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;
537 struct alg_msg_data sig;
540 static int32_t wait_timeout(struct site *st) {
541 int32_t t = st->wait_timeout_mean;
544 st->random->generate(st->random->st,sizeof(factor),&factor);
545 t += (t / 256) * factor;
550 static _Bool set_new_transform(struct site *st, char *pk)
554 /* Make room for the shared key */
555 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
556 assert(st->sharedsecretlen);
557 if (st->sharedsecretlen > st->sharedsecretallocd) {
558 st->sharedsecretallocd=st->sharedsecretlen;
559 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
560 st->sharedsecretallocd,
561 "site:sharedsecret");
564 /* Generate the shared key */
565 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
566 st->sharedsecret,st->sharedsecretlen);
568 /* Set up the transform */
569 struct transform_if *generator=st->chosen_transform;
570 struct transform_inst_if *generated=generator->create(generator->st);
571 ok = generated->setkey(generated->st,st->sharedsecret,
572 st->sharedsecretlen,st->our_name_later);
574 dispose_transform(&st->new_transform);
575 if (!ok) return False;
576 st->new_transform=generated;
578 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
579 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
580 st->chosen_transform->capab_bit,
581 st->local_capabilities, st->remote_capabilities);
586 int32_t lenpos, afternul;
588 static void append_string_xinfo_start(struct buffer_if *buf,
589 struct xinfoadd *xia,
591 /* Helps construct one of the names with additional info as found
592 * in MSG1..4. Call this function first, then append all the
593 * desired extra info (not including the nul byte) to the buffer,
594 * then call append_string_xinfo_done. */
596 xia->lenpos = buf->size;
597 buf_append_string(buf,str);
598 buf_append_uint8(buf,0);
599 xia->afternul = buf->size;
601 static void append_string_xinfo_done(struct buffer_if *buf,
602 struct xinfoadd *xia)
604 /* we just need to adjust the string length */
605 if (buf->size == xia->afternul) {
606 /* no extra info, strip the nul too */
607 buf_unappend_uint8(buf);
609 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
613 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
614 out using a transform of config data supplied by netlink */
615 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
622 st->retries=st->setup_retries;
623 BUF_ALLOC(&st->buffer,what);
624 buffer_init(&st->buffer,0);
625 buf_append_uint32(&st->buffer,
626 (type==LABEL_MSG1?0:st->setup_session_id));
627 buf_append_uint32(&st->buffer,st->index);
628 buf_append_uint32(&st->buffer,type);
631 append_string_xinfo_start(&st->buffer,&xia,st->localname);
632 if ((st->local_capabilities & st->early_capabilities) ||
633 (type != LABEL_MSG1)) {
634 buf_append_uint32(&st->buffer,st->local_capabilities);
636 if (type_is_msg34(type)) {
637 buf_append_uint16(&st->buffer,st->mtu_target);
639 append_string_xinfo_done(&st->buffer,&xia);
641 buf_append_string(&st->buffer,st->remotename);
642 BUF_ADD_OBJ(append,&st->buffer,st->localN);
643 if (type==LABEL_MSG1) return True;
644 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
645 if (type==LABEL_MSG2) return True;
647 if (hacky_par_mid_failnow()) return False;
649 if (MSGMAJOR(type) == 3) do {
650 minor = MSGMINOR(type);
651 if (minor < 1) break;
652 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
655 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
656 buf_append_string(&st->buffer,dhpub);
658 hash=safe_malloc(st->hash->len, "generate_msg");
659 hst=st->hash->init();
660 st->hash->update(hst,st->buffer.start,st->buffer.size);
661 st->hash->final(hst,hash);
662 bool_t ok=st->privkey->sign(st->privkey->st,hash,st->hash->len,
673 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
676 nm->len=buf_unprepend_uint16(msg);
677 CHECK_AVAIL(msg,nm->len);
678 nm->name=buf_unprepend(msg,nm->len);
679 uint8_t *nul=memchr(nm->name,0,nm->len);
681 buffer_readonly_view(&nm->extrainfo,0,0);
683 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
684 nm->len=nul-nm->name;
689 static bool_t unpick_msg(struct site *st, uint32_t type,
690 struct buffer_if *msg, struct msg *m)
694 m->capab_transformnum=-1;
695 m->hashstart=msg->start;
697 m->dest=buf_unprepend_uint32(msg);
699 m->source=buf_unprepend_uint32(msg);
700 CHECK_TYPE(msg,type);
701 if (!unpick_name(msg,&m->remote)) return False;
702 m->remote_capabilities=0;
704 if (m->remote.extrainfo.size) {
705 CHECK_AVAIL(&m->remote.extrainfo,4);
706 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
708 if (type_is_msg34(type) && m->remote.extrainfo.size) {
709 CHECK_AVAIL(&m->remote.extrainfo,2);
710 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
712 if (!unpick_name(msg,&m->local)) return False;
713 if (type==LABEL_PROD) {
717 CHECK_AVAIL(msg,NONCELEN);
718 m->nR=buf_unprepend(msg,NONCELEN);
719 if (type==LABEL_MSG1) {
723 CHECK_AVAIL(msg,NONCELEN);
724 m->nL=buf_unprepend(msg,NONCELEN);
725 if (type==LABEL_MSG2) {
729 if (MSGMAJOR(type) == 3) do {
730 minor = MSGMINOR(type);
731 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
732 if (minor < (minminor)) \
733 m->capab_##kind##num = (dflt); \
735 CHECK_AVAIL(msg, 1); \
736 m->capab_##kind##num = buf_unprepend_uint8(msg); \
739 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
740 #undef MAYBE_READ_CAP
743 m->pklen=buf_unprepend_uint16(msg);
744 CHECK_AVAIL(msg,m->pklen);
745 m->pk=buf_unprepend(msg,m->pklen);
746 m->hashlen=msg->start-m->hashstart;
748 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
757 static bool_t name_matches(const struct parsedname *nm, const char *expected)
759 int expected_len=strlen(expected);
761 nm->len == expected_len &&
762 !memcmp(nm->name, expected, expected_len);
765 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
768 if (type==LABEL_MSG1) return True;
770 /* Check that the site names and our nonce have been sent
771 back correctly, and then store our peer's nonce. */
772 if (!name_matches(&m->remote,st->remotename)) {
773 *error="wrong remote site name";
776 if (!name_matches(&m->local,st->localname)) {
777 *error="wrong local site name";
780 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
781 *error="wrong locally-generated nonce";
784 if (type==LABEL_MSG2) return True;
785 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
786 *error="wrong remotely-generated nonce";
789 /* MSG3 has complicated rules about capabilities, which are
790 * handled in process_msg3. */
791 if (MSGMAJOR(type) == 3) return True;
792 if (m->remote_capabilities!=st->remote_capabilities) {
793 *error="remote capabilities changed";
796 if (type==LABEL_MSG4) return True;
797 *error="unknown message type";
801 static bool_t generate_msg1(struct site *st)
803 st->random->generate(st->random->st,NONCELEN,st->localN);
804 return generate_msg(st,LABEL_MSG1,"site:MSG1");
807 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
808 const struct comm_addr *src, struct msg *m)
810 /* We've already determined we're in an appropriate state to
811 process an incoming MSG1, and that the MSG1 has correct values
814 st->setup_session_id=m->source;
815 st->remote_capabilities=m->remote_capabilities;
816 memcpy(st->remoteN,m->nR,NONCELEN);
820 static bool_t generate_msg2(struct site *st)
