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 local_mobile, 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 */
238 struct netlink_if *netlink;
239 struct comm_if **comms;
241 struct resolver_if *resolver;
243 struct random_if *random;
244 struct rsaprivkey_if *privkey;
245 struct rsapubkey_if *pubkey;
246 struct transform_if **transforms;
249 struct hash_if *hash;
251 uint32_t index; /* Index of this site */
252 uint32_t local_capabilities;
253 int32_t setup_retries; /* How many times to send setup packets */
254 int32_t setup_retry_interval; /* Initial timeout for setup packets */
255 int32_t wait_timeout; /* How long to wait if setup unsuccessful */
256 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
257 int32_t key_lifetime; /* How long a key lasts once set up */
258 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
259 after this time, initiate a new
262 bool_t setup_priority; /* Do we have precedence if both sites emit
263 message 1 simultaneously? */
266 /* runtime information */
268 uint64_t now; /* Most recently seen time */
269 bool_t allow_send_prod;
272 /* The currently established session */
273 struct data_key current;
274 struct data_key auxiliary_key;
275 bool_t auxiliary_is_new;
276 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
277 uint64_t auxiliary_renegotiate_key_time;
278 transport_peers peers; /* Current address(es) of peer for data traffic */
280 /* The current key setup protocol exchange. We can only be
281 involved in one of these at a time. There's a potential for
282 denial of service here (the attacker keeps sending a setup
283 packet; we keep trying to continue the exchange, and have to
284 timeout before we can listen for another setup packet); perhaps
285 we should keep a list of 'bad' sources for setup packets. */
286 uint32_t remote_capabilities;
287 uint16_t remote_adv_mtu;
288 struct transform_if *chosen_transform;
289 uint32_t setup_session_id;
290 transport_peers setup_peers;
291 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
292 uint8_t remoteN[NONCELEN];
293 struct buffer_if buffer; /* Current outgoing key exchange packet */
294 struct buffer_if scratch;
295 int32_t retries; /* Number of retries remaining */
296 uint64_t timeout; /* Timeout for current state */
298 uint8_t *sharedsecret;
299 uint32_t sharedsecretlen, sharedsecretallocd;
300 struct transform_inst_if *new_transform; /* For key setup/verify */
303 static uint32_t event_log_priority(struct site *st, uint32_t event)
305 if (!(event&st->log_events))
308 case LOG_UNEXPECTED: return M_INFO;
309 case LOG_SETUP_INIT: return M_INFO;
310 case LOG_SETUP_TIMEOUT: return M_NOTICE;
311 case LOG_ACTIVATE_KEY: return M_INFO;
312 case LOG_TIMEOUT_KEY: return M_INFO;
313 case LOG_SEC: return M_SECURITY;
314 case LOG_STATE: return M_DEBUG;
315 case LOG_DROP: return M_DEBUG;
316 case LOG_DUMP: return M_DEBUG;
317 case LOG_ERROR: return M_ERR;
318 case LOG_PEER_ADDRS: return M_DEBUG;
319 default: return M_ERR;
323 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
325 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
329 class=event_log_priority(st, event);
331 slilog_part(st->log,class,"%s: ",st->tunname);
332 vslilog_part(st->log,class,msg,ap);
333 slilog_part(st->log,class,"\n");
337 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
339 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
343 vslog(st,event,msg,ap);
347 static void logtimeout(struct site *st, const char *fmt, ...)
349 static void logtimeout(struct site *st, const char *fmt, ...)
351 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
358 slilog_part(st->log,class,"%s: ",st->tunname);
359 vslilog_part(st->log,class,fmt,ap);
363 for (i=0, delim=" (tried ";
364 i<st->setup_peers.npeers;
366 transport_peer *peer=&st->setup_peers.peers[i];
367 const char *s=comm_addr_to_string(&peer->addr);
368 slilog_part(st->log,class,"%s%s",delim,s);
371 slilog_part(st->log,class,")\n");
375 static void set_link_quality(struct site *st);
376 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
377 static void delete_one_key(struct site *st, struct data_key *key,
378 const char *reason /* may be 0 meaning don't log*/,
379 const char *which /* ignored if !reasonn */,
380 uint32_t loglevel /* ignored if !reasonn */);
381 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
382 const struct comm_addr *prod_hint);
383 static void enter_state_run(struct site *st);
384 static bool_t enter_state_resolve(struct site *st);
385 static bool_t enter_new_state(struct site *st,uint32_t next);
386 static void enter_state_wait(struct site *st);
387 static void activate_new_key(struct site *st);
389 static bool_t is_transform_valid(struct transform_inst_if *transform)
391 return transform && transform->valid(transform->st);
394 static bool_t current_valid(struct site *st)
396 return is_transform_valid(st->current.transform);
399 #define DEFINE_CALL_TRANSFORM(fwdrev) \
400 static int call_transform_##fwdrev(struct site *st, \
401 struct transform_inst_if *transform, \
402 struct buffer_if *buf, \
403 const char **errmsg) \
405 if (!is_transform_valid(transform)) { \
406 *errmsg="transform not set up"; \
409 return transform->fwdrev(transform->st,buf,errmsg); \
412 DEFINE_CALL_TRANSFORM(forwards)
413 DEFINE_CALL_TRANSFORM(reverse)
415 static void dispose_transform(struct transform_inst_if **transform_var)
417 struct transform_inst_if *transform=*transform_var;
419 transform->delkey(transform->st);
420 transform->destroy(transform->st);
425 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
426 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
427 #define CHECK_TYPE(b,t) do { uint32_t type; \
428 CHECK_AVAIL((b),4); \
429 type=buf_unprepend_uint32((b)); \
430 if (type!=(t)) return False; } while(0)
432 static _Bool type_is_msg34(uint32_t type)
435 type == LABEL_MSG3 ||
436 type == LABEL_MSG3BIS ||
443 struct buffer_if extrainfo;
450 struct parsedname remote;
451 struct parsedname local;
452 uint32_t remote_capabilities;
454 int capab_transformnum;
464 static void set_new_transform(struct site *st, char *pk)
466 /* Make room for the shared key */
467 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
