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;
320 struct hash_if *hash;
322 uint32_t index; /* Index of this site */
323 uint32_t early_capabilities;
324 uint32_t local_capabilities;
325 int32_t setup_retries; /* How many times to send setup packets */
326 int32_t setup_retry_interval; /* Initial timeout for setup packets */
327 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
328 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
329 int32_t key_lifetime; /* How long a key lasts once set up */
330 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
331 after this time, initiate a new
334 bool_t our_name_later; /* our name > peer name */
337 /* runtime information */
339 uint64_t now; /* Most recently seen time */
340 bool_t allow_send_prod;
341 bool_t msg1_crossed_logged;
343 int resolving_n_results_all;
344 int resolving_n_results_stored;
345 struct comm_addr resolving_results[MAX_PEER_ADDRS];
347 /* The currently established session */
348 struct data_key current;
349 struct data_key auxiliary_key;
350 bool_t auxiliary_is_new;
351 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
352 uint64_t auxiliary_renegotiate_key_time;
353 transport_peers peers; /* Current address(es) of peer for data traffic */
355 /* The current key setup protocol exchange. We can only be
356 involved in one of these at a time. There's a potential for
357 denial of service here (the attacker keeps sending a setup
358 packet; we keep trying to continue the exchange, and have to
359 timeout before we can listen for another setup packet); perhaps
360 we should keep a list of 'bad' sources for setup packets. */
361 uint32_t remote_capabilities;
362 uint16_t remote_adv_mtu;
363 struct transform_if *chosen_transform;
364 uint32_t setup_session_id;
365 transport_peers setup_peers;
366 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
367 uint8_t remoteN[NONCELEN];
368 struct buffer_if buffer; /* Current outgoing key exchange packet */
369 struct buffer_if scratch;
370 int32_t retries; /* Number of retries remaining */
371 uint64_t timeout; /* Timeout for current state */
373 uint8_t *sharedsecret;
374 uint32_t sharedsecretlen, sharedsecretallocd;
375 struct transform_inst_if *new_transform; /* For key setup/verify */
378 static uint32_t event_log_priority(struct site *st, uint32_t event)
380 if (!(event&st->log_events))
383 case LOG_UNEXPECTED: return M_INFO;
384 case LOG_SETUP_INIT: return M_INFO;
385 case LOG_SETUP_TIMEOUT: return M_NOTICE;
386 case LOG_ACTIVATE_KEY: return M_INFO;
387 case LOG_TIMEOUT_KEY: return M_INFO;
388 case LOG_SEC: return M_SECURITY;
389 case LOG_STATE: return M_DEBUG;
390 case LOG_DROP: return M_DEBUG;
391 case LOG_DUMP: return M_DEBUG;
392 case LOG_ERROR: return M_ERR;
393 case LOG_PEER_ADDRS: return M_DEBUG;
394 default: return M_ERR;
398 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
400 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
404 class=event_log_priority(st, event);
406 slilog_part(st->log,class,"%s: ",st->tunname);
407 vslilog_part(st->log,class,msg,ap);
408 slilog_part(st->log,class,"\n");
412 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
414 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
418 vslog(st,event,msg,ap);
422 static void logtimeout(struct site *st, const char *fmt, ...)
424 static void logtimeout(struct site *st, const char *fmt, ...)
426 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
433 slilog_part(st->log,class,"%s: ",st->tunname);
434 vslilog_part(st->log,class,fmt,ap);
438 for (i=0, delim=" (tried ";
439 i<st->setup_peers.npeers;
441 transport_peer *peer=&st->setup_peers.peers[i];
442 const char *s=comm_addr_to_string(&peer->addr);
443 slilog_part(st->log,class,"%s%s",delim,s);
446 slilog_part(st->log,class,")\n");
450 static void set_link_quality(struct site *st);
451 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
452 static void delete_one_key(struct site *st, struct data_key *key,
453 const char *reason /* may be 0 meaning don't log*/,
454 const char *which /* ignored if !reasonn */,
455 uint32_t loglevel /* ignored if !reasonn */);
456 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
457 const struct comm_addr *prod_hint);
458 static void enter_state_run(struct site *st);
459 static bool_t enter_state_resolve(struct site *st);
460 static void decrement_resolving_count(struct site *st, int by);
461 static bool_t enter_new_state(struct site *st,uint32_t next);
462 static void enter_state_wait(struct site *st);
463 static void activate_new_key(struct site *st);
465 static bool_t is_transform_valid(struct transform_inst_if *transform)
467 return transform && transform->valid(transform->st);
470 static bool_t current_valid(struct site *st)
472 return is_transform_valid(st->current.transform);
475 #define DEFINE_CALL_TRANSFORM(fwdrev) \
476 static transform_apply_return \
477 call_transform_##fwdrev(struct site *st, \
478 struct transform_inst_if *transform, \
479 struct buffer_if *buf, \
480 const char **errmsg) \
482 if (!is_transform_valid(transform)) { \
483 *errmsg="transform not set up"; \
484 return transform_apply_err; \
486 return transform->fwdrev(transform->st,buf,errmsg); \
489 DEFINE_CALL_TRANSFORM(forwards)
490 DEFINE_CALL_TRANSFORM(reverse)
492 static void dispose_transform(struct transform_inst_if **transform_var)
494 struct transform_inst_if *transform=*transform_var;
496 transform->delkey(transform->st);
497 transform->destroy(transform->st);
502 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
503 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
504 #define CHECK_TYPE(b,t) do { uint32_t type; \
505 CHECK_AVAIL((b),4); \
506 type=buf_unprepend_uint32((b)); \
507 if (type!=(t)) return False; } while(0)
509 static _Bool type_is_msg34(uint32_t type)
512 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
513 default: return False;
520 struct buffer_if extrainfo;
527 struct parsedname remote;
528 struct parsedname local;
529 uint32_t remote_capabilities;
531 int capab_transformnum;
541 static int32_t wait_timeout(struct site *st) {
542 int32_t t = st->wait_timeout_mean;
545 st->random->generate(st->random->st,sizeof(factor),&factor);
546 t += (t / 256) * factor;
551 static _Bool set_new_transform(struct site *st, char *pk)
555 /* Make room for the shared key */
556 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
557 assert(st->sharedsecretlen);
558 if (st->sharedsecretlen > st->sharedsecretallocd) {
559 st->sharedsecretallocd=st->sharedsecretlen;
560 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
561 st->sharedsecretallocd,
562 "site:sharedsecret");
565 /* Generate the shared key */
566 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
567 st->sharedsecret,st->sharedsecretlen);
569 /* Set up the transform */
570 struct transform_if *generator=st->chosen_transform;
571 struct transform_inst_if *generated=generator->create(generator->st);
572 ok = generated->setkey(generated->st,st->sharedsecret,
573 st->sharedsecretlen,st->our_name_later);
575 dispose_transform(&st->new_transform);
576 if (!ok) return False;
577 st->new_transform=generated;
579 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
580 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
581 st->chosen_transform->capab_bit,
582 st->local_capabilities, st->remote_capabilities);
587 int32_t lenpos, afternul;
589 static void append_string_xinfo_start(struct buffer_if *buf,
590 struct xinfoadd *xia,
592 /* Helps construct one of the names with additional info as found
593 * in MSG1..4. Call this function first, then append all the
594 * desired extra info (not including the nul byte) to the buffer,
595 * then call append_string_xinfo_done. */
597 xia->lenpos = buf->size;
598 buf_append_string(buf,str);
599 buf_append_uint8(buf,0);
600 xia->afternul = buf->size;
602 static void append_string_xinfo_done(struct buffer_if *buf,
603 struct xinfoadd *xia)
605 /* we just need to adjust the string length */
606 if (buf->size == xia->afternul) {
607 /* no extra info, strip the nul too */
608 buf_unappend_uint8(buf);
610 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
614 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
615 out using a transform of config data supplied by netlink */
616 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
