;
594 struct sctp_shutdownhdr *shutdown_hdr;
595 struct sctp_signed_cookie *cookie_hdr;
596 struct sctp_ecnehdr *ecne_hdr;
597 struct sctp_cwrhdr *ecn_cwr_hdr;
598 struct sctp_errhdr *err_hdr;
599 struct sctp_addiphdr *addip_hdr;
600 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
601 struct sctp_authhdr *auth_hdr;
602 struct sctp_idatahdr *idata_hdr;
603 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
604 } subh;
605
606 __u8 *chunk_end;
607
608 struct sctp_chunkhdr *chunk_hdr;
609 struct sctphdr *sctp_hdr;
610
611 /* This needs to be recoverable for SCTP_SEND_FAILED events. */
612 struct sctp_sndrcvinfo sinfo;
613
614 /* Which association does this belong to? */
615 struct sctp_association *asoc;
616
617 /* What endpoint received this chunk? */
618 struct sctp_ep_common *rcvr;
619
620 /* We fill this in if we are calculating RTT. */
621 unsigned long sent_at;
622
623 /* What is the origin IP address for this chunk? */
624 union sctp_addr source;
625 /* Destination address for this chunk. */
626 union sctp_addr dest;
627
628 /* For outbound message, track all fragments for SEND_FAILED. */
629 struct sctp_datamsg *msg;
630
631 /* For an inbound chunk, this tells us where it came from.
632 * For an outbound chunk, it tells us where we'd like it to
633 * go. It is NULL if we have no preference.
634 */
635 struct sctp_transport *transport;
636
637 /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO
638 * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
639 * spec violates the principle premis that all chunks are processed
640 * in order.
641 */
642 struct sk_buff *auth_chunk;
643
644 #define SCTP_CAN_FRTX 0x0
645 #define SCTP_NEED_FRTX 0x1
646 #define SCTP_DONT_FRTX 0x2
647 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */
648 has_tsn:1, /* Does this chunk have a TSN yet? */
649 has_ssn:1, /* Does this chunk have a SSN yet? */
650 #define has_mid has_ssn
651 singleton:1, /* Only chunk in the packet? */
652 end_of_packet:1, /* Last chunk in the packet? */
653 ecn_ce_done:1, /* Have we processed the ECN CE bit? */
654 pdiscard:1, /* Discard the whole packet now? */
655 tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */
656 data_accepted:1, /* At least 1 chunk accepted */
657 auth:1, /* IN: was auth'ed | OUT: needs auth */
658 has_asconf:1, /* IN: have seen an asconf before */
659 pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */
660 tsn_missing_report:2, /* Data chunk missing counter. */
661 fast_retransmit:2; /* Is this chunk fast retransmitted? */
662 };
663
664 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
665 void sctp_chunk_hold(struct sctp_chunk *);
666 void sctp_chunk_put(struct sctp_chunk *);
667 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
668 struct iov_iter *from);
669 void sctp_chunk_free(struct sctp_chunk *);
670 void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
671 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
672 const struct sctp_association *,
673 struct sock *, gfp_t gfp);
674 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
675 union sctp_addr *);
676 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
677
sctp_chunk_stream_no(struct sctp_chunk * ch)678 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
679 {
680 return ntohs(ch->subh.data_hdr->stream);
681 }
682
683 enum {
684 SCTP_ADDR_NEW, /* new address added to assoc/ep */
685 SCTP_ADDR_SRC, /* address can be used as source */
686 SCTP_ADDR_DEL, /* address about to be deleted */
687 };
688
689 /* This is a structure for holding either an IPv6 or an IPv4 address. */
690 struct sctp_sockaddr_entry {
691 struct list_head list;
692 struct rcu_head rcu;
693 union sctp_addr a;
694 __u8 state;
695 __u8 valid;
696 };
697
698 #define SCTP_ADDRESS_TICK_DELAY 500
699
700 /* This structure holds lists of chunks as we are assembling for
701 * transmission.
702 */
703 struct sctp_packet {
704 /* These are the SCTP header values (host order) for the packet. */
705 __u16 source_port;
706 __u16 destination_port;
707 __u32 vtag;
708
709 /* This contains the payload chunks. */
710 struct list_head chunk_list;
711
712 /* This is the overhead of the sctp and ip headers. */
713 size_t overhead;
714 /* This is the total size of all chunks INCLUDING padding. */
715 size_t size;
716 /* This is the maximum size this packet may have */
717 size_t max_size;
718
719 /* The packet is destined for this transport address.
720 * The function we finally use to pass down to the next lower
721 * layer lives in the transport structure.
722 */
723 struct sctp_transport *transport;
724
725 /* pointer to the auth chunk for this packet */
726 struct sctp_chunk *auth;
727
728 u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */
729 has_sack:1, /* This packet contains a SACK chunk. */
730 has_auth:1, /* This packet contains an AUTH chunk */
731 has_data:1, /* This packet contains at least 1 DATA chunk */
732 ipfragok:1; /* So let ip fragment this packet */
733 };
734
735 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
736 __u16 sport, __u16 dport);
737 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
738 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
739 struct sctp_chunk *chunk,
740 int one_packet, gfp_t gfp);
741 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
742 struct sctp_chunk *chunk);
743 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
744 void sctp_packet_free(struct sctp_packet *);
745
sctp_packet_empty(struct sctp_packet * packet)746 static inline int sctp_packet_empty(struct sctp_packet *packet)
747 {
748 return packet->size == packet->overhead;
749 }
750
751 /* This represents a remote transport address.
752 * For local transport addresses, we just use union sctp_addr.
753 *
754 * RFC2960 Section 1.4 Key Terms
755 *
756 * o Transport address: A Transport Address is traditionally defined
757 * by Network Layer address, Transport Layer protocol and Transport
758 * Layer port number. In the case of SCTP running over IP, a
759 * transport address is defined by the combination of an IP address
760 * and an SCTP port number (where SCTP is the Transport protocol).
761 *
762 * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
763 *
764 * o The sender keeps a separate congestion control parameter set for
765 * each of the destination addresses it can send to (not each
766 * source-destination pair but for each destination). The parameters
767 * should decay if the address is not used for a long enough time
768 * period.
769 *
770 */
771 struct sctp_transport {
772 /* A list of transports. */
773 struct list_head transports;
774 struct rhlist_head node;
775
776 /* Reference counting. */
777 refcount_t refcnt;
778 __u32 dead:1,
779 /* RTO-Pending : A flag used to track if one of the DATA
780 * chunks sent to this address is currently being
781 * used to compute a RTT. If this flag is 0,
782 * the next DATA chunk sent to this destination
783 * should be used to compute a RTT and this flag
784 * should be set. Every time the RTT
785 * calculation completes (i.e. the DATA chunk
786 * is SACK'd) clear this flag.
