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[secnet] / site.c
CommitLineData
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
ff05a229
SE		 12/* At some point in the future the netlink code will be asked for
13 configuration information to go in the PING/PONG packets at the end
14 of the key exchange. */
15
8689b3a9 16#include "secnet.h"
2fe58dfd 17#include <stdio.h>
469fd1d9 18#include <string.h>
fe5e9cc4 19#include <limits.h>
58650a70 20#include <assert.h>
8689b3a9 21#include <sys/socket.h>
2fe58dfd 22
8689b3a9 23#include <sys/mman.h>
2fe58dfd 24#include "util.h"
59635212 25#include "unaligned.h"
ff05a229 26#include "magic.h"
2fe58dfd
SE		 27
28#define SETUP_BUFFER_LEN 2048
29
e7f8ec2a
IJ		 30#define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
31#define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
2fe58dfd 32#define DEFAULT_SETUP_RETRIES 5
e7f8ec2a
IJ		 33#define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
34#define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
e57264d6
IJ		 35
36#define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
37#define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
38#define DEFAULT_MOBILE_SETUP_RETRIES 30
39#define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
40#define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
41
446353cd
IJ		 42#define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
43#define DEFAULT_MOBILE_PEERS_MAX 3 /* send at most this many copies (default) */
2fe58dfd
SE		 44
45/* Each site can be in one of several possible states. */
46
47/* States:
48 SITE_STOP - nothing is allowed to happen; tunnel is down;
49 all session keys have been erased
50 -> SITE_RUN upon external instruction
51 SITE_RUN - site up, maybe with valid key
52 -> SITE_RESOLVE upon outgoing packet and no valid key
53 we start name resolution for the other end of the tunnel
54 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
55 we send an appropriate message 2
56 SITE_RESOLVE - waiting for name resolution
57 -> SITE_SENTMSG1 upon successful resolution
58 we send an appropriate message 1
59 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
60 we abort resolution and
61 -> SITE_WAIT on timeout or resolution failure
62 SITE_SENTMSG1
63 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
64 -> SITE_SENTMSG3 upon valid incoming message 2
65 -> SITE_WAIT on timeout
66 SITE_SENTMSG2
67 -> SITE_SENTMSG4 upon valid incoming message 3
68 -> SITE_WAIT on timeout
69 SITE_SENTMSG3
70 -> SITE_SENTMSG5 upon valid incoming message 4
71 -> SITE_WAIT on timeout
72 SITE_SENTMSG4
73 -> SITE_RUN upon valid incoming message 5
74 -> SITE_WAIT on timeout
75 SITE_SENTMSG5
76 -> SITE_RUN upon valid incoming message 6
77 -> SITE_WAIT on timeout
78 SITE_WAIT - failed to establish key; do nothing for a while
79 -> SITE_RUN on timeout
80 */
81
82#define SITE_STOP 0
83#define SITE_RUN 1
84#define SITE_RESOLVE 2
85#define SITE_SENTMSG1 3
86#define SITE_SENTMSG2 4
87#define SITE_SENTMSG3 5
88#define SITE_SENTMSG4 6
89#define SITE_SENTMSG5 7
90#define SITE_WAIT 8
91
fe5e9cc4 92static cstring_t state_name(uint32_t state)
2fe58dfd
SE		 93{
94 switch (state) {
3454dce4
SE		 95 case 0: return "STOP";
96 case 1: return "RUN";
97 case 2: return "RESOLVE";
98 case 3: return "SENTMSG1";
99 case 4: return "SENTMSG2";
100 case 5: return "SENTMSG3";
101 case 6: return "SENTMSG4";
102 case 7: return "SENTMSG5";
103 case 8: return "WAIT";
2fe58dfd
SE		 104 default: return "*bad state*";
105 }
106}
107
2fe58dfd
SE		 108#define NONCELEN 8
109
110#define LOG_UNEXPECTED 0x00000001
111#define LOG_SETUP_INIT 0x00000002
112#define LOG_SETUP_TIMEOUT 0x00000004
113#define LOG_ACTIVATE_KEY 0x00000008
114#define LOG_TIMEOUT_KEY 0x00000010
9d3a4132 115#define LOG_SEC 0x00000020
2fe58dfd
SE		 116#define LOG_STATE 0x00000040
117#define LOG_DROP 0x00000080
118#define LOG_DUMP 0x00000100
119#define LOG_ERROR 0x00000400
446353cd 120#define LOG_PEER_ADDRS 0x00000800
2fe58dfd 121
9d3a4132
SE		 122static struct flagstr log_event_table[]={
123 { "unexpected", LOG_UNEXPECTED },
124 { "setup-init", LOG_SETUP_INIT },
125 { "setup-timeout", LOG_SETUP_TIMEOUT },
126 { "activate-key", LOG_ACTIVATE_KEY },
127 { "timeout-key", LOG_TIMEOUT_KEY },
128 { "security", LOG_SEC },
129 { "state-change", LOG_STATE },
130 { "packet-drop", LOG_DROP },
131 { "dump-packets", LOG_DUMP },
132 { "errors", LOG_ERROR },
446353cd 133 { "peer-addrs", LOG_PEER_ADDRS },
ff05a229
SE		 134 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
135 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
9d3a4132
SE		 136 { "all", 0xffffffff },
137 { NULL, 0 }
138};
139
446353cd
IJ		 140
141/***** TRANSPORT PEERS declarations *****/
142
143/* Details of "mobile peer" semantics:
144
145 - We record mobile_peers_max peer address/port numbers ("peers")
146 for key setup, and separately mobile_peers_max for data
147 transfer. If these lists fill up, we retain the newest peers.
148 (For non-mobile peers we only record one of each.)
149
150 - Outgoing packets are sent to every recorded peer in the
151 applicable list.
152
153 - Data transfer peers are straightforward: whenever we successfully
154 process a data packet, we record the peer. Also, whenever we
155 successfully complete a key setup, we merge the key setup
156 peers into the data transfer peers.
157
158 (For "non-mobile" peers we simply copy the peer used for
159 successful key setup, and don't change the peer otherwise.)
160
161 - Key setup peers are slightly more complicated.
162
163 Whenever we receive and successfully process a key exchange
164 packet, we record the peer.
165
166 Whenever we try to initiate a key setup, we copy the list of data
167 transfer peers and use it for key setup. But we also look to see
168 if the config supplies an address and port number and if so we
169 add that as a key setup peer (possibly evicting one of the data
170 transfer peers we just copied).
171
172 (For "non-mobile" peers, if we if we have a configured peer
173 address and port, we always use that; otherwise if we have a
174 current data peer address we use that; otherwise we do not
175 attempt to initiate a key setup for lack of a peer address.)
176
177 "Record the peer" means
178 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
179 2. add the peer of the just received packet to the applicable list
180 (possibly evicting older entries)
181 NB that we do not expire peers until an incoming packet arrives.
182
183 */
184
185#define MAX_MOBILE_PEERS_MAX 5 /* send at most this many copies, compiled max */
186
187typedef struct {
188 struct timeval last;
189 struct comm_addr addr;
190} transport_peer;
191
192typedef struct {
193/* configuration information */
194/* runtime information */
195 int npeers;
196 transport_peer peers[MAX_MOBILE_PEERS_MAX];
197} transport_peers;
198
199static void transport_peers_clear(struct site *st, transport_peers *peers);
200static int transport_peers_valid(transport_peers *peers);
201static void transport_peers_copy(struct site *st, transport_peers *dst,
202 const transport_peers *src);
203
204static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
205static void transport_data_msgok(struct site *st, const struct comm_addr *a);
206static bool_t transport_compute_setupinit_peers(struct site *st,
207 const struct comm_addr *configured_addr /* 0 if none or not found */);
208static void transport_record_peer(struct site *st, transport_peers *peers,
209 const struct comm_addr *addr, const char *m);
210
211static void transport_xmit(struct site *st, transport_peers *peers,
212 struct buffer_if *buf, bool_t candebug);
213
214 /***** END of transport peers declarations *****/
215
216
19e9a588
IJ		 217struct data_key {
218 struct transform_inst_if *transform;
219 uint64_t key_timeout; /* End of life of current key */
220 uint32_t remote_session_id;
221};
222
2fe58dfd
SE		 223struct site {
224 closure_t cl;
225 struct site_if ops;
226/* configuration information */
227 string_t localname;
228 string_t remotename;
446353cd
IJ		 229 bool_t peer_mobile; /* Mobile client support */
230 int32_t transport_peers_max;
ff05a229 231 string_t tunname; /* localname<->remotename by default, used in logs */
2fe58dfd 232 string_t address; /* DNS name for bootstrapping, optional */
ff05a229 233 int remoteport; /* Port for bootstrapping, optional */
2fe58dfd 234 struct netlink_if *netlink;
59533c16
IJ		 235 struct comm_if **comms;
236 int ncomms;
2fe58dfd
SE		 237 struct resolver_if *resolver;
238 struct log_if *log;
239 struct random_if *random;
240 struct rsaprivkey_if *privkey;
