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 append_string_xinfo_done(&st->buffer,&xia);
655 buf_append_string(&st->buffer,st->remotename);
656 BUF_ADD_OBJ(append,&st->buffer,st->localN);
657 if (type==LABEL_MSG1) return True;
658 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
659 if (type==LABEL_MSG2) return True;
661 if (hacky_par_mid_failnow()) return False;
663 if (MSGMAJOR(type) == 3) do {
664 minor = MSGMINOR(type);
665 if (minor < 1) break;
666 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
669 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
670 buf_append_string(&st->buffer,dhpub);
673 bool_t ok=st->privkey->sign(st->privkey->st,
684 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
687 nm->len=buf_unprepend_uint16(msg);
688 CHECK_AVAIL(msg,nm->len);
689 nm->name=buf_unprepend(msg,nm->len);
690 uint8_t *nul=memchr(nm->name,0,nm->len);
692 buffer_readonly_view(&nm->extrainfo,0,0);
694 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
695 nm->len=nul-nm->name;
700 static bool_t unpick_msg(struct site *st, uint32_t type,
701 struct buffer_if *msg, struct msg *m)
705 m->capab_transformnum=-1;
706 m->hashstart=msg->start;
708 m->dest=buf_unprepend_uint32(msg);
710 m->source=buf_unprepend_uint32(msg);
711 CHECK_TYPE(msg,type);
712 if (!unpick_name(msg,&m->remote)) return False;
713 m->remote_capabilities=0;
715 if (m->remote.extrainfo.size) {
716 CHECK_AVAIL(&m->remote.extrainfo,4);
717 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
719 if (type_is_msg34(type) && m->remote.extrainfo.size) {
720 CHECK_AVAIL(&m->remote.extrainfo,2);
721 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
723 if (!unpick_name(msg,&m->local)) return False;
724 if (type==LABEL_PROD) {
728 CHECK_AVAIL(msg,NONCELEN);
729 m->nR=buf_unprepend(msg,NONCELEN);
730 if (type==LABEL_MSG1) {
734 CHECK_AVAIL(msg,NONCELEN);
735 m->nL=buf_unprepend(msg,NONCELEN);
736 if (type==LABEL_MSG2) {
740 if (MSGMAJOR(type) == 3) do {
741 minor = MSGMINOR(type);
742 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
743 if (minor < (minminor)) \
744 m->capab_##kind##num = (dflt); \
746 CHECK_AVAIL(msg, 1); \
747 m->capab_##kind##num = buf_unprepend_uint8(msg); \
750 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
751 #undef MAYBE_READ_CAP
754 m->pklen=buf_unprepend_uint16(msg);
755 CHECK_AVAIL(msg,m->pklen);
756 m->pk=buf_unprepend(msg,m->pklen);
757 m->hashlen=msg->start-m->hashstart;
759 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
768 static bool_t name_matches(const struct parsedname *nm, const char *expected)
770 int expected_len=strlen(expected);
772 nm->len == expected_len &&
773 !memcmp(nm->name, expected, expected_len);
776 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
779 if (type==LABEL_MSG1) return True;
781 /* Check that the site names and our nonce have been sent
782 back correctly, and then store our peer's nonce. */
783 if (!name_matches(&m->remote,st->remotename)) {
784 *error="wrong remote site name";
787 if (!name_matches(&m->local,st->localname)) {
788 *error="wrong local site name";
791 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
792 *error="wrong locally-generated nonce";
795 if (type==LABEL_MSG2) return True;
796 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
797 *error="wrong remotely-generated nonce";
800 /* MSG3 has complicated rules about capabilities, which are
801 * handled in process_msg3. */
802 if (MSGMAJOR(type) == 3) return True;
803 if (m->remote_capabilities!=st->remote_capabilities) {
804 *error="remote capabilities changed";
807 if (type==LABEL_MSG4) return True;
808 *error="unknown message type";
812 static bool_t kex_init(struct site *st)
814 st->random->generate(st->random->st,NONCELEN,st->localN);
818 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
821 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
824 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
825 const struct comm_addr *src,
828 /* We've already determined we're in an appropriate state to
829 process an incoming MSG1, and that the MSG1 has correct values
832 st->setup_session_id=m->source;
833 st->remote_capabilities=m->remote_capabilities;
834 memcpy(st->remoteN,m->nR,NONCELEN);
838 static bool_t generate_msg2(struct site *st,
839 const struct msg *prompt_may_be_null)
842 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
845 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
846 const struct comm_addr *src,
847 struct msg *m /* returned */)
851 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
852 if (!check_msg(st,LABEL_MSG2,m,&err)) {
853 slog(st,LOG_SEC,"msg2: %s",err);
856 st->setup_session_id=m->source;
857 st->remote_capabilities=m->remote_capabilities;
859 /* Select the transform to use */
861 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
862 if (!remote_crypto_caps)
863 /* old secnets only had this one transform */
864 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
866 #define CHOOSE_CRYPTO(kind, whats) do { \
867 struct kind##_if *iface; \
868 uint32_t bit, ours = 0; \
870 for (i= 0; i < st->n##kind##s; i++) { \
871 iface=st->kind##s[i]; \
872 bit = 1UL << iface->capab_bit; \
873 if (bit & remote_crypto_caps) goto kind##_found; \
876 slog(st,LOG_ERROR,"no " whats " in common" \
877 " (us %#"PRIx32"; them: %#"PRIx32")", \
878 st->local_capabilities & ours, remote_crypto_caps); \
881 st->chosen_##kind = iface; \
884 CHOOSE_CRYPTO(transform, "transforms");
888 memcpy(st->remoteN,m->nR,NONCELEN);
892 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
894 /* Now we have our nonce and their nonce. Think of a secret key,
895 and create message number 3. */
896 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
897 return generate_msg(st,
898 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
904 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
906 /* Check signature and store g^x mod m */
907 if (!st->pubkey->check(st->pubkey->st,
908 m->hashstart,m->hashlen,
910 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
914 st->remote_adv_mtu=m->remote_mtu;
919 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
920 const struct comm_addr *src, uint32_t msgtype,
921 struct msg *m /* returned */)
926 case CASES_MSG3_KNOWN: break;
930 if (!unpick_msg(st,msgtype,msg3,m)) return False;
931 if (!check_msg(st,msgtype,m,&err)) {
932 slog(st,LOG_SEC,"msg3: %s",err);
935 uint32_t capab_adv_late = m->remote_capabilities
936 & ~st->remote_capabilities & st->early_capabilities;
937 if (capab_adv_late) {
938 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
939 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
940 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
944 #define CHOSE_CRYPTO(kind, what) do { \
945 struct kind##_if *iface; \
947 for (i=0; i<st->n##kind##s; i++) { \
948 iface=st->kind##s[i]; \
949 if (iface->capab_bit == m->capab_##kind##num) \
952 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
953 m->capab_##kind##num); \
956 st->chosen_##kind=iface; \
959 CHOSE_CRYPTO(transform, "transform");
963 if (!process_msg3_msg4(st,m))
966 /* Update our idea of the remote site's capabilities, now that we've
967 * verified that its message was authentic.