787 */
788 rto_pending:1,
789
790 /*
791 * hb_sent : a flag that signals that we have a pending
792 * heartbeat.
793 */
794 hb_sent:1,
795
796 /* Is the Path MTU update pending on this transport */
797 pmtu_pending:1,
798
799 dst_pending_confirm:1, /* need to confirm neighbour */
800
801 /* Has this transport moved the ctsn since we last sacked */
802 sack_generation:1;
803 u32 dst_cookie;
804
805 struct flowi fl;
806
807 /* This is the peer's IP address and port. */
808 union sctp_addr ipaddr;
809
810 /* These are the functions we call to handle LLP stuff. */
811 struct sctp_af *af_specific;
812
813 /* Which association do we belong to? */
814 struct sctp_association *asoc;
815
816 /* RFC2960
817 *
818 * 12.3 Per Transport Address Data
819 *
820 * For each destination transport address in the peer's
821 * address list derived from the INIT or INIT ACK chunk, a
822 * number of data elements needs to be maintained including:
823 */
824 /* RTO : The current retransmission timeout value. */
825 unsigned long rto;
826
827 __u32 rtt; /* This is the most recent RTT. */
828
829 /* RTTVAR : The current RTT variation. */
830 __u32 rttvar;
831
832 /* SRTT : The current smoothed round trip time. */
833 __u32 srtt;
834
835 /*
836 * These are the congestion stats.
837 */
838 /* cwnd : The current congestion window. */
839 __u32 cwnd; /* This is the actual cwnd. */
840
841 /* ssthresh : The current slow start threshold value. */
842 __u32 ssthresh;
843
844 /* partial : The tracking method for increase of cwnd when in
845 * bytes acked : congestion avoidance mode (see Section 6.2.2)
846 */
847 __u32 partial_bytes_acked;
848
849 /* Data that has been sent, but not acknowledged. */
850 __u32 flight_size;
851
852 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
853
854 /* Destination */
855 struct dst_entry *dst;
856 /* Source address. */
857 union sctp_addr saddr;
858
859 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
860 * the destination address every heartbeat interval.
861 */
862 unsigned long hbinterval;
863 unsigned long probe_interval;
864
865 /* SACK delay timeout */
866 unsigned long sackdelay;
867 __u32 sackfreq;
868
869 atomic_t mtu_info;
870
871 /* When was the last time that we heard from this transport? We use
872 * this to pick new active and retran paths.
873 */
874 ktime_t last_time_heard;
875
876 /* When was the last time that we sent a chunk using this
877 * transport? We use this to check for idle transports
878 */
879 unsigned long last_time_sent;
880
881 /* Last time(in jiffies) when cwnd is reduced due to the congestion
882 * indication based on ECNE chunk.
883 */
884 unsigned long last_time_ecne_reduced;
885
886 __be16 encap_port;
887
888 /* This is the max_retrans value for the transport and will
889 * be initialized from the assocs value. This can be changed
890 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
891 */
892 __u16 pathmaxrxt;
893
894 __u32 flowlabel;
895 __u8 dscp;
896
897 /* This is the partially failed retrans value for the transport
898 * and will be initialized from the assocs value. This can be changed
899 * using the SCTP_PEER_ADDR_THLDS socket option
900 */
901 __u16 pf_retrans;
902 /* Used for primary path switchover. */
903 __u16 ps_retrans;
904 /* PMTU : The current known path MTU. */
905 __u32 pathmtu;
906
907 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
908 __u32 param_flags;
909
910 /* The number of times INIT has been sent on this transport. */
911 int init_sent_count;
912
913 /* state : The current state of this destination,
914 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
915 */
916 int state;
917
918 /* These are the error stats for this destination. */
919
920 /* Error count : The current error count for this destination. */
921 unsigned short error_count;
922
923 /* Per : A timer used by each destination.
924 * Destination :
925 * Timer :
926 *
927 * [Everywhere else in the text this is called T3-rtx. -ed]
928 */
929 struct timer_list T3_rtx_timer;
930
931 /* Heartbeat timer is per destination. */
932 struct timer_list hb_timer;
933
934 /* Timer to handle ICMP proto unreachable envets */
935 struct timer_list proto_unreach_timer;
936
937 /* Timer to handler reconf chunk rtx */
938 struct timer_list reconf_timer;
939
940 /* Timer to send a probe HB packet for PLPMTUD */
941 struct timer_list probe_timer;
942
943 /* Since we're using per-destination retransmission timers
944 * (see above), we're also using per-destination "transmitted"
945 * queues. This probably ought to be a private struct
946 * accessible only within the outqueue, but it's not, yet.
947 */
948 struct list_head transmitted;
949
950 /* We build bundle-able packets for this transport here. */
951 struct sctp_packet packet;
952
953 /* This is the list of transports that have chunks to send. */
954 struct list_head send_ready;
955
956 /* State information saved for SFR_CACC algorithm. The key
957 * idea in SFR_CACC is to maintain state at the sender on a
958 * per-destination basis when a changeover happens.
959 * char changeover_active;
960 * char cycling_changeover;
961 * __u32 next_tsn_at_change;
962 * char cacc_saw_newack;
963 */
964 struct {
965 /* An unsigned integer, which stores the next TSN to be
966 * used by the sender, at the moment of changeover.
967 */
968 __u32 next_tsn_at_change;
969
970 /* A flag which indicates the occurrence of a changeover */
971 char changeover_active;
972
973 /* A flag which indicates whether the change of primary is
974 * the first switch to this destination address during an
975 * active switch.
976 */
977 char cycling_changeover;
978
979 /* A temporary flag, which is used during the processing of
980 * a SACK to estimate the causative TSN(s)'s group.