623 st->retries=st->setup_retries;
624 BUF_ALLOC(&st->buffer,what);
625 buffer_init(&st->buffer,0);
626 buf_append_uint32(&st->buffer,
627 (type==LABEL_MSG1?0:st->setup_session_id));
628 buf_append_uint32(&st->buffer,st->index);
629 buf_append_uint32(&st->buffer,type);
632 append_string_xinfo_start(&st->buffer,&xia,st->localname);
633 if ((st->local_capabilities & st->early_capabilities) ||
634 (type != LABEL_MSG1)) {
635 buf_append_uint32(&st->buffer,st->local_capabilities);
637 if (type_is_msg34(type)) {
638 buf_append_uint16(&st->buffer,st->mtu_target);
640 append_string_xinfo_done(&st->buffer,&xia);
642 buf_append_string(&st->buffer,st->remotename);
643 BUF_ADD_OBJ(append,&st->buffer,st->localN);
644 if (type==LABEL_MSG1) return True;
645 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
646 if (type==LABEL_MSG2) return True;
648 if (hacky_par_mid_failnow()) return False;
650 if (MSGMAJOR(type) == 3) do {
651 minor = MSGMINOR(type);
652 if (minor < 1) break;
653 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
656 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
657 buf_append_string(&st->buffer,dhpub);
659 hash=safe_malloc(st->hash->len, "generate_msg");
660 hst=st->hash->init();
661 st->hash->update(hst,st->buffer.start,st->buffer.size);
662 st->hash->final(hst,hash);
663 bool_t ok=st->privkey->sign(st->privkey->st,hash,st->hash->len,
674 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
677 nm->len=buf_unprepend_uint16(msg);
678 CHECK_AVAIL(msg,nm->len);
679 nm->name=buf_unprepend(msg,nm->len);
680 uint8_t *nul=memchr(nm->name,0,nm->len);
682 buffer_readonly_view(&nm->extrainfo,0,0);
684 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
685 nm->len=nul-nm->name;
690 static bool_t unpick_msg(struct site *st, uint32_t type,
691 struct buffer_if *msg, struct msg *m)
695 m->capab_transformnum=-1;
696 m->hashstart=msg->start;
698 m->dest=buf_unprepend_uint32(msg);
700 m->source=buf_unprepend_uint32(msg);
701 CHECK_TYPE(msg,type);
702 if (!unpick_name(msg,&m->remote)) return False;
703 m->remote_capabilities=0;
705 if (m->remote.extrainfo.size) {
706 CHECK_AVAIL(&m->remote.extrainfo,4);
707 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
709 if (type_is_msg34(type) && m->remote.extrainfo.size) {
710 CHECK_AVAIL(&m->remote.extrainfo,2);
711 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
713 if (!unpick_name(msg,&m->local)) return False;
714 if (type==LABEL_PROD) {
718 CHECK_AVAIL(msg,NONCELEN);
719 m->nR=buf_unprepend(msg,NONCELEN);
720 if (type==LABEL_MSG1) {
724 CHECK_AVAIL(msg,NONCELEN);
725 m->nL=buf_unprepend(msg,NONCELEN);
726 if (type==LABEL_MSG2) {
730 if (MSGMAJOR(type) == 3) do {
731 minor = MSGMINOR(type);
732 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
733 if (minor < (minminor)) \
734 m->capab_##kind##num = (dflt); \
736 CHECK_AVAIL(msg, 1); \
737 m->capab_##kind##num = buf_unprepend_uint8(msg); \
740 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
741 #undef MAYBE_READ_CAP
744 m->pklen=buf_unprepend_uint16(msg);
745 CHECK_AVAIL(msg,m->pklen);
746 m->pk=buf_unprepend(msg,m->pklen);
747 m->hashlen=msg->start-m->hashstart;
749 m->siglen=buf_unprepend_uint16(msg);
750 CHECK_AVAIL(msg,m->siglen);
751 m->sig=buf_unprepend(msg,m->siglen);
754 /* In `process_msg3_msg4' below, we assume that we can write a nul
755 * terminator following the signature. Make sure there's enough space.
757 if (msg->start >= msg->base + msg->alloclen)
763 static bool_t name_matches(const struct parsedname *nm, const char *expected)
765 int expected_len=strlen(expected);
767 nm->len == expected_len &&
768 !memcmp(nm->name, expected, expected_len);
771 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
774 if (type==LABEL_MSG1) return True;
776 /* Check that the site names and our nonce have been sent
777 back correctly, and then store our peer's nonce. */
778 if (!name_matches(&m->remote,st->remotename)) {
779 *error="wrong remote site name";
782 if (!name_matches(&m->local,st->localname)) {
783 *error="wrong local site name";
786 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
787 *error="wrong locally-generated nonce";
790 if (type==LABEL_MSG2) return True;
791 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
792 *error="wrong remotely-generated nonce";
795 /* MSG3 has complicated rules about capabilities, which are
796 * handled in process_msg3. */
797 if (MSGMAJOR(type) == 3) return True;
798 if (m->remote_capabilities!=st->remote_capabilities) {
799 *error="remote capabilities changed";
802 if (type==LABEL_MSG4) return True;
803 *error="unknown message type";
807 static bool_t generate_msg1(struct site *st)
809 st->random->generate(st->random->st,NONCELEN,st->localN);
810 return generate_msg(st,LABEL_MSG1,"site:MSG1");
813 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
814 const struct comm_addr *src, struct msg *m)
816 /* We've already determined we're in an appropriate state to
817 process an incoming MSG1, and that the MSG1 has correct values
820 st->setup_session_id=m->source;
821 st->remote_capabilities=m->remote_capabilities;
822 memcpy(st->remoteN,m->nR,NONCELEN);
826 static bool_t generate_msg2(struct site *st)
828 st->random->generate(st->random->st,NONCELEN,st->localN);
829 return generate_msg(st,LABEL_MSG2,"site:MSG2");
832 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
833 const struct comm_addr *src)
838 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
839 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
840 slog(st,LOG_SEC,"msg2: %s",err);
843 st->setup_session_id=m.source;
844 st->remote_capabilities=m.remote_capabilities;
846 /* Select the transform to use */
848 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
849 if (!remote_crypto_caps)
850 /* old secnets only had this one transform */
851 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
853 #define CHOOSE_CRYPTO(kind, whats) do { \
854 struct kind##_if *iface; \
855 uint32_t bit, ours = 0; \
857 for (i= 0; i < st->n##kind##s; i++) { \
858 iface=st->kind##s[i]; \
859 bit = 1UL << iface->capab_bit; \
860 if (bit & remote_crypto_caps) goto kind##_found; \
863 slog(st,LOG_ERROR,"no " whats " in common" \
864 " (us %#"PRIx32"; them: %#"PRIx32")", \
865 st->local_capabilities & ours, remote_crypto_caps); \
868 st->chosen_##kind = iface; \
871 CHOOSE_CRYPTO(transform, "transforms");
875 memcpy(st->remoteN,m.nR,NONCELEN);
879 static bool_t generate_msg3(struct site *st)
881 /* Now we have our nonce and their nonce. Think of a secret key,
882 and create message number 3. */
883 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
884 return generate_msg(st,
885 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
891 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
896 /* Check signature and store g^x mod m */
897 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
898 hst=st->hash->init();
899 st->hash->update(hst,m->hashstart,m->hashlen);
900 st->hash->final(hst,hash);
901 /* Terminate signature with a '0' - already checked that this will fit */
903 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
904 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
910 st->remote_adv_mtu=m->remote_mtu;
915 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
916 const struct comm_addr *src, uint32_t msgtype)
922 case CASES_MSG3_KNOWN: break;
926 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
927 if (!check_msg(st,msgtype,&m,&err)) {
928 slog(st,LOG_SEC,"msg3: %s",err);
931 uint32_t capab_adv_late = m.remote_capabilities
932 & ~st->remote_capabilities & st->early_capabilities;
933 if (capab_adv_late) {
934 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
935 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
936 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
940 #define CHOSE_CRYPTO(kind, what) do { \
941 struct kind##_if *iface; \
943 for (i=0; i<st->n##kind##s; i++) { \
944 iface=st->kind##s[i]; \
945 if (iface->capab_bit == m.capab_##kind##num) \
948 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
949 m.capab_##kind##num); \
952 st->chosen_##kind=iface; \
955 CHOSE_CRYPTO(transform, "transform");
959 if (!process_msg3_msg4(st,&m))
962 /* Update our idea of the remote site's capabilities, now that we've
963 * verified that its message was authentic.