969 * Our previous idea of the remote site's capabilities came from the
970 * unauthenticated MSG1. We've already checked that this new message
971 * doesn't change any of the bits we relied upon in the past, but it may
972 * also have set additional capability bits. We simply throw those away
973 * now, and use the authentic capabilities from this MSG3. */
974 st->remote_capabilities=m->remote_capabilities;
976 /* Terminate their DH public key with a '0' */
978 /* Invent our DH secret key */
979 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
981 /* Generate the shared key and set up the transform */
982 if (!set_new_transform(st,m->pk)) return False;
987 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
989 /* We have both nonces, their public key and our private key. Generate
990 our public key, sign it and send it to them. */
991 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
994 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
995 const struct comm_addr *src,
996 struct msg *m /* returned */)
1000 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1001 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1002 slog(st,LOG_SEC,"msg4: %s",err);
1006 if (!process_msg3_msg4(st,m))
1009 /* Terminate their DH public key with a '0' */
1012 /* Generate the shared key and set up the transform */
1013 if (!set_new_transform(st,m->pk)) return False;
1024 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1027 CHECK_AVAIL(msg0,4);
1028 m->dest=buf_unprepend_uint32(msg0);
1029 CHECK_AVAIL(msg0,4);
1030 m->source=buf_unprepend_uint32(msg0);
1031 CHECK_AVAIL(msg0,4);
1032 m->type=buf_unprepend_uint32(msg0);
1034 /* Leaves transformed part of buffer untouched */
1037 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1039 cstring_t transform_err;
1041 BUF_ALLOC(&st->buffer,"site:MSG5");
1042 /* We are going to add four words to the message */
1043 buffer_init(&st->buffer,calculate_max_start_pad());
1044 /* Give the netlink code an opportunity to put its own stuff in the
1045 message (configuration information, etc.) */
1046 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1047 if (call_transform_forwards(st,st->new_transform,
1048 &st->buffer,&transform_err))
1050 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1051 buf_prepend_uint32(&st->buffer,st->index);
1052 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1054 st->retries=st->setup_retries;
1058 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1059 const struct comm_addr *src,
1060 struct transform_inst_if *transform)
1063 cstring_t transform_err;
1065 if (!unpick_msg0(st,msg5,&m)) return False;
1067 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1068 /* There's a problem */
1069 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1072 /* Buffer should now contain untransformed PING packet data */
1073 CHECK_AVAIL(msg5,4);
1074 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1075 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1078 /* Older versions of secnet used to write some config data here
1079 * which we ignore. So we don't CHECK_EMPTY */
1083 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1084 uint32_t session_id)
1086 cstring_t transform_err;
1088 BUF_ALLOC(&st->buffer,"site:MSG6");
1089 /* We are going to add four words to the message */
1090 buffer_init(&st->buffer,calculate_max_start_pad());
1091 /* Give the netlink code an opportunity to put its own stuff in the
1092 message (configuration information, etc.) */
1093 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1094 transform_apply_return problem =
1095 call_transform_forwards(st,transform,
1096 &st->buffer,&transform_err);
1098 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1099 buf_prepend_uint32(&st->buffer,st->index);
1100 buf_prepend_uint32(&st->buffer,session_id);
1103 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1105 if (!is_transform_valid(st->new_transform))
1107 create_msg6(st,st->new_transform,st->setup_session_id);
1108 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1112 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1113 const struct comm_addr *src)
1116 cstring_t transform_err;
1118 if (!unpick_msg0(st,msg6,&m)) return False;
1120 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1121 /* There's a problem */
1122 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1125 /* Buffer should now contain untransformed PING packet data */
1126 CHECK_AVAIL(msg6,4);
1127 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1128 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1131 /* Older versions of secnet used to write some config data here
1132 * which we ignore. So we don't CHECK_EMPTY */
1136 static transform_apply_return
1137 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1138 const struct comm_addr *src)
1140 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1142 transform_apply_return problem;
1144 if (!unpick_msg0(st,msg0,&m)) return False;
1146 /* Keep a copy so we can try decrypting it with multiple keys */
1147 buffer_copy(&st->scratch, msg0);
1149 problem = call_transform_reverse(st,st->current.transform,
1150 msg0,&transform_err);
1152 if (!st->auxiliary_is_new)
1153 delete_one_key(st,&st->auxiliary_key,
1154 "peer has used new key","auxiliary key",LOG_SEC);
1157 if (transform_apply_return_badseq(problem))
1160 buffer_copy(msg0, &st->scratch);
1161 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1164 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1165 if (st->auxiliary_is_new) {
1166 /* We previously timed out in state SENTMSG5 but it turns
1167 * out that our peer did in fact get our MSG5 and is
1168 * using the new key. So we should switch to it too. */
1169 /* This is a bit like activate_new_key. */
1172 st->current=st->auxiliary_key;
1173 st->auxiliary_key=t;
1175 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1176 "previous key",LOG_SEC);
1177 st->auxiliary_is_new=0;
1178 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1182 if (transform_apply_return_badseq(problem))
1185 if (st->state==SITE_SENTMSG5) {
1186 buffer_copy(msg0, &st->scratch);
1187 problem = call_transform_reverse(st,st->new_transform,
1190 /* It looks like we didn't get the peer's MSG6 */
1191 /* This is like a cut-down enter_new_state(SITE_RUN) */
1192 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1193 BUF_FREE(&st->buffer);
1195 activate_new_key(st);
1196 return 0; /* do process the data in this packet */
1198 if (transform_apply_return_badseq(problem))
1202 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1203 transform_err,auxkey_err,newkey_err);
1204 initiate_key_setup(st,"incoming message would not decrypt",0);
1205 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1210 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1215 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1216 const struct comm_addr *src)
1219 transform_apply_return problem;
1221 problem = decrypt_msg0(st,msg0,src);
1222 if (problem==transform_apply_seqdupe) {
1223 /* We recently received another copy of this packet, maybe due
1224 * to polypath. That's not a problem; indeed, for the
1225 * purposes of transport address management it is a success.