822 st->random->generate(st->random->st,NONCELEN,st->localN);
823 return generate_msg(st,LABEL_MSG2,"site:MSG2");
826 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
827 const struct comm_addr *src)
832 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
833 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
834 slog(st,LOG_SEC,"msg2: %s",err);
837 st->setup_session_id=m.source;
838 st->remote_capabilities=m.remote_capabilities;
840 /* Select the transform to use */
842 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
843 if (!remote_crypto_caps)
844 /* old secnets only had this one transform */
845 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
847 #define CHOOSE_CRYPTO(kind, whats) do { \
848 struct kind##_if *iface; \
849 uint32_t bit, ours = 0; \
851 for (i= 0; i < st->n##kind##s; i++) { \
852 iface=st->kind##s[i]; \
853 bit = 1UL << iface->capab_bit; \
854 if (bit & remote_crypto_caps) goto kind##_found; \
857 slog(st,LOG_ERROR,"no " whats " in common" \
858 " (us %#"PRIx32"; them: %#"PRIx32")", \
859 st->local_capabilities & ours, remote_crypto_caps); \
862 st->chosen_##kind = iface; \
865 CHOOSE_CRYPTO(transform, "transforms");
869 memcpy(st->remoteN,m.nR,NONCELEN);
873 static bool_t generate_msg3(struct site *st)
875 /* Now we have our nonce and their nonce. Think of a secret key,
876 and create message number 3. */
877 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
878 return generate_msg(st,
879 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
885 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
890 /* Check signature and store g^x mod m */
891 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
892 hst=st->hash->init();
893 st->hash->update(hst,m->hashstart,m->hashlen);
894 st->hash->final(hst,hash);
895 if (!st->pubkey->check(st->pubkey->st,
898 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
904 st->remote_adv_mtu=m->remote_mtu;
909 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
910 const struct comm_addr *src, uint32_t msgtype)
916 case CASES_MSG3_KNOWN: break;
920 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
921 if (!check_msg(st,msgtype,&m,&err)) {
922 slog(st,LOG_SEC,"msg3: %s",err);
925 uint32_t capab_adv_late = m.remote_capabilities
926 & ~st->remote_capabilities & st->early_capabilities;
927 if (capab_adv_late) {
928 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
929 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
930 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
934 #define CHOSE_CRYPTO(kind, what) do { \
935 struct kind##_if *iface; \
937 for (i=0; i<st->n##kind##s; i++) { \
938 iface=st->kind##s[i]; \
939 if (iface->capab_bit == m.capab_##kind##num) \
942 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
943 m.capab_##kind##num); \
946 st->chosen_##kind=iface; \
949 CHOSE_CRYPTO(transform, "transform");
953 if (!process_msg3_msg4(st,&m))
956 /* Update our idea of the remote site's capabilities, now that we've
957 * verified that its message was authentic.
959 * Our previous idea of the remote site's capabilities came from the
960 * unauthenticated MSG1. We've already checked that this new message
961 * doesn't change any of the bits we relied upon in the past, but it may
962 * also have set additional capability bits. We simply throw those away
963 * now, and use the authentic capabilities from this MSG3. */
964 st->remote_capabilities=m.remote_capabilities;
966 /* Terminate their DH public key with a '0' */
968 /* Invent our DH secret key */
969 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
971 /* Generate the shared key and set up the transform */
972 if (!set_new_transform(st,m.pk)) return False;
977 static bool_t generate_msg4(struct site *st)
979 /* We have both nonces, their public key and our private key. Generate
980 our public key, sign it and send it to them. */
981 return generate_msg(st,LABEL_MSG4,"site:MSG4");
984 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
985 const struct comm_addr *src)
990 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
991 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
992 slog(st,LOG_SEC,"msg4: %s",err);
996 if (!process_msg3_msg4(st,&m))
999 /* Terminate their DH public key with a '0' */
1002 /* Generate the shared key and set up the transform */
1003 if (!set_new_transform(st,m.pk)) return False;
1014 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1017 CHECK_AVAIL(msg0,4);
1018 m->dest=buf_unprepend_uint32(msg0);
1019 CHECK_AVAIL(msg0,4);
1020 m->source=buf_unprepend_uint32(msg0);
1021 CHECK_AVAIL(msg0,4);
1022 m->type=buf_unprepend_uint32(msg0);
1024 /* Leaves transformed part of buffer untouched */
1027 static bool_t generate_msg5(struct site *st)
1029 cstring_t transform_err;
1031 BUF_ALLOC(&st->buffer,"site:MSG5");
1032 /* We are going to add four words to the message */
1033 buffer_init(&st->buffer,calculate_max_start_pad());
1034 /* Give the netlink code an opportunity to put its own stuff in the
1035 message (configuration information, etc.) */
1036 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1037 if (call_transform_forwards(st,st->new_transform,
1038 &st->buffer,&transform_err))
1040 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1041 buf_prepend_uint32(&st->buffer,st->index);
1042 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1044 st->retries=st->setup_retries;
1048 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1049 const struct comm_addr *src,
1050 struct transform_inst_if *transform)
1053 cstring_t transform_err;
1055 if (!unpick_msg0(st,msg5,&m)) return False;
1057 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1058 /* There's a problem */
1059 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1062 /* Buffer should now contain untransformed PING packet data */
1063 CHECK_AVAIL(msg5,4);
1064 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1065 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1068 /* Older versions of secnet used to write some config data here
1069 * which we ignore. So we don't CHECK_EMPTY */
1073 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1074 uint32_t session_id)
1076 cstring_t transform_err;
1078 BUF_ALLOC(&st->buffer,"site:MSG6");
1079 /* We are going to add four words to the message */
1080 buffer_init(&st->buffer,calculate_max_start_pad());
1081 /* Give the netlink code an opportunity to put its own stuff in the
1082 message (configuration information, etc.) */
1083 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1084 transform_apply_return problem =
1085 call_transform_forwards(st,transform,
1086 &st->buffer,&transform_err);
1088 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1089 buf_prepend_uint32(&st->buffer,st->index);
1090 buf_prepend_uint32(&st->buffer,session_id);
1093 static bool_t generate_msg6(struct site *st)
1095 if (!is_transform_valid(st->new_transform))
1097 create_msg6(st,st->new_transform,st->setup_session_id);
1098 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1102 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1103 const struct comm_addr *src)
1106 cstring_t transform_err;
1108 if (!unpick_msg0(st,msg6,&m)) return False;
1110 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1111 /* There's a problem */
1112 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1115 /* Buffer should now contain untransformed PING packet data */