981 */
982 char cacc_saw_newack;
983 } cacc;
984
985 struct {
986 __u16 pmtu;
987 __u16 probe_size;
988 __u16 probe_high;
989 __u8 probe_count;
990 __u8 state;
991 } pl; /* plpmtud related */
992
993 /* 64-bit random number sent with heartbeat. */
994 __u64 hb_nonce;
995
996 struct rcu_head rcu;
997 };
998
999 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
1000 gfp_t);
1001 void sctp_transport_set_owner(struct sctp_transport *,
1002 struct sctp_association *);
1003 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1004 struct sctp_sock *);
1005 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1006 void sctp_transport_free(struct sctp_transport *);
1007 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1008 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1009 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1010 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1011 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1012 int sctp_transport_hold(struct sctp_transport *);
1013 void sctp_transport_put(struct sctp_transport *);
1014 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1015 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1016 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1017 enum sctp_lower_cwnd reason);
1018 void sctp_transport_burst_limited(struct sctp_transport *);
1019 void sctp_transport_burst_reset(struct sctp_transport *);
1020 unsigned long sctp_transport_timeout(struct sctp_transport *);
1021 void sctp_transport_reset(struct sctp_transport *t);
1022 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1023 void sctp_transport_immediate_rtx(struct sctp_transport *);
1024 void sctp_transport_dst_release(struct sctp_transport *t);
1025 void sctp_transport_dst_confirm(struct sctp_transport *t);
1026 void sctp_transport_pl_send(struct sctp_transport *t);
1027 bool sctp_transport_pl_recv(struct sctp_transport *t);
1028
1029
1030 /* This is the structure we use to queue packets as they come into
1031 * SCTP. We write packets to it and read chunks from it.
1032 */
1033 struct sctp_inq {
1034 /* This is actually a queue of sctp_chunk each
1035 * containing a partially decoded packet.
1036 */
1037 struct list_head in_chunk_list;
1038 /* This is the packet which is currently off the in queue and is
1039 * being worked on through the inbound chunk processing.
1040 */
1041 struct sctp_chunk *in_progress;
1042
1043 /* This is the delayed task to finish delivering inbound
1044 * messages.
1045 */
1046 struct work_struct immediate;
1047 };
1048
1049 void sctp_inq_init(struct sctp_inq *);
1050 void sctp_inq_free(struct sctp_inq *);
1051 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1052 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1053 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1054 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1055
1056 /* This is the structure we use to hold outbound chunks. You push
1057 * chunks in and they automatically pop out the other end as bundled
1058 * packets (it calls (*output_handler)()).
1059 *
1060 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1061 * and 8.2 of the v13 draft.
1062 *
1063 * It handles retransmissions. The connection to the timeout portion
1064 * of the state machine is through sctp_..._timeout() and timeout_handler.
1065 *
1066 * If you feed it SACKs, it will eat them.
1067 *
1068 * If you give it big chunks, it will fragment them.
1069 *
1070 * It assigns TSN's to data chunks. This happens at the last possible
1071 * instant before transmission.
1072 *
1073 * When free()'d, it empties itself out via output_handler().
1074 */
1075 struct sctp_outq {
1076 struct sctp_association *asoc;
1077
1078 /* Data pending that has never been transmitted. */
1079 struct list_head out_chunk_list;
1080
1081 /* Stream scheduler being used */
1082 struct sctp_sched_ops *sched;
1083
1084 unsigned int out_qlen; /* Total length of queued data chunks. */
1085
1086 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1087 unsigned int error;
1088
1089 /* These are control chunks we want to send. */
1090 struct list_head control_chunk_list;
1091
1092 /* These are chunks that have been sacked but are above the
1093 * CTSN, or cumulative tsn ack point.
1094 */
1095 struct list_head sacked;
1096
1097 /* Put chunks on this list to schedule them for
1098 * retransmission.
1099 */
1100 struct list_head retransmit;
1101
1102 /* Put chunks on this list to save them for FWD TSN processing as
1103 * they were abandoned.
1104 */
1105 struct list_head abandoned;
1106
1107 /* How many unackd bytes do we have in-flight? */
1108 __u32 outstanding_bytes;
1109
1110 /* Are we doing fast-rtx on this queue */
1111 char fast_rtx;
1112
1113 /* Corked? */
1114 char cork;
1115 };
1116
1117 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1118 void sctp_outq_teardown(struct sctp_outq *);
1119 void sctp_outq_free(struct sctp_outq*);
1120 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1121 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1122 int sctp_outq_is_empty(const struct sctp_outq *);
1123 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1124 enum sctp_retransmit_reason reason);
1125 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1126 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1127 void sctp_prsctp_prune(struct sctp_association *asoc,
1128 struct sctp_sndrcvinfo *sinfo, int msg_len);
1129 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1130 /* Uncork and flush an outqueue. */
sctp_outq_cork(struct sctp_outq * q)1131 static inline void sctp_outq_cork(struct sctp_outq *q)
1132 {
1133 q->cork = 1;
1134 }
1135
1136 /* SCTP skb control block.
1137 * sctp_input_cb is currently used on rx and sock rx queue
1138 */
1139 struct sctp_input_cb {
1140 union {
1141 struct inet_skb_parm h4;
1142 #if IS_ENABLED(CONFIG_IPV6)
1143 struct inet6_skb_parm h6;
1144 #endif
1145 } header;
1146 struct sctp_chunk *chunk;
1147 struct sctp_af *af;
1148 __be16 encap_port;
1149 };
1150 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1151
1152 struct sctp_output_cb {
1153 struct sk_buff *last;
1154 };
1155 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1156
sctp_gso_headskb(const struct sk_buff * skb)1157 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1158 {
1159 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1160
1161 return chunk->head_skb ? : skb;
1162 }
1163
1164 /* These bind address data fields common between endpoints and associations */
1165 struct sctp_bind_addr {
1166
1167 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1168 *
1169 * SCTP Port: The local SCTP port number the endpoint is
1170 * bound to.
1171 */
1172 __u16 port;
1173
1174 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1175 *
1176 * Address List: The list of IP addresses that this instance
1177 * has bound. This information is passed to one's
1178 * peer(s) in INIT and INIT ACK chunks.
1179 */
1180 struct list_head address_list;
1181 };
1182
1183 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1184 void sctp_bind_addr_free(struct sctp_bind_addr *);
1185 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1186 const struct sctp_bind_addr *src,
1187 enum sctp_scope scope, gfp_t gfp,
1188 int flags);
1189 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1190 const struct sctp_bind_addr *src,
1191 gfp_t gfp);
1192 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1193 int new_size, __u8 addr_state, gfp_t gfp);
1194 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1195 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1196 struct sctp_sock *);
1197 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1198 struct sctp_sock *, struct sctp_sock *);
1199 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1200 const union sctp_addr *addr);
1201 int sctp_bind_addrs_check(struct sctp_sock *sp,
1202 struct sctp_sock *sp2, int cnt2);
1203 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1204 const union sctp_addr *addrs,
1205 int addrcnt,
1206 struct sctp_sock *opt);
1207 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1208 int *addrs_len,
1209 gfp_t gfp);
1210 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1211 __u16 port, gfp_t gfp);
1212
1213 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1214 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1215 const enum sctp_scope scope);
1216 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1217 int sctp_is_ep_boundall(struct sock *sk);
1218
1219
1220 /* What type of endpoint? */
1221 enum sctp_endpoint_type {
1222 SCTP_EP_TYPE_SOCKET,
1223 SCTP_EP_TYPE_ASSOCIATION,
1224 };
1225
1226 /*
1227 * A common base class to bridge the implementation view of a
1228 * socket (usually listening) endpoint versus an association's
1229 * local endpoint.