1226 * But we don't want to process the packet. */
1227 transport_data_msgok(st,src);
1233 CHECK_AVAIL(msg0,4);
1234 type=buf_unprepend_uint32(msg0);
1237 /* We must forget about the current session. */
1238 delete_keys(st,"request from peer",LOG_SEC);
1239 /* probably, the peer is shutting down, and this is going to fail,
1240 * but we need to be trying to bring the link up again */
1242 initiate_key_setup(st,"peer requested key teardown",0);
1245 /* Deliver to netlink layer */
1246 st->netlink->deliver(st->netlink->st,msg0);
1247 transport_data_msgok(st,src);
1248 /* See whether we should start negotiating a new key */
1249 if (st->now > st->renegotiate_key_time)
1250 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1253 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1260 static void dump_packet(struct site *st, struct buffer_if *buf,
1261 const struct comm_addr *addr, bool_t incoming,
1264 uint32_t dest=get_uint32(buf->start);
1265 uint32_t source=get_uint32(buf->start+4);
1266 uint32_t msgtype=get_uint32(buf->start+8);
1268 if (st->log_events & LOG_DUMP)
1269 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1270 st->tunname,incoming?"incoming":"outgoing",
1271 dest,source,msgtype,comm_addr_to_string(addr),
1275 static bool_t comm_addr_sendmsg(struct site *st,
1276 const struct comm_addr *dest,
1277 struct buffer_if *buf)
1280 struct comm_clientinfo *commclientinfo = 0;
1282 for (i=0; i < st->ncomms; i++) {
1283 if (st->comms[i] == dest->comm) {
1284 commclientinfo = st->commclientinfos[i];
1288 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1291 static uint32_t site_status(void *st)
1296 static bool_t send_msg(struct site *st)
1298 if (st->retries>0) {
1299 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1300 st->timeout=st->now+st->setup_retry_interval;
1303 } else if (st->state==SITE_SENTMSG5) {
1304 logtimeout(st,"timed out sending MSG5, stashing new key");
1305 /* We stash the key we have produced, in case it turns out that
1306 * our peer did see our MSG5 after all and starts using it. */
1307 /* This is a bit like some of activate_new_key */
1308 struct transform_inst_if *t;
1309 t=st->auxiliary_key.transform;
1310 st->auxiliary_key.transform=st->new_transform;
1311 st->new_transform=t;
1312 dispose_transform(&st->new_transform);
1314 st->auxiliary_is_new=1;
1315 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1316 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1317 st->auxiliary_key.remote_session_id=st->setup_session_id;
1319 enter_state_wait(st);
1322 logtimeout(st,"timed out sending key setup packet "
1323 "(in state %s)",state_name(st->state));
1324 enter_state_wait(st);
1329 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1330 int stored_naddrs, int all_naddrs,
1331 const char *address, const char *failwhy)
1333 struct site *st=sst;
1335 if (!stored_naddrs) {
1336 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1338 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1339 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1341 int space=st->transport_peers_max-st->resolving_n_results_stored;
1342 int n_tocopy=MIN(stored_naddrs,space);
1343 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1346 st->resolving_n_results_stored += n_tocopy;
1347 st->resolving_n_results_all += all_naddrs;
1350 decrement_resolving_count(st,1);
1353 static void decrement_resolving_count(struct site *st, int by)
1355 assert(st->resolving_count>0);
1356 st->resolving_count-=by;
1358 if (st->resolving_count)
1361 /* OK, we are done with them all. Handle combined results. */
1363 const struct comm_addr *addrs=st->resolving_results;
1364 int naddrs=st->resolving_n_results_stored;
1365 assert(naddrs<=st->transport_peers_max);
1368 if (naddrs != st->resolving_n_results_all) {
1369 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1370 " yielded too many results (%d > %d), some ignored",
1371 st->resolving_n_results_all, naddrs);
1373 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1374 naddrs, iaddr_to_string(&addrs[0].ia));;
1377 switch (st->state) {
1379 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1380 enter_new_state(st,SITE_SENTMSG1,0);
1382 /* Can't figure out who to try to to talk to */
1383 slog(st,LOG_SETUP_INIT,
1384 "key exchange failed: cannot find peer address");
1385 enter_state_run(st);
1388 case SITE_SENTMSG1: case SITE_SENTMSG2:
1389 case SITE_SENTMSG3: case SITE_SENTMSG4:
1392 /* We start using the address immediately for data too.
