1 /* site.c - manage communication with a remote network site */
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). */
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. */
21 #include <sys/socket.h>
25 #include "unaligned.h"
28 #define SETUP_BUFFER_LEN 2048
30 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
31 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
32 #define DEFAULT_SETUP_RETRIES 5
33 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
34 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
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] */
42 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
43 #define DEFAULT_MOBILE_PEERS_MAX 3 /* send at most this many copies (default) */
45 /* Each site can be in one of several possible 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
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
67 -> SITE_SENTMSG4 upon valid incoming message 3
68 -> SITE_WAIT on timeout
70 -> SITE_SENTMSG5 upon valid incoming message 4
71 -> SITE_WAIT on timeout
73 -> SITE_RUN upon valid incoming message 5
74 -> SITE_WAIT on timeout
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
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
92 static cstring_t state_name(uint32_t state)
95 case 0: return "STOP";
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";
104 default: return "*bad state*";
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
115 #define LOG_SEC 0x00000020
116 #define LOG_STATE 0x00000040
117 #define LOG_DROP 0x00000080
118 #define LOG_DUMP 0x00000100
119 #define LOG_ERROR 0x00000400
120 #define LOG_PEER_ADDRS 0x00000800
122 static 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 },
133 { "peer-addrs", LOG_PEER_ADDRS },
134 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
135 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
136 { "all", 0xffffffff },
141 /***** TRANSPORT PEERS declarations *****/
143 /* Details of "mobile peer" semantics:
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.)
150 - Outgoing packets are sent to every recorded peer in the
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.
158 (For "non-mobile" peers we simply copy the peer used for
159 successful key setup, and don't change the peer otherwise.)
161 - Key setup peers are slightly more complicated.
163 Whenever we receive and successfully process a key exchange
164 packet, we record the peer.
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).
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.)
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.
185 #define MAX_MOBILE_PEERS_MAX 5 /* send at most this many copies, compiled max */
189 struct comm_addr addr;
193 /* configuration information */
194 /* runtime information */
196 transport_peer peers[MAX_MOBILE_PEERS_MAX];
199 static void transport_peers_clear(struct site *st, transport_peers *peers);
200 static int transport_peers_valid(transport_peers *peers);
201 static void transport_peers_copy(struct site *st, transport_peers *dst,
202 const transport_peers *src);
204 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
205 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
206 static bool_t transport_compute_setupinit_peers(struct site *st,
207 const struct comm_addr *configured_addr /* 0 if none or not found */);
208 static void transport_record_peer(struct site *st, transport_peers *peers,
209 const struct comm_addr *addr, const char *m);
211 static void transport_xmit(struct site *st, transport_peers *peers,
212 struct buffer_if *buf, bool_t candebug);
214 /***** END of transport peers declarations *****/
218 struct transform_inst_if *transform;
219 uint64_t key_timeout; /* End of life of current key */
220 uint32_t remote_session_id;
226 /* configuration information */
229 bool_t peer_mobile; /* Mobile client support */
230 int32_t transport_peers_max;
231 string_t tunname; /* localname<->remotename by default, used in logs */
232 string_t address; /* DNS name for bootstrapping, optional */
233 int remoteport; /* Port for bootstrapping, optional */
234 struct netlink_if *netlink;
235 struct comm_if **comms;
237 struct resolver_if *resolver;
239 struct random_if *random;
240 struct rsaprivkey_if *privkey;
241 struct rsapubkey_if *pubkey;
242 struct transform_if *transform;
244 struct hash_if *hash;
246 uint32_t index; /* Index of this site */
247 uint32_t local_capabilities;
248 int32_t setup_retries; /* How many times to send setup packets */
249 int32_t setup_retry_interval; /* Initial timeout for setup packets */
250 int32_t wait_timeout; /* How long to wait if setup unsuccessful */
251 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
252 int32_t key_lifetime; /* How long a key lasts once set up */
253 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
254 after this time, initiate a new
257 bool_t setup_priority; /* Do we have precedence if both sites emit
258 message 1 simultaneously? */
261 /* runtime information */
263 uint64_t now; /* Most recently seen time */
265 /* The currently established session */
266 struct data_key current;
267 struct data_key auxiliary_key;
268 bool_t auxiliary_is_new;
269 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
270 uint64_t auxiliary_renegotiate_key_time;
271 transport_peers peers; /* Current address(es) of peer for data traffic */
273 /* The current key setup protocol exchange. We can only be
274 involved in one of these at a time. There's a potential for
275 denial of service here (the attacker keeps sending a setup
276 packet; we keep trying to continue the exchange, and have to
277 timeout before we can listen for another setup packet); perhaps
278 we should keep a list of 'bad' sources for setup packets. */
279 uint32_t remote_capabilities;
280 uint32_t setup_session_id;
281 transport_peers setup_peers;
282 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
283 uint8_t remoteN[NONCELEN];
284 struct buffer_if buffer; /* Current outgoing key exchange packet */
285 struct buffer_if scratch;
286 int32_t retries; /* Number of retries remaining */
287 uint64_t timeout; /* Timeout for current state */
289 uint8_t *sharedsecret;
290 uint32_t sharedsecretlen;
