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_msg4(struct site *st, struct msg *m)
711 /* Check signature and store g^x mod m */
712 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
713 hst=st->hash->init();
714 st->hash->update(hst,m->hashstart,m->hashlen);
715 st->hash->final(hst,hash);
716 /* Terminate signature with a '0' - cheating, but should be ok */
718 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
719 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
728 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
729 const struct comm_addr *src, uint32_t msgtype)
734 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
736 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
737 if (!check_msg(st,msgtype,&m,&err)) {
738 slog(st,LOG_SEC,"msg3: %s",err);
741 uint32_t capab_adv_late = m.remote_capabilities
742 & ~st->remote_capabilities & CAPAB_EARLY;
743 if (capab_adv_late) {
744 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
745 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
746 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
749 st->remote_capabilities|=m.remote_capabilities;
751 struct transform_if *ti;
753 for (i=0; i<st->ntransforms; i++) {
754 ti=st->transforms[i];
755 if (ti->capab_transformnum == m.capab_transformnum)
756 goto transform_found;
758 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
759 m.capab_transformnum);
762 st->chosen_transform=ti;
764 if (!process_msg3_msg4(st,&m))
767 /* Terminate their DH public key with a '0' */
769 /* Invent our DH secret key */
770 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
772 /* Generate the shared key and set up the transform */
773 set_new_transform(st,m.pk);
778 static bool_t generate_msg4(struct site *st)
780 /* We have both nonces, their public key and our private key. Generate
781 our public key, sign it and send it to them. */
782 return generate_msg(st,LABEL_MSG4,"site:MSG4");
785 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
786 const struct comm_addr *src)
791 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
792 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
793 slog(st,LOG_SEC,"msg4: %s",err);
797 if (!process_msg3_msg4(st,&m))
800 /* Terminate their DH public key with a '0' */
803 /* Generate the shared key and set up the transform */
804 set_new_transform(st,m.pk);
815 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
819 m->dest=buf_unprepend_uint32(msg0);
821 m->source=buf_unprepend_uint32(msg0);
823 m->type=buf_unprepend_uint32(msg0);
825 /* Leaves transformed part of buffer untouched */
828 static bool_t generate_msg5(struct site *st)
830 cstring_t transform_err;
832 BUF_ALLOC(&st->buffer,"site:MSG5");
833 /* We are going to add four words to the message */
834 buffer_init(&st->buffer,calculate_max_start_pad());
835 /* Give the netlink code an opportunity to put its own stuff in the
836 message (configuration information, etc.) */
837 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
838 if (call_transform_forwards(st,st->new_transform,
839 &st->buffer,&transform_err))
841 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
842 buf_prepend_uint32(&st->buffer,st->index);
843 buf_prepend_uint32(&st->buffer,st->setup_session_id);
845 st->retries=st->setup_retries;
849 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
850 const struct comm_addr *src,
851 struct transform_inst_if *transform)
854 cstring_t transform_err;
856 if (!unpick_msg0(st,msg5,&m)) return False;
858 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
859 /* There's a problem */
860 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
863 /* Buffer should now contain untransformed PING packet data */
865 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
866 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
869 /* Older versions of secnet used to write some config data here
870 * which we ignore. So we don't CHECK_EMPTY */
874 static void create_msg6(struct site *st, struct transform_inst_if *transform,
877 cstring_t transform_err;
879 BUF_ALLOC(&st->buffer,"site:MSG6");
880 /* We are going to add four words to the message */
881 buffer_init(&st->buffer,calculate_max_start_pad());
882 /* Give the netlink code an opportunity to put its own stuff in the
883 message (configuration information, etc.) */
884 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
885 int problem = call_transform_forwards(st,transform,
886 &st->buffer,&transform_err);
888 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
889 buf_prepend_uint32(&st->buffer,st->index);
890 buf_prepend_uint32(&st->buffer,session_id);
893 static bool_t generate_msg6(struct site *st)
895 if (!is_transform_valid(st->new_transform))
897 create_msg6(st,st->new_transform,st->setup_session_id);
