1 /* site.c - manage communication with a remote network site */
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
22 /* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
31 /* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
40 #include <sys/socket.h>
44 #include "unaligned.h"
47 #define SETUP_BUFFER_LEN 2048
49 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
50 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
51 #define DEFAULT_SETUP_RETRIES 5
52 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
53 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
55 #define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
56 #define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
57 #define DEFAULT_MOBILE_SETUP_RETRIES 30
58 #define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
59 #define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
61 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
63 /* Each site can be in one of several possible states. */
66 SITE_STOP - nothing is allowed to happen; tunnel is down;
67 all session keys have been erased
68 -> SITE_RUN upon external instruction
69 SITE_RUN - site up, maybe with valid key
70 -> SITE_RESOLVE upon outgoing packet and no valid key
71 we start name resolution for the other end of the tunnel
72 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
73 we send an appropriate message 2
74 SITE_RESOLVE - waiting for name resolution
75 -> SITE_SENTMSG1 upon successful resolution
76 we send an appropriate message 1
77 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
78 we abort resolution and
79 -> SITE_WAIT on timeout or resolution failure
81 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
82 -> SITE_SENTMSG3 upon valid incoming message 2
83 -> SITE_WAIT on timeout
85 -> SITE_SENTMSG4 upon valid incoming message 3
86 -> SITE_WAIT on timeout
88 -> SITE_SENTMSG5 upon valid incoming message 4
89 -> SITE_WAIT on timeout
91 -> SITE_RUN upon valid incoming message 5
92 -> SITE_WAIT on timeout
94 -> SITE_RUN upon valid incoming message 6
95 -> SITE_WAIT on timeout
96 SITE_WAIT - failed to establish key; do nothing for a while
97 -> SITE_RUN on timeout
102 #define SITE_RESOLVE 2
103 #define SITE_SENTMSG1 3
104 #define SITE_SENTMSG2 4
105 #define SITE_SENTMSG3 5
106 #define SITE_SENTMSG4 6
107 #define SITE_SENTMSG5 7
110 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
114 int32_t site_max_start_pad = 4*4;
116 static cstring_t state_name(uint32_t state)
119 case 0: return "STOP";
120 case 1: return "RUN";
121 case 2: return "RESOLVE";
122 case 3: return "SENTMSG1";
123 case 4: return "SENTMSG2";
124 case 5: return "SENTMSG3";
125 case 6: return "SENTMSG4";
126 case 7: return "SENTMSG5";
127 case 8: return "WAIT";
128 default: return "*bad state*";
134 #define LOG_UNEXPECTED 0x00000001
135 #define LOG_SETUP_INIT 0x00000002
136 #define LOG_SETUP_TIMEOUT 0x00000004
137 #define LOG_ACTIVATE_KEY 0x00000008
138 #define LOG_TIMEOUT_KEY 0x00000010
139 #define LOG_SEC 0x00000020
140 #define LOG_STATE 0x00000040
141 #define LOG_DROP 0x00000080
142 #define LOG_DUMP 0x00000100
143 #define LOG_ERROR 0x00000400
144 #define LOG_PEER_ADDRS 0x00000800
145 #define LOG_SIGKEYS 0x00001000
147 static struct flagstr log_event_table[]={
148 { "unexpected", LOG_UNEXPECTED },
149 { "setup-init", LOG_SETUP_INIT },
150 { "setup-timeout", LOG_SETUP_TIMEOUT },
151 { "activate-key", LOG_ACTIVATE_KEY },
152 { "timeout-key", LOG_TIMEOUT_KEY },
153 { "security", LOG_SEC },
154 { "state-change", LOG_STATE },
155 { "packet-drop", LOG_DROP },
156 { "dump-packets", LOG_DUMP },
157 { "errors", LOG_ERROR },
158 { "peer-addrs", LOG_PEER_ADDRS },
159 { "sigkeys", LOG_SIGKEYS },
160 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
161 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR|LOG_SIGKEYS },
162 { "all", 0xffffffff },
167 /***** TRANSPORT PEERS declarations *****/
169 /* Details of "mobile peer" semantics:
171 - We use the same data structure for the different configurations,
172 but manage it with different algorithms.
174 - We record up to mobile_peers_max peer address/port numbers
175 ("peers") for key setup, and separately up to mobile_peers_max
178 - In general, we make a new set of addrs (see below) when we start
179 a new key exchange; the key setup addrs become the data transport
180 addrs when key setup complets.
182 If our peer is mobile:
184 - We send to all recent addresses of incoming packets, plus
185 initially all configured addresses (which we also expire).
187 - So, we record addrs of good incoming packets, as follows:
188 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
189 2. add the peer of the just received packet to the applicable list
190 (possibly evicting the oldest entries to make room)
191 NB that we do not expire peers until an incoming packet arrives.
193 - If the peer has a configured address or name, we record them the
194 same way, but only as a result of our own initiation of key
195 setup. (We might evict some incoming packet addrs to make room.)
197 - The default number of addrs to keep is 3, or 4 if we have a
198 configured name or address. That's space for two configured
199 addresses (one IPv6 and one IPv4), plus two received addresses.
201 - Outgoing packets are sent to every recorded address in the
202 applicable list. Any unsupported[1] addresses are deleted from
203 the list right away. (This should only happen to configured
204 addresses, of course, but there is no need to check that.)
206 - When we successfully complete a key setup, we merge the key setup
207 peers into the data transfer peers.
209 [1] An unsupported address is one for whose AF we don't have a
210 socket (perhaps because we got EAFNOSUPPORT or some such) or for
211 which sendto gives ENETUNREACH.
213 If neither end is mobile:
215 - When peer initiated the key exchange, we use the incoming packet
218 - When we initiate the key exchange, we try configured addresses
219 until we get one which isn't unsupported then fixate on that.
221 - When we complete a key setup, we replace the data transport peers
222 with those from the key setup.
226 - We can't tell when local network setup changes so we can't cache
227 the unsupported addrs and completely remove the spurious calls to
228 sendto, but we can optimise things a bit by deprioritising addrs
229 which seem to be unsupported.
231 - Use only configured addresses. (Except, that if our peer
232 initiated a key exchange we use the incoming packet address until
233 our name resolution completes.)
235 - When we send a packet, try each address in turn; if addr
236 supported, put that address to the end of the list for future
237 packets, and go onto the next address.
239 - When we complete a key setup, we replace the data transport peers
240 with those from the key setup.
