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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel reference Implementation
8 *
9 * These are definitions needed by the state machine.
10 *
11 * The SCTP reference implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * The SCTP reference implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, write to
25 * the Free Software Foundation, 59 Temple Place - Suite 330,
26 * Boston, MA 02111-1307, USA.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email addresses:
30 * lksctp developers <lksctp-developers@lists.sourceforge.net>
31 *
32 * Or submit a bug report through the following website:
33 * http://www.sf.net/projects/lksctp
34 *
35 * Written or modified by:
36 * La Monte H.P. Yarroll <piggy@acm.org>
37 * Karl Knutson <karl@athena.chicago.il.us>
38 * Xingang Guo <xingang.guo@intel.com>
39 * Jon Grimm <jgrimm@us.ibm.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Sridhar Samudrala <sri@us.ibm.com>
42 * Daisy Chang <daisyc@us.ibm.com>
43 * Ardelle Fan <ardelle.fan@intel.com>
44 * Kevin Gao <kevin.gao@intel.com>
45 *
46 * Any bugs reported given to us we will try to fix... any fixes shared will
47 * be incorporated into the next SCTP release.
48 */
49
50#include <linux/types.h>
51#include <linux/compiler.h>
52#include <linux/slab.h>
53#include <linux/in.h>
54#include <net/sctp/command.h>
55#include <net/sctp/sctp.h>
56
57#ifndef __sctp_sm_h__
58#define __sctp_sm_h__
59
60/*
61 * Possible values for the disposition are:
62 */
63typedef enum {
64 SCTP_DISPOSITION_DISCARD, /* No further processing. */
65 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */
66 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */
67 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */
68 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */
69 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */
70 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */
71 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */
72 SCTP_DISPOSITION_BUG, /* This is a bug. */
73} sctp_disposition_t;
74
75typedef struct {
76 int name;
77 int action;
78} sctp_sm_command_t;
79
80typedef sctp_disposition_t (sctp_state_fn_t) (const struct sctp_endpoint *,
81 const struct sctp_association *,
82 const sctp_subtype_t type,
83 void *arg,
84 sctp_cmd_seq_t *);
85typedef void (sctp_timer_event_t) (unsigned long);
86typedef struct {
87 sctp_state_fn_t *fn;
88 const char *name;
89} sctp_sm_table_entry_t;
90
91/* A naming convention of "sctp_sf_xxx" applies to all the state functions
92 * currently in use.
93 */
94
95/* Prototypes for generic state functions. */
96sctp_state_fn_t sctp_sf_not_impl;
97sctp_state_fn_t sctp_sf_bug;
98
99/* Prototypes for gener timer state functions. */
100sctp_state_fn_t sctp_sf_timer_ignore;
101
102/* Prototypes for chunk state functions. */
103sctp_state_fn_t sctp_sf_do_9_1_abort;
104sctp_state_fn_t sctp_sf_cookie_wait_abort;
105sctp_state_fn_t sctp_sf_cookie_echoed_abort;
106sctp_state_fn_t sctp_sf_shutdown_pending_abort;
107sctp_state_fn_t sctp_sf_shutdown_sent_abort;
108sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
109sctp_state_fn_t sctp_sf_do_5_1B_init;
110sctp_state_fn_t sctp_sf_do_5_1C_ack;
111sctp_state_fn_t sctp_sf_do_5_1D_ce;
112sctp_state_fn_t sctp_sf_do_5_1E_ca;
113sctp_state_fn_t sctp_sf_do_4_C;
114sctp_state_fn_t sctp_sf_eat_data_6_2;
115sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
116sctp_state_fn_t sctp_sf_eat_sack_6_2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117sctp_state_fn_t sctp_sf_operr_notify;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700118sctp_state_fn_t sctp_sf_t1_init_timer_expire;
119sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120sctp_state_fn_t sctp_sf_t2_timer_expire;
121sctp_state_fn_t sctp_sf_t4_timer_expire;
122sctp_state_fn_t sctp_sf_t5_timer_expire;
123sctp_state_fn_t sctp_sf_sendbeat_8_3;
124sctp_state_fn_t sctp_sf_beat_8_3;
125sctp_state_fn_t sctp_sf_backbeat_8_3;
126sctp_state_fn_t sctp_sf_do_9_2_final;
127sctp_state_fn_t sctp_sf_do_9_2_shutdown;
128sctp_state_fn_t sctp_sf_do_ecn_cwr;
129sctp_state_fn_t sctp_sf_do_ecne;
130sctp_state_fn_t sctp_sf_ootb;
131sctp_state_fn_t sctp_sf_pdiscard;
132sctp_state_fn_t sctp_sf_violation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133sctp_state_fn_t sctp_sf_discard_chunk;
134sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
135sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
Vlad Yasevich610ab732007-01-15 19:18:30 -0800136sctp_state_fn_t sctp_sf_do_5_2_3_initack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
138sctp_state_fn_t sctp_sf_unk_chunk;
139sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
140sctp_state_fn_t sctp_sf_cookie_echoed_err;
141sctp_state_fn_t sctp_sf_do_asconf;
142sctp_state_fn_t sctp_sf_do_asconf_ack;
143sctp_state_fn_t sctp_sf_do_9_2_reshutack;
144sctp_state_fn_t sctp_sf_eat_fwd_tsn;
145sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
146
147/* Prototypes for primitive event state functions. */
148sctp_state_fn_t sctp_sf_do_prm_asoc;
149sctp_state_fn_t sctp_sf_do_prm_send;
150sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
151sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
152sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
153sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
154sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
155sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
156sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
157sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
158sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
159sctp_state_fn_t sctp_sf_error_closed;
160sctp_state_fn_t sctp_sf_error_shutdown;
161sctp_state_fn_t sctp_sf_ignore_primitive;
162sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
163sctp_state_fn_t sctp_sf_do_prm_asconf;
164
165/* Prototypes for other event state functions. */
166sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
167sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
168sctp_state_fn_t sctp_sf_ignore_other;
169sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
170
171/* Prototypes for timeout event state functions. */
172sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
173sctp_state_fn_t sctp_sf_do_6_2_sack;
174sctp_state_fn_t sctp_sf_autoclose_timer_expire;
175
176/* Prototypes for utility support functions. */
177__u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
178const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t,
179 sctp_state_t,
180 sctp_subtype_t);
181int sctp_chunk_iif(const struct sctp_chunk *);
182struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
183 struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100184 gfp_t gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185__u32 sctp_generate_verification_tag(void);
186void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
187
188/* Prototypes for chunk-building functions. */
189struct sctp_chunk *sctp_make_init(const struct sctp_association *,
190 const struct sctp_bind_addr *,
Al Virodd0fc662005-10-07 07:46:04 +0100191 gfp_t gfp, int vparam_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,
193 const struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100194 const gfp_t gfp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 const int unkparam_len);
196struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,
197 const struct sctp_chunk *);
198struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,
199 const struct sctp_chunk *);
200struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,
201 const __u32 lowest_tsn,
202 const struct sctp_chunk *);
203struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,
204 const struct sctp_sndrcvinfo *sinfo,
205 int len, const __u8 flags,
206 __u16 ssn);
207struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
208 const __u32);
209struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
210struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
211 const struct sctp_chunk *chunk);
212struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
213 const struct sctp_chunk *);
214struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
215 const struct sctp_chunk *);
Wei Yongjun00f1c2d2007-08-21 15:50:01 +0800216void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
218 const struct sctp_chunk *,
219 const size_t hint);
220struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,
221 const struct sctp_chunk *,
222 __u32 tsn);
223struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,
Sridhar Samudralac164a9b2006-08-22 11:50:39 -0700224 const struct msghdr *, size_t msg_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
226 const struct sctp_chunk *,
227 const __u8 *,
228 const size_t );
229struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
230 const struct sctp_transport *,
231 const void *payload,
232 const size_t paylen);
233struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
234 const struct sctp_chunk *,
235 const void *payload,
236 const size_t paylen);
237struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,
238 const struct sctp_chunk *chunk,
Al Viro63706c52006-11-20 17:00:05 -0800239 __be16 cause_code,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 const void *payload,
241 size_t paylen);
242
243struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
244 union sctp_addr *,
245 struct sockaddr *,
Al Virodbc16db2006-11-20 17:01:42 -0800246 int, __be16);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
248 union sctp_addr *addr);
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800249int sctp_verify_asconf(const struct sctp_association *asoc,
250 struct sctp_paramhdr *param_hdr, void *chunk_end,
251 struct sctp_paramhdr **errp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
253 struct sctp_chunk *asconf);
254int sctp_process_asconf_ack(struct sctp_association *asoc,
255 struct sctp_chunk *asconf_ack);
256struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
257 __u32 new_cum_tsn, size_t nstreams,
258 struct sctp_fwdtsn_skip *skiplist);
259
260void sctp_chunk_assign_tsn(struct sctp_chunk *);
261void sctp_chunk_assign_ssn(struct sctp_chunk *);
262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263/* Prototypes for statetable processing. */
264
265int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
266 sctp_state_t state,
267 struct sctp_endpoint *,
268 struct sctp_association *asoc,
269 void *event_arg,
Al Virodd0fc662005-10-07 07:46:04 +0100270 gfp_t gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
272/* 2nd level prototypes */
273void sctp_generate_t3_rtx_event(unsigned long peer);
274void sctp_generate_heartbeat_event(unsigned long peer);
275
276void sctp_ootb_pkt_free(struct sctp_packet *);
277
278struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,
279 const struct sctp_association *,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -0700280 struct sctp_chunk *,
Al Virodd0fc662005-10-07 07:46:04 +0100281 gfp_t gfp, int *err,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 struct sctp_chunk **err_chk_p);
283int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,
284 struct sockaddr_storage*, int);
285
286/* 3rd level prototypes */
287__u32 sctp_generate_tag(const struct sctp_endpoint *);
288__u32 sctp_generate_tsn(const struct sctp_endpoint *);
289
290/* Extern declarations for major data structures. */
291extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
292
293
294/* Get the size of a DATA chunk payload. */
295static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
296{
297 __u16 size;
298
299 size = ntohs(chunk->chunk_hdr->length);
300 size -= sizeof(sctp_data_chunk_t);
301
302 return size;
303}
304
305/* Compare two TSNs */
306
307/* RFC 1982 - Serial Number Arithmetic
308 *
309 * 2. Comparison
310 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,
311 * in all other cases, s1 is not equal to s2.