898 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
902 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
903 const struct comm_addr *src)
906 cstring_t transform_err;
908 if (!unpick_msg0(st,msg6,&m)) return False;
910 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
911 /* There's a problem */
912 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
915 /* Buffer should now contain untransformed PING packet data */
917 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
918 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
921 /* Older versions of secnet used to write some config data here
922 * which we ignore. So we don't CHECK_EMPTY */
926 static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
927 const struct comm_addr *src)
929 cstring_t transform_err, auxkey_err, newkey_err="n/a";
933 if (!unpick_msg0(st,msg0,&m)) return False;
935 /* Keep a copy so we can try decrypting it with multiple keys */
936 buffer_copy(&st->scratch, msg0);
938 problem = call_transform_reverse(st,st->current.transform,
939 msg0,&transform_err);
941 if (!st->auxiliary_is_new)
942 delete_one_key(st,&st->auxiliary_key,
943 "peer has used new key","auxiliary key",LOG_SEC);
949 buffer_copy(msg0, &st->scratch);
950 problem = call_transform_reverse(st,st->auxiliary_key.transform,
953 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
954 if (st->auxiliary_is_new) {
955 /* We previously timed out in state SENTMSG5 but it turns
956 * out that our peer did in fact get our MSG5 and is
957 * using the new key. So we should switch to it too. */
958 /* This is a bit like activate_new_key. */
961 st->current=st->auxiliary_key;
964 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
965 "previous key",LOG_SEC);
966 st->auxiliary_is_new=0;
967 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
974 if (st->state==SITE_SENTMSG5) {
975 buffer_copy(msg0, &st->scratch);
976 problem = call_transform_reverse(st,st->new_transform,
979 /* It looks like we didn't get the peer's MSG6 */
980 /* This is like a cut-down enter_new_state(SITE_RUN) */
981 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
982 BUF_FREE(&st->buffer);
984 activate_new_key(st);
985 return True; /* do process the data in this packet */
991 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
992 transform_err,auxkey_err,newkey_err);
993 initiate_key_setup(st,"incoming message would not decrypt",0);
994 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
998 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
1002 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1003 const struct comm_addr *src)
1007 if (!decrypt_msg0(st,msg0,src))
1010 CHECK_AVAIL(msg0,4);
1011 type=buf_unprepend_uint32(msg0);
1014 /* We must forget about the current session. */
1015 delete_keys(st,"request from peer",LOG_SEC);
1018 /* Deliver to netlink layer */
1019 st->netlink->deliver(st->netlink->st,msg0);
1020 transport_data_msgok(st,src);
1021 /* See whether we should start negotiating a new key */
1022 if (st->now > st->renegotiate_key_time)
1023 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1026 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1033 static void dump_packet(struct site *st, struct buffer_if *buf,
1034 const struct comm_addr *addr, bool_t incoming)
1036 uint32_t dest=get_uint32(buf->start);
1037 uint32_t source=get_uint32(buf->start+4);
1038 uint32_t msgtype=get_uint32(buf->start+8);
1040 if (st->log_events & LOG_DUMP)
1041 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
1042 st->tunname,incoming?"incoming":"outgoing",
1043 dest,source,msgtype);
1046 static uint32_t site_status(void *st)
1051 static bool_t send_msg(struct site *st)
1053 if (st->retries>0) {
1054 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1055 st->timeout=st->now+st->setup_retry_interval;
1058 } else if (st->state==SITE_SENTMSG5) {
1059 slog(st,LOG_SETUP_TIMEOUT,"timed out sending MSG5, stashing new key");
1060 /* We stash the key we have produced, in case it turns out that
1061 * our peer did see our MSG5 after all and starts using it. */
1062 /* This is a bit like some of activate_new_key */
1063 struct transform_inst_if *t;
1064 t=st->auxiliary_key.transform;
1065 st->auxiliary_key.transform=st->new_transform;
1066 st->new_transform=t;
1067 dispose_transform(&st->new_transform);
1069 st->auxiliary_is_new=1;
1070 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1071 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1072 st->auxiliary_key.remote_session_id=st->setup_session_id;
1074 enter_state_wait(st);
1077 slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
1078 "(in state %s)",state_name(st->state));
1079 enter_state_wait(st);
1084 static void site_resolve_callback(void *sst, struct in_addr *address)
1086 struct site *st=sst;
