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, see
25 * <http://www.gnu.org/licenses/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email addresses:
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
31 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Karl Knutson <karl@athena.chicago.il.us>
34 * Xingang Guo <xingang.guo@intel.com>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Dajiang Zhang <dajiang.zhang@nokia.com>
37 * Sridhar Samudrala <sri@us.ibm.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Ardelle Fan <ardelle.fan@intel.com>
40 * Kevin Gao <kevin.gao@intel.com>
41 */
42
43 #include <linux/types.h>
44 #include <linux/compiler.h>
45 #include <linux/slab.h>
46 #include <linux/in.h>
47 #include <net/sctp/command.h>
48 #include <net/sctp/sctp.h>
49
50 #ifndef __sctp_sm_h__
51 #define __sctp_sm_h__
52
53 /*
54 * Possible values for the disposition are:
55 */
56 enum sctp_disposition {
57 SCTP_DISPOSITION_DISCARD, /* No further processing. */
58 SCTP_DISPOSITION_CONSUME, /* Process return values normally. */
59 SCTP_DISPOSITION_NOMEM, /* We ran out of memory--recover. */
60 SCTP_DISPOSITION_DELETE_TCB, /* Close the association. */
61 SCTP_DISPOSITION_ABORT, /* Close the association NOW. */
62 SCTP_DISPOSITION_VIOLATION, /* The peer is misbehaving. */
63 SCTP_DISPOSITION_NOT_IMPL, /* This entry is not implemented. */
64 SCTP_DISPOSITION_ERROR, /* This is plain old user error. */
65 SCTP_DISPOSITION_BUG, /* This is a bug. */
66 };
67
68 typedef enum sctp_disposition (sctp_state_fn_t) (
69 struct net *net,
70 const struct sctp_endpoint *ep,
71 const struct sctp_association *asoc,
72 const union sctp_subtype type,
73 void *arg,
74 struct sctp_cmd_seq *commands);
75 typedef void (sctp_timer_event_t) (struct timer_list *);
76 struct sctp_sm_table_entry {
77 sctp_state_fn_t *fn;
78 const char *name;
79 };
80
81 /* A naming convention of "sctp_sf_xxx" applies to all the state functions
82 * currently in use.
83 */
84
85 /* Prototypes for generic state functions. */
86 sctp_state_fn_t sctp_sf_not_impl;
87 sctp_state_fn_t sctp_sf_bug;
88
89 /* Prototypes for gener timer state functions. */
90 sctp_state_fn_t sctp_sf_timer_ignore;
91
92 /* Prototypes for chunk state functions. */
93 sctp_state_fn_t sctp_sf_do_9_1_abort;
94 sctp_state_fn_t sctp_sf_cookie_wait_abort;
95 sctp_state_fn_t sctp_sf_cookie_echoed_abort;
96 sctp_state_fn_t sctp_sf_shutdown_pending_abort;
97 sctp_state_fn_t sctp_sf_shutdown_sent_abort;
98 sctp_state_fn_t sctp_sf_shutdown_ack_sent_abort;
99 sctp_state_fn_t sctp_sf_do_5_1B_init;
100 sctp_state_fn_t sctp_sf_do_5_1C_ack;
101 sctp_state_fn_t sctp_sf_do_5_1D_ce;
102 sctp_state_fn_t sctp_sf_do_5_1E_ca;
103 sctp_state_fn_t sctp_sf_do_4_C;
104 sctp_state_fn_t sctp_sf_eat_data_6_2;
105 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
106 sctp_state_fn_t sctp_sf_eat_sack_6_2;
107 sctp_state_fn_t sctp_sf_operr_notify;
108 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
109 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;
110 sctp_state_fn_t sctp_sf_t2_timer_expire;
111 sctp_state_fn_t sctp_sf_t4_timer_expire;
112 sctp_state_fn_t sctp_sf_t5_timer_expire;
113 sctp_state_fn_t sctp_sf_sendbeat_8_3;
114 sctp_state_fn_t sctp_sf_beat_8_3;
115 sctp_state_fn_t sctp_sf_backbeat_8_3;
116 sctp_state_fn_t sctp_sf_do_9_2_final;
117 sctp_state_fn_t sctp_sf_do_9_2_shutdown;
118 sctp_state_fn_t sctp_sf_do_9_2_shut_ctsn;
119 sctp_state_fn_t sctp_sf_do_ecn_cwr;
120 sctp_state_fn_t sctp_sf_do_ecne;
121 sctp_state_fn_t sctp_sf_ootb;
122 sctp_state_fn_t sctp_sf_pdiscard;
123 sctp_state_fn_t sctp_sf_violation;
124 sctp_state_fn_t sctp_sf_discard_chunk;
125 sctp_state_fn_t sctp_sf_do_5_2_1_siminit;
126 sctp_state_fn_t sctp_sf_do_5_2_2_dupinit;
127 sctp_state_fn_t sctp_sf_do_5_2_3_initack;
128 sctp_state_fn_t sctp_sf_do_5_2_4_dupcook;
129 sctp_state_fn_t sctp_sf_unk_chunk;
130 sctp_state_fn_t sctp_sf_do_8_5_1_E_sa;
131 sctp_state_fn_t sctp_sf_cookie_echoed_err;
132 sctp_state_fn_t sctp_sf_do_asconf;
133 sctp_state_fn_t sctp_sf_do_asconf_ack;