2fe58dfd 241 struct rsapubkey_if *pubkey;
5b5f297f
IJ		 242 struct transform_if **transforms;
243 int ntransforms;
2fe58dfd
SE		 244 struct dh_if *dh;
245 struct hash_if *hash;
2fe58dfd 246
58650a70 247 uint32_t index; /* Index of this site */
09a385fb 248 uint32_t local_capabilities;
1caa23ff 249 int32_t setup_retries; /* How many times to send setup packets */
e7f8ec2a 250 int32_t setup_retry_interval; /* Initial timeout for setup packets */
4a8aed08 251 int32_t wait_timeout; /* How long to wait if setup unsuccessful */
446353cd 252 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
4a8aed08
IJ		 253 int32_t key_lifetime; /* How long a key lasts once set up */
254 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
9d3a4132
SE		 255 after this time, initiate a new
256 key exchange */
2fe58dfd 257
2fe58dfd
SE		 258 bool_t setup_priority; /* Do we have precedence if both sites emit
259 message 1 simultaneously? */
260 uint32_t log_events;
261
262/* runtime information */
263 uint32_t state;
264 uint64_t now; /* Most recently seen time */
265
ff05a229 266 /* The currently established session */
19e9a588 267 struct data_key current;
02b0959b 268 struct data_key auxiliary_key;
bd98cd6b 269 bool_t auxiliary_is_new;
ff05a229 270 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
bd98cd6b 271 uint64_t auxiliary_renegotiate_key_time;
446353cd 272 transport_peers peers; /* Current address(es) of peer for data traffic */
2fe58dfd 273
ff05a229
SE		 274 /* The current key setup protocol exchange. We can only be
275 involved in one of these at a time. There's a potential for
276 denial of service here (the attacker keeps sending a setup
277 packet; we keep trying to continue the exchange, and have to
278 timeout before we can listen for another setup packet); perhaps
279 we should keep a list of 'bad' sources for setup packets. */
09a385fb 280 uint32_t remote_capabilities;
5b5f297f 281 struct transform_if *chosen_transform;
2fe58dfd 282 uint32_t setup_session_id;
446353cd 283 transport_peers setup_peers;
2fe58dfd
SE		 284 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
285 uint8_t remoteN[NONCELEN];
286 struct buffer_if buffer; /* Current outgoing key exchange packet */
05f39b4d 287 struct buffer_if scratch;
4a8aed08 288 int32_t retries; /* Number of retries remaining */
2fe58dfd
SE		 289 uint64_t timeout; /* Timeout for current state */
290 uint8_t *dhsecret;
291 uint8_t *sharedsecret;
5b5f297f 292 uint32_t sharedsecretlen, sharedsecretallocd;
2fe58dfd
SE		 293 struct transform_inst_if *new_transform; /* For key setup/verify */
294};
295
fe5e9cc4 296static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
779837e1
IJ		 297FORMAT(printf,3,4);
298static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
2fe58dfd
SE		 299{
300 va_list ap;
7c006408 301 char buf[240];
b2a56f7c 302 uint32_t class;
2fe58dfd
SE		 303
304 va_start(ap,msg);
305
306 if (event&st->log_events) {
b2a56f7c
SE		 307 switch(event) {
308 case LOG_UNEXPECTED: class=M_INFO; break;
309 case LOG_SETUP_INIT: class=M_INFO; break;
310 case LOG_SETUP_TIMEOUT: class=M_NOTICE; break;
311 case LOG_ACTIVATE_KEY: class=M_INFO; break;
312 case LOG_TIMEOUT_KEY: class=M_INFO; break;
313 case LOG_SEC: class=M_SECURITY; break;
314 case LOG_STATE: class=M_DEBUG; break;
315 case LOG_DROP: class=M_DEBUG; break;
316 case LOG_DUMP: class=M_DEBUG; break;
469fd1d9 317 case LOG_ERROR: class=M_ERR; break;
446353cd 318 case LOG_PEER_ADDRS: class=M_DEBUG; break;
469fd1d9 319 default: class=M_ERR; break;
b2a56f7c
SE		 320 }
321
c1d2109a 322 vsnprintf(buf,sizeof(buf),msg,ap);
779837e1 323 slilog(st->log,class,"%s: %s",st->tunname,buf);
2fe58dfd
SE		 324 }
325 va_end(ap);
326}
327
9d3a4132 328static void set_link_quality(struct site *st);
1d388569
IJ		 329static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
330static void delete_one_key(struct site *st, struct data_key *key,
331 const char *reason /* may be 0 meaning don't log*/,
332 const char *which /* ignored if !reasonn */,
333 uint32_t loglevel /* ignored if !reasonn */);
fe5e9cc4 334static bool_t initiate_key_setup(struct site *st, cstring_t reason);
2fe58dfd
SE		 335static void enter_state_run(struct site *st);
336static bool_t enter_state_resolve(struct site *st);
ff05a229 337static bool_t enter_new_state(struct site *st,uint32_t next);
2fe58dfd 338static void enter_state_wait(struct site *st);
05f39b4d 339static void activate_new_key(struct site *st);
2fe58dfd 340
0afd257e
IJ		 341static bool_t is_transform_valid(struct transform_inst_if *transform)
342{
fcad4b0b 343 return transform && transform->valid(transform->st);
0afd257e
IJ		 344}
345
3d8d8f4e
IJ		 346static bool_t current_valid(struct site *st)
347{
0afd257e
IJ		 348 return is_transform_valid(st->current.transform);
349}
350
351#define DEFINE_CALL_TRANSFORM(fwdrev) \
352static int call_transform_##fwdrev(struct site *st, \
353 struct transform_inst_if *transform, \
354 struct buffer_if *buf, \
355 const char **errmsg) \
356{ \
fcad4b0b
IJ		 357 if (!is_transform_valid(transform)) { \
358 *errmsg="transform not set up"; \
359 return 1; \
360 } \
0afd257e 361 return transform->fwdrev(transform->st,buf,errmsg); \
3d8d8f4e
IJ		 362}
363
0afd257e
IJ		 364DEFINE_CALL_TRANSFORM(forwards)
365DEFINE_CALL_TRANSFORM(reverse)
366
367static void dispose_transform(struct transform_inst_if **transform_var)
368{
0afd257e 369 struct transform_inst_if *transform=*transform_var;
fcad4b0b
IJ		 370 if (transform) {
371 transform->delkey(transform->st);
372 transform->destroy(transform->st);
373 }
374 *transform_var = 0;
0afd257e
IJ		 375}
376
2fe58dfd
SE		 377#define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
378#define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
379#define CHECK_TYPE(b,t) do { uint32_t type; \
380 CHECK_AVAIL((b),4); \
59635212 381 type=buf_unprepend_uint32((b)); \
2fe58dfd
SE		 382 if (type!=(t)) return False; } while(0)
383
1737eeef
IJ		 384struct parsedname {
385 int32_t len;
386 uint8_t *name;
09a385fb 387 struct buffer_if extrainfo;
1737eeef
IJ		 388};
389
2fe58dfd
SE		 390struct msg {
391 uint8_t *hashstart;
392 uint32_t dest;
393 uint32_t source;
1737eeef
IJ		 394 struct parsedname remote;
395 struct parsedname local;
09a385fb 396 uint32_t remote_capabilities;
5b5f297f 397 int capab_transformnum;
2fe58dfd
SE		 398 uint8_t *nR;
399 uint8_t *nL;
1caa23ff 400 int32_t pklen;
3e8addad 401 char *pk;
1caa23ff
IJ		 402 int32_t hashlen;
403 int32_t siglen;
3e8addad 404 char *sig;
2fe58dfd
SE		 405};
406
5b5f297f 407static void set_new_transform(struct site *st, char *pk)
0afd257e 408{
5b5f297f
IJ		 409 /* Make room for the shared key */
410 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
411 assert(st->sharedsecretlen);
412 if (st->sharedsecretlen > st->sharedsecretallocd) {
413 st->sharedsecretallocd=st->sharedsecretlen;
414 st->sharedsecret=realloc(st->sharedsecret,st->sharedsecretallocd);
415 }
416 if (!st->sharedsecret) fatal_perror("site:sharedsecret");
417
418 /* Generate the shared key */
419 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
420 st->sharedsecret,st->sharedsecretlen);
421
422 /* Set up the transform */
423 struct transform_if *generator=st->chosen_transform;
fcad4b0b
IJ		 424 struct transform_inst_if *generated=generator->create(generator->st);
425 generated->setkey(generated->st,st->sharedsecret,
426 st->sharedsecretlen,st->setup_priority);
427 dispose_transform(&st->new_transform);
428 st->new_transform=generated;
5b5f297f
IJ		 429
430 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
431 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
432 st->chosen_transform->capab_transformnum,
433 st->local_capabilities, st->remote_capabilities);
0afd257e
IJ		 434}
435
09a385fb
IJ		 436struct xinfoadd {
437 int32_t lenpos, afternul;
438};
439static void append_string_xinfo_start(struct buffer_if *buf,
440 struct xinfoadd *xia,
441 const char *str)
442 /* Helps construct one of the names with additional info as found
443 * in MSG1..4. Call this function first, then append all the
444 * desired extra info (not including the nul byte) to the buffer,
445 * then call append_string_xinfo_done. */
446{
447 xia->lenpos = buf->size;
448 buf_append_string(buf,str);
449 buf_append_uint8(buf,0);
450 xia->afternul = buf->size;
451}
452static void append_string_xinfo_done(struct buffer_if *buf,
453 struct xinfoadd *xia)
454{
455 /* we just need to adjust the string length */
456 if (buf->size == xia->afternul) {
457 /* no extra info, strip the nul too */
458 buf_unappend_uint8(buf);
459 } else {
