1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * Please send any bug reports or fixes you make to the
11 * email addresses:
12 * lksctp developers <linux-sctp@vger.kernel.org>
13 *
14 * Written or modified by:
15 * Randall Stewart <randall@sctp.chicago.il.us>
16 * Ken Morneau <kmorneau@cisco.com>
17 * Qiaobing Xie <qxie1@email.mot.com>
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Xingang Guo <xingang.guo@intel.com>
22 * Hui Huang <hui.huang@nokia.com>
23 * Sridhar Samudrala <sri@us.ibm.com>
24 * Daisy Chang <daisyc@us.ibm.com>
25 * Dajiang Zhang <dajiang.zhang@nokia.com>
26 * Ardelle Fan <ardelle.fan@intel.com>
27 * Ryan Layer <rmlayer@us.ibm.com>
28 * Anup Pemmaiah <pemmaiah@cc.usu.edu>
29 * Kevin Gao <kevin.gao@intel.com>
30 */
31
32 #ifndef __sctp_structs_h__
33 #define __sctp_structs_h__
34
35 #include <linux/ktime.h>
36 #include <linux/generic-radix-tree.h>
37 #include <linux/rhashtable-types.h>
38 #include <linux/socket.h> /* linux/in.h needs this!! */
39 #include <linux/in.h> /* We get struct sockaddr_in. */
40 #include <linux/in6.h> /* We get struct in6_addr */
41 #include <linux/ipv6.h>
42 #include <asm/param.h> /* We get MAXHOSTNAMELEN. */
43 #include <linux/atomic.h> /* This gets us atomic counters. */
44 #include <linux/skbuff.h> /* We need sk_buff_head. */
45 #include <linux/workqueue.h> /* We need tq_struct. */
46 #include <linux/sctp.h> /* We need sctp* header structs. */
47 #include <net/sctp/auth.h> /* We need auth specific structs */
48 #include <net/ip.h> /* For inet_skb_parm */
49
50 /* A convenience structure for handling sockaddr structures.
51 * We should wean ourselves off this.
52 */
53 union sctp_addr {
54 struct sockaddr_in v4;
55 struct sockaddr_in6 v6;
56 struct sockaddr sa;
57 };
58
59 /* Forward declarations for data structures. */
60 struct sctp_globals;
61 struct sctp_endpoint;
62 struct sctp_association;
63 struct sctp_transport;
64 struct sctp_packet;
65 struct sctp_chunk;
66 struct sctp_inq;
67 struct sctp_outq;
68 struct sctp_bind_addr;
69 struct sctp_ulpq;
70 struct sctp_ep_common;
71 struct crypto_shash;
72 struct sctp_stream;
73
74
75 #include <net/sctp/tsnmap.h>
76 #include <net/sctp/ulpevent.h>
77 #include <net/sctp/ulpqueue.h>
78 #include <net/sctp/stream_interleave.h>
79
80 /* Structures useful for managing bind/connect. */
81
82 struct sctp_bind_bucket {
83 unsigned short port;
84 signed char fastreuse;
85 signed char fastreuseport;
86 kuid_t fastuid;
87 struct hlist_node node;
88 struct hlist_head owner;
89 struct net *net;
90 };
91
92 struct sctp_bind_hashbucket {
93 spinlock_t lock;
94 struct hlist_head chain;
95 };
96
97 /* Used for hashing all associations. */
98 struct sctp_hashbucket {
99 rwlock_t lock;
100 struct hlist_head chain;
101 } __attribute__((__aligned__(8)));
102
103
104 /* The SCTP globals structure. */
105 extern struct sctp_globals {
106 /* This is a list of groups of functions for each address
107 * family that we support.
108 */
109 struct list_head address_families;
110
111 /* This is the hash of all endpoints. */
112 struct sctp_hashbucket *ep_hashtable;
113 /* This is the sctp port control hash. */
114 struct sctp_bind_hashbucket *port_hashtable;
115 /* This is the hash of all transports. */
116 struct rhltable transport_hashtable;
117
118 /* Sizes of above hashtables. */
119 int ep_hashsize;
120 int port_hashsize;
121
122 /* Default initialization values to be applied to new associations. */
123 __u16 max_instreams;
124 __u16 max_outstreams;
125
126 /* Flag to indicate whether computing and verifying checksum
127 * is disabled. */
128 bool checksum_disable;
129 } sctp_globals;
130
131 #define sctp_max_instreams (sctp_globals.max_instreams)
132 #define sctp_max_outstreams (sctp_globals.max_outstreams)
133 #define sctp_address_families (sctp_globals.address_families)
134 #define sctp_ep_hashsize (sctp_globals.ep_hashsize)
135 #define sctp_ep_hashtable (sctp_globals.ep_hashtable)
136 #define sctp_port_hashsize (sctp_globals.port_hashsize)
137 #define sctp_port_hashtable (sctp_globals.port_hashtable)
138 #define sctp_transport_hashtable (sctp_globals.transport_hashtable)
139 #define sctp_checksum_disable (sctp_globals.checksum_disable)
140
141 /* SCTP Socket type: UDP or TCP style. */
142 enum sctp_socket_type {
143 SCTP_SOCKET_UDP = 0,
144 SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
145 SCTP_SOCKET_TCP
146 };
147
148 /* Per socket SCTP information. */
149 struct sctp_sock {
150 /* inet_sock has to be the first member of sctp_sock */
151 struct inet_sock inet;
152 /* What kind of a socket is this? */
153 enum sctp_socket_type type;
154
155 /* PF_ family specific functions. */
156 struct sctp_pf *pf;
157
158 /* Access to HMAC transform. */
159 struct crypto_shash *hmac;
160 char *sctp_hmac_alg;
161
162 /* What is our base endpointer? */
163 struct sctp_endpoint *ep;
164
165 struct sctp_bind_bucket *bind_hash;
166 /* Various Socket Options. */
167 __u16 default_stream;
168 __u32 default_ppid;
169 __u16 default_flags;
170 __u32 default_context;
171 __u32 default_timetolive;
172 __u32 default_rcv_context;
173 int max_burst;
174
175 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
176 * the destination address every heartbeat interval. This value
177 * will be inherited by all new associations.
178 */
179 __u32 hbinterval;
180 __u32 probe_interval;
181
182 __be16 udp_port;
183 __be16 encap_port;
184
185 /* This is the max_retrans value for new associations. */
186 __u16 pathmaxrxt;
187
188 __u32 flowlabel;
189 __u8 dscp;
190
191 __u16 pf_retrans;
192 __u16 ps_retrans;
193
194 /* The initial Path MTU to use for new associations. */
195 __u32 pathmtu;
196
197 /* The default SACK delay timeout for new associations. */
198 __u32 sackdelay;
199 __u32 sackfreq;
200
201 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
202 __u32 param_flags;
203
204 __u32 default_ss;
205
206 struct sctp_rtoinfo rtoinfo;
207 struct sctp_paddrparams paddrparam;
208 struct sctp_assocparams assocparams;
209
210 /*
211 * These two structures must be grouped together for the usercopy
212 * whitelist region.