134 sctp_state_fn_t sctp_sf_do_reconf;
135 sctp_state_fn_t sctp_sf_do_9_2_reshutack;
136 sctp_state_fn_t sctp_sf_eat_fwd_tsn;
137 sctp_state_fn_t sctp_sf_eat_fwd_tsn_fast;
138 sctp_state_fn_t sctp_sf_eat_auth;
139
140 /* Prototypes for primitive event state functions. */
141 sctp_state_fn_t sctp_sf_do_prm_asoc;
142 sctp_state_fn_t sctp_sf_do_prm_send;
143 sctp_state_fn_t sctp_sf_do_9_2_prm_shutdown;
144 sctp_state_fn_t sctp_sf_cookie_wait_prm_shutdown;
145 sctp_state_fn_t sctp_sf_cookie_echoed_prm_shutdown;
146 sctp_state_fn_t sctp_sf_do_9_1_prm_abort;
147 sctp_state_fn_t sctp_sf_cookie_wait_prm_abort;
148 sctp_state_fn_t sctp_sf_cookie_echoed_prm_abort;
149 sctp_state_fn_t sctp_sf_shutdown_pending_prm_abort;
150 sctp_state_fn_t sctp_sf_shutdown_sent_prm_abort;
151 sctp_state_fn_t sctp_sf_shutdown_ack_sent_prm_abort;
152 sctp_state_fn_t sctp_sf_error_closed;
153 sctp_state_fn_t sctp_sf_error_shutdown;
154 sctp_state_fn_t sctp_sf_ignore_primitive;
155 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
156 sctp_state_fn_t sctp_sf_do_prm_asconf;
157 sctp_state_fn_t sctp_sf_do_prm_reconf;
158
159 /* Prototypes for other event state functions. */
160 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
161 sctp_state_fn_t sctp_sf_do_9_2_start_shutdown;
162 sctp_state_fn_t sctp_sf_do_9_2_shutdown_ack;
163 sctp_state_fn_t sctp_sf_ignore_other;
164 sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
165
166 /* Prototypes for timeout event state functions. */
167 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
168 sctp_state_fn_t sctp_sf_send_reconf;
169 sctp_state_fn_t sctp_sf_do_6_2_sack;
170 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
171
172 /* Prototypes for utility support functions. */
173 __u8 sctp_get_chunk_type(struct sctp_chunk *chunk);
174 const struct sctp_sm_table_entry *sctp_sm_lookup_event(
175 struct net *net,
176 enum sctp_event event_type,
177 enum sctp_state state,
178 union sctp_subtype event_subtype);
179 int sctp_chunk_iif(const struct sctp_chunk *);
180 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *,
181 struct sctp_chunk *,
182 gfp_t gfp);
183 __u32 sctp_generate_verification_tag(void);
184 void sctp_populate_tie_tags(__u8 *cookie, __u32 curTag, __u32 hisTag);
185
186 /* Prototypes for chunk-building functions. */
187 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
188 const struct sctp_bind_addr *bp,
189 gfp_t gfp, int vparam_len);
190 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
191 const struct sctp_chunk *chunk,
192 const gfp_t gfp, const int unkparam_len);
193 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
194 const struct sctp_chunk *chunk);
195 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
196 const struct sctp_chunk *chunk);
197 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
198 const __u32 lowest_tsn,
199 const struct sctp_chunk *chunk);
200 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
201 __u8 flags, int paylen, gfp_t gfp);
202 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
203 __u32 new_cum_tsn, size_t nstreams,
204 struct sctp_ifwdtsn_skip *skiplist);
205 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
206 const struct sctp_sndrcvinfo *sinfo,
207 int len, __u8 flags, gfp_t gfp);
208 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
209 const __u32 lowest_tsn);
210 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc);
211 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
212 const struct sctp_chunk *chunk);
213 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
214 const struct sctp_chunk *chunk);
215 struct sctp_chunk *sctp_make_shutdown_complete(
216 const struct sctp_association *asoc,
217 const struct sctp_chunk *chunk);
218 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause, size_t paylen);
219 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
220 const struct sctp_chunk *chunk,
221 const size_t hint);
222 struct sctp_chunk *sctp_make_abort_no_data(const struct sctp_association *asoc,