460 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
461 }
462}
463
ff05a229
SE		 464/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
465 out using a transform of config data supplied by netlink */
fe5e9cc4 466static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
2fe58dfd
SE		 467{
468 void *hst;
3b83c932 469 uint8_t *hash;
2fe58dfd
SE		 470 string_t dhpub, sig;
471
472 st->retries=st->setup_retries;
473 BUF_ALLOC(&st->buffer,what);
474 buffer_init(&st->buffer,0);
59635212
SE		 475 buf_append_uint32(&st->buffer,
476 (type==LABEL_MSG1?0:st->setup_session_id));
58650a70 477 buf_append_uint32(&st->buffer,st->index);
59635212 478 buf_append_uint32(&st->buffer,type);
09a385fb
IJ		 479
480 struct xinfoadd xia;
481 append_string_xinfo_start(&st->buffer,&xia,st->localname);
482 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
483 buf_append_uint32(&st->buffer,st->local_capabilities);
484 }
485 append_string_xinfo_done(&st->buffer,&xia);
486
2fe58dfd
SE		 487 buf_append_string(&st->buffer,st->remotename);
488 memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
489 if (type==LABEL_MSG1) return True;
490 memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN);
491 if (type==LABEL_MSG2) return True;
3b83c932
SE		 492
493 if (hacky_par_mid_failnow()) return False;
494
5b5f297f
IJ		 495 if (type==LABEL_MSG3BIS)
496 buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
497
2fe58dfd
SE		 498 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
499 buf_append_string(&st->buffer,dhpub);
500 free(dhpub);
3b83c932 501 hash=safe_malloc(st->hash->len, "generate_msg");
2fe58dfd
SE		 502 hst=st->hash->init();
503 st->hash->update(hst,st->buffer.start,st->buffer.size);
504 st->hash->final(hst,hash);
505 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
506 buf_append_string(&st->buffer,sig);
507 free(sig);
3b83c932 508 free(hash);
2fe58dfd
SE		 509 return True;
510}
511
1737eeef
IJ		 512static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
513{
514 CHECK_AVAIL(msg,2);
515 nm->len=buf_unprepend_uint16(msg);
516 CHECK_AVAIL(msg,nm->len);
517 nm->name=buf_unprepend(msg,nm->len);
518 uint8_t *nul=memchr(nm->name,0,nm->len);
519 if (!nul) {
09a385fb 520 buffer_readonly_view(&nm->extrainfo,0,0);
1737eeef 521 } else {
09a385fb 522 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
1737eeef
IJ		 523 nm->len=nul-nm->name;
524 }
525 return True;
526}
527
2fe58dfd
SE		 528static bool_t unpick_msg(struct site *st, uint32_t type,
529 struct buffer_if *msg, struct msg *m)
530{
5b5f297f 531 m->capab_transformnum=-1;
2fe58dfd
SE		 532 m->hashstart=msg->start;
533 CHECK_AVAIL(msg,4);
59635212 534 m->dest=buf_unprepend_uint32(msg);
2fe58dfd 535 CHECK_AVAIL(msg,4);
59635212 536 m->source=buf_unprepend_uint32(msg);
2fe58dfd 537 CHECK_TYPE(msg,type);
1737eeef 538 if (!unpick_name(msg,&m->remote)) return False;
09a385fb
IJ		 539 m->remote_capabilities=0;
540 if (m->remote.extrainfo.size) {
541 CHECK_AVAIL(&m->remote.extrainfo,4);
542 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
543 }
1737eeef 544 if (!unpick_name(msg,&m->local)) return False;
2fe58dfd
SE		 545 CHECK_AVAIL(msg,NONCELEN);
546 m->nR=buf_unprepend(msg,NONCELEN);
547 if (type==LABEL_MSG1) {
548 CHECK_EMPTY(msg);
549 return True;
550 }
551 CHECK_AVAIL(msg,NONCELEN);
552 m->nL=buf_unprepend(msg,NONCELEN);
553 if (type==LABEL_MSG2) {
554 CHECK_EMPTY(msg);
555 return True;
556 }
5b5f297f
IJ		 557 if (type==LABEL_MSG3BIS) {
558 CHECK_AVAIL(msg,1);
559 m->capab_transformnum = buf_unprepend_uint8(msg);
560 } else {
561 m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
562 }
2fe58dfd 563 CHECK_AVAIL(msg,2);
59635212 564 m->pklen=buf_unprepend_uint16(msg);
2fe58dfd
SE		 565 CHECK_AVAIL(msg,m->pklen);
566 m->pk=buf_unprepend(msg,m->pklen);
567 m->hashlen=msg->start-m->hashstart;
568 CHECK_AVAIL(msg,2);
59635212 569 m->siglen=buf_unprepend_uint16(msg);
2fe58dfd
SE		 570 CHECK_AVAIL(msg,m->siglen);
571 m->sig=buf_unprepend(msg,m->siglen);
572 CHECK_EMPTY(msg);
573 return True;
574}
575
1737eeef
IJ		 576static bool_t name_matches(const struct parsedname *nm, const char *expected)
577{
578 int expected_len=strlen(expected);
579 return
580 nm->len == expected_len &&
581 !memcmp(nm->name, expected, expected_len);
582}
583
ff05a229 584static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
fe5e9cc4 585 cstring_t *error)
ff05a229
SE		 586{
587 if (type==LABEL_MSG1) return True;
588
589 /* Check that the site names and our nonce have been sent
590 back correctly, and then store our peer's nonce. */
1737eeef 591 if (!name_matches(&m->remote,st->remotename)) {
ff05a229
SE		 592 *error="wrong remote site name";
593 return False;
594 }
1737eeef 595 if (!name_matches(&m->local,st->localname)) {
ff05a229
SE		 596 *error="wrong local site name";
597 return False;
598 }
599 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
600 *error="wrong locally-generated nonce";
601 return False;
602 }
603 if (type==LABEL_MSG2) return True;
5ad34db2 604 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
ff05a229
SE		 605 *error="wrong remotely-generated nonce";
606 return False;
607 }
09a385fb
IJ		 608 /* MSG3 has complicated rules about capabilities, which are
609 * handled in process_msg3. */
5b5f297f 610 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
09a385fb
IJ		 611 if (m->remote_capabilities!=st->remote_capabilities) {
612 *error="remote capabilities changed";
613 return False;
614 }
ff05a229
SE		 615 if (type==LABEL_MSG4) return True;
616 *error="unknown message type";
617 return False;
618}
619
2fe58dfd
SE		 620static bool_t generate_msg1(struct site *st)
621{
622 st->random->generate(st->random->st,NONCELEN,st->localN);
623 return generate_msg(st,LABEL_MSG1,"site:MSG1");
624}
625
626static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
7e29719e 627 const struct comm_addr *src, struct msg *m)
2fe58dfd 628{
2fe58dfd
SE		 629 /* We've already determined we're in an appropriate state to
630 process an incoming MSG1, and that the MSG1 has correct values
631 of A and B. */
632
446353cd 633 transport_record_peer(st,&st->setup_peers,src,"msg1");
7e29719e 634 st->setup_session_id=m->source;
09a385fb 635 st->remote_capabilities=m->remote_capabilities;
7e29719e 636 memcpy(st->remoteN,m->nR,NONCELEN);
2fe58dfd
SE		 637 return True;
638}
639
640static bool_t generate_msg2(struct site *st)
641{
642 st->random->generate(st->random->st,NONCELEN,st->localN);
643 return generate_msg(st,LABEL_MSG2,"site:MSG2");
644}
645
646static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
a15faeb2 647 const struct comm_addr *src)
2fe58dfd
SE		 648{
649 struct msg m;
fe5e9cc4 650 cstring_t err;
2fe58dfd
SE		 651
652 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
ff05a229
SE		 653 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
654 slog(st,LOG_SEC,"msg2: %s",err);
2fe58dfd
SE		 655 return False;
656 }
657 st->setup_session_id=m.source;
09a385fb 658 st->remote_capabilities=m.remote_capabilities;
5b5f297f
IJ		 659
660 /* Select the transform to use */
661
662 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
663 if (!remote_transforms)
664 /* old secnets only had this one transform */
665 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
666
667 struct transform_if *ti;
668 int i;
669 for (i=0; i<st->ntransforms; i++) {
670 ti=st->transforms[i];
671 if ((1UL << ti->capab_transformnum) & remote_transforms)
672 goto transform_found;
673 }
674 slog(st,LOG_ERROR,"no transforms in common"
675 " (us %#"PRIx32"; them: %#"PRIx32")",
676 st->local_capabilities & CAPAB_TRANSFORM_MASK,
677 remote_transforms);
678 return False;
679 transform_found:
680 st->chosen_transform=ti;
681
2fe58dfd
SE		 682 memcpy(st->remoteN,m.nR,NONCELEN);
683 return True;
684}
685
686static bool_t generate_msg3(struct site *st)
687{
688 /* Now we have our nonce and their nonce. Think of a secret key,
689 and create message number 3. */
690 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
5b5f297f
IJ		 691 return generate_msg(st,
692 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
693 ? LABEL_MSG3BIS : LABEL_MSG3),
694 "site:MSG3");
2fe58dfd
SE		 695}
696
697static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
5b5f297f 698 const struct comm_addr *src, uint32_t msgtype)
2fe58dfd
SE		 699{
700 struct msg m;
3b83c932 701 uint8_t *hash;
2fe58dfd 702 void *hst;
fe5e9cc4 703 cstring_t err;
2fe58dfd 704
5b5f297f
IJ		 705 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
706
707 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
708 if (!check_msg(st,msgtype,&m,&err)) {