1393 * It's best to store it in st->peers now because we might
1394 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1395 * the new key (without updating the data peer addrs). */
1396 transport_resolve_complete(st,addrs,naddrs);
1397 } else if (st->local_mobile) {
1398 /* We can't let this rest because we may have a peer
1399 * address which will break in the future. */
1400 slog(st,LOG_SETUP_INIT,"resolution failed: "
1401 "abandoning key exchange");
1402 enter_state_wait(st);
1404 slog(st,LOG_SETUP_INIT,"resolution failed: "
1405 " continuing to use source address of peer's packets"
1406 " for key exchange and ultimately data");
1411 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1412 " updating peer address(es)");
1413 transport_resolve_complete_tardy(st,addrs,naddrs);
1414 } else if (st->local_mobile) {
1415 /* Not very good. We should queue (another) renegotiation
1416 * so that we can update the peer address. */
1417 st->key_renegotiate_time=st->now+wait_timeout(st);
1419 slog(st,LOG_SETUP_INIT,"resolution failed: "
1420 " continuing to use source address of peer's packets");
1430 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1431 const struct comm_addr *prod_hint)
1433 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1434 if (st->state!=SITE_RUN) return False;
1435 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1436 if (st->addresses) {
1437 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1438 return enter_state_resolve(st);
1439 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1440 return enter_new_state(st,SITE_SENTMSG1,0);
1442 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1446 static void activate_new_key(struct site *st)
1448 struct transform_inst_if *t;
1450 /* We have three transform instances, which we swap between old,
1452 t=st->auxiliary_key.transform;
1453 st->auxiliary_key.transform=st->current.transform;
1454 st->current.transform=st->new_transform;
1455 st->new_transform=t;
1456 dispose_transform(&st->new_transform);
1459 st->auxiliary_is_new=0;
1460 st->auxiliary_key.key_timeout=st->current.key_timeout;
1461 st->current.key_timeout=st->now+st->key_lifetime;
1462 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1463 transport_peers_copy(st,&st->peers,&st->setup_peers);
1464 st->current.remote_session_id=st->setup_session_id;
1466 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1467 * But their mtu be unspecified, in which case we just use ours. */
1468 uint32_t intersite_mtu=
1469 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1470 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1472 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1473 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1474 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1475 enter_state_run(st);
1478 static void delete_one_key(struct site *st, struct data_key *key,
1479 cstring_t reason, cstring_t which, uint32_t loglevel)
1481 if (!is_transform_valid(key->transform)) return;
1482 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1483 dispose_transform(&key->transform);
1487 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1489 if (current_valid(st)) {
1490 slog(st,loglevel,"session closed (%s)",reason);
1492 delete_one_key(st,&st->current,0,0,0);
1493 set_link_quality(st);
1495 delete_one_key(st,&st->auxiliary_key,0,0,0);
1498 static void state_assert(struct site *st, bool_t ok)
1500 if (!ok) fatal("site:state_assert");
1503 static void enter_state_stop(struct site *st)
1505 st->state=SITE_STOP;
1507 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1508 dispose_transform(&st->new_transform);
1511 static void set_link_quality(struct site *st)
1514 if (current_valid(st))
1515 quality=LINK_QUALITY_UP;
1516 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1517 quality=LINK_QUALITY_DOWN;
1518 else if (st->addresses)
1519 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1520 else if (transport_peers_valid(&st->peers))
1521 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1523 quality=LINK_QUALITY_DOWN;
1525 st->netlink->set_quality(st->netlink->st,quality);
1528 static void enter_state_run(struct site *st)
1530 slog(st,LOG_STATE,"entering state RUN%s",
1531 current_valid(st) ? " (keyed)" : " (unkeyed)");
1535 st->setup_session_id=0;
1536 transport_peers_clear(st,&st->setup_peers);
1537 FILLZERO(st->localN);
1538 FILLZERO(st->remoteN);
1539 dispose_transform(&st->new_transform);
1540 memset(st->dhsecret,0,st->dh->len);
1541 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1542 set_link_quality(st);
1544 if (st->keepalive && !current_valid(st))
1545 initiate_key_setup(st, "keepalive", 0);
1548 static bool_t ensure_resolving(struct site *st)
1550 /* Reentrancy hazard: may call site_resolve_callback and hence
1551 * enter_new_state, enter_state_* and generate_msg*. */
1552 if (st->resolving_count)
1555 assert(st->addresses);
1557 /* resolver->request might reentrantly call site_resolve_callback
1558 * which will decrement st->resolving, so we need to increment it
1559 * twice beforehand to prevent decrement from thinking we're
1560 * finished, and decrement it ourselves. Alternatively if
1561 * everything fails then there are no callbacks due and we simply
1562 * set it to 0 and return false.. */
1563 st->resolving_n_results_stored=0;
1564 st->resolving_n_results_all=0;
1565 st->resolving_count+=2;
1566 const char **addrp=st->addresses;
1567 const char *address;
1569 for (; (address=*addrp++); ) {
1570 bool_t ok = st->resolver->request(st->resolver->st,address,
1571 st->remoteport,st->comms[0],
1572 site_resolve_callback,st);
1574 st->resolving_count++;
1578 st->resolving_count=0;
1581 decrement_resolving_count(st,2);
1585 static bool_t enter_state_resolve(struct site *st)
1587 /* Reentrancy hazard! See ensure_resolving. */
1588 state_assert(st,st->state==SITE_RUN);
1589 slog(st,LOG_STATE,"entering state RESOLVE");
1590 st->state=SITE_RESOLVE;
1591 return ensure_resolving(st);
1594 static bool_t enter_new_state(struct site *st, uint32_t next,
1595 const struct msg *prompt
1596 /* may be 0 for SENTMSG1 */)
1598 bool_t (*gen)(struct site *st, const struct msg *prompt);
1601 slog(st,LOG_STATE,"entering state %s",state_name(next));
1604 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1605 if (!kex_init(st)) return False;
1607 st->msg1_crossed_logged = False;
1610 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1611 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1612 if (!kex_init(st)) return False;
1616 state_assert(st,st->state==SITE_SENTMSG1);
1617 BUF_FREE(&st->buffer);
1621 state_assert(st,st->state==SITE_SENTMSG2);
1622 BUF_FREE(&st->buffer);
1626 state_assert(st,st->state==SITE_SENTMSG3);
1627 BUF_FREE(&st->buffer);
1631 state_assert(st,st->state==SITE_SENTMSG4);
