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 int32_t site_max_start_pad = 4*4;
94 static cstring_t state_name(uint32_t state)
97 case 0: return "STOP";
99 case 2: return "RESOLVE";
100 case 3: return "SENTMSG1";
101 case 4: return "SENTMSG2";
102 case 5: return "SENTMSG3";
103 case 6: return "SENTMSG4";
104 case 7: return "SENTMSG5";
105 case 8: return "WAIT";
106 default: return "*bad state*";
112 #define LOG_UNEXPECTED 0x00000001
113 #define LOG_SETUP_INIT 0x00000002
114 #define LOG_SETUP_TIMEOUT 0x00000004
115 #define LOG_ACTIVATE_KEY 0x00000008
116 #define LOG_TIMEOUT_KEY 0x00000010
117 #define LOG_SEC 0x00000020
118 #define LOG_STATE 0x00000040
119 #define LOG_DROP 0x00000080
120 #define LOG_DUMP 0x00000100
121 #define LOG_ERROR 0x00000400
122 #define LOG_PEER_ADDRS 0x00000800
124 static struct flagstr log_event_table[]={
125 { "unexpected", LOG_UNEXPECTED },
126 { "setup-init", LOG_SETUP_INIT },
127 { "setup-timeout", LOG_SETUP_TIMEOUT },
128 { "activate-key", LOG_ACTIVATE_KEY },
129 { "timeout-key", LOG_TIMEOUT_KEY },
130 { "security", LOG_SEC },
131 { "state-change", LOG_STATE },
132 { "packet-drop", LOG_DROP },
133 { "dump-packets", LOG_DUMP },
134 { "errors", LOG_ERROR },
135 { "peer-addrs", LOG_PEER_ADDRS },
136 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
137 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
138 { "all", 0xffffffff },
143 /***** TRANSPORT PEERS declarations *****/
145 /* Details of "mobile peer" semantics:
147 - We record mobile_peers_max peer address/port numbers ("peers")
148 for key setup, and separately mobile_peers_max for data
149 transfer. If these lists fill up, we retain the newest peers.
150 (For non-mobile peers we only record one of each.)
152 - Outgoing packets are sent to every recorded peer in the
155 - Data transfer peers are straightforward: whenever we successfully
156 process a data packet, we record the peer. Also, whenever we
157 successfully complete a key setup, we merge the key setup
158 peers into the data transfer peers.
160 (For "non-mobile" peers we simply copy the peer used for
161 successful key setup, and don't change the peer otherwise.)
163 - Key setup peers are slightly more complicated.
165 Whenever we receive and successfully process a key exchange
166 packet, we record the peer.
168 Whenever we try to initiate a key setup, we copy the list of data
169 transfer peers and use it for key setup. But we also look to see
170 if the config supplies an address and port number and if so we
171 add that as a key setup peer (possibly evicting one of the data
172 transfer peers we just copied).
174 (For "non-mobile" peers, if we if we have a configured peer
175 address and port, we always use that; otherwise if we have a
176 current data peer address we use that; otherwise we do not
177 attempt to initiate a key setup for lack of a peer address.)
179 "Record the peer" means
180 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
181 2. add the peer of the just received packet to the applicable list
182 (possibly evicting older entries)
183 NB that we do not expire peers until an incoming packet arrives.
187 #define MAX_MOBILE_PEERS_MAX 5 /* send at most this many copies, compiled max */
191 struct comm_addr addr;
195 /* configuration information */
196 /* runtime information */
198 transport_peer peers[MAX_MOBILE_PEERS_MAX];
201 static void transport_peers_clear(struct site *st, transport_peers *peers);
202 static int transport_peers_valid(transport_peers *peers);
203 static void transport_peers_copy(struct site *st, transport_peers *dst,
204 const transport_peers *src);
206 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
207 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
208 static bool_t transport_compute_setupinit_peers(struct site *st,
209 const struct comm_addr *configured_addr /* 0 if none or not found */,
210 const struct comm_addr *prod_hint_addr /* 0 if none */);
211 static void transport_record_peer(struct site *st, transport_peers *peers,
212 const struct comm_addr *addr, const char *m);
214 static void transport_xmit(struct site *st, transport_peers *peers,
215 struct buffer_if *buf, bool_t candebug);
217 /***** END of transport peers declarations *****/
221 struct transform_inst_if *transform;
222 uint64_t key_timeout; /* End of life of current key */
223 uint32_t remote_session_id;
229 /* configuration information */
232 bool_t peer_mobile; /* Mobile client support */
233 int32_t transport_peers_max;
234 string_t tunname; /* localname<->remotename by default, used in logs */
235 string_t address; /* DNS name for bootstrapping, optional */
236 int remoteport; /* Port for bootstrapping, optional */
237 struct netlink_if *netlink;
238 struct comm_if **comms;
240 struct resolver_if *resolver;
242 struct random_if *random;
243 struct rsaprivkey_if *privkey;
244 struct rsapubkey_if *pubkey;
245 struct transform_if **transforms;
248 struct hash_if *hash;
250 uint32_t index; /* Index of this site */
251 uint32_t local_capabilities;
252 int32_t setup_retries; /* How many times to send setup packets */
253 int32_t setup_retry_interval; /* Initial timeout for setup packets */
254 int32_t wait_timeout; /* How long to wait if setup unsuccessful */
255 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
256 int32_t key_lifetime; /* How long a key lasts once set up */
257 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
258 after this time, initiate a new
261 bool_t setup_priority; /* Do we have precedence if both sites emit
262 message 1 simultaneously? */
265 /* runtime information */
267 uint64_t now; /* Most recently seen time */
268 bool_t allow_send_prod;
270 /* The currently established session */
271 struct data_key current;
272 struct data_key auxiliary_key;
273 bool_t auxiliary_is_new;
274 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
275 uint64_t auxiliary_renegotiate_key_time;
276 transport_peers peers; /* Current address(es) of peer for data traffic */
278 /* The current key setup protocol exchange. We can only be
279 involved in one of these at a time. There's a potential for
280 denial of service here (the attacker keeps sending a setup
281 packet; we keep trying to continue the exchange, and have to
282 timeout before we can listen for another setup packet); perhaps
283 we should keep a list of 'bad' sources for setup packets. */
284 uint32_t remote_capabilities;
285 struct transform_if *chosen_transform;
286 uint32_t setup_session_id;
287 transport_peers setup_peers;
288 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
289 uint8_t remoteN[NONCELEN];
290 struct buffer_if buffer; /* Current outgoing key exchange packet */
291 struct buffer_if scratch;
292 int32_t retries; /* Number of retries remaining */
293 uint64_t timeout; /* Timeout for current state */
295 uint8_t *sharedsecret;
296 uint32_t sharedsecretlen, sharedsecretallocd;
297 struct transform_inst_if *new_transform; /* For key setup/verify */