965 * Our previous idea of the remote site's capabilities came from the
966 * unauthenticated MSG1. We've already checked that this new message
967 * doesn't change any of the bits we relied upon in the past, but it may
968 * also have set additional capability bits. We simply throw those away
969 * now, and use the authentic capabilities from this MSG3. */
970 st->remote_capabilities=m.remote_capabilities;
972 /* Terminate their DH public key with a '0' */
974 /* Invent our DH secret key */
975 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
977 /* Generate the shared key and set up the transform */
978 if (!set_new_transform(st,m.pk)) return False;
983 static bool_t generate_msg4(struct site *st)
985 /* We have both nonces, their public key and our private key. Generate
986 our public key, sign it and send it to them. */
987 return generate_msg(st,LABEL_MSG4,"site:MSG4");
990 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
991 const struct comm_addr *src)
996 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
997 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
998 slog(st,LOG_SEC,"msg4: %s",err);
1002 if (!process_msg3_msg4(st,&m))
1005 /* Terminate their DH public key with a '0' */
1008 /* Generate the shared key and set up the transform */
1009 if (!set_new_transform(st,m.pk)) return False;
1020 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1023 CHECK_AVAIL(msg0,4);
1024 m->dest=buf_unprepend_uint32(msg0);
1025 CHECK_AVAIL(msg0,4);
1026 m->source=buf_unprepend_uint32(msg0);
1027 CHECK_AVAIL(msg0,4);
1028 m->type=buf_unprepend_uint32(msg0);
1030 /* Leaves transformed part of buffer untouched */
1033 static bool_t generate_msg5(struct site *st)
1035 cstring_t transform_err;
1037 BUF_ALLOC(&st->buffer,"site:MSG5");
1038 /* We are going to add four words to the message */
1039 buffer_init(&st->buffer,calculate_max_start_pad());
1040 /* Give the netlink code an opportunity to put its own stuff in the
1041 message (configuration information, etc.) */
1042 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1043 if (call_transform_forwards(st,st->new_transform,
1044 &st->buffer,&transform_err))
1046 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1047 buf_prepend_uint32(&st->buffer,st->index);
1048 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1050 st->retries=st->setup_retries;
1054 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1055 const struct comm_addr *src,
1056 struct transform_inst_if *transform)
1059 cstring_t transform_err;
1061 if (!unpick_msg0(st,msg5,&m)) return False;
1063 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1064 /* There's a problem */
1065 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1068 /* Buffer should now contain untransformed PING packet data */
1069 CHECK_AVAIL(msg5,4);
1070 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1071 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1074 /* Older versions of secnet used to write some config data here
1075 * which we ignore. So we don't CHECK_EMPTY */
1079 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1080 uint32_t session_id)
1082 cstring_t transform_err;
1084 BUF_ALLOC(&st->buffer,"site:MSG6");
1085 /* We are going to add four words to the message */
1086 buffer_init(&st->buffer,calculate_max_start_pad());
1087 /* Give the netlink code an opportunity to put its own stuff in the
1088 message (configuration information, etc.) */
1089 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1090 transform_apply_return problem =
1091 call_transform_forwards(st,transform,
1092 &st->buffer,&transform_err);
1094 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1095 buf_prepend_uint32(&st->buffer,st->index);
1096 buf_prepend_uint32(&st->buffer,session_id);
1099 static bool_t generate_msg6(struct site *st)
1101 if (!is_transform_valid(st->new_transform))
1103 create_msg6(st,st->new_transform,st->setup_session_id);
1104 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1108 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1109 const struct comm_addr *src)
1112 cstring_t transform_err;
1114 if (!unpick_msg0(st,msg6,&m)) return False;
1116 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1117 /* There's a problem */
1118 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1121 /* Buffer should now contain untransformed PING packet data */
1122 CHECK_AVAIL(msg6,4);
1123 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1124 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1127 /* Older versions of secnet used to write some config data here
1128 * which we ignore. So we don't CHECK_EMPTY */
1132 static transform_apply_return
1133 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1134 const struct comm_addr *src)
1136 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1138 transform_apply_return problem;
1140 if (!unpick_msg0(st,msg0,&m)) return False;
1142 /* Keep a copy so we can try decrypting it with multiple keys */
1143 buffer_copy(&st->scratch, msg0);
1145 problem = call_transform_reverse(st,st->current.transform,
1146 msg0,&transform_err);
1148 if (!st->auxiliary_is_new)
1149 delete_one_key(st,&st->auxiliary_key,
1150 "peer has used new key","auxiliary key",LOG_SEC);
1153 if (transform_apply_return_badseq(problem))
1156 buffer_copy(msg0, &st->scratch);
1157 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1160 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1161 if (st->auxiliary_is_new) {
1162 /* We previously timed out in state SENTMSG5 but it turns
1163 * out that our peer did in fact get our MSG5 and is
1164 * using the new key. So we should switch to it too. */
1165 /* This is a bit like activate_new_key. */
1168 st->current=st->auxiliary_key;
1169 st->auxiliary_key=t;
1171 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1172 "previous key",LOG_SEC);
1173 st->auxiliary_is_new=0;
1174 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1178 if (transform_apply_return_badseq(problem))
1181 if (st->state==SITE_SENTMSG5) {
1182 buffer_copy(msg0, &st->scratch);
1183 problem = call_transform_reverse(st,st->new_transform,
1186 /* It looks like we didn't get the peer's MSG6 */
1187 /* This is like a cut-down enter_new_state(SITE_RUN) */
1188 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1189 BUF_FREE(&st->buffer);
1191 activate_new_key(st);
1192 return 0; /* do process the data in this packet */
1194 if (transform_apply_return_badseq(problem))
1198 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1199 transform_err,auxkey_err,newkey_err);
1200 initiate_key_setup(st,"incoming message would not decrypt",0);
1201 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1206 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1211 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1212 const struct comm_addr *src)
1215 transform_apply_return problem;
1217 problem = decrypt_msg0(st,msg0,src);
1218 if (problem==transform_apply_seqdupe) {
1219 /* We recently received another copy of this packet, maybe due
1220 * to polypath. That's not a problem; indeed, for the
1221 * purposes of transport address management it is a success.