312 *
313 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,
314 * and
315 *
316 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or
317 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))
318 *
319 * s1 is said to be greater than s2 if, and only if, s1 is not equal to
320 * s2, and
321 *
322 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or
323 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))
324 */
325
326/*
327 * RFC 2960
328 * 1.6 Serial Number Arithmetic
329 *
330 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial
331 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.
332 */
333
334enum {
335 TSN_SIGN_BIT = (1<<31)
336};
337
338static inline int TSN_lt(__u32 s, __u32 t)
339{
340 return (((s) - (t)) & TSN_SIGN_BIT);
341}
342
343static inline int TSN_lte(__u32 s, __u32 t)
344{
345 return (((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT));
346}
347
348/* Compare two SSNs */
349
350/*
351 * RFC 2960
352 * 1.6 Serial Number Arithmetic
353 *
354 * Comparisons and arithmetic on Stream Sequence Numbers in this document
355 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where
356 * SERIAL_BITS = 16.
357 */
358enum {
359 SSN_SIGN_BIT = (1<<15)
360};
361
362static inline int SSN_lt(__u16 s, __u16 t)
363{
364 return (((s) - (t)) & SSN_SIGN_BIT);
365}
366
367static inline int SSN_lte(__u16 s, __u16 t)
368{
369 return (((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT));
370}
371
372/*
373 * ADDIP 3.1.1
374 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial
375 * Numbers wrap back to 0 after reaching 4294967295.
376 */
377enum {
378 ADDIP_SERIAL_SIGN_BIT = (1<<31)
379};
380
381static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)
382{
383 return (((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT));
384}
385
386
387/* Run sctp_add_cmd() generating a BUG() if there is a failure. */
388static inline void sctp_add_cmd_sf(sctp_cmd_seq_t *seq, sctp_verb_t verb, sctp_arg_t obj)
389{
390 if (unlikely(!sctp_add_cmd(seq, verb, obj)))
391 BUG();
392}
393
394/* Check VTAG of the packet matches the sender's own tag. */
395static inline int
396sctp_vtag_verify(const struct sctp_chunk *chunk,
397 const struct sctp_association *asoc)
398{
399 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
400 * MUST ensure that the value in the Verification Tag field of
401 * the received SCTP packet matches its own Tag. If the received
402 * Verification Tag value does not match the receiver's own
403 * tag value, the receiver shall silently discard the packet...
404 */
405 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
406 return 1;
407
408 return 0;
409}
410
Jerome Forissier047a2422005-04-28 11:58:43 -0700411/* Check VTAG of the packet matches the sender's own tag and the T bit is
412 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 */
414static inline int
415sctp_vtag_verify_either(const struct sctp_chunk *chunk,
416 const struct sctp_association *asoc)
417{
Jerome Forissier047a2422005-04-28 11:58:43 -0700418 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700420 * B) The receiver of a ABORT MUST accept the packet
421 * if the Verification Tag field of the packet matches its own tag
422 * and the T bit is not set
423 * OR
424 * it is set to its peer's tag and the T bit is set in the Chunk
425 * Flags.
426 * Otherwise, the receiver MUST silently discard the packet
427 * and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700429 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
430 * if the Verification Tag field of the packet matches its own tag
431 * and the T bit is not set
432 * OR
433 * it is set to its peer's tag and the T bit is set in the Chunk
434 * Flags.
435 * Otherwise, the receiver MUST silently discard the packet
436 * and take no further action. An endpoint MUST ignore the
437 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 */
Jerome Forissier047a2422005-04-28 11:58:43 -0700439 if ((!sctp_test_T_bit(chunk) &&
440 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
441 (sctp_test_T_bit(chunk) &&
442 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 return 1;
444 }
445
446 return 0;
447}
448
449#endif /* __sctp_sm_h__ */