291 struct transform_inst_if *new_transform; /* For key setup/verify */
294 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
302 if (event&st->log_events) {
304 case LOG_UNEXPECTED: class=M_INFO; break;
305 case LOG_SETUP_INIT: class=M_INFO; break;
306 case LOG_SETUP_TIMEOUT: class=M_NOTICE; break;
307 case LOG_ACTIVATE_KEY: class=M_INFO; break;
308 case LOG_TIMEOUT_KEY: class=M_INFO; break;
309 case LOG_SEC: class=M_SECURITY; break;
310 case LOG_STATE: class=M_DEBUG; break;
311 case LOG_DROP: class=M_DEBUG; break;
312 case LOG_DUMP: class=M_DEBUG; break;
313 case LOG_ERROR: class=M_ERR; break;
314 case LOG_PEER_ADDRS: class=M_DEBUG; break;
315 default: class=M_ERR; break;
318 vsnprintf(buf,sizeof(buf),msg,ap);
319 st->log->log(st->log->st,class,"%s: %s",st->tunname,buf);
324 static void set_link_quality(struct site *st);
325 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
326 static void delete_one_key(struct site *st, struct data_key *key,
327 const char *reason /* may be 0 meaning don't log*/,
328 const char *which /* ignored if !reasonn */,
329 uint32_t loglevel /* ignored if !reasonn */);
330 static bool_t initiate_key_setup(struct site *st, cstring_t reason);
331 static void enter_state_run(struct site *st);
332 static bool_t enter_state_resolve(struct site *st);
333 static bool_t enter_new_state(struct site *st,uint32_t next);
334 static void enter_state_wait(struct site *st);
335 static void activate_new_key(struct site *st);
337 static bool_t is_transform_valid(struct transform_inst_if *transform)
339 return transform && transform->valid(transform->st);
342 static bool_t current_valid(struct site *st)
344 return is_transform_valid(st->current.transform);
347 #define DEFINE_CALL_TRANSFORM(fwdrev) \
348 static int call_transform_##fwdrev(struct site *st, \
349 struct transform_inst_if *transform, \
350 struct buffer_if *buf, \
351 const char **errmsg) \
353 if (!is_transform_valid(transform)) { \
354 *errmsg="transform not set up"; \
357 return transform->fwdrev(transform->st,buf,errmsg); \
360 DEFINE_CALL_TRANSFORM(forwards)
361 DEFINE_CALL_TRANSFORM(reverse)
363 static void dispose_transform(struct transform_inst_if **transform_var)
365 struct transform_inst_if *transform=*transform_var;
367 transform->delkey(transform->st);
368 transform->destroy(transform->st);
373 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
374 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
375 #define CHECK_TYPE(b,t) do { uint32_t type; \
376 CHECK_AVAIL((b),4); \
377 type=buf_unprepend_uint32((b)); \
378 if (type!=(t)) return False; } while(0)
383 struct buffer_if extrainfo;
390 struct parsedname remote;
391 struct parsedname local;
392 uint32_t remote_capabilities;
402 static void set_new_transform(struct site *st)
404 struct transform_if *generator=st->transform;
405 struct transform_inst_if *generated=generator->create(generator->st);
406 generated->setkey(generated->st,st->sharedsecret,
407 st->sharedsecretlen,st->setup_priority);
408 dispose_transform(&st->new_transform);
409 st->new_transform=generated;
413 int32_t lenpos, afternul;
415 static void append_string_xinfo_start(struct buffer_if *buf,
416 struct xinfoadd *xia,
418 /* Helps construct one of the names with additional info as found
419 * in MSG1..4. Call this function first, then append all the
420 * desired extra info (not including the nul byte) to the buffer,
421 * then call append_string_xinfo_done. */
423 xia->lenpos = buf->size;
424 buf_append_string(buf,str);
425 buf_append_uint8(buf,0);
426 xia->afternul = buf->size;
428 static void append_string_xinfo_done(struct buffer_if *buf,
429 struct xinfoadd *xia)
431 /* we just need to adjust the string length */
432 if (buf->size == xia->afternul) {
433 /* no extra info, strip the nul too */
434 buf_unappend_uint8(buf);
436 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
440 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
441 out using a transform of config data supplied by netlink */
442 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
448 st->retries=st->setup_retries;
449 BUF_ALLOC(&st->buffer,what);
450 buffer_init(&st->buffer,0);
451 buf_append_uint32(&st->buffer,
452 (type==LABEL_MSG1?0:st->setup_session_id));
453 buf_append_uint32(&st->buffer,st->index);
454 buf_append_uint32(&st->buffer,type);
457 append_string_xinfo_start(&st->buffer,&xia,st->localname);
458 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
459 buf_append_uint32(&st->buffer,st->local_capabilities);
461 append_string_xinfo_done(&st->buffer,&xia);
463 buf_append_string(&st->buffer,st->remotename);
464 memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
465 if (type==LABEL_MSG1) return True;
466 memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN);
467 if (type==LABEL_MSG2) return True;
469 if (hacky_par_mid_failnow()) return False;
471 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
472 buf_append_string(&st->buffer,dhpub);
474 hash=safe_malloc(st->hash->len, "generate_msg");
475 hst=st->hash->init();
476 st->hash->update(hst,st->buffer.start,st->buffer.size);
477 st->hash->final(hst,hash);
478 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
479 buf_append_string(&st->buffer,sig);
485 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
488 nm->len=buf_unprepend_uint16(msg);
489 CHECK_AVAIL(msg,nm->len);
490 nm->name=buf_unprepend(msg,nm->len);
491 uint8_t *nul=memchr(nm->name,0,nm->len);
493 buffer_readonly_view(&nm->extrainfo,0,0);
495 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
496 nm->len=nul-nm->name;
501 static bool_t unpick_msg(struct site *st, uint32_t type,
502 struct buffer_if *msg, struct msg *m)
504 m->hashstart=msg->start;
506 m->dest=buf_unprepend_uint32(msg);
508 m->source=buf_unprepend_uint32(msg);
509 CHECK_TYPE(msg,type);
510 if (!unpick_name(msg,&m->remote)) return False;
511 m->remote_capabilities=0;
512 if (m->remote.extrainfo.size) {
513 CHECK_AVAIL(&m->remote.extrainfo,4);
514 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
516 if (!unpick_name(msg,&m->local)) return False;
517 CHECK_AVAIL(msg,NONCELEN);
518 m->nR=buf_unprepend(msg,NONCELEN);
519 if (type==LABEL_MSG1) {
523 CHECK_AVAIL(msg,NONCELEN);
524 m->nL=buf_unprepend(msg,NONCELEN);
525 if (type==LABEL_MSG2) {