1632 BUF_FREE(&st->buffer);
1637 fatal("enter_new_state(%s): invalid new state",state_name(next));
1641 if (hacky_par_start_failnow()) return False;
1643 r= gen(st,prompt) && send_msg(st);
1646 st->setup_retries, st->setup_retry_interval,
1651 if (next==SITE_RUN) {
1652 BUF_FREE(&st->buffer); /* Never reused */
1653 st->timeout=0; /* Never retransmit */
1654 activate_new_key(st);
1658 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1659 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1660 in either state, and enter_state_wait() will
1662 enter_state_wait(st);
1666 /* msg7 tells our peer that we're about to forget our key */
1667 static bool_t send_msg7(struct site *st, cstring_t reason)
1669 cstring_t transform_err;
1671 if (current_valid(st) && st->buffer.free
1672 && transport_peers_valid(&st->peers)) {
1673 BUF_ALLOC(&st->buffer,"site:MSG7");
1674 buffer_init(&st->buffer,calculate_max_start_pad());
1675 buf_append_uint32(&st->buffer,LABEL_MSG7);
1676 buf_append_string(&st->buffer,reason);
1677 if (call_transform_forwards(st, st->current.transform,
1678 &st->buffer, &transform_err))
1680 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1681 buf_prepend_uint32(&st->buffer,st->index);
1682 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1683 transport_xmit(st,&st->peers,&st->buffer,True);
1684 BUF_FREE(&st->buffer);
1691 /* We go into this state if our peer becomes uncommunicative. Similar to
1692 the "stop" state, we forget all session keys for a while, before
1693 re-entering the "run" state. */
1694 static void enter_state_wait(struct site *st)
1696 slog(st,LOG_STATE,"entering state WAIT");
1697 st->timeout=st->now+wait_timeout(st);
1698 st->state=SITE_WAIT;
1699 set_link_quality(st);
1700 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1701 /* XXX Erase keys etc. */
1704 static void generate_prod(struct site *st, struct buffer_if *buf)
1707 buf_append_uint32(buf,0);
1708 buf_append_uint32(buf,0);
1709 buf_append_uint32(buf,LABEL_PROD);
1710 buf_append_string(buf,st->localname);
1711 buf_append_string(buf,st->remotename);
1714 static void generate_send_prod(struct site *st,
1715 const struct comm_addr *source)
1717 if (!st->allow_send_prod) return; /* too soon */
1718 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1719 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1721 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1722 st->allow_send_prod=0;
1723 generate_prod(st,&st->scratch);
1724 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1725 dump_packet(st,&st->scratch,source,False,ok);
1728 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1731 int64_t offset=timeout-*now;
1732 if (offset<0) offset=0;
1733 if (offset>INT_MAX) offset=INT_MAX;
1734 if (*timeout_io<0 || offset<*timeout_io)
1739 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1742 struct site *st=sst;
1744 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1747 /* Work out when our next timeout is. The earlier of 'timeout' or
1748 'current.key_timeout'. A stored value of '0' indicates no timeout
1750 site_settimeout(st->timeout, timeout_io);
1751 site_settimeout(st->current.key_timeout, timeout_io);
1752 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1754 return 0; /* success */
1757 static void check_expiry(struct site *st, struct data_key *key,
1760 if (key->key_timeout && *now>key->key_timeout) {
1761 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1765 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1766 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1768 struct site *st=sst;
1771 if (st->timeout && *now>st->timeout) {
1773 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1774 if (!hacky_par_start_failnow())
1776 } else if (st->state==SITE_WAIT) {
1777 enter_state_run(st);
1779 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1783 check_expiry(st,&st->current,"current key");
1784 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1787 /* This function is called by the netlink device to deliver packets
1788 intended for the remote network. The packet is in "raw" wire
1789 format, but is guaranteed to be word-aligned. */
1790 static void site_outgoing(void *sst, struct buffer_if *buf)
1792 struct site *st=sst;
1793 cstring_t transform_err;
1795 if (st->state==SITE_STOP) {
1800 st->allow_send_prod=1;
1802 /* In all other states we consider delivering the packet if we have
1803 a valid key and a valid address to send it to. */
1804 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1805 /* Transform it and send it */
1807 buf_prepend_uint32(buf,LABEL_MSG9);
1808 if (call_transform_forwards(st, st->current.transform,
1809 buf, &transform_err))
1811 buf_prepend_uint32(buf,LABEL_MSG0);
1812 buf_prepend_uint32(buf,st->index);
1813 buf_prepend_uint32(buf,st->current.remote_session_id);
1814 transport_xmit(st,&st->peers,buf,False);
1821 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1823 initiate_key_setup(st,"outgoing packet",0);
1826 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1827 uint32_t type, struct msg *m,
1828 struct priomsg *whynot)
1829 /* For packets which are identified by the local and remote names.
1830 * If it has our name and our peer's name in it it's for us. */
1832 struct buffer_if buf[1];
1833 buffer_readonly_clone(buf,buf_in);
1835 if (!unpick_msg(st,type,buf,m)) {
1836 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
1839 #define NAME_MATCHES(lr) \
1840 if (!name_matches(&m->lr, st->lr##name)) { \
1841 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
1842 "unknown " #lr " name: ")) { \
1843 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
1847 NAME_MATCHES(remote);
1848 NAME_MATCHES(local );
1854 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1855 if (st->local_capabilities & m->remote_capabilities &
1856 CAPAB_PRIORITY_MOBILE) {
1857 if (st->local_mobile) return True;
1858 if (st-> peer_mobile) return False;
1860 return st->our_name_later;
1863 static bool_t setup_late_msg_ok(struct site *st,
1864 const struct buffer_if *buf_in,
1866 const struct comm_addr *source,
1867 struct msg *m /* returned */) {
1868 /* For setup packets which seem from their type like they are
1869 * late. Maybe they came via a different path. All we do is make
1870 * a note of the sending address, iff they look like they are part
1871 * of the current key setup attempt. */
1872 if (!named_for_us(st,buf_in,msgtype,m,0))
1873 /* named_for_us calls unpick_msg which gets the nonces */
1875 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1876 !consttime_memeq(m->nL,st->localN, NONCELEN))
1877 /* spoof ? from stale run ? who knows */
1879 transport_setup_msgok(st,source);
1883 /* This function is called by the communication device to deliver
1884 packets from our peers.
