c943a11a53c6dfbc499090cb4573d52755080eb1
[strongswan.git] / src / pluto / demux.c
1 /* demultiplex incoming IKE messages
2 * Copyright (C) 1997 Angelos D. Keromytis.
3 * Copyright (C) 1998-2002 D. Hugh Redelmeier.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * for more details.
14 *
15 * RCSID $Id$
16 */
17
18 /* Ordering Constraints on Payloads
19 *
20 * rfc2409: The Internet Key Exchange (IKE)
21 *
22 * 5 Exchanges:
23 * "The SA payload MUST precede all other payloads in a phase 1 exchange."
24 *
25 * "Except where otherwise noted, there are no requirements for ISAKMP
26 * payloads in any message to be in any particular order."
27 *
28 * 5.3 Phase 1 Authenticated With a Revised Mode of Public Key Encryption:
29 *
30 * "If the HASH payload is sent it MUST be the first payload of the
31 * second message exchange and MUST be followed by the encrypted
32 * nonce. If the HASH payload is not sent, the first payload of the
33 * second message exchange MUST be the encrypted nonce."
34 *
35 * "Save the requirements on the location of the optional HASH payload
36 * and the mandatory nonce payload there are no further payload
37 * requirements. All payloads-- in whatever order-- following the
38 * encrypted nonce MUST be encrypted with Ke_i or Ke_r depending on the
39 * direction."
40 *
41 * 5.5 Phase 2 - Quick Mode
42 *
43 * "In Quick Mode, a HASH payload MUST immediately follow the ISAKMP
44 * header and a SA payload MUST immediately follow the HASH."
45 * [NOTE: there may be more than one SA payload, so this is not
46 * totally reasonable. Probably all SAs should be so constrained.]
47 *
48 * "If ISAKMP is acting as a client negotiator on behalf of another
49 * party, the identities of the parties MUST be passed as IDci and
50 * then IDcr."
51 *
52 * "With the exception of the HASH, SA, and the optional ID payloads,
53 * there are no payload ordering restrictions on Quick Mode."
54 */
55
56 /* Unfolding of Identity -- a central mystery
57 *
58 * This concerns Phase 1 identities, those of the IKE hosts.
59 * These are the only ones that are authenticated. Phase 2
60 * identities are for IPsec SAs.
61 *
62 * There are three case of interest:
63 *
64 * (1) We initiate, based on a whack command specifying a Connection.
65 * We know the identity of the peer from the Connection.
66 *
67 * (2) (to be implemented) we initiate based on a flow from our client
68 * to some IP address.
69 * We immediately know one of the peer's client IP addresses from
70 * the flow. We must use this to figure out the peer's IP address
71 * and Id. To be solved.
72 *
73 * (3) We respond to an IKE negotiation.
74 * We immediately know the peer's IP address.
75 * We get an ID Payload in Main I2.
76 *
77 * Unfortunately, this is too late for a number of things:
78 * - the ISAKMP SA proposals have already been made (Main I1)
79 * AND one accepted (Main R1)
80 * - the SA includes a specification of the type of ID
81 * authentication so this is negotiated without being told the ID.
82 * - with Preshared Key authentication, Main I2 is encrypted
83 * using the key, so it cannot be decoded to reveal the ID
84 * without knowing (or guessing) which key to use.
85 *
86 * There are three reasonable choices here for the responder:
87 * + assume that the initiator is making wise offers since it
88 * knows the IDs involved. We can balk later (but not gracefully)
89 * when we find the actual initiator ID
90 * + attempt to infer identity by IP address. Again, we can balk
91 * when the true identity is revealed. Actually, it is enough
92 * to infer properties of the identity (eg. SA properties and
93 * PSK, if needed).
94 * + make all properties universal so discrimination based on
95 * identity isn't required. For example, always accept the same
96 * kinds of encryption. Accept Public Key Id authentication
97 * since the Initiator presumably has our public key and thinks
98 * we must have / can find his. This approach is weakest
99 * for preshared key since the actual key must be known to
100 * decrypt the Initiator's ID Payload.
101 * These choices can be blended. For example, a class of Identities
102 * can be inferred, sufficient to select a preshared key but not
103 * sufficient to infer a unique identity.
104 */
105
106 #include <stdio.h>
107 #include <stdlib.h>
108 #include <stddef.h>
109 #include <string.h>
110 #include <unistd.h>
111 #include <errno.h>
112 #include <sys/types.h>
113 #include <sys/time.h> /* only used for belt-and-suspenders select call */
114 #include <sys/poll.h> /* only used for forensic poll call */
115 #include <sys/socket.h>
116 #include <sys/ioctl.h>
117 #include <netinet/in.h>
118 #include <arpa/inet.h>
119 #include <sys/queue.h>
120
121 #if defined(IP_RECVERR) && defined(MSG_ERRQUEUE)
122 # include <asm/types.h> /* for __u8, __u32 */
123 # include <linux/errqueue.h>
124 # include <sys/uio.h> /* struct iovec */
125 #endif
126
127 #include <freeswan.h>
128
129 #include "constants.h"
130 #include "defs.h"
131 #include "cookie.h"
132 #include "connections.h"
133 #include "state.h"
134 #include "packet.h"
135 #include "md5.h"
136 #include "sha1.h"
137 #include "crypto.h" /* requires sha1.h and md5.h */
138 #include "ike_alg.h"
139 #include "log.h"
140 #include "demux.h" /* needs packet.h */
141 #include "ipsec_doi.h" /* needs demux.h and state.h */
142 #include "timer.h"
143 #include "whack.h" /* requires connections.h */
144 #include "server.h"
145 #include "nat_traversal.h"
146 #include "vendor.h"
147 #include "modecfg.h"
148
149 /* This file does basic header checking and demux of
150 * incoming packets.
151 */
152
153 /* forward declarations */
154 static bool read_packet(struct msg_digest *md);
155 static void process_packet(struct msg_digest **mdp);
156
157 /* Reply messages are built in this buffer.
158 * Only one state transition function can be using it at a time
159 * so suspended STFs must save and restore it.
160 * It could be an auto variable of complete_state_transition except for the fact
161 * that when a suspended STF resumes, its reply message buffer
162 * must be at the same location -- there are pointers into it.
163 */
164 u_int8_t reply_buffer[MAX_OUTPUT_UDP_SIZE];
165
166 /* state_microcode is a tuple of information parameterizing certain
167 * centralized processing of a packet. For example, it roughly
168 * specifies what payloads are expected in this message.
169 * The microcode is selected primarily based on the state.
170 * In Phase 1, the payload structure often depends on the
171 * authentication technique, so that too plays a part in selecting
172 * the state_microcode to use.
173 */
174
175 struct state_microcode {
176 enum state_kind state, next_state;
177 lset_t flags;
178 lset_t req_payloads; /* required payloads (allows just one) */
179 lset_t opt_payloads; /* optional payloads (any mumber) */
180 /* if not ISAKMP_NEXT_NONE, process_packet will emit HDR with this as np */
181 u_int8_t first_out_payload;
182 enum event_type timeout_event;
183 state_transition_fn *processor;
184 };
185
186 /* State Microcode Flags, in several groups */
187
188 /* Oakley Auth values: to which auth values does this entry apply?
189 * Most entries will use SMF_ALL_AUTH because they apply to all.
190 * Note: SMF_ALL_AUTH matches 0 for those circumstances when no auth
191 * has been set.
192 */
193 #define SMF_ALL_AUTH LRANGE(0, OAKLEY_AUTH_ROOF-1)
194 #define SMF_PSK_AUTH LELEM(OAKLEY_PRESHARED_KEY)
195 #define SMF_DS_AUTH (LELEM(OAKLEY_DSS_SIG) | LELEM(OAKLEY_RSA_SIG))
196 #define SMF_PKE_AUTH (LELEM(OAKLEY_RSA_ENC) | LELEM(OAKLEY_ELGAMAL_ENC))
197 #define SMF_RPKE_AUTH (LELEM(OAKLEY_RSA_ENC_REV) | LELEM(OAKLEY_ELGAMAL_ENC_REV))
198
199 /* misc flags */
200
201 #define SMF_INITIATOR LELEM(OAKLEY_AUTH_ROOF + 0)
202 #define SMF_FIRST_ENCRYPTED_INPUT LELEM(OAKLEY_AUTH_ROOF + 1)
203 #define SMF_INPUT_ENCRYPTED LELEM(OAKLEY_AUTH_ROOF + 2)
204 #define SMF_OUTPUT_ENCRYPTED LELEM(OAKLEY_AUTH_ROOF + 3)
205 #define SMF_RETRANSMIT_ON_DUPLICATE LELEM(OAKLEY_AUTH_ROOF + 4)
206
207 #define SMF_ENCRYPTED (SMF_INPUT_ENCRYPTED | SMF_OUTPUT_ENCRYPTED)
208
209 /* this state generates a reply message */
210 #define SMF_REPLY LELEM(OAKLEY_AUTH_ROOF + 5)
211
212 /* this state completes P1, so any pending P2 negotiations should start */
213 #define SMF_RELEASE_PENDING_P2 LELEM(OAKLEY_AUTH_ROOF + 6)
214
215 /* end of flags */
216
217
218 static state_transition_fn /* forward declaration */
219 unexpected,
220 informational;
221
222 /* state_microcode_table is a table of all state_microcode tuples.
223 * It must be in order of state (the first element).
224 * After initialization, ike_microcode_index[s] points to the
225 * first entry in state_microcode_table for state s.
226 * Remember that each state name in Main or Quick Mode describes
227 * what has happened in the past, not what this message is.
228 */
229
230 static const struct state_microcode
231 *ike_microcode_index[STATE_IKE_ROOF - STATE_IKE_FLOOR];
232
233 static const struct state_microcode state_microcode_table[] = {
234 #define PT(n) ISAKMP_NEXT_##n
235 #define P(n) LELEM(PT(n))
236
237 /***** Phase 1 Main Mode *****/
238
239 /* No state for main_outI1: --> HDR, SA */
240
241 /* STATE_MAIN_R0: I1 --> R1
242 * HDR, SA --> HDR, SA
243 */
244 { STATE_MAIN_R0, STATE_MAIN_R1
245 , SMF_ALL_AUTH | SMF_REPLY
246 , P(SA), P(VID) | P(CR), PT(NONE)
247 , EVENT_RETRANSMIT, main_inI1_outR1},
248
249 /* STATE_MAIN_I1: R1 --> I2
250 * HDR, SA --> auth dependent
251 * SMF_PSK_AUTH, SMF_DS_AUTH: --> HDR, KE, Ni
252 * SMF_PKE_AUTH:
253 * --> HDR, KE, [ HASH(1), ] <IDi1_b>PubKey_r, <Ni_b>PubKey_r
254 * SMF_RPKE_AUTH:
255 * --> HDR, [ HASH(1), ] <Ni_b>Pubkey_r, <KE_b>Ke_i, <IDi1_b>Ke_i [,<<Cert-I_b>Ke_i]
256 * Note: since we don't know auth at start, we cannot differentiate
257 * microcode entries based on it.