ff05a229 709 slog(st,LOG_SEC,"msg3: %s",err);
2fe58dfd
SE		 710 return False;
711 }
09a385fb
IJ		 712 uint32_t capab_adv_late = m.remote_capabilities
713 & ~st->remote_capabilities & CAPAB_EARLY;
714 if (capab_adv_late) {
715 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
716 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
717 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
718 return False;
719 }
720 st->remote_capabilities|=m.remote_capabilities;
ff05a229 721
5b5f297f
IJ		 722 struct transform_if *ti;
723 int i;
724 for (i=0; i<st->ntransforms; i++) {
725 ti=st->transforms[i];
726 if (ti->capab_transformnum == m.capab_transformnum)
727 goto transform_found;
728 }
729 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
730 m.capab_transformnum);
731 return False;
732 transform_found:
733 st->chosen_transform=ti;
734
2fe58dfd 735 /* Check signature and store g^x mod m */
3b83c932 736 hash=safe_malloc(st->hash->len, "process_msg3");
2fe58dfd
SE		 737 hst=st->hash->init();
738 st->hash->update(hst,m.hashstart,m.hashlen);
739 st->hash->final(hst,hash);
740 /* Terminate signature with a '0' - cheating, but should be ok */
741 m.sig[m.siglen]=0;
742 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
59635212 743 slog(st,LOG_SEC,"msg3 signature failed check!");
3b83c932 744 free(hash);
2fe58dfd
SE		 745 return False;
746 }
3b83c932 747 free(hash);
2fe58dfd
SE		 748
749 /* Terminate their DH public key with a '0' */
750 m.pk[m.pklen]=0;
751 /* Invent our DH secret key */
752 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
753
5b5f297f
IJ		 754 /* Generate the shared key and set up the transform */
755 set_new_transform(st,m.pk);
2fe58dfd
SE		 756
757 return True;
758}
759
760static bool_t generate_msg4(struct site *st)
761{
762 /* We have both nonces, their public key and our private key. Generate
763 our public key, sign it and send it to them. */
764 return generate_msg(st,LABEL_MSG4,"site:MSG4");
765}
766
767static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
a15faeb2 768 const struct comm_addr *src)
2fe58dfd
SE		 769{
770 struct msg m;
3b83c932 771 uint8_t *hash;
2fe58dfd 772 void *hst;
fe5e9cc4 773 cstring_t err;
2fe58dfd
SE		 774
775 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
ff05a229
SE		 776 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
777 slog(st,LOG_SEC,"msg4: %s",err);
2fe58dfd
SE		 778 return False;
779 }
780
781 /* Check signature and store g^x mod m */
3b83c932 782 hash=safe_malloc(st->hash->len, "process_msg4");
2fe58dfd
SE		 783 hst=st->hash->init();
784 st->hash->update(hst,m.hashstart,m.hashlen);
785 st->hash->final(hst,hash);
786 /* Terminate signature with a '0' - cheating, but should be ok */
787 m.sig[m.siglen]=0;
788 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
59635212 789 slog(st,LOG_SEC,"msg4 signature failed check!");
3b83c932 790 free(hash);
2fe58dfd
SE		 791 return False;
792 }
3b83c932 793 free(hash);
2fe58dfd
SE		 794
795 /* Terminate their DH public key with a '0' */
796 m.pk[m.pklen]=0;
5b5f297f
IJ		 797
798 /* Generate the shared key and set up the transform */
799 set_new_transform(st,m.pk);
2fe58dfd
SE		 800
801 return True;
802}
803
2fe58dfd
SE		 804struct msg0 {
805 uint32_t dest;
806 uint32_t source;
807 uint32_t type;
808};
809
810static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
811 struct msg0 *m)
812{
813 CHECK_AVAIL(msg0,4);
59635212 814 m->dest=buf_unprepend_uint32(msg0);
2fe58dfd 815 CHECK_AVAIL(msg0,4);
59635212 816 m->source=buf_unprepend_uint32(msg0);
2fe58dfd 817 CHECK_AVAIL(msg0,4);
59635212 818 m->type=buf_unprepend_uint32(msg0);
2fe58dfd
SE		 819 return True;
820 /* Leaves transformed part of buffer untouched */
821}
822
ff05a229
SE		 823static bool_t generate_msg5(struct site *st)
824{
fe5e9cc4 825 cstring_t transform_err;
ff05a229
SE		 826
827 BUF_ALLOC(&st->buffer,"site:MSG5");
828 /* We are going to add four words to the message */
1ce2f8bc 829 buffer_init(&st->buffer,st->new_transform->max_start_pad+(4*4));
ff05a229
SE		 830 /* Give the netlink code an opportunity to put its own stuff in the
831 message (configuration information, etc.) */
ff05a229 832 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
0afd257e
IJ		 833 if (call_transform_forwards(st,st->new_transform,
834 &st->buffer,&transform_err))
835 return False;
ff05a229 836 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
58650a70 837 buf_prepend_uint32(&st->buffer,st->index);
ff05a229
SE		 838 buf_prepend_uint32(&st->buffer,st->setup_session_id);
839
840 st->retries=st->setup_retries;
841 return True;
842}
843
2fe58dfd 844static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
c90cc2a7
IJ		 845 const struct comm_addr *src,
846 struct transform_inst_if *transform)
2fe58dfd
SE		 847{
848 struct msg0 m;
fe5e9cc4 849 cstring_t transform_err;
2fe58dfd
SE		 850
851 if (!unpick_msg0(st,msg5,&m)) return False;
852
0afd257e 853 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
2fe58dfd 854 /* There's a problem */
59635212 855 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
2fe58dfd
SE		 856 return False;
857 }
858 /* Buffer should now contain untransformed PING packet data */
859 CHECK_AVAIL(msg5,4);
59635212 860 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
ff05a229 861 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
2fe58dfd
SE		 862 return False;
863 }
ff7cdc9e
IJ		 864 /* Older versions of secnet used to write some config data here
865 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE		 866 return True;
867}
868
c90cc2a7
IJ		 869static void create_msg6(struct site *st, struct transform_inst_if *transform,
870 uint32_t session_id)
2fe58dfd 871{
fe5e9cc4 872 cstring_t transform_err;
2fe58dfd
SE		 873
874 BUF_ALLOC(&st->buffer,"site:MSG6");
ff05a229 875 /* We are going to add four words to the message */
1ce2f8bc 876 buffer_init(&st->buffer,transform->max_start_pad+(4*4));
794f2398
SE		 877 /* Give the netlink code an opportunity to put its own stuff in the
878 message (configuration information, etc.) */
ff05a229 879 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
0afd257e
IJ		 880 int problem = call_transform_forwards(st,transform,
881 &st->buffer,&transform_err);
882 assert(!problem);
59635212 883 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
58650a70 884 buf_prepend_uint32(&st->buffer,st->index);
c90cc2a7
IJ		 885 buf_prepend_uint32(&st->buffer,session_id);
886}
2fe58dfd 887
c90cc2a7
IJ		 888static bool_t generate_msg6(struct site *st)
889{
0afd257e
IJ		 890 if (!is_transform_valid(st->new_transform))
891 return False;
c90cc2a7 892 create_msg6(st,st->new_transform,st->setup_session_id);
ff05a229 893 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
2fe58dfd
SE		 894 return True;
895}
896
897static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
a15faeb2 898 const struct comm_addr *src)
2fe58dfd
SE		 899{
900 struct msg0 m;
fe5e9cc4 901 cstring_t transform_err;
2fe58dfd
SE		 902
903 if (!unpick_msg0(st,msg6,&m)) return False;
904
0afd257e 905 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
2fe58dfd 906 /* There's a problem */
59635212 907 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
2fe58dfd
SE		 908 return False;
909 }
910 /* Buffer should now contain untransformed PING packet data */
911 CHECK_AVAIL(msg6,4);
59635212
SE		 912 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
913 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
2fe58dfd
SE		 914 return False;
915 }
ff7cdc9e
IJ		 916 /* Older versions of secnet used to write some config data here
917 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE		 918 return True;
919}
920
48b97423
IJ		 921static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
922 const struct comm_addr *src)
2fe58dfd 923{
02b0959b 924 cstring_t transform_err, auxkey_err, newkey_err="n/a";
065e1922
IJ		 925 struct msg0 m;
926 uint32_t problem;
2fe58dfd 927
2fe58dfd
SE		 928 if (!unpick_msg0(st,msg0,&m)) return False;
929
05f39b4d
IJ		 930 /* Keep a copy so we can try decrypting it with multiple keys */
931 buffer_copy(&st->scratch, msg0);
932
0afd257e
IJ		 933 problem = call_transform_reverse(st,st->current.transform,
934 msg0,&transform_err);
02b0959b 935 if (!problem) {
bd98cd6b
IJ		 936 if (!st->auxiliary_is_new)
937 delete_one_key(st,&st->auxiliary_key,
938 "peer has used new key","auxiliary key",LOG_SEC);
02b0959b
IJ		 939 return True;
940 }
48b97423
IJ		 941 if (problem==2)
942 goto skew;
07e4774c 943
02b0959b 944 buffer_copy(msg0, &st->scratch);
fcad4b0b
IJ		 945 problem = call_transform_reverse(st,st->auxiliary_key.transform,