1116 CHECK_AVAIL(msg6,4);
1117 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1118 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1121 /* Older versions of secnet used to write some config data here
1122 * which we ignore. So we don't CHECK_EMPTY */
1126 static transform_apply_return
1127 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1128 const struct comm_addr *src)
1130 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1132 transform_apply_return problem;
1134 if (!unpick_msg0(st,msg0,&m)) return False;
1136 /* Keep a copy so we can try decrypting it with multiple keys */
1137 buffer_copy(&st->scratch, msg0);
1139 problem = call_transform_reverse(st,st->current.transform,
1140 msg0,&transform_err);
1142 if (!st->auxiliary_is_new)
1143 delete_one_key(st,&st->auxiliary_key,
1144 "peer has used new key","auxiliary key",LOG_SEC);
1147 if (transform_apply_return_badseq(problem))
1150 buffer_copy(msg0, &st->scratch);
1151 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1154 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1155 if (st->auxiliary_is_new) {
1156 /* We previously timed out in state SENTMSG5 but it turns
1157 * out that our peer did in fact get our MSG5 and is
1158 * using the new key. So we should switch to it too. */
1159 /* This is a bit like activate_new_key. */
1162 st->current=st->auxiliary_key;
1163 st->auxiliary_key=t;
1165 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1166 "previous key",LOG_SEC);
1167 st->auxiliary_is_new=0;
1168 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1172 if (transform_apply_return_badseq(problem))
1175 if (st->state==SITE_SENTMSG5) {
1176 buffer_copy(msg0, &st->scratch);
1177 problem = call_transform_reverse(st,st->new_transform,
1180 /* It looks like we didn't get the peer's MSG6 */
1181 /* This is like a cut-down enter_new_state(SITE_RUN) */
1182 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1183 BUF_FREE(&st->buffer);
1185 activate_new_key(st);
1186 return 0; /* do process the data in this packet */
1188 if (transform_apply_return_badseq(problem))
1192 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1193 transform_err,auxkey_err,newkey_err);
1194 initiate_key_setup(st,"incoming message would not decrypt",0);
1195 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1200 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1205 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1206 const struct comm_addr *src)
1209 transform_apply_return problem;
1211 problem = decrypt_msg0(st,msg0,src);
1212 if (problem==transform_apply_seqdupe) {
1213 /* We recently received another copy of this packet, maybe due
1214 * to polypath. That's not a problem; indeed, for the
1215 * purposes of transport address management it is a success.
1216 * But we don't want to process the packet. */
1217 transport_data_msgok(st,src);
1223 CHECK_AVAIL(msg0,4);
1224 type=buf_unprepend_uint32(msg0);
1227 /* We must forget about the current session. */
1228 delete_keys(st,"request from peer",LOG_SEC);
1229 /* probably, the peer is shutting down, and this is going to fail,
1230 * but we need to be trying to bring the link up again */
1232 initiate_key_setup(st,"peer requested key teardown",0);
1235 /* Deliver to netlink layer */
1236 st->netlink->deliver(st->netlink->st,msg0);
1237 transport_data_msgok(st,src);
1238 /* See whether we should start negotiating a new key */
1239 if (st->now > st->renegotiate_key_time)
1240 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1243 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1250 static void dump_packet(struct site *st, struct buffer_if *buf,
1251 const struct comm_addr *addr, bool_t incoming,
1254 uint32_t dest=get_uint32(buf->start);
1255 uint32_t source=get_uint32(buf->start+4);
1256 uint32_t msgtype=get_uint32(buf->start+8);
1258 if (st->log_events & LOG_DUMP)
1259 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1260 st->tunname,incoming?"incoming":"outgoing",
1261 dest,source,msgtype,comm_addr_to_string(addr),
1265 static bool_t comm_addr_sendmsg(struct site *st,
1266 const struct comm_addr *dest,
1267 struct buffer_if *buf)
1270 struct comm_clientinfo *commclientinfo = 0;
1272 for (i=0; i < st->ncomms; i++) {
1273 if (st->comms[i] == dest->comm) {
1274 commclientinfo = st->commclientinfos[i];
1278 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1281 static uint32_t site_status(void *st)
1286 static bool_t send_msg(struct site *st)
1288 if (st->retries>0) {
1289 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1290 st->timeout=st->now+st->setup_retry_interval;
1293 } else if (st->state==SITE_SENTMSG5) {
1294 logtimeout(st,"timed out sending MSG5, stashing new key");
1295 /* We stash the key we have produced, in case it turns out that
1296 * our peer did see our MSG5 after all and starts using it. */
1297 /* This is a bit like some of activate_new_key */
1298 struct transform_inst_if *t;
1299 t=st->auxiliary_key.transform;
1300 st->auxiliary_key.transform=st->new_transform;
1301 st->new_transform=t;
1302 dispose_transform(&st->new_transform);
1304 st->auxiliary_is_new=1;
1305 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1306 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1307 st->auxiliary_key.remote_session_id=st->setup_session_id;
1309 enter_state_wait(st);
1312 logtimeout(st,"timed out sending key setup packet "
1313 "(in state %s)",state_name(st->state));
1314 enter_state_wait(st);
1319 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1320 int stored_naddrs, int all_naddrs,
1321 const char *address, const char *failwhy)
1323 struct site *st=sst;
1325 if (!stored_naddrs) {
1326 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1328 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1329 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1331 int space=st->transport_peers_max-st->resolving_n_results_stored;
1332 int n_tocopy=MIN(stored_naddrs,space);
1333 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1336 st->resolving_n_results_stored += n_tocopy;
1337 st->resolving_n_results_all += all_naddrs;
1340 decrement_resolving_count(st,1);
1343 static void decrement_resolving_count(struct site *st, int by)
1345 assert(st->resolving_count>0);
1346 st->resolving_count-=by;
1348 if (st->resolving_count)
1351 /* OK, we are done with them all. Handle combined results. */
1353 const struct comm_addr *addrs=st->resolving_results;
1354 int naddrs=st->resolving_n_results_stored;
1355 assert(naddrs<=st->transport_peers_max);
1358 if (naddrs != st->resolving_n_results_all) {
1359 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1360 " yielded too many results (%d > %d), some ignored",
1361 st->resolving_n_results_all, naddrs);
1363 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1364 naddrs, iaddr_to_string(&addrs[0].ia));;
1367 switch (st->state) {
1369 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1370 enter_new_state(st,SITE_SENTMSG1);
1372 /* Can't figure out who to try to to talk to */
1373 slog(st,LOG_SETUP_INIT,
1374 "key exchange failed: cannot find peer address");
1375 enter_state_run(st);
1378 case SITE_SENTMSG1: case SITE_SENTMSG2:
1379 case SITE_SENTMSG3: case SITE_SENTMSG4:
1382 /* We start using the address immediately for data too.