258 */
259 { STATE_MAIN_I1, STATE_MAIN_I2
260 , SMF_ALL_AUTH | SMF_INITIATOR | SMF_REPLY
261 , P(SA), P(VID) | P(CR), PT(NONE) /* don't know yet */
262 , EVENT_RETRANSMIT, main_inR1_outI2 },
263
264 /* STATE_MAIN_R1: I2 --> R2
265 * SMF_PSK_AUTH, SMF_DS_AUTH: HDR, KE, Ni --> HDR, KE, Nr
266 * SMF_PKE_AUTH: HDR, KE, [ HASH(1), ] <IDi1_b>PubKey_r, <Ni_b>PubKey_r
267 * --> HDR, KE, <IDr1_b>PubKey_i, <Nr_b>PubKey_i
268 * SMF_RPKE_AUTH:
269 * HDR, [ HASH(1), ] <Ni_b>Pubkey_r, <KE_b>Ke_i, <IDi1_b>Ke_i [,<<Cert-I_b>Ke_i]
270 * --> HDR, <Nr_b>PubKey_i, <KE_b>Ke_r, <IDr1_b>Ke_r
271 */
272 { STATE_MAIN_R1, STATE_MAIN_R2
273 , SMF_PSK_AUTH | SMF_DS_AUTH | SMF_REPLY
274 , P(KE) | P(NONCE), P(VID) | P(CR) | P(NATD_RFC), PT(KE)
275 , EVENT_RETRANSMIT, main_inI2_outR2 },
276
277 { STATE_MAIN_R1, STATE_UNDEFINED
278 , SMF_PKE_AUTH | SMF_REPLY
279 , P(KE) | P(ID) | P(NONCE), P(VID) | P(CR) | P(HASH), PT(KE)
280 , EVENT_RETRANSMIT, unexpected /* ??? not yet implemented */ },
281
282 { STATE_MAIN_R1, STATE_UNDEFINED
283 , SMF_RPKE_AUTH | SMF_REPLY
284 , P(NONCE) | P(KE) | P(ID), P(VID) | P(CR) | P(HASH) | P(CERT), PT(NONCE)
285 , EVENT_RETRANSMIT, unexpected /* ??? not yet implemented */ },
286
287 /* for states from here on, output message must be encrypted */
288
289 /* STATE_MAIN_I2: R2 --> I3
290 * SMF_PSK_AUTH: HDR, KE, Nr --> HDR*, IDi1, HASH_I
291 * SMF_DS_AUTH: HDR, KE, Nr --> HDR*, IDi1, [ CERT, ] SIG_I
292 * SMF_PKE_AUTH: HDR, KE, <IDr1_b>PubKey_i, <Nr_b>PubKey_i
293 * --> HDR*, HASH_I
294 * SMF_RPKE_AUTH: HDR, <Nr_b>PubKey_i, <KE_b>Ke_r, <IDr1_b>Ke_r
295 * --> HDR*, HASH_I
296 */
297 { STATE_MAIN_I2, STATE_MAIN_I3
298 , SMF_PSK_AUTH | SMF_DS_AUTH | SMF_INITIATOR | SMF_OUTPUT_ENCRYPTED | SMF_REPLY
299 , P(KE) | P(NONCE), P(VID) | P(CR) | P(NATD_RFC), PT(ID)
300 , EVENT_RETRANSMIT, main_inR2_outI3 },
301
302 { STATE_MAIN_I2, STATE_UNDEFINED
303 , SMF_PKE_AUTH | SMF_INITIATOR | SMF_OUTPUT_ENCRYPTED | SMF_REPLY
304 , P(KE) | P(ID) | P(NONCE), P(VID) | P(CR), PT(HASH)
305 , EVENT_RETRANSMIT, unexpected /* ??? not yet implemented */ },
306
307 { STATE_MAIN_I2, STATE_UNDEFINED
308 , SMF_ALL_AUTH | SMF_INITIATOR | SMF_OUTPUT_ENCRYPTED | SMF_REPLY
309 , P(NONCE) | P(KE) | P(ID), P(VID) | P(CR), PT(HASH)
310 , EVENT_RETRANSMIT, unexpected /* ??? not yet implemented */ },
311
312 /* for states from here on, input message must be encrypted */
313
314 /* STATE_MAIN_R2: I3 --> R3
315 * SMF_PSK_AUTH: HDR*, IDi1, HASH_I --> HDR*, IDr1, HASH_R
316 * SMF_DS_AUTH: HDR*, IDi1, [ CERT, ] SIG_I --> HDR*, IDr1, [ CERT, ] SIG_R
317 * SMF_PKE_AUTH, SMF_RPKE_AUTH: HDR*, HASH_I --> HDR*, HASH_R
318 */
319 { STATE_MAIN_R2, STATE_MAIN_R3
320 , SMF_PSK_AUTH | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED
321 | SMF_REPLY | SMF_RELEASE_PENDING_P2
322 , P(ID) | P(HASH), P(VID) | P(CR), PT(NONE)
323 , EVENT_SA_REPLACE, main_inI3_outR3 },
324
325 { STATE_MAIN_R2, STATE_MAIN_R3
326 , SMF_DS_AUTH | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED
327 | SMF_REPLY | SMF_RELEASE_PENDING_P2
328 , P(ID) | P(SIG), P(VID) | P(CR) | P(CERT), PT(NONE)
329 , EVENT_SA_REPLACE, main_inI3_outR3 },
330
331 { STATE_MAIN_R2, STATE_UNDEFINED
332 , SMF_PKE_AUTH | SMF_RPKE_AUTH | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED
333 | SMF_REPLY | SMF_RELEASE_PENDING_P2
334 , P(HASH), P(VID) | P(CR), PT(NONE)
335 , EVENT_SA_REPLACE, unexpected /* ??? not yet implemented */ },
336
337 /* STATE_MAIN_I3: R3 --> done
338 * SMF_PSK_AUTH: HDR*, IDr1, HASH_R --> done
339 * SMF_DS_AUTH: HDR*, IDr1, [ CERT, ] SIG_R --> done
340 * SMF_PKE_AUTH, SMF_RPKE_AUTH: HDR*, HASH_R --> done
341 * May initiate quick mode by calling quick_outI1
342 */
343 { STATE_MAIN_I3, STATE_MAIN_I4
344 , SMF_PSK_AUTH | SMF_INITIATOR
345 | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
346 , P(ID) | P(HASH), P(VID) | P(CR), PT(NONE)
347 , EVENT_SA_REPLACE, main_inR3 },
348
349 { STATE_MAIN_I3, STATE_MAIN_I4
350 , SMF_DS_AUTH | SMF_INITIATOR
351 | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
352 , P(ID) | P(SIG), P(VID) | P(CR) | P(CERT), PT(NONE)
353 , EVENT_SA_REPLACE, main_inR3 },
354
355 { STATE_MAIN_I3, STATE_UNDEFINED
356 , SMF_PKE_AUTH | SMF_RPKE_AUTH | SMF_INITIATOR
357 | SMF_FIRST_ENCRYPTED_INPUT | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
358 , P(HASH), P(VID) | P(CR), PT(NONE)
359 , EVENT_SA_REPLACE, unexpected /* ??? not yet implemented */ },
360
361 /* STATE_MAIN_R3: can only get here due to packet loss */
362 { STATE_MAIN_R3, STATE_UNDEFINED
363 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_RETRANSMIT_ON_DUPLICATE
364 , LEMPTY, LEMPTY
365 , PT(NONE), EVENT_NULL, unexpected },
366
367 /* STATE_MAIN_I4: can only get here due to packet loss */
368 { STATE_MAIN_I4, STATE_UNDEFINED
369 , SMF_ALL_AUTH | SMF_INITIATOR | SMF_ENCRYPTED
370 , LEMPTY, LEMPTY
371 , PT(NONE), EVENT_NULL, unexpected },
372
373
374 /***** Phase 2 Quick Mode *****/
375
376 /* No state for quick_outI1:
377 * --> HDR*, HASH(1), SA, Nr [, KE ] [, IDci, IDcr ]
378 */
379
380 /* STATE_QUICK_R0:
381 * HDR*, HASH(1), SA, Ni [, KE ] [, IDci, IDcr ] -->
382 * HDR*, HASH(2), SA, Nr [, KE ] [, IDci, IDcr ]
383 * Installs inbound IPsec SAs.
384 * Because it may suspend for asynchronous DNS, first_out_payload
385 * is set to NONE to suppress early emission of HDR*.
386 * ??? it is legal to have multiple SAs, but we don't support it yet.
387 */
388 { STATE_QUICK_R0, STATE_QUICK_R1
389 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_REPLY
390 , P(HASH) | P(SA) | P(NONCE), /* P(SA) | */ P(KE) | P(ID) | P(NATOA_RFC), PT(NONE)
391 , EVENT_RETRANSMIT, quick_inI1_outR1 },
392
393 /* STATE_QUICK_I1:
394 * HDR*, HASH(2), SA, Nr [, KE ] [, IDci, IDcr ] -->
395 * HDR*, HASH(3)
396 * Installs inbound and outbound IPsec SAs, routing, etc.
397 * ??? it is legal to have multiple SAs, but we don't support it yet.
398 */
399 { STATE_QUICK_I1, STATE_QUICK_I2
400 , SMF_ALL_AUTH | SMF_INITIATOR | SMF_ENCRYPTED | SMF_REPLY
401 , P(HASH) | P(SA) | P(NONCE), /* P(SA) | */ P(KE) | P(ID) | P(NATOA_RFC), PT(HASH)
402 , EVENT_SA_REPLACE, quick_inR1_outI2 },
403
404 /* STATE_QUICK_R1: HDR*, HASH(3) --> done
405 * Installs outbound IPsec SAs, routing, etc.
406 */
407 { STATE_QUICK_R1, STATE_QUICK_R2
408 , SMF_ALL_AUTH | SMF_ENCRYPTED
409 , P(HASH), LEMPTY, PT(NONE)
410 , EVENT_SA_REPLACE, quick_inI2 },
411
412 /* STATE_QUICK_I2: can only happen due to lost packet */
413 { STATE_QUICK_I2, STATE_UNDEFINED
414 , SMF_ALL_AUTH | SMF_INITIATOR | SMF_ENCRYPTED | SMF_RETRANSMIT_ON_DUPLICATE
415 , LEMPTY, LEMPTY, PT(NONE)
416 , EVENT_NULL, unexpected },
417
418 /* STATE_QUICK_R2: can only happen due to lost packet */
419 { STATE_QUICK_R2, STATE_UNDEFINED
420 , SMF_ALL_AUTH | SMF_ENCRYPTED
421 , LEMPTY, LEMPTY, PT(NONE)
422 , EVENT_NULL, unexpected },
423
424
425 /***** informational messages *****/
426
427 /* STATE_INFO: */
428 { STATE_INFO, STATE_UNDEFINED
429 , SMF_ALL_AUTH
430 , LEMPTY, LEMPTY, PT(NONE)
431 , EVENT_NULL, informational },
432
433 /* STATE_INFO_PROTECTED: */
434 { STATE_INFO_PROTECTED, STATE_UNDEFINED
435 , SMF_ALL_AUTH | SMF_ENCRYPTED
436 , P(HASH), LEMPTY, PT(NONE)
437 , EVENT_NULL, informational },
438
439 /* XAUTH state transitions */
440 { STATE_XAUTH_I0, STATE_XAUTH_I1
441 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_REPLY
442 , P(ATTR) | P(HASH), P(VID), PT(HASH)
443 , EVENT_RETRANSMIT, xauth_inI0 },
444
445 { STATE_XAUTH_R1, STATE_XAUTH_R2
446 , SMF_ALL_AUTH | SMF_ENCRYPTED
447 , P(ATTR) | P(HASH), P(VID), PT(HASH)
448 , EVENT_RETRANSMIT, xauth_inR1 },
449
450 { STATE_XAUTH_I1, STATE_XAUTH_I2
451 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_REPLY | SMF_RELEASE_PENDING_P2
452 , P(ATTR) | P(HASH), P(VID), PT(HASH)
453 , EVENT_SA_REPLACE, xauth_inI1 },
454
455 { STATE_XAUTH_R2, STATE_XAUTH_R3
456 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
457 , P(ATTR) | P(HASH), P(VID), PT(NONE)
458 , EVENT_SA_REPLACE, xauth_inR2 },
459
460 { STATE_XAUTH_I2, STATE_UNDEFINED
461 , SMF_ALL_AUTH | SMF_ENCRYPTED
462 , LEMPTY, LEMPTY, PT(NONE)
463 , EVENT_NULL, unexpected },
464
465 { STATE_XAUTH_R3, STATE_UNDEFINED
466 , SMF_ALL_AUTH | SMF_ENCRYPTED
467 , LEMPTY, LEMPTY, PT(NONE)
468 , EVENT_NULL, unexpected },
469
470 /* ModeCfg pull mode state transitions */
471
472 { STATE_MODE_CFG_R0, STATE_MODE_CFG_R1
473 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_REPLY | SMF_RELEASE_PENDING_P2
474 , P(ATTR) | P(HASH), P(VID), PT(HASH)
475 , EVENT_SA_REPLACE, modecfg_inR0 },
476
477 { STATE_MODE_CFG_I1, STATE_MODE_CFG_I2
478 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
479 , P(ATTR) | P(HASH), P(VID), PT(HASH)
480 , EVENT_SA_REPLACE, modecfg_inI1 },
481
482 { STATE_MODE_CFG_R1, STATE_UNDEFINED
483 , SMF_ALL_AUTH | SMF_ENCRYPTED
484 , LEMPTY, LEMPTY, PT(NONE)
485 , EVENT_NULL, unexpected },
486
487 { STATE_MODE_CFG_I2, STATE_UNDEFINED
488 , SMF_ALL_AUTH | SMF_ENCRYPTED
489 , LEMPTY, LEMPTY, PT(NONE)
490 , EVENT_NULL, unexpected },
491
492 /* ModeCfg push mode state transitions */
493
494 { STATE_MODE_CFG_I0, STATE_MODE_CFG_I3
495 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_REPLY | SMF_RELEASE_PENDING_P2
496 , P(ATTR) | P(HASH), P(VID), PT(HASH)
497 , EVENT_SA_REPLACE, modecfg_inI0 },
498
499 { STATE_MODE_CFG_R3, STATE_MODE_CFG_R4
500 , SMF_ALL_AUTH | SMF_ENCRYPTED | SMF_RELEASE_PENDING_P2
501 , P(ATTR) | P(HASH), P(VID), PT(HASH)
502 , EVENT_SA_REPLACE, modecfg_inR3 },
503
504 { STATE_MODE_CFG_I3, STATE_UNDEFINED
505 , SMF_ALL_AUTH | SMF_ENCRYPTED
506 , LEMPTY, LEMPTY, PT(NONE)
507 , EVENT_NULL, unexpected },
508
509 { STATE_MODE_CFG_R4, STATE_UNDEFINED
510 , SMF_ALL_AUTH | SMF_ENCRYPTED
511 , LEMPTY, LEMPTY, PT(NONE)
512 , EVENT_NULL, unexpected },
513
514 #undef P
515 #undef PT
516 };
517
518 void
519 init_demux(void)
520 {
521 /* fill ike_microcode_index:
522 * make ike_microcode_index[s] point to first entry in
523 * state_microcode_table for state s (backward scan makes this easier).
