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
112 int32_t site_max_start_pad = 4*4;
114 static cstring_t state_name(uint32_t state)
117 case 0: return "STOP";
118 case 1: return "RUN";
119 case 2: return "RESOLVE";
120 case 3: return "SENTMSG1";
121 case 4: return "SENTMSG2";
122 case 5: return "SENTMSG3";
123 case 6: return "SENTMSG4";
124 case 7: return "SENTMSG5";
125 case 8: return "WAIT";
126 default: return "*bad state*";
132 #define LOG_UNEXPECTED 0x00000001
133 #define LOG_SETUP_INIT 0x00000002
134 #define LOG_SETUP_TIMEOUT 0x00000004
135 #define LOG_ACTIVATE_KEY 0x00000008
136 #define LOG_TIMEOUT_KEY 0x00000010
137 #define LOG_SEC 0x00000020
138 #define LOG_STATE 0x00000040
139 #define LOG_DROP 0x00000080
140 #define LOG_DUMP 0x00000100
141 #define LOG_ERROR 0x00000400
142 #define LOG_PEER_ADDRS 0x00000800
144 static struct flagstr log_event_table[]={
145 { "unexpected", LOG_UNEXPECTED },
146 { "setup-init", LOG_SETUP_INIT },
147 { "setup-timeout", LOG_SETUP_TIMEOUT },
148 { "activate-key", LOG_ACTIVATE_KEY },
149 { "timeout-key", LOG_TIMEOUT_KEY },
150 { "security", LOG_SEC },
151 { "state-change", LOG_STATE },
152 { "packet-drop", LOG_DROP },
153 { "dump-packets", LOG_DUMP },
154 { "errors", LOG_ERROR },
155 { "peer-addrs", LOG_PEER_ADDRS },
156 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
157 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
158 { "all", 0xffffffff },
163 /***** TRANSPORT PEERS declarations *****/
165 /* Details of "mobile peer" semantics:
167 - We use the same data structure for the different configurations,
168 but manage it with different algorithms.
170 - We record up to mobile_peers_max peer address/port numbers
171 ("peers") for key setup, and separately up to mobile_peers_max
174 - In general, we make a new set of addrs (see below) when we start
175 a new key exchange; the key setup addrs become the data transport
176 addrs when key setup complets.
178 If our peer is mobile:
180 - We send to all recent addresses of incoming packets, plus
181 initially all configured addresses (which we also expire).
183 - So, we record addrs of good incoming packets, as follows:
184 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
185 2. add the peer of the just received packet to the applicable list
186 (possibly evicting the oldest entries to make room)
187 NB that we do not expire peers until an incoming packet arrives.
189 - If the peer has a configured address or name, we record them the
190 same way, but only as a result of our own initiation of key
191 setup. (We might evict some incoming packet addrs to make room.)
193 - The default number of addrs to keep is 3, or 4 if we have a
194 configured name or address. That's space for two configured
195 addresses (one IPv6 and one IPv4), plus two received addresses.
197 - Outgoing packets are sent to every recorded address in the
198 applicable list. Any unsupported[1] addresses are deleted from
199 the list right away. (This should only happen to configured
200 addresses, of course, but there is no need to check that.)
202 - When we successfully complete a key setup, we merge the key setup
203 peers into the data transfer peers.
205 [1] An unsupported address is one for whose AF we don't have a
206 socket (perhaps because we got EAFNOSUPPORT or some such) or for
207 which sendto gives ENETUNREACH.
209 If neither end is mobile:
211 - When peer initiated the key exchange, we use the incoming packet
214 - When we initiate the key exchange, we try configured addresses
215 until we get one which isn't unsupported then fixate on that.
217 - When we complete a key setup, we replace the data transport peers
218 with those from the key setup.
222 - We can't tell when local network setup changes so we can't cache
223 the unsupported addrs and completely remove the spurious calls to
224 sendto, but we can optimise things a bit by deprioritising addrs
225 which seem to be unsupported.
227 - Use only configured addresses. (Except, that if our peer
228 initiated a key exchange we use the incoming packet address until
229 our name resolution completes.)
231 - When we send a packet, try each address in turn; if addr
232 supported, put that address to the end of the list for future
233 packets, and go onto the next address.
235 - When we complete a key setup, we replace the data transport peers
236 with those from the key setup.
242 struct comm_addr addr;
246 /* configuration information */
247 /* runtime information */
249 transport_peer peers[MAX_PEER_ADDRS];
252 /* Basic operations on transport peer address sets */
253 static void transport_peers_clear(struct site *st, transport_peers *peers);
254 static int transport_peers_valid(transport_peers *peers);
255 static void transport_peers_copy(struct site *st, transport_peers *dst,
256 const transport_peers *src);
258 /* Record address of incoming setup packet; resp. data packet. */
259 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
260 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
262 /* Initialise the setup addresses. Called before we send the first
263 * packet in a key exchange. If we are the initiator, as a result of
264 * resolve completing (or being determined not to be relevant) or an
265 * incoming PROD; if we are the responder, as a result of the MSG1. */
266 static bool_t transport_compute_setupinit_peers(struct site *st,
267 const struct comm_addr *configured_addrs /* 0 if none or not found */,
268 int n_configured_addrs /* 0 if none or not found */,
269 const struct comm_addr *incoming_packet_addr /* 0 if none */);
271 /* Called if we are the responder in a key setup, when the resolve
272 * completes. transport_compute_setupinit_peers will hvae been called
273 * earlier. If _complete is called, we are still doing the key setup
274 * (and we should use the new values for both the rest of the key
275 * setup and the ongoing data exchange); if _tardy is called, the key
276 * setup is done (either completed or not) and only the data peers are
278 static void transport_resolve_complete(struct site *st,
279 const struct comm_addr *addrs, int naddrs);
280 static void transport_resolve_complete_tardy(struct site *st,
281 const struct comm_addr *addrs, int naddrs);
283 static void transport_xmit(struct site *st, transport_peers *peers,
284 struct buffer_if *buf, bool_t candebug);
286 /***** END of transport peers declarations *****/
290 struct transform_inst_if *transform;
291 uint64_t key_timeout; /* End of life of current key */
292 uint32_t remote_session_id;
298 /* configuration information */
302 bool_t local_mobile, peer_mobile; /* Mobile client support */
303 int32_t transport_peers_max;
304 string_t tunname; /* localname<->remotename by default, used in logs */
305 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
306 int remoteport; /* Port for bootstrapping, optional */
308 struct netlink_if *netlink;
309 struct comm_if **comms;
310 struct comm_clientinfo **commclientinfos;
312 struct resolver_if *resolver;
314 struct random_if *random;
315 struct sigprivkey_if *privkey;
316 struct sigpubkey_if *pubkey;
317 struct transform_if **transforms;
321 uint32_t index; /* Index of this site */
322 uint32_t early_capabilities;
323 uint32_t local_capabilities;
324 int32_t setup_retries; /* How many times to send setup packets */
325 int32_t setup_retry_interval; /* Initial timeout for setup packets */
326 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
327 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
328 int32_t key_lifetime; /* How long a key lasts once set up */
329 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
330 after this time, initiate a new
333 bool_t our_name_later; /* our name > peer name */
336 /* runtime information */
338 uint64_t now; /* Most recently seen time */
339 bool_t allow_send_prod;
340 bool_t msg1_crossed_logged;
342 int resolving_n_results_all;
343 int resolving_n_results_stored;
344 struct comm_addr resolving_results[MAX_PEER_ADDRS];
346 /* The currently established session */
347 struct data_key current;
348 struct data_key auxiliary_key;
349 bool_t auxiliary_is_new;
350 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
351 uint64_t auxiliary_renegotiate_key_time;
352 transport_peers peers; /* Current address(es) of peer for data traffic */
354 /* The current key setup protocol exchange. We can only be
355 involved in one of these at a time. There's a potential for
356 denial of service here (the attacker keeps sending a setup
357 packet; we keep trying to continue the exchange, and have to
358 timeout before we can listen for another setup packet); perhaps
359 we should keep a list of 'bad' sources for setup packets. */
360 uint32_t remote_capabilities;
361 uint16_t remote_adv_mtu;
362 struct transform_if *chosen_transform;
363 uint32_t setup_session_id;
364 transport_peers setup_peers;
365 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
366 uint8_t remoteN[NONCELEN];
367 struct buffer_if buffer; /* Current outgoing key exchange packet */
368 struct buffer_if scratch;
369 int32_t retries; /* Number of retries remaining */
370 uint64_t timeout; /* Timeout for current state */
372 uint8_t *sharedsecret;
373 uint32_t sharedsecretlen, sharedsecretallocd;
374 struct transform_inst_if *new_transform; /* For key setup/verify */
377 static uint32_t event_log_priority(struct site *st, uint32_t event)
379 if (!(event&st->log_events))
382 case LOG_UNEXPECTED: return M_INFO;
383 case LOG_SETUP_INIT: return M_INFO;
384 case LOG_SETUP_TIMEOUT: return M_NOTICE;
385 case LOG_ACTIVATE_KEY: return M_INFO;
386 case LOG_TIMEOUT_KEY: return M_INFO;
387 case LOG_SEC: return M_SECURITY;
388 case LOG_STATE: return M_DEBUG;
389 case LOG_DROP: return M_DEBUG;
390 case LOG_DUMP: return M_DEBUG;
391 case LOG_ERROR: return M_ERR;
392 case LOG_PEER_ADDRS: return M_DEBUG;
393 default: return M_ERR;
397 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
399 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
403 class=event_log_priority(st, event);
405 slilog_part(st->log,class,"%s: ",st->tunname);
406 vslilog_part(st->log,class,msg,ap);
407 slilog_part(st->log,class,"\n");
411 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
413 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
417 vslog(st,event,msg,ap);
421 static void logtimeout(struct site *st, const char *fmt, ...)
