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 sigprivkey_if *privkey;
320 struct sigpubkey_if *pubkey;
321 struct transform_if **transforms;
325 uint32_t index; /* Index of this site */
326 uint32_t early_capabilities;
327 uint32_t local_capabilities;
328 int32_t setup_retries; /* How many times to send setup packets */
329 int32_t setup_retry_interval; /* Initial timeout for setup packets */
330 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
331 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
332 int32_t key_lifetime; /* How long a key lasts once set up */
333 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
334 after this time, initiate a new
337 bool_t our_name_later; /* our name > peer name */
340 /* runtime information */
342 uint64_t now; /* Most recently seen time */
343 bool_t allow_send_prod;
344 bool_t msg1_crossed_logged;
346 int resolving_n_results_all;
347 int resolving_n_results_stored;
348 struct comm_addr resolving_results[MAX_PEER_ADDRS];
350 /* The currently established session */
351 struct data_key current;
352 struct data_key auxiliary_key;
353 bool_t auxiliary_is_new;
354 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
355 uint64_t auxiliary_renegotiate_key_time;
356 transport_peers peers; /* Current address(es) of peer for data traffic */
358 /* The current key setup protocol exchange. We can only be
359 involved in one of these at a time. There's a potential for
360 denial of service here (the attacker keeps sending a setup
361 packet; we keep trying to continue the exchange, and have to
362 timeout before we can listen for another setup packet); perhaps
363 we should keep a list of 'bad' sources for setup packets. */
364 uint32_t remote_capabilities;
365 uint16_t remote_adv_mtu;
366 struct transform_if *chosen_transform;
367 uint32_t setup_session_id;
368 transport_peers setup_peers;
369 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
370 uint8_t remoteN[NONCELEN];
371 struct buffer_if buffer; /* Current outgoing key exchange packet */
372 struct buffer_if scratch;
373 int32_t retries; /* Number of retries remaining */
374 uint64_t timeout; /* Timeout for current state */
376 uint8_t *sharedsecret;
377 uint32_t sharedsecretlen, sharedsecretallocd;
378 struct transform_inst_if *new_transform; /* For key setup/verify */
381 static uint32_t event_log_priority(struct site *st, uint32_t event)
383 if (!(event&st->log_events))
386 case LOG_UNEXPECTED: return M_INFO;
387 case LOG_SETUP_INIT: return M_INFO;
388 case LOG_SETUP_TIMEOUT: return M_NOTICE;
389 case LOG_ACTIVATE_KEY: return M_INFO;
390 case LOG_TIMEOUT_KEY: return M_INFO;
391 case LOG_SEC: return M_SECURITY;
392 case LOG_STATE: return M_DEBUG;
393 case LOG_DROP: return M_DEBUG;
394 case LOG_DUMP: return M_DEBUG;
395 case LOG_ERROR: return M_ERR;
396 case LOG_PEER_ADDRS: return M_DEBUG;
397 case LOG_SIGKEYS: return M_INFO;
398 default: return M_ERR;
402 static uint32_t slog_start(struct site *st, uint32_t event)
404 uint32_t class=event_log_priority(st, event);
406 slilog_part(st->log,class,"%s: ",st->tunname);
411 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
413 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
417 class=slog_start(st,event);
419 vslilog_part(st->log,class,msg,ap);
420 slilog_part(st->log,class,"\n");
424 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
426 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
430 vslog(st,event,msg,ap);
434 static void logtimeout(struct site *st, const char *fmt, ...)
436 static void logtimeout(struct site *st, const char *fmt, ...)
438 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
445 slilog_part(st->log,class,"%s: ",st->tunname);
446 vslilog_part(st->log,class,fmt,ap);
450 for (i=0, delim=" (tried ";
451 i<st->setup_peers.npeers;
453 transport_peer *peer=&st->setup_peers.peers[i];
454 const char *s=comm_addr_to_string(&peer->addr);
455 slilog_part(st->log,class,"%s%s",delim,s);
458 slilog_part(st->log,class,")\n");
462 static void set_link_quality(struct site *st);
463 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
464 static void delete_one_key(struct site *st, struct data_key *key,
465 const char *reason /* may be 0 meaning don't log*/,
466 const char *which /* ignored if !reasonn */,
467 uint32_t loglevel /* ignored if !reasonn */);
468 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
469 const struct comm_addr *prod_hint);
470 static void enter_state_run(struct site *st);
471 static bool_t enter_state_resolve(struct site *st);
472 static void decrement_resolving_count(struct site *st, int by);
473 static bool_t enter_new_state(struct site *st,uint32_t next,
474 const struct msg *prompt
475 /* may be 0 for SENTMSG1 */);
476 static void enter_state_wait(struct site *st);
477 static void activate_new_key(struct site *st);
479 static bool_t is_transform_valid(struct transform_inst_if *transform)
481 return transform && transform->valid(transform->st);
484 static bool_t current_valid(struct site *st)
486 return is_transform_valid(st->current.transform);
489 #define DEFINE_CALL_TRANSFORM(fwdrev) \
490 static transform_apply_return \
491 call_transform_##fwdrev(struct site *st, \
492 struct transform_inst_if *transform, \
493 struct buffer_if *buf, \
494 const char **errmsg) \
496 if (!is_transform_valid(transform)) { \
497 *errmsg="transform not set up"; \
498 return transform_apply_err; \
500 return transform->fwdrev(transform->st,buf,errmsg); \
503 DEFINE_CALL_TRANSFORM(forwards)
504 DEFINE_CALL_TRANSFORM(reverse)
506 static void dispose_transform(struct transform_inst_if **transform_var)
508 struct transform_inst_if *transform=*transform_var;
510 transform->delkey(transform->st);
511 transform->destroy(transform->st);
516 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
517 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
518 #define CHECK_TYPE(b,t) do { uint32_t type; \
519 CHECK_AVAIL((b),4); \
520 type=buf_unprepend_uint32((b)); \
521 if (type!=(t)) return False; } while(0)
523 static _Bool type_is_msg34(uint32_t type)
526 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
527 default: return False;
534 struct buffer_if extrainfo;
541 struct parsedname remote;
542 struct parsedname local;
543 uint32_t remote_capabilities;
545 int capab_transformnum;
551 struct alg_msg_data sig;
554 static int32_t wait_timeout(struct site *st) {
555 int32_t t = st->wait_timeout_mean;
558 st->random->generate(st->random->st,sizeof(factor),&factor);
559 t += (t / 256) * factor;
564 static _Bool set_new_transform(struct site *st, char *pk)
568 /* Make room for the shared key */
569 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
570 assert(st->sharedsecretlen);
571 if (st->sharedsecretlen > st->sharedsecretallocd) {
572 st->sharedsecretallocd=st->sharedsecretlen;
573 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
574 st->sharedsecretallocd,
575 "site:sharedsecret");
578 /* Generate the shared key */
579 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
580 st->sharedsecret,st->sharedsecretlen);
582 /* Set up the transform */
583 struct transform_if *generator=st->chosen_transform;
584 struct transform_inst_if *generated=generator->create(generator->st);
585 ok = generated->setkey(generated->st,st->sharedsecret,
586 st->sharedsecretlen,st->our_name_later);
588 dispose_transform(&st->new_transform);
589 if (!ok) return False;
590 st->new_transform=generated;
592 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
593 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
594 st->chosen_transform->capab_bit,
595 st->local_capabilities, st->remote_capabilities);
600 int32_t lenpos, afternul;
602 static void append_string_xinfo_start(struct buffer_if *buf,
603 struct xinfoadd *xia,
605 /* Helps construct one of the names with additional info as found
606 * in MSG1..4. Call this function first, then append all the
607 * desired extra info (not including the nul byte) to the buffer,
608 * then call append_string_xinfo_done. */
610 xia->lenpos = buf->size;
611 buf_append_string(buf,str);
612 buf_append_uint8(buf,0);
613 xia->afternul = buf->size;
615 static void append_string_xinfo_done(struct buffer_if *buf,
616 struct xinfoadd *xia)