1230 * This common structure is useful for several purposes:
1231 * 1) Common interface for lookup routines.
1232 * a) Subfunctions work for either endpoint or association
1233 * b) Single interface to lookup allows hiding the lookup lock rather
1234 * than acquiring it externally.
1235 * 2) Common interface for the inbound chunk handling/state machine.
1236 * 3) Common object handling routines for reference counting, etc.
1237 * 4) Disentangle association lookup from endpoint lookup, where we
1238 * do not have to find our endpoint to find our association.
1239 *
1240 */
1241
1242 struct sctp_ep_common {
1243 /* Runtime type information. What kind of endpoint is this? */
1244 enum sctp_endpoint_type type;
1245
1246 /* Some fields to help us manage this object.
1247 * refcnt - Reference count access to this object.
1248 * dead - Do not attempt to use this object.
1249 */
1250 refcount_t refcnt;
1251 bool dead;
1252
1253 /* What socket does this endpoint belong to? */
1254 struct sock *sk;
1255
1256 /* Cache netns and it won't change once set */
1257 struct net *net;
1258
1259 /* This is where we receive inbound chunks. */
1260 struct sctp_inq inqueue;
1261
1262 /* This substructure includes the defining parameters of the
1263 * endpoint:
1264 * bind_addr.port is our shared port number.
1265 * bind_addr.address_list is our set of local IP addresses.
1266 */
1267 struct sctp_bind_addr bind_addr;
1268 };
1269
1270
1271 /* RFC Section 1.4 Key Terms
1272 *
1273 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1274 * multi-homed host, an SCTP endpoint is represented to its peers as a
1275 * combination of a set of eligible destination transport addresses to
1276 * which SCTP packets can be sent and a set of eligible source
1277 * transport addresses from which SCTP packets can be received.
1278 * All transport addresses used by an SCTP endpoint must use the
1279 * same port number, but can use multiple IP addresses. A transport
1280 * address used by an SCTP endpoint must not be used by another
1281 * SCTP endpoint. In other words, a transport address is unique
1282 * to an SCTP endpoint.
1283 *
1284 * From an implementation perspective, each socket has one of these.
1285 * A TCP-style socket will have exactly one association on one of
1286 * these. An UDP-style socket will have multiple associations hanging
1287 * off one of these.
1288 */
1289
1290 struct sctp_endpoint {
1291 /* Common substructure for endpoint and association. */
1292 struct sctp_ep_common base;
1293
1294 /* Fields to help us manage our entries in the hash tables. */
1295 struct hlist_node node;
1296 int hashent;
1297
1298 /* Associations: A list of current associations and mappings
1299 * to the data consumers for each association. This
1300 * may be in the form of a hash table or other
1301 * implementation dependent structure. The data
1302 * consumers may be process identification
1303 * information such as file descriptors, named pipe
1304 * pointer, or table pointers dependent on how SCTP
1305 * is implemented.
1306 */
1307 /* This is really a list of struct sctp_association entries. */
1308 struct list_head asocs;
1309
1310 /* Secret Key: A secret key used by this endpoint to compute
1311 * the MAC. This SHOULD be a cryptographic quality
1312 * random number with a sufficient length.
1313 * Discussion in [RFC1750] can be helpful in
1314 * selection of the key.
1315 */
1316 __u8 secret_key[SCTP_SECRET_SIZE];
1317
1318 /* digest: This is a digest of the sctp cookie. This field is
1319 * only used on the receive path when we try to validate
1320 * that the cookie has not been tampered with. We put
1321 * this here so we pre-allocate this once and can re-use
1322 * on every receive.
1323 */
1324 __u8 *digest;
1325
1326 /* sendbuf acct. policy. */
1327 __u32 sndbuf_policy;
1328
1329 /* rcvbuf acct. policy. */
1330 __u32 rcvbuf_policy;
1331
1332 /* SCTP AUTH: array of the HMACs that will be allocated
1333 * we need this per association so that we don't serialize
1334 */
1335 struct crypto_shash **auth_hmacs;
1336
1337 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1338 struct sctp_hmac_algo_param *auth_hmacs_list;
1339
1340 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1341 struct sctp_chunks_param *auth_chunk_list;
1342
1343 /* SCTP-AUTH: endpoint shared keys */
1344 struct list_head endpoint_shared_keys;
1345 __u16 active_key_id;
1346 __u8 ecn_enable:1,
1347 auth_enable:1,
1348 intl_enable:1,
1349 prsctp_enable:1,
1350 asconf_enable:1,
1351 reconf_enable:1;
1352
1353 __u8 strreset_enable;
1354 struct rcu_head rcu;
1355 };
1356
1357 /* Recover the outer endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1358 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1359 {
1360 struct sctp_endpoint *ep;
1361
1362 ep = container_of(base, struct sctp_endpoint, base);
1363 return ep;
1364 }
1365
1366 /* These are function signatures for manipulating endpoints. */
1367 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1368 void sctp_endpoint_free(struct sctp_endpoint *);
1369 void sctp_endpoint_put(struct sctp_endpoint *);
1370 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1371 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1372 struct sctp_association *sctp_endpoint_lookup_assoc(
1373 const struct sctp_endpoint *ep,
1374 const union sctp_addr *paddr,
1375 struct sctp_transport **);
1376 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1377 const union sctp_addr *paddr);
1378 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1379 struct net *net,
1380 const union sctp_addr *laddr,
1381 int dif, int sdif);
1382 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1383 const union sctp_addr *paddr, int dif, int sdif);
1384
1385 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1386 const struct sctp_association *asoc,
1387 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1388 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1389 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1390 const union sctp_addr *peer,
1391 struct sctp_init_chunk *init, gfp_t gfp);
1392 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1393 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1394
1395 struct sctp_inithdr_host {
1396 __u32 init_tag;
1397 __u32 a_rwnd;
1398 __u16 num_outbound_streams;
1399 __u16 num_inbound_streams;
1400 __u32 initial_tsn;
1401 };
1402
1403 struct sctp_stream_priorities {
1404 /* List of priorities scheduled */