1087 struct comm_addr ca_buf, *ca_use;
1089 if (st->state!=SITE_RESOLVE) {
1090 slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
1095 ca_buf.comm=st->comms[0];
1096 ca_buf.sin.sin_family=AF_INET;
1097 ca_buf.sin.sin_port=htons(st->remoteport);
1098 ca_buf.sin.sin_addr=*address;
1101 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
1104 if (transport_compute_setupinit_peers(st,ca_use,0)) {
1105 enter_new_state(st,SITE_SENTMSG1);
1107 /* Can't figure out who to try to to talk to */
1108 slog(st,LOG_SETUP_INIT,"key exchange failed: cannot find peer address");
1109 enter_state_run(st);
1113 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1114 const struct comm_addr *prod_hint)
1116 if (st->state!=SITE_RUN) return False;
1117 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1119 slog(st,LOG_SETUP_INIT,"resolving peer address");
1120 return enter_state_resolve(st);
1121 } else if (transport_compute_setupinit_peers(st,0,prod_hint)) {
1122 return enter_new_state(st,SITE_SENTMSG1);
1124 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1128 static void activate_new_key(struct site *st)
1130 struct transform_inst_if *t;
1132 /* We have three transform instances, which we swap between old,
1134 t=st->auxiliary_key.transform;
1135 st->auxiliary_key.transform=st->current.transform;
1136 st->current.transform=st->new_transform;
1137 st->new_transform=t;
1138 dispose_transform(&st->new_transform);
1141 st->auxiliary_is_new=0;
1142 st->auxiliary_key.key_timeout=st->current.key_timeout;
1143 st->current.key_timeout=st->now+st->key_lifetime;
1144 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1145 transport_peers_copy(st,&st->peers,&st->setup_peers);
1146 st->current.remote_session_id=st->setup_session_id;
1148 slog(st,LOG_ACTIVATE_KEY,"new key activated");
1149 enter_state_run(st);
1152 static void delete_one_key(struct site *st, struct data_key *key,
1153 cstring_t reason, cstring_t which, uint32_t loglevel)
1155 if (!is_transform_valid(key->transform)) return;
1156 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1157 dispose_transform(&key->transform);
1161 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1163 if (current_valid(st)) {
1164 slog(st,loglevel,"session closed (%s)",reason);
1166 delete_one_key(st,&st->current,0,0,0);
1167 set_link_quality(st);
1169 delete_one_key(st,&st->auxiliary_key,0,0,0);
1172 static void state_assert(struct site *st, bool_t ok)
1174 if (!ok) fatal("site:state_assert");
1177 static void enter_state_stop(struct site *st)
1179 st->state=SITE_STOP;
1181 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1182 dispose_transform(&st->new_transform);
1185 static void set_link_quality(struct site *st)
1188 if (current_valid(st))
1189 quality=LINK_QUALITY_UP;
1190 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1191 quality=LINK_QUALITY_DOWN;
1192 else if (st->address)
1193 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1194 else if (transport_peers_valid(&st->peers))
1195 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1197 quality=LINK_QUALITY_DOWN;
1199 st->netlink->set_quality(st->netlink->st,quality);
1202 static void enter_state_run(struct site *st)
1204 slog(st,LOG_STATE,"entering state RUN");
1208 st->setup_session_id=0;
1209 transport_peers_clear(st,&st->setup_peers);
1210 memset(st->localN,0,NONCELEN);
1211 memset(st->remoteN,0,NONCELEN);
1212 dispose_transform(&st->new_transform);
1213 memset(st->dhsecret,0,st->dh->len);
1214 memset(st->sharedsecret,0,st->sharedsecretlen);
1215 set_link_quality(st);
1218 static bool_t enter_state_resolve(struct site *st)
1220 state_assert(st,st->state==SITE_RUN);
1221 slog(st,LOG_STATE,"entering state RESOLVE");
1222 st->state=SITE_RESOLVE;
1223 st->resolver->request(st->resolver->st,st->address,
1224 site_resolve_callback,st);
1228 static bool_t enter_new_state(struct site *st, uint32_t next)
1230 bool_t (*gen)(struct site *st);
1233 slog(st,LOG_STATE,"entering state %s",state_name(next));
1236 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1240 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1241 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1245 state_assert(st,st->state==SITE_SENTMSG1);
1246 BUF_FREE(&st->buffer);
1250 state_assert(st,st->state==SITE_SENTMSG2);
1251 BUF_FREE(&st->buffer);
1255 state_assert(st,st->state==SITE_SENTMSG3);
1256 BUF_FREE(&st->buffer);
1260 state_assert(st,st->state==SITE_SENTMSG4);
1261 BUF_FREE(&st->buffer);
1266 fatal("enter_new_state(%s): invalid new state",state_name(next));
1270 if (hacky_par_start_failnow()) return False;
1272 r= gen(st) && send_msg(st);
1275 st->setup_retries, st->setup_retry_interval,
1280 if (next==SITE_RUN) {
1281 BUF_FREE(&st->buffer); /* Never reused */
1282 st->timeout=0; /* Never retransmit */