213 */
214 __u16 subscribe;
215 struct sctp_initmsg initmsg;
216
217 int user_frag;
218
219 __u32 autoclose;
220 __u32 adaptation_ind;
221 __u32 pd_point;
222 __u16 nodelay:1,
223 pf_expose:2,
224 reuse:1,
225 disable_fragments:1,
226 v4mapped:1,
227 frag_interleave:1,
228 recvrcvinfo:1,
229 recvnxtinfo:1,
230 data_ready_signalled:1;
231
232 atomic_t pd_mode;
233
234 /* Fields after this point will be skipped on copies, like on accept
235 * and peeloff operations
236 */
237
238 /* Receive to here while partial delivery is in effect. */
239 struct sk_buff_head pd_lobby;
240
241 struct list_head auto_asconf_list;
242 int do_auto_asconf;
243 };
244
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 messenge 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 /* RTO-Pending : A flag used to track if one of the DATA
779 * chunks sent to this address is currently being
780 * used to compute a RTT. If this flag is 0,
781 * the next DATA chunk sent to this destination
782 * should be used to compute a RTT and this flag
783 * should be set. Every time the RTT
784 * calculation completes (i.e. the DATA chunk
785 * is SACK'd) clear this flag.
786 */
787 __u32 rto_pending:1,
788
789 /*
790 * hb_sent : a flag that signals that we have a pending
791 * heartbeat.
792 */
793 hb_sent:1,
794
795 /* Is the Path MTU update pending on this tranport */
796 pmtu_pending:1,
797
798 dst_pending_confirm:1, /* need to confirm neighbour */
799
800 /* Has this transport moved the ctsn since we last sacked */
801 sack_generation:1;
802 u32 dst_cookie;
803
804 struct flowi fl;
805
806 /* This is the peer's IP address and port. */
807 union sctp_addr ipaddr;
808
809 /* These are the functions we call to handle LLP stuff. */
810 struct sctp_af *af_specific;
811
812 /* Which association do we belong to? */
813 struct sctp_association *asoc;
814
815 /* RFC2960
816 *
817 * 12.3 Per Transport Address Data
818 *
819 * For each destination transport address in the peer's
820 * address list derived from the INIT or INIT ACK chunk, a
821 * number of data elements needs to be maintained including:
822 */
823 /* RTO : The current retransmission timeout value. */
824 unsigned long rto;
825
826 __u32 rtt; /* This is the most recent RTT. */
827
828 /* RTTVAR : The current RTT variation. */
829 __u32 rttvar;
830
831 /* SRTT : The current smoothed round trip time. */
832 __u32 srtt;
833
834 /*
835 * These are the congestion stats.
836 */
837 /* cwnd : The current congestion window. */
838 __u32 cwnd; /* This is the actual cwnd. */
839
840 /* ssthresh : The current slow start threshold value. */
841 __u32 ssthresh;
842
843 /* partial : The tracking method for increase of cwnd when in
844 * bytes acked : congestion avoidance mode (see Section 6.2.2)
845 */
846 __u32 partial_bytes_acked;
847
848 /* Data that has been sent, but not acknowledged. */
849 __u32 flight_size;
850
851 __u32 burst_limited; /* Holds old cwnd when max.burst is applied */
852
853 /* Destination */
854 struct dst_entry *dst;
855 /* Source address. */
856 union sctp_addr saddr;
857
858 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
859 * the destination address every heartbeat interval.
860 */
861 unsigned long hbinterval;
862 unsigned long probe_interval;
863
864 /* SACK delay timeout */
865 unsigned long sackdelay;
866 __u32 sackfreq;
867
868 atomic_t mtu_info;
869
870 /* When was the last time that we heard from this transport? We use
871 * this to pick new active and retran paths.
872 */
873 ktime_t last_time_heard;
874
875 /* When was the last time that we sent a chunk using this
876 * transport? We use this to check for idle transports
877 */
878 unsigned long last_time_sent;
879
880 /* Last time(in jiffies) when cwnd is reduced due to the congestion
881 * indication based on ECNE chunk.
882 */
883 unsigned long last_time_ecne_reduced;
884
885 __be16 encap_port;
886
887 /* This is the max_retrans value for the transport and will
888 * be initialized from the assocs value. This can be changed
889 * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
890 */
891 __u16 pathmaxrxt;
892
893 __u32 flowlabel;
894 __u8 dscp;
895
896 /* This is the partially failed retrans value for the transport
897 * and will be initialized from the assocs value. This can be changed
898 * using the SCTP_PEER_ADDR_THLDS socket option
899 */
900 __u16 pf_retrans;
901 /* Used for primary path switchover. */
902 __u16 ps_retrans;
903 /* PMTU : The current known path MTU. */
904 __u32 pathmtu;
905
906 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
907 __u32 param_flags;
908
909 /* The number of times INIT has been sent on this transport. */
910 int init_sent_count;
911
912 /* state : The current state of this destination,
913 * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
914 */
915 int state;
916
917 /* These are the error stats for this destination. */
918
919 /* Error count : The current error count for this destination. */
920 unsigned short error_count;
921
922 /* Per : A timer used by each destination.
923 * Destination :
924 * Timer :
925 *
926 * [Everywhere else in the text this is called T3-rtx. -ed]
927 */
928 struct timer_list T3_rtx_timer;
929
930 /* Heartbeat timer is per destination. */
931 struct timer_list hb_timer;
932
933 /* Timer to handle ICMP proto unreachable envets */
934 struct timer_list proto_unreach_timer;
935
936 /* Timer to handler reconf chunk rtx */
937 struct timer_list reconf_timer;
938
939 /* Timer to send a probe HB packet for PLPMTUD */
940 struct timer_list probe_timer;
941
942 /* Since we're using per-destination retransmission timers
943 * (see above), we're also using per-destination "transmitted"
944 * queues. This probably ought to be a private struct
945 * accessible only within the outqueue, but it's not, yet.
946 */
947 struct list_head transmitted;
948
949 /* We build bundle-able packets for this transport here. */
950 struct sctp_packet packet;
951
952 /* This is the list of transports that have chunks to send. */
953 struct list_head send_ready;
954
955 /* State information saved for SFR_CACC algorithm. The key
956 * idea in SFR_CACC is to maintain state at the sender on a
957 * per-destination basis when a changeover happens.
958 * char changeover_active;
959 * char cycling_changeover;
960 * __u32 next_tsn_at_change;
961 * char cacc_saw_newack;
962 */
963 struct {
964 /* An unsigned integer, which stores the next TSN to be
965 * used by the sender, at the moment of changeover.
966 */
967 __u32 next_tsn_at_change;
968
969 /* A flag which indicates the occurrence of a changeover */
970 char changeover_active;
971
972 /* A flag which indicates whether the change of primary is
973 * the first switch to this destination address during an
974 * active switch.
