xref: /openbmc/linux/include/net/sctp/sm.h (revision 4800cd83)
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. */
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 
346 static inline int TSN_lt(__u32 s, __u32 t)
347 {
348 	return ((s) - (t)) & TSN_SIGN_BIT;
349 }
350 
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 
370 static inline int SSN_lt(__u16 s, __u16 t)
371 {
372 	return ((s) - (t)) & SSN_SIGN_BIT;
373 }
374 
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 
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
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
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