423 static void logtimeout(struct site *st, const char *fmt, ...)
425 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
432 slilog_part(st->log,class,"%s: ",st->tunname);
433 vslilog_part(st->log,class,fmt,ap);
437 for (i=0, delim=" (tried ";
438 i<st->setup_peers.npeers;
440 transport_peer *peer=&st->setup_peers.peers[i];
441 const char *s=comm_addr_to_string(&peer->addr);
442 slilog_part(st->log,class,"%s%s",delim,s);
445 slilog_part(st->log,class,")\n");
449 static void set_link_quality(struct site *st);
450 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
451 static void delete_one_key(struct site *st, struct data_key *key,
452 const char *reason /* may be 0 meaning don't log*/,
453 const char *which /* ignored if !reasonn */,
454 uint32_t loglevel /* ignored if !reasonn */);
455 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
456 const struct comm_addr *prod_hint);
457 static void enter_state_run(struct site *st);
458 static bool_t enter_state_resolve(struct site *st);
459 static void decrement_resolving_count(struct site *st, int by);
460 static bool_t enter_new_state(struct site *st,uint32_t next);
461 static void enter_state_wait(struct site *st);
462 static void activate_new_key(struct site *st);
464 static bool_t is_transform_valid(struct transform_inst_if *transform)
466 return transform && transform->valid(transform->st);
469 static bool_t current_valid(struct site *st)
471 return is_transform_valid(st->current.transform);
474 #define DEFINE_CALL_TRANSFORM(fwdrev) \
475 static transform_apply_return \
476 call_transform_##fwdrev(struct site *st, \
477 struct transform_inst_if *transform, \
478 struct buffer_if *buf, \
479 const char **errmsg) \
481 if (!is_transform_valid(transform)) { \
482 *errmsg="transform not set up"; \
483 return transform_apply_err; \
485 return transform->fwdrev(transform->st,buf,errmsg); \
488 DEFINE_CALL_TRANSFORM(forwards)
489 DEFINE_CALL_TRANSFORM(reverse)
491 static void dispose_transform(struct transform_inst_if **transform_var)
493 struct transform_inst_if *transform=*transform_var;
495 transform->delkey(transform->st);
496 transform->destroy(transform->st);
501 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
502 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
503 #define CHECK_TYPE(b,t) do { uint32_t type; \
504 CHECK_AVAIL((b),4); \
505 type=buf_unprepend_uint32((b)); \
506 if (type!=(t)) return False; } while(0)
508 static _Bool type_is_msg34(uint32_t type)
511 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
512 default: return False;
519 struct buffer_if extrainfo;
526 struct parsedname remote;
527 struct parsedname local;
528 uint32_t remote_capabilities;
530 int capab_transformnum;
536 struct alg_msg_data sig;
539 static int32_t wait_timeout(struct site *st) {
540 int32_t t = st->wait_timeout_mean;
543 st->random->generate(st->random->st,sizeof(factor),&factor);
544 t += (t / 256) * factor;
549 static _Bool set_new_transform(struct site *st, char *pk)
553 /* Make room for the shared key */
554 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
555 assert(st->sharedsecretlen);
556 if (st->sharedsecretlen > st->sharedsecretallocd) {
557 st->sharedsecretallocd=st->sharedsecretlen;
558 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
559 st->sharedsecretallocd,
560 "site:sharedsecret");
563 /* Generate the shared key */
564 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
565 st->sharedsecret,st->sharedsecretlen);
567 /* Set up the transform */
568 struct transform_if *generator=st->chosen_transform;
569 struct transform_inst_if *generated=generator->create(generator->st);
570 ok = generated->setkey(generated->st,st->sharedsecret,
571 st->sharedsecretlen,st->our_name_later);
573 dispose_transform(&st->new_transform);
574 if (!ok) return False;
575 st->new_transform=generated;
577 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
578 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
579 st->chosen_transform->capab_bit,
580 st->local_capabilities, st->remote_capabilities);
585 int32_t lenpos, afternul;
587 static void append_string_xinfo_start(struct buffer_if *buf,
588 struct xinfoadd *xia,
590 /* Helps construct one of the names with additional info as found
591 * in MSG1..4. Call this function first, then append all the
592 * desired extra info (not including the nul byte) to the buffer,
593 * then call append_string_xinfo_done. */
595 xia->lenpos = buf->size;
596 buf_append_string(buf,str);
597 buf_append_uint8(buf,0);
598 xia->afternul = buf->size;
600 static void append_string_xinfo_done(struct buffer_if *buf,
601 struct xinfoadd *xia)
603 /* we just need to adjust the string length */
604 if (buf->size == xia->afternul) {
605 /* no extra info, strip the nul too */
606 buf_unappend_uint8(buf);
608 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
612 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
613 out using a transform of config data supplied by netlink */
614 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
619 st->retries=st->setup_retries;
620 BUF_ALLOC(&st->buffer,what);
621 buffer_init(&st->buffer,0);
622 buf_append_uint32(&st->buffer,
623 (type==LABEL_MSG1?0:st->setup_session_id));
624 buf_append_uint32(&st->buffer,st->index);
625 buf_append_uint32(&st->buffer,type);
628 append_string_xinfo_start(&st->buffer,&xia,st->localname);
629 if ((st->local_capabilities & st->early_capabilities) ||
630 (type != LABEL_MSG1)) {
631 buf_append_uint32(&st->buffer,st->local_capabilities);
633 if (type_is_msg34(type)) {
634 buf_append_uint16(&st->buffer,st->mtu_target);
636 append_string_xinfo_done(&st->buffer,&xia);
638 buf_append_string(&st->buffer,st->remotename);
639 BUF_ADD_OBJ(append,&st->buffer,st->localN);
640 if (type==LABEL_MSG1) return True;
641 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
642 if (type==LABEL_MSG2) return True;
644 if (hacky_par_mid_failnow()) return False;
646 if (MSGMAJOR(type) == 3) do {
647 minor = MSGMINOR(type);
648 if (minor < 1) break;
649 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
652 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
653 buf_append_string(&st->buffer,dhpub);
656 bool_t ok=st->privkey->sign(st->privkey->st,
667 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
670 nm->len=buf_unprepend_uint16(msg);
