Commit | Line | Data |
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2fe58dfd SE |
1 | /* site.c - manage communication with a remote network site */ |
2 | ||
469fd1d9 SE |
3 | /* The 'site' code doesn't know anything about the structure of the |
4 | packets it's transmitting. In fact, under the new netlink | |
5 | configuration scheme it doesn't need to know anything at all about | |
6 | IP addresses, except how to contact its peer. This means it could | |
7 | potentially be used to tunnel other protocols too (IPv6, IPX, plain | |
8 | old Ethernet frames) if appropriate netlink code can be written | |
9 | (and that ought not to be too hard, eg. using the TUN/TAP device to | |
10 | pretend to be an Ethernet interface). */ | |
11 | ||
8689b3a9 | 12 | #include "secnet.h" |
2fe58dfd | 13 | #include <stdio.h> |
469fd1d9 | 14 | #include <string.h> |
8689b3a9 SE |
15 | /* MBM asserts the next one is needed for compilation under BSD. */ |
16 | #include <sys/socket.h> | |
2fe58dfd | 17 | |
8689b3a9 | 18 | #include <sys/mman.h> |
2fe58dfd | 19 | #include "util.h" |
59635212 | 20 | #include "unaligned.h" |
2fe58dfd SE |
21 | |
22 | #define SETUP_BUFFER_LEN 2048 | |
23 | ||
9d3a4132 SE |
24 | #define DEFAULT_KEY_LIFETIME 3600000 /* One hour */ |
25 | #define DEFAULT_KEY_RENEGOTIATE_GAP 300000 /* Five minutes */ | |
2fe58dfd | 26 | #define DEFAULT_SETUP_RETRIES 5 |
59635212 | 27 | #define DEFAULT_SETUP_TIMEOUT 1000 |
3454dce4 | 28 | #define DEFAULT_WAIT_TIME 20000 |
2fe58dfd SE |
29 | |
30 | /* Each site can be in one of several possible states. */ | |
31 | ||
32 | /* States: | |
33 | SITE_STOP - nothing is allowed to happen; tunnel is down; | |
34 | all session keys have been erased | |
35 | -> SITE_RUN upon external instruction | |
36 | SITE_RUN - site up, maybe with valid key | |
37 | -> SITE_RESOLVE upon outgoing packet and no valid key | |
38 | we start name resolution for the other end of the tunnel | |
39 | -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time | |
40 | we send an appropriate message 2 | |
41 | SITE_RESOLVE - waiting for name resolution | |
42 | -> SITE_SENTMSG1 upon successful resolution | |
43 | we send an appropriate message 1 | |
44 | -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution) | |
45 | we abort resolution and | |
46 | -> SITE_WAIT on timeout or resolution failure | |
47 | SITE_SENTMSG1 | |
48 | -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end | |
49 | -> SITE_SENTMSG3 upon valid incoming message 2 | |
50 | -> SITE_WAIT on timeout | |
51 | SITE_SENTMSG2 | |
52 | -> SITE_SENTMSG4 upon valid incoming message 3 | |
53 | -> SITE_WAIT on timeout | |
54 | SITE_SENTMSG3 | |
55 | -> SITE_SENTMSG5 upon valid incoming message 4 | |
56 | -> SITE_WAIT on timeout | |
57 | SITE_SENTMSG4 | |
58 | -> SITE_RUN upon valid incoming message 5 | |
59 | -> SITE_WAIT on timeout | |
60 | SITE_SENTMSG5 | |
61 | -> SITE_RUN upon valid incoming message 6 | |
62 | -> SITE_WAIT on timeout | |
63 | SITE_WAIT - failed to establish key; do nothing for a while | |
64 | -> SITE_RUN on timeout | |
65 | */ | |
66 | ||
67 | #define SITE_STOP 0 | |
68 | #define SITE_RUN 1 | |
69 | #define SITE_RESOLVE 2 | |
70 | #define SITE_SENTMSG1 3 | |
71 | #define SITE_SENTMSG2 4 | |
72 | #define SITE_SENTMSG3 5 | |
73 | #define SITE_SENTMSG4 6 | |
74 | #define SITE_SENTMSG5 7 | |
75 | #define SITE_WAIT 8 | |
76 | ||
77 | static string_t state_name(uint32_t state) | |
78 | { | |
79 | switch (state) { | |
3454dce4 SE |
80 | case 0: return "STOP"; |
81 | case 1: return "RUN"; | |
82 | case 2: return "RESOLVE"; | |
83 | case 3: return "SENTMSG1"; | |
84 | case 4: return "SENTMSG2"; | |
85 | case 5: return "SENTMSG3"; | |
86 | case 6: return "SENTMSG4"; | |
87 | case 7: return "SENTMSG5"; | |
88 | case 8: return "WAIT"; | |
2fe58dfd SE |
89 | default: return "*bad state*"; |
90 | } | |
91 | } | |
92 | ||
93 | #define LABEL_MSG0 0x00020200 | |
94 | #define LABEL_MSG1 0x01010101 | |
95 | #define LABEL_MSG2 0x02020202 | |
96 | #define LABEL_MSG3 0x03030303 | |
97 | #define LABEL_MSG4 0x04040404 | |
98 | #define LABEL_MSG5 0x05050505 | |
99 | #define LABEL_MSG6 0x06060606 | |
100 | #define LABEL_MSG7 0x07070707 | |
101 | #define LABEL_MSG8 0x08080808 | |
102 | #define LABEL_MSG9 0x09090909 | |
103 | ||
104 | #define NONCELEN 8 | |
105 | ||
106 | #define LOG_UNEXPECTED 0x00000001 | |
107 | #define LOG_SETUP_INIT 0x00000002 | |
108 | #define LOG_SETUP_TIMEOUT 0x00000004 | |
109 | #define LOG_ACTIVATE_KEY 0x00000008 | |
110 | #define LOG_TIMEOUT_KEY 0x00000010 | |
9d3a4132 | 111 | #define LOG_SEC 0x00000020 |
2fe58dfd SE |
112 | #define LOG_STATE 0x00000040 |
113 | #define LOG_DROP 0x00000080 | |
114 | #define LOG_DUMP 0x00000100 | |
115 | #define LOG_ERROR 0x00000400 | |
116 | ||
9d3a4132 SE |
117 | static struct flagstr log_event_table[]={ |
118 | { "unexpected", LOG_UNEXPECTED }, | |
119 | { "setup-init", LOG_SETUP_INIT }, | |
120 | { "setup-timeout", LOG_SETUP_TIMEOUT }, | |
121 | { "activate-key", LOG_ACTIVATE_KEY }, | |
122 | { "timeout-key", LOG_TIMEOUT_KEY }, | |
123 | { "security", LOG_SEC }, | |
124 | { "state-change", LOG_STATE }, | |
125 | { "packet-drop", LOG_DROP }, | |
126 | { "dump-packets", LOG_DUMP }, | |
127 | { "errors", LOG_ERROR }, | |
128 | { "all", 0xffffffff }, | |
129 | { NULL, 0 } | |
130 | }; | |
131 | ||
2fe58dfd SE |
132 | struct site { |
133 | closure_t cl; | |
134 | struct site_if ops; | |
135 | /* configuration information */ | |
136 | string_t localname; | |
137 | string_t remotename; | |
4efd681a | 138 | string_t tunname; /* localname<->remotename by default */ |
2fe58dfd SE |
139 | string_t address; /* DNS name for bootstrapping, optional */ |
140 | int remoteport; | |
141 | struct netlink_if *netlink; | |
142 | struct comm_if *comm; | |
143 | struct resolver_if *resolver; | |
144 | struct log_if *log; | |
145 | struct random_if *random; | |
146 | struct rsaprivkey_if *privkey; | |
2fe58dfd SE |
147 | struct rsapubkey_if *pubkey; |
148 | struct transform_if *transform; | |
149 | struct dh_if *dh; | |
150 | struct hash_if *hash; | |
2fe58dfd SE |
151 | |
152 | uint32_t setup_retries; /* How many times to send setup packets */ | |
153 | uint32_t setup_timeout; /* Initial timeout for setup packets */ | |
154 | uint32_t wait_timeout; /* How long to wait if setup unsuccessful */ | |
155 | uint32_t key_lifetime; /* How long a key lasts once set up */ | |
9d3a4132 SE |
156 | uint32_t key_renegotiate_time; /* If we see traffic (or a keepalive) |
157 | after this time, initiate a new | |
158 | key exchange */ | |
159 | ||
160 | bool_t keepalive; /* Always keep the tunnel up */ | |