618 /* we just need to adjust the string length */
619 if (buf->size == xia->afternul) {
620 /* no extra info, strip the nul too */
621 buf_unappend_uint8(buf);
623 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
627 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
628 out using a transform of config data supplied by netlink */
629 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
630 const struct msg *prompt
631 /* may be 0 for MSG1 */)
636 st->retries=st->setup_retries;
637 BUF_ALLOC(&st->buffer,what);
638 buffer_init(&st->buffer,0);
639 buf_append_uint32(&st->buffer,
640 (type==LABEL_MSG1?0:st->setup_session_id));
641 buf_append_uint32(&st->buffer,st->index);
642 buf_append_uint32(&st->buffer,type);
645 append_string_xinfo_start(&st->buffer,&xia,st->localname);
646 if ((st->local_capabilities & st->early_capabilities) ||
647 (type != LABEL_MSG1)) {
648 buf_append_uint32(&st->buffer,st->local_capabilities);
650 if (type_is_msg34(type)) {
651 buf_append_uint16(&st->buffer,st->mtu_target);
653 struct sigprivkey_if *privkey=st->privkey;
654 append_string_xinfo_done(&st->buffer,&xia);
656 buf_append_string(&st->buffer,st->remotename);
657 BUF_ADD_OBJ(append,&st->buffer,st->localN);
658 if (type==LABEL_MSG1) return True;
659 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
660 if (type==LABEL_MSG2) return True;
662 if (hacky_par_mid_failnow()) return False;
664 if (MSGMAJOR(type) == 3) do {
665 minor = MSGMINOR(type);
666 if (minor < 1) break;
667 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
670 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
671 buf_append_string(&st->buffer,dhpub);
674 bool_t ok=privkey->sign(privkey->st,
685 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
688 nm->len=buf_unprepend_uint16(msg);
689 CHECK_AVAIL(msg,nm->len);
690 nm->name=buf_unprepend(msg,nm->len);
691 uint8_t *nul=memchr(nm->name,0,nm->len);
693 buffer_readonly_view(&nm->extrainfo,0,0);
695 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
696 nm->len=nul-nm->name;
701 static bool_t unpick_msg(struct site *st, uint32_t type,
702 struct buffer_if *msg, struct msg *m)
706 m->capab_transformnum=-1;
707 m->hashstart=msg->start;
709 m->dest=buf_unprepend_uint32(msg);
711 m->source=buf_unprepend_uint32(msg);
712 CHECK_TYPE(msg,type);
713 if (!unpick_name(msg,&m->remote)) return False;
714 m->remote_capabilities=0;
716 if (m->remote.extrainfo.size) {
717 CHECK_AVAIL(&m->remote.extrainfo,4);
718 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
720 if (type_is_msg34(type) && m->remote.extrainfo.size) {
721 CHECK_AVAIL(&m->remote.extrainfo,2);
722 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
724 if (!unpick_name(msg,&m->local)) return False;
725 if (type==LABEL_PROD) {
729 CHECK_AVAIL(msg,NONCELEN);
730 m->nR=buf_unprepend(msg,NONCELEN);
731 if (type==LABEL_MSG1) {
735 CHECK_AVAIL(msg,NONCELEN);
736 m->nL=buf_unprepend(msg,NONCELEN);
737 if (type==LABEL_MSG2) {
741 if (MSGMAJOR(type) == 3) do {
742 minor = MSGMINOR(type);
743 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
744 if (minor < (minminor)) \
745 m->capab_##kind##num = (dflt); \
747 CHECK_AVAIL(msg, 1); \
748 m->capab_##kind##num = buf_unprepend_uint8(msg); \
751 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
752 #undef MAYBE_READ_CAP
755 m->pklen=buf_unprepend_uint16(msg);
756 CHECK_AVAIL(msg,m->pklen);
757 m->pk=buf_unprepend(msg,m->pklen);
758 m->hashlen=msg->start-m->hashstart;
760 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
769 static bool_t name_matches(const struct parsedname *nm, const char *expected)
771 int expected_len=strlen(expected);
773 nm->len == expected_len &&
774 !memcmp(nm->name, expected, expected_len);
777 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
780 if (type==LABEL_MSG1) return True;
782 /* Check that the site names and our nonce have been sent
783 back correctly, and then store our peer's nonce. */
784 if (!name_matches(&m->remote,st->remotename)) {
785 *error="wrong remote site name";
788 if (!name_matches(&m->local,st->localname)) {
789 *error="wrong local site name";
792 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
793 *error="wrong locally-generated nonce";
796 if (type==LABEL_MSG2) return True;
797 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
798 *error="wrong remotely-generated nonce";
801 /* MSG3 has complicated rules about capabilities, which are
802 * handled in process_msg3. */
803 if (MSGMAJOR(type) == 3) return True;
804 if (m->remote_capabilities!=st->remote_capabilities) {
805 *error="remote capabilities changed";
808 if (type==LABEL_MSG4) return True;
809 *error="unknown message type";
813 static bool_t kex_init(struct site *st)
815 st->random->generate(st->random->st,NONCELEN,st->localN);
819 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
822 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
825 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
826 const struct comm_addr *src,
829 /* We've already determined we're in an appropriate state to
830 process an incoming MSG1, and that the MSG1 has correct values
833 st->setup_session_id=m->source;
834 st->remote_capabilities=m->remote_capabilities;
835 memcpy(st->remoteN,m->nR,NONCELEN);
839 static bool_t generate_msg2(struct site *st,
840 const struct msg *prompt_may_be_null)
843 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
846 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
847 const struct comm_addr *src,
848 struct msg *m /* returned */)
852 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
853 if (!check_msg(st,LABEL_MSG2,m,&err)) {
854 slog(st,LOG_SEC,"msg2: %s",err);
857 st->setup_session_id=m->source;
858 st->remote_capabilities=m->remote_capabilities;
860 /* Select the transform to use */
862 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
863 if (!remote_crypto_caps)
864 /* old secnets only had this one transform */
865 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
867 #define CHOOSE_CRYPTO(kind, whats) do { \
868 struct kind##_if *iface; \
869 uint32_t bit, ours = 0; \
871 for (i= 0; i < st->n##kind##s; i++) { \
872 iface=st->kind##s[i]; \
873 bit = 1UL << iface->capab_bit; \
874 if (bit & remote_crypto_caps) goto kind##_found; \
877 slog(st,LOG_ERROR,"no " whats " in common" \
878 " (us %#"PRIx32"; them: %#"PRIx32")", \
879 st->local_capabilities & ours, remote_crypto_caps); \
882 st->chosen_##kind = iface; \
885 CHOOSE_CRYPTO(transform, "transforms");
889 memcpy(st->remoteN,m->nR,NONCELEN);
893 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
895 /* Now we have our nonce and their nonce. Think of a secret key,
896 and create message number 3. */
897 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
898 return generate_msg(st,
899 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
905 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
907 /* Check signature and store g^x mod m */
908 if (!st->pubkey->check(st->pubkey->st,
909 m->hashstart,m->hashlen,
911 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
915 st->remote_adv_mtu=m->remote_mtu;
920 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
921 const struct comm_addr *src, uint32_t msgtype,
922 struct msg *m /* returned */)
927 case CASES_MSG3_KNOWN: break;
931 if (!unpick_msg(st,msgtype,msg3,m)) return False;
932 if (!check_msg(st,msgtype,m,&err)) {
933 slog(st,LOG_SEC,"msg3: %s",err);
936 uint32_t capab_adv_late = m->remote_capabilities
937 & ~st->remote_capabilities & st->early_capabilities;
938 if (capab_adv_late) {
939 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
940 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
941 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
945 #define CHOSE_CRYPTO(kind, what) do { \
946 struct kind##_if *iface; \
948 for (i=0; i<st->n##kind##s; i++) { \
949 iface=st->kind##s[i]; \
950 if (iface->capab_bit == m->capab_##kind##num) \
953 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
954 m->capab_##kind##num); \
957 st->chosen_##kind=iface; \
960 CHOSE_CRYPTO(transform, "transform");
964 if (!process_msg3_msg4(st,m))
967 /* Update our idea of the remote site's capabilities, now that we've
968 * verified that its message was authentic.