671 CHECK_AVAIL(msg,nm->len);
672 nm->name=buf_unprepend(msg,nm->len);
673 uint8_t *nul=memchr(nm->name,0,nm->len);
675 buffer_readonly_view(&nm->extrainfo,0,0);
677 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
678 nm->len=nul-nm->name;
683 static bool_t unpick_msg(struct site *st, uint32_t type,
684 struct buffer_if *msg, struct msg *m)
688 m->capab_transformnum=-1;
689 m->hashstart=msg->start;
691 m->dest=buf_unprepend_uint32(msg);
693 m->source=buf_unprepend_uint32(msg);
694 CHECK_TYPE(msg,type);
695 if (!unpick_name(msg,&m->remote)) return False;
696 m->remote_capabilities=0;
698 if (m->remote.extrainfo.size) {
699 CHECK_AVAIL(&m->remote.extrainfo,4);
700 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
702 if (type_is_msg34(type) && m->remote.extrainfo.size) {
703 CHECK_AVAIL(&m->remote.extrainfo,2);
704 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
706 if (!unpick_name(msg,&m->local)) return False;
707 if (type==LABEL_PROD) {
711 CHECK_AVAIL(msg,NONCELEN);
712 m->nR=buf_unprepend(msg,NONCELEN);
713 if (type==LABEL_MSG1) {
717 CHECK_AVAIL(msg,NONCELEN);
718 m->nL=buf_unprepend(msg,NONCELEN);
719 if (type==LABEL_MSG2) {
723 if (MSGMAJOR(type) == 3) do {
724 minor = MSGMINOR(type);
725 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
726 if (minor < (minminor)) \
727 m->capab_##kind##num = (dflt); \
729 CHECK_AVAIL(msg, 1); \
730 m->capab_##kind##num = buf_unprepend_uint8(msg); \
733 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
734 #undef MAYBE_READ_CAP
737 m->pklen=buf_unprepend_uint16(msg);
738 CHECK_AVAIL(msg,m->pklen);
739 m->pk=buf_unprepend(msg,m->pklen);
740 m->hashlen=msg->start-m->hashstart;
742 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
751 static bool_t name_matches(const struct parsedname *nm, const char *expected)
753 int expected_len=strlen(expected);
755 nm->len == expected_len &&
756 !memcmp(nm->name, expected, expected_len);
759 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
762 if (type==LABEL_MSG1) return True;
764 /* Check that the site names and our nonce have been sent
765 back correctly, and then store our peer's nonce. */
766 if (!name_matches(&m->remote,st->remotename)) {
767 *error="wrong remote site name";
770 if (!name_matches(&m->local,st->localname)) {
771 *error="wrong local site name";
774 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
775 *error="wrong locally-generated nonce";
778 if (type==LABEL_MSG2) return True;
779 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
780 *error="wrong remotely-generated nonce";
783 /* MSG3 has complicated rules about capabilities, which are
784 * handled in process_msg3. */
785 if (MSGMAJOR(type) == 3) return True;
786 if (m->remote_capabilities!=st->remote_capabilities) {
787 *error="remote capabilities changed";
790 if (type==LABEL_MSG4) return True;
791 *error="unknown message type";
795 static bool_t generate_msg1(struct site *st)
797 st->random->generate(st->random->st,NONCELEN,st->localN);
798 return generate_msg(st,LABEL_MSG1,"site:MSG1");
801 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
802 const struct comm_addr *src, struct msg *m)
804 /* We've already determined we're in an appropriate state to
805 process an incoming MSG1, and that the MSG1 has correct values
808 st->setup_session_id=m->source;
809 st->remote_capabilities=m->remote_capabilities;
810 memcpy(st->remoteN,m->nR,NONCELEN);
814 static bool_t generate_msg2(struct site *st)
816 st->random->generate(st->random->st,NONCELEN,st->localN);
817 return generate_msg(st,LABEL_MSG2,"site:MSG2");
820 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
821 const struct comm_addr *src)
826 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
827 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
828 slog(st,LOG_SEC,"msg2: %s",err);
831 st->setup_session_id=m.source;
832 st->remote_capabilities=m.remote_capabilities;
834 /* Select the transform to use */
836 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
837 if (!remote_crypto_caps)
838 /* old secnets only had this one transform */
839 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
841 #define CHOOSE_CRYPTO(kind, whats) do { \
842 struct kind##_if *iface; \
843 uint32_t bit, ours = 0; \
845 for (i= 0; i < st->n##kind##s; i++) { \
846 iface=st->kind##s[i]; \
847 bit = 1UL << iface->capab_bit; \
848 if (bit & remote_crypto_caps) goto kind##_found; \
851 slog(st,LOG_ERROR,"no " whats " in common" \
852 " (us %#"PRIx32"; them: %#"PRIx32")", \
853 st->local_capabilities & ours, remote_crypto_caps); \
856 st->chosen_##kind = iface; \
859 CHOOSE_CRYPTO(transform, "transforms");
863 memcpy(st->remoteN,m.nR,NONCELEN);
867 static bool_t generate_msg3(struct site *st)
869 /* Now we have our nonce and their nonce. Think of a secret key,
870 and create message number 3. */
871 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
872 return generate_msg(st,
873 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
879 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
881 /* Check signature and store g^x mod m */
882 if (!st->pubkey->check(st->pubkey->st,
883 m->hashstart,m->hashlen,
885 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
889 st->remote_adv_mtu=m->remote_mtu;
894 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
895 const struct comm_addr *src, uint32_t msgtype)
901 case CASES_MSG3_KNOWN: break;
905 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
906 if (!check_msg(st,msgtype,&m,&err)) {
907 slog(st,LOG_SEC,"msg3: %s",err);
910 uint32_t capab_adv_late = m.remote_capabilities
911 & ~st->remote_capabilities & st->early_capabilities;
912 if (capab_adv_late) {
913 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
914 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
915 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
919 #define CHOSE_CRYPTO(kind, what) do { \
920 struct kind##_if *iface; \
922 for (i=0; i<st->n##kind##s; i++) { \
923 iface=st->kind##s[i]; \
924 if (iface->capab_bit == m.capab_##kind##num) \
927 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
928 m.capab_##kind##num); \
931 st->chosen_##kind=iface; \
934 CHOSE_CRYPTO(transform, "transform");
938 if (!process_msg3_msg4(st,&m))
941 /* Update our idea of the remote site's capabilities, now that we've
942 * verified that its message was authentic.