2fe58dfd SE |
161 | |
162 | uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */ | |
163 | uint32_t setupsiglen; /* Allows us to discard packets quickly if | |
164 | they are not for us */ | |
165 | bool_t setup_priority; /* Do we have precedence if both sites emit | |
166 | message 1 simultaneously? */ | |
167 | uint32_t log_events; | |
168 | ||
169 | /* runtime information */ | |
170 | uint32_t state; | |
171 | uint64_t now; /* Most recently seen time */ | |
172 | ||
173 | uint32_t remote_session_id; | |
174 | struct transform_inst_if *current_transform; | |
175 | bool_t current_valid; | |
176 | uint64_t current_key_timeout; /* End of life of current key */ | |
177 | struct sockaddr_in peer; /* Current address of peer */ | |
178 | bool_t peer_valid; /* Peer address becomes invalid when key times out, | |
179 | but only if we have a DNS name for our peer */ | |
180 | ||
181 | uint32_t setup_session_id; | |
182 | struct sockaddr_in setup_peer; | |
183 | uint8_t localN[NONCELEN]; /* Nonces for key exchange */ | |
184 | uint8_t remoteN[NONCELEN]; | |
185 | struct buffer_if buffer; /* Current outgoing key exchange packet */ | |
186 | uint32_t retries; /* Number of retries remaining */ | |
187 | uint64_t timeout; /* Timeout for current state */ | |
188 | uint8_t *dhsecret; | |
189 | uint8_t *sharedsecret; | |
190 | ||
191 | struct transform_inst_if *new_transform; /* For key setup/verify */ | |
192 | }; | |
193 | ||
194 | static void slog(struct site *st, uint32_t event, string_t msg, ...) | |
195 | { | |
196 | va_list ap; | |
197 | uint8_t buf[240]; | |
b2a56f7c | 198 | uint32_t class; |
2fe58dfd SE |
199 | |
200 | va_start(ap,msg); | |
201 | ||
202 | if (event&st->log_events) { | |
b2a56f7c SE |
203 | switch(event) { |
204 | case LOG_UNEXPECTED: class=M_INFO; break; | |
205 | case LOG_SETUP_INIT: class=M_INFO; break; | |
206 | case LOG_SETUP_TIMEOUT: class=M_NOTICE; break; | |
207 | case LOG_ACTIVATE_KEY: class=M_INFO; break; | |
208 | case LOG_TIMEOUT_KEY: class=M_INFO; break; | |
209 | case LOG_SEC: class=M_SECURITY; break; | |
210 | case LOG_STATE: class=M_DEBUG; break; | |
211 | case LOG_DROP: class=M_DEBUG; break; | |
212 | case LOG_DUMP: class=M_DEBUG; break; | |
469fd1d9 SE |
213 | case LOG_ERROR: class=M_ERR; break; |
214 | default: class=M_ERR; break; | |
b2a56f7c SE |
215 | } |
216 | ||
2fe58dfd | 217 | vsnprintf(buf,240,msg,ap); |
b2a56f7c | 218 | st->log->log(st->log->st,class,"%s: %s",st->tunname,buf); |
2fe58dfd SE |
219 | } |
220 | va_end(ap); | |
221 | } | |
222 | ||
9d3a4132 | 223 | static void set_link_quality(struct site *st); |
794f2398 SE |
224 | static void delete_key(struct site *st, string_t reason, uint32_t loglevel); |
225 | static bool_t initiate_key_setup(struct site *st, string_t reason); | |
2fe58dfd SE |
226 | static void enter_state_run(struct site *st); |
227 | static bool_t enter_state_resolve(struct site *st); | |
228 | static bool_t enter_state_sentmsg1(struct site *st); | |
229 | static bool_t enter_state_sentmsg2(struct site *st); | |
230 | static bool_t enter_state_sentmsg3(struct site *st); | |
231 | static bool_t enter_state_sentmsg4(struct site *st); | |
232 | static bool_t enter_state_sentmsg5(struct site *st); | |
233 | static void enter_state_wait(struct site *st); | |
234 | ||
235 | #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0) | |
236 | #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0) | |
237 | #define CHECK_TYPE(b,t) do { uint32_t type; \ | |
238 | CHECK_AVAIL((b),4); \ | |
59635212 | 239 | type=buf_unprepend_uint32((b)); \ |
2fe58dfd SE |
240 | if (type!=(t)) return False; } while(0) |
241 | ||
242 | struct msg { | |
243 | uint8_t *hashstart; | |
244 | uint32_t dest; | |
245 | uint32_t source; | |
246 | uint32_t remlen; | |
247 | uint8_t *remote; | |
248 | uint32_t loclen; | |
249 | uint8_t *local; | |
250 | uint8_t *nR; | |
251 | uint8_t *nL; | |
252 | uint32_t pklen; | |
253 | uint8_t *pk; | |
254 | uint32_t hashlen; | |
255 | uint32_t siglen; | |
256 | uint8_t *sig; | |
257 | }; | |
258 | ||
259 | /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside out | |
260 | using a transform. */ | |
261 | static bool_t generate_msg(struct site *st, uint32_t type, string_t what) | |
262 | { | |
263 | void *hst; | |
264 | uint8_t *hash=alloca(st->hash->len); | |
265 | string_t dhpub, sig; | |
266 | ||
267 | st->retries=st->setup_retries; | |
268 | BUF_ALLOC(&st->buffer,what); | |
269 | buffer_init(&st->buffer,0); | |
59635212 SE |
270 | buf_append_uint32(&st->buffer, |
271 | (type==LABEL_MSG1?0:st->setup_session_id)); | |
272 | buf_append_uint32(&st->buffer,(uint32_t)st); | |
273 | buf_append_uint32(&st->buffer,type); | |
2fe58dfd SE |
274 | buf_append_string(&st->buffer,st->localname); |
275 | buf_append_string(&st->buffer,st->remotename); | |
276 | memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN); | |
277 | if (type==LABEL_MSG1) return True; | |
278 | memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN); | |
279 | if (type==LABEL_MSG2) return True; | |
280 | dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len); | |
281 | buf_append_string(&st->buffer,dhpub); | |
282 | free(dhpub); | |
283 | hst=st->hash->init(); | |
284 | st->hash->update(hst,st->buffer.start,st->buffer.size); | |
285 | st->hash->final(hst,hash); | |
286 | sig=st->privkey->sign(st->privkey->st,hash,st->hash->len); | |
287 | buf_append_string(&st->buffer,sig); | |
288 | free(sig); | |
289 | return True; | |
290 | } | |
291 | ||
292 | static bool_t unpick_msg(struct site *st, uint32_t type, | |
293 | struct buffer_if *msg, struct msg *m) | |
294 | { | |
295 | m->hashstart=msg->start; | |
296 | CHECK_AVAIL(msg,4); | |
59635212 | 297 | m->dest=buf_unprepend_uint32(msg); |
2fe58dfd | 298 | CHECK_AVAIL(msg,4); |
59635212 | 299 | m->source=buf_unprepend_uint32(msg); |
2fe58dfd SE |
300 | CHECK_TYPE(msg,type); |
301 | CHECK_AVAIL(msg,2); | |
59635212 | 302 | m->remlen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
303 | CHECK_AVAIL(msg,m->remlen); |
304 | m->remote=buf_unprepend(msg,m->remlen); | |
305 | CHECK_AVAIL(msg,2); | |
59635212 | 306 | m->loclen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
307 | CHECK_AVAIL(msg,m->loclen); |
308 | m->local=buf_unprepend(msg,m->loclen); | |
309 | CHECK_AVAIL(msg,NONCELEN); | |
310 | m->nR=buf_unprepend(msg,NONCELEN); | |
311 | if (type==LABEL_MSG1) { | |
312 | CHECK_EMPTY(msg); | |
313 | return True; | |
314 | } | |
315 | CHECK_AVAIL(msg,NONCELEN); | |
316 | m->nL=buf_unprepend(msg,NONCELEN); | |
317 | if (type==LABEL_MSG2) { | |
318 | CHECK_EMPTY(msg); | |
319 | return True; | |
320 | } | |