1405 struct list_head prio_sched;
1406 /* List of streams scheduled */
1407 struct list_head active;
1408 /* The next stream in line */
1409 struct sctp_stream_out_ext *next;
1410 __u16 prio;
1411 __u16 users;
1412 };
1413
1414 struct sctp_stream_out_ext {
1415 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1416 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1417 struct list_head outq; /* chunks enqueued by this stream */
1418 union {
1419 struct {
1420 /* Scheduled streams list */
1421 struct list_head prio_list;
1422 struct sctp_stream_priorities *prio_head;
1423 };
1424 /* Fields used by RR scheduler */
1425 struct {
1426 struct list_head rr_list;
1427 };
1428 struct {
1429 struct list_head fc_list;
1430 __u32 fc_length;
1431 __u16 fc_weight;
1432 };
1433 };
1434 };
1435
1436 struct sctp_stream_out {
1437 union {
1438 __u32 mid;
1439 __u16 ssn;
1440 };
1441 __u32 mid_uo;
1442 struct sctp_stream_out_ext *ext;
1443 __u8 state;
1444 };
1445
1446 struct sctp_stream_in {
1447 union {
1448 __u32 mid;
1449 __u16 ssn;
1450 };
1451 __u32 mid_uo;
1452 __u32 fsn;
1453 __u32 fsn_uo;
1454 char pd_mode;
1455 char pd_mode_uo;
1456 };
1457
1458 struct sctp_stream {
1459 GENRADIX(struct sctp_stream_out) out;
1460 GENRADIX(struct sctp_stream_in) in;
1461
1462 __u16 outcnt;
1463 __u16 incnt;
1464 /* Current stream being sent, if any */
1465 struct sctp_stream_out *out_curr;
1466 union {
1467 /* Fields used by priority scheduler */
1468 struct {
1469 /* List of priorities scheduled */
1470 struct list_head prio_list;
1471 };
1472 /* Fields used by RR scheduler */
1473 struct {
1474 /* List of streams scheduled */
1475 struct list_head rr_list;
1476 /* The next stream in line */
1477 struct sctp_stream_out_ext *rr_next;
1478 };
1479 struct {
1480 struct list_head fc_list;
1481 };
1482 };
1483 struct sctp_stream_interleave *si;
1484 };
1485
sctp_stream_out(struct sctp_stream * stream,__u16 sid)1486 static inline struct sctp_stream_out *sctp_stream_out(
1487 struct sctp_stream *stream,
1488 __u16 sid)
1489 {
1490 return genradix_ptr(&stream->out, sid);
1491 }
1492
sctp_stream_in(struct sctp_stream * stream,__u16 sid)1493 static inline struct sctp_stream_in *sctp_stream_in(
1494 struct sctp_stream *stream,
1495 __u16 sid)
1496 {
1497 return genradix_ptr(&stream->in, sid);
1498 }
1499
1500 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1501 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1502
1503 #define SCTP_STREAM_CLOSED 0x00
1504 #define SCTP_STREAM_OPEN 0x01
1505
sctp_datachk_len(const struct sctp_stream * stream)1506 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1507 {
1508 return stream->si->data_chunk_len;
1509 }
1510
sctp_datahdr_len(const struct sctp_stream * stream)1511 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1512 {
1513 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1514 }
1515
sctp_ftsnchk_len(const struct sctp_stream * stream)1516 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1517 {
1518 return stream->si->ftsn_chunk_len;
1519 }
1520
sctp_ftsnhdr_len(const struct sctp_stream * stream)1521 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1522 {
1523 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1524 }
1525
1526 /* SCTP_GET_ASSOC_STATS counters */
1527 struct sctp_priv_assoc_stats {
1528 /* Maximum observed rto in the association during subsequent
1529 * observations. Value is set to 0 if no RTO measurement took place
1530 * The transport where the max_rto was observed is returned in
1531 * obs_rto_ipaddr
1532 */
1533 struct sockaddr_storage obs_rto_ipaddr;
1534 __u64 max_obs_rto;
1535 /* Total In and Out SACKs received and sent */
1536 __u64 isacks;
1537 __u64 osacks;
1538 /* Total In and Out packets received and sent */
1539 __u64 opackets;
1540 __u64 ipackets;
1541 /* Total retransmitted chunks */
1542 __u64 rtxchunks;
1543 /* TSN received > next expected */
1544 __u64 outofseqtsns;
1545 /* Duplicate Chunks received */
1546 __u64 idupchunks;
1547 /* Gap Ack Blocks received */
1548 __u64 gapcnt;
1549 /* Unordered data chunks sent and received */
1550 __u64 ouodchunks;
1551 __u64 iuodchunks;
1552 /* Ordered data chunks sent and received */
1553 __u64 oodchunks;
1554 __u64 iodchunks;
1555 /* Control chunks sent and received */
1556 __u64 octrlchunks;
1557 __u64 ictrlchunks;
1558 };
1559
1560 /* RFC2960
1561 *
1562 * 12. Recommended Transmission Control Block (TCB) Parameters
1563 *
1564 * This section details a recommended set of parameters that should
1565 * be contained within the TCB for an implementation. This section is
1566 * for illustrative purposes and should not be deemed as requirements
1567 * on an implementation or as an exhaustive list of all parameters
1568 * inside an SCTP TCB. Each implementation may need its own additional
1569 * parameters for optimization.
1570 */
1571
1572
1573 /* Here we have information about each individual association. */
1574 struct sctp_association {
1575
1576 /* A base structure common to endpoint and association.
1577 * In this context, it represents the associations's view
1578 * of the local endpoint of the association.
1579 */
1580 struct sctp_ep_common base;
1581
1582 /* Associations on the same socket. */
1583 struct list_head asocs;
1584
1585 /* association id. */
1586 sctp_assoc_t assoc_id;
1587
1588 /* This is our parent endpoint. */
1589 struct sctp_endpoint *ep;
1590
1591 /* These are those association elements needed in the cookie. */
1592 struct sctp_cookie c;
1593
1594 /* This is all information about our peer. */
1595 struct {
1596 /* transport_addr_list
1597 *
1598 * Peer : A list of SCTP transport addresses that the
1599 * Transport : peer is bound to. This information is derived
1600 * Address : from the INIT or INIT ACK and is used to
1601 * List : associate an inbound packet with a given
1602 * : association. Normally this information is
1603 * : hashed or keyed for quick lookup and access
1604 * : of the TCB.
1605 * : The list is also initialized with the list
1606 * : of addresses passed with the sctp_connectx()
1607 * : call.
1608 *
1609 * It is a list of SCTP_transport's.
1610 */
1611 struct list_head transport_addr_list;
1612
1613 /* rwnd
1614 *
1615 * Peer Rwnd : Current calculated value of the peer's rwnd.
1616 */
1617 __u32 rwnd;
1618
1619 /* transport_count
1620 *
1621 * Peer : A count of the number of peer addresses
1622 * Transport : in the Peer Transport Address List.
