1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These are definitions needed by the state machine.
10 *
11 * This SCTP 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 * This SCTP 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 */
63 typedef 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
75 typedef struct {
76 int name;
77 int action;
78 } sctp_sm_command_t;
79
80 typedef 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 *);
85 typedef void (sctp_timer_event_t) (unsigned long);
86 typedef 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. */
96 sctp_state_fn_t sctp_sf_not_impl;
97 sctp_state_fn_t sctp_sf_bug;
98
99 /* Prototypes for gener timer state functions. */
100 sctp_state_fn_t sctp_sf_timer_ignore;
101
102 /* Prototypes for chunk state functions. */
103 sctp_state_fn_t sctp_sf_do_9_1_abort;
104 sctp_state_fn_t sctp_sf_cookie_wait_abort;
105 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
106 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
107 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
108 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
109 sctp_state_fn_t sctp_sf_do_5_1B_init;
110 sctp_state_fn_t sctp_sf_do_5_1C_ack;
111 sctp_state_fn_t sctp_sf_do_5_1D_ce;
112 sctp_state_fn_t sctp_sf_do_5_1E_ca;
113 sctp_state_fn_t sctp_sf_do_4_C;
114 sctp_state_fn_t sctp_sf_eat_data_6_2;
115 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
116 sctp_state_fn_t sctp_sf_eat_sack_6_2;
117 sctp_state_fn_t sctp_sf_operr_notify;
118 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
119 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
120 sctp_state_fn_t sctp_sf_t2_timer_expire;
121 sctp_state_fn_t sctp_sf_t4_timer_expire;
122 sctp_state_fn_t sctp_sf_t5_timer_expire;
123 sctp_state_fn_t sctp_sf_sendbeat_8_3;
124 sctp_state_fn_t sctp_sf_beat_8_3;
125 sctp_state_fn_t sctp_sf_backbeat_8_3;
126 sctp_state_fn_t sctp_sf_do_9_2_final;
127 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
128 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
129 sctp_state_fn_t sctp_sf_do_ecn_cwr;
130 sctp_state_fn_t sctp_sf_do_ecne;
131 sctp_state_fn_t sctp_sf_ootb;
132 sctp_state_fn_t sctp_sf_pdiscard;
133 sctp_state_fn_t sctp_sf_violation;
134 sctp_state_fn_t sctp_sf_discard_chunk;
135 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
136 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
137 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
138 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
139 sctp_state_fn_t sctp_sf_unk_chunk;
140 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
141 sctp_state_fn_t sctp_sf_cookie_echoed_err;
142 sctp_state_fn_t sctp_sf_do_asconf;
143 sctp_state_fn_t sctp_sf_do_asconf_ack;
144 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
145 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
146 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
147 sctp_state_fn_t sctp_sf_eat_auth;
148
149 /* Prototypes for primitive event state functions. */
150 sctp_state_fn_t sctp_sf_do_prm_asoc;
151 sctp_state_fn_t sctp_sf_do_prm_send;
152 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
153 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
154 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
155 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
156 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
157 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
158 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
159 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
160 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
161 sctp_state_fn_t sctp_sf_error_closed;
162 sctp_state_fn_t sctp_sf_error_shutdown;
163 sctp_state_fn_t sctp_sf_ignore_primitive;
164 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
165 sctp_state_fn_t sctp_sf_do_prm_asconf;
166
167 /* Prototypes for other event state functions. */
168 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
169 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
170 sctp_state_fn_t sctp_sf_ignore_other;
171 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
172
173 /* Prototypes for timeout event state functions. */
174 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
175 sctp_state_fn_t sctp_sf_do_6_2_sack;
176 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
177
178 /* Prototypes for utility support functions. */
179 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
180 const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t,
181 sctp_state_t,
182 sctp_subtype_t);
183 int sctp_chunk_iif(const struct sctp_chunk *);
184 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
185 struct sctp_chunk *,
186 gfp_t gfp);
187 __u32 sctp_generate_verification_tag(void);
188 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
189
190 /* Prototypes for chunk-building functions. */
191 struct sctp_chunk *sctp_make_init(const struct sctp_association *,
192 const struct sctp_bind_addr *,
193 gfp_t gfp, int vparam_len);
194 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *,
195 const struct sctp_chunk *,
196 const gfp_t gfp,
197 const int unkparam_len);
198 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *,
199 const struct sctp_chunk *);
200 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *,
201 const struct sctp_chunk *);
202 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *,
203 const __u32 lowest_tsn,
204 const struct sctp_chunk *);
205 struct sctp_chunk * sctp_make_datafrag_empty(struct sctp_association *,
206 const struct sctp_sndrcvinfo *sinfo,
207 int len, const __u8 flags,
208 __u16 ssn);
209 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *,
210 const __u32);
211 struct sctp_chunk *sctp_make_sack(const struct sctp_association *);
212 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
213 const struct sctp_chunk *chunk);
214 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
215 const struct sctp_chunk *);
216 struct sctp_chunk *sctp_make_shutdown_complete(const struct sctp_association *,
217 const struct sctp_chunk *);
218 void sctp_init_cause(struct sctp_chunk *, __be16 cause, size_t);
219 struct sctp_chunk *sctp_make_abort(const struct sctp_association *,
220 const struct sctp_chunk *,
221 const size_t hint);
222 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *,
223 const struct sctp_chunk *,
