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 */
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 transport_record_peer(st,&st->setup_peers,src,"msg1");
703 st->setup_session_id=m->source;
704 st->remote_capabilities=m->remote_capabilities;
705 memcpy(st->remoteN,m->nR,NONCELEN);
709 static bool_t generate_msg2(struct site *st)
711 st->random->generate(st->random->st,NONCELEN,st->localN);
712 return generate_msg(st,LABEL_MSG2,"site:MSG2");
715 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
716 const struct comm_addr *src)
721 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
722 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
723 slog(st,LOG_SEC,"msg2: %s",err);
726 st->setup_session_id=m.source;
727 st->remote_capabilities=m.remote_capabilities;
729 /* Select the transform to use */
731 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
732 if (!remote_transforms)
733 /* old secnets only had this one transform */
734 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
736 struct transform_if *ti;
738 for (i=0; i<st->ntransforms; i++) {
739 ti=st->transforms[i];
740 if ((1UL << ti->capab_transformnum) & remote_transforms)
741 goto transform_found;
743 slog(st,LOG_ERROR,"no transforms in common"
744 " (us %#"PRIx32"; them: %#"PRIx32")",
745 st->local_capabilities & CAPAB_TRANSFORM_MASK,
749 st->chosen_transform=ti;
751 memcpy(st->remoteN,m.nR,NONCELEN);
755 static bool_t generate_msg3(struct site *st)
757 /* Now we have our nonce and their nonce. Think of a secret key,
758 and create message number 3. */
759 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
760 return generate_msg(st,
761 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
762 ? LABEL_MSG3BIS : LABEL_MSG3),
766 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
771 /* Check signature and store g^x mod m */
772 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
773 hst=st->hash->init();
774 st->hash->update(hst,m->hashstart,m->hashlen);
775 st->hash->final(hst,hash);
776 /* Terminate signature with a '0' - cheating, but should be ok */
778 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
779 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
785 st->remote_adv_mtu=m->remote_mtu;
790 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
791 const struct comm_addr *src, uint32_t msgtype)
796 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
798 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
799 if (!check_msg(st,msgtype,&m,&err)) {
800 slog(st,LOG_SEC,"msg3: %s",err);
803 uint32_t capab_adv_late = m.remote_capabilities
804 & ~st->remote_capabilities & CAPAB_EARLY;
805 if (capab_adv_late) {
806 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
807 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
808 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
811 st->remote_capabilities|=m.remote_capabilities;
813 struct transform_if *ti;
815 for (i=0; i<st->ntransforms; i++) {
816 ti=st->transforms[i];
817 if (ti->capab_transformnum == m.capab_transformnum)
818 goto transform_found;
820 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
821 m.capab_transformnum);
824 st->chosen_transform=ti;
826 if (!process_msg3_msg4(st,&m))
829 /* Terminate their DH public key with a '0' */
831 /* Invent our DH secret key */
832 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
834 /* Generate the shared key and set up the transform */
835 set_new_transform(st,m.pk);
840 static bool_t generate_msg4(struct site *st)
842 /* We have both nonces, their public key and our private key. Generate
843 our public key, sign it and send it to them. */
844 return generate_msg(st,LABEL_MSG4,"site:MSG4");
847 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
848 const struct comm_addr *src)
853 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
854 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
855 slog(st,LOG_SEC,"msg4: %s",err);
859 if (!process_msg3_msg4(st,&m))
862 /* Terminate their DH public key with a '0' */
865 /* Generate the shared key and set up the transform */
866 set_new_transform(st,m.pk);
877 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
881 m->dest=buf_unprepend_uint32(msg0);
883 m->source=buf_unprepend_uint32(msg0);
885 m->type=buf_unprepend_uint32(msg0);
887 /* Leaves transformed part of buffer untouched */
890 static bool_t generate_msg5(struct site *st)
892 cstring_t transform_err;
894 BUF_ALLOC(&st->buffer,"site:MSG5");
895 /* We are going to add four words to the message */
896 buffer_init(&st->buffer,calculate_max_start_pad());
897 /* Give the netlink code an opportunity to put its own stuff in the
898 message (configuration information, etc.) */
899 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
900 if (call_transform_forwards(st,st->new_transform,
901 &st->buffer,&transform_err))
903 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