1623 * Address :
1624 * Count :
1625 */
1626 __u16 transport_count;
1627
1628 /* port
1629 * The transport layer port number.
1630 */
1631 __u16 port;
1632
1633 /* primary_path
1634 *
1635 * Primary : This is the current primary destination
1636 * Path : transport address of the peer endpoint. It
1637 * : may also specify a source transport address
1638 * : on this endpoint.
1639 *
1640 * All of these paths live on transport_addr_list.
1641 *
1642 * At the bakeoffs, we discovered that the intent of
1643 * primaryPath is that it only changes when the ULP
1644 * asks to have it changed. We add the activePath to
1645 * designate the connection we are currently using to
1646 * transmit new data and most control chunks.
1647 */
1648 struct sctp_transport *primary_path;
1649
1650 /* Cache the primary path address here, when we
1651 * need a an address for msg_name.
1652 */
1653 union sctp_addr primary_addr;
1654
1655 /* active_path
1656 * The path that we are currently using to
1657 * transmit new data and most control chunks.
1658 */
1659 struct sctp_transport *active_path;
1660
1661 /* retran_path
1662 *
1663 * RFC2960 6.4 Multi-homed SCTP Endpoints
1664 * ...
1665 * Furthermore, when its peer is multi-homed, an
1666 * endpoint SHOULD try to retransmit a chunk to an
1667 * active destination transport address that is
1668 * different from the last destination address to
1669 * which the DATA chunk was sent.
1670 */
1671 struct sctp_transport *retran_path;
1672
1673 /* Pointer to last transport I have sent on. */
1674 struct sctp_transport *last_sent_to;
1675
1676 /* This is the last transport I have received DATA on. */
1677 struct sctp_transport *last_data_from;
1678
1679 /*
1680 * Mapping An array of bits or bytes indicating which out of
1681 * Array order TSN's have been received (relative to the
1682 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1683 * order packets have been received, this array
1684 * will be set to all zero. This structure may be
1685 * in the form of a circular buffer or bit array.
1686 *
1687 * Last Rcvd : This is the last TSN received in
1688 * TSN : sequence. This value is set initially by
1689 * : taking the peer's Initial TSN, received in
1690 * : the INIT or INIT ACK chunk, and subtracting
1691 * : one from it.
1692 *
1693 * Throughout most of the specification this is called the
1694 * "Cumulative TSN ACK Point". In this case, we
1695 * ignore the advice in 12.2 in favour of the term
1696 * used in the bulk of the text. This value is hidden
1697 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1698 */
1699 struct sctp_tsnmap tsn_map;
1700
1701 /* This mask is used to disable sending the ASCONF chunk
1702 * with specified parameter to peer.
1703 */
1704 __be16 addip_disabled_mask;
1705
1706 /* These are capabilities which our peer advertised. */
1707 __u16 ecn_capable:1, /* Can peer do ECN? */
1708 ipv4_address:1, /* Peer understands IPv4 addresses? */
1709 ipv6_address:1, /* Peer understands IPv6 addresses? */
1710 asconf_capable:1, /* Does peer support ADDIP? */
1711 prsctp_capable:1, /* Can peer do PR-SCTP? */
1712 reconf_capable:1, /* Can peer do RE-CONFIG? */
1713 intl_capable:1, /* Can peer do INTERLEAVE */
1714 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1715 /* sack_needed:
1716 * This flag indicates if the next received
1717 * packet is to be responded to with a
1718 * SACK. This is initialized to 0. When a packet
1719 * is received sack_cnt is incremented. If this value
1720 * reaches 2 or more, a SACK is sent and the
1721 * value is reset to 0. Note: This is used only
1722 * when no DATA chunks are received out of
1723 * order. When DATA chunks are out of order,
1724 * SACK's are not delayed (see Section 6).
1725 */
1726 sack_needed:1, /* Do we need to sack the peer? */
1727 sack_generation:1,
1728 zero_window_announced:1;
1729
1730 __u32 sack_cnt;
1731
1732 __u32 adaptation_ind; /* Adaptation Code point. */
1733
1734 struct sctp_inithdr_host i;
1735 void *cookie;
1736 int cookie_len;
1737
1738 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1739 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1740 * Initial TSN Value minus 1
1741 */
1742 __u32 addip_serial;
1743
1744 /* SCTP-AUTH: We need to know pears random number, hmac list
1745 * and authenticated chunk list. All that is part of the
1746 * cookie and these are just pointers to those locations
1747 */
1748 struct sctp_random_param *peer_random;
1749 struct sctp_chunks_param *peer_chunks;
1750 struct sctp_hmac_algo_param *peer_hmacs;
1751 } peer;
1752
1753 /* State : A state variable indicating what state the
1754 * : association is in, i.e. COOKIE-WAIT,
1755 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1756 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1757 *
1758 * Note: No "CLOSED" state is illustrated since if a
1759 * association is "CLOSED" its TCB SHOULD be removed.
1760 *
1761 * In this implementation we DO have a CLOSED
1762 * state which is used during initiation and shutdown.
1763 *
1764 * State takes values from SCTP_STATE_*.
1765 */
1766 enum sctp_state state;
1767
1768 /* Overall : The overall association error count.
1769 * Error Count : [Clear this any time I get something.]
1770 */
1771 int overall_error_count;
1772
1773 /* The cookie life I award for any cookie. */
1774 ktime_t cookie_life;
1775
1776 /* These are the association's initial, max, and min RTO values.
1777 * These values will be initialized by system defaults, but can
1778 * be modified via the SCTP_RTOINFO socket option.
1779 */
1780 unsigned long rto_initial;
1781 unsigned long rto_max;
1782 unsigned long rto_min;
1783
1784 /* Maximum number of new data packets that can be sent in a burst. */
1785 int max_burst;
1786
1787 /* This is the max_retrans value for the association. This value will
1788 * be initialized from system defaults, but can be
1789 * modified by the SCTP_ASSOCINFO socket option.
1790 */
1791 int max_retrans;
1792
1793 /* This is the partially failed retrans value for the transport
1794 * and will be initialized from the assocs value. This can be
1795 * changed using the SCTP_PEER_ADDR_THLDS socket option
1796 */
1797 __u16 pf_retrans;
1798 /* Used for primary path switchover. */
1799 __u16 ps_retrans;
1800
1801 /* Maximum number of times the endpoint will retransmit INIT */
1802 __u16 max_init_attempts;
1803
1804 /* How many times have we resent an INIT? */
1805 __u16 init_retries;
1806
1807 /* The largest timeout or RTO value to use in attempting an INIT */
1808 unsigned long max_init_timeo;
1809
1810 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1811 * the destination address every heartbeat interval. This value
1812 * will be inherited by all new transports.