944 * Our previous idea of the remote site's capabilities came from the
945 * unauthenticated MSG1. We've already checked that this new message
946 * doesn't change any of the bits we relied upon in the past, but it may
947 * also have set additional capability bits. We simply throw those away
948 * now, and use the authentic capabilities from this MSG3. */
949 st->remote_capabilities=m.remote_capabilities;
951 /* Terminate their DH public key with a '0' */
953 /* Invent our DH secret key */
954 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
956 /* Generate the shared key and set up the transform */
957 if (!set_new_transform(st,m.pk)) return False;
962 static bool_t generate_msg4(struct site *st)
964 /* We have both nonces, their public key and our private key. Generate
965 our public key, sign it and send it to them. */
966 return generate_msg(st,LABEL_MSG4,"site:MSG4");
969 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
970 const struct comm_addr *src)
975 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
976 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
977 slog(st,LOG_SEC,"msg4: %s",err);
981 if (!process_msg3_msg4(st,&m))
984 /* Terminate their DH public key with a '0' */
987 /* Generate the shared key and set up the transform */
988 if (!set_new_transform(st,m.pk)) return False;
999 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1002 CHECK_AVAIL(msg0,4);
1003 m->dest=buf_unprepend_uint32(msg0);
1004 CHECK_AVAIL(msg0,4);
1005 m->source=buf_unprepend_uint32(msg0);
1006 CHECK_AVAIL(msg0,4);
1007 m->type=buf_unprepend_uint32(msg0);
1009 /* Leaves transformed part of buffer untouched */
1012 static bool_t generate_msg5(struct site *st)
1014 cstring_t transform_err;
1016 BUF_ALLOC(&st->buffer,"site:MSG5");
1017 /* We are going to add four words to the message */
1018 buffer_init(&st->buffer,calculate_max_start_pad());
1019 /* Give the netlink code an opportunity to put its own stuff in the
1020 message (configuration information, etc.) */
1021 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1022 if (call_transform_forwards(st,st->new_transform,
1023 &st->buffer,&transform_err))
1025 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1026 buf_prepend_uint32(&st->buffer,st->index);
1027 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1029 st->retries=st->setup_retries;
1033 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1034 const struct comm_addr *src,
1035 struct transform_inst_if *transform)
1038 cstring_t transform_err;
1040 if (!unpick_msg0(st,msg5,&m)) return False;
1042 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1043 /* There's a problem */
1044 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1047 /* Buffer should now contain untransformed PING packet data */
1048 CHECK_AVAIL(msg5,4);
1049 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1050 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1053 /* Older versions of secnet used to write some config data here
1054 * which we ignore. So we don't CHECK_EMPTY */
1058 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1059 uint32_t session_id)
1061 cstring_t transform_err;
1063 BUF_ALLOC(&st->buffer,"site:MSG6");
1064 /* We are going to add four words to the message */
1065 buffer_init(&st->buffer,calculate_max_start_pad());
1066 /* Give the netlink code an opportunity to put its own stuff in the
1067 message (configuration information, etc.) */
1068 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1069 transform_apply_return problem =
1070 call_transform_forwards(st,transform,
1071 &st->buffer,&transform_err);
1073 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1074 buf_prepend_uint32(&st->buffer,st->index);
1075 buf_prepend_uint32(&st->buffer,session_id);
1078 static bool_t generate_msg6(struct site *st)
1080 if (!is_transform_valid(st->new_transform))
1082 create_msg6(st,st->new_transform,st->setup_session_id);
1083 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1087 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1088 const struct comm_addr *src)
1091 cstring_t transform_err;
1093 if (!unpick_msg0(st,msg6,&m)) return False;
1095 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1096 /* There's a problem */
1097 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1100 /* Buffer should now contain untransformed PING packet data */
1101 CHECK_AVAIL(msg6,4);
1102 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1103 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1106 /* Older versions of secnet used to write some config data here
1107 * which we ignore. So we don't CHECK_EMPTY */
1111 static transform_apply_return
1112 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1113 const struct comm_addr *src)
1115 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1117 transform_apply_return problem;
1119 if (!unpick_msg0(st,msg0,&m)) return False;
1121 /* Keep a copy so we can try decrypting it with multiple keys */
1122 buffer_copy(&st->scratch, msg0);
1124 problem = call_transform_reverse(st,st->current.transform,
1125 msg0,&transform_err);
1127 if (!st->auxiliary_is_new)
1128 delete_one_key(st,&st->auxiliary_key,
1129 "peer has used new key","auxiliary key",LOG_SEC);
1132 if (transform_apply_return_badseq(problem))
1135 buffer_copy(msg0, &st->scratch);
1136 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1139 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1140 if (st->auxiliary_is_new) {
1141 /* We previously timed out in state SENTMSG5 but it turns
1142 * out that our peer did in fact get our MSG5 and is
1143 * using the new key. So we should switch to it too. */
1144 /* This is a bit like activate_new_key. */
1147 st->current=st->auxiliary_key;
1148 st->auxiliary_key=t;
1150 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1151 "previous key",LOG_SEC);
1152 st->auxiliary_is_new=0;
1153 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1157 if (transform_apply_return_badseq(problem))
1160 if (st->state==SITE_SENTMSG5) {
1161 buffer_copy(msg0, &st->scratch);
1162 problem = call_transform_reverse(st,st->new_transform,
1165 /* It looks like we didn't get the peer's MSG6 */
1166 /* This is like a cut-down enter_new_state(SITE_RUN) */
1167 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1168 BUF_FREE(&st->buffer);
1170 activate_new_key(st);
1171 return 0; /* do process the data in this packet */
1173 if (transform_apply_return_badseq(problem))
1177 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1178 transform_err,auxkey_err,newkey_err);
1179 initiate_key_setup(st,"incoming message would not decrypt",0);
1180 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1185 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1190 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1191 const struct comm_addr *src)
1194 transform_apply_return problem;
1196 problem = decrypt_msg0(st,msg0,src);
1197 if (problem==transform_apply_seqdupe) {
1198 /* We recently received another copy of this packet, maybe due
1199 * to polypath. That's not a problem; indeed, for the
1200 * purposes of transport address management it is a success.
1201 * But we don't want to process the packet. */
1202 transport_data_msgok(st,src);
1208 CHECK_AVAIL(msg0,4);
1209 type=buf_unprepend_uint32(msg0);
1212 /* We must forget about the current session. */
1213 delete_keys(st,"request from peer",LOG_SEC);
1214 /* probably, the peer is shutting down, and this is going to fail,
1215 * but we need to be trying to bring the link up again */
1217 initiate_key_setup(st,"peer requested key teardown",0);
1220 /* Deliver to netlink layer */
1221 st->netlink->deliver(st->netlink->st,msg0);
1222 transport_data_msgok(st,src);
1223 /* See whether we should start negotiating a new key */
1224 if (st->now > st->renegotiate_key_time)
1225 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1228 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1235 static void dump_packet(struct site *st, struct buffer_if *buf,
1236 const struct comm_addr *addr, bool_t incoming,
1239 uint32_t dest=get_uint32(buf->start);
1240 uint32_t source=get_uint32(buf->start+4);
1241 uint32_t msgtype=get_uint32(buf->start+8);
1243 if (st->log_events & LOG_DUMP)
1244 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1245 st->tunname,incoming?"incoming":"outgoing",
1246 dest,source,msgtype,comm_addr_to_string(addr),
1250 static bool_t comm_addr_sendmsg(struct site *st,
1251 const struct comm_addr *dest,
1252 struct buffer_if *buf)
1255 struct comm_clientinfo *commclientinfo = 0;
1257 for (i=0; i < st->ncomms; i++) {
1258 if (st->comms[i] == dest->comm) {
1259 commclientinfo = st->commclientinfos[i];
1263 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1266 static uint32_t site_status(void *st)
1271 static bool_t send_msg(struct site *st)
1273 if (st->retries>0) {
1274 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1275 st->timeout=st->now+st->setup_retry_interval;
1278 } else if (st->state==SITE_SENTMSG5) {
1279 logtimeout(st,"timed out sending MSG5, stashing new key");
1280 /* We stash the key we have produced, in case it turns out that
1281 * our peer did see our MSG5 after all and starts using it. */
1282 /* This is a bit like some of activate_new_key */
1283 struct transform_inst_if *t;
1284 t=st->auxiliary_key.transform;
1285 st->auxiliary_key.transform=st->new_transform;
1286 st->new_transform=t;
1287 dispose_transform(&st->new_transform);
1289 st->auxiliary_is_new=1;
1290 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1291 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1292 st->auxiliary_key.remote_session_id=st->setup_session_id;
1294 enter_state_wait(st);
1297 logtimeout(st,"timed out sending key setup packet "
1298 "(in state %s)",state_name(st->state));
1299 enter_state_wait(st);
1304 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1305 int stored_naddrs, int all_naddrs,
1306 const char *address, const char *failwhy)
1308 struct site *st=sst;
1310 if (!stored_naddrs) {
1311 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1313 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1314 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1316 int space=st->transport_peers_max-st->resolving_n_results_stored;
1317 int n_tocopy=MIN(stored_naddrs,space);
1318 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1321 st->resolving_n_results_stored += n_tocopy;
1322 st->resolving_n_results_all += all_naddrs;
1325 decrement_resolving_count(st,1);
1328 static void decrement_resolving_count(struct site *st, int by)
1330 assert(st->resolving_count>0);
1331 st->resolving_count-=by;
1333 if (st->resolving_count)
1336 /* OK, we are done with them all. Handle combined results. */
1338 const struct comm_addr *addrs=st->resolving_results;
1339 int naddrs=st->resolving_n_results_stored;
1340 assert(naddrs<=st->transport_peers_max);
1343 if (naddrs != st->resolving_n_results_all) {
1344 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1345 " yielded too many results (%d > %d), some ignored",
1346 st->resolving_n_results_all, naddrs);
1348 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1349 naddrs, iaddr_to_string(&addrs[0].ia));;
1352 switch (st->state) {
1354 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1355 enter_new_state(st,SITE_SENTMSG1);
1357 /* Can't figure out who to try to to talk to */
1358 slog(st,LOG_SETUP_INIT,
1359 "key exchange failed: cannot find peer address");
1360 enter_state_run(st);
1363 case SITE_SENTMSG1: case SITE_SENTMSG2:
1364 case SITE_SENTMSG3: case SITE_SENTMSG4:
1367 /* We start using the address immediately for data too.