246 struct comm_addr addr;
250 /* configuration information */
251 /* runtime information */
253 transport_peer peers[MAX_PEER_ADDRS];
256 /* Basic operations on transport peer address sets */
257 static void transport_peers_clear(struct site *st, transport_peers *peers);
258 static int transport_peers_valid(transport_peers *peers);
259 static void transport_peers_copy(struct site *st, transport_peers *dst,
260 const transport_peers *src);
262 /* Record address of incoming setup packet; resp. data packet. */
263 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
264 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
266 /* Initialise the setup addresses. Called before we send the first
267 * packet in a key exchange. If we are the initiator, as a result of
268 * resolve completing (or being determined not to be relevant) or an
269 * incoming PROD; if we are the responder, as a result of the MSG1. */
270 static bool_t transport_compute_setupinit_peers(struct site *st,
271 const struct comm_addr *configured_addrs /* 0 if none or not found */,
272 int n_configured_addrs /* 0 if none or not found */,
273 const struct comm_addr *incoming_packet_addr /* 0 if none */);
275 /* Called if we are the responder in a key setup, when the resolve
276 * completes. transport_compute_setupinit_peers will hvae been called
277 * earlier. If _complete is called, we are still doing the key setup
278 * (and we should use the new values for both the rest of the key
279 * setup and the ongoing data exchange); if _tardy is called, the key
280 * setup is done (either completed or not) and only the data peers are
282 static void transport_resolve_complete(struct site *st,
283 const struct comm_addr *addrs, int naddrs);
284 static void transport_resolve_complete_tardy(struct site *st,
285 const struct comm_addr *addrs, int naddrs);
287 static void transport_xmit(struct site *st, transport_peers *peers,
288 struct buffer_if *buf, bool_t candebug);
290 /***** END of transport peers declarations *****/
294 struct transform_inst_if *transform;
295 uint64_t key_timeout; /* End of life of current key */
296 uint32_t remote_session_id;
302 /* configuration information */
306 bool_t local_mobile, peer_mobile; /* Mobile client support */
307 int32_t transport_peers_max;
308 string_t tunname; /* localname<->remotename by default, used in logs */
309 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
310 int remoteport; /* Port for bootstrapping, optional */
312 struct netlink_if *netlink;
313 struct comm_if **comms;
314 struct comm_clientinfo **commclientinfos;
316 struct resolver_if *resolver;
318 struct random_if *random;
319 struct privcache_if *privkeys;
320 struct sigprivkey_if *privkey_fixed;
321 struct sigpubkey_if *pubkey;
322 struct transform_if **transforms;
326 uint32_t index; /* Index of this site */
327 uint32_t early_capabilities;
328 uint32_t local_capabilities;
329 int32_t setup_retries; /* How many times to send setup packets */
330 int32_t setup_retry_interval; /* Initial timeout for setup packets */
331 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
332 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
333 int32_t key_lifetime; /* How long a key lasts once set up */
334 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
335 after this time, initiate a new
338 bool_t our_name_later; /* our name > peer name */
341 /* runtime information */
343 uint64_t now; /* Most recently seen time */
344 bool_t allow_send_prod;
345 bool_t msg1_crossed_logged;
347 int resolving_n_results_all;
348 int resolving_n_results_stored;
349 struct comm_addr resolving_results[MAX_PEER_ADDRS];
351 /* The currently established session */
352 struct data_key current;
353 struct data_key auxiliary_key;
354 bool_t auxiliary_is_new;
355 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
356 uint64_t auxiliary_renegotiate_key_time;
357 transport_peers peers; /* Current address(es) of peer for data traffic */
359 /* The current key setup protocol exchange. We can only be
360 involved in one of these at a time. There's a potential for
361 denial of service here (the attacker keeps sending a setup
362 packet; we keep trying to continue the exchange, and have to
363 timeout before we can listen for another setup packet); perhaps
364 we should keep a list of 'bad' sources for setup packets. */
365 uint32_t remote_capabilities;
366 uint16_t remote_adv_mtu;
367 struct transform_if *chosen_transform;
368 uint32_t setup_session_id;
369 transport_peers setup_peers;
370 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
371 uint8_t remoteN[NONCELEN];
372 struct buffer_if buffer; /* Current outgoing key exchange packet */
373 struct buffer_if scratch;
374 int32_t retries; /* Number of retries remaining */
375 uint64_t timeout; /* Timeout for current state */
377 uint8_t *sharedsecret;
378 uint32_t sharedsecretlen, sharedsecretallocd;
379 struct transform_inst_if *new_transform; /* For key setup/verify */
382 static uint32_t event_log_priority(struct site *st, uint32_t event)
384 if (!(event&st->log_events))
387 case LOG_UNEXPECTED: return M_INFO;
388 case LOG_SETUP_INIT: return M_INFO;
389 case LOG_SETUP_TIMEOUT: return M_NOTICE;
390 case LOG_ACTIVATE_KEY: return M_INFO;
391 case LOG_TIMEOUT_KEY: return M_INFO;
392 case LOG_SEC: return M_SECURITY;
393 case LOG_STATE: return M_DEBUG;
394 case LOG_DROP: return M_DEBUG;
395 case LOG_DUMP: return M_DEBUG;
396 case LOG_ERROR: return M_ERR;
397 case LOG_PEER_ADDRS: return M_DEBUG;
398 case LOG_SIGKEYS: return M_INFO;
399 default: return M_ERR;
403 static uint32_t slog_start(struct site *st, uint32_t event)
405 uint32_t class=event_log_priority(st, event);
407 slilog_part(st->log,class,"%s: ",st->tunname);
412 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
414 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
418 class=slog_start(st,event);
420 vslilog_part(st->log,class,msg,ap);
421 slilog_part(st->log,class,"\n");
425 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
427 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
431 vslog(st,event,msg,ap);
435 static void logtimeout(struct site *st, const char *fmt, ...)
437 static void logtimeout(struct site *st, const char *fmt, ...)
439 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
446 slilog_part(st->log,class,"%s: ",st->tunname);
447 vslilog_part(st->log,class,fmt,ap);
451 for (i=0, delim=" (tried ";
452 i<st->setup_peers.npeers;
454 transport_peer *peer=&st->setup_peers.peers[i];
455 const char *s=comm_addr_to_string(&peer->addr);
456 slilog_part(st->log,class,"%s%s",delim,s);
459 slilog_part(st->log,class,")\n");
463 static void set_link_quality(struct site *st);
464 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
465 static void delete_one_key(struct site *st, struct data_key *key,
466 const char *reason /* may be 0 meaning don't log*/,
467 const char *which /* ignored if !reasonn */,
468 uint32_t loglevel /* ignored if !reasonn */);
469 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
470 const struct comm_addr *prod_hint);
471 static void enter_state_run(struct site *st);
472 static bool_t enter_state_resolve(struct site *st);
473 static void decrement_resolving_count(struct site *st, int by);
474 static bool_t enter_new_state(struct site *st,uint32_t next,
475 const struct msg *prompt
476 /* may be 0 for SENTMSG1 */);
477 static void enter_state_wait(struct site *st);
478 static void activate_new_key(struct site *st);
480 static bool_t is_transform_valid(struct transform_inst_if *transform)
482 return transform && transform->valid(transform->st);
485 static bool_t current_valid(struct site *st)
487 return is_transform_valid(st->current.transform);
490 #define DEFINE_CALL_TRANSFORM(fwdrev) \
491 static transform_apply_return \
492 call_transform_##fwdrev(struct site *st, \
493 struct transform_inst_if *transform, \
494 struct buffer_if *buf, \
495 const char **errmsg) \
497 if (!is_transform_valid(transform)) { \
498 *errmsg="transform not set up"; \
499 return transform_apply_err; \
501 return transform->fwdrev(transform->st,buf,errmsg); \
504 DEFINE_CALL_TRANSFORM(forwards)
505 DEFINE_CALL_TRANSFORM(reverse)
507 static void dispose_transform(struct transform_inst_if **transform_var)
509 struct transform_inst_if *transform=*transform_var;
511 transform->delkey(transform->st);
512 transform->destroy(transform->st);
517 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
518 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
519 #define CHECK_TYPE(b,t) do { uint32_t type; \
520 CHECK_AVAIL((b),4); \
521 type=buf_unprepend_uint32((b)); \
522 if (type!=(t)) return False; } while(0)
524 static _Bool type_is_msg23(uint32_t type)
527 case LABEL_MSG2: case CASES_MSG3_KNOWN: return True;
528 default: return False;
531 static _Bool type_is_msg34(uint32_t type)
534 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
535 default: return False;
542 struct buffer_if extrainfo;
549 struct parsedname remote;
550 struct parsedname local;
551 uint32_t remote_capabilities;
553 int capab_transformnum;
559 struct alg_msg_data sig;
560 int n_pubkeys_accepted_nom; /* may be > MAX_SIG_KEYS ! */
561 const struct sigkeyid *pubkeys_accepted[MAX_SIG_KEYS];
564 static const struct sigkeyid keyid_zero;
566 static int32_t wait_timeout(struct site *st) {
567 int32_t t = st->wait_timeout_mean;
570 st->random->generate(st->random->st,sizeof(factor),&factor);
571 t += (t / 256) * factor;
576 static _Bool set_new_transform(struct site *st, char *pk)
580 /* Make room for the shared key */
581 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
582 assert(st->sharedsecretlen);
583 if (st->sharedsecretlen > st->sharedsecretallocd) {
584 st->sharedsecretallocd=st->sharedsecretlen;
585 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
586 st->sharedsecretallocd,
587 "site:sharedsecret");
590 /* Generate the shared key */
591 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
592 st->sharedsecret,st->sharedsecretlen);
594 /* Set up the transform */
595 struct transform_if *generator=st->chosen_transform;
596 struct transform_inst_if *generated=generator->create(generator->st);
597 ok = generated->setkey(generated->st,st->sharedsecret,
598 st->sharedsecretlen,st->our_name_later);
600 dispose_transform(&st->new_transform);
601 if (!ok) return False;
602 st->new_transform=generated;
604 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
605 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
606 st->chosen_transform->capab_bit,
607 st->local_capabilities, st->remote_capabilities);
612 int32_t lenpos, afternul;
614 static void append_string_xinfo_start(struct buffer_if *buf,