321 | CHECK_AVAIL(msg,2); | |
59635212 | 322 | m->pklen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
323 | CHECK_AVAIL(msg,m->pklen); |
324 | m->pk=buf_unprepend(msg,m->pklen); | |
325 | m->hashlen=msg->start-m->hashstart; | |
326 | CHECK_AVAIL(msg,2); | |
59635212 | 327 | m->siglen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
328 | CHECK_AVAIL(msg,m->siglen); |
329 | m->sig=buf_unprepend(msg,m->siglen); | |
330 | CHECK_EMPTY(msg); | |
331 | return True; | |
332 | } | |
333 | ||
334 | static bool_t generate_msg1(struct site *st) | |
335 | { | |
336 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
337 | return generate_msg(st,LABEL_MSG1,"site:MSG1"); | |
338 | } | |
339 | ||
340 | static bool_t process_msg1(struct site *st, struct buffer_if *msg1, | |
341 | struct sockaddr_in *src) | |
342 | { | |
343 | struct msg m; | |
344 | ||
345 | /* We've already determined we're in an appropriate state to | |
346 | process an incoming MSG1, and that the MSG1 has correct values | |
347 | of A and B. */ | |
348 | ||
349 | if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False; | |
350 | ||
351 | /* XXX save src as our peer address here? */ | |
352 | st->setup_peer=*src; | |
353 | ||
354 | st->setup_session_id=m.source; | |
355 | memcpy(st->remoteN,m.nR,NONCELEN); | |
356 | return True; | |
357 | } | |
358 | ||
359 | static bool_t generate_msg2(struct site *st) | |
360 | { | |
361 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
362 | return generate_msg(st,LABEL_MSG2,"site:MSG2"); | |
363 | } | |
364 | ||
365 | static bool_t process_msg2(struct site *st, struct buffer_if *msg2, | |
366 | struct sockaddr_in *src) | |
367 | { | |
368 | struct msg m; | |
369 | ||
370 | if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False; | |
371 | ||
372 | /* Check that the site names and our nonce have been sent | |
373 | back correctly, and then store our peer's nonce. */ | |
374 | if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) { | |
59635212 | 375 | slog(st,LOG_SEC,"msg2: bad B (remote site name)"); |
2fe58dfd SE |
376 | return False; |
377 | } | |
378 | if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) { | |
59635212 | 379 | slog(st,LOG_SEC,"msg2: bad A (local site name)"); |
2fe58dfd SE |
380 | return False; |
381 | } | |
382 | if (memcmp(m.nL,st->localN,NONCELEN)!=0) { | |
59635212 | 383 | slog(st,LOG_SEC,"msg2: bad nA (locally generated nonce)"); |
2fe58dfd SE |
384 | return False; |
385 | } | |
386 | st->setup_session_id=m.source; | |
387 | memcpy(st->remoteN,m.nR,NONCELEN); | |
388 | return True; | |
389 | } | |
390 | ||
391 | static bool_t generate_msg3(struct site *st) | |
392 | { | |
393 | /* Now we have our nonce and their nonce. Think of a secret key, | |
394 | and create message number 3. */ | |
395 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
396 | return generate_msg(st,LABEL_MSG3,"site:MSG3"); | |
397 | } | |
398 | ||
399 | static bool_t process_msg3(struct site *st, struct buffer_if *msg3, | |
400 | struct sockaddr_in *src) | |
401 | { | |
402 | struct msg m; | |
403 | uint8_t *hash=alloca(st->hash->len); | |
404 | void *hst; | |
405 | ||
406 | if (!unpick_msg(st,LABEL_MSG3,msg3,&m)) return False; | |
407 | ||
408 | /* Check that the site names and nonces have been sent back | |
409 | correctly */ | |
410 | if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) { | |
59635212 | 411 | slog(st,LOG_SEC,"msg3: bad A (remote site name)"); |
2fe58dfd SE |
412 | return False; |
413 | } | |
414 | if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) { | |
59635212 | 415 | slog(st,LOG_SEC,"msg3: bad B (local site name)"); |
2fe58dfd SE |
416 | return False; |
417 | } | |
418 | if (memcmp(m.nR,st->remoteN,NONCELEN)!=0) { | |
59635212 | 419 | slog(st,LOG_SEC,"msg3: bad nA (remotely generated nonce)"); |
2fe58dfd SE |
420 | return False; |
421 | } | |
422 | if (memcmp(m.nL,st->localN,NONCELEN)!=0) { | |
59635212 | 423 | slog(st,LOG_SEC,"msg3: bad nB (locally generated nonce)"); |
2fe58dfd SE |
424 | return False; |
425 | } | |
426 | ||
427 | /* Check signature and store g^x mod m */ | |
428 | hst=st->hash->init(); | |
429 | st->hash->update(hst,m.hashstart,m.hashlen); | |
430 | st->hash->final(hst,hash); | |
431 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
432 | m.sig[m.siglen]=0; | |
433 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 434 | slog(st,LOG_SEC,"msg3 signature failed check!"); |
2fe58dfd SE |
435 | return False; |
436 | } | |
437 | ||
438 | /* Terminate their DH public key with a '0' */ | |
439 | m.pk[m.pklen]=0; | |
440 | /* Invent our DH secret key */ | |
441 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
442 | ||
443 | /* Generate the shared key */ | |
444 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
445 | st->sharedsecret,st->transform->keylen); | |
446 | ||
447 | /* Set up the transform */ | |
448 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
449 | st->transform->keylen); | |
450 | ||
451 | return True; | |
452 | } | |
453 | ||
454 | static bool_t generate_msg4(struct site *st) | |
455 | { | |
456 | /* We have both nonces, their public key and our private key. Generate | |
457 | our public key, sign it and send it to them. */ | |
458 | return generate_msg(st,LABEL_MSG4,"site:MSG4"); | |
459 | } | |
460 | ||
461 | static bool_t process_msg4(struct site *st, struct buffer_if *msg4, | |
462 | struct sockaddr_in *src) | |
463 | { | |
464 | struct msg m; | |
465 | uint8_t *hash=alloca(st->hash->len); | |
466 | void *hst; | |
467 | ||
468 | if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False; | |
469 | ||
470 | /* Check that the site names and nonces have been sent back | |
471 | correctly */ | |
472 | if (memcmp(m.remote,st->remotename,strlen(st->remotename)!=0)) { | |
59635212 | 473 | slog(st,LOG_SEC,"msg4: bad B (remote site name)"); |
2fe58dfd SE |
474 | return False; |
475 | } | |
476 | if (memcmp(m.local,st->localname,strlen(st->localname)!=0)) { | |
59635212 | 477 | slog(st,LOG_SEC,"msg4: bad A (local site name)"); |
2fe58dfd SE |
478 | return False; |
479 | } | |
480 | if (memcmp(m.nR,st->remoteN,NONCELEN)!=0) { | |
59635212 | 481 | slog(st,LOG_SEC,"msg4: bad nB (remotely generated nonce)"); |
2fe58dfd SE |
482 | return False; |
483 | } | |
484 | if (memcmp(m.nL,st->localN,NONCELEN)!=0) { | |
59635212 | 485 | slog(st,LOG_SEC,"msg4: bad nA (locally generated nonce)"); |
2fe58dfd SE |
486 | return False; |
487 | } | |
488 | ||
489 | /* Check signature and store g^x mod m */ | |
490 | hst=st->hash->init(); | |
491 | st->hash->update(hst,m.hashstart,m.hashlen); | |
492 | st->hash->final(hst,hash); | |