524 * Check that table is in order -- catch coding errors.
525 * For what it's worth, this routine is idempotent.
526 */
527 const struct state_microcode *t;
528
529 for (t = &state_microcode_table[countof(state_microcode_table) - 1];;)
530 {
531 passert(STATE_IKE_FLOOR <= t->state && t->state < STATE_IKE_ROOF);
532 ike_microcode_index[t->state - STATE_IKE_FLOOR] = t;
533 if (t == state_microcode_table)
534 break;
535 t--;
536 passert(t[0].state <= t[1].state);
537 }
538 }
539
540 /* Process any message on the MSG_ERRQUEUE
541 *
542 * This information is generated because of the IP_RECVERR socket option.
543 * The API is sparsely documented, and may be LINUX-only, and only on
544 * fairly recent versions at that (hence the conditional compilation).
545 *
546 * - ip(7) describes IP_RECVERR
547 * - recvmsg(2) describes MSG_ERRQUEUE
548 * - readv(2) describes iovec
549 * - cmsg(3) describes how to process auxilliary messages
550 *
551 * ??? we should link this message with one we've sent
552 * so that the diagnostic can refer to that negotiation.
553 *
554 * ??? how long can the messge be?
555 *
556 * ??? poll(2) has a very incomplete description of the POLL* events.
557 * We assume that POLLIN, POLLOUT, and POLLERR are all we need to deal with
558 * and that POLLERR will be on iff there is a MSG_ERRQUEUE message.
559 *
560 * We have to code around a couple of surprises:
561 *
562 * - Select can say that a socket is ready to read from, and
563 * yet a read will hang. It turns out that a message available on the
564 * MSG_ERRQUEUE will cause select to say something is pending, but
565 * a normal read will hang. poll(2) can tell when a MSG_ERRQUEUE
566 * message is pending.
567 *
568 * This is dealt with by calling check_msg_errqueue after select
569 * has indicated that there is something to read, but before the
570 * read is performed. check_msg_errqueue will return TRUE if there
571 * is something left to read.
572 *
573 * - A write to a socket may fail because there is a pending MSG_ERRQUEUE
574 * message, without there being anything wrong with the write. This
575 * makes for confusing diagnostics.
576 *
577 * To avoid this, we call check_msg_errqueue before a write. True,
578 * there is a race condition (a MSG_ERRQUEUE message might arrive
579 * between the check and the write), but we should eliminate many
580 * of the problematic events. To narrow the window, the poll(2)
581 * will await until an event happens (in the case or a write,
582 * POLLOUT; this should be benign for POLLIN).
583 */
584
585 #if defined(IP_RECVERR) && defined(MSG_ERRQUEUE)
586 static bool
587 check_msg_errqueue(const struct iface *ifp, short interest)
588 {
589 struct pollfd pfd;
590
591 pfd.fd = ifp->fd;
592 pfd.events = interest | POLLPRI | POLLOUT;
593
594 while (pfd.revents = 0
595 , poll(&pfd, 1, -1) > 0 && (pfd.revents & POLLERR))
596 {
597 u_int8_t buffer[3000]; /* hope that this is big enough */
598 union
599 {
600 struct sockaddr sa;
601 struct sockaddr_in sa_in4;
602 struct sockaddr_in6 sa_in6;
603 } from;
604
605 int from_len = sizeof(from);
606
607 int packet_len;
608
609 struct msghdr emh;
610 struct iovec eiov;
611 union {
612 /* force alignment (not documented as necessary) */
613 struct cmsghdr ecms;
614
615 /* how much space is enough? */
616 unsigned char space[256];
617 } ecms_buf;
618
619 struct cmsghdr *cm;
620 char fromstr[sizeof(" for message to port 65536") + INET6_ADDRSTRLEN];
621 struct state *sender = NULL;
622
623 zero(&from.sa);
624 from_len = sizeof(from);
625
626 emh.msg_name = &from.sa; /* ??? filled in? */
627 emh.msg_namelen = sizeof(from);
628 emh.msg_iov = &eiov;
629 emh.msg_iovlen = 1;
630 emh.msg_control = &ecms_buf;
631 emh.msg_controllen = sizeof(ecms_buf);
632 emh.msg_flags = 0;
633
634 eiov.iov_base = buffer; /* see readv(2) */
635 eiov.iov_len = sizeof(buffer);
636
637 packet_len = recvmsg(ifp->fd, &emh, MSG_ERRQUEUE);
638
639 if (packet_len == -1)
640 {
641 log_errno((e, "recvmsg(,, MSG_ERRQUEUE) on %s failed in comm_handle"
642 , ifp->rname));
643 break;
644 }
645 else if (packet_len == sizeof(buffer))
646 {
647 plog("MSG_ERRQUEUE message longer than %lu bytes; truncated"
648 , (unsigned long) sizeof(buffer));
649 }
650 else
651 {
652 sender = find_sender((size_t) packet_len, buffer);
653 }
654
655 DBG_cond_dump(DBG_ALL, "rejected packet:\n", buffer, packet_len);
656 DBG_cond_dump(DBG_ALL, "control:\n", emh.msg_control, emh.msg_controllen);
657 /* ??? Andi Kleen <ak@suse.de> and misc documentation
658 * suggests that name will have the original destination
659 * of the packet. We seem to see msg_namelen == 0.
660 * Andi says that this is a kernel bug and has fixed it.
661 * Perhaps in 2.2.18/2.4.0.
662 */
663 passert(emh.msg_name == &from.sa);
664 DBG_cond_dump(DBG_ALL, "name:\n", emh.msg_name
665 , emh.msg_namelen);
666
667 fromstr[0] = '\0'; /* usual case :-( */
668 switch (from.sa.sa_family)
669 {
670 char as[INET6_ADDRSTRLEN];
671
672 case AF_INET:
673 if (emh.msg_namelen == sizeof(struct sockaddr_in))
674 snprintf(fromstr, sizeof(fromstr)
675 , " for message to %s port %u"
676 , inet_ntop(from.sa.sa_family
677 , &from.sa_in4.sin_addr, as, sizeof(as))
678 , ntohs(from.sa_in4.sin_port));
679 break;
680 case AF_INET6:
681 if (emh.msg_namelen == sizeof(struct sockaddr_in6))
682 snprintf(fromstr, sizeof(fromstr)
683 , " for message to %s port %u"
684 , inet_ntop(from.sa.sa_family
685 , &from.sa_in6.sin6_addr, as, sizeof(as))
686 , ntohs(from.sa_in6.sin6_port));
687 break;
688 }
689
690 for (cm = CMSG_FIRSTHDR(&emh)
691 ; cm != NULL
692 ; cm = CMSG_NXTHDR(&emh,cm))
693 {
694 if (cm->cmsg_level == SOL_IP
695 && cm->cmsg_type == IP_RECVERR)
696 {
697 /* ip(7) and recvmsg(2) specify:
698 * ee_origin is SO_EE_ORIGIN_ICMP for ICMP
699 * or SO_EE_ORIGIN_LOCAL for locally generated errors.
700 * ee_type and ee_code are from the ICMP header.
701 * ee_info is the discovered MTU for EMSGSIZE errors
702 * ee_data is not used.
703 *
704 * ??? recvmsg(2) says "SOCK_EE_OFFENDER" but
705 * means "SO_EE_OFFENDER". The OFFENDER is really
706 * the router that complained. As such, the port
707 * is meaningless.
708 */
709
710 /* ??? cmsg(3) claims that CMSG_DATA returns
711 * void *, but RFC 2292 and /usr/include/bits/socket.h
712 * say unsigned char *. The manual is being fixed.
713 */
714 struct sock_extended_err *ee = (void *)CMSG_DATA(cm);
715 const char *offstr = "unspecified";
716 char offstrspace[INET6_ADDRSTRLEN];
717 char orname[50];
718
719 if (cm->cmsg_len > CMSG_LEN(sizeof(struct sock_extended_err)))
720 {
721 const struct sockaddr *offender = SO_EE_OFFENDER(ee);
722
723 switch (offender->sa_family)
724 {
725 case AF_INET:
726 offstr = inet_ntop(offender->sa_family
727 , &((const struct sockaddr_in *)offender)->sin_addr
728 , offstrspace, sizeof(offstrspace));
729 break;
730 case AF_INET6:
731 offstr = inet_ntop(offender->sa_family
732 , &((const struct sockaddr_in6 *)offender)->sin6_addr
733 , offstrspace, sizeof(offstrspace));
734 break;
735 default:
736 offstr = "unknown";
737 break;
738 }
739 }
740
741 switch (ee->ee_origin)
742 {
743 case SO_EE_ORIGIN_NONE:
744 snprintf(orname, sizeof(orname), "none");
745 break;
746 case SO_EE_ORIGIN_LOCAL:
747 snprintf(orname, sizeof(orname), "local");
748 break;
749 case SO_EE_ORIGIN_ICMP:
750 snprintf(orname, sizeof(orname)
751 , "ICMP type %d code %d (not authenticated)"
752 , ee->ee_type, ee->ee_code
753 );
754 break;
755 case SO_EE_ORIGIN_ICMP6:
756 snprintf(orname, sizeof(orname)
757 , "ICMP6 type %d code %d (not authenticated)"
758 , ee->ee_type, ee->ee_code
759 );
760 break;
761 default:
762 snprintf(orname, sizeof(orname), "invalid origin %lu"
763 , (unsigned long) ee->ee_origin);
764 break;
765 }
766
767 {
768 struct state *old_state = cur_state;
769
770 cur_state = sender;
771
772 /* note dirty trick to suppress ~ at start of format
773 * if we know what state to blame.
774 */
775 if ((packet_len == 1) && (buffer[0] = 0xff)
776 #ifdef DEBUG
777 && ((cur_debugging & DBG_NATT) == 0)
778 #endif
779 ) {
780 /* don't log NAT-T keepalive related errors unless NATT debug is
781 * enabled
782 */
783 }
784 else
785 plog((sender != NULL) + "~"
786 "ERROR: asynchronous network error report on %s"
787 "%s"
788 ", complainant %s"
789 ": %s"
790 " [errno %lu, origin %s"
791 /* ", pad %d, info %ld" */
792 /* ", data %ld" */
793 "]"
794 , ifp->rname
795 , fromstr
796 , offstr
797 , strerror(ee->ee_errno)
798 , (unsigned long) ee->ee_errno
799 , orname
800 /* , ee->ee_pad, (unsigned long)ee->ee_info */
801 /* , (unsigned long)ee->ee_data */
802 );
803 cur_state = old_state;
804 }
805 }
806 else
807 {
808 /* .cmsg_len is a kernel_size_t(!), but the value
809 * certainly ought to fit in an unsigned long.