970 * Our previous idea of the remote site's capabilities came from the
971 * unauthenticated MSG1. We've already checked that this new message
972 * doesn't change any of the bits we relied upon in the past, but it may
973 * also have set additional capability bits. We simply throw those away
974 * now, and use the authentic capabilities from this MSG3. */
975 st->remote_capabilities=m->remote_capabilities;
977 /* Terminate their DH public key with a '0' */
979 /* Invent our DH secret key */
980 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
982 /* Generate the shared key and set up the transform */
983 if (!set_new_transform(st,m->pk)) return False;
988 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
990 /* We have both nonces, their public key and our private key. Generate
991 our public key, sign it and send it to them. */
992 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
995 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
996 const struct comm_addr *src,
997 struct msg *m /* returned */)
1001 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1002 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1003 slog(st,LOG_SEC,"msg4: %s",err);
1007 if (!process_msg3_msg4(st,m))
1010 /* Terminate their DH public key with a '0' */
1013 /* Generate the shared key and set up the transform */
1014 if (!set_new_transform(st,m->pk)) return False;
1025 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1028 CHECK_AVAIL(msg0,4);
1029 m->dest=buf_unprepend_uint32(msg0);
1030 CHECK_AVAIL(msg0,4);
1031 m->source=buf_unprepend_uint32(msg0);
1032 CHECK_AVAIL(msg0,4);
1033 m->type=buf_unprepend_uint32(msg0);
1035 /* Leaves transformed part of buffer untouched */
1038 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1040 cstring_t transform_err;
1042 BUF_ALLOC(&st->buffer,"site:MSG5");
1043 /* We are going to add four words to the message */
1044 buffer_init(&st->buffer,calculate_max_start_pad());
1045 /* Give the netlink code an opportunity to put its own stuff in the
1046 message (configuration information, etc.) */
1047 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1048 if (call_transform_forwards(st,st->new_transform,
1049 &st->buffer,&transform_err))
1051 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1052 buf_prepend_uint32(&st->buffer,st->index);
1053 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1055 st->retries=st->setup_retries;
1059 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1060 const struct comm_addr *src,
1061 struct transform_inst_if *transform)
1064 cstring_t transform_err;
1066 if (!unpick_msg0(st,msg5,&m)) return False;
1068 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1069 /* There's a problem */
1070 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1073 /* Buffer should now contain untransformed PING packet data */
1074 CHECK_AVAIL(msg5,4);
1075 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1076 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1079 /* Older versions of secnet used to write some config data here
1080 * which we ignore. So we don't CHECK_EMPTY */
1084 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1085 uint32_t session_id)
1087 cstring_t transform_err;
1089 BUF_ALLOC(&st->buffer,"site:MSG6");
1090 /* We are going to add four words to the message */
1091 buffer_init(&st->buffer,calculate_max_start_pad());
1092 /* Give the netlink code an opportunity to put its own stuff in the
1093 message (configuration information, etc.) */
1094 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1095 transform_apply_return problem =
1096 call_transform_forwards(st,transform,
1097 &st->buffer,&transform_err);
1099 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1100 buf_prepend_uint32(&st->buffer,st->index);
1101 buf_prepend_uint32(&st->buffer,session_id);
1104 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1106 if (!is_transform_valid(st->new_transform))
1108 create_msg6(st,st->new_transform,st->setup_session_id);
1109 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1113 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1114 const struct comm_addr *src)
1117 cstring_t transform_err;
1119 if (!unpick_msg0(st,msg6,&m)) return False;
1121 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1122 /* There's a problem */
1123 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1126 /* Buffer should now contain untransformed PING packet data */
1127 CHECK_AVAIL(msg6,4);
1128 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1129 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1132 /* Older versions of secnet used to write some config data here
1133 * which we ignore. So we don't CHECK_EMPTY */
1137 static transform_apply_return
1138 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1139 const struct comm_addr *src)
1141 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1143 transform_apply_return problem;
1145 if (!unpick_msg0(st,msg0,&m)) return False;
1147 /* Keep a copy so we can try decrypting it with multiple keys */
1148 buffer_copy(&st->scratch, msg0);
1150 problem = call_transform_reverse(st,st->current.transform,
1151 msg0,&transform_err);
1153 if (!st->auxiliary_is_new)
1154 delete_one_key(st,&st->auxiliary_key,
1155 "peer has used new key","auxiliary key",LOG_SEC);
1158 if (transform_apply_return_badseq(problem))
1161 buffer_copy(msg0, &st->scratch);
1162 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1165 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1166 if (st->auxiliary_is_new) {
1167 /* We previously timed out in state SENTMSG5 but it turns
1168 * out that our peer did in fact get our MSG5 and is
1169 * using the new key. So we should switch to it too. */
1170 /* This is a bit like activate_new_key. */
1173 st->current=st->auxiliary_key;
1174 st->auxiliary_key=t;
1176 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1177 "previous key",LOG_SEC);
1178 st->auxiliary_is_new=0;
1179 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1183 if (transform_apply_return_badseq(problem))
1186 if (st->state==SITE_SENTMSG5) {
1187 buffer_copy(msg0, &st->scratch);
1188 problem = call_transform_reverse(st,st->new_transform,
1191 /* It looks like we didn't get the peer's MSG6 */
1192 /* This is like a cut-down enter_new_state(SITE_RUN) */
1193 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1194 BUF_FREE(&st->buffer);
1196 activate_new_key(st);
1197 return 0; /* do process the data in this packet */
1199 if (transform_apply_return_badseq(problem))
1203 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1204 transform_err,auxkey_err,newkey_err);
1205 initiate_key_setup(st,"incoming message would not decrypt",0);
1206 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1211 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1216 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1217 const struct comm_addr *src)
1220 transform_apply_return problem;
1222 problem = decrypt_msg0(st,msg0,src);
1223 if (problem==transform_apply_seqdupe) {
1224 /* We recently received another copy of this packet, maybe due
1225 * to polypath. That's not a problem; indeed, for the
1226 * purposes of transport address management it is a success.