946 msg0,&auxkey_err);
02b0959b
IJ		 947 if (problem==0) {
948 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
bd98cd6b
IJ		 949 if (st->auxiliary_is_new) {
950 /* We previously timed out in state SENTMSG5 but it turns
951 * out that our peer did in fact get our MSG5 and is
952 * using the new key. So we should switch to it too. */
953 /* This is a bit like activate_new_key. */
954 struct data_key t;
955 t=st->current;
956 st->current=st->auxiliary_key;
957 st->auxiliary_key=t;
958
959 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
960 "previous key",LOG_SEC);
961 st->auxiliary_is_new=0;
962 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
963 }
02b0959b
IJ		 964 return True;
965 }
48b97423
IJ		 966 if (problem==2)
967 goto skew;
02b0959b 968
05f39b4d
IJ		 969 if (st->state==SITE_SENTMSG5) {
970 buffer_copy(msg0, &st->scratch);
0afd257e
IJ		 971 problem = call_transform_reverse(st,st->new_transform,
972 msg0,&newkey_err);
48b97423 973 if (!problem) {
05f39b4d
IJ		 974 /* It looks like we didn't get the peer's MSG6 */
975 /* This is like a cut-down enter_new_state(SITE_RUN) */
976 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
977 BUF_FREE(&st->buffer);
978 st->timeout=0;
979 activate_new_key(st);
980 return True; /* do process the data in this packet */
981 }
48b97423
IJ		 982 if (problem==2)
983 goto skew;
05f39b4d
IJ		 984 }
985
02b0959b
IJ		 986 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
987 transform_err,auxkey_err,newkey_err);
065e1922 988 initiate_key_setup(st,"incoming message would not decrypt");
48b97423
IJ		 989 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
990 return False;
991
992 skew:
993 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
065e1922
IJ		 994 return False;
995}
996
997static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
998 const struct comm_addr *src)
999{
1000 uint32_t type;
1001
48b97423 1002 if (!decrypt_msg0(st,msg0,src))
065e1922
IJ		 1003 return False;
1004
2fe58dfd 1005 CHECK_AVAIL(msg0,4);
59635212 1006 type=buf_unprepend_uint32(msg0);
2fe58dfd 1007 switch(type) {
794f2398
SE		 1008 case LABEL_MSG7:
1009 /* We must forget about the current session. */
1d388569 1010 delete_keys(st,"request from peer",LOG_SEC);
794f2398 1011 return True;
2fe58dfd
SE		 1012 case LABEL_MSG9:
1013 /* Deliver to netlink layer */
469fd1d9 1014 st->netlink->deliver(st->netlink->st,msg0);
446353cd 1015 transport_data_msgok(st,src);
837cf01e
IJ		 1016 /* See whether we should start negotiating a new key */
1017 if (st->now > st->renegotiate_key_time)
1018 initiate_key_setup(st,"incoming packet in renegotiation window");
2fe58dfd 1019 return True;
2fe58dfd 1020 default:
ff05a229
SE		 1021 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1022 "(unknown)",type);
2fe58dfd
SE		 1023 break;
1024 }
1025 return False;
1026}
1027
1028static void dump_packet(struct site *st, struct buffer_if *buf,
a15faeb2 1029 const struct comm_addr *addr, bool_t incoming)
2fe58dfd 1030{
0a6cbade
IJ		 1031 uint32_t dest=get_uint32(buf->start);
1032 uint32_t source=get_uint32(buf->start+4);
1033 uint32_t msgtype=get_uint32(buf->start+8);
2fe58dfd
SE		 1034
1035 if (st->log_events & LOG_DUMP)
040ee979
SE		 1036 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
1037 st->tunname,incoming?"incoming":"outgoing",
1038 dest,source,msgtype);
2fe58dfd
SE		 1039}
1040
1041static uint32_t site_status(void *st)
1042{
1043 return 0;
1044}
1045
1046static bool_t send_msg(struct site *st)
1047{
1048 if (st->retries>0) {
446353cd 1049 transport_xmit(st, &st->setup_peers, &st->buffer, True);
e7f8ec2a 1050 st->timeout=st->now+st->setup_retry_interval;
2fe58dfd
SE		 1051 st->retries--;
1052 return True;
bd98cd6b
IJ		 1053 } else if (st->state==SITE_SENTMSG5) {
1054 slog(st,LOG_SETUP_TIMEOUT,"timed out sending MSG5, stashing new key");
1055 /* We stash the key we have produced, in case it turns out that
1056 * our peer did see our MSG5 after all and starts using it. */
1057 /* This is a bit like some of activate_new_key */
1058 struct transform_inst_if *t;
1059 t=st->auxiliary_key.transform;
1060 st->auxiliary_key.transform=st->new_transform;
1061 st->new_transform=t;
0afd257e 1062 dispose_transform(&st->new_transform);
bd98cd6b 1063
bd98cd6b
IJ		 1064 st->auxiliary_is_new=1;
1065 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1066 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1067 st->auxiliary_key.remote_session_id=st->setup_session_id;
1068
1069 enter_state_wait(st);
1070 return False;
2fe58dfd 1071 } else {
3454dce4
SE		 1072 slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
1073 "(in state %s)",state_name(st->state));
2fe58dfd
SE		 1074 enter_state_wait(st);
1075 return False;
1076 }
1077}
1078
1079static void site_resolve_callback(void *sst, struct in_addr *address)
1080{
1081 struct site *st=sst;
446353cd 1082 struct comm_addr ca_buf, *ca_use;
2fe58dfd
SE		 1083
1084 if (st->state!=SITE_RESOLVE) {
1085 slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
1086 return;
1087 }
1088 if (address) {
446353cd 1089 FILLZERO(ca_buf);
59533c16 1090 ca_buf.comm=st->comms[0];
446353cd
IJ		 1091 ca_buf.sin.sin_family=AF_INET;
1092 ca_buf.sin.sin_port=htons(st->remoteport);
1093 ca_buf.sin.sin_addr=*address;
1094 ca_use=&ca_buf;
2fe58dfd 1095 } else {
2fe58dfd 1096 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
446353cd
IJ		 1097 ca_use=0;
1098 }
1099 if (transport_compute_setupinit_peers(st,ca_use)) {
1100 enter_new_state(st,SITE_SENTMSG1);
1101 } else {
1102 /* Can't figure out who to try to to talk to */
1103 slog(st,LOG_SETUP_INIT,"key exchange failed: cannot find peer address");
2fe58dfd
SE		 1104 enter_state_run(st);
1105 }
1106}
1107
fe5e9cc4 1108static bool_t initiate_key_setup(struct site *st, cstring_t reason)
9d3a4132
SE		 1109{
1110 if (st->state!=SITE_RUN) return False;
794f2398 1111 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
9d3a4132 1112 if (st->address) {
794f2398 1113 slog(st,LOG_SETUP_INIT,"resolving peer address");
9d3a4132 1114 return enter_state_resolve(st);
446353cd 1115 } else if (transport_compute_setupinit_peers(st,0)) {
ff05a229 1116 return enter_new_state(st,SITE_SENTMSG1);
9d3a4132 1117 }
ff05a229 1118 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
9d3a4132
SE		 1119 return False;
1120}
1121
2fe58dfd
SE		 1122static void activate_new_key(struct site *st)
1123{
1124 struct transform_inst_if *t;
1125
02b0959b
IJ		 1126 /* We have three transform instances, which we swap between old,
1127 active and setup */
1128 t=st->auxiliary_key.transform;
1129 st->auxiliary_key.transform=st->current.transform;
19e9a588 1130 st->current.transform=st->new_transform;
2fe58dfd 1131 st->new_transform=t;
0afd257e 1132 dispose_transform(&st->new_transform);
2fe58dfd 1133
2fe58dfd 1134 st->timeout=0;
bd98cd6b 1135 st->auxiliary_is_new=0;
02b0959b 1136 st->auxiliary_key.key_timeout=st->current.key_timeout;
19e9a588 1137 st->current.key_timeout=st->now+st->key_lifetime;
ff05a229 1138 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
446353cd 1139 transport_peers_copy(st,&st->peers,&st->setup_peers);
19e9a588 1140 st->current.remote_session_id=st->setup_session_id;
2fe58dfd
SE		 1141
1142 slog(st,LOG_ACTIVATE_KEY,"new key activated");
9d3a4132 1143 enter_state_run(st);
2fe58dfd
SE		 1144}
1145
1d388569
IJ		 1146static void delete_one_key(struct site *st, struct data_key *key,
1147 cstring_t reason, cstring_t which, uint32_t loglevel)
1148{
0afd257e 1149 if (!is_transform_valid(key->transform)) return;
1d388569 1150 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
0afd257e 1151 dispose_transform(&key->transform);
1d388569
IJ		 1152 key->key_timeout=0;
1153}
1154
1155static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
794f2398 1156{
3d8d8f4e 1157 if (current_valid(st)) {
794f2398
SE		 1158 slog(st,loglevel,"session closed (%s)",reason);
1159
1d388569 1160 delete_one_key(st,&st->current,0,0,0);
794f2398
SE		 1161 set_link_quality(st);
1162 }
02b0959b 1163 delete_one_key(st,&st->auxiliary_key,0,0,0);
794f2398
SE		 1164}
1165
2fe58dfd
SE		 1166static void state_assert(struct site *st, bool_t ok)
1167{
4f5e39ec 1168 if (!ok) fatal("site:state_assert");
2fe58dfd
SE		 1169}
1170
1171static void enter_state_stop(struct site *st)
1172{
1173 st->state=SITE_STOP;
1174 st->timeout=0;
1d388569 1175 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
0afd257e 1176 dispose_transform(&st->new_transform);
2fe58dfd
SE		 1177}
1178
9d3a4132
SE		 1179static void set_link_quality(struct site *st)
1180{
1181 uint32_t quality;
3d8d8f4e 1182 if (current_valid(st))