300 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
302 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
310 if (event&st->log_events) {
312 case LOG_UNEXPECTED: class=M_INFO; break;
313 case LOG_SETUP_INIT: class=M_INFO; break;
314 case LOG_SETUP_TIMEOUT: class=M_NOTICE; break;
315 case LOG_ACTIVATE_KEY: class=M_INFO; break;
316 case LOG_TIMEOUT_KEY: class=M_INFO; break;
317 case LOG_SEC: class=M_SECURITY; break;
318 case LOG_STATE: class=M_DEBUG; break;
319 case LOG_DROP: class=M_DEBUG; break;
320 case LOG_DUMP: class=M_DEBUG; break;
321 case LOG_ERROR: class=M_ERR; break;
322 case LOG_PEER_ADDRS: class=M_DEBUG; break;
323 default: class=M_ERR; break;
326 vsnprintf(buf,sizeof(buf),msg,ap);
327 slilog(st->log,class,"%s: %s",st->tunname,buf);
332 static void set_link_quality(struct site *st);
333 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
334 static void delete_one_key(struct site *st, struct data_key *key,
335 const char *reason /* may be 0 meaning don't log*/,
336 const char *which /* ignored if !reasonn */,
337 uint32_t loglevel /* ignored if !reasonn */);
338 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
339 const struct comm_addr *prod_hint);
340 static void enter_state_run(struct site *st);
341 static bool_t enter_state_resolve(struct site *st);
342 static bool_t enter_new_state(struct site *st,uint32_t next);
343 static void enter_state_wait(struct site *st);
344 static void activate_new_key(struct site *st);
346 static bool_t is_transform_valid(struct transform_inst_if *transform)
348 return transform && transform->valid(transform->st);
351 static bool_t current_valid(struct site *st)
353 return is_transform_valid(st->current.transform);
356 #define DEFINE_CALL_TRANSFORM(fwdrev) \
357 static int call_transform_##fwdrev(struct site *st, \
358 struct transform_inst_if *transform, \
359 struct buffer_if *buf, \
360 const char **errmsg) \
362 if (!is_transform_valid(transform)) { \
363 *errmsg="transform not set up"; \
366 return transform->fwdrev(transform->st,buf,errmsg); \
369 DEFINE_CALL_TRANSFORM(forwards)
370 DEFINE_CALL_TRANSFORM(reverse)
372 static void dispose_transform(struct transform_inst_if **transform_var)
374 struct transform_inst_if *transform=*transform_var;
376 transform->delkey(transform->st);
377 transform->destroy(transform->st);
382 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
383 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
384 #define CHECK_TYPE(b,t) do { uint32_t type; \
385 CHECK_AVAIL((b),4); \
386 type=buf_unprepend_uint32((b)); \
387 if (type!=(t)) return False; } while(0)
392 struct buffer_if extrainfo;
399 struct parsedname remote;
400 struct parsedname local;
401 uint32_t remote_capabilities;
402 int capab_transformnum;
412 static void set_new_transform(struct site *st, char *pk)
414 /* Make room for the shared key */
415 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
416 assert(st->sharedsecretlen);
417 if (st->sharedsecretlen > st->sharedsecretallocd) {
418 st->sharedsecretallocd=st->sharedsecretlen;
419 st->sharedsecret=realloc(st->sharedsecret,st->sharedsecretallocd);
421 if (!st->sharedsecret) fatal_perror("site:sharedsecret");
423 /* Generate the shared key */
424 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
425 st->sharedsecret,st->sharedsecretlen);
427 /* Set up the transform */
428 struct transform_if *generator=st->chosen_transform;
429 struct transform_inst_if *generated=generator->create(generator->st);
430 generated->setkey(generated->st,st->sharedsecret,
431 st->sharedsecretlen,st->setup_priority);
432 dispose_transform(&st->new_transform);
433 st->new_transform=generated;
435 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
436 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
437 st->chosen_transform->capab_transformnum,
438 st->local_capabilities, st->remote_capabilities);
442 int32_t lenpos, afternul;
444 static void append_string_xinfo_start(struct buffer_if *buf,
445 struct xinfoadd *xia,
447 /* Helps construct one of the names with additional info as found
448 * in MSG1..4. Call this function first, then append all the
449 * desired extra info (not including the nul byte) to the buffer,
450 * then call append_string_xinfo_done. */
452 xia->lenpos = buf->size;
453 buf_append_string(buf,str);
454 buf_append_uint8(buf,0);
455 xia->afternul = buf->size;
457 static void append_string_xinfo_done(struct buffer_if *buf,
458 struct xinfoadd *xia)
460 /* we just need to adjust the string length */
461 if (buf->size == xia->afternul) {
462 /* no extra info, strip the nul too */
463 buf_unappend_uint8(buf);
465 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
469 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
470 out using a transform of config data supplied by netlink */
471 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
477 st->retries=st->setup_retries;
478 BUF_ALLOC(&st->buffer,what);
479 buffer_init(&st->buffer,0);
480 buf_append_uint32(&st->buffer,
481 (type==LABEL_MSG1?0:st->setup_session_id));
482 buf_append_uint32(&st->buffer,st->index);
483 buf_append_uint32(&st->buffer,type);
486 append_string_xinfo_start(&st->buffer,&xia,st->localname);
487 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
488 buf_append_uint32(&st->buffer,st->local_capabilities);
490 append_string_xinfo_done(&st->buffer,&xia);
492 buf_append_string(&st->buffer,st->remotename);
493 memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
494 if (type==LABEL_MSG1) return True;
495 memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN);
496 if (type==LABEL_MSG2) return True;
498 if (hacky_par_mid_failnow()) return False;
500 if (type==LABEL_MSG3BIS)
501 buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
503 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
504 buf_append_string(&st->buffer,dhpub);
506 hash=safe_malloc(st->hash->len, "generate_msg");
507 hst=st->hash->init();
508 st->hash->update(hst,st->buffer.start,st->buffer.size);
509 st->hash->final(hst,hash);
510 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
511 buf_append_string(&st->buffer,sig);
517 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
520 nm->len=buf_unprepend_uint16(msg);
521 CHECK_AVAIL(msg,nm->len);
522 nm->name=buf_unprepend(msg,nm->len);
523 uint8_t *nul=memchr(nm->name,0,nm->len);
525 buffer_readonly_view(&nm->extrainfo,0,0);
527 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
528 nm->len=nul-nm->name;
533 static bool_t unpick_msg(struct site *st, uint32_t type,
534 struct buffer_if *msg, struct msg *m)
536 m->capab_transformnum=-1;
537 m->hashstart=msg->start;
539 m->dest=buf_unprepend_uint32(msg);
541 m->source=buf_unprepend_uint32(msg);
542 CHECK_TYPE(msg,type);
543 if (!unpick_name(msg,&m->remote)) return False;
544 m->remote_capabilities=0;
545 if (m->remote.extrainfo.size) {
546 CHECK_AVAIL(&m->remote.extrainfo,4);