1227 * But we don't want to process the packet. */
1228 transport_data_msgok(st,src);
1234 CHECK_AVAIL(msg0,4);
1235 type=buf_unprepend_uint32(msg0);
1238 /* We must forget about the current session. */
1239 delete_keys(st,"request from peer",LOG_SEC);
1240 /* probably, the peer is shutting down, and this is going to fail,
1241 * but we need to be trying to bring the link up again */
1243 initiate_key_setup(st,"peer requested key teardown",0);
1246 /* Deliver to netlink layer */
1247 st->netlink->deliver(st->netlink->st,msg0);
1248 transport_data_msgok(st,src);
1249 /* See whether we should start negotiating a new key */
1250 if (st->now > st->renegotiate_key_time)
1251 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1254 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1261 static void dump_packet(struct site *st, struct buffer_if *buf,
1262 const struct comm_addr *addr, bool_t incoming,
1265 uint32_t dest=get_uint32(buf->start);
1266 uint32_t source=get_uint32(buf->start+4);
1267 uint32_t msgtype=get_uint32(buf->start+8);
1269 if (st->log_events & LOG_DUMP)
1270 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1271 st->tunname,incoming?"incoming":"outgoing",
1272 dest,source,msgtype,comm_addr_to_string(addr),
1276 static bool_t comm_addr_sendmsg(struct site *st,
1277 const struct comm_addr *dest,
1278 struct buffer_if *buf)
1281 struct comm_clientinfo *commclientinfo = 0;
1283 for (i=0; i < st->ncomms; i++) {
1284 if (st->comms[i] == dest->comm) {
1285 commclientinfo = st->commclientinfos[i];
1289 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1292 static uint32_t site_status(void *st)
1297 static bool_t send_msg(struct site *st)
1299 if (st->retries>0) {
1300 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1301 st->timeout=st->now+st->setup_retry_interval;
1304 } else if (st->state==SITE_SENTMSG5) {
1305 logtimeout(st,"timed out sending MSG5, stashing new key");
1306 /* We stash the key we have produced, in case it turns out that
1307 * our peer did see our MSG5 after all and starts using it. */
1308 /* This is a bit like some of activate_new_key */
1309 struct transform_inst_if *t;
1310 t=st->auxiliary_key.transform;
1311 st->auxiliary_key.transform=st->new_transform;
1312 st->new_transform=t;
1313 dispose_transform(&st->new_transform);
1315 st->auxiliary_is_new=1;
1316 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1317 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1318 st->auxiliary_key.remote_session_id=st->setup_session_id;
1320 enter_state_wait(st);
1323 logtimeout(st,"timed out sending key setup packet "
1324 "(in state %s)",state_name(st->state));
1325 enter_state_wait(st);
1330 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1331 int stored_naddrs, int all_naddrs,
1332 const char *address, const char *failwhy)
1334 struct site *st=sst;
1336 if (!stored_naddrs) {
1337 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1339 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1340 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1342 int space=st->transport_peers_max-st->resolving_n_results_stored;
1343 int n_tocopy=MIN(stored_naddrs,space);
1344 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1347 st->resolving_n_results_stored += n_tocopy;
1348 st->resolving_n_results_all += all_naddrs;
1351 decrement_resolving_count(st,1);
1354 static void decrement_resolving_count(struct site *st, int by)
1356 assert(st->resolving_count>0);
1357 st->resolving_count-=by;
1359 if (st->resolving_count)
1362 /* OK, we are done with them all. Handle combined results. */
1364 const struct comm_addr *addrs=st->resolving_results;
1365 int naddrs=st->resolving_n_results_stored;
1366 assert(naddrs<=st->transport_peers_max);
1369 if (naddrs != st->resolving_n_results_all) {
1370 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1371 " yielded too many results (%d > %d), some ignored",
1372 st->resolving_n_results_all, naddrs);
1374 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1375 naddrs, iaddr_to_string(&addrs[0].ia));;
1378 switch (st->state) {
1380 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1381 enter_new_state(st,SITE_SENTMSG1,0);
1383 /* Can't figure out who to try to to talk to */
1384 slog(st,LOG_SETUP_INIT,
1385 "key exchange failed: cannot find peer address");
1386 enter_state_run(st);
1389 case SITE_SENTMSG1: case SITE_SENTMSG2:
1390 case SITE_SENTMSG3: case SITE_SENTMSG4:
1393 /* We start using the address immediately for data too.
1394 * It's best to store it in st->peers now because we might
1395 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1396 * the new key (without updating the data peer addrs). */
1397 transport_resolve_complete(st,addrs,naddrs);
1398 } else if (st->local_mobile) {
1399 /* We can't let this rest because we may have a peer
1400 * address which will break in the future. */
1401 slog(st,LOG_SETUP_INIT,"resolution failed: "
1402 "abandoning key exchange");
1403 enter_state_wait(st);
1405 slog(st,LOG_SETUP_INIT,"resolution failed: "
1406 " continuing to use source address of peer's packets"
1407 " for key exchange and ultimately data");
1412 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1413 " updating peer address(es)");
1414 transport_resolve_complete_tardy(st,addrs,naddrs);
1415 } else if (st->local_mobile) {
1416 /* Not very good. We should queue (another) renegotiation
1417 * so that we can update the peer address. */
1418 st->key_renegotiate_time=st->now+wait_timeout(st);
1420 slog(st,LOG_SETUP_INIT,"resolution failed: "
1421 " continuing to use source address of peer's packets");
1431 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1432 const struct comm_addr *prod_hint)
1434 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1435 if (st->state!=SITE_RUN) return False;
1436 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1437 if (st->addresses) {
1438 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1439 return enter_state_resolve(st);
1440 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1441 return enter_new_state(st,SITE_SENTMSG1,0);
1443 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1447 static void activate_new_key(struct site *st)
1449 struct transform_inst_if *t;
1451 /* We have three transform instances, which we swap between old,
1453 t=st->auxiliary_key.transform;
1454 st->auxiliary_key.transform=st->current.transform;
1455 st->current.transform=st->new_transform;
1456 st->new_transform=t;
1457 dispose_transform(&st->new_transform);
1460 st->auxiliary_is_new=0;
1461 st->auxiliary_key.key_timeout=st->current.key_timeout;
1462 st->current.key_timeout=st->now+st->key_lifetime;
1463 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1464 transport_peers_copy(st,&st->peers,&st->setup_peers);
1465 st->current.remote_session_id=st->setup_session_id;
1467 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1468 * But their mtu be unspecified, in which case we just use ours. */
1469 uint32_t intersite_mtu=
1470 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1471 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1473 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1474 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1475 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1476 enter_state_run(st);
1479 static void delete_one_key(struct site *st, struct data_key *key,
1480 cstring_t reason, cstring_t which, uint32_t loglevel)
1482 if (!is_transform_valid(key->transform)) return;
1483 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1484 dispose_transform(&key->transform);
1488 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1490 if (current_valid(st)) {
1491 slog(st,loglevel,"session closed (%s)",reason);
1493 delete_one_key(st,&st->current,0,0,0);
1494 set_link_quality(st);
1496 delete_one_key(st,&st->auxiliary_key,0,0,0);
1499 static void state_assert(struct site *st, bool_t ok)
1501 if (!ok) fatal("site:state_assert");
1504 static void enter_state_stop(struct site *st)
1506 st->state=SITE_STOP;
1508 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1509 dispose_transform(&st->new_transform);
1512 static void set_link_quality(struct site *st)
1515 if (current_valid(st))
1516 quality=LINK_QUALITY_UP;