1383 * It's best to store it in st->peers now because we might
1384 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1385 * the new key (without updating the data peer addrs). */
1386 transport_resolve_complete(st,addrs,naddrs);
1387 } else if (st->local_mobile) {
1388 /* We can't let this rest because we may have a peer
1389 * address which will break in the future. */
1390 slog(st,LOG_SETUP_INIT,"resolution failed: "
1391 "abandoning key exchange");
1392 enter_state_wait(st);
1394 slog(st,LOG_SETUP_INIT,"resolution failed: "
1395 " continuing to use source address of peer's packets"
1396 " for key exchange and ultimately data");
1401 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1402 " updating peer address(es)");
1403 transport_resolve_complete_tardy(st,addrs,naddrs);
1404 } else if (st->local_mobile) {
1405 /* Not very good. We should queue (another) renegotiation
1406 * so that we can update the peer address. */
1407 st->key_renegotiate_time=st->now+wait_timeout(st);
1409 slog(st,LOG_SETUP_INIT,"resolution failed: "
1410 " continuing to use source address of peer's packets");
1420 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1421 const struct comm_addr *prod_hint)
1423 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1424 if (st->state!=SITE_RUN) return False;
1425 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1426 if (st->addresses) {
1427 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1428 return enter_state_resolve(st);
1429 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1430 return enter_new_state(st,SITE_SENTMSG1);
1432 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1436 static void activate_new_key(struct site *st)
1438 struct transform_inst_if *t;
1440 /* We have three transform instances, which we swap between old,
1442 t=st->auxiliary_key.transform;
1443 st->auxiliary_key.transform=st->current.transform;
1444 st->current.transform=st->new_transform;
1445 st->new_transform=t;
1446 dispose_transform(&st->new_transform);
1449 st->auxiliary_is_new=0;
1450 st->auxiliary_key.key_timeout=st->current.key_timeout;
1451 st->current.key_timeout=st->now+st->key_lifetime;
1452 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1453 transport_peers_copy(st,&st->peers,&st->setup_peers);
1454 st->current.remote_session_id=st->setup_session_id;
1456 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1457 * But their mtu be unspecified, in which case we just use ours. */
1458 uint32_t intersite_mtu=
1459 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1460 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1462 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1463 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1464 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1465 enter_state_run(st);
1468 static void delete_one_key(struct site *st, struct data_key *key,
1469 cstring_t reason, cstring_t which, uint32_t loglevel)
1471 if (!is_transform_valid(key->transform)) return;
1472 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1473 dispose_transform(&key->transform);
1477 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1479 if (current_valid(st)) {
1480 slog(st,loglevel,"session closed (%s)",reason);
1482 delete_one_key(st,&st->current,0,0,0);
1483 set_link_quality(st);
1485 delete_one_key(st,&st->auxiliary_key,0,0,0);
1488 static void state_assert(struct site *st, bool_t ok)
1490 if (!ok) fatal("site:state_assert");
1493 static void enter_state_stop(struct site *st)
1495 st->state=SITE_STOP;
1497 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1498 dispose_transform(&st->new_transform);
1501 static void set_link_quality(struct site *st)
1504 if (current_valid(st))
1505 quality=LINK_QUALITY_UP;
1506 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1507 quality=LINK_QUALITY_DOWN;
1508 else if (st->addresses)
1509 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1510 else if (transport_peers_valid(&st->peers))
1511 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1513 quality=LINK_QUALITY_DOWN;
1515 st->netlink->set_quality(st->netlink->st,quality);
1518 static void enter_state_run(struct site *st)
1520 slog(st,LOG_STATE,"entering state RUN%s",
1521 current_valid(st) ? " (keyed)" : " (unkeyed)");
1525 st->setup_session_id=0;
1526 transport_peers_clear(st,&st->setup_peers);
1527 FILLZERO(st->localN);
1528 FILLZERO(st->remoteN);
1529 dispose_transform(&st->new_transform);
1530 memset(st->dhsecret,0,st->dh->len);
1531 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1532 set_link_quality(st);
1534 if (st->keepalive && !current_valid(st))
1535 initiate_key_setup(st, "keepalive", 0);
1538 static bool_t ensure_resolving(struct site *st)
1540 /* Reentrancy hazard: may call site_resolve_callback and hence
1541 * enter_new_state, enter_state_* and generate_msg*. */
1542 if (st->resolving_count)
1545 assert(st->addresses);
1547 /* resolver->request might reentrantly call site_resolve_callback
1548 * which will decrement st->resolving, so we need to increment it
1549 * twice beforehand to prevent decrement from thinking we're
1550 * finished, and decrement it ourselves. Alternatively if
1551 * everything fails then there are no callbacks due and we simply
1552 * set it to 0 and return false.. */
1553 st->resolving_n_results_stored=0;
1554 st->resolving_n_results_all=0;
1555 st->resolving_count+=2;
1556 const char **addrp=st->addresses;
1557 const char *address;
1559 for (; (address=*addrp++); ) {
1560 bool_t ok = st->resolver->request(st->resolver->st,address,
1561 st->remoteport,st->comms[0],
1562 site_resolve_callback,st);
1564 st->resolving_count++;
1568 st->resolving_count=0;
1571 decrement_resolving_count(st,2);
1575 static bool_t enter_state_resolve(struct site *st)
1577 /* Reentrancy hazard! See ensure_resolving. */
1578 state_assert(st,st->state==SITE_RUN);
1579 slog(st,LOG_STATE,"entering state RESOLVE");
1580 st->state=SITE_RESOLVE;
1581 return ensure_resolving(st);
1584 static bool_t enter_new_state(struct site *st, uint32_t next)
1586 bool_t (*gen)(struct site *st);
1589 slog(st,LOG_STATE,"entering state %s",state_name(next));
1592 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1594 st->msg1_crossed_logged = False;
1597 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1598 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1602 state_assert(st,st->state==SITE_SENTMSG1);
1603 BUF_FREE(&st->buffer);
1607 state_assert(st,st->state==SITE_SENTMSG2);
1608 BUF_FREE(&st->buffer);
1612 state_assert(st,st->state==SITE_SENTMSG3);