1222 * But we don't want to process the packet. */
1223 transport_data_msgok(st,src);
1229 CHECK_AVAIL(msg0,4);
1230 type=buf_unprepend_uint32(msg0);
1233 /* We must forget about the current session. */
1234 delete_keys(st,"request from peer",LOG_SEC);
1235 /* probably, the peer is shutting down, and this is going to fail,
1236 * but we need to be trying to bring the link up again */
1238 initiate_key_setup(st,"peer requested key teardown",0);
1241 /* Deliver to netlink layer */
1242 st->netlink->deliver(st->netlink->st,msg0);
1243 transport_data_msgok(st,src);
1244 /* See whether we should start negotiating a new key */
1245 if (st->now > st->renegotiate_key_time)
1246 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1249 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1256 static void dump_packet(struct site *st, struct buffer_if *buf,
1257 const struct comm_addr *addr, bool_t incoming,
1260 uint32_t dest=get_uint32(buf->start);
1261 uint32_t source=get_uint32(buf->start+4);
1262 uint32_t msgtype=get_uint32(buf->start+8);
1264 if (st->log_events & LOG_DUMP)
1265 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1266 st->tunname,incoming?"incoming":"outgoing",
1267 dest,source,msgtype,comm_addr_to_string(addr),
1271 static bool_t comm_addr_sendmsg(struct site *st,
1272 const struct comm_addr *dest,
1273 struct buffer_if *buf)
1276 struct comm_clientinfo *commclientinfo = 0;
1278 for (i=0; i < st->ncomms; i++) {
1279 if (st->comms[i] == dest->comm) {
1280 commclientinfo = st->commclientinfos[i];
1284 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1287 static uint32_t site_status(void *st)
1292 static bool_t send_msg(struct site *st)
1294 if (st->retries>0) {
1295 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1296 st->timeout=st->now+st->setup_retry_interval;
1299 } else if (st->state==SITE_SENTMSG5) {
1300 logtimeout(st,"timed out sending MSG5, stashing new key");
1301 /* We stash the key we have produced, in case it turns out that
1302 * our peer did see our MSG5 after all and starts using it. */
1303 /* This is a bit like some of activate_new_key */
1304 struct transform_inst_if *t;
1305 t=st->auxiliary_key.transform;
1306 st->auxiliary_key.transform=st->new_transform;
1307 st->new_transform=t;
1308 dispose_transform(&st->new_transform);
1310 st->auxiliary_is_new=1;
1311 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1312 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1313 st->auxiliary_key.remote_session_id=st->setup_session_id;
1315 enter_state_wait(st);
1318 logtimeout(st,"timed out sending key setup packet "
1319 "(in state %s)",state_name(st->state));
1320 enter_state_wait(st);
1325 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1326 int stored_naddrs, int all_naddrs,
1327 const char *address, const char *failwhy)
1329 struct site *st=sst;
1331 if (!stored_naddrs) {
1332 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1334 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1335 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1337 int space=st->transport_peers_max-st->resolving_n_results_stored;
1338 int n_tocopy=MIN(stored_naddrs,space);
1339 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1342 st->resolving_n_results_stored += n_tocopy;
1343 st->resolving_n_results_all += all_naddrs;
1346 decrement_resolving_count(st,1);
1349 static void decrement_resolving_count(struct site *st, int by)
1351 assert(st->resolving_count>0);
1352 st->resolving_count-=by;
1354 if (st->resolving_count)
1357 /* OK, we are done with them all. Handle combined results. */
1359 const struct comm_addr *addrs=st->resolving_results;
1360 int naddrs=st->resolving_n_results_stored;
1361 assert(naddrs<=st->transport_peers_max);
1364 if (naddrs != st->resolving_n_results_all) {
1365 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1366 " yielded too many results (%d > %d), some ignored",
1367 st->resolving_n_results_all, naddrs);
1369 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1370 naddrs, iaddr_to_string(&addrs[0].ia));;
1373 switch (st->state) {
1375 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1376 enter_new_state(st,SITE_SENTMSG1);
1378 /* Can't figure out who to try to to talk to */
1379 slog(st,LOG_SETUP_INIT,
1380 "key exchange failed: cannot find peer address");
1381 enter_state_run(st);
1384 case SITE_SENTMSG1: case SITE_SENTMSG2:
1385 case SITE_SENTMSG3: case SITE_SENTMSG4:
1388 /* We start using the address immediately for data too.