615 struct xinfoadd *xia,
617 /* Helps construct one of the names with additional info as found
618 * in MSG1..4. Call this function first, then append all the
619 * desired extra info (not including the nul byte) to the buffer,
620 * then call append_string_xinfo_done. */
622 xia->lenpos = buf->size;
623 buf_append_string(buf,str);
624 buf_append_uint8(buf,0);
625 xia->afternul = buf->size;
627 static void append_string_xinfo_done(struct buffer_if *buf,
628 struct xinfoadd *xia)
630 /* we just need to adjust the string length */
631 if (buf->size == xia->afternul) {
632 /* no extra info, strip the nul too */
633 buf_unappend_uint8(buf);
635 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
639 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
640 out using a transform of config data supplied by netlink */
641 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
642 const struct msg *prompt
643 /* may be 0 for MSG1 */)
649 st->retries=st->setup_retries;
650 BUF_ALLOC(&st->buffer,what);
651 buffer_init(&st->buffer,0);
652 buf_append_uint32(&st->buffer,
653 (type==LABEL_MSG1?0:st->setup_session_id));
654 buf_append_uint32(&st->buffer,st->index);
655 buf_append_uint32(&st->buffer,type);
658 append_string_xinfo_start(&st->buffer,&xia,st->localname);
659 if ((st->local_capabilities & st->early_capabilities) ||
660 (type != LABEL_MSG1)) {
661 buf_append_uint32(&st->buffer,st->local_capabilities);
663 if (type_is_msg34(type)) {
664 buf_append_uint16(&st->buffer,st->mtu_target);
666 if (type_is_msg23(type)) {
667 /* The code to advertise a public key acceptance list will
668 * come in a moment. But right now we must add the byte
669 * indicating which key advertised by our peer we used, which
670 * comes after the public key acceptance list. So for now,
671 * explicitly advertise a list with just 0000000000. */
672 buf_append_uint8(&st->buffer,1);
673 BUF_ADD_OBJ(append,&st->buffer,keyid_zero);
675 struct sigprivkey_if *privkey=0;
676 if (type_is_msg34(type)) {
677 assert(prompt->n_pubkeys_accepted_nom>0);
679 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
681 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
683 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
684 if (privkey) goto privkey_found;
686 if (sigkeyid_equal(&keyid_zero,kid)) {
687 privkey=st->privkey_fixed;
692 uint32_t class = slog_start(st,LOG_ERROR);
694 slilog_part(st->log,class,"no suitable private key, peer wanted");
696 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
698 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
699 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
701 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
702 slilog_part(st->log,class," +%d",
703 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
704 slilog_part(st->log,class,"\n");
709 buf_append_uint8(&st->buffer,ki);
712 append_string_xinfo_done(&st->buffer,&xia);
714 buf_append_string(&st->buffer,st->remotename);
715 BUF_ADD_OBJ(append,&st->buffer,st->localN);
716 if (type==LABEL_MSG1) return True;
717 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
718 if (type==LABEL_MSG2) return True;
720 if (hacky_par_mid_failnow()) return False;
722 if (MSGMAJOR(type) == 3) do {
723 minor = MSGMINOR(type);
724 if (minor < 1) break;
725 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
728 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
729 buf_append_string(&st->buffer,dhpub);
732 bool_t ok=privkey->sign(privkey->st,
743 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
746 nm->len=buf_unprepend_uint16(msg);
747 CHECK_AVAIL(msg,nm->len);
748 nm->name=buf_unprepend(msg,nm->len);
749 uint8_t *nul=memchr(nm->name,0,nm->len);
751 buffer_readonly_view(&nm->extrainfo,0,0);
753 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
754 nm->len=nul-nm->name;
759 static bool_t unpick_msg(struct site *st, uint32_t type,
760 struct buffer_if *msg, struct msg *m)
764 m->n_pubkeys_accepted_nom=-1;
765 m->capab_transformnum=-1;
766 m->hashstart=msg->start;
768 m->dest=buf_unprepend_uint32(msg);
770 m->source=buf_unprepend_uint32(msg);
771 CHECK_TYPE(msg,type);
772 if (!unpick_name(msg,&m->remote)) return False;
773 m->remote_capabilities=0;
775 if (m->remote.extrainfo.size) {
776 CHECK_AVAIL(&m->remote.extrainfo,4);
777 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
779 if (type_is_msg34(type) && m->remote.extrainfo.size) {
780 CHECK_AVAIL(&m->remote.extrainfo,2);
781 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
783 if (type_is_msg23(type) && m->remote.extrainfo.size) {
784 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
785 if (!m->n_pubkeys_accepted_nom) return False;
786 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
787 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
788 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
789 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
792 m->n_pubkeys_accepted_nom = 1;
793 m->pubkeys_accepted[0] = &keyid_zero;
795 if (!unpick_name(msg,&m->local)) return False;
796 if (type==LABEL_PROD) {
800 CHECK_AVAIL(msg,NONCELEN);
801 m->nR=buf_unprepend(msg,NONCELEN);
802 if (type==LABEL_MSG1) {
806 CHECK_AVAIL(msg,NONCELEN);
807 m->nL=buf_unprepend(msg,NONCELEN);
808 if (type==LABEL_MSG2) {
812 if (MSGMAJOR(type) == 3) do {
813 minor = MSGMINOR(type);
814 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
815 if (minor < (minminor)) \
816 m->capab_##kind##num = (dflt); \
818 CHECK_AVAIL(msg, 1); \
819 m->capab_##kind##num = buf_unprepend_uint8(msg); \
822 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
823 #undef MAYBE_READ_CAP
826 m->pklen=buf_unprepend_uint16(msg);
827 CHECK_AVAIL(msg,m->pklen);
828 m->pk=buf_unprepend(msg,m->pklen);
829 m->hashlen=msg->start-m->hashstart;
830 struct sigpubkey_if *pubkey=st->pubkey;
832 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
841 static bool_t name_matches(const struct parsedname *nm, const char *expected)
843 int expected_len=strlen(expected);
845 nm->len == expected_len &&
846 !memcmp(nm->name, expected, expected_len);
849 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
852 if (type==LABEL_MSG1) return True;
854 /* Check that the site names and our nonce have been sent
855 back correctly, and then store our peer's nonce. */
856 if (!name_matches(&m->remote,st->remotename)) {
857 *error="wrong remote site name";
860 if (!name_matches(&m->local,st->localname)) {
861 *error="wrong local site name";
864 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
865 *error="wrong locally-generated nonce";
868 if (type==LABEL_MSG2) return True;
869 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
870 *error="wrong remotely-generated nonce";
873 /* MSG3 has complicated rules about capabilities, which are
874 * handled in process_msg3. */
875 if (MSGMAJOR(type) == 3) return True;
876 if (m->remote_capabilities!=st->remote_capabilities) {
877 *error="remote capabilities changed";
880 if (type==LABEL_MSG4) return True;
881 *error="unknown message type";
885 static bool_t kex_init(struct site *st)
887 st->random->generate(st->random->st,NONCELEN,st->localN);
891 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
894 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
897 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
898 const struct comm_addr *src,
901 /* We've already determined we're in an appropriate state to
902 process an incoming MSG1, and that the MSG1 has correct values
905 st->setup_session_id=m->source;
906 st->remote_capabilities=m->remote_capabilities;
907 memcpy(st->remoteN,m->nR,NONCELEN);
911 static bool_t generate_msg2(struct site *st,
912 const struct msg *prompt_may_be_null)
915 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
918 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
919 const struct comm_addr *src,
920 struct msg *m /* returned */)
924 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
925 if (!check_msg(st,LABEL_MSG2,m,&err)) {
926 slog(st,LOG_SEC,"msg2: %s",err);
929 st->setup_session_id=m->source;
930 st->remote_capabilities=m->remote_capabilities;
932 /* Select the transform to use */
934 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
935 if (!remote_crypto_caps)
936 /* old secnets only had this one transform */
937 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
939 #define CHOOSE_CRYPTO(kind, whats) do { \
940 struct kind##_if *iface; \
941 uint32_t bit, ours = 0; \
943 for (i= 0; i < st->n##kind##s; i++) { \
944 iface=st->kind##s[i]; \
945 bit = 1UL << iface->capab_bit; \
946 if (bit & remote_crypto_caps) goto kind##_found; \
949 slog(st,LOG_ERROR,"no " whats " in common" \
950 " (us %#"PRIx32"; them: %#"PRIx32")", \
951 st->local_capabilities & ours, remote_crypto_caps); \
954 st->chosen_##kind = iface; \
957 CHOOSE_CRYPTO(transform, "transforms");
961 memcpy(st->remoteN,m->nR,NONCELEN);
965 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
967 /* Now we have our nonce and their nonce. Think of a secret key,
968 and create message number 3. */
969 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
970 return generate_msg(st,
971 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
977 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
979 struct sigpubkey_if *pubkey=st->pubkey;
981 /* Check signature and store g^x mod m */
982 if (!pubkey->check(pubkey->st,
983 m->hashstart,m->hashlen,
985 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
989 st->remote_adv_mtu=m->remote_mtu;
994 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
995 const struct comm_addr *src, uint32_t msgtype,
996 struct msg *m /* returned */)
1001 case CASES_MSG3_KNOWN: break;
1005 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1006 if (!check_msg(st,msgtype,m,&err)) {
1007 slog(st,LOG_SEC,"msg3: %s",err);
1010 uint32_t capab_adv_late = m->remote_capabilities
1011 & ~st->remote_capabilities & st->early_capabilities;
1012 if (capab_adv_late) {
1013 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1014 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1015 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1019 #define CHOSE_CRYPTO(kind, what) do { \
1020 struct kind##_if *iface; \
1022 for (i=0; i<st->n##kind##s; i++) { \
1023 iface=st->kind##s[i]; \
1024 if (iface->capab_bit == m->capab_##kind##num) \
1025 goto kind##_found; \
1027 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1028 m->capab_##kind##num); \
1031 st->chosen_##kind=iface; \
1034 CHOSE_CRYPTO(transform, "transform");
1038 if (!process_msg3_msg4(st,m))
1041 /* Update our idea of the remote site's capabilities, now that we've
1042 * verified that its message was authentic.