904 buf_prepend_uint32(&st->buffer,st->index);
905 buf_prepend_uint32(&st->buffer,st->setup_session_id);
907 st->retries=st->setup_retries;
911 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
912 const struct comm_addr *src,
913 struct transform_inst_if *transform)
916 cstring_t transform_err;
918 if (!unpick_msg0(st,msg5,&m)) return False;
920 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
921 /* There's a problem */
922 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
925 /* Buffer should now contain untransformed PING packet data */
927 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
928 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
931 /* Older versions of secnet used to write some config data here
932 * which we ignore. So we don't CHECK_EMPTY */
936 static void create_msg6(struct site *st, struct transform_inst_if *transform,
939 cstring_t transform_err;
941 BUF_ALLOC(&st->buffer,"site:MSG6");
942 /* We are going to add four words to the message */
943 buffer_init(&st->buffer,calculate_max_start_pad());
944 /* Give the netlink code an opportunity to put its own stuff in the
945 message (configuration information, etc.) */
946 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
947 int problem = call_transform_forwards(st,transform,
948 &st->buffer,&transform_err);
950 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
951 buf_prepend_uint32(&st->buffer,st->index);
952 buf_prepend_uint32(&st->buffer,session_id);
955 static bool_t generate_msg6(struct site *st)
957 if (!is_transform_valid(st->new_transform))
959 create_msg6(st,st->new_transform,st->setup_session_id);
960 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
964 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
965 const struct comm_addr *src)
968 cstring_t transform_err;
970 if (!unpick_msg0(st,msg6,&m)) return False;
972 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
973 /* There's a problem */
974 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
977 /* Buffer should now contain untransformed PING packet data */
979 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
980 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
983 /* Older versions of secnet used to write some config data here
984 * which we ignore. So we don't CHECK_EMPTY */
988 static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
989 const struct comm_addr *src)
991 cstring_t transform_err, auxkey_err, newkey_err="n/a";
995 if (!unpick_msg0(st,msg0,&m)) return False;
997 /* Keep a copy so we can try decrypting it with multiple keys */
998 buffer_copy(&st->scratch, msg0);
1000 problem = call_transform_reverse(st,st->current.transform,
1001 msg0,&transform_err);
1003 if (!st->auxiliary_is_new)
1004 delete_one_key(st,&st->auxiliary_key,
1005 "peer has used new key","auxiliary key",LOG_SEC);
1011 buffer_copy(msg0, &st->scratch);
1012 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1015 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1016 if (st->auxiliary_is_new) {
1017 /* We previously timed out in state SENTMSG5 but it turns
1018 * out that our peer did in fact get our MSG5 and is
1019 * using the new key. So we should switch to it too. */
1020 /* This is a bit like activate_new_key. */
1023 st->current=st->auxiliary_key;
1024 st->auxiliary_key=t;
1026 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1027 "previous key",LOG_SEC);
1028 st->auxiliary_is_new=0;
1029 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1036 if (st->state==SITE_SENTMSG5) {
1037 buffer_copy(msg0, &st->scratch);
1038 problem = call_transform_reverse(st,st->new_transform,
1041 /* It looks like we didn't get the peer's MSG6 */
1042 /* This is like a cut-down enter_new_state(SITE_RUN) */
1043 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1044 BUF_FREE(&st->buffer);
1046 activate_new_key(st);
1047 return True; /* do process the data in this packet */
1053 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1054 transform_err,auxkey_err,newkey_err);
1055 initiate_key_setup(st,"incoming message would not decrypt",0);
1056 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1060 slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
1064 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1065 const struct comm_addr *src)
1069 if (!decrypt_msg0(st,msg0,src))
1072 CHECK_AVAIL(msg0,4);
1073 type=buf_unprepend_uint32(msg0);
1076 /* We must forget about the current session. */
1077 delete_keys(st,"request from peer",LOG_SEC);
1080 /* Deliver to netlink layer */
1081 st->netlink->deliver(st->netlink->st,msg0);
1082 transport_data_msgok(st,src);
1083 /* See whether we should start negotiating a new key */
1084 if (st->now > st->renegotiate_key_time)
1085 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1088 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1095 static void dump_packet(struct site *st, struct buffer_if *buf,