1283 activate_new_key(st);
1287 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1288 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1289 in either state, and enter_state_wait() will
1291 enter_state_wait(st);
1295 /* msg7 tells our peer that we're about to forget our key */
1296 static bool_t send_msg7(struct site *st, cstring_t reason)
1298 cstring_t transform_err;
1300 if (current_valid(st) && st->buffer.free
1301 && transport_peers_valid(&st->peers)) {
1302 BUF_ALLOC(&st->buffer,"site:MSG7");
1303 buffer_init(&st->buffer,calculate_max_start_pad());
1304 buf_append_uint32(&st->buffer,LABEL_MSG7);
1305 buf_append_string(&st->buffer,reason);
1306 if (call_transform_forwards(st, st->current.transform,
1307 &st->buffer, &transform_err))
1309 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1310 buf_prepend_uint32(&st->buffer,st->index);
1311 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1312 transport_xmit(st,&st->peers,&st->buffer,True);
1313 BUF_FREE(&st->buffer);
1320 /* We go into this state if our peer becomes uncommunicative. Similar to
1321 the "stop" state, we forget all session keys for a while, before
1322 re-entering the "run" state. */
1323 static void enter_state_wait(struct site *st)
1325 slog(st,LOG_STATE,"entering state WAIT");
1326 st->timeout=st->now+st->wait_timeout;
1327 st->state=SITE_WAIT;
1328 set_link_quality(st);
1329 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1330 /* XXX Erase keys etc. */
1333 static void generate_prod(struct site *st, struct buffer_if *buf)
1336 buf_append_uint32(buf,0);
1337 buf_append_uint32(buf,0);
1338 buf_append_uint32(buf,LABEL_PROD);
1339 buf_append_string(buf,st->localname);
1340 buf_append_string(buf,st->remotename);
1343 static void generate_send_prod(struct site *st,
1344 const struct comm_addr *source)
1346 if (!st->allow_send_prod) return; /* too soon */
1347 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1348 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1350 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1351 st->allow_send_prod=0;
1352 generate_prod(st,&st->scratch);
1353 dump_packet(st,&st->scratch,source,False);
1354 source->comm->sendmsg(source->comm->st, &st->scratch, source);
1357 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1360 int64_t offset=timeout-*now;
1361 if (offset<0) offset=0;
1362 if (offset>INT_MAX) offset=INT_MAX;
1363 if (*timeout_io<0 || offset<*timeout_io)
1368 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1371 struct site *st=sst;
1373 *nfds_io=0; /* We don't use any file descriptors */
1376 /* Work out when our next timeout is. The earlier of 'timeout' or
1377 'current.key_timeout'. A stored value of '0' indicates no timeout
1379 site_settimeout(st->timeout, timeout_io);
1380 site_settimeout(st->current.key_timeout, timeout_io);
1381 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1383 return 0; /* success */
1386 static void check_expiry(struct site *st, struct data_key *key,
1389 if (key->key_timeout && *now>key->key_timeout) {
1390 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1394 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1395 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1397 struct site *st=sst;
1400 if (st->timeout && *now>st->timeout) {
1402 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1403 if (!hacky_par_start_failnow())
1405 } else if (st->state==SITE_WAIT) {
1406 enter_state_run(st);
1408 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1412 check_expiry(st,&st->current,"current key");
1413 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1416 /* This function is called by the netlink device to deliver packets
1417 intended for the remote network. The packet is in "raw" wire
1418 format, but is guaranteed to be word-aligned. */
1419 static void site_outgoing(void *sst, struct buffer_if *buf)
1421 struct site *st=sst;
1422 cstring_t transform_err;
1424 if (st->state==SITE_STOP) {
1429 st->allow_send_prod=1;
1431 /* In all other states we consider delivering the packet if we have
1432 a valid key and a valid address to send it to. */
1433 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1434 /* Transform it and send it */
1436 buf_prepend_uint32(buf,LABEL_MSG9);
1437 if (call_transform_forwards(st, st->current.transform,
1438 buf, &transform_err))
1440 buf_prepend_uint32(buf,LABEL_MSG0);
1441 buf_prepend_uint32(buf,st->index);
1442 buf_prepend_uint32(buf,st->current.remote_session_id);
1443 transport_xmit(st,&st->peers,buf,False);
1450 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1452 initiate_key_setup(st,"outgoing packet",0);
1455 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1456 uint32_t type, struct msg *m)
1457 /* For packets which are identified by the local and remote names.