1517 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1518 quality=LINK_QUALITY_DOWN;
1519 else if (st->addresses)
1520 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1521 else if (transport_peers_valid(&st->peers))
1522 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1524 quality=LINK_QUALITY_DOWN;
1526 st->netlink->set_quality(st->netlink->st,quality);
1529 static void enter_state_run(struct site *st)
1531 slog(st,LOG_STATE,"entering state RUN%s",
1532 current_valid(st) ? " (keyed)" : " (unkeyed)");
1536 st->setup_session_id=0;
1537 transport_peers_clear(st,&st->setup_peers);
1538 FILLZERO(st->localN);
1539 FILLZERO(st->remoteN);
1540 dispose_transform(&st->new_transform);
1541 memset(st->dhsecret,0,st->dh->len);
1542 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1543 set_link_quality(st);
1545 if (st->keepalive && !current_valid(st))
1546 initiate_key_setup(st, "keepalive", 0);
1549 static bool_t ensure_resolving(struct site *st)
1551 /* Reentrancy hazard: may call site_resolve_callback and hence
1552 * enter_new_state, enter_state_* and generate_msg*. */
1553 if (st->resolving_count)
1556 assert(st->addresses);
1558 /* resolver->request might reentrantly call site_resolve_callback
1559 * which will decrement st->resolving, so we need to increment it
1560 * twice beforehand to prevent decrement from thinking we're
1561 * finished, and decrement it ourselves. Alternatively if
1562 * everything fails then there are no callbacks due and we simply
1563 * set it to 0 and return false.. */
1564 st->resolving_n_results_stored=0;
1565 st->resolving_n_results_all=0;
1566 st->resolving_count+=2;
1567 const char **addrp=st->addresses;
1568 const char *address;
1570 for (; (address=*addrp++); ) {
1571 bool_t ok = st->resolver->request(st->resolver->st,address,
1572 st->remoteport,st->comms[0],
1573 site_resolve_callback,st);
1575 st->resolving_count++;
1579 st->resolving_count=0;
1582 decrement_resolving_count(st,2);
1586 static bool_t enter_state_resolve(struct site *st)
1588 /* Reentrancy hazard! See ensure_resolving. */
1589 state_assert(st,st->state==SITE_RUN);
1590 slog(st,LOG_STATE,"entering state RESOLVE");
1591 st->state=SITE_RESOLVE;
1592 return ensure_resolving(st);
1595 static bool_t enter_new_state(struct site *st, uint32_t next,
1596 const struct msg *prompt
1597 /* may be 0 for SENTMSG1 */)
1599 bool_t (*gen)(struct site *st, const struct msg *prompt);
1602 slog(st,LOG_STATE,"entering state %s",state_name(next));
1605 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1606 if (!kex_init(st)) return False;
1608 st->msg1_crossed_logged = False;
1611 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1612 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1613 if (!kex_init(st)) return False;
1617 state_assert(st,st->state==SITE_SENTMSG1);
1618 BUF_FREE(&st->buffer);
1622 state_assert(st,st->state==SITE_SENTMSG2);
1623 BUF_FREE(&st->buffer);
1627 state_assert(st,st->state==SITE_SENTMSG3);
1628 BUF_FREE(&st->buffer);
1632 state_assert(st,st->state==SITE_SENTMSG4);
1633 BUF_FREE(&st->buffer);
1638 fatal("enter_new_state(%s): invalid new state",state_name(next));
1642 if (hacky_par_start_failnow()) return False;
1644 r= gen(st,prompt) && send_msg(st);
1647 st->setup_retries, st->setup_retry_interval,
1652 if (next==SITE_RUN) {
1653 BUF_FREE(&st->buffer); /* Never reused */
1654 st->timeout=0; /* Never retransmit */
1655 activate_new_key(st);
1659 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1660 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1661 in either state, and enter_state_wait() will
1663 enter_state_wait(st);
1667 /* msg7 tells our peer that we're about to forget our key */
1668 static bool_t send_msg7(struct site *st, cstring_t reason)
1670 cstring_t transform_err;
1672 if (current_valid(st) && st->buffer.free
1673 && transport_peers_valid(&st->peers)) {
1674 BUF_ALLOC(&st->buffer,"site:MSG7");
1675 buffer_init(&st->buffer,calculate_max_start_pad());
1676 buf_append_uint32(&st->buffer,LABEL_MSG7);
1677 buf_append_string(&st->buffer,reason);
1678 if (call_transform_forwards(st, st->current.transform,
1679 &st->buffer, &transform_err))
1681 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1682 buf_prepend_uint32(&st->buffer,st->index);
1683 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1684 transport_xmit(st,&st->peers,&st->buffer,True);
1685 BUF_FREE(&st->buffer);
1692 /* We go into this state if our peer becomes uncommunicative. Similar to
1693 the "stop" state, we forget all session keys for a while, before
1694 re-entering the "run" state. */
1695 static void enter_state_wait(struct site *st)
1697 slog(st,LOG_STATE,"entering state WAIT");
1698 st->timeout=st->now+wait_timeout(st);
1699 st->state=SITE_WAIT;
1700 set_link_quality(st);
1701 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1702 /* XXX Erase keys etc. */
1705 static void generate_prod(struct site *st, struct buffer_if *buf)
1708 buf_append_uint32(buf,0);
1709 buf_append_uint32(buf,0);
1710 buf_append_uint32(buf,LABEL_PROD);
1711 buf_append_string(buf,st->localname);
1712 buf_append_string(buf,st->remotename);
1715 static void generate_send_prod(struct site *st,
1716 const struct comm_addr *source)
1718 if (!st->allow_send_prod) return; /* too soon */
1719 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1720 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1722 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1723 st->allow_send_prod=0;
1724 generate_prod(st,&st->scratch);
1725 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1726 dump_packet(st,&st->scratch,source,False,ok);
1729 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1732 int64_t offset=timeout-*now;
1733 if (offset<0) offset=0;
1734 if (offset>INT_MAX) offset=INT_MAX;
1735 if (*timeout_io<0 || offset<*timeout_io)
1740 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1743 struct site *st=sst;
1745 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1748 /* Work out when our next timeout is. The earlier of 'timeout' or
1749 'current.key_timeout'. A stored value of '0' indicates no timeout
1751 site_settimeout(st->timeout, timeout_io);
1752 site_settimeout(st->current.key_timeout, timeout_io);
1753 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1755 return 0; /* success */
1758 static void check_expiry(struct site *st, struct data_key *key,
1761 if (key->key_timeout && *now>key->key_timeout) {
1762 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1766 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1767 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1769 struct site *st=sst;
1772 if (st->timeout && *now>st->timeout) {
1774 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1775 if (!hacky_par_start_failnow())
1777 } else if (st->state==SITE_WAIT) {
1778 enter_state_run(st);
1780 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1784 check_expiry(st,&st->current,"current key");
1785 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1788 /* This function is called by the netlink device to deliver packets
1789 intended for the remote network. The packet is in "raw" wire
1790 format, but is guaranteed to be word-aligned. */
1791 static void site_outgoing(void *sst, struct buffer_if *buf)
1793 struct site *st=sst;
1794 cstring_t transform_err;
1796 if (st->state==SITE_STOP) {
1801 st->allow_send_prod=1;
1803 /* In all other states we consider delivering the packet if we have
1804 a valid key and a valid address to send it to. */
1805 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1806 /* Transform it and send it */
1808 buf_prepend_uint32(buf,LABEL_MSG9);
1809 if (call_transform_forwards(st, st->current.transform,
1810 buf, &transform_err))
1812 buf_prepend_uint32(buf,LABEL_MSG0);
1813 buf_prepend_uint32(buf,st->index);
1814 buf_prepend_uint32(buf,st->current.remote_session_id);
1815 transport_xmit(st,&st->peers,buf,False);
1822 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1824 initiate_key_setup(st,"outgoing packet",0);
1827 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1828 uint32_t type, struct msg *m,
1829 struct priomsg *whynot)
1830 /* For packets which are identified by the local and remote names.