975 */
976 char cycling_changeover;
977
978 /* A temporary flag, which is used during the processing of
979 * a SACK to estimate the causative TSN(s)'s group.
980 */
981 char cacc_saw_newack;
982 } cacc;
983
984 struct {
985 __u16 pmtu;
986 __u16 probe_size;
987 __u16 probe_high;
988 __u8 probe_count;
989 __u8 state;
990 } pl; /* plpmtud related */
991
992 /* 64-bit random number sent with heartbeat. */
993 __u64 hb_nonce;
994
995 struct rcu_head rcu;
996 };
997
998 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
999 gfp_t);
1000 void sctp_transport_set_owner(struct sctp_transport *,
1001 struct sctp_association *);
1002 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
1003 struct sctp_sock *);
1004 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1005 void sctp_transport_free(struct sctp_transport *);
1006 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1007 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1008 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1009 void sctp_transport_reset_probe_timer(struct sctp_transport *transport);
1010 void sctp_transport_reset_raise_timer(struct sctp_transport *transport);
1011 int sctp_transport_hold(struct sctp_transport *);
1012 void sctp_transport_put(struct sctp_transport *);
1013 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1014 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1015 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1016 enum sctp_lower_cwnd reason);
1017 void sctp_transport_burst_limited(struct sctp_transport *);
1018 void sctp_transport_burst_reset(struct sctp_transport *);
1019 unsigned long sctp_transport_timeout(struct sctp_transport *);
1020 void sctp_transport_reset(struct sctp_transport *t);
1021 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1022 void sctp_transport_immediate_rtx(struct sctp_transport *);
1023 void sctp_transport_dst_release(struct sctp_transport *t);
1024 void sctp_transport_dst_confirm(struct sctp_transport *t);
1025 void sctp_transport_pl_send(struct sctp_transport *t);
1026 bool sctp_transport_pl_recv(struct sctp_transport *t);
1027
1028
1029 /* This is the structure we use to queue packets as they come into
1030 * SCTP. We write packets to it and read chunks from it.
1031 */
1032 struct sctp_inq {
1033 /* This is actually a queue of sctp_chunk each
1034 * containing a partially decoded packet.
1035 */
1036 struct list_head in_chunk_list;
1037 /* This is the packet which is currently off the in queue and is
1038 * being worked on through the inbound chunk processing.
1039 */
1040 struct sctp_chunk *in_progress;
1041
1042 /* This is the delayed task to finish delivering inbound
1043 * messages.
1044 */
1045 struct work_struct immediate;
1046 };
1047
1048 void sctp_inq_init(struct sctp_inq *);
1049 void sctp_inq_free(struct sctp_inq *);
1050 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1051 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1052 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1053 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1054
1055 /* This is the structure we use to hold outbound chunks. You push
1056 * chunks in and they automatically pop out the other end as bundled
1057 * packets (it calls (*output_handler)()).
1058 *
1059 * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1060 * and 8.2 of the v13 draft.
1061 *
1062 * It handles retransmissions. The connection to the timeout portion
1063 * of the state machine is through sctp_..._timeout() and timeout_handler.
1064 *
1065 * If you feed it SACKs, it will eat them.
1066 *
1067 * If you give it big chunks, it will fragment them.
1068 *
1069 * It assigns TSN's to data chunks. This happens at the last possible
1070 * instant before transmission.
1071 *
1072 * When free()'d, it empties itself out via output_handler().
1073 */
1074 struct sctp_outq {
1075 struct sctp_association *asoc;
1076
1077 /* Data pending that has never been transmitted. */
1078 struct list_head out_chunk_list;
1079
1080 /* Stream scheduler being used */
1081 struct sctp_sched_ops *sched;
1082
1083 unsigned int out_qlen; /* Total length of queued data chunks. */
1084
1085 /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1086 unsigned int error;
1087
1088 /* These are control chunks we want to send. */
1089 struct list_head control_chunk_list;
1090
1091 /* These are chunks that have been sacked but are above the
1092 * CTSN, or cumulative tsn ack point.
1093 */
1094 struct list_head sacked;
1095
1096 /* Put chunks on this list to schedule them for
1097 * retransmission.
1098 */
1099 struct list_head retransmit;
1100
1101 /* Put chunks on this list to save them for FWD TSN processing as
1102 * they were abandoned.
1103 */
1104 struct list_head abandoned;
1105
1106 /* How many unackd bytes do we have in-flight? */
1107 __u32 outstanding_bytes;
1108
1109 /* Are we doing fast-rtx on this queue */
1110 char fast_rtx;
1111
1112 /* Corked? */
1113 char cork;
1114 };
1115
1116 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1117 void sctp_outq_teardown(struct sctp_outq *);
1118 void sctp_outq_free(struct sctp_outq*);
1119 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1120 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1121 int sctp_outq_is_empty(const struct sctp_outq *);
1122 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1123 enum sctp_retransmit_reason reason);
1124 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1125 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1126 void sctp_prsctp_prune(struct sctp_association *asoc,
1127 struct sctp_sndrcvinfo *sinfo, int msg_len);
1128 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1129 /* Uncork and flush an outqueue. */
sctp_outq_cork(struct sctp_outq * q)1130 static inline void sctp_outq_cork(struct sctp_outq *q)
1131 {
1132 q->cork = 1;
1133 }
1134
1135 /* SCTP skb control block.
1136 * sctp_input_cb is currently used on rx and sock rx queue
1137 */
1138 struct sctp_input_cb {
1139 union {
1140 struct inet_skb_parm h4;
1141 #if IS_ENABLED(CONFIG_IPV6)
1142 struct inet6_skb_parm h6;
1143 #endif
1144 } header;
1145 struct sctp_chunk *chunk;
1146 struct sctp_af *af;
1147 __be16 encap_port;
1148 };
1149 #define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
1150
1151 struct sctp_output_cb {
1152 struct sk_buff *last;
1153 };
1154 #define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
1155
sctp_gso_headskb(const struct sk_buff * skb)1156 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1157 {
1158 const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1159
1160 return chunk->head_skb ? : skb;
1161 }
1162
1163 /* These bind address data fields common between endpoints and associations */
1164 struct sctp_bind_addr {
1165
1166 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1167 *
1168 * SCTP Port: The local SCTP port number the endpoint is
1169 * bound to.
1170 */
1171 __u16 port;
1172
1173 /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1174 *
1175 * Address List: The list of IP addresses that this instance
1176 * has bound. This information is passed to one's
1177 * peer(s) in INIT and INIT ACK chunks.