1044 * Our previous idea of the remote site's capabilities came from the
1045 * unauthenticated MSG1. We've already checked that this new message
1046 * doesn't change any of the bits we relied upon in the past, but it may
1047 * also have set additional capability bits. We simply throw those away
1048 * now, and use the authentic capabilities from this MSG3. */
1049 st->remote_capabilities=m->remote_capabilities;
1051 /* Terminate their DH public key with a '0' */
1053 /* Invent our DH secret key */
1054 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1056 /* Generate the shared key and set up the transform */
1057 if (!set_new_transform(st,m->pk)) return False;
1062 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1064 /* We have both nonces, their public key and our private key. Generate
1065 our public key, sign it and send it to them. */
1066 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1069 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1070 const struct comm_addr *src,
1071 struct msg *m /* returned */)
1075 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1076 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1077 slog(st,LOG_SEC,"msg4: %s",err);
1081 if (!process_msg3_msg4(st,m))
1084 /* Terminate their DH public key with a '0' */
1087 /* Generate the shared key and set up the transform */
1088 if (!set_new_transform(st,m->pk)) return False;
1099 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1102 CHECK_AVAIL(msg0,4);
1103 m->dest=buf_unprepend_uint32(msg0);
1104 CHECK_AVAIL(msg0,4);
1105 m->source=buf_unprepend_uint32(msg0);
1106 CHECK_AVAIL(msg0,4);
1107 m->type=buf_unprepend_uint32(msg0);
1109 /* Leaves transformed part of buffer untouched */
1112 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1114 cstring_t transform_err;
1116 BUF_ALLOC(&st->buffer,"site:MSG5");
1117 /* We are going to add four words to the message */
1118 buffer_init(&st->buffer,calculate_max_start_pad());
1119 /* Give the netlink code an opportunity to put its own stuff in the
1120 message (configuration information, etc.) */
1121 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1122 if (call_transform_forwards(st,st->new_transform,
1123 &st->buffer,&transform_err))
1125 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1126 buf_prepend_uint32(&st->buffer,st->index);
1127 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1129 st->retries=st->setup_retries;
1133 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1134 const struct comm_addr *src,
1135 struct transform_inst_if *transform)
1138 cstring_t transform_err;
1140 if (!unpick_msg0(st,msg5,&m)) return False;
1142 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1143 /* There's a problem */
1144 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1147 /* Buffer should now contain untransformed PING packet data */
1148 CHECK_AVAIL(msg5,4);
1149 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1150 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1153 /* Older versions of secnet used to write some config data here
1154 * which we ignore. So we don't CHECK_EMPTY */
1158 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1159 uint32_t session_id)
1161 cstring_t transform_err;
1163 BUF_ALLOC(&st->buffer,"site:MSG6");
1164 /* We are going to add four words to the message */
1165 buffer_init(&st->buffer,calculate_max_start_pad());
1166 /* Give the netlink code an opportunity to put its own stuff in the
1167 message (configuration information, etc.) */
1168 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1169 transform_apply_return problem =
1170 call_transform_forwards(st,transform,
1171 &st->buffer,&transform_err);
1173 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1174 buf_prepend_uint32(&st->buffer,st->index);
1175 buf_prepend_uint32(&st->buffer,session_id);
1178 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1180 if (!is_transform_valid(st->new_transform))
1182 create_msg6(st,st->new_transform,st->setup_session_id);
1183 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1187 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1188 const struct comm_addr *src)
1191 cstring_t transform_err;
1193 if (!unpick_msg0(st,msg6,&m)) return False;
1195 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1196 /* There's a problem */
1197 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1200 /* Buffer should now contain untransformed PING packet data */
1201 CHECK_AVAIL(msg6,4);
1202 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1203 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1206 /* Older versions of secnet used to write some config data here
1207 * which we ignore. So we don't CHECK_EMPTY */
1211 static transform_apply_return
1212 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1213 const struct comm_addr *src)
1215 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1217 transform_apply_return problem;
1219 if (!unpick_msg0(st,msg0,&m)) return False;
1221 /* Keep a copy so we can try decrypting it with multiple keys */
1222 buffer_copy(&st->scratch, msg0);
1224 problem = call_transform_reverse(st,st->current.transform,
1225 msg0,&transform_err);
1227 if (!st->auxiliary_is_new)
1228 delete_one_key(st,&st->auxiliary_key,
1229 "peer has used new key","auxiliary key",LOG_SEC);
1232 if (transform_apply_return_badseq(problem))
1235 buffer_copy(msg0, &st->scratch);
1236 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1239 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1240 if (st->auxiliary_is_new) {
1241 /* We previously timed out in state SENTMSG5 but it turns
1242 * out that our peer did in fact get our MSG5 and is
1243 * using the new key. So we should switch to it too. */
1244 /* This is a bit like activate_new_key. */
1247 st->current=st->auxiliary_key;
1248 st->auxiliary_key=t;
1250 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1251 "previous key",LOG_SEC);
1252 st->auxiliary_is_new=0;
1253 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1257 if (transform_apply_return_badseq(problem))
1260 if (st->state==SITE_SENTMSG5) {
1261 buffer_copy(msg0, &st->scratch);
1262 problem = call_transform_reverse(st,st->new_transform,
1265 /* It looks like we didn't get the peer's MSG6 */
1266 /* This is like a cut-down enter_new_state(SITE_RUN) */
1267 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1268 BUF_FREE(&st->buffer);
1270 activate_new_key(st);
1271 return 0; /* do process the data in this packet */
1273 if (transform_apply_return_badseq(problem))
1277 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1278 transform_err,auxkey_err,newkey_err);
1279 initiate_key_setup(st,"incoming message would not decrypt",0);
1280 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1285 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1290 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1291 const struct comm_addr *src)
1294 transform_apply_return problem;
1296 problem = decrypt_msg0(st,msg0,src);
1297 if (problem==transform_apply_seqdupe) {
1298 /* We recently received another copy of this packet, maybe due
1299 * to polypath. That's not a problem; indeed, for the
1300 * purposes of transport address management it is a success.