547 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
549 if (!unpick_name(msg,&m->local)) return False;
550 if (type==LABEL_PROD) {
554 CHECK_AVAIL(msg,NONCELEN);
555 m->nR=buf_unprepend(msg,NONCELEN);
556 if (type==LABEL_MSG1) {
560 CHECK_AVAIL(msg,NONCELEN);
561 m->nL=buf_unprepend(msg,NONCELEN);
562 if (type==LABEL_MSG2) {
566 if (type==LABEL_MSG3BIS) {
568 m->capab_transformnum = buf_unprepend_uint8(msg);
570 m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
573 m->pklen=buf_unprepend_uint16(msg);
574 CHECK_AVAIL(msg,m->pklen);
575 m->pk=buf_unprepend(msg,m->pklen);
576 m->hashlen=msg->start-m->hashstart;
578 m->siglen=buf_unprepend_uint16(msg);
579 CHECK_AVAIL(msg,m->siglen);
580 m->sig=buf_unprepend(msg,m->siglen);
585 static bool_t name_matches(const struct parsedname *nm, const char *expected)
587 int expected_len=strlen(expected);
589 nm->len == expected_len &&
590 !memcmp(nm->name, expected, expected_len);
593 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
596 if (type==LABEL_MSG1) return True;
598 /* Check that the site names and our nonce have been sent
599 back correctly, and then store our peer's nonce. */
600 if (!name_matches(&m->remote,st->remotename)) {
601 *error="wrong remote site name";
604 if (!name_matches(&m->local,st->localname)) {
605 *error="wrong local site name";
608 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
609 *error="wrong locally-generated nonce";
612 if (type==LABEL_MSG2) return True;
613 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
614 *error="wrong remotely-generated nonce";
617 /* MSG3 has complicated rules about capabilities, which are
618 * handled in process_msg3. */
619 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
620 if (m->remote_capabilities!=st->remote_capabilities) {
621 *error="remote capabilities changed";
624 if (type==LABEL_MSG4) return True;
625 *error="unknown message type";
629 static bool_t generate_msg1(struct site *st)
631 st->random->generate(st->random->st,NONCELEN,st->localN);
632 return generate_msg(st,LABEL_MSG1,"site:MSG1");
635 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
636 const struct comm_addr *src, struct msg *m)
638 /* We've already determined we're in an appropriate state to
639 process an incoming MSG1, and that the MSG1 has correct values
642 transport_record_peer(st,&st->setup_peers,src,"msg1");
643 st->setup_session_id=m->source;
644 st->remote_capabilities=m->remote_capabilities;
645 memcpy(st->remoteN,m->nR,NONCELEN);
649 static bool_t generate_msg2(struct site *st)
651 st->random->generate(st->random->st,NONCELEN,st->localN);
652 return generate_msg(st,LABEL_MSG2,"site:MSG2");
655 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
656 const struct comm_addr *src)
661 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
662 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
663 slog(st,LOG_SEC,"msg2: %s",err);
666 st->setup_session_id=m.source;
667 st->remote_capabilities=m.remote_capabilities;
669 /* Select the transform to use */
671 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
672 if (!remote_transforms)
673 /* old secnets only had this one transform */
674 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
676 struct transform_if *ti;
678 for (i=0; i<st->ntransforms; i++) {
679 ti=st->transforms[i];
680 if ((1UL << ti->capab_transformnum) & remote_transforms)
681 goto transform_found;
683 slog(st,LOG_ERROR,"no transforms in common"
684 " (us %#"PRIx32"; them: %#"PRIx32")",
685 st->local_capabilities & CAPAB_TRANSFORM_MASK,
689 st->chosen_transform=ti;
691 memcpy(st->remoteN,m.nR,NONCELEN);
695 static bool_t generate_msg3(struct site *st)
697 /* Now we have our nonce and their nonce. Think of a secret key,
698 and create message number 3. */
699 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
700 return generate_msg(st,
701 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
702 ? LABEL_MSG3BIS : LABEL_MSG3),
706 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
707 const struct comm_addr *src, uint32_t msgtype)
714 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
716 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
717 if (!check_msg(st,msgtype,&m,&err)) {
718 slog(st,LOG_SEC,"msg3: %s",err);
721 uint32_t capab_adv_late = m.remote_capabilities
722 & ~st->remote_capabilities & CAPAB_EARLY;
723 if (capab_adv_late) {
724 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
725 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
726 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
729 st->remote_capabilities|=m.remote_capabilities;
731 struct transform_if *ti;
733 for (i=0; i<st->ntransforms; i++) {
734 ti=st->transforms[i];
735 if (ti->capab_transformnum == m.capab_transformnum)
736 goto transform_found;
738 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
739 m.capab_transformnum);
742 st->chosen_transform=ti;
744 /* Check signature and store g^x mod m */
745 hash=safe_malloc(st->hash->len, "process_msg3");
746 hst=st->hash->init();
747 st->hash->update(hst,m.hashstart,m.hashlen);
748 st->hash->final(hst,hash);
749 /* Terminate signature with a '0' - cheating, but should be ok */
751 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
752 slog(st,LOG_SEC,"msg3 signature failed check!");
758 /* Terminate their DH public key with a '0' */
760 /* Invent our DH secret key */
761 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
763 /* Generate the shared key and set up the transform */
764 set_new_transform(st,m.pk);
769 static bool_t generate_msg4(struct site *st)
771 /* We have both nonces, their public key and our private key. Generate
772 our public key, sign it and send it to them. */
773 return generate_msg(st,LABEL_MSG4,"site:MSG4");
776 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
777 const struct comm_addr *src)
784 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
785 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
786 slog(st,LOG_SEC,"msg4: %s",err);
790 /* Check signature and store g^x mod m */
791 hash=safe_malloc(st->hash->len, "process_msg4");
792 hst=st->hash->init();
793 st->hash->update(hst,m.hashstart,m.hashlen);
794 st->hash->final(hst,hash);
795 /* Terminate signature with a '0' - cheating, but should be ok */
797 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) {
798 slog(st,LOG_SEC,"msg4 signature failed check!");
804 /* Terminate their DH public key with a '0' */
807 /* Generate the shared key and set up the transform */
808 set_new_transform(st,m.pk);
819 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
823 m->dest=buf_unprepend_uint32(msg0);
825 m->source=buf_unprepend_uint32(msg0);
827 m->type=buf_unprepend_uint32(msg0);
829 /* Leaves transformed part of buffer untouched */
832 static bool_t generate_msg5(struct site *st)
834 cstring_t transform_err;
836 BUF_ALLOC(&st->buffer,"site:MSG5");
837 /* We are going to add four words to the message */
838 buffer_init(&st->buffer,calculate_max_start_pad());