1831 * If it has our name and our peer's name in it it's for us. */
1833 struct buffer_if buf[1];
1834 buffer_readonly_clone(buf,buf_in);
1836 if (!unpick_msg(st,type,buf,m)) {
1837 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
1840 #define NAME_MATCHES(lr) \
1841 if (!name_matches(&m->lr, st->lr##name)) { \
1842 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
1843 "unknown " #lr " name: ")) { \
1844 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
1848 NAME_MATCHES(remote);
1849 NAME_MATCHES(local );
1855 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1856 if (st->local_capabilities & m->remote_capabilities &
1857 CAPAB_PRIORITY_MOBILE) {
1858 if (st->local_mobile) return True;
1859 if (st-> peer_mobile) return False;
1861 return st->our_name_later;
1864 static bool_t setup_late_msg_ok(struct site *st,
1865 const struct buffer_if *buf_in,
1867 const struct comm_addr *source,
1868 struct msg *m /* returned */) {
1869 /* For setup packets which seem from their type like they are
1870 * late. Maybe they came via a different path. All we do is make
1871 * a note of the sending address, iff they look like they are part
1872 * of the current key setup attempt. */
1873 if (!named_for_us(st,buf_in,msgtype,m,0))
1874 /* named_for_us calls unpick_msg which gets the nonces */
1876 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1877 !consttime_memeq(m->nL,st->localN, NONCELEN))
1878 /* spoof ? from stale run ? who knows */
1880 transport_setup_msgok(st,source);
1884 /* This function is called by the communication device to deliver
1885 packets from our peers.
1886 It should return True if the packet is recognised as being for
1887 this current site instance (and should therefore not be processed
1888 by other sites), even if the packet was otherwise ignored. */
1889 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1890 const struct comm_addr *source,
1891 struct priomsg *whynot)
1893 struct site *st=sst;
1895 if (buf->size < 12) return False;
1897 uint32_t dest=get_uint32(buf->start);
1898 uint32_t msgtype=get_uint32(buf->start+8);
1900 /* initialised by named_for_us, or process_msgN for N!=1 */
1902 if (msgtype==LABEL_MSG1) {
1903 if (!named_for_us(st,buf,msgtype,&msg,whynot))
1905 /* It's a MSG1 addressed to us. Decide what to do about it. */
1906 dump_packet(st,buf,source,True,True);
1907 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1908 st->state==SITE_WAIT) {
1909 /* We should definitely process it */
1910 transport_compute_setupinit_peers(st,0,0,source);
1911 if (process_msg1(st,buf,source,&msg)) {
1912 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1913 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1914 if (entered && st->addresses && st->local_mobile)
1915 /* We must do this as the very last thing, because
1916 the resolver callback might reenter us. */
1917 ensure_resolving(st);
1919 slog(st,LOG_ERROR,"failed to process incoming msg1");
1923 } else if (st->state==SITE_SENTMSG1) {
1924 /* We've just sent a message 1! They may have crossed on
1925 the wire. If we have priority then we ignore the
1926 incoming one, otherwise we process it as usual. */
1927 if (we_have_priority(st,&msg)) {
1929 if (!st->msg1_crossed_logged++)
1930 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1931 "priority => ignore incoming msg1");
1934 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1935 "priority => use incoming msg1");
1936 if (process_msg1(st,buf,source,&msg)) {
1937 BUF_FREE(&st->buffer); /* Free our old message 1 */
1938 transport_setup_msgok(st,source);
1939 enter_new_state(st,SITE_SENTMSG2,&msg);
1941 slog(st,LOG_ERROR,"failed to process an incoming "
1942 "crossed msg1 (we have low priority)");
1947 } else if (st->state==SITE_SENTMSG2 ||
1948 st->state==SITE_SENTMSG4) {
1949 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1950 /* We are ahead in the protocol, but that msg1 had the
1951 * peer's nonce so presumably it is from this key
1952 * exchange run, via a slower route */
1953 transport_setup_msgok(st,source);
1955 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1960 /* The message 1 was received at an unexpected stage of the
1961 key setup. Well, they lost the race. */
1962 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1966 if (msgtype==LABEL_PROD) {
1967 if (!named_for_us(st,buf,msgtype,&msg,whynot))
1969 dump_packet(st,buf,source,True,True);
1970 if (st->state!=SITE_RUN) {
1971 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1972 } else if (current_valid(st)) {
1973 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1975 initiate_key_setup(st,"peer sent PROD packet",source);
1980 if (dest==st->index) {
1981 /* Explicitly addressed to us */
1982 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1985 /* If the source is our current peer then initiate a key setup,
1986 because our peer's forgotten the key */
1987 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1989 initiated = initiate_key_setup(st,"received a NAK",source);
1990 if (!initiated) generate_send_prod(st,source);
1992 slog(st,LOG_SEC,"bad incoming NAK");
1996 process_msg0(st,buf,source);
1999 /* Setup packet: should not have been explicitly addressed
2001 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2004 /* Setup packet: expected only in state SENTMSG1 */
2005 if (st->state!=SITE_SENTMSG1) {
2006 if ((st->state==SITE_SENTMSG3 ||
2007 st->state==SITE_SENTMSG5) &&
2008 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2010 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2011 } else if (process_msg2(st,buf,source,&msg)) {
2012 transport_setup_msgok(st,source);
2013 enter_new_state(st,SITE_SENTMSG3,&msg);
2015 slog(st,LOG_SEC,"invalid MSG2");
2018 case CASES_MSG3_KNOWN:
2019 /* Setup packet: expected only in state SENTMSG2 */
2020 if (st->state!=SITE_SENTMSG2) {
2021 if ((st->state==SITE_SENTMSG4) &&
2022 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2024 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2025 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2026 transport_setup_msgok(st,source);
2027 enter_new_state(st,SITE_SENTMSG4,&msg);
2029 slog(st,LOG_SEC,"invalid MSG3");
2033 /* Setup packet: expected only in state SENTMSG3 */
2034 if (st->state!=SITE_SENTMSG3) {
2035 if ((st->state==SITE_SENTMSG5) &&
2036 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2038 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2039 } else if (process_msg4(st,buf,source,&msg)) {
2040 transport_setup_msgok(st,source);
2041 enter_new_state(st,SITE_SENTMSG5,&msg);
2043 slog(st,LOG_SEC,"invalid MSG4");
2047 /* Setup packet: expected only in state SENTMSG4 */
2048 /* (may turn up in state RUN if our return MSG6 was lost
2049 and the new key has already been activated. In that
2050 case we discard it. The peer will realise that we
2051 are using the new key when they see our data packets.