9d3a4132
SE		 1183 quality=LINK_QUALITY_UP;
1184 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1185 quality=LINK_QUALITY_DOWN;
1186 else if (st->address)
1187 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
446353cd 1188 else if (transport_peers_valid(&st->peers))
9d3a4132
SE		 1189 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1190 else
1191 quality=LINK_QUALITY_DOWN;
1192
469fd1d9 1193 st->netlink->set_quality(st->netlink->st,quality);
9d3a4132
SE		 1194}
1195
2fe58dfd
SE		 1196static void enter_state_run(struct site *st)
1197{
1198 slog(st,LOG_STATE,"entering state RUN");
1199 st->state=SITE_RUN;
1200 st->timeout=0;
9d3a4132 1201
ff05a229 1202 st->setup_session_id=0;
446353cd 1203 transport_peers_clear(st,&st->setup_peers);
ff05a229
SE		 1204 memset(st->localN,0,NONCELEN);
1205 memset(st->remoteN,0,NONCELEN);
0afd257e 1206 dispose_transform(&st->new_transform);
ff05a229 1207 memset(st->dhsecret,0,st->dh->len);
7c9ca4bd 1208 memset(st->sharedsecret,0,st->sharedsecretlen);
9d3a4132 1209 set_link_quality(st);
2fe58dfd
SE		 1210}
1211
1212static bool_t enter_state_resolve(struct site *st)
1213{
1214 state_assert(st,st->state==SITE_RUN);
1215 slog(st,LOG_STATE,"entering state RESOLVE");
1216 st->state=SITE_RESOLVE;
1217 st->resolver->request(st->resolver->st,st->address,
1218 site_resolve_callback,st);
1219 return True;
1220}
1221
ff05a229 1222static bool_t enter_new_state(struct site *st, uint32_t next)
2fe58dfd 1223{
ff05a229 1224 bool_t (*gen)(struct site *st);
3b83c932
SE		 1225 int r;
1226
ff05a229
SE		 1227 slog(st,LOG_STATE,"entering state %s",state_name(next));
1228 switch(next) {
1229 case SITE_SENTMSG1:
1230 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1231 gen=generate_msg1;
1232 break;
1233 case SITE_SENTMSG2:
1234 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1235 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1236 gen=generate_msg2;
1237 break;
1238 case SITE_SENTMSG3:
1239 state_assert(st,st->state==SITE_SENTMSG1);
1240 BUF_FREE(&st->buffer);
1241 gen=generate_msg3;
1242 break;
1243 case SITE_SENTMSG4:
1244 state_assert(st,st->state==SITE_SENTMSG2);
1245 BUF_FREE(&st->buffer);
1246 gen=generate_msg4;
1247 break;
1248 case SITE_SENTMSG5:
1249 state_assert(st,st->state==SITE_SENTMSG3);
1250 BUF_FREE(&st->buffer);
1251 gen=generate_msg5;
1252 break;
1253 case SITE_RUN:
1254 state_assert(st,st->state==SITE_SENTMSG4);
1255 BUF_FREE(&st->buffer);
1256 gen=generate_msg6;
1257 break;
1258 default:
1259 gen=NULL;
4f5e39ec 1260 fatal("enter_new_state(%s): invalid new state",state_name(next));
ff05a229 1261 break;
2fe58dfd 1262 }
2fe58dfd 1263
3b83c932
SE		 1264 if (hacky_par_start_failnow()) return False;
1265
1266 r= gen(st) && send_msg(st);
1267
1268 hacky_par_end(&r,
e7f8ec2a 1269 st->setup_retries, st->setup_retry_interval,
3b83c932
SE		 1270 send_msg, st);
1271
1272 if (r) {
ff05a229
SE		 1273 st->state=next;
1274 if (next==SITE_RUN) {
1275 BUF_FREE(&st->buffer); /* Never reused */
1276 st->timeout=0; /* Never retransmit */
1277 activate_new_key(st);
1278 }
2fe58dfd
SE		 1279 return True;
1280 }
ff05a229
SE		 1281 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1282 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1283 in either state, and enter_state_wait() will
1284 do a BUF_FREE() */
2fe58dfd
SE		 1285 enter_state_wait(st);
1286 return False;
1287}
1288
ff05a229 1289/* msg7 tells our peer that we're about to forget our key */
fe5e9cc4 1290static bool_t send_msg7(struct site *st, cstring_t reason)
794f2398 1291{
fe5e9cc4 1292 cstring_t transform_err;
794f2398 1293
3d8d8f4e 1294 if (current_valid(st) && st->buffer.free
446353cd 1295 && transport_peers_valid(&st->peers)) {
794f2398 1296 BUF_ALLOC(&st->buffer,"site:MSG7");
1ce2f8bc 1297 buffer_init(&st->buffer,st->current.transform->max_start_pad+(4*3));
794f2398
SE		 1298 buf_append_uint32(&st->buffer,LABEL_MSG7);
1299 buf_append_string(&st->buffer,reason);
0afd257e
IJ		 1300 if (call_transform_forwards(st, st->current.transform,
1301 &st->buffer, &transform_err))
1302 goto free_out;
794f2398 1303 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
58650a70 1304 buf_prepend_uint32(&st->buffer,st->index);
19e9a588 1305 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
446353cd 1306 transport_xmit(st,&st->peers,&st->buffer,True);
794f2398 1307 BUF_FREE(&st->buffer);
0afd257e 1308 free_out:
794f2398
SE		 1309 return True;
1310 }
1311 return False;
1312}
1313
2fe58dfd
SE		 1314/* We go into this state if our peer becomes uncommunicative. Similar to
1315 the "stop" state, we forget all session keys for a while, before
1316 re-entering the "run" state. */
1317static void enter_state_wait(struct site *st)
1318{
1319 slog(st,LOG_STATE,"entering state WAIT");
1320 st->timeout=st->now+st->wait_timeout;
1321 st->state=SITE_WAIT;
9d3a4132 1322 set_link_quality(st);
2fe58dfd
SE		 1323 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1324 /* XXX Erase keys etc. */
1325}
1326
16f73fa6 1327static inline void site_settimeout(uint64_t timeout, int *timeout_io)
fe5e9cc4
SE		 1328{
1329 if (timeout) {
0009e60a
IJ		 1330 int64_t offset=timeout-*now;
1331 if (offset<0) offset=0;
fe5e9cc4
SE		 1332 if (offset>INT_MAX) offset=INT_MAX;
1333 if (*timeout_io<0 || offset<*timeout_io)
1334 *timeout_io=offset;
1335 }
1336}
1337
2fe58dfd 1338static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
90a39563 1339 int *timeout_io)
2fe58dfd
SE		 1340{
1341 struct site *st=sst;
1342
1343 *nfds_io=0; /* We don't use any file descriptors */
1344 st->now=*now;
1345
1346 /* Work out when our next timeout is. The earlier of 'timeout' or
19e9a588 1347 'current.key_timeout'. A stored value of '0' indicates no timeout
2fe58dfd 1348 active. */
16f73fa6 1349 site_settimeout(st->timeout, timeout_io);
19e9a588 1350 site_settimeout(st->current.key_timeout, timeout_io);
02b0959b 1351 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
2fe58dfd
SE		 1352
1353 return 0; /* success */
1354}
1355
1d388569
IJ		 1356static void check_expiry(struct site *st, struct data_key *key,
1357 const char *which)
1358{
1359 if (key->key_timeout && *now>key->key_timeout) {
1360 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1361 }
1362}
1363
2fe58dfd 1364/* NB site_afterpoll will be called before site_beforepoll is ever called */
90a39563 1365static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
2fe58dfd
SE		 1366{
1367 struct site *st=sst;
1368
1369 st->now=*now;
1370 if (st->timeout && *now>st->timeout) {
2fe58dfd 1371 st->timeout=0;
3b83c932
SE		 1372 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1373 if (!hacky_par_start_failnow())
1374 send_msg(st);
1375 } else if (st->state==SITE_WAIT) {
2fe58dfd
SE		 1376 enter_state_run(st);
1377 } else {
1378 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1379 st->state);
1380 }
1381 }
1d388569 1382 check_expiry(st,&st->current,"current key");
02b0959b 1383 check_expiry(st,&st->auxiliary_key,"auxiliary key");
2fe58dfd
SE		 1384}
1385
1386/* This function is called by the netlink device to deliver packets
1387 intended for the remote network. The packet is in "raw" wire
1388 format, but is guaranteed to be word-aligned. */
469fd1d9 1389static void site_outgoing(void *sst, struct buffer_if *buf)
2fe58dfd
SE		 1390{
1391 struct site *st=sst;
fe5e9cc4 1392 cstring_t transform_err;
2fe58dfd
SE		 1393
1394 if (st->state==SITE_STOP) {
1395 BUF_FREE(buf);
1396 return;
1397 }
1398
1399 /* In all other states we consider delivering the packet if we have
1400 a valid key and a valid address to send it to. */
3d8d8f4e 1401 if (current_valid(st) && transport_peers_valid(&st->peers)) {
2fe58dfd 1402 /* Transform it and send it */
70dc107b
SE		 1403 if (buf->size>0) {
1404 buf_prepend_uint32(buf,LABEL_MSG9);
0afd257e
IJ		 1405 if (call_transform_forwards(st, st->current.transform,
1406 buf, &transform_err))
1407 goto free_out;
70dc107b 1408 buf_prepend_uint32(buf,LABEL_MSG0);
58650a70 1409 buf_prepend_uint32(buf,st->index);
19e9a588 1410 buf_prepend_uint32(buf,st->current.remote_session_id);
446353cd 1411 transport_xmit(st,&st->peers,buf,False);
70dc107b 1412 }
0afd257e 1413 free_out:
2fe58dfd
SE		 1414 BUF_FREE(buf);
1415 return;
1416 }
1417
70dc107b 1418 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2fe58dfd 1419 BUF_FREE(buf);
794f2398 1420 initiate_key_setup(st,"outgoing packet");
2fe58dfd
SE		 1421}
1422
7e29719e
IJ		 1423static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1424 uint32_t type, struct msg *m)
1425 /* For packets which are identified by the local and remote names.