223 const struct sctp_chunk *chunk,
224 __u32 tsn);
225 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
226 struct msghdr *msg, size_t msg_len);
227 struct sctp_chunk *sctp_make_abort_violation(
228 const struct sctp_association *asoc,
229 const struct sctp_chunk *chunk,
230 const __u8 *payload,
231 const size_t paylen);
232 struct sctp_chunk *sctp_make_violation_paramlen(
233 const struct sctp_association *asoc,
234 const struct sctp_chunk *chunk,
235 struct sctp_paramhdr *param);
236 struct sctp_chunk *sctp_make_violation_max_retrans(
237 const struct sctp_association *asoc,
238 const struct sctp_chunk *chunk);
239 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
240 const struct sctp_transport *transport);
241 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
242 const struct sctp_chunk *chunk,
243 const void *payload,
244 const size_t paylen);
245 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
246 const struct sctp_chunk *chunk,
247 __be16 cause_code, const void *payload,
248 size_t paylen, size_t reserve_tail);
249
250 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
251 union sctp_addr *laddr,
252 struct sockaddr *addrs,
253 int addrcnt, __be16 flags);
254 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
255 union sctp_addr *addr);
256 bool sctp_verify_asconf(const struct sctp_association *asoc,
257 struct sctp_chunk *chunk, bool addr_param_needed,
258 struct sctp_paramhdr **errp);
259 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
260 struct sctp_chunk *asconf);
261 int sctp_process_asconf_ack(struct sctp_association *asoc,
262 struct sctp_chunk *asconf_ack);
263 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
264 __u32 new_cum_tsn, size_t nstreams,
265 struct sctp_fwdtsn_skip *skiplist);
266 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
267 __u16 key_id);
268 struct sctp_chunk *sctp_make_strreset_req(const struct sctp_association *asoc,
269 __u16 stream_num, __be16 *stream_list,
270 bool out, bool in);
271 struct sctp_chunk *sctp_make_strreset_tsnreq(
272 const struct sctp_association *asoc);
273 struct sctp_chunk *sctp_make_strreset_addstrm(
274 const struct sctp_association *asoc,
275 __u16 out, __u16 in);
276 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
277 __u32 result, __u32 sn);
278 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
279 __u32 result, __u32 sn,
280 __u32 sender_tsn,
281 __u32 receiver_tsn);
282 bool sctp_verify_reconf(const struct sctp_association *asoc,
283 struct sctp_chunk *chunk,
284 struct sctp_paramhdr **errp);
285 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk);
286 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk);
287
288 /* Prototypes for stream-processing functions. */
289 struct sctp_chunk *sctp_process_strreset_outreq(
290 struct sctp_association *asoc,
291 union sctp_params param,
292 struct sctp_ulpevent **evp);
293 struct sctp_chunk *sctp_process_strreset_inreq(
294 struct sctp_association *asoc,
295 union sctp_params param,
296 struct sctp_ulpevent **evp);
297 struct sctp_chunk *sctp_process_strreset_tsnreq(
298 struct sctp_association *asoc,
299 union sctp_params param,
300 struct sctp_ulpevent **evp);
301 struct sctp_chunk *sctp_process_strreset_addstrm_out(
302 struct sctp_association *asoc,
303 union sctp_params param,
304 struct sctp_ulpevent **evp);
305 struct sctp_chunk *sctp_process_strreset_addstrm_in(
306 struct sctp_association *asoc,
307 union sctp_params param,
308 struct sctp_ulpevent **evp);
309 struct sctp_chunk *sctp_process_strreset_resp(
310 struct sctp_association *asoc,
311 union sctp_params param,
312 struct sctp_ulpevent **evp);
313
314 /* Prototypes for statetable processing. */
315
316 int sctp_do_sm(struct net *net, enum sctp_event event_type,
317 union sctp_subtype subtype, enum sctp_state state,
318 struct sctp_endpoint *ep, struct sctp_association *asoc,
319 void *event_arg, gfp_t gfp);
320
321 /* 2nd level prototypes */
322 void sctp_generate_t3_rtx_event(struct timer_list *t);