1178 */
1179 struct list_head address_list;
1180 };
1181
1182 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1183 void sctp_bind_addr_free(struct sctp_bind_addr *);
1184 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1185 const struct sctp_bind_addr *src,
1186 enum sctp_scope scope, gfp_t gfp,
1187 int flags);
1188 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1189 const struct sctp_bind_addr *src,
1190 gfp_t gfp);
1191 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1192 int new_size, __u8 addr_state, gfp_t gfp);
1193 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1194 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1195 struct sctp_sock *);
1196 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1197 struct sctp_sock *, struct sctp_sock *);
1198 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1199 const union sctp_addr *addr);
1200 int sctp_bind_addrs_check(struct sctp_sock *sp,
1201 struct sctp_sock *sp2, int cnt2);
1202 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp,
1203 const union sctp_addr *addrs,
1204 int addrcnt,
1205 struct sctp_sock *opt);
1206 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1207 int *addrs_len,
1208 gfp_t gfp);
1209 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1210 __u16 port, gfp_t gfp);
1211
1212 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1213 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1214 const enum sctp_scope scope);
1215 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1216 int sctp_is_ep_boundall(struct sock *sk);
1217
1218
1219 /* What type of endpoint? */
1220 enum sctp_endpoint_type {
1221 SCTP_EP_TYPE_SOCKET,
1222 SCTP_EP_TYPE_ASSOCIATION,
1223 };
1224
1225 /*
1226 * A common base class to bridge the implmentation view of a
1227 * socket (usually listening) endpoint versus an association's
1228 * local endpoint.
1229 * This common structure is useful for several purposes:
1230 * 1) Common interface for lookup routines.
1231 * a) Subfunctions work for either endpoint or association
1232 * b) Single interface to lookup allows hiding the lookup lock rather
1233 * than acquiring it externally.
1234 * 2) Common interface for the inbound chunk handling/state machine.
1235 * 3) Common object handling routines for reference counting, etc.
1236 * 4) Disentangle association lookup from endpoint lookup, where we
1237 * do not have to find our endpoint to find our association.
1238 *
1239 */
1240
1241 struct sctp_ep_common {
1242 /* Runtime type information. What kind of endpoint is this? */
1243 enum sctp_endpoint_type type;
1244
1245 /* Some fields to help us manage this object.
1246 * refcnt - Reference count access to this object.
1247 * dead - Do not attempt to use this object.
1248 */
1249 refcount_t refcnt;
1250 bool dead;
1251
1252 /* What socket does this endpoint belong to? */
1253 struct sock *sk;
1254
1255 /* Cache netns and it won't change once set */
1256 struct net *net;
1257
1258 /* This is where we receive inbound chunks. */
1259 struct sctp_inq inqueue;
1260
1261 /* This substructure includes the defining parameters of the
1262 * endpoint:
1263 * bind_addr.port is our shared port number.
1264 * bind_addr.address_list is our set of local IP addresses.
1265 */
1266 struct sctp_bind_addr bind_addr;
1267 };
1268
1269
1270 /* RFC Section 1.4 Key Terms
1271 *
1272 * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1273 * multi-homed host, an SCTP endpoint is represented to its peers as a
1274 * combination of a set of eligible destination transport addresses to
1275 * which SCTP packets can be sent and a set of eligible source
1276 * transport addresses from which SCTP packets can be received.
1277 * All transport addresses used by an SCTP endpoint must use the
1278 * same port number, but can use multiple IP addresses. A transport
1279 * address used by an SCTP endpoint must not be used by another
1280 * SCTP endpoint. In other words, a transport address is unique
1281 * to an SCTP endpoint.
1282 *
1283 * From an implementation perspective, each socket has one of these.
1284 * A TCP-style socket will have exactly one association on one of
1285 * these. An UDP-style socket will have multiple associations hanging
1286 * off one of these.
1287 */
1288
1289 struct sctp_endpoint {
1290 /* Common substructure for endpoint and association. */
1291 struct sctp_ep_common base;
1292
1293 /* Fields to help us manage our entries in the hash tables. */
1294 struct hlist_node node;
1295 int hashent;
1296
1297 /* Associations: A list of current associations and mappings
1298 * to the data consumers for each association. This
1299 * may be in the form of a hash table or other
1300 * implementation dependent structure. The data
1301 * consumers may be process identification
1302 * information such as file descriptors, named pipe
1303 * pointer, or table pointers dependent on how SCTP
1304 * is implemented.
1305 */
1306 /* This is really a list of struct sctp_association entries. */
1307 struct list_head asocs;
1308
1309 /* Secret Key: A secret key used by this endpoint to compute
1310 * the MAC. This SHOULD be a cryptographic quality
1311 * random number with a sufficient length.
1312 * Discussion in [RFC1750] can be helpful in
1313 * selection of the key.
1314 */
1315 __u8 secret_key[SCTP_SECRET_SIZE];
1316
1317 /* digest: This is a digest of the sctp cookie. This field is
1318 * only used on the receive path when we try to validate
1319 * that the cookie has not been tampered with. We put
1320 * this here so we pre-allocate this once and can re-use
1321 * on every receive.
1322 */
1323 __u8 *digest;
1324
1325 /* sendbuf acct. policy. */
1326 __u32 sndbuf_policy;
1327
1328 /* rcvbuf acct. policy. */
1329 __u32 rcvbuf_policy;
1330
1331 /* SCTP AUTH: array of the HMACs that will be allocated
1332 * we need this per association so that we don't serialize
1333 */
1334 struct crypto_shash **auth_hmacs;
1335
1336 /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1337 struct sctp_hmac_algo_param *auth_hmacs_list;
1338
1339 /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1340 struct sctp_chunks_param *auth_chunk_list;
1341
1342 /* SCTP-AUTH: endpoint shared keys */
1343 struct list_head endpoint_shared_keys;
1344 __u16 active_key_id;
1345 __u8 ecn_enable:1,
1346 auth_enable:1,
1347 intl_enable:1,
1348 prsctp_enable:1,
1349 asconf_enable:1,
1350 reconf_enable:1;
1351
1352 __u8 strreset_enable;
1353 struct rcu_head rcu;
1354 };
1355
1356 /* Recover the outter endpoint structure. */
sctp_ep(struct sctp_ep_common * base)1357 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1358 {
1359 struct sctp_endpoint *ep;
1360
1361 ep = container_of(base, struct sctp_endpoint, base);
1362 return ep;
1363 }
1364
1365 /* These are function signatures for manipulating endpoints. */
1366 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1367 void sctp_endpoint_free(struct sctp_endpoint *);
1368 void sctp_endpoint_put(struct sctp_endpoint *);
1369 int sctp_endpoint_hold(struct sctp_endpoint *ep);
1370 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1371 struct sctp_association *sctp_endpoint_lookup_assoc(
1372 const struct sctp_endpoint *ep,
1373 const union sctp_addr *paddr,