224 __u32 tsn);
225 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *,
226 const struct msghdr *, size_t msg_len);
227 struct sctp_chunk *sctp_make_abort_violation(const struct sctp_association *,
228 const struct sctp_chunk *,
229 const __u8 *,
230 const size_t );
231 struct sctp_chunk *sctp_make_violation_paramlen(const struct sctp_association *,
232 const struct sctp_chunk *,
233 struct sctp_paramhdr *);
234 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *,
235 const struct sctp_transport *,
236 const void *payload,
237 const size_t paylen);
238 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *,
239 const struct sctp_chunk *,
240 const void *payload,
241 const size_t paylen);
242 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *,
243 const struct sctp_chunk *chunk,
244 __be16 cause_code,
245 const void *payload,
246 size_t paylen,
247 size_t reserve_tail);
248
249 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
250 union sctp_addr *,
251 struct sockaddr *,
252 int, __be16);
253 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
254 union sctp_addr *addr);
255 int sctp_verify_asconf(const struct sctp_association *asoc,
256 struct sctp_paramhdr *param_hdr, void *chunk_end,
257 struct sctp_paramhdr **errp);
258 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
259 struct sctp_chunk *asconf);
260 int sctp_process_asconf_ack(struct sctp_association *asoc,
261 struct sctp_chunk *asconf_ack);
262 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
263 __u32 new_cum_tsn, size_t nstreams,
264 struct sctp_fwdtsn_skip *skiplist);
265 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
266
267 void sctp_chunk_assign_tsn(struct sctp_chunk *);
268 void sctp_chunk_assign_ssn(struct sctp_chunk *);
269
270 /* Prototypes for statetable processing. */
271
272 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
273 sctp_state_t state,
274 struct sctp_endpoint *,
275 struct sctp_association *asoc,
276 void *event_arg,
277 gfp_t gfp);
278
279 /* 2nd level prototypes */
280 void sctp_generate_t3_rtx_event(unsigned long peer);
281 void sctp_generate_heartbeat_event(unsigned long peer);
282 void sctp_generate_proto_unreach_event(unsigned long peer);
283
284 void sctp_ootb_pkt_free(struct sctp_packet *);
285
286 struct sctp_association *sctp_unpack_cookie(const struct sctp_endpoint *,
287 const struct sctp_association *,
288 struct sctp_chunk *,
289 gfp_t gfp, int *err,
290 struct sctp_chunk **err_chk_p);
291 int sctp_addip_addr_config(struct sctp_association *, sctp_param_t,
292 struct sockaddr_storage*, int);
293
294 /* 3rd level prototypes */
295 __u32 sctp_generate_tag(const struct sctp_endpoint *);
296 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
297
298 /* Extern declarations for major data structures. */
299 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
300
301
302 /* Get the size of a DATA chunk payload. */
sctp_data_size(struct sctp_chunk * chunk)303 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
304 {
305 __u16 size;
306
307 size = ntohs(chunk->chunk_hdr->length);
308 size -= sizeof(sctp_data_chunk_t);
309
310 return size;
311 }
312
313 /* Compare two TSNs */
314
315 /* RFC 1982 - Serial Number Arithmetic
316 *
317 * 2. Comparison
318 * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,
319 * in all other cases, s1 is not equal to s2.
320 *
321 * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,
322 * and
323 *
324 * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or
325 * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))
326 *
327 * s1 is said to be greater than s2 if, and only if, s1 is not equal to
328 * s2, and
329 *
330 * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or
331 * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))
332 */
333
334 /*
335 * RFC 2960
336 * 1.6 Serial Number Arithmetic
337 *
338 * Comparisons and arithmetic on TSNs in this document SHOULD use Serial
339 * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.
340 */
341
342 enum {
343 TSN_SIGN_BIT = (1<<31)
344 };
345
TSN_lt(__u32 s,__u32 t)346 static inline int TSN_lt(__u32 s, __u32 t)
347 {
348 return ((s) - (t)) & TSN_SIGN_BIT;
349 }
350
TSN_lte(__u32 s,__u32 t)351 static inline int TSN_lte(__u32 s, __u32 t)
352 {
353 return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT);
354 }
355
356 /* Compare two SSNs */
357
358 /*
359 * RFC 2960
360 * 1.6 Serial Number Arithmetic
361 *
362 * Comparisons and arithmetic on Stream Sequence Numbers in this document
363 * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where
364 * SERIAL_BITS = 16.
365 */
366 enum {
367 SSN_SIGN_BIT = (1<<15)
368 };
369
SSN_lt(__u16 s,__u16 t)370 static inline int SSN_lt(__u16 s, __u16 t)
371 {
372 return ((s) - (t)) & SSN_SIGN_BIT;
373 }
374
SSN_lte(__u16 s,__u16 t)375 static inline int SSN_lte(__u16 s, __u16 t)
376 {
377 return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT);
378 }
379
380 /*
381 * ADDIP 3.1.1
382 * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial
383 * Numbers wrap back to 0 after reaching 4294967295.
384 */
385 enum {
386 ADDIP_SERIAL_SIGN_BIT = (1<<31)
387 };
388
ADDIP_SERIAL_gte(__u16 s,__u16 t)389 static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)
390 {
391 return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT);
392 }
393
394 /* Check VTAG of the packet matches the sender's own tag. */
395 static inline int
sctp_vtag_verify(const struct sctp_chunk * chunk,const struct sctp_association * asoc)396 sctp_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
411 /* 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.
413 */
414 static inline int
sctp_vtag_verify_either(const struct sctp_chunk * chunk,const struct sctp_association * asoc)415 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
416 const struct sctp_association *asoc)
417 {
418 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
419 *
420 * 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.
428 *
429 * 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.
438 */
439 if ((!sctp_test_T_bit(chunk) &&
440 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
441 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
442 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
443 return 1;
444 }
445
446 return 0;
447 }
448
449 #endif /* __sctp_sm_h__ */
450