1613 BUF_FREE(&st->buffer);
1617 state_assert(st,st->state==SITE_SENTMSG4);
1618 BUF_FREE(&st->buffer);
1623 fatal("enter_new_state(%s): invalid new state",state_name(next));
1627 if (hacky_par_start_failnow()) return False;
1629 r= gen(st) && send_msg(st);
1632 st->setup_retries, st->setup_retry_interval,
1637 if (next==SITE_RUN) {
1638 BUF_FREE(&st->buffer); /* Never reused */
1639 st->timeout=0; /* Never retransmit */
1640 activate_new_key(st);
1644 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1645 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1646 in either state, and enter_state_wait() will
1648 enter_state_wait(st);
1652 /* msg7 tells our peer that we're about to forget our key */
1653 static bool_t send_msg7(struct site *st, cstring_t reason)
1655 cstring_t transform_err;
1657 if (current_valid(st) && st->buffer.free
1658 && transport_peers_valid(&st->peers)) {
1659 BUF_ALLOC(&st->buffer,"site:MSG7");
1660 buffer_init(&st->buffer,calculate_max_start_pad());
1661 buf_append_uint32(&st->buffer,LABEL_MSG7);
1662 buf_append_string(&st->buffer,reason);
1663 if (call_transform_forwards(st, st->current.transform,
1664 &st->buffer, &transform_err))
1666 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1667 buf_prepend_uint32(&st->buffer,st->index);
1668 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1669 transport_xmit(st,&st->peers,&st->buffer,True);
1670 BUF_FREE(&st->buffer);
1677 /* We go into this state if our peer becomes uncommunicative. Similar to
1678 the "stop" state, we forget all session keys for a while, before
1679 re-entering the "run" state. */
1680 static void enter_state_wait(struct site *st)
1682 slog(st,LOG_STATE,"entering state WAIT");
1683 st->timeout=st->now+wait_timeout(st);
1684 st->state=SITE_WAIT;
1685 set_link_quality(st);
1686 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1687 /* XXX Erase keys etc. */
1690 static void generate_prod(struct site *st, struct buffer_if *buf)
1693 buf_append_uint32(buf,0);
1694 buf_append_uint32(buf,0);
1695 buf_append_uint32(buf,LABEL_PROD);
1696 buf_append_string(buf,st->localname);
1697 buf_append_string(buf,st->remotename);
1700 static void generate_send_prod(struct site *st,
1701 const struct comm_addr *source)
1703 if (!st->allow_send_prod) return; /* too soon */
1704 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1705 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1707 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1708 st->allow_send_prod=0;
1709 generate_prod(st,&st->scratch);
1710 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1711 dump_packet(st,&st->scratch,source,False,ok);
1714 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1717 int64_t offset=timeout-*now;
1718 if (offset<0) offset=0;
1719 if (offset>INT_MAX) offset=INT_MAX;
1720 if (*timeout_io<0 || offset<*timeout_io)
1725 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1728 struct site *st=sst;
1730 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1733 /* Work out when our next timeout is. The earlier of 'timeout' or
1734 'current.key_timeout'. A stored value of '0' indicates no timeout
1736 site_settimeout(st->timeout, timeout_io);
1737 site_settimeout(st->current.key_timeout, timeout_io);
1738 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1740 return 0; /* success */
1743 static void check_expiry(struct site *st, struct data_key *key,
1746 if (key->key_timeout && *now>key->key_timeout) {
1747 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1751 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1752 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1754 struct site *st=sst;
1757 if (st->timeout && *now>st->timeout) {
1759 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1760 if (!hacky_par_start_failnow())
1762 } else if (st->state==SITE_WAIT) {
1763 enter_state_run(st);
1765 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1769 check_expiry(st,&st->current,"current key");
1770 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1773 /* This function is called by the netlink device to deliver packets
1774 intended for the remote network. The packet is in "raw" wire
1775 format, but is guaranteed to be word-aligned. */
1776 static void site_outgoing(void *sst, struct buffer_if *buf)
1778 struct site *st=sst;
1779 cstring_t transform_err;
1781 if (st->state==SITE_STOP) {
1786 st->allow_send_prod=1;
1788 /* In all other states we consider delivering the packet if we have
1789 a valid key and a valid address to send it to. */
1790 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1791 /* Transform it and send it */
1793 buf_prepend_uint32(buf,LABEL_MSG9);
1794 if (call_transform_forwards(st, st->current.transform,
1795 buf, &transform_err))
1797 buf_prepend_uint32(buf,LABEL_MSG0);
1798 buf_prepend_uint32(buf,st->index);
1799 buf_prepend_uint32(buf,st->current.remote_session_id);
1800 transport_xmit(st,&st->peers,buf,False);
1807 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1809 initiate_key_setup(st,"outgoing packet",0);
1812 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1813 uint32_t type, struct msg *m)
1814 /* For packets which are identified by the local and remote names.
1815 * If it has our name and our peer's name in it it's for us. */
1817 struct buffer_if buf[1];
1818 buffer_readonly_clone(buf,buf_in);
1819 return unpick_msg(st,type,buf,m)
1820 && name_matches(&m->remote,st->remotename)
1821 && name_matches(&m->local,st->localname);
1824 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1825 if (st->local_capabilities & m->remote_capabilities &
1826 CAPAB_PRIORITY_MOBILE) {
1827 if (st->local_mobile) return True;
1828 if (st-> peer_mobile) return False;
1830 return st->our_name_later;
1833 static bool_t setup_late_msg_ok(struct site *st,
1834 const struct buffer_if *buf_in,
1836 const struct comm_addr *source) {
1837 /* For setup packets which seem from their type like they are
1838 * late. Maybe they came via a different path. All we do is make
1839 * a note of the sending address, iff they look like they are part
1840 * of the current key setup attempt. */
1842 if (!named_for_us(st,buf_in,msgtype,&m))
1843 /* named_for_us calls unpick_msg which gets the nonces */
1845 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1846 !consttime_memeq(m.nL,st->localN, NONCELEN))
1847 /* spoof ? from stale run ? who knows */
1849 transport_setup_msgok(st,source);
1853 /* This function is called by the communication device to deliver
1854 packets from our peers.