1389 * It's best to store it in st->peers now because we might
1390 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1391 * the new key (without updating the data peer addrs). */
1392 transport_resolve_complete(st,addrs,naddrs);
1393 } else if (st->local_mobile) {
1394 /* We can't let this rest because we may have a peer
1395 * address which will break in the future. */
1396 slog(st,LOG_SETUP_INIT,"resolution failed: "
1397 "abandoning key exchange");
1398 enter_state_wait(st);
1400 slog(st,LOG_SETUP_INIT,"resolution failed: "
1401 " continuing to use source address of peer's packets"
1402 " for key exchange and ultimately data");
1407 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1408 " updating peer address(es)");
1409 transport_resolve_complete_tardy(st,addrs,naddrs);
1410 } else if (st->local_mobile) {
1411 /* Not very good. We should queue (another) renegotiation
1412 * so that we can update the peer address. */
1413 st->key_renegotiate_time=st->now+wait_timeout(st);
1415 slog(st,LOG_SETUP_INIT,"resolution failed: "
1416 " continuing to use source address of peer's packets");
1426 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1427 const struct comm_addr *prod_hint)
1429 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1430 if (st->state!=SITE_RUN) return False;
1431 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1432 if (st->addresses) {
1433 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1434 return enter_state_resolve(st);
1435 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1436 return enter_new_state(st,SITE_SENTMSG1);
1438 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1442 static void activate_new_key(struct site *st)
1444 struct transform_inst_if *t;
1446 /* We have three transform instances, which we swap between old,
1448 t=st->auxiliary_key.transform;
1449 st->auxiliary_key.transform=st->current.transform;
1450 st->current.transform=st->new_transform;
1451 st->new_transform=t;
1452 dispose_transform(&st->new_transform);
1455 st->auxiliary_is_new=0;
1456 st->auxiliary_key.key_timeout=st->current.key_timeout;
1457 st->current.key_timeout=st->now+st->key_lifetime;
1458 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1459 transport_peers_copy(st,&st->peers,&st->setup_peers);
1460 st->current.remote_session_id=st->setup_session_id;
1462 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1463 * But their mtu be unspecified, in which case we just use ours. */
1464 uint32_t intersite_mtu=
1465 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1466 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1468 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1469 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1470 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1471 enter_state_run(st);
1474 static void delete_one_key(struct site *st, struct data_key *key,
1475 cstring_t reason, cstring_t which, uint32_t loglevel)
1477 if (!is_transform_valid(key->transform)) return;
1478 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1479 dispose_transform(&key->transform);
1483 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1485 if (current_valid(st)) {
1486 slog(st,loglevel,"session closed (%s)",reason);
1488 delete_one_key(st,&st->current,0,0,0);
1489 set_link_quality(st);
1491 delete_one_key(st,&st->auxiliary_key,0,0,0);
1494 static void state_assert(struct site *st, bool_t ok)
1496 if (!ok) fatal("site:state_assert");
1499 static void enter_state_stop(struct site *st)
1501 st->state=SITE_STOP;
1503 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1504 dispose_transform(&st->new_transform);
1507 static void set_link_quality(struct site *st)
1510 if (current_valid(st))
1511 quality=LINK_QUALITY_UP;
1512 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1513 quality=LINK_QUALITY_DOWN;
1514 else if (st->addresses)
1515 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1516 else if (transport_peers_valid(&st->peers))
1517 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1519 quality=LINK_QUALITY_DOWN;
1521 st->netlink->set_quality(st->netlink->st,quality);
1524 static void enter_state_run(struct site *st)
1526 slog(st,LOG_STATE,"entering state RUN%s",
1527 current_valid(st) ? " (keyed)" : " (unkeyed)");
1531 st->setup_session_id=0;
1532 transport_peers_clear(st,&st->setup_peers);
1533 FILLZERO(st->localN);
1534 FILLZERO(st->remoteN);
1535 dispose_transform(&st->new_transform);
1536 memset(st->dhsecret,0,st->dh->len);
1537 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1538 set_link_quality(st);
1540 if (st->keepalive && !current_valid(st))
1541 initiate_key_setup(st, "keepalive", 0);
1544 static bool_t ensure_resolving(struct site *st)
1546 /* Reentrancy hazard: may call site_resolve_callback and hence
1547 * enter_new_state, enter_state_* and generate_msg*. */
1548 if (st->resolving_count)
1551 assert(st->addresses);
1553 /* resolver->request might reentrantly call site_resolve_callback
1554 * which will decrement st->resolving, so we need to increment it
1555 * twice beforehand to prevent decrement from thinking we're
1556 * finished, and decrement it ourselves. Alternatively if
1557 * everything fails then there are no callbacks due and we simply
1558 * set it to 0 and return false.. */
1559 st->resolving_n_results_stored=0;
1560 st->resolving_n_results_all=0;
1561 st->resolving_count+=2;
1562 const char **addrp=st->addresses;
1563 const char *address;
1565 for (; (address=*addrp++); ) {
1566 bool_t ok = st->resolver->request(st->resolver->st,address,
1567 st->remoteport,st->comms[0],
1568 site_resolve_callback,st);
1570 st->resolving_count++;
1574 st->resolving_count=0;
1577 decrement_resolving_count(st,2);
1581 static bool_t enter_state_resolve(struct site *st)
1583 /* Reentrancy hazard! See ensure_resolving. */
1584 state_assert(st,st->state==SITE_RUN);
1585 slog(st,LOG_STATE,"entering state RESOLVE");
1586 st->state=SITE_RESOLVE;
1587 return ensure_resolving(st);
1590 static bool_t enter_new_state(struct site *st, uint32_t next)
1592 bool_t (*gen)(struct site *st);
1595 slog(st,LOG_STATE,"entering state %s",state_name(next));
1598 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1600 st->msg1_crossed_logged = False;
1603 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1604 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1608 state_assert(st,st->state==SITE_SENTMSG1);
1609 BUF_FREE(&st->buffer);
1613 state_assert(st,st->state==SITE_SENTMSG2);
1614 BUF_FREE(&st->buffer);
1618 state_assert(st,st->state==SITE_SENTMSG3);
1619 BUF_FREE(&st->buffer);
1623 state_assert(st,st->state==SITE_SENTMSG4);
1624 BUF_FREE(&st->buffer);
1629 fatal("enter_new_state(%s): invalid new state",state_name(next));
1633 if (hacky_par_start_failnow()) return False;
1635 r= gen(st) && send_msg(st);
1638 st->setup_retries, st->setup_retry_interval,
1643 if (next==SITE_RUN) {
1644 BUF_FREE(&st->buffer); /* Never reused */
1645 st->timeout=0; /* Never retransmit */
1646 activate_new_key(st);
1650 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1651 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1652 in either state, and enter_state_wait() will
1654 enter_state_wait(st);
1658 /* msg7 tells our peer that we're about to forget our key */
1659 static bool_t send_msg7(struct site *st, cstring_t reason)
1661 cstring_t transform_err;
1663 if (current_valid(st) && st->buffer.free
1664 && transport_peers_valid(&st->peers)) {
1665 BUF_ALLOC(&st->buffer,"site:MSG7");
1666 buffer_init(&st->buffer,calculate_max_start_pad());
1667 buf_append_uint32(&st->buffer,LABEL_MSG7);
1668 buf_append_string(&st->buffer,reason);
1669 if (call_transform_forwards(st, st->current.transform,
1670 &st->buffer, &transform_err))
1672 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1673 buf_prepend_uint32(&st->buffer,st->index);
1674 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1675 transport_xmit(st,&st->peers,&st->buffer,True);
1676 BUF_FREE(&st->buffer);
1683 /* We go into this state if our peer becomes uncommunicative. Similar to
1684 the "stop" state, we forget all session keys for a while, before
1685 re-entering the "run" state. */
1686 static void enter_state_wait(struct site *st)
1688 slog(st,LOG_STATE,"entering state WAIT");
1689 st->timeout=st->now+wait_timeout(st);
1690 st->state=SITE_WAIT;
1691 set_link_quality(st);
1692 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1693 /* XXX Erase keys etc. */
1696 static void generate_prod(struct site *st, struct buffer_if *buf)
1699 buf_append_uint32(buf,0);
1700 buf_append_uint32(buf,0);
1701 buf_append_uint32(buf,LABEL_PROD);
1702 buf_append_string(buf,st->localname);
1703 buf_append_string(buf,st->remotename);
1706 static void generate_send_prod(struct site *st,
1707 const struct comm_addr *source)
1709 if (!st->allow_send_prod) return; /* too soon */
1710 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1711 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1713 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1714 st->allow_send_prod=0;
1715 generate_prod(st,&st->scratch);
1716 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1717 dump_packet(st,&st->scratch,source,False,ok);
1720 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1723 int64_t offset=timeout-*now;
1724 if (offset<0) offset=0;
1725 if (offset>INT_MAX) offset=INT_MAX;
1726 if (*timeout_io<0 || offset<*timeout_io)
1731 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1734 struct site *st=sst;
1736 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1739 /* Work out when our next timeout is. The earlier of 'timeout' or
1740 'current.key_timeout'. A stored value of '0' indicates no timeout
1742 site_settimeout(st->timeout, timeout_io);
1743 site_settimeout(st->current.key_timeout, timeout_io);
1744 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1746 return 0; /* success */
1749 static void check_expiry(struct site *st, struct data_key *key,
1752 if (key->key_timeout && *now>key->key_timeout) {
1753 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1757 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1758 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1760 struct site *st=sst;
1763 if (st->timeout && *now>st->timeout) {
1765 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1766 if (!hacky_par_start_failnow())
1768 } else if (st->state==SITE_WAIT) {
1769 enter_state_run(st);
1771 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1775 check_expiry(st,&st->current,"current key");
1776 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1779 /* This function is called by the netlink device to deliver packets
1780 intended for the remote network. The packet is in "raw" wire
1781 format, but is guaranteed to be word-aligned. */
1782 static void site_outgoing(void *sst, struct buffer_if *buf)
1784 struct site *st=sst;
1785 cstring_t transform_err;
1787 if (st->state==SITE_STOP) {
1792 st->allow_send_prod=1;
1794 /* In all other states we consider delivering the packet if we have
1795 a valid key and a valid address to send it to. */
1796 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1797 /* Transform it and send it */
1799 buf_prepend_uint32(buf,LABEL_MSG9);
1800 if (call_transform_forwards(st, st->current.transform,
1801 buf, &transform_err))
1803 buf_prepend_uint32(buf,LABEL_MSG0);
1804 buf_prepend_uint32(buf,st->index);
1805 buf_prepend_uint32(buf,st->current.remote_session_id);
1806 transport_xmit(st,&st->peers,buf,False);
1813 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1815 initiate_key_setup(st,"outgoing packet",0);
1818 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1819 uint32_t type, struct msg *m)
1820 /* For packets which are identified by the local and remote names.