810 */
811 plog("unknown cmsg: level %d, type %d, len %lu"
812 , cm->cmsg_level, cm->cmsg_type
813 , (unsigned long) cm->cmsg_len);
814 }
815 }
816 }
817 return (pfd.revents & interest) != 0;
818 }
819 #endif /* defined(IP_RECVERR) && defined(MSG_ERRQUEUE) */
820
821 bool
822 send_packet(struct state *st, const char *where)
823 {
824 struct connection *c = st->st_connection;
825 int port_buf;
826 bool err;
827 u_int8_t ike_pkt[MAX_OUTPUT_UDP_SIZE];
828 u_int8_t *ptr;
829 unsigned long len;
830
831 if (c->interface->ike_float && st->st_tpacket.len != 1)
832 {
833 if ((unsigned long) st->st_tpacket.len > (MAX_OUTPUT_UDP_SIZE-sizeof(u_int32_t)))
834 {
835 DBG_log("send_packet(): really too big");
836 return FALSE;
837 }
838 ptr = ike_pkt;
839 /** Add Non-ESP marker **/
840 memset(ike_pkt, 0, sizeof(u_int32_t));
841 memcpy(ike_pkt + sizeof(u_int32_t), st->st_tpacket.ptr,
842 (unsigned long)st->st_tpacket.len);
843 len = (unsigned long) st->st_tpacket.len + sizeof(u_int32_t);
844 }
845 else
846 {
847 ptr = st->st_tpacket.ptr;
848 len = (unsigned long) st->st_tpacket.len;
849 }
850
851 DBG(DBG_RAW,
852 {
853 DBG_log("sending %lu bytes for %s through %s to %s:%u:"
854 , (unsigned long) st->st_tpacket.len
855 , where
856 , c->interface->rname
857 , ip_str(&c->spd.that.host_addr)
858 , (unsigned)c->spd.that.host_port);
859 DBG_dump_chunk(NULL, st->st_tpacket);
860 });
861
862 /* XXX: Not very clean. We manipulate the port of the ip_address to
863 * have a port in the sockaddr*, but we retain the original port
864 * and restore it afterwards.
865 */
866
867 port_buf = portof(&c->spd.that.host_addr);
868 setportof(htons(c->spd.that.host_port), &c->spd.that.host_addr);
869
870 #if defined(IP_RECVERR) && defined(MSG_ERRQUEUE)
871 (void) check_msg_errqueue(c->interface, POLLOUT);
872 #endif /* defined(IP_RECVERR) && defined(MSG_ERRQUEUE) */
873
874 err = sendto(c->interface->fd
875 , ptr, len, 0
876 , sockaddrof(&c->spd.that.host_addr)
877 , sockaddrlenof(&c->spd.that.host_addr)) != (ssize_t)len;
878
879 /* restore port */
880 setportof(port_buf, &c->spd.that.host_addr);
881
882 if (err)
883 {
884 /* do not log NAT-T Keep Alive packets */
885 if (streq(where, "NAT-T Keep Alive"))
886 return FALSE;
887 log_errno((e, "sendto on %s to %s:%u failed in %s"
888 , c->interface->rname
889 , ip_str(&c->spd.that.host_addr)
890 , (unsigned)c->spd.that.host_port
891 , where));
892 return FALSE;
893 }
894 else
895 {
896 return TRUE;
897 }
898 }
899
900 static stf_status
901 unexpected(struct msg_digest *md)
902 {
903 loglog(RC_LOG_SERIOUS, "unexpected message received in state %s"
904 , enum_name(&state_names, md->st->st_state));
905 return STF_IGNORE;
906 }
907
908 static stf_status
909 informational(struct msg_digest *md UNUSED)
910 {
911 struct payload_digest *const n_pld = md->chain[ISAKMP_NEXT_N];
912
913 /* If the Notification Payload is not null... */
914 if (n_pld != NULL)
915 {
916 pb_stream *const n_pbs = &n_pld->pbs;
917 struct isakmp_notification *const n = &n_pld->payload.notification;
918 int disp_len;
919 char disp_buf[200];
920
921 /* Switch on Notification Type (enum) */
922 switch (n->isan_type)
923 {
924 case R_U_THERE:
925 return dpd_inI_outR(md->st, n, n_pbs);
926
927 case R_U_THERE_ACK:
928 return dpd_inR(md->st, n, n_pbs);
929 default:
930 if (pbs_left(n_pbs) >= sizeof(disp_buf)-1)
931 disp_len = sizeof(disp_buf)-1;
932 else
933 disp_len = pbs_left(n_pbs);
934 memcpy(disp_buf, n_pbs->cur, disp_len);
935 disp_buf[disp_len] = '\0';
936 break;
937 }
938 }
939 return STF_IGNORE;
940 }
941
942 /* message digest allocation and deallocation */
943
944 static struct msg_digest *md_pool = NULL;
945
946 /* free_md_pool is only used to avoid leak reports */
947 void
948 free_md_pool(void)
949 {
950 for (;;)
951 {
952 struct msg_digest *md = md_pool;
953
954 if (md == NULL)
955 break;
956 md_pool = md->next;
957 free(md);
958 }
959 }
960
961 static struct msg_digest *
962 malloc_md(void)
963 {
964 struct msg_digest *md = md_pool;
965
966 /* convenient initializer:
967 * - all pointers NULL
968 * - .note = NOTHING_WRONG
969 * - .encrypted = FALSE
970 */
971 static const struct msg_digest blank_md;
972
973 if (md == NULL)
974 md = malloc_thing(struct msg_digest);
975 else
976 md_pool = md->next;
977
978 *md = blank_md;
979 md->digest_roof = md->digest;
980
981 /* note: although there may be multiple msg_digests at once
982 * (due to suspended state transitions), there is a single
983 * global reply_buffer. It will need to be saved and restored.
984 */
985 init_pbs(&md->reply, reply_buffer, sizeof(reply_buffer), "reply packet");
986
987 return md;
988 }
989
990 void
991 release_md(struct msg_digest *md)
992 {
993 chunk_free(&md->raw_packet);
994 free(md->packet_pbs.start);
995 md->packet_pbs.start = NULL;
996 md->next = md_pool;
997 md_pool = md;
998 }
999
1000 /* wrapper for read_packet and process_packet
1001 *
1002 * The main purpose of this wrapper is to factor out teardown code
1003 * from the many return points in process_packet. This amounts to
1004 * releasing the msg_digest and resetting global variables.
1005 *
1006 * When processing of a packet is suspended (STF_SUSPEND),
1007 * process_packet sets md to NULL to prevent the msg_digest being freed.
1008 * Someone else must ensure that msg_digest is freed eventually.
1009 *
1010 * read_packet is broken out to minimize the lifetime of the
1011 * enormous input packet buffer, an auto.
1012 */
1013 void
1014 comm_handle(const struct iface *ifp)
1015 {
1016 static struct msg_digest *md;
1017
1018 #if defined(IP_RECVERR) && defined(MSG_ERRQUEUE)
1019 /* Even though select(2) says that there is a message,
1020 * it might only be a MSG_ERRQUEUE message. At least
1021 * sometimes that leads to a hanging recvfrom. To avoid
1022 * what appears to be a kernel bug, check_msg_errqueue
1023 * uses poll(2) and tells us if there is anything for us
1024 * to read.
1025 *
1026 * This is early enough that teardown isn't required:
1027 * just return on failure.
1028 */
1029 if (!check_msg_errqueue(ifp, POLLIN))
1030 return; /* no normal message to read */
1031 #endif /* defined(IP_RECVERR) && defined(MSG_ERRQUEUE) */
1032
1033 md = malloc_md();
1034 md->iface = ifp;
1035
1036 if (read_packet(md))
1037 process_packet(&md);
1038
1039 if (md != NULL)
1040 release_md(md);
1041
1042 cur_state = NULL;
1043 reset_cur_connection();
1044 cur_from = NULL;
1045 }
1046
1047 /* read the message.
1048 * Since we don't know its size, we read it into
1049 * an overly large buffer and then copy it to a
1050 * new, properly sized buffer.
1051 */
1052 static bool
1053 read_packet(struct msg_digest *md)
1054 {
1055 const struct iface *ifp = md->iface;
1056 int packet_len;
1057 u_int8_t *buffer;
1058 u_int8_t *buffer_nat;
1059 union
1060 {
1061 struct sockaddr sa;
1062 struct sockaddr_in sa_in4;
1063 struct sockaddr_in6 sa_in6;
1064 } from;
1065 int from_len = sizeof(from);
1066 err_t from_ugh = NULL;
1067 static const char undisclosed[] = "unknown source";
1068
1069 happy(anyaddr(addrtypeof(&ifp->addr), &md->sender));
1070 zero(&from.sa);
1071 ioctl(ifp->fd, FIONREAD, &packet_len);
1072 buffer = malloc(packet_len);
1073 packet_len = recvfrom(ifp->fd, buffer, packet_len, 0
1074 , &from.sa, &from_len);
1075
1076 /* First: digest the from address.
1077 * We presume that nothing here disturbs errno.
1078 */
1079 if (packet_len == -1
1080 && from_len == sizeof(from)
1081 && all_zero((const void *)&from.sa, sizeof(from)))
1082 {
1083 /* "from" is untouched -- not set by recvfrom */
1084 from_ugh = undisclosed;
1085 }
1086 else if (from_len
1087 < (int) (offsetof(struct sockaddr, sa_family) + sizeof(from.sa.sa_family)))
1088 {
1089 from_ugh = "truncated";
1090 }
1091 else
1092 {
1093 const struct af_info *afi = aftoinfo(from.sa.sa_family);
1094
1095 if (afi == NULL)
1096 {
1097 from_ugh = "unexpected Address Family";
1098 }
1099 else if (from_len != (int)afi->sa_sz)
1100 {
1101 from_ugh = "wrong length";
1102 }
1103 else
1104 {
1105 switch (from.sa.sa_family)
1106 {
1107 case AF_INET:
1108 from_ugh = initaddr((void *) &from.sa_in4.sin_addr
1109 , sizeof(from.sa_in4.sin_addr), AF_INET, &md->sender);
1110 md->sender_port = ntohs(from.sa_in4.sin_port);
1111 break;
1112 case AF_INET6:
1113 from_ugh = initaddr((void *) &from.sa_in6.sin6_addr
1114 , sizeof(from.sa_in6.sin6_addr), AF_INET6, &md->sender);
1115 md->sender_port = ntohs(from.sa_in6.sin6_port);
1116 break;
1117 }
1118 }
1119 }
1120
1121 /* now we report any actual I/O error */
1122 if (packet_len == -1)
1123 {
1124 if (from_ugh == undisclosed
1125 && errno == ECONNREFUSED)
1126 {
1127 /* Tone down scary message for vague event:
1128 * We get "connection refused" in response to some
1129 * datagram we sent, but we cannot tell which one.