2052 Until then the peer's data packets to us get discarded. */
2053 if (st->state==SITE_SENTMSG4) {
2054 if (process_msg5(st,buf,source,st->new_transform)) {
2055 transport_setup_msgok(st,source);
2056 enter_new_state(st,SITE_RUN,&msg);
2058 slog(st,LOG_SEC,"invalid MSG5");
2060 } else if (st->state==SITE_RUN) {
2061 if (process_msg5(st,buf,source,st->current.transform)) {
2062 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2063 transport_setup_msgok(st,source);
2064 create_msg6(st,st->current.transform,
2065 st->current.remote_session_id);
2066 transport_xmit(st,&st->peers,&st->buffer,True);
2067 BUF_FREE(&st->buffer);
2069 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2072 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2076 /* Setup packet: expected only in state SENTMSG5 */
2077 if (st->state!=SITE_SENTMSG5) {
2078 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2079 } else if (process_msg6(st,buf,source)) {
2080 BUF_FREE(&st->buffer); /* Free message 5 */
2081 transport_setup_msgok(st,source);
2082 activate_new_key(st);
2084 slog(st,LOG_SEC,"invalid MSG6");
2088 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2096 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2097 "not MSG1 or PROD; unknown dest index");
2101 static void site_control(void *vst, bool_t run)
2103 struct site *st=vst;
2104 if (run) enter_state_run(st);
2105 else enter_state_stop(st);
2108 static void site_phase_hook(void *sst, uint32_t newphase)
2110 struct site *st=sst;
2112 /* The program is shutting down; tell our peer */
2113 send_msg7(st,"shutting down");
2116 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2118 struct site *st=sst;
2119 dispose_transform(&st->current.transform);
2120 dispose_transform(&st->auxiliary_key.transform);
2121 dispose_transform(&st->new_transform);
2122 /* Not much point overwiting the signing key, since we loaded it
2123 from disk, and it is only valid prospectively if at all,
2125 /* XXX it would be best to overwrite the DH state, because that
2126 _is_ relevant to forward secrecy. However we have no
2127 convenient interface for doing that and in practice gmp has
2128 probably dribbled droppings all over the malloc arena. A good
2129 way to fix this would be to have a privsep child for asymmetric
2130 crypto operations, but that's a task for another day. */
2133 static void setup_sethash(struct site *st, dict_t *dict,
2134 struct hash_if **hash, struct cloc loc,
2135 sig_sethash_fn *sethash, void *sigkey_st) {
2136 if (!*hash) *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2137 sethash(sigkey_st,*hash);
2139 #define SETUP_SETHASH(k) do{ \
2141 setup_sethash(st,dict, &hash,loc, (k)->sethash,(k)->st); \
2144 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2147 static uint32_t index_sequence;
2155 st->cl.description="site";
2156 st->cl.type=CL_SITE;
2158 st->cl.interface=&st->ops;
2160 st->ops.control=site_control;
2161 st->ops.status=site_status;
2163 /* First parameter must be a dict */
2164 item=list_elem(args,0);
2165 if (!item || item->type!=t_dict)
2166 cfgfatal(loc,"site","parameter must be a dictionary\n");
2168 dict=item->data.dict;
2169 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2170 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2172 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2174 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2176 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2178 /* Sanity check (which also allows the 'sites' file to include
2179 site() closures for all sites including our own): refuse to
2180 talk to ourselves */
2181 if (strcmp(st->localname,st->remotename)==0) {
2182 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2184 if (st->peer_mobile != st->local_mobile)
2185 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2186 " but our local-mobile=%d\n",
2187 st->localname, st->peer_mobile, st->local_mobile);
2191 if (st->peer_mobile && st->local_mobile) {
2192 Message(M_WARNING,"site %s: site is mobile but so are we"
2193 " -> ignoring this site\n", st->remotename);
2198 assert(index_sequence < 0xffffffffUL);
2199 st->index = ++index_sequence;
2200 st->local_capabilities = 0;
2201 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2202 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2204 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2205 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2206 if (!things##_cfg) \
2207 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2208 st->nthings=list_length(things##_cfg); \
2209 NEW_ARY(st->things,st->nthings); \
2210 assert(st->nthings); \
2211 for (i=0; i<st->nthings; i++) { \
2212 item_t *item=list_elem(things##_cfg,i); \
2213 if (item->type!=t_closure) \
2214 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2215 closure_t *cl=item->data.closure; \
2216 if (cl->type!=CL_TYPE) \
2217 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2218 st->things[i]=cl->interface; \
2222 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2224 NEW_ARY(st->commclientinfos, st->ncomms);
2225 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2226 for (i=0; i<st->ncomms; i++) {
2227 st->commclientinfos[i] =
2229 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2232 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2233 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2234 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2236 struct hash_if *hash=0;
2237 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2238 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2240 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2241 else st->remoteport=0;
2242 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2244 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2246 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2248 SETUP_SETHASH(st->privkey);
2249 SETUP_SETHASH(st->pubkey);
2251 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2252 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2253 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2255 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2256 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2257 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2258 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2259 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2261 st->mobile_peer_expiry= dict_read_number(
2262 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2264 const char *peerskey= st->peer_mobile
2265 ? "mobile-peers-max" : "static-peers-max";
2266 st->transport_peers_max= dict_read_number(
2267 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2268 if (st->transport_peers_max<1 ||
2269 st->transport_peers_max>MAX_PEER_ADDRS) {
2270 cfgfatal(loc,"site", "%s must be in range 1.."