1096 const struct comm_addr *addr, bool_t incoming)
1098 uint32_t dest=get_uint32(buf->start);
1099 uint32_t source=get_uint32(buf->start+4);
1100 uint32_t msgtype=get_uint32(buf->start+8);
1102 if (st->log_events & LOG_DUMP)
1103 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
1104 st->tunname,incoming?"incoming":"outgoing",
1105 dest,source,msgtype);
1108 static uint32_t site_status(void *st)
1113 static bool_t send_msg(struct site *st)
1115 if (st->retries>0) {
1116 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1117 st->timeout=st->now+st->setup_retry_interval;
1120 } else if (st->state==SITE_SENTMSG5) {
1121 logtimeout(st,"timed out sending MSG5, stashing new key");
1122 /* We stash the key we have produced, in case it turns out that
1123 * our peer did see our MSG5 after all and starts using it. */
1124 /* This is a bit like some of activate_new_key */
1125 struct transform_inst_if *t;
1126 t=st->auxiliary_key.transform;
1127 st->auxiliary_key.transform=st->new_transform;
1128 st->new_transform=t;
1129 dispose_transform(&st->new_transform);
1131 st->auxiliary_is_new=1;
1132 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1133 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1134 st->auxiliary_key.remote_session_id=st->setup_session_id;
1136 enter_state_wait(st);
1139 logtimeout(st,"timed out sending key setup packet "
1140 "(in state %s)",state_name(st->state));
1141 enter_state_wait(st);
1146 static void site_resolve_callback(void *sst, struct in_addr *address)
1148 struct site *st=sst;
1149 struct comm_addr ca_buf, *ca_use;
1151 st->resolving=False;
1153 if (st->state!=SITE_RESOLVE) {
1154 slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
1159 ca_buf.comm=st->comms[0];
1160 ca_buf.sin.sin_family=AF_INET;
1161 ca_buf.sin.sin_port=htons(st->remoteport);
1162 ca_buf.sin.sin_addr=*address;
1165 slog(st,LOG_ERROR,"resolution of %s failed",st->address);
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,"key exchange failed: cannot find peer address");
1173 enter_state_run(st);
1177 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1178 const struct comm_addr *prod_hint)
1180 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1181 if (st->state!=SITE_RUN) return False;
1182 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1184 slog(st,LOG_SETUP_INIT,"resolving peer address");
1185 return enter_state_resolve(st);
1186 } else if (transport_compute_setupinit_peers(st,0,prod_hint)) {
1187 return enter_new_state(st,SITE_SENTMSG1);
1189 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1193 static void activate_new_key(struct site *st)
1195 struct transform_inst_if *t;
1197 /* We have three transform instances, which we swap between old,
1199 t=st->auxiliary_key.transform;
1200 st->auxiliary_key.transform=st->current.transform;
1201 st->current.transform=st->new_transform;
1202 st->new_transform=t;
1203 dispose_transform(&st->new_transform);
1206 st->auxiliary_is_new=0;
1207 st->auxiliary_key.key_timeout=st->current.key_timeout;
1208 st->current.key_timeout=st->now+st->key_lifetime;
1209 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1210 transport_peers_copy(st,&st->peers,&st->setup_peers);
1211 st->current.remote_session_id=st->setup_session_id;
1213 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1214 * But their mtu be unspecified, in which case we just use ours. */
1215 uint32_t intersite_mtu=
1216 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1217 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1219 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1220 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1221 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1222 enter_state_run(st);
1225 static void delete_one_key(struct site *st, struct data_key *key,
1226 cstring_t reason, cstring_t which, uint32_t loglevel)
1228 if (!is_transform_valid(key->transform)) return;
1229 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1230 dispose_transform(&key->transform);
1234 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1236 if (current_valid(st)) {
1237 slog(st,loglevel,"session closed (%s)",reason);
1239 delete_one_key(st,&st->current,0,0,0);
1240 set_link_quality(st);
1242 delete_one_key(st,&st->auxiliary_key,0,0,0);
1245 static void state_assert(struct site *st, bool_t ok)
1247 if (!ok) fatal("site:state_assert");
1250 static void enter_state_stop(struct site *st)
1252 st->state=SITE_STOP;
1254 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1255 dispose_transform(&st->new_transform);
1258 static void set_link_quality(struct site *st)
1261 if (current_valid(st))
1262 quality=LINK_QUALITY_UP;
1263 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1264 quality=LINK_QUALITY_DOWN;
1265 else if (st->address)