530 m->pklen=buf_unprepend_uint16(msg);
531 CHECK_AVAIL(msg,m->pklen);
532 m->pk=buf_unprepend(msg,m->pklen);
533 m->hashlen=msg->start-m->hashstart;
535 m->siglen=buf_unprepend_uint16(msg);
536 CHECK_AVAIL(msg,m->siglen);
537 m->sig=buf_unprepend(msg,m->siglen);
542 static bool_t name_matches(const struct parsedname *nm, const char *expected)
544 int expected_len=strlen(expected);
546 nm->len == expected_len &&
547 !memcmp(nm->name, expected, expected_len);
550 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
553 if (type==LABEL_MSG1) return True;
555 /* Check that the site names and our nonce have been sent
556 back correctly, and then store our peer's nonce. */
557 if (!name_matches(&m->remote,st->remotename)) {
558 *error="wrong remote site name";
561 if (!name_matches(&m->local,st->localname)) {
562 *error="wrong local site name";
565 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
566 *error="wrong locally-generated nonce";
569 if (type==LABEL_MSG2) return True;
570 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
571 *error="wrong remotely-generated nonce";
574 /* MSG3 has complicated rules about capabilities, which are
575 * handled in process_msg3. */
576 if (type==LABEL_MSG3) return True;
577 if (m->remote_capabilities!=st->remote_capabilities) {
578 *error="remote capabilities changed";
581 if (type==LABEL_MSG4) return True;
582 *error="unknown message type";
586 static bool_t generate_msg1(struct site *st)
588 st->random->generate(st->random->st,NONCELEN,st->localN);
589 return generate_msg(st,LABEL_MSG1,"site:MSG1");
592 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
593 const struct comm_addr *src, struct msg *m)
595 /* We've already determined we're in an appropriate state to
596 process an incoming MSG1, and that the MSG1 has correct values
599 transport_record_peer(st,&st->setup_peers,src,"msg1");
600 st->setup_session_id=m->source;
601 st->remote_capabilities=m->remote_capabilities;
602 memcpy(st->remoteN,m->nR,NONCELEN);
606 static bool_t generate_msg2(struct site *st)
608 st->random->generate(st->random->st,NONCELEN,st->localN);
609 return generate_msg(st,LABEL_MSG2,"site:MSG2");
612 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
613 const struct comm_addr *src)
618 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
619 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
620 slog(st,LOG_SEC,"msg2: %s",err);
623 st->setup_session_id=m.source;
624 st->remote_capabilities=m.remote_capabilities;
625 memcpy(st->remoteN,m.nR,NONCELEN);
629 static bool_t generate_msg3(struct site *st)
631 /* Now we have our nonce and their nonce. Think of a secret key,
632 and create message number 3. */
633 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
634 return generate_msg(st,LABEL_MSG3,"site:MSG3");
637 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
638 const struct comm_addr *src)
645 if (!unpick_msg(st,LABEL_MSG3,msg3,&m)) return False;
646 if (!check_msg(st,LABEL_MSG3,&m,&err)) {
647 slog(st,LOG_SEC,"msg3: %s",err);
650 uint32_t capab_adv_late = m.remote_capabilities
651 & ~st->remote_capabilities & CAPAB_EARLY;
652 if (capab_adv_late) {
653 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
654 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
655 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
658 st->remote_capabilities|=m.remote_capabilities;
660 /* Check signature and store g^x mod m */
661 hash=safe_malloc(st->hash->len, "process_msg3");
662 hst=st->hash->init();
663 st->hash->update(hst,m.hashstart,m.hashlen);
664 st->hash->final(hst,hash);
665 /* Terminate signature with a '0' - cheating, but should be ok */
667 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
668 slog(st,LOG_SEC,"msg3 signature failed check!");
674 /* Terminate their DH public key with a '0' */
676 /* Invent our DH secret key */
677 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
679 /* Generate the shared key */
680 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk,
681 st->sharedsecret,st->sharedsecretlen);
683 /* Set up the transform */
684 set_new_transform(st);
689 static bool_t generate_msg4(struct site *st)
691 /* We have both nonces, their public key and our private key. Generate
692 our public key, sign it and send it to them. */
693 return generate_msg(st,LABEL_MSG4,"site:MSG4");
696 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
697 const struct comm_addr *src)
704 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
705 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
706 slog(st,LOG_SEC,"msg4: %s",err);
710 /* Check signature and store g^x mod m */
711 hash=safe_malloc(st->hash->len, "process_msg4");
712 hst=st->hash->init();
713 st->hash->update(hst,m.hashstart,m.hashlen);
714 st->hash->final(hst,hash);
715 /* Terminate signature with a '0' - cheating, but should be ok */
717 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
718 slog(st,LOG_SEC,"msg4 signature failed check!");
724 /* Terminate their DH public key with a '0' */
726 /* Generate the shared key */
727 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk,
728 st->sharedsecret,st->sharedsecretlen);
729 /* Set up the transform */
730 set_new_transform(st);
741 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
745 m->dest=buf_unprepend_uint32(msg0);
747 m->source=buf_unprepend_uint32(msg0);
749 m->type=buf_unprepend_uint32(msg0);
751 /* Leaves transformed part of buffer untouched */
754 static bool_t generate_msg5(struct site *st)
756 cstring_t transform_err;
758 BUF_ALLOC(&st->buffer,"site:MSG5");
759 /* We are going to add four words to the message */
760 buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
761 /* Give the netlink code an opportunity to put its own stuff in the
762 message (configuration information, etc.) */
763 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
764 if (call_transform_forwards(st,st->new_transform,
765 &st->buffer,&transform_err))
767 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
768 buf_prepend_uint32(&st->buffer,st->index);
769 buf_prepend_uint32(&st->buffer,st->setup_session_id);
771 st->retries=st->setup_retries;
775 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
776 const struct comm_addr *src,