1855 It should return True if the packet is recognised as being for
1856 this current site instance (and should therefore not be processed
1857 by other sites), even if the packet was otherwise ignored. */
1858 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1859 const struct comm_addr *source)
1861 struct site *st=sst;
1863 if (buf->size < 12) return False;
1865 uint32_t dest=get_uint32(buf->start);
1866 uint32_t msgtype=get_uint32(buf->start+8);
1867 struct msg named_msg;
1869 if (msgtype==LABEL_MSG1) {
1870 if (!named_for_us(st,buf,msgtype,&named_msg))
1872 /* It's a MSG1 addressed to us. Decide what to do about it. */
1873 dump_packet(st,buf,source,True,True);
1874 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1875 st->state==SITE_WAIT) {
1876 /* We should definitely process it */
1877 transport_compute_setupinit_peers(st,0,0,source);
1878 if (process_msg1(st,buf,source,&named_msg)) {
1879 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1880 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1881 if (entered && st->addresses && st->local_mobile)
1882 /* We must do this as the very last thing, because
1883 the resolver callback might reenter us. */
1884 ensure_resolving(st);
1886 slog(st,LOG_ERROR,"failed to process incoming msg1");
1890 } else if (st->state==SITE_SENTMSG1) {
1891 /* We've just sent a message 1! They may have crossed on
1892 the wire. If we have priority then we ignore the
1893 incoming one, otherwise we process it as usual. */
1894 if (we_have_priority(st,&named_msg)) {
1896 if (!st->msg1_crossed_logged++)
1897 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1898 "priority => ignore incoming msg1");
1901 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1902 "priority => use incoming msg1");
1903 if (process_msg1(st,buf,source,&named_msg)) {
1904 BUF_FREE(&st->buffer); /* Free our old message 1 */
1905 transport_setup_msgok(st,source);
1906 enter_new_state(st,SITE_SENTMSG2);
1908 slog(st,LOG_ERROR,"failed to process an incoming "
1909 "crossed msg1 (we have low priority)");
1914 } else if (st->state==SITE_SENTMSG2 ||
1915 st->state==SITE_SENTMSG4) {
1916 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1917 /* We are ahead in the protocol, but that msg1 had the
1918 * peer's nonce so presumably it is from this key
1919 * exchange run, via a slower route */
1920 transport_setup_msgok(st,source);
1922 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1927 /* The message 1 was received at an unexpected stage of the
1928 key setup. Well, they lost the race. */
1929 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1933 if (msgtype==LABEL_PROD) {
1934 if (!named_for_us(st,buf,msgtype,&named_msg))
1936 dump_packet(st,buf,source,True,True);
1937 if (st->state!=SITE_RUN) {
1938 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1939 } else if (current_valid(st)) {
1940 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1942 initiate_key_setup(st,"peer sent PROD packet",source);
1947 if (dest==st->index) {
1948 /* Explicitly addressed to us */
1949 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1952 /* If the source is our current peer then initiate a key setup,
1953 because our peer's forgotten the key */
1954 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1956 initiated = initiate_key_setup(st,"received a NAK",source);
1957 if (!initiated) generate_send_prod(st,source);
1959 slog(st,LOG_SEC,"bad incoming NAK");
1963 process_msg0(st,buf,source);
1966 /* Setup packet: should not have been explicitly addressed
1968 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1971 /* Setup packet: expected only in state SENTMSG1 */
1972 if (st->state!=SITE_SENTMSG1) {
1973 if ((st->state==SITE_SENTMSG3 ||
1974 st->state==SITE_SENTMSG5) &&
1975 setup_late_msg_ok(st,buf,msgtype,source))
1977 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1978 } else if (process_msg2(st,buf,source)) {
1979 transport_setup_msgok(st,source);
1980 enter_new_state(st,SITE_SENTMSG3);
1982 slog(st,LOG_SEC,"invalid MSG2");
1985 case CASES_MSG3_KNOWN:
1986 /* Setup packet: expected only in state SENTMSG2 */
1987 if (st->state!=SITE_SENTMSG2) {
1988 if ((st->state==SITE_SENTMSG4) &&
1989 setup_late_msg_ok(st,buf,msgtype,source))
1991 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1992 } else if (process_msg3(st,buf,source,msgtype)) {
1993 transport_setup_msgok(st,source);
1994 enter_new_state(st,SITE_SENTMSG4);
1996 slog(st,LOG_SEC,"invalid MSG3");
2000 /* Setup packet: expected only in state SENTMSG3 */
2001 if (st->state!=SITE_SENTMSG3) {
2002 if ((st->state==SITE_SENTMSG5) &&
2003 setup_late_msg_ok(st,buf,msgtype,source))
2005 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2006 } else if (process_msg4(st,buf,source)) {
2007 transport_setup_msgok(st,source);
2008 enter_new_state(st,SITE_SENTMSG5);
2010 slog(st,LOG_SEC,"invalid MSG4");
2014 /* Setup packet: expected only in state SENTMSG4 */
2015 /* (may turn up in state RUN if our return MSG6 was lost
2016 and the new key has already been activated. In that
2017 case we discard it. The peer will realise that we
2018 are using the new key when they see our data packets.