323 void sctp_generate_heartbeat_event(struct timer_list *t);
324 void sctp_generate_reconf_event(struct timer_list *t);
325 void sctp_generate_proto_unreach_event(struct timer_list *t);
326
327 void sctp_ootb_pkt_free(struct sctp_packet *packet);
328
329 struct sctp_association *sctp_unpack_cookie(
330 const struct sctp_endpoint *ep,
331 const struct sctp_association *asoc,
332 struct sctp_chunk *chunk,
333 gfp_t gfp, int *err,
334 struct sctp_chunk **err_chk_p);
335
336 /* 3rd level prototypes */
337 __u32 sctp_generate_tag(const struct sctp_endpoint *ep);
338 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep);
339
340 /* Extern declarations for major data structures. */
341 extern sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES];
342
343
344 /* Get the size of a DATA chunk payload. */
sctp_data_size(struct sctp_chunk * chunk)345 static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
346 {
347 __u16 size;
348
349 size = ntohs(chunk->chunk_hdr->length);
350 size -= sctp_datachk_len(&chunk->asoc->stream);
351
352 return size;
353 }
354
355 /* Compare two TSNs */
356 #define TSN_lt(a,b) \
357 (typecheck(__u32, a) && \
358 typecheck(__u32, b) && \
359 ((__s32)((a) - (b)) < 0))
360
361 #define TSN_lte(a,b) \
362 (typecheck(__u32, a) && \
363 typecheck(__u32, b) && \
364 ((__s32)((a) - (b)) <= 0))
365
366 /* Compare two MIDs */
367 #define MID_lt(a, b) \
368 (typecheck(__u32, a) && \
369 typecheck(__u32, b) && \
370 ((__s32)((a) - (b)) < 0))
371
372 /* Compare two SSNs */
373 #define SSN_lt(a,b) \
374 (typecheck(__u16, a) && \
375 typecheck(__u16, b) && \
376 ((__s16)((a) - (b)) < 0))
377
378 /* ADDIP 3.1.1 */
379 #define ADDIP_SERIAL_gte(a,b) \
380 (typecheck(__u32, a) && \
381 typecheck(__u32, b) && \
382 ((__s32)((b) - (a)) <= 0))
383
384 /* Check VTAG of the packet matches the sender's own tag. */
385 static inline int
sctp_vtag_verify(const struct sctp_chunk * chunk,const struct sctp_association * asoc)386 sctp_vtag_verify(const struct sctp_chunk *chunk,
387 const struct sctp_association *asoc)
388 {
389 /* RFC 2960 Sec 8.5 When receiving an SCTP packet, the endpoint
390 * MUST ensure that the value in the Verification Tag field of
391 * the received SCTP packet matches its own Tag. If the received
392 * Verification Tag value does not match the receiver's own
393 * tag value, the receiver shall silently discard the packet...
394 */
395 if (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)
396 return 1;
397
398 return 0;
399 }
400
401 /* Check VTAG of the packet matches the sender's own tag and the T bit is
402 * not set, OR its peer's tag and the T bit is set in the Chunk Flags.
403 */
404 static inline int
sctp_vtag_verify_either(const struct sctp_chunk * chunk,const struct sctp_association * asoc)405 sctp_vtag_verify_either(const struct sctp_chunk *chunk,
406 const struct sctp_association *asoc)
407 {
408 /* RFC 2960 Section 8.5.1, sctpimpguide Section 2.41
409 *
410 * B) The receiver of a ABORT MUST accept the packet
411 * if the Verification Tag field of the packet matches its own tag
412 * and the T bit is not set
413 * OR
414 * it is set to its peer's tag and the T bit is set in the Chunk
415 * Flags.
416 * Otherwise, the receiver MUST silently discard the packet
417 * and take no further action.
418 *
419 * C) The receiver of a SHUTDOWN COMPLETE shall accept the packet
420 * if the Verification Tag field of the packet matches its own tag
421 * and the T bit is not set
422 * OR
423 * it is set to its peer's tag and the T bit is set in the Chunk
424 * Flags.
425 * Otherwise, the receiver MUST silently discard the packet
426 * and take no further action. An endpoint MUST ignore the
427 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
428 */
429 if ((!sctp_test_T_bit(chunk) &&
430 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.my_vtag)) ||
431 (sctp_test_T_bit(chunk) && asoc->c.peer_vtag &&
432 (ntohl(chunk->sctp_hdr->vtag) == asoc->c.peer_vtag))) {
433 return 1;
434 }
435
436 return 0;
437 }
438
439 #endif /* __sctp_sm_h__ */
440