1374 struct sctp_transport **);
1375 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1376 const union sctp_addr *paddr);
1377 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
1378 struct net *net,
1379 const union sctp_addr *laddr,
1380 int dif, int sdif);
1381 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1382 const union sctp_addr *paddr, int dif, int sdif);
1383
1384 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1385 const struct sctp_association *asoc,
1386 enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1387 struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1388 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1389 const union sctp_addr *peer,
1390 struct sctp_init_chunk *init, gfp_t gfp);
1391 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1392 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1393
1394 struct sctp_inithdr_host {
1395 __u32 init_tag;
1396 __u32 a_rwnd;
1397 __u16 num_outbound_streams;
1398 __u16 num_inbound_streams;
1399 __u32 initial_tsn;
1400 };
1401
1402 struct sctp_stream_priorities {
1403 /* List of priorities scheduled */
1404 struct list_head prio_sched;
1405 /* List of streams scheduled */
1406 struct list_head active;
1407 /* The next stream in line */
1408 struct sctp_stream_out_ext *next;
1409 __u16 prio;
1410 __u16 users;
1411 };
1412
1413 struct sctp_stream_out_ext {
1414 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1415 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1416 struct list_head outq; /* chunks enqueued by this stream */
1417 union {
1418 struct {
1419 /* Scheduled streams list */
1420 struct list_head prio_list;
1421 struct sctp_stream_priorities *prio_head;
1422 };
1423 /* Fields used by RR scheduler */
1424 struct {
1425 struct list_head rr_list;
1426 };
1427 struct {
1428 struct list_head fc_list;
1429 __u32 fc_length;
1430 __u16 fc_weight;
1431 };
1432 };
1433 };
1434
1435 struct sctp_stream_out {
1436 union {
1437 __u32 mid;
1438 __u16 ssn;
1439 };
1440 __u32 mid_uo;
1441 struct sctp_stream_out_ext *ext;
1442 __u8 state;
1443 };
1444
1445 struct sctp_stream_in {
1446 union {
1447 __u32 mid;
1448 __u16 ssn;
1449 };
1450 __u32 mid_uo;
1451 __u32 fsn;
1452 __u32 fsn_uo;
1453 char pd_mode;
1454 char pd_mode_uo;
1455 };
1456
1457 struct sctp_stream {
1458 GENRADIX(struct sctp_stream_out) out;
1459 GENRADIX(struct sctp_stream_in) in;
1460
1461 __u16 outcnt;
1462 __u16 incnt;
1463 /* Current stream being sent, if any */
1464 struct sctp_stream_out *out_curr;
1465 union {
1466 /* Fields used by priority scheduler */
1467 struct {
1468 /* List of priorities scheduled */
1469 struct list_head prio_list;
1470 };
1471 /* Fields used by RR scheduler */
1472 struct {
1473 /* List of streams scheduled */
1474 struct list_head rr_list;
1475 /* The next stream in line */
1476 struct sctp_stream_out_ext *rr_next;
1477 };
1478 struct {
1479 struct list_head fc_list;
1480 };
1481 };
1482 struct sctp_stream_interleave *si;
1483 };
1484
sctp_stream_out(struct sctp_stream * stream,__u16 sid)1485 static inline struct sctp_stream_out *sctp_stream_out(
1486 struct sctp_stream *stream,
1487 __u16 sid)
1488 {
1489 return genradix_ptr(&stream->out, sid);
1490 }
1491
sctp_stream_in(struct sctp_stream * stream,__u16 sid)1492 static inline struct sctp_stream_in *sctp_stream_in(
1493 struct sctp_stream *stream,
1494 __u16 sid)
1495 {
1496 return genradix_ptr(&stream->in, sid);
1497 }
1498
1499 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1500 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1501
1502 #define SCTP_STREAM_CLOSED 0x00
1503 #define SCTP_STREAM_OPEN 0x01
1504
sctp_datachk_len(const struct sctp_stream * stream)1505 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1506 {
1507 return stream->si->data_chunk_len;
1508 }
1509
sctp_datahdr_len(const struct sctp_stream * stream)1510 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1511 {
1512 return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1513 }
1514
sctp_ftsnchk_len(const struct sctp_stream * stream)1515 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1516 {
1517 return stream->si->ftsn_chunk_len;
1518 }
1519
sctp_ftsnhdr_len(const struct sctp_stream * stream)1520 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1521 {
1522 return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1523 }
1524
1525 /* SCTP_GET_ASSOC_STATS counters */
1526 struct sctp_priv_assoc_stats {
1527 /* Maximum observed rto in the association during subsequent
1528 * observations. Value is set to 0 if no RTO measurement took place
1529 * The transport where the max_rto was observed is returned in
1530 * obs_rto_ipaddr
1531 */
1532 struct sockaddr_storage obs_rto_ipaddr;
1533 __u64 max_obs_rto;
1534 /* Total In and Out SACKs received and sent */
1535 __u64 isacks;
1536 __u64 osacks;
1537 /* Total In and Out packets received and sent */
1538 __u64 opackets;
1539 __u64 ipackets;
1540 /* Total retransmitted chunks */
1541 __u64 rtxchunks;
1542 /* TSN received > next expected */
1543 __u64 outofseqtsns;
1544 /* Duplicate Chunks received */
1545 __u64 idupchunks;
1546 /* Gap Ack Blocks received */
1547 __u64 gapcnt;
1548 /* Unordered data chunks sent and received */
1549 __u64 ouodchunks;
1550 __u64 iuodchunks;
1551 /* Ordered data chunks sent and received */
1552 __u64 oodchunks;
1553 __u64 iodchunks;
1554 /* Control chunks sent and received */
1555 __u64 octrlchunks;
1556 __u64 ictrlchunks;
1557 };
1558
1559 /* RFC2960
1560 *
1561 * 12. Recommended Transmission Control Block (TCB) Parameters
1562 *
1563 * This section details a recommended set of parameters that should
1564 * be contained within the TCB for an implementation. This section is
1565 * for illustrative purposes and should not be deemed as requirements
1566 * on an implementation or as an exhaustive list of all parameters
1567 * inside an SCTP TCB. Each implementation may need its own additional
1568 * parameters for optimization.
1569 */
1570
1571
1572 /* Here we have information about each individual association. */
1573 struct sctp_association {
1574
1575 /* A base structure common to endpoint and association.
1576 * In this context, it represents the associations's view
1577 * of the local endpoint of the association.
1578 */
1579 struct sctp_ep_common base;
1580
1581 /* Associations on the same socket. */
1582 struct list_head asocs;
1583
1584 /* association id. */
1585 sctp_assoc_t assoc_id;
1586
1587 /* This is our parent endpoint. */
1588 struct sctp_endpoint *ep;
1589
1590 /* These are those association elements needed in the cookie. */
1591 struct sctp_cookie c;
1592
1593 /* This is all information about our peer. */
1594 struct {
1595 /* transport_addr_list
1596 *
1597 * Peer : A list of SCTP transport addresses that the
1598 * Transport : peer is bound to. This information is derived
1599 * Address : from the INIT or INIT ACK and is used to
1600 * List : associate an inbound packet with a given
1601 * : association. Normally this information is
1602 * : hashed or keyed for quick lookup and access
1603 * : of the TCB.
1604 * : The list is also initialized with the list
1605 * : of addresses passed with the sctp_connectx()
1606 * : call.