1426 * If it has our name and our peer's name in it it's for us. */
1427{
1428 struct buffer_if buf[1];
1429 buffer_readonly_clone(buf,buf_in);
1430 return unpick_msg(st,type,buf,m)
1431 && name_matches(&m->remote,st->remotename)
1432 && name_matches(&m->local,st->localname);
1433}
1434
2fe58dfd
SE		 1435/* This function is called by the communication device to deliver
1436 packets from our peers. */
1437static bool_t site_incoming(void *sst, struct buffer_if *buf,
a15faeb2 1438 const struct comm_addr *source)
2fe58dfd
SE		 1439{
1440 struct site *st=sst;
20138876
IJ		 1441
1442 if (buf->size < 12) return False;
1443
0a6cbade
IJ		 1444 uint32_t dest=get_uint32(buf->start);
1445 uint32_t msgtype=get_uint32(buf->start+8);
7e29719e
IJ		 1446 struct msg named_msg;
1447
1448 if (msgtype==LABEL_MSG1) {
1449 if (!named_for_us(st,buf,msgtype,&named_msg))
1450 return False;
1451 /* It's a MSG1 addressed to us. Decide what to do about it. */
1452 dump_packet(st,buf,source,True);
1453 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1454 st->state==SITE_WAIT) {
1455 /* We should definitely process it */
1456 if (process_msg1(st,buf,source,&named_msg)) {
1457 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1458 enter_new_state(st,SITE_SENTMSG2);
1459 } else {
1460 slog(st,LOG_ERROR,"failed to process incoming msg1");
1461 }
1462 BUF_FREE(buf);
1463 return True;
1464 } else if (st->state==SITE_SENTMSG1) {
1465 /* We've just sent a message 1! They may have crossed on
1466 the wire. If we have priority then we ignore the
1467 incoming one, otherwise we process it as usual. */
1468 if (st->setup_priority) {
1469 BUF_FREE(buf);
1470 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1471 "priority => ignore incoming msg1");
1472 return True;
1473 } else {
1474 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1475 "priority => use incoming msg1");
1476 if (process_msg1(st,buf,source,&named_msg)) {
1477 BUF_FREE(&st->buffer); /* Free our old message 1 */
ff05a229 1478 enter_new_state(st,SITE_SENTMSG2);
2fe58dfd 1479 } else {
7e29719e
IJ		 1480 slog(st,LOG_ERROR,"failed to process an incoming "
1481 "crossed msg1 (we have low priority)");
2fe58dfd
SE		 1482 }
1483 BUF_FREE(buf);
1484 return True;
2fe58dfd 1485 }
2fe58dfd 1486 }
7e29719e
IJ		 1487 /* The message 1 was received at an unexpected stage of the
1488 key setup. XXX POLICY - what do we do? */
1489 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1490 BUF_FREE(buf);
1491 return True;
2fe58dfd 1492 }
58650a70 1493 if (dest==st->index) {
2fe58dfd
SE		 1494 /* Explicitly addressed to us */
1495 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1496 switch (msgtype) {
136740e6 1497 case LABEL_NAK:
794f2398
SE		 1498 /* If the source is our current peer then initiate a key setup,
1499 because our peer's forgotten the key */
19e9a588 1500 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
794f2398
SE		 1501 initiate_key_setup(st,"received a NAK");
1502 } else {
1503 slog(st,LOG_SEC,"bad incoming NAK");
1504 }
1505 break;
2fe58dfd
SE		 1506 case LABEL_MSG0:
1507 process_msg0(st,buf,source);
1508 break;
1509 case LABEL_MSG1:
1510 /* Setup packet: should not have been explicitly addressed
1511 to us */
59635212 1512 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2fe58dfd
SE		 1513 break;
1514 case LABEL_MSG2:
1515 /* Setup packet: expected only in state SENTMSG1 */
1516 if (st->state!=SITE_SENTMSG1) {
1517 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
446353cd
IJ		 1518 } else if (process_msg2(st,buf,source)) {
1519 transport_setup_msgok(st,source);
ff05a229 1520 enter_new_state(st,SITE_SENTMSG3);
446353cd 1521 } else {
59635212 1522 slog(st,LOG_SEC,"invalid MSG2");
2fe58dfd
SE		 1523 }
1524 break;
1525 case LABEL_MSG3:
5b5f297f 1526 case LABEL_MSG3BIS:
2fe58dfd
SE		 1527 /* Setup packet: expected only in state SENTMSG2 */
1528 if (st->state!=SITE_SENTMSG2) {
1529 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
5b5f297f 1530 } else if (process_msg3(st,buf,source,msgtype)) {
446353cd 1531 transport_setup_msgok(st,source);
ff05a229 1532 enter_new_state(st,SITE_SENTMSG4);
446353cd 1533 } else {
59635212 1534 slog(st,LOG_SEC,"invalid MSG3");
2fe58dfd
SE		 1535 }
1536 break;
1537 case LABEL_MSG4:
1538 /* Setup packet: expected only in state SENTMSG3 */
1539 if (st->state!=SITE_SENTMSG3) {
1540 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
446353cd
IJ		 1541 } else if (process_msg4(st,buf,source)) {
1542 transport_setup_msgok(st,source);
ff05a229 1543 enter_new_state(st,SITE_SENTMSG5);
446353cd 1544 } else {
59635212 1545 slog(st,LOG_SEC,"invalid MSG4");
2fe58dfd
SE		 1546 }
1547 break;
1548 case LABEL_MSG5:
4efd681a
SE		 1549 /* Setup packet: expected only in state SENTMSG4 */
1550 /* (may turn up in state RUN if our return MSG6 was lost
1551 and the new key has already been activated. In that
05f39b4d
IJ		 1552 case we discard it. The peer will realise that we
1553 are using the new key when they see our data packets.
1554 Until then the peer's data packets to us get discarded. */
c90cc2a7
IJ		 1555 if (st->state==SITE_SENTMSG4) {
1556 if (process_msg5(st,buf,source,st->new_transform)) {
1557 transport_setup_msgok(st,source);
1558 enter_new_state(st,SITE_RUN);
1559 } else {
1560 slog(st,LOG_SEC,"invalid MSG5");
1561 }
1562 } else if (st->state==SITE_RUN) {
19e9a588 1563 if (process_msg5(st,buf,source,st->current.transform)) {
c90cc2a7
IJ		 1564 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1565 transport_setup_msgok(st,source);
19e9a588
IJ		 1566 create_msg6(st,st->current.transform,
1567 st->current.remote_session_id);
c90cc2a7
IJ		 1568 transport_xmit(st,&st->peers,&st->buffer,True);
1569 BUF_FREE(&st->buffer);
1570 } else {
1571 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1572 }
2fe58dfd 1573 } else {
c90cc2a7 1574 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2fe58dfd
SE		 1575 }
1576 break;
1577 case LABEL_MSG6:
1578 /* Setup packet: expected only in state SENTMSG5 */
1579 if (st->state!=SITE_SENTMSG5) {
1580 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1581 } else if (process_msg6(st,buf,source)) {
1582 BUF_FREE(&st->buffer); /* Free message 5 */
446353cd 1583 transport_setup_msgok(st,source);
2fe58dfd
SE		 1584 activate_new_key(st);
1585 } else {
59635212 1586 slog(st,LOG_SEC,"invalid MSG6");
2fe58dfd
SE		 1587 }
1588 break;
2fe58dfd 1589 default:
59635212 1590 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2fe58dfd
SE		 1591 msgtype);
1592 break;
1593 }
1594 BUF_FREE(buf);
1595 return True;
1596 }
1597
1598 return False;
1599}
1600
1601static void site_control(void *vst, bool_t run)
1602{
1603 struct site *st=vst;
1604 if (run) enter_state_run(st);
1605 else enter_state_stop(st);
1606}
1607
794f2398
SE		 1608static void site_phase_hook(void *sst, uint32_t newphase)
1609{
1610 struct site *st=sst;
1611
1612 /* The program is shutting down; tell our peer */
1613 send_msg7(st,"shutting down");
1614}
1615
2fe58dfd
SE		 1616static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1617 list_t *args)
1618{
58650a70 1619 static uint32_t index_sequence;
2fe58dfd
SE		 1620 struct site *st;
1621 item_t *item;
1622 dict_t *dict;
59533c16 1623 int i;
2fe58dfd
SE		 1624
1625 st=safe_malloc(sizeof(*st),"site_apply");
1626
1627 st->cl.description="site";
1628 st->cl.type=CL_SITE;
1629 st->cl.apply=NULL;
1630 st->cl.interface=&st->ops;
1631 st->ops.st=st;
1632 st->ops.control=site_control;
1633 st->ops.status=site_status;
1634
1635 /* First parameter must be a dict */
1636 item=list_elem(args,0);
1637 if (!item || item->type!=t_dict)
1638 cfgfatal(loc,"site","parameter must be a dictionary\n");
1639
1640 dict=item->data.dict;
558fa3fb
SE		 1641 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1642 st->remotename=dict_read_string(dict, "name", True, "site", loc);
dba19f84
IJ		 1643
1644 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1645 bool_t local_mobile=
1646 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1647
558fa3fb
SE		 1648 /* Sanity check (which also allows the 'sites' file to include
1649 site() closures for all sites including our own): refuse to
1650 talk to ourselves */
1651 if (strcmp(st->localname,st->remotename)==0) {
b2a56f7c 1652 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
baa06aeb 1653 st->localname);
dba19f84
IJ		 1654 if (st->peer_mobile != local_mobile)
1655 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1656 " but our local-mobile=%d\n",
1657 st->localname, st->peer_mobile, local_mobile);
1658 free(st);
1659 return NULL;
1660 }
1661 if (st->peer_mobile && local_mobile) {
1662 Message(M_WARNING,"site %s: site is mobile but so are we"
1663 " -> ignoring this site\n", st->remotename);
558fa3fb
SE		 1664 free(st);
1665 return NULL;
1666 }
dba19f84 1667
58650a70
RK		 1668 assert(index_sequence < 0xffffffffUL);
1669 st->index = ++index_sequence;
09a385fb 1670 st->local_capabilities = 0;
469fd1d9 1671 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
59533c16 1672
5b5f297f
IJ		 1673#define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
1674 list_t *things##_cfg=dict_lookup(dict,dictkey); \
1675 if (!things##_cfg) \
1676 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
1677 st->nthings=list_length(things##_cfg); \
1678 st->things=safe_malloc_ary(sizeof(*st->things),st->nthings,dictkey "s"); \
1679 assert(st->nthings); \
1680 for (i=0; i<st->nthings; i++) { \
1681 item_t *item=list_elem(things##_cfg,i); \
1682 if (item->type!=t_closure) \
1683 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
1684 closure_t *cl=item->data.closure; \
1685 if (cl->type!=CL_TYPE) \
1686 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
1687 st->things[i]=cl->interface; \
1688 } \
1689}while(0)
1690
1691 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
59533c16 1692
2fe58dfd
SE		 1693 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1694 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1695 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1696
2fe58dfd 1697 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