1458 * If it has our name and our peer's name in it it's for us. */
1460 struct buffer_if buf[1];
1461 buffer_readonly_clone(buf,buf_in);
1462 return unpick_msg(st,type,buf,m)
1463 && name_matches(&m->remote,st->remotename)
1464 && name_matches(&m->local,st->localname);
1467 /* This function is called by the communication device to deliver
1468 packets from our peers.
1469 It should return True if the packet is recognised as being for
1470 this current site instance (and should therefore not be processed
1471 by other sites), even if the packet was otherwise ignored. */
1472 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1473 const struct comm_addr *source)
1475 struct site *st=sst;
1477 if (buf->size < 12) return False;
1479 uint32_t dest=get_uint32(buf->start);
1480 uint32_t msgtype=get_uint32(buf->start+8);
1481 struct msg named_msg;
1483 if (msgtype==LABEL_MSG1) {
1484 if (!named_for_us(st,buf,msgtype,&named_msg))
1486 /* It's a MSG1 addressed to us. Decide what to do about it. */
1487 dump_packet(st,buf,source,True);
1488 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1489 st->state==SITE_WAIT) {
1490 /* We should definitely process it */
1491 if (process_msg1(st,buf,source,&named_msg)) {
1492 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1493 enter_new_state(st,SITE_SENTMSG2);
1495 slog(st,LOG_ERROR,"failed to process incoming msg1");
1499 } else if (st->state==SITE_SENTMSG1) {
1500 /* We've just sent a message 1! They may have crossed on
1501 the wire. If we have priority then we ignore the
1502 incoming one, otherwise we process it as usual. */
1503 if (st->setup_priority) {
1505 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1506 "priority => ignore incoming msg1");
1509 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1510 "priority => use incoming msg1");
1511 if (process_msg1(st,buf,source,&named_msg)) {
1512 BUF_FREE(&st->buffer); /* Free our old message 1 */
1513 enter_new_state(st,SITE_SENTMSG2);
1515 slog(st,LOG_ERROR,"failed to process an incoming "
1516 "crossed msg1 (we have low priority)");
1522 /* The message 1 was received at an unexpected stage of the
1523 key setup. XXX POLICY - what do we do? */
1524 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1528 if (msgtype==LABEL_PROD) {
1529 if (!named_for_us(st,buf,msgtype,&named_msg))
1531 dump_packet(st,buf,source,True);
1532 if (st->state!=SITE_RUN) {
1533 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1534 } else if (current_valid(st)) {
1535 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1537 initiate_key_setup(st,"peer sent PROD packet",source);
1542 if (dest==st->index) {
1543 /* Explicitly addressed to us */
1544 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1547 /* If the source is our current peer then initiate a key setup,
1548 because our peer's forgotten the key */
1549 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1551 initiated = initiate_key_setup(st,"received a NAK",0);
1552 if (!initiated) generate_send_prod(st,source);
1554 slog(st,LOG_SEC,"bad incoming NAK");
1558 process_msg0(st,buf,source);
1561 /* Setup packet: should not have been explicitly addressed
1563 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1566 /* Setup packet: expected only in state SENTMSG1 */
1567 if (st->state!=SITE_SENTMSG1) {
1568 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1569 } else if (process_msg2(st,buf,source)) {
1570 transport_setup_msgok(st,source);
1571 enter_new_state(st,SITE_SENTMSG3);
1573 slog(st,LOG_SEC,"invalid MSG2");
1578 /* Setup packet: expected only in state SENTMSG2 */
1579 if (st->state!=SITE_SENTMSG2) {
1580 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1581 } else if (process_msg3(st,buf,source,msgtype)) {
1582 transport_setup_msgok(st,source);
1583 enter_new_state(st,SITE_SENTMSG4);
1585 slog(st,LOG_SEC,"invalid MSG3");
1589 /* Setup packet: expected only in state SENTMSG3 */
1590 if (st->state!=SITE_SENTMSG3) {
1591 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1592 } else if (process_msg4(st,buf,source)) {
1593 transport_setup_msgok(st,source);
1594 enter_new_state(st,SITE_SENTMSG5);
1596 slog(st,LOG_SEC,"invalid MSG4");
1600 /* Setup packet: expected only in state SENTMSG4 */