1607 *
1608 * It is a list of SCTP_transport's.
1609 */
1610 struct list_head transport_addr_list;
1611
1612 /* rwnd
1613 *
1614 * Peer Rwnd : Current calculated value of the peer's rwnd.
1615 */
1616 __u32 rwnd;
1617
1618 /* transport_count
1619 *
1620 * Peer : A count of the number of peer addresses
1621 * Transport : in the Peer Transport Address List.
1622 * Address :
1623 * Count :
1624 */
1625 __u16 transport_count;
1626
1627 /* port
1628 * The transport layer port number.
1629 */
1630 __u16 port;
1631
1632 /* primary_path
1633 *
1634 * Primary : This is the current primary destination
1635 * Path : transport address of the peer endpoint. It
1636 * : may also specify a source transport address
1637 * : on this endpoint.
1638 *
1639 * All of these paths live on transport_addr_list.
1640 *
1641 * At the bakeoffs, we discovered that the intent of
1642 * primaryPath is that it only changes when the ULP
1643 * asks to have it changed. We add the activePath to
1644 * designate the connection we are currently using to
1645 * transmit new data and most control chunks.
1646 */
1647 struct sctp_transport *primary_path;
1648
1649 /* Cache the primary path address here, when we
1650 * need a an address for msg_name.
1651 */
1652 union sctp_addr primary_addr;
1653
1654 /* active_path
1655 * The path that we are currently using to
1656 * transmit new data and most control chunks.
1657 */
1658 struct sctp_transport *active_path;
1659
1660 /* retran_path
1661 *
1662 * RFC2960 6.4 Multi-homed SCTP Endpoints
1663 * ...
1664 * Furthermore, when its peer is multi-homed, an
1665 * endpoint SHOULD try to retransmit a chunk to an
1666 * active destination transport address that is
1667 * different from the last destination address to
1668 * which the DATA chunk was sent.
1669 */
1670 struct sctp_transport *retran_path;
1671
1672 /* Pointer to last transport I have sent on. */
1673 struct sctp_transport *last_sent_to;
1674
1675 /* This is the last transport I have received DATA on. */
1676 struct sctp_transport *last_data_from;
1677
1678 /*
1679 * Mapping An array of bits or bytes indicating which out of
1680 * Array order TSN's have been received (relative to the
1681 * Last Rcvd TSN). If no gaps exist, i.e. no out of
1682 * order packets have been received, this array
1683 * will be set to all zero. This structure may be
1684 * in the form of a circular buffer or bit array.
1685 *
1686 * Last Rcvd : This is the last TSN received in
1687 * TSN : sequence. This value is set initially by
1688 * : taking the peer's Initial TSN, received in
1689 * : the INIT or INIT ACK chunk, and subtracting
1690 * : one from it.
1691 *
1692 * Throughout most of the specification this is called the
1693 * "Cumulative TSN ACK Point". In this case, we
1694 * ignore the advice in 12.2 in favour of the term
1695 * used in the bulk of the text. This value is hidden
1696 * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1697 */
1698 struct sctp_tsnmap tsn_map;
1699
1700 /* This mask is used to disable sending the ASCONF chunk
1701 * with specified parameter to peer.
1702 */
1703 __be16 addip_disabled_mask;
1704
1705 /* These are capabilities which our peer advertised. */
1706 __u16 ecn_capable:1, /* Can peer do ECN? */
1707 ipv4_address:1, /* Peer understands IPv4 addresses? */
1708 ipv6_address:1, /* Peer understands IPv6 addresses? */
1709 asconf_capable:1, /* Does peer support ADDIP? */
1710 prsctp_capable:1, /* Can peer do PR-SCTP? */
1711 reconf_capable:1, /* Can peer do RE-CONFIG? */
1712 intl_capable:1, /* Can peer do INTERLEAVE */
1713 auth_capable:1, /* Is peer doing SCTP-AUTH? */
1714 /* sack_needed:
1715 * This flag indicates if the next received
1716 * packet is to be responded to with a
1717 * SACK. This is initialized to 0. When a packet
1718 * is received sack_cnt is incremented. If this value
1719 * reaches 2 or more, a SACK is sent and the
1720 * value is reset to 0. Note: This is used only
1721 * when no DATA chunks are received out of
1722 * order. When DATA chunks are out of order,
1723 * SACK's are not delayed (see Section 6).
1724 */
1725 sack_needed:1, /* Do we need to sack the peer? */
1726 sack_generation:1,
1727 zero_window_announced:1;
1728
1729 __u32 sack_cnt;
1730
1731 __u32 adaptation_ind; /* Adaptation Code point. */
1732
1733 struct sctp_inithdr_host i;
1734 void *cookie;
1735 int cookie_len;
1736
1737 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1738 * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1739 * Initial TSN Value minus 1
1740 */
1741 __u32 addip_serial;
1742
1743 /* SCTP-AUTH: We need to know pears random number, hmac list
1744 * and authenticated chunk list. All that is part of the
1745 * cookie and these are just pointers to those locations
1746 */
1747 struct sctp_random_param *peer_random;
1748 struct sctp_chunks_param *peer_chunks;
1749 struct sctp_hmac_algo_param *peer_hmacs;
1750 } peer;
1751
1752 /* State : A state variable indicating what state the
1753 * : association is in, i.e. COOKIE-WAIT,
1754 * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1755 * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1756 *
1757 * Note: No "CLOSED" state is illustrated since if a
1758 * association is "CLOSED" its TCB SHOULD be removed.
1759 *
1760 * In this implementation we DO have a CLOSED
1761 * state which is used during initiation and shutdown.
1762 *
1763 * State takes values from SCTP_STATE_*.
1764 */
1765 enum sctp_state state;
1766
1767 /* Overall : The overall association error count.
1768 * Error Count : [Clear this any time I get something.]
1769 */
1770 int overall_error_count;
1771
1772 /* The cookie life I award for any cookie. */
1773 ktime_t cookie_life;
1774
1775 /* These are the association's initial, max, and min RTO values.
1776 * These values will be initialized by system defaults, but can
1777 * be modified via the SCTP_RTOINFO socket option.
1778 */
1779 unsigned long rto_initial;
1780 unsigned long rto_max;
1781 unsigned long rto_min;
1782
1783 /* Maximum number of new data packets that can be sent in a burst. */
1784 int max_burst;
1785
1786 /* This is the max_retrans value for the association. This value will
1787 * be initialized from system defaults, but can be
1788 * modified by the SCTP_ASSOCINFO socket option.
1789 */
1790 int max_retrans;
1791
1792 /* This is the partially failed retrans value for the transport
1793 * and will be initialized from the assocs value. This can be
1794 * changed using the SCTP_PEER_ADDR_THLDS socket option
1795 */
1796 __u16 pf_retrans;
1797 /* Used for primary path switchover. */
1798 __u16 ps_retrans;
1799
1800 /* Maximum number of times the endpoint will retransmit INIT */
1801 __u16 max_init_attempts;
1802
1803 /* How many times have we resent an INIT? */
1804 __u16 init_retries;
1805
1806 /* The largest timeout or RTO value to use in attempting an INIT */
1807 unsigned long max_init_timeo;
1808
1809 /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1810 * the destination address every heartbeat interval. This value
1811 * will be inherited by all new transports.