777 struct transform_inst_if *transform)
780 cstring_t transform_err;
782 if (!unpick_msg0(st,msg5,&m)) return False;
784 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
785 /* There's a problem */
786 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
789 /* Buffer should now contain untransformed PING packet data */
791 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
792 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
795 /* Older versions of secnet used to write some config data here
796 * which we ignore. So we don't CHECK_EMPTY */
800 static void create_msg6(struct site *st, struct transform_inst_if *transform,
803 cstring_t transform_err;
805 BUF_ALLOC(&st->buffer,"site:MSG6");
806 /* We are going to add four words to the message */
807 buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
808 /* Give the netlink code an opportunity to put its own stuff in the
809 message (configuration information, etc.) */
810 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
811 int problem = call_transform_forwards(st,transform,
812 &st->buffer,&transform_err);
814 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
815 buf_prepend_uint32(&st->buffer,st->index);
816 buf_prepend_uint32(&st->buffer,session_id);
819 static bool_t generate_msg6(struct site *st)
821 if (!is_transform_valid(st->new_transform))
823 create_msg6(st,st->new_transform,st->setup_session_id);
824 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
828 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
829 const struct comm_addr *src)
832 cstring_t transform_err;
834 if (!unpick_msg0(st,msg6,&m)) return False;
836 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
837 /* There's a problem */
838 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
841 /* Buffer should now contain untransformed PING packet data */
843 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
844 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
847 /* Older versions of secnet used to write some config data here
848 * which we ignore. So we don't CHECK_EMPTY */
852 static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
853 const struct comm_addr *src)
855 cstring_t transform_err, auxkey_err, newkey_err="n/a";
859 if (!unpick_msg0(st,msg0,&m)) return False;
861 /* Keep a copy so we can try decrypting it with multiple keys */
862 buffer_copy(&st->scratch, msg0);
864 problem = call_transform_reverse(st,st->current.transform,
865 msg0,&transform_err);
867 if (!st->auxiliary_is_new)
868 delete_one_key(st,&st->auxiliary_key,
869 "peer has used new key","auxiliary key",LOG_SEC);
875 buffer_copy(msg0, &st->scratch);
876 problem = call_transform_reverse(st,st->auxiliary_key.transform,
879 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
880 if (st->auxiliary_is_new) {
881 /* We previously timed out in state SENTMSG5 but it turns
882 * out that our peer did in fact get our MSG5 and is
883 * using the new key. So we should switch to it too. */
884 /* This is a bit like activate_new_key. */
887 st->current=st->auxiliary_key;
890 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
891 "previous key",LOG_SEC);
892 st->auxiliary_is_new=0;
893 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
900 if (st->state==SITE_SENTMSG5) {
901 buffer_copy(msg0, &st->scratch);
902 problem = call_transform_reverse(st,st->new_transform,
905 /* It looks like we didn't get the peer's MSG6 */
906 /* This is like a cut-down enter_new_state(SITE_RUN) */
907 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
908 BUF_FREE(&st->buffer);
910 activate_new_key(st);
911 return True; /* do process the data in this packet */
917 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
918 transform_err,auxkey_err,newkey_err);
919 initiate_key_setup(st,"incoming message would not decrypt");
920 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
924 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
928 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
929 const struct comm_addr *src)
933 if (!decrypt_msg0(st,msg0,src))
937 type=buf_unprepend_uint32(msg0);
940 /* We must forget about the current session. */
941 delete_keys(st,"request from peer",LOG_SEC);
944 /* Deliver to netlink layer */
945 st->netlink->deliver(st->netlink->st,msg0);
946 transport_data_msgok(st,src);
947 /* See whether we should start negotiating a new key */
948 if (st->now > st->renegotiate_key_time)
949 initiate_key_setup(st,"incoming packet in renegotiation window");
952 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
959 static void dump_packet(struct site *st, struct buffer_if *buf,
960 const struct comm_addr *addr, bool_t incoming)
962 uint32_t dest=get_uint32(buf->start);
963 uint32_t source=get_uint32(buf->start+4);
964 uint32_t msgtype=get_uint32(buf->start+8);
966 if (st->log_events & LOG_DUMP)
967 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
968 st->tunname,incoming?"incoming":"outgoing",
969 dest,source,msgtype);
972 static uint32_t site_status(void *st)
977 static bool_t send_msg(struct site *st)
980 transport_xmit(st, &st->setup_peers, &st->buffer, True);
981 st->timeout=st->now+st->setup_retry_interval;
984 } else if (st->state==SITE_SENTMSG5) {
985 slog(st,LOG_SETUP_TIMEOUT,"timed out sending MSG5, stashing new key");
986 /* We stash the key we have produced, in case it turns out that
987 * our peer did see our MSG5 after all and starts using it. */
988 /* This is a bit like some of activate_new_key */
989 struct transform_inst_if *t;
990 t=st->auxiliary_key.transform;
991 st->auxiliary_key.transform=st->new_transform;
993 dispose_transform(&st->new_transform);
995 st->auxiliary_is_new=1;
996 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
997 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
998 st->auxiliary_key.remote_session_id=st->setup_session_id;
1000 enter_state_wait(st);
1003 slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
1004 "(in state %s)",state_name(st->state));
1005 enter_state_wait(st);
1010 static void site_resolve_callback(void *sst, struct in_addr *address)
1012 struct site *st=sst;
1013 struct comm_addr ca_buf, *ca_use;
1015 if (st->state!=SITE_RESOLVE) {
1016 slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