839 /* Give the netlink code an opportunity to put its own stuff in the
840 message (configuration information, etc.) */
841 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
842 if (call_transform_forwards(st,st->new_transform,
843 &st->buffer,&transform_err))
845 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
846 buf_prepend_uint32(&st->buffer,st->index);
847 buf_prepend_uint32(&st->buffer,st->setup_session_id);
849 st->retries=st->setup_retries;
853 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
854 const struct comm_addr *src,
855 struct transform_inst_if *transform)
858 cstring_t transform_err;
860 if (!unpick_msg0(st,msg5,&m)) return False;
862 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
863 /* There's a problem */
864 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
867 /* Buffer should now contain untransformed PING packet data */
869 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
870 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
873 /* Older versions of secnet used to write some config data here
874 * which we ignore. So we don't CHECK_EMPTY */
878 static void create_msg6(struct site *st, struct transform_inst_if *transform,
881 cstring_t transform_err;
883 BUF_ALLOC(&st->buffer,"site:MSG6");
884 /* We are going to add four words to the message */
885 buffer_init(&st->buffer,calculate_max_start_pad());
886 /* Give the netlink code an opportunity to put its own stuff in the
887 message (configuration information, etc.) */
888 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
889 int problem = call_transform_forwards(st,transform,
890 &st->buffer,&transform_err);
892 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
893 buf_prepend_uint32(&st->buffer,st->index);
894 buf_prepend_uint32(&st->buffer,session_id);
897 static bool_t generate_msg6(struct site *st)
899 if (!is_transform_valid(st->new_transform))
901 create_msg6(st,st->new_transform,st->setup_session_id);
902 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
906 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
907 const struct comm_addr *src)
910 cstring_t transform_err;
912 if (!unpick_msg0(st,msg6,&m)) return False;
914 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
915 /* There's a problem */
916 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
919 /* Buffer should now contain untransformed PING packet data */
921 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
922 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
925 /* Older versions of secnet used to write some config data here
926 * which we ignore. So we don't CHECK_EMPTY */
930 static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
931 const struct comm_addr *src)
933 cstring_t transform_err, auxkey_err, newkey_err="n/a";
937 if (!unpick_msg0(st,msg0,&m)) return False;
939 /* Keep a copy so we can try decrypting it with multiple keys */
940 buffer_copy(&st->scratch, msg0);
942 problem = call_transform_reverse(st,st->current.transform,
943 msg0,&transform_err);
945 if (!st->auxiliary_is_new)
946 delete_one_key(st,&st->auxiliary_key,
947 "peer has used new key","auxiliary key",LOG_SEC);
953 buffer_copy(msg0, &st->scratch);
954 problem = call_transform_reverse(st,st->auxiliary_key.transform,
957 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
958 if (st->auxiliary_is_new) {
959 /* We previously timed out in state SENTMSG5 but it turns
960 * out that our peer did in fact get our MSG5 and is
961 * using the new key. So we should switch to it too. */
962 /* This is a bit like activate_new_key. */
965 st->current=st->auxiliary_key;
968 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
969 "previous key",LOG_SEC);
970 st->auxiliary_is_new=0;
971 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
978 if (st->state==SITE_SENTMSG5) {
979 buffer_copy(msg0, &st->scratch);
980 problem = call_transform_reverse(st,st->new_transform,
983 /* It looks like we didn't get the peer's MSG6 */
984 /* This is like a cut-down enter_new_state(SITE_RUN) */
985 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
986 BUF_FREE(&st->buffer);
988 activate_new_key(st);
989 return True; /* do process the data in this packet */
995 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
996 transform_err,auxkey_err,newkey_err);
997 initiate_key_setup(st,"incoming message would not decrypt",0);
998 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1002 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
1006 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1007 const struct comm_addr *src)
1011 if (!decrypt_msg0(st,msg0,src))
1014 CHECK_AVAIL(msg0,4);
1015 type=buf_unprepend_uint32(msg0);
1018 /* We must forget about the current session. */
1019 delete_keys(st,"request from peer",LOG_SEC);
1022 /* Deliver to netlink layer */
1023 st->netlink->deliver(st->netlink->st,msg0);
1024 transport_data_msgok(st,src);
1025 /* See whether we should start negotiating a new key */
1026 if (st->now > st->renegotiate_key_time)
1027 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1030 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1037 static void dump_packet(struct site *st, struct buffer_if *buf,
1038 const struct comm_addr *addr, bool_t incoming)
1040 uint32_t dest=get_uint32(buf->start);
1041 uint32_t source=get_uint32(buf->start+4);
1042 uint32_t msgtype=get_uint32(buf->start+8);
1044 if (st->log_events & LOG_DUMP)
1045 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
1046 st->tunname,incoming?"incoming":"outgoing",
1047 dest,source,msgtype);
1050 static uint32_t site_status(void *st)
1055 static bool_t send_msg(struct site *st)
1057 if (st->retries>0) {
1058 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1059 st->timeout=st->now+st->setup_retry_interval;
1062 } else if (st->state==SITE_SENTMSG5) {
1063 slog(st,LOG_SETUP_TIMEOUT,"timed out sending MSG5, stashing new key");
1064 /* We stash the key we have produced, in case it turns out that
1065 * our peer did see our MSG5 after all and starts using it. */
1066 /* This is a bit like some of activate_new_key */
1067 struct transform_inst_if *t;
1068 t=st->auxiliary_key.transform;
1069 st->auxiliary_key.transform=st->new_transform;
1070 st->new_transform=t;
1071 dispose_transform(&st->new_transform);
1073 st->auxiliary_is_new=1;
1074 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1075 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1076 st->auxiliary_key.remote_session_id=st->setup_session_id;
1078 enter_state_wait(st);
1081 slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
1082 "(in state %s)",state_name(st->state));
1083 enter_state_wait(st);
1088 static void site_resolve_callback(void *sst, struct in_addr *address)
1090 struct site *st=sst;
1091 struct comm_addr ca_buf, *ca_use;
1093 if (st->state!=SITE_RESOLVE) {
1094 slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
1099 ca_buf.comm=st->comms[0];