1130 */
1131 plog("some IKE message we sent has been rejected with ECONNREFUSED (kernel supplied no details)");
1132 }
1133 else if (from_ugh != NULL)
1134 {
1135 log_errno((e, "recvfrom on %s failed; Pluto cannot decode source sockaddr in rejection: %s"
1136 , ifp->rname, from_ugh));
1137 }
1138 else
1139 {
1140 log_errno((e, "recvfrom on %s from %s:%u failed"
1141 , ifp->rname
1142 , ip_str(&md->sender), (unsigned)md->sender_port));
1143 }
1144
1145 return FALSE;
1146 }
1147 else if (from_ugh != NULL)
1148 {
1149 plog("recvfrom on %s returned misformed source sockaddr: %s"
1150 , ifp->rname, from_ugh);
1151 return FALSE;
1152 }
1153 cur_from = &md->sender;
1154 cur_from_port = md->sender_port;
1155
1156 if (ifp->ike_float == TRUE)
1157 {
1158 u_int32_t non_esp;
1159
1160 if (packet_len < (int)sizeof(u_int32_t))
1161 {
1162 plog("recvfrom %s:%u too small packet (%d)"
1163 , ip_str(cur_from), (unsigned) cur_from_port, packet_len);
1164 return FALSE;
1165 }
1166 memcpy(&non_esp, buffer, sizeof(u_int32_t));
1167 if (non_esp != 0)
1168 {
1169 plog("recvfrom %s:%u has no Non-ESP marker"
1170 , ip_str(cur_from), (unsigned) cur_from_port);
1171 return FALSE;
1172 }
1173 packet_len -= sizeof(u_int32_t);
1174 buffer_nat = malloc(packet_len);
1175 memcpy(buffer_nat, buffer + sizeof(u_int32_t), packet_len);
1176 free(buffer);
1177 buffer = buffer_nat;
1178 }
1179
1180 /* Clone actual message contents
1181 * and set up md->packet_pbs to describe it.
1182 */
1183 init_pbs(&md->packet_pbs, buffer, packet_len, "packet");
1184
1185 DBG(DBG_RAW | DBG_CRYPT | DBG_PARSING | DBG_CONTROL,
1186 {
1187 DBG_log(BLANK_FORMAT);
1188 DBG_log("*received %d bytes from %s:%u on %s"
1189 , (int) pbs_room(&md->packet_pbs)
1190 , ip_str(cur_from), (unsigned) cur_from_port
1191 , ifp->rname);
1192 });
1193
1194 DBG(DBG_RAW,
1195 DBG_dump("", md->packet_pbs.start, pbs_room(&md->packet_pbs)));
1196
1197 if ((pbs_room(&md->packet_pbs)==1) && (md->packet_pbs.start[0]==0xff))
1198 {
1199 /**
1200 * NAT-T Keep-alive packets should be discarded by kernel ESPinUDP
1201 * layer. But bogus keep-alive packets (sent with a non-esp marker)
1202 * can reach this point. Complain and discard them.
1203 */
1204 DBG(DBG_NATT,
1205 DBG_log("NAT-T keep-alive (bogus ?) should not reach this point. "
1206 "Ignored. Sender: %s:%u", ip_str(cur_from),
1207 (unsigned) cur_from_port);
1208 )
1209 return FALSE;
1210 }
1211
1212 #define IKEV2_VERSION_OFFSET 17
1213 #define IKEV2_VERSION 0x20
1214
1215 /* ignore IKEv2 packets - they will be handled by charon */
1216 if (pbs_room(&md->packet_pbs) > IKEV2_VERSION_OFFSET
1217 && md->packet_pbs.start[IKEV2_VERSION_OFFSET] == IKEV2_VERSION)
1218 {
1219 DBG(DBG_CONTROLMORE,
1220 DBG_log(" ignoring IKEv2 packet")
1221 )
1222 return FALSE;
1223 }
1224
1225 return TRUE;
1226 }
1227
1228 /* process an input packet, possibly generating a reply.
1229 *
1230 * If all goes well, this routine eventually calls a state-specific
1231 * transition function.
1232 */
1233 static void
1234 process_packet(struct msg_digest **mdp)
1235 {
1236 struct msg_digest *md = *mdp;
1237 const struct state_microcode *smc;
1238 bool new_iv_set = FALSE;
1239 bool restore_iv = FALSE;
1240 u_char new_iv[MAX_DIGEST_LEN];
1241 u_int new_iv_len = 0;
1242
1243 struct state *st = NULL;
1244 enum state_kind from_state = STATE_UNDEFINED; /* state we started in */
1245
1246 #define SEND_NOTIFICATION(t) { \
1247 if (st) send_notification_from_state(st, from_state, t); \
1248 else send_notification_from_md(md, t); }
1249
1250 if (!in_struct(&md->hdr, &isakmp_hdr_desc, &md->packet_pbs, &md->message_pbs))
1251 {
1252 /* Identify specific failures:
1253 * - bad ISAKMP major/minor version numbers
1254 */
1255 if (md->packet_pbs.roof - md->packet_pbs.cur >= (ptrdiff_t)isakmp_hdr_desc.size)
1256 {
1257 struct isakmp_hdr *hdr = (struct isakmp_hdr *)md->packet_pbs.cur;
1258 if ((hdr->isa_version >> ISA_MAJ_SHIFT) != ISAKMP_MAJOR_VERSION)
1259 {
1260 SEND_NOTIFICATION(INVALID_MAJOR_VERSION);
1261 return;
1262 }
1263 else if ((hdr->isa_version & ISA_MIN_MASK) != ISAKMP_MINOR_VERSION)
1264 {
1265 SEND_NOTIFICATION(INVALID_MINOR_VERSION);
1266 return;
1267 }
1268 }
1269 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1270 return;
1271 }
1272
1273 if (md->packet_pbs.roof != md->message_pbs.roof)
1274 {
1275 plog("size (%u) differs from size specified in ISAKMP HDR (%u)"
1276 , (unsigned) pbs_room(&md->packet_pbs), md->hdr.isa_length);
1277 #ifdef CISCO_QUIRKS
1278 if (pbs_room(&md->packet_pbs) - md->hdr.isa_length == 16)
1279 plog("Cisco VPN client appends 16 surplus NULL bytes");
1280 else
1281 #endif
1282 return;
1283 }
1284
1285 switch (md->hdr.isa_xchg)
1286 {
1287 #ifdef NOTYET
1288 case ISAKMP_XCHG_NONE:
1289 case ISAKMP_XCHG_BASE:
1290 #endif
1291
1292 case ISAKMP_XCHG_IDPROT: /* part of a Main Mode exchange */
1293 if (md->hdr.isa_msgid != MAINMODE_MSGID)
1294 {
1295 plog("Message ID was 0x%08lx but should be zero in Main Mode",
1296 (unsigned long) md->hdr.isa_msgid);
1297 SEND_NOTIFICATION(INVALID_MESSAGE_ID);
1298 return;
1299 }
1300
1301 if (is_zero_cookie(md->hdr.isa_icookie))
1302 {
1303 plog("Initiator Cookie must not be zero in Main Mode message");
1304 SEND_NOTIFICATION(INVALID_COOKIE);
1305 return;
1306 }
1307
1308 if (is_zero_cookie(md->hdr.isa_rcookie))
1309 {
1310 /* initial message from initiator
1311 * ??? what if this is a duplicate of another message?
1312 */
1313 if (md->hdr.isa_flags & ISAKMP_FLAG_ENCRYPTION)
1314 {
1315 plog("initial Main Mode message is invalid:"
1316 " its Encrypted Flag is on");
1317 SEND_NOTIFICATION(INVALID_FLAGS);
1318 return;
1319 }
1320
1321 /* don't build a state until the message looks tasty */
1322 from_state = STATE_MAIN_R0;
1323 }
1324 else
1325 {
1326 /* not an initial message */
1327
1328 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1329 , &md->sender, md->hdr.isa_msgid);
1330
1331 if (st == NULL)
1332 {
1333 /* perhaps this is a first message from the responder
1334 * and contains a responder cookie that we've not yet seen.
1335 */
1336 st = find_state(md->hdr.isa_icookie, zero_cookie
1337 , &md->sender, md->hdr.isa_msgid);
1338
1339 if (st == NULL)
1340 {
1341 plog("Main Mode message is part of an unknown exchange");
1342 /* XXX Could send notification back */
1343 return;
1344 }
1345 }
1346 set_cur_state(st);
1347 from_state = st->st_state;
1348 }
1349 break;
1350
1351 #ifdef NOTYET
1352 case ISAKMP_XCHG_AO:
1353 case ISAKMP_XCHG_AGGR:
1354 #endif
1355
1356 case ISAKMP_XCHG_INFO: /* an informational exchange */
1357 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1358 , &md->sender, MAINMODE_MSGID);
1359
1360 if (st != NULL)
1361 set_cur_state(st);
1362
1363 if (md->hdr.isa_flags & ISAKMP_FLAG_ENCRYPTION)
1364 {
1365 if (st == NULL)
1366 {
1367 plog("Informational Exchange is for an unknown (expired?) SA");
1368 /* XXX Could send notification back */
1369 return;
1370 }
1371
1372 if (!IS_ISAKMP_ENCRYPTED(st->st_state))
1373 {
1374 loglog(RC_LOG_SERIOUS, "encrypted Informational Exchange message is invalid"
1375 " because no key is known");
1376 /* XXX Could send notification back */
1377 return;
1378 }
1379
1380 if (md->hdr.isa_msgid == MAINMODE_MSGID)
1381 {
1382 loglog(RC_LOG_SERIOUS, "Informational Exchange message is invalid because"
1383 " it has a Message ID of 0");
1384 /* XXX Could send notification back */
1385 return;
1386 }
1387
1388 if (!reserve_msgid(st, md->hdr.isa_msgid))
1389 {
1390 loglog(RC_LOG_SERIOUS, "Informational Exchange message is invalid because"
1391 " it has a previously used Message ID (0x%08lx)"
1392 , (unsigned long)md->hdr.isa_msgid);
1393 /* XXX Could send notification back */
1394 return;
1395 }
1396
1397 if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state))
1398 {
1399 memcpy(st->st_ph1_iv, st->st_new_iv, st->st_new_iv_len);
1400 st->st_ph1_iv_len = st->st_new_iv_len;
1401
1402 /* backup new_iv */
1403 new_iv_len = st->st_new_iv_len;
1404 passert(new_iv_len <= MAX_DIGEST_LEN)
1405 memcpy(new_iv, st->st_new_iv, new_iv_len);
1406 restore_iv = TRUE;
1407 }
1408 init_phase2_iv(st, &md->hdr.isa_msgid);
1409 new_iv_set = TRUE;
1410
1411 from_state = STATE_INFO_PROTECTED;
1412 }
1413 else
1414 {
1415 if (st != NULL && IS_ISAKMP_ENCRYPTED(st->st_state))
1416 {
1417 loglog(RC_LOG_SERIOUS, "Informational Exchange message"
1418 " must be encrypted");
1419 /* XXX Could send notification back */
1420 return;
1421 }
1422 from_state = STATE_INFO;
1423 }
1424 break;
1425
1426 case ISAKMP_XCHG_QUICK: /* part of a Quick Mode exchange */
1427 if (is_zero_cookie(md->hdr.isa_icookie))
1428 {
1429 plog("Quick Mode message is invalid because"
1430 " it has an Initiator Cookie of 0");
1431 SEND_NOTIFICATION(INVALID_COOKIE);
1432 return;
1433 }
1434
1435 if (is_zero_cookie(md->hdr.isa_rcookie))
1436 {
1437 plog("Quick Mode message is invalid because"
1438 " it has a Responder Cookie of 0");
1439 SEND_NOTIFICATION(INVALID_COOKIE);
1440 return;
1441 }
1442
1443 if (md->hdr.isa_msgid == MAINMODE_MSGID)
1444 {
1445 plog("Quick Mode message is invalid because"
1446 " it has a Message ID of 0");
1447 SEND_NOTIFICATION(INVALID_MESSAGE_ID);
1448 return;
1449 }
1450
1451 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1452 , &md->sender, md->hdr.isa_msgid);
1453
1454 if (st == NULL)
1455 {
1456 /* No appropriate Quick Mode state.
1457 * See if we have a Main Mode state.
1458 * ??? what if this is a duplicate of another message?
1459 */
1460 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1461 , &md->sender, MAINMODE_MSGID);
1462
1463 if (st == NULL)
1464 {
1465 plog("Quick Mode message is for a non-existent (expired?)"