1021 ca_buf.comm=st->comms[0];
1022 ca_buf.sin.sin_family=AF_INET;
1023 ca_buf.sin.sin_port=htons(st->remoteport);
1024 ca_buf.sin.sin_addr=*address;
1027 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
1030 if (transport_compute_setupinit_peers(st,ca_use)) {
1031 enter_new_state(st,SITE_SENTMSG1);
1033 /* Can't figure out who to try to to talk to */
1034 slog(st,LOG_SETUP_INIT,"key exchange failed: cannot find peer address");
1035 enter_state_run(st);
1039 static bool_t initiate_key_setup(struct site *st, cstring_t reason)
1041 if (st->state!=SITE_RUN) return False;
1042 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1044 slog(st,LOG_SETUP_INIT,"resolving peer address");
1045 return enter_state_resolve(st);
1046 } else if (transport_compute_setupinit_peers(st,0)) {
1047 return enter_new_state(st,SITE_SENTMSG1);
1049 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1053 static void activate_new_key(struct site *st)
1055 struct transform_inst_if *t;
1057 /* We have three transform instances, which we swap between old,
1059 t=st->auxiliary_key.transform;
1060 st->auxiliary_key.transform=st->current.transform;
1061 st->current.transform=st->new_transform;
1062 st->new_transform=t;
1063 dispose_transform(&st->new_transform);
1066 st->auxiliary_is_new=0;
1067 st->auxiliary_key.key_timeout=st->current.key_timeout;
1068 st->current.key_timeout=st->now+st->key_lifetime;
1069 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1070 transport_peers_copy(st,&st->peers,&st->setup_peers);
1071 st->current.remote_session_id=st->setup_session_id;
1073 slog(st,LOG_ACTIVATE_KEY,"new key activated");
1074 enter_state_run(st);
1077 static void delete_one_key(struct site *st, struct data_key *key,
1078 cstring_t reason, cstring_t which, uint32_t loglevel)
1080 if (!is_transform_valid(key->transform)) return;
1081 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1082 dispose_transform(&key->transform);
1086 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1088 if (current_valid(st)) {
1089 slog(st,loglevel,"session closed (%s)",reason);
1091 delete_one_key(st,&st->current,0,0,0);
1092 set_link_quality(st);
1094 delete_one_key(st,&st->auxiliary_key,0,0,0);
1097 static void state_assert(struct site *st, bool_t ok)
1099 if (!ok) fatal("site:state_assert");
1102 static void enter_state_stop(struct site *st)
1104 st->state=SITE_STOP;
1106 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1107 dispose_transform(&st->new_transform);
1110 static void set_link_quality(struct site *st)
1113 if (current_valid(st))
1114 quality=LINK_QUALITY_UP;
1115 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1116 quality=LINK_QUALITY_DOWN;
1117 else if (st->address)
1118 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1119 else if (transport_peers_valid(&st->peers))
1120 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1122 quality=LINK_QUALITY_DOWN;
1124 st->netlink->set_quality(st->netlink->st,quality);
1127 static void enter_state_run(struct site *st)
1129 slog(st,LOG_STATE,"entering state RUN");
1133 st->setup_session_id=0;
1134 transport_peers_clear(st,&st->setup_peers);
1135 memset(st->localN,0,NONCELEN);
1136 memset(st->remoteN,0,NONCELEN);
1137 dispose_transform(&st->new_transform);
1138 memset(st->dhsecret,0,st->dh->len);
1139 memset(st->sharedsecret,0,st->sharedsecretlen);
1140 set_link_quality(st);
1143 static bool_t enter_state_resolve(struct site *st)
1145 state_assert(st,st->state==SITE_RUN);
1146 slog(st,LOG_STATE,"entering state RESOLVE");
1147 st->state=SITE_RESOLVE;
1148 st->resolver->request(st->resolver->st,st->address,
1149 site_resolve_callback,st);
1153 static bool_t enter_new_state(struct site *st, uint32_t next)
1155 bool_t (*gen)(struct site *st);
1158 slog(st,LOG_STATE,"entering state %s",state_name(next));
1161 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1165 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1166 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1170 state_assert(st,st->state==SITE_SENTMSG1);
1171 BUF_FREE(&st->buffer);
1175 state_assert(st,st->state==SITE_SENTMSG2);
1176 BUF_FREE(&st->buffer);
1180 state_assert(st,st->state==SITE_SENTMSG3);
1181 BUF_FREE(&st->buffer);
1185 state_assert(st,st->state==SITE_SENTMSG4);
1186 BUF_FREE(&st->buffer);
1191 fatal("enter_new_state(%s): invalid new state",state_name(next));
1195 if (hacky_par_start_failnow()) return False;
1197 r= gen(st) && send_msg(st);
1200 st->setup_retries, st->setup_retry_interval,
1205 if (next==SITE_RUN) {
1206 BUF_FREE(&st->buffer); /* Never reused */
1207 st->timeout=0; /* Never retransmit */
1208 activate_new_key(st);
1212 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1213 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1214 in either state, and enter_state_wait() will
1216 enter_state_wait(st);
1220 /* msg7 tells our peer that we're about to forget our key */
1221 static bool_t send_msg7(struct site *st, cstring_t reason)
1223 cstring_t transform_err;
1225 if (current_valid(st) && st->buffer.free
1226 && transport_peers_valid(&st->peers)) {
1227 BUF_ALLOC(&st->buffer,"site:MSG7");
1228 buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
1229 buf_append_uint32(&st->buffer,LABEL_MSG7);
1230 buf_append_string(&st->buffer,reason);
1231 if (call_transform_forwards(st, st->current.transform,
1232 &st->buffer, &transform_err))
1234 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1235 buf_prepend_uint32(&st->buffer,st->index);
1236 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1237 transport_xmit(st,&st->peers,&st->buffer,True);
1238 BUF_FREE(&st->buffer);
1245 /* We go into this state if our peer becomes uncommunicative. Similar to
1246 the "stop" state, we forget all session keys for a while, before
1247 re-entering the "run" state. */
1248 static void enter_state_wait(struct site *st)
1250 slog(st,LOG_STATE,"entering state WAIT");
1251 st->timeout=st->now+st->wait_timeout;
1252 st->state=SITE_WAIT;
1253 set_link_quality(st);
1254 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1255 /* XXX Erase keys etc. */
1258 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1261 int64_t offset=timeout-*now;
1262 if (offset<0) offset=0;