468 assert(st->sharedsecretlen);
469 if (st->sharedsecretlen > st->sharedsecretallocd) {
470 st->sharedsecretallocd=st->sharedsecretlen;
471 st->sharedsecret=realloc(st->sharedsecret,st->sharedsecretallocd);
473 if (!st->sharedsecret) fatal_perror("site:sharedsecret");
475 /* Generate the shared key */
476 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
477 st->sharedsecret,st->sharedsecretlen);
479 /* Set up the transform */
480 struct transform_if *generator=st->chosen_transform;
481 struct transform_inst_if *generated=generator->create(generator->st);
482 generated->setkey(generated->st,st->sharedsecret,
483 st->sharedsecretlen,st->setup_priority);
484 dispose_transform(&st->new_transform);
485 st->new_transform=generated;
487 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
488 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
489 st->chosen_transform->capab_transformnum,
490 st->local_capabilities, st->remote_capabilities);
494 int32_t lenpos, afternul;
496 static void append_string_xinfo_start(struct buffer_if *buf,
497 struct xinfoadd *xia,
499 /* Helps construct one of the names with additional info as found
500 * in MSG1..4. Call this function first, then append all the
501 * desired extra info (not including the nul byte) to the buffer,
502 * then call append_string_xinfo_done. */
504 xia->lenpos = buf->size;
505 buf_append_string(buf,str);
506 buf_append_uint8(buf,0);
507 xia->afternul = buf->size;
509 static void append_string_xinfo_done(struct buffer_if *buf,
510 struct xinfoadd *xia)
512 /* we just need to adjust the string length */
513 if (buf->size == xia->afternul) {
514 /* no extra info, strip the nul too */
515 buf_unappend_uint8(buf);
517 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
521 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
522 out using a transform of config data supplied by netlink */
523 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
529 st->retries=st->setup_retries;
530 BUF_ALLOC(&st->buffer,what);
531 buffer_init(&st->buffer,0);
532 buf_append_uint32(&st->buffer,
533 (type==LABEL_MSG1?0:st->setup_session_id));
534 buf_append_uint32(&st->buffer,st->index);
535 buf_append_uint32(&st->buffer,type);
538 append_string_xinfo_start(&st->buffer,&xia,st->localname);
539 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
540 buf_append_uint32(&st->buffer,st->local_capabilities);
542 if (type_is_msg34(type)) {
543 buf_append_uint16(&st->buffer,st->mtu_target);
545 append_string_xinfo_done(&st->buffer,&xia);
547 buf_append_string(&st->buffer,st->remotename);
548 memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
549 if (type==LABEL_MSG1) return True;
550 memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN);
551 if (type==LABEL_MSG2) return True;
553 if (hacky_par_mid_failnow()) return False;
555 if (type==LABEL_MSG3BIS)
556 buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
558 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
559 buf_append_string(&st->buffer,dhpub);
561 hash=safe_malloc(st->hash->len, "generate_msg");
562 hst=st->hash->init();
563 st->hash->update(hst,st->buffer.start,st->buffer.size);
564 st->hash->final(hst,hash);
565 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
566 buf_append_string(&st->buffer,sig);
572 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
575 nm->len=buf_unprepend_uint16(msg);
576 CHECK_AVAIL(msg,nm->len);
577 nm->name=buf_unprepend(msg,nm->len);
578 uint8_t *nul=memchr(nm->name,0,nm->len);
580 buffer_readonly_view(&nm->extrainfo,0,0);
582 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
583 nm->len=nul-nm->name;
588 static bool_t unpick_msg(struct site *st, uint32_t type,
589 struct buffer_if *msg, struct msg *m)
591 m->capab_transformnum=-1;
592 m->hashstart=msg->start;
594 m->dest=buf_unprepend_uint32(msg);
596 m->source=buf_unprepend_uint32(msg);
597 CHECK_TYPE(msg,type);
598 if (!unpick_name(msg,&m->remote)) return False;
599 m->remote_capabilities=0;
601 if (m->remote.extrainfo.size) {
602 CHECK_AVAIL(&m->remote.extrainfo,4);
603 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
605 if (type_is_msg34(type) && m->remote.extrainfo.size) {
606 CHECK_AVAIL(&m->remote.extrainfo,2);
607 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
609 if (!unpick_name(msg,&m->local)) return False;
610 if (type==LABEL_PROD) {
614 CHECK_AVAIL(msg,NONCELEN);
615 m->nR=buf_unprepend(msg,NONCELEN);
616 if (type==LABEL_MSG1) {
620 CHECK_AVAIL(msg,NONCELEN);
621 m->nL=buf_unprepend(msg,NONCELEN);
622 if (type==LABEL_MSG2) {
626 if (type==LABEL_MSG3BIS) {
628 m->capab_transformnum = buf_unprepend_uint8(msg);
630 m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
633 m->pklen=buf_unprepend_uint16(msg);
634 CHECK_AVAIL(msg,m->pklen);
635 m->pk=buf_unprepend(msg,m->pklen);
636 m->hashlen=msg->start-m->hashstart;
638 m->siglen=buf_unprepend_uint16(msg);
639 CHECK_AVAIL(msg,m->siglen);
640 m->sig=buf_unprepend(msg,m->siglen);
645 static bool_t name_matches(const struct parsedname *nm, const char *expected)
647 int expected_len=strlen(expected);
649 nm->len == expected_len &&
650 !memcmp(nm->name, expected, expected_len);
653 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
656 if (type==LABEL_MSG1) return True;
658 /* Check that the site names and our nonce have been sent
659 back correctly, and then store our peer's nonce. */
660 if (!name_matches(&m->remote,st->remotename)) {
661 *error="wrong remote site name";
664 if (!name_matches(&m->local,st->localname)) {
665 *error="wrong local site name";
668 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
669 *error="wrong locally-generated nonce";
672 if (type==LABEL_MSG2) return True;
673 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
674 *error="wrong remotely-generated nonce";
677 /* MSG3 has complicated rules about capabilities, which are
678 * handled in process_msg3. */
679 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
680 if (m->remote_capabilities!=st->remote_capabilities) {
681 *error="remote capabilities changed";
684 if (type==LABEL_MSG4) return True;
685 *error="unknown message type";
689 static bool_t generate_msg1(struct site *st)