1368 * It's best to store it in st->peers now because we might
1369 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1370 * the new key (without updating the data peer addrs). */
1371 transport_resolve_complete(st,addrs,naddrs);
1372 } else if (st->local_mobile) {
1373 /* We can't let this rest because we may have a peer
1374 * address which will break in the future. */
1375 slog(st,LOG_SETUP_INIT,"resolution failed: "
1376 "abandoning key exchange");
1377 enter_state_wait(st);
1379 slog(st,LOG_SETUP_INIT,"resolution failed: "
1380 " continuing to use source address of peer's packets"
1381 " for key exchange and ultimately data");
1386 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1387 " updating peer address(es)");
1388 transport_resolve_complete_tardy(st,addrs,naddrs);
1389 } else if (st->local_mobile) {
1390 /* Not very good. We should queue (another) renegotiation
1391 * so that we can update the peer address. */
1392 st->key_renegotiate_time=st->now+wait_timeout(st);
1394 slog(st,LOG_SETUP_INIT,"resolution failed: "
1395 " continuing to use source address of peer's packets");
1405 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1406 const struct comm_addr *prod_hint)
1408 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1409 if (st->state!=SITE_RUN) return False;
1410 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1411 if (st->addresses) {
1412 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1413 return enter_state_resolve(st);
1414 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1415 return enter_new_state(st,SITE_SENTMSG1);
1417 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1421 static void activate_new_key(struct site *st)
1423 struct transform_inst_if *t;
1425 /* We have three transform instances, which we swap between old,
1427 t=st->auxiliary_key.transform;
1428 st->auxiliary_key.transform=st->current.transform;
1429 st->current.transform=st->new_transform;
1430 st->new_transform=t;
1431 dispose_transform(&st->new_transform);
1434 st->auxiliary_is_new=0;
1435 st->auxiliary_key.key_timeout=st->current.key_timeout;
1436 st->current.key_timeout=st->now+st->key_lifetime;
1437 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1438 transport_peers_copy(st,&st->peers,&st->setup_peers);
1439 st->current.remote_session_id=st->setup_session_id;
1441 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1442 * But their mtu be unspecified, in which case we just use ours. */
1443 uint32_t intersite_mtu=
1444 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1445 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1447 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1448 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1449 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1450 enter_state_run(st);
1453 static void delete_one_key(struct site *st, struct data_key *key,
1454 cstring_t reason, cstring_t which, uint32_t loglevel)
1456 if (!is_transform_valid(key->transform)) return;
1457 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1458 dispose_transform(&key->transform);
1462 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1464 if (current_valid(st)) {
1465 slog(st,loglevel,"session closed (%s)",reason);
1467 delete_one_key(st,&st->current,0,0,0);
1468 set_link_quality(st);
1470 delete_one_key(st,&st->auxiliary_key,0,0,0);
1473 static void state_assert(struct site *st, bool_t ok)
1475 if (!ok) fatal("site:state_assert");
1478 static void enter_state_stop(struct site *st)
1480 st->state=SITE_STOP;
1482 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1483 dispose_transform(&st->new_transform);
1486 static void set_link_quality(struct site *st)
1489 if (current_valid(st))
1490 quality=LINK_QUALITY_UP;
1491 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1492 quality=LINK_QUALITY_DOWN;
1493 else if (st->addresses)
1494 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1495 else if (transport_peers_valid(&st->peers))
1496 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1498 quality=LINK_QUALITY_DOWN;
1500 st->netlink->set_quality(st->netlink->st,quality);
1503 static void enter_state_run(struct site *st)
1505 slog(st,LOG_STATE,"entering state RUN%s",
1506 current_valid(st) ? " (keyed)" : " (unkeyed)");
1510 st->setup_session_id=0;
1511 transport_peers_clear(st,&st->setup_peers);
1512 FILLZERO(st->localN);
1513 FILLZERO(st->remoteN);
1514 dispose_transform(&st->new_transform);
1515 memset(st->dhsecret,0,st->dh->len);
1516 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1517 set_link_quality(st);
1519 if (st->keepalive && !current_valid(st))
1520 initiate_key_setup(st, "keepalive", 0);
1523 static bool_t ensure_resolving(struct site *st)
1525 /* Reentrancy hazard: may call site_resolve_callback and hence
1526 * enter_new_state, enter_state_* and generate_msg*. */
1527 if (st->resolving_count)
1530 assert(st->addresses);
1532 /* resolver->request might reentrantly call site_resolve_callback
1533 * which will decrement st->resolving, so we need to increment it
1534 * twice beforehand to prevent decrement from thinking we're
1535 * finished, and decrement it ourselves. Alternatively if
1536 * everything fails then there are no callbacks due and we simply
1537 * set it to 0 and return false.. */
1538 st->resolving_n_results_stored=0;
1539 st->resolving_n_results_all=0;
1540 st->resolving_count+=2;
1541 const char **addrp=st->addresses;
1542 const char *address;
1544 for (; (address=*addrp++); ) {
1545 bool_t ok = st->resolver->request(st->resolver->st,address,
1546 st->remoteport,st->comms[0],
1547 site_resolve_callback,st);
1549 st->resolving_count++;
1553 st->resolving_count=0;
1556 decrement_resolving_count(st,2);
1560 static bool_t enter_state_resolve(struct site *st)
1562 /* Reentrancy hazard! See ensure_resolving. */
1563 state_assert(st,st->state==SITE_RUN);
1564 slog(st,LOG_STATE,"entering state RESOLVE");
1565 st->state=SITE_RESOLVE;
1566 return ensure_resolving(st);
1569 static bool_t enter_new_state(struct site *st, uint32_t next)
1571 bool_t (*gen)(struct site *st);
1574 slog(st,LOG_STATE,"entering state %s",state_name(next));
1577 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1579 st->msg1_crossed_logged = False;
1582 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1583 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1587 state_assert(st,st->state==SITE_SENTMSG1);
1588 BUF_FREE(&st->buffer);
1592 state_assert(st,st->state==SITE_SENTMSG2);
1593 BUF_FREE(&st->buffer);
1597 state_assert(st,st->state==SITE_SENTMSG3);
1598 BUF_FREE(&st->buffer);
1602 state_assert(st,st->state==SITE_SENTMSG4);
1603 BUF_FREE(&st->buffer);
1608 fatal("enter_new_state(%s): invalid new state",state_name(next));
1612 if (hacky_par_start_failnow()) return False;
1614 r= gen(st) && send_msg(st);
1617 st->setup_retries, st->setup_retry_interval,
1622 if (next==SITE_RUN) {
1623 BUF_FREE(&st->buffer); /* Never reused */
1624 st->timeout=0; /* Never retransmit */
1625 activate_new_key(st);
1629 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1630 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1631 in either state, and enter_state_wait() will
1633 enter_state_wait(st);
1637 /* msg7 tells our peer that we're about to forget our key */
1638 static bool_t send_msg7(struct site *st, cstring_t reason)
1640 cstring_t transform_err;
1642 if (current_valid(st) && st->buffer.free
1643 && transport_peers_valid(&st->peers)) {
1644 BUF_ALLOC(&st->buffer,"site:MSG7");
1645 buffer_init(&st->buffer,calculate_max_start_pad());
1646 buf_append_uint32(&st->buffer,LABEL_MSG7);
1647 buf_append_string(&st->buffer,reason);
1648 if (call_transform_forwards(st, st->current.transform,
1649 &st->buffer, &transform_err))
1651 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1652 buf_prepend_uint32(&st->buffer,st->index);
1653 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1654 transport_xmit(st,&st->peers,&st->buffer,True);
1655 BUF_FREE(&st->buffer);
1662 /* We go into this state if our peer becomes uncommunicative. Similar to
1663 the "stop" state, we forget all session keys for a while, before
1664 re-entering the "run" state. */
1665 static void enter_state_wait(struct site *st)
1667 slog(st,LOG_STATE,"entering state WAIT");
1668 st->timeout=st->now+wait_timeout(st);
1669 st->state=SITE_WAIT;
1670 set_link_quality(st);
1671 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1672 /* XXX Erase keys etc. */
1675 static void generate_prod(struct site *st, struct buffer_if *buf)
1678 buf_append_uint32(buf,0);
1679 buf_append_uint32(buf,0);
1680 buf_append_uint32(buf,LABEL_PROD);
1681 buf_append_string(buf,st->localname);
1682 buf_append_string(buf,st->remotename);
1685 static void generate_send_prod(struct site *st,
1686 const struct comm_addr *source)
1688 if (!st->allow_send_prod) return; /* too soon */
1689 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1690 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1692 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1693 st->allow_send_prod=0;
1694 generate_prod(st,&st->scratch);