1466 " ISAKMP SA");
1467 /* XXX Could send notification back */
1468 return;
1469 }
1470
1471 set_cur_state(st);
1472
1473 if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state))
1474 {
1475 loglog(RC_LOG_SERIOUS, "Quick Mode message is unacceptable because"
1476 " it is for an incomplete ISAKMP SA");
1477 SEND_NOTIFICATION(PAYLOAD_MALFORMED /* XXX ? */);
1478 return;
1479 }
1480
1481 /* only accept this new Quick Mode exchange if it has a unique message ID */
1482 if (!reserve_msgid(st, md->hdr.isa_msgid))
1483 {
1484 loglog(RC_LOG_SERIOUS, "Quick Mode I1 message is unacceptable because"
1485 " it uses a previously used Message ID 0x%08lx"
1486 " (perhaps this is a duplicated packet)"
1487 , (unsigned long) md->hdr.isa_msgid);
1488 SEND_NOTIFICATION(INVALID_MESSAGE_ID);
1489 return;
1490 }
1491
1492 /* Quick Mode Initial IV */
1493 init_phase2_iv(st, &md->hdr.isa_msgid);
1494 new_iv_set = TRUE;
1495
1496 from_state = STATE_QUICK_R0;
1497 }
1498 else
1499 {
1500 set_cur_state(st);
1501 from_state = st->st_state;
1502 }
1503
1504 break;
1505
1506 case ISAKMP_XCHG_MODE_CFG:
1507 if (is_zero_cookie(md->hdr.isa_icookie))
1508 {
1509 plog("ModeCfg message is invalid because"
1510 " it has an Initiator Cookie of 0");
1511 /* XXX Could send notification back */
1512 return;
1513 }
1514
1515 if (is_zero_cookie(md->hdr.isa_rcookie))
1516 {
1517 plog("ModeCfg message is invalid because"
1518 " it has a Responder Cookie of 0");
1519 /* XXX Could send notification back */
1520 return;
1521 }
1522
1523 if (md->hdr.isa_msgid == 0)
1524 {
1525 plog("ModeCfg message is invalid because"
1526 " it has a Message ID of 0");
1527 /* XXX Could send notification back */
1528 return;
1529 }
1530
1531 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1532 , &md->sender, md->hdr.isa_msgid);
1533
1534 if (st == NULL)
1535 {
1536 bool has_xauth_policy;
1537
1538 /* No appropriate ModeCfg state.
1539 * See if we have a Main Mode state.
1540 * ??? what if this is a duplicate of another message?
1541 */
1542 st = find_state(md->hdr.isa_icookie, md->hdr.isa_rcookie
1543 , &md->sender, 0);
1544
1545 if (st == NULL)
1546 {
1547 plog("ModeCfg message is for a non-existent (expired?)"
1548 " ISAKMP SA");
1549 /* XXX Could send notification back */
1550 return;
1551 }
1552
1553 set_cur_state(st);
1554
1555 /* the XAUTH_STATUS message might have a new msgid */
1556 if (st->st_state == STATE_XAUTH_I1)
1557 {
1558 init_phase2_iv(st, &md->hdr.isa_msgid);
1559 new_iv_set = TRUE;
1560 from_state = st->st_state;
1561 break;
1562 }
1563
1564 if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state))
1565 {
1566 loglog(RC_LOG_SERIOUS, "ModeCfg message is unacceptable because"
1567 " it is for an incomplete ISAKMP SA (state=%s)"
1568 , enum_name(&state_names, st->st_state));
1569 /* XXX Could send notification back */
1570 return;
1571 }
1572 init_phase2_iv(st, &md->hdr.isa_msgid);
1573 new_iv_set = TRUE;
1574
1575 /*
1576 * okay, now we have to figure out if we are receiving a bogus
1577 * new message in an oustanding XAUTH server conversation
1578 * (i.e. a reply to our challenge)
1579 * (this occurs with some broken other implementations).
1580 *
1581 * or if receiving for the first time, an XAUTH challenge.
1582 *
1583 * or if we are getting a MODECFG request.
1584 *
1585 * we distinguish these states because we can not both be an
1586 * XAUTH server and client, and our policy tells us which
1587 * one we are.
1588 *
1589 * to complicate further, it is normal to start a new msgid
1590 * when going from one state to another, or when restarting
1591 * the challenge.
1592 *
1593 */
1594
1595 has_xauth_policy = (st->st_connection->policy
1596 & (POLICY_XAUTH_RSASIG | POLICY_XAUTH_PSK))
1597 != LEMPTY;
1598
1599 if (has_xauth_policy && !st->st_xauth.started
1600 && IS_PHASE1(st->st_state))
1601 {
1602 from_state = STATE_XAUTH_I0;
1603 }
1604 else if (st->st_connection->spd.that.modecfg
1605 && IS_PHASE1(st->st_state))
1606 {
1607 from_state = STATE_MODE_CFG_R0;
1608 }
1609 else if (st->st_connection->spd.this.modecfg
1610 && IS_PHASE1(st->st_state))
1611 {
1612 from_state = STATE_MODE_CFG_I0;
1613 }
1614 else
1615 {
1616 /* XXX check if we are being a mode config server here */
1617 plog("received ModeCfg message when in state %s, and we aren't mode config client"
1618 , enum_name(&state_names, st->st_state));
1619 return;
1620 }
1621 }
1622 else
1623 {
1624 set_cur_state(st);
1625 from_state = st->st_state;
1626 }
1627 break;
1628
1629 #ifdef NOTYET
1630 case ISAKMP_XCHG_NGRP:
1631 case ISAKMP_XCHG_ACK_INFO:
1632 #endif
1633
1634 default:
1635 plog("unsupported exchange type %s in message"
1636 , enum_show(&exchange_names, md->hdr.isa_xchg));
1637 SEND_NOTIFICATION(UNSUPPORTED_EXCHANGE_TYPE);
1638 return;
1639 }
1640
1641 /* We have found a from_state, and perhaps a state object.
1642 * If we need to build a new state object,
1643 * we wait until the packet has been sanity checked.
1644 */
1645
1646 /* We don't support the Commit Flag. It is such a bad feature.
1647 * It isn't protected -- neither encrypted nor authenticated.
1648 * A man in the middle turns it on, leading to DoS.
1649 * We just ignore it, with a warning.
1650 * By placing the check here, we could easily add a policy bit
1651 * to a connection to suppress the warning. This might be useful
1652 * because the Commit Flag is expected from some peers.
1653 */
1654 if (md->hdr.isa_flags & ISAKMP_FLAG_COMMIT)
1655 {
1656 plog("IKE message has the Commit Flag set but Pluto doesn't implement this feature; ignoring flag");
1657 }
1658
1659 /* Set smc to describe this state's properties.
1660 * Look up the appropriate microcode based on state and
1661 * possibly Oakley Auth type.
1662 */
1663 passert(STATE_IKE_FLOOR <= from_state && from_state <= STATE_IKE_ROOF);
1664 smc = ike_microcode_index[from_state - STATE_IKE_FLOOR];
1665
1666 if (st != NULL)
1667 {
1668 u_int16_t auth;
1669
1670 switch (st->st_oakley.auth)
1671 {
1672 case XAUTHInitPreShared:
1673 case XAUTHRespPreShared:
1674 auth = OAKLEY_PRESHARED_KEY;
1675 break;
1676 case XAUTHInitRSA:
1677 case XAUTHRespRSA:
1678 auth = OAKLEY_RSA_SIG;
1679 break;
1680 default:
1681 auth = st->st_oakley.auth;
1682 }
1683
1684 while (!LHAS(smc->flags, auth))
1685 {
1686 smc++;
1687 passert(smc->state == from_state);
1688 }
1689 }
1690
1691 /* Ignore a packet if the state has a suspended state transition
1692 * Probably a duplicated packet but the original packet is not yet
1693 * recorded in st->st_rpacket, so duplicate checking won't catch.
1694 * ??? Should the packet be recorded earlier to improve diagnosis?
1695 */
1696 if (st != NULL && st->st_suspended_md != NULL)
1697 {
1698 loglog(RC_LOG, "discarding packet received during DNS lookup in %s"
1699 , enum_name(&state_names, st->st_state));
1700 return;
1701 }
1702
1703 /* Detect and handle duplicated packets.
1704 * This won't work for the initial packet of an exchange
1705 * because we won't have a state object to remember it.
1706 * If we are in a non-receiving state (terminal), and the preceding
1707 * state did transmit, then the duplicate may indicate that that
1708 * transmission wasn't received -- retransmit it.
1709 * Otherwise, just discard it.
1710 * ??? Notification packets are like exchanges -- I hope that
1711 * they are idempotent!
1712 */
1713 if (st != NULL
1714 && st->st_rpacket.ptr != NULL
1715 && st->st_rpacket.len == pbs_room(&md->packet_pbs)
1716 && memeq(st->st_rpacket.ptr, md->packet_pbs.start, st->st_rpacket.len))
1717 {
1718 if (smc->flags & SMF_RETRANSMIT_ON_DUPLICATE)
1719 {
1720 if (st->st_retransmit < MAXIMUM_RETRANSMISSIONS)
1721 {
1722 st->st_retransmit++;
1723 loglog(RC_RETRANSMISSION
1724 , "retransmitting in response to duplicate packet; already %s"
1725 , enum_name(&state_names, st->st_state));
1726 send_packet(st, "retransmit in response to duplicate");
1727 }
1728 else
1729 {
1730 loglog(RC_LOG_SERIOUS, "discarding duplicate packet -- exhausted retransmission; already %s"
1731 , enum_name(&state_names, st->st_state));
1732 }
1733 }
1734 else
1735 {
1736 loglog(RC_LOG_SERIOUS, "discarding duplicate packet; already %s"
1737 , enum_name(&state_names, st->st_state));
1738 }
1739 return;
1740 }
1741
1742 if (md->hdr.isa_flags & ISAKMP_FLAG_ENCRYPTION)
1743 {
1744 DBG(DBG_CRYPT, DBG_log("received encrypted packet from %s:%u"
1745 , ip_str(&md->sender), (unsigned)md->sender_port));
1746
1747 if (st == NULL)
1748 {
1749 plog("discarding encrypted message for an unknown ISAKMP SA");
1750 SEND_NOTIFICATION(PAYLOAD_MALFORMED /* XXX ? */);
1751 return;
1752 }
1753 if (st->st_skeyid_e.ptr == (u_char *) NULL)
1754 {
1755 loglog(RC_LOG_SERIOUS, "discarding encrypted message"
1756 " because we haven't yet negotiated keying materiel");
1757 SEND_NOTIFICATION(INVALID_FLAGS);
1758 return;
1759 }
1760
1761 /* Mark as encrypted */
1762 md->encrypted = TRUE;
1763
1764 DBG(DBG_CRYPT, DBG_log("decrypting %u bytes using algorithm %s"
1765 , (unsigned) pbs_left(&md->message_pbs)
1766 , enum_show(&oakley_enc_names, st->st_oakley.encrypt)));
1767
1768 /* do the specified decryption
1769 *
1770 * IV is from st->st_iv or (if new_iv_set) st->st_new_iv.
1771 * The new IV is placed in st->st_new_iv
1772 *
1773 * See RFC 2409 "IKE" Appendix B
1774 *
1775 * XXX The IV should only be updated really if the packet
1776 * is successfully processed.
1777 * We should keep this value, check for a success return
1778 * value from the parsing routines and then replace.
1779 *
1780 * Each post phase 1 exchange generates IVs from
1781 * the last phase 1 block, not the last block sent.
1782 */
1783 {
1784 const struct encrypt_desc *e = st->st_oakley.encrypter;
1785
1786 if (pbs_left(&md->message_pbs) % e->enc_blocksize != 0)
1787 {
1788 loglog(RC_LOG_SERIOUS, "malformed message: not a multiple of encryption blocksize");
1789 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1790 return;
1791 }
1792
1793 /* XXX Detect weak keys */
1794
1795 /* grab a copy of raw packet (for duplicate packet detection) */
1796 md->raw_packet = chunk_create(md->packet_pbs.start, pbs_room(&md->packet_pbs));
1797 md->raw_packet = chunk_clone(md->raw_packet);
1798
1799 /* Decrypt everything after header */
1800 if (!new_iv_set)
1801 {
1802 /* use old IV */
1803 passert(st->st_iv_len <= sizeof(st->st_new_iv));
1804 st->st_new_iv_len = st->st_iv_len;
1805 memcpy(st->st_new_iv, st->st_iv, st->st_new_iv_len);
1806 }
1807 crypto_cbc_encrypt(e, FALSE, md->message_pbs.cur,
1808 pbs_left(&md->message_pbs) , st);
1809 if (restore_iv)
1810 {
1811 memcpy(st->st_new_iv, new_iv, new_iv_len);
1812 st->st_new_iv_len = new_iv_len;
1813 }
1814 }
1815
1816 DBG_cond_dump(DBG_CRYPT, "decrypted:\n", md->message_pbs.cur
1817 , md->message_pbs.roof - md->message_pbs.cur);
1818
1819 DBG_cond_dump(DBG_CRYPT, "next IV:"
1820 , st->st_new_iv, st->st_new_iv_len);
1821 }
1822 else
1823 {
1824 /* packet was not encryped -- should it have been? */
1825
1826 if (smc->flags & SMF_INPUT_ENCRYPTED)
1827 {
1828 loglog(RC_LOG_SERIOUS, "packet rejected: should have been encrypted");
1829 SEND_NOTIFICATION(INVALID_FLAGS);
1830 return;
1831 }
1832 }
1833
1834 /* Digest the message.