691 st->random->generate(st->random->st,NONCELEN,st->localN);
692 return generate_msg(st,LABEL_MSG1,"site:MSG1");
695 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
696 const struct comm_addr *src, struct msg *m)
698 /* We've already determined we're in an appropriate state to
699 process an incoming MSG1, and that the MSG1 has correct values
702 st->setup_session_id=m->source;
703 st->remote_capabilities=m->remote_capabilities;
704 memcpy(st->remoteN,m->nR,NONCELEN);
708 static bool_t generate_msg2(struct site *st)
710 st->random->generate(st->random->st,NONCELEN,st->localN);
711 return generate_msg(st,LABEL_MSG2,"site:MSG2");
714 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
715 const struct comm_addr *src)
720 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
721 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
722 slog(st,LOG_SEC,"msg2: %s",err);
725 st->setup_session_id=m.source;
726 st->remote_capabilities=m.remote_capabilities;
728 /* Select the transform to use */
730 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
731 if (!remote_transforms)
732 /* old secnets only had this one transform */
733 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
735 struct transform_if *ti;
737 for (i=0; i<st->ntransforms; i++) {
738 ti=st->transforms[i];
739 if ((1UL << ti->capab_transformnum) & remote_transforms)
740 goto transform_found;
742 slog(st,LOG_ERROR,"no transforms in common"
743 " (us %#"PRIx32"; them: %#"PRIx32")",
744 st->local_capabilities & CAPAB_TRANSFORM_MASK,
748 st->chosen_transform=ti;
750 memcpy(st->remoteN,m.nR,NONCELEN);
754 static bool_t generate_msg3(struct site *st)
756 /* Now we have our nonce and their nonce. Think of a secret key,
757 and create message number 3. */
758 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
759 return generate_msg(st,
760 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
761 ? LABEL_MSG3BIS : LABEL_MSG3),
765 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
770 /* Check signature and store g^x mod m */
771 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
772 hst=st->hash->init();
773 st->hash->update(hst,m->hashstart,m->hashlen);
774 st->hash->final(hst,hash);
775 /* Terminate signature with a '0' - cheating, but should be ok */
777 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
778 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
784 st->remote_adv_mtu=m->remote_mtu;
789 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
790 const struct comm_addr *src, uint32_t msgtype)
795 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
797 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
798 if (!check_msg(st,msgtype,&m,&err)) {
799 slog(st,LOG_SEC,"msg3: %s",err);
802 uint32_t capab_adv_late = m.remote_capabilities
803 & ~st->remote_capabilities & CAPAB_EARLY;
804 if (capab_adv_late) {
805 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
806 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
807 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
810 st->remote_capabilities|=m.remote_capabilities;
812 struct transform_if *ti;
814 for (i=0; i<st->ntransforms; i++) {
815 ti=st->transforms[i];
816 if (ti->capab_transformnum == m.capab_transformnum)
817 goto transform_found;
819 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
820 m.capab_transformnum);
823 st->chosen_transform=ti;
825 if (!process_msg3_msg4(st,&m))
828 /* Terminate their DH public key with a '0' */
830 /* Invent our DH secret key */
831 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
833 /* Generate the shared key and set up the transform */
834 set_new_transform(st,m.pk);
839 static bool_t generate_msg4(struct site *st)
841 /* We have both nonces, their public key and our private key. Generate
842 our public key, sign it and send it to them. */
843 return generate_msg(st,LABEL_MSG4,"site:MSG4");
846 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
847 const struct comm_addr *src)
852 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
853 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
854 slog(st,LOG_SEC,"msg4: %s",err);
858 if (!process_msg3_msg4(st,&m))
861 /* Terminate their DH public key with a '0' */
864 /* Generate the shared key and set up the transform */
865 set_new_transform(st,m.pk);
876 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
880 m->dest=buf_unprepend_uint32(msg0);
882 m->source=buf_unprepend_uint32(msg0);
884 m->type=buf_unprepend_uint32(msg0);
886 /* Leaves transformed part of buffer untouched */
889 static bool_t generate_msg5(struct site *st)
891 cstring_t transform_err;
893 BUF_ALLOC(&st->buffer,"site:MSG5");
894 /* We are going to add four words to the message */
895 buffer_init(&st->buffer,calculate_max_start_pad());
896 /* Give the netlink code an opportunity to put its own stuff in the
897 message (configuration information, etc.) */
898 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
899 if (call_transform_forwards(st,st->new_transform,
900 &st->buffer,&transform_err))
902 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
903 buf_prepend_uint32(&st->buffer,st->index);
904 buf_prepend_uint32(&st->buffer,st->setup_session_id);
906 st->retries=st->setup_retries;
910 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
911 const struct comm_addr *src,
912 struct transform_inst_if *transform)
915 cstring_t transform_err;
917 if (!unpick_msg0(st,msg5,&m)) return False;
919 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
920 /* There's a problem */
921 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
924 /* Buffer should now contain untransformed PING packet data */
926 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
927 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
930 /* Older versions of secnet used to write some config data here
931 * which we ignore. So we don't CHECK_EMPTY */
935 static void create_msg6(struct site *st, struct transform_inst_if *transform,
938 cstring_t transform_err;
940 BUF_ALLOC(&st->buffer,"site:MSG6");
941 /* We are going to add four words to the message */
942 buffer_init(&st->buffer,calculate_max_start_pad());