1821 * If it has our name and our peer's name in it it's for us. */
1823 struct buffer_if buf[1];
1824 buffer_readonly_clone(buf,buf_in);
1825 return unpick_msg(st,type,buf,m)
1826 && name_matches(&m->remote,st->remotename)
1827 && name_matches(&m->local,st->localname);
1830 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1831 if (st->local_capabilities & m->remote_capabilities &
1832 CAPAB_PRIORITY_MOBILE) {
1833 if (st->local_mobile) return True;
1834 if (st-> peer_mobile) return False;
1836 return st->our_name_later;
1839 static bool_t setup_late_msg_ok(struct site *st,
1840 const struct buffer_if *buf_in,
1842 const struct comm_addr *source) {
1843 /* For setup packets which seem from their type like they are
1844 * late. Maybe they came via a different path. All we do is make
1845 * a note of the sending address, iff they look like they are part
1846 * of the current key setup attempt. */
1848 if (!named_for_us(st,buf_in,msgtype,&m))
1849 /* named_for_us calls unpick_msg which gets the nonces */
1851 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1852 !consttime_memeq(m.nL,st->localN, NONCELEN))
1853 /* spoof ? from stale run ? who knows */
1855 transport_setup_msgok(st,source);
1859 /* This function is called by the communication device to deliver
1860 packets from our peers.
1861 It should return True if the packet is recognised as being for
1862 this current site instance (and should therefore not be processed
1863 by other sites), even if the packet was otherwise ignored. */
1864 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1865 const struct comm_addr *source)
1867 struct site *st=sst;
1869 if (buf->size < 12) return False;
1871 uint32_t dest=get_uint32(buf->start);
1872 uint32_t msgtype=get_uint32(buf->start+8);
1873 struct msg named_msg;
1875 if (msgtype==LABEL_MSG1) {
1876 if (!named_for_us(st,buf,msgtype,&named_msg))
1878 /* It's a MSG1 addressed to us. Decide what to do about it. */
1879 dump_packet(st,buf,source,True,True);
1880 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1881 st->state==SITE_WAIT) {
1882 /* We should definitely process it */
1883 transport_compute_setupinit_peers(st,0,0,source);
1884 if (process_msg1(st,buf,source,&named_msg)) {
1885 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1886 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1887 if (entered && st->addresses && st->local_mobile)
1888 /* We must do this as the very last thing, because
1889 the resolver callback might reenter us. */
1890 ensure_resolving(st);
1892 slog(st,LOG_ERROR,"failed to process incoming msg1");
1896 } else if (st->state==SITE_SENTMSG1) {
1897 /* We've just sent a message 1! They may have crossed on
1898 the wire. If we have priority then we ignore the
1899 incoming one, otherwise we process it as usual. */
1900 if (we_have_priority(st,&named_msg)) {
1902 if (!st->msg1_crossed_logged++)
1903 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1904 "priority => ignore incoming msg1");
1907 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1908 "priority => use incoming msg1");
1909 if (process_msg1(st,buf,source,&named_msg)) {
1910 BUF_FREE(&st->buffer); /* Free our old message 1 */
1911 transport_setup_msgok(st,source);
1912 enter_new_state(st,SITE_SENTMSG2);
1914 slog(st,LOG_ERROR,"failed to process an incoming "
1915 "crossed msg1 (we have low priority)");
1920 } else if (st->state==SITE_SENTMSG2 ||
1921 st->state==SITE_SENTMSG4) {
1922 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1923 /* We are ahead in the protocol, but that msg1 had the
1924 * peer's nonce so presumably it is from this key
1925 * exchange run, via a slower route */
1926 transport_setup_msgok(st,source);
1928 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1933 /* The message 1 was received at an unexpected stage of the
1934 key setup. Well, they lost the race. */
1935 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1939 if (msgtype==LABEL_PROD) {
1940 if (!named_for_us(st,buf,msgtype,&named_msg))
1942 dump_packet(st,buf,source,True,True);
1943 if (st->state!=SITE_RUN) {
1944 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1945 } else if (current_valid(st)) {
1946 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1948 initiate_key_setup(st,"peer sent PROD packet",source);
1953 if (dest==st->index) {
1954 /* Explicitly addressed to us */
1955 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1958 /* If the source is our current peer then initiate a key setup,
1959 because our peer's forgotten the key */
1960 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1962 initiated = initiate_key_setup(st,"received a NAK",source);
1963 if (!initiated) generate_send_prod(st,source);
1965 slog(st,LOG_SEC,"bad incoming NAK");
1969 process_msg0(st,buf,source);
1972 /* Setup packet: should not have been explicitly addressed
1974 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1977 /* Setup packet: expected only in state SENTMSG1 */
1978 if (st->state!=SITE_SENTMSG1) {
1979 if ((st->state==SITE_SENTMSG3 ||
1980 st->state==SITE_SENTMSG5) &&
1981 setup_late_msg_ok(st,buf,msgtype,source))
1983 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1984 } else if (process_msg2(st,buf,source)) {
1985 transport_setup_msgok(st,source);
1986 enter_new_state(st,SITE_SENTMSG3);
1988 slog(st,LOG_SEC,"invalid MSG2");
1991 case CASES_MSG3_KNOWN:
1992 /* Setup packet: expected only in state SENTMSG2 */
1993 if (st->state!=SITE_SENTMSG2) {
1994 if ((st->state==SITE_SENTMSG4) &&
1995 setup_late_msg_ok(st,buf,msgtype,source))
1997 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1998 } else if (process_msg3(st,buf,source,msgtype)) {
1999 transport_setup_msgok(st,source);
2000 enter_new_state(st,SITE_SENTMSG4);
2002 slog(st,LOG_SEC,"invalid MSG3");
2006 /* Setup packet: expected only in state SENTMSG3 */
2007 if (st->state!=SITE_SENTMSG3) {
2008 if ((st->state==SITE_SENTMSG5) &&
2009 setup_late_msg_ok(st,buf,msgtype,source))
2011 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2012 } else if (process_msg4(st,buf,source)) {
2013 transport_setup_msgok(st,source);
2014 enter_new_state(st,SITE_SENTMSG5);
2016 slog(st,LOG_SEC,"invalid MSG4");
2020 /* Setup packet: expected only in state SENTMSG4 */
2021 /* (may turn up in state RUN if our return MSG6 was lost
2022 and the new key has already been activated. In that
2023 case we discard it. The peer will realise that we
2024 are using the new key when they see our data packets.