1835 * Padding must be removed to make hashing work.
1836 * Padding comes from encryption (so this code must be after decryption).
1837 * Padding rules are described before the definition of
1838 * struct isakmp_hdr in packet.h.
1839 */
1840 {
1841 struct payload_digest *pd = md->digest;
1842 int np = md->hdr.isa_np;
1843 lset_t needed = smc->req_payloads;
1844 const char *excuse
1845 = LIN(SMF_PSK_AUTH | SMF_FIRST_ENCRYPTED_INPUT, smc->flags)
1846 ? "probable authentication failure (mismatch of preshared secrets?): "
1847 : "";
1848
1849 while (np != ISAKMP_NEXT_NONE)
1850 {
1851 struct_desc *sd = np < ISAKMP_NEXT_ROOF? payload_descs[np] : NULL;
1852
1853 if (pd == &md->digest[PAYLIMIT])
1854 {
1855 loglog(RC_LOG_SERIOUS, "more than %d payloads in message; ignored", PAYLIMIT);
1856 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1857 return;
1858 }
1859
1860 switch (np)
1861 {
1862 case ISAKMP_NEXT_NATD_RFC:
1863 case ISAKMP_NEXT_NATOA_RFC:
1864 if (!st || !(st->nat_traversal & NAT_T_WITH_RFC_VALUES))
1865 {
1866 /*
1867 * don't accept NAT-D/NAT-OA reloc directly in message, unless
1868 * we're using NAT-T RFC
1869 */
1870 sd = NULL;
1871 }
1872 break;
1873 }
1874
1875 if (sd == NULL)
1876 {
1877 /* payload type is out of range or requires special handling */
1878 switch (np)
1879 {
1880 case ISAKMP_NEXT_ID:
1881 sd = IS_PHASE1(from_state)
1882 ? &isakmp_identification_desc : &isakmp_ipsec_identification_desc;
1883 break;
1884 case ISAKMP_NEXT_NATD_DRAFTS:
1885 np = ISAKMP_NEXT_NATD_RFC; /* NAT-D relocated */
1886 sd = payload_descs[np];
1887 break;
1888 case ISAKMP_NEXT_NATOA_DRAFTS:
1889 np = ISAKMP_NEXT_NATOA_RFC; /* NAT-OA relocated */
1890 sd = payload_descs[np];
1891 break;
1892 default:
1893 loglog(RC_LOG_SERIOUS, "%smessage ignored because it contains an unknown or"
1894 " unexpected payload type (%s) at the outermost level"
1895 , excuse, enum_show(&payload_names, np));
1896 SEND_NOTIFICATION(INVALID_PAYLOAD_TYPE);
1897 return;
1898 }
1899 }
1900
1901 {
1902 lset_t s = LELEM(np);
1903
1904 if (LDISJOINT(s
1905 , needed | smc->opt_payloads| LELEM(ISAKMP_NEXT_N) | LELEM(ISAKMP_NEXT_D)))
1906 {
1907 loglog(RC_LOG_SERIOUS, "%smessage ignored because it "
1908 "contains an unexpected payload type (%s)"
1909 , excuse, enum_show(&payload_names, np));
1910 SEND_NOTIFICATION(INVALID_PAYLOAD_TYPE);
1911 return;
1912 }
1913 needed &= ~s;
1914 }
1915
1916 if (!in_struct(&pd->payload, sd, &md->message_pbs, &pd->pbs))
1917 {
1918 loglog(RC_LOG_SERIOUS, "%smalformed payload in packet", excuse);
1919 if (md->hdr.isa_xchg != ISAKMP_XCHG_INFO)
1920 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1921 return;
1922 }
1923
1924 /* place this payload at the end of the chain for this type */
1925 {
1926 struct payload_digest **p;
1927
1928 for (p = &md->chain[np]; *p != NULL; p = &(*p)->next)
1929 ;
1930 *p = pd;
1931 pd->next = NULL;
1932 }
1933
1934 np = pd->payload.generic.isag_np;
1935 pd++;
1936
1937 /* since we've digested one payload happily, it is probably
1938 * the case that any decryption worked. So we will not suggest
1939 * encryption failure as an excuse for subsequent payload
1940 * problems.
1941 */
1942 excuse = "";
1943 }
1944
1945 md->digest_roof = pd;
1946
1947 DBG(DBG_PARSING,
1948 if (pbs_left(&md->message_pbs) != 0)
1949 DBG_log("removing %d bytes of padding", (int) pbs_left(&md->message_pbs)));
1950
1951 md->message_pbs.roof = md->message_pbs.cur;
1952
1953 /* check that all mandatory payloads appeared */
1954
1955 if (needed != 0)
1956 {
1957 loglog(RC_LOG_SERIOUS, "message for %s is missing payloads %s"
1958 , enum_show(&state_names, from_state)
1959 , bitnamesof(payload_name, needed));
1960 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1961 return;
1962 }
1963 }
1964
1965 /* more sanity checking: enforce most ordering constraints */
1966
1967 if (IS_PHASE1(from_state))
1968 {
1969 /* rfc2409: The Internet Key Exchange (IKE), 5 Exchanges:
1970 * "The SA payload MUST precede all other payloads in a phase 1 exchange."
1971 */
1972 if (md->chain[ISAKMP_NEXT_SA] != NULL
1973 && md->hdr.isa_np != ISAKMP_NEXT_SA)
1974 {
1975 loglog(RC_LOG_SERIOUS, "malformed Phase 1 message: does not start with an SA payload");
1976 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
1977 return;
1978 }
1979 }
1980 else if (IS_QUICK(from_state))
1981 {
1982 /* rfc2409: The Internet Key Exchange (IKE), 5.5 Phase 2 - Quick Mode
1983 *
1984 * "In Quick Mode, a HASH payload MUST immediately follow the ISAKMP
1985 * header and a SA payload MUST immediately follow the HASH."
1986 * [NOTE: there may be more than one SA payload, so this is not
1987 * totally reasonable. Probably all SAs should be so constrained.]
1988 *
1989 * "If ISAKMP is acting as a client negotiator on behalf of another
1990 * party, the identities of the parties MUST be passed as IDci and
1991 * then IDcr."
1992 *
1993 * "With the exception of the HASH, SA, and the optional ID payloads,
1994 * there are no payload ordering restrictions on Quick Mode."
1995 */
1996
1997 if (md->hdr.isa_np != ISAKMP_NEXT_HASH)
1998 {
1999 loglog(RC_LOG_SERIOUS, "malformed Quick Mode message: does not start with a HASH payload");
2000 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
2001 return;
2002 }
2003
2004 {
2005 struct payload_digest *p;
2006 int i;
2007
2008 for (p = md->chain[ISAKMP_NEXT_SA], i = 1; p != NULL
2009 ; p = p->next, i++)
2010 {
2011 if (p != &md->digest[i])
2012 {
2013 loglog(RC_LOG_SERIOUS, "malformed Quick Mode message: SA payload is in wrong position");
2014 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
2015 return;
2016 }
2017 }
2018 }
2019
2020 /* rfc2409: The Internet Key Exchange (IKE), 5.5 Phase 2 - Quick Mode:
2021 * "If ISAKMP is acting as a client negotiator on behalf of another
2022 * party, the identities of the parties MUST be passed as IDci and
2023 * then IDcr."
2024 */
2025 {
2026 struct payload_digest *id = md->chain[ISAKMP_NEXT_ID];
2027
2028 if (id != NULL)
2029 {
2030 if (id->next == NULL || id->next->next != NULL)
2031 {
2032 loglog(RC_LOG_SERIOUS, "malformed Quick Mode message:"
2033 " if any ID payload is present,"
2034 " there must be exactly two");
2035 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
2036 return;
2037 }
2038 if (id+1 != id->next)
2039 {
2040 loglog(RC_LOG_SERIOUS, "malformed Quick Mode message:"
2041 " the ID payloads are not adjacent");
2042 SEND_NOTIFICATION(PAYLOAD_MALFORMED);
2043 return;
2044 }
2045 }
2046 }
2047 }
2048
2049 /* Ignore payloads that we don't handle:
2050 * Delete, Notification, VendorID
2051 */
2052 /* XXX Handle deletions */
2053 /* XXX Handle Notifications */
2054 /* XXX Handle VID payloads */
2055 {
2056 struct payload_digest *p;
2057
2058 for (p = md->chain[ISAKMP_NEXT_N]; p != NULL; p = p->next)
2059 {
2060 if (p->payload.notification.isan_type != R_U_THERE
2061 && p->payload.notification.isan_type != R_U_THERE_ACK)
2062 {
2063 loglog(RC_LOG_SERIOUS, "ignoring informational payload, type %s"
2064 , enum_show(&notification_names, p->payload.notification.isan_type));
2065 }
2066 DBG_cond_dump(DBG_PARSING, "info:", p->pbs.cur, pbs_left(&p->pbs));
2067 }
2068
2069 for (p = md->chain[ISAKMP_NEXT_D]; p != NULL; p = p->next)
2070 {
2071 accept_delete(st, md, p);
2072 DBG_cond_dump(DBG_PARSING, "del:", p->pbs.cur, pbs_left(&p->pbs));
2073 }
2074
2075 for (p = md->chain[ISAKMP_NEXT_VID]; p != NULL; p = p->next)
2076 {
2077 handle_vendorid(md, p->pbs.cur, pbs_left(&p->pbs));
2078 }
2079 }
2080 md->from_state = from_state;
2081 md->smc = smc;
2082 md->st = st;
2083
2084 /* possibly fill in hdr */
2085 if (smc->first_out_payload != ISAKMP_NEXT_NONE)
2086 echo_hdr(md, (smc->flags & SMF_OUTPUT_ENCRYPTED) != 0
2087 , smc->first_out_payload);
2088
2089 complete_state_transition(mdp, smc->processor(md));
2090 }
2091
2092 /* complete job started by the state-specific state transition function */
2093
2094 void
2095 complete_state_transition(struct msg_digest **mdp, stf_status result)
2096 {
2097 bool has_xauth_policy;
2098 bool is_xauth_server;
2099 struct msg_digest *md = *mdp;
2100 const struct state_microcode *smc = md->smc;
2101 enum state_kind from_state = md->from_state;
2102 struct state *st;
2103
2104 cur_state = st = md->st; /* might have changed */
2105
2106 /* If state has DPD support, import it */
2107 if (st && md->dpd)
2108 st->st_dpd = TRUE;
2109
2110 switch (result)
2111 {
2112 case STF_IGNORE:
2113 break;
2114
2115 case STF_SUSPEND:
2116 /* the stf didn't complete its job: don't relase md */
2117 *mdp = NULL;
2118 break;
2119
2120 case STF_OK:
2121 /* advance the state */
2122 st->st_state = smc->next_state;
2123
2124 /* Delete previous retransmission event.
2125 * New event will be scheduled below.