1695 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1696 dump_packet(st,&st->scratch,source,False,ok);
1699 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1702 int64_t offset=timeout-*now;
1703 if (offset<0) offset=0;
1704 if (offset>INT_MAX) offset=INT_MAX;
1705 if (*timeout_io<0 || offset<*timeout_io)
1710 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1713 struct site *st=sst;
1715 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1718 /* Work out when our next timeout is. The earlier of 'timeout' or
1719 'current.key_timeout'. A stored value of '0' indicates no timeout
1721 site_settimeout(st->timeout, timeout_io);
1722 site_settimeout(st->current.key_timeout, timeout_io);
1723 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1725 return 0; /* success */
1728 static void check_expiry(struct site *st, struct data_key *key,
1731 if (key->key_timeout && *now>key->key_timeout) {
1732 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1736 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1737 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1739 struct site *st=sst;
1742 if (st->timeout && *now>st->timeout) {
1744 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1745 if (!hacky_par_start_failnow())
1747 } else if (st->state==SITE_WAIT) {
1748 enter_state_run(st);
1750 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1754 check_expiry(st,&st->current,"current key");
1755 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1758 /* This function is called by the netlink device to deliver packets
1759 intended for the remote network. The packet is in "raw" wire
1760 format, but is guaranteed to be word-aligned. */
1761 static void site_outgoing(void *sst, struct buffer_if *buf)
1763 struct site *st=sst;
1764 cstring_t transform_err;
1766 if (st->state==SITE_STOP) {
1771 st->allow_send_prod=1;
1773 /* In all other states we consider delivering the packet if we have
1774 a valid key and a valid address to send it to. */
1775 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1776 /* Transform it and send it */
1778 buf_prepend_uint32(buf,LABEL_MSG9);
1779 if (call_transform_forwards(st, st->current.transform,
1780 buf, &transform_err))
1782 buf_prepend_uint32(buf,LABEL_MSG0);
1783 buf_prepend_uint32(buf,st->index);
1784 buf_prepend_uint32(buf,st->current.remote_session_id);
1785 transport_xmit(st,&st->peers,buf,False);
1792 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1794 initiate_key_setup(st,"outgoing packet",0);
1797 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1798 uint32_t type, struct msg *m)
1799 /* For packets which are identified by the local and remote names.
1800 * If it has our name and our peer's name in it it's for us. */
1802 struct buffer_if buf[1];
1803 buffer_readonly_clone(buf,buf_in);
1804 return unpick_msg(st,type,buf,m)
1805 && name_matches(&m->remote,st->remotename)
1806 && name_matches(&m->local,st->localname);
1809 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1810 if (st->local_capabilities & m->remote_capabilities &
1811 CAPAB_PRIORITY_MOBILE) {
1812 if (st->local_mobile) return True;
1813 if (st-> peer_mobile) return False;
1815 return st->our_name_later;
1818 static bool_t setup_late_msg_ok(struct site *st,
1819 const struct buffer_if *buf_in,
1821 const struct comm_addr *source) {
1822 /* For setup packets which seem from their type like they are
1823 * late. Maybe they came via a different path. All we do is make
1824 * a note of the sending address, iff they look like they are part
1825 * of the current key setup attempt. */
1827 if (!named_for_us(st,buf_in,msgtype,&m))
1828 /* named_for_us calls unpick_msg which gets the nonces */
1830 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1831 !consttime_memeq(m.nL,st->localN, NONCELEN))
1832 /* spoof ? from stale run ? who knows */
1834 transport_setup_msgok(st,source);
1838 /* This function is called by the communication device to deliver
1839 packets from our peers.
1840 It should return True if the packet is recognised as being for
1841 this current site instance (and should therefore not be processed
1842 by other sites), even if the packet was otherwise ignored. */
1843 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1844 const struct comm_addr *source)
1846 struct site *st=sst;
1848 if (buf->size < 12) return False;
1850 uint32_t dest=get_uint32(buf->start);
1851 uint32_t msgtype=get_uint32(buf->start+8);
1852 struct msg named_msg;
1854 if (msgtype==LABEL_MSG1) {
1855 if (!named_for_us(st,buf,msgtype,&named_msg))
1857 /* It's a MSG1 addressed to us. Decide what to do about it. */
1858 dump_packet(st,buf,source,True,True);
1859 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1860 st->state==SITE_WAIT) {
1861 /* We should definitely process it */
1862 transport_compute_setupinit_peers(st,0,0,source);
1863 if (process_msg1(st,buf,source,&named_msg)) {
1864 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1865 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1866 if (entered && st->addresses && st->local_mobile)
1867 /* We must do this as the very last thing, because
1868 the resolver callback might reenter us. */
1869 ensure_resolving(st);
1871 slog(st,LOG_ERROR,"failed to process incoming msg1");
1875 } else if (st->state==SITE_SENTMSG1) {
1876 /* We've just sent a message 1! They may have crossed on
1877 the wire. If we have priority then we ignore the
1878 incoming one, otherwise we process it as usual. */
1879 if (we_have_priority(st,&named_msg)) {
1881 if (!st->msg1_crossed_logged++)
1882 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1883 "priority => ignore incoming msg1");
1886 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1887 "priority => use incoming msg1");
1888 if (process_msg1(st,buf,source,&named_msg)) {
1889 BUF_FREE(&st->buffer); /* Free our old message 1 */
1890 transport_setup_msgok(st,source);
1891 enter_new_state(st,SITE_SENTMSG2);
1893 slog(st,LOG_ERROR,"failed to process an incoming "
1894 "crossed msg1 (we have low priority)");
1899 } else if (st->state==SITE_SENTMSG2 ||
1900 st->state==SITE_SENTMSG4) {
1901 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1902 /* We are ahead in the protocol, but that msg1 had the
1903 * peer's nonce so presumably it is from this key
1904 * exchange run, via a slower route */
1905 transport_setup_msgok(st,source);
1907 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1912 /* The message 1 was received at an unexpected stage of the
1913 key setup. Well, they lost the race. */
1914 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1918 if (msgtype==LABEL_PROD) {
1919 if (!named_for_us(st,buf,msgtype,&named_msg))
1921 dump_packet(st,buf,source,True,True);
1922 if (st->state!=SITE_RUN) {
1923 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1924 } else if (current_valid(st)) {
1925 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1927 initiate_key_setup(st,"peer sent PROD packet",source);
1932 if (dest==st->index) {
1933 /* Explicitly addressed to us */
1934 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1937 /* If the source is our current peer then initiate a key setup,
1938 because our peer's forgotten the key */
1939 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1941 initiated = initiate_key_setup(st,"received a NAK",source);
1942 if (!initiated) generate_send_prod(st,source);
1944 slog(st,LOG_SEC,"bad incoming NAK");
1948 process_msg0(st,buf,source);
1951 /* Setup packet: should not have been explicitly addressed
1953 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1956 /* Setup packet: expected only in state SENTMSG1 */
1957 if (st->state!=SITE_SENTMSG1) {
1958 if ((st->state==SITE_SENTMSG3 ||
1959 st->state==SITE_SENTMSG5) &&
1960 setup_late_msg_ok(st,buf,msgtype,source))
1962 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1963 } else if (process_msg2(st,buf,source)) {
1964 transport_setup_msgok(st,source);
1965 enter_new_state(st,SITE_SENTMSG3);
1967 slog(st,LOG_SEC,"invalid MSG2");
1970 case CASES_MSG3_KNOWN:
1971 /* Setup packet: expected only in state SENTMSG2 */
1972 if (st->state!=SITE_SENTMSG2) {
1973 if ((st->state==SITE_SENTMSG4) &&
1974 setup_late_msg_ok(st,buf,msgtype,source))
1976 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1977 } else if (process_msg3(st,buf,source,msgtype)) {
1978 transport_setup_msgok(st,source);
1979 enter_new_state(st,SITE_SENTMSG4);
1981 slog(st,LOG_SEC,"invalid MSG3");
1985 /* Setup packet: expected only in state SENTMSG3 */
1986 if (st->state!=SITE_SENTMSG3) {
1987 if ((st->state==SITE_SENTMSG5) &&
1988 setup_late_msg_ok(st,buf,msgtype,source))
1990 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1991 } else if (process_msg4(st,buf,source)) {
1992 transport_setup_msgok(st,source);
1993 enter_new_state(st,SITE_SENTMSG5);
1995 slog(st,LOG_SEC,"invalid MSG4");
1999 /* Setup packet: expected only in state SENTMSG4 */
2000 /* (may turn up in state RUN if our return MSG6 was lost
2001 and the new key has already been activated. In that
2002 case we discard it. The peer will realise that we
2003 are using the new key when they see our data packets.