2025 Until then the peer's data packets to us get discarded. */
2026 if (st->state==SITE_SENTMSG4) {
2027 if (process_msg5(st,buf,source,st->new_transform)) {
2028 transport_setup_msgok(st,source);
2029 enter_new_state(st,SITE_RUN);
2031 slog(st,LOG_SEC,"invalid MSG5");
2033 } else if (st->state==SITE_RUN) {
2034 if (process_msg5(st,buf,source,st->current.transform)) {
2035 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2036 transport_setup_msgok(st,source);
2037 create_msg6(st,st->current.transform,
2038 st->current.remote_session_id);
2039 transport_xmit(st,&st->peers,&st->buffer,True);
2040 BUF_FREE(&st->buffer);
2042 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2045 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2049 /* Setup packet: expected only in state SENTMSG5 */
2050 if (st->state!=SITE_SENTMSG5) {
2051 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2052 } else if (process_msg6(st,buf,source)) {
2053 BUF_FREE(&st->buffer); /* Free message 5 */
2054 transport_setup_msgok(st,source);
2055 activate_new_key(st);
2057 slog(st,LOG_SEC,"invalid MSG6");
2061 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2072 static void site_control(void *vst, bool_t run)
2074 struct site *st=vst;
2075 if (run) enter_state_run(st);
2076 else enter_state_stop(st);
2079 static void site_phase_hook(void *sst, uint32_t newphase)
2081 struct site *st=sst;
2083 /* The program is shutting down; tell our peer */
2084 send_msg7(st,"shutting down");
2087 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2089 struct site *st=sst;
2090 dispose_transform(&st->current.transform);
2091 dispose_transform(&st->auxiliary_key.transform);
2092 dispose_transform(&st->new_transform);
2093 /* Not much point overwiting the signing key, since we loaded it
2094 from disk, and it is only valid prospectively if at all,
2096 /* XXX it would be best to overwrite the DH state, because that
2097 _is_ relevant to forward secrecy. However we have no
2098 convenient interface for doing that and in practice gmp has
2099 probably dribbled droppings all over the malloc arena. A good
2100 way to fix this would be to have a privsep child for asymmetric
2101 crypto operations, but that's a task for another day. */
2104 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2107 static uint32_t index_sequence;
2115 st->cl.description="site";
2116 st->cl.type=CL_SITE;
2118 st->cl.interface=&st->ops;
2120 st->ops.control=site_control;
2121 st->ops.status=site_status;
2123 /* First parameter must be a dict */
2124 item=list_elem(args,0);
2125 if (!item || item->type!=t_dict)
2126 cfgfatal(loc,"site","parameter must be a dictionary\n");
2128 dict=item->data.dict;
2129 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2130 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2132 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2134 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2136 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2138 /* Sanity check (which also allows the 'sites' file to include
2139 site() closures for all sites including our own): refuse to
2140 talk to ourselves */
2141 if (strcmp(st->localname,st->remotename)==0) {
2142 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2144 if (st->peer_mobile != st->local_mobile)
2145 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2146 " but our local-mobile=%d\n",
2147 st->localname, st->peer_mobile, st->local_mobile);
2151 if (st->peer_mobile && st->local_mobile) {
2152 Message(M_WARNING,"site %s: site is mobile but so are we"
2153 " -> ignoring this site\n", st->remotename);
2158 assert(index_sequence < 0xffffffffUL);
2159 st->index = ++index_sequence;
2160 st->local_capabilities = 0;
2161 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2162 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2164 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2165 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2166 if (!things##_cfg) \
2167 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2168 st->nthings=list_length(things##_cfg); \
2169 NEW_ARY(st->things,st->nthings); \
2170 assert(st->nthings); \
2171 for (i=0; i<st->nthings; i++) { \
2172 item_t *item=list_elem(things##_cfg,i); \
2173 if (item->type!=t_closure) \
2174 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2175 closure_t *cl=item->data.closure; \
2176 if (cl->type!=CL_TYPE) \
2177 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2178 st->things[i]=cl->interface; \
2182 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2184 NEW_ARY(st->commclientinfos, st->ncomms);
2185 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2186 for (i=0; i<st->ncomms; i++) {
2187 st->commclientinfos[i] =
2189 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2192 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2193 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2194 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2196 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2197 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2199 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2200 else st->remoteport=0;
2201 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2203 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2205 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2206 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2208 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2209 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2210 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2212 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2213 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2214 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2215 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2216 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2218 st->mobile_peer_expiry= dict_read_number(
2219 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2221 const char *peerskey= st->peer_mobile
2222 ? "mobile-peers-max" : "static-peers-max";
2223 st->transport_peers_max= dict_read_number(
2224 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2225 if (st->transport_peers_max<1 ||
2226 st->transport_peers_max>MAX_PEER_ADDRS) {
2227 cfgfatal(loc,"site", "%s must be in range 1.."