1301 * But we don't want to process the packet. */
1302 transport_data_msgok(st,src);
1308 CHECK_AVAIL(msg0,4);
1309 type=buf_unprepend_uint32(msg0);
1312 /* We must forget about the current session. */
1313 delete_keys(st,"request from peer",LOG_SEC);
1314 /* probably, the peer is shutting down, and this is going to fail,
1315 * but we need to be trying to bring the link up again */
1317 initiate_key_setup(st,"peer requested key teardown",0);
1320 /* Deliver to netlink layer */
1321 st->netlink->deliver(st->netlink->st,msg0);
1322 transport_data_msgok(st,src);
1323 /* See whether we should start negotiating a new key */
1324 if (st->now > st->renegotiate_key_time)
1325 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1328 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1335 static void dump_packet(struct site *st, struct buffer_if *buf,
1336 const struct comm_addr *addr, bool_t incoming,
1339 uint32_t dest=get_uint32(buf->start);
1340 uint32_t source=get_uint32(buf->start+4);
1341 uint32_t msgtype=get_uint32(buf->start+8);
1343 if (st->log_events & LOG_DUMP)
1344 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1345 st->tunname,incoming?"incoming":"outgoing",
1346 dest,source,msgtype,comm_addr_to_string(addr),
1350 static bool_t comm_addr_sendmsg(struct site *st,
1351 const struct comm_addr *dest,
1352 struct buffer_if *buf)
1355 struct comm_clientinfo *commclientinfo = 0;
1357 for (i=0; i < st->ncomms; i++) {
1358 if (st->comms[i] == dest->comm) {
1359 commclientinfo = st->commclientinfos[i];
1363 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1366 static uint32_t site_status(void *st)
1371 static bool_t send_msg(struct site *st)
1373 if (st->retries>0) {
1374 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1375 st->timeout=st->now+st->setup_retry_interval;
1378 } else if (st->state==SITE_SENTMSG5) {
1379 logtimeout(st,"timed out sending MSG5, stashing new key");
1380 /* We stash the key we have produced, in case it turns out that
1381 * our peer did see our MSG5 after all and starts using it. */
1382 /* This is a bit like some of activate_new_key */
1383 struct transform_inst_if *t;
1384 t=st->auxiliary_key.transform;
1385 st->auxiliary_key.transform=st->new_transform;
1386 st->new_transform=t;
1387 dispose_transform(&st->new_transform);
1389 st->auxiliary_is_new=1;
1390 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1391 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1392 st->auxiliary_key.remote_session_id=st->setup_session_id;
1394 enter_state_wait(st);
1397 logtimeout(st,"timed out sending key setup packet "
1398 "(in state %s)",state_name(st->state));
1399 enter_state_wait(st);
1404 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1405 int stored_naddrs, int all_naddrs,
1406 const char *address, const char *failwhy)
1408 struct site *st=sst;
1410 if (!stored_naddrs) {
1411 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1413 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1414 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1416 int space=st->transport_peers_max-st->resolving_n_results_stored;
1417 int n_tocopy=MIN(stored_naddrs,space);
1418 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1421 st->resolving_n_results_stored += n_tocopy;
1422 st->resolving_n_results_all += all_naddrs;
1425 decrement_resolving_count(st,1);
1428 static void decrement_resolving_count(struct site *st, int by)
1430 assert(st->resolving_count>0);
1431 st->resolving_count-=by;
1433 if (st->resolving_count)
1436 /* OK, we are done with them all. Handle combined results. */
1438 const struct comm_addr *addrs=st->resolving_results;
1439 int naddrs=st->resolving_n_results_stored;
1440 assert(naddrs<=st->transport_peers_max);
1443 if (naddrs != st->resolving_n_results_all) {
1444 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1445 " yielded too many results (%d > %d), some ignored",
1446 st->resolving_n_results_all, naddrs);
1448 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1449 naddrs, iaddr_to_string(&addrs[0].ia));;
1452 switch (st->state) {
1454 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1455 enter_new_state(st,SITE_SENTMSG1,0);
1457 /* Can't figure out who to try to to talk to */
1458 slog(st,LOG_SETUP_INIT,
1459 "key exchange failed: cannot find peer address");
1460 enter_state_run(st);
1463 case SITE_SENTMSG1: case SITE_SENTMSG2:
1464 case SITE_SENTMSG3: case SITE_SENTMSG4:
1467 /* We start using the address immediately for data too.
1468 * It's best to store it in st->peers now because we might
1469 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1470 * the new key (without updating the data peer addrs). */
1471 transport_resolve_complete(st,addrs,naddrs);
1472 } else if (st->local_mobile) {
1473 /* We can't let this rest because we may have a peer
1474 * address which will break in the future. */
1475 slog(st,LOG_SETUP_INIT,"resolution failed: "
1476 "abandoning key exchange");
1477 enter_state_wait(st);
1479 slog(st,LOG_SETUP_INIT,"resolution failed: "
1480 " continuing to use source address of peer's packets"
1481 " for key exchange and ultimately data");
1486 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1487 " updating peer address(es)");
1488 transport_resolve_complete_tardy(st,addrs,naddrs);
1489 } else if (st->local_mobile) {
1490 /* Not very good. We should queue (another) renegotiation
1491 * so that we can update the peer address. */
1492 st->key_renegotiate_time=st->now+wait_timeout(st);
1494 slog(st,LOG_SETUP_INIT,"resolution failed: "
1495 " continuing to use source address of peer's packets");
1505 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1506 const struct comm_addr *prod_hint)
1508 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1509 if (st->state!=SITE_RUN) return False;
1510 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1511 if (st->addresses) {
1512 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1513 return enter_state_resolve(st);
1514 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1515 return enter_new_state(st,SITE_SENTMSG1,0);
1517 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1521 static void activate_new_key(struct site *st)
1523 struct transform_inst_if *t;
1525 /* We have three transform instances, which we swap between old,
1527 t=st->auxiliary_key.transform;
1528 st->auxiliary_key.transform=st->current.transform;
1529 st->current.transform=st->new_transform;
1530 st->new_transform=t;
1531 dispose_transform(&st->new_transform);
1534 st->auxiliary_is_new=0;
1535 st->auxiliary_key.key_timeout=st->current.key_timeout;
1536 st->current.key_timeout=st->now+st->key_lifetime;
1537 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1538 transport_peers_copy(st,&st->peers,&st->setup_peers);
1539 st->current.remote_session_id=st->setup_session_id;
1541 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1542 * But their mtu be unspecified, in which case we just use ours. */
1543 uint32_t intersite_mtu=
1544 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1545 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1547 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1548 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1549 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1550 enter_state_run(st);
1553 static void delete_one_key(struct site *st, struct data_key *key,
1554 cstring_t reason, cstring_t which, uint32_t loglevel)
1556 if (!is_transform_valid(key->transform)) return;
1557 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1558 dispose_transform(&key->transform);
1562 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1564 if (current_valid(st)) {
1565 slog(st,loglevel,"session closed (%s)",reason);
1567 delete_one_key(st,&st->current,0,0,0);
1568 set_link_quality(st);
1570 delete_one_key(st,&st->auxiliary_key,0,0,0);
1573 static void state_assert(struct site *st, bool_t ok)
1575 if (!ok) fatal("site:state_assert");
1578 static void enter_state_stop(struct site *st)
1580 st->state=SITE_STOP;
1582 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1583 dispose_transform(&st->new_transform);
1586 static void set_link_quality(struct site *st)
1589 if (current_valid(st))
1590 quality=LINK_QUALITY_UP;
1591 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1592 quality=LINK_QUALITY_DOWN;
1593 else if (st->addresses)
1594 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1595 else if (transport_peers_valid(&st->peers))
1596 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1598 quality=LINK_QUALITY_DOWN;
1600 st->netlink->set_quality(st->netlink->st,quality);
1603 static void enter_state_run(struct site *st)
1605 slog(st,LOG_STATE,"entering state RUN%s",
1606 current_valid(st) ? " (keyed)" : " (unkeyed)");
1610 st->setup_session_id=0;
1611 transport_peers_clear(st,&st->setup_peers);
1612 FILLZERO(st->localN);
1613 FILLZERO(st->remoteN);
1614 dispose_transform(&st->new_transform);
1615 memset(st->dhsecret,0,st->dh->len);
1616 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1617 set_link_quality(st);