943 /* Give the netlink code an opportunity to put its own stuff in the
944 message (configuration information, etc.) */
945 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
946 int problem = call_transform_forwards(st,transform,
947 &st->buffer,&transform_err);
949 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
950 buf_prepend_uint32(&st->buffer,st->index);
951 buf_prepend_uint32(&st->buffer,session_id);
954 static bool_t generate_msg6(struct site *st)
956 if (!is_transform_valid(st->new_transform))
958 create_msg6(st,st->new_transform,st->setup_session_id);
959 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
963 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
964 const struct comm_addr *src)
967 cstring_t transform_err;
969 if (!unpick_msg0(st,msg6,&m)) return False;
971 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
972 /* There's a problem */
973 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
976 /* Buffer should now contain untransformed PING packet data */
978 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
979 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
982 /* Older versions of secnet used to write some config data here
983 * which we ignore. So we don't CHECK_EMPTY */
987 static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
988 const struct comm_addr *src)
990 cstring_t transform_err, auxkey_err, newkey_err="n/a";
994 if (!unpick_msg0(st,msg0,&m)) return False;
996 /* Keep a copy so we can try decrypting it with multiple keys */
997 buffer_copy(&st->scratch, msg0);
999 problem = call_transform_reverse(st,st->current.transform,
1000 msg0,&transform_err);
1002 if (!st->auxiliary_is_new)
1003 delete_one_key(st,&st->auxiliary_key,
1004 "peer has used new key","auxiliary key",LOG_SEC);
1010 buffer_copy(msg0, &st->scratch);
1011 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1014 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1015 if (st->auxiliary_is_new) {
1016 /* We previously timed out in state SENTMSG5 but it turns
1017 * out that our peer did in fact get our MSG5 and is
1018 * using the new key. So we should switch to it too. */
1019 /* This is a bit like activate_new_key. */
1022 st->current=st->auxiliary_key;
1023 st->auxiliary_key=t;
1025 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1026 "previous key",LOG_SEC);
1027 st->auxiliary_is_new=0;
1028 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1035 if (st->state==SITE_SENTMSG5) {
1036 buffer_copy(msg0, &st->scratch);
1037 problem = call_transform_reverse(st,st->new_transform,
1040 /* It looks like we didn't get the peer's MSG6 */
1041 /* This is like a cut-down enter_new_state(SITE_RUN) */
1042 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1043 BUF_FREE(&st->buffer);
1045 activate_new_key(st);
1046 return True; /* do process the data in this packet */
1052 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1053 transform_err,auxkey_err,newkey_err);
1054 initiate_key_setup(st,"incoming message would not decrypt",0);
1055 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1059 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
1063 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1064 const struct comm_addr *src)
1068 if (!decrypt_msg0(st,msg0,src))
1071 CHECK_AVAIL(msg0,4);
1072 type=buf_unprepend_uint32(msg0);
1075 /* We must forget about the current session. */
1076 delete_keys(st,"request from peer",LOG_SEC);
1079 /* Deliver to netlink layer */
1080 st->netlink->deliver(st->netlink->st,msg0);
1081 transport_data_msgok(st,src);
1082 /* See whether we should start negotiating a new key */
1083 if (st->now > st->renegotiate_key_time)
1084 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1087 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1094 static void dump_packet(struct site *st, struct buffer_if *buf,
1095 const struct comm_addr *addr, bool_t incoming)
1097 uint32_t dest=get_uint32(buf->start);
1098 uint32_t source=get_uint32(buf->start+4);
1099 uint32_t msgtype=get_uint32(buf->start+8);
1101 if (st->log_events & LOG_DUMP)
1102 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
1103 st->tunname,incoming?"incoming":"outgoing",
1104 dest,source,msgtype);
1107 static uint32_t site_status(void *st)
1112 static bool_t send_msg(struct site *st)
1114 if (st->retries>0) {
1115 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1116 st->timeout=st->now+st->setup_retry_interval;
1119 } else if (st->state==SITE_SENTMSG5) {
1120 logtimeout(st,"timed out sending MSG5, stashing new key");
1121 /* We stash the key we have produced, in case it turns out that
1122 * our peer did see our MSG5 after all and starts using it. */
1123 /* This is a bit like some of activate_new_key */
1124 struct transform_inst_if *t;
1125 t=st->auxiliary_key.transform;
1126 st->auxiliary_key.transform=st->new_transform;
1127 st->new_transform=t;
1128 dispose_transform(&st->new_transform);
1130 st->auxiliary_is_new=1;
1131 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1132 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1133 st->auxiliary_key.remote_session_id=st->setup_session_id;
1135 enter_state_wait(st);
1138 logtimeout(st,"timed out sending key setup packet "
1139 "(in state %s)",state_name(st->state));
1140 enter_state_wait(st);
1145 static void site_resolve_callback(void *sst, struct in_addr *address)
1147 struct site *st=sst;
1148 struct comm_addr ca_buf, *ca_use;
1150 st->resolving=False;
1154 ca_buf.comm=st->comms[0];
1155 ca_buf.sin.sin_family=AF_INET;
1156 ca_buf.sin.sin_port=htons(st->remoteport);
1157 ca_buf.sin.sin_addr=*address;
1159 slog(st,LOG_STATE,"resolution of %s completed: %s",
1160 st->address, comm_addr_to_string(ca_use));;
1162 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
1166 switch (st->state) {
1168 if (transport_compute_setupinit_peers(st,ca_use,0)) {
1169 enter_new_state(st,SITE_SENTMSG1);
1171 /* Can't figure out who to try to to talk to */
1172 slog(st,LOG_SETUP_INIT,
1173 "key exchange failed: cannot find peer address");
1174 enter_state_run(st);
1177 case SITE_SENTMSG1: case SITE_SENTMSG2:
1178 case SITE_SENTMSG3: case SITE_SENTMSG4:
1181 /* We start using the address immediately for data too.