2228 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2231 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2232 st->key_renegotiate_time=st->key_lifetime/2;
2234 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2235 st->key_renegotiate_time=dict_read_number(
2236 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2237 if (st->key_renegotiate_time > st->key_lifetime) {
2238 cfgfatal(loc,"site",
2239 "renegotiate-time must be less than key-lifetime\n");
2242 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2243 log_event_table,"site");
2245 st->resolving_count=0;
2246 st->allow_send_prod=0;
2248 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2250 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2252 /* The information we expect to see in incoming messages of type 1 */
2253 /* fixme: lots of unchecked overflows here, but the results are only
2254 corrupted packets rather than undefined behaviour */
2255 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2257 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2259 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2260 BUF_ALLOC(&st->scratch,"site:scratch");
2262 /* We are interested in poll(), but only for timeouts. We don't have
2263 any fds of our own. */
2264 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2267 st->remote_capabilities=0;
2268 st->chosen_transform=0;
2269 st->current.key_timeout=0;
2270 st->auxiliary_key.key_timeout=0;
2271 transport_peers_clear(st,&st->peers);
2272 transport_peers_clear(st,&st->setup_peers);
2273 /* XXX mlock these */
2274 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2275 st->sharedsecretlen=st->sharedsecretallocd=0;
2278 #define SET_CAPBIT(bit) do { \
2279 uint32_t capflag = 1UL << (bit); \
2280 if (st->local_capabilities & capflag) \
2281 slog(st,LOG_ERROR,"capability bit" \
2282 " %d (%#"PRIx32") reused", (bit), capflag); \
2283 st->local_capabilities |= capflag; \
2286 for (i=0; i<st->ntransforms; i++)
2287 SET_CAPBIT(st->transforms[i]->capab_bit);
2291 if (st->local_mobile || st->peer_mobile)
2292 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2294 /* We need to register the remote networks with the netlink device */
2295 uint32_t netlink_mtu; /* local virtual interface mtu */
2296 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2297 if (!st->mtu_target)
2298 st->mtu_target=netlink_mtu;
2300 for (i=0; i<st->ncomms; i++)
2301 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2303 st->current.transform=0;
2304 st->auxiliary_key.transform=0;
2305 st->new_transform=0;
2306 st->auxiliary_is_new=0;
2308 enter_state_stop(st);
2310 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2311 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2313 return new_closure(&st->cl);
2316 void site_module(dict_t *dict)
2318 add_closure(dict,"site",site_apply);
2322 /***** TRANSPORT PEERS definitions *****/
2324 static void transport_peers_debug(struct site *st, transport_peers *dst,
2325 const char *didwhat,
2326 int nargs, const struct comm_addr *args,
2331 if (!(st->log_events & LOG_PEER_ADDRS))
2332 return; /* an optimisation */
2334 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2335 (dst==&st->peers ? "data" :
2336 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2337 didwhat, nargs, dst->npeers);
2339 for (i=0, argp=(void*)args;
2341 i++, (argp+=stride?stride:sizeof(*args))) {
2342 const struct comm_addr *ca=(void*)argp;
2343 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2344 i, comm_addr_to_string(ca));
2346 for (i=0; i<dst->npeers; i++) {
2347 struct timeval diff;
2348 timersub(tv_now,&dst->peers[i].last,&diff);
2349 const struct comm_addr *ca=&dst->peers[i].addr;
2350 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2351 i, comm_addr_to_string(ca),
2352 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2356 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2357 /* peers must be sorted first */
2358 int previous_peers=peers->npeers;
2359 struct timeval oldest;
2360 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2361 oldest.tv_usec = tv_now->tv_usec;
2362 while (peers->npeers>1 &&
2363 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2365 if (peers->npeers != previous_peers)
2366 transport_peers_debug(st,peers,"expire", 0,0,0);
2369 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2370 const struct comm_addr *ca,
2371 const struct timeval *tv) {
2372 /* returns false if output is full */
2375 if (peers->npeers >= st->transport_peers_max)
2378 for (search=0; search<peers->npeers; search++)
2379 if (comm_addr_equal(&peers->peers[search].addr, ca))
2382 peers->peers[peers->npeers].addr = *ca;
2383 peers->peers[peers->npeers].last = *tv;
2388 static void transport_record_peers(struct site *st, transport_peers *peers,
2389 const struct comm_addr *addrs, int naddrs,
2391 /* We add addrs into peers. The new entries end up at the front
2392 * and displace entries towards the end (perhaps even off the
2393 * end). Any existing matching entries are moved up to the front.
2395 * Caller must first call transport_peers_expire. */
2398 /* avoids debug for uninteresting updates */
2400 for (i=0; i<peers->npeers; i++) {
2401 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2402 memmove(peers->peers+1, peers->peers,
2403 sizeof(peers->peers[0]) * i);
2404 peers->peers[0].addr = addrs[0];
2405 peers->peers[0].last = *tv_now;
2411 int old_npeers=peers->npeers;
2412 transport_peer old_peers[old_npeers];
2413 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2417 for (i=0; i<naddrs; i++) {
2418 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2421 for (i=0; i<old_npeers; i++) {
2422 const transport_peer *old=&old_peers[i];
2423 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2427 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2430 static void transport_expire_record_peers(struct site *st,
2431 transport_peers *peers,
2432 const struct comm_addr *addrs,
2433 int naddrs, const char *m) {
2434 /* Convenience function */
2435 transport_peers_expire(st,peers);
2436 transport_record_peers(st,peers,addrs,naddrs,m);
2439 static bool_t transport_compute_setupinit_peers(struct site *st,
2440 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2441 int n_configured_addrs /* 0 if none or not found */,
2442 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2443 if (!n_configured_addrs && !incoming_packet_addr &&
2444 !transport_peers_valid(&st->peers))
2447 slog(st,LOG_SETUP_INIT,
2448 "using: %d configured addr(s);%s %d old peer addrs(es)",
2450 incoming_packet_addr ? " incoming packet address;" : "",
2453 /* Non-mobile peers try addresses until one is plausible. The
2454 * effect is that this code always tries first the configured
2455 * address if supplied, or otherwise the address of the incoming
2456 * PROD, or finally the existing data peer if one exists; this is
2459 transport_peers_copy(st,&st->setup_peers,&st->peers);
2460 transport_peers_expire(st,&st->setup_peers);
2462 if (incoming_packet_addr)
2463 transport_record_peers(st,&st->setup_peers,
2464 incoming_packet_addr,1, "incoming");
2466 if (n_configured_addrs)
2467 transport_record_peers(st,&st->setup_peers,
2468 configured_addrs,n_configured_addrs, "setupinit");
2470 assert(transport_peers_valid(&st->setup_peers));
2474 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2475 if (st->peer_mobile)
2476 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2478 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2479 if (st->peer_mobile)
2480 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2483 static int transport_peers_valid(transport_peers *peers) {
2484 return peers->npeers;
2486 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2488 transport_peers_debug(st,peers,"clear",0,0,0);
2490 static void transport_peers_copy(struct site *st, transport_peers *dst,
2491 const transport_peers *src) {
2492 dst->npeers=src->npeers;
2493 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2494 transport_peers_debug(st,dst,"copy",
2495 src->npeers, &src->peers->addr, sizeof(*src->peers));
2498 static void transport_resolve_complete(struct site *st,
2499 const struct comm_addr *addrs,
2501 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2503 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2507 static void transport_resolve_complete_tardy(struct site *st,
2508 const struct comm_addr *addrs,
2510 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2511 "resolved tardily");
2514 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2516 const transport_peers *inp) {
2517 /* out and in->peers may be the same region, or nonoverlapping */
2518 const transport_peer *in=inp->peers;
2520 for (slot=0; slot<inp->npeers; slot++) {
2521 if (!(mask & (1U << slot)))
2523 if (!(out==in && slot==*nout_io))
2524 COPY_OBJ(out[*nout_io], in[slot]);
2529 void transport_xmit(struct site *st, transport_peers *peers,
2530 struct buffer_if *buf, bool_t candebug) {
2532 transport_peers_expire(st, peers);
2533 unsigned failed=0; /* bitmask */
2534 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2537 for (slot=0; slot<peers->npeers; slot++) {
2538 transport_peer *peer=&peers->peers[slot];
2539 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2541 dump_packet(st, buf, &peer->addr, False, ok);
2543 failed |= 1U << slot;
2546 if (ok && !st->peer_mobile)
2549 /* Now we need to demote/delete failing addrs: if we are mobile we
2550 * merely demote them; otherwise we delete them. */
2551 if (st->local_mobile) {
2552 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2553 /* `expected' has all the failures at the end already */
2554 if (failed != expected) {
2556 transport_peer failedpeers[nfailed];
2557 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2558 assert(fslot == nfailed);
2560 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2561 assert(wslot+nfailed == peers->npeers);
2562 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2563 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2566 if (failed && peers->npeers > 1) {
2568 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2569 peers->npeers=wslot;
2570 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2575 /***** END of transport peers declarations *****/