493 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
494 | m.sig[m.siglen]=0; | |
495 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 496 | slog(st,LOG_SEC,"msg4 signature failed check!"); |
2fe58dfd SE |
497 | return False; |
498 | } | |
499 | ||
500 | /* Terminate their DH public key with a '0' */ | |
501 | m.pk[m.pklen]=0; | |
502 | /* Generate the shared key */ | |
503 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
504 | st->sharedsecret,st->transform->keylen); | |
505 | /* Set up the transform */ | |
506 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
507 | st->transform->keylen); | |
508 | ||
509 | return True; | |
510 | } | |
511 | ||
512 | static bool_t generate_msg5(struct site *st) | |
513 | { | |
514 | string_t transform_err; | |
515 | ||
516 | BUF_ALLOC(&st->buffer,"site:MSG5"); | |
517 | /* We are going to add three words to the transformed message */ | |
518 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*3)); | |
59635212 | 519 | buf_append_uint32(&st->buffer,LABEL_MSG5); |
794f2398 SE |
520 | /* Give the netlink code an opportunity to put its own stuff in the |
521 | message (configuration information, etc.) */ | |
522 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
2fe58dfd SE |
523 | st->new_transform->forwards(st->new_transform->st,&st->buffer, |
524 | &transform_err); | |
59635212 SE |
525 | buf_prepend_uint32(&st->buffer,LABEL_MSG5); |
526 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
527 | buf_prepend_uint32(&st->buffer,st->setup_session_id); | |
2fe58dfd SE |
528 | |
529 | st->retries=st->setup_retries; | |
530 | return True; | |
531 | } | |
532 | ||
533 | struct msg0 { | |
534 | uint32_t dest; | |
535 | uint32_t source; | |
536 | uint32_t type; | |
537 | }; | |
538 | ||
539 | static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0, | |
540 | struct msg0 *m) | |
541 | { | |
542 | CHECK_AVAIL(msg0,4); | |
59635212 | 543 | m->dest=buf_unprepend_uint32(msg0); |
2fe58dfd | 544 | CHECK_AVAIL(msg0,4); |
59635212 | 545 | m->source=buf_unprepend_uint32(msg0); |
2fe58dfd | 546 | CHECK_AVAIL(msg0,4); |
59635212 | 547 | m->type=buf_unprepend_uint32(msg0); |
2fe58dfd SE |
548 | return True; |
549 | /* Leaves transformed part of buffer untouched */ | |
550 | } | |
551 | ||
552 | static bool_t process_msg5(struct site *st, struct buffer_if *msg5, | |
553 | struct sockaddr_in *src) | |
554 | { | |
555 | struct msg0 m; | |
556 | string_t transform_err; | |
557 | ||
558 | if (!unpick_msg0(st,msg5,&m)) return False; | |
559 | ||
560 | if (st->new_transform->reverse(st->new_transform->st, | |
561 | msg5,&transform_err)) { | |
562 | /* There's a problem */ | |
59635212 | 563 | slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err); |
2fe58dfd SE |
564 | return False; |
565 | } | |
566 | /* Buffer should now contain untransformed PING packet data */ | |
567 | CHECK_AVAIL(msg5,4); | |
59635212 SE |
568 | if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) { |
569 | slog(st,LOG_SEC,"MSG5/PING packet contained invalid data"); | |
2fe58dfd SE |
570 | return False; |
571 | } | |
794f2398 SE |
572 | if (!st->netlink->check_config(st->netlink->st,msg5)) { |
573 | slog(st,LOG_SEC,"MSG5/PING packet contained bad netlink config"); | |
574 | return False; | |
575 | } | |
2fe58dfd SE |
576 | CHECK_EMPTY(msg5); |
577 | return True; | |
578 | } | |
579 | ||
580 | static bool_t generate_msg6(struct site *st) | |
581 | { | |
582 | string_t transform_err; | |
583 | ||
584 | BUF_ALLOC(&st->buffer,"site:MSG6"); | |
585 | /* We are going to add three words to the transformed message */ | |
586 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*3)); | |
59635212 | 587 | buf_append_uint32(&st->buffer,LABEL_MSG6); |
794f2398 SE |
588 | /* Give the netlink code an opportunity to put its own stuff in the |
589 | message (configuration information, etc.) */ | |
590 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
2fe58dfd SE |
591 | st->new_transform->forwards(st->new_transform->st,&st->buffer, |
592 | &transform_err); | |
59635212 SE |
593 | buf_prepend_uint32(&st->buffer,LABEL_MSG6); |
594 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
595 | buf_prepend_uint32(&st->buffer,st->setup_session_id); | |
2fe58dfd SE |
596 | |
597 | st->retries=1; /* Peer will retransmit MSG5 if necessary */ | |
598 | return True; | |
599 | } | |
600 | ||
601 | static bool_t process_msg6(struct site *st, struct buffer_if *msg6, | |
602 | struct sockaddr_in *src) | |
603 | { | |
604 | struct msg0 m; | |
605 | string_t transform_err; | |
606 | ||
607 | if (!unpick_msg0(st,msg6,&m)) return False; | |
608 | ||
609 | if (st->new_transform->reverse(st->new_transform->st, | |
610 | msg6,&transform_err)) { | |
611 | /* There's a problem */ | |
59635212 | 612 | slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err); |
2fe58dfd SE |
613 | return False; |
614 | } | |
615 | /* Buffer should now contain untransformed PING packet data */ | |
616 | CHECK_AVAIL(msg6,4); | |
59635212 SE |
617 | if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) { |
618 | slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data"); | |
2fe58dfd SE |
619 | return False; |
620 | } | |
794f2398 SE |
621 | if (!st->netlink->check_config(st->netlink->st,msg6)) { |
622 | slog(st,LOG_SEC,"MSG6/PONG packet contained bad netlink config"); | |
623 | return False; | |
624 | } | |
2fe58dfd SE |
625 | CHECK_EMPTY(msg6); |
626 | return True; | |
627 | } | |
628 | ||
629 | static bool_t process_msg0(struct site *st, struct buffer_if *msg0, | |
630 | struct sockaddr_in *src) | |
631 | { | |
632 | struct msg0 m; | |
633 | string_t transform_err; | |
634 | uint32_t type; | |
635 | ||
636 | if (!st->current_valid) { | |
637 | slog(st,LOG_DROP,"incoming message but no current key -> dropping"); | |
794f2398 | 638 | return initiate_key_setup(st,"incoming message but no current key"); |
2fe58dfd SE |
639 | } |
640 | ||
641 | if (!unpick_msg0(st,msg0,&m)) return False; | |
642 | ||
643 | if (st->current_transform->reverse(st->current_transform->st, | |
644 | msg0,&transform_err)) { | |
645 | /* There's a problem */ | |
59635212 | 646 | slog(st,LOG_SEC,"transform: %s",transform_err); |
794f2398 | 647 | return initiate_key_setup(st,"incoming message would not decrypt"); |
2fe58dfd SE |
648 | } |
649 | CHECK_AVAIL(msg0,4); | |
59635212 | 650 | type=buf_unprepend_uint32(msg0); |
2fe58dfd | 651 | switch(type) { |
794f2398 SE |
652 | case LABEL_MSG7: |
653 | /* We must forget about the current session. */ | |
654 | delete_key(st,"request from peer",LOG_SEC); | |
655 | return True; | |
656 | break; | |
2fe58dfd SE |