2fe58dfd 1698 st->address=dict_read_string(dict, "address", False, "site", loc);
3454dce4
SE		 1699 if (st->address)
1700 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1701 else st->remoteport=0;
2fe58dfd
SE		 1702 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1703
5b5f297f 1704 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2fe58dfd
SE		 1705
1706 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1707 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1708
e57264d6
IJ		 1709#define DEFAULT(D) (st->peer_mobile || local_mobile \
1710 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
e7f8ec2a 1711#define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
c27ca22f 1712
e7f8ec2a
IJ		 1713 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1714 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1715 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1716 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1717
446353cd
IJ		 1718 st->mobile_peer_expiry= dict_read_number(
1719 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1720
1721 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1722 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1723 if (st->transport_peers_max<1 ||
1724 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1725 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1726 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1727 }
1728
e7f8ec2a 1729 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
c27ca22f
IJ		 1730 st->key_renegotiate_time=st->key_lifetime/2;
1731 else
e7f8ec2a 1732 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
9d3a4132 1733 st->key_renegotiate_time=dict_read_number(
cce0051f 1734 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
9d3a4132
SE		 1735 if (st->key_renegotiate_time > st->key_lifetime) {
1736 cfgfatal(loc,"site",
1737 "renegotiate-time must be less than key-lifetime\n");
1738 }
9d3a4132
SE		 1739
1740 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1741 log_event_table,"site");
2fe58dfd 1742
4efd681a
SE		 1743 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1744 "site_apply");
1745 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1746
2fe58dfd 1747 /* The information we expect to see in incoming messages of type 1 */
59230b9b
IJ		 1748 /* fixme: lots of unchecked overflows here, but the results are only
1749 corrupted packets rather than undefined behaviour */
2fe58dfd
SE		 1750 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1751
1752 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1753
05f39b4d
IJ		 1754 buffer_new(&st->scratch,0);
1755 BUF_ALLOC(&st->scratch,"site:scratch");
1756
2fe58dfd
SE		 1757 /* We are interested in poll(), but only for timeouts. We don't have
1758 any fds of our own. */
1759 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1760 st->timeout=0;
1761
09a385fb 1762 st->remote_capabilities=0;
5b5f297f 1763 st->chosen_transform=0;
19e9a588 1764 st->current.key_timeout=0;
02b0959b 1765 st->auxiliary_key.key_timeout=0;
446353cd
IJ		 1766 transport_peers_clear(st,&st->peers);
1767 transport_peers_clear(st,&st->setup_peers);
2fe58dfd
SE		 1768 /* XXX mlock these */
1769 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
5b5f297f
IJ		 1770 st->sharedsecretlen=st->sharedsecretallocd=0;
1771 st->sharedsecret=0;
1772
1773 /* We need to compute some properties of our comms and transports */
1774#define COMPUTE_WORST(things,pad) \
1775 int things##_worst_##pad=0; \
1776 for (i=0; i<st->n##things; i++) { \
1777 int thispad=st->things[i]->pad; \
1778 if (thispad > things##_worst_##pad) \
1779 things##_worst_##pad=thispad; \
1780 }
1781 COMPUTE_WORST(comms,min_start_pad)
1782 COMPUTE_WORST(transforms,max_start_pad)
1783
1784 for (i=0; i<st->ntransforms; i++) {
1785 struct transform_if *ti=st->transforms[i];
1786 uint32_t capbit = 1UL << ti->capab_transformnum;
1787 if (st->local_capabilities & capbit)
1788 slog(st,LOG_ERROR,"transformnum capability bit"
1789 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
1790 st->local_capabilities |= capbit;
59533c16 1791 }
59533c16 1792
2fe58dfd 1793 /* We need to register the remote networks with the netlink device */
469fd1d9 1794 st->netlink->reg(st->netlink->st, site_outgoing, st,
5b5f297f
IJ		 1795 transforms_worst_max_start_pad+(4*4)+
1796 comms_worst_min_start_pad);
ff05a229 1797
59533c16
IJ		 1798 for (i=0; i<st->ncomms; i++)
1799 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2fe58dfd 1800
fcad4b0b
IJ		 1801 st->current.transform=0;
1802 st->auxiliary_key.transform=0;
1803 st->new_transform=0;
bd98cd6b 1804 st->auxiliary_is_new=0;
2fe58dfd
SE		 1805
1806 enter_state_stop(st);
1807
794f2398
SE		 1808 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
1809
2fe58dfd
SE		 1810 return new_closure(&st->cl);
1811}
1812
2fe58dfd
SE		 1813void site_module(dict_t *dict)
1814{
1815 add_closure(dict,"site",site_apply);
1816}
446353cd
IJ		 1817
1818
1819/***** TRANSPORT PEERS definitions *****/
1820
1821static void transport_peers_debug(struct site *st, transport_peers *dst,
1822 const char *didwhat,
1823 int nargs, const struct comm_addr *args,
1824 size_t stride) {
1825 int i;
1826 char *argp;
1827
1828 if (!(st->log_events & LOG_PEER_ADDRS))
1829 return; /* an optimisation */
1830
1831 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
1832 (dst==&st->peers ? "data" :
1833 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
1834 didwhat, nargs, dst->npeers);
1835
1836 for (i=0, argp=(void*)args;
1837 i<nargs;
1838 i++, (argp+=stride?stride:sizeof(*args))) {
1839 const struct comm_addr *ca=(void*)argp;
1840 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1841 i, ca->comm->addr_to_string(ca->comm->st,ca));
1842 }
1843 for (i=0; i<dst->npeers; i++) {
1844 struct timeval diff;
1845 timersub(tv_now,&dst->peers[i].last,&diff);
1846 const struct comm_addr *ca=&dst->peers[i].addr;
1847 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1848 i, ca->comm->addr_to_string(ca->comm->st,ca),
1849 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
1850 }
1851}
1852
1853static int transport_peer_compar(const void *av, const void *bv) {
1854 const transport_peer *a=av;
1855 const transport_peer *b=bv;
1856 /* put most recent first in the array */
1857 if (timercmp(&a->last, &b->last, <)) return +1;
1858 if (timercmp(&a->last, &b->last, >)) return -11;
1859 return 0;
1860}
1861
1862static void transport_peers_expire(struct site *st, transport_peers *peers) {
1863 /* peers must be sorted first */
1864 int previous_peers=peers->npeers;
1865 struct timeval oldest;
1866 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
1867 oldest.tv_usec = tv_now->tv_usec;
1868 while (peers->npeers>1 &&
1869 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
1870 peers->npeers--;
1871 if (peers->npeers != previous_peers)
1872 transport_peers_debug(st,peers,"expire", 0,0,0);
1873}
1874
1875static void transport_record_peer(struct site *st, transport_peers *peers,
1876 const struct comm_addr *addr, const char *m) {
1877 int slot, changed=0;
1878
1879 for (slot=0; slot<peers->npeers; slot++)
1880 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
1881 goto found;
1882
1883 changed=1;
1884 if (peers->npeers==st->transport_peers_max)
1885 slot=st->transport_peers_max;
1886 else
1887 slot=peers->npeers++;
1888
1889 found:
1890 peers->peers[slot].addr=*addr;
1891 peers->peers[slot].last=*tv_now;
1892
1893 if (peers->npeers>1)
1894 qsort(peers->peers, peers->npeers,
1895 sizeof(*peers->peers), transport_peer_compar);
1896
1897 if (changed || peers->npeers!=1)
1898 transport_peers_debug(st,peers,m, 1,addr,0);
1899 transport_peers_expire(st, peers);
1900}
1901
1902static bool_t transport_compute_setupinit_peers(struct site *st,
1903 const struct comm_addr *configured_addr /* 0 if none or not found */) {
1904
1905 if (!configured_addr && !transport_peers_valid(&st->peers))
1906 return False;
1907
1908 slog(st,LOG_SETUP_INIT,
1909 (!configured_addr ? "using only %d old peer address(es)"
1910 : "using configured address, and/or perhaps %d old peer address(es)"),
779837e1 1911 st->peers.npeers);
446353cd
IJ		 1912
1913 /* Non-mobile peers havve st->peers.npeers==0 or ==1, since they
1914 * have transport_peers_max==1. The effect is that this code
1915 * always uses the configured address if supplied, or otherwise
1916 * the existing data peer if one exists; this is as desired. */
1917
1918 transport_peers_copy(st,&st->setup_peers,&st->peers);
1919
1920 if (configured_addr)
1921 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
1922
1923 assert(transport_peers_valid(&st->setup_peers));
1924 return True;
1925}
1926
1927static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
1928 if (st->peer_mobile)
1929 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
1930}
1931static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
1932 if (st->peer_mobile)
1933 transport_record_peer(st,&st->peers,a,"datamsg");
1934}
1935
1936static int transport_peers_valid(transport_peers *peers) {
1937 return peers->npeers;
1938}
1939static void transport_peers_clear(struct site *st, transport_peers *peers) {
1940 peers->npeers= 0;
1941 transport_peers_debug(st,peers,"clear",0,0,0);
1942}
1943static void transport_peers_copy(struct site *st, transport_peers *dst,
1944 const transport_peers *src) {
1945 dst->npeers=src->npeers;
1946 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
1947 transport_peers_debug(st,dst,"copy",
a620a048 1948 src->npeers, &src->peers->addr, sizeof(*src->peers));
446353cd
IJ		 1949}
1950
1951void transport_xmit(struct site *st, transport_peers *peers,
1952 struct buffer_if *buf, bool_t candebug) {
1953 int slot;
1954 transport_peers_expire(st, peers);
1955 for (slot=0; slot<peers->npeers; slot++) {
1956 transport_peer *peer=&peers->peers[slot];
1957 if (candebug)
1958 dump_packet(st, buf, &peer->addr, False);
1959 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
1960 }
1961}
1962
1963/***** END of transport peers declarations *****/
Secnet virtual private network: clone of http://www.chiark.greenend.org.uk/ucgi/~ian/git/secnet.git/