2019 Until then the peer's data packets to us get discarded. */
2020 if (st->state==SITE_SENTMSG4) {
2021 if (process_msg5(st,buf,source,st->new_transform)) {
2022 transport_setup_msgok(st,source);
2023 enter_new_state(st,SITE_RUN);
2025 slog(st,LOG_SEC,"invalid MSG5");
2027 } else if (st->state==SITE_RUN) {
2028 if (process_msg5(st,buf,source,st->current.transform)) {
2029 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2030 transport_setup_msgok(st,source);
2031 create_msg6(st,st->current.transform,
2032 st->current.remote_session_id);
2033 transport_xmit(st,&st->peers,&st->buffer,True);
2034 BUF_FREE(&st->buffer);
2036 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2039 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2043 /* Setup packet: expected only in state SENTMSG5 */
2044 if (st->state!=SITE_SENTMSG5) {
2045 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2046 } else if (process_msg6(st,buf,source)) {
2047 BUF_FREE(&st->buffer); /* Free message 5 */
2048 transport_setup_msgok(st,source);
2049 activate_new_key(st);
2051 slog(st,LOG_SEC,"invalid MSG6");
2055 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2066 static void site_control(void *vst, bool_t run)
2068 struct site *st=vst;
2069 if (run) enter_state_run(st);
2070 else enter_state_stop(st);
2073 static void site_phase_hook(void *sst, uint32_t newphase)
2075 struct site *st=sst;
2077 /* The program is shutting down; tell our peer */
2078 send_msg7(st,"shutting down");
2081 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2083 struct site *st=sst;
2084 dispose_transform(&st->current.transform);
2085 dispose_transform(&st->auxiliary_key.transform);
2086 dispose_transform(&st->new_transform);
2087 /* Not much point overwiting the signing key, since we loaded it
2088 from disk, and it is only valid prospectively if at all,
2090 /* XXX it would be best to overwrite the DH state, because that
2091 _is_ relevant to forward secrecy. However we have no
2092 convenient interface for doing that and in practice gmp has
2093 probably dribbled droppings all over the malloc arena. A good
2094 way to fix this would be to have a privsep child for asymmetric
2095 crypto operations, but that's a task for another day. */
2098 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2101 static uint32_t index_sequence;
2109 st->cl.description="site";
2110 st->cl.type=CL_SITE;
2112 st->cl.interface=&st->ops;
2114 st->ops.control=site_control;
2115 st->ops.status=site_status;
2117 /* First parameter must be a dict */
2118 item=list_elem(args,0);
2119 if (!item || item->type!=t_dict)
2120 cfgfatal(loc,"site","parameter must be a dictionary\n");
2122 dict=item->data.dict;
2123 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2124 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2126 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2128 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2130 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2132 /* Sanity check (which also allows the 'sites' file to include
2133 site() closures for all sites including our own): refuse to
2134 talk to ourselves */
2135 if (strcmp(st->localname,st->remotename)==0) {
2136 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2138 if (st->peer_mobile != st->local_mobile)
2139 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2140 " but our local-mobile=%d\n",
2141 st->localname, st->peer_mobile, st->local_mobile);
2145 if (st->peer_mobile && st->local_mobile) {
2146 Message(M_WARNING,"site %s: site is mobile but so are we"
2147 " -> ignoring this site\n", st->remotename);
2152 assert(index_sequence < 0xffffffffUL);
2153 st->index = ++index_sequence;
2154 st->local_capabilities = 0;
2155 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2156 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2158 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2159 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2160 if (!things##_cfg) \
2161 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2162 st->nthings=list_length(things##_cfg); \
2163 NEW_ARY(st->things,st->nthings); \
2164 assert(st->nthings); \
2165 for (i=0; i<st->nthings; i++) { \
2166 item_t *item=list_elem(things##_cfg,i); \
2167 if (item->type!=t_closure) \
2168 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2169 closure_t *cl=item->data.closure; \
2170 if (cl->type!=CL_TYPE) \
2171 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2172 st->things[i]=cl->interface; \
2176 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2178 NEW_ARY(st->commclientinfos, st->ncomms);
2179 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2180 for (i=0; i<st->ncomms; i++) {
2181 st->commclientinfos[i] =
2183 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2186 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2187 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2188 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2190 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2191 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2193 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2194 else st->remoteport=0;
2195 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2197 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2199 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2200 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2202 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2203 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2204 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2206 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2207 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2208 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2209 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2210 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2212 st->mobile_peer_expiry= dict_read_number(
2213 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2215 const char *peerskey= st->peer_mobile
2216 ? "mobile-peers-max" : "static-peers-max";
2217 st->transport_peers_max= dict_read_number(
2218 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2219 if (st->transport_peers_max<1 ||
2220 st->transport_peers_max>MAX_PEER_ADDRS) {
2221 cfgfatal(loc,"site", "%s must be in range 1.."
2222 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2225 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2226 st->key_renegotiate_time=st->key_lifetime/2;
2228 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2229 st->key_renegotiate_time=dict_read_number(
2230 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2231 if (st->key_renegotiate_time > st->key_lifetime) {
2232 cfgfatal(loc,"site",
2233 "renegotiate-time must be less than key-lifetime\n");
2236 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2237 log_event_table,"site");
2239 st->resolving_count=0;
2240 st->allow_send_prod=0;
2242 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2244 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2246 /* The information we expect to see in incoming messages of type 1 */
2247 /* fixme: lots of unchecked overflows here, but the results are only
2248 corrupted packets rather than undefined behaviour */
2249 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2251 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2253 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2254 BUF_ALLOC(&st->scratch,"site:scratch");
2256 /* We are interested in poll(), but only for timeouts. We don't have
2257 any fds of our own. */
2258 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2261 st->remote_capabilities=0;
2262 st->chosen_transform=0;
2263 st->current.key_timeout=0;
2264 st->auxiliary_key.key_timeout=0;
2265 transport_peers_clear(st,&st->peers);
2266 transport_peers_clear(st,&st->setup_peers);
2267 /* XXX mlock these */
2268 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2269 st->sharedsecretlen=st->sharedsecretallocd=0;
2272 #define SET_CAPBIT(bit) do { \
2273 uint32_t capflag = 1UL << (bit); \
2274 if (st->local_capabilities & capflag) \
2275 slog(st,LOG_ERROR,"capability bit" \
2276 " %d (%#"PRIx32") reused", (bit), capflag); \
2277 st->local_capabilities |= capflag; \
2280 for (i=0; i<st->ntransforms; i++)