1601 /* (may turn up in state RUN if our return MSG6 was lost
1602 and the new key has already been activated. In that
1603 case we discard it. The peer will realise that we
1604 are using the new key when they see our data packets.
1605 Until then the peer's data packets to us get discarded. */
1606 if (st->state==SITE_SENTMSG4) {
1607 if (process_msg5(st,buf,source,st->new_transform)) {
1608 transport_setup_msgok(st,source);
1609 enter_new_state(st,SITE_RUN);
1611 slog(st,LOG_SEC,"invalid MSG5");
1613 } else if (st->state==SITE_RUN) {
1614 if (process_msg5(st,buf,source,st->current.transform)) {
1615 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1616 transport_setup_msgok(st,source);
1617 create_msg6(st,st->current.transform,
1618 st->current.remote_session_id);
1619 transport_xmit(st,&st->peers,&st->buffer,True);
1620 BUF_FREE(&st->buffer);
1622 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1625 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
1629 /* Setup packet: expected only in state SENTMSG5 */
1630 if (st->state!=SITE_SENTMSG5) {
1631 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1632 } else if (process_msg6(st,buf,source)) {
1633 BUF_FREE(&st->buffer); /* Free message 5 */
1634 transport_setup_msgok(st,source);
1635 activate_new_key(st);
1637 slog(st,LOG_SEC,"invalid MSG6");
1641 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
1652 static void site_control(void *vst, bool_t run)
1654 struct site *st=vst;
1655 if (run) enter_state_run(st);
1656 else enter_state_stop(st);
1659 static void site_phase_hook(void *sst, uint32_t newphase)
1661 struct site *st=sst;
1663 /* The program is shutting down; tell our peer */
1664 send_msg7(st,"shutting down");
1667 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1670 static uint32_t index_sequence;
1676 st=safe_malloc(sizeof(*st),"site_apply");
1678 st->cl.description="site";
1679 st->cl.type=CL_SITE;
1681 st->cl.interface=&st->ops;
1683 st->ops.control=site_control;
1684 st->ops.status=site_status;
1686 /* First parameter must be a dict */
1687 item=list_elem(args,0);
1688 if (!item || item->type!=t_dict)
1689 cfgfatal(loc,"site","parameter must be a dictionary\n");
1691 dict=item->data.dict;
1692 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1693 st->remotename=dict_read_string(dict, "name", True, "site", loc);
1695 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1696 bool_t local_mobile=
1697 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1699 /* Sanity check (which also allows the 'sites' file to include
1700 site() closures for all sites including our own): refuse to
1701 talk to ourselves */
1702 if (strcmp(st->localname,st->remotename)==0) {
1703 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
1705 if (st->peer_mobile != local_mobile)
1706 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1707 " but our local-mobile=%d\n",
1708 st->localname, st->peer_mobile, local_mobile);
1712 if (st->peer_mobile && local_mobile) {
1713 Message(M_WARNING,"site %s: site is mobile but so are we"
1714 " -> ignoring this site\n", st->remotename);
1719 assert(index_sequence < 0xffffffffUL);
1720 st->index = ++index_sequence;
1721 st->local_capabilities = 0;
1722 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
1724 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
1725 list_t *things##_cfg=dict_lookup(dict,dictkey); \
1726 if (!things##_cfg) \
1727 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
1728 st->nthings=list_length(things##_cfg); \
1729 st->things=safe_malloc_ary(sizeof(*st->things),st->nthings,dictkey "s"); \
1730 assert(st->nthings); \
1731 for (i=0; i<st->nthings; i++) { \
1732 item_t *item=list_elem(things##_cfg,i); \
1733 if (item->type!=t_closure) \
1734 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
1735 closure_t *cl=item->data.closure; \
1736 if (cl->type!=CL_TYPE) \
1737 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
1738 st->things[i]=cl->interface; \
1742 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
1744 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1745 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1746 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1748 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