657 | case LABEL_MSG9: |
658 | /* Deliver to netlink layer */ | |
469fd1d9 | 659 | st->netlink->deliver(st->netlink->st,msg0); |
2fe58dfd SE |
660 | return True; |
661 | break; | |
662 | default: | |
59635212 | 663 | slog(st,LOG_SEC,"incoming message of type %08x (unknown)",type); |
2fe58dfd SE |
664 | break; |
665 | } | |
666 | return False; | |
667 | } | |
668 | ||
669 | static void dump_packet(struct site *st, struct buffer_if *buf, | |
670 | struct sockaddr_in *addr, bool_t incoming) | |
671 | { | |
59635212 SE |
672 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
673 | uint32_t source=ntohl(*(uint32_t *)(buf->start+4)); | |
674 | uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8)); | |
2fe58dfd SE |
675 | |
676 | if (st->log_events & LOG_DUMP) | |
b2a56f7c | 677 | log(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:", |
9d3a4132 | 678 | st->tunname,incoming?"incoming":"outgoing", |
2fe58dfd SE |
679 | dest,source,msgtype); |
680 | } | |
681 | ||
682 | static uint32_t site_status(void *st) | |
683 | { | |
684 | return 0; | |
685 | } | |
686 | ||
687 | static bool_t send_msg(struct site *st) | |
688 | { | |
689 | if (st->retries>0) { | |
690 | dump_packet(st,&st->buffer,&st->setup_peer,False); | |
691 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->setup_peer); | |
692 | st->timeout=st->now+st->setup_timeout; | |
693 | st->retries--; | |
694 | return True; | |
695 | } else { | |
3454dce4 SE |
696 | slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet " |
697 | "(in state %s)",state_name(st->state)); | |
2fe58dfd SE |
698 | enter_state_wait(st); |
699 | return False; | |
700 | } | |
701 | } | |
702 | ||
703 | static void site_resolve_callback(void *sst, struct in_addr *address) | |
704 | { | |
705 | struct site *st=sst; | |
706 | ||
707 | if (st->state!=SITE_RESOLVE) { | |
708 | slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly"); | |
709 | return; | |
710 | } | |
711 | if (address) { | |
712 | memset(&st->setup_peer,0,sizeof(st->setup_peer)); | |
713 | st->setup_peer.sin_family=AF_INET; | |
714 | st->setup_peer.sin_port=htons(st->remoteport); | |
715 | st->setup_peer.sin_addr=*address; | |
716 | enter_state_sentmsg1(st); | |
717 | } else { | |
718 | /* Resolution failed */ | |
719 | slog(st,LOG_ERROR,"resolution of %s failed",st->address); | |
720 | enter_state_run(st); | |
721 | } | |
722 | } | |
723 | ||
794f2398 | 724 | static bool_t initiate_key_setup(struct site *st,string_t reason) |
9d3a4132 SE |
725 | { |
726 | if (st->state!=SITE_RUN) return False; | |
794f2398 | 727 | slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason); |
9d3a4132 | 728 | if (st->address) { |
794f2398 | 729 | slog(st,LOG_SETUP_INIT,"resolving peer address"); |
9d3a4132 SE |
730 | return enter_state_resolve(st); |
731 | } else if (st->peer_valid) { | |
794f2398 | 732 | slog(st,LOG_SETUP_INIT,"using old peer address"); |
9d3a4132 SE |
733 | st->setup_peer=st->peer; |
734 | return enter_state_sentmsg1(st); | |
735 | } | |
736 | return False; | |
737 | } | |
738 | ||
2fe58dfd SE |
739 | static void activate_new_key(struct site *st) |
740 | { | |
741 | struct transform_inst_if *t; | |
742 | ||
743 | t=st->current_transform; | |
744 | st->current_transform=st->new_transform; | |
745 | st->new_transform=t; | |
746 | ||
747 | t->delkey(t->st); | |
2fe58dfd SE |
748 | st->timeout=0; |
749 | st->current_valid=True; | |
750 | st->current_key_timeout=st->now+st->key_lifetime; | |
751 | st->peer=st->setup_peer; | |
752 | st->peer_valid=True; | |
753 | st->remote_session_id=st->setup_session_id; | |
754 | ||
755 | slog(st,LOG_ACTIVATE_KEY,"new key activated"); | |
9d3a4132 | 756 | enter_state_run(st); |
2fe58dfd SE |
757 | } |
758 | ||
794f2398 SE |
759 | static void delete_key(struct site *st, string_t reason, uint32_t loglevel) |
760 | { | |
761 | if (st->current_valid) { | |
762 | slog(st,loglevel,"session closed (%s)",reason); | |
763 | ||
764 | st->current_valid=False; | |
765 | st->current_transform->delkey(st->current_transform->st); | |
766 | st->current_key_timeout=0; | |
767 | set_link_quality(st); | |
768 | } | |
769 | } | |
770 | ||
2fe58dfd SE |
771 | static void state_assert(struct site *st, bool_t ok) |
772 | { | |
773 | if (!ok) fatal("state_assert\n"); | |
774 | } | |
775 | ||
776 | static void enter_state_stop(struct site *st) | |
777 | { | |
778 | st->state=SITE_STOP; | |
779 | st->timeout=0; | |
794f2398 | 780 | delete_key(st,"entering state STOP",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
781 | st->new_transform->delkey(st->new_transform->st); |
782 | } | |
783 | ||
9d3a4132 SE |
784 | static void set_link_quality(struct site *st) |
785 | { | |
786 | uint32_t quality; | |
787 | if (st->current_valid) | |
788 | quality=LINK_QUALITY_UP; | |
789 | else if (st->state==SITE_WAIT || st->state==SITE_STOP) | |
790 | quality=LINK_QUALITY_DOWN; | |
791 | else if (st->address) | |
792 | quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS; | |
793 | else if (st->peer_valid) | |
794 | quality=LINK_QUALITY_DOWN_STALE_ADDRESS; | |
795 | else | |
796 | quality=LINK_QUALITY_DOWN; | |
797 | ||
469fd1d9 | 798 | st->netlink->set_quality(st->netlink->st,quality); |
9d3a4132 SE |
799 | } |
800 | ||
2fe58dfd SE |
801 | static void enter_state_run(struct site *st) |
802 | { | |
803 | slog(st,LOG_STATE,"entering state RUN"); | |
804 | st->state=SITE_RUN; | |
805 | st->timeout=0; | |
9d3a4132 SE |
806 | |
807 | set_link_quality(st); | |
2fe58dfd SE |
808 | /* XXX get rid of key setup data */ |
809 | } | |
810 | ||
811 | static bool_t enter_state_resolve(struct site *st) | |
812 | { | |
813 | state_assert(st,st->state==SITE_RUN); | |
814 | slog(st,LOG_STATE,"entering state RESOLVE"); | |
815 | st->state=SITE_RESOLVE; | |
816 | st->resolver->request(st->resolver->st,st->address, | |
817 | site_resolve_callback,st); | |
818 | return True; | |
819 | } | |
820 | ||
821 | static bool_t enter_state_sentmsg1(struct site *st) | |
822 | { | |
823 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE); | |
824 | slog(st,LOG_STATE,"entering state SENTMSG1"); | |
825 | if (generate_msg1(st) && send_msg(st)) { | |
826 | st->state=SITE_SENTMSG1; | |
827 | return True; | |
828 | } | |
829 | slog(st,LOG_ERROR,"error entering state SENTMSG1"); | |
830 | st->buffer.free=False; /* Can't tell which it was, but enter_state_wait() | |
831 | will do a BUF_FREE() */ | |
832 | enter_state_wait(st); | |
833 | return False; | |
834 | } | |
835 | ||
836 | static bool_t enter_state_sentmsg2(struct site *st) | |
837 | { | |
838 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE || | |
839 | st->state==SITE_SENTMSG1 || st->state==SITE_WAIT); | |
840 | slog(st,LOG_STATE,"entering state SENTMSG2"); | |
841 | if (generate_msg2(st) && send_msg(st)) { | |
842 | st->state=SITE_SENTMSG2; | |
843 | return True; | |
844 | } | |
845 | slog(st,LOG_ERROR,"error entering state SENTMSG2"); | |
846 | st->buffer.free=False; | |
847 | enter_state_wait(st); | |
848 | return False; | |
849 | } | |
850 | ||
851 | static bool_t enter_state_sentmsg3(struct site *st) | |
852 | { | |
853 | state_assert(st,st->state==SITE_SENTMSG1); | |
854 | slog(st,LOG_STATE,"entering state SENTMSG3"); | |
855 | BUF_FREE(&st->buffer); /* Free message 1 */ | |
856 | if (generate_msg3(st) && send_msg(st)) { | |
857 | st->state=SITE_SENTMSG3; | |
858 | return True; | |
859 | } | |
860 | slog(st,LOG_ERROR,"error entering state SENTMSG3"); | |
861 | st->buffer.free=False; | |
862 | enter_state_wait(st); | |
863 | return False; | |
864 | } | |
865 | ||
866 | static bool_t enter_state_sentmsg4(struct site *st) | |
867 | { | |
868 | state_assert(st,st->state==SITE_SENTMSG2); | |
869 | slog(st,LOG_STATE,"entering state SENTMSG4"); | |
870 | BUF_FREE(&st->buffer); /* Free message 2 */ | |
871 | if (generate_msg4(st) && send_msg(st)) { | |
872 | st->state=SITE_SENTMSG4; | |
873 | return True; | |
874 | } | |
875 | slog(st,LOG_ERROR,"error entering state SENTMSG4"); | |
876 | st->buffer.free=False; | |
877 | enter_state_wait(st); | |
878 | return False; | |
879 | } | |
880 | ||
881 | static bool_t enter_state_sentmsg5(struct site *st) | |
882 | { | |
883 | state_assert(st,st->state==SITE_SENTMSG3); | |
884 | slog(st,LOG_STATE,"entering state SENTMSG5"); | |
885 | BUF_FREE(&st->buffer); /* Free message 3 */ | |
886 | ||
887 | if (generate_msg5(st) && send_msg(st)) { | |
888 | st->state=SITE_SENTMSG5; | |
889 | return True; | |
890 | } | |
891 | slog(st,LOG_ERROR,"error entering state SENTMSG5"); | |
892 | st->buffer.free=False; | |
893 | enter_state_wait(st); | |
894 | ||
895 | return False; | |
896 | } | |
897 | ||
898 | static bool_t send_msg6(struct site *st) | |
899 | { | |
900 | state_assert(st,st->state==SITE_SENTMSG4); | |
901 | slog(st,LOG_STATE,"entering state RUN after sending msg6"); | |
902 | BUF_FREE(&st->buffer); /* Free message 4 */ | |
903 | if (generate_msg6(st) && send_msg(st)) { | |
904 | BUF_FREE(&st->buffer); /* Never reused */ | |
905 | st->timeout=0; /* Never retransmit */ | |
906 | activate_new_key(st); | |
907 | return True; | |
908 | } | |
909 | slog(st,LOG_ERROR,"error entering state RUN after sending msg6"); | |
910 | st->buffer.free=False; | |
911 | enter_state_wait(st); | |
912 | return False; | |
913 | } | |
914 | ||
794f2398 SE |
915 | static bool_t send_msg7(struct site *st,string_t reason) |
916 | { | |
917 | string_t transform_err; | |
918 | ||
919 | if (st->current_valid && st->peer_valid && st->buffer.free) { | |
920 | BUF_ALLOC(&st->buffer,"site:MSG7"); | |
921 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*3)); | |
922 | buf_append_uint32(&st->buffer,LABEL_MSG7); | |
923 | buf_append_string(&st->buffer,reason); | |
924 | st->current_transform->forwards(st->current_transform->st, | |
925 | &st->buffer, &transform_err); | |
926 | buf_prepend_uint32(&st->buffer,LABEL_MSG0); | |
927 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
928 | buf_prepend_uint32(&st->buffer,st->remote_session_id); | |
929 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->peer); | |
930 | BUF_FREE(&st->buffer); | |
931 | return True; | |
932 | } | |
933 | return False; | |
934 | } | |
935 | ||
2fe58dfd SE |
936 | /* We go into this state if our peer becomes uncommunicative. Similar to |
937 | the "stop" state, we forget all session keys for a while, before | |
938 | re-entering the "run" state. */ | |
939 | static void enter_state_wait(struct site *st) | |
940 | { | |
941 | slog(st,LOG_STATE,"entering state WAIT"); | |
942 | st->timeout=st->now+st->wait_timeout; | |
943 | st->state=SITE_WAIT; | |
944 | st->peer_valid=False; | |
9d3a4132 | 945 | set_link_quality(st); |
2fe58dfd SE |
946 | BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */ |
947 | /* XXX Erase keys etc. */ | |
948 | } | |
949 | ||
950 | static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, | |
951 | int *timeout_io, const struct timeval *tv_now, | |
952 | uint64_t *now) | |
953 | { | |
954 | struct site *st=sst; | |
955 | ||
956 | *nfds_io=0; /* We don't use any file descriptors */ | |
957 | st->now=*now; | |
958 | ||
959 | /* Work out when our next timeout is. The earlier of 'timeout' or | |
960 | 'current_key_timeout'. A stored value of '0' indicates no timeout | |
961 | active. */ | |
962 | if (st->timeout && st->timeout-*now < *timeout_io) { | |
963 | *timeout_io=st->timeout-*now; | |
964 | } | |
965 | ||
966 | if (st->current_key_timeout && st->current_key_timeout-*now < *timeout_io) | |
967 | *timeout_io=st->current_key_timeout-*now; | |
968 | ||
969 | return 0; /* success */ | |
970 | } | |
971 | ||
972 | /* NB site_afterpoll will be called before site_beforepoll is ever called */ | |
973 | static void site_afterpoll(void *sst, struct pollfd *fds, int nfds, | |
974 | const struct timeval *tv_now, uint64_t *now) | |
975 | { | |
976 | struct site *st=sst; | |
977 | ||
978 | st->now=*now; | |
979 | if (st->timeout && *now>st->timeout) { | |
980 | /* Do stuff */ | |
981 | st->timeout=0; | |
982 | if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) | |
983 | send_msg(st); | |
984 | else if (st->state==SITE_WAIT) { | |
985 | enter_state_run(st); | |
986 | } else { | |
987 | slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d", | |
988 | st->state); | |
989 | } | |
990 | } | |
991 | if (st->current_key_timeout && *now>st->current_key_timeout) { | |
794f2398 | 992 | delete_key(st,"maximum key life exceeded",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
993 | } |
994 | } | |
995 | ||
996 | /* This function is called by the netlink device to deliver packets | |
997 | intended for the remote network. The packet is in "raw" wire | |
998 | format, but is guaranteed to be word-aligned. */ | |
469fd1d9 | 999 | static void site_outgoing(void *sst, struct buffer_if *buf) |
2fe58dfd SE |
1000 | { |
1001 | struct site *st=sst; | |
1002 | string_t transform_err; | |
1003 | ||
1004 | if (st->state==SITE_STOP) { | |
1005 | BUF_FREE(buf); | |
1006 | return; | |
1007 | } | |
1008 | ||
1009 | /* In all other states we consider delivering the packet if we have | |
1010 | a valid key and a valid address to send it to. */ | |
1011 | if (st->current_valid && st->peer_valid) { | |
1012 | /* Transform it and send it */ | |
70dc107b SE |