1812 */
1813 unsigned long hbinterval;
1814 unsigned long probe_interval;
1815
1816 __be16 encap_port;
1817
1818 /* This is the max_retrans value for new transports in the
1819 * association.
1820 */
1821 __u16 pathmaxrxt;
1822
1823 __u32 flowlabel;
1824 __u8 dscp;
1825
1826 /* Flag that path mtu update is pending */
1827 __u8 pmtu_pending;
1828
1829 /* Association : The smallest PMTU discovered for all of the
1830 * PMTU : peer's transport addresses.
1831 */
1832 __u32 pathmtu;
1833
1834 /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1835 __u32 param_flags;
1836
1837 __u32 sackfreq;
1838 /* SACK delay timeout */
1839 unsigned long sackdelay;
1840
1841 unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1842 struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1843
1844 /* Transport to which SHUTDOWN chunk was last sent. */
1845 struct sctp_transport *shutdown_last_sent_to;
1846
1847 /* Transport to which INIT chunk was last sent. */
1848 struct sctp_transport *init_last_sent_to;
1849
1850 /* How many times have we resent a SHUTDOWN */
1851 int shutdown_retries;
1852
1853 /* Next TSN : The next TSN number to be assigned to a new
1854 * : DATA chunk. This is sent in the INIT or INIT
1855 * : ACK chunk to the peer and incremented each
1856 * : time a DATA chunk is assigned a TSN
1857 * : (normally just prior to transmit or during
1858 * : fragmentation).
1859 */
1860 __u32 next_tsn;
1861
1862 /*
1863 * Last Rcvd : This is the last TSN received in sequence. This value
1864 * TSN : is set initially by taking the peer's Initial TSN,
1865 * : received in the INIT or INIT ACK chunk, and
1866 * : subtracting one from it.
1867 *
1868 * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1869 */
1870
1871 __u32 ctsn_ack_point;
1872
1873 /* PR-SCTP Advanced.Peer.Ack.Point */
1874 __u32 adv_peer_ack_point;
1875
1876 /* Highest TSN that is acknowledged by incoming SACKs. */
1877 __u32 highest_sacked;
1878
1879 /* TSN marking the fast recovery exit point */
1880 __u32 fast_recovery_exit;
1881
1882 /* Flag to track the current fast recovery state */
1883 __u8 fast_recovery;
1884
1885 /* The number of unacknowledged data chunks. Reported through
1886 * the SCTP_STATUS sockopt.
1887 */
1888 __u16 unack_data;
1889
1890 /* The total number of data chunks that we've had to retransmit
1891 * as the result of a T3 timer expiration
1892 */
1893 __u32 rtx_data_chunks;
1894
1895 /* This is the association's receive buffer space. This value is used
1896 * to set a_rwnd field in an INIT or a SACK chunk.
1897 */
1898 __u32 rwnd;
1899
1900 /* This is the last advertised value of rwnd over a SACK chunk. */
1901 __u32 a_rwnd;
1902
1903 /* Number of bytes by which the rwnd has slopped. The rwnd is allowed
1904 * to slop over a maximum of the association's frag_point.
1905 */
1906 __u32 rwnd_over;
1907
1908 /* Keeps treack of rwnd pressure. This happens when we have
1909 * a window, but not recevie buffer (i.e small packets). This one
1910 * is releases slowly (1 PMTU at a time ).
1911 */
1912 __u32 rwnd_press;
1913
1914 /* This is the sndbuf size in use for the association.
1915 * This corresponds to the sndbuf size for the association,
1916 * as specified in the sk->sndbuf.
1917 */
1918 int sndbuf_used;
1919
1920 /* This is the amount of memory that this association has allocated
1921 * in the receive path at any given time.
1922 */
1923 atomic_t rmem_alloc;
1924
1925 /* This is the wait queue head for send requests waiting on
1926 * the association sndbuf space.
1927 */
1928 wait_queue_head_t wait;
1929
1930 /* The message size at which SCTP fragmentation will occur. */
1931 __u32 frag_point;
1932 __u32 user_frag;
1933
1934 /* Counter used to count INIT errors. */
1935 int init_err_counter;
1936
1937 /* Count the number of INIT cycles (for doubling timeout). */
1938 int init_cycle;
1939
1940 /* Default send parameters. */
1941 __u16 default_stream;
1942 __u16 default_flags;
1943 __u32 default_ppid;
1944 __u32 default_context;
1945 __u32 default_timetolive;
1946
1947 /* Default receive parameters */
1948 __u32 default_rcv_context;
1949
1950 /* Stream arrays */
1951 struct sctp_stream stream;
1952
1953 /* All outbound chunks go through this structure. */
1954 struct sctp_outq outqueue;
1955
1956 /* A smart pipe that will handle reordering and fragmentation,
1957 * as well as handle passing events up to the ULP.
1958 */
1959 struct sctp_ulpq ulpq;
1960
1961 /* Last TSN that caused an ECNE Chunk to be sent. */
1962 __u32 last_ecne_tsn;
1963
1964 /* Last TSN that caused a CWR Chunk to be sent. */
1965 __u32 last_cwr_tsn;
1966
1967 /* How many duplicated TSNs have we seen? */
1968 int numduptsns;
1969
1970 /* These are to support
1971 * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1972 * and Enforcement of Flow and Message Limits"
1973 * <draft-ietf-tsvwg-addip-sctp-02.txt>
1974 * or "ADDIP" for short.
1975 */
1976
1977
1978
1979 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1980 *
1981 * R1) One and only one ASCONF Chunk MAY be in transit and
1982 * unacknowledged at any one time. If a sender, after sending
1983 * an ASCONF chunk, decides it needs to transfer another
1984 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1985 * returns from the previous ASCONF Chunk before sending a
1986 * subsequent ASCONF. Note this restriction binds each side,
1987 * so at any time two ASCONF may be in-transit on any given
1988 * association (one sent from each endpoint).
1989 *
1990 * [This is our one-and-only-one ASCONF in flight. If we do
1991 * not have an ASCONF in flight, this is NULL.]
1992 */
1993 struct sctp_chunk *addip_last_asconf;
1994
1995 /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1996 *
1997 * This is needed to implement itmes E1 - E4 of the updated
1998 * spec. Here is the justification:
1999 *
2000 * Since the peer may bundle multiple ASCONF chunks toward us,
2001 * we now need the ability to cache multiple ACKs. The section
2002 * describes in detail how they are cached and cleaned up.
2003 */
2004 struct list_head asconf_ack_list;
2005
2006 /* These ASCONF chunks are waiting to be sent.