2126 */
2127 delete_event(st);
2128
2129 /* replace previous receive packet with latest */
2130
2131 free(st->st_rpacket.ptr);
2132
2133 if (md->encrypted)
2134 {
2135 /* if encrypted, duplication already done */
2136 st->st_rpacket = md->raw_packet;
2137 md->raw_packet.ptr = NULL;
2138 }
2139 else
2140 {
2141 st->st_rpacket = chunk_create(md->packet_pbs.start,
2142 pbs_room(&md->packet_pbs));
2143 st->st_rpacket = chunk_clone(st->st_rpacket);
2144 }
2145
2146 /* free previous transmit packet */
2147 chunk_free(&st->st_tpacket);
2148
2149 /* if requested, send the new reply packet */
2150 if (smc->flags & SMF_REPLY)
2151 {
2152 close_output_pbs(&md->reply); /* good form, but actually a no-op */
2153
2154 st->st_tpacket = chunk_create(md->reply.start, pbs_offset(&md->reply));
2155 st->st_tpacket = chunk_clone(st->st_tpacket);
2156
2157 if (nat_traversal_enabled)
2158 nat_traversal_change_port_lookup(md, md->st);
2159
2160 /* actually send the packet
2161 * Note: this is a great place to implement "impairments"
2162 * for testing purposes. Suppress or duplicate the
2163 * send_packet call depending on st->st_state.
2164 */
2165 send_packet(st, enum_name(&state_names, from_state));
2166 }
2167
2168 /* Schedule for whatever timeout is specified */
2169 {
2170 time_t delay = UNDEFINED_TIME;
2171 enum event_type kind = smc->timeout_event;
2172 bool agreed_time = FALSE;
2173 struct connection *c = st->st_connection;
2174
2175 switch (kind)
2176 {
2177 case EVENT_RETRANSMIT: /* Retransmit packet */
2178 delay = EVENT_RETRANSMIT_DELAY_0;
2179 break;
2180
2181 case EVENT_SA_REPLACE: /* SA replacement event */
2182 if (IS_PHASE1(st->st_state))
2183 {
2184 /* Note: we will defer to the "negotiated" (dictated)
2185 * lifetime if we are POLICY_DONT_REKEY.
2186 * This allows the other side to dictate
2187 * a time we would not otherwise accept
2188 * but it prevents us from having to initiate
2189 * rekeying. The negative consequences seem
2190 * minor.
2191 */
2192 delay = c->sa_ike_life_seconds;
2193 if ((c->policy & POLICY_DONT_REKEY)
2194 || delay >= st->st_oakley.life_seconds)
2195 {
2196 agreed_time = TRUE;
2197 delay = st->st_oakley.life_seconds;
2198 }
2199 }
2200 else
2201 {
2202 /* Delay is min of up to four things:
2203 * each can limit the lifetime.
2204 */
2205 delay = c->sa_ipsec_life_seconds;
2206 if (st->st_ah.present
2207 && delay >= st->st_ah.attrs.life_seconds)
2208 {
2209 agreed_time = TRUE;
2210 delay = st->st_ah.attrs.life_seconds;
2211 }
2212 if (st->st_esp.present
2213 && delay >= st->st_esp.attrs.life_seconds)
2214 {
2215 agreed_time = TRUE;
2216 delay = st->st_esp.attrs.life_seconds;
2217 }
2218 if (st->st_ipcomp.present
2219 && delay >= st->st_ipcomp.attrs.life_seconds)
2220 {
2221 agreed_time = TRUE;
2222 delay = st->st_ipcomp.attrs.life_seconds;
2223 }
2224 }
2225
2226 /* By default, we plan to rekey.
2227 *
2228 * If there isn't enough time to rekey, plan to
2229 * expire.
2230 *
2231 * If we are --dontrekey, a lot more rules apply.
2232 * If we are the Initiator, use REPLACE_IF_USED.
2233 * If we are the Responder, and the dictated time
2234 * was unacceptable (too large), plan to REPLACE
2235 * (the only way to ratchet down the time).
2236 * If we are the Responder, and the dictated time
2237 * is acceptable, plan to EXPIRE.
2238 *
2239 * Important policy lies buried here.
2240 * For example, we favour the initiator over the
2241 * responder by making the initiator start rekeying
2242 * sooner. Also, fuzz is only added to the
2243 * initiator's margin.
2244 *
2245 * Note: for ISAKMP SA, we let the negotiated
2246 * time stand (implemented by earlier logic).
2247 */
2248 if (agreed_time
2249 && (c->policy & POLICY_DONT_REKEY))
2250 {
2251 kind = (smc->flags & SMF_INITIATOR)
2252 ? EVENT_SA_REPLACE_IF_USED
2253 : EVENT_SA_EXPIRE;
2254 }
2255 if (kind != EVENT_SA_EXPIRE)
2256 {
2257 unsigned long marg = c->sa_rekey_margin;
2258
2259 if (smc->flags & SMF_INITIATOR)
2260 marg += marg
2261 * c->sa_rekey_fuzz / 100.E0
2262 * (rand() / (RAND_MAX + 1.E0));
2263 else
2264 marg /= 2;
2265
2266 if ((unsigned long)delay > marg)
2267 {
2268 delay -= marg;
2269 st->st_margin = marg;
2270 }
2271 else
2272 {
2273 kind = EVENT_SA_EXPIRE;
2274 }
2275 }
2276 break;
2277
2278 case EVENT_NULL: /* non-event */
2279 case EVENT_REINIT_SECRET: /* Refresh cookie secret */
2280 default:
2281 bad_case(kind);
2282 }
2283 event_schedule(kind, delay, st);
2284 }
2285
2286 /* tell whack and log of progress */
2287 {
2288 const char *story = state_story[st->st_state - STATE_MAIN_R0];
2289 enum rc_type w = RC_NEW_STATE + st->st_state;
2290 char sadetails[128];
2291
2292 sadetails[0]='\0';
2293
2294 if (IS_IPSEC_SA_ESTABLISHED(st->st_state))
2295 {
2296 char *b = sadetails;
2297 const char *ini = " {";
2298 const char *fin = "";
2299
2300 /* -1 is to leave space for "fin" */
2301
2302 if (st->st_esp.present)
2303 {
2304 snprintf(b, sizeof(sadetails)-(b-sadetails)-1
2305 , "%sESP=>0x%08x <0x%08x"
2306 , ini
2307 , ntohl(st->st_esp.attrs.spi)
2308 , ntohl(st->st_esp.our_spi));
2309 ini = " ";
2310 fin = "}";
2311 }
2312 /* advance b to end of string */
2313 b = b + strlen(b);
2314
2315 if (st->st_ah.present)
2316 {
2317 snprintf(b, sizeof(sadetails)-(b-sadetails)-1
2318 , "%sAH=>0x%08x <0x%08x"
2319 , ini
2320 , ntohl(st->st_ah.attrs.spi)
2321 , ntohl(st->st_ah.our_spi));
2322 ini = " ";
2323 fin = "}";
2324 }
2325 /* advance b to end of string */
2326 b = b + strlen(b);
2327
2328 if (st->st_ipcomp.present)
2329 {
2330 snprintf(b, sizeof(sadetails)-(b-sadetails)-1
2331 , "%sIPCOMP=>0x%08x <0x%08x"
2332 , ini
2333 , ntohl(st->st_ipcomp.attrs.spi)
2334 , ntohl(st->st_ipcomp.our_spi));
2335 ini = " ";
2336 fin = "}";
2337 }
2338 /* advance b to end of string */
2339 b = b + strlen(b);
2340
2341 if (st->nat_traversal)
2342 {
2343 char oa[ADDRTOT_BUF];
2344 addrtot(&st->nat_oa, 0, oa, sizeof(oa));
2345 snprintf(b, sizeof(sadetails)-(b-sadetails)-1
2346 , "%sNATOA=%s"
2347 , ini, oa);
2348 ini = " ";
2349 fin = "}";
2350 }
2351
2352 /* advance b to end of string */
2353 b = b + strlen(b);
2354
2355 if (st->st_dpd)
2356 {
2357 snprintf(b, sizeof(sadetails)-(b-sadetails)-1
2358 , "%sDPD"
2359 , ini);
2360 ini = " ";
2361 fin = "}";
2362 }
2363
2364 strcat(b, fin);
2365 }
2366
2367 if (IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2368 || IS_IPSEC_SA_ESTABLISHED(st->st_state))
2369 {
2370 /* log our success */
2371 plog("%s%s", story, sadetails);
2372 w = RC_SUCCESS;
2373 }
2374
2375 /* tell whack our progress */
2376 whack_log(w
2377 , "%s: %s%s"
2378 , enum_name(&state_names, st->st_state)
2379 , story, sadetails);
2380 }
2381
2382 has_xauth_policy = (st->st_connection->policy
2383 & (POLICY_XAUTH_RSASIG | POLICY_XAUTH_PSK))
2384 != LEMPTY;
2385 is_xauth_server = (st->st_connection->policy
2386 & POLICY_XAUTH_SERVER)
2387 != LEMPTY;
2388
2389 /* Should we start XAUTH as a server */
2390 if (has_xauth_policy && is_xauth_server
2391 && IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2392 && !st->st_xauth.started)
2393 {
2394 DBG(DBG_CONTROL,
2395 DBG_log("starting XAUTH server")
2396 )
2397 xauth_send_request(st);
2398 break;
2399 }
2400
2401 /* Wait for XAUTH request from server */
2402 if (has_xauth_policy && !is_xauth_server
2403 && IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2404 && !st->st_xauth.started)
2405 {
2406 DBG(DBG_CONTROL,
2407 DBG_log("waiting for XAUTH request from server")
2408 )
2409 break;
2410 }
2411
2412 /* Should we start ModeConfig as a client? */
2413 if (st->st_connection->spd.this.modecfg
2414 && IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2415 && !(st->st_connection->policy & POLICY_MODECFG_PUSH)
2416 && !st->st_modecfg.started)
2417 {
2418 DBG(DBG_CONTROL,
2419 DBG_log("starting ModeCfg client in pull mode")
2420 )
2421 modecfg_send_request(st);
2422 break;
2423 }
2424
2425 /* Should we start ModeConfig as a server? */
2426 if (st->st_connection->spd.that.modecfg
2427 && IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2428 && !st->st_modecfg.started
2429 && (st->st_connection->policy & POLICY_MODECFG_PUSH))
2430 {
2431 DBG(DBG_CONTROL,
2432 DBG_log("starting ModeCfg server in push mode")
2433 )
2434 modecfg_send_set(st);
2435 break;
2436 }
2437
2438 /* Wait for ModeConfig set from server */
2439 if (st->st_connection->spd.this.modecfg
2440 && IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2441 && !st->st_modecfg.vars_set)
2442 {
2443 DBG(DBG_CONTROL,
2444 DBG_log("waiting for ModeCfg set from server")
2445 )
2446 break;
2447 }
2448
2449 if (smc->flags & SMF_RELEASE_PENDING_P2)
2450 {
2451 /* Initiate any Quick Mode negotiations that
2452 * were waiting to piggyback on this Keying Channel.
2453 *
2454 * ??? there is a potential race condition
2455 * if we are the responder: the initial Phase 2
2456 * message might outrun the final Phase 1 message.
2457 * I think that retransmission will recover.
2458 */
2459 unpend(st);
2460 }
2461
2462 if (IS_ISAKMP_SA_ESTABLISHED(st->st_state)
2463 || IS_IPSEC_SA_ESTABLISHED(st->st_state))
2464 release_whack(st);
2465 break;
2466
2467 case STF_INTERNAL_ERROR:
2468 whack_log(RC_INTERNALERR + md->note
2469 , "%s: internal error"
2470 , enum_name(&state_names, st->st_state));
2471
2472 DBG(DBG_CONTROL,
2473 DBG_log("state transition function for %s had internal error"
2474 , enum_name(&state_names, from_state)));
2475 break;
2476
2477 default: /* a shortcut to STF_FAIL, setting md->note */
2478 passert(result > STF_FAIL);
2479 md->note = result - STF_FAIL;
2480 result = STF_FAIL;
2481 /* FALL THROUGH ... */
2482 case STF_FAIL:
2483 /* As it is, we act as if this message never happened:
2484 * whatever retrying was in place, remains in place.
2485 */
2486 whack_log(RC_NOTIFICATION + md->note
2487 , "%s: %s"
2488 , enum_name(&state_names, (st == NULL)? STATE_MAIN_R0:st->st_state)
2489 , enum_name(&notification_names, md->note));
2490
2491 SEND_NOTIFICATION(md->note);
2492
2493 DBG(DBG_CONTROL,
2494 DBG_log("state transition function for %s failed: %s"
2495 , enum_name(&state_names, from_state)
2496 , enum_name(&notification_names, md->note)));
2497 break;
2498 }
2499 }