2281 SET_CAPBIT(st->transforms[i]->capab_bit);
2285 if (st->local_mobile || st->peer_mobile)
2286 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2288 /* We need to register the remote networks with the netlink device */
2289 uint32_t netlink_mtu; /* local virtual interface mtu */
2290 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2291 if (!st->mtu_target)
2292 st->mtu_target=netlink_mtu;
2294 for (i=0; i<st->ncomms; i++)
2295 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2297 st->current.transform=0;
2298 st->auxiliary_key.transform=0;
2299 st->new_transform=0;
2300 st->auxiliary_is_new=0;
2302 enter_state_stop(st);
2304 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2305 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2307 return new_closure(&st->cl);
2310 void site_module(dict_t *dict)
2312 add_closure(dict,"site",site_apply);
2316 /***** TRANSPORT PEERS definitions *****/
2318 static void transport_peers_debug(struct site *st, transport_peers *dst,
2319 const char *didwhat,
2320 int nargs, const struct comm_addr *args,
2325 if (!(st->log_events & LOG_PEER_ADDRS))
2326 return; /* an optimisation */
2328 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2329 (dst==&st->peers ? "data" :
2330 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2331 didwhat, nargs, dst->npeers);
2333 for (i=0, argp=(void*)args;
2335 i++, (argp+=stride?stride:sizeof(*args))) {
2336 const struct comm_addr *ca=(void*)argp;
2337 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2338 i, comm_addr_to_string(ca));
2340 for (i=0; i<dst->npeers; i++) {
2341 struct timeval diff;
2342 timersub(tv_now,&dst->peers[i].last,&diff);
2343 const struct comm_addr *ca=&dst->peers[i].addr;
2344 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2345 i, comm_addr_to_string(ca),
2346 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2350 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2351 /* peers must be sorted first */
2352 int previous_peers=peers->npeers;
2353 struct timeval oldest;
2354 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2355 oldest.tv_usec = tv_now->tv_usec;
2356 while (peers->npeers>1 &&
2357 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2359 if (peers->npeers != previous_peers)
2360 transport_peers_debug(st,peers,"expire", 0,0,0);
2363 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2364 const struct comm_addr *ca,
2365 const struct timeval *tv) {
2366 /* returns false if output is full */
2369 if (peers->npeers >= st->transport_peers_max)
2372 for (search=0; search<peers->npeers; search++)
2373 if (comm_addr_equal(&peers->peers[search].addr, ca))
2376 peers->peers[peers->npeers].addr = *ca;
2377 peers->peers[peers->npeers].last = *tv;
2382 static void transport_record_peers(struct site *st, transport_peers *peers,
2383 const struct comm_addr *addrs, int naddrs,
2385 /* We add addrs into peers. The new entries end up at the front
2386 * and displace entries towards the end (perhaps even off the
2387 * end). Any existing matching entries are moved up to the front.
2389 * Caller must first call transport_peers_expire. */
2392 /* avoids debug for uninteresting updates */
2394 for (i=0; i<peers->npeers; i++) {
2395 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2396 memmove(peers->peers+1, peers->peers,
2397 sizeof(peers->peers[0]) * i);
2398 peers->peers[0].addr = addrs[0];
2399 peers->peers[0].last = *tv_now;
2405 int old_npeers=peers->npeers;
2406 transport_peer old_peers[old_npeers];
2407 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2411 for (i=0; i<naddrs; i++) {
2412 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2415 for (i=0; i<old_npeers; i++) {
2416 const transport_peer *old=&old_peers[i];
2417 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2421 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2424 static void transport_expire_record_peers(struct site *st,
2425 transport_peers *peers,
2426 const struct comm_addr *addrs,
2427 int naddrs, const char *m) {
2428 /* Convenience function */
2429 transport_peers_expire(st,peers);
2430 transport_record_peers(st,peers,addrs,naddrs,m);
2433 static bool_t transport_compute_setupinit_peers(struct site *st,
2434 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2435 int n_configured_addrs /* 0 if none or not found */,
2436 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2437 if (!n_configured_addrs && !incoming_packet_addr &&
2438 !transport_peers_valid(&st->peers))
2441 slog(st,LOG_SETUP_INIT,
2442 "using: %d configured addr(s);%s %d old peer addrs(es)",
2444 incoming_packet_addr ? " incoming packet address;" : "",
2447 /* Non-mobile peers try addresses until one is plausible. The
2448 * effect is that this code always tries first the configured
2449 * address if supplied, or otherwise the address of the incoming
2450 * PROD, or finally the existing data peer if one exists; this is
2453 transport_peers_copy(st,&st->setup_peers,&st->peers);
2454 transport_peers_expire(st,&st->setup_peers);
2456 if (incoming_packet_addr)
2457 transport_record_peers(st,&st->setup_peers,
2458 incoming_packet_addr,1, "incoming");
2460 if (n_configured_addrs)
2461 transport_record_peers(st,&st->setup_peers,
2462 configured_addrs,n_configured_addrs, "setupinit");
2464 assert(transport_peers_valid(&st->setup_peers));
2468 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2469 if (st->peer_mobile)
2470 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2472 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2473 if (st->peer_mobile)
2474 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2477 static int transport_peers_valid(transport_peers *peers) {
2478 return peers->npeers;
2480 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2482 transport_peers_debug(st,peers,"clear",0,0,0);
2484 static void transport_peers_copy(struct site *st, transport_peers *dst,
2485 const transport_peers *src) {
2486 dst->npeers=src->npeers;
2487 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2488 transport_peers_debug(st,dst,"copy",
2489 src->npeers, &src->peers->addr, sizeof(*src->peers));
2492 static void transport_resolve_complete(struct site *st,
2493 const struct comm_addr *addrs,
2495 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2497 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2501 static void transport_resolve_complete_tardy(struct site *st,
2502 const struct comm_addr *addrs,
2504 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2505 "resolved tardily");
2508 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2510 const transport_peers *inp) {
2511 /* out and in->peers may be the same region, or nonoverlapping */
2512 const transport_peer *in=inp->peers;
2514 for (slot=0; slot<inp->npeers; slot++) {
2515 if (!(mask & (1U << slot)))
2517 if (!(out==in && slot==*nout_io))
2518 COPY_OBJ(out[*nout_io], in[slot]);
2523 void transport_xmit(struct site *st, transport_peers *peers,
2524 struct buffer_if *buf, bool_t candebug) {
2526 transport_peers_expire(st, peers);
2527 unsigned failed=0; /* bitmask */
2528 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2531 for (slot=0; slot<peers->npeers; slot++) {
2532 transport_peer *peer=&peers->peers[slot];
2533 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2535 dump_packet(st, buf, &peer->addr, False, ok);
2537 failed |= 1U << slot;
2540 if (ok && !st->peer_mobile)
2543 /* Now we need to demote/delete failing addrs: if we are mobile we
2544 * merely demote them; otherwise we delete them. */
2545 if (st->local_mobile) {
2546 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2547 /* `expected' has all the failures at the end already */
2548 if (failed != expected) {
2550 transport_peer failedpeers[nfailed];
2551 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2552 assert(fslot == nfailed);
2554 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2555 assert(wslot+nfailed == peers->npeers);
2556 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2557 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2560 if (failed && peers->npeers > 1) {
2562 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2563 peers->npeers=wslot;
2564 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2569 /***** END of transport peers declarations *****/