1266 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1267 else if (transport_peers_valid(&st->peers))
1268 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1270 quality=LINK_QUALITY_DOWN;
1272 st->netlink->set_quality(st->netlink->st,quality);
1275 static void enter_state_run(struct site *st)
1277 slog(st,LOG_STATE,"entering state RUN");
1281 st->setup_session_id=0;
1282 transport_peers_clear(st,&st->setup_peers);
1283 memset(st->localN,0,NONCELEN);
1284 memset(st->remoteN,0,NONCELEN);
1285 dispose_transform(&st->new_transform);
1286 memset(st->dhsecret,0,st->dh->len);
1287 memset(st->sharedsecret,0,st->sharedsecretlen);
1288 set_link_quality(st);
1291 static bool_t ensure_resolving(struct site *st)
1293 /* Reentrancy hazard: may call site_resolve_callback and hence
1294 * enter_new_state, enter_state_* and generate_msg*. */
1298 /* resolver->request might reentrantly call site_resolve_callback
1299 * which will clear st->resolving, so we need to set it beforehand
1300 * rather than afterwards; also, it might return False, in which
1301 * case we have to clear ->resolving again. */
1303 bool_t ok = st->resolver->request(st->resolver->st,st->address,
1304 site_resolve_callback,st);
1306 st->resolving=False;
1311 static bool_t enter_state_resolve(struct site *st)
1313 /* Reentrancy hazard! See ensure_resolving. */
1314 state_assert(st,st->state==SITE_RUN);
1315 slog(st,LOG_STATE,"entering state RESOLVE");
1316 st->state=SITE_RESOLVE;
1317 return ensure_resolving(st);
1320 static bool_t enter_new_state(struct site *st, uint32_t next)
1322 bool_t (*gen)(struct site *st);
1325 slog(st,LOG_STATE,"entering state %s",state_name(next));
1328 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1332 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1333 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1337 state_assert(st,st->state==SITE_SENTMSG1);
1338 BUF_FREE(&st->buffer);
1342 state_assert(st,st->state==SITE_SENTMSG2);
1343 BUF_FREE(&st->buffer);
1347 state_assert(st,st->state==SITE_SENTMSG3);
1348 BUF_FREE(&st->buffer);
1352 state_assert(st,st->state==SITE_SENTMSG4);
1353 BUF_FREE(&st->buffer);
1358 fatal("enter_new_state(%s): invalid new state",state_name(next));
1362 if (hacky_par_start_failnow()) return False;
1364 r= gen(st) && send_msg(st);
1367 st->setup_retries, st->setup_retry_interval,
1372 if (next==SITE_RUN) {
1373 BUF_FREE(&st->buffer); /* Never reused */
1374 st->timeout=0; /* Never retransmit */
1375 activate_new_key(st);
1379 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1380 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1381 in either state, and enter_state_wait() will
1383 enter_state_wait(st);
1387 /* msg7 tells our peer that we're about to forget our key */
1388 static bool_t send_msg7(struct site *st, cstring_t reason)
1390 cstring_t transform_err;
1392 if (current_valid(st) && st->buffer.free
1393 && transport_peers_valid(&st->peers)) {
1394 BUF_ALLOC(&st->buffer,"site:MSG7");
1395 buffer_init(&st->buffer,calculate_max_start_pad());
1396 buf_append_uint32(&st->buffer,LABEL_MSG7);
1397 buf_append_string(&st->buffer,reason);
1398 if (call_transform_forwards(st, st->current.transform,
1399 &st->buffer, &transform_err))
1401 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1402 buf_prepend_uint32(&st->buffer,st->index);
1403 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1404 transport_xmit(st,&st->peers,&st->buffer,True);
1405 BUF_FREE(&st->buffer);
1412 /* We go into this state if our peer becomes uncommunicative. Similar to
1413 the "stop" state, we forget all session keys for a while, before
1414 re-entering the "run" state. */
1415 static void enter_state_wait(struct site *st)
1417 slog(st,LOG_STATE,"entering state WAIT");
1418 st->timeout=st->now+st->wait_timeout;
1419 st->state=SITE_WAIT;
1420 set_link_quality(st);
1421 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1422 /* XXX Erase keys etc. */
1425 static void generate_prod(struct site *st, struct buffer_if *buf)
1428 buf_append_uint32(buf,0);
1429 buf_append_uint32(buf,0);
1430 buf_append_uint32(buf,LABEL_PROD);
1431 buf_append_string(buf,st->localname);
1432 buf_append_string(buf,st->remotename);
1435 static void generate_send_prod(struct site *st,
1436 const struct comm_addr *source)
1438 if (!st->allow_send_prod) return; /* too soon */
1439 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1440 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1442 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1443 st->allow_send_prod=0;
1444 generate_prod(st,&st->scratch);
1445 dump_packet(st,&st->scratch,source,False);
1446 source->comm->sendmsg(source->comm->st, &st->scratch, source);
1449 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1452 int64_t offset=timeout-*now;
1453 if (offset<0) offset=0;
1454 if (offset>INT_MAX) offset=INT_MAX;
1455 if (*timeout_io<0 || offset<*timeout_io)