1619 if (st->keepalive && !current_valid(st))
1620 initiate_key_setup(st, "keepalive", 0);
1623 static bool_t ensure_resolving(struct site *st)
1625 /* Reentrancy hazard: may call site_resolve_callback and hence
1626 * enter_new_state, enter_state_* and generate_msg*. */
1627 if (st->resolving_count)
1630 assert(st->addresses);
1632 /* resolver->request might reentrantly call site_resolve_callback
1633 * which will decrement st->resolving, so we need to increment it
1634 * twice beforehand to prevent decrement from thinking we're
1635 * finished, and decrement it ourselves. Alternatively if
1636 * everything fails then there are no callbacks due and we simply
1637 * set it to 0 and return false.. */
1638 st->resolving_n_results_stored=0;
1639 st->resolving_n_results_all=0;
1640 st->resolving_count+=2;
1641 const char **addrp=st->addresses;
1642 const char *address;
1644 for (; (address=*addrp++); ) {
1645 bool_t ok = st->resolver->request(st->resolver->st,address,
1646 st->remoteport,st->comms[0],
1647 site_resolve_callback,st);
1649 st->resolving_count++;
1653 st->resolving_count=0;
1656 decrement_resolving_count(st,2);
1660 static bool_t enter_state_resolve(struct site *st)
1662 /* Reentrancy hazard! See ensure_resolving. */
1663 state_assert(st,st->state==SITE_RUN);
1664 slog(st,LOG_STATE,"entering state RESOLVE");
1665 st->state=SITE_RESOLVE;
1666 return ensure_resolving(st);
1669 static bool_t enter_new_state(struct site *st, uint32_t next,
1670 const struct msg *prompt
1671 /* may be 0 for SENTMSG1 */)
1673 bool_t (*gen)(struct site *st, const struct msg *prompt);
1676 slog(st,LOG_STATE,"entering state %s",state_name(next));
1679 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1680 if (!kex_init(st)) return False;
1682 st->msg1_crossed_logged = False;
1685 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1686 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1687 if (!kex_init(st)) return False;
1691 state_assert(st,st->state==SITE_SENTMSG1);
1692 BUF_FREE(&st->buffer);
1696 state_assert(st,st->state==SITE_SENTMSG2);
1697 BUF_FREE(&st->buffer);
1701 state_assert(st,st->state==SITE_SENTMSG3);
1702 BUF_FREE(&st->buffer);
1706 state_assert(st,st->state==SITE_SENTMSG4);
1707 BUF_FREE(&st->buffer);
1712 fatal("enter_new_state(%s): invalid new state",state_name(next));
1716 if (hacky_par_start_failnow()) return False;
1718 r= gen(st,prompt) && send_msg(st);
1721 st->setup_retries, st->setup_retry_interval,
1726 if (next==SITE_RUN) {
1727 BUF_FREE(&st->buffer); /* Never reused */
1728 st->timeout=0; /* Never retransmit */
1729 activate_new_key(st);
1733 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1734 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1735 in either state, and enter_state_wait() will
1737 enter_state_wait(st);
1741 /* msg7 tells our peer that we're about to forget our key */
1742 static bool_t send_msg7(struct site *st, cstring_t reason)
1744 cstring_t transform_err;
1746 if (current_valid(st) && st->buffer.free
1747 && transport_peers_valid(&st->peers)) {
1748 BUF_ALLOC(&st->buffer,"site:MSG7");
1749 buffer_init(&st->buffer,calculate_max_start_pad());
1750 buf_append_uint32(&st->buffer,LABEL_MSG7);
1751 buf_append_string(&st->buffer,reason);
1752 if (call_transform_forwards(st, st->current.transform,
1753 &st->buffer, &transform_err))
1755 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1756 buf_prepend_uint32(&st->buffer,st->index);
1757 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1758 transport_xmit(st,&st->peers,&st->buffer,True);
1759 BUF_FREE(&st->buffer);
1766 /* We go into this state if our peer becomes uncommunicative. Similar to
1767 the "stop" state, we forget all session keys for a while, before
1768 re-entering the "run" state. */
1769 static void enter_state_wait(struct site *st)
1771 slog(st,LOG_STATE,"entering state WAIT");
1772 st->timeout=st->now+wait_timeout(st);
1773 st->state=SITE_WAIT;
1774 set_link_quality(st);
1775 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1776 /* XXX Erase keys etc. */
1779 static void generate_prod(struct site *st, struct buffer_if *buf)
1782 buf_append_uint32(buf,0);
1783 buf_append_uint32(buf,0);
1784 buf_append_uint32(buf,LABEL_PROD);
1785 buf_append_string(buf,st->localname);
1786 buf_append_string(buf,st->remotename);
1789 static void generate_send_prod(struct site *st,
1790 const struct comm_addr *source)
1792 if (!st->allow_send_prod) return; /* too soon */
1793 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1794 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1796 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1797 st->allow_send_prod=0;
1798 generate_prod(st,&st->scratch);
1799 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1800 dump_packet(st,&st->scratch,source,False,ok);
1803 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1806 int64_t offset=timeout-*now;
1807 if (offset<0) offset=0;
1808 if (offset>INT_MAX) offset=INT_MAX;
1809 if (*timeout_io<0 || offset<*timeout_io)
1814 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1817 struct site *st=sst;
1819 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1822 /* Work out when our next timeout is. The earlier of 'timeout' or
1823 'current.key_timeout'. A stored value of '0' indicates no timeout
1825 site_settimeout(st->timeout, timeout_io);
1826 site_settimeout(st->current.key_timeout, timeout_io);
1827 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1829 return 0; /* success */
1832 static void check_expiry(struct site *st, struct data_key *key,
1835 if (key->key_timeout && *now>key->key_timeout) {
1836 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1840 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1841 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1843 struct site *st=sst;
1846 if (st->timeout && *now>st->timeout) {
1848 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1849 if (!hacky_par_start_failnow())
1851 } else if (st->state==SITE_WAIT) {
1852 enter_state_run(st);
1854 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1858 check_expiry(st,&st->current,"current key");
1859 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1862 /* This function is called by the netlink device to deliver packets
1863 intended for the remote network. The packet is in "raw" wire
1864 format, but is guaranteed to be word-aligned. */
1865 static void site_outgoing(void *sst, struct buffer_if *buf)
1867 struct site *st=sst;
1868 cstring_t transform_err;
1870 if (st->state==SITE_STOP) {
1875 st->allow_send_prod=1;
1877 /* In all other states we consider delivering the packet if we have
1878 a valid key and a valid address to send it to. */
1879 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1880 /* Transform it and send it */
1882 buf_prepend_uint32(buf,LABEL_MSG9);
1883 if (call_transform_forwards(st, st->current.transform,
1884 buf, &transform_err))
1886 buf_prepend_uint32(buf,LABEL_MSG0);
1887 buf_prepend_uint32(buf,st->index);
1888 buf_prepend_uint32(buf,st->current.remote_session_id);
1889 transport_xmit(st,&st->peers,buf,False);
1896 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1898 initiate_key_setup(st,"outgoing packet",0);
1901 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1902 uint32_t type, struct msg *m,
1903 struct priomsg *whynot)
1904 /* For packets which are identified by the local and remote names.
1905 * If it has our name and our peer's name in it it's for us. */
1907 struct buffer_if buf[1];
1908 buffer_readonly_clone(buf,buf_in);
1910 if (!unpick_msg(st,type,buf,m)) {
1911 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
1914 #define NAME_MATCHES(lr) \
1915 if (!name_matches(&m->lr, st->lr##name)) { \
1916 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
1917 "unknown " #lr " name: ")) { \
1918 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
1922 NAME_MATCHES(remote);
1923 NAME_MATCHES(local );
1929 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1930 if (st->local_capabilities & m->remote_capabilities &
1931 CAPAB_PRIORITY_MOBILE) {
1932 if (st->local_mobile) return True;
1933 if (st-> peer_mobile) return False;
1935 return st->our_name_later;
1938 static bool_t setup_late_msg_ok(struct site *st,
1939 const struct buffer_if *buf_in,
1941 const struct comm_addr *source,
1942 struct msg *m /* returned */) {
1943 /* For setup packets which seem from their type like they are
1944 * late. Maybe they came via a different path. All we do is make
1945 * a note of the sending address, iff they look like they are part
1946 * of the current key setup attempt. */
1947 if (!named_for_us(st,buf_in,msgtype,m,0))
1948 /* named_for_us calls unpick_msg which gets the nonces */
1950 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1951 !consttime_memeq(m->nL,st->localN, NONCELEN))
1952 /* spoof ? from stale run ? who knows */
1954 transport_setup_msgok(st,source);
1958 /* This function is called by the communication device to deliver
1959 packets from our peers.