1749 st->address=dict_read_string(dict, "address", False, "site", loc);
1751 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1752 else st->remoteport=0;
1753 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1755 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
1757 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1758 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1760 #define DEFAULT(D) (st->peer_mobile || local_mobile \
1761 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
1762 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
1764 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1765 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1766 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1767 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1769 st->mobile_peer_expiry= dict_read_number(
1770 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1772 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1773 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1774 if (st->transport_peers_max<1 ||
1775 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1776 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1777 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1780 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
1781 st->key_renegotiate_time=st->key_lifetime/2;
1783 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
1784 st->key_renegotiate_time=dict_read_number(
1785 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
1786 if (st->key_renegotiate_time > st->key_lifetime) {
1787 cfgfatal(loc,"site",
1788 "renegotiate-time must be less than key-lifetime\n");
1791 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1792 log_event_table,"site");
1794 st->allow_send_prod=0;
1796 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1798 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1800 /* The information we expect to see in incoming messages of type 1 */
1801 /* fixme: lots of unchecked overflows here, but the results are only
1802 corrupted packets rather than undefined behaviour */
1803 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1805 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1807 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
1808 BUF_ALLOC(&st->scratch,"site:scratch");
1810 /* We are interested in poll(), but only for timeouts. We don't have
1811 any fds of our own. */
1812 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1815 st->remote_capabilities=0;
1816 st->chosen_transform=0;
1817 st->current.key_timeout=0;
1818 st->auxiliary_key.key_timeout=0;
1819 transport_peers_clear(st,&st->peers);
1820 transport_peers_clear(st,&st->setup_peers);
1821 /* XXX mlock these */
1822 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
1823 st->sharedsecretlen=st->sharedsecretallocd=0;
1826 for (i=0; i<st->ntransforms; i++) {
1827 struct transform_if *ti=st->transforms[i];
1828 uint32_t capbit = 1UL << ti->capab_transformnum;
1829 if (st->local_capabilities & capbit)
1830 slog(st,LOG_ERROR,"transformnum capability bit"
1831 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
1832 st->local_capabilities |= capbit;
1835 /* We need to register the remote networks with the netlink device */
1836 st->netlink->reg(st->netlink->st, site_outgoing, st, 0);
1838 for (i=0; i<st->ncomms; i++)
1839 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
1841 st->current.transform=0;
1842 st->auxiliary_key.transform=0;
1843 st->new_transform=0;
1844 st->auxiliary_is_new=0;
1846 enter_state_stop(st);
1848 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
1850 return new_closure(&st->cl);
1853 void site_module(dict_t *dict)
1855 add_closure(dict,"site",site_apply);
1859 /***** TRANSPORT PEERS definitions *****/
1861 static void transport_peers_debug(struct site *st, transport_peers *dst,
1862 const char *didwhat,
1863 int nargs, const struct comm_addr *args,
1868 if (!(st->log_events & LOG_PEER_ADDRS))
1869 return; /* an optimisation */
1871 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
1872 (dst==&st->peers ? "data" :
1873 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
1874 didwhat, nargs, dst->npeers);
1876 for (i=0, argp=(void*)args;
1878 i++, (argp+=stride?stride:sizeof(*args))) {