1460 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1463 struct site *st=sst;
1465 *nfds_io=0; /* We don't use any file descriptors */
1468 /* Work out when our next timeout is. The earlier of 'timeout' or
1469 'current.key_timeout'. A stored value of '0' indicates no timeout
1471 site_settimeout(st->timeout, timeout_io);
1472 site_settimeout(st->current.key_timeout, timeout_io);
1473 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1475 return 0; /* success */
1478 static void check_expiry(struct site *st, struct data_key *key,
1481 if (key->key_timeout && *now>key->key_timeout) {
1482 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1486 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1487 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1489 struct site *st=sst;
1492 if (st->timeout && *now>st->timeout) {
1494 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1495 if (!hacky_par_start_failnow())
1497 } else if (st->state==SITE_WAIT) {
1498 enter_state_run(st);
1500 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1504 check_expiry(st,&st->current,"current key");
1505 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1508 /* This function is called by the netlink device to deliver packets
1509 intended for the remote network. The packet is in "raw" wire
1510 format, but is guaranteed to be word-aligned. */
1511 static void site_outgoing(void *sst, struct buffer_if *buf)
1513 struct site *st=sst;
1514 cstring_t transform_err;
1516 if (st->state==SITE_STOP) {
1521 st->allow_send_prod=1;
1523 /* In all other states we consider delivering the packet if we have
1524 a valid key and a valid address to send it to. */
1525 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1526 /* Transform it and send it */
1528 buf_prepend_uint32(buf,LABEL_MSG9);
1529 if (call_transform_forwards(st, st->current.transform,
1530 buf, &transform_err))
1532 buf_prepend_uint32(buf,LABEL_MSG0);
1533 buf_prepend_uint32(buf,st->index);
1534 buf_prepend_uint32(buf,st->current.remote_session_id);
1535 transport_xmit(st,&st->peers,buf,False);
1542 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1544 initiate_key_setup(st,"outgoing packet",0);
1547 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1548 uint32_t type, struct msg *m)
1549 /* For packets which are identified by the local and remote names.
1550 * If it has our name and our peer's name in it it's for us. */
1552 struct buffer_if buf[1];
1553 buffer_readonly_clone(buf,buf_in);
1554 return unpick_msg(st,type,buf,m)
1555 && name_matches(&m->remote,st->remotename)
1556 && name_matches(&m->local,st->localname);
1559 /* This function is called by the communication device to deliver
1560 packets from our peers.
1561 It should return True if the packet is recognised as being for
1562 this current site instance (and should therefore not be processed
1563 by other sites), even if the packet was otherwise ignored. */
1564 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1565 const struct comm_addr *source)
1567 struct site *st=sst;
1569 if (buf->size < 12) return False;
1571 uint32_t dest=get_uint32(buf->start);
1572 uint32_t msgtype=get_uint32(buf->start+8);
1573 struct msg named_msg;
1575 if (msgtype==LABEL_MSG1) {
1576 if (!named_for_us(st,buf,msgtype,&named_msg))
1578 /* It's a MSG1 addressed to us. Decide what to do about it. */
1579 dump_packet(st,buf,source,True);
1580 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1581 st->state==SITE_WAIT) {
1582 /* We should definitely process it */
1583 if (process_msg1(st,buf,source,&named_msg)) {
1584 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1585 enter_new_state(st,SITE_SENTMSG2);
1587 slog(st,LOG_ERROR,"failed to process incoming msg1");
1591 } else if (st->state==SITE_SENTMSG1) {
1592 /* We've just sent a message 1! They may have crossed on
1593 the wire. If we have priority then we ignore the
1594 incoming one, otherwise we process it as usual. */
1595 if (st->setup_priority) {
1597 slog(st,LOG_DUMP,"crossed msg1s; we are higher "
1598 "priority => ignore incoming msg1");
1601 slog(st,LOG_DUMP,"crossed msg1s; we are lower "
1602 "priority => use incoming msg1");
1603 if (process_msg1(st,buf,source,&named_msg)) {
1604 BUF_FREE(&st->buffer); /* Free our old message 1 */
1605 enter_new_state(st,SITE_SENTMSG2);
1607 slog(st,LOG_ERROR,"failed to process an incoming "
1608 "crossed msg1 (we have low priority)");
1614 /* The message 1 was received at an unexpected stage of the
1615 key setup. XXX POLICY - what do we do? */
1616 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1620 if (msgtype==LABEL_PROD) {
1621 if (!named_for_us(st,buf,msgtype,&named_msg))
1623 dump_packet(st,buf,source,True);
1624 if (st->state!=SITE_RUN) {
1625 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1626 } else if (current_valid(st)) {