1100 ca_buf.sin.sin_family=AF_INET;
1101 ca_buf.sin.sin_port=htons(st->remoteport);
1102 ca_buf.sin.sin_addr=*address;
1105 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
1108 if (transport_compute_setupinit_peers(st,ca_use,0)) {
1109 enter_new_state(st,SITE_SENTMSG1);
1111 /* Can't figure out who to try to to talk to */
1112 slog(st,LOG_SETUP_INIT,"key exchange failed: cannot find peer address");
1113 enter_state_run(st);
1117 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1118 const struct comm_addr *prod_hint)
1120 if (st->state!=SITE_RUN) return False;
1121 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1123 slog(st,LOG_SETUP_INIT,"resolving peer address");
1124 return enter_state_resolve(st);
1125 } else if (transport_compute_setupinit_peers(st,0,prod_hint)) {
1126 return enter_new_state(st,SITE_SENTMSG1);
1128 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1132 static void activate_new_key(struct site *st)
1134 struct transform_inst_if *t;
1136 /* We have three transform instances, which we swap between old,
1138 t=st->auxiliary_key.transform;
1139 st->auxiliary_key.transform=st->current.transform;
1140 st->current.transform=st->new_transform;
1141 st->new_transform=t;
1142 dispose_transform(&st->new_transform);
1145 st->auxiliary_is_new=0;
1146 st->auxiliary_key.key_timeout=st->current.key_timeout;
1147 st->current.key_timeout=st->now+st->key_lifetime;
1148 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1149 transport_peers_copy(st,&st->peers,&st->setup_peers);
1150 st->current.remote_session_id=st->setup_session_id;
1152 slog(st,LOG_ACTIVATE_KEY,"new key activated");
1153 enter_state_run(st);
1156 static void delete_one_key(struct site *st, struct data_key *key,
1157 cstring_t reason, cstring_t which, uint32_t loglevel)
1159 if (!is_transform_valid(key->transform)) return;
1160 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1161 dispose_transform(&key->transform);
1165 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1167 if (current_valid(st)) {
1168 slog(st,loglevel,"session closed (%s)",reason);
1170 delete_one_key(st,&st->current,0,0,0);
1171 set_link_quality(st);
1173 delete_one_key(st,&st->auxiliary_key,0,0,0);
1176 static void state_assert(struct site *st, bool_t ok)
1178 if (!ok) fatal("site:state_assert");
1181 static void enter_state_stop(struct site *st)
1183 st->state=SITE_STOP;
1185 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1186 dispose_transform(&st->new_transform);
1189 static void set_link_quality(struct site *st)
1192 if (current_valid(st))
1193 quality=LINK_QUALITY_UP;
1194 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1195 quality=LINK_QUALITY_DOWN;
1196 else if (st->address)
1197 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1198 else if (transport_peers_valid(&st->peers))
1199 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1201 quality=LINK_QUALITY_DOWN;
1203 st->netlink->set_quality(st->netlink->st,quality);
1206 static void enter_state_run(struct site *st)
1208 slog(st,LOG_STATE,"entering state RUN");
1212 st->setup_session_id=0;
1213 transport_peers_clear(st,&st->setup_peers);
1214 memset(st->localN,0,NONCELEN);
1215 memset(st->remoteN,0,NONCELEN);
1216 dispose_transform(&st->new_transform);
1217 memset(st->dhsecret,0,st->dh->len);
1218 memset(st->sharedsecret,0,st->sharedsecretlen);
1219 set_link_quality(st);
1222 static bool_t enter_state_resolve(struct site *st)
1224 state_assert(st,st->state==SITE_RUN);
1225 slog(st,LOG_STATE,"entering state RESOLVE");
1226 st->state=SITE_RESOLVE;
1227 st->resolver->request(st->resolver->st,st->address,
1228 site_resolve_callback,st);
1232 static bool_t enter_new_state(struct site *st, uint32_t next)
1234 bool_t (*gen)(struct site *st);
1237 slog(st,LOG_STATE,"entering state %s",state_name(next));
1240 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1244 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1245 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1249 state_assert(st,st->state==SITE_SENTMSG1);
1250 BUF_FREE(&st->buffer);
1254 state_assert(st,st->state==SITE_SENTMSG2);
1255 BUF_FREE(&st->buffer);
1259 state_assert(st,st->state==SITE_SENTMSG3);
1260 BUF_FREE(&st->buffer);
1264 state_assert(st,st->state==SITE_SENTMSG4);
1265 BUF_FREE(&st->buffer);
1270 fatal("enter_new_state(%s): invalid new state",state_name(next));
1274 if (hacky_par_start_failnow()) return False;
1276 r= gen(st) && send_msg(st);
1279 st->setup_retries, st->setup_retry_interval,
1284 if (next==SITE_RUN) {
1285 BUF_FREE(&st->buffer); /* Never reused */
1286 st->timeout=0; /* Never retransmit */
1287 activate_new_key(st);
1291 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1292 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1293 in either state, and enter_state_wait() will
1295 enter_state_wait(st);
1299 /* msg7 tells our peer that we're about to forget our key */
1300 static bool_t send_msg7(struct site *st, cstring_t reason)
1302 cstring_t transform_err;
1304 if (current_valid(st) && st->buffer.free
1305 && transport_peers_valid(&st->peers)) {
1306 BUF_ALLOC(&st->buffer,"site:MSG7");
1307 buffer_init(&st->buffer,calculate_max_start_pad());
1308 buf_append_uint32(&st->buffer,LABEL_MSG7);
1309 buf_append_string(&st->buffer,reason);
1310 if (call_transform_forwards(st, st->current.transform,
1311 &st->buffer, &transform_err))
1313 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1314 buf_prepend_uint32(&st->buffer,st->index);
1315 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1316 transport_xmit(st,&st->peers,&st->buffer,True);
1317 BUF_FREE(&st->buffer);
1324 /* We go into this state if our peer becomes uncommunicative. Similar to
1325 the "stop" state, we forget all session keys for a while, before
1326 re-entering the "run" state. */
1327 static void enter_state_wait(struct site *st)
1329 slog(st,LOG_STATE,"entering state WAIT");
1330 st->timeout=st->now+st->wait_timeout;
1331 st->state=SITE_WAIT;
1332 set_link_quality(st);
1333 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1334 /* XXX Erase keys etc. */
1337 static void generate_prod(struct site *st, struct buffer_if *buf)
1340 buf_append_uint32(buf,0);
1341 buf_append_uint32(buf,0);
1342 buf_append_uint32(buf,LABEL_PROD);
1343 buf_append_string(buf,st->localname);
1344 buf_append_string(buf,st->remotename);
1347 static void generate_send_prod(struct site *st,
1348 const struct comm_addr *source)
1350 if (!st->allow_send_prod) return; /* too soon */
1351 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1352 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1354 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1355 st->allow_send_prod=0;
1356 generate_prod(st,&st->scratch);
1357 dump_packet(st,&st->scratch,source,False);
1358 source->comm->sendmsg(source->comm->st, &st->scratch, source);
1361 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1364 int64_t offset=timeout-*now;