2004 Until then the peer's data packets to us get discarded. */
2005 if (st->state==SITE_SENTMSG4) {
2006 if (process_msg5(st,buf,source,st->new_transform)) {
2007 transport_setup_msgok(st,source);
2008 enter_new_state(st,SITE_RUN);
2010 slog(st,LOG_SEC,"invalid MSG5");
2012 } else if (st->state==SITE_RUN) {
2013 if (process_msg5(st,buf,source,st->current.transform)) {
2014 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2015 transport_setup_msgok(st,source);
2016 create_msg6(st,st->current.transform,
2017 st->current.remote_session_id);
2018 transport_xmit(st,&st->peers,&st->buffer,True);
2019 BUF_FREE(&st->buffer);
2021 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2024 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2028 /* Setup packet: expected only in state SENTMSG5 */
2029 if (st->state!=SITE_SENTMSG5) {
2030 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2031 } else if (process_msg6(st,buf,source)) {
2032 BUF_FREE(&st->buffer); /* Free message 5 */
2033 transport_setup_msgok(st,source);
2034 activate_new_key(st);
2036 slog(st,LOG_SEC,"invalid MSG6");
2040 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2051 static void site_control(void *vst, bool_t run)
2053 struct site *st=vst;
2054 if (run) enter_state_run(st);
2055 else enter_state_stop(st);
2058 static void site_phase_hook(void *sst, uint32_t newphase)
2060 struct site *st=sst;
2062 /* The program is shutting down; tell our peer */
2063 send_msg7(st,"shutting down");
2066 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2068 struct site *st=sst;
2069 dispose_transform(&st->current.transform);
2070 dispose_transform(&st->auxiliary_key.transform);
2071 dispose_transform(&st->new_transform);
2072 /* Not much point overwiting the signing key, since we loaded it
2073 from disk, and it is only valid prospectively if at all,
2075 /* XXX it would be best to overwrite the DH state, because that
2076 _is_ relevant to forward secrecy. However we have no
2077 convenient interface for doing that and in practice gmp has
2078 probably dribbled droppings all over the malloc arena. A good
2079 way to fix this would be to have a privsep child for asymmetric
2080 crypto operations, but that's a task for another day. */
2083 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2086 static uint32_t index_sequence;
2094 st->cl.description="site";
2095 st->cl.type=CL_SITE;
2097 st->cl.interface=&st->ops;
2099 st->ops.control=site_control;
2100 st->ops.status=site_status;
2102 /* First parameter must be a dict */
2103 item=list_elem(args,0);
2104 if (!item || item->type!=t_dict)
2105 cfgfatal(loc,"site","parameter must be a dictionary\n");
2107 dict=item->data.dict;
2108 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2109 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2111 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2113 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2115 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2117 /* Sanity check (which also allows the 'sites' file to include
2118 site() closures for all sites including our own): refuse to
2119 talk to ourselves */
2120 if (strcmp(st->localname,st->remotename)==0) {
2121 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2123 if (st->peer_mobile != st->local_mobile)
2124 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2125 " but our local-mobile=%d\n",
2126 st->localname, st->peer_mobile, st->local_mobile);
2130 if (st->peer_mobile && st->local_mobile) {
2131 Message(M_WARNING,"site %s: site is mobile but so are we"
2132 " -> ignoring this site\n", st->remotename);
2137 assert(index_sequence < 0xffffffffUL);
2138 st->index = ++index_sequence;
2139 st->local_capabilities = 0;
2140 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2141 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2143 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2144 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2145 if (!things##_cfg) \
2146 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2147 st->nthings=list_length(things##_cfg); \
2148 NEW_ARY(st->things,st->nthings); \
2149 assert(st->nthings); \
2150 for (i=0; i<st->nthings; i++) { \
2151 item_t *item=list_elem(things##_cfg,i); \
2152 if (item->type!=t_closure) \
2153 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2154 closure_t *cl=item->data.closure; \
2155 if (cl->type!=CL_TYPE) \
2156 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2157 st->things[i]=cl->interface; \
2161 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2163 NEW_ARY(st->commclientinfos, st->ncomms);
2164 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2165 for (i=0; i<st->ncomms; i++) {
2166 st->commclientinfos[i] =
2168 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2171 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2172 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2173 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2175 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2176 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2178 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2179 else st->remoteport=0;
2180 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2182 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2184 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2186 if (st->privkey->sethash || st->pubkey->sethash) {
2187 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2188 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2189 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2192 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2193 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2194 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2196 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2197 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2198 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2199 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2200 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2202 st->mobile_peer_expiry= dict_read_number(
2203 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2205 const char *peerskey= st->peer_mobile
2206 ? "mobile-peers-max" : "static-peers-max";
2207 st->transport_peers_max= dict_read_number(
2208 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2209 if (st->transport_peers_max<1 ||
2210 st->transport_peers_max>MAX_PEER_ADDRS) {
2211 cfgfatal(loc,"site", "%s must be in range 1.."