1627 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1629 initiate_key_setup(st,"peer sent PROD packet",source);
1634 if (dest==st->index) {
1635 /* Explicitly addressed to us */
1636 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
1639 /* If the source is our current peer then initiate a key setup,
1640 because our peer's forgotten the key */
1641 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1643 initiated = initiate_key_setup(st,"received a NAK",0);
1644 if (!initiated) generate_send_prod(st,source);
1646 slog(st,LOG_SEC,"bad incoming NAK");
1650 process_msg0(st,buf,source);
1653 /* Setup packet: should not have been explicitly addressed
1655 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1658 /* Setup packet: expected only in state SENTMSG1 */
1659 if (st->state!=SITE_SENTMSG1) {
1660 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1661 } else if (process_msg2(st,buf,source)) {
1662 transport_setup_msgok(st,source);
1663 enter_new_state(st,SITE_SENTMSG3);
1665 slog(st,LOG_SEC,"invalid MSG2");
1670 /* Setup packet: expected only in state SENTMSG2 */
1671 if (st->state!=SITE_SENTMSG2) {
1672 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1673 } else if (process_msg3(st,buf,source,msgtype)) {
1674 transport_setup_msgok(st,source);
1675 enter_new_state(st,SITE_SENTMSG4);
1677 slog(st,LOG_SEC,"invalid MSG3");
1681 /* Setup packet: expected only in state SENTMSG3 */
1682 if (st->state!=SITE_SENTMSG3) {
1683 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1684 } else if (process_msg4(st,buf,source)) {
1685 transport_setup_msgok(st,source);
1686 enter_new_state(st,SITE_SENTMSG5);
1688 slog(st,LOG_SEC,"invalid MSG4");
1692 /* Setup packet: expected only in state SENTMSG4 */
1693 /* (may turn up in state RUN if our return MSG6 was lost
1694 and the new key has already been activated. In that
1695 case we discard it. The peer will realise that we
1696 are using the new key when they see our data packets.
1697 Until then the peer's data packets to us get discarded. */
1698 if (st->state==SITE_SENTMSG4) {
1699 if (process_msg5(st,buf,source,st->new_transform)) {
1700 transport_setup_msgok(st,source);
1701 enter_new_state(st,SITE_RUN);
1703 slog(st,LOG_SEC,"invalid MSG5");
1705 } else if (st->state==SITE_RUN) {
1706 if (process_msg5(st,buf,source,st->current.transform)) {
1707 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1708 transport_setup_msgok(st,source);
1709 create_msg6(st,st->current.transform,
1710 st->current.remote_session_id);
1711 transport_xmit(st,&st->peers,&st->buffer,True);
1712 BUF_FREE(&st->buffer);
1714 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1717 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
1721 /* Setup packet: expected only in state SENTMSG5 */
1722 if (st->state!=SITE_SENTMSG5) {
1723 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
1724 } else if (process_msg6(st,buf,source)) {
1725 BUF_FREE(&st->buffer); /* Free message 5 */
1726 transport_setup_msgok(st,source);
1727 activate_new_key(st);
1729 slog(st,LOG_SEC,"invalid MSG6");
1733 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
1744 static void site_control(void *vst, bool_t run)
1746 struct site *st=vst;
1747 if (run) enter_state_run(st);
1748 else enter_state_stop(st);
1751 static void site_phase_hook(void *sst, uint32_t newphase)
1753 struct site *st=sst;
1755 /* The program is shutting down; tell our peer */
1756 send_msg7(st,"shutting down");
1759 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
1762 static uint32_t index_sequence;
1768 st=safe_malloc(sizeof(*st),"site_apply");
1770 st->cl.description="site";
1771 st->cl.type=CL_SITE;
1773 st->cl.interface=&st->ops;
1775 st->ops.control=site_control;
1776 st->ops.status=site_status;
1778 /* First parameter must be a dict */
1779 item=list_elem(args,0);
1780 if (!item || item->type!=t_dict)
1781 cfgfatal(loc,"site","parameter must be a dictionary\n");
1783 dict=item->data.dict;
1784 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
1785 st->remotename=dict_read_string(dict, "name", True, "site", loc);
1787 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
1788 bool_t local_mobile=
1789 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
1791 /* Sanity check (which also allows the 'sites' file to include
1792 site() closures for all sites including our own): refuse to
1793 talk to ourselves */
1794 if (strcmp(st->localname,st->remotename)==0) {
1795 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
1797 if (st->peer_mobile != local_mobile)
1798 cfgfatal(loc,"site","site %s's peer-mobile=%d"
1799 " but our local-mobile=%d\n",
1800 st->localname, st->peer_mobile, local_mobile);
1804 if (st->peer_mobile && local_mobile) {
1805 Message(M_WARNING,"site %s: site is mobile but so are we"
1806 " -> ignoring this site\n", st->remotename);
1811 assert(index_sequence < 0xffffffffUL);
1812 st->index = ++index_sequence;