1365 if (offset<0) offset=0;
1366 if (offset>INT_MAX) offset=INT_MAX;
1367 if (*timeout_io<0 || offset<*timeout_io)
1372 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1375 struct site *st=sst;
1377 *nfds_io=0; /* We don't use any file descriptors */
1380 /* Work out when our next timeout is. The earlier of 'timeout' or
1381 'current.key_timeout'. A stored value of '0' indicates no timeout
1383 site_settimeout(st->timeout, timeout_io);
1384 site_settimeout(st->current.key_timeout, timeout_io);
1385 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1387 return 0; /* success */
1390 static void check_expiry(struct site *st, struct data_key *key,
1393 if (key->key_timeout && *now>key->key_timeout) {
1394 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1398 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1399 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1401 struct site *st=sst;
1404 if (st->timeout && *now>st->timeout) {
1406 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1407 if (!hacky_par_start_failnow())
1409 } else if (st->state==SITE_WAIT) {
1410 enter_state_run(st);
1412 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1416 check_expiry(st,&st->current,"current key");
1417 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1420 /* This function is called by the netlink device to deliver packets
1421 intended for the remote network. The packet is in "raw" wire
1422 format, but is guaranteed to be word-aligned. */
1423 static void site_outgoing(void *sst, struct buffer_if *buf)
1425 struct site *st=sst;
1426 cstring_t transform_err;
1428 if (st->state==SITE_STOP) {
1433 st->allow_send_prod=1;
1435 /* In all other states we consider delivering the packet if we have
1436 a valid key and a valid address to send it to. */
1437 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1438 /* Transform it and send it */
1440 buf_prepend_uint32(buf,LABEL_MSG9);
1441 if (call_transform_forwards(st, st->current.transform,
1442 buf, &transform_err))
1444 buf_prepend_uint32(buf,LABEL_MSG0);
1445 buf_prepend_uint32(buf,st->index);
1446 buf_prepend_uint32(buf,st->current.remote_session_id);
1447 transport_xmit(st,&st->peers,buf,False);
1454 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1456 initiate_key_setup(st,"outgoing packet",0);
1459 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1460 uint32_t type, struct msg *m)
1461 /* For packets which are identified by the local and remote names.
1462 * If it has our name and our peer's name in it it's for us. */
1464 struct buffer_if buf[1];
1465 buffer_readonly_clone(buf,buf_in);
1466 return unpick_msg(st,type,buf,m)
1467 && name_matches(&m->remote,st->remotename)
1468 && name_matches(&m->local,st->localname);
1471 /* This function is called by the communication device to deliver
1472 packets from our peers.
1473 It should return True if the packet is recognised as being for
1474 this current site instance (and should therefore not be processed
1475 by other sites), even if the packet was otherwise ignored. */
1476 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1477 const struct comm_addr *source)
1479 struct site *st=sst;
1481 if (buf->size < 12) return False;
1483 uint32_t dest=get_uint32(buf->start);
1484 uint32_t msgtype=get_uint32(buf->start+8);
1485 struct msg named_msg;
1487 if (msgtype==LABEL_MSG1) {
1488 if (!named_for_us(st,buf,msgtype,&named_msg))
1490 /* It's a MSG1 addressed to us. Decide what to do about it. */
1491 dump_packet(st,buf,source,True);
1492 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1493 st->state==SITE_WAIT) {
1494 /* We should definitely process it */
1495 if (process_msg1(st,buf,source,&named_msg)) {
1496 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1497 enter_new_state(st,SITE_SENTMSG2);
1499 slog(st,LOG_ERROR,"failed to process incoming msg1");
1503 } else if (st->state==SITE_SENTMSG1) {
1504 /* We've just sent a message 1! They may have crossed on
1505 the wire. If we have priority then we ignore the
1506 incoming one, otherwise we process it as usual. */
1507 if (st->setup_priority) {
1509 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1510 "priority => ignore incoming msg1");
1513 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1514 "priority => use incoming msg1");
1515 if (process_msg1(st,buf,source,&named_msg)) {
1516 BUF_FREE(&st->buffer); /* Free our old message 1 */
1517 enter_new_state(st,SITE_SENTMSG2);
1519 slog(st,LOG_ERROR,"failed to process an incoming "
1520 "crossed msg1 (we have low priority)");
1526 /* The message 1 was received at an unexpected stage of the
1527 key setup. XXX POLICY - what do we do? */
1528 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1532 if (msgtype==LABEL_PROD) {
1533 if (!named_for_us(st,buf,msgtype,&named_msg))
1535 dump_packet(st,buf,source,True);
1536 if (st->state!=SITE_RUN) {
1537 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1538 } else if (current_valid(st)) {
1539 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1541 initiate_key_setup(st,"peer sent PROD packet",source);
1546 if (dest==st->index) {
1547 /* Explicitly addressed to us */
1548 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1551 /* If the source is our current peer then initiate a key setup,
1552 because our peer's forgotten the key */
1553 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1555 initiated = initiate_key_setup(st,"received a NAK",0);
1556 if (!initiated) generate_send_prod(st,source);
1558 slog(st,LOG_SEC,"bad incoming NAK");
1562 process_msg0(st,buf,source);
1565 /* Setup packet: should not have been explicitly addressed
1567 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1570 /* Setup packet: expected only in state SENTMSG1 */
1571 if (st->state!=SITE_SENTMSG1) {
1572 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1573 } else if (process_msg2(st,buf,source)) {
1574 transport_setup_msgok(st,source);
1575 enter_new_state(st,SITE_SENTMSG3);
1577 slog(st,LOG_SEC,"invalid MSG2");
1582 /* Setup packet: expected only in state SENTMSG2 */
1583 if (st->state!=SITE_SENTMSG2) {
1584 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1585 } else if (process_msg3(st,buf,source,msgtype)) {
1586 transport_setup_msgok(st,source);
1587 enter_new_state(st,SITE_SENTMSG4);
1589 slog(st,LOG_SEC,"invalid MSG3");
1593 /* Setup packet: expected only in state SENTMSG3 */
1594 if (st->state!=SITE_SENTMSG3) {
1595 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1596 } else if (process_msg4(st,buf,source)) {
1597 transport_setup_msgok(st,source);
1598 enter_new_state(st,SITE_SENTMSG5);
1600 slog(st,LOG_SEC,"invalid MSG4");
1604 /* Setup packet: expected only in state SENTMSG4 */
1605 /* (may turn up in state RUN if our return MSG6 was lost
1606 and the new key has already been activated. In that
1607 case we discard it. The peer will realise that we
1608 are using the new key when they see our data packets.