1182 * It's best to store it in st->peers now because we might
1183 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1184 * the new key (without updating the data peer addrs). */
1185 transport_record_peer(st,&st->peers,ca_use,"resolved data");
1186 transport_record_peer(st,&st->setup_peers,ca_use,"resolved setup");
1187 } else if (st->local_mobile) {
1188 /* We can't let this rest because we may have a peer
1189 * address which will break in the future. */
1190 slog(st,LOG_SETUP_INIT,"resolution of %s failed: "
1191 "abandoning key exchange",st->address);
1192 enter_state_wait(st);
1194 slog(st,LOG_SETUP_INIT,"resolution of %s failed: "
1195 " continuing to use source address of peer's packets"
1196 " for key exchange and ultimately data",
1202 slog(st,LOG_SETUP_INIT,"resolution of %s completed tardily,"
1203 " updating peer address(es)",st->address);
1204 transport_record_peer(st,&st->peers,ca_use,"resolved tardily");
1205 } else if (st->local_mobile) {
1206 /* Not very good. We should queue (another) renegotiation
1207 * so that we can update the peer address. */
1208 st->key_renegotiate_time=st->now+st->wait_timeout;
1210 slog(st,LOG_SETUP_INIT,"resolution of %s failed: "
1211 " continuing to use source address of peer's packets",
1222 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1223 const struct comm_addr *prod_hint)
1225 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1226 if (st->state!=SITE_RUN) return False;
1227 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1229 slog(st,LOG_SETUP_INIT,"resolving peer address");
1230 return enter_state_resolve(st);
1231 } else if (transport_compute_setupinit_peers(st,0,prod_hint)) {
1232 return enter_new_state(st,SITE_SENTMSG1);
1234 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1238 static void activate_new_key(struct site *st)
1240 struct transform_inst_if *t;
1242 /* We have three transform instances, which we swap between old,
1244 t=st->auxiliary_key.transform;
1245 st->auxiliary_key.transform=st->current.transform;
1246 st->current.transform=st->new_transform;
1247 st->new_transform=t;
1248 dispose_transform(&st->new_transform);
1251 st->auxiliary_is_new=0;
1252 st->auxiliary_key.key_timeout=st->current.key_timeout;
1253 st->current.key_timeout=st->now+st->key_lifetime;
1254 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1255 transport_peers_copy(st,&st->peers,&st->setup_peers);
1256 st->current.remote_session_id=st->setup_session_id;
1258 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1259 * But their mtu be unspecified, in which case we just use ours. */
1260 uint32_t intersite_mtu=
1261 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1262 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1264 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1265 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1266 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1267 enter_state_run(st);
1270 static void delete_one_key(struct site *st, struct data_key *key,
1271 cstring_t reason, cstring_t which, uint32_t loglevel)
1273 if (!is_transform_valid(key->transform)) return;
1274 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1275 dispose_transform(&key->transform);
1279 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1281 if (current_valid(st)) {
1282 slog(st,loglevel,"session closed (%s)",reason);
1284 delete_one_key(st,&st->current,0,0,0);
1285 set_link_quality(st);
1287 delete_one_key(st,&st->auxiliary_key,0,0,0);
1290 static void state_assert(struct site *st, bool_t ok)
1292 if (!ok) fatal("site:state_assert");
1295 static void enter_state_stop(struct site *st)
1297 st->state=SITE_STOP;
1299 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1300 dispose_transform(&st->new_transform);
1303 static void set_link_quality(struct site *st)
1306 if (current_valid(st))
1307 quality=LINK_QUALITY_UP;
1308 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1309 quality=LINK_QUALITY_DOWN;
1310 else if (st->address)
1311 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1312 else if (transport_peers_valid(&st->peers))
1313 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1315 quality=LINK_QUALITY_DOWN;
1317 st->netlink->set_quality(st->netlink->st,quality);
1320 static void enter_state_run(struct site *st)
1322 slog(st,LOG_STATE,"entering state RUN");
1326 st->setup_session_id=0;
1327 transport_peers_clear(st,&st->setup_peers);
1328 memset(st->localN,0,NONCELEN);
1329 memset(st->remoteN,0,NONCELEN);
1330 dispose_transform(&st->new_transform);
1331 memset(st->dhsecret,0,st->dh->len);
1332 memset(st->sharedsecret,0,st->sharedsecretlen);
1333 set_link_quality(st);
1336 static bool_t ensure_resolving(struct site *st)
1338 /* Reentrancy hazard: may call site_resolve_callback and hence
1339 * enter_new_state, enter_state_* and generate_msg*. */
1343 assert(st->address);
1345 /* resolver->request might reentrantly call site_resolve_callback
1346 * which will clear st->resolving, so we need to set it beforehand
1347 * rather than afterwards; also, it might return False, in which
1348 * case we have to clear ->resolving again. */
1350 bool_t ok = st->resolver->request(st->resolver->st,st->address,
1351 site_resolve_callback,st);
1353 st->resolving=False;
1358 static bool_t enter_state_resolve(struct site *st)
1360 /* Reentrancy hazard! See ensure_resolving. */
1361 state_assert(st,st->state==SITE_RUN);
1362 slog(st,LOG_STATE,"entering state RESOLVE");
1363 st->state=SITE_RESOLVE;
1364 return ensure_resolving(st);
1367 static bool_t enter_new_state(struct site *st, uint32_t next)
1369 bool_t (*gen)(struct site *st);
1372 slog(st,LOG_STATE,"entering state %s",state_name(next));
1375 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1379 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1380 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1384 state_assert(st,st->state==SITE_SENTMSG1);
1385 BUF_FREE(&st->buffer);
1389 state_assert(st,st->state==SITE_SENTMSG2);
1390 BUF_FREE(&st->buffer);
1394 state_assert(st,st->state==SITE_SENTMSG3);
1395 BUF_FREE(&st->buffer);
1399 state_assert(st,st->state==SITE_SENTMSG4);
1400 BUF_FREE(&st->buffer);
1405 fatal("enter_new_state(%s): invalid new state",state_name(next));
1409 if (hacky_par_start_failnow()) return False;
1411 r= gen(st) && send_msg(st);
1414 st->setup_retries, st->setup_retry_interval,
1419 if (next==SITE_RUN) {
1420 BUF_FREE(&st->buffer); /* Never reused */
1421 st->timeout=0; /* Never retransmit */
1422 activate_new_key(st);
1426 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1427 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1428 in either state, and enter_state_wait() will
1430 enter_state_wait(st);
1434 /* msg7 tells our peer that we're about to forget our key */
1435 static bool_t send_msg7(struct site *st, cstring_t reason)
1437 cstring_t transform_err;
1439 if (current_valid(st) && st->buffer.free
1440 && transport_peers_valid(&st->peers)) {
1441 BUF_ALLOC(&st->buffer,"site:MSG7");
1442 buffer_init(&st->buffer,calculate_max_start_pad());
1443 buf_append_uint32(&st->buffer,LABEL_MSG7);
1444 buf_append_string(&st->buffer,reason);
1445 if (call_transform_forwards(st, st->current.transform,
1446 &st->buffer, &transform_err))
1448 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1449 buf_prepend_uint32(&st->buffer,st->index);
1450 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1451 transport_xmit(st,&st->peers,&st->buffer,True);
1452 BUF_FREE(&st->buffer);
1459 /* We go into this state if our peer becomes uncommunicative. Similar to
1460 the "stop" state, we forget all session keys for a while, before
1461 re-entering the "run" state. */
1462 static void enter_state_wait(struct site *st)
1464 slog(st,LOG_STATE,"entering state WAIT");
1465 st->timeout=st->now+st->wait_timeout;
1466 st->state=SITE_WAIT;
1467 set_link_quality(st);
1468 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1469 /* XXX Erase keys etc. */
1472 static void generate_prod(struct site *st, struct buffer_if *buf)