1013 | if (buf->size>0) { |
1014 | buf_prepend_uint32(buf,LABEL_MSG9); | |
1015 | st->current_transform->forwards(st->current_transform->st, | |
1016 | buf, &transform_err); | |
1017 | buf_prepend_uint32(buf,LABEL_MSG0); | |
1018 | buf_prepend_uint32(buf,(uint32_t)st); | |
1019 | buf_prepend_uint32(buf,st->remote_session_id); | |
1020 | st->comm->sendmsg(st->comm->st,buf,&st->peer); | |
1021 | } | |
2fe58dfd SE |
1022 | BUF_FREE(buf); |
1023 | return; | |
1024 | } | |
1025 | ||
70dc107b | 1026 | slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size); |
2fe58dfd | 1027 | BUF_FREE(buf); |
794f2398 | 1028 | initiate_key_setup(st,"outgoing packet"); |
2fe58dfd SE |
1029 | } |
1030 | ||
1031 | /* This function is called by the communication device to deliver | |
1032 | packets from our peers. */ | |
1033 | static bool_t site_incoming(void *sst, struct buffer_if *buf, | |
1034 | struct sockaddr_in *source) | |
1035 | { | |
1036 | struct site *st=sst; | |
59635212 | 1037 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
2fe58dfd SE |
1038 | |
1039 | if (dest==0) { | |
1040 | if (buf->size<(st->setupsiglen+8+NONCELEN)) return False; | |
1041 | /* It could be for any site - it should have LABEL_MSG1 and | |
1042 | might have our name and our peer's name in it */ | |
1043 | if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) { | |
1044 | dump_packet(st,buf,source,True); | |
1045 | /* It's addressed to us. Decide what to do about it. */ | |
1046 | if (st->state==SITE_RUN || st->state==SITE_RESOLVE || | |
1047 | st->state==SITE_WAIT) { | |
1048 | /* We should definitely process it */ | |
1049 | if (process_msg1(st,buf,source)) { | |
1050 | slog(st,LOG_SETUP_INIT,"key setup initiated by peer"); | |
1051 | enter_state_sentmsg2(st); | |
1052 | } else { | |
1053 | slog(st,LOG_ERROR,"failed to process incoming msg1"); | |
1054 | } | |
1055 | BUF_FREE(buf); | |
1056 | return True; | |
1057 | } | |
1058 | if (st->state==SITE_SENTMSG1) { | |
1059 | /* We've just sent a message 1! They may have crossed on | |
1060 | the wire. If we have priority then we ignore the | |
1061 | incoming one, otherwise we process it as usual. */ | |
1062 | if (st->setup_priority) { | |
1063 | BUF_FREE(buf); | |
1064 | slog(st,LOG_DUMP,"crossed msg1s; we are higher " | |
1065 | "priority => ignore incoming msg1"); | |
1066 | return True; | |
1067 | } else { | |
1068 | slog(st,LOG_DUMP,"crossed msg1s; we are lower " | |
1069 | "priority => use incoming msg1"); | |
1070 | if (process_msg1(st,buf,source)) { | |
1071 | BUF_FREE(&st->buffer); /* Free our old message 1 */ | |
1072 | enter_state_sentmsg2(st); | |
1073 | } else { | |
1074 | slog(st,LOG_ERROR,"failed to process an incoming " | |
1075 | "crossed msg1 (we have low priority)"); | |
1076 | } | |
1077 | BUF_FREE(buf); | |
1078 | return True; | |
1079 | } | |
1080 | } | |
1081 | /* The message 1 was received at an unexpected stage of the | |
1082 | key setup. XXX POLICY - what do we do? */ | |
1083 | slog(st,LOG_UNEXPECTED,"unexpected incoming message 1"); | |
1084 | BUF_FREE(buf); | |
1085 | return True; | |
1086 | } | |
1087 | return False; /* Not for us. */ | |
1088 | } | |
1089 | if (dest==(uint32_t)st) { | |
794f2398 | 1090 | uint32_t msgtype=ntohl(get_uint32(buf->start+8)); |
2fe58dfd SE |
1091 | /* Explicitly addressed to us */ |
1092 | if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True); | |
1093 | switch (msgtype) { | |
794f2398 SE |
1094 | case 0: /* NAK */ |
1095 | /* If the source is our current peer then initiate a key setup, | |
1096 | because our peer's forgotten the key */ | |
1097 | if (get_uint32(buf->start+4)==st->remote_session_id) { | |
1098 | initiate_key_setup(st,"received a NAK"); | |
1099 | } else { | |
1100 | slog(st,LOG_SEC,"bad incoming NAK"); | |
1101 | } | |
1102 | break; | |
2fe58dfd SE |
1103 | case LABEL_MSG0: |
1104 | process_msg0(st,buf,source); | |
1105 | break; | |
1106 | case LABEL_MSG1: | |
1107 | /* Setup packet: should not have been explicitly addressed | |
1108 | to us */ | |
59635212 | 1109 | slog(st,LOG_SEC,"incoming explicitly addressed msg1"); |
2fe58dfd SE |
1110 | break; |
1111 | case LABEL_MSG2: | |
1112 | /* Setup packet: expected only in state SENTMSG1 */ | |
1113 | if (st->state!=SITE_SENTMSG1) { | |
1114 | slog(st,LOG_UNEXPECTED,"unexpected MSG2"); | |
1115 | } else if (process_msg2(st,buf,source)) | |
1116 | enter_state_sentmsg3(st); | |
1117 | else { | |
59635212 | 1118 | slog(st,LOG_SEC,"invalid MSG2"); |
2fe58dfd SE |
1119 | } |
1120 | break; | |
1121 | case LABEL_MSG3: | |
1122 | /* Setup packet: expected only in state SENTMSG2 */ | |
1123 | if (st->state!=SITE_SENTMSG2) { | |
1124 | slog(st,LOG_UNEXPECTED,"unexpected MSG3"); | |
1125 | } else if (process_msg3(st,buf,source)) | |
1126 | enter_state_sentmsg4(st); | |
1127 | else { | |
59635212 | 1128 | slog(st,LOG_SEC,"invalid MSG3"); |
2fe58dfd SE |
1129 | } |
1130 | break; | |
1131 | case LABEL_MSG4: | |
1132 | /* Setup packet: expected only in state SENTMSG3 */ | |
1133 | if (st->state!=SITE_SENTMSG3) { | |
1134 | slog(st,LOG_UNEXPECTED,"unexpected MSG4"); | |
1135 | } else if (process_msg4(st,buf,source)) | |
1136 | enter_state_sentmsg5(st); | |
1137 | else { | |
59635212 | 1138 | slog(st,LOG_SEC,"invalid MSG4"); |
2fe58dfd SE |
1139 | } |
1140 | break; | |
1141 | case LABEL_MSG5: | |
4efd681a SE |
1142 | /* Setup packet: expected only in state SENTMSG4 */ |
1143 | /* (may turn up in state RUN if our return MSG6 was lost | |
1144 | and the new key has already been activated. In that | |
1145 | case we should treat it as an ordinary PING packet. We | |
1146 | can't pass it to process_msg5() because the | |
1147 | new_transform will now be null. XXX) */ | |
1148 | if (st->state!=SITE_SENTMSG4) { | |
2fe58dfd SE |
1149 | slog(st,LOG_UNEXPECTED,"unexpected MSG5"); |
1150 | } else if (process_msg5(st,buf,source)) { | |
1151 | send_msg6(st); | |
1152 | } else { | |
59635212 | 1153 | slog(st,LOG_SEC,"invalid MSG5"); |
2fe58dfd SE |
1154 | } |
1155 | break; | |
1156 | case LABEL_MSG6: | |
1157 | /* Setup packet: expected only in state SENTMSG5 */ | |
1158 | if (st->state!=SITE_SENTMSG5) { | |
1159 | slog(st,LOG_UNEXPECTED,"unexpected MSG6"); | |
1160 | } else if (process_msg6(st,buf,source)) { | |
1161 | BUF_FREE(&st->buffer); /* Free message 5 */ | |
1162 | activate_new_key(st); | |
1163 | } else { | |
59635212 | 1164 | slog(st,LOG_SEC,"invalid MSG6"); |
2fe58dfd SE |
1165 | } |
1166 | break; | |
2fe58dfd | 1167 | default: |
59635212 | 1168 | slog(st,LOG_SEC,"received message of unknown type 0x%08x", |
2fe58dfd SE |
1169 | msgtype); |
1170 | break; | |
1171 | } | |