1609 Until then the peer's data packets to us get discarded. */
1610 if (st->state==SITE_SENTMSG4) {
1611 if (process_msg5(st,buf,source,st->new_transform)) {
1612 transport_setup_msgok(st,source);
1613 enter_new_state(st,SITE_RUN);
1615 slog(st,LOG_SEC,"invalid MSG5");
1617 } else if (st->state==SITE_RUN) {
1618 if (process_msg5(st,buf,source,st->current.transform)) {
1619 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1620 transport_setup_msgok(st,source);
1621 create_msg6(st,st->current.transform,
1622 st->current.remote_session_id);
1623 transport_xmit(st,&st->peers,&st->buffer,True);
1624 BUF_FREE(&st->buffer);
1626 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1629 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
1633 /* Setup packet: expected only in state SENTMSG5 */
1634 if (st->state!=SITE_SENTMSG5) {
1635 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1636 } else if (process_msg6(st,buf,source)) {
1637 BUF_FREE(&st->buffer); /* Free message 5 */
1638 transport_setup_msgok(st,source);
1639 activate_new_key(st);
1641 slog(st,LOG_SEC,"invalid MSG6");
1645 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
1656 static void site_control(void *vst, bool_t run)
1658 struct site *st=vst;
1659 if (run) enter_state_run(st);
1660 else enter_state_stop(st);
1663 static void site_phase_hook(void *sst, uint32_t newphase)
1665 struct site *st=sst;
1667 /* The program is shutting down; tell our peer */
1668 send_msg7(st,"shutting down");
1671 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1674 static uint32_t index_sequence;
1680 st=safe_malloc(sizeof(*st),"site_apply");
1682 st->cl.description="site";
1683 st->cl.type=CL_SITE;
1685 st->cl.interface=&st->ops;
1687 st->ops.control=site_control;
1688 st->ops.status=site_status;
1690 /* First parameter must be a dict */
1691 item=list_elem(args,0);
1692 if (!item || item->type!=t_dict)
1693 cfgfatal(loc,"site","parameter must be a dictionary\n");
1695 dict=item->data.dict;
1696 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1697 st->remotename=dict_read_string(dict, "name", True, "site", loc);
1699 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1700 bool_t local_mobile=
1701 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1703 /* Sanity check (which also allows the 'sites' file to include
1704 site() closures for all sites including our own): refuse to
1705 talk to ourselves */
1706 if (strcmp(st->localname,st->remotename)==0) {
1707 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
1709 if (st->peer_mobile != local_mobile)
1710 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1711 " but our local-mobile=%d\n",
1712 st->localname, st->peer_mobile, local_mobile);
1716 if (st->peer_mobile && local_mobile) {
1717 Message(M_WARNING,"site %s: site is mobile but so are we"
1718 " -> ignoring this site\n", st->remotename);
1723 assert(index_sequence < 0xffffffffUL);
1724 st->index = ++index_sequence;
1725 st->local_capabilities = 0;
1726 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
1728 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
1729 list_t *things##_cfg=dict_lookup(dict,dictkey); \
1730 if (!things##_cfg) \
1731 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
1732 st->nthings=list_length(things##_cfg); \
1733 st->things=safe_malloc_ary(sizeof(*st->things),st->nthings,dictkey "s"); \
1734 assert(st->nthings); \
1735 for (i=0; i<st->nthings; i++) { \
1736 item_t *item=list_elem(things##_cfg,i); \
1737 if (item->type!=t_closure) \
1738 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
1739 closure_t *cl=item->data.closure; \
1740 if (cl->type!=CL_TYPE) \
1741 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
1742 st->things[i]=cl->interface; \
1746 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
1748 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1749 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1750 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1752 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
1753 st->address=dict_read_string(dict, "address", False, "site", loc);
1755 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1756 else st->remoteport=0;
1757 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1759 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
1761 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1762 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1764 #define DEFAULT(D) (st->peer_mobile || local_mobile \
1765 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
1766 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
1768 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1769 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1770 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1771 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1773 st->mobile_peer_expiry= dict_read_number(
1774 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1776 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1777 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1778 if (st->transport_peers_max<1 ||
1779 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1780 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1781 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1784 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
1785 st->key_renegotiate_time=st->key_lifetime/2;
1787 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
1788 st->key_renegotiate_time=dict_read_number(
1789 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
1790 if (st->key_renegotiate_time > st->key_lifetime) {
1791 cfgfatal(loc,"site",
1792 "renegotiate-time must be less than key-lifetime\n");
1795 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1796 log_event_table,"site");
1798 st->allow_send_prod=0;
1800 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1802 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1804 /* The information we expect to see in incoming messages of type 1 */
1805 /* fixme: lots of unchecked overflows here, but the results are only
1806 corrupted packets rather than undefined behaviour */
1807 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1809 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1811 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