1475 buf_append_uint32(buf,0);
1476 buf_append_uint32(buf,0);
1477 buf_append_uint32(buf,LABEL_PROD);
1478 buf_append_string(buf,st->localname);
1479 buf_append_string(buf,st->remotename);
1482 static void generate_send_prod(struct site *st,
1483 const struct comm_addr *source)
1485 if (!st->allow_send_prod) return; /* too soon */
1486 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1487 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1489 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1490 st->allow_send_prod=0;
1491 generate_prod(st,&st->scratch);
1492 dump_packet(st,&st->scratch,source,False);
1493 source->comm->sendmsg(source->comm->st, &st->scratch, source);
1496 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1499 int64_t offset=timeout-*now;
1500 if (offset<0) offset=0;
1501 if (offset>INT_MAX) offset=INT_MAX;
1502 if (*timeout_io<0 || offset<*timeout_io)
1507 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1510 struct site *st=sst;
1512 *nfds_io=0; /* We don't use any file descriptors */
1515 /* Work out when our next timeout is. The earlier of 'timeout' or
1516 'current.key_timeout'. A stored value of '0' indicates no timeout
1518 site_settimeout(st->timeout, timeout_io);
1519 site_settimeout(st->current.key_timeout, timeout_io);
1520 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1522 return 0; /* success */
1525 static void check_expiry(struct site *st, struct data_key *key,
1528 if (key->key_timeout && *now>key->key_timeout) {
1529 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1533 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1534 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1536 struct site *st=sst;
1539 if (st->timeout && *now>st->timeout) {
1541 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1542 if (!hacky_par_start_failnow())
1544 } else if (st->state==SITE_WAIT) {
1545 enter_state_run(st);
1547 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1551 check_expiry(st,&st->current,"current key");
1552 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1555 /* This function is called by the netlink device to deliver packets
1556 intended for the remote network. The packet is in "raw" wire
1557 format, but is guaranteed to be word-aligned. */
1558 static void site_outgoing(void *sst, struct buffer_if *buf)
1560 struct site *st=sst;
1561 cstring_t transform_err;
1563 if (st->state==SITE_STOP) {
1568 st->allow_send_prod=1;
1570 /* In all other states we consider delivering the packet if we have
1571 a valid key and a valid address to send it to. */
1572 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1573 /* Transform it and send it */
1575 buf_prepend_uint32(buf,LABEL_MSG9);
1576 if (call_transform_forwards(st, st->current.transform,
1577 buf, &transform_err))
1579 buf_prepend_uint32(buf,LABEL_MSG0);
1580 buf_prepend_uint32(buf,st->index);
1581 buf_prepend_uint32(buf,st->current.remote_session_id);
1582 transport_xmit(st,&st->peers,buf,False);
1589 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1591 initiate_key_setup(st,"outgoing packet",0);
1594 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1595 uint32_t type, struct msg *m)
1596 /* For packets which are identified by the local and remote names.
1597 * If it has our name and our peer's name in it it's for us. */
1599 struct buffer_if buf[1];
1600 buffer_readonly_clone(buf,buf_in);
1601 return unpick_msg(st,type,buf,m)
1602 && name_matches(&m->remote,st->remotename)
1603 && name_matches(&m->local,st->localname);
1606 /* This function is called by the communication device to deliver
1607 packets from our peers.
1608 It should return True if the packet is recognised as being for
1609 this current site instance (and should therefore not be processed
1610 by other sites), even if the packet was otherwise ignored. */
1611 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1612 const struct comm_addr *source)
1614 struct site *st=sst;
1616 if (buf->size < 12) return False;
1618 uint32_t dest=get_uint32(buf->start);
1619 uint32_t msgtype=get_uint32(buf->start+8);
1620 struct msg named_msg;
1622 if (msgtype==LABEL_MSG1) {
1623 if (!named_for_us(st,buf,msgtype,&named_msg))
1625 /* It's a MSG1 addressed to us. Decide what to do about it. */
1626 dump_packet(st,buf,source,True);
1627 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1628 st->state==SITE_WAIT) {
1629 /* We should definitely process it */
1630 transport_record_peer(st,&st->setup_peers,source,"msg1");
1631 if (process_msg1(st,buf,source,&named_msg)) {
1632 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1633 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1634 if (entered && st->address && st->local_mobile)
1635 /* We must do this as the very last thing, because
1636 the resolver callback might reenter us. */
1637 ensure_resolving(st);
1639 slog(st,LOG_ERROR,"failed to process incoming msg1");
1643 } else if (st->state==SITE_SENTMSG1) {
1644 /* We've just sent a message 1! They may have crossed on
1645 the wire. If we have priority then we ignore the
1646 incoming one, otherwise we process it as usual. */
1647 if (st->setup_priority) {
1649 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1650 "priority => ignore incoming msg1");
1653 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1654 "priority => use incoming msg1");
1655 if (process_msg1(st,buf,source,&named_msg)) {
1656 BUF_FREE(&st->buffer); /* Free our old message 1 */
1657 transport_setup_msgok(st,source);
1658 enter_new_state(st,SITE_SENTMSG2);
1660 slog(st,LOG_ERROR,"failed to process an incoming "
1661 "crossed msg1 (we have low priority)");
1667 /* The message 1 was received at an unexpected stage of the
1668 key setup. XXX POLICY - what do we do? */
1669 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1673 if (msgtype==LABEL_PROD) {
1674 if (!named_for_us(st,buf,msgtype,&named_msg))
1676 dump_packet(st,buf,source,True);
1677 if (st->state!=SITE_RUN) {
1678 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1679 } else if (current_valid(st)) {
1680 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1682 initiate_key_setup(st,"peer sent PROD packet",source);
1687 if (dest==st->index) {
1688 /* Explicitly addressed to us */
1689 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1692 /* If the source is our current peer then initiate a key setup,
1693 because our peer's forgotten the key */
1694 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1696 initiated = initiate_key_setup(st,"received a NAK",0);
1697 if (!initiated) generate_send_prod(st,source);
1699 slog(st,LOG_SEC,"bad incoming NAK");
1703 process_msg0(st,buf,source);
1706 /* Setup packet: should not have been explicitly addressed
1708 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1711 /* Setup packet: expected only in state SENTMSG1 */
1712 if (st->state!=SITE_SENTMSG1) {
1713 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1714 } else if (process_msg2(st,buf,source)) {
1715 transport_setup_msgok(st,source);
1716 enter_new_state(st,SITE_SENTMSG3);
1718 slog(st,LOG_SEC,"invalid MSG2");
1723 /* Setup packet: expected only in state SENTMSG2 */
1724 if (st->state!=SITE_SENTMSG2) {
1725 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1726 } else if (process_msg3(st,buf,source,msgtype)) {
1727 transport_setup_msgok(st,source);
1728 enter_new_state(st,SITE_SENTMSG4);
1730 slog(st,LOG_SEC,"invalid MSG3");
1734 /* Setup packet: expected only in state SENTMSG3 */
1735 if (st->state!=SITE_SENTMSG3) {
1736 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1737 } else if (process_msg4(st,buf,source)) {
1738 transport_setup_msgok(st,source);
1739 enter_new_state(st,SITE_SENTMSG5);
1741 slog(st,LOG_SEC,"invalid MSG4");
1745 /* Setup packet: expected only in state SENTMSG4 */
1746 /* (may turn up in state RUN if our return MSG6 was lost
1747 and the new key has already been activated. In that
1748 case we discard it. The peer will realise that we
1749 are using the new key when they see our data packets.