1885 It should return True if the packet is recognised as being for
1886 this current site instance (and should therefore not be processed
1887 by other sites), even if the packet was otherwise ignored. */
1888 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1889 const struct comm_addr *source,
1890 struct priomsg *whynot)
1892 struct site *st=sst;
1894 if (buf->size < 12) return False;
1896 uint32_t dest=get_uint32(buf->start);
1897 uint32_t msgtype=get_uint32(buf->start+8);
1899 /* initialised by named_for_us, or process_msgN for N!=1 */
1901 if (msgtype==LABEL_MSG1) {
1902 if (!named_for_us(st,buf,msgtype,&msg,whynot))
1904 /* It's a MSG1 addressed to us. Decide what to do about it. */
1905 dump_packet(st,buf,source,True,True);
1906 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1907 st->state==SITE_WAIT) {
1908 /* We should definitely process it */
1909 transport_compute_setupinit_peers(st,0,0,source);
1910 if (process_msg1(st,buf,source,&msg)) {
1911 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1912 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1913 if (entered && st->addresses && st->local_mobile)
1914 /* We must do this as the very last thing, because
1915 the resolver callback might reenter us. */
1916 ensure_resolving(st);
1918 slog(st,LOG_ERROR,"failed to process incoming msg1");
1922 } else if (st->state==SITE_SENTMSG1) {
1923 /* We've just sent a message 1! They may have crossed on
1924 the wire. If we have priority then we ignore the
1925 incoming one, otherwise we process it as usual. */
1926 if (we_have_priority(st,&msg)) {
1928 if (!st->msg1_crossed_logged++)
1929 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1930 "priority => ignore incoming msg1");
1933 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1934 "priority => use incoming msg1");
1935 if (process_msg1(st,buf,source,&msg)) {
1936 BUF_FREE(&st->buffer); /* Free our old message 1 */
1937 transport_setup_msgok(st,source);
1938 enter_new_state(st,SITE_SENTMSG2,&msg);
1940 slog(st,LOG_ERROR,"failed to process an incoming "
1941 "crossed msg1 (we have low priority)");
1946 } else if (st->state==SITE_SENTMSG2 ||
1947 st->state==SITE_SENTMSG4) {
1948 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1949 /* We are ahead in the protocol, but that msg1 had the
1950 * peer's nonce so presumably it is from this key
1951 * exchange run, via a slower route */
1952 transport_setup_msgok(st,source);
1954 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1959 /* The message 1 was received at an unexpected stage of the
1960 key setup. Well, they lost the race. */
1961 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1965 if (msgtype==LABEL_PROD) {
1966 if (!named_for_us(st,buf,msgtype,&msg,whynot))
1968 dump_packet(st,buf,source,True,True);
1969 if (st->state!=SITE_RUN) {
1970 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1971 } else if (current_valid(st)) {
1972 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1974 initiate_key_setup(st,"peer sent PROD packet",source);
1979 if (dest==st->index) {
1980 /* Explicitly addressed to us */
1981 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1984 /* If the source is our current peer then initiate a key setup,
1985 because our peer's forgotten the key */
1986 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1988 initiated = initiate_key_setup(st,"received a NAK",source);
1989 if (!initiated) generate_send_prod(st,source);
1991 slog(st,LOG_SEC,"bad incoming NAK");
1995 process_msg0(st,buf,source);
1998 /* Setup packet: should not have been explicitly addressed
2000 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2003 /* Setup packet: expected only in state SENTMSG1 */
2004 if (st->state!=SITE_SENTMSG1) {
2005 if ((st->state==SITE_SENTMSG3 ||
2006 st->state==SITE_SENTMSG5) &&
2007 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2009 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2010 } else if (process_msg2(st,buf,source,&msg)) {
2011 transport_setup_msgok(st,source);
2012 enter_new_state(st,SITE_SENTMSG3,&msg);
2014 slog(st,LOG_SEC,"invalid MSG2");
2017 case CASES_MSG3_KNOWN:
2018 /* Setup packet: expected only in state SENTMSG2 */
2019 if (st->state!=SITE_SENTMSG2) {
2020 if ((st->state==SITE_SENTMSG4) &&
2021 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2023 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2024 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2025 transport_setup_msgok(st,source);
2026 enter_new_state(st,SITE_SENTMSG4,&msg);
2028 slog(st,LOG_SEC,"invalid MSG3");
2032 /* Setup packet: expected only in state SENTMSG3 */
2033 if (st->state!=SITE_SENTMSG3) {
2034 if ((st->state==SITE_SENTMSG5) &&
2035 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2037 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2038 } else if (process_msg4(st,buf,source,&msg)) {
2039 transport_setup_msgok(st,source);
2040 enter_new_state(st,SITE_SENTMSG5,&msg);
2042 slog(st,LOG_SEC,"invalid MSG4");
2046 /* Setup packet: expected only in state SENTMSG4 */
2047 /* (may turn up in state RUN if our return MSG6 was lost
2048 and the new key has already been activated. In that
2049 case we discard it. The peer will realise that we
2050 are using the new key when they see our data packets.
2051 Until then the peer's data packets to us get discarded. */
2052 if (st->state==SITE_SENTMSG4) {
2053 if (process_msg5(st,buf,source,st->new_transform)) {
2054 transport_setup_msgok(st,source);
2055 enter_new_state(st,SITE_RUN,&msg);
2057 slog(st,LOG_SEC,"invalid MSG5");
2059 } else if (st->state==SITE_RUN) {
2060 if (process_msg5(st,buf,source,st->current.transform)) {
2061 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2062 transport_setup_msgok(st,source);
2063 create_msg6(st,st->current.transform,
2064 st->current.remote_session_id);
2065 transport_xmit(st,&st->peers,&st->buffer,True);
2066 BUF_FREE(&st->buffer);
2068 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2071 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2075 /* Setup packet: expected only in state SENTMSG5 */
2076 if (st->state!=SITE_SENTMSG5) {
2077 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2078 } else if (process_msg6(st,buf,source)) {
2079 BUF_FREE(&st->buffer); /* Free message 5 */
2080 transport_setup_msgok(st,source);
2081 activate_new_key(st);
2083 slog(st,LOG_SEC,"invalid MSG6");
2087 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2095 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2096 "not MSG1 or PROD; unknown dest index");
2100 static void site_control(void *vst, bool_t run)
2102 struct site *st=vst;
2103 if (run) enter_state_run(st);
2104 else enter_state_stop(st);
2107 static void site_phase_hook(void *sst, uint32_t newphase)
2109 struct site *st=sst;
2111 /* The program is shutting down; tell our peer */
2112 send_msg7(st,"shutting down");
2115 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2117 struct site *st=sst;
2118 dispose_transform(&st->current.transform);
2119 dispose_transform(&st->auxiliary_key.transform);
2120 dispose_transform(&st->new_transform);
2121 /* Not much point overwiting the signing key, since we loaded it
2122 from disk, and it is only valid prospectively if at all,
2124 /* XXX it would be best to overwrite the DH state, because that
2125 _is_ relevant to forward secrecy. However we have no
2126 convenient interface for doing that and in practice gmp has
2127 probably dribbled droppings all over the malloc arena. A good
2128 way to fix this would be to have a privsep child for asymmetric
2129 crypto operations, but that's a task for another day. */
2132 static void setup_sethash(struct site *st, dict_t *dict,
2133 struct hash_if **hash, struct cloc loc,
2134 sig_sethash_fn *sethash, void *sigkey_st) {
2135 if (!*hash) *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2136 sethash(sigkey_st,*hash);
2138 #define SETUP_SETHASH(k) do{ \
2140 setup_sethash(st,dict, &hash,loc, (k)->sethash,(k)->st); \
2143 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2146 static uint32_t index_sequence;
2154 st->cl.description="site";
2155 st->cl.type=CL_SITE;
2157 st->cl.interface=&st->ops;
2159 st->ops.control=site_control;
2160 st->ops.status=site_status;
2162 /* First parameter must be a dict */
2163 item=list_elem(args,0);
2164 if (!item || item->type!=t_dict)
2165 cfgfatal(loc,"site","parameter must be a dictionary\n");
2167 dict=item->data.dict;