2271 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2274 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2275 st->key_renegotiate_time=st->key_lifetime/2;
2277 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2278 st->key_renegotiate_time=dict_read_number(
2279 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2280 if (st->key_renegotiate_time > st->key_lifetime) {
2281 cfgfatal(loc,"site",
2282 "renegotiate-time must be less than key-lifetime\n");
2285 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2286 log_event_table,"site");
2288 st->resolving_count=0;
2289 st->allow_send_prod=0;
2291 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2293 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2295 /* The information we expect to see in incoming messages of type 1 */
2296 /* fixme: lots of unchecked overflows here, but the results are only
2297 corrupted packets rather than undefined behaviour */
2298 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2300 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2302 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2303 BUF_ALLOC(&st->scratch,"site:scratch");
2305 /* We are interested in poll(), but only for timeouts. We don't have
2306 any fds of our own. */
2307 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2310 st->remote_capabilities=0;
2311 st->chosen_transform=0;
2312 st->current.key_timeout=0;
2313 st->auxiliary_key.key_timeout=0;
2314 transport_peers_clear(st,&st->peers);
2315 transport_peers_clear(st,&st->setup_peers);
2316 /* XXX mlock these */
2317 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2318 st->sharedsecretlen=st->sharedsecretallocd=0;
2321 #define SET_CAPBIT(bit) do { \
2322 uint32_t capflag = 1UL << (bit); \
2323 if (st->local_capabilities & capflag) \
2324 slog(st,LOG_ERROR,"capability bit" \
2325 " %d (%#"PRIx32") reused", (bit), capflag); \
2326 st->local_capabilities |= capflag; \
2329 for (i=0; i<st->ntransforms; i++)
2330 SET_CAPBIT(st->transforms[i]->capab_bit);
2334 if (st->local_mobile || st->peer_mobile)
2335 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2337 /* We need to register the remote networks with the netlink device */
2338 uint32_t netlink_mtu; /* local virtual interface mtu */
2339 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2340 if (!st->mtu_target)
2341 st->mtu_target=netlink_mtu;
2343 for (i=0; i<st->ncomms; i++)
2344 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2346 st->current.transform=0;
2347 st->auxiliary_key.transform=0;
2348 st->new_transform=0;
2349 st->auxiliary_is_new=0;
2351 enter_state_stop(st);
2353 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2354 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2356 return new_closure(&st->cl);
2359 void site_module(dict_t *dict)
2361 add_closure(dict,"site",site_apply);
2365 /***** TRANSPORT PEERS definitions *****/
2367 static void transport_peers_debug(struct site *st, transport_peers *dst,
2368 const char *didwhat,
2369 int nargs, const struct comm_addr *args,
2374 if (!(st->log_events & LOG_PEER_ADDRS))
2375 return; /* an optimisation */
2377 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2378 (dst==&st->peers ? "data" :
2379 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2380 didwhat, nargs, dst->npeers);
2382 for (i=0, argp=(void*)args;
2384 i++, (argp+=stride?stride:sizeof(*args))) {
2385 const struct comm_addr *ca=(void*)argp;
2386 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2387 i, comm_addr_to_string(ca));
2389 for (i=0; i<dst->npeers; i++) {
2390 struct timeval diff;
2391 timersub(tv_now,&dst->peers[i].last,&diff);
2392 const struct comm_addr *ca=&dst->peers[i].addr;
2393 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2394 i, comm_addr_to_string(ca),
2395 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2399 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2400 /* peers must be sorted first */
2401 int previous_peers=peers->npeers;
2402 struct timeval oldest;
2403 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2404 oldest.tv_usec = tv_now->tv_usec;
2405 while (peers->npeers>1 &&
2406 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2408 if (peers->npeers != previous_peers)
2409 transport_peers_debug(st,peers,"expire", 0,0,0);
2412 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2413 const struct comm_addr *ca,
2414 const struct timeval *tv) {
2415 /* returns false if output is full */
2418 if (peers->npeers >= st->transport_peers_max)
2421 for (search=0; search<peers->npeers; search++)
2422 if (comm_addr_equal(&peers->peers[search].addr, ca))
2425 peers->peers[peers->npeers].addr = *ca;
2426 peers->peers[peers->npeers].last = *tv;
2431 static void transport_record_peers(struct site *st, transport_peers *peers,
2432 const struct comm_addr *addrs, int naddrs,
2434 /* We add addrs into peers. The new entries end up at the front
2435 * and displace entries towards the end (perhaps even off the
2436 * end). Any existing matching entries are moved up to the front.
2438 * Caller must first call transport_peers_expire. */
2441 /* avoids debug for uninteresting updates */
2443 for (i=0; i<peers->npeers; i++) {
2444 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2445 memmove(peers->peers+1, peers->peers,
2446 sizeof(peers->peers[0]) * i);
2447 peers->peers[0].addr = addrs[0];
2448 peers->peers[0].last = *tv_now;
2454 int old_npeers=peers->npeers;
2455 transport_peer old_peers[old_npeers];
2456 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2460 for (i=0; i<naddrs; i++) {
2461 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2464 for (i=0; i<old_npeers; i++) {
2465 const transport_peer *old=&old_peers[i];
2466 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2470 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2473 static void transport_expire_record_peers(struct site *st,
2474 transport_peers *peers,
2475 const struct comm_addr *addrs,
2476 int naddrs, const char *m) {
2477 /* Convenience function */
2478 transport_peers_expire(st,peers);
2479 transport_record_peers(st,peers,addrs,naddrs,m);
2482 static bool_t transport_compute_setupinit_peers(struct site *st,
2483 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2484 int n_configured_addrs /* 0 if none or not found */,
2485 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2486 if (!n_configured_addrs && !incoming_packet_addr &&
2487 !transport_peers_valid(&st->peers))
2490 slog(st,LOG_SETUP_INIT,
2491 "using: %d configured addr(s);%s %d old peer addrs(es)",
2493 incoming_packet_addr ? " incoming packet address;" : "",
2496 /* Non-mobile peers try addresses until one is plausible. The
2497 * effect is that this code always tries first the configured
2498 * address if supplied, or otherwise the address of the incoming
2499 * PROD, or finally the existing data peer if one exists; this is
2502 transport_peers_copy(st,&st->setup_peers,&st->peers);
2503 transport_peers_expire(st,&st->setup_peers);
2505 if (incoming_packet_addr)
2506 transport_record_peers(st,&st->setup_peers,
2507 incoming_packet_addr,1, "incoming");
2509 if (n_configured_addrs)
2510 transport_record_peers(st,&st->setup_peers,
2511 configured_addrs,n_configured_addrs, "setupinit");
2513 assert(transport_peers_valid(&st->setup_peers));
2517 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2518 if (st->peer_mobile)
2519 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2521 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2522 if (st->peer_mobile)
2523 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2526 static int transport_peers_valid(transport_peers *peers) {
2527 return peers->npeers;
2529 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2531 transport_peers_debug(st,peers,"clear",0,0,0);
2533 static void transport_peers_copy(struct site *st, transport_peers *dst,
2534 const transport_peers *src) {
2535 dst->npeers=src->npeers;
2536 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2537 transport_peers_debug(st,dst,"copy",
2538 src->npeers, &src->peers->addr, sizeof(*src->peers));
2541 static void transport_resolve_complete(struct site *st,
2542 const struct comm_addr *addrs,
2544 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2546 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2550 static void transport_resolve_complete_tardy(struct site *st,
2551 const struct comm_addr *addrs,
2553 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2554 "resolved tardily");
2557 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2559 const transport_peers *inp) {
2560 /* out and in->peers may be the same region, or nonoverlapping */
2561 const transport_peer *in=inp->peers;
2563 for (slot=0; slot<inp->npeers; slot++) {
2564 if (!(mask & (1U << slot)))
2566 if (!(out==in && slot==*nout_io))
2567 COPY_OBJ(out[*nout_io], in[slot]);
2572 void transport_xmit(struct site *st, transport_peers *peers,
2573 struct buffer_if *buf, bool_t candebug) {
2575 transport_peers_expire(st, peers);
2576 unsigned failed=0; /* bitmask */
2577 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2580 for (slot=0; slot<peers->npeers; slot++) {
2581 transport_peer *peer=&peers->peers[slot];
2582 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2584 dump_packet(st, buf, &peer->addr, False, ok);
2586 failed |= 1U << slot;
2589 if (ok && !st->peer_mobile)
2592 /* Now we need to demote/delete failing addrs: if we are mobile we
2593 * merely demote them; otherwise we delete them. */
2594 if (st->local_mobile) {
2595 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2596 /* `expected' has all the failures at the end already */
2597 if (failed != expected) {
2599 transport_peer failedpeers[nfailed];
2600 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2601 assert(fslot == nfailed);
2603 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2604 assert(wslot+nfailed == peers->npeers);
2605 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2606 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2609 if (failed && peers->npeers > 1) {
2611 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2612 peers->npeers=wslot;
2613 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2618 /***** END of transport peers declarations *****/