1750 Until then the peer's data packets to us get discarded. */
1751 if (st->state==SITE_SENTMSG4) {
1752 if (process_msg5(st,buf,source,st->new_transform)) {
1753 transport_setup_msgok(st,source);
1754 enter_new_state(st,SITE_RUN);
1756 slog(st,LOG_SEC,"invalid MSG5");
1758 } else if (st->state==SITE_RUN) {
1759 if (process_msg5(st,buf,source,st->current.transform)) {
1760 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1761 transport_setup_msgok(st,source);
1762 create_msg6(st,st->current.transform,
1763 st->current.remote_session_id);
1764 transport_xmit(st,&st->peers,&st->buffer,True);
1765 BUF_FREE(&st->buffer);
1767 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1770 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
1774 /* Setup packet: expected only in state SENTMSG5 */
1775 if (st->state!=SITE_SENTMSG5) {
1776 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1777 } else if (process_msg6(st,buf,source)) {
1778 BUF_FREE(&st->buffer); /* Free message 5 */
1779 transport_setup_msgok(st,source);
1780 activate_new_key(st);
1782 slog(st,LOG_SEC,"invalid MSG6");
1786 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
1797 static void site_control(void *vst, bool_t run)
1799 struct site *st=vst;
1800 if (run) enter_state_run(st);
1801 else enter_state_stop(st);
1804 static void site_phase_hook(void *sst, uint32_t newphase)
1806 struct site *st=sst;
1808 /* The program is shutting down; tell our peer */
1809 send_msg7(st,"shutting down");
1812 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1815 static uint32_t index_sequence;
1821 st=safe_malloc(sizeof(*st),"site_apply");
1823 st->cl.description="site";
1824 st->cl.type=CL_SITE;
1826 st->cl.interface=&st->ops;
1828 st->ops.control=site_control;
1829 st->ops.status=site_status;
1831 /* First parameter must be a dict */
1832 item=list_elem(args,0);
1833 if (!item || item->type!=t_dict)
1834 cfgfatal(loc,"site","parameter must be a dictionary\n");
1836 dict=item->data.dict;
1837 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1838 st->remotename=dict_read_string(dict, "name", True, "site", loc);
1840 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1842 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1844 /* Sanity check (which also allows the 'sites' file to include
1845 site() closures for all sites including our own): refuse to
1846 talk to ourselves */
1847 if (strcmp(st->localname,st->remotename)==0) {
1848 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
1850 if (st->peer_mobile != st->local_mobile)
1851 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1852 " but our local-mobile=%d\n",
1853 st->localname, st->peer_mobile, st->local_mobile);
1857 if (st->peer_mobile && st->local_mobile) {
1858 Message(M_WARNING,"site %s: site is mobile but so are we"
1859 " -> ignoring this site\n", st->remotename);
1864 assert(index_sequence < 0xffffffffUL);
1865 st->index = ++index_sequence;
1866 st->local_capabilities = 0;
1867 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
1869 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
1870 list_t *things##_cfg=dict_lookup(dict,dictkey); \
1871 if (!things##_cfg) \
1872 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
1873 st->nthings=list_length(things##_cfg); \
1874 st->things=safe_malloc_ary(sizeof(*st->things),st->nthings,dictkey "s"); \
1875 assert(st->nthings); \
1876 for (i=0; i<st->nthings; i++) { \
1877 item_t *item=list_elem(things##_cfg,i); \
1878 if (item->type!=t_closure) \
1879 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
1880 closure_t *cl=item->data.closure; \
1881 if (cl->type!=CL_TYPE) \
1882 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
1883 st->things[i]=cl->interface; \
1887 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
1889 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1890 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1891 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1893 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
1894 st->address=dict_read_string(dict, "address", False, "site", loc);
1896 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1897 else st->remoteport=0;
1898 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1900 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
1902 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1903 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1905 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
1906 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
1907 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
1909 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1910 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1911 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1912 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1913 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
1915 st->mobile_peer_expiry= dict_read_number(
1916 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1918 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1919 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1920 if (st->transport_peers_max<1 ||
1921 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1922 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1923 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1926 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
1927 st->key_renegotiate_time=st->key_lifetime/2;
1929 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
1930 st->key_renegotiate_time=dict_read_number(
1931 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
1932 if (st->key_renegotiate_time > st->key_lifetime) {
1933 cfgfatal(loc,"site",
1934 "renegotiate-time must be less than key-lifetime\n");
1937 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1938 log_event_table,"site");
1940 st->resolving=False;
1941 st->allow_send_prod=0;
1943 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1945 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1947 /* The information we expect to see in incoming messages of type 1 */
1948 /* fixme: lots of unchecked overflows here, but the results are only
1949 corrupted packets rather than undefined behaviour */
1950 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1952 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1954 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