1263 if (offset>INT_MAX) offset=INT_MAX;
1264 if (*timeout_io<0 || offset<*timeout_io)
1269 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1272 struct site *st=sst;
1274 *nfds_io=0; /* We don't use any file descriptors */
1277 /* Work out when our next timeout is. The earlier of 'timeout' or
1278 'current.key_timeout'. A stored value of '0' indicates no timeout
1280 site_settimeout(st->timeout, timeout_io);
1281 site_settimeout(st->current.key_timeout, timeout_io);
1282 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1284 return 0; /* success */
1287 static void check_expiry(struct site *st, struct data_key *key,
1290 if (key->key_timeout && *now>key->key_timeout) {
1291 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1295 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1296 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1298 struct site *st=sst;
1301 if (st->timeout && *now>st->timeout) {
1303 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1304 if (!hacky_par_start_failnow())
1306 } else if (st->state==SITE_WAIT) {
1307 enter_state_run(st);
1309 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1313 check_expiry(st,&st->current,"current key");
1314 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1317 /* This function is called by the netlink device to deliver packets
1318 intended for the remote network. The packet is in "raw" wire
1319 format, but is guaranteed to be word-aligned. */
1320 static void site_outgoing(void *sst, struct buffer_if *buf)
1322 struct site *st=sst;
1323 cstring_t transform_err;
1325 if (st->state==SITE_STOP) {
1330 /* In all other states we consider delivering the packet if we have
1331 a valid key and a valid address to send it to. */
1332 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1333 /* Transform it and send it */
1335 buf_prepend_uint32(buf,LABEL_MSG9);
1336 if (call_transform_forwards(st, st->current.transform,
1337 buf, &transform_err))
1339 buf_prepend_uint32(buf,LABEL_MSG0);
1340 buf_prepend_uint32(buf,st->index);
1341 buf_prepend_uint32(buf,st->current.remote_session_id);
1342 transport_xmit(st,&st->peers,buf,False);
1349 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1351 initiate_key_setup(st,"outgoing packet");
1354 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1355 uint32_t type, struct msg *m)
1356 /* For packets which are identified by the local and remote names.
1357 * If it has our name and our peer's name in it it's for us. */
1359 struct buffer_if buf[1];
1360 buffer_readonly_clone(buf,buf_in);
1361 return unpick_msg(st,type,buf,m)
1362 && name_matches(&m->remote,st->remotename)
1363 && name_matches(&m->local,st->localname);
1366 /* This function is called by the communication device to deliver
1367 packets from our peers. */
1368 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1369 const struct comm_addr *source)
1371 struct site *st=sst;
1373 if (buf->size < 12) return False;
1375 uint32_t dest=get_uint32(buf->start);
1376 uint32_t msgtype=get_uint32(buf->start+8);
1377 struct msg named_msg;
1379 if (msgtype==LABEL_MSG1) {
1380 if (!named_for_us(st,buf,msgtype,&named_msg))
1382 /* It's a MSG1 addressed to us. Decide what to do about it. */
1383 dump_packet(st,buf,source,True);
1384 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1385 st->state==SITE_WAIT) {
1386 /* We should definitely process it */
1387 if (process_msg1(st,buf,source,&named_msg)) {
1388 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1389 enter_new_state(st,SITE_SENTMSG2);
1391 slog(st,LOG_ERROR,"failed to process incoming msg1");
1395 } else if (st->state==SITE_SENTMSG1) {
1396 /* We've just sent a message 1! They may have crossed on
1397 the wire. If we have priority then we ignore the
1398 incoming one, otherwise we process it as usual. */
1399 if (st->setup_priority) {
1401 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1402 "priority => ignore incoming msg1");
1405 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1406 "priority => use incoming msg1");
1407 if (process_msg1(st,buf,source,&named_msg)) {
1408 BUF_FREE(&st->buffer); /* Free our old message 1 */
1409 enter_new_state(st,SITE_SENTMSG2);
1411 slog(st,LOG_ERROR,"failed to process an incoming "
1412 "crossed msg1 (we have low priority)");
1418 /* The message 1 was received at an unexpected stage of the
1419 key setup. XXX POLICY - what do we do? */
1420 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1424 if (dest==st->index) {
1425 /* Explicitly addressed to us */
1426 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1429 /* If the source is our current peer then initiate a key setup,
1430 because our peer's forgotten the key */
1431 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1432 initiate_key_setup(st,"received a NAK");
1434 slog(st,LOG_SEC,"bad incoming NAK");
1438 process_msg0(st,buf,source);
1441 /* Setup packet: should not have been explicitly addressed
1443 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1446 /* Setup packet: expected only in state SENTMSG1 */
1447 if (st->state!=SITE_SENTMSG1) {
1448 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1449 } else if (process_msg2(st,buf,source)) {
1450 transport_setup_msgok(st,source);
1451 enter_new_state(st,SITE_SENTMSG3);
1453 slog(st,LOG_SEC,"invalid MSG2");
1457 /* Setup packet: expected only in state SENTMSG2 */
1458 if (st->state!=SITE_SENTMSG2) {
1459 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1460 } else if (process_msg3(st,buf,source)) {
1461 transport_setup_msgok(st,source);
1462 enter_new_state(st,SITE_SENTMSG4);
1464 slog(st,LOG_SEC,"invalid MSG3");
1468 /* Setup packet: expected only in state SENTMSG3 */
1469 if (st->state!=SITE_SENTMSG3) {
1470 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1471 } else if (process_msg4(st,buf,source)) {
1472 transport_setup_msgok(st,source);
1473 enter_new_state(st,SITE_SENTMSG5);
1475 slog(st,LOG_SEC,"invalid MSG4");
1479 /* Setup packet: expected only in state SENTMSG4 */
1480 /* (may turn up in state RUN if our return MSG6 was lost
1481 and the new key has already been activated. In that
1482 case we discard it. The peer will realise that we
1483 are using the new key when they see our data packets.