1960 It should return True if the packet is recognised as being for
1961 this current site instance (and should therefore not be processed
1962 by other sites), even if the packet was otherwise ignored. */
1963 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1964 const struct comm_addr *source,
1965 struct priomsg *whynot)
1967 struct site *st=sst;
1969 if (buf->size < 12) return False;
1971 uint32_t dest=get_uint32(buf->start);
1972 uint32_t msgtype=get_uint32(buf->start+8);
1974 /* initialised by named_for_us, or process_msgN for N!=1 */
1976 if (msgtype==LABEL_MSG1) {
1977 if (!named_for_us(st,buf,msgtype,&msg,whynot))
1979 /* It's a MSG1 addressed to us. Decide what to do about it. */
1980 dump_packet(st,buf,source,True,True);
1981 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1982 st->state==SITE_WAIT) {
1983 /* We should definitely process it */
1984 transport_compute_setupinit_peers(st,0,0,source);
1985 if (process_msg1(st,buf,source,&msg)) {
1986 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1987 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1988 if (entered && st->addresses && st->local_mobile)
1989 /* We must do this as the very last thing, because
1990 the resolver callback might reenter us. */
1991 ensure_resolving(st);
1993 slog(st,LOG_ERROR,"failed to process incoming msg1");
1997 } else if (st->state==SITE_SENTMSG1) {
1998 /* We've just sent a message 1! They may have crossed on
1999 the wire. If we have priority then we ignore the
2000 incoming one, otherwise we process it as usual. */
2001 if (we_have_priority(st,&msg)) {
2003 if (!st->msg1_crossed_logged++)
2004 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2005 "priority => ignore incoming msg1");
2008 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2009 "priority => use incoming msg1");
2010 if (process_msg1(st,buf,source,&msg)) {
2011 BUF_FREE(&st->buffer); /* Free our old message 1 */
2012 transport_setup_msgok(st,source);
2013 enter_new_state(st,SITE_SENTMSG2,&msg);
2015 slog(st,LOG_ERROR,"failed to process an incoming "
2016 "crossed msg1 (we have low priority)");
2021 } else if (st->state==SITE_SENTMSG2 ||
2022 st->state==SITE_SENTMSG4) {
2023 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2024 /* We are ahead in the protocol, but that msg1 had the
2025 * peer's nonce so presumably it is from this key
2026 * exchange run, via a slower route */
2027 transport_setup_msgok(st,source);
2029 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2034 /* The message 1 was received at an unexpected stage of the
2035 key setup. Well, they lost the race. */
2036 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2040 if (msgtype==LABEL_PROD) {
2041 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2043 dump_packet(st,buf,source,True,True);
2044 if (st->state!=SITE_RUN) {
2045 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2046 } else if (current_valid(st)) {
2047 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2049 initiate_key_setup(st,"peer sent PROD packet",source);
2054 if (dest==st->index) {
2055 /* Explicitly addressed to us */
2056 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2059 /* If the source is our current peer then initiate a key setup,
2060 because our peer's forgotten the key */
2061 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2063 initiated = initiate_key_setup(st,"received a NAK",source);
2064 if (!initiated) generate_send_prod(st,source);
2066 slog(st,LOG_SEC,"bad incoming NAK");
2070 process_msg0(st,buf,source);
2073 /* Setup packet: should not have been explicitly addressed
2075 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2078 /* Setup packet: expected only in state SENTMSG1 */
2079 if (st->state!=SITE_SENTMSG1) {
2080 if ((st->state==SITE_SENTMSG3 ||
2081 st->state==SITE_SENTMSG5) &&
2082 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2084 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2085 } else if (process_msg2(st,buf,source,&msg)) {
2086 transport_setup_msgok(st,source);
2087 enter_new_state(st,SITE_SENTMSG3,&msg);
2089 slog(st,LOG_SEC,"invalid MSG2");
2092 case CASES_MSG3_KNOWN:
2093 /* Setup packet: expected only in state SENTMSG2 */
2094 if (st->state!=SITE_SENTMSG2) {
2095 if ((st->state==SITE_SENTMSG4) &&
2096 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2098 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2099 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2100 transport_setup_msgok(st,source);
2101 enter_new_state(st,SITE_SENTMSG4,&msg);
2103 slog(st,LOG_SEC,"invalid MSG3");
2107 /* Setup packet: expected only in state SENTMSG3 */
2108 if (st->state!=SITE_SENTMSG3) {
2109 if ((st->state==SITE_SENTMSG5) &&
2110 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2112 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2113 } else if (process_msg4(st,buf,source,&msg)) {
2114 transport_setup_msgok(st,source);
2115 enter_new_state(st,SITE_SENTMSG5,&msg);
2117 slog(st,LOG_SEC,"invalid MSG4");
2121 /* Setup packet: expected only in state SENTMSG4 */
2122 /* (may turn up in state RUN if our return MSG6 was lost
2123 and the new key has already been activated. In that
2124 case we discard it. The peer will realise that we
2125 are using the new key when they see our data packets.
2126 Until then the peer's data packets to us get discarded. */
2127 if (st->state==SITE_SENTMSG4) {
2128 if (process_msg5(st,buf,source,st->new_transform)) {
2129 transport_setup_msgok(st,source);
2130 enter_new_state(st,SITE_RUN,&msg);
2132 slog(st,LOG_SEC,"invalid MSG5");
2134 } else if (st->state==SITE_RUN) {
2135 if (process_msg5(st,buf,source,st->current.transform)) {
2136 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2137 transport_setup_msgok(st,source);
2138 create_msg6(st,st->current.transform,
2139 st->current.remote_session_id);
2140 transport_xmit(st,&st->peers,&st->buffer,True);
2141 BUF_FREE(&st->buffer);
2143 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2146 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2150 /* Setup packet: expected only in state SENTMSG5 */
2151 if (st->state!=SITE_SENTMSG5) {
2152 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2153 } else if (process_msg6(st,buf,source)) {
2154 BUF_FREE(&st->buffer); /* Free message 5 */
2155 transport_setup_msgok(st,source);
2156 activate_new_key(st);
2158 slog(st,LOG_SEC,"invalid MSG6");
2162 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2170 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2171 "not MSG1 or PROD; unknown dest index");
2175 static void site_control(void *vst, bool_t run)
2177 struct site *st=vst;
2178 if (run) enter_state_run(st);
2179 else enter_state_stop(st);
2182 static void site_phase_hook(void *sst, uint32_t newphase)
2184 struct site *st=sst;
2186 /* The program is shutting down; tell our peer */
2187 send_msg7(st,"shutting down");
2190 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2192 struct site *st=sst;
2193 dispose_transform(&st->current.transform);
2194 dispose_transform(&st->auxiliary_key.transform);
2195 dispose_transform(&st->new_transform);
2196 /* Not much point overwiting the signing key, since we loaded it
2197 from disk, and it is only valid prospectively if at all,
2199 /* XXX it would be best to overwrite the DH state, because that
2200 _is_ relevant to forward secrecy. However we have no
2201 convenient interface for doing that and in practice gmp has
2202 probably dribbled droppings all over the malloc arena. A good
2203 way to fix this would be to have a privsep child for asymmetric
2204 crypto operations, but that's a task for another day. */
2207 static void setup_sethash(struct site *st, dict_t *dict,
2208 struct hash_if **hash, struct cloc loc,
2209 sig_sethash_fn *sethash, void *sigkey_st) {
2210 if (!*hash) *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2211 sethash(sigkey_st,*hash);
2213 #define SETUP_SETHASH(k) do{ \
2215 setup_sethash(st,dict, &hash,loc, (k)->sethash,(k)->st); \
2218 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2221 static uint32_t index_sequence;
2229 st->cl.description="site";
2230 st->cl.type=CL_SITE;
2232 st->cl.interface=&st->ops;
2234 st->ops.control=site_control;
2235 st->ops.status=site_status;
2237 /* First parameter must be a dict */
2238 item=list_elem(args,0);
2239 if (!item || item->type!=t_dict)
2240 cfgfatal(loc,"site","parameter must be a dictionary\n");
2242 dict=item->data.dict;
2243 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2244 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2246 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2248 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2250 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2252 /* Sanity check (which also allows the 'sites' file to include
2253 site() closures for all sites including our own): refuse to
2254 talk to ourselves */
2255 if (strcmp(st->localname,st->remotename)==0) {
2256 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2258 if (st->peer_mobile != st->local_mobile)
2259 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2260 " but our local-mobile=%d\n",
2261 st->localname, st->peer_mobile, st->local_mobile);
2265 if (st->peer_mobile && st->local_mobile) {
2266 Message(M_WARNING,"site %s: site is mobile but so are we"
2267 " -> ignoring this site\n", st->remotename);
2272 assert(index_sequence < 0xffffffffUL);
2273 st->index = ++index_sequence;
2274 st->local_capabilities = 0;
2275 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2276 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2278 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2279 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2280 if (!things##_cfg) \
2281 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2282 st->nthings=list_length(things##_cfg); \
2283 NEW_ARY(st->things,st->nthings); \
2284 assert(st->nthings); \
2285 for (i=0; i<st->nthings; i++) { \
2286 item_t *item=list_elem(things##_cfg,i); \
2287 if (item->type!=t_closure) \
2288 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2289 closure_t *cl=item->data.closure; \
2290 if (cl->type!=CL_TYPE) \
2291 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2292 st->things[i]=cl->interface; \
2296 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2298 NEW_ARY(st->commclientinfos, st->ncomms);
2299 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2300 for (i=0; i<st->ncomms; i++) {
2301 st->commclientinfos[i] =
2303 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2306 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2307 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2308 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2310 struct hash_if *hash=0;
2312 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2313 if (!st->privkeys) {
2315 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2316 SETUP_SETHASH(st->privkey_fixed);
2319 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2321 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2322 else st->remoteport=0;
2323 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2325 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2327 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2329 SETUP_SETHASH(st->pubkey);
2331 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2332 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2333 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2335 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2336 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2337 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2338 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2339 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2341 st->mobile_peer_expiry= dict_read_number(
2342 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2344 const char *peerskey= st->peer_mobile
2345 ? "mobile-peers-max" : "static-peers-max";
2346 st->transport_peers_max= dict_read_number(
2347 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2348 if (st->transport_peers_max<1 ||
2349 st->transport_peers_max>MAX_PEER_ADDRS) {
2350 cfgfatal(loc,"site", "%s must be in range 1.."