1813 */
1814 unsigned long hbinterval;
1815 unsigned long probe_interval;
1816
1817 __be16 encap_port;
1818
1819 /* This is the max_retrans value for new transports in the
1820 * association.
1821 */
1822 __u16 pathmaxrxt;
1823
1824 __u32 flowlabel;
1825 __u8 dscp;
1826
1827 /* Flag that path mtu update is pending */
1828 __u8 pmtu_pending;
1829
1830 /* Association : The smallest PMTU discovered for all of the
1831 * PMTU : peer's transport addresses.
1832 */
1833 __u32 pathmtu;
1834
1835 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1836 __u32 param_flags;
1837
1838 __u32 sackfreq;
1839 /* SACK delay timeout */
1840 unsigned long sackdelay;
1841
1842 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1843 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1844
1845 /* Transport to which SHUTDOWN chunk was last sent. */
1846 struct sctp_transport *shutdown_last_sent_to;
1847
1848 /* Transport to which INIT chunk was last sent. */
1849 struct sctp_transport *init_last_sent_to;
1850
1851 /* How many times have we resent a SHUTDOWN */
1852 int shutdown_retries;
1853
1854 /* Next TSN : The next TSN number to be assigned to a new
1855 * : DATA chunk. This is sent in the INIT or INIT
1856 * : ACK chunk to the peer and incremented each
1857 * : time a DATA chunk is assigned a TSN
1858 * : (normally just prior to transmit or during
1859 * : fragmentation).
1860 */
1861 __u32 next_tsn;
1862
1863 /*
1864 * Last Rcvd : This is the last TSN received in sequence. This value
1865 * TSN : is set initially by taking the peer's Initial TSN,
1866 * : received in the INIT or INIT ACK chunk, and
1867 * : subtracting one from it.
1868 *
1869 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1870 */
1871
1872 __u32 ctsn_ack_point;
1873
1874 /* PR-SCTP Advanced.Peer.Ack.Point */
1875 __u32 adv_peer_ack_point;
1876
1877 /* Highest TSN that is acknowledged by incoming SACKs. */
1878 __u32 highest_sacked;
1879
1880 /* TSN marking the fast recovery exit point */
1881 __u32 fast_recovery_exit;
1882
1883 /* Flag to track the current fast recovery state */
1884 __u8 fast_recovery;
1885
1886 /* The number of unacknowledged data chunks. Reported through
1887 * the SCTP_STATUS sockopt.
1888 */
1889 __u16 unack_data;
1890
1891 /* The total number of data chunks that we've had to retransmit
1892 * as the result of a T3 timer expiration
1893 */
1894 __u32 rtx_data_chunks;
1895
1896 /* This is the association's receive buffer space. This value is used
1897 * to set a_rwnd field in an INIT or a SACK chunk.
1898 */
1899 __u32 rwnd;
1900
1901 /* This is the last advertised value of rwnd over a SACK chunk. */
1902 __u32 a_rwnd;
1903
1904 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1905 * to slop over a maximum of the association's frag_point.
1906 */
1907 __u32 rwnd_over;
1908
1909 /* Keeps treack of rwnd pressure. This happens when we have
1910 * a window, but not receive buffer (i.e small packets). This one
1911 * is releases slowly (1 PMTU at a time ).
1912 */
1913 __u32 rwnd_press;
1914
1915 /* This is the sndbuf size in use for the association.
1916 * This corresponds to the sndbuf size for the association,
1917 * as specified in the sk->sndbuf.
1918 */
1919 int sndbuf_used;
1920
1921 /* This is the amount of memory that this association has allocated
1922 * in the receive path at any given time.
1923 */
1924 atomic_t rmem_alloc;
1925
1926 /* This is the wait queue head for send requests waiting on
1927 * the association sndbuf space.
1928 */
1929 wait_queue_head_t wait;
1930
1931 /* The message size at which SCTP fragmentation will occur. */
1932 __u32 frag_point;
1933 __u32 user_frag;
1934
1935 /* Counter used to count INIT errors. */
1936 int init_err_counter;
1937
1938 /* Count the number of INIT cycles (for doubling timeout). */
1939 int init_cycle;
1940
1941 /* Default send parameters. */
1942 __u16 default_stream;
1943 __u16 default_flags;
1944 __u32 default_ppid;
1945 __u32 default_context;
1946 __u32 default_timetolive;
1947
1948 /* Default receive parameters */
1949 __u32 default_rcv_context;
1950
1951 /* Stream arrays */
1952 struct sctp_stream stream;
1953
1954 /* All outbound chunks go through this structure. */
1955 struct sctp_outq outqueue;
1956
1957 /* A smart pipe that will handle reordering and fragmentation,
1958 * as well as handle passing events up to the ULP.
1959 */
1960 struct sctp_ulpq ulpq;
1961
1962 /* Last TSN that caused an ECNE Chunk to be sent. */
1963 __u32 last_ecne_tsn;
1964
1965 /* Last TSN that caused a CWR Chunk to be sent. */
1966 __u32 last_cwr_tsn;
1967
1968 /* How many duplicated TSNs have we seen? */
1969 int numduptsns;
1970
1971 /* These are to support
1972 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1973 * and Enforcement of Flow and Message Limits"
1974 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1975 * or "ADDIP" for short.
1976 */
1977
1978
1979
1980 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1981 *
1982 * R1) One and only one ASCONF Chunk MAY be in transit and
1983 * unacknowledged at any one time. If a sender, after sending
1984 * an ASCONF chunk, decides it needs to transfer another
1985 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1986 * returns from the previous ASCONF Chunk before sending a
1987 * subsequent ASCONF. Note this restriction binds each side,
1988 * so at any time two ASCONF may be in-transit on any given
1989 * association (one sent from each endpoint).
1990 *
1991 * [This is our one-and-only-one ASCONF in flight. If we do
1992 * not have an ASCONF in flight, this is NULL.]
1993 */
1994 struct sctp_chunk *addip_last_asconf;
1995
1996 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1997 *
1998 * This is needed to implement items E1 - E4 of the updated
1999 * spec. Here is the justification:
2000 *
2001 * Since the peer may bundle multiple ASCONF chunks toward us,
2002 * we now need the ability to cache multiple ACKs. The section
2003 * describes in detail how they are cached and cleaned up.
2004 */
2005 struct list_head asconf_ack_list;
2006
2007 /* These ASCONF chunks are waiting to be sent.
2008 *
2009 * These chunks can't be pushed to outqueue until receiving
2010 * ASCONF_ACK for the previous ASCONF indicated by
2011 * addip_last_asconf, so as to guarantee that only one ASCONF
2012 * is in flight at any time.