1484 Until then the peer's data packets to us get discarded. */
1485 if (st->state==SITE_SENTMSG4) {
1486 if (process_msg5(st,buf,source,st->new_transform)) {
1487 transport_setup_msgok(st,source);
1488 enter_new_state(st,SITE_RUN);
1490 slog(st,LOG_SEC,"invalid MSG5");
1492 } else if (st->state==SITE_RUN) {
1493 if (process_msg5(st,buf,source,st->current.transform)) {
1494 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1495 transport_setup_msgok(st,source);
1496 create_msg6(st,st->current.transform,
1497 st->current.remote_session_id);
1498 transport_xmit(st,&st->peers,&st->buffer,True);
1499 BUF_FREE(&st->buffer);
1501 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1504 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
1508 /* Setup packet: expected only in state SENTMSG5 */
1509 if (st->state!=SITE_SENTMSG5) {
1510 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1511 } else if (process_msg6(st,buf,source)) {
1512 BUF_FREE(&st->buffer); /* Free message 5 */
1513 transport_setup_msgok(st,source);
1514 activate_new_key(st);
1516 slog(st,LOG_SEC,"invalid MSG6");
1520 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
1531 static void site_control(void *vst, bool_t run)
1533 struct site *st=vst;
1534 if (run) enter_state_run(st);
1535 else enter_state_stop(st);
1538 static void site_phase_hook(void *sst, uint32_t newphase)
1540 struct site *st=sst;
1542 /* The program is shutting down; tell our peer */
1543 send_msg7(st,"shutting down");
1546 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1549 static uint32_t index_sequence;
1555 st=safe_malloc(sizeof(*st),"site_apply");
1557 st->cl.description="site";
1558 st->cl.type=CL_SITE;
1560 st->cl.interface=&st->ops;
1562 st->ops.control=site_control;
1563 st->ops.status=site_status;
1565 /* First parameter must be a dict */
1566 item=list_elem(args,0);
1567 if (!item || item->type!=t_dict)
1568 cfgfatal(loc,"site","parameter must be a dictionary\n");
1570 dict=item->data.dict;
1571 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1572 st->remotename=dict_read_string(dict, "name", True, "site", loc);
1574 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1575 bool_t local_mobile=
1576 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1578 /* Sanity check (which also allows the 'sites' file to include
1579 site() closures for all sites including our own): refuse to
1580 talk to ourselves */
1581 if (strcmp(st->localname,st->remotename)==0) {
1582 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
1584 if (st->peer_mobile != local_mobile)
1585 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1586 " but our local-mobile=%d\n",
1587 st->localname, st->peer_mobile, local_mobile);
1591 if (st->peer_mobile && local_mobile) {
1592 Message(M_WARNING,"site %s: site is mobile but so are we"
1593 " -> ignoring this site\n", st->remotename);
1598 assert(index_sequence < 0xffffffffUL);
1599 st->index = ++index_sequence;
1600 st->local_capabilities = 0;
1601 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
1603 list_t *comms_cfg=dict_lookup(dict,"comm");
1604 if (!comms_cfg) cfgfatal(loc,"site","closure list \"comm\" not found\n");
1605 st->ncomms=list_length(comms_cfg);
1606 st->comms=safe_malloc_ary(sizeof(*st->comms),st->ncomms,"comms");
1608 for (i=0; i<st->ncomms; i++) {
1609 item_t *item=list_elem(comms_cfg,i);
1610 if (item->type!=t_closure)
1611 cfgfatal(loc,"site","comm is not a closure\n");
1612 closure_t *cl=item->data.closure;
1613 if (cl->type!=CL_COMM) cfgfatal(loc,"site","comm closure wrong type\n");
1614 st->comms[i]=cl->interface;
1617 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1618 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1619 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1621 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
1622 st->address=dict_read_string(dict, "address", False, "site", loc);
1624 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1625 else st->remoteport=0;
1626 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1629 find_cl_if(dict,"transform",CL_TRANSFORM,True,"site",loc);
1631 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1632 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1634 #define DEFAULT(D) (st->peer_mobile || local_mobile \
1635 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
1636 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
1638 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1639 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1640 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1641 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1643 st->mobile_peer_expiry= dict_read_number(
1644 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1646 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1647 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1648 if (st->transport_peers_max<1 ||
1649 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1650 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1651 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1654 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
1655 st->key_renegotiate_time=st->key_lifetime/2;
1657 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
1658 st->key_renegotiate_time=dict_read_number(
1659 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
1660 if (st->key_renegotiate_time > st->key_lifetime) {
1661 cfgfatal(loc,"site",
1662 "renegotiate-time must be less than key-lifetime\n");
1665 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1666 log_event_table,"site");
1668 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1670 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1672 /* The information we expect to see in incoming messages of type 1 */
1673 /* fixme: lots of unchecked overflows here, but the results are only
1674 corrupted packets rather than undefined behaviour */
1675 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1677 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1679 buffer_new(&st->scratch,0);
1680 BUF_ALLOC(&st->scratch,"site:scratch");