2168 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2169 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2171 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2173 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2175 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2177 /* Sanity check (which also allows the 'sites' file to include
2178 site() closures for all sites including our own): refuse to
2179 talk to ourselves */
2180 if (strcmp(st->localname,st->remotename)==0) {
2181 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2183 if (st->peer_mobile != st->local_mobile)
2184 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2185 " but our local-mobile=%d\n",
2186 st->localname, st->peer_mobile, st->local_mobile);
2190 if (st->peer_mobile && st->local_mobile) {
2191 Message(M_WARNING,"site %s: site is mobile but so are we"
2192 " -> ignoring this site\n", st->remotename);
2197 assert(index_sequence < 0xffffffffUL);
2198 st->index = ++index_sequence;
2199 st->local_capabilities = 0;
2200 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2201 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2203 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2204 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2205 if (!things##_cfg) \
2206 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2207 st->nthings=list_length(things##_cfg); \
2208 NEW_ARY(st->things,st->nthings); \
2209 assert(st->nthings); \
2210 for (i=0; i<st->nthings; i++) { \
2211 item_t *item=list_elem(things##_cfg,i); \
2212 if (item->type!=t_closure) \
2213 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2214 closure_t *cl=item->data.closure; \
2215 if (cl->type!=CL_TYPE) \
2216 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2217 st->things[i]=cl->interface; \
2221 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2223 NEW_ARY(st->commclientinfos, st->ncomms);
2224 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2225 for (i=0; i<st->ncomms; i++) {
2226 st->commclientinfos[i] =
2228 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2231 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2232 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2233 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2235 struct hash_if *hash=0;
2236 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2237 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2239 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2240 else st->remoteport=0;
2241 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2243 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2245 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2247 SETUP_SETHASH(st->privkey);
2248 SETUP_SETHASH(st->pubkey);
2250 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2251 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2252 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2254 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2255 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2256 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2257 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2258 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2260 st->mobile_peer_expiry= dict_read_number(
2261 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2263 const char *peerskey= st->peer_mobile
2264 ? "mobile-peers-max" : "static-peers-max";
2265 st->transport_peers_max= dict_read_number(
2266 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2267 if (st->transport_peers_max<1 ||
2268 st->transport_peers_max>MAX_PEER_ADDRS) {
2269 cfgfatal(loc,"site", "%s must be in range 1.."
2270 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2273 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2274 st->key_renegotiate_time=st->key_lifetime/2;
2276 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2277 st->key_renegotiate_time=dict_read_number(
2278 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2279 if (st->key_renegotiate_time > st->key_lifetime) {
2280 cfgfatal(loc,"site",
2281 "renegotiate-time must be less than key-lifetime\n");
2284 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2285 log_event_table,"site");
2287 st->resolving_count=0;
2288 st->allow_send_prod=0;
2290 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2292 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2294 /* The information we expect to see in incoming messages of type 1 */
2295 /* fixme: lots of unchecked overflows here, but the results are only
2296 corrupted packets rather than undefined behaviour */
2297 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2299 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2301 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2302 BUF_ALLOC(&st->scratch,"site:scratch");
2304 /* We are interested in poll(), but only for timeouts. We don't have
2305 any fds of our own. */
2306 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2309 st->remote_capabilities=0;
2310 st->chosen_transform=0;
2311 st->current.key_timeout=0;
2312 st->auxiliary_key.key_timeout=0;
2313 transport_peers_clear(st,&st->peers);
2314 transport_peers_clear(st,&st->setup_peers);
2315 /* XXX mlock these */
2316 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2317 st->sharedsecretlen=st->sharedsecretallocd=0;
2320 #define SET_CAPBIT(bit) do { \
2321 uint32_t capflag = 1UL << (bit); \
2322 if (st->local_capabilities & capflag) \
2323 slog(st,LOG_ERROR,"capability bit" \
2324 " %d (%#"PRIx32") reused", (bit), capflag); \
2325 st->local_capabilities |= capflag; \
2328 for (i=0; i<st->ntransforms; i++)
2329 SET_CAPBIT(st->transforms[i]->capab_bit);
2333 if (st->local_mobile || st->peer_mobile)
2334 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2336 /* We need to register the remote networks with the netlink device */
2337 uint32_t netlink_mtu; /* local virtual interface mtu */
2338 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2339 if (!st->mtu_target)
2340 st->mtu_target=netlink_mtu;
2342 for (i=0; i<st->ncomms; i++)
2343 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2345 st->current.transform=0;
2346 st->auxiliary_key.transform=0;
2347 st->new_transform=0;
2348 st->auxiliary_is_new=0;
2350 enter_state_stop(st);
2352 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2353 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2355 return new_closure(&st->cl);
2358 void site_module(dict_t *dict)
2360 add_closure(dict,"site",site_apply);
2364 /***** TRANSPORT PEERS definitions *****/
2366 static void transport_peers_debug(struct site *st, transport_peers *dst,
2367 const char *didwhat,
2368 int nargs, const struct comm_addr *args,
2373 if (!(st->log_events & LOG_PEER_ADDRS))
2374 return; /* an optimisation */
2376 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2377 (dst==&st->peers ? "data" :
2378 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2379 didwhat, nargs, dst->npeers);
2381 for (i=0, argp=(void*)args;
2383 i++, (argp+=stride?stride:sizeof(*args))) {
2384 const struct comm_addr *ca=(void*)argp;
2385 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2386 i, comm_addr_to_string(ca));
2388 for (i=0; i<dst->npeers; i++) {
2389 struct timeval diff;
2390 timersub(tv_now,&dst->peers[i].last,&diff);
2391 const struct comm_addr *ca=&dst->peers[i].addr;
2392 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2393 i, comm_addr_to_string(ca),
2394 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2398 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2399 /* peers must be sorted first */
2400 int previous_peers=peers->npeers;
2401 struct timeval oldest;
2402 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2403 oldest.tv_usec = tv_now->tv_usec;
2404 while (peers->npeers>1 &&
2405 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2407 if (peers->npeers != previous_peers)
2408 transport_peers_debug(st,peers,"expire", 0,0,0);
2411 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2412 const struct comm_addr *ca,
2413 const struct timeval *tv) {
2414 /* returns false if output is full */
2417 if (peers->npeers >= st->transport_peers_max)
2420 for (search=0; search<peers->npeers; search++)
2421 if (comm_addr_equal(&peers->peers[search].addr, ca))
2424 peers->peers[peers->npeers].addr = *ca;
2425 peers->peers[peers->npeers].last = *tv;
2430 static void transport_record_peers(struct site *st, transport_peers *peers,
2431 const struct comm_addr *addrs, int naddrs,
2433 /* We add addrs into peers. The new entries end up at the front
2434 * and displace entries towards the end (perhaps even off the
2435 * end). Any existing matching entries are moved up to the front.