1813 st->local_capabilities = 0;
1814 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
1816 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
1817 list_t *things##_cfg=dict_lookup(dict,dictkey); \
1818 if (!things##_cfg) \
1819 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
1820 st->nthings=list_length(things##_cfg); \
1821 st->things=safe_malloc_ary(sizeof(*st->things),st->nthings,dictkey "s"); \
1822 assert(st->nthings); \
1823 for (i=0; i<st->nthings; i++) { \
1824 item_t *item=list_elem(things##_cfg,i); \
1825 if (item->type!=t_closure) \
1826 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
1827 closure_t *cl=item->data.closure; \
1828 if (cl->type!=CL_TYPE) \
1829 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
1830 st->things[i]=cl->interface; \
1834 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
1836 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
1837 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
1838 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
1840 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
1841 st->address=dict_read_string(dict, "address", False, "site", loc);
1843 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
1844 else st->remoteport=0;
1845 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
1847 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
1849 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
1850 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
1852 #define DEFAULT(D) (st->peer_mobile || local_mobile \
1853 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
1854 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
1856 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
1857 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
1858 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
1859 st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME);
1860 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
1862 st->mobile_peer_expiry= dict_read_number(
1863 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
1865 st->transport_peers_max= !st->peer_mobile ? 1 : dict_read_number(
1866 dict,"mobile-peers-max",False,"site",loc,DEFAULT_MOBILE_PEERS_MAX);
1867 if (st->transport_peers_max<1 ||
1868 st->transport_peers_max>=MAX_MOBILE_PEERS_MAX) {
1869 cfgfatal(loc,"site","mobile-peers-max must be in range 1.."
1870 STRING(MAX_MOBILE_PEERS_MAX) "\n");
1873 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
1874 st->key_renegotiate_time=st->key_lifetime/2;
1876 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
1877 st->key_renegotiate_time=dict_read_number(
1878 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
1879 if (st->key_renegotiate_time > st->key_lifetime) {
1880 cfgfatal(loc,"site",
1881 "renegotiate-time must be less than key-lifetime\n");
1884 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
1885 log_event_table,"site");
1887 st->resolving=False;
1888 st->allow_send_prod=0;
1890 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
1892 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
1894 /* The information we expect to see in incoming messages of type 1 */
1895 /* fixme: lots of unchecked overflows here, but the results are only
1896 corrupted packets rather than undefined behaviour */
1897 st->setup_priority=(strcmp(st->localname,st->remotename)>0);
1899 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
1901 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
1902 BUF_ALLOC(&st->scratch,"site:scratch");
1904 /* We are interested in poll(), but only for timeouts. We don't have
1905 any fds of our own. */
1906 register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
1909 st->remote_capabilities=0;
1910 st->chosen_transform=0;
1911 st->current.key_timeout=0;
1912 st->auxiliary_key.key_timeout=0;
1913 transport_peers_clear(st,&st->peers);
1914 transport_peers_clear(st,&st->setup_peers);
1915 /* XXX mlock these */
1916 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
1917 st->sharedsecretlen=st->sharedsecretallocd=0;
1920 for (i=0; i<st->ntransforms; i++) {
1921 struct transform_if *ti=st->transforms[i];
1922 uint32_t capbit = 1UL << ti->capab_transformnum;
1923 if (st->local_capabilities & capbit)
1924 slog(st,LOG_ERROR,"transformnum capability bit"
1925 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
1926 st->local_capabilities |= capbit;
1929 /* We need to register the remote networks with the netlink device */
1930 uint32_t netlink_mtu; /* local virtual interface mtu */
1931 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
1932 if (!st->mtu_target)
1933 st->mtu_target=netlink_mtu;
1935 for (i=0; i<st->ncomms; i++)
1936 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
1938 st->current.transform=0;
1939 st->auxiliary_key.transform=0;
1940 st->new_transform=0;
1941 st->auxiliary_is_new=0;
1943 enter_state_stop(st);