2013 *
2014 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2015 *
2016 * In defining the ASCONF Chunk transfer procedures, it is
2017 * essential that these transfers MUST NOT cause congestion
2018 * within the network. To achieve this, we place these
2019 * restrictions on the transfer of ASCONF Chunks:
2020 *
2021 * R1) One and only one ASCONF Chunk MAY be in transit and
2022 * unacknowledged at any one time. If a sender, after sending
2023 * an ASCONF chunk, decides it needs to transfer another
2024 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2025 * returns from the previous ASCONF Chunk before sending a
2026 * subsequent ASCONF. Note this restriction binds each side,
2027 * so at any time two ASCONF may be in-transit on any given
2028 * association (one sent from each endpoint).
2029 *
2030 *
2031 * [I really think this is EXACTLY the sort of intelligence
2032 * which already resides in sctp_outq. Please move this
2033 * queue and its supporting logic down there. --piggy]
2034 */
2035 struct list_head addip_chunk_list;
2036
2037 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2038 *
2039 * A2) A serial number should be assigned to the Chunk. The
2040 * serial number SHOULD be a monotonically increasing
2041 * number. The serial number SHOULD be initialized at
2042 * the start of the association to the same value as the
2043 * Initial TSN and every time a new ASCONF chunk is created
2044 * it is incremented by one after assigning the serial number
2045 * to the newly created chunk.
2046 *
2047 * ADDIP
2048 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2049 *
2050 * Serial Number : 32 bits (unsigned integer)
2051 *
2052 * This value represents a Serial Number for the ASCONF
2053 * Chunk. The valid range of Serial Number is from 0 to
2054 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2055 * after reaching 4294967295.
2056 */
2057 __u32 addip_serial;
2058 int src_out_of_asoc_ok;
2059 union sctp_addr *asconf_addr_del_pending;
2060 struct sctp_transport *new_transport;
2061
2062 /* SCTP AUTH: list of the endpoint shared keys. These
2063 * keys are provided out of band by the user application
2064 * and can't change during the lifetime of the association
2065 */
2066 struct list_head endpoint_shared_keys;
2067
2068 /* SCTP AUTH:
2069 * The current generated association shared key (secret)
2070 */
2071 struct sctp_auth_bytes *asoc_shared_key;
2072 struct sctp_shared_key *shkey;
2073
2074 /* SCTP AUTH: hmac id of the first peer requested algorithm
2075 * that we support.
2076 */
2077 __u16 default_hmac_id;
2078
2079 __u16 active_key_id;
2080
2081 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2082 temp:1, /* Is it a temporary association? */
2083 pf_expose:2, /* Expose pf state? */
2084 force_delay:1;
2085
2086 __u8 strreset_enable;
2087 __u8 strreset_outstanding; /* request param count on the fly */
2088
2089 __u32 strreset_outseq; /* Update after receiving response */
2090 __u32 strreset_inseq; /* Update after receiving request */
2091 __u32 strreset_result[2]; /* save the results of last 2 responses */
2092
2093 struct sctp_chunk *strreset_chunk; /* save request chunk */
2094
2095 struct sctp_priv_assoc_stats stats;
2096
2097 int sent_cnt_removable;
2098
2099 __u16 subscribe;
2100
2101 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2102 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2103
2104 /* Security identifiers from incoming (INIT). These are set by
2105 * security_sctp_assoc_request(). These will only be used by
2106 * SCTP TCP type sockets and peeled off connections as they
2107 * cause a new socket to be generated. security_sctp_sk_clone()
2108 * will then plug these into the new socket.
2109 */
2110
2111 u32 secid;
2112 u32 peer_secid;
2113
2114 struct rcu_head rcu;
2115 };
2116
2117
2118 /* An eyecatcher for determining if we are really looking at an
2119 * association data structure.
2120 */
2121 enum {
2122 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2123 };
2124
2125 /* Recover the outer association structure. */
sctp_assoc(struct sctp_ep_common * base)2126 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2127 {
2128 struct sctp_association *asoc;
2129
2130 asoc = container_of(base, struct sctp_association, base);
2131 return asoc;
2132 }
2133
2134 /* These are function signatures for manipulating associations. */
2135
2136
2137 struct sctp_association *
2138 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2139 enum sctp_scope scope, gfp_t gfp);
2140 void sctp_association_free(struct sctp_association *);
2141 void sctp_association_put(struct sctp_association *);
2142 void sctp_association_hold(struct sctp_association *);
2143
2144 struct sctp_transport *sctp_assoc_choose_alter_transport(
2145 struct sctp_association *, struct sctp_transport *);
2146 void sctp_assoc_update_retran_path(struct sctp_association *);
2147 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2148 const union sctp_addr *);
2149 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2150 const union sctp_addr *laddr);
2151 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2152 const union sctp_addr *address,
2153 const gfp_t gfp,
2154 const int peer_state);
2155 void sctp_assoc_del_peer(struct sctp_association *asoc,
2156 const union sctp_addr *addr);
2157 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2158 struct sctp_transport *peer);
2159 void sctp_assoc_control_transport(struct sctp_association *asoc,
2160 struct sctp_transport *transport,
2161 enum sctp_transport_cmd command,
2162 sctp_sn_error_t error);
2163 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2164 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2165 int sctp_assoc_update(struct sctp_association *old,
2166 struct sctp_association *new);
2167
2168 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2169
2170 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2171 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2172 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2173 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2174 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2175 void sctp_assoc_set_primary(struct sctp_association *,
2176 struct sctp_transport *);
2177 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2178 struct sctp_transport *);
2179 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2180 enum sctp_scope scope, gfp_t gfp);
2181 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2182 struct sctp_cookie*,
2183 gfp_t gfp);
2184 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2185 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2186 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2187 const struct sctp_association *asoc,
2188 __be32 serial);
2189 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2190
2191 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2192 const union sctp_addr *ss2);
2193 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2194
2195 /* A convenience structure to parse out SCTP specific CMSGs. */
2196 struct sctp_cmsgs {
2197 struct sctp_initmsg *init;
2198 struct sctp_sndrcvinfo *srinfo;
2199 struct sctp_sndinfo *sinfo;
2200 struct sctp_prinfo *prinfo;
2201 struct sctp_authinfo *authinfo;
2202 struct msghdr *addrs_msg;
2203 };
2204
2205 /* Structure for tracking memory objects */
2206 struct sctp_dbg_objcnt_entry {
2207 char *label;
2208 atomic_t *counter;
2209 };
2210
2211 #endif /* __sctp_structs_h__ */
2212