2437 * Caller must first call transport_peers_expire. */
2440 /* avoids debug for uninteresting updates */
2442 for (i=0; i<peers->npeers; i++) {
2443 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2444 memmove(peers->peers+1, peers->peers,
2445 sizeof(peers->peers[0]) * i);
2446 peers->peers[0].addr = addrs[0];
2447 peers->peers[0].last = *tv_now;
2453 int old_npeers=peers->npeers;
2454 transport_peer old_peers[old_npeers];
2455 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2459 for (i=0; i<naddrs; i++) {
2460 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2463 for (i=0; i<old_npeers; i++) {
2464 const transport_peer *old=&old_peers[i];
2465 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2469 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2472 static void transport_expire_record_peers(struct site *st,
2473 transport_peers *peers,
2474 const struct comm_addr *addrs,
2475 int naddrs, const char *m) {
2476 /* Convenience function */
2477 transport_peers_expire(st,peers);
2478 transport_record_peers(st,peers,addrs,naddrs,m);
2481 static bool_t transport_compute_setupinit_peers(struct site *st,
2482 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2483 int n_configured_addrs /* 0 if none or not found */,
2484 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2485 if (!n_configured_addrs && !incoming_packet_addr &&
2486 !transport_peers_valid(&st->peers))
2489 slog(st,LOG_SETUP_INIT,
2490 "using: %d configured addr(s);%s %d old peer addrs(es)",
2492 incoming_packet_addr ? " incoming packet address;" : "",
2495 /* Non-mobile peers try addresses until one is plausible. The
2496 * effect is that this code always tries first the configured
2497 * address if supplied, or otherwise the address of the incoming
2498 * PROD, or finally the existing data peer if one exists; this is
2501 transport_peers_copy(st,&st->setup_peers,&st->peers);
2502 transport_peers_expire(st,&st->setup_peers);
2504 if (incoming_packet_addr)
2505 transport_record_peers(st,&st->setup_peers,
2506 incoming_packet_addr,1, "incoming");
2508 if (n_configured_addrs)
2509 transport_record_peers(st,&st->setup_peers,
2510 configured_addrs,n_configured_addrs, "setupinit");
2512 assert(transport_peers_valid(&st->setup_peers));
2516 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2517 if (st->peer_mobile)
2518 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2520 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2521 if (st->peer_mobile)
2522 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2525 static int transport_peers_valid(transport_peers *peers) {
2526 return peers->npeers;
2528 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2530 transport_peers_debug(st,peers,"clear",0,0,0);
2532 static void transport_peers_copy(struct site *st, transport_peers *dst,
2533 const transport_peers *src) {
2534 dst->npeers=src->npeers;
2535 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2536 transport_peers_debug(st,dst,"copy",
2537 src->npeers, &src->peers->addr, sizeof(*src->peers));
2540 static void transport_resolve_complete(struct site *st,
2541 const struct comm_addr *addrs,
2543 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2545 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2549 static void transport_resolve_complete_tardy(struct site *st,
2550 const struct comm_addr *addrs,
2552 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2553 "resolved tardily");
2556 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2558 const transport_peers *inp) {
2559 /* out and in->peers may be the same region, or nonoverlapping */
2560 const transport_peer *in=inp->peers;
2562 for (slot=0; slot<inp->npeers; slot++) {
2563 if (!(mask & (1U << slot)))
2565 if (!(out==in && slot==*nout_io))
2566 COPY_OBJ(out[*nout_io], in[slot]);
2571 void transport_xmit(struct site *st, transport_peers *peers,
2572 struct buffer_if *buf, bool_t candebug) {
2574 transport_peers_expire(st, peers);
2575 unsigned failed=0; /* bitmask */
2576 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2579 for (slot=0; slot<peers->npeers; slot++) {
2580 transport_peer *peer=&peers->peers[slot];
2581 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2583 dump_packet(st, buf, &peer->addr, False, ok);
2585 failed |= 1U << slot;
2588 if (ok && !st->peer_mobile)
2591 /* Now we need to demote/delete failing addrs: if we are mobile we
2592 * merely demote them; otherwise we delete them. */
2593 if (st->local_mobile) {
2594 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2595 /* `expected' has all the failures at the end already */
2596 if (failed != expected) {
2598 transport_peer failedpeers[nfailed];
2599 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2600 assert(fslot == nfailed);
2602 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2603 assert(wslot+nfailed == peers->npeers);
2604 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2605 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2608 if (failed && peers->npeers > 1) {
2610 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2611 peers->npeers=wslot;
2612 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2617 /***** END of transport peers declarations *****/