2351 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2354 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2355 st->key_renegotiate_time=st->key_lifetime/2;
2357 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2358 st->key_renegotiate_time=dict_read_number(
2359 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2360 if (st->key_renegotiate_time > st->key_lifetime) {
2361 cfgfatal(loc,"site",
2362 "renegotiate-time must be less than key-lifetime\n");
2365 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2366 log_event_table,"site");
2368 st->resolving_count=0;
2369 st->allow_send_prod=0;
2371 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2373 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2375 /* The information we expect to see in incoming messages of type 1 */
2376 /* fixme: lots of unchecked overflows here, but the results are only
2377 corrupted packets rather than undefined behaviour */
2378 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2380 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2382 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2383 BUF_ALLOC(&st->scratch,"site:scratch");
2385 /* We are interested in poll(), but only for timeouts. We don't have
2386 any fds of our own. */
2387 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2390 st->remote_capabilities=0;
2391 st->chosen_transform=0;
2392 st->current.key_timeout=0;
2393 st->auxiliary_key.key_timeout=0;
2394 transport_peers_clear(st,&st->peers);
2395 transport_peers_clear(st,&st->setup_peers);
2396 /* XXX mlock these */
2397 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2398 st->sharedsecretlen=st->sharedsecretallocd=0;
2401 #define SET_CAPBIT(bit) do { \
2402 uint32_t capflag = 1UL << (bit); \
2403 if (st->local_capabilities & capflag) \
2404 slog(st,LOG_ERROR,"capability bit" \
2405 " %d (%#"PRIx32") reused", (bit), capflag); \
2406 st->local_capabilities |= capflag; \
2409 for (i=0; i<st->ntransforms; i++)
2410 SET_CAPBIT(st->transforms[i]->capab_bit);
2414 if (st->local_mobile || st->peer_mobile)
2415 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2417 /* We need to register the remote networks with the netlink device */
2418 uint32_t netlink_mtu; /* local virtual interface mtu */
2419 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2420 if (!st->mtu_target)
2421 st->mtu_target=netlink_mtu;
2423 for (i=0; i<st->ncomms; i++)
2424 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2426 st->current.transform=0;
2427 st->auxiliary_key.transform=0;
2428 st->new_transform=0;
2429 st->auxiliary_is_new=0;
2431 enter_state_stop(st);
2433 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2434 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2436 return new_closure(&st->cl);
2439 void site_module(dict_t *dict)
2441 add_closure(dict,"site",site_apply);
2445 /***** TRANSPORT PEERS definitions *****/
2447 static void transport_peers_debug(struct site *st, transport_peers *dst,
2448 const char *didwhat,
2449 int nargs, const struct comm_addr *args,
2454 if (!(st->log_events & LOG_PEER_ADDRS))
2455 return; /* an optimisation */
2457 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2458 (dst==&st->peers ? "data" :
2459 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2460 didwhat, nargs, dst->npeers);
2462 for (i=0, argp=(void*)args;
2464 i++, (argp+=stride?stride:sizeof(*args))) {
2465 const struct comm_addr *ca=(void*)argp;
2466 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2467 i, comm_addr_to_string(ca));
2469 for (i=0; i<dst->npeers; i++) {
2470 struct timeval diff;
2471 timersub(tv_now,&dst->peers[i].last,&diff);
2472 const struct comm_addr *ca=&dst->peers[i].addr;
2473 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2474 i, comm_addr_to_string(ca),
2475 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2479 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2480 /* peers must be sorted first */
2481 int previous_peers=peers->npeers;
2482 struct timeval oldest;
2483 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2484 oldest.tv_usec = tv_now->tv_usec;
2485 while (peers->npeers>1 &&
2486 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2488 if (peers->npeers != previous_peers)
2489 transport_peers_debug(st,peers,"expire", 0,0,0);
2492 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2493 const struct comm_addr *ca,
2494 const struct timeval *tv) {
2495 /* returns false if output is full */
2498 if (peers->npeers >= st->transport_peers_max)
2501 for (search=0; search<peers->npeers; search++)
2502 if (comm_addr_equal(&peers->peers[search].addr, ca))
2505 peers->peers[peers->npeers].addr = *ca;
2506 peers->peers[peers->npeers].last = *tv;
2511 static void transport_record_peers(struct site *st, transport_peers *peers,
2512 const struct comm_addr *addrs, int naddrs,
2514 /* We add addrs into peers. The new entries end up at the front
2515 * and displace entries towards the end (perhaps even off the
2516 * end). Any existing matching entries are moved up to the front.
2518 * Caller must first call transport_peers_expire. */
2521 /* avoids debug for uninteresting updates */
2523 for (i=0; i<peers->npeers; i++) {
2524 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2525 memmove(peers->peers+1, peers->peers,
2526 sizeof(peers->peers[0]) * i);
2527 peers->peers[0].addr = addrs[0];
2528 peers->peers[0].last = *tv_now;
2534 int old_npeers=peers->npeers;
2535 transport_peer old_peers[old_npeers];
2536 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2540 for (i=0; i<naddrs; i++) {
2541 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2544 for (i=0; i<old_npeers; i++) {
2545 const transport_peer *old=&old_peers[i];
2546 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2550 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2553 static void transport_expire_record_peers(struct site *st,
2554 transport_peers *peers,
2555 const struct comm_addr *addrs,
2556 int naddrs, const char *m) {
2557 /* Convenience function */
2558 transport_peers_expire(st,peers);
2559 transport_record_peers(st,peers,addrs,naddrs,m);
2562 static bool_t transport_compute_setupinit_peers(struct site *st,
2563 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2564 int n_configured_addrs /* 0 if none or not found */,
2565 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2566 if (!n_configured_addrs && !incoming_packet_addr &&
2567 !transport_peers_valid(&st->peers))
2570 slog(st,LOG_SETUP_INIT,
2571 "using: %d configured addr(s);%s %d old peer addrs(es)",
2573 incoming_packet_addr ? " incoming packet address;" : "",
2576 /* Non-mobile peers try addresses until one is plausible. The
2577 * effect is that this code always tries first the configured
2578 * address if supplied, or otherwise the address of the incoming
2579 * PROD, or finally the existing data peer if one exists; this is
2582 transport_peers_copy(st,&st->setup_peers,&st->peers);
2583 transport_peers_expire(st,&st->setup_peers);
2585 if (incoming_packet_addr)
2586 transport_record_peers(st,&st->setup_peers,
2587 incoming_packet_addr,1, "incoming");
2589 if (n_configured_addrs)
2590 transport_record_peers(st,&st->setup_peers,
2591 configured_addrs,n_configured_addrs, "setupinit");
2593 assert(transport_peers_valid(&st->setup_peers));
2597 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2598 if (st->peer_mobile)
2599 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2601 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2602 if (st->peer_mobile)
2603 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2606 static int transport_peers_valid(transport_peers *peers) {
2607 return peers->npeers;
2609 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2611 transport_peers_debug(st,peers,"clear",0,0,0);
2613 static void transport_peers_copy(struct site *st, transport_peers *dst,
2614 const transport_peers *src) {
2615 dst->npeers=src->npeers;
2616 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2617 transport_peers_debug(st,dst,"copy",
2618 src->npeers, &src->peers->addr, sizeof(*src->peers));
2621 static void transport_resolve_complete(struct site *st,
2622 const struct comm_addr *addrs,
2624 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2626 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2630 static void transport_resolve_complete_tardy(struct site *st,
2631 const struct comm_addr *addrs,
2633 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2634 "resolved tardily");
2637 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2639 const transport_peers *inp) {
2640 /* out and in->peers may be the same region, or nonoverlapping */
2641 const transport_peer *in=inp->peers;
2643 for (slot=0; slot<inp->npeers; slot++) {
2644 if (!(mask & (1U << slot)))
2646 if (!(out==in && slot==*nout_io))
2647 COPY_OBJ(out[*nout_io], in[slot]);
2652 void transport_xmit(struct site *st, transport_peers *peers,
2653 struct buffer_if *buf, bool_t candebug) {
2655 transport_peers_expire(st, peers);
2656 unsigned failed=0; /* bitmask */
2657 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2660 for (slot=0; slot<peers->npeers; slot++) {
2661 transport_peer *peer=&peers->peers[slot];
2662 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2664 dump_packet(st, buf, &peer->addr, False, ok);
2666 failed |= 1U << slot;
2669 if (ok && !st->peer_mobile)
2672 /* Now we need to demote/delete failing addrs: if we are mobile we
2673 * merely demote them; otherwise we delete them. */
2674 if (st->local_mobile) {
2675 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2676 /* `expected' has all the failures at the end already */
2677 if (failed != expected) {
2679 transport_peer failedpeers[nfailed];
2680 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2681 assert(fslot == nfailed);
2683 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2684 assert(wslot+nfailed == peers->npeers);
2685 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2686 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2689 if (failed && peers->npeers > 1) {
2691 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2692 peers->npeers=wslot;
2693 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2698 /***** END of transport peers declarations *****/