2007 *
2008 * These chunaks can't be pushed to outqueue until receiving
2009 * ASCONF_ACK for the previous ASCONF indicated by
2010 * addip_last_asconf, so as to guarantee that only one ASCONF
2011 * is in flight at any time.
2012 *
2013 * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
2014 *
2015 * In defining the ASCONF Chunk transfer procedures, it is
2016 * essential that these transfers MUST NOT cause congestion
2017 * within the network. To achieve this, we place these
2018 * restrictions on the transfer of ASCONF Chunks:
2019 *
2020 * R1) One and only one ASCONF Chunk MAY be in transit and
2021 * unacknowledged at any one time. If a sender, after sending
2022 * an ASCONF chunk, decides it needs to transfer another
2023 * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2024 * returns from the previous ASCONF Chunk before sending a
2025 * subsequent ASCONF. Note this restriction binds each side,
2026 * so at any time two ASCONF may be in-transit on any given
2027 * association (one sent from each endpoint).
2028 *
2029 *
2030 * [I really think this is EXACTLY the sort of intelligence
2031 * which already resides in sctp_outq. Please move this
2032 * queue and its supporting logic down there. --piggy]
2033 */
2034 struct list_head addip_chunk_list;
2035
2036 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2037 *
2038 * A2) A serial number should be assigned to the Chunk. The
2039 * serial number SHOULD be a monotonically increasing
2040 * number. The serial number SHOULD be initialized at
2041 * the start of the association to the same value as the
2042 * Initial TSN and every time a new ASCONF chunk is created
2043 * it is incremented by one after assigning the serial number
2044 * to the newly created chunk.
2045 *
2046 * ADDIP
2047 * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF)
2048 *
2049 * Serial Number : 32 bits (unsigned integer)
2050 *
2051 * This value represents a Serial Number for the ASCONF
2052 * Chunk. The valid range of Serial Number is from 0 to
2053 * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0
2054 * after reaching 4294967295.
2055 */
2056 __u32 addip_serial;
2057 int src_out_of_asoc_ok;
2058 union sctp_addr *asconf_addr_del_pending;
2059 struct sctp_transport *new_transport;
2060
2061 /* SCTP AUTH: list of the endpoint shared keys. These
2062 * keys are provided out of band by the user applicaton
2063 * and can't change during the lifetime of the association
2064 */
2065 struct list_head endpoint_shared_keys;
2066
2067 /* SCTP AUTH:
2068 * The current generated assocaition shared key (secret)
2069 */
2070 struct sctp_auth_bytes *asoc_shared_key;
2071 struct sctp_shared_key *shkey;
2072
2073 /* SCTP AUTH: hmac id of the first peer requested algorithm
2074 * that we support.
2075 */
2076 __u16 default_hmac_id;
2077
2078 __u16 active_key_id;
2079
2080 __u8 need_ecne:1, /* Need to send an ECNE Chunk? */
2081 temp:1, /* Is it a temporary association? */
2082 pf_expose:2, /* Expose pf state? */
2083 force_delay:1;
2084
2085 __u8 strreset_enable;
2086 __u8 strreset_outstanding; /* request param count on the fly */
2087
2088 __u32 strreset_outseq; /* Update after receiving response */
2089 __u32 strreset_inseq; /* Update after receiving request */
2090 __u32 strreset_result[2]; /* save the results of last 2 responses */
2091
2092 struct sctp_chunk *strreset_chunk; /* save request chunk */
2093
2094 struct sctp_priv_assoc_stats stats;
2095
2096 int sent_cnt_removable;
2097
2098 __u16 subscribe;
2099
2100 __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2101 __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2102
2103 /* Security identifiers from incoming (INIT). These are set by
2104 * security_sctp_assoc_request(). These will only be used by
2105 * SCTP TCP type sockets and peeled off connections as they
2106 * cause a new socket to be generated. security_sctp_sk_clone()
2107 * will then plug these into the new socket.
2108 */
2109
2110 u32 secid;
2111 u32 peer_secid;
2112
2113 struct rcu_head rcu;
2114 };
2115
2116
2117 /* An eyecatcher for determining if we are really looking at an
2118 * association data structure.
2119 */
2120 enum {
2121 SCTP_ASSOC_EYECATCHER = 0xa550c123,
2122 };
2123
2124 /* Recover the outter association structure. */
sctp_assoc(struct sctp_ep_common * base)2125 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2126 {
2127 struct sctp_association *asoc;
2128
2129 asoc = container_of(base, struct sctp_association, base);
2130 return asoc;
2131 }
2132
2133 /* These are function signatures for manipulating associations. */
2134
2135
2136 struct sctp_association *
2137 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2138 enum sctp_scope scope, gfp_t gfp);
2139 void sctp_association_free(struct sctp_association *);
2140 void sctp_association_put(struct sctp_association *);
2141 void sctp_association_hold(struct sctp_association *);
2142
2143 struct sctp_transport *sctp_assoc_choose_alter_transport(
2144 struct sctp_association *, struct sctp_transport *);
2145 void sctp_assoc_update_retran_path(struct sctp_association *);
2146 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2147 const union sctp_addr *);
2148 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2149 const union sctp_addr *laddr);
2150 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2151 const union sctp_addr *address,
2152 const gfp_t gfp,
2153 const int peer_state);
2154 void sctp_assoc_del_peer(struct sctp_association *asoc,
2155 const union sctp_addr *addr);
2156 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2157 struct sctp_transport *peer);
2158 void sctp_assoc_control_transport(struct sctp_association *asoc,
2159 struct sctp_transport *transport,
2160 enum sctp_transport_cmd command,
2161 sctp_sn_error_t error);
2162 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2163 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2164 int sctp_assoc_update(struct sctp_association *old,
2165 struct sctp_association *new);
2166
2167 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2168
2169 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2170 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2171 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2172 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2173 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2174 void sctp_assoc_set_primary(struct sctp_association *,
2175 struct sctp_transport *);
2176 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2177 struct sctp_transport *);
2178 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2179 enum sctp_scope scope, gfp_t gfp);
2180 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2181 struct sctp_cookie*,
2182 gfp_t gfp);
2183 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2184 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2185 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2186 const struct sctp_association *asoc,
2187 __be32 serial);
2188 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2189
2190 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2191 const union sctp_addr *ss2);
2192 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2193
2194 /* A convenience structure to parse out SCTP specific CMSGs. */
2195 struct sctp_cmsgs {
2196 struct sctp_initmsg *init;
2197 struct sctp_sndrcvinfo *srinfo;
2198 struct sctp_sndinfo *sinfo;
2199 struct sctp_prinfo *prinfo;
2200 struct sctp_authinfo *authinfo;
2201 struct msghdr *addrs_msg;
2202 };
2203
2204 /* Structure for tracking memory objects */
2205 struct sctp_dbg_objcnt_entry {
2206 char *label;
2207 atomic_t *counter;
2208 };
2209
2210 #endif /* __sctp_structs_h__ */
2211