1812 BUF_ALLOC(&st->scratch,"site:scratch");
1814 /* We are interested in poll(), but only for timeouts. We don't have
1815 any fds of our own. */
1816 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1819 st->remote_capabilities=0;
1820 st->chosen_transform=0;
1821 st->current.key_timeout=0;
1822 st->auxiliary_key.key_timeout=0;
1823 transport_peers_clear(st,&st->peers);
1824 transport_peers_clear(st,&st->setup_peers);
1825 /* XXX mlock these */
1826 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
1827 st->sharedsecretlen=st->sharedsecretallocd=0;
1830 for (i=0; i<st->ntransforms; i++) {
1831 struct transform_if *ti=st->transforms[i];
1832 uint32_t capbit = 1UL << ti->capab_transformnum;
1833 if (st->local_capabilities & capbit)
1834 slog(st,LOG_ERROR,"transformnum capability bit"
1835 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
1836 st->local_capabilities |= capbit;
1839 /* We need to register the remote networks with the netlink device */
1840 st->netlink->reg(st->netlink->st, site_outgoing, st);
1842 for (i=0; i<st->ncomms; i++)
1843 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
1845 st->current.transform=0;
1846 st->auxiliary_key.transform=0;
1847 st->new_transform=0;
1848 st->auxiliary_is_new=0;
1850 enter_state_stop(st);
1852 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
1854 return new_closure(&st->cl);
1857 void site_module(dict_t *dict)
1859 add_closure(dict,"site",site_apply);
1863 /***** TRANSPORT PEERS definitions *****/
1865 static void transport_peers_debug(struct site *st, transport_peers *dst,
1866 const char *didwhat,
1867 int nargs, const struct comm_addr *args,
1872 if (!(st->log_events & LOG_PEER_ADDRS))
1873 return; /* an optimisation */
1875 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
1876 (dst==&st->peers ? "data" :
1877 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
1878 didwhat, nargs, dst->npeers);
1880 for (i=0, argp=(void*)args;
1882 i++, (argp+=stride?stride:sizeof(*args))) {
1883 const struct comm_addr *ca=(void*)argp;
1884 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1885 i, ca->comm->addr_to_string(ca->comm->st,ca));
1887 for (i=0; i<dst->npeers; i++) {
1888 struct timeval diff;
1889 timersub(tv_now,&dst->peers[i].last,&diff);
1890 const struct comm_addr *ca=&dst->peers[i].addr;
1891 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1892 i, ca->comm->addr_to_string(ca->comm->st,ca),
1893 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
1897 static int transport_peer_compar(const void *av, const void *bv) {
1898 const transport_peer *a=av;
1899 const transport_peer *b=bv;
1900 /* put most recent first in the array */
1901 if (timercmp(&a->last, &b->last, <)) return +1;
1902 if (timercmp(&a->last, &b->last, >)) return -11;
1906 static void transport_peers_expire(struct site *st, transport_peers *peers) {
1907 /* peers must be sorted first */
1908 int previous_peers=peers->npeers;
1909 struct timeval oldest;
1910 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
1911 oldest.tv_usec = tv_now->tv_usec;
1912 while (peers->npeers>1 &&
1913 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
1915 if (peers->npeers != previous_peers)
1916 transport_peers_debug(st,peers,"expire", 0,0,0);
1919 static void transport_record_peer(struct site *st, transport_peers *peers,
1920 const struct comm_addr *addr, const char *m) {
1921 int slot, changed=0;
1923 for (slot=0; slot<peers->npeers; slot++)
1924 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
1928 if (peers->npeers==st->transport_peers_max)
1929 slot=st->transport_peers_max;
1931 slot=peers->npeers++;
1934 peers->peers[slot].addr=*addr;
1935 peers->peers[slot].last=*tv_now;
1937 if (peers->npeers>1)
1938 qsort(peers->peers, peers->npeers,
1939 sizeof(*peers->peers), transport_peer_compar);
1941 if (changed || peers->npeers!=1)
1942 transport_peers_debug(st,peers,m, 1,addr,0);
1943 transport_peers_expire(st, peers);
1946 static bool_t transport_compute_setupinit_peers(struct site *st,
1947 const struct comm_addr *configured_addr /* 0 if none or not found */,
1948 const struct comm_addr *prod_hint_addr /* 0 if none */) {
1950 if (!configured_addr && !prod_hint_addr &&
1951 !transport_peers_valid(&st->peers))
1954 slog(st,LOG_SETUP_INIT,
1955 "using:%s%s %d old peer address(es)",
1956 configured_addr ? " configured address;" : "",
1957 prod_hint_addr ? " PROD hint address;" : "",
1960 /* Non-mobile peers havve st->peers.npeers==0 or ==1, since they
1961 * have transport_peers_max==1. The effect is that this code
1962 * always uses the configured address if supplied, or otherwise
1963 * the address of the incoming PROD, or the existing data peer if
1964 * one exists; this is as desired. */
1966 transport_peers_copy(st,&st->setup_peers,&st->peers);
1969 transport_record_peer(st,&st->setup_peers,prod_hint_addr,"prod");
1971 if (configured_addr)
1972 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
1974 assert(transport_peers_valid(&st->setup_peers));
1978 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
1979 if (st->peer_mobile)
1980 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
1982 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
1983 if (st->peer_mobile)
1984 transport_record_peer(st,&st->peers,a,"datamsg");
1987 static int transport_peers_valid(transport_peers *peers) {
1988 return peers->npeers;
1990 static void transport_peers_clear(struct site *st, transport_peers *peers) {
1992 transport_peers_debug(st,peers,"clear",0,0,0);
1994 static void transport_peers_copy(struct site *st, transport_peers *dst,
1995 const transport_peers *src) {
1996 dst->npeers=src->npeers;
1997 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
1998 transport_peers_debug(st,dst,"copy",
1999 src->npeers, &src->peers->addr, sizeof(*src->peers));
2002 void transport_xmit(struct site *st, transport_peers *peers,
2003 struct buffer_if *buf, bool_t candebug) {
2005 transport_peers_expire(st, peers);
2006 for (slot=0; slot<peers->npeers; slot++) {
2007 transport_peer *peer=&peers->peers[slot];
2009 dump_packet(st, buf, &peer->addr, False);
2010 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
2014 /***** END of transport peers declarations *****/