2212 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2215 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2216 st->key_renegotiate_time=st->key_lifetime/2;
2218 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2219 st->key_renegotiate_time=dict_read_number(
2220 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2221 if (st->key_renegotiate_time > st->key_lifetime) {
2222 cfgfatal(loc,"site",
2223 "renegotiate-time must be less than key-lifetime\n");
2226 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2227 log_event_table,"site");
2229 st->resolving_count=0;
2230 st->allow_send_prod=0;
2232 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2234 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2236 /* The information we expect to see in incoming messages of type 1 */
2237 /* fixme: lots of unchecked overflows here, but the results are only
2238 corrupted packets rather than undefined behaviour */
2239 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2241 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2243 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2244 BUF_ALLOC(&st->scratch,"site:scratch");
2246 /* We are interested in poll(), but only for timeouts. We don't have
2247 any fds of our own. */
2248 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2251 st->remote_capabilities=0;
2252 st->chosen_transform=0;
2253 st->current.key_timeout=0;
2254 st->auxiliary_key.key_timeout=0;
2255 transport_peers_clear(st,&st->peers);
2256 transport_peers_clear(st,&st->setup_peers);
2257 /* XXX mlock these */
2258 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2259 st->sharedsecretlen=st->sharedsecretallocd=0;
2262 #define SET_CAPBIT(bit) do { \
2263 uint32_t capflag = 1UL << (bit); \
2264 if (st->local_capabilities & capflag) \
2265 slog(st,LOG_ERROR,"capability bit" \
2266 " %d (%#"PRIx32") reused", (bit), capflag); \
2267 st->local_capabilities |= capflag; \
2270 for (i=0; i<st->ntransforms; i++)
2271 SET_CAPBIT(st->transforms[i]->capab_bit);
2275 if (st->local_mobile || st->peer_mobile)
2276 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2278 /* We need to register the remote networks with the netlink device */
2279 uint32_t netlink_mtu; /* local virtual interface mtu */
2280 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2281 if (!st->mtu_target)
2282 st->mtu_target=netlink_mtu;
2284 for (i=0; i<st->ncomms; i++)
2285 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2287 st->current.transform=0;
2288 st->auxiliary_key.transform=0;
2289 st->new_transform=0;
2290 st->auxiliary_is_new=0;
2292 enter_state_stop(st);
2294 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2295 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2297 return new_closure(&st->cl);
2300 void site_module(dict_t *dict)
2302 add_closure(dict,"site",site_apply);
2306 /***** TRANSPORT PEERS definitions *****/
2308 static void transport_peers_debug(struct site *st, transport_peers *dst,
2309 const char *didwhat,
2310 int nargs, const struct comm_addr *args,
2315 if (!(st->log_events & LOG_PEER_ADDRS))
2316 return; /* an optimisation */
2318 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2319 (dst==&st->peers ? "data" :
2320 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2321 didwhat, nargs, dst->npeers);
2323 for (i=0, argp=(void*)args;
2325 i++, (argp+=stride?stride:sizeof(*args))) {
2326 const struct comm_addr *ca=(void*)argp;
2327 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2328 i, comm_addr_to_string(ca));
2330 for (i=0; i<dst->npeers; i++) {
2331 struct timeval diff;
2332 timersub(tv_now,&dst->peers[i].last,&diff);
2333 const struct comm_addr *ca=&dst->peers[i].addr;
2334 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2335 i, comm_addr_to_string(ca),
2336 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2340 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2341 /* peers must be sorted first */
2342 int previous_peers=peers->npeers;
2343 struct timeval oldest;
2344 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2345 oldest.tv_usec = tv_now->tv_usec;
2346 while (peers->npeers>1 &&
2347 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2349 if (peers->npeers != previous_peers)
2350 transport_peers_debug(st,peers,"expire", 0,0,0);
2353 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2354 const struct comm_addr *ca,
2355 const struct timeval *tv) {
2356 /* returns false if output is full */
2359 if (peers->npeers >= st->transport_peers_max)
2362 for (search=0; search<peers->npeers; search++)
2363 if (comm_addr_equal(&peers->peers[search].addr, ca))
2366 peers->peers[peers->npeers].addr = *ca;
2367 peers->peers[peers->npeers].last = *tv;
2372 static void transport_record_peers(struct site *st, transport_peers *peers,
2373 const struct comm_addr *addrs, int naddrs,
2375 /* We add addrs into peers. The new entries end up at the front
2376 * and displace entries towards the end (perhaps even off the
2377 * end). Any existing matching entries are moved up to the front.
2379 * Caller must first call transport_peers_expire. */
2382 /* avoids debug for uninteresting updates */
2384 for (i=0; i<peers->npeers; i++) {
2385 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2386 memmove(peers->peers+1, peers->peers,
2387 sizeof(peers->peers[0]) * i);
2388 peers->peers[0].addr = addrs[0];
2389 peers->peers[0].last = *tv_now;
2395 int old_npeers=peers->npeers;
2396 transport_peer old_peers[old_npeers];
2397 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2401 for (i=0; i<naddrs; i++) {
2402 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2405 for (i=0; i<old_npeers; i++) {
2406 const transport_peer *old=&old_peers[i];
2407 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2411 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2414 static void transport_expire_record_peers(struct site *st,
2415 transport_peers *peers,
2416 const struct comm_addr *addrs,
2417 int naddrs, const char *m) {
2418 /* Convenience function */
2419 transport_peers_expire(st,peers);
2420 transport_record_peers(st,peers,addrs,naddrs,m);
2423 static bool_t transport_compute_setupinit_peers(struct site *st,
2424 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2425 int n_configured_addrs /* 0 if none or not found */,
2426 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2427 if (!n_configured_addrs && !incoming_packet_addr &&
2428 !transport_peers_valid(&st->peers))
2431 slog(st,LOG_SETUP_INIT,
2432 "using: %d configured addr(s);%s %d old peer addrs(es)",
2434 incoming_packet_addr ? " incoming packet address;" : "",
2437 /* Non-mobile peers try addresses until one is plausible. The
2438 * effect is that this code always tries first the configured
2439 * address if supplied, or otherwise the address of the incoming
2440 * PROD, or finally the existing data peer if one exists; this is
2443 transport_peers_copy(st,&st->setup_peers,&st->peers);
2444 transport_peers_expire(st,&st->setup_peers);
2446 if (incoming_packet_addr)
2447 transport_record_peers(st,&st->setup_peers,
2448 incoming_packet_addr,1, "incoming");
2450 if (n_configured_addrs)
2451 transport_record_peers(st,&st->setup_peers,
2452 configured_addrs,n_configured_addrs, "setupinit");
2454 assert(transport_peers_valid(&st->setup_peers));
2458 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2459 if (st->peer_mobile)
2460 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2462 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2463 if (st->peer_mobile)
2464 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2467 static int transport_peers_valid(transport_peers *peers) {
2468 return peers->npeers;
2470 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2472 transport_peers_debug(st,peers,"clear",0,0,0);
2474 static void transport_peers_copy(struct site *st, transport_peers *dst,
2475 const transport_peers *src) {
2476 dst->npeers=src->npeers;
2477 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2478 transport_peers_debug(st,dst,"copy",
2479 src->npeers, &src->peers->addr, sizeof(*src->peers));
2482 static void transport_resolve_complete(struct site *st,
2483 const struct comm_addr *addrs,
2485 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2487 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2491 static void transport_resolve_complete_tardy(struct site *st,
2492 const struct comm_addr *addrs,
2494 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2495 "resolved tardily");
2498 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2500 const transport_peers *inp) {
2501 /* out and in->peers may be the same region, or nonoverlapping */
2502 const transport_peer *in=inp->peers;
2504 for (slot=0; slot<inp->npeers; slot++) {
2505 if (!(mask & (1U << slot)))
2507 if (!(out==in && slot==*nout_io))
2508 COPY_OBJ(out[*nout_io], in[slot]);
2513 void transport_xmit(struct site *st, transport_peers *peers,
2514 struct buffer_if *buf, bool_t candebug) {
2516 transport_peers_expire(st, peers);
2517 unsigned failed=0; /* bitmask */
2518 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2521 for (slot=0; slot<peers->npeers; slot++) {
2522 transport_peer *peer=&peers->peers[slot];
2523 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2525 dump_packet(st, buf, &peer->addr, False, ok);
2527 failed |= 1U << slot;
2530 if (ok && !st->peer_mobile)
2533 /* Now we need to demote/delete failing addrs: if we are mobile we
2534 * merely demote them; otherwise we delete them. */
2535 if (st->local_mobile) {
2536 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2537 /* `expected' has all the failures at the end already */
2538 if (failed != expected) {
2540 transport_peer failedpeers[nfailed];
2541 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2542 assert(fslot == nfailed);
2544 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2545 assert(wslot+nfailed == peers->npeers);
2546 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2547 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2550 if (failed && peers->npeers > 1) {
2552 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2553 peers->npeers=wslot;
2554 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2559 /***** END of transport peers declarations *****/