1945 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
1947 return new_closure(&st->cl);
1950 void site_module(dict_t *dict)
1952 add_closure(dict,"site",site_apply);
1956 /***** TRANSPORT PEERS definitions *****/
1958 static void transport_peers_debug(struct site *st, transport_peers *dst,
1959 const char *didwhat,
1960 int nargs, const struct comm_addr *args,
1965 if (!(st->log_events & LOG_PEER_ADDRS))
1966 return; /* an optimisation */
1968 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
1969 (dst==&st->peers ? "data" :
1970 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
1971 didwhat, nargs, dst->npeers);
1973 for (i=0, argp=(void*)args;
1975 i++, (argp+=stride?stride:sizeof(*args))) {
1976 const struct comm_addr *ca=(void*)argp;
1977 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1978 i, comm_addr_to_string(ca));
1980 for (i=0; i<dst->npeers; i++) {
1981 struct timeval diff;
1982 timersub(tv_now,&dst->peers[i].last,&diff);
1983 const struct comm_addr *ca=&dst->peers[i].addr;
1984 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1985 i, comm_addr_to_string(ca),
1986 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
1990 static int transport_peer_compar(const void *av, const void *bv) {
1991 const transport_peer *a=av;
1992 const transport_peer *b=bv;
1993 /* put most recent first in the array */
1994 if (timercmp(&a->last, &b->last, <)) return +1;
1995 if (timercmp(&a->last, &b->last, >)) return -11;
1999 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2000 /* peers must be sorted first */
2001 int previous_peers=peers->npeers;
2002 struct timeval oldest;
2003 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2004 oldest.tv_usec = tv_now->tv_usec;
2005 while (peers->npeers>1 &&
2006 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2008 if (peers->npeers != previous_peers)
2009 transport_peers_debug(st,peers,"expire", 0,0,0);
2012 static void transport_record_peer(struct site *st, transport_peers *peers,
2013 const struct comm_addr *addr, const char *m) {
2014 int slot, changed=0;
2016 for (slot=0; slot<peers->npeers; slot++)
2017 if (!memcmp(&peers->peers[slot].addr, addr, sizeof(*addr)))
2021 if (peers->npeers==st->transport_peers_max)
2022 slot=st->transport_peers_max-1;
2024 slot=peers->npeers++;
2027 peers->peers[slot].addr=*addr;
2028 peers->peers[slot].last=*tv_now;
2030 if (peers->npeers>1)
2031 qsort(peers->peers, peers->npeers,
2032 sizeof(*peers->peers), transport_peer_compar);
2034 if (changed || peers->npeers!=1)
2035 transport_peers_debug(st,peers,m, 1,addr,0);
2036 transport_peers_expire(st, peers);
2039 static bool_t transport_compute_setupinit_peers(struct site *st,
2040 const struct comm_addr *configured_addr /* 0 if none or not found */,
2041 const struct comm_addr *prod_hint_addr /* 0 if none */) {
2043 if (!configured_addr && !prod_hint_addr &&
2044 !transport_peers_valid(&st->peers))
2047 slog(st,LOG_SETUP_INIT,
2048 "using:%s%s %d old peer address(es)",
2049 configured_addr ? " configured address;" : "",
2050 prod_hint_addr ? " PROD hint address;" : "",
2053 /* Non-mobile peers havve st->peers.npeers==0 or ==1, since they
2054 * have transport_peers_max==1. The effect is that this code
2055 * always uses the configured address if supplied, or otherwise
2056 * the address of the incoming PROD, or the existing data peer if
2057 * one exists; this is as desired. */
2059 transport_peers_copy(st,&st->setup_peers,&st->peers);
2062 transport_record_peer(st,&st->setup_peers,prod_hint_addr,"prod");
2064 if (configured_addr)
2065 transport_record_peer(st,&st->setup_peers,configured_addr,"setupinit");
2067 assert(transport_peers_valid(&st->setup_peers));
2071 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2072 if (st->peer_mobile)
2073 transport_record_peer(st,&st->setup_peers,a,"setupmsg");
2075 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2076 if (st->peer_mobile)
2077 transport_record_peer(st,&st->peers,a,"datamsg");
2080 static int transport_peers_valid(transport_peers *peers) {
2081 return peers->npeers;
2083 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2085 transport_peers_debug(st,peers,"clear",0,0,0);
2087 static void transport_peers_copy(struct site *st, transport_peers *dst,
2088 const transport_peers *src) {
2089 dst->npeers=src->npeers;
2090 memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
2091 transport_peers_debug(st,dst,"copy",
2092 src->npeers, &src->peers->addr, sizeof(*src->peers));
2095 void transport_xmit(struct site *st, transport_peers *peers,
2096 struct buffer_if *buf, bool_t candebug) {
2098 transport_peers_expire(st, peers);
2099 for (slot=0; slot<peers->npeers; slot++) {
2100 transport_peer *peer=&peers->peers[slot];
2102 dump_packet(st, buf, &peer->addr, False);
2103 peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
2107 /***** END of transport peers declarations *****/