1682 /* We are interested in poll(), but only for timeouts. We don't have
1683 any fds of our own. */
1684 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1687 st->remote_capabilities=0;
1688 st->current.key_timeout=0;
1689 st->auxiliary_key.key_timeout=0;
1690 transport_peers_clear(st,&st->peers);
1691 transport_peers_clear(st,&st->setup_peers);
1692 /* XXX mlock these */
1693 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
1694 st->sharedsecretlen=st->transform->keylen?:st->dh->ceil_len;
1695 st->sharedsecret=safe_malloc(st->sharedsecretlen,"site:sharedsecret");
1697 /* We need to compute some properties of our comms */
1698 #define COMPUTE_WORST(pad) \
1699 int worst_##pad=0; \
1700 for (i=0; i<st->ncomms; i++) { \
1701 int thispad=st->comms[i]->pad; \
1702 if (thispad > worst_##pad) \
1703 worst_##pad=thispad; \
1705 COMPUTE_WORST(min_start_pad)
1706 COMPUTE_WORST(min_end_pad)
1708 /* We need to register the remote networks with the netlink device */
1709 st->netlink->reg(st->netlink->st, site_outgoing, st,
1710 st->transform->max_start_pad+(4*4)+
1711 worst_min_start_pad,
1712 st->transform->max_end_pad+worst_min_end_pad);
1714 for (i=0; i<st->ncomms; i++)
1715 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
1717 st->current.transform=0;
1718 st->auxiliary_key.transform=0;
1719 st->new_transform=0;
1720 st->auxiliary_is_new=0;
1722 enter_state_stop(st);
1724 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
1726 return new_closure(&st->cl);
1729 void site_module(dict_t *dict)
1731 add_closure(dict,"site",site_apply);
1735 /***** TRANSPORT PEERS definitions *****/
1737 static void transport_peers_debug(struct site *st, transport_peers *dst,
1738 const char *didwhat,
1739 int nargs, const struct comm_addr *args,
1744 if (!(st->log_events & LOG_PEER_ADDRS))
1745 return; /* an optimisation */
1747 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
1748 (dst==&st->peers ? "data" :
1749 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
1750 didwhat, nargs, dst->npeers);
1752 for (i=0, argp=(void*)args;
1754 i++, (argp+=stride?stride:sizeof(*args))) {
1755 const struct comm_addr *ca=(void*)argp;
1756 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1757 i, ca->comm->addr_to_string(ca->comm->st,ca));
1759 for (i=0; i<dst->npeers; i++) {
1760 struct timeval diff;
1761 timersub(tv_now,&dst->peers[i].last,&diff);
1762 const struct comm_addr *ca=&dst->peers[i].addr;
1763 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1764 i, ca->comm->addr_to_string(ca->comm->st,ca),
1765 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
1769 static int transport_peer_compar(const void *av, const void *bv) {
1770 const transport_peer *a=av;
1771 const transport_peer *b=bv;
1772 /* put most recent first in the array */
1773 if (timercmp(&a->last, &b->last, <)) return +1;
1774 if (timercmp(&a->last, &b->last, >)) return -11;
1778 static void transport_peers_expire(struct site *st, transport_peers *peers) {
1779 /* peers must be sorted first */
1780 int previous_peers=peers->npeers;
1781 struct timeval oldest;
1782 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
1783 oldest.tv_usec = tv_now->tv_usec;
1784 while (peers->npeers>1 &&
1785 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
1787 if (peers->npeers != previous_peers)
1788 transport_peers_debug(st,peers,"expire", 0,0,0);
1791 static void transport_record_peer(struct site *st, transport_peers *peers,
1792 const struct comm_addr *addr, const char *m) {
1793 int slot, changed=0;
1795 for (slot=0; slot<peers->npeers; slot++)
1796 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
1800 if (peers->npeers==st->transport_peers_max)
1801 slot=st->transport_peers_max;
1803 slot=peers->npeers++;
1806 peers->peers[slot].addr=*addr;
1807 peers->peers[slot].last=*tv_now;
1809 if (peers->npeers>1)
1810 qsort(peers->peers, peers->npeers,
1811 sizeof(*peers->peers), transport_peer_compar);
1813 if (changed || peers->npeers!=1)
1814 transport_peers_debug(st,peers,m, 1,addr,0);
1815 transport_peers_expire(st, peers);
1818 static bool_t transport_compute_setupinit_peers(struct site *st,
1819 const struct comm_addr *configured_addr /* 0 if none or not found */) {
1821 if (!configured_addr && !transport_peers_valid(&st->peers))
1824 slog(st,LOG_SETUP_INIT,
1825 (!configured_addr ? "using only %d old peer address(es)"
1826 : "using configured address, and/or perhaps %d old peer address(es)"),
1829 /* Non-mobile peers havve st->peers.npeers==0 or ==1, since they
1830 * have transport_peers_max==1. The effect is that this code
1831 * always uses the configured address if supplied, or otherwise
1832 * the existing data peer if one exists; this is as desired. */
1834 transport_peers_copy(st,&st->setup_peers,&st->peers);
1836 if (configured_addr)
1837 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
1839 assert(transport_peers_valid(&st->setup_peers));
1843 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
1844 if (st->peer_mobile)
1845 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
1847 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
1848 if (st->peer_mobile)
1849 transport_record_peer(st,&st->peers,a,"datamsg");
1852 static int transport_peers_valid(transport_peers *peers) {
1853 return peers->npeers;
1855 static void transport_peers_clear(struct site *st, transport_peers *peers) {
1857 transport_peers_debug(st,peers,"clear",0,0,0);
1859 static void transport_peers_copy(struct site *st, transport_peers *dst,
1860 const transport_peers *src) {
1861 dst->npeers=src->npeers;
1862 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
1863 transport_peers_debug(st,dst,"copy",
1864 src->npeers, &src->peers->addr, sizeof(*src->peers));
1867 void transport_xmit(struct site *st, transport_peers *peers,
1868 struct buffer_if *buf, bool_t candebug) {
1870 transport_peers_expire(st, peers);
1871 for (slot=0; slot<peers->npeers; slot++) {
1872 transport_peer *peer=&peers->peers[slot];
1874 dump_packet(st, buf, &peer->addr, False);
1875 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
1879 /***** END of transport peers declarations *****/