1955 BUF_ALLOC(&st->scratch,"site:scratch");
1957 /* We are interested in poll(), but only for timeouts. We don't have
1958 any fds of our own. */
1959 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1962 st->remote_capabilities=0;
1963 st->chosen_transform=0;
1964 st->current.key_timeout=0;
1965 st->auxiliary_key.key_timeout=0;
1966 transport_peers_clear(st,&st->peers);
1967 transport_peers_clear(st,&st->setup_peers);
1968 /* XXX mlock these */
1969 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
1970 st->sharedsecretlen=st->sharedsecretallocd=0;
1973 for (i=0; i<st->ntransforms; i++) {
1974 struct transform_if *ti=st->transforms[i];
1975 uint32_t capbit = 1UL << ti->capab_transformnum;
1976 if (st->local_capabilities & capbit)
1977 slog(st,LOG_ERROR,"transformnum capability bit"
1978 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
1979 st->local_capabilities |= capbit;
1982 /* We need to register the remote networks with the netlink device */
1983 uint32_t netlink_mtu; /* local virtual interface mtu */
1984 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
1985 if (!st->mtu_target)
1986 st->mtu_target=netlink_mtu;
1988 for (i=0; i<st->ncomms; i++)
1989 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
1991 st->current.transform=0;
1992 st->auxiliary_key.transform=0;
1993 st->new_transform=0;
1994 st->auxiliary_is_new=0;
1996 enter_state_stop(st);
1998 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2000 return new_closure(&st->cl);
2003 void site_module(dict_t *dict)
2005 add_closure(dict,"site",site_apply);
2009 /***** TRANSPORT PEERS definitions *****/
2011 static void transport_peers_debug(struct site *st, transport_peers *dst,
2012 const char *didwhat,
2013 int nargs, const struct comm_addr *args,
2018 if (!(st->log_events & LOG_PEER_ADDRS))
2019 return; /* an optimisation */
2021 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2022 (dst==&st->peers ? "data" :
2023 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2024 didwhat, nargs, dst->npeers);
2026 for (i=0, argp=(void*)args;
2028 i++, (argp+=stride?stride:sizeof(*args))) {
2029 const struct comm_addr *ca=(void*)argp;
2030 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2031 i, comm_addr_to_string(ca));
2033 for (i=0; i<dst->npeers; i++) {
2034 struct timeval diff;
2035 timersub(tv_now,&dst->peers[i].last,&diff);
2036 const struct comm_addr *ca=&dst->peers[i].addr;
2037 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2038 i, comm_addr_to_string(ca),
2039 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2043 static int transport_peer_compar(const void *av, const void *bv) {
2044 const transport_peer *a=av;
2045 const transport_peer *b=bv;
2046 /* put most recent first in the array */
2047 if (timercmp(&a->last, &b->last, <)) return +1;
2048 if (timercmp(&a->last, &b->last, >)) return -11;
2052 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2053 /* peers must be sorted first */
2054 int previous_peers=peers->npeers;
2055 struct timeval oldest;
2056 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2057 oldest.tv_usec = tv_now->tv_usec;
2058 while (peers->npeers>1 &&
2059 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2061 if (peers->npeers != previous_peers)
2062 transport_peers_debug(st,peers,"expire", 0,0,0);
2065 static void transport_record_peer(struct site *st, transport_peers *peers,
2066 const struct comm_addr *addr, const char *m) {
2067 int slot, changed=0;
2069 for (slot=0; slot<peers->npeers; slot++)
2070 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
2074 if (peers->npeers==st->transport_peers_max)
2075 slot=st->transport_peers_max-1;
2077 slot=peers->npeers++;
2080 peers->peers[slot].addr=*addr;
2081 peers->peers[slot].last=*tv_now;
2083 if (peers->npeers>1)
2084 qsort(peers->peers, peers->npeers,
2085 sizeof(*peers->peers), transport_peer_compar);
2087 if (changed || peers->npeers!=1)
2088 transport_peers_debug(st,peers,m, 1,addr,0);
2089 transport_peers_expire(st, peers);
2092 static bool_t transport_compute_setupinit_peers(struct site *st,
2093 const struct comm_addr *configured_addr /* 0 if none or not found */,
2094 const struct comm_addr *prod_hint_addr /* 0 if none */) {
2096 if (!configured_addr && !prod_hint_addr &&
2097 !transport_peers_valid(&st->peers))
2100 slog(st,LOG_SETUP_INIT,
2101 "using:%s%s %d old peer address(es)",
2102 configured_addr ? " configured address;" : "",
2103 prod_hint_addr ? " PROD hint address;" : "",
2106 /* Non-mobile peers have st->peers.npeers==0 or ==1, since they
2107 * have transport_peers_max==1. The effect is that this code
2108 * always uses the configured address if supplied, or otherwise
2109 * the address of the incoming PROD, or the existing data peer if
2110 * one exists; this is as desired. */
2112 transport_peers_copy(st,&st->setup_peers,&st->peers);
2115 transport_record_peer(st,&st->setup_peers,prod_hint_addr,"prod");
2117 if (configured_addr)
2118 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
2120 assert(transport_peers_valid(&st->setup_peers));
2124 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2125 if (st->peer_mobile)
2126 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
2128 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2129 if (st->peer_mobile)
2130 transport_record_peer(st,&st->peers,a,"datamsg");
2133 static int transport_peers_valid(transport_peers *peers) {
2134 return peers->npeers;
2136 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2138 transport_peers_debug(st,peers,"clear",0,0,0);
2140 static void transport_peers_copy(struct site *st, transport_peers *dst,
2141 const transport_peers *src) {
2142 dst->npeers=src->npeers;
2143 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
2144 transport_peers_debug(st,dst,"copy",
2145 src->npeers, &src->peers->addr, sizeof(*src->peers));
2148 void transport_xmit(struct site *st, transport_peers *peers,
2149 struct buffer_if *buf, bool_t candebug) {
2151 transport_peers_expire(st, peers);
2152 for (slot=0; slot<peers->npeers; slot++) {
2153 transport_peer *peer=&peers->peers[slot];
2155 dump_packet(st, buf, &peer->addr, False);
2156 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
2160 /***** END of transport peers declarations *****/