1172 | BUF_FREE(buf); | |
1173 | return True; | |
1174 | } | |
1175 | ||
1176 | return False; | |
1177 | } | |
1178 | ||
1179 | static void site_control(void *vst, bool_t run) | |
1180 | { | |
1181 | struct site *st=vst; | |
1182 | if (run) enter_state_run(st); | |
1183 | else enter_state_stop(st); | |
1184 | } | |
1185 | ||
794f2398 SE |
1186 | static void site_phase_hook(void *sst, uint32_t newphase) |
1187 | { | |
1188 | struct site *st=sst; | |
1189 | ||
1190 | /* The program is shutting down; tell our peer */ | |
1191 | send_msg7(st,"shutting down"); | |
1192 | } | |
1193 | ||
2fe58dfd SE |
1194 | static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, |
1195 | list_t *args) | |
1196 | { | |
1197 | struct site *st; | |
1198 | item_t *item; | |
1199 | dict_t *dict; | |
1200 | ||
1201 | st=safe_malloc(sizeof(*st),"site_apply"); | |
1202 | ||
1203 | st->cl.description="site"; | |
1204 | st->cl.type=CL_SITE; | |
1205 | st->cl.apply=NULL; | |
1206 | st->cl.interface=&st->ops; | |
1207 | st->ops.st=st; | |
1208 | st->ops.control=site_control; | |
1209 | st->ops.status=site_status; | |
1210 | ||
1211 | /* First parameter must be a dict */ | |
1212 | item=list_elem(args,0); | |
1213 | if (!item || item->type!=t_dict) | |
1214 | cfgfatal(loc,"site","parameter must be a dictionary\n"); | |
1215 | ||
1216 | dict=item->data.dict; | |
558fa3fb SE |
1217 | st->localname=dict_read_string(dict, "local-name", True, "site", loc); |
1218 | st->remotename=dict_read_string(dict, "name", True, "site", loc); | |
1219 | /* Sanity check (which also allows the 'sites' file to include | |
1220 | site() closures for all sites including our own): refuse to | |
1221 | talk to ourselves */ | |
1222 | if (strcmp(st->localname,st->remotename)==0) { | |
b2a56f7c | 1223 | Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n", |
baa06aeb | 1224 | st->localname); |
558fa3fb SE |
1225 | free(st); |
1226 | return NULL; | |
1227 | } | |
469fd1d9 | 1228 | st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc); |
2fe58dfd SE |
1229 | st->comm=find_cl_if(dict,"comm",CL_COMM,True,"site",loc); |
1230 | st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc); | |
1231 | st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc); | |
1232 | st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc); | |
1233 | ||
2fe58dfd | 1234 | st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc); |
2fe58dfd | 1235 | st->address=dict_read_string(dict, "address", False, "site", loc); |
3454dce4 SE |
1236 | if (st->address) |
1237 | st->remoteport=dict_read_number(dict,"port",True,"site",loc,0); | |
1238 | else st->remoteport=0; | |
2fe58dfd SE |
1239 | st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc); |
1240 | ||
1241 | st->transform= | |
1242 | find_cl_if(dict,"transform",CL_TRANSFORM,True,"site",loc); | |
1243 | ||
1244 | st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc); | |
1245 | st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc); | |
1246 | ||
9d3a4132 SE |
1247 | st->key_lifetime=dict_read_number( |
1248 | dict,"key-lifetime",False,"site",loc,DEFAULT_KEY_LIFETIME); | |
1249 | if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP) | |
1250 | st->key_renegotiate_time=st->key_lifetime/2; | |
1251 | else | |
1252 | st->key_renegotiate_time=st->key_lifetime-DEFAULT_KEY_RENEGOTIATE_GAP; | |
1253 | st->setup_retries=dict_read_number( | |
1254 | dict,"setup-retries",False,"site",loc,DEFAULT_SETUP_RETRIES); | |
1255 | st->setup_timeout=dict_read_number( | |
1256 | dict,"setup-timeout",False,"site",loc,DEFAULT_SETUP_TIMEOUT); | |
1257 | st->wait_timeout=dict_read_number( | |
1258 | dict,"wait-time",False,"site",loc,DEFAULT_WAIT_TIME); | |
1259 | st->key_renegotiate_time=dict_read_number( | |
1260 | dict,"renegotiate-time",False,"site",loc,st->key_lifetime); | |
1261 | if (st->key_renegotiate_time > st->key_lifetime) { | |
1262 | cfgfatal(loc,"site", | |
1263 | "renegotiate-time must be less than key-lifetime\n"); | |
1264 | } | |
1265 | /* XXX keepalive will eventually default to True */ | |
1266 | st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False); | |
1267 | ||
1268 | st->log_events=string_list_to_word(dict_lookup(dict,"log-events"), | |
1269 | log_event_table,"site"); | |
2fe58dfd | 1270 | |
4efd681a SE |
1271 | st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5, |
1272 | "site_apply"); | |
1273 | sprintf(st->tunname,"%s<->%s",st->localname,st->remotename); | |
1274 | ||
2fe58dfd SE |
1275 | /* The information we expect to see in incoming messages of type 1 */ |
1276 | st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8; | |
1277 | st->setupsig=safe_malloc(st->setupsiglen,"site_apply"); | |
8689b3a9 SE |
1278 | put_uint32(st->setupsig+0,LABEL_MSG1); |
1279 | put_uint16(st->setupsig+4,strlen(st->remotename)); | |
2fe58dfd | 1280 | memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename)); |
8689b3a9 | 1281 | put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname)); |
2fe58dfd SE |
1282 | memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname, |
1283 | strlen(st->localname)); | |
1284 | st->setup_priority=(strcmp(st->localname,st->remotename)>0); | |
1285 | ||
1286 | buffer_new(&st->buffer,SETUP_BUFFER_LEN); | |
1287 | ||
1288 | /* We are interested in poll(), but only for timeouts. We don't have | |
1289 | any fds of our own. */ | |
1290 | register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site"); | |
1291 | st->timeout=0; | |
1292 | ||
1293 | st->current_valid=False; | |
1294 | st->current_key_timeout=0; | |
1295 | st->peer_valid=False; | |
1296 | /* XXX mlock these */ | |
1297 | st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret"); | |
1298 | st->sharedsecret=safe_malloc(st->transform->keylen,"site:sharedsecret"); | |
1299 | ||
1300 | /* We need to register the remote networks with the netlink device */ | |
469fd1d9 SE |
1301 | st->netlink->reg(st->netlink->st, site_outgoing, st, |
1302 | st->transform->max_start_pad+(4*4), | |
1303 | st->transform->max_end_pad); | |
2fe58dfd SE |
1304 | |
1305 | st->comm->request_notify(st->comm->st, st, site_incoming); | |
1306 | ||
1307 | st->current_transform=st->transform->create(st->transform->st); | |
1308 | st->new_transform=st->transform->create(st->transform->st); | |
1309 | ||
1310 | enter_state_stop(st); | |
1311 | ||
794f2398 SE |
1312 | add_hook(PHASE_SHUTDOWN,site_phase_hook,st); |
1313 | ||
2fe58dfd SE |
1314 | return new_closure(&st->cl); |
1315 | } | |
1316 | ||
1317 | init_module site_module; | |
1318 | void site_module(dict_t *dict) | |
1319 | { | |
1320 | add_closure(dict,"site",site_apply); | |
1321 | } |