1879 const struct comm_addr *ca=(void*)argp;
1880 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1881 i, ca->comm->addr_to_string(ca->comm->st,ca));
1883 for (i=0; i<dst->npeers; i++) {
1884 struct timeval diff;
1885 timersub(tv_now,&dst->peers[i].last,&diff);
1886 const struct comm_addr *ca=&dst->peers[i].addr;
1887 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1888 i, ca->comm->addr_to_string(ca->comm->st,ca),
1889 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
1893 static int transport_peer_compar(const void *av, const void *bv) {
1894 const transport_peer *a=av;
1895 const transport_peer *b=bv;
1896 /* put most recent first in the array */
1897 if (timercmp(&a->last, &b->last, <)) return +1;
1898 if (timercmp(&a->last, &b->last, >)) return -11;
1902 static void transport_peers_expire(struct site *st, transport_peers *peers) {
1903 /* peers must be sorted first */
1904 int previous_peers=peers->npeers;
1905 struct timeval oldest;
1906 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
1907 oldest.tv_usec = tv_now->tv_usec;
1908 while (peers->npeers>1 &&
1909 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
1911 if (peers->npeers != previous_peers)
1912 transport_peers_debug(st,peers,"expire", 0,0,0);
1915 static void transport_record_peer(struct site *st, transport_peers *peers,
1916 const struct comm_addr *addr, const char *m) {
1917 int slot, changed=0;
1919 for (slot=0; slot<peers->npeers; slot++)
1920 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
1924 if (peers->npeers==st->transport_peers_max)
1925 slot=st->transport_peers_max;
1927 slot=peers->npeers++;
1930 peers->peers[slot].addr=*addr;
1931 peers->peers[slot].last=*tv_now;
1933 if (peers->npeers>1)
1934 qsort(peers->peers, peers->npeers,
1935 sizeof(*peers->peers), transport_peer_compar);
1937 if (changed || peers->npeers!=1)
1938 transport_peers_debug(st,peers,m, 1,addr,0);
1939 transport_peers_expire(st, peers);
1942 static bool_t transport_compute_setupinit_peers(struct site *st,
1943 const struct comm_addr *configured_addr /* 0 if none or not found */,
1944 const struct comm_addr *prod_hint_addr /* 0 if none */) {
1946 if (!configured_addr && !prod_hint_addr &&
1947 !transport_peers_valid(&st->peers))
1950 slog(st,LOG_SETUP_INIT,
1951 "using:%s%s %d old peer address(es)",
1952 configured_addr ? " configured address;" : "",
1953 prod_hint_addr ? " PROD hint address;" : "",
1956 /* Non-mobile peers havve st->peers.npeers==0 or ==1, since they
1957 * have transport_peers_max==1. The effect is that this code
1958 * always uses the configured address if supplied, or otherwise
1959 * the address of the incoming PROD, or the existing data peer if
1960 * one exists; this is as desired. */
1962 transport_peers_copy(st,&st->setup_peers,&st->peers);
1965 transport_record_peer(st,&st->setup_peers,prod_hint_addr,"prod");
1967 if (configured_addr)
1968 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
1970 assert(transport_peers_valid(&st->setup_peers));
1974 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
1975 if (st->peer_mobile)
1976 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
1978 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
1979 if (st->peer_mobile)
1980 transport_record_peer(st,&st->peers,a,"datamsg");
1983 static int transport_peers_valid(transport_peers *peers) {
1984 return peers->npeers;
1986 static void transport_peers_clear(struct site *st, transport_peers *peers) {
1988 transport_peers_debug(st,peers,"clear",0,0,0);
1990 static void transport_peers_copy(struct site *st, transport_peers *dst,
1991 const transport_peers *src) {
1992 dst->npeers=src->npeers;
1993 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
1994 transport_peers_debug(st,dst,"copy",
1995 src->npeers, &src->peers->addr, sizeof(*src->peers));
1998 void transport_xmit(struct site *st, transport_peers *peers,
1999 struct buffer_if *buf, bool_t candebug) {
2001 transport_peers_expire(st, peers);
2002 for (slot=0; slot<peers->npeers; slot++) {
2003 transport_peer *peer=&peers->peers[slot];
2005 dump_packet(st, buf, &peer->addr, False);
2006 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